一、KGPS- Parallel resonance medium frequency power supply.
KGPS - Parallel resonance medium frequency power supply is the most widely used power supply in China. There are more than 4500 SG users in the use of this product. Its technology is very mature, simple structure、 easy maintenance and low fault rate, power factor can reach more than 0.93 in the melting. The main parts of the power supply unit: SCR, electrothermal capacitor, circuit breaker, reactor, main control circuit board, control transformer, pulse, etc.

二、CL- series resonance energy-saving medium frequency power supply.
CL-series resonance medium frequency power supply control system use the most advanced technology in the world .The power factor can reach more than 0.95 in the smelting and holding; The working principle is using the inverter load circuit and compensation capacitor in series resonant composed of series inverter. The power supply unit not only can supply power to a furnace body, but also can supply 2 or more furnace bodies at the same time. In some process, such as melting metal for a long time, two furnace bodies pouring large castings simultaneously etc., effectively reduce the loss of reactive power, saving the production plays an irreplaceable role.

For example：
There are two furnace bodies A&B and one CL- series resonance energy-saving medium frequency power supply unit（for twin-power systems）in a factory.
In the following two cases, the use of this system is most appropriate.
1、 The time of pouring metal liquid after end the melting is last for more than half an hour from furnace body to ladle。When factory use the twin power system，workers can melt metal in the B furnace body during the period of tilting A.
2、 The casting is heavy. Workers can use smaller furnace body to produce heavier product. For example：the capacity of furnace body is 2T，workers can produce about 4T product（one furnace is holding，the other is melting, then Pouring metal liquid together）.