Motor deceleration control method and device by inverter

Abstract

The invention provides a motor deceleration control method by an inverter. Multiple sub processes with the same processing flow are adopted to adjust the deceleration time repeatedly, and as for two adjacent sub processes, the deceleration time of a next sub process is adjusted according to the processing result of a former sub process. Each sub process comprises steps: the current operating parameters of the motor, the corresponding parameters of a DC bus of the inverter and the limiting values of the corresponding parameters of the DC bus are acquired; according to the difference between thecurrent operating parameters of the motor or the corresponding parameters of the DC bus and the limiting values of the corresponding parameters of the DC bus, PID control operation is carried out toobtain an adjustment amount; the deceleration time of the current sub process is calculated; and according to the deceleration time, the output frequency of the inverter in the current sub process iscalculated, and motor deceleration is controlled according to the output frequency. Thus, quick motor deceleration can be achieved while no brake resistor needs to be mounted.

Description

technical field [0001] The present application relates to the field of frequency converter control, in particular to a method and device for a frequency converter to control motor deceleration. Background technique [0002] The frequency converter is a motor control device that integrates control and drive. Generally, the power grid is used to rectify the AC voltage into DC voltage, and through the DC bus capacitor built in the frequency converter, it is then inverted into AC voltage through the three-phase inverter bridge, which is the so-called AC-DC-AC structure. [0003] The main function of the frequency converter is to drive the motor to rotate, including: acceleration, deceleration and other actions. In some industrial sites, frequency converters are required to control the motor's rapid acceleration and deceleration. Due to the inertia of the load, when the inverter controls the motor to decelerate rapidly, the motor is equivalent to a generator, which converts the...

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Problems solved by technology

[0004] 1) The frequency converter must increase the braking unit, increasing the cost of the frequency converter;

[0005] 2) The cost of braking resistors with high power is very high, and sometimes additional heat dissipation measures are required;

[0006] 3) Braking resistors with higher power are bulky and cannot be installed in some occasions

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