소용량 직류단 커패시터를 적용한 인버터 시스템의 고조파 저감 대책

Abstract

Recently, Inverter System has been used in various industries. For this reason, there are many different types of research studies industry and academia for low-cost and long-life drive. Previously, large electrolytic capacitors are used as DC-link capacitors. There has recently been developed a inverter system using film capacitor.

By using the film capacitor, the DC link capacitor capacity is reduced. This the harmonic distortion is generated in the input current. Harmonic distortion has been regulated in countries such as Europe, CIS, China, and Turkey. Accordingly, it is necessary to attenuate harmonic contents. Therefore, we have analyzed for two ways to attenuate harmonic distortions at this thesis.

First, the method is an algorithm for adding a reactor to decrease a current harmonics, and suppressing the LC resonance generated at this time. We propose an adaptive DC-link voltage compensation algorithm. this algorithm is simple to implementation and has a short operating time. This corrects the compensation gain by accumulating the DC bus voltage error and using the adaptive filter. When using the algorithms, it is possible to achieve a stabilization of the inverter with the film capacitor.

Second, the method is reduce the PWHC by eliminating the reactor and decreasing the PWM switching times.

The proposed algorithm reduces the PWM switching when the reference voltage exceeds the hexagon vector using the close magnitude overmodulation in order to reduce the harmonic components of the input current.