阅读说明：本技术 一种三相交流电机相序的校验方法及系统 (three-phase alternating current motor phase sequence checking method and system ) 是由 张磊 李军营 王冬 高乐 徐亚美 于 2019-09-25 设计创作，主要内容包括：本发明提供一种三相交流电机相序的校验方法及系统,实时采集三相交流电机的电机控制器对应的三相电流；给定交轴电压和正向夹角,调节直轴电压；通过电机控制器的三相电流判断电机控制器与三相交流电机的相序是否一致；若不一致,在三相交流电机处于电流闭环模式下时,交换B相调制波和C相调制波,交换B相电流和C相电流。本方案中,给定交轴电压和正向夹角,通过电机控制器的三相电流的大小和方向,确定三相交流电机和电机控制器的相序方向是否一致。若不一致,交换B相调制波和C相调制波,以及交换B相电流和C相电流,完成三相交流电机的相序校正,使得三相交流电机和电机控制器的相序方向一致,以保证三相交流电机稳定运行。(The invention provides a method and a system for checking the phase sequence of a three-phase alternating current motor, which are used for acquiring the three-phase current corresponding to a motor controller of the three-phase alternating current motor in real time; giving quadrature axis voltage and a forward included angle, and adjusting direct axis voltage; judging whether the phase sequence of the motor controller is consistent with that of the three-phase alternating current motor or not through the three-phase current of the motor controller; if the phase difference is not consistent, when the three-phase alternating current motor is in the current closed-loop mode, exchanging the B-phase modulation wave and the C-phase modulation wave, and exchanging the B-phase current and the C-phase current. In the scheme, the quadrature axis voltage and the forward included angle are given, and whether the phase sequence directions of the three-phase alternating current motor and the motor controller are consistent or not is determined through the size and the direction of the three-phase current of the motor controller. And if the phase sequence of the three-phase alternating current motor is inconsistent with the phase sequence of the motor controller, exchanging the B-phase modulation wave and the C-phase modulation wave, exchanging the B-phase current and the C-phase current, and finishing the phase sequence correction of the three-phase alternating current motor so that the directions of the phase sequences of the three-phase alternating current motor and the motor controller are consistent to ensure the stable operation of the three-phase alternating current motor.)

1. A method for checking the phase sequence of a three-phase alternating current motor is characterized by comprising the following steps:

Acquiring phase A current, phase B current and phase C current corresponding to a motor controller of a three-phase alternating current motor in real time;

When the three-phase alternating current motor is in an open-loop voltage mode, setting a quadrature axis voltage and a forward included angle as 0 and a first included angle threshold value, and increasing a direct axis voltage until the U-phase current of the three-phase alternating current motor is equal to a current threshold value, wherein the forward included angle is the included angle between the direct axis forward direction and the U-phase forward direction;

Clearing the direct axis voltage;

When the three-phase alternating current motor is in an open-loop voltage mode, setting the quadrature axis voltage and the forward included angle as 0 and a second included angle threshold value, and increasing the direct axis voltage on the premise that the phase current A, the phase current B and the phase current C meet preset conditions;

If the acquired A-phase current and the B-phase current are smaller than 0 and the C-phase current is larger than 0, determining that the phase sequence directions of the three-phase alternating current motor and the motor controller are inconsistent;

And if the phase sequence directions of the three-phase alternating current motor and the motor controller are not consistent, exchanging a B-phase modulation wave and a C-phase modulation wave and exchanging the B-phase current and the C-phase current when the three-phase alternating current motor is in a current closed-loop mode.

2. The method according to claim 1, wherein exchanging the B-phase modulation wave and the C-phase modulation wave, and exchanging the B-phase current and the C-phase current when the three-phase alternating current motor is in a current closed-loop mode comprises:

When the three-phase alternating current motor is subjected to closed-loop control, controlling a C-phase Insulated Gate Bipolar Transistor (IGBT) based on a B-phase modulation wave, and controlling the B-phase IGBT based on the C-phase modulation wave;

And taking the phase-B current as the actual phase-C current in the closed-loop control process, and taking the phase-C current as the actual phase-B current in the closed-loop control process.

