Detailed explanation of ten commissioning steps of diesel engine set
1、 Visual inspection before unit test
The appearance inspection mainly includes the data inspection of the name plate, welding quality, installation quality, no leakage of the pipeline, and whether the starting system and wiring are correct.
2、 Measuring insulation resistance of generator
Measure the insulation resistance of each independent electrical circuit to the ground and between the circuits. When measuring with a megohmmeter, semiconductor devices, capacitors, etc. should be removed, and all switches should be in the on state. The reading after the megohmmeter pointer is stable is the measurement result.
3、 Starting performance test of generator set
When the ambient temperature is not lower than 5 ℃, the cooling water and lubricating oil are not preheated. The emergency unit shall be able to start smoothly under the environment of 0 ℃ (preheating measures are allowed when starting is difficult). Continuous starting for six times, the one with more than five successful starts in six times is qualified. The time interval for each start-up shall not exceed 1 min (the automatic unit shall also undergo three self starting failure tests).
4、 Unit operation inspection
After the diesel engine is started, gradually accelerate to the rated speed, and observe whether the unit has abnormal sound. Whether the temperature of motor bearing is normal, whether the diesel engine has three leakage, whether the motor and diesel engine are running normally.
5、 Adjustment range of speed remote control mechanism
It can be divided into two states: active and automatic, and test whether it is within the specified range.
6、 Check the no-load voltage setting range
At rated power factor and rated frequency, whether the measured voltage is within the rated range under manual and automatic conditions.
7、 Unit protection device test
After starting the unit, adjust the speed to the rated speed under no-load, and then slowly increase the speed to the specified alarm value to test the overspeed protection. The high water temperature protection should distinguish whether the water temperature sensor adopts the switch value or the analog value. The switch value sensor will short-circuit both ends to make it alarm. In the case of analog quantity, the alarm and shutdown parameters of the controller can be changed to complete the test. Oil temperature and oil pressure tests are similar.
8、 Sudden loading and unloading test of generator set During the sudden load test, the voltage and frequency waveforms experienced a fluctuation from the steady state before the sudden increase and sudden discharge to the sudden increase and sudden discharge. Then, when the waveform returns to stable, measure whether the voltage, frequency and stability time are within the range.
9、 Transient voltage change rate and stability time of generator
The capacity of marine power station is relatively small. When the load changes, the terminal voltage of generator set will change greatly. Maintaining a stable voltage is an important index for generating units. The transient voltage change rate of generator is an important index to measure the quality of power supply.
10、 Unit load test
The test is carried out under rated condition. After 10 minutes of no-load operation, the unit changes the load and records the power, frequency, current and other parameters at regular intervals. Within the rated operation time, the unit shall be free from three leakage and other abnormal phenomena.