Laplace Transform Application to Model and Analysis of D-STATCOM

This paper proposes mathematical modeling of D-STATCOM based on Laplace transform technique in which the proposed model is in the complex frequency domain. The power circuit of D-STATCOM is modeled by a controlled current source. All state variables in the model are transformed and therefore analyzed in dq reference frame. The compensating current from the D-STATCOM is assumed to be purely sinusoidal. Therefore, the transformed signals in dq axes are DC. For performance evaluation, loads of the D-STATCOM are divided into two types: i) constant impedance and ii) constant power. The proposed model can be linearised and then Laplace transform is applicable to transform the model into the frequency domain. Together with DC-link capacitor voltage control, the proposed D-STATCOM model of reactive power compensation can be evaluated. A simplified 11-kV, 2-bus test power system is employed for simulation.atisfactory results obtained by simulating the proposed model are compared to those obtained by simulating the switching control of D-STATCOM power circuit created in MATLAB’s Power System Blockset. As a result, the effectiveness of proposed model is verified. It gave satisfactory responses to estimate nonlinear characteristics of the D-STATCOM operation

Keywords:

Static synchronous compensator , Laplace transform , Reactive power control , Voltage control , Constant power model , D-STATCOM