Three-phase converter and its control method and device

Abstract

The invention discloses a three-phase converter and its control method and device. The method includes the following steps: obtaining the phase angle of the dq-axis current and the voltage vector; setting the current according to the dq-axis, the dq-axis current and the previous cycle The dq-axis limiting voltage of the current cycle obtains the dq-axis voltage of the current cycle; the dq-axis dead zone compensation voltage of the current cycle is obtained according to the phase angle of the voltage vector and the given current of the dq axis, and the dq axis voltage of the current cycle and the dq axis dead zone The compensation voltage is accumulated to obtain the expected voltage of the dq axis, and the expected voltage of the dq axis is subjected to voltage clipping processing to obtain the actual output voltage of the dq axis, so as to control the three-phase converter, and at the same time according to the actual output voltage of the dq axis in the current cycle and the dq-axis dead zone compensation voltage of the current cycle to obtain the dq-axis clipping voltage of the current cycle. The method does not need filtering processing, has fast response speed, reduces the amount of calculation, and can accelerate the desaturation speed of the current loop regulator after saturation.

Description

technical field [0001] The invention relates to the technical field of dead zone compensation, in particular to a control method for a three-phase converter, a control device for a three-phase converter and a three-phase converter. Background technique [0002] In the converter, due to the delay in the turn-on and turn-off of the power device, one of the upper and lower switch tubes of the same bridge arm has not been completely turned off, and the other has been turned on, resulting in a straight-through of the bridge arm, and the switch tube damaged, such as figure 1 shown. Therefore, the dead time T must be inserted into the driving signals of the upper and lower switching tubes of the same bridge arm. d ,Such as figure 2 As shown, S1 and S3 are ideal output signals, and S1' and S3' are actual output signals, which can effectively prevent the upper and lower switch tubes of the same bridge arm from being turned on at the same time. However, the addition of the dead t...

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Problems solved by technology

[0009] 1) The feedback current is filtered and then restored. Due to the presence of the filter, the response will lag, and response errors will occur when there is a large dynamic;

[0010] 2) Due to the existence of the dead zone effect, the voltage output capability of the converter decreases, and the above two methods perform dead zone compensation in the three-phase static coordinate system, which may cause the output voltage setting of the current loop regulator to exceed the converter current The actual output capability of the regulator, thereby reducing the desaturation speed of the current loop regulator in the case of modulation saturation;

[0011] 3) Both of the above two methods require coordinate inverse transformation, which requires a large amount of calculation, especially the former, which also requires coordinate forward transformation and filter calculation

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