3. the method of claim 1, wherein setting the quadrature axis voltage and the forward angle to 0 and a first angle threshold, and increasing the direct axis voltage until the phase current of the three-phase ac motor equals to a current threshold comprises:

and setting the included angle between the quadrature axis voltage and the positive direction to be 0, and increasing the direct axis voltage until the U-phase current of the three-phase alternating current motor is equal to a current threshold, wherein the A-phase current is a positive value, and the B-phase current and the C-phase current are negative values.

4. the method according to claim 1, wherein the setting of the quadrature axis voltage and the forward angle as 0 and a second angle threshold, respectively, and the increasing of the direct axis voltage on the premise that the a-phase current, the B-phase current, and the C-phase current satisfy preset conditions comprises:

Setting the quadrature axis voltage and the forward included angle to be 0 and 2 pi/3 respectively;

and increasing the direct-axis voltage on the premise that the A-phase current, the B-phase current and the C-phase current are all smaller than the current threshold.

5. the method of claim 1, further comprising:

and if the phase A current and the phase C current collected after the two actions are executed are both smaller than 0, and the phase B current is larger than 0, determining that the phase sequence directions of the three-phase alternating current motor and the motor controller are consistent.

6. the method of claim 1, wherein the setting of the quadrature axis voltage and the forward angle to 0 and a first angle threshold and the increasing of the direct axis voltage until the phase current of the three-phase ac motor is equal to the current threshold further comprises:

And if the phase current A is a negative value and/or any current in the phase current B and the phase current C is a positive value, stopping checking the phase sequence of the three-phase alternating current motor.

7. a system for checking the phase sequence of a three-phase ac power machine, the system comprising:

The acquisition unit is used for acquiring the phase A current, the phase B current and the phase C current corresponding to a motor controller of the three-phase alternating current motor in real time;

The first execution unit is used for setting a quadrature axis voltage and a forward included angle as 0 and a first included angle threshold value when the three-phase alternating current motor is in an open-loop voltage mode, increasing a direct axis voltage until the U-phase current of the three-phase alternating current motor is equal to a current threshold value, wherein the forward included angle is the included angle between the direct axis forward direction and the U-phase forward direction;

the zero clearing unit is used for clearing the direct-axis voltage;

the second execution unit is used for setting the quadrature axis voltage and the forward included angle as 0 and a second included angle threshold value when the three-phase alternating current motor is in an open-loop voltage mode, and increasing the direct axis voltage on the premise that the phase current A, the phase current B and the phase current C meet preset conditions;

The determining unit is used for determining that the phase sequence directions of the three-phase alternating current motor and the motor controller are inconsistent if the acquired A-phase current and the acquired B-phase current are smaller than 0 and the C-phase current is larger than 0;

And the exchange unit is used for exchanging the B-phase modulation wave and the C-phase modulation wave and exchanging the B-phase current and the C-phase current when the three-phase alternating current motor is in a current closed-loop mode if the phase sequence directions of the three-phase alternating current motor and the motor controller are not consistent.

8. The system of claim 7, wherein the switching unit comprises:

The modulation wave switching module is used for controlling the C-phase insulated gate bipolar transistor IGBT based on the B-phase modulation wave and controlling the B-phase IGBT based on the C-phase modulation wave when the three-phase alternating current motor is subjected to closed-loop control;

And the current exchange module is used for taking the phase B current as the actual phase C current in the closed-loop control process and taking the phase C current as the actual phase B current in the closed-loop control process.

9. The system of claim 7, wherein the first execution unit is specifically configured to: and setting the included angle between the quadrature axis voltage and the positive direction to be 0, and increasing the direct axis voltage until the U-phase current of the three-phase alternating current motor is equal to a current threshold, wherein the A-phase current is a positive value, and the B-phase current and the C-phase current are negative values.

10. The system of claim 7, wherein the second execution unit is specifically configured to: and respectively setting the quadrature axis voltage and the forward included angle as 0 and 2 pi/3, and increasing the direct axis voltage on the premise that the phase A current, the phase B current and the phase C current are all smaller than the current threshold.

