Design Of Measurement Unit On Excitation Regulator Of Large Synchronous Generator

While we are conducting rapid survey of multiparameter connected with ACsignals produced by the synchronous machine which belongs to the power system,the running state of generator can be realized by the measuring results and thefluctuation is able to be adjusted in real time. So it is necessary to develop a kind ofmeasuring system with fine cost performance, stable property, fast response speed,good precision and the ability to complete testing of multiparameter. The task is soimportant that it attracts so many people. The measurement function connected withthis system mainly include voltage effective value, current effective value, activepower, reactive power, power factor, etc. And the system can send the testing resultsto excitation regulator for the subsequent processing.This paper firstly summarize the working principle and systematic structure ofthe generator and its excitation adjustment. Regarding related background knowledgeof measurement parameter as an important premise, we compare and analysis thecommon algorithms involved in the process of measurement and then obtain thescheme of the whole system. We usually adopt a periodic sampling method tomeasure the effective value at intervals and proceed mean-root-square operationabout several sampling values. The average value can be obtained by recursivefiltering method. The frequency algorithm adopt frequency measurement tracking ofhardware and take sampling method at intervals between the two points of software.Based on the measurement results of effective measurement, power testing substitutetheoretical formula into it to solve the problem.On the account of theoretically analyzing different kinds of algorithms, wepropose a set of implementation methods of measuring system. At the aspect ofhardware design, the microprocessor chip TMS320F2812produced by TI enterprise can be used as the main controller. The front end conditioning circuit produce digitalquantity by the use of flowing pressure transducer, filtering and analog-digitalconversion, then the digital quantity is sent into the controller to complete algorithmprocessing. The processing results can be transmitted through serials communicationports to excitation regulator. Instead of using the internal A/D, we adopt ADS8556chip to complete6roads simulation voltage signal at the same time. The data storageadopt external SRAM to realize the high-speed storage by the means of parallelextensions. At the aspect of software designing, the controller firstly finishinitialization of external hardware and the drive its relevant function Secondly, thecontroller proceed algorithm processing to finish corresponding measuring functionbased on the digital data sampling.The design of this system has a strong theoretical basis, reliable support fromalgorithm and rigorous assist provided by software. On the development board, wetest the ideal AC signals in the laboratory and the results can meet the expectation setbefore.