Circuit and methods for detecting resistance value, temperature and state of motor winding in real time

Abstract

The invention relates to a circuit and methods for detecting a resistance value, temperature and a state of a motor winding in real time. The circuit comprises a constant current source and a switching circuit which are connected with each other, wherein the control port of the constant current source is connected with an external constant current source control signal for controlling current output of the constant current source; the current output port of the constant current source is connected with the output port of the switching circuit; the control port of the switching circuit is connected with an external switching control signal; and the output port of the switching circuit is connected with a three-phase winding of an asynchronous motor. In the method, the resistance value, thetemperature or an open-circuit or short-circuit state of the winding are measured by controlling constant current output by the constant current source and the output port of the switching circuit. The circuit is simple and the methods are convenient to implement, so that the problem that the real-time resistance value of the motor winding cannot be acquired after the temperature of the motor winding is changed is solved; therefore, the control precision of a motor controller is improved, the motor and the motor controller can be protected well, and safety accidents are reduced.

Description

technical field [0001] The invention belongs to the field of motors, in particular to a real-time detection circuit and method for the resistance value, temperature and state of motor windings. Background technique [0002] During the use of asynchronous motors, the abnormal state of the windings, such as excessive temperature, open circuit, short circuit, etc., often leads to damage to the motor or other electrical equipment, which may cause safety accidents in severe cases. At present, the detection circuit and method of the state of the motor winding are usually to embed a temperature sensor inside the motor to measure the winding temperature, but this method has the following disadvantages: 1. The measured temperature value is only the local temperature of the winding, which cannot reflect the temperature of the motor. The overall temperature of the winding; 2. The mechanical processing requirements of the motor are very high, which cannot be installed on many motors; 3....

AI Technical Summary

Problems solved by technology

[0002] During the use of asynchronous motors, the abnormal state of the windings, such as excessive temperature, open circuit, short circuit, etc., often leads to damage to the motor or other electrical equipment, which may lead to safety accidents in severe cases

At present, the detection circuit and method of the state of the motor winding are usually to embed a temperature sensor inside the motor to measure the winding temperature, but this method has the following disadvantages: 1. The measured temperature value is only the local temperature of the winding, which cannot reflect the temperature of the motor. The overall temperature of the winding; 2. The mechanical processing requirements of the motor are very high, which cannot be installed on many motors; 3. If the sensor or the connecting sensor line is damaged, it cannot be repaired, and the entire motor can only be replaced

However, there is no better way to detect the resistance value, temperature and open circuit or short circuit state of the motor winding resistance

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