A direct torque control device and method

A technology of direct torque control and torque, applied in the direction of controlling electromechanical transmission devices, control systems, and control generators, etc., can solve problems such as difficult to meet the voltage requirements of induction motors and low voltage transmission, achieve high voltage transmission ratio, improve Effect of voltage transfer ratio and complexity reduction

CN104579091BActive Publication Date: 2017-03-22SHANGHAI UNIVERSITY OF ELECTRIC POWER
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2017-03-22

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Abstract

The invention relates to a direct torque control device and method. The direct torque control device comprises a main control unit, an inductor motor, an input filter, a matrix converter, an output filter, an input voltage detection unit, a motor voltage detection unit, a motor current detection unit, a driving isolation circuit and a rotation speed measuring unit. The direct torque control method comprises the first step of obtaining estimated values of torque and flux linkage, the second step of determining a torque reference value, the third step of conducting hysteresis comparison on the estimated values of the torque and the flux linkage and the reference value, the fourth step of obtaining on-off state selection signals according to the sector where the flux linkage is located and state values of the torque and the flux linkage, the fifth step of calculating the amplitude and phase of voltages through input three-phase voltages and conducting power-factor adjustment, the sixth step of obtaining combined control signals through input voltage sector signals, a power factor state value and the on-off state selection signals to control the matrix converter. Compared with the prior art, the direct torque control device and method have the advantages that the operating complexity is reduced, the voltage transmission ratio is guaranteed, and pollution to a power grid is avoided.
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Description

technical field

[0001] The invention relates to the field of motor torque control, in particular to a direct torque control device and method. Background technique

[0002] Direct torque control overcomes the parameter-sensitive defect in traditional field-oriented vector control, does not need to convert the induction motor output torque into an equivalent current reference value, and does not require a complex controller. It takes torque as the center and realizes comprehensive control in the way of stator magnetic field orientation, which avoids the complex coordinate transformation of vector control and the mathematical processing of the motor model, and directly calculates the flux linkage and torque on the stator coordinates of the motor to realize the stator magnetic field. The double closed-loop control of chain and electromagnetic torque can obtain real-time and fast control effect. However, the conventional direct torque control (DTC) system uses PI controller to ...

Examples

Embodiment Construction

[0047] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0048] The invention provides a direct torque control method, comprising the following steps:

[0049] (1) On the input side of the induction motor, detect the stator voltage and stator current, and perform a 3 / 2 transformation on them, and then calculate the amplitude and phase of the output voltage and estimate the stator flux linkage and torque. Specifically, it can be obtained by Calculated as follows:

[0050]

[0051]

[0052] Where: R s is the stator resistance; Ψ sα , Ψ sβ are respectively stator α-axis and β-axis flux linkage; i sα i sβ are the current components of the stator α-axis and β-axis respectively; P n is the number of motor pole pairs; L m is the mutual inductance of the stator; T e is the electromagnetic torque.

[0053] (2) Detect the motor speed and compare it with the given value, and the comparison resu...