Technical Field

The invention relates to the technical field of three-phase alternating current motors, in particular to a method and a system for checking a phase sequence of a three-phase alternating current motor.

background

with the development of science and technology, three-phase alternating current motors are widely applied to various fields. In the process of specifically applying the three-phase alternating current motor, the stable operation of the three-phase alternating current motor is ensured to be important.

A motor controller of the three-phase alternating current motor comprises a three-phase current sensor, and the phase sequence of the three-phase current sensor is respectively an A phase, a B phase and a C phase. When current closed-loop control is performed on the three-phase alternating current motor, in order to ensure stable operation of the three-phase alternating current motor, the phase A, the phase B and the phase C are respectively connected with the phase U, the phase V and the phase W of the three-phase alternating current motor. When the phase sequence of the three-phase current sensor is inconsistent with that of the three-phase alternating current motor, the three-phase alternating current motor can be caused to have faults, so that the three-phase alternating current motor does not rotate, shakes or rotates reversely.

Therefore, a method for checking the phase sequence of the three-phase ac motor is needed to ensure the stable operation of the three-phase ac motor.

Disclosure of Invention

in view of this, embodiments of the present invention provide a method and a system for checking a phase sequence of a three-phase ac motor, so as to ensure stable operation of the three-phase ac motor.

in order to achieve the above purpose, the embodiments of the present invention provide the following technical solutions:

the first aspect of the embodiments of the present invention discloses a method for checking a phase sequence of a three-phase ac motor, the method including:

acquiring phase A current, phase B current and phase C current corresponding to a motor controller of a three-phase alternating current motor in real time;

when the three-phase alternating current motor is in an open-loop voltage mode, setting a quadrature axis voltage and a forward included angle as 0 and a first included angle threshold value, and increasing a direct axis voltage until the U-phase current of the three-phase alternating current motor is equal to a current threshold value, wherein the forward included angle is the included angle between the direct axis forward direction and the U-phase forward direction;

Clearing the direct axis voltage;

when the three-phase alternating current motor is in an open-loop voltage mode, setting the quadrature axis voltage and the forward included angle as 0 and a second included angle threshold value, and increasing the direct axis voltage on the premise that the phase current A, the phase current B and the phase current C meet preset conditions;

If the acquired A-phase current and the B-phase current are smaller than 0 and the C-phase current is larger than 0, determining that the phase sequence directions of the three-phase alternating current motor and the motor controller are inconsistent;

and if the phase sequence directions of the three-phase alternating current motor and the motor controller are not consistent, exchanging a B-phase modulation wave and a C-phase modulation wave and exchanging the B-phase current and the C-phase current when the three-phase alternating current motor is in a current closed-loop mode.

Preferably, the exchanging the B-phase modulation wave and the C-phase modulation wave and the B-phase current and the C-phase current when the three-phase ac motor is in the current closed-loop mode includes:

When the three-phase alternating current motor is subjected to closed-loop control, controlling a C-phase Insulated Gate Bipolar Transistor (IGBT) based on a B-phase modulation wave, and controlling the B-phase IGBT based on the C-phase modulation wave;

And taking the phase-B current as the actual phase-C current in the closed-loop control process, and taking the phase-C current as the actual phase-B current in the closed-loop control process.

preferably, the setting of the quadrature axis voltage and the forward included angle as 0 and a first included angle threshold value, and increasing the direct axis voltage until the U-phase current of the three-phase ac motor is equal to the current threshold value includes:

and setting the included angle between the quadrature axis voltage and the positive direction to be 0, and increasing the direct axis voltage until the U-phase current of the three-phase alternating current motor is equal to a current threshold, wherein the A-phase current is a positive value, and the B-phase current and the C-phase current are negative values.

Preferably, the setting the quadrature axis voltage and the forward included angle as 0 and a second included angle threshold respectively, and increasing the direct axis voltage on the premise that the phase a current, the phase B current, and the phase C current satisfy a preset condition includes:

Setting the quadrature axis voltage and the forward included angle to be 0 and 2 pi/3 respectively;

and increasing the direct-axis voltage on the premise that the A-phase current, the B-phase current and the C-phase current are all smaller than the current threshold.

