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Short-term load forecasting for streaming load data is an important issue for power system planning, operation and control. Smart meters of Advanced Meter Infrastructure distributed around the distribution power grid produce streams of load at high-speed. The collected data can be characterized as a non-stationary continuous flow. A stream-based short-term demand forecasting model based on ARIMA is proposed. This method is used to forecast hourly electricity demand for next few days ahead. The performance of this methodology is validated with streaming data collected in real-time from the power grid.

The principle of quasi-synchronous discrete fourier transform (DFT) algorithm was introduced and the simulation on the algorithm was carried out. The quasi-synchronous DFT algorithm is independent of the first sample point and it is able to start sampling at any moment. The maximum relative amplitude error and phase error of the algorithm are 0.05 % and 5.4° when the frequency of the signal is between 49.5 Hz and 50.5 Hz. The accuracy of quasi-synchronous DFT algorithm can be improved by scores of times than that of DFT algorithm.

This paper puts forward a dielectric barrier discharge detection system using PMT for photoelectric element. According to faint light signal characteristics and testing purpose of dielectric barrier discharge, this system is designed, including three parts: optical fiber transmission, photoelectric conversion and signal processing circuit. This paper introduces design and ideas of the system framework and presents circuit design parameter. Results in atmospheric pressure of dielectric barrier discharge detection experiment show that the system has high sensitivity, fast response, can effectively distinguish discharge and interference signals, gather more signals in different areas.

Introduces the analog phase compensation technology used in electronic instrument transformer, put forward a method of digital phase compensation in electronic transformer and carries out in the 220KV electronic instrument transformer measurement system, the resolution ratio of the phase compensation is 1 second and the maximum range of the phase compensation is 270 second, which can meet the phase adjustment of electronic instrument transformer; compares the analog compensation technology and digital phase compensation technology, analyzes their characteristics and different applications.