Research On The Theory And Application Of Hardware-in-the-loop In Smart Grid

Hardware-in-the-loop simulation combines the merits of real-time digital simulationand dynamic physical simulation, which is a key technology to study the systemproperties and the integration technologies of the renewable energy, energy storagedevices and microgrid in the smart grid. According to the difference of physicalhardware under test, hardware-in-the-loop simulation system can be divided into twotypes which are PHIL system and CHIL system. The paper analyzes the two systemsrespectively in detail. Firstly, the paper studies and establishes the stability andaccuracy characteristics of the PHIL interface algorithms. Then the paper simplifies theDamping Impedance model (DIM) interface and discovers that, when the dampingimpedance in the VES matches the equivalent impedance in the HUT, the simplifiedDIM interface has ‘transparent’ feature which means that the response in the digitalsimulation is not affected by the delay introduced by the interface. And it also drawsthe conclusion that driving capability of the Ideal Transformer model (ITM) interface isgood when the HUT contains power source. According to the above conclusion, thepaper proposes a novel interface algorithm, which uses the ITM to drive the physicalhardware under test and employs the Simplified DIM to obtain accurate response in thevirtual electrical system. The result of simulation shows that the novel interfacecombines the merits of the Simplified DIM and the ITM when the hardware under testis active. Secondly, the paper applies the CHIL simulation technology to test the DFIGcontroller and establishes the wind farm simulation platform in which the short-circuitfault characteristics after Crowbar’s starting are analyzed and simulated. The resultsshow that the ability of anti-transition impedance in distance relay will be related to theoperational status when using bus memory voltage as polarization voltage. Bycomparison, when using positive sequence voltage as polarization voltage, the ability ofanti-transition impedance will be reduced. Based on the results, this paper designs thepreliminary adaptive distance protection for wind farm.