TPH series power controller has been successfully applied to the electric heating system in the iron and steel industry. The electric heating system is powered by the low-voltage distribution cabinet. The 380V power supply enters the power controller through the circuit breaker and the fast fuse. The power controller outputs power to the heater in the heating furnace. As the power regulating unit of the electric heating system, the power controller can effectively and accurately control the output electric power. At the same time, it receives the signal from the upper computer system to realize the temperature closed-loop control. It has the characteristics of high regulation accuracy, good temperature control effect and abundant peripheral interfaces.