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Rockwell Automation Allen-Bradley PowerFlex 755T Flux Vector Tuning Original Instructions Manual Download Page 52

52

Rockwell Automation Publication 750-AT006D-EN-P - January 2022

Chapter 2          Product Features

Lead Lag Filters

Lead-lag filters are represented by the following first order transfer function, where F is the filter bandwidth in units of [Hz] and K is the 
filter gain.

The filter is disabled when F = 0 Hz, regardless of the other settings.

The filter has a DC gain of 1, a user-configurable pole (lag) at F, and a user-configurable zero (lead) at F/K. Bode plots with differing gain 
settings are shown in 

Figure 53

.

10:1005

[u Vel Fb LPF Gain]

Sets the primary velocity feedback filter gain. The 
parameter's value sets the mode of the filter and gain of 
its first order transfer function. This value affects the 
filtering applied to the primary velocity feedback channel 
and is only active in Flux Vector motor control modes. 
Entering a value of 1 turns off the filter.

•  For a low pass filter, enter a value of 0. This is the user default and the 

calculated gain value.

• For a lag-lead filter, enter a value between 0 and 1. 
• For a lead-lag filter, enter a value greater than 1. This value is applied 

when parameter 10:905 [System C/U Sel] is set to 'User Entered' (1). 

10:1008

[c AltVelFbLPF BW]

An automatically calculated value for the alternate 
velocity feedback low pass filter bandwidth. It is applied 
to the drive when 
10:905 [System C/U Select] = Calculated (0). It is 
calculated as a function of the following parameters and it 
affects the DMTC and 10:1010 [Alt Fb GnScale] values.

• 10:407 [Motor Poles] – This parameter is the number of motor poles (p). It 

is calculated as follows
p = round (120 x [Motor NP Hertz] / [Motor NP RPM])

• Alternate Encoder Resolution – The total resolution in edge counts per 

revolution (EPR) is specified by parameters on the alternate feedback 
option card.
– Low-Resolution Example: Resolution = 1024 pulses per revolution * 4 

quadrature edge counts per pulse = 4096 EPR (12-bit). The low-
resolution PPR comes directly from a parameter on the option card. 
When both A and B channels are selected for an incremental encoder, 
the edge count multiplier is 4. This value is the typical and default 
setting. When only channel A is selected, then the edge count multiplier 
is 2.

– High-Resolution Example: Resolution = 1024 pulses per revolution * 

1024 edge counts per pulse = 1,048,576 EPR (20-bit). For high-resolution 
devices, the overall resolution choices are 20-bit default or an optional 
24-bit when the corresponding configuration bit is selected.

10:1009

[u AltVelFbLPF BW]

Sets the alternate velocity feedback low pass filter bandwidth. It is applied to the drive when parameter 10:905 [System C/U Select] = 
User Entered (1).

10:1021

[c AltVelFbLPF Gn]

Displays the calculated value of the alternate velocity 
feedback filter gain. This gain value is applied when 
parameter 10:905 [System C/U Sel] = 'Calculated' (0). The 
'calculated' filter gain is always zero.

•  Because this is a Lead Lag Filter, a filter gain of zero will configure the 

filter as a Low Pass Filter. See 

Lead Lag Filters on page 52

.

• This filter determines the amount of filtering applied to the alternate 

velocity feedback channel and is only active in Flux Vector motor control 
modes.

10:1022

[u AltVelFbLPF Gain]

Sets the alternate velocity feedback filter gain. The 
parameter's value sets the mode of the filter and gain of 
its first order transfer function. This value determines the 
amount of filtering applied to the alternate velocity 
feedback channel and is only active in Flux Vector motor 
control modes. Entering a value of 1 turns off the filter.

• For a low pass filter, enter a value of 0. This is the user default and the 

calculated gain value.

• For a lag-lead filter, enter a value between 0 and 1.
• For a lead-lag filter, enter a value greater than 1. This value is applied 

when parameter 10:905 [System C/U Sel] is set to 'User Entered' (1).

10:2154

[c Trq LPF BW]

An automatically calculated value for the torque low pass 
filter bandwidth. It is applied to 10:2156 [Trq LPF BW Act] 
when 10:905 [System C/U Select] = Calculated (0) and the 
adaptive tuning Gain Stabilization function is disabled. 

• The  value  =  max  (K

VP

, K

OP

) * 5 when the load observer is enabled. 

• The  value  =  K

VP

 * 5 when the load observer is disabled.

10:2155

[u Trq LPF BW]

Sets the torque low pass filter bandwidth. It is applied to 10:2156 [Trq LPF BW Act] when 10:905 [System C/U Select] = User Entered (1) 
and the adaptive tuning Gain Stabilization function is disabled.

Table 19 - Low Pass Filter Parameters (Continued)

Parameter 

No.

Parameter Name Description

G s

 

Ks

2

F

+

s

2

F

+

----------------------------

=

K

s

2

F

K

--------

+

s

2

F

+

------------------------

=

Summary of Contents for Allen-Bradley PowerFlex 755T Flux Vector Tuning

Page 1: ...Application Technique Original Instructions PowerFlex 755T Flux Vector Tuning Bulletins 20G 20J ...

Page 2: ... to our products and content Please excuse the use of such terms in our content while we implement these changes Topic Page Updated figures throughout Updated rigid load explanation 27 Corrected rigid load torque scaler calculation 28 Corrected non rigid load torque scaler calculation 28 Corrected calculation for both rigid and non rigid loads 28 Corrected torque scaler equations in Recommended Lo...

Page 3: ...elocity Loop 21 Torque Loop 25 Chapter 2 Product Features Torque Scaler 27 Explanation of Calculation 27 Cases of Calculation 27 Load Observer 29 Benefits 30 How It Works 30 Configuration 31 Adaptive Tuning 34 Benefits 34 How It Works 35 Configuration 35 Adaptive Tuning Modes 40 Notch Filters 46 Configuration 47 Low Pass Filters 51 Lead Lag Filters 52 Finite Impulse Response Filters 53 Chapter 3 O...

