Multi-Index Nonlinear Coordinated Control For BESS And Generator Excitation

Battery Energy Storage System (BESS) can regulate active power and reactive power in power system. It can be operated in four quadrants. It can afford the fast response capability for high voltage transmit electricity system, enhance the system stability and restrained the fluctuation of frequency and voltage. When it is connected in load side, it can also reduce the influence of the power bus subjected to a disturbance on load voltage and active power, improve the power quality of load.The multi-index nonlinear coordinated control scheme is a new design way, which is being focused on in the nearly years. This control design method is effective both for improving the dynamic and the static characteristics of the state variables, and especially for solving the control problems of static excursion. This paper can be divided into two parts.First, this paper deduced a new mathematic model of single machine infinite bus power system with BESS, and proposed a multi-index nonlinear coordinated control scheme for it. The proposed multi-index nonlinear coordinated controller can effectively coordinate the dynamic and steady-state performance of the controlled system. It can enhance the stability of the system, improve the dynamic characteristics of state variables, and can improve the control accuracy of output variables such as terminal voltage, active power output of the generator. Simulation results show that to control BESS and generator coordinately has the advantage of enhancing the stability of the system. With the ability of BESS to control the active power and reactive power, and the regulate of generator excitation, the dynamic characteristics of state variables can changes more smoothness, responds more speediness and still be kept at their setting values after a step disturbance.Second, this paper deduced a new mathematic model of BESS and integrated load model, and a multi-index nonlinear coordinated control scheme for the system is proposed. As a new FACTS facility, BESS can regulate active power and reactive power of the power bus synchronously. Simulation results show that BESS has the advantage of availably reducing the influence of the power bus subjected to a disturbance on load voltage and active power. It can enhance the control accuracy of output variables and voltage stability, improve the power quality of load. With the ability of BESS, the dynamic characteristics of load voltage and active power can be controlled more smoothness, and the responses of the system is more speediness.