700kw Diesel Generator Set Quasi Synchronous Parallel

Diesel generator sets can be widely used in various types of enterprises in different industries such as communications, power, petroleum and petrochemical, civil aviation, expressways, ports, ships, national defense, nuclear industry, energy, radio and television, metallurgy, construction, and postal services. It is particularly important for users to have a good understanding of professional knowledge about generator sets. Just as the saying goes, "Know yourself and your enemy, and you can fight a hundred battles with no danger of defeat." Mastering certain professional knowledge about the 700kW Shangchai generator set can help solve problems efficiently and quickly when encountering faults later. Dingbo Power's Generator Knowledge Mini - Course is sharing knowledge about generator set paralleling today, hoping to help everyone solve their problems.

What are the conditions for parallel operation of generator sets?

The whole process of putting a generator set into parallel operation is called paralleling. First, start one generator set and send the voltage to the bus. Then, start another generator set and parallel it with the previous one. At the moment of closing the switch, there should be no harmful inrush current in the generator set, and the rotating shaft should not be suddenly impacted. After closing the switch, the rotor should be quickly pulled into synchronization (i.e., the rotor speed equals the rated speed).

What is the quasi - synchronous paralleling method of generator sets? How to perform synchronous paralleling?

Quasi - synchronous means accurate cycle. When using the quasi - synchronous method for paralleling operation, the voltage, frequency, and phase of the generator sets must be the same. This can be monitored through two voltmeters, two frequency meters, a synchronizing meter, and non - synchronizing indicator lights installed on the synchronizing panel. The steps of the paralleling operation are as follows:

Close the load switch of one of the generator sets and send the voltage to the bus, while the other generator set is in the standby state.

Close the synchronizing switch and adjust the speed of the standby generator set to make it equal to or close to the synchronous speed (with a frequency difference of less than half a cycle from the other generator set). Adjust the voltage of the standby generator set to make it close to that of the other generator set. When the frequency and voltage are both similar, the rotation speed of the synchronizing meter becomes slower and slower, and the synchronizing indicator light flickers on and off. When the phases of the standby generator set and the other generator set are the same, the pointer of the synchronizing meter points to the upper middle position, and the synchronizing light is the dimmest. When the phase difference between the standby generator set and the other generator set is the largest, the synchronizing meter points to the lower middle position, and at this time, the synchronizing light is the brightest. When the pointer of the synchronizing meter rotates clockwise, it means that the frequency of the standby generator is higher than that of the other generator set, and the speed of the standby generator set should be reduced. Conversely, when the pointer of the synchronizing meter rotates counter - clockwise, the speed of the standby generator set should be increased. When the pointer of the synchronizing meter rotates slowly clockwise and approaches the synchronization point, immediately close the circuit breaker of the standby generator set to parallel the two generator sets. After paralleling, turn off the synchronizing meter switch and relevant synchronizing switches.

What should be noted when performing quasi - synchronous paralleling of generator sets?

Quasi - synchronous paralleling is a manual operation, and the success of the operation is highly related to the experience of the operator. To prevent non - synchronous paralleling, the following three situations are not allowed for closing the switch:

1.Do not close the switch when the pointer of the synchronizing meter jumps, because there may be a jamming phenomenon inside the synchronizing meter, which cannot reflect the correct paralleling conditions.

2.Do not close the switch when the synchronizing meter rotates too fast, which indicates that the frequency difference between the standby generator set and the other generator set is too large. Since it is difficult to master the closing time of the circuit breaker, the circuit breaker often does not close at the synchronization point.

3.Do not close the switch when the pointer of the synchronizing meter stops at the synchronization point. This is because if the frequency of one of the generator sets suddenly changes during the closing process of the circuit breaker, the circuit breaker may close at a non - synchronization point.

The paralleling of diesel generator sets is a professional technical knowledge that needs to be understood step by step. The editor of Dingbo Power has simply shared the conditions and precautions for the parallel operation of diesel generator sets, hoping to help everyone understand the knowledge of generator sets more easily. The in - depth problem of the reverse power phenomenon in the paralleling of diesel generators will be revealed next time.

Dingbo Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to [email protected] we will pay highly attention on your question.