Anti-demagnetization control method for deep well permanent magnet synchronous motor based on temperature rise model reconstruction

Abstract

The invention provides an anti-demagnetization control method for a deep well permanent magnet synchronous motor based on temperature rise model reconstruction. The method comprises the following steps: recording motor temperature and winding temperature changes at intervals of 10 minutes according to room temperature and rated load conditions; calculating the motor temperature rise under the room temperature condition according to a temperature rise formula and drawing a temperature rise curve; calculating a theoretical temperature rise value corresponding to the current load and time according to a temperature rise reconstruction formula; repeatedly recording time and operation current according to the time interval; drawing a temperature rise curve again according to the calculation theoretical temperature rise and the time point and storing the temperature rise curve in a data table form; and calculating a current motor temperature value according to the reconstructed temperature rise curve, judging whether the motor is in an over-temperature state or not, if not, continuing to operate, and if so, controlling the temperature rise of the motor to be within a reasonable interval. According to the method, the motor temperature can be monitored in real time, and the motor temperature is ensured to be in a reasonable operation interval in a mode of adjusting the motor output power in real time.

Description

technical field [0001] The invention relates to the technical field of anti-demagnetization of permanent magnet synchronous motors, in particular to an anti-demagnetization control method of deep well permanent magnet synchronous motors based on temperature rise model reconstruction. Background technique [0002] At present, permanent magnet synchronous motors are widely used in various industries due to their superior performance in various aspects, but their disadvantages are that they are prone to slow demagnetization due to heat generation when encountering extreme temperature or load conditions. Permanent magnet motors used on the ground Effective protection can be carried out by temperature sensors and other means, but for severe environments such as deep well oil and gas production, due to high temperature, high pressure environment and long-distance control, it is impossible to install sensors, and the real working status of the motor cannot be truly fed back. Withou...

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Problems solved by technology

[0002] At present, permanent magnet synchronous motors are widely used in various industries due to their superior performance in various aspects, but their disadvantages are that they are prone to slow demagnetization due to heat generation when encountering extreme temperature or load conditions. Permanent magnet motors used on the ground Effective protection can be carried out by temperature sensors and other means, but for severe environments such as deep well oil and gas production, due to high temperature, high pressure environment and long-distance control, it is impossible to install sensors, and the real working status of the motor cannot be truly fed back. Without effective protection when changing, the permanent magnet will demagnetize slowly due to long-term high temperature, resulting in reduced service life

[0003] Therefore, a reliable method is needed to solve the problem of demagnetization caused by uncontrollable factors. At present, the method of online detection of motor resistance changes is used to estimate the motor temperature. The step change, the cable resistance change is even greater than the motor stator resistance, resulting in a large deviation between the calculated motor temperature and the actual value, which cannot be used to effectively protect the motor

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