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CN-121984369-A - Energy storage converter, control method and device thereof, computer equipment and storage medium

CN121984369ACN 121984369 ACN121984369 ACN 121984369ACN-121984369-A

Abstract

The invention provides an energy storage converter, a control method, a control device, computer equipment and a storage medium thereof, and relates to the technical field of energy storage converters, wherein the energy storage converter comprises a three-phase inverter, a zero line, a first relay and a control component; the three-phase inverter comprises a zero line end, the zero line is coupled to the zero line end through a first relay, when the energy storage converter is switched from a three-phase four-wire mode to a three-phase three-wire mode, the control component is used for controlling the first relay to be in an open-circuit state and is also used for switching a modulation strategy of the three-phase inverter from sinusoidal pulse width modulation to space vector pulse width modulation, and when the energy storage converter is switched from the three-phase three-wire mode to the three-phase four-wire mode, the control component is used for switching the modulation strategy of the three-phase inverter from space vector pulse width modulation to sinusoidal pulse width modulation and is also used for controlling the first relay to be in a conducting state, so that the utilization rate of direct current voltage of the energy storage converter in the three-phase three-wire mode is improved.

Inventors

  • Jin Dianheng

Assignees

  • 深圳市科陆电子科技股份有限公司

Dates

Publication Date
20260505
Application Date
20260211

Claims (12)

  1. 1. The energy storage converter is characterized by comprising a three-phase inverter, a zero line, a first relay and a control assembly; the three-phase inverter comprises a zero line end; The zero line is coupled to the zero line end through the first relay; The control assembly is coupled with the control end of the first relay and is also coupled with the three-phase inverter; the energy storage converter comprises a three-phase four-wire mode and a three-phase three-wire mode; When the energy storage converter is switched from the three-phase four-wire mode to the three-phase three-wire mode, the control component is used for controlling the first relay to be in an open-circuit state and is also used for switching a modulation strategy of the three-phase inverter from sinusoidal pulse width modulation to space vector pulse width modulation; when the energy storage converter is switched from the three-phase three-wire mode to the three-phase four-wire mode, the control component is used for switching the modulation strategy of the three-phase inverter from space vector pulse width modulation to sine pulse width modulation and is also used for controlling the first relay to be in a conducting state.
  2. 2. The energy storage converter of claim 1, wherein the three-phase inverter further comprises a first phase output, a second phase output, and a third phase output; The star connection elements are coupled to the first phase output, the second phase output, the third phase output, and the neutral line, respectively; The neutral point of the star connection element group is coupled to the zero line through the first relay, and the neutral point is used for detecting inversion voltage.
  3. 3. The energy storage converter of claim 2, wherein said set of star connection elements comprises a first capacitor, a second capacitor, and a third capacitor; One end of the first capacitor is coupled to the first phase output end, one end of the second capacitor is coupled to the second phase output end, and one end of the third capacitor is coupled to the third phase output end; the other end of the first capacitor, the other end of the second capacitor and the other end of the third capacitor are connected in a star shape to form the neutral point.
  4. 4. The energy storage converter of claim 1, wherein the control assembly comprises: a first controller coupled to the three-phase inverter for controlling a modulation strategy of the three-phase inverter, the first controller further coupled to the first relay for controlling a state of the first relay; And the second controller is coupled with the first relay and is used for controlling the state of the first relay.
  5. 5. A control method of an energy storage converter is characterized in that, an energy storage converter according to any one of claims 1 to 4, the control method of the energy storage converter comprising: Determining a mode switching state of the energy storage converter; When the energy storage converter is switched from the three-phase four-wire mode to the three-phase three-wire mode, the first relay is controlled to be in an open-circuit state, and the modulation strategy of the three-phase inverter is switched from sinusoidal pulse width modulation to space vector pulse width modulation; When the energy storage converter is switched from the three-phase three-wire mode to the three-phase four-wire mode, the modulation strategy of the three-phase inverter is switched from space vector pulse width modulation to sine pulse width modulation, and the first relay is controlled to be in a conducting state.
  6. 6. The method of claim 5, wherein determining a mode switching state of the energy storage converter comprises: detecting the running state of the energy storage converter; Determining that the energy storage converter is switched from the three-phase four-wire mode to the three-phase three-wire mode under the condition that the energy storage converter is switched from an off-grid state to a grid-connected state; and under the condition that the energy storage converter is switched from a grid-connected state to an off-grid state, determining that the energy storage converter is switched from the three-phase three-wire mode to the three-phase four-wire mode.
  7. 7. The method for controlling an energy storage converter according to claim 5 or 6, wherein, Monitoring the energy storage converter in the mode switching state process of the energy storage converter; And under the condition that the energy storage converter runs abnormally, stopping mode switching and maintaining the original mode.
  8. 8. The method for controlling an energy storage converter according to claim 5 or 6, wherein, And during the operation process of the energy storage converter, the neutral point of the star connection element group in the energy storage converter is utilized to sample the inversion voltage.
  9. 9. The control method according to claim 5 or 6, wherein when the energy storage converter is switched from the three-phase four-wire mode to the three-phase three-wire mode, the first relay is controlled to be in an open state, and the modulation strategy of the three-phase inverter is switched from sinusoidal pulse width modulation to space vector pulse width modulation, comprising: When the energy storage converter is switched from the three-phase four-wire mode to the three-phase three-wire mode, controlling the first relay to be in an open circuit state; Determining that the first relay is already in the open circuit state; And switching the modulation strategy of the three-phase inverter from sinusoidal pulse width modulation to space vector pulse width modulation.
  10. 10. A control device of an energy storage converter is characterized in that, an energy storage converter as claimed in any one of claims 1 to 4, the control device of the energy storage converter comprising: the determining module is used for determining the mode switching state of the energy storage converter; The first switching module is used for controlling the first relay to be in an open-circuit state when the energy storage converter is switched from the three-phase four-wire mode to the three-phase three-wire mode; The second switching module is used for switching the modulation strategy of the three-phase inverter from space vector pulse width modulation to sine pulse width modulation when the energy storage converter is switched from the three-phase three-wire mode to the three-phase four-wire mode, and controlling the first relay to be in a conducting state.
  11. 11. A computer device comprising a processor and a memory storing a program or instructions executable on the processor, which when executed by the processor, implement the steps of the method of controlling an energy storage converter according to any one of claims 5 to 9.
  12. 12. A storage medium having stored thereon a program or instructions which, when executed by a processor, implement the steps of the method of controlling an energy storage converter according to any one of claims 5 to 9.

