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At present, motor systems consume hugely and the running efficiency is not high. Therefore, there is great space for saving energy. In this case, a variety of motor energy-saving devices occur in order to improve efficiency and reduce the energy consumption. As the basis for regulating the motor, it is necessary to monitor the running state of motors effectively. Consequently, the electrical parameter measure such as power measure has practical significance.The paper introduces the development of electrical parameter measure and takes a detailed analysis of the power measure methods for three-phase system as two-wattmeter method and three-wattmeter method. To meet the demands of small size, low cost, real time performance, high accuracy, convenient communication and powerful parameter measure, the paper adopts the circuit design structure using a special energy metering IC ADE7758 and MCU. ADE7758 integrates six second-order△-ΣADCS, voltage reference circuit, digital integrator, temperature sensor and digital signal processing unit for all the RMS and power calculation. The MCU is used as the powerful AVR microcontroller.The system software modules are divided into SPI communication unit, electrical parameter calculation unit, LCD display unit, 32-bit CRC serial communication unit and fault detection unit. System can effectively measure the voltage RMS, current RMS, active power, reactive power, power factor, frequency, etc.
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