Fast acting static synchronous compensator (STATCOM), a representative of FACTS family, is a promising technology being extensively used as the state-of-the-art dynamic shunt compensator for reactive power control in transmission and distribution system. Over the last couple of decades, researchers and engineers have made path-breaking research on this technology and by virtue of which, many STATCOM controllers based on the self-commutating solid-state voltage-source converter (VSC) have been developed and commercially put in operation to control system dynamics under stressed conditions. Because of its many attributes, STATCOM has emerged as a qualitatively superior controller relative to the line commutating static VAR compensator (SVC). This controller is called with different terminologies as STATic COMpensator advanced static VAR compensator, advanced static VAR generator or static VAR generator, STATic CONdenser, synchronous solid-state VAR compensator, VSC-based SVC or self-commutated SVC or static synchronous compensator (SSC or S2C). The development of STATCOM controller employing various solid-state converter topologies, magnetics configurations, control algorithms, switching techniques and so on, has been well reported in literature with its versatile applications in power system. A review on the state-of-the-art STATCOM technology and further research potential are presented classifying more than 300 research publications.

Static synchronous compensators (STATCOM): a review

Grid connected wind turbines may produce flicker during continuous operation. This paper presents a simulation model of a MW-level variable speed wind turbine with a doubly fed induction generator developed in the simulation tool of PSCAD/EMTDC. Flicker emission of variable speed wind turbines with doubly fed induction generators is investigated during continuous operation, and the dependence of flicker emission on mean wind speed, wind turbulence intensity, short circuit capacity of grid and grid impedance angle are analyzed. A comparison is done with the fixed speed wind turbine, which leads to a conclusion that the factors mentioned above have different influences on flicker emission compared with that in the case of the fixed speed wind turbine. Flicker mitigation is realized by output reactive power control of the variable speed wind turbine with doubly fed induction generator. Simulation results show the wind turbine output reactive power control provides an effective means for flicker mitigation regardless of mean wind speed, turbulence intensity and short circuit capacity ratio.

Flicker study on variable speed wind turbines with doubly fed induction generators

This paper presents a digital hardware realization of a real-time simulator for a complete induction machine drive using a field-programmable gate array (FPGA) as the computational engine. The simulator was developed using Very High Speed Integrated Circuit Hardware Description Language (VHDL), making it flexible and portable. A novel device-characteristic based model suitable for FPGA implementation has been proposed for the 2-level 6-pulse IGBT-based voltage-source converter (VSC). The VSC model is computed at a fixed time-step of 12.5 ns allowing a highly detailed and precise accounting of gating signals. The simulator also models a squirrel cage induction machine, a direct field-oriented control system, a space-vector pulse-width modulation scheme (SVPWM) and a measurement system. A multirate simulation of the system shows the slow (machine) as well as the fast (VSC and control) dynamic components. Real time simulation results under steady-state and transient conditions demonstrate modeling accuracy and efficiency

Real-Time Digital Hardware Simulation of Power Electronics and Drives

The paper investigates the dynamic operation of novel control scheme for both Static Synchronous Compensator (STATCOM) and Static Synchronous Series Compensator (SSSC) based on a new full model comprising a 48-pulse Gate Turn-Off thyristor voltage source converter for combined reactive power compensation and voltage stabilization of the electric grid network. The complete digital simulation of the STATCOM and SSSC within the power system is performed in the MATLAB/Simulink environment using the Power System Blockset (PSB). The STATCOM scheme and the electric grid network are modeled by specific electric blocks from the power system blockset, while the control system is modeled using Simulink. Two novel controllers for the STATCOM and SSSC are presented in this paper based on a decoupled current control strategy. The performance of both STATCOM and SSSC schemes connected to the 230-kV grid are evaluated. The proposed novel control schemes for the STATCOM and SSSC are fully validated by digital simulation.

Novel controllers for the 48-pulse VSC STATCOM and SSSC for voltage regulation and reactive power compensation

The fast development of wind power generation brings new requirements for wind turbine integration into the network. After clearance of an external short-circuit fault, grid-connected wind turbines should restore their normal operation without power loss caused by disconnections. This article concentrates on the transient stability of variable speed wind turbines with doubly fed induction generators (DFIGs) at an external short-circuit fault. A simulation model of a MW-level variable speed wind turbine with a DFIG developed in PSCAD/EMTDC is presented and the control and protection schemes are described in detail. The transient process of grid-connected wind turbines with DFIGs at an external short-circuit fault is analysed, and in critical post-fault situations a measure is proposed for the voltage recovery of DFIG wind turbines after fault clearance. Simulation results demonstrate that in uncritical post-fault situations the control schemes are able to restore the wind turbine's normal operation without disconnections. It is also proved that the proposed measure is effective in re-establishing the voltage at the wind turbine terminal in critical post-fault situations. Copyright © 2005 John Wiley & Sons, Ltd.

Transient stability of DFIG wind turbines at an external short‐circuit fault

This paper presents a study on the modeling of a STATCOM (Static Synchronous Compensator) used for reactive power compensation on a distribution network. The power circuits of the D-STATCOM and the distribution network are modeled by specific blocks from the Power System Blockset while the control system is modeled by Simulink blocks. Static and dynamic performance of a /spl plusmn/3 MVar D-STATCOM on a 25-kV network is evaluated. An "average modeling" approach is proposed to simplify the PWM inverter operation and to accelerate the simulation for control parameters adjusting purpose. Simulation performance obtained with both modeling approaches are presented and compared.

Modeling and simulation of a distribution STATCOM using Simulink's Power System Blockset

This paper presents a digital real-time simulation of a four-quadrant DC motor drive used in a manufacturing plant subjected to operation of a solid-state transfer switch. The objective of the simulation is to allow laboratory evaluation of the performance of a DC drive controller under realistic operating conditions. A real-time model of an industrial 200-hp DC drive including a 12-thyristor reversible converter and a DC motor has been developed to run on a parallel processor system. The model has been first developed and tested offline using the Simulink Power System Blockset. Real-time parallel code is then generated and distributed to six DEC Alpha processors operating at 300 MHz. The simulator was designed in order to allow interfacing of actual controllers of motor drives and solid-state power transfer switch. Experimental results including real-time simulation waveforms illustrating the operation of DC drive and transfer switch are presented to demonstrate the feasibility and the usefulness of such a simulator in closed loop testing of industrial controllers.

http://ieeexplore.ieee.org/iel4/6033/16105/00747552.pdf

P. Giroux

Papers

Modeling and simulation of a distribution STATCOM using Simulink's Power System Blockset

Digital real-time simulation of a four-quadrant DC drive for static transfer switch testing