Thyristor series inverter and parallel inverter circuit

Compared with parallel inverters, silicon-controlled series inverters have more advantages: 1. The current IL flowing through the inductor in the series inverter circuit is close to the active current, so Il is very small, and Il is in the inductor resistance. The electrical loss caused is very small. According to theoretical calculations and experimental tests, the electrical efficiency of the induction furnace can reach as high as 97%. The series inverter induction furnace can save more than 10% of electricity. 2. The series inverter circuit can maintain full power throughout the entire process from cold material to casting, greatly improving operating efficiency. The highest melting rate. 3. The series inverter circuit requires the input to be a constant voltage source and uses large capacitance Cd filtering. First, the three-phase power frequency input current is maintained as a sine wave, and the intermediate frequency current is all bypassed by Cd at the DC end. The regulation of the series inverter The power is realized in the inverter bridge, the controllable rectifier a angle is all at zero degrees, there is no rectifier and commutation gap, and there is no interference to the power grid. 4. During operation of the three-phase rectifier bridge, angle a is always at zero degrees. That is, the DC voltage is at its maximum value. The large-capacity CD is directly integrated into the DC end to automatically maintain the grid power factor above 0.97. 5. The startup success rate is 100%. Since the current flowing through the inverter thyristor is a sine wave, there is no problem of turning on and off the thyristor. That is, the inverter will not fail to commutate and there will be no startup problems. The emergence of the new series inverter medium frequency power supply was immediately favored by users. The product was successfully developed in 2000 and mass-produced in 2001.