Page 4: ...p in Encoderless Mode 79 Tune the Position Loop Optional 80 Chapter 6 Active Front End Tuning Function 81 Configuration 82 Regulators 83 Voltage Regulator Tuning 83 Current Regulator Tuning 83 Disturbance Rejection 85 Feed Forward Power 86 DC Bus Observer 87 Resonance Mitigation and Feed Forward Components of Grid Voltages 89 Phase Locked Loop 90 PLL Configuration 91 Unbalance Rejection 91 DC Offs...

Page 5: ...ary 2022 5 Table of Contents Chapter 7 Applications Friction Compensation 100 Types of Friction 100 Configuration 101 Torque Sharing 102 Droop 102 Vertical Loads 103 Process PID Controller 104 Modes 104 Features 107 Diagrams 111 Additional Resources 115 ...

Page 6: ...s intended for drive users with skill levels ranging from novice to advanced Each component of the control structure is described in detail Out of box tuning autotuning manual and active front end tuning techniques are presented Quick Start Guide See Recommended Default Settings on page 58 Download Firmware AOP EDS and Other Files Download firmware associated files such as AOP EDS and DTM and acce...

Page 7: ... high performance first understand the mechanical properties of the system that dictate performance This section describes these mechanical properties how they limit performance and what tuning features apply to compensate for them The best approach is to build a mechanical system that is as rigid as possible and with a constant inertia but that is not always possible or cost effective This sectio...

Page 8: ...ed for by enabling the Load Observer on page 29 10 901 Load Ratio is the ratio of load inertia divided by motor inertia It tells you how large the load is with respect to the motor driving it Load ratio is used to calculate the Torque Scaler which compensates for the effects of inertia and is described in Torque Scaler on page 27 This parameter affects overall tuning Load ratio is also used in cal...

Page 9: ...ot immediately rotate the load The energy is then released when the motor torque is removed which causes continued acceleration of the load A dynamic model is given where PI is a proportional integral controller and LPF is a low pass filter Figure 3 Compliant Load Model Here the spring constant k is in units of N m rad which can be typically found in rotary coupling specifications For example a sh...

Page 10: ...ns As the spring constant decreases the coupling becomes less rigid and twists more As the load ratio increases the load on the end of the spring becomes larger which causes it to twist more Larger load ratios amplify tuning problems Compliance is also referred to as non rigid There are only two absolutes When k 0 the load is disconnected When k the load is rigid When 0 k everything else is compli...

Page 11: ...other mechanical components In gearboxes it is a small space between two inter meshing gear teeth Figure 5 Backlash in Gears When the gears are not in contact and motor torque is applied the input gear momentarily moves without transferring torque to the load Here the total inertia driven by the motor is JM When the gears come in contact torque is then transferred to the load Here the total inerti...

Page 12: ... control because even small input forces can produce large magnitude oscillations in the output Figure 8 Tuning Fork Resonance Anti resonant frequencies are frequencies where the magnitude is at a relative minimum Here the system does not respond well to input and the gain is very low Anti resonances are difficult to control because even large input forces can produce little or no response in the ...

Page 13: ...hey are suppressed using torque loop filters Adaptive tuning addresses these resonances by automatically configuring these filters See Adaptive Tuning on page 34 for more information Otherwise it is left to the user to identify the audible frequencies and manually configure torque notch filters If there are more HF resonances than there are notch filters available a torque low pass filter is appli...

Page 14: ...technique is recommended and is the simplest to implement Select a move type in 10 931 Ref Move Type that generates a reference profile that will not excite the load side resonance Choices for move type are LinScurve SineSquared Poly5 and Cubic Determine the load oscillation frequency with a stopwatch and generate a smooth reference CAM profile that does not contain any load oscillation frequency ...

Page 15: ...ulator in the drive Higher bandwidth improves transient response decreases error and makes the motor shaft performance stiffer Figure 12 shows how bandwidth affects actual response solid compared to its reference move profile dashed Here feed forward gains are disabled Figure 12 How Bandwidth Affects Transient Response The drive motor and feedback device have a significant impact on the bandwidth ...

Page 16: ...over damped responses System Bandwidth System bandwidth is calculated from an internal quantity that is called the drive model time constant DMTC The DMTC is the sum of all delays around the torque loop for a given drive and motor combination Figure 14 Delays Associated with DMTC The following parameters are used to calculate the DMTC 10 445 VCL CReg BW This parameter is the current regulator band...

Page 17: ...ning to account for different encoders on the primary and alternate feedback channels The following controller gains can be calculated or user entered These controller gains are internally scaled Load Observer Bandwidth KOP Load Observer Integrator Bandwidth KOI Position and Velocity Loop Bandwidth KPP and KVP Position and Velocity Loop Integrator Bandwidth KPI and KVI The torque low pass filter b...

Page 18: ... Integrator Bandwidth Hz KVP 10 1955 c VReg Kp Velocity Loop Bandwidth Hz KVI 10 1957 c VReg Ki Velocity Integrator Bandwidth Hz KOP 10 2021 c LdObs Kp Load Observer Bandwidth Hz KOI 10 2023 c LdObs Ki Load Observer Integrator Bandwidth Hz KVFF 10 1760 c Vel FF Gain Velocity Feed Forward Gain KAFF 10 1973 c Accel FF Gain Acceleration Feed Forward Gain 10 2154 c Trq LPF BW Torque Low Pass Filter Ba...

Page 19: ...ed Kpi Kvp Kvi Kpp Kop Koi Kaff Trq LPF BW VelFb LPF BW AltVelFbLPF BW Vel Comp Gain 1009 1022 u AltVelFbLPF BW u AltVelFbLPF Gn 1008 1021 c AltVelFbLPF BW c AltVelFbLPF Gn 1959 1760 c Alt Kvi OL Fb c Vel FF Gain 1960 1761 u Alt Kvi OL Fb u Vel FF Gain System C USelect Calculated User Entered 1756 1955 1957 2021 2023 1754 1757 1956 1958 2022 2024 1755 905 Automatic Calculations c PReg Ki c VReg Kp ...

Page 20: ...Network Communication from Logix Controller position direct mode Internal PTP planner point to point Position mode Encoder Position Reference Internal PCAM planner Position CAM Internal PLL planner Position Phase Locked Loop See the PowerFlex 750 Reference Manual publication 750 RM002 and PowerFlex Drives with TotalFORCE Control Programming Manual publication 750 PM100 for more information Referen...