Preferably, the method further comprises:

And if the phase A current and the phase C current collected after the two actions are executed are both smaller than 0, and the phase B current is larger than 0, determining that the phase sequence directions of the three-phase alternating current motor and the motor controller are consistent.

preferably, the setting of the quadrature axis voltage and the forward included angle as 0 and a first included angle threshold value, and increasing the direct axis voltage until the phase current of the three-phase ac motor is equal to the current threshold value, further includes:

And if the phase current A is a negative value and/or any current in the phase current B and the phase current C is a positive value, stopping checking the phase sequence of the three-phase alternating current motor.

the second aspect of the embodiments of the present invention discloses a system for checking a phase sequence of a three-phase ac power supply, the system including:

The acquisition unit is used for acquiring the phase A current, the phase B current and the phase C current corresponding to a motor controller of the three-phase alternating current motor in real time;

the first execution unit is used for setting a quadrature axis voltage and a forward included angle as 0 and a first included angle threshold value when the three-phase alternating current motor is in an open-loop voltage mode, increasing a direct axis voltage until the U-phase current of the three-phase alternating current motor is equal to a current threshold value, wherein the forward included angle is the included angle between the direct axis forward direction and the U-phase forward direction;

the zero clearing unit is used for clearing the direct-axis voltage;

The second execution unit is used for setting the quadrature axis voltage and the forward included angle as 0 and a second included angle threshold value when the three-phase alternating current motor is in an open-loop voltage mode, and increasing the direct axis voltage on the premise that the phase current A, the phase current B and the phase current C meet preset conditions;

The determining unit is used for determining that the phase sequence directions of the three-phase alternating current motor and the motor controller are inconsistent if the acquired A-phase current and the acquired B-phase current are smaller than 0 and the C-phase current is larger than 0;

and the exchange unit is used for exchanging the B-phase modulation wave and the C-phase modulation wave and exchanging the B-phase current and the C-phase current when the three-phase alternating current motor is in a current closed-loop mode if the phase sequence directions of the three-phase alternating current motor and the motor controller are not consistent.

preferably, the switching unit includes:

The modulation wave switching module is used for controlling the C-phase insulated gate bipolar transistor IGBT based on the B-phase modulation wave and controlling the B-phase IGBT based on the C-phase modulation wave when the three-phase alternating current motor is subjected to closed-loop control;

and the current exchange module is used for taking the phase B current as the actual phase C current in the closed-loop control process and taking the phase C current as the actual phase B current in the closed-loop control process.

preferably, the first execution unit is specifically configured to: and setting the included angle between the quadrature axis voltage and the positive direction to be 0, and increasing the direct axis voltage until the U-phase current of the three-phase alternating current motor is equal to a current threshold, wherein the A-phase current is a positive value, and the B-phase current and the C-phase current are negative values.

preferably, the second execution unit is specifically configured to: and respectively setting the quadrature axis voltage and the forward included angle as 0 and 2 pi/3, and increasing the direct axis voltage on the premise that the phase A current, the phase B current and the phase C current are all smaller than the current threshold.

based on the method and the system for checking the phase sequence of the three-phase alternating current motor provided by the embodiment of the invention, the method comprises the following steps: acquiring phase A current, phase B current and phase C current corresponding to a motor controller of a three-phase alternating current motor in real time; setting a quadrature axis voltage and a forward included angle as 0 and a first included angle threshold value, increasing a direct axis voltage until the U-phase current of the three-phase alternating current motor is equal to a current threshold value, and resetting the direct axis voltage; setting a quadrature axis voltage and a forward included angle as 0 and a second included angle threshold value, and increasing a direct axis voltage on the premise that phase A current, phase B current and phase C current meet preset conditions; the phase sequence directions of the three-phase alternating current motor and the motor controller are determined to be inconsistent when the phase A current and the phase B current are smaller than 0 and the phase C current is larger than 0; when the three-phase alternating-current motor is in the current closed-loop mode, the B-phase modulation wave and the C-phase modulation wave are exchanged, and the B-phase current and the C-phase current are exchanged. In the scheme, the quadrature axis voltage and the forward included angle are given, and whether the phase sequence directions of the three-phase alternating current motor and the motor controller are inconsistent or not is determined according to the size and the direction of the three-phase current of the motor controller. And if the phase difference is not consistent, exchanging the B-phase modulation wave and the C-phase modulation wave, and exchanging the B-phase current and the C-phase current to finish the phase sequence correction of the three-phase alternating current motor and ensure the stable operation of the three-phase alternating current motor.

drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

fig. 1 is a flowchart of a method for checking a phase sequence of a three-phase ac motor according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of phase sequence detection provided by an embodiment of the present invention;

Fig. 3 is a schematic diagram of a current closed-loop control before phase sequence correction according to an embodiment of the present invention;

Fig. 4 is a schematic diagram of a current closed-loop control after phase sequence correction according to an embodiment of the present invention;

fig. 5 is a block diagram of a system for checking a phase sequence of a three-phase ac power supply according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

in this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

As known from the background art, in order to ensure stable operation of a three-phase ac motor, the a phase, the B phase, and the C phase are connected to the U phase, the V phase, and the W phase of the three-phase ac motor, respectively. When the phase sequence of the three-phase current sensor is inconsistent with that of the three-phase alternating current motor, the three-phase alternating current motor can be caused to have faults, so that the three-phase alternating current motor does not rotate, shakes or rotates reversely.

therefore, the embodiment of the invention provides a method and a system for checking the phase sequence of a three-phase alternating current motor. And if the phase difference is not consistent, exchanging the B-phase modulation wave and the C-phase modulation wave, exchanging the B-phase current and the C-phase current, and finishing the phase sequence correction of the three-phase alternating current motor so as to ensure the stable operation of the three-phase alternating current motor.

The three-phase ac motor according to the embodiments of the present invention includes, but is not limited to, a permanent magnet synchronous motor, and as can be seen from the foregoing, there is only one case where the three-phase ac motor is connected to the motor controller in the correct phase sequence, that is, the phases a, B, and C of the motor controller are connected to the phases U, V, and W of the three-phase ac motor, respectively. The following wrong connection conditions exist when the phase sequence directions of the three-phase alternating current motor and the motor controller are inconsistent:

And in the case of wrong connection, the phase A, the phase B and the phase C are respectively connected with the phase U, the phase W and the phase V.

And in the case of wrong connection, the second phase, the A phase, the B phase and the C phase are respectively connected with the V phase, the U phase and the W phase.

and in the case of wrong connection, the third phase, the A phase, the B phase and the C phase are respectively connected with the W phase, the V phase and the U phase.

For the three wrong connection conditions, the phase sequence correction is performed by the method for checking the phase sequence of the three-phase alternating current motor, so that the directions of the phase sequences of the three-phase alternating current motor and the motor controller are consistent, and the stable operation of the three-phase alternating current motor is ensured.

Referring to fig. 1, a flowchart of a method for checking a phase sequence of a three-phase ac motor according to an embodiment of the present invention is shown, where the method includes the following steps:

Step S101: the method comprises the steps of collecting phase A current, phase B current and phase C current corresponding to a motor controller of the three-phase alternating current motor in real time.

In the process of implementing step S101, the current acquisition device samples the phase a current, the phase B current, and the phase C current corresponding to the motor controller in real time. The current collection device includes, but is not limited to, a current sensor, and the type of the current collection device is not particularly limited.

step S102: and when the three-phase alternating current motor is in an open-loop voltage mode, setting a quadrature axis voltage and a forward included angle as 0 and a first included angle threshold value, and increasing a direct axis voltage until the U-phase current of the three-phase alternating current motor is equal to a current threshold value.

It should be noted that, the three-phase ac motor is in an open-loop voltage mode or a current closed-loop mode, and can be switched by a technician according to actual requirements.

In the process of implementing step S102 specifically, when the three-phase ac motor is in the open-loop voltage mode, the quadrature axis voltage is set to 0, and the forward included angle is set to 0 (a manner of the first included angle threshold). And gradually increasing the direct-axis voltage until the U-phase current iu of the three-phase alternating current motor is equal to a current threshold value. Wherein, in the process of gradually increasing the direct-axis voltage, the A-phase current is a positive value and gradually increases. When the U-phase current is equal to the current threshold, the B-phase current and the C-phase current are negative values.

It should be noted that the forward included angle is an included angle between a straight-axis forward direction and a U-phase forward direction.