Description

Energy storage converter, control method and device thereof, computer equipment and storage medium Technical Field The invention relates to the technical field of energy storage converters, in particular to an energy storage converter, a control method and device thereof, computer equipment and a storage medium. Background A three-phase energy storage converter (Power Conversion System, PCS) is a key device connecting a battery energy storage system to an ac grid/load, and the core task of the three-phase energy storage converter is to perform efficient and reliable energy conversion between dc and ac. In the related art, a part of the three-phase energy storage converters support three-phase four-wire system and three-phase three-wire system switching, and the switchable three-phase energy storage converters generally use sinusoidal pulse width modulation inverters, because in the three-phase four-wire system mode, there is a zero line, and the sinusoidal pulse width modulation can match the zero line. But the sinusoidal pulse width modulation has low utilization rate on the direct current voltage, and affects the voltage range of the three-phase energy storage converter. Disclosure of Invention The invention aims to at least solve or improve the technical problem that the voltage utilization rate of the energy storage converter capable of realizing three-phase four-wire system and three-phase three-wire system switching in the related technology is lower. To this end, an embodiment of a first aspect of the present invention proposes an energy storage converter. An embodiment of a second aspect of the present invention provides a control method of an energy storage converter. An embodiment of a third aspect of the present invention provides a control device for an energy storage converter. An embodiment of a fourth aspect of the present invention is directed to a computer device. A fifth aspect of the present invention provides a storage medium. In view of this, according to a first aspect of the present invention, the present invention proposes an energy storage converter comprising a three-phase inverter, a zero line, a first relay and a control assembly, the three-phase inverter comprising a zero line end, the zero line being coupled to the zero line end through the first relay, the control assembly being coupled to the control end of the first relay and also to the three-phase inverter, wherein the energy storage converter comprises a three-phase four-wire mode and a three-phase three-wire mode, the control assembly being configured to control the first relay to be in an open state when the energy storage converter is switched from the three-phase four-wire mode to the three-phase three-wire mode, and to switch a modulation strategy of the three-phase inverter from sinusoidal pulse width modulation to space vector pulse width modulation when the energy storage converter is switched from the three-phase three-wire mode to the three-phase four-wire mode, and to control the first relay to be in a conductive state. The invention provides an energy storage converter which comprises a three-phase inverter, a zero line, a first relay and a control component, wherein the three-phase inverter comprises a zero line end, the zero line is coupled to the zero line end of the three-phase inverter through the first relay, the control component is coupled with the control end of the first relay, and the control component is further coupled with the three-phase inverter. The energy storage converter comprises a three-phase four-wire mode and a three-phase three-wire mode, and the energy storage converter can switch the working modes between the three-phase four-wire mode and the three-phase three-wire mode. When the energy storage converter is switched from the three-phase four-wire mode to the three-phase three-wire mode, the control component is used for controlling the first relay to be in an open-circuit state, and then switching the modulation strategy of the three-phase inverter from sinusoidal pulse width modulation to space vector pulse width modulation. When the energy storage converter is switched from the three-phase three-wire mode to the three-phase four-wire mode, the control component is used for firstly switching the modulation strategy of the three-phase inverter from space vector pulse width modulation to sine pulse width modulation and then controlling the first relay to be in a conducting state. The zero sequence component contained in the space vector pulse width modulated wave can generate uncontrollable zero sequence current on the zero line, and risks such as instability of a system and overheating of the zero line can be caused, so that the three-phase inverter can be switched to space vector pulse width modulation only when the first relay breaks the zero line, and the risks of instability of the energy storage inverter and overheating of the zero line are reduced. And the space vector pulse w