CN112398382B - Method and device for detecting phase current - Google Patents

Method and device for detecting phase current Download PDF

Info

Publication number
CN112398382B
CN112398382B CN201910755457.6A CN201910755457A CN112398382B CN 112398382 B CN112398382 B CN 112398382B CN 201910755457 A CN201910755457 A CN 201910755457A CN 112398382 B CN112398382 B CN 112398382B
Authority
CN
China
Prior art keywords
phase
current
motor
conduction mode
calculation formula
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201910755457.6A
Other languages
Chinese (zh)
Other versions
CN112398382A (en
Inventor
张毅鸣
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
United Automotive Electronic Systems Co Ltd
Original Assignee
United Automotive Electronic Systems Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by United Automotive Electronic Systems Co Ltd filed Critical United Automotive Electronic Systems Co Ltd
Priority to CN201910755457.6A priority Critical patent/CN112398382B/en
Publication of CN112398382A publication Critical patent/CN112398382A/en
Application granted granted Critical
Publication of CN112398382B publication Critical patent/CN112398382B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/28—Arrangements for controlling current
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/34—Modelling or simulation for control purposes

Abstract

The invention provides a method and a device for detecting phase current, which can calculate the current of each phase in a motor in real time according to the measurable line current and the current flow direction (namely the current conduction state). By adopting an algorithm based on an accurate discrete mathematical model, the phase current calculation of any phase at the current sampling moment is based on the phase current at the previous sampling moment and the line current at the current sampling moment, so that the accuracy of the phase current calculation can be effectively improved. The real-time phase current calculation of the motor is realized by combining the software line current collection and the motor drive, and the dynamic change process of the current of the motor during phase change can be better restored through a calculation model deduced from the dynamic process of the motor.

