Frequency-constrained Stochastic Unit Commitment Considering Voltage Security

With the increase of renewable energy penetration ratio, the randomness and volatility of power system are continuously enhanced, and the problems of frequency and voltage security of the system are prominent. To improve the frequency regulation ability and voltage regulating ability of the power system, this paper proposes a modified frequency-constrained stochastic unit commitment (M-FCUC) model considering the voltage amplitude. In the model, ROCOF and frequency nadir security constraints are established to limit the system frequency after disturbance, and linear voltage amplitude constraints are established to guarantee node voltage security of the system. The case studies in IEEE 118-bus system show that compare with traditional stochastic unit commitment, M-FCUC can make more reasonable day-ahead scheduling decisions that better guarantee frequency security and voltage security.