background image

User’s Guide

MCF8316A Tuning Guide

ABSTRACT

This Tuning guide provided step by step guidence to setup MCx8316AEVM, connect MCF8316A GUI to the 
EVM and tune a 3-phase Brushless DC motor using 

MCF8316A

.

Table of Contents

1 Revision History

......................................................................................................................................................................

2

2 Introduction

.............................................................................................................................................................................

3

2.1 Hardware and GUI Setup...................................................................................................................................................

3

3 Essential Controls

..................................................................................................................................................................

6

3.1 Recommended Default Values...........................................................................................................................................

6

3.2 Device and Pin Configuration.............................................................................................................................................

6

3.3 Control Configuration - Motor Parameters.........................................................................................................................

7

3.4 Control configuration - Closed Loop...................................................................................................................................

7

3.5 Testing for Successful Startup into Closed Loop................................................................................................................

7

3.6 Fault Handling....................................................................................................................................................................

9

4 Basic Controls

.......................................................................................................................................................................

12

4.1 Device and Pin Configuration...........................................................................................................................................

12

4.2 System Level Configuration.............................................................................................................................................

12

4.3 Control Configurations.....................................................................................................................................................

14

List of Figures

Figure 2-1. Simplified Schematic of MCF8316A..........................................................................................................................

3

Figure 2-2. MCx8316A EVM Jumper Configuration....................................................................................................................

4

Figure 2-3. MCx8316A EVM External Configuration...................................................................................................................

5

Figure 3-1. Fault Status...............................................................................................................................................................

8

Figure 3-2. Motor Resistance......................................................................................................................................................

9

Figure 3-3. Motor Inductance.......................................................................................................................................................

9

Figure 3-4. Motor BEMF Constant.............................................................................................................................................

10

Figure 3-5. Phase Current Waveform Showing a Spike due to Short Circuit.............................................................................

11

Figure 4-1. Phase current and FFT - Dead time compensation disabled..................................................................................

13

Figure 4-2. Phase current and FFT - Dead time compensation enabled...................................................................................

13

Figure 4-3. Power Supply voltage and phase current waveform when AVS is disabled............................................................

14

Figure 4-4. Power Supply voltage and phase current waveform when AVS is enabled............................................................

14

Figure 4-5. MPET - Phase current.............................................................................................................................................

15

Figure 4-6. IPD current waveform during Rand L measurement...............................................................................................

15

Figure 4-7. Reverse Drive Function...........................................................................................................................................

16

List of Tables

Table 3-1. Recommended Default Values....................................................................................................................................

6

www.ti.com

Table of Contents

SLLU335A – AUGUST 2021 – REVISED JANUARY 2022

Submit Document Feedback

MCF8316A Tuning Guide

1

Copyright © 2022 Texas Instruments Incorporated

Содержание MCF8316A

Страница 1: ...MCx8316A EVM Jumper Configuration 4 Figure 2 3 MCx8316A EVM External Configuration 5 Figure 3 1 Fault Status 8 Figure 3 2 Motor Resistance 9 Figure 3 3 Motor Inductance 9 Figure 3 4 Motor BEMF Constant 10 Figure 3 5 Phase Current Waveform Showing a Spike due to Short Circuit 11 Figure 4 1 Phase current and FFT Dead time compensation disabled 13 Figure 4 2 Phase current and FFT Dead time compensati...

Страница 2: ...Changes from Revision August 2021 to Revision A January 2022 Page RTM updates 1 Trademarks All trademarks are the property of their respective owners Revision History www ti com 2 MCF8316A Tuning Guide SLLU335A AUGUST 2021 REVISED JANUARY 2022 Submit Document Feedback Copyright 2022 Texas Instruments Incorporated ...

Страница 3: ... and Basic controls This process is also detailed in the Guided tuning section in the GUI Essential controls Tuning steps to successfully spin the motor in closed loop Basic controls Tuning steps to conform to use case and explore features in the device 2 1 Hardware and GUI Setup Below are the items that are required to run through this tuning guide 1 MCx8316AEVM Board 2 A computer with the MCF831...

Страница 4: ...ion or wires for Hall effect sensors leave these wires unconnected Supply a voltage compliant with the Power Supply Voltage VM range using J7 Recommended voltage range for the device is 4 5 V 35 V Introduction www ti com 4 MCF8316A Tuning Guide SLLU335A AUGUST 2021 REVISED JANUARY 2022 Submit Document Feedback Copyright 2022 Texas Instruments Incorporated ...