Description

Method and device for detecting phase current
Technical Field
The invention belongs to the technical field of motor control, and particularly relates to a method and a device for detecting phase current.
Background
FIG. 1 is a schematic diagram of electrical connection of a brushless DC motor driving end, and a driving section is composed of 3-phase 6-bridge arm switching circuits and is connected with a load through U/V/W three phases. Generally, three-phase line currents iu, iv, and iw flowing into or out of the motor can be obtained by installing a current detection device on the phase line side. Fig. 2 is a schematic diagram of an equivalent circuit of a brushless dc motor as a load on the inner stator side in a star connection. Fig. 3 is a schematic diagram of an equivalent circuit of an inner stator side of a brushless dc motor as a load in a delta connection. Since the brushless dc motor is an inductive load, each phase can be equivalent to an RL series circuit of a resistor and an inductor. In more application occasions, such as motor thermal model calculation, motor torque estimation and motor running state rationality diagnosis, current values of all phases of a motor need to be acquired. The current flow direction of the motor in the star connection mode is as shown in fig. 2, at the moment, the three-phase current of the motor is equal to the three-phase line current, and the three-phase current value can be obtained by collecting the three-phase line current, namely:
Figure BDA0002168574670000011
in the delta connection mode, the motor current flows as shown in fig. 3, and the three-phase line current and the three-phase current have different mathematical relationships according to different motor driving modes. In three-phase drive mode (sine wave modulation), the line current being equal to the phase current
Figure BDA0002168574670000012
And (4) multiplying. Under a two-phase driving mode (square wave modulation), according to kirchhoff's law, a circuit is processed by a voltage division circuit, and the following results are obtained:
if the U phase and the V phase are conducted, the following steps are provided:
Figure BDA0002168574670000013
if the U phase and the W phase are conducted, the following steps are provided:
Figure BDA0002168574670000021
if the V phase and the W phase are conducted, the following are provided:
Figure BDA0002168574670000022
the mathematical relationship can only be established under the conditions of steady state and magnetic circuit saturation, and because the motor is an inductive load, in the transient process of motor commutation conduction, current fluctuation exists due to follow current or switching tube switching, and the current relationship of the phase line at the moment can not be obtained by the formula. The conventional phase current relationship of delta-connected motors is therefore only applicable in the steady state. However, in practical applications, any application scenario based on phase current calculation needs to consider the transient phase, and the following disadvantages may exist with the conventional technical solution: firstly, the motors connected in a triangular mode cannot be provided with current collecting devices on each phase inside the motors, and therefore the current of each phase of the motors cannot be directly measured. Furthermore, with the method of reconstructing phase currents using line currents, the calculation formula derived based on the steady state equation is subject to theoretical errors, particularly during commutation.
Therefore, a method of detecting the phase current with higher accuracy is required.
Disclosure of Invention
The invention aims to provide a method and a device for detecting phase current, which are used for solving the problems that the phase current cannot be directly measured, the error of the calculated phase current is large and the like in the prior art.
In order to solve the above technical problem, a first aspect of the present invention provides a method for detecting phase currents, which is applied to a delta-connected motor, where the motor includes a U-phase, a V-phase, and a W-phase, and the U-phase, the V-phase, and the W-phase are all connected to an acquisition component for periodically acquiring line current magnitudes according to Δ t, and the method includes the following steps:
s1: each acquisition component respectively acquires the real-time line current magnitude of the U phase, the V phase and the W phase corresponding to the time t;
s2: obtaining a conduction mode of the motor by utilizing the real-time line current;
s3: and according to the obtained conduction mode, obtaining the real-time phase current at the current moment by using the phase current at the t-delta t moment of the previous period, the line current at the t-delta t moment of the previous period and the real-time line current, wherein t is more than or equal to delta t.
Optionally, the magnitudes of the real-time line currents of the U-phase, the V-phase and the W-phase are iu、ivAnd iwSaid S2 includes:
when the said iu>0, the said iv>0 and iwWhen the current is equal to 0, the conduction mode of the motor is a UV conduction mode;
when the said iu>0, the said iv0 and said iw>When 0, the conduction mode of the motor is a UW conduction mode;
when said i isu0, said iv>0 and iw>And when 0, the conduction mode of the motor is a VW conduction mode.
Optionally, the equivalent circuit on the stator side inside the motor is a triangular circuit, each side of the triangle is connected in series with a resistor and an inductor which are equal in size, the resistor is R, and the inductor is L;
the three vertexes of the triangle are respectively connected with the U phase, the V phase and the W phase, the three sides of the equivalent circuit are respectively a first side, a second side and a third side, the three sides flow through the first side, the second side and the current of the third side is phase current, the first side, the second side and the current of the third side are i phase current respectivelyuw、iuvAnd iwv。
