予測形瞬時値制御を用いた単相アクティブパワーフィルタ

抄録

Line-current harmonics generated by semiconductor power converters and other nonlinear loads in power systems have undesirable influence such as overheating on the power apparatuses. This is one of the most important problems to be solved in electrical engineering in recent years. To reduce or eliminate such harmonics, active power filters (APF) tend to be used as a promising solution to the problems. It is, however, pointed out that faster response is required in APF's in order to improve the current distortion and the transient performance when the load changes.
In this paper, a new single-phase APF with a predictive-instantaneous-current PWM controller is proposed. The controller predetermines a pulsewidth at the beginning of each switching period and controls the switching devices of the APF so that the total power factor approaches unity and the line-current harmonics are reduced. The controller can be composed of digital or analog circuits. This paper deals with an analog-technique approach. Four different control schemes are discussed: the basic control scheme and its modifications with a linear extrapolation method and/or a method with a double pulsewidth composed of double-frequency sampling. These schemes effectively improve the line-current waveform and the transient performance of the APF for abrupt changes of the load.
This paper describes the control schemes, implements the controller, and discusses the performance characteristics of the APF. The usefulness of the proposed methods is verified by computer simulation and experiment.