Page 21: ...rward gain provides a prediction of the motor velocity required to perform the move instead of waiting for the position error to become large enough to produce an equivalent signal Parameter 10 1760 c Vel FF Gain is applied as the velocity feed forward gain when 10 905 System C U Select Calculated Parameter 10 1761 u Vel FF Gain is applied as the velocity feed forward gain when 10 905 System C U S...

Page 22: ...Resonances on page 14 for more information These filters are capable of adjustable width and depth See Notch Filters on page 46 for more information Velocity Feedback Filter Fs The velocity feedback filter actually consists of two filters that work in combination to remove quantization noise that is generated by low resolution feedback devices These filters are typically disabled when high resolut...

Page 23: ...el and is only active in Flux Vector motor control modes Entering a value of 1 turns off the filter For a low pass filter enter a value of 0 This is the user default and the calculated gain value For a lag lead filter enter a value between 0 and 1 For a lead lag filter enter a value greater than 1 10 1006 Alt Vel Fb Sel Enter the 2 digit port location followed by the 4 digit parameter number of th...

Page 24: ...y response to a load disturbance It behaves like a position regulator with velocity feed forward but without the pulse accuracy of a true position regulator The gain is normally set to less than one third of the system bandwidth or for the desired response A value of zero disables this feature Load Observer Load observer forces mechanical loads to behave consistently by compensating for unknown in...

Page 25: ...r the source This reference comes from 10 1978 Ext Ramped Ref This setting is available for applications that supply a ramped speed reference external to the drive For example when the velocity ramp is generated in a Logix Controller Spd Rate Ref 3 Selects the Feed Forward Velocity Rate for the source This rate comes from 10 1931 FF Vel Rate Ref This selection is also used with an externally suppl...

Page 26: ...S is also defined Friction Compensation Friction compensation is used in some applications to compensate for known amounts of friction It is not shown in the previous figures See Friction Compensation on page 100 for more information However load observer is often used instead because it requires no knowledge of these mechanical quantities See Load Observer on page 29 for more information Torque N...

Page 27: ...aler is recalculated any time one of these parameters change Equations for torque scaler are given When 10 405 Mtr NP Pwr Units 0 and 10 406 Motor NP Power are in units of Hp Motor Rated Torque N m Motor NP Power Motor NP RPM x 7120 91 System Acceleration rev sec2 Motor NP Power Motor NP RPM x Motor Inertia x Load Ratio 1 x 1133 33 When 10 405 Mtr NP Pwr Units 1 and 10 406 Motor NP Power are in un...

Page 28: ...non rigid load They exhibit some combination of compliance backlash unknown dynamics and unknown or changing inertia Here only the effect of motor inertia JM is immediate and a direct multiplier on rigid body mechanics As a result the motor and load mechanics are represented with JM and the effect of load inertia is dynamic and reflected in the load torque signal being applied to the motor shaft F...

Page 29: ...s been performed to determine the load ratio the control loop gains are configured for a load ratio R 0 and the load coupling is rigid See Auto Tuning on page 63 for more information This value is the primary difference affecting out of box and autotune rules Thus the term out of box implies a compliant load with R 0 and the term autotune implies a rigid load with R 0 Recommended settings are show...

Page 30: ...nternal plant model P of an ideal motor and generates a load Torque Estimate signal that represents any deviation in response between the actual loaded motor and the ideal model This deviation represents the reaction torque that is placed on the motor shaft by a mechanical load The load torque is estimated in real time and compensated by closed loop operation This technique provides system respons...

Page 31: ...d Observer Parameters Parameter No Parameter Name Description 10 2027 LdObs Acc Ref In Load observer acceleration reference input signal 10 2028 LdObs VelFb In Load observer velocity feedback input signal 10 2031 LdObs Vel Error Load observer velocity error signal 10 2034 LdObs Vel Est Load observer velocity estimate signal 10 2035 LdObs Accel Est Load observer acceleration estimate signal 10 2036...

Page 32: ...Obs Only 1 This mode is recommended for velocity control applications and it functions equivalent to the legacy PowerFlex load observer It compensates for dynamic loads that are connected to the motor providing high disturbance rejection and dynamic stiffness However the aggressive behavior in position control applications often requires the observer bandwidth to be decreased for stable operation ...

Page 33: ... Only 3 This mode can be used in some position control applications It removes phase lag associated with velocity feedback filtering and allows gains to be increased for quicker system response It is not desirable for Velocity mode applications because a steady state velocity error is present that is hard to detect This mode applies the Velocity Estimate signal to the control loops but not the Tor...

Page 34: ... functions of adaptive tuning are Monitor motor side resonances Automatically adjust torque loop notch and low pass filter parameters to suppress resonances Automatically de tune control loop gains to avoid instability when it is detected Automatically up tune control loop gains for best performance This section includes Benefits How It Works on page 35 Configuration on page 35 Adaptive Tuning Mod...

Page 35: ...adaptive tuning mode of operation This approach is covered in Configuration on page 35 An overview of how adaptive tuning works is shown in Figure 35 Figure 35 Adaptive Tuning Overview Configuration Figure 36 shows parameters that are relevant to adaptive tuning P U Torque Ref Magnitude Frequency Hz Low Freq range where Gain Stabiliza on de tunes and Gain Op miza on up tunes High Freq range where ...

Page 36: ...e frequency estimate is equal to the low frequency limit It sets torque notch filter widths equal to maximum width when the frequency estimate is equal to the high frequency limit Default setting is 0 707 for minimum and maximum width 10 2115 Trq NF WidthMax Torque Notch Filter Maximum Width 10 2116 Trq LPF BW LLim Torque Low Pass Filter Bandwidth Low Limit The adaptive tuning Gain Stabilization f...

Page 37: ...0 2136 GnOpt Scale Inc regardless of measured error until parameter 10 2130 AdptTuneStabMag reaches between the 10 2135 GnOpt TorqueLim and 10 2134 GnStab TorqueLim lines as shown in Figure 35 on page 35 10 2141 GnOptSclHiLim Gain Optimization Scale High Limit Enter the gain scale high limit for gain optimization Gain optimization will not increase parameter 10 2121 AdptTune GnScale beyond this li...

Page 38: ...hen the adaptive tuning Tracking Notch function is active See 10 2110 AdptTune Config for adaptive tuning modes 10 2170 Trq NF2 Freq Act Torque Notch Filter 2 Frequency Active Displays the active center frequency of the second torque notch filter The user entered value 10 2169 Trq NF2 Freq is applied when the adaptive tuning Tracking Notch function is not active The adaptive tuning estimated value...

Page 39: ...racking Notch function is active See 10 2110 AdptTune Config for adaptive tuning modes 10 2196 Trq NF4 Gain Act Torque Notch Filter 4 Gain Active Displays the active gain of the fourth torque notch filter The user entered value 10 2195 Trq NF4 Gain is applied when the adaptive tuning Tracking Notch function is not active Adaptive tuning sets this value to 1 when the adaptive tuning Tracking Notch ...

Page 40: ... the resonance s center frequency and magnitude are measured and placed in 10 2123 Trq NF Freq Est and 10 2124 Trq NF Mag Est respectively A suitable notch filter width is also calculated and placed in 10 2125 Trq NF Wdth Est by interpolating a value between 10 2114 Trq NF WidthMin and 10 2115 Trq NF WidthMax based on the location of 10 2123 Trq NF Freq Est between 10 2112 Trq NF Freq LLim and 10 ...

Page 41: ...tive tuning Tracking Notch function configures the notch filter as a notch filter during operation regardless of the user entered settings 3 It applies the torque notch filter width estimate to the active torque notch filter 1 Width This allows tracking notch filters to suppress MF resonances without causing instability by adjusting the width in relation to the torque notch filter width high and l...

Page 42: ...op gains to suppress any remaining resonances and stabilize the system if necessary Here the following gains are scaled by adaptive tuning 10 2121 AdptTune GnScale the Gain Scaling Factor Load Observer Bandwidth Load Observer Integrator Bandwidth Velocity Loop Bandwidth Velocity Loop Integrator Bandwidth Position Loop Bandwidth Position Loop Integrator Bandwidth This scaling means that the actual ...

Page 43: ... Tracking Notch and Gain Stabilization 10 2110 AdptTune Config TrkNFGainStb 3 In this mode adaptive tuning applies the Tracking Notch function if necessary followed by Gain Stabilization function if necessary Parts of the control loop structure affected by this mode are highlighted in Figure 43 Figure 43 Tracking Notch Filter and Gain Stabilization Configuration First the adaptive tuning Tracking ...

Page 44: ... is detuned if one or more of the following conditions exist The torque notch filter 1 is set to suppress the MF resonance but its width is wide enough or its frequency is close enough to the closed loop bandwidth to cause instability The torque low pass filter is set to suppress the MF resonance but its bandwidth is close enough to the closed loop bandwidth to cause instability Additional unsuppr...

Page 45: ...o a fixed value equal to 10 2136 GnOpt Scale Inc See Figure 46 on page 46 While in velocity mode a velocity error threshold 10 2140 GnOptVelErrThrsh can be set to increase 10 2121 AdptTune GnScale in increments 10 2136 GnOpt Scale Inc scaler proportional to error until 10 2130 AdptTuneStab Mag increases above the 10 2135 GnOpt TorqueLim line or until the velocity error is less than 10 2140 GnOptVe...

Page 46: ...f reference notch filters share common parameters which allow all command signals to be affected uniformly The torque notch filters suppress MF and HF motor side resonances and the reference notch filters suppress load side resonances See Resonances on page 12 for more information on the various types of resonances and how to suppress them Corresponding reference notch filter parameters are given ...

Page 47: ... ZW The default depth ZD 0 provides maximum notch attenuation Also adaptive tuning sets ZD 0 when tracking a notch filter Note that the filter is off when K 1 and ZD ZW or when F 0 Furthermore the filter becomes an inverse notch generating resonance when ZD ZW Notch filter width can be approximated in units of Hz as the range of frequencies impacted by the filter between 3 dB points Notch filter d...

Page 48: ...e 47 and Figure 48 on page 48 Figure 47 Variable Width Notch Filter Configurations Figure 48 Variable Depth Notch Filter Configurations Configured as a Second Order Low Pass Filter K 0 When K 0 the notch filter is configured to operate as a second order low pass filter with bandwidth F and damping ZW Bode plots with differing low pass filter settings for K 0 are shown in Figure 49 ...

Page 49: ...er Lag Lead Filter 0 K 1 When 0 K 1 the notch filter is configured to operate as a second order lag lead filter It has two user configurable poles lag at F with damping ZW and two user configurable zeros lead at FD F K with damping ZD Bode plots with differing lag lead filter settings for 0 K 1 are shown in Figure 50 Figure 50 Lag Lead Filter Configurations ...

Page 50: ...wever using the filter in this way can make the drive more sensitive to disturbances Furthermore the load observer is recommended to compensate for load compliance and disturbances because it typically does a better job without having to determine these parameters Configured as a Second Order Lead Lag Filter K 1 When K 1 the notch filter is configured to operate as a second order lead lag filter I...

Page 51: ...resolution in edge counts per revolution EPR is specified by parameters on the primary feedback option card Low Resolution Example Resolution 1024 pulses per revolution 4 quadrature edge counts per pulse 4096 EPR 12 bit The low resolution PPR comes directly from a parameter on the option card When both A and B channels are selected for an incremental encoder the edge count multiplier is 4 This val...

Page 52: ... count multiplier is 2 High Resolution Example Resolution 1024 pulses per revolution 1024 edge counts per pulse 1 048 576 EPR 20 bit For high resolution devices the overall resolution choices are 20 bit default or an optional 24 bit when the corresponding configuration bit is selected 10 1009 u AltVelFbLPF BW Sets the alternate velocity feedback low pass filter bandwidth It is applied to the drive...

Page 53: ...n be placed at the anti resonant frequency and a zero can be placed at the resonant frequency using the following calculations However use of the filter in this way can make the drive more sensitive to disturbances Furthermore the load observer is recommended to compensate for load compliance and disturbances because it typically does a better job without having to determine these parameters When ...

Page 54: ...lied to smooth out high frequency impulses A discrete difference filter is applied to generate a derivative of the input signal corresponding to the discrete difference between two input samples that are N samples apart More taps filter out more noise but reduces the overall bandwidth attainable in the velocity and position loops Setting the number of taps to 0 disables the filter There are two di...