Optionally, the S3 includes:
when the conduction mode of the motor is a UV conduction mode, iuwThe calculation formula of (c) is:
Figure BDA0002168574670000031
i is describeduvThe calculation formula of (2) is as follows:
iuv＝iu-iuw
i is describedwvThe calculation formula of (2) is as follows:
Figure BDA0002168574670000032
wherein iu1Line current i at the time of the previous cycle t- Δ t of the U phaseuw1And the phase current at the time of the previous period t-delta t of the first side edge.
Optionally, the S3 further includes:
when the conduction mode of the motor is a VW conduction mode, i isuwThe calculation formula of (2) is as follows:
Figure BDA0002168574670000041
i is describeduvThe calculation formula of (2) is as follows:
Figure BDA0002168574670000042
i is describedwvThe calculation formula of (c) is:
Figure BDA0002168574670000043
wherein iv1Is the former of said V phaseLine current, i, at time t- Δ t of the perioduv1And the phase current at the time of the previous period t-delta t of the second side edge.
Optionally, the S3 further includes:
when the conduction mode of the motor is a UW conduction mode, the iuwThe calculation formula of (2) is as follows:
iuw＝iu-iuv
i is describeduvThe calculation formula of (2) is as follows:
Figure BDA0002168574670000044
i is describedwvThe calculation formula of (c) is:
iwv＝-iv+iuw。
optionally, the collecting component collects the line currents of the U-phase, the V-phase and the W-phase according to a sampling frequency, where the sampling frequency is equal to an integer multiple of a carrier frequency of a control signal of the motor.
Optionally, the collecting component is a current sensor.
Optionally, the motor is a brushless dc motor or a permanent magnet synchronous motor.
In a second aspect of the invention, a device for detecting phase currents is proposed, which employs a method for detecting phase currents as described in any of the above-mentioned features.
The invention provides a method and a device for detecting phase current, which can calculate the current of each phase in a motor in real time according to the measurable line current and the current flow direction (namely the current conduction state). By adopting an algorithm based on an accurate discrete mathematical model, the phase current calculation of any phase at the current sampling moment is based on the phase current at the previous sampling moment and the line current at the current sampling moment, so that the accuracy of the phase current calculation can be effectively improved. The real-time phase current calculation of the motor is realized by combining the software line current collection and the motor drive, and the dynamic change process of the current of the motor during phase change can be better restored through a calculation model deduced from the dynamic process of the motor.
Drawings
FIG. 1 is a schematic diagram of electrical connections of a brushless DC motor;
FIG. 2 is an equivalent circuit diagram of a star-connected brushless DC motor;
FIG. 3 is an equivalent circuit diagram of the inner circuit of the delta connection brushless DC motor;
FIG. 4 is a circuit diagram of an electric delta brushless DC motor control circuit according to an embodiment of the present invention;
FIG. 5 is an equivalent schematic diagram of an internal circuit of the U-phase to the V-phase according to an embodiment of the present invention;
FIG. 6 is an equivalent schematic diagram of an internal circuit of the phase V flowing to the phase U according to the embodiment of the present invention;
FIG. 7 is an equivalent schematic diagram of an internal circuit of the U-phase to the W-phase according to an embodiment of the present invention;
FIG. 8 is an equivalent schematic diagram of an internal circuit of the W phase to the U phase according to the embodiment of the present invention;
FIG. 9 is an equivalent circuit diagram of the V-phase to W-phase in the embodiment of the present invention;
FIG. 10 is an equivalent schematic diagram of an internal circuit of the W-phase to the V-phase according to an embodiment of the present invention;
fig. 11 is a flowchart illustrating a method for detecting phase current according to an embodiment of the present invention;
10-a first side, 20-a second side, 30-a third side, 40-a motor drive circuit.
Detailed Description
The method and apparatus for detecting phase current according to the present invention will be described in detail with reference to the accompanying drawings and embodiments. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.
In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "left", "right", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless explicitly specified otherwise.
As shown in fig. 4 to 11, an embodiment of the present invention provides a method for detecting phase currents, which is applied to a delta-connected motor, where the motor includes a U phase, a V phase, and a W phase, and an acquisition component is connected to each of the U phase, the V phase, and the W phase and is used for periodically acquiring a line current according to Δ t, and the method includes the following steps:
s1: each acquisition component respectively acquires the real-time line current magnitude of the U phase, the V phase and the W phase corresponding to the time t;
s2: obtaining a conduction mode of the motor by using the real-time line current;
s3: and according to the obtained conduction mode, obtaining the real-time phase current at the current moment by using the phase current at the t-delta t moment of the previous period, the line current at the t-delta t moment of the previous period and the real-time line current, wherein t is more than or equal to delta t.
