Parallel Operation Control System

Product Description

First, what are the conditions for parallel operation of generator sets?
The whole process of putting the generator set into parallel operation is called parallel operation. The first generator set will run, the voltage is sent to the bus, and the other generator set after starting, and the previous generator set, should be in the closing moment, the generator set should not appear harmful impulse current, the shaft is not subject to sudden impact. After closing, the rotor should be quickly pulled into sync. (that is, the rotor speed is equal to the rated speed) Therefore, the generator set must meet the following conditions:
1. The effective value and waveform of the generator set voltage must be the same.
2. The voltage phase of the two generators is the same.
3. The frequency of the two generator sets is the same.
4. The phase sequence of the two generator sets is consistent.

Second, what is the quasi-synchronous juxtaposition method of generator sets? How to make simultaneous juxtapositions?
Quasi-synchronous is the exact period. With the quasi-synchronous method for parallel operation, the generator set voltage must be the same, the frequency is the same and the phase is consistent, which can be monitored by two voltmeters, two frequency meters and synchronous and non-synchronous indicators installed on the synchronous disk, and the parallel operation steps are as follows:
The load switch of one generator set is closed, and the voltage is sent to the bus bar, while the other unit is in the standby state.
Close the beginning of the same period, adjust the speed of the standby generator set, so that it is equal to or close to the synchronous speed (frequency difference with another unit within half a cycle), adjust the voltage of the standby generator set, so that it is close to the voltage of the other generator set, when the frequency and voltage are similar, the rotation speed of the synchronous table is slower and slower, and the indicator light is also bright and dark at the same time; When the phase of the unit to be combined is the same as that of the other unit, the synchronous meter pointer indicates the upward square middle position, and the synchronous lamp is dim. When the phase difference between the unit to be combined and the other unit is large, the synchronous meter points to the center position below, and the synchronous lamp is on at this time. When the synchronous meter pointer rotates clockwise, it indicates that the frequency of the synchronous generator is higher than that of the other unit. The speed of the standby generator set should be reduced, and the speed of the standby generator set should be increased when the clock pointer is rotated counterclockwise. When the clock pointer rotates slowly in the clockwise direction and the pointer approaches the same point, the circuit breaker of the unit to be combined is closed immediately, so that the two generator sets are in parallel. Side-by-side excised chronograph switches and associated chronoswitches.

Third, what should be paid attention to when carrying out the quasi-synchronous juxtaposition of the generator set?
Quasi-synchronous parallel is manual operation, whether the operation is smooth and the experience of the operator has a great relationship, in order to prevent different synchronous parallel, the following three cases are not allowed to close.
1. When the pointer of the synchronous table appears jumping phenomenon, it is not allowed to close, because there may be a cassette phenomenon inside the synchronous table, which does not reflect the correct juxtaposition conditions.
2. When the synchronous table rotates too fast, it indicates that the frequency difference between the generator set and the other generator set is too large, because the closing time of the circuit breaker is difficult to master, often the circuit breaker is not closed at the same time, so it is not allowed to close at this time.
3. If the clock pointer stops at the same time, it is not allowed to close. This is because if the frequency of one of the generator sets changes suddenly during the closing process, it is possible to make the circuit breaker just close at the non-synchronous point.

Fourth, how to adjust the reverse power phenomenon of parallel units?
When the two generator sets are idle, there will be a frequency difference and voltage difference between the two sets. And on the monitoring instrument of the two units (ammeter, power meter, power factor meter), the actual inverse power situation is reflected, one is the inverse power caused by inconsistent speed (frequency), the other is the inverse power caused by unequal voltage, which is adjusted as follows: