Sensorless driving system for three-phase motor of four-switch inverter

Abstract

The invention relates to a sensorless driving system for a three-phase motor of a four-switch inverter. The sensorless driving system for the three-phase motor of the four-switch inverter is characterized by comprising a four-switch inverter, wherein an input signal of the four-switch inverter is direct-current voltage; a four-switch full-bridge inverter circuit comprises two capacitors C1 and C2 and four controllable switches S1-S4; the inverter is provided with three voltage output ports which are respectively connected with three voltage input ends of a motor. According to the technical scheme, the three-phase full-bridge inverter is formed by the four-switch inverter and two capacitors, an ARM chip with low cost is used as a master control processor, three-phase symmetric voltage signal output of the inverter can be realized by adopting a voltage compensation scheme, and meanwhile, the problem of fluctuation of neutral-point voltage of capacitors can be solved; and the position and rotating speed of the motor are evaluated by adopting a sensorless algorithm, the robustness of a control system can be reinforced, the structure is effectively simplified, and the cost can be saved by about 35 percent.

Description

technical field [0001] The invention relates to a drive system, in particular to a sensorless drive system of a four-switch inverter three-phase motor, belonging to the field of motors and electrical appliances. Background technique [0002] With the improvement of electrification and industrialization level in various industries, electrification applications have been unprecedentedly popularized, and the optimization of the structure under the premise of meeting the stability requirements is a current research focus. [0003] The adjustable speed electric drive system has been widely used in the field of electric drive and is the core system component of the electric drive. In industrial applications, the three-phase motor used in the adjustable-speed electric drive system is more efficient than the single-phase motor, and the system accuracy and stability are better. The core component of the three-phase motor drive system is a three-phase inverter, and the most basic and...

AI Technical Summary

Problems solved by technology

However, in occasions where the accuracy of speed regulation is not very high, such as mine electric locomotives, fans, water pumps, etc., the cost of using a six-switch inverter is relatively higher

[0004] However, using the traditional method to directly reduce the number of switches in the conventional three-phase six-switch inverter cannot make the inverter output a symmetrical three-phase voltage signal, and it cannot meet the requirements of the drive system such as the motor at all.

In the existing technology, the invention patent with the application number 201610533077.4: a model predictive control method for a three-phase four-switch inverter driving a permanent magnet synchronous motor, although it also involves a three-phase four-switch inverter driving a permanent magnet synchronous motor, However, the model predictive control algorithm used requires repeated iterative calculations, so the amount of calculation is huge, and the requirements for hardware performance and cost are higher, which deviates from the original intention of reducing costs

Especially in the case of low-precision motor control, the feasibility of implementing predictive control with high-cost hardware is low

In addition, model predictive control requires multiple sets of raw data to initialize the value function, and the steady-state response of the system is slow

Those skilled in the art try new solutions all the time, but this problem has not been properly solved

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