GE SPM Series, Instruction Manual

Page: 79 / 126

GE Power Management SPM Synchronous Motor Protection & Control 7-
5
7 TESTING AND TROUBLESHOOTING 7.3 REGULATOR TUNE-UP
7
7.3 REGULATOR TUNE-UP 7.3.1 INSTRUCTIONS
Following these instructions will permit tune-up of the regulator during the initial start-up of the motor. Perform
all start-up procedures in Section 7.1: START-UP PROCEDURE on page 7–1 before proceeding.
1. Enter the following initial values into the SPM (see Section 5.3: OPTIONAL POWER FACTOR REGULA-
TION SETPOINTS on page 5–10 for additional information on these setpoints):
REG PF = OFF
STABILITY = 1 cyc
REG GAIN = 10
REG. OUTPUT = 10 V
FLOOR = 5.0 V
• Setting REG PF = OFF places FLOOR in control of the motor field. The power factor regulator is disabled.
• FLOOR = 5.0 V is sufficiently high enough to not trip the motor due to underexcitation when started.
2. After the above values are stored in memory and SPM READY is displayed, start the motor (unloaded if pos-
sible) and allow it to synchronize. The display should indicate a leading (positive) power factor.
3. To facilitate regulator tune-up, the five power factor regulator parameters can be changed while the motor
is running. These are the only parameters that can be changed while in the "tuning mode".
To get in "tuning mode" while the motor is running, enter programming mode and scroll to the REGULATOR
TUNING menu. Press the key to enter the menu.
4. Press / until the FLOOR VOLTS setpoint is displayed. Adjust the motor field current for a desired
minimum (typically between 80 to 100% of rated field current). Change the floor value to a value above or
below the initial value of 5.0, depending on whether more or less field current is desired. The floor parame-
ter is the output voltage across the PF regulator output terN and –N.
This method of parameter entry can only be employed while the motor is running and only for the
five power factor regulator parameters.
5. Once the desired minimum motor field current is obtained, press to deselect FLOOR VOLTS . Press
/ until the PF REG setpoint appears. Program the desired power factor (typically between 0.8 and
1.0). The control of the motor field current should now be in control of the closed-loop power factor regula-
tor. Press
again to deselect the PF REG setpoint.
6. Reset the REG OUTPUT setpoint to the original factory setting. This setpoint has been chosen to match the
input of the separate variable exciter.
7. The regulator gain setpoint can probably be left at 10. However, should instability (hunting) occur, or if
more optimum response is desired, the gain may be increased or decreased as desired. Press
/
until REG GAIN appears in the display and enter new setpoints (range 1 to 100) using the same procedure
as for the FLOOR and REG PF setpoints. The optimum gain is the highest possible gain setting without power
factor instability detectable by a fluctuating exciter output and power factor. If instability still occurs, then
increase the value of the
STABILITY setpoint as required to dampen the fluctuating power factor. These
parameters are automatically stored in the E
2
PROM when the motor is shut down.
Do not attempt to regulate 1.0 power factor with an unloaded or lightly loaded machine. A synchro-
nous machine running unloaded at or near unity power factor is inherently unstable and will probably
be tripped from power factor protection. Adjust the
FLOOR setpoint high enough to override the regula-
tor and avoid the instability while allowing the PF to move near zero lead power factor.
ENTER
NOTE
ENTER
ENTER
NOTE