CN-122001235-A - Driving method of three-phase conversion half-bridge

CN122001235ACN 122001235 ACN122001235 ACN 122001235ACN-122001235-A

Abstract

The application relates to a driving method of a three-phase conversion half-bridge. The method comprises the steps of driving a three-phase conversion half-bridge through a first conversion strategy, obtaining first detection voltages, second detection voltages and third detection voltages of three bridge arms in the three-phase conversion half-bridge, enabling the first detection voltages to be larger than the second detection voltages and enabling the second detection voltages to be larger than the third detection voltages, and driving the three-phase conversion half-bridge through the first driving strategy in a corresponding switching period when the first detection voltages, the second detection voltages and the third detection voltages meet preset conditions so that the three bridge arms of the three-phase conversion half-bridge can convert current normally. When the first detection voltage, the second detection voltage and the third detection voltage meet preset conditions, the three-phase conversion half-bridge is driven by a first driving strategy, so that the short circuit of the capacitance of the two bridge arms is avoided, and the three-phase conversion half-bridge is further enabled to stably output current.

Inventors

YANG BO
ZHAO YI
DENG JINYI
LI ZHI
YU HONGBIN
SHI KEYAN

Assignees

杭州禾迈电力电子股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260410

Claims (11)

1. The driving method of the three-phase conversion half-bridge is characterized in that the three-phase conversion half-bridge comprises three bridge arms, and an upper bridge arm of each bridge arm comprises two switching tubes connected in series, and the method comprises the following steps: Driving the three-phase conversion half-bridge with a first commutation strategy; Acquiring first detection voltages, second detection voltages and third detection voltages of three bridge arms in the three-phase conversion half-bridge, wherein the first detection voltages are larger than the second detection voltages, and the second detection voltages are larger than the third detection voltages; When the first detection voltage, the second detection voltage and the third detection voltage meet preset conditions, driving the three-phase conversion half-bridge in a corresponding switching period by a first driving strategy so as to enable three bridge arms of the three-phase conversion half-bridge to normally convert current; The first detection voltage, the second detection voltage and the third detection voltage meet preset conditions, wherein the difference between the first detection voltage and the second detection voltage is smaller than a preset threshold value, or the difference between the second detection voltage and the third detection voltage is smaller than the preset threshold value; the first driving strategy is determined according to a first current conversion strategy and bridge arms corresponding to two detection voltages meeting preset conditions.
2. The method of claim 1, wherein the lower leg of each leg of the three-phase conversion half-bridge comprises a capacitor, the method further comprising: The method comprises the steps of taking a bridge arm corresponding to a first detection voltage as a first phase bridge arm, taking a bridge arm corresponding to a second detection voltage as a second phase bridge arm, taking a bridge arm corresponding to a third detection voltage as a third phase bridge arm, wherein an upper bridge arm of the first phase bridge arm comprises a first switching tube and a second switching tube which are connected in series, an upper bridge arm of the second phase bridge arm comprises a third switching tube and a fourth switching tube which are connected in series, and an upper bridge arm of the third phase bridge arm comprises a fifth switching tube and a sixth switching tube which are connected in series.
3. The method of claim 2, wherein driving the three-phase conversion half-bridge with the first driving strategy in the corresponding switching cycle when the first, second and third detection voltages satisfy a preset condition, so as to normally convert three bridge legs of the three-phase conversion half-bridge comprises: When the difference between the second detection voltage and the third detection voltage is smaller than a preset threshold value, driving the three-phase conversion half-bridge with a first target driving strategy in a corresponding switching period so as to enable at least part of switching tubes corresponding to three bridge arms of the three-phase conversion half-bridge to be turned on at zero voltage, and/or When the difference value between the first detection voltage and the second detection voltage is smaller than a preset threshold value, driving the three-phase conversion half-bridge in a corresponding switching period by a second target driving strategy so as to enable at least part of switching tubes corresponding to three bridge arms of the three-phase conversion half-bridge to be turned on at zero voltage.
4. The method of claim 3, wherein the step of, The first target driving strategy includes that the third switching tube is conducted with the sixth switching tube Guan Jiaoti, and the fourth switching tube is conducted with the fifth switching tube alternately.
5. The method of claim 4, wherein driving the three-phase conversion half-bridge with a first target driving strategy in a corresponding switching cycle when the difference between the second detected voltage and the third detected voltage is less than a preset threshold value, such that at least a portion of switching tube zero voltages corresponding to three legs of the three-phase conversion half-bridge are turned on comprises: When the difference value between the second detection voltage and the third detection voltage is smaller than a preset threshold value, if the first commutation strategy is driven to be an LMS driving strategy, the first target driving strategy is the first LMS target driving strategy, and the three-phase conversion half-bridge is driven by the first LMS target driving strategy in a corresponding switching period so as to enable the second switching tube, the third switching tube, the fourth switching tube and the fifth switching tube to be switched on in zero voltage; When the difference between the second detection voltage and the third detection voltage is smaller than a preset threshold, if the first commutation strategy is driven as an LSM driving strategy, the first target driving strategy is the first LSM target driving strategy, the three-phase conversion half-bridge is driven by the first LSM target driving strategy in a corresponding switching period, so that the second switching tube, the fourth switching tube, the fifth switching tube and the sixth switching tube are turned on at zero voltage, short circuit can not occur in the third switching tube when the second actual voltage is smaller than the third actual voltage, and the third switching tube is turned on at zero voltage when the second actual voltage is larger than the third actual voltage.
