What should be taken note of when quasi-synchronized paralleling of generator collections?
Quasi-simultaneous association is a hands-on procedure. Whether the operation is smooth or otherwise has a great partnership with the experience of the operator. In order to prevent association in different durations, the adhering to 3 circumstances are not allowed to close.
1. When the tip of the synchronization table leaps, it is not enabled to shut, due to the fact that there might be a tape sensation inside the synchronization table, which can not show the appropriate parallel problems.
2. When the simultaneous table turns as well fast, it indicates that the frequency distinction in between the generator readied to be paralleled and that of the various other generator collection is as well huge. Due to the fact that the closing time of the circuit breaker is difficult to realize, the circuit breaker is typically not closed at the synchronization point. Not allowed to shut.
3. If the tip of the synchronizing table stops at the integrating point, it is not allowed to close the switch when it stops. This is since if the frequency of one of the generator establishes changes all of a sudden during the closing procedure of the breaker, it is possible for the breaker to shut at the non-synchronized factor.
4. Just how to readjust the reverse power sensation of parallel systems?
When 2 generator sets are juxtaposed with no tons, there will be a problem of frequency difference as well as voltage difference between the two generator collections. And on the monitoring tools (ammeter, power meter, power element meter) of both systems, the real reverse power scenario is reflected, one is the reverse power caused by the irregular speed (regularity), and the other is triggered by the voltage difference. Inverted job, its modification is as complies with:
1. Modification of the reverse power phenomenon caused by the frequency: if the frequencies of the two systems are not equal, as well as the distinction is huge, it will be displayed on the instrument (ammeter, power meter), the current of the device with high speed reveals a positive worth, as well as the power meter indicates a favorable worth. Power, on the other hand, present shows an adverse worth, and also power shows an adverse worth. Currently, change the rate (frequency) of one of the units, and change it according to the indicator of the power meter, and change the sign of the power meter to absolutely no. Make the power indicators of both units no, so that the rotational rates (regularity) of both devices are basically the same. However, when the ammeter still indicates right now, this is the reverse power phenomenon caused by the voltage difference.
2. Modification of the reverse power phenomenon triggered by the voltage distinction: when the power meter indications of the two generator sets are both no, and the ammeter still has a current indication (that is, one inverted and one favorable indicator), the voltage modification of among the generator sets can be readjusted. When changing the knob, it depends upon the indication of the ammeter and also the power aspect. Eliminate the sign of the ammeter (that is, adjust it to absolutely no). After the ammeter has no indication, readjust the power aspect to a lag of greater than 0.5 depending upon the sign of the power element meter. Normally, it can be adjusted to about 0.8, which is the very best state.
5. Generator security circuit
1. Reverse power The reverse power sensation is brought on by the distinction in the rate (regularity) and also voltage of the generator collection, that is, one generator collection has favorable power, while the various other collection has negative power. That is to claim, the system with adverse power comes to be a tons currently (the frequency of this system is low and the rotational rate is inconsistent). When the voltages are not the same, the system with high voltage will certainly give a responsive current and also reactive voltage to the device with reduced voltage (the ammeter of this unit indicates the favorable direction), which amounts adding a phase control system in the power supply system. The unit with low voltage ends up being a huge lots at this time, obtaining a big reactive current to keep the voltage equilibrium of the two units (the ammeter of this system shows the reverse direction). When surveillance, readjust the voltage of a certain unit greater or lower the voltage of another system, causing a device to have a reverse power existing, and also its operating current has to do with 20% of the rated existing. The reverse power relay runs, trips, and also alarms, yet does not quit.
2. Overcurrent: The rated power of the current generator set is certain, and its overload capacity is extremely low, generally regarding 5% of the ranked power. The permitted load time is 15 ~ 30 minutes, and also the maximum is not greater than 60 mins. The generator set will heat up, and also the cord insulation will certainly be decreased, which will decrease the service life. For that reason, if there is no unique need when establishing the overcurrent defense, the overcurrent protection can be set at 110% of the rated current. Throughout the on-load test, bring the current to 110% of the rated current, as well as the overcurrent relay will certainly act. Trip, alarm system, no closure.
3. Overvoltage: When the generator sets are utilized in parallel, one of the most are afraid is that the power supply system will certainly oscillate. As soon as the voltage of the oscillating system increases, it is easy to trigger the insulation break down of the electric tools and also the power supply equipment, and the power supply devices and also the electric tools will be immobilized with each other. For this objective, the generator sets used in parallel are outfitted with overvoltage protection, and also its setup value is 105% of the rated voltage is the most effective. Short-circuit over-voltage relay, trip as well as quit, alarm action.
Post time: Dec-30-2022