Simulation of Dynamic Reactive Power Compensation Device Based on Variable Reactance Converter

Abstract

In the power system, the reactive power causes low power factor and power loss. The reactive power compensation device can ensure normal and stable operation of the power system. The traditional reactive power compensation device is difficult to meet the needs of high power factor and low power loss. Therefore, a dynamic reactive power compensation device has been presented by authors to achieve high power factor and low power loss. Based on the previous research results, the dynamic reactive power compensation device based on variable reactance converter is simulated. The following works have been done in the study: topology of dynamic reactive power compensation device, simulation model of dynamic reactive power compensation device, and simulation. The simulation results show that the dynamic reactive power compensation device based on variable reactance converter improves the power factor of power system and saves energy. The research of this paper has laid a theoretical foundation for the dynamic reactive power compensation device in practical applications. Introduction There are many inductive loads in the power system. They absorb the reactive power. It causes power loss and low power factor. The reactive power compensation device can improve the power factor of power system and reduce the power loss. At present, the reactive power compensation device includes the synchronous compensatory, the saturable reactor, the thyristor controlled reactor, the thyristor switched capacitor and the static var compensator [1]. The dynamic reactive power compensation device doesn’t adopt the structure of series anti-parallel thyristors and reactor. It consists of variable reactance converter and capacitor banks. The reactive power is compensated by switching capacitor banks and adjusting variable reactance converter dynamically. The compensation mode is dynamic and smooth [2]. Based on the previous research results, the dynamic reactive power compensation device based on variable reactance converter is simulated. The following works have been done in the study: topology of dynamic reactive power compensation device, simulation model of dynamic reactive power compensation device, and simulation. Topology of Dynamic Reactive Power Compensation Device The topology of the dynamic reactive power compensation device is shown in Fig.1. In Fig.1, the dynamic reactive power compensation device consists of the capacitor banks (CB), the variable reactance converter (LV) and the intelligent controller (ICC) [3]. The load (FZ) is connected to the primary side of LV, and the secondary side is connected to the power converter (PCC). The required compensation capacity QB of the power system is expressed as follow:       − − − = 1 cos 1 1 cos 1 2 2 1 2 φ φ P QB (1) Where, P is the rated active power, cosφ1 is the power factor of FZ, and cosφ2 is the target power factor. International Power, Electronics and Materials Engineering Conference (IPEMEC 2015) © 2015. The authors Published by Atlantis Press 183 witched on appropriately to produce reactive power QC based on QB. It can increase the power factor close to cosφ2. In practical case, CB is difficult to meet the needs of QB. When it is over-compensated, LV is adjusted to absorb the amount of overcompensation reactive power (QL) [4]. The inductance value of LV is adjusted continuously by adjusting the control signal of PCC. In this way, CB is cooperated with LV to realize the fast, dynamic and smooth reactive power compensation [5]. Simulation of Dynamic Reactive Power Compensation Device According to the topology of dynamic reactive power compensation device, a simulation model is constructed by MATLAB/Simulink tool. The simulation model of dynamic reactive power compensation device is shown in Fig.2.