Preferably, in the process of executing step S102, if the phase a current is a negative value and/or any one of the phase B current and the phase C current is a positive value, the checking of the phase sequence of the three-phase ac motor is stopped. Notifying a technician in a manner that a prompt is sent to the technician that hardware of the motor controller needs to be tested.

Step S103: and clearing the direct-axis voltage.

in the process of implementing step S103, after the direct-axis voltage is gradually increased until iu is equal to the current threshold in step S102, the direct-axis voltage is at a certain voltage value. In order to execute the following step S104, the direct-axis voltage needs to be cleared before executing the step S104.

step S104: and when the three-phase alternating current motor is in an open-loop voltage mode, setting the quadrature axis voltage and the forward included angle as 0 and a second included angle threshold value, and increasing the direct axis voltage on the premise that the phase A current, the phase B current and the phase C current meet preset conditions.

in the process of implementing step S104 specifically, when the three-phase ac motor is in the open-loop voltage mode, the quadrature axis voltage is set to 0, and the forward included angle is set to 2 pi/3 (a manner of the second included angle threshold). And on the premise that the phase A current, the phase B current and the phase C current are all smaller than the current threshold, gradually increasing the direct-axis voltage.

To better explain the contents of the above steps S102 to S104, the phase sequence detection schematic diagram shown in fig. 2 is used for illustration, and it should be noted that the contents shown in fig. 2 are only used for illustration.

in fig. 2, Ud is a direct-axis voltage, Uq is a quadrature-axis voltage, θ is a forward angle, ta, tb, and tc are an a-phase modulation wave, a B-phase modulation wave, and a C-phase modulation wave, respectively, and ia, ib, and ic are an a-phase current, a B-phase current, and a C-phase current, respectively.

And when the three-phase motor is in an open-loop voltage mode, setting both Uq and theta to be 0, gradually increasing Ud until the U-phase current is equal to a current threshold value, and clearing the Ud.

and when the three-phase motor is in an open-loop voltage mode, setting Uq to be 0, setting theta to be 2 pi/3, and gradually increasing Ud on the premise that ia, ib and ic are all smaller than the current threshold.

Step S105: and if the phase current A and the phase current B are smaller than 0 and the phase current C is larger than 0, determining that the phase sequence directions of the three-phase alternating current motor and the motor controller are inconsistent.

In the process of specifically implementing step S105, after the above steps S102 to S104 are performed, if the acquired a-phase current and B-phase current are less than 0, and the C-phase current is greater than 0, it is determined that the phase sequence directions of the three-phase ac motor and the motor controller are not consistent. That is, in conjunction with the content in fig. 2, if ic >0, ia <0, and ib <0, it is determined that the phase sequence directions of the three-phase ac motor and the motor controller are not consistent.

Preferably, after the steps S102 to S104 are executed, if the acquired a-phase current and C-phase current are both less than 0 and the acquired B-phase current is greater than 0, it is determined that the phase sequence directions of the three-phase ac motor and the motor controller are the same. That is, with reference to the content in fig. 2, if ib >0, ia <0, and ic <0, it is determined that the directions of the phase sequences of the three-phase ac motor and the motor controller are the same, and at this time, stable operation of the three-phase ac motor can be ensured without adjusting the phase sequence of the three-phase ac motor.

Step S106: and if the phase sequence directions of the three-phase alternating current motor and the motor controller are not consistent, exchanging a B-phase modulation wave and a C-phase modulation wave and exchanging the B-phase current and the C-phase current when the three-phase alternating current motor is in a current closed-loop mode.

in addition, the upper bridge and the lower bridge in each phase of the motor controller are respectively provided with an Insulated Gate Bipolar Transistor (IGBT). When closed-loop control is performed, Pulse Width Modulation (PWM) control is adopted, that is, three-phase PWM modulation waves are respectively output for three phases of the motor controller. PWM 1 indicates the upper bridge arm is conducted, and PWM 0 indicates the lower bridge arm is conducted.

in the process of implementing step S106 specifically, when the three-phase ac motor is subjected to closed-loop control, the C-phase IGBT is controlled based on the B-phase modulation wave, and the B-phase IGBT is controlled based on the C-phase modulation wave. And taking the phase-B current as the actual phase-C current in the closed-loop control process, and taking the phase-C current as the actual phase-B current in the closed-loop control process.

