Overview
This is a power filtering compensation device which applies new digital processing chips and advanced control technology. It numerically filter and control the current by DSP processor, to achieving the purpose of optimizing the power quality. Moreover, this device also has an automatic compensation function for power factor, which ensures the stability of the power grid while saving power resources and reducing enterprise power costs.
APF/SVG Functional Principle
APF/SVG acquires the current signal in real time through an external current transformer, and separates the harmonic part through the internal detection circuit, and generates a compensation current with the opposite phase of the harmonics in the system through the IGBT power converter to realize the function of filtering out harmonic.
According to the reactive power of the system, APF/SVG generates capacitive or inductive fundamental current through the IGBT power converter to achieve the purpose of dynamic reactive power compensation.
The APF/SVG extracts the unbalanced component according to the system current, and the three phases emit a current of the same phase as the unbalanced component, and the unbalanced portion is compensated to zero, so that the three-phase unbalanced current can be corrected to the three-phase balanced.
Control Principle
Schematic Diagram of APF/SVG Internal Control
APF/SVG charges the DC bus capacitor by the soft-start resistor in order to prevent the instantaneous impact during power-on,after circuit breaker closed. As the bus voltage Udc reaches the predetermined value, the main contactor will be closed.The DC capacitor supplies energy for the external output of the compensation current through the IGBT inverter and the internal reactor.The APF/SVG sends the current signal through the external CT to the signal conditioning circuit and then sends to the controller.After taht the controller will decomposes the sampling current, extracts each harmonic current, reactive current, and three-phase unbalanced current. Then compares the collected current component to be compensated with the compensation current that has been sent by APF/SVG to obtain a difference. The real-time compensation signal is output to the driving circuit, and the IGBT converter is triggered to inject the compensation current into the power grid to realize closed-loop control and complete the compensation function.
Hot Tags: capacitor harmonic filter, China capacitor harmonic filter manufacturers, suppliers, factory, power factor correction for integrated circuits, capacitor cabinet wiring, low power factor solution, capacitor cabinet for power systems, advanced power factor correction, refurbished capacitor cabinet