An active control technique for integration of distributed generation resources to the power grid

• Small-signal analysis of converter-based DG system is carried out.
• A simple compensator is proposed for solving the system instability problem.
• The proposed active method depends on reshaping the input impedance of converter.

This paper explores stability issues for integration of distributed generation (DG) resources to the power grid by power electronic converters. Application of power converters in power distribution systems is becoming more and more common. Stability study of this kind of systems is crucial because of the potential for negative impedance instability of interfacing converters. In addition, in a power distribution system, a converter can lead to local instabilities when interacting with other dynamic subsystems. In this paper, to investigate the stability of system, the impedance-based small-signal model of each of the subsystem is respectively achieved and then an active control technique is proposed to stabilize the system. The proposed method depends on reshaping the input impedance of the interfaced converter by injection of an active stabilization signal at the control loop of the converter. MATLAB/Simulink simulations are conducted to demonstrate the effectiveness of the proposed control technique during various operating conditions.