Detection In Distributed Generation System Research Articles

Comprehensive Review of Islanding Detection Methods for Distributed Generation Systems

The increased penetration of distributed generation (DG), renewable energy utilization, and the introduction of the microgrid concept have changed the shape of conventional electric power networks. Most of the new power system networks are transforming into the DG model integrated with renewable and non-renewable energy resources by forming a microgrid. Islanding detection in DG systems is a challenging issue that causes several protection and safety problems. A microgrid operates in the grid-connected or stand-alone mode. In the grid-connected mode, the main utility network is responsible for a smooth operation in coordination with the protection and control units, while in the stand-alone mode, the microgrid operates as an independent power island that is electrically separated from the main utility network. Fast islanding detection is, therefore, necessary for efficient and reliable microgrid operations. Many islanding detection methods (IdMs) are proposed in the literature, and each of them claims better reliability and high accuracy. This study describes a comprehensive review of various IdMs in terms of their merits, viability, effectiveness, and feasibility. The IdMs are extensively analysed by providing a fair comparison from different aspects. Moreover, a fair analysis of a feasible and economical solution in view of the recent research trend is presented.

An Advanced SVPWM-Based Predictive Current Controller for Three-Phase Inverters in Distributed Generation Systems

Space vector pulsewidth modulation (SVPWM) has been widely applied in the current control of three-phase voltage source inverters (VSIs). However, for grid-connected VSIs in distributed generation (DG) systems, the performance of current controllers based on SVPWM is compromised by the grid harmonics and the control delay due to computation and sampling. In this paper, an advanced SVPWM-based predictive current controller is proposed and studied. The controller mimics deadbeat control in the synchronous d-q reference frame, and is very simple and robust to implement. With the necessary grid voltage detection in DG systems for protection, grid harmonics disturbance is effectively suppressed through feedforward compensation. Based on a dual-timer sampling scheme, the control delay compensation becomes more simple yet effective. The comprehensive analysis on the proposed predictive current control system is provided. The simulation and experimental test results show that the proposed current controller has an excellent steady-state response as well as an extremely fast dynamic response.