Comprehensive analysis of the control strategy for hybrid active power filter with injection circuit

International Journal of Scientific Engineering and Technology (ISSN : 2277-1581)

Volume No.2, Issue No.7, pp : 694-699 1 July 2013

IJSET@2013 Page 694

Comprehensive Analysis of the Control Strategy for Hybrid Active Power

Filter with Injection Circuit

MinhThuyen Chau, VanBao Chau

Faculty of Electrical Engineering - Industrial University of Ho Chi Minh City, Viet Nam

Email: [email protected]

Abstract: This paper proposes an overview of the analysis of

control strategies for Hybrid Active Power Filter with

Injection Circuit (IHAPF). This analysis will be the basis of

researches of the IHAPF in the future. Simulation results

have shown the effectiveness of the control strategies.

Keywords— Hybrid Active Power Filter (HAPF), control

strategy, passive power filter, active power filter.

I. Introduction

Nowadays, the power quality problem is always of top

interest, harmonics is one of the causes influence of power

system quality. They are usually generated by non-linear loads.

The presence of harmonic components in the power system will

be cause of the problems such as: power losses, voltage

distortion, overheating, overloading, etc. So, to cancel harmonic

problems we often use passive power filters (PPFs) [1]. The

PPFs has simple structure, and is inexpensive but it also has

several disadvantages due to resonance, robustly sensitive to

environments, compensation characteristic is often influenced

by the source impedance, effective in improving harmonic

distortion is poor and able to be no flexibility. In order to

improve the PPF’s disadvantage, the Active Power Filter (APF)

[2-6] appears in 1970s. It is often shunt-connected with

nonlinear load to eliminate harmonic currents and reactive

power compensation, which has the capability of online

compensation cling to harmonic currents of non-linear load. The

APF does not cause symptoms consonance with the impedance

of the grid. However, APF also exits many disadvantages as

high cost, low capacity and is difficult to use in high voltage

grids. Another topology was expanded to exterminate

harmonics namely Hybrid Active Power Filter (HAPF) [7]. The

HAPF topology is the combination of APF and PPFs.

Therefore, it has the advantages of both PPF and APF. The

purpose of HAPF development is to decrease APF duty. For this

reason, the HAPF can be used in high voltage and high capacity

grids. The IHAPF [8-12] is a new form of the HAPF; it has

achieved high performance in reducing harmonics and reactive

power compensation with a low capacity APF.

However, there is no paper propose an overview of control

strategies for IHAPF, with the parameters of the system are

given then what is the best control strategy? So, this paper

analyzes mathematical model of the IHAPF and then

implements an overview analysis of control strategies for

IHAPF to discover out the best control strategy. The influence

of each parameter to each the control strategy is analyzed

clearly.

This paper is structured as follows: section I said at the birth

and outstanding performance of IHAPF. The structure and

mathematical description of the IHAPF are highlighted in

section II. Comprehensive analysis of the control strategy for

IHAPF is analyzed in section III. Simulation results are

presented in section IV. Finally, conclusions are drawn in

section V.

II. Structure and mathematical description of IHAPF

The structure of IHAPF is shown as in Fig 1.

ZS

US CF

C1

L1 L0

0 C C 380V

AC PPFs

CP

LP Uncontrolled rectifier inverter Injection circuit Injection capacitor Fundamental Resonance circuit Coupling transformer

Nonlinear load

Fig1. Structure of the IHAPF

The structure of an IHAPF consists of an APF composed of

uncontrolled rectifier and inverter, output filter, injection circuit

and passive power filters. An ideal coupling transformer and its

voltage ratio is n:1 is put between output filter and injection

circuit. To further decrease the power of APF, a fundamental

resonance circuit L1 and C1 tune at the fundamental frequency

and then compose with the injection capacitor CF.

The parameters of IHAPF system are given following as:

CF=19.65μF, C1=690μF, L1=14.75mH, C11=49.75μF,

L11=1.77mH, C13=44.76μF, L13=1.37mH, L0=0.2mH, C0=60

μF.

Single-phase equivalent circuit of IHAPF is shown as in Fig 2.

US IL ZS

I

S IF

UL ZP PF

Z1

Z CF

0 2 n ZC

0 2 n ZL

nUinv Fig 2. Single - phase equivalent circuit of the IHAPF.