Research On Dynamic Parameter Identification And Transient Stability Constrained Emergency Control

Power system simulation calculation is the basic tool for power system dynamic security analysis and the reliability of the power system simulation results is directly dependent on the accuracy of power system model parameters. So how to accurately determine the power system " four type parameters", that is the excitation system parameters and its regulator parameters, the prime mover and governor parameters, synchronous generator parameters and the electrical load parameters, is a urgent one among power system research areas. Transient stability constrained emergency control is an important means for maintaing transient stabiltiy of power systems and the efficiency of transient stabiltiy constrained emergency control algorithm has been a bottleneck restricting its online application. On the basis of the power system model parameters obtained from parameter identification, it is quite important and meaningful to develop high-efficiency transient stabiltiy constrained emergency control algorithm and achieve its on-line application. This paper focuses on the power system dynamic parameter identification and transient stabiltiy constrained emergency control algorithm. The main work is presented as follow:(1) Generator parameters identifcation of multi-machine system. Based on WAMS, a mathematical multi-generator parameters identification formulation is developed for the overall identification of multi-generator parameters. The generator parameter identifiablity is analyzed and theoretically proves the feasibility of overall identification of multi-generator parameters. A PMU placement method is proposed for parameter identification, resulting better identification with fewer PMU. For overall parameter identification, the optimization problems scale is larger and the computational time is consummeing, this paper proposed a parallel reduced-space interior point method for the solution and showed an excellent computational efficiency.(2) Wide-area power system parameter identification. Based on WAMS, this paper obtained the parameters of synchronous generator, excitation system, governor system and electrical load meanwhile and developed the mathematical formulation of the overall power system parameter identification. First this paper use classification identification and parameter trajectory sensitivity analysis to reduce the identification parameters. The parameter identifiablity is then analysized and a PMU placement method is proposed. For wide-area power system parameter identification, the optimization problem scale is large and the gradient calculation is much complex. This paper proposed a parameter identification algorithm based on reduced-space interior point method and automatic differentiation, which greatly reduces the difficulty of the algorithm development and remarkably reduces the computational time.(3) A parallel transient stability constrained emergency control based on multi-core platforms. Transient stability constrained emergency control is a large scale dynamic optimization problem. This paper introduced the reduced-space interior point method for the solution since the degeree of freedom of the numerical discretization based-transient stabiltiy constrained emergency control is relative small. Mover over, the key time-consmumming parts of the algorithm are implemented with multi-thread technique and greately improve the computational efficiency.(4) A parallel transient stability constrained emergency control based on cluster system. This paper discretized the transient stabiltiy constrained emergency control using orthogonal collocation of finite element and reduced the optimization problem scale from the source compared with the tranditional implicit trapezoidal. With the characteristic of the low degree of freedom of the optimization problem after discretization, this paper introduced reduced-space interior point method for the solution. Further this paper develops a two-level parallel algorithm and implemented the parallel algorithm on cluster system, greately accelerating the computational efficiency and having the potential of online applications.