Advanced Digital Power System Simulator Research Of Application In Ningxia Power Grid

With the accelerated pace of construction, the power grid of Ningxia gradually developed into a power source one with thermal power, wind power, solar power and hydroelectric power and other types. The complexity of the grid structure and the diversity of the grid operation also significantly developed. Un-stability factor in the grid increased and the control strategy becomes more complex. So higher and higher requirements are raised to the ability of grid planning, means of operation scheduling, protection and automatic security devices, which requires the application of advanced technology as an auxiliary power system simulation tools to improve the safety of the system operation.This paper introduces the all-digital real-time power system simulation device (ADPSS) of Ningxia Electrical Power Research Institute (EPRI), which was developed by EPRI of China. ADPSS can simulate electromechanical transient Electromagnetic Transient Hybrid operation of large grid, and can take advantage of the physical interface to connect an external device to make a closed-loop digital-physical hybrid simulation. Using this feature we have embarked on a series of simulation studies such as a stable strategy validation, protection devices testing, accident analysis and so on.First, electromechanical transient model of the whole Ningxia network and electromagnetic transient model of key research areas were created in the ADPSS. Then a safety stability control device was connected to the ADPSS to construct a closed-loop control, to verify the safety stability control strategy against failures in±660kV DC transmission system of east Ningxia-Shandong. The results show there would be a positive affect when the safety stability control device cuts off the units according to the control strategy. The system operation remained stable. Afterwards, a simulation of the affect to the relay of Ningxia grid by a massive electrolytic aluminum load was made, to test the line protection device with the same type as on site, by making different faults inside or around the electrolytic aluminum load, and draw conclusions of the simulation. Finally, a simulation of accident by dis-matching between reclosing protections with different software versions was conducted. The devices testing and simulation results based on the real background of the large grid are more accurate, more realistic and more valuable.This research work pioneered the testing and simulation of the grid of Ningxia, and made the simulation technique of Ningxia power grid onto a new level, then would make more powerful support to the safe operation of Ningxia grid.