Stability analysis and control of microgrids by sliding mode control

• A SMC of a seamless transfer between grid connected and island modes is presented.
• An appropriate power sharing between the main grid and DG is occurs.
• Simulations show good performance and a fast response of proposed controller.
• The controller maintains sinusoidal voltage/current waveforms without distortion.
• Synchronization between the main grid and microgrid is achieved.

In this paper stability analysis and control of microgrids using sliding mode control are presented. Renewable energy based distributed generation (DG) is increasingly play a dominant role in the generation of electricity. Microgrid consists of cluster of load and distributed generators that operate as a single controllable system. The interconnection of the DG to the grid by power electronic converters has raised concern about safe operation and protection of the equipment. Many control strategy have been proposed for enhancing the stability of microgrid as for proper load sharing. Parallel converters have been proposed to deliver desired real power and reactive power to the system. The active power and reactive power sharing can be achieved by controlling two independent quantities, of frequency and voltage magnitude. In this paper, a sliding mode control (SMC) is proposed to smooth transition between grid connected and islanded modes of operation which this work through converter firing pulses controlled the output voltage magnitude. Finally the simulation results obtained using the MATLAB/SIMULINK software. Simulation results show the effectiveness of using SMC in transient response of load current and in load voltage and current during immediate load variations.