摘要：Abstract This paper aimed to investigate the multi‐objective optimization and decision‐making of the combined control law of guide vane (CCLGV) and pressure regulating valve (PRV) for hydroelectric unit under load rejection. Firstly, the multi‐objective optimization problem of CCLGV‐PRV is formulated. Then, a new multi‐objective gravitation search algorithm with non‐dominated screening and chaos mutation (NCMOGSA) is adopted to solve it. Moreover, an improved entropy weight method and relative objective proximity method are applied to select suitable solution. Finally, a comprehensive comparative study is carried out to reveal the mechanism between the CCLGV‐PRV and several basic parameters. The results indicate that replacing surge tank with PRV can effectively solve the contradictory between water pressure at the bottom of volute and rotational speed under load rejection. The NCMOGSA shows excellent performance in solving the multi‐objective optimization problem of CCLGV‐PRV and get a group of Pareto set. The improved entropy weight and relative objective proximity method make the final scheme clear. The rise rate of rotational speed is completely determined by the guide vane (GV), and the water pressure is jointly determined by the control law of the GV and PRV. The two‐stage closing and two‐stage opening (TCTO) is the final recommendation for CCLGV‐PRV.
