Online acquisition method for input active power and reactive power of induction motor

Abstract

The invention discloses an online acquisition method for input active power and reactive power of an induction motor, belonging to the field of motor measurement and control. Through the manner of online calculation, the input power information of the induction motor can be better obtained in real time, so a basis is provided for operation monitoring and fault diagnosis extension research of an induction motor system. The method is implemented in a system through a software module, and no extra device needs to be added in the motor driving system, so the cost of the system is not increased. The average value of the reconstructed voltage of a current period and the reconstructed voltage of a previous switching period is used for replacing the output voltage of an inverter at an initial moment of the current period, so the phases of measured current and the reconstructed voltage are aligned; the input power of the induction motor is calculated once in each current loop period, so the real-time performance of power acquisition is improved, and updating time is short. The influence of a nonlinear part in the inverter is considered in the reconstruction of motor end voltage, so the accuracy of the reconstruction voltage is improved, and the accuracy of power estimation is further improved.

Description

technical field [0001] The invention belongs to the technical field of motor measurement and control, and more specifically relates to an online acquisition method for input active power and reactive power of an induction motor. Background technique [0002] Due to the advantages of simple structure, convenient manufacture, and low cost, induction motors are widely used in fields such as industry, agriculture, and household appliances. With the rapid development of modern industry, higher requirements are put forward for the monitoring and fault diagnosis of the induction motor system. In the induction motor system, the input active power of the induction motor can reflect the operating characteristics of the load in the induction motor system, and the input reactive power can reflect the operating status of the motor itself and the inverter. Diagnosis is important. [0003] The input power of traditional induction motors is usually measured by using a power analyzer or an...

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Problems solved by technology

[0004] Aiming at the problems of high cost, long period and poor real-time performance of the prior art methods for obtaining input power of induction motors, the present invention provides an online method for obtaining input active power and reactive power of induction motors, the purpose of which is not to increase the premise of system cost , the input power of the induction motor is calculated in real time in each current loop cycle

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