6. A method as defined in claim 5, wherein the first LMS target driving policy comprises: the first switching tube is continuously conducted in the switching period; In the switching period, the second switching tube is turned off at the first moment, the sixth switching tube is turned off at the second moment, the third switching tube is turned on at the third moment, after the conduction period of the second phase bridge arm is continued, the third switching tube is turned off at the fourth moment, the sixth switching tube is turned on at the fifth moment, the fourth switching tube is turned off at the sixth moment, the fifth switching tube is turned on at the seventh moment, after the conduction period of the third phase bridge arm is continued, the fifth switching tube is turned off at the eighth moment, the second switching tube and the fourth switching tube are turned on at the ninth moment, and the switching period is finished after the conduction period of the first phase bridge arm is continued.
7. The method of claim 5, wherein the first LSM target driving policy comprises: the first switching tube is continuously conducted in the switching period; In the switching period, the second switching tube is turned off at the first moment, the fourth switching tube is turned off at the second moment, the fifth switching tube is turned on at the third moment, the sixth switching tube is turned off at the fourth moment after the conduction period of the third phase bridge arm is continued, the third switching tube is turned on at the fifth moment, the fifth switching tube is turned off at the sixth moment, the fourth switching tube is turned on at the seventh moment, the third switching tube is turned off at the eighth moment after the conduction period of the second phase bridge arm is continued, the second switching tube and the sixth switching tube are turned on at the ninth moment, and the switching period is finished after the conduction period of the first phase bridge arm is continued.
8. The method of claim 3, wherein the step of, The second target driving strategy includes that the first switching tube is conducted with the fourth switching Guan Jiaoti, and the second switching tube is alternately conducted with the third switching tube.
9. The method of claim 8, wherein driving the three-phase conversion half-bridge with a second target driving strategy in a corresponding switching cycle when the difference between the first detected voltage and the second detected voltage is less than a preset threshold value, such that at least a portion of switching tube zero voltages corresponding to three legs of the three-phase conversion half-bridge are turned on comprises: When the difference between the first detection voltage and the second detection voltage is smaller than a preset threshold, if the first commutation strategy is driven as an LMS driving strategy, the second target driving strategy is the second LMS target driving strategy, and the three-phase conversion half-bridge is driven by the second LMS target driving strategy in a corresponding switching period so as to enable the first switching tube, the second switching tube, the third switching tube and the fifth switching tube to be opened with zero voltage; When the difference between the first detection voltage and the second detection voltage is smaller than a preset threshold, if the first commutation strategy is driven as an LSM driving strategy, the second target driving strategy is the second LSM target driving strategy, the three-phase conversion half-bridge is driven by the second LSM target driving strategy in a corresponding switching period, so that the second switching tube, the third switching tube, the fourth switching tube and the fifth switching tube are turned on at zero voltage, short circuit can not occur in the first switching tube when the first actual voltage is smaller than the second actual voltage, and the first switching tube is turned on at zero voltage when the first actual voltage is larger than the second actual voltage.
10. A method as recited in claim 9, wherein the second LMS target driving policy comprises: The sixth switching tube is continuously conducted in the switching period; In the switching period, the fifth switching tube is turned off at the first moment, the third switching tube is turned off at the second moment, the second switching tube is turned on at the third moment, after the conduction period of the first-phase bridge arm is continued, the first switching tube is turned off at the fourth moment, the fourth switching tube is turned on at the fifth moment, the second switching tube is turned off at the sixth moment, the third switching tube is turned on at the seventh moment, after the conduction period of the second-phase bridge arm is continued, the fourth switching tube is turned off at the eighth moment, the fifth switching tube and the first switching tube are turned on at the ninth moment, and the switching period is ended after the conduction period of the third-phase bridge arm is continued.
11. The method of claim 9, wherein the second LSM target driving policy comprises: The sixth switching tube is continuously conducted in the switching period; In the switching period, the fifth switching tube is turned off at the first moment, the first switching tube is turned off at the second moment, the fourth switching tube is turned on at the third moment, after the conduction period of the second phase bridge arm is continued, the fourth switching tube is turned off at the fourth moment, the first switching tube is turned on at the fifth moment, the third switching tube is turned off at the sixth moment, the second switching tube is turned on at the seventh moment, after the conduction period of the first phase bridge arm is continued, the second switching tube is turned off at the eighth moment, the third switching tube and the fifth switching tube are turned on at the ninth moment, and the switching period is finished after the conduction period of the third phase bridge arm is continued.

