Ikuo Kawaguchi

Novel active filter system composed of inverter bypass circuit for suppression of harmonic resonance at the Yamanashi Maglev test line

The authors have developed and proposed a novel active filter system composed of an inverter bypass circuit for the suppression of harmonic resonance conditions caused between the inductance behind the load bus and the capacitance of VAr equipment, especially at lower harmonic frequencies. They have installed this new harmonic compensation system in combination with TCR-type SVC and shunt LC filters at the Yamanashi Maglev test line. Here, they describe the outline of the reactive power and harmonic compensation systems, and harmonic resonance test results which show satisfactory performance of the active filter.

Harmonic resonance phenomenon in the DC circuit of inverter to drive LSM

In large-scale inverter systems, a DC circuit connects the rectifier and inverter. And the DC circuit has DC capacitors to smooth and stabilize the DC voltage and the inductance of distribution wires. Therefore, it is possible that a harmonic resonance phenomenon is induced in this circuit. This harmonic resonance phenomenon depends on the characteristics of the DC circuit and the harmonic current generated by the rectifier and inverter. This paper describes the analysis of the input current of the inverter system caused by PWM control and the harmonic resonance phenomenon induced in the DC circuit.

Novel active filter system composed of inverter bypass circuit for suppression of harmonic resonance

We have developed a novel harmonic compensation system consisting of shunt LC filters on the load side, a step-down transformer on the receiving end, and a small-capacity active filter with one end connected to the secondary winding of the transformer and the other to the load bus. The active filter which constitutes the bypass circuit for the main service transformer is current-controlled to give adequate damping of the harmonic resonance caused by the inductance behind the load bus, especially at lower harmonic frequencies. We have installed this new compensation system in combination with a TCR-type SVC and shunt LC filters at the Yamanashi Maglev Test Line. We present an outline of the reactive power and harmonic current compensation systems, and harmonic resonance test results which show satisfactory performance of the active filter.