Research And Development Of Combined Power Metering Device

For a long time, some administrative departments attach great importance to whether the power metering device can accurately measure energy value in the power generation, transmission, distribution and all aspects of energy consumption, put the AC power metering device into the legal management, and implement compulsory verification and supervision. Based on the new power measurement technology, a combined power metering device which installs a secondary instrument into a combined transformer is developed in this thesis. After the device is calibrated, it can correct combined transformer and secondary instrument’s composite errors, and improve the device’s measurement accuracy. Combined power metering device follows the development trend of energy measurement technology, with characteristics of integration, network, and miniaturization.The thesis is based on the structural characteristics of dry-type combined transformer, and a mechanical structure of embedded secondary instrument is designed, which is on the secondary terminals in dry-type combined transformer. Centering in the international advanced energy metering chip CS5484, by the two meters method for energy measuring, the hardware circuit of the embedded secondary instrument is designed in this thesis. Analysis of the error sources achieves a reasonable distribution of errors. By analyzing the calibration principle of voltage channel gain, voltage channel DC offset, gain of current channel and AC offset of current channel, on the basis of the measurement software, the embedded secondary instrument’s calibration software is parallel designed in the thesis. Through analysis on the test data of the calibrated embedded secondary instrument, which is test by the national metrology institute, it realizes the design goals that current and voltage measurement accuracy rating reaches 0.2 levels; active power, reactive power, power factor measurement accuracy rating reaches 0.5 levels; active energy measurement accuracy rating reaches 0.5S levels.