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An Adaptive Hysteresis Band Current Controlled Shunt Active Power Filter

Vaddi Ramesh, B Haritha, P Rabeya Sulthana M Diveswar Reddy

Solid state control of ac power using thyristors and other semiconductor devices are used extensively in number of applications such as adjustable speed drives (ASD’s), furnaces, computers power supplies and asynchronous ac– dc–ac links. These power converters behave as non-linear loads to ac supply system and cause harmonic injection, lower power-factor, poor voltage regulation, and utilization of ac network. There is a great need to mitigate these harmonic and reactive current components. Active Power Filters are a viable solution to these problems. In this project work both simulation and hardware of a single-phase Shunt Active Power Filter was implemented. To eliminate supply current harmonics, correct supply power-factor, and balance the non-linear/linear loads. A single-phase insulated gate bipolar transistor based current controlled voltage source inverter with a dc bus capacitor is used as an active filter. To compensate the generated harmonics and to make the balanced and sinusoidal source currents by the injection of compensation currents. APF reference current generation by using a simple technique sampling and integration of the one complete power cycle. This method simplifies the calculation algorithm. Among the available current control methods, Hysteresis Band Current Control method, ease of implementation with high accuracy and quick response. Conventional hystresis band current control is limited due to wide variations in switching frequency and its associated effects. An Adaptive hysteresis band calculator varies the hysteresis band width, HB, according to diref*(t)/dt and Vdc and supply voltage Vs. This controller ensures least variation in device switching frequency by maintaining the merits of the basic technique