Intelligent voltage follower braking device and control method thereof

Abstract

The invention discloses an intelligent voltage follower braking device and a control method thereof. The device comprises an isolation filter module, a signal acquisition and conditioning module, a brake main circuit module and the like. The method comprises the steps of system fault judgment, current motor state judgment, dual redundancy acquisition of the current bus voltage and so on. The intelligent voltage follower braking device can automatically adapt to the change of the bus voltage and realize the on-line automatic setting of the discharge voltage threshold. When a motor is braking, the device consumes excess electric energy through an energy dissipation resistor, and prevents the bus voltage from surging during the braking process.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to an intelligent voltage following braking device and a control method thereof. Background technique [0002] Modern power electronics technology has made great progress, and inverters, servo drives, etc. have been widely used in motor drive systems, and they are all equipped with braking systems. The power supply of motor drive system is generally classified into two categories, one is constant voltage power supply, which is characterized by constant supply voltage and little voltage fluctuation; the other is battery-powered motor drive system, which is characterized by power supply The voltage of the battery will gradually decrease due to the loss of battery energy. Only when the voltage of the battery drops to a certain level, the driver will stop working, while the motor driver and motor can work normally within this wide voltage range. In these two types...

AI Technical Summary

Problems solved by technology

In these two types of systems, the motor is switched between the motor state and the generator state. When the drag system is in the driving state, the motor works in the motor state, and the electric energy flows from the power supply to the motor. In the dynamic state, the motor works in the generator state. At this time, the electric energy flows from the motor to the driver, and the feedback current formed will flow to the DC bus through the absorption circuit of the driver switch tube, and the supporting capacitor of the bus will be quickly charged in a short time. The charge of the capacitor The rapid increase will cause the DC bus voltage to rise rapidly. If the excess electric energy is not released in time, it is very likely to threaten the safety of the motor controller, or even burn the motor controller

[0003] At present, the energy consumption braking technology with a constant discharge voltage threshold is relatively mature, but this technology has obvious limitations, mainly because the discharge voltage threshold cannot be flexibly adjusted according to the bus voltage, and its versatility is poor.

Especially when this technology is applied to the variable voltage power supply system, since the protection voltage threshold is constant, it can only be determined according to the highest voltage. When the bus voltage drops a lot, this energy-consuming braking device cannot respond to the bus voltage in time. The rapid rise of the bus voltage can not be controlled at its current level in time, which will cause the rapid rise of the bus voltage. When it rises to the original maximum value of the bus voltage, the discharge protection will be activated, and the excess power will be consumed. This will cause the bus The voltage changes in a large range in a short period of time or it is too late to protect, which is very likely to threaten the safety of the system and cause the system to work unstable.

In addition, even if it is applied to a fixed bus voltage system, due to the diversity of voltage values, the diversity of drive products will also make this technology inflexible.

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