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Nuclear Power Plant And Pumped Storage Station Modelling And Coordinated Operation

Posted on:2007-12-01Degree:DoctorType:Dissertation
Country:ChinaCandidate:H M GaoFull Text:PDF
GTID:1102360242964304Subject:Power system and its automation
Abstract/Summary:PDF Full Text Request
With the development of economy, the power demand is increasing and the energy is relatively in shortage. Nuclear power is clear and economic modern energy that can replace the traditional energy in large scale and is not restricted by regions. The large capacity supercritical thermal units and nuclear units are put into operation in order to save energy and decrease the energy transport expenses. In China, the nuclear power plants will keep on increasing in the next 20 years. On the other hand, the peak-valley difference of power system is increasing, thus the regulation of peak load is becoming more and more important. However, in practical engineering, the large capacity thermal units and nuclear units can only run with base load and middle load because of the minimum power output constraints. The medium- and small-sized thermal units and the hydraulic units often run with peak load, but the economic benefit level and the efficiency are relatively low. The pumped storage stations can shift the peak load and fill the valley load and follow or backup load. The pumped storage stations will increase in order to settle with the regulating peak load and improve the economy and reliability of power system. Thus the economic efficiency of the whole power system can be improved.Under such circumstance, the power system security is more complicated. The power system transient analysis, the medium-term and long-term stability analysis are all considered. In power system transient analysis, the steam turbine, the hydro turbine, the governor, the excited system are modeled, but the boiler, the reactor of the nuclear power plants, and the hydraulic system are not modeled. As we know, the dynamic behaviors have great effects on power system medium-term and long-term stability analysis. For example, the nuclear power unit may stop running because of the affiliated facility failures due to voltage and frequency problems. In pumped storage station the hammer and frequency oscillation of the conduit system have negative effect on the governor, and the power system stability will also be influenced. Thus it is necessary to study the detail models of the nuclear power plants and the pumped storage stations and analyze the mutual action of power system and power stations.The pumped storage station often united run with the nuclear power stations in order to improve the system economic level and security. The capacity proportion of the nuclear power stations and the pumped storage stations should be determined based on the optimal calculation and not by experience. It is also necessary to study coordinated operation of the nuclear power plants and the pumped storage stations in order to ensure that the power system run safely and economically.This dissertation studies those unsolved problems together with modelling and the coordination operation of nuclear power plant and pumped storage station. Then some effective strategies are proposed to solve the above problems. Those novel strategies are as follows:(1) A detailed pressurized water reactor (PWR) nuclear unit model for power system analysis is proposed by PSS/E Matlab-Simulink interface. This model is applied to the example of TIANWAN nuclear power station. The model includes the reactor neutron dynamics module, the reactor thermal dynamics module, the steam generator dynamics module, the reactor power control system module and the coolant pump integrated parameter module. Each module can be revised and debugged very easily, for the user only needs to modify the Matlab transfer function diagram of certain module if needed. Based on PSS/E, this model can be used for united simulation with single unit or the bulk power system.(2) Based on this detailed nuclear power plant model, each module of the nuclear power plant model is simulated respectively. The simulation results ensure the model's validity. The response characteristics of each module is also studied. Then the response of nuclear power plant to the disturbance of power grid is simulated and analyzed through two examples: one is the single unit infinite system and the other is the Jiangxu province power grid.(3) The detailed pumped storage station model and hydro power station model are established based on the PSS/E user-written model. The hydro turbine models include the nonlinear analytical hydro turbine model, the linearized model based on the prototype characteristics, the linearized model based on the internal characteristics, and the improved SUTER transform characteristics model. The conduit system models include the single conduit rigid hammer model, the single conduit elastic hammer model and the complex conduit system auto-modelling model. Complex conduit system auto-modelling model is based on the characteristic method combining with numbering the conduit system according to its topological structure. The model describes the dynamic behavior of the complex conduit system, the elastic effect of pipe wall and water and the interaction of the complex conduit system, thus it can be applied to any complex conduit system without recoding for different conduit systems. Thus the flexibility and the portability of the model are greatly increased.(4) Based on the detailed pumped storage station model and hydro power station model, the effect of different hydro turbine model and different conduit system model on power system analysis and small disturbance analysis are studied by comparative method. (5) The planning and operation of the nuclear power plants and the pumped storage stations are introduced. A new optimal operation scheduling method of the pumped storage station with the thermal power station is proposed based on PSS/E OPF and IPLAN. This method considers the transmission losses and characteristics of the pumped storage stations at the same time. Simulation results based on the proposed method and the method of probabilistic production simulation are compared. The results show that the proposed method is valid and can be used in the hydrothermal coordination optimal operation scheduling of bulk power system. Works done in this dissertation are particularly valuable for later planning and operation of power system.
Keywords/Search Tags:power system, nuclear power plant, pumped storage station, mathematical model, extended term stability, power planning, coordinated operation
PDF Full Text Request
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