Page 55: ...g is rigid See Auto Tuning on page 63 for more information These settings are the primary difference affecting out of box and autotune rules Thus the term out of box implies a compliant load with R 0 and the term autotune implies a rigid load with R 0 In a new drive configuration or when the load is unknown 10 901 Load Ratio 0 but the actual load ratio R 0 As a result the torque scaler is lower th...

Page 56: ...tion Feedback When 10 901 Load Ratio 0 and 10 2020 LdObs Mode LdObs Only 1 or 10 2020 LdObs Mode Accel Fdbk 4 there is no need to decrease the position loop gains by an additional factor of 10 because the load observer accounts for the unknown load to maintain that KVP is not artificially lowered Also KVI is disabled because the load observer operates as a good velocity integrator Load Observer On...

Page 57: ...1 Load Ratio 0 and 10 2020 LdObs Mode LdObs VelEst 2 the load observer bandwidth increases by 4Z2 because the velocity estimate removes enough phase lag from the closed loop to do so while maintaining stability Also KVI is disabled because load observer operates as a good velocity integrator This mode is recommended for position control applications Load Observer with Velocity Estimate automatical...

Page 58: ...s connected to the drive Parameter No Parameter Name Description 10 400 Motor NP Volts Enter the motor nameplate rated volts 10 401 Motor NP amps Enter the motor nameplate rated full load amps 10 402 Motor NP Hertz Enter the motor nameplate frequency in units of Hz 10 403 Motor NP RPM Enter the motor nameplate speed in units of RPM 10 405 Mtr NP Pwr Units Enter the motor nameplate power units 0 Hp...

Page 59: ... EPR The feedback option module is not required when velocity feedback is set to 10 1048 Open Loop Fb Alternate Encoder Resolution Parameters on the alternate feedback option card specify the total resolution in edge counts per revolution EPR Encoderless Mode Alternate Encoder Resolution with Virtual Encoder when the Open Loop Virtual Encoder is selected as the alternate feedback device 10 1006 Al...

Page 60: ...rq NF Freq LLim to a value that is at least 2 3 times the value of 10 906 System BW 12 Run the drive and adjust 10 906 System BW if necessary It initiates motion and rotates the load Decreasing 10 906 System BW stabilizes the system and increasing it improves performance Typically high gain results in a quicker response time but excessive gain causes system instability The following parameters are...

Page 61: ... operates with the alternate feedback The drive operates with the alternate feedback when a feedback fault happens and the drive switches to the alternate feedback selected in 10 1006 Alt VelFb Sel which can be either an encoder connected to an encoder module or the Open Loop Virtual Encoder To adjust the performance of the system with the alternate feedback temporarily set 10 1019 Fb Loss Action ...

Page 62: ...ut of Box Tuning Chapter 3 Manual Tuning Is problem resolved Adjust 10 900 Motor Inertia Enter a data sheet value or use formula Re adjust 10 906 System BW Is problem resolved Yes Run 10 910 Autotune JMtr BW Calc 7 Re adjust 10 906 System BW Is problem resolved Run 10 910 Autotune JTotalBWCalc 8 Is problem resolved Set 10 905 System C U Sel User Entered Manually adjust User entered tuning paramete...

Page 63: ...se tests is provided in the rest of this chapter General Modes This section covers the general Autotune modes 10 910 Autotune Ready 0 Indicates that the Autotune function is available Autotune returns to Ready 0 after a test from one of the other settings After it returns to Ready 0 another start transition is required to operate the drive in Normal mode 10 910 Autotune Direction 1 Enables the Aut...

Page 64: ...Slip RPM atFLA 10 512 u IM Stator Res 10 515 u IM Leakage L 10 518 u Flux Cur Ref 10 521 u EndLs AngCmp 10 524 IM StatResComp Permanent Magnet PM 10 510 MtrParam C U Sel Calculated 10 613 c PM CEMF Vltg 10 619 c PM Stator Res 10 626 c PM Ld at 0 10 628 c PM Ld at 100 10 636 c PM Lq at 25 10 638 c PM Lq at 50 10 640 c PM Lq at 75 10 642 c PM Lq at 100 10 644 c PM Lq at 125 10 646 c PM Lq at 150 10 ...

Page 65: ...r Entered 510 510 Automatic Calculations Motor Control Autotune Static MtrID IM only Or Rotate MtrID Motor NP Amps 400 Motor NP Volts 401 Motor NP Hertz 402 Motor NP RPM 403 405 406 407 910 Motor NP Pwr Units Motor NP Power Motor Poles Autotune Motor NP Amps 400 Motor NP Volts 401 Motor NP Hertz 402 Motor NP RPM 403 405 406 407 910 Motor NP Pwr Units Motor NP Power Motor Poles Autotune 000 Read On...

Page 66: ...Lq at 175 c PM Lq at 200 c PM Stator Res c PM Ld at 0 c PM Ld at 100 c PM Lq at 25 c PM Lq at 50 u PM Lq at 100 u PM Lq at 125 u PM Lq at 150 u PM Lq at 75 u PM Lq at 175 u PM Lq at 200 u PM Stator Res u PM Ld at 0 u PM Ld at 100 u PM Lq at 25 u PM Lq at 50 Motor NP Amps 400 Motor NP Volts 401 Motor NP Hertz 402 Motor NP RPM 403 405 406 407 910 Motor NP Pwr Units Motor NP Power Motor Poles Autotun...

Page 67: ...r induction motors only After selecting this value you must issue a start command to begin the test Use this test when the motor cannot rotate freely or when it is already coupled to the load The static test does not initiate momentary motor rotation to measure motor electrical parameters Instead it only measures electrical parameters that do not generate motor movement The rest of the parameters ...

Page 68: ...mp 10 524 IM StatResComp During the rotate test for PM motors a stator resistor test is first performed to obtain the following parameter 10 620 u PM Stator Res The inductance test is then performed to calculate Ld and Lq at various current level as follows 10 627 u PM Ld at 0 10 629 u PM Ld at 100 10 637 u PM Lq at 25 10 639 u PM Lq at 50 10 641 u PM Lq at 75 10 643 u PM Lq at 100 10 645 u PM Lq ...

