Research On Power Grid Planning Considering Power System Flexibility For Regulation

Rational power network planning is the precondition to guarantee the the security,reliability and economy of power system.Considering high proportion of renewable energy integration and lack of transmission corridor,power network in China is supposed to make good use of increments and revitalize reserve,in order to develop full potential of transmission capacity.According the guideline,the flexibility in power system is applied to release the bottleneck of power transmission and reduce the investment.The achievement in study can be listed as follows:(1)The transmission network planning model considering load transfer is proposed to settle power congestion caused by N-1 contingency.The planning schemes for different ratio of load transfer is analyzed to define “the best ratio”.The analysis results show that the transmission network planning considering load transfer can significantly reduce the investment.The effectiveness of the proposed model is verified by simulation.(2)Demand response is combined with data-adaptive robust transmission network planning in the second part to cope with the power congestion from both wind power uncertainty and N-1 contingency.The extreme scenario of wind power output generated by dataadaptive method reduces the conservativeness of planning result.The case study is taken to confirm the validity of the proposed model.(3)The coordinated planning of substation and circuit in multi-level power system is investigated.The substations of higher voltage level are considered as power supply while the circuits in lower layer determine network configuration.The PSO algorithm is used to solve the proposed model.The quantitative analysis indicates a more economical scheme obtained by the coordinated planning than the sequential method.(4)A comprehensive evaluation system for power network planning is put forward in the last part.The flexibility indices as well as coordination indices are set to reflect the coordination between planning result and flexible resources.In order to reduce the subjective factors,entropy weight method and TOPSIS technique are employed to determine weight of indices.The simulation based on the case in the third part is conduct and the results verify the effectiveness of the proposed evaluation system.