Reactive compensation circuit based on improved Buck-boost alternating current chopper

[0015] exist figure 1 Among them, the AC chopper reactive power compensator is mainly composed of three parts: grid side filter, AC / AC chopper and compensation capacitor.

[0016] exist figure 2 Among them, , and,——a bidirectional switch composed of two IGBTs in reverse series, which are complementary to each other; inductance—energy storage inductance;——filter the high-order harmonic components of the switching frequency and its multiples.

[0017] exist image 3 , Figure 4 Among them, A is the zero-crossing comparator, and B is the comparator (B1, B2 are the corresponding comparators respectively). In the improved Buck-boost chopper circuit, due to the existence of the filter mode, in addition to the reactive power reference value, two other reference values ​​should be set. And a slight change on the basis of the Buck and Boost type AC chopper control circuit , you can complete the precise control of the three modes after the improvement. The specific process is: comp