Voltage space vector control device and control method for soft start

A voltage space vector, control device technology, applied in vector control systems, motor generator control, control of electromechanical transmission devices, etc., can solve problems such as low starting torque, large starting current, and sudden current changes.

CN103633910AActive Publication Date: 2014-03-12SHAANXI UNIV OF SCI & TECH +1
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2014-03-12

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Abstract

The invention relates to a voltage space vector control device and a voltage space vector control method for soft start. At present, a soft start technology has the problems of high starting current and low starting torque, and frequency converter soft start has the shortcoming of difficulty in the implementation of power frequency switching. A three-phase alternating current power supply is used for supplying power, six electric GTOs (gate-turn-off thyristors) can be reversely connected in parallel, an IGBT (insulated gate bipolar transistor) is adopted for a continuous current circuit, a voltage space vector control circuit is formed under the control of a microcontroller, and a current transformer is used for transmitting a three-phase current signal to the microcontroller for current limiting start and current monitoring. The phases A, B and C of the power supply of a three-phase alternating current asynchronous motor are subjected to alternating current voltage regulation and frequency modulation control under the control of the microcontroller, a voltage space vector control strategy is used for realizing hexagonal flux linkage track control over the alternating current motor, the voltage / frequency ratio is relatively stable, and the stability of main magnetic flux of the motor is ensured.
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Description

technical field

[0001] The patent of the present invention relates to a voltage space vector control device and a control method for soft starting. Background technique

[0002] At present, ordinary soft starters mainly use three-phase thyristors for step-down starting. It uses two thyristors or bidirectional thyristors connected in series and anti-parallel in each phase in the circuit structure, and realizes step-down starting by changing the conduction time of each phase voltage. Ordinary three-phase thyristor step-down soft starter controls the triggering time of six power gates to turn off the thyristor GTO in sequence, and converts the three-phase power frequency AC waveform into image 3 In the middle shaded area, the mains frequency cannot be changed while changing the voltage. This method has two important disadvantages. First, the starting torque is small, and the starting torque of the three-phase AC asynchronous motor is proportional to the square of the starting...

Examples

Embodiment Construction

[0026] The present invention is powered by a three-phase AC power supply, and uses six power gates to turn off thyristors GTO1, 2, 3, 4, 5, and 6 to form a voltage space vector control circuit under the control of a microcontroller 7, wherein thyristors 1 and 4 Realize the control of phase A of the AC power supply, the thyristors 3 and 6 realize the control of the B phase of the AC power supply, and the thyristors 5 and 2 realize the control of the C phase of the AC power supply. Among them, thyristors 1, 3, and 5 control the positive half cycles of A, B, and C phases respectively, and thyristors 4, 6, and 2 control the negative half cycles of A, B, and C phases respectively. The current transformers 8, 9, 10 are used to transmit the three-phase current signals to the microcontroller 7 for current-limited starting and current monitoring. An insulated gate bipolar transistor IGBT is used to form a freewheeling circuit. Under the control of the microcontroller 7, the thyristors ...