Страница 5: ...erial port is selected by going to the top menu Options Serial Port Then click on the chain link icon on the left of the status bar to connect to the EVM 2 1 3 3 Verify Hardware Connection After the GUI establishes connection with the EVM through USB you can verify the communication with the MCx8316 device by clicking on the Read All Registers button on the top right of this GUI After a few second...

Страница 6: ...96 0x00000000 SPEED_PROFILES3 0x00000098 0x00000000 SPEED_PROFILES4 0x0000009A 0x00000000 SPEED_PROFILES5 0x0000009C 0x00000000 SPEED_PROFILES6 0x0000009E 0x00000000 FAULT_CONFIG1 0x00000090 0x5FE80206 FAULT_CONFIG2 0x00000092 0x74000000 PIN_CONFIG 0x000000A4 0x00000000 DEVICE_CONFIG1 0x000000A6 0x00000000 DEVICE_CONFIG2 0x000000A8 0x0000B000 PERI_CONFIG1 0x000000AA 0x40000000 GD_CONFIG1 0x000000A...

Страница 7: ...3 phases can be chosen at random if they are not labeled 3 Turn on supply The rotor should have settled at one position with the injecting current 4 Manually rotate the rotor until rotor snaps to another settle position It will have several settle down positions around one mechanical cycle 5 Count the number of settle down positions for one fully mechanical cycle which is the number of pole pairs ...

Страница 8: ... speed In closed loop the motor should spin at the commanded speed and there should not be any faults triggered a Enable the Auto read fault status toggle button towards the top right corner of the GUI Then monitor the Fault Status in the side panel to the right If no fault gets triggered skip Section 3 6 and proceed to Section 4 4 Prepare device for fault handling if any fault gets triggered If t...

Страница 9: ...n in equation Equation 2 The motor phase resistance refers to the equivalent phase to center tap resistance RPH as shown in Figure 3 2 This measurement holds good for both star wound and delta wound motors RPH Pℎase resistance RPH_PH Pℎase to Pℎase resistance 2 2 Phase A Phase B Phase C RPH_PH R P H _ P H RP H _ P H RPH R PH RPH CT Figure 3 2 Motor Resistance To know the motor inductance measure t...

Страница 10: ...onstant Ke EPH TE 3 5 3 6 3 Abnormal BEMF Fault ABN_BEMF This fault gets triggered when the estimated BEMF voltage drops below the programmed Abnormal BEMF threshold ABNNORMAL_BEMF_THR of the programmed or MPET estimated BEMF constant Ke MOTOR_BEMF_CONST which is programmed as 40 default value For example if the estimated measured Ke is 5 mV Hz and programmed Abnormal BEMF threshold is 40 this fau...

Страница 11: ...rt Circuit Step 1 Program Speed loop Kp SPD_LOOP_KP Speed loop Ki SPD_LOOP_KI current loop Kp CURR_LOOP_KP and current loop Ki CURR_LOOP_KI to zero This enables auto calculation of speed loop and current loop PI controller gains Step 2 Increase the MCC Dead time MCC_DEAD_TIME and retry again Step 3 If the fault still persists check the continuity across phase to phase phase to GND or Vm to GND to ...

Страница 12: ...lockwise direction will be OUTA OUTC OUTB BRAKE pin in MCF8316A can be overwritten by configuring BRAKE_INPUT Configuring BRAKE_INPUT to 01b will overwrite Hardware pin to low side brake Align according to BRAKE_PIN_MODE Configuring BRAKE_INPUT to 10b will overwrite Hardware pin and not low side brake align In Low side braking mode all the LS FETs will be turned ON In Align braking mode MCF8316A a...

Страница 13: ...gets better Note Decreasing the dead time might trigger Hardware lock detection current limit fault HW_LOCK_ILIMIT If this fault gets triggered increase the dead time Figure 4 1 shows the phase current waveform when dead time compensation is disabled Fundamental frequency of phase current is 40 Hz Fast Fourier transform FFT of phase current plot shows harmonics at 160 Hz and 220 Hz Figure 4 2 show...

Страница 14: ...and motor may be stressed with continued operation in high voltage Step 1 Keep decreasing the supply voltage till we see a drop in the speed Measure the bus voltage at which the speed drops and set MIN_VM_MOTOR to that value Range of minimum bus voltage that can be configured is between 4 5 V and 12 5 V Step 2 Keep increasing the bus voltage to a point where the motor phase voltage reaches the max...