Page 69: ...01 Motor NP Hertz 402 Motor NP RPM 403 405 406 407 910 Motor NP Pwr Units Motor NP Power Motor Poles Autotune Motor NP Amps 400 Motor NP Volts 401 Motor NP Hertz 402 Motor NP RPM 403 405 406 407 910 Motor NP Pwr Units Motor NP Power Motor Poles Autotune 000 Read Only 000 User Entered 000 Read Only 000 User Entered 620 627 629 637 639 614 643 645 647 649 651 641 512 515 518 521 524 490 u IM Stator ...

Page 70: ...ion times are measured As a result the motor shaft moves which ramps the speed up and down The following parameters allow you to set dynamic limits on the torque profiles that are used during the rotate tests 10 911 Autotune Psn Lim 10 912 Autotune Vel Lim 10 913 Autotune Trq Lim 10 910 Autotune InertiaMotor 4 Enables the Autotune function to perform the Motor Inertia Test After selecting this val...

Page 71: ...his section includes Modes on page 71 Configuration on page 72 Modes The following Autotune modes perform Bandwidth Calculations Some modes perform inertia tests before bandwidth calculations because bandwidth calculations use 10 900 Motor Inertia and 10 901 Load Ratio in their computation 10 910 Autotune BW Calc 6 Enables the Autotune function to perform Bandwidth Calculations which means that th...

Page 72: ...t Pos The positive velocity limit that is placed on the velocity reference 10 1899 Vel Limit Neg The negative velocity limit that is placed on the velocity reference 10 1965 Accel Limit Pos The positive acceleration limit on the velocity regulator output 10 1966 Accel Limit Neg The negative acceleration limit on the velocity regulator output 10 2083 Torque Limit Pos The positive limit that is plac...

Page 73: ... maintain stability Figure 67 Autotune Gain Relationships for Load Observer Disabled or Velocity Estimate Only Load Observer Only Load Observer with Velocity Estimate or Acceleration Feedback When 10 901 Load Ratio 0 and 10 2020 LdObs Mode LdObs Only 1 or 10 2020 LdObs Mode LdObs VelEst 2 or 10 2020 LdObs Mode Accel Fdbk 4 KVI is disabled because load observer operates as a good velocity integrato...

Page 74: ...1956 1958 2022 2024 1755 905 c PReg Ki c VReg Kp c VReg Ki c PReg Kp c LdObs Kp c LdObs Ki u PReg Ki u VReg Kp u VReg Ki u PReg Kp u LdObs Kp u LdObs Ki 2154 1973 c Trq LPF BW c Accel FF Gain 1002 1004 1928 c Vel Fb LPF BW c Vel Fb LPF Gn c Vel Comp Gain 2155 1974 u Trq LPF BW u Accel FF Gain 1003 1005 u Vel Fb LPF BW u Vel Fb LPF Gn 1929 u Vel Comp Gain To Control Loops 1009 1022 u AltVelFbLPF BW...

Page 75: ...ou may also want to compare various design options for gear ratio load size coupling configuration high versus low resolution feedback devices reference move types and so on Simulate the load in online Motion Analyzer software to conclude that the desired motion can be achieved Problems are often minimized by creating a more direct and stiff coupling between the motor and load Quality mechanical c...

Page 76: ... manually tune the drive in Encoderless Mode The drive operates in Encoderless Mode when 1 2 and 3 are all true 1 The drive is set to Induction FV 0 65 Pri MtrCtrl Mode 4 2 Velocity Regulator mode 10 30 PsnVelTrq Mode A 1 3 Either Case a or Case b is true a The primary feedback 10 1000 Pri Vel Fb Sel is set to the Open Loop Virtual Encoder b The alternate feedback 10 1006 Alt VelFb Sel is set to t...

Page 77: ...ou cannot rotate the load for an induction motor IM then run 10 910 Autotune Static MtrID 2 to measure the motor electrical parameters c Run the drive and adjust 10 445 VCL CReg BW to achieve a desired performance 4 If the desired current torque loop performance is not yet achieved do the following a Set 10 444 VCL CReg C U Sel User Entered 1 You can first set it to copy the calculated parameter v...

Page 78: ... identified in Hz If this parameter displays a value of 0 then a high frequency resonance is not present It may be necessary to adjust parameter 10 2112 Trq NF Freq LLim to be able to see a resonant frequency See Adaptive Tuning on page 34 for more information on how to configure Adaptive Tuning Method 2 Use an FFT mobile application to identify resonances An iAnalyzer Lite example shows that the ...

Page 79: ...le the position loop if necessary Tune the Velocity Loop in Encoderless Mode If the drive is operating in Encoderless Mode the procedure describe in Tune the Velocity Loop on page 77 also applies with the minor considerations described in this section The drive will be in Encoderless Mode when 1 2 and 3 are all true 1 The drive is set to Induction FV 0 65 Pri MtrCtrl Mode 4 2 Velocity regulator mo...

Page 80: ... any further 3 Decrease 10 1755 u PReg Kp by dividing it by 2 Decreasing this parameter establishes a sufficient stability margin 4 Determine which integrator and feed forward gains are required for your application a See Application Types on page 79 to reference some common application types and which ones are enabled or given nonzero values b Typical ranges for integrator and feed forward gains ...

Page 81: ...enerates the command to the q axis current control loop that represents either an absorbed or regenerated power The d axis current control loop is responsible for reactive power control which means that the AFE converter can operate as a reactive power compensator provided that the total current supplied by the converter does not exceed the converter rating The q axis current reference the d axis ...

Page 82: ... reference in 13 48 DC BusRef Preset Commanded DC bus reference is limited to a higher value than the Auto DC reference value or to a maximum value depending on the frame rating 13 45 DC Bus Ref Sel Droop Ctrl 2 selects a voltage reference generated by Droop Control DC bus voltage is controlled to allow parallel operation of two or more AFE units without them fighting each other The DC bus command...

Page 83: ... Capacitance of common bus inverters and DC input drives that share the common DC bus Any additional capacitor modules added to the common DC bus 13 54 Volt Reg C U Sel Volt Reg Calc User Select Enter a value to select whether the DC bus voltage regulator uses calculated values or user entered values for proportional and integral gains Calculated values are determined by equations in the drive The...

