Alternating current physical quantity measuring device and method as well as data acquisition device and method

Abstract

The invention provides a device capable of measuring physical quantity of alternating current at a long distance. The device comprises an analogue sampling passageway, a sampling switch, a register, a bus and a timing controller, wherein the analogue sampling passageway is used for inputting the alternating current to carry out analogue sampling so as to output an analogue sampling value, the sampling switch is used for resampling so as to obtain a remote-measurement data frequency required at a receiving side, the register is used for storing a resampling value from the sampling switch, the bus is used for outputting the resampling value in the register to the receiving side, and the timing controller is used for controlling resampling frequencies of the analogue sampling passageway and the sampling switch; and the device is characterized by further comprising a digital low-pass filter which is used for filtering a high-frequency component in the sampling value, wherein an input of the digital low-pass filter is connected with the analogue sampling value output by the analogue sampling passageway, an output of the digital low-pass filter is connected with the sampling switch, and cut-off frequency of the digital low-pass filter must be 0.5 folds smaller than the resampling frequency of the sampling switch. The invention also provides a corresponding method. When the device is adopted, the remote measurement accuracy of power physical quantity is increased, a waveform value is output through resampling, and an effective value, a steady-state value as well as a fundamental harmonic effective value and steady-state value are also output, so that many requirements of the receiving side for remote measurement data can be met.

Description

technical field [0001] The invention relates to electric power system automation technology, in particular to a method and a device for measuring AC physical quantities and collecting data. Background technique [0002] In the automation of power dispatching, the measurement and data collection of electric physical quantities were completed by the telecontrol terminal RTU in the early years, and in recent years by the integrated automation of substations, and by the measurement unit in digital substations; , Intelligent power consumption), it is completed by the electric energy meter or distribution transformer terminal; in power distribution automation, it is completed by the distribution switch terminal; in the generator excitation controller, it is completed by the measurement and transmission unit. In all the measurement units or terminals mentioned above, the process of measurement and data acquisition (hereinafter referred to as telemetry) is to input AC current i and ...

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Problems solved by technology

[0007] Chinese invention patents ZL200910158375.x and ZL200910158370.7 (inventor: Hao Yushan, invention name "continuous physical quantity measurement device and method") provide steady-state quantity telemetry and full-state quantity telemetry for general physical quantities, but the output frequency does not meet The above resampling frequency and output content are too many, so it is inconvenient to be directly applied to the power automation system

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