Six-phase Rectifier With Tap-changer And Application In Frequency Converter

Inverter is a widely used power electronic devices, and the structure of it is mostly AC - DC - AC voltage type, which is often used uncontrolled rectifier. The uncontrolled rectifier will produce a large number of nonlinear harmonic ,which is a great power hazards, but also to the EMC of the system itself become a very prominent issue. In this paper, multi-phase rectifier with tap-changer reactor system, which can effectively increase the number of rectifier pulse wave, significantly restrain harmonics of three-phase rectifier of AC-side input current, to better meet the requirements of the EMC and improve the performance of the inverter. Its structure is compared to the conventional rectifier, a mere increase of a few switches.The structure of the rectifier circuit, the output DC voltage and input AC current characteristics are detailed studied. And then analyzed the core of the circuit--tap-changer reactor , including its structure characteristics , different location and variables turn ratio of tap-changers, and then establish a simulation model. tap-changer reactor bring new features for the harmonics to the rectifier circuit , designed DC output and AC input LC filter circuit based on these features. Simulations and experiments show that the rectifier circuit can effectively inhibit the AC side input current harmonics, reduce output voltage ripple and pulse, and improve the characteristics of rectifier circuit.In the research of variable frequency speed regulation system on inverter side, the U/F variable frequency speed control scheme, the inverter instantaneous voltage PID controller based on pole-assignment feedback control technology, and SVPWM pulse width modulation technology is studied at length. Based on theoretical analysis, in accordance with the design parameters and a variety of performance requirements, completed the design and manufacture of the inverter device, with satisfactory results.