As shown in fig. 4, the method provided by the embodiment of the present invention is applied to a delta connection two-phase conduction mode of a motor, and a current flows into the motor from a certain phase of an inverter, and flows back to an inverter circuit from another phase of the inverter after passing through a stator loop of the motor. Two-phase conduction mode, i.e. square wave driving mode, for a square wave driven motor, there are 6 possible current flow directions, as shown in fig. 5 to 10, which are: the U-phase flows to the V-phase, the V-phase flows to the U-phase, the U-phase flows to the W-phase, the W-phase flows to the U-phase, the V-phase flows to the W-phase, and the W-phase flows to the V-phase. The method provided by the embodiment of the invention is realized by calculating the phase current of each phase in the motor in real time according to the line current which can be measured and the current flow direction. The acquisition component is used for acquiring line currents of the U phase, the V phase and the W phase, and the conduction mode inside the motor, namely the current flow direction inside the motor, is judged by acquiring the feedback value of the line currents. And then according to the conduction mode, obtaining the value of the phase current at the current moment by using the acquired line current and the calculated phase current at the previous moment. By the scheme, the calculation accuracy of the motor phase current can be effectively improved, the dynamic change of the motor phase current is reduced, and the reduction degree of the motor current measurement and reconstruction is effectively improved. It should be noted here that, when the initial state is the line current sampled by the acquisition component for the first time, the real-time phase current at the present time is calculated, because the line current and the phase current in the previous period do not exist, only the line current at the present time needs to be considered, that is, the phase current in the initial state can be calculated according to the formula in the prior art.
Optionally, the line currents of the U-phase, the V-phase and the W-phase are iu、ivAnd iwThe specific process of judging the conduction mode of the motor through the line current value is as follows:
if said iu>0, the said iv>0 and iwIf the conduction mode of the motor is 0, the conduction mode of the motor is a UV conduction mode;
if said iu>0, the said iv0 and said iw>0, the conduction mode of the motor is a UW conduction mode;
if said iu0, said iv>0 and iw>And 0, the conduction mode of the motor is a VW conduction mode.
It should be noted that in the embodiment of the present invention, the determination about the conduction mode of the motor is to set acquisition components on all three phases to acquire the line current, and then determine the conduction mode of the motor through the line current. However, in addition to this three-wire current sampling method, there are many other methods available for determining the motor conduction mode, such as directly from the current control output of the motor drive circuit 40. In order to save cost, a bus current sampling method can be used instead of a three-wire sampling method, i.e., a collecting component is arranged in front of the grounding end in the motor driving circuit 40, bus current is obtained through the collecting component, the motor conduction mode can be directly obtained through the current control output of the motor driving circuit 40, and corresponding line current is calculated according to the conduction mode and the bus current. The bus current sampling scheme has the advantages that the hardware cost is low, the software calculation is complex, and the current sampling mode needs to be selected according to the requirement in actual application.
As shown in fig. 3, the equivalent circuit at the stator side inside the motor is a triangular circuit, and a resistor and an inductor with the same size are connected in series on each side of the triangle, wherein the resistor size is R, and the inductor size is L;
the three vertexes of the triangle are respectively connected with the U phase, the V phase and the W phase, the three sides of the equivalent circuit are respectively a first side 10, a second side 20 and a third side 30, the currents flowing through the first side 10, the second side 20 and the third side 30 are respectively i phase currents, and the currents of the first side 10, the second side 20 and the third side 30 are respectively i phase currentsuw、iuvAnd iwv。
As to a specific calculation formula for obtaining the current-time phase current by using the current magnitude of the previous-time phase current and the line current in step S3, there is a derivation procedure as follows, according to kirchhoff' S law, a closed loop is formed in the direction of the arrow in fig. 4, and the electric potential thereof is zero, that is:
Figure BDA0002168574670000071
substituting phase voltage formula (4) to obtain:
Figure BDA0002168574670000081
wherein euw、ewv、euvFor the back electromotive force on three phases of the motor stator, the back electromotive forces of the three phases are respectively added after Fourier expansion according to the motor principle, the vector sum is zero, and therefore, euw+ewv+euvWhen 0, this gives:
Figure BDA0002168574670000082
as shown in fig. 5, when current flows into the motor from the U-phase and flows out of the motor from the V-phase, i is satisfieduw＝iwv、iuv＝iu-iuwAnd iu＝-ivObtaining:
Figure BDA0002168574670000083
as shown in fig. 6, when current flows into the motor from the V-phase and flows out of the motor from the U-phase, i-i is satisfieduw＝-iwv、-iuv＝-iu+iuwAnd-iu＝ivObtaining:
Figure BDA0002168574670000084
as shown in fig. 7, when current flows into the motor from the U-phase and flows out of the motor from the W-phase, i is satisfieduv＝-iwv、iuw＝iu-iuvAnd iu＝-iwObtaining:
Figure BDA0002168574670000085
as shown in fig. 8, when current flows into the motor from the W-phase and flows out of the motor from the U-phase, i-i is satisfieduv＝iwv、-iuw＝-iu+iuvAnd-iu＝iwObtaining:
Figure BDA0002168574670000086
as shown in fig. 9, when current flows into the motor from the V-phase and flows out of the motor from the W-phase, i-i is satisfieduv＝iuw、-iwv＝iv-iuwAnd iv＝-iwObtaining:
Figure BDA0002168574670000087
as shown in fig. 10, when current flows into the motor from the W-phase and flows out of the motor from the V-phase, i is satisfieduv＝-iuw、iwv＝-iv+iuwAnd-iv＝iwObtaining:
