Method and device for determining overload protection point of motor and medium

Abstract

The invention discloses a motor overload protection point determination method and device and a medium, is applied to the field of motors, and aims to prevent the situation that the temperature in a motor is too high due to the fact that the current of the motor runs above a current threshold for a long time, the current value of the motor is obtained, and the first time value when the current value is larger than the current threshold is determined; when the current value is greater than the current threshold value, the temperature of the motor rises, so that the initial step length of the motor is correspondingly increased by a first step length as a final step length, and the first step length is in positive correlation with a first time value, namely the longer the operation time of the motor is under the condition that the current value is greater than the current threshold value, the more the temperature of the motor rises; and if the final step length exceeds the step length threshold value, representing that the temperature of the motor is very high, and judging that the motor reaches an overload protection point. According to the method provided by the invention, the temperature of the motor can be estimated by using the current of the motor to determine whether the motor reaches an overload protection point, thereby preventing loss caused by overhigh temperature.

Description

technical field [0001] The present application relates to the field of motors, in particular to a method, device and medium for determining an overload protection point of a motor. Background technique [0002] Generally, when the motor is running at the rated current or below, the heat generated can be dissipated normally so it can run for a long time, but when the current of the motor exceeds the rated current and the motor runs for a long time, the heat inside the machine will gradually increase and the temperature will rise. The aging of the internal insulation is accelerated. When the temperature that the insulation layer can withstand is exceeded, the heat will accumulate in the insulation layer, which will rapidly age the coil and damage the motor. More seriously, it may cause a fire and cause serious accidents. For permanent magnet synchronous motors, the temperature is too high It will also cause irreversible permanent demagnetization of the permanent magnet of the ...

AI Technical Summary

Problems solved by technology

[0002] Generally, when the motor is running at the rated current or below, the heat generated can be dissipated normally so it can run for a long time, but when the current of the motor exceeds the rated current and the motor runs for a long time, the heat inside the machine will gradually increase and the temperature will rise. The aging of the internal insulation is accelerated. When the temperature that the insulation layer can withstand is exceeded, the heat will accumulate in the insulation layer, which will rapidly age the coil and damage the motor. More seriously, it may cause a fire and cause serious accidents. For permanent magnet synchronous motors, the temperature is too high It will also cause irreversible permanent demagnetization of the permanent magnet of the rotor. Since most motors have no temperature sensor and cannot detect the internal temperature, how to protect the motor from overload is very important.

Images