Inverter circuit design that can eliminate high-order harmonics

Inverters are widely used due to their high conversion efficiency, fast startup, and good safety performance. The following will introduce the design of a thyristor ladder wave inverter. The main circuit of this circuit is simple, and the output waveform is close to a sine wave, which can better eliminate high-order harmonics .

The inverter design circuit diagram is shown in the figure below. The six taps of the transformer T of this circuit are connected to the unidirectional thyristors VS1~VS6 to form the main circuit of the thyristor inverter.

Figure: Simple design circuit diagram of an inverter that can eliminate high-order harmonics

Under the action of the trigger control circuit, the action procedure of the circuit is as follows: let thyristor vS1 conduct 30° first, then let VS2 conduct 30°, and then let VS3 conduct 60°. During this period, each thyristor relies on the induced voltage generated by the transformer winding to automatically Shut down. After VS3 is turned off, VS2 is turned on for 30°, then VS2 is forced to turn off, and VS1 is turned on for 30°, ending the output of the half-cycle step wave. In the second half cycle, the thyristors VS6, VS5, and VS4 work alternately like the first half cycle to obtain the output of the step wave in the second half cycle. The main circuit of this circuit is simple, and the output waveform is close to a sine wave, which can better eliminate high-order harmonics .