Page 84: ...ator for FR5 and FR6 is set to 150 Hz it is set to 300 Hz for other frames The converter can maintain an excellent dynamic performance at relatively low bandwidths 100 150 Hz provided that the disturbance rejection is properly configured If needed the proportional gains KP and the integral gains KI for the current regulators in the d axis and the q axis of the current regulator loops can be direct...

Page 85: ... control loop Using the disturbance rejection functions results in an excellent dynamic performance even at relatively low BW settings of the current and voltage regulators This is achieved by using two main functions the feed forward power and the DC bus observer which are configured using 13 300 PwrFeedFwdConfig and 13 320 BusObsConfig Table 29 explains the parameters for these functions Table 2...

Page 86: ... on the DC bus 13 320 BusObs Config Bus Observer Configuration Select the mode for the Bus Observer function Parameter values are as follows Disabled 0 Bus Observer disabled BusObs Only 1 Bus Observer Only mode In this mode the Bus Observer compensates for the unknown capacitance and it only decouples that load The voltage control loop uses the actual measured DC bus voltage as the feedback signal...

Page 87: ... real time for the purpose of load monitoring see 13 325 BusObs Curr Est In Figure 73 notice that the current regulator BW is usually set 5 to 10 times higher than the voltage regulator BW Consequently the dynamics of the current regulator can be ignored and it can be represented by a unity again The total capacitance of the system C is defined as the summation of the internal capacitance Cint and...

Page 88: ... is useful for starting with the calculated values and then adjusting them After performing the copy this switch will revert to position User Entered 1 13 306 BusObs Sys BW Bus Observer System Bandwidth Enter the system bandwidth of the Bus Observer in units of Hz Used to generate calculated values of the voltage regulator and the Bus Observer gains This value only affects the calculated regulator...

Page 89: ...ar loads and achieve proper resonance rejection under distorted lines with a relatively lower frequencies 5th 7th 11th 13th etc Notice that the disturbance rejection is affected by size of the nonlinear load the inductance connecting the nonlinear load to the PCC the inductance connecting the AFE power converter to the PCC as well as the firing angle in case of controlled rectifiers In application...

Page 90: ...eter Name Description 13 45 DC Bus Ref Sel Feed Forward Voltage LPF Time Constant Enter a value to select the source for the DC Bus Voltage reference Parameter values are as follows Auto 0 selects an automatically generated reference that is based on the level of the incoming AC line voltage This signal comes from 13 46 Auto DC Bus Ref Manual 1 selects a manual reference in 13 48 DC BusRef Preset ...

Page 91: ...ages can degrade the performance of a standard PLL and the standard PLL must be detuned to reject unbalance effects The unbalance rejection is enabled by setting 13 85 PLL Config Bit 1 Unbl Rej Unbalance rejection can enhance the performance of the PLL by rejecting the effects of the unbalance in the input line voltages no detuning is required A key parameter that controls the transient performanc...

Page 92: ...set Bit 3 PLL Freq Src selects the PLL center frequency When this bit is clear the center frequency source is the value in 13 30 Nom Line Freq When this bit is set the center frequency is generated internally 13 86 Basic PLL Kp Basic Phase Lock Loop Proportional Gain Enter a value to set the Phase locked loop PLL proportional gain for the basic PLL with or without 2nd harmonic elimination Units ar...

Page 93: ...if the error exceeds a certain threshold Wrong connections and transient conditions on the grid cause loss of synchronization Transient conditions include the following power interruption voltage sag sudden frequency disturbance angle jump Loss of Synchronization is a critical condition You can choose Ride Through or Fault by configuring 13 181 PLL LOS Det Actn When Ride Through is selected the dr...

Page 94: ...less than 15 of the nominal value You can choose Ignore Alarm Ride Through or Fault by configuring parameter P13 170 PwrLoss Det Actn When the Ride Through is selected the drive activates the Ride Through function when it detects a phase loss condition for a period of time that is configured using 13 172 RideThrough Time see Ride Through Mode on page 94 If a power loss condition is cleared before ...

Page 95: ...ne side converter We set 10 116 Bus Reg Mode A to 1 Adjust Freq 10 270 Pwr Loss Actn to 1 Alarm 10 271 Pwr Loss Mode A to 1 Decel 10 272 Pwr Loss A Level to 50V and 10 273 Pwr Loss A Time to 60 s in the motor side inverter The duration of the power loss in this test was approximately 10 s Figure 78 Ride Through for PowerFlex 755TR Drives Power Disturbance Disturbance Ac on Ride Thru Ride Thru Time...

Page 96: ...r the duration of the Ride Through Timer If the Power Loss condition clears before the timer expires it resumes operation During the Ride Through attempt it logs a Type 2 Alarm Major Fault 3 A Major Fault occurs immediately Major Faults stop the line side converter from modulating 13 171 PwrLossRTExpActn LSC Power Loss Ride Thru Expired Action Enter a value to select the action taken when the Powe...

Page 97: ...clears before the timer expires it resumes operation During the Ride Through attempt it logs a Type 2 Alarm Major Fault 3 A Major Fault occurs immediately Major Faults stop the line side converter from modulating 13 177 PhsLossRTExpActn Input Phase Loss Ride Through Expire Action Enter a value to select the action taken when the Input Phase Loss condition lasts longer than the Ride Through Timer P...

Page 98: ... to the DC bus 13 69 kVAR Ref Reactive Power Reference Enter a value to set the Reactive Power kVAR reference Negative values command a leading power factor injecting reactive power to the line and positive values command a lagging power factor consuming reactive power from the line When the value is zero the line side converter will regulate reactive current to maintain a unity power factor If th...

Page 99: ...er of reactive power to the AC line 13 83 BusAutoAdjReg Ki VAR Control Bus Auto Adjust Regulator Ki Enter the value for the integral gain of the DC Bus Automatic Adjustment Regulator This feature is active only when13 45 DC Bus Reference Sel is set to VAR Control 3 It automatically raises the DC bus level to improve the efficiency of transfer of reactive power to the AC line Table 35 Reactive Powe...

Page 100: ...rigger velocity parameter then a nonzero friction compensation output signal is momentarily applied A stiction parameter sets this torque level Within the window the position and velocity loop integrators are also disabled to avoid the hunting effect that occurs when the integrators wind up After the velocity reference reaches or exceeds the friction compensation window value the full static frict...