In the process of performing the closed-loop control calculation, the C-phase IGBT operation is controlled by the B-phase modulation wave, and the B-phase IGBT operation is controlled by the C-phase modulation wave. Meanwhile, when closed-loop control operation is carried out, the acquired B-phase current is used as the actual C-phase current in the closed-loop control operation, and the acquired C-phase current is used as the actual B-phase current in the closed-loop control operation. And finishing the phase sequence correction of the three-phase alternating current motor by exchanging the B-phase modulation wave and the C-phase modulation wave and exchanging the B-phase current and the C-phase current.

To better explain the above-mentioned process of correcting the phase sequence of the three-phase ac motor, the process is illustrated by the contents shown in fig. 3 and 4, and it should be noted that fig. 3 and 4 are only for illustration.

Referring to fig. 3, a schematic diagram of a current closed-loop control before phase sequence correction according to an embodiment of the present invention is shown, where the directions of the phase sequences of the three-phase ac motor and the motor controller are not the same, and the phase sequence of the three-phase ac motor needs to be corrected.

By the execution principle shown in the above step S106, the B-phase modulation wave and the C-phase modulation wave are exchanged, and the B-phase current and the C-phase current are exchanged. The schematic diagram of the current closed-loop control after the modulated wave and the current exchange is shown in fig. 4.

Referring to fig. 4, a schematic diagram of a current closed-loop control after phase sequence correction according to an embodiment of the present invention is shown. In fig. 4, the B-phase modulation wave and the C-phase modulation wave are transposed, and the B-phase current and the C-phase current are transposed.

In the embodiment of the invention, the quadrature axis voltage and the forward included angle are given, and whether the phase sequence directions of the three-phase alternating current motor and the motor controller are inconsistent is determined according to the magnitude and the direction of the three-phase current of the motor controller. And if the phase sequence of the three-phase alternating current motor is inconsistent with the phase sequence of the motor controller, exchanging the B-phase modulation wave and the C-phase modulation wave, exchanging the B-phase current and the C-phase current, and finishing the phase sequence correction of the three-phase alternating current motor so that the directions of the phase sequences of the three-phase alternating current motor and the motor controller are consistent to ensure the stable operation of the three-phase alternating current motor.

Corresponding to the method for checking the phase sequence of the three-phase ac motor provided in the embodiment of the present invention, referring to fig. 5, an embodiment of the present invention further provides a structural block diagram of a system for checking the phase sequence of the three-phase ac motor, where the system for checking the phase sequence of the three-phase ac motor includes: the device comprises an acquisition unit 501, a first execution unit 502, a zero clearing unit 503, a second execution unit 504, a determination unit 505 and a switching unit 506.

The acquisition unit 501 is configured to acquire phase a current, phase B current, and phase C current corresponding to a motor controller of a three-phase ac motor in real time.

The first execution unit 502 is configured to set a quadrature axis voltage and a forward included angle as 0 and a first included angle threshold when the three-phase ac motor is in an open-loop voltage mode, increase a direct axis voltage until a U-phase current of the three-phase ac motor is equal to a current threshold, and the forward included angle is a direct axis forward included angle and a U-phase forward included angle.

In a specific implementation, the first executing unit 502 is specifically configured to set both a quadrature axis voltage and a positive direction included angle to 0, and increase a direct axis voltage until a U-phase current of the three-phase ac motor is equal to a current threshold, where the a-phase current is a positive value, and the B-phase current and the C-phase current are negative values.

A zero clearing unit 503, configured to zero the direct-axis voltage.

A second executing unit 504, configured to set the quadrature axis voltage and the forward included angle as 0 and a second included angle threshold when the three-phase ac motor is in an open-loop voltage mode, and increase the direct axis voltage on the premise that the phase-a current, the phase-B current, and the phase-C current satisfy a preset condition.

In a specific implementation, the second execution unit 504 is specifically configured to: and respectively setting the quadrature axis voltage and the forward included angle as 0 and 2 pi/3, and increasing the direct axis voltage on the premise that the phase A current, the phase B current and the phase C current are all smaller than the current threshold.

