The main functions of an online power quality monitoring device

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This post was last edited by liwei618 on 2020-2-22 at 22:05. What is an online power quality monitoring device? A power quality monitoring device, also known as a harmonic power monitoring device, is a high-performance, multi-functional instrument for testing and analyzing power quality. It primarily addresses the sharp increase in electrical load, especially the growing capacity of impulsive and nonlinear loads, which leads to power quality issues such as waveform distortion, voltage fluctuations and flicker, as well as three-phase imbalance. Suitable for power supply systems in power plants, substations, wind farms, photovoltaic power stations, as well as large industrial enterprises in the petroleum, coal mining, steel, metallurgy, chemical industries, etc., across various voltage levels of 220KV, 110KV, 35KV, 10KV, 6KV, and 380V. Main functions of online power quality monitoring devices: 1. For the relay protection in power systems, safety and reliability are of great importance: a high-voltage isolation module is used for voltage input, while a high-precision current transformer is used for current input, thereby ensuring safe isolation between the input signals and the measurement system. **It improved the instrument’s resistance to interference. 2. Numerous testing parameters: It is used to measure all the parameters specified in the five national standards for power quality, including system frequency, grid harmonics, three-phase voltage imbalance, voltage fluctuations and flicker, voltage deviation, the RMS and true RMS values of the voltage, the RMS and true RMS values of the current, fundamental active power, fundamental apparent power, harmonics from the 2nd to the 63rd order, and the true power factor. 3. High precision: Meets the requirements of Class A instruments per national standards. Reference algorithms are used for harmonics, three-phase unbalance, flicker, and fluctuations; no approximate calculations are employed. A high-precision 16-bit A/D converter is utilized for simultaneous sampling at a rate of 12.8 kHz. 4. Communication and multi-channel testing: The communication interface supports RS-232 and 485, and this microcomputer-based protection device features a large number of testing channels with flexible configuration; it can measure up to 8 three-phase voltage signals and 8 three-phase current signals. 5. Large-capacity storage: It has 512M of built-in memory for storing data in 5-minute intervals, with each channel capable of storing historical data for up to 4 months continuously. Main applications: 1. Measurement and analysis: frequency and voltage deviations, voltage fluctuations and flicker, allowable imbalance of three-phase voltages, power grid harmonics. 2. Apply wavelet transform to measure and analyze the harmonics of non-stationary time-varying signals. 3. Measure and analyze the power quality of the public power grid affected by various electrical equipment under different operating conditions. 4. Record and store the trend changes of electrical parameters such as voltage, current, active power, reactive power, frequency, and phase. 5. The power quality online monitoring device enables dynamic monitoring of the adjustment and operation process of electrical equipment. 6. Analyze the dynamic parameters of reactive power compensation and filtering devices in power systems, and provide a quantitative evaluation of their functions and technical specifications.