Research On 1kVA Three-state Quasi-PWM Hysteresis Current Controlled Inverters

Todays, the three-state current hysteresis control has an extensive application. in the most field, the three-state DPM current hysteresis control is more familiar. The discrete variety of the frequency of modulation causes such disadvantages as difficult design of the output filtering circuit, bigger bulk, higher weight, unperfect output spectrum characteristics, higher noise of the inverter. The three-state quasi-PWM current hysteresis control discards the disadvantages of the three-state DPM current hysteresis control, and make the inverter has more excellent comprehensive performances by the introduction of a constant frequency signal and the frequency- inspected and phase- inspected circuit, which adjust the width of hysteresis, make the frequency of modulation meet with the constant frequency signal, and restrain the discrete variety of the frequency of modulation. The operation principle, control strategy of three-state quasi PWM hysteresis current, static character and stabilization of the three-state quasi-PWM hysteresis current controlled inverter are deeply analyzed and studied. The design criterions of key circuit parameter are gained. A prototype for 1kVA 190VDC/115V400HzAC three-state quasi-PWM hysteresis current controlled inverter is designed and developed successfully. The test results demonstrate that this prototype has excellent comprehensive performances such as high efficiency, small bulk, lower weight, good output spectrum characteristics, easy design of the output filtering circuit, good output waveforms, good stability, high steady precision, fast dynamic response, strong function with different nature load, strong over-load and short-circuit ability, low noise and low cost, etc.