Research And Improvement Of Low Q Frequency Power Supply

Compared with traditional series compensation inverter circuit, the shortcomings of traditional inverter circuit is high quality factor Q and adverse effects caused by the introduction freewheeling diode, we design a new circuit structure-low Q thyristor IF power inverter circuit, it is essentially a half-bridge series compensation inverter circuit which is supplied power by constant current source. There is a energy conversion circuit loop in the new inverter circuit, a virtual function can be converted to the real amount of the functional capacity in the circuit, when the load coil and the compensation capacitor is selected, the Q of the circuit can be reduced to about3. So that a cumulative series compensation circuit voltage is greatly reduced, therefore we only need to select the appropriate pressure switch, then we can remove the freewheeling diode to eliminate adverse effects caused by freewheeling diode in the circuit.This paper is based low Q value frequency power inverter circuit which has removed the freewheeling diode, through theoretical analysis, the low Q thyristor frequency power inverter circuit can make further improvements:first, the circuit switches can be replaced from a semi-controlled devices to the full-controlled thyristor device IGBT; second, blocking capacitor Cd which is used to prevent the inverter subversion is removed; we can make the circuit more virtual functions into a solid amount of functional capacity, so that the quality factor Q is further reduced, the circuit efficiency. We designed a prototype power of about200W low Q IGBT inverter circuit, we can measure the current and IGBT turn-off voltage, then verify that the circuit can be started and stabilized work and achieve quality factor Q of reduced.Overall, the new low-Q IGBT frequency power supply has the following advantages: first, the quality factor Q is greatly reduced, circuit cumulative voltage is greatly reduced, circuit security is better performance, the circuit is higher efficiency; second, the circuit structure is further simplified, the volume and cost of circuit is reduced; third, using IGBT as a switch, we can make circuit to be used in the field of high frequency development, making this new circuit can be applied not only to melting, can also be applied to quenching, diathermy, surface treatment and other fields, it will create greater economic benefits.