Research On Dsp-Based Automatic Excitation Regulator In Small Rural Hydropower Station

Excitation regulator is the key part of synchronous generator system, it plays an important role in the normal operation and fault operation time of power system. It has the important meaning to control the output voltage of generator, distributes the reactive power reasonable among the parallel operation generator sets, ensure the safe and stable operation of the power system and so on. However, in some remote areas, the rural small generator excitation control system is very backward, it has hindered the development of Chinese agriculture and the pace of new countryside construction. In this paper, we considered the present situation of some small hydropower stations built before1980s as the research target, which have the characteristics of low automation level, backward in technology and urgent need technical reform, take the Suihua City North Forest Happiness Hydropower Station as the research target, and designed an DSP-based automatic excitation adjusting device, and verified the function of part of the experiment by tests.This paper work mainly includes the following four parts;The first, according to the field investigation, we understand that the Happiness Hydropower Station——water diversion type power station is located in southwest of the double river town, north forest region, suihua city, heilongjiang province, it is about30km from the city. There are four horizontal hydro-generator units of hydropower station, and the capacity is320kW. The generator export voltage is6.3KV, and installed two transformers and four excitation ark to regulate the voltage respectively. A control room is set in the station, the operation personnel can observe the each unit of the operation parameters from the control room; No matter the power station is in the normal operation or in the accident treatment, the operation personnel control these instruments mainly by their work experience.The second, according to the characteristics of low work efficiency and adjust accuracy, high artificial cost and adjustment error, bad real-time adjustment, we designed TMS320LF2407A-based hardware composition and function automatic excitation regulator for the Happiness Hydropower Station, and introduced the design idea and method, include input/output channel unit, signal timing acquisition unit, triggering pulse adjustment and amplification unit, fault detection unit, communication unit and man-machine interface unit, etc.The third, we took the idea of modular design in the software unit, and devided the whole software unit into two parts which are the main program and interrupt service program; the main program includes initialization, open the interruption, power calculation, adjusting control and limit protection modules; the interrupt service program includes synchronized signal capture, A/D transformation completement, phase shifting and pulsing, the watchdog and the computer operation and display; adding the watchdog interrupts into design of the software can effectively improve the stability and reliability of the system.The fourth, after designed and adjusted the software and hardware automatic excitation regulators, according to the conditions of laboratory, we used a small generator completed many experiments, such as A/D sampling experiment, PWM experiment,start excitation experiment, the voltage/frequency characteristic test and load operation experiment, through the experiment shows that the controller can achieve expected excitation design goal, excitation system functions can satisfy the design requirement.