Study On Modelling Simulation And Control Optimization Of Pumped Storage Unit Regulating System In Engineering

The pumped storage units(PSU)are developed in the directions of high water heads and intelligentize.However,some negative traits existed,i.e.,the large capacity of units,the high degree of integration,the complicated layout of the conduit tubes,the continual condition transformations,the close couple of hydraulic-mechanical-electrical systems,and the high request of the abilities that peak load and frequency regulation.Those characteristics not only bring great difficulties to the control and operation of the PSU,but also cause increasingly prominent security issue.Therefore it is urgent to study the modeling simulation and control optimization of complex pumped storage units and solve the practical problems in engineering.This paper focuses on the key scientific problems of the simulation and control optimization of PSU,and the key scientific problems of the safe and stable operation of PSU are discussed,then a real-time accurate equivalent circuit model are established.The evolution mechanism of the transition process of PSU in the whole working conditions is described with the RAECM.The new control strategy of the regulating system under low water heads is studied.Whereafter the new optimization model of “ nonlinear controlled object and nonlinear controller” based on novel intelligent optimization algorithm.Finally,the integration device of simulation experiment and performance test is designed.The research innovations of the paper play an important role in ensuring the safe,effcient and stable operation of the PSU that can be summarized in the following aspects:(1)The RAECM is proposed to reconcile the conflict between real-time online simulation and accuracy under various operating conditions.Respectively,all hydraulic factors in pipeline system are fully considered based on equivalent lumped-circuits theorem.The pretreatment,which consists of improved Suter-transformation and BP neural network,and online simulation method featured by two iterative loops are synthetically proposed to improve the solving accuracy of the pump-turbine.All non-linear factors are taken into account for the servo-mechanism including the dead zone of the servo-device,the saturation of the pressure regulating valve,the rate limit of the main servomotor,and the output limit of guide vane opening.Moreover the modified formulas for compensating error are derived with variable-spatial discretization to improve the accuracy of the real-time simulation further.The implicit RadauIIA method is verified to be more suitable for PSUGS owing to wider stable domain.Static and dynamic tests are set up respectively to verify the validity and stability of the RAECM.(2)Focused on the rotation speed fluctuation and difficult synchronizing problems when the unit is working at low head and entering ‘S' characteristic zone,the novel controllers are studied in two aspects of independence and syncretic of PSU model.Firstly,the heuristic gain-scheduling nonlinear PID(HGS-NPID)inspired by field intensity in capacitance and expert experience is proposed and the parameters are optimized with Artificial Sheep Algorithm.Simultaneously,Then adaptive predicted fuzzy PID(APFPID)controller is constructed based on the integration of fuzzy PID and the model predictive control.Rolling prediction by RAECM is proposed to replace rolling optimization with its computational speed guaranteed.The nonlinear damping of weighted formula presented by integrate the control output increment sequence makes APFPID control output reasonably contains the possible state deviation of the future system and the current state of deviation information.Comparative experiments also indicate that APFPID controller outperforms other controllers in most cases,especially low water head conditions.(3)Based on the theoretical achievements about the study on RAECM and simulation in whole conditions,the integration device of simulation experiment and performance test with independent intellectual property rights is developed based on the High performance embedded architecture of DSP and total isolation array.It breaks through the bottleneck between real-time online simulation and accuracy under various operating conditions.The simulation experiment in whole conditions and the performance test in the hump zone and the “S” characteristic interval are realized with the integration device,that can provide system and technical support for improving the control quality of the unit,realizing early warning of potential failures and ensuring safe and stable operation of PSU.