Control Strategy Of STATCOM Research Articles

Supercapacitor energy storage system for fault ride-through of a DFIG wind generation system

The doubly fed induction generators (DFIGs) are preferred over other variable speed generators because of their advantages in terms of economy and control. One of the problems associated with high wind power penetration DFIG systems, however, is the inability of their converters to work properly under extreme low voltage conditions. This article presents a decoupled P–Q control strategy of a supercapacitor energy storage system, interfaced through a STATCOM, for low voltage ride through as well as damping enhancement of the DFIG system. The STATCOM meets the reactive power need under the depressed voltage condition, while the supercapacitor caters to the real power unbalance. An extensive dynamic model of the DFIG system including a supercapacitor DC–DC buck–boost converter and the STATCOM circuit has been developed. The fault ride-thorough capability of the generator has been investigated for a severe symmetrical three-phase to ground fault on the grid bus. Simulation results suggest that the proposed decoupled control of the supercapacitor STATCOM control strategy can help the DFIG ride through extreme low voltage conditions for significant duration. The proposed control strategy also damps the electromechanical transients, and thus quickly restores normal operation of the converters.

Study of Modified Sliding Mode Control Strategy for STATCOM with LCL Filter

This paper studies the control strategy of STATCOM with LCL filter. The STATCOM sixth orders differential equations in dq coordinate separate to two parts. Invert system theory deals with their uncoupling and nonlinearity. Then the sliding mode control strategy is used to the differential equations. Finally simulation results show validity and effectiveness of the design by comparing with PI controller.

Research of Control Strategy of STATCOM in AC/DC Hybrid Power System

This paper analyzed the control strategy of dynamical reactive power in AC/DC hybrid power grid, and presented the limitation of the control strategy based on location bus voltage, which can improve the transient stability under AC line faults but not DC block faults. Thus, control strategy of STATCOM based on real-time wide-area signal was presented by introducing the tie-line power flow of power grid. To consider the transient stability, the dynamical stability and the voltage stability at the same time, a nonlinear control mode in sections is also proposed. Simulation results showed that the control strategy would increase the transient stability and improve the dynamical stability of the AC/DC hybrid system under AC line faults either DC block faults

A STATCOM-Control Scheme for Grid Connected Wind Energy System for Power Quality Improvement

Injection of the wind power into an electric grid affects the power quality. The performance of the wind turbine and thereby power quality are determined on the basis of measurements and the norms followed according to the guideline specified in International Electro-technical Commission standard, IEC-61400. The influence of the wind turbine in the grid system concerning the power quality measurements are-the active power, reactive power, variation of voltage, flicker, harmonics, and electrical behavior of switching operation and these are measured according to national/international guidelines. The paper study demonstrates the power quality problem due to installation of wind turbine with the grid. In this proposed scheme STATic COMpensator (STATCOM) is connected at a point of common coupling with a battery energy storage system (BESS) to mitigate the power quality issues. The battery energy storage is integrated to sustain the real power source under fluctuating wind power. The STATCOM control scheme for the grid connected wind energy generation system for power quality improvement is simulated using MATLAB/SIMULINK in power system block set. The effectiveness of the proposed scheme relives the main supply source from the reactive power demand of the load and the induction generator. The development of the grid co-ordination rule and the scheme for improvement in power quality norms as per IEC-standard on the grid has been presented.

Rule-Based Damping Controller for Statcom

A fuzzy logic rule-based damping controller for STATCOM has been proposed in this paper. The proposed controller has two control loops. One is voltage control, with traditional PI control; the other is damping control, with the proposed rule-based controller. The input signal to the voltage control loop is the terminal voltage, and the input signal to the damping control loop is the generator speed, which can calculated from local variables. The effectiveness of the proposed controller was demonstrated in a single machine infinite bus system with Siemens NETOMAC. Further study will focus on the control strategy of STATCOM on multi-machine system.