Description

Driving method of three-phase conversion half-bridge Technical Field The application relates to the technical field of electronic circuits, in particular to a driving method of a three-phase conversion half-bridge. Background A single-stage three-phase resonant DC/AC converter is a power electronic device that integrates DC-AC conversion, electrical isolation, and resonant soft switching techniques into a single power stage. Compared with the traditional two-stage structure, the device has the advantages of low cost and high efficiency. The alternating current side of the single-stage three-phase resonance type DC/AC converter uses a half-bridge frequency conversion structure, the half-bridge frequency conversion structure is realized by two switching tubes, and three phases use three half-bridge frequency conversion structures, namely three-phase conversion half-bridges. The three-phase conversion half-bridge realizes the output of three-phase current by arranging three half-bridge frequency conversion structures and six switching tubes in total. In the prior art, when voltages of two bridge arms are similar, the measured voltages of the two bridge arms are misjudged due to noise, measurement errors and the like, and at the moment, the capacitors of the two bridge arms are short-circuited due to a traditional driving strategy, so that the output current of the three-phase conversion half-bridge is affected. Disclosure of Invention In view of the above, it is necessary to provide a driving method of a three-phase conversion half-bridge. The application provides a driving method of a three-phase conversion half-bridge, wherein the three-phase conversion half-bridge comprises three bridge arms, an upper bridge arm of each bridge arm comprises two switching tubes connected in series, the method comprises the steps of driving the three-phase conversion half-bridge through a first conversion strategy, obtaining first detection voltages, second detection voltages and third detection voltages of the three bridge arms in the three-phase conversion half-bridge, wherein the first detection voltages are larger than the second detection voltages, the second detection voltages are larger than the third detection voltages, when the first detection voltages, the second detection voltages and the third detection voltages meet preset conditions, driving the three-phase conversion half-bridge through a first driving strategy in a corresponding switching period to enable the three bridge arms of the three-phase conversion half-bridge to convert current normally, and the first detection voltages, the second detection voltages and the third detection voltages meet preset conditions and comprise that differences between the first detection voltages and the second detection voltages or differences between the second detection voltages and the third detection voltages are smaller than preset threshold values, or the differences between the second detection voltages and the third detection voltages are smaller than preset threshold values, and the first detection voltages and the first detection strategies meet the preset conditions and the corresponding conversion strategies. In one embodiment, the lower bridge arm of each bridge arm of the three-phase conversion half bridge comprises a capacitor, the method further comprises the steps of taking a bridge arm corresponding to the first detection voltage as a first phase bridge arm, taking a bridge arm corresponding to the second detection voltage as a second phase bridge arm, taking a bridge arm corresponding to the third detection voltage as a third phase bridge arm, the upper bridge arm of the first phase bridge arm comprises a first switching tube and a second switching tube which are connected in series, the upper bridge arm of the second phase bridge arm comprises a third switching tube and a fourth switching tube which are connected in series, and the upper bridge arm of the third phase bridge arm comprises a fifth switching tube and a sixth switching tube which are connected in series. In one embodiment, when the first detection voltage, the second detection voltage and the third detection voltage meet preset conditions, driving the three-phase conversion half-bridge with a first driving strategy in a corresponding switching period to enable three bridge arms of the three-phase conversion half-bridge to convert current normally comprises driving the three-phase conversion half-bridge with a first target driving strategy in a corresponding switching period to enable at least part of switching tube zero voltages corresponding to the three bridge arms of the three-phase conversion half-bridge to be turned on when the difference between the first detection voltage and the second detection voltage is smaller than a preset threshold value, and/or driving the three-phase conversion half-bridge with a second target driving strategy in a corresponding switching period to enable three