OFF-LINE HALF-BRIDGE INVERTER AND ITS OPERATION CONTROL PROCESS Russian patent published in 2004 - IPC

FIELD: converter engineering; power inverters of control systems for metal induction heating and smelting.

SUBSTANCE: inverter has half-bridge circuit set up of controlled switches shorted out by diodes, filter capacitor, and blocking capacitors connected in parallel with dc power supply terminals. Inverter is loaded into parallel high-frequency oscillatory LC circuit. Low-frequency choke is connected to common point of capacitors and in series with LC circuit wherein signal incorporating both high- and low-frequency currents is generated. Unbalance is brought in operation of antiphase controlled switches and diodes by controlling half-bridge switches in shaping half-wave of inverter current high-frequency component and high-frequency oscillations in the form of sine wave are shaped in inverter; center line of sine wave varies obeying low-frequency signal law. Inverter choke and capacitor form resonance-tuned oscillatory circuit whose resonant frequency corresponds to low-frequency component of high-frequency signal current in inverter load.

EFFECT: provision for shaping high- and low-frequency signals in inverter load simultaneously.

3 cl, 2 dwg