Research On Hamiltonian Control And Dynamic Performance Of Coordinated Hydro And Wind Power Generation

The purpose of coordinated hydro and wind power generation（GHWG）system is to mitigate random wind power by utilizing the rapid regulation ability of hydroelectric generating unit.This not only improves the utilization rate of wind power but also has important significance for maintaining the stability of the power system.However,conventional PID and PI control are adopted by hydroelectric generating unit and wind generating unit,which are easy to cause disadvantages such as slow response time and large overshoot in GHWG system.This will lead to large fluctuation of power output,poor regulation effect and serious impact on the balance of load demand.Therefore,to optimize the regulation performance of the GHWG system,this paper designed the control strategy of hydroelectric generating unit and wind generating unit respectively based on Hamiltonian control theory and explored the dynamic response performance of the GHWG system.The contacts and conclusions of this paper mainly include the following three aspects:（1）Superposition controller design of hydroelectric generating unit based on Hamiltonian theory.To improve the regulation ability and anti-interference performance of hydroelectric generating unit,superposition controller composed of feedback controller and L₂ disturbance attenuation controller is designed on the basis of Hamiltonian control theory.The five-dimensional mathematical model of hydroelectric generating unit regulating system is taken as the research object and the Hamiltonian energy function is constructed.According to the design principle of feedback stabilization and L₂ disturbance attenuation controller,the superposition controller of the hydroelectric generating unit is designed.Under the step external disturbance,the dynamic response performance of state variables is compared under the regulation of the superposition controller and the conventional PID controller,and the regulation ability and anti-interference performance of the closed-loop control system are explored.The simulation results show that compared with the PID controller,the superposition controller greatly avoids the overshoot phenomenon and reduces the regulation time by at least0.05s.Therefore,maintaining the stability of the hydroelectric generating unit,the superposition controller can accelerate the dynamic response time and effectively improve the regulation performance of the control system.（2）Hybrid passive controller design of wind generating unit based on Hamiltonian theory.To improve the utilization rate and grid-connected power quality of wind generating unit in low and medium wind speed range,the hybrid passive controller based on Hamiltonian control theory is proposed.According to the mathematical model of the permanent magnet synchronous generator-based wind energy conversion system（PMSG-based-WECS）,the Hamiltonian energy functions of the machine and grid-side converters are constructed.The passive controller of the inner current loop is designed,and the hybrid passive controller of PMSG-based-WECS is established by combining the outer loop PI of the rotational speed on the machine side and the voltage on the grid side,respectively.The simulation results of the50s short-term wind speed disturbance show that,compared with the conventional PI vector control,the hybrid passive controller reduces the output fluctuation by 2%and the THD rate of the grid side currents and voltages decreases by 18.3%and 48.6%,respectively.The hybrid passive controller not only improves the efficiency and stability of the wind generating unit but also reduces the THD rate of the grid side currents and voltages,which is conducive to ensuring high power quality.（3）Performance analysis of GHWG system.To explore the dynamic performance of GHWG system,the model of GHWG system is established and the dynamic response performance of hydroelectric generating unit and mitigating performance of GHWG system are analyzed.From the time domain and frequency domain,the output of wind generating unit regulated by the hybrid passive controller is analyzed to verify the feasibility of GHWG system.And compare the dynamic performance of the hydroelectric generating unit in the superposition controller and the conventional PID controller for mitigating wind power output.Based on the mitigating evaluation index,the mitigating performance of hydroelectric generating unit under different wind speed models and capacity ratio are quantified.The research results show that the superposition control strategy of the hydroelectric generating unit speeds up the output response by a minimum of 0.5s comparing with the conventional PID.The increase of capacity ratio and the decrease of wind power output frequency are conducive to the improvement of the stability performance of Hydroelectric generating unit,which provides effective engineering value for improving the efficient operation of the GHWG system.