Modelling and Implementation of Multi-source Isolated Microgrid Using Virtual Synchronous Generator Technology

To improve the living standards,economical efficiency and environmental protection of isolated islands,remote areas and other areas with weak electric power facilities construction,a multi-source independent microgrid system is studied,including diesel generators,photovoltaic power generation system,wind power generation system and energy storage unit.Meanwhile,in order to realize the voltage and frequency stability control of AC bus of multisource microgrid,the virtual synchronous generator technology is introduced into the energy storage unit,and the charge and discharge control of the energy storage battery are simulated as the control behavior characteristics of synchronous motors,so as to provide damping and inertia support for the microgrid.The operation mode and control principle of each energy subsystem are expounded and analyzed.The algorithm principle of virtual synchronous generator and the control method of energy storage unit are given.Then,the working modes of the microgrid system under different environmental conditions are analyzed,and the multi-source microgrid system simulation model is built based on MATLAB/Simulink.The simulation results show that the microgrid system can run stably under different working modes and the energy storage unit using the virtual synchronous generator technology can provide good voltage and frequency support for the microgrid system.Finally,experiments verify the supporting function of energy storage unit on the voltage and frequency of the microgrid system.

Research and practice of designing hydro/ photovoltaic hybrid power system in microgrid

Small-hydro power station is often used in remote areas beside a river,but it doesn't match electricity demand so well,especially in dry seasons. A photovoltaic (PV) system with battery is a suitable option to complement the electricity gap. In this paper,a new structure of megawatt-class PV system integrating battery at DC-bus (DC: direct current) is proposed to be used in hydro/PV hybrid power system,and 4 main designing considerations and several key equipments are discussed. In 2011,a 2 MWp PV station with the proposed structure was built up in Yushu,China. From stability analysis,the station shows a strong stability under load cut-in/off and solar irradiance's fluctuation.

Optimal economic operation of isolated community microgrid incorporating temperature controlling devices

With the increasing connection of controllable devices to isolated community microgrid,an economic operation model of isolated community microgrid based on the temperature regulation characteristics of temperature controlling devices composed of wind turbine,micro-gas turbine,energy storage battery and heat pump is proposed.With full consideration of various economic costs,including fuel cost,start-stop cost,energy storage battery depletion expense and penalty for wind curtailment,the model is solved by hybrid particle swarm optimization(HPSO)algorithm.The optimal output of the micro-sources and total operating cost of the system in the scheduling cycle are also obtained.The case study demonstrates that temperature adjustment of temperature controlling devices can adjust the power load indirectly and increase the schedulability of the isolated community microgrid,and reduce the operating cost of the microgrid.