Research And Design Of Excitation System For The Small Synchronous Generator

The Excitation Control Systems of synchronous generators have an important effect on the stability of power systems; moreover, excitation regulators play the role of a nucleus in the excitation control systems. However,for the small synchronous generator connected to grid, it is unfeasible to improve the net voltage and the transient stability of generator by adjusting excitation system, so maintaining power factor invariable after it is connected to the grid is more practically. This article adopts excitation current and power factor double-loop control method, designs a kind of digital excitation controller based on TMS320F2812 DSP.Compared to traditional phase controlled rectifiers, PWM converter has the attractive features such as controllable power factor, nearly sinusoidal input current, simplicity in control circuit and bidirectional power flow ability. So,this article adopts PWM converter instead of traditional phase controlled rectifiers to completed high power factor rectify.Due to the nonlinear relation between excitation current and power factor, a sequential algorithm for radial basis function (RBF) networks referred to as the generalized growing and pruning algorithm for RBF (GGAP-RBF) is introduced and then uses it in the learning algorithm to realize parsimonious networks. The structure of this controller makes no need to use another neural network for on-line system identification and determining the structure of neural network controller in advance.In this paper, the design scheme of the whole Digital Excitation system using three- phase full control bridge rectifier is presented. All of the logic diagram of the hardware, the circuit schematic figures and the software's flowcharts are also presented.