Research On Control And Protection About Distributed Photovoltaic And Storage Power System Based On RTDS

With the expansion of microgrid scale and the uncertainty of the location access to the power grid with different control modes,the relay protection of microgrid is very important.The illogical configure will damage the equipment and the safety of maintainer and customer can not be assured.It could even cause widespread power outages on the regional grid.In this paper,the control strategy and protection scheme of the distributed photovoltaic-energy storage power generation microgrid are researched.Firstly,the frame of microgrid are elaborated and control scheme of pv,energy storage unit and diesel generator are described in detail.In this paper,the control scheme of power generation unit under two modes is described,and the control scheme of smooth switching is introduced.RTDS platform is used to stimulate the microgrid,main grid,load and protection.Secondly,the relay protection on line,point of common coupling,distributed generator,busbar and transformer are introduced,especially at the point of common coupling,the protection contains three phase symmetrical fault protection,asymmetrical fault protection and anti-island protection in the main grid as well as the microgrid.The current differential protection is used as the main protection for line.The direction overcurrent protection and negative sequence current protection are used as the backup protection.The corresponding protection schemes are configured for busbar and transformer respectively.Thirdly,the time and cooperation about protection are shown,when the fault occurs,the circuit breaker can be cut off quickly and reliably.And load shedding and reclosing in islanding microgrid are described.Finally,the simulation and experiment are introduced.The design principle,hardware design and software design of the distributed photovoltaic-energy storage power generation microgrid experimental platform are introduced,the hardware platform and software platform of relay protection are used to test the relay protectionconfiguration scheme,the hardware equipment conclude PMU,DCU,DTU and router.The protection configuration is compiled by software.