Certain investigations on the power flow control of advanced statcom and energy storage systems

Abstract

Static var compensator based on a voltage source inverter, known as STATic synchronous COMpensator (STATCOM), have high speed switching capability that allows for rapid adjustment of line power flows in response to various contingencies. Harmonic effects, network resonances and controls interact and desirable performance of STATCOM is not always guaranteed without some detailed engineering effort using electromagnetic transient design tools. High frequency Pulse Width Modulated (PWM) technique on large power system voltage source inverters and their controls place high demands on precision in simulation. PWM voltage source inverter based STATCOM offers a more flexible option than the fundamental frequency switching methods favoured in Flexible AC Transmission Systems (FACTS) devices due to its advantages like fast response to a var command and lower harmonics. Installation of FACTS devices on key locations in a meshed network changes the effective reactance of the parallel paths, and consequently the way that power is shared among them. In the proposed research work, a STATCOM employing PWM inverter with interpolation switching control is designed, analyzed and simulated in Power System Computer Aided Design (PSCAD). The STATCOM regulates voltage at its terminals by controlling the amount of reactive power injected into or absorbed from the power system. To harness the wind power efficiently the most reliable system in the present era is grid connected Fixed Speed Induction Generator (FSIG). Reactive power compensation is a key issue to be taken into account during the operation of wind farms equipped with FSIG being connected to the Point of Common Coupling (PCC). The application of a conventional STATCOM control scheme for the grid connected wind energy generation system relieves the main supply source from the reactive power demand of the load and the induction generator.