The Simulation Analysis Of Operating Performance For Heilongjiang Power Grid Under The Integration Of Ultra-High-Voltage Transmission

With the developing of modern power system,a complex AC/DC hybrid grid with the character of nonlinear transient change is formed.Under the background of complex hybrid grid,the utilization of traditional simulation technique and tools might fall in troubles.To dispose the problems,a hybrid simulation method that combines electromagnetic and electromechanical transient is proposed in this work.By the proposed simulation technique,the electromechanical transient performance of the whole grid and the electromagnetic transient performance of specific UHV parts could be simulated at once.Based on the electric sources,loads,grid structure and development planning,this work deeply analyzes the operating stability of Heilongjiang power grid after the integration of UHV transmission by the hybrid simulating calculation.A power system database and a simulation model are established which fit the analysis of system stability after the access of UHV.Base on the hybrid simulating calculation,an analyzing approach for grid stability is built in this work which obtains the stable conditions after the integration of UHV,moreover,the influence of the compensation allowance of electric reactor on the steady state voltage is studied,In this work,also,the influence of N-1 and N-2 faults on Heilongjiang power system transient stability after the integration of UHV is summarized through simulation experiments,as well as the frequency overvoltage caused by grounded short circuit and switching overvoltage reason from the re-closure of breaker.Finally,the affects of compensation of shunt reactor on frequency overvoltage are analyzed.The analysis results prove that the whole grid could satisfy the demands of power delivery under N-1 and N-2 fault,the power angle stability of the system could be maintained and non-overload problem would occur on 1000 kV and 500 kV power lines,while the voltage drop would happen,the thyristor switched capacitors and other measures should come into use according to the operating voltage.With the increasing of the degree of compensation provided by reactors,the steady-state voltage of the buses near UHV would decrease.Under the compensation of parallel reactor,the frequency overvoltage and switching overvoltage could meet the requirements of the reletive standards.