Страница 15: ...t waveform during R and L measurement R is measured during the rising of phase current and L is measured during the falling of phase current After R and L measurement motor spins in open loop Once the speed reaches MPET open loop speed reference MPET_OPEN_LOOP_SPEED_REF motor is coasted BEMF voltage of all three phases are measured and Ke is calculated Figure 4 5 MPET Phase current Figure 4 6 IPD ...

Страница 16: ...ed loop as shown in Figure 4 7 Reverse Deceleration Open Loop Handoff to close loop Open loop Close loop Speed Time Handoff to open loop Figure 4 7 Reverse Drive Function MCF8316A provides an option to apply brakes and stop the motor while the motor is coasting or spinning in reverse direction and then accelerate into closed loop after changing the direction In applications such as ceiling fans an...

Страница 17: ...owever higher current might result in rotor movement vibration and noise It is recommended to start with 50 of the rated current of the motor If the motor startup is unsuccessful then we recommend increasing the threshold till the motor starts up successfully Note that the IPD current threshold should not be higher than the rated current of the motor Step 3 Select IPD clock value IPD_CLK_FREQ IPD ...

Страница 18: ...the frequency 4 3 5 Faster Startup Timing Startup time is the time taken for the motor to reach the target speed from zero speed For applications that require quick startup time we recommend choosing either Initial Position Detection IPD or Slow first cycle as the startup method Option 1 Initial Position Detection IPD Step 1 Select IPD MTR_STARTUP as the motor startup method Step 2 Increase IPD cu...

Страница 19: ...oving Speed Regulation For applications that require better speed regulation it is recommended to tune Speed loop PI controllers SPD_LOOP_KP and SPD_LOOP_KI Kp coefficient of speed loop SPD_LOOP_KP controls the settling time and speed overshoots Ki coefficient of Speed loop SPD_LOOP_KI controls speed overshoot and ensures regulation of speed at set value and drives the error to zero Speed loop PI ...

Страница 20: ...tions Recirculation brake can be used as a motor stop option in applications where fast stop is not required but any inductive energy going back to power supply is not acceptable Active spin down can be used as a motor stop option in applications where fast stop is not required but some amount of inductive energy going back to power supply is acceptable Option 1 Recirculation Mode Step 1 Configure...

Страница 21: ...put supply When active braking is enabled energy taken from DC power supply is used to brake the motor this prevents DC voltage spike during fast deceleration The mechanical energy of the motor and energy taken from DC source both are dissipated within the motor itself Follow below steps to decelerate the motor quickly Step 1 Enable active braking ACTIVE_BRAKE_EN Step 2 Configure ACTIVE_BRAKE_CURR...

Страница 22: ...other than TI b the nonconformity resulted from User s design specifications or instructions for such EVMs or improper system design or c User has not paid on time Testing and other quality control techniques are used to the extent TI deems necessary TI does not test all parameters of each EVM User s claims against TI under this Section 2 are void if User fails to notify TI of any apparent defects...

Страница 23: ... These limits are designed to provide reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications However there is no guarantee that interference will not occur in a particular installation...

Страница 24: ...y for convenience and should be verified by User 1 Use EVMs in a shielded room or any other test facility as defined in the notification 173 issued by Ministry of Internal Affairs and Communications on March 28 2006 based on Sub section 1 1 of Article 6 of the Ministry s Rule for Enforcement of Radio Law of Japan 2 Use EVMs only after User obtains the license of Test Radio Station as provided in R...

Страница 25: ... any interfaces electronic and or mechanical between the EVM and any human body are designed with suitable isolation and means to safely limit accessible leakage currents to minimize the risk of electrical shock hazard User assumes all responsibility and liability for any improper or unsafe handling or use of the EVM by User or its employees affiliates contractors or designees 4 4 User assumes all...

Страница 26: ...OR DAMAGES ARE CLAIMED THE EXISTENCE OF MORE THAN ONE CLAIM SHALL NOT ENLARGE OR EXTEND THIS LIMIT 9 Return Policy Except as otherwise provided TI does not offer any refunds returns or exchanges Furthermore no return of EVM s will be accepted if the package has been opened and no return of the EVM s will be accepted if they are damaged or otherwise not in a resalable condition If User feels it has...

Страница 27: ...o change without notice TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource Other reproduction and display of these resources is prohibited No license is granted to any other TI intellectual property right or to any third party intellectual property right TI disclaims responsibility for and you will fully indemn...

Отзывы: