One of the important steps in the operation of the reactive power capacitor compensation cabinet is switching. The choice of the switching mode is very important. If the switching mode is not selected correctly, the problem of overcompensation or undercompensation will arise in an intuitive manner. In case that the correct switching mode has been selected, however the delay setting is too high, the problems of overcompensation and undercompensation may still arise. In case that the delay setting is too low, this may cause too frequent switching, which will lead to the fluctuations in the power grid and consequently cause damages to the switching switches and reduce the service life of the capacitors.
There are two reasons for the problem of frequent switching:
1. The controller of the automatic reactive power capacitor compensation cabinet itself is in abnormal or faulty conditions.
2, The delay setting of the controller has not been debugged properly. The delay time has not been set according to the accurate needs. The delay time is too short, the switching is frequent, and the contactor is easy to be damaged. The delay time is too long. The reactive power capacitor compensation cabinet is not switched off at the time when it should be switched off; and the reactive power capacitor compensation cabinet is not switched on at the time when it should be switched on. The effect of the reactive power capacitor compensation cabinet is not good.
What are the solutions:
Generally speaking, the first reflection of the user is that this is not a problem of the controller. It is usually thought that the quality of the contactor is not up to standard, so after only the contactor has been changing and then continue to use the reactive power capacitor compensation cabinet. This has obviously not solved the fundamental problem. After a period of time, it may be found that the contactor is broken again. If you have not drawn the conclusion that the contactor has been damaged due to frequent switching, the only way is to change the contactor and continue to use the reactive power capacitor compensation cabinet.
In view of the two main reasons of frequent switching of the reactive power capacitor compensation cabinet, it is necessary to select a controller which has excellent quality and good anti-interference ability. Selecting a suitable controller for the reactive power capacitor compensation cabinet is very important. The switching mode can be divided into three kinds: the dynamic mode, the static mode and the dynamic and static combination mode. The switching mode of the reactive power capacitor compensation cabinet shall be designed according to the speed of the load. The dynamic mode and the static mode should be used separately. In the dynamic mode, the contactors can not be put into operation; and in the static mode, it is best not to put the thyristor into operation. According to the demand of the reactive power compensation, our reactive power capacitor compensation cabinet can perform operation in the common manner or in the separate manner. The reactive power capacitor compensation cabinet can even perform the cross-phase compensation operation in the two phases, which has been rarely seen in the industry. In this way, it is possible for the reactive power capacitor compensation cabinet on each site to achieve a good effect.
For the delay setting, Zhongsheng Technology will set different switching delay according to different systems, set the switching delay between 5s and 10s, and make a trade-off between the compensation effect and the life of the compensation device. if 5s can still not meet the requirements of compensation effect, we will recommend the dynamic compensation mode of thyristor to customers.