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A MATLAB Model of Hybrid Active Filter Based on SVPWM Technique
| Content Provider | Semantic Scholar |
|---|---|
| Author | Patel, Rajnikant V. Kumar, Naresh Patel, Amit |
| Copyright Year | 2012 |
| Abstract | A method for active filter having hybrid feature is discussed in this paper. The method uses space vector pulse width modulation (SVPWM). In the proposed control method, the Active Power Filter (APF) reference voltage vector is generated instead of the reference current, and the desired APF output voltage is generated by SVPWM. The whole power system block set model of the proposed scheme is developed in MATLAB environment. A MATLAB code is developed to generate the SVPWM switching pulses fed to the two-level inverter topology. The developed control algorithm is simple. The APF based on the proposed method can eliminate harmonics, compensate reactive power and balance load asymmetry. Keyword: SVPWM, Mathematical Modeling, Active Power Filter Introduction The growing use of non-linear and time-varying loads has led to distortion of voltage and current waveforms and increased reactive power demand in ac mains. Harmonic distortion is known to be source of several problems, such as increased power losses, excessive heating in rotating machinery, significant interference with communication circuits, flicker and audible noise, incorrect operation of sensitive loads [1-2]. Passive filters are traditional method to eliminate harmonics, but with recent developments in power semiconductor switches and converters, coupled with developments in control techniques and analog and digital implementations, active filters are becoming an effective and commercially viable alternative to passive filters. [3]. The performance of active power filters depends on the adoptive control approaches. Various current detection methods, such as instantaneous reactive power theory [5], synchronous reference frame method [6], supplying current regulation [7] and etc., are presented. The commonness of these methods is the request for generating reference current of 558 Rajni Patel et al APF, either with the load current or the mains current. The second is that controls the VSI to inject the compensating current into AC mains. The proposed method differs from previously discussed approaches in the following ways: a) To generate APF reference voltage vector instead of reference current; b) to generate desired APF output voltage by space vector modulation based on generated reference voltage at step a). Mathematical Modelling of Svpwm Technique with APF This literature is briefly discusses the theory and operation of Space Vector Pulse Width Modulation (SVPWM) explains the implementation of SVPWM for the two level inverter topology. Philosophy of SVPWM Technique SVPWM technique was originally developed as a vector approach to pulse width modulation for three-phase inverters. The SVPWM method is frequently used in vector controlled applications. In vector controlled applications this technique is used for reference voltage generation when current control is exercised. The SVPWM technique is more popular than conventional technique because of its excellent features. • More efficient use of DC supply voltage. • 15% more output voltage then conventional modulation. • Lower Total Harmonic distortion (THD). • Prevent un-necessary switching hence less commutation losses. Principle of SVPWM Firstly model of a three-phase inverter is presented on the basis of space vector representation. The three-phase VSI is reproduced in Fig.1. , 1 S to , 6 S are the six power switches that shape the output, which are controlled by the switching variables , a , a ,b , , , b c and , c When an upper transistor is switched on, i.e., the corresponding , a , , , b , or , c is 0 . Therefore, the on and off states of the upper switches , 1 S , 3 S , 5 S can be used to determine the output voltage. Figure 1: Power circuit of a three-phase VSI A MATLAB Model of Hybrid Active Filter Based on SVPWM Technique 559 The relationship between the switching variable vector a [ b c t ] and line-to-line voltage vector [ , ab V , bc V ca V ] is given by (1) in the following: |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://irphouse.com/ijee/ijeev5n5_04.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