Figure BDA0002168574670000088
discretizing the formula to obtain a calculation formula of each phase current when a certain two phases are conducted, wherein when the conduction mode of the motor is a UV conduction mode, i isuwThe calculation formula of (2) is as follows:
Figure BDA0002168574670000091
i is describeduvThe calculation formula of (2) is as follows:
iuv＝iu-iuw
i is describedwvThe calculation formula of (2) is as follows:
Figure BDA0002168574670000092
wherein iu1Line current i at the time of the previous cycle t- Δ t of the U phaseuw1The phase current is at the time of the previous period t-delta t of the first side edge, and delta t is the sampling period of the acquisition component.
When the conduction mode of the motor is a VW conduction mode, iuwThe calculation formula of (2) is as follows:
Figure BDA0002168574670000093
i is describeduvThe calculation formula of (2) is as follows:
Figure BDA0002168574670000094
i is describedwvThe calculation formula of (c) is:
Figure BDA0002168574670000095
wherein iv1Line current i at the time of the previous cycle t- Δ t of the V phaseuv1And the phase current is obtained at the time of the previous period t-delta t of the second side edge.
When the conduction mode of the motor is a UW conduction mode, iuwThe calculation formula of (2) is as follows:
iuw＝iu-iuv
i is describeduvThe calculation formula of (c) is:
Figure BDA0002168574670000096
i is describedwvThe calculation formula of (c) is:
iwv＝-iv+iuw。
the calculation formula of the phase current of each phase under various motor conduction modes can be obtained through the derivation process. The technical scheme provided by the embodiment of the invention is based on an accurate discrete mathematical model, and combines the linear current acquisition and the motor drive circuit 40 to realize the real-time phase current calculation of the motor. It should be noted that the function of calculating the phase current is not activated when the motor is not operating, and is activated when the motor is requested to operate, and the evaluation value calculated is equal to the sampling frequency of the line current, and the conduction mode can be determined according to the line current, and if the conduction state is not within the expected conduction state range, it is determined as an abnormal condition. In addition, in the above formula, the calculation of the phase current depends on the resistance R and the inductance L of the stator of the motor, and the values of R and L are from the values calibrated in the motor specification. Therefore, to obtain more accurate phase currents, compensation calculations for these values are required. For example, the resistance is a compensation value of resistance, Rs ═ R [1+ η (T-T0) ], where R is a resistance value at room temperature, which can be obtained from a motor parameter table, T0 is a resistance temperature coefficient of the material of the motor stator coil, which can be generally 20 ° or 25 °, η is a resistance temperature coefficient of the material of the motor stator coil, for example, the resistance temperature coefficient of copper at 20 ℃ is 0.00393, and the specific value is selected according to the actual situation.
Optionally, the collecting component may be a current sensor, but may also be other devices having a current collecting function, which is not limited herein. It should be noted that the current sensor is to collect the corresponding U-phase, V-phase and W-phase line currents according to a certain sampling frequency, and the sampling frequency of the current sensor may be equal to an integer multiple of the carrier frequency of the control signal of the motor. In addition, experiments show that the smaller the multiple, the better the dynamic following performance of the detected phase current is, therefore, the preferred scheme of the sampling frequency is equal to the carrier frequency of the control signal of the motor, and a proper multiple needs to be selected according to actual needs in specific practical applications.
The technical scheme provided by the embodiment of the invention is explained by taking a square-wave-driven triangular-connection brushless direct current motor as an example, and is also applicable to other types of motors with the same connection method and the same two-phase conduction mode. For example, the motor may be a brushless dc motor, or a permanent magnet synchronous motor, and some other types of motors are not described herein.
In an embodiment of the present invention, a device for detecting phase current is further provided, wherein the method for detecting phase current according to any one of the above features is adopted.
In summary, the present invention provides a method and an apparatus for detecting phase current, which can calculate the current of each phase inside the motor in real time according to the measurable line current and the current flowing direction (i.e. the current conducting state). By adopting an algorithm based on an accurate discrete mathematical model, the phase current calculation of any phase at the current sampling moment is based on the phase current at the previous sampling moment and the line current at the current sampling moment, so that the accuracy of the phase current calculation can be effectively improved. The real-time phase current calculation of the motor is realized by combining the software line current acquisition and the motor drive, and the dynamic change process of the current of the motor during phase change can be better restored through a calculation model deduced from the dynamic process of the motor.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example" or "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. And the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments. Furthermore, various embodiments or examples described in this specification can be combined and combined by those skilled in the art.
Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims (10)

