1. The thyristor parallel circuit is a parallel resonant intermediate frequency furnace. During the melting process, especially for smelting aluminum, copper and other materials, the load is very light, its power output is very small, and it has a great relationship with the nature of the load, so its melting speed is slow. It is difficult to heat up. The thyristor series intermediate frequency melting furnace adjusts the power by frequency modulation, so the influence of the load property is relatively small, and the whole process of smelting almost keeps the constant power output. Because it is series resonance, that is, voltage resonance, the induction coil voltage is high and the current is small, so The power loss is small.
2. Because it is a series inverter, the power factor is high and the harmonics are small. It is not necessary to use the reactive power compensation device. This can save users a small amount of expenses, and is also an advanced device that the power supply department strongly advocates to promote.
3. When the series intermediate frequency furnace is working, the rectification always works in the all-on state. Changing the output power of the inverter circuit is realized by controlling the inverter trigger pulse frequency. And the load current is sinusoidal, so the series intermediate frequency furnace will not have high harmonics and seriously pollute the power grid, and the power factor is high. Parallel inverter can not realize one-to-two automatic power-regulating operation, because the parallel inverter power supply can only be realized by adjusting the output voltage of the rectifier bridge. When the parallel inverter rectifier bridge works at low voltage, the rectification conduction angle is very small. In the state, the power factor of the device will be very low, and the parallel inverter load current is a square wave, which will seriously pollute the power grid. If the power is adjusted by adjusting the inverter back pressure angle, the power adjustment range is very narrow, so the parallel inverter power supply cannot achieve one-to-two operation.