A determining unit 505, configured to determine that the phase sequence directions of the three-phase ac motor and the motor controller are not consistent if the acquired a-phase current and the acquired B-phase current are less than 0 and the C-phase current is greater than 0.

preferably, the determining unit 505 is further configured to: and if the acquired A-phase current and the C-phase current are both smaller than 0 and the B-phase current is larger than 0, determining that the phase sequence directions of the three-phase alternating current motor and the motor controller are consistent.

an exchanging unit 506, configured to, if the phase sequence directions of the three-phase ac motor and the motor controller are not consistent, exchange the B-phase modulation wave and the C-phase modulation wave, and exchange the B-phase current and the C-phase current when the three-phase ac motor is in the current closed-loop mode.

In the embodiment of the invention, the quadrature axis voltage and the forward included angle are given, and whether the phase sequence directions of the three-phase alternating current motor and the motor controller are inconsistent is determined according to the magnitude and the direction of the three-phase current of the motor controller. And if the phase difference is not consistent, exchanging the B-phase modulation wave and the C-phase modulation wave, and exchanging the B-phase current and the C-phase current to finish the phase sequence correction of the three-phase alternating current motor and ensure the stable operation of the three-phase alternating current motor.

Preferably, in combination with the content shown in fig. 5, the verification system further includes:

and the stopping unit is used for setting the quadrature axis voltage and the positive included angle as 0 and a first included angle threshold value, increasing the direct axis voltage until the phase current of the three-phase alternating current motor is equal to the current threshold value, and stopping checking the phase sequence of the three-phase alternating current motor if the phase current of the phase A is a negative value and/or any current of the phase B and the phase current of the phase C is a positive value.

preferably, in conjunction with the content shown in fig. 5, the switching unit 506 includes a modulated wave switching module and a current switching module. The execution principle of each module is as follows:

And the modulation wave exchange module is used for controlling the C-phase IGBT based on the B-phase modulation wave and controlling the B-phase IGBT based on the C-phase modulation wave when the three-phase alternating current motor is subjected to closed-loop control.

And the current exchange module is used for taking the phase B current as the actual phase C current in the closed-loop control process and taking the phase C current as the actual phase B current in the closed-loop control process.

In summary, the embodiments of the present invention provide a method and a system for checking a phase sequence of a three-phase ac motor, where the method includes: acquiring phase A current, phase B current and phase C current corresponding to a motor controller of a three-phase alternating current motor in real time; setting a quadrature axis voltage and a forward included angle as 0 and a first included angle threshold value, increasing a direct axis voltage until the U-phase current of the three-phase alternating current motor is equal to a current threshold value, and resetting the direct axis voltage; setting a quadrature axis voltage and a forward included angle as 0 and a second included angle threshold value, and increasing a direct axis voltage on the premise that phase A current, phase B current and phase C current meet preset conditions; the phase sequence directions of the three-phase alternating current motor and the motor controller are determined to be inconsistent when the phase A current and the phase B current are smaller than 0 and the phase C current is larger than 0; when the three-phase alternating-current motor is in the current closed-loop mode, the B-phase modulation wave and the C-phase modulation wave are exchanged, and the B-phase current and the C-phase current are exchanged. In the scheme, the quadrature axis voltage and the forward included angle are given, and whether the phase sequence directions of the three-phase alternating current motor and the motor controller are inconsistent or not is determined according to the size and the direction of the three-phase current of the motor controller. And if the phase sequence of the three-phase alternating current motor is inconsistent with the phase sequence of the motor controller, exchanging the B-phase modulation wave and the C-phase modulation wave, exchanging the B-phase current and the C-phase current, and finishing the phase sequence correction of the three-phase alternating current motor so that the directions of the phase sequences of the three-phase alternating current motor and the motor controller are consistent to ensure the stable operation of the three-phase alternating current motor.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, the system or system embodiments are substantially similar to the method embodiments and therefore are described in a relatively simple manner, and reference may be made to some of the descriptions of the method embodiments for related points. The above-described system and system embodiments are only illustrative, wherein the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.