1. A method for detecting phase current is applied to a delta connection motor, and is characterized in that the motor comprises a U phase, a V phase and a W phase, the U phase, the V phase and the W phase are all connected with an acquisition component for periodically acquiring the magnitude of the line current according to delta t, and delta t is the sampling period of the acquisition component, and the method comprises the following steps:
s1: each acquisition component respectively acquires the real-time line current magnitude of the U phase, the V phase and the W phase corresponding to the time t;
s2: obtaining a conduction mode of the motor by utilizing the real-time line current;
s3: and according to the obtained conduction mode, obtaining the real-time phase current at the current moment by using the phase current at the t-delta t moment of the previous period, the line current at the t-delta t moment of the previous period and the real-time line current, wherein t is more than or equal to delta t.
2. The method for phase current detection according to claim 1, wherein the magnitude of the real-time line current of each of the U-phase, the V-phase and the W-phase is iu、ivAnd iwSaid S2 includes:
when the said iu>0, the said iv>0 and iwWhen the current is equal to 0, the conduction mode of the motor is a UV conduction mode;
when said i isu>0, the said iv0 and said iw>When 0, the conduction mode of the motor is a UW conduction mode;
when the said iu0, said iv>0 and iw>And when 0, the conduction mode of the motor is a VW conduction mode.
3. The method for detecting phase currents according to claim 2, wherein the equivalent circuit on the stator side inside the motor is a triangular circuit, and a resistor and an inductor of equal size are connected in series on each side of the triangle, wherein the resistor size is R, and the inductor size is L;
the three vertexes of the triangle are respectively connected with the U phase, the V phase and the W phase, the three sides of the equivalent circuit are respectively a first side, a second side and a third side, and the current flowing through the first side, the second side and the third side is the phase currentThe currents of the first side, the second side and the third side are i respectivelyuw、iuvAnd iwv。
4. The method for detecting phase currents according to claim 3, wherein said S3 includes:
when the conduction mode of the motor is a UV conduction mode, iuwThe calculation formula of (2) is as follows:
Figure FDA0003619414800000021
i is describeduvThe calculation formula of (2) is as follows:
iuv＝iu-iuw
i is describedwvThe calculation formula of (2) is as follows:
Figure FDA0003619414800000022
wherein iu1Line current i at the time t- Δ t of the previous cycle of the U phaseuw1The phase current is obtained at the time of the previous period t-delta t of the first side edge.
5. The method for phase current detection according to claim 4, wherein said S3 further comprises:
when the conduction mode of the motor is a VW conduction mode, iuwThe calculation formula of (2) is as follows:
Figure FDA0003619414800000023
i is describeduvThe calculation formula of (2) is as follows:
Figure FDA0003619414800000024
i is describedwvThe calculation formula of (2) is as follows:
Figure FDA0003619414800000025
wherein iv1Line current at time t- Δ t of a previous cycle of said V-phase, iuv1And the phase current is obtained at the time of the previous period t-delta t of the second side edge.
6. The method for detecting phase currents according to claim 5, wherein said S3 further comprises:
when the conduction mode of the motor is a UW conduction mode, iuwThe calculation formula of (2) is as follows:
iuw＝iu-iuv
i is describeduvThe calculation formula of (2) is as follows:
Figure FDA0003619414800000026
i is describedwvThe calculation formula of (2) is as follows:
iwv＝-iv+iuw。
7. the method for detecting phase currents according to claim 1, wherein said acquisition unit acquires the magnitudes of the line currents of the U-phase, the V-phase, and the W-phase respectively at a sampling frequency, said sampling frequency being equal to an integer multiple of a carrier frequency of a control signal of said motor.
8. The method for detecting phase currents of claim 1, wherein said pick-up element is a current sensor.
9. The method of phase current detection according to claim 1, wherein said motor is a brushless dc motor or a permanent magnet synchronous motor.
10. A device for detecting phase currents, characterized by using a method for detecting phase currents according to any of claims 1-9.
CN201910755457.6A 2019-08-15 2019-08-15 Method and device for detecting phase current Active CN112398382B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910755457.6A CN112398382B (en) 2019-08-15 2019-08-15 Method and device for detecting phase current

