Technical Education Faculty Technical Education Faculty Technical Education Faculty Technical Education Faculty. Electrical Education. Electrical Education.
The Design and Implementation of a Shunt Active Power Filter based on Source Current Measurement Engin Ozdemir
Mehmet Ucar
Metin Kesler Kocaeli University Technical Education Faculty
Kocaeli University Kocaeli University Technical Education Faculty Technical Education Faculty Electrical Education Electrical Education Department Department Kocaeli, TURKEY Kocaeli, TURKEY Email: eozdemir@kou. edu. tr mucar@kou. edu. tr
Murat Kale Kocaeli University Technical Education Faculty
Electrical Education Department Kocaeli, TURKEY metinkesler@kou. edu. tr
Abstract- In this study, design and implementation of a shunt active power filter (APF) based on a simplified control method is given without load and filter current measurement. The proposed simplified control method is based on instantaneous reactive power theory (IRP) and requires only measuring the source currents to reduce the number of current sensors (CSs) required in the conventional control approach. The source currents are exactly in phase with the line voltages and approximately in sinusoidal waveform after reactive power and harmonic compensation. The proposed control technique has been tested under different load conditions using Matlab/Simulink simulations and validated with a 10 kVA/380 V experimental prototype based on digital signal processor (DSP) TMS320F2812. Both simulation and experimental test results demonstrate that the proposed method is feasible in meeting the IEEE 519-1992 recommended harmonic standard limits.
Electrical Education Department Kocaeli, TURKEY muratkale @gmail. com
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Shunt Active Power Filter
Fig. 1. The basic compensation principle of the three-phase shunt APF.
In recent years, several methods based on the IRP theory [4]-[6], also known as p-q theory, have been used to obtain the current reference in the APFs. Although several improved I. INTRODUCTION algorithms are proposed [7]-[10], most control circuits are Harmonic current pollution of three-phase electrical power complicated and it is not easy to implement them. In systems is becoming a serious problem due to the wide use of conventional p-q theory based control approach for the shunt compensation current references are generated based non-linear loads, such as diode or thyristor rectifiers and a vast APF,thethemeasurement of load currents as shown in 2. variety of electronics variety of power electronics basedapplianceson based appliances. Traditonally, However, the current feedback from the shunt APF Fig. output passive inductance-capacitance (LC) filters have been used to current is also required, and therefore, minimum four CSs are eliminate the current harmonics and to improve the power desired. In the proposed method, the number of required factor. However, passive LC filters are bulky, load dependent CSs is minimized as shown in Fig. 3. and inflexible. They can also cause resonance to the system. _ _ LL In order to solve these problems, APFs have been reported . C E Non-linear [1]-[3] and considered as a possible solution for reducing rAA0J 9 ~~~~~~~~~~~~~~~~~~~~~~~~load current harmonics and improving the power factor. -i, I AcSource PT Fig. 1 shows the basic compensation principle of the threephase shunt APF. It is designed to be connected in parallel with cs the non-linear load to detect its harmonic and reactive current and then to inject a compensating current into the system. c Therefore, the current drawn from the power system at the coupling point of the shunt APF will result in sinusoidal 6 Active Power Filter DSP Control Unit waveform. The source current (is) is the result of summing the load current (iL) and the compensating current (ic) as in (1 ). power
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iS=iL+iC
1 -4244-0743-5/07/$20.00 ©2007 IEEE
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Fig. 2. Schematic diagram of the conventional shunt APF configuration.
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the sums of both the instantaneous source voltages and currents of the three phases are zero. As a result, measuring only two source voltages and currents are adequate for the reference current calculations. Therefore, the conventional Clarke Transformation of the source voltages and currents are calculated as shown in (2) and (3) [11].