Page 101: ...d set by this parameter the non viscous friction ramps down to the value set in 10 2055 FrctnComp Slip The remainder of the time that 10 2057 FrctnComp Out remains nonzero the non viscous friction remains constant at the value of 10 2055 FrctnComp Slip 10 2054 FrctnComp Stick Sets the level for the static friction torque It is the torque level that is required to break away from zero speed When in...

Page 102: ... 10 1763 PReg Droop This parameter sets the position regulator droop It limits the position regulator integral gain KPI 1 droop This parameter provides a means to fine tune the stability for load mounted feedback devices where compliance and backlash can cause problems Droop is displayed in units of seconds Here a 1 second droop represents a load position error equal to the change in position coun...

Page 103: ...tical load with a holding brake Controlling a brake is not difficult when you use the tools that are provided Here are some things to consider The holding brake is not a stopping brake If the application attempts to stop the load with the brake the brake does not engage However if the zero speed detection occurs with significant torque at the brake the brake can be damaged over time You can use a ...

Page 104: ...trolled and in a stable manner by adding or subtracting small amounts directly to the speed In the example shown in Figure 84 the master speed reference sets the wind unwind speed and the dancer potentiometer signal is used as a PID feedback to control the tension in the system An equilibrium point is programmed as the PID setpoint and as the tension increases or decreases during winding the maste...

Page 105: ...reference Figure 86 Winder When PID Is Enabled Exclusive Mode The output of PID controller is the speed reference in this mode and does not trim a master speed reference This mode is appropriate when speed is unimportant and the only important thing is to follow the reference or setpoint In the pumping application example shown in Figure 87 the setpoint is the required pressure in the system The p...

Page 106: ...Mode However when additional valves in the system are opened and the pressure in the system drops the PID error alters the commanded speed to bring the process back into control When the PID is disabled the commanded speed is restored as the ramped speed reference Figure 88 Pump When PID Is Disabled When the PID is enabled the speed reference is disconnected and PID output has exclusive control of...

Page 107: ...manded speed With the integrator preset to the commanded speed there is no disturbance in commanded speed when the PID is enabled After the PID is enabled the PID output is regulated to the required level Figure 91 Effect of PID Preload to Commanded Speed When the PID is configured to have exclusive control of the commanded speed and the drive is in the current limit or voltage limit the integrato...

Page 108: ...sult of the square root is normalized back to full scale to provide a consistent range of operation The option to take the square root is selected in the PID configuration parameter Figure 92 Normalized Square Root of Feedback Stop Mode When 10 110 Mtr Stop Mode A or 10 111 Mtr Stop Mode B is set to Ramp 1 and a stop command is issued to the drive the PID controller continues to operate during the...

Page 109: ...ID is put into hold Figure 94 PID Hold Logic PI Reset This feature holds the output of the integral function at 0 The term anti windup is often applied to similar features It can be used for integrator preloading during transfer and can be used to hold the integrator at 0 during Manual mode For example a process can create error when the feedback signal is below the reference point The drive incre...

Page 110: ...2 as a 0 10V DC signal 9 25 PID Ref Sel PI Setpoint 0 9 28 PID Setpoint 50 9 35 PID Fdbk Sel Analog In 2 2 9 29 PID Ref AnlgHi 100 9 30 PID Ref AnlgLo 100 9 39 PID Fdbk AnlgHi 100 9 40 PID Fdbk AnlgLo 0 The PI Feedback Scaling is Now 5V corresponds to 50 on the PID feedback and we try to maintain a PID setpoint of 50 5V 9 9 PID Deadband This parameter conditions the PID reference If the PID refere...

Page 111: ... the error is changing the larger the change to the output Derivative control is generally used in Torque Trim mode and is generally not needed in Speed mode For example winders using torque control rely on PD control instead of PI control Also 9 10 PID LPF BW is useful in setting the low pass filter bandwidth to remove unwanted signal response in the PID controller PID Output Scaling The output v...

Page 112: ...est 945 951 VRef Freq I4 Trq Ref Sel H5 942 944 943 Ref NF1 Freq Ref NF1 Depth Ref NF1 Width Ref NF1 Gain 948 950 949 Ref NF2 Freq Ref NF2 Depth Ref NF2 Width Ref NF2 Gain P Gain kp I Gain ki s PID Setpoint Default 9 28 9 29 9 30 Scale PID Ref AnlgHi PID Ref AnlgLo Option Port Analog In PID Fdbk Stpt PID Ref Sel 9 25 PID Fdbk Sel 9 35 9 39 9 40 Scale PID Fdbk AnlgHi PID Fdbk AnlgLo 9 37 Trq Comman...

Page 113: ...ng 0 1 1 0 1 A B 0 354 18 355 10 Motor Side Sts 2 Proc 1 C4 9 13 PID Output Meter PID Output Limited 9 13 PID Output Meter VRef Vect B5 VRef Freq A5 Trq Ref Sel G4 9 14 X Vref Limited 9 1 6 PID Cfg Percent Ref 1 0 9 1 2 PID Cfg Zero Clamp 0 VRef Ramped 0 1 1 0 Neg Limit Pos Limit 1 9 42 1800 Default Float Types PID FBLoss SpSel VRef A Sel 1906 1923 9 1 2 PID Cfg Zero Clamp 0 Torq Ref A 0 1 1 0 Neg...

Page 114: ...114 Rockwell Automation Publication 750 AT006D EN P January 2022 Chapter 7 Applications Notes ...

Page 115: ... servo drives Kinetix 5700 Drive Systems Design Guide publication KNX RM010 Determine what you need for Kinetix 5700 applications Kinetix 5700 Servo Drives User Manual publication 2198 UM002 Install configure and troubleshoot Kinetix 5700 applications EtherNet IP Network Devices User Manual ENET UM006 Describes how to configure and use EtherNet IP devices to communicate on the EtherNet IP network ...

Page 116: ...elephone number for your country rok auto phonesupport Literature Library Find installation instructions manuals brochures and technical data publications rok auto literature Product Compatibility and Download Center PCDC Download firmware associated files such as AOP EDS and DTM and access product release notes rok auto pcdc Rockwell Automation maintains current product environmental compliance i...

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