CN-122026774-A - Three-phase current determining method, current detecting circuit, compressor and vehicle

Abstract

The application discloses a three-phase current determining method, a current detecting circuit, a compressor and a vehicle, and relates to the technical field of electronic power. The three-phase current determining method comprises the steps of obtaining the running speed of a three-phase motor, determining a first sampling current as a target sampling parameter when the running speed is in a first speed interval, wherein the first sampling current is a three-bridge-arm current sampling parameter of an inverter in a space vector pulse width modulation control period in a zero vector state, determining a second sampling current as a target sampling parameter when the running speed is in a second speed interval, wherein the lower limit value of a second speed area is larger than the upper limit value of the first speed interval, the second sampling current is a three-bridge-arm current sampling parameter of the inverter in a space vector pulse width modulation control period in a non-zero vector state, and determining the three-phase current of the three-phase motor according to the target sampling parameter. By adopting the three-phase current determining method, the three-phase current can be detected in real time.

Inventors

• ZHANG TING

Assignees

• 安徽威灵汽车部件有限公司
• 安庆威灵汽车部件有限公司
• 广东威灵汽车部件有限公司

Dates

Publication Date

20260512

Application Date

20241112

Claims (10)

1. 1. A method of three-phase current determination, the method comprising: Acquiring the running speed of a three-phase motor; under the condition that the running speed is in a first speed interval, determining a first sampling current as the target sampling parameter, wherein the first sampling current is a three-bridge arm current sampling parameter of an inverter in a space vector pulse width modulation control period zero vector state; Determining a second sampling current as the target sampling parameter when the running speed is in a second speed interval, wherein the lower limit value of the second speed area is larger than the upper limit value of the first speed interval, and the second sampling current is a three-bridge arm current sampling parameter of the inverter in a non-zero vector state of a space vector pulse width modulation control period; And determining the three-phase current of the three-phase motor according to the target sampling parameter.
2. 2. The three-phase current determination method according to claim 1, characterized in that the method further comprises: under the condition that the running speed is smaller than or equal to a preset speed threshold value, judging that the running speed is in a first speed interval; And under the condition that the running speed is greater than the preset speed threshold, judging that the running speed is in a second speed interval.
3. 3. The method of claim 1, wherein the target sampling parameter is the first sampling current, and wherein determining the three-phase current of the three-phase motor based on the target sampling parameter comprises: acquiring a first current of a first phase and a second current of a second phase according to the larger two bridge arm sampling currents in the first sampling currents; and reconstructing a third current of a third phase according to the first current and the second current.
4. 4. The method of three-phase current determination according to claim 1, wherein the target sampling parameter is the second sampling current, and wherein determining the three-phase current of the three-phase motor based on the target sampling parameter comprises: Acquiring sampling current corresponding to at least one sector according to the second sampling current, wherein each sector respectively comprises a first non-zero vector state and a second non-zero vector state; Reconstructing a first phase current and a second phase current according to the effective bridge arm sampling current sampled in the first non-zero vector state and the second non-zero vector state of the same sector; and reconstructing a third phase current according to the first phase current and the second phase current.
5. 5. The method for determining three-phase current according to claim 4, wherein reconstructing the first phase circuit and the second phase current from the effective bridge arm sampling currents sampled in the first non-zero vector state and the second non-zero vector state of the same sector comprises: determining a first phase current corresponding to the other bridge arm according to the two effective bridge arm sampling currents sampled in the first non-zero vector state; and determining a second phase current corresponding to the sampling bridge arm according to the effective bridge arm sampling current sampled in the second non-zero vector state.
6. 6. The three-phase current determination method according to any one of claims 1 to 5, characterized in that the method further comprises: Acquiring switching state information of each power device in the inverter; and determining the vector state of the inverter according to the switching state information of each power device.
7. 7. A current detection circuit, the current detection circuit comprising: the sampling circuit is used for detecting three-bridge arm current sampling parameters of each vector state of the inverter in the space vector pulse width modulation control period; processing circuitry, coupled to the sampling circuitry, for performing the steps of the three-phase current determination method of any one of claims 1 to 6.
8. 8. The current detection circuit of claim 7, wherein the sampling circuit comprises three sampling units, the three sampling units being respectively connected in series with three lower legs of the inverter three-phase inverter bridge circuit.
9. 9. A compressor comprising an inverter, a three-phase motor, a memory, a processor and a computer program stored on the memory and executable on the processor, the computer program being configured to implement the steps of the three-phase current determination method according to any one of claims 1 to 6.
10. 10. A vehicle comprising a compressor as claimed in claim 9.

Description

Three-phase current determining method, current detecting circuit, compressor and vehicle Technical Field The application relates to the technical field of electronic power, in particular to a three-phase current determining method, a current detecting circuit, a compressor and a vehicle. Background In the control process of a three-phase motor, current sampling is a key to realizing accurate control. By monitoring the three-phase current of the three-phase motor in real time, the abnormal problem of the three-phase motor can be detected in time, the current closed-loop control can be realized based on the feedback of the detected current, and the dynamic response and the steady-state performance of the three-phase motor are improved. However, the sampling method in the prior art usually adopts a fixed sampling mode, and is often only capable of sampling fixed parameters when the three-phase motor operates in a specific state, so that three-phase current of the three-phase motor is difficult to acquire in real time. The foregoing is provided merely for the purpose of facilitating understanding of the technical scheme of the present application and is not intended to represent an admission that the foregoing is related art. Disclosure of Invention The application mainly aims to provide a three-phase current determining method, a current detecting circuit, a compressor and a vehicle, which can acquire three-phase current of a three-phase motor in real time. To achieve the above object, in a first aspect, the present application proposes a three-phase current determination method, the method comprising: Acquiring the running speed of a three-phase motor; under the condition that the running speed is in a first speed interval, determining a first sampling current as the target sampling parameter, wherein the first sampling current is a three-bridge arm current sampling parameter of an inverter in a space vector pulse width modulation control period zero vector state; Determining a second sampling current as the target sampling parameter when the running speed is in a second speed interval, wherein the lower limit value of the second speed area is larger than the upper limit value of the first speed interval, and the second sampling current is a three-bridge arm current sampling parameter of the inverter in a non-zero vector state of a space vector pulse width modulation control period; And determining the three-phase current of the three-phase motor according to the target sampling parameter. In one embodiment, the determining the target sampling parameter according to the target speed interval in which the running speed is located further includes: under the condition that the running speed is smaller than or equal to a preset speed threshold value, judging that the running speed is in a first speed interval; And under the condition that the running speed is greater than the preset speed threshold, judging that the running speed is in a second speed interval. In one embodiment, the target sampling parameter is the first sampling current, and the determining the three-phase current of the three-phase motor according to the target sampling parameter includes: acquiring a first current of a first phase and a second current of a second phase according to the larger two bridge arm sampling currents in the first sampling currents; and reconstructing a third current of a third phase according to the first current and the second current. In one embodiment, the target sampling parameter is the second sampling current, and the determining the three-phase current of the three-phase motor according to the target sampling parameter includes: Acquiring sampling current corresponding to at least one sector according to the second sampling current, wherein each sector respectively comprises a first non-zero vector state and a second non-zero vector state; Reconstructing a first phase current and a second phase current according to the effective bridge arm sampling current sampled in the first non-zero vector state and the second non-zero vector state of the same sector; and reconstructing a third phase current according to the first phase current and the second phase current. In one embodiment, the reconstructing the first phase circuit and the second phase current from the effective bridge arm sampling currents sampled in the first non-zero vector state and the second non-zero vector state of the same sector includes: determining a first phase current corresponding to the other bridge arm according to the two effective bridge arm sampling currents sampled in the first non-zero vector state; and determining a second phase current corresponding to the sampling bridge arm according to the effective bridge arm sampling current sampled in the second non-zero vector state. In one embodiment, the method further comprises: Acquiring switching state information of each power device in the inverter; and determining the vector state of