Application Of Static Var Compensator Research Articles

Application of Static VAR Compensators and HVDC Converters for Damping Subsynchronous Oscillations in Power Systems

A new concept for controlling thyristor-controlled static VAr compensators and HVDC converters in power systems is presented. With such a concept it is possible to damp all low frequency (including subsynchronous) oscillations besides controlling the system voltage. For developing this controller a pole shifting approach is utilized. Eigenvalues are used for the analysis of the problem and determining system damping for all modes of oscillations. To support the analytical results, time simulations of the complete non-linear system are presented.

A Static Var Compensator Using a Superconducting Coil

A superconducting coil has virtually no losses for a dc current. To utilize this feature in a static VAR compensator application the conventional conversion equipment between the three phase system and the coil must be modified to obtain variable ac currents with a constant coil current. In the description of a recently introduced control scheme of a bridge converter it is shown that by the method of variable free-wheeling the line currents of a converter can be made variable while the coil current remains nearly constant [1]. In this paper the novel static VAR circuit, called SAVAR (Superconductor Application for VAR control) is analyzed, and some derived voltage and current shapes are compared with experimental results. A 40 MVA SAVAR system, including the appropriate harmonic filters, is designed and compared technically and economically with a conventional static VAR generator. It is concluded that the dynamic characteristics of the SAVAR circuit satisfy the requirements of the voltage support operation in electric utility systems. At this time the economic advantages of a SAVAR system are marginal. However, continuing improvements in thyristor ratings and expected increases in energy cost are factors which could give additional economic benefits to SAVAR in the future.

Comparison Of Physical Modelling And CADRepresentation Of Compensated RailwaySystems

Comparison Of Physical Modelling And CADRepresentation Of Compensated RailwaySystems