Research Of Synchronous Phasor And Techniques Based On The Metro Electric Power System

In safe operation and efficient management of urban rail transit as thetotal target, to carry out the real-time condition monitoring, the wide-areahybrid system information fusion and fault early warning disposal research,establish a dynamic real-time fault diagnosis of power key equipment status,reliability evaluation and safety early warning platform form the rapiddiagnosis and effective early warning and comprehensive control of powersupply security system, enhance the safe operation of the rail transit supportcapability.Based on synchronized phasor measurement technology of the phasormeasurement unit (-PMU-2) can provide high precision, real time phasordata of urban rail transit power system operation state can be effectivemonitoring and control, this topic is the Shanghai committee of science andtechnology research plan project titled "urban rail transit power systemmeasurement and transmission technology research", is "rail traffic safetycomputer platform key technology research and application demonstration"of corpus, mainly study the synchronous phasor measurement unit (-PMU-2) under the unified time scale of measurement algorithm and method ofreal-time data transmission.In this paper, the rail transit power system phasor measurement technologyto do the following research work: (1) Power system for rail transit site condition made field investigationfor in-depth understanding of the status quo, based on the platform systemto achieve the goal of the overall solution framework of the design, functionand performance requirements, plan involves network architecture and themain technical parameters of the hardware and software platform, discussesthe performance of the key equipment, clarify the rail transit power system,the three key technologies (phasor measurement technology, the timesynchronization technology, network communication technology) solutions.(2) The basic principle of high precision, real-time synchronous phasormeasurement is introduced, this paper introduces the use of classicalalgorithm of discrete Fourier transform (DFT) to calculate the phasor(frequency, amplitude and phase Angle) data, explain theory DFT algorithmin actual power grid frequency real-time dynamic change under theconditions of sampling frequency and generating system can’t satisfy theinteger times frequency (non-synchronous sampling), causes the spectrumleakage, cause measurement error, the non-synchronous sampling caseswere analyzed and summarized in this paper the current by using theprinciple of the algorithm, the algorithm of the practical scope, advantagesand disadvantages are compared, finally get to add window algorithmprecision, better meet the needs of actual engineering survey.(3) Analyzed the traditional DFT phasor measurement error analysis,put forward a kind of based on window DFT algorithm, improve thealgorithm accuracy. In order to strengthen the algorithm of real-time, aniterative recursive algorithm was deduced. Based on PC-118agreement,synchronous phasor measurement accuracy validation criteria are given, andthrough Matlab simulation, the dynamic change of network phasor simulation experiment, the experimental results show that the algorithmeffectively for the power grid frequency tracking precision, tracking.(4) Finally, the scheme and synchronous phasor data transmissiondevice in detail in this paper, the error reasons, under the guarantee based onGPS clock synchronization technology of each measuring point data can getaccurate phasor under unified clock coordinate values.In conclusion, this paper deeply studies the rail transit power systemssynchronized phasor measurement technology, from engineering solutions,phasor measurement principle and the software and hardware involved,analyzes the key technology rail transit phasor measurement of powersystem. And put forward a kind of high precision and reliable phasormeasurement method.