Electronic Governor and Voltage Regulator of Volvo Generator

Methods to adjust electronic governor of Volvo diesel generator set

Our company produces generator sets, some of which are equipped with mechanical governors and some with electronic governors. Both speed governors can guarantee the power quality absolutely, but the generator set equipped with electronic governor realizes automatic protection and automatic control is very convenient. The electronic governor of diesel generator set has been adjusted and the user does not need to do this. However, after the engine overhaul or the fault that affects the operation of the electronic governor, it needs to be adjusted. The electronic governor control unit is mounted in the control box at the top of the generator.

A. Turn switch C1 to the engaged position. If there is rapid ride during the engine running, turn C2 to the (OFF) position.

B. Turn switch C2 to the engaged position.

C. Turn the gain (GAN) and stability potention meters to the middle position.

D. Temporarily connect terminals L and M together.

Adjustment of the electronic governor after starting

A. After starting the generator set, the engine runs at idle speed (about 400 rpm), and the idle speed (IDLE) potentiometer is turned clockwise to increase the idle speed. This potentiometer is single turn. Therefore, the adjustment should be carried out carefully and the potentiometer must not be turned to the maximum position.

Warning: Prolonged operation at very low speeds can damage the elastic coupling/engine/generator.

B. After confirming that the engine is working properly, remove the connection of the L and M terminals and the engine speed rises to approximately 1567 rpm.

C. Final adjustment

The engine is idling and the gain (GAN) potentiometer is turned clockwise until the engine starts to be unstable. Then return the potentiometer to the engine to resume stability, and then continue to retreat 1 / 8 circle.

Adjust the stability in the same way as above (STABILITY)

Note: When adjusting the gain potentiometer, the preset engine speed may change, so the engine speed should be adjusted by the SPEED potentiometer to 1567 rpm (52.2HZ on the frequency meter).

After the above speed adjustment is completed, the load can be applied. Under normal circumstances, these adjustments have a critical point when the machine is cold, so it may need to be adjusted again.

Rotating the gain (GAN) potentiometer clockwise will increase the response speed of the governor to load changes, and counterclockwise decrease the governor reaction speed.

Clockwise rotation stability (STABILITY) potentiometer shortens the recovery time of the speed control system after the load changes, and increases the recovery time counterclockwise.

Volvo generator voltage regulator data and excitation system wiring diagram

Volvo generator's automatic voltage regulators AVR and D202, all of its components are mounted on a printed circuit board, the lead wire is connected to the outside through multi-core connectors or bolts, can be installed in the junction box, also It can be removed from the machine and installed in the control panel. When removing the machine, special attention should be paid to adjusting the ventilation and cooling of the AVR.

1 Exciter field winding

2 Exciter rotor winding

3 Rotary rectifier

4 Generator field winding

5 Generator set stator winding

6 Auxiliary winding

7 Tolerance transformer

8 Tolerance potentiometer

9 Remote voltage adjustment potentiometer

10 Third harmonic winding

RP1：Voltage regulation

RP2：Stable adjustment 

R1: integral time constant adjustment

RP3：50Hz frequency inflection point adjustment (K2 open)

RP4：Voltage down regulation at 50Hz or 60Hz

RP5：60Hz frequency inflection point adjustment (K2 on) 3.6.1 can be used in 50Hz and 60Hz generators. For 60Hz generators, the K2 switch is placed in the "ON" position (ie, the off position).

Measure the transformer input voltage to 400 volts (also 230 volts), short-circuit and overload protection for rapid blown 10A, 5 seconds (this fuse is mounted on the regulator board). When the load buffer function and U/f=constant function are required, the K3 switch is placed in the “ON” position. When these two functions are not required, the K3 switch is placed in the “OFF” position. When remote voltage regulation is required, disconnect the short-circuit between RV1 and RV2 and connect a KΩ potentiometer (multi-turn potentiometer is recommended). N1, W1 is short-circuited at the factory. If there is parallel operation requirement, fold the short wiring, and connect the difference adjustment device at the two ends (the device is composed of a current transformer and a potentiometer and connected). The current transformer has a sideband capacity of 1VA, a current of 1A, and a potentiometer of 20W5Ω. Note that the current transformer of the adjustment device cannot be connected to the same phase of the voltage measurement transformer of the AVR. For example, the voltage measurement transformer of the AVR is connected to the V-W phase, and the current mutual susceptor for the adjustment should be connected to the U phase.