Compensation of unbalanced voltage dips using vector-controlled static series compensator with LC-filter

Abstract

Voltage dips due to faults are considered the most critical power quality problem to sensitive industrial loads. The voltage source converter, connected in series with the grid as a static series compensator (SSC), is suited to protect sensitive loads against such disturbances. This paper proposes a fast control algorithm to improve the dynamic performance of the SSC. Because most faults are single-or double-phase, this algorithm uses a fast technique for separating positive and negative sequence components of the supply voltage, which are then controlled separately. Thus, two controllers are implemented for the two sequences, each based on double vector control, i.e. constituted by a voltage-control loop and a currentcontrol loop. The validity of the proposed algorithm is demonstrated through PSCAD/EMTDC simulation, when the grid is subjected to unbalanced three-phase voltage dips. 904 0-7803-7420-7/02/$17.00 he also works part-time at ABB Sweden, where he is involved in the development of Light-concept devices. His interests are control of grid-connected converters, wind power and power quality.

Voltage asymmetry compensation using new adaptive control for STATCOM

“…For the q-current regulator and DC voltage regulators is used classical PI regulators, which adjusted through symmetrical optimum algorithm [10] regulator is continuously identification the controlled object by lineal model from low order and creates the controlling signal. In the suggested STATCOM control is used singleinput optimal singular adaptive (OSA) observer (SISO -single input single output).…”

“…The observed system could be presented by a linear model in the state space described in next differential equations [12]: (10) where x(0)=x 0 , k=0,1,2,…. ; x(k), x(k+1) are an unknown current state vector in two neighbor sample moments; x(0) is an initial unknown state vector; u(k) is an input signal; z(k) is a limited input sequence using for identification.…”