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910755457.6A CN112398382B (en) 2019-08-15 2019-08-15 Method and device for detecting phase current

Publications (2)

Publication Number Publication Date
CN112398382A CN112398382A (en) 2021-02-23
CN112398382B true CN112398382B (en) 2022-07-19

Family

ID=74601755

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910755457.6A Active CN112398382B (en) 2019-08-15 2019-08-15 Method and device for detecting phase current

Country Status (1)

Country Link
CN (1) CN112398382B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB671906A (en) * 1949-09-09 1952-05-14 British Thomson Houston Co Ltd Improvements in and relating to electric valve converting circuits
JP2013115884A (en) * 2011-11-28 2013-06-10 Daikin Ind Ltd Line current detection device and power conversion system
CN108667378A (en) * 2018-05-22 2018-10-16 北京因时机器人科技有限公司 A kind of list resistance dephased current method of sampling and device
WO2019095878A1 (en) * 2017-11-17 2019-05-23 美的集团股份有限公司 Motor driving system, method and device for simultaneous calculation of reconstructed phase and current phase voltages

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB671906A (en) * 1949-09-09 1952-05-14 British Thomson Houston Co Ltd Improvements in and relating to electric valve converting circuits
JP2013115884A (en) * 2011-11-28 2013-06-10 Daikin Ind Ltd Line current detection device and power conversion system
WO2019095878A1 (en) * 2017-11-17 2019-05-23 美的集团股份有限公司 Motor driving system, method and device for simultaneous calculation of reconstructed phase and current phase voltages
CN108667378A (en) * 2018-05-22 2018-10-16 北京因时机器人科技有限公司 A kind of list resistance dephased current method of sampling and device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
一种新的基于霍尔传感器的电流测量方法;谢完成 等;《电子测量与仪器学报》;20120831;第26卷(第8期);全文 *

Also Published As

Publication number Publication date
CN112398382A (en) 2021-02-23

Similar Documents

Publication Publication Date Title
Suresh et al. Inductance based position encoding for sensorless SRM drives
AU2008302740B2 (en) System and method to determine electric motor efficiency nonintrusively
US7525269B2 (en) Method and apparatus for sensorless position control of a permanent magnet synchronous motor (PMSM) drive system
US8283881B2 (en) Methods, systems and apparatus for synchronous current regulation of a five-phase machine
EP1944860B1 (en) A method for sensorless estimation of rotor speed and position of a permanent magnet synchronous machine
US8941339B2 (en) Apparatus and method for measuring position deviation of rotor of permanent magnet synchronous motor
US20110133678A1 (en) Motor control device, motor drive system and inverter control device
US7936146B2 (en) Motor control device
CN107222135B (en) A kind of D-C brushless electric machine no-position sensor control system phase change control method
KR100999352B1 (en) Dead-time Compensator and Method for Permanent Magnet Synchronous Drives
CN111614288B (en) Control method and controller
CN109039199B (en) Bus current estimation method and system for EPS controller
CN102170262B (en) Non-speed sensor control method of direct-drive permanent-magnet synchronous wind turbine
CN103647482A (en) Brushless DC (direct current) motor 180-degree square wave control method and module and converter
CN112398382B (en) Method and device for detecting phase current
CN109546904B (en) Rotor position detection method of double three-phase permanent magnet synchronous motor
JP4670044B2 (en) Method and apparatus for estimating magnetic pole position of electric motor
KR101742554B1 (en) Position detection signal linearity apparatus of sensor with low resolution and its method, motor control apparatus for washing machine using it and its method
CN112713824A (en) Sensorless control method and system for permanent magnet synchronous motor
Toliyat et al. Parameter estimation algorithm using spectral analysis for vector controlled induction motor drives
CN108448960B (en) Real-time simulation method for power level of four-quadrant running permanent magnet motor
JP2002272195A (en) Synchronous motor control device
CN112636653A (en) Non-inductive control circuit and method for permanent magnet synchronous motor of automobile electronic water pump
CN109194231A (en) Permanent-magnet synchronous reluctance motor control system and its control method
KR101694167B1 (en) Method for estimating rotar position of synchronous motor and motor driver using the same

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant