CN117554678A - Three-phase current correction circuit and method - Google Patents

Three-phase current correction circuit and method Download PDF

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Publication number
CN117554678A
CN117554678A CN202311408082.9A CN202311408082A CN117554678A CN 117554678 A CN117554678 A CN 117554678A CN 202311408082 A CN202311408082 A CN 202311408082A CN 117554678 A CN117554678 A CN 117554678A
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China
Prior art keywords
current
nmos tube
phase current
acquisition unit
electrically connected
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CN202311408082.9A
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Chinese (zh)
Inventor
陈毅东
刘旺
张志源
李智顺
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Shenzhen Zhaowei Machinery and Electronics Co Ltd
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Shenzhen Zhaowei Machinery and Electronics Co Ltd
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Priority to CN202311408082.9A priority Critical patent/CN117554678A/en
Publication of CN117554678A publication Critical patent/CN117554678A/en
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    • 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
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/14—Estimation or adaptation of machine parameters, e.g. flux, current or voltage
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/02—Measuring effective values, i.e. root-mean-square values
    • 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
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/22—Current control, e.g. using a current control loop

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Current Or Voltage (AREA)

Abstract

The invention provides a three-phase current correction circuit and a method, and relates to the technical field of data sampling, wherein the circuit comprises a first current acquisition unit, a second current acquisition unit and a control unit; a first current acquisition unit for acquiring a first phase current i _U Second phase current i _V Third phase current i _W The method comprises the steps of carrying out a first treatment on the surface of the A second current acquisition unit for acquiring a second effective value i of the bus current _buseve The method comprises the steps of carrying out a first treatment on the surface of the A control unit for according to i _U 、i _V I _W Determining a first effective value i of the bus current _calcbuseve The method comprises the steps of carrying out a first treatment on the surface of the According to i _calcbuseve And i _buseve Determining a correction proportion P; respectively correct i according to P _U 、i _V I _W Obtaining the target three-phase current. According to the bus current second effective value obtained by carrying out strong filtering treatment on the bus resistance sampling current and the bus current second effective value determined by the MOS tube internal resistance sampling current, the correction proportion is obtained, and the MOS tube internal resistance sampling current, namely the three-phase sampling current, is corrected, so that more accurate three-phase current is obtained.

Description

Three-phase current correction circuit and method
Technical Field
The invention relates to the technical field of data sampling, in particular to a three-phase current correction circuit and a method.
Background
In FOC algorithm i d In the control mode of =0, the existing three-phase current sampling method generally includes single-resistance sampling, double-resistance sampling and three-resistance sampling, where the three-resistance sampling algorithm is relatively simple, but the cost is higher, so that in some occasions, the three-resistance sampling is replaced by the internal resistance current sampling of the MOS tube, however, as the internal resistance of the MOS tube changes along with the rise of temperature, the three-phase current value obtained by sampling also has deviation, so that the torque control precision of the subsequent motor is affected.
Disclosure of Invention
In view of the above, the invention provides a three-phase current correction circuit and a method, which aim to obtain three-phase current by correcting internal resistance sampling of a MOS tube through bus current after hardware strong filtering. The invention provides the following technical scheme:
in a first aspect, the present invention provides a three-phase current correction circuit, the circuit comprising: the device comprises a first current acquisition unit, a second current acquisition unit and a control unit;
the first end of the first current acquisition unit is electrically connected with the bus, the second end of the first current acquisition unit is electrically connected with the first end of the control unit, the third end of the first current acquisition unit is electrically connected with the second end of the control unit, and the fourth end of the first current acquisition unit is electrically connected with the first end of the second current acquisition unit; the fifth end of the first current acquisition unit is electrically connected with the motor; the second end of the second current acquisition unit is electrically connected with the third end of the control unit, and the third end and the fourth end of the second current acquisition unit are respectively grounded;
the first current acquisition unit is used for acquiring a first phase current i _U Second phase current i _V Third phase current i _W ；
The second current acquisition unit is used for acquiring a second effective value i of the bus current _buseve ；
The control unit is used for controlling the control unit according to the i _U Said i _V The i _W Determining a first effective value i of the bus current _calcbuseve The method comprises the steps of carrying out a first treatment on the surface of the According to said i _calcbuseve And said i _buseve Determining a correction proportion P; correcting the i respectively according to the P _U Said i _V The i _W Obtaining the target three-phase current.
In an embodiment, the first current collecting unit includes a first NMOS transistor, a second NMOS transistor, a third NMOS transistor, a fourth NMOS transistor, a fifth NMOS transistor, and a sixth NMOS transistor;
the drain electrode of the first NMOS tube, the drain electrode of the second NMOS tube and the drain electrode of the third NMOS tube are respectively and electrically connected with the bus;
the gates of the first NMOS tube, the second NMOS tube, the third NMOS tube, the fourth NMOS tube, the fifth NMOS tube and the sixth NMOS tube are respectively and electrically connected with the first end of the control unit;
the source electrode of the fourth NMOS tube, the source electrode of the fifth NMOS tube and the source electrode of the sixth NMOS tube are respectively and electrically connected with the first end of the second current acquisition unit;
the source electrode of the first NMOS tube is electrically connected with the drain electrode of the fourth NMOS tube, the source electrode of the second NMOS tube is electrically connected with the drain electrode of the fifth NMOS tube, and the source electrode of the third NMOS tube is electrically connected with the drain electrode of the sixth NMOS tube.
In an embodiment, the first current collecting unit further includes a first operational amplifier, a second operational amplifier, and a third operational amplifier;
the input end of the first operational amplifier is connected with the fourth NMOS tube in parallel, the input end of the second operational amplifier is connected with the fifth NMOS tube in parallel, and the input end of the third operational amplifier is connected with the sixth NMOS tube in parallel;
the output ends of the first operational amplifier, the second operational amplifier and the third operational amplifier are respectively and electrically connected with the second end of the control unit.
In an embodiment, the second current collecting unit includes a bus resistor, a fourth operational amplifier, a filter capacitor and a filter resistor;
the first end of the bus resistor is electrically connected with the source electrode of the fourth NMOS tube, the source electrode of the fifth NMOS tube and the source electrode of the sixth NMOS tube respectively;
the input end of the fourth operational amplifier is connected with the bus resistor in parallel, and the output end of the fourth operational amplifier is electrically connected with the first end of the filter resistor;
the second end of the filter resistor is electrically connected with the third end of the control unit and the first end of the filter capacitor respectively;
and the second end of the bus resistor is grounded, and the second end of the filter capacitor is grounded.
In an embodiment, the source of the first NMOS transistor, the source of the second NMOS transistor, and the source of the third NMOS transistor are respectively electrically connected to different phase lines of the three-phase motor.
In a second aspect, the present invention provides a three-phase current correction method applied to a three-phase current correction circuit, the method comprising:
the first current acquisition unit acquires a first phase current i _U Second phase current i _V Third phase current i _W ；
The second current acquisition unit acquires a second effective value i of the bus current _buseve ；
The control unit is based on the i _U Said i _V The i _W Determining a first effective value i of the bus current _calcbuseve The method comprises the steps of carrying out a first treatment on the surface of the According to said i _calcbuseve And said i _buseve Determining a correction proportion P; correcting the i respectively according to the P _U Said i _V The i _W Obtaining the target three-phase current.
In one embodiment, the first current acquisition unit acquiresFirst phase current i _U Second phase current i _V Third phase current i _W Comprising:
the control unit sends a control signal to the first current acquisition unit;
the first current acquisition unit determines the i according to the control signal _U Said i _V The i _W 。
In one embodiment, the method according to i _U Said i _V The i _W Determining a first effective value i of the bus current _calcbuseve Comprising:
the control unit acquires a period T PWM In, the conduction time T of the fourth NMOS tube U Conduction time T of fifth NMOS tube V Conduction time T of sixth NMOS tube W ；
According to said i _U Said i _V Said i _W Said T PWM Said T U Said T V The T is W Determining the i _calcbuseve The calculation formula is as follows:
in one embodiment, the method according to i _calcbuseve And said i _buseve The correction ratio P is determined, and the calculation formula is as follows:
in one embodiment, the correction of the i is based on the P _U Said i _V The i _W Obtaining a target three-phase current, comprising:
respectively correcting the i _U Said i _V The i _W Obtaining corrected first phase current i' _U Corrected second phase current i' _V Correction ofThe third phase current i' _W The calculation formula is as follows:
i' _x ＝P×i _x
wherein x is U, V or W;
the i' _U 、i' _V I's' _W And determining the three-phase current as a target three-phase current.
The invention provides a three-phase current correction circuit and a method, wherein the circuit comprises the following components: the device comprises a first current acquisition unit, a second current acquisition unit and a control unit; the first current acquisition unit is used for acquiring a first phase current i _U Second phase current i _V Third phase current i _W The method comprises the steps of carrying out a first treatment on the surface of the The second current acquisition unit is used for acquiring a second effective value i of the bus current _buseve The method comprises the steps of carrying out a first treatment on the surface of the The control unit is used for controlling the control unit according to the i _U Said i _V The i _W Determining a first effective value i of the bus current _calcbuseve The method comprises the steps of carrying out a first treatment on the surface of the According to said i _calcbuseve And said i _buseve Determining a correction proportion P; correcting the i respectively according to the P _U Said i _V The i _W Obtaining the target three-phase current. According to the bus current second effective value obtained by carrying out strong filtering treatment on the bus resistance sampling current and the bus current second effective value determined by the MOS tube internal resistance sampling current, the correction proportion is obtained, and the MOS tube internal resistance sampling current, namely the three-phase current, is corrected accordingly.
In order to make the above objects, features and advantages of the present invention more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 shows a schematic diagram of a three-phase current correction circuit according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a first current collecting unit and a second current collecting unit according to an embodiment of the present invention;
fig. 3 is a schematic flow chart of a three-phase current correction method according to an embodiment of the invention.
Description of main reference numerals:
100-three-phase current correction circuit; 110-a first current acquisition unit; 120-a second current acquisition unit; 130-a control unit; VBUS-bus; m1-motor.
Detailed Description
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.
It will be understood that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only.
In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the templates herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
Example 1
Embodiment 1 of the present invention provides a three-phase current correction circuit, specifically, referring to fig. 1 and 2, the three-phase current correction circuit 100 includes: the first current acquisition unit 110, the second current acquisition unit 120 and the control unit 130;
a first end of the first current collecting unit 110 is electrically connected to the bus VBUS, a second end of the first current collecting unit 110 is electrically connected to a first end of the control unit 130, a third end of the first current collecting unit 110 is electrically connected to a second end of the control unit 130, and a fourth end of the first current collecting unit 110 is electrically connected to a first end of the second current collecting unit 120; the fifth end of the first current collecting unit 110 is electrically connected with the motor M1; a second end of the second current collecting unit 120 is electrically connected to a third end of the control unit 130, and the third end and a fourth end of the second current collecting unit 120 are respectively grounded;
the first current acquisition unit 110 is configured to acquire a first phase current i _U Second phase current i _V Third phase current i _W ；
The second current collection unit 120 is configured to obtain a second effective value i of the bus current _buseve ；
The control unit 130 is configured to, according to the i _U Said i _V The i _W Determining a first effective value i of the bus current _calcbuseve The method comprises the steps of carrying out a first treatment on the surface of the According to said i _calcbuseve And said i _buseve Determining a correction proportion P; correcting the i respectively according to the P _U Said i _V The i _W Obtaining the target three-phase current.
It should be noted that, the FOC algorithm is an advanced control algorithm widely applied to brushless motor control, and by accurately positioning and controlling a rotor magnetic field and current of a motor, efficient motor driving and accurate torque control are realized, and the FOC algorithm mainly has two control modes: vector Control (Vector Control) and direct torque Control (Direct Torque Control), wherein Vector Control generally comprises: i.e d Control strategy of=0, maximum torque/current ratio control strategy, flux weakening control strategy,Control strategy, etc., the three-phase current correction circuit provided by the invention is mainly applied to i in the FOC algorithm vector control mode d Control strategy=0.
In the present embodiment, the control unit 130 realizes accurate control of the brushless motor M1 through the current loop, and the control unit 130 performs closed-loop control of the phase current of the motor M1 according to the corrected three-phase current, i.e., the target three-phase current. Specifically, the control unit 130 outputs a control signal to the first current collecting unit 110, and the first current collecting unit 110 can obtain the first phase current i according to the control signal _U Second phase current i _V Third phase current i _W First currentThe acquisition unit 110 will i _U 、i _V I _W The current signals are respectively converted into corresponding voltage signals and then input into the control unit 130, and the control unit 130 then respectively converts the received voltage signals into corresponding current signals i _U 、i _V I _W According to i _U 、i _V I _W Determining a first effective value i of the bus current _calcbuseve 。
The second current collecting unit 120 is connected in series with the first current collecting unit 110, the second current collecting unit 120 comprises a bus resistor R1, the second current collecting unit 120 converts the bus current collected by the bus resistor R1 into a corresponding voltage signal, the voltage signal is input to the control unit 130 after being subjected to hardware strong filtering, and the control unit 130 converts the received voltage signal into a corresponding current signal again, so that a second effective value i of the bus current can be obtained _buseve 。
The control unit 130 is based on the first effective value i of the bus current _calcbuseve And the second effective value of the bus current can determine the correction proportion P, so that the target three-phase current is obtained according to P correction, and then the control signal is regulated and output according to the target three-phase current, thereby realizing closed-loop control.
In an embodiment, the first current collecting unit includes a first NMOS transistor Q1, a second NMOS transistor Q2, a third NMOS transistor Q3, a fourth NMOS transistor Q4, a fifth NMOS transistor Q5, and a sixth NMOS transistor Q6;
the drain electrode of the first NMOS transistor Q1, the drain electrode of the second NMOS transistor Q2, and the drain electrode of the third NMOS transistor Q3 are electrically connected to the bus VBUS, respectively;
the gates of the first NMOS transistor Q1, the second NMOS transistor Q2, the third NMOS transistor Q3, the fourth NMOS transistor Q4, the fifth NMOS transistor Q5, and the sixth NMOS transistor Q6 are respectively electrically connected to the first end of the control unit 130;
the source of the fourth NMOS transistor Q4, the source of the fifth NMOS transistor Q5, and the source of the sixth NMOS transistor Q6 are electrically connected to the first end of the second current collecting unit 120, respectively;
the source of the first NMOS transistor Q1 is electrically connected to the drain of the fourth NMOS transistor Q4, the source of the second NMOS transistor Q2 is electrically connected to the drain of the fifth NMOS transistor Q5, and the source of the third NMOS transistor Q3 is electrically connected to the drain of the sixth NMOS transistor Q6.
Referring to fig. 2, fig. 2 shows a schematic structural diagram of a first current collecting unit 110 and a second current collecting unit 120 according to an embodiment of the present application.
In this embodiment, the first current collecting unit 110 includes six NMOS transistors, including a first NMOS transistor Q1, a second NMOS transistor Q2, a third NMOS transistor Q3, a fourth NMOS transistor Q4, a fifth NMOS transistor Q5, and a sixth NMOS transistor Q6, which form a three-way inverting half-bridge circuit for driving the brushless motor M1, and the first current collecting unit 110 controls the six NMOS transistors to be turned on or off according to the received control signal, respectively, when the NMOS transistors are turned on, due to internal resistance between the source and the drain, when the first phase current i is generated _U Second phase current i _V Third phase current i _W When the current flows through the internal resistance of the NMOS tube, voltage drop is generated, at the moment, the operational amplifier connected in parallel with the two ends of the NMOS tube can convert the current signal into a voltage signal, amplify the voltage signal and output the voltage signal to the control unit 130, and the control unit 130 obtains a first phase current i according to ohm's law U=IR _U Second phase current i _V Third phase current i _W . It is noted that i _U 、i _V I _W The three-phase current obtained by sampling the NMOS tube is obtained.
Further, the control unit 130 can calculate the on time of each NMOS transistor in real time, and according to the cycle time T PWM In, the conduction time T of the fourth NMOS tube U Conduction time T of fifth NMOS tube V Conduction time T of sixth NMOS tube W And the conduction current i corresponding to each of the fourth NMOS tube, the fifth NMOS tube and the sixth NMOS tube _U 、i _V I _W Determining a first effective value i of the bus current _calcbuseve The calculation formula is as follows:
for example, during cycle time 5S, the control unit130 obtain the conduction time T of the fourth NMOS tube U =4s, on-current i _U Time T of turn-on of fifth NMOS transistor =1a V =4.5S, on current i _V Time T of turn-on of sixth NMOS transistor =1a W =4s, on-current i _W =1.5A, then the first effective value of the bus current
In an embodiment, the first current collecting unit 110 further includes a first operational amplifier U1, a second operational amplifier U2, and a third operational amplifier U3;
the input end of the first operational amplifier U1 is connected in parallel with the fourth NMOS tube Q4, the input end of the second operational amplifier U2 is connected in parallel with the fifth NMOS tube Q5, and the input end of the third operational amplifier U3 is connected in parallel with the sixth NMOS tube Q6;
the output ends of the first operational amplifier U1, the second operational amplifier U2 and the third operational amplifier U3 are respectively electrically connected to the second end of the control unit 130.
In the present embodiment, the operational amplifier will source a first phase current i _U Second phase current i _V Third phase current i _W The voltage signals are converted into voltage signals respectively, and after the voltage signals are input into the control unit 130, the control unit 130 converts the voltage signals into current signals according to ohm's law u=ir. The first operational amplifier U1 is configured to detect a voltage drop across the fourth NMOS Q4, the second operational amplifier U2 is configured to detect a voltage drop across the fifth NMOS Q5, and the third operational amplifier U3 is configured to detect a voltage drop across the sixth NMOS Q6.
In an embodiment, the second current collecting unit 120 includes a bus resistor R1, a fourth operational amplifier U4, a filter capacitor C1, and a filter resistor R2;
the first end of the bus resistor R1 is electrically connected with the source electrode of the fourth NMOS transistor Q4, the source electrode of the fifth NMOS transistor Q5 and the source electrode of the sixth NMOS transistor Q6, respectively;
the input end of the fourth operational amplifier U4 is connected with the busbar resistor R1 in parallel, and the output end of the fourth operational amplifier U4 is electrically connected with the first end of the filter resistor R2;
the second end of the filter resistor R2 is electrically connected to the third end of the control unit 130 and the first end of the filter capacitor C1, respectively;
the second end of the bus resistor R1 is grounded, and the second end of the filter capacitor C1 is grounded.
In this embodiment, the current flowing through the bus resistor R1 is a bus current, the fourth operational amplifier U1 connected in parallel to two ends of the bus resistor R1 converts the bus current into a voltage signal and outputs the voltage signal to the control unit 130, and the control unit 130 converts the voltage signal into a current signal according to ohm's law u=ir to obtain the second effective value i of the bus current _buseve 。
It should be noted that, before the bus current is converted to a voltage signal and output to the control unit 130, the voltage signal is filtered by an RC circuit formed by the filter resistor R2 and the filter capacitor C1, so as to filter out high-frequency interference.
The control unit 130 again obtains the first effective value i of the bus current _calcbuseve And a second effective value i of the bus current _buseve After that, can be according to the i _calcbuseve And said i _buseve The correction proportion P is calculated, and the calculation formula is as follows:
after the correction proportion P is determined, the sampling current of the NMOS tube, namely the first phase current i, is corrected respectively _U Second phase current i _V Third phase current i _W The correction formula is:
i' _x ＝P×i _x
wherein x is U, V or W. For example, the correction ratio is p=1.1, i _U ＝1A，i _V ＝1A，i _W = -2A, then the corrected first phase current i' _U =1.1×1=1.1A, corrected second phase current i' _V =1.1×1=1.1A, corrected third phase current i' _W ＝1.1×(-2)＝-2.2A。
Corrected first phase current i' _U Second phase current i' _V Third phase current i' _W The target three-phase current is obtained.
In an embodiment, the source of the first NMOS transistor Q1, the source of the second NMOS transistor Q2, and the source of the third NMOS transistor Q3 are electrically connected to different phase lines of the motor M1, respectively.
In this embodiment, the control unit 130 may adjust the output control signal according to the corrected target three-phase current, to realize closed-loop control of the motor M1.
It should be noted that, since the accuracy of the three-phase current is improved, the accuracy of the control of the motor M1 by the control unit is also improved accordingly.
The three-phase current correction circuit provided by the invention comprises: the device comprises a first current acquisition unit, a second current acquisition unit and a control unit; the first end of the first current acquisition unit is electrically connected with the bus, the second end of the first current acquisition unit is electrically connected with the first end of the control unit, the third end of the first current acquisition unit is electrically connected with the second end of the control unit, and the fourth end of the first current acquisition unit is electrically connected with the first end of the second current acquisition unit; the fifth end of the first current collecting unit 110 is electrically connected with the motor M1; the second end of the second current acquisition unit is electrically connected with the third end of the control unit, and the third end and the fourth end of the second current acquisition unit are respectively grounded; the first current acquisition unit is used for acquiring a first phase current i _U Second phase current i _V Third phase current i _W The method comprises the steps of carrying out a first treatment on the surface of the The second current acquisition unit is used for acquiring a second effective value i of the bus current _buseve The method comprises the steps of carrying out a first treatment on the surface of the The control unit is used for controlling the control unit according to the i _U Said i _V The i _W Determining a first effective value i of the bus current _calcbuseve The method comprises the steps of carrying out a first treatment on the surface of the According to said i _calcbuseve And said i _buseve Determining a correction proportion P; correcting the i respectively according to the P _U Said i _V The i _W Obtaining the target three-phase current. The inventionThe second current acquisition unit is added, the bus resistor sampling current is subjected to hardware strong filtering treatment to obtain a second effective value of the bus current, before the second effective value of the bus current is obtained, the first effective value of the bus current is determined according to the MOS tube internal resistance sampling current by the first current acquisition unit, the control unit corrects the three-phase sampling current according to the correction proportion of the three-phase sampling current and the correction proportion of the three-phase sampling current by the control unit, namely the MOS tube internal resistance sampling current, so that a more accurate three-phase current value is obtained, the influence of the MOS tube internal resistance on the current sampling precision in a MOS tube current sampling mode is reduced, and the control precision of a motor is improved.
Example 2
In addition, the present invention provides a three-phase current correction method applied to the three-phase current correction circuit provided in embodiment 1, specifically, referring to fig. 3, the method includes:
step S301, a first current acquisition unit acquires a first phase current i _U Second phase current i _V Third phase current i _W 。
In one embodiment, the first current acquisition unit acquires a first phase current i _U Second phase current i _V Third phase current i _W Comprising: the control unit sends a control signal to the first current acquisition unit; the first current acquisition unit determines the i according to the control signal _U Said i _V The i _W 。
Step S302, a second current acquisition unit acquires a second effective value i of the bus current _buseve 。
Step S303, the control unit according to the i _U Said i _V The i _W Determining a first effective value i of the bus current _calcbuseve 。
In one embodiment, the method according to i _U Said i _V The i _W Determining a first effective value i of the bus current _calcbuseve Comprising: the control unit acquires a period T PWM In, the conduction time T of the fourth NMOS tube U Conduction time T of fifth NMOS tube V Conduction time T of sixth NMOS tube W The method comprises the steps of carrying out a first treatment on the surface of the According to said i _U Said i _V Said i _W Said T PWM Said T U Said T V The T is W Determining the i _calcbuseve The calculation formula is as follows:
step S304, the control unit according to the i _calcbuseve And said i _buseve The correction ratio P is determined.
In one embodiment, the method according to i _calcbuseve And said i _buseve The correction ratio P is determined, and the calculation formula is as follows:
step S305, the control unit corrects the i according to the P _U Said i _V The i _W Obtaining the target three-phase current.
In one embodiment, the correction of the i is based on the P _U Said i _V The i _W Obtaining a target three-phase current, comprising: respectively correcting the i _U Said i _V The i _W Obtaining corrected first phase current i _U Corrected second phase current i _V Corrected third phase current i _W The calculation formula is as follows:
i' _x ＝P×i _x
wherein x is U, V or W; the i' _U 、i' _V I's' _W And determining the three-phase current as a target three-phase current.
The three-phase current correction method provided by the invention obtains the first phase current i through the first current acquisition unit _U Second phase current i _V Third onePhase current i _W The method comprises the steps of carrying out a first treatment on the surface of the The second current acquisition unit acquires a second effective value i of the bus current _buseve The method comprises the steps of carrying out a first treatment on the surface of the The control unit is based on the i _U Said i _V The i _W Determining a first effective value i of the bus current _calcbuseve The method comprises the steps of carrying out a first treatment on the surface of the According to said i _calcbuseve And said i _buseve Determining a correction proportion P; correcting the i respectively according to the P _U Said i _V The i _W Obtaining the target three-phase current. According to the invention, the second current acquisition unit is added, the bus resistor sampling current is subjected to hardware strong filtering treatment to obtain the second effective value of the bus current, and before the second effective value, the first effective value of the bus current is determined by the first current acquisition unit according to the MOS tube internal resistance sampling current. The control unit corrects the three-phase sampling current according to the correction proportion of the three-phase sampling current according to the first effective value of the bus and the second effective value of the bus, namely the MOS tube internal resistance sampling current, so that a more accurate three-phase current value is obtained, the influence of the MOS tube internal resistance on the current sampling precision in a MOS tube current sampling mode is reduced, and the control precision of the motor is improved.
The three-phase current correction method provided in this embodiment is applied to the three-phase current correction circuit described in embodiment 1, and is not described here again to avoid repetition.
Any particular values in all examples shown and described herein are to be construed as merely illustrative and not a limitation, and thus other examples of exemplary embodiments may have different values.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.
The above examples merely represent a few embodiments of the present invention, which are described in more detail and are not to be construed as limiting the scope of the present invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention.

Claims (10)

1. A three-phase current correction circuit, the circuit comprising: the device comprises a first current acquisition unit, a second current acquisition unit and a control unit;
the first end of the first current acquisition unit is electrically connected with the bus, the second end of the first current acquisition unit is electrically connected with the first end of the control unit, the third end of the first current acquisition unit is electrically connected with the second end of the control unit, and the fourth end of the first current acquisition unit is electrically connected with the first end of the second current acquisition unit; the fifth end of the first current acquisition unit is electrically connected with the motor;
the second end of the second current acquisition unit is electrically connected with the third end of the control unit, and the third end and the fourth end of the second current acquisition unit are respectively grounded;
the first current acquisition unit is used for acquiring a first phase current i _U Second phase current i _V Third phase current i _W ；
The second current acquisition unit is used for acquiring a second effective value i of the bus current _buseve ；
The control unit is used for controlling the control unit according to the i _U Said i _V The i _W Determining a first effective value i of the bus current _calcbuseve The method comprises the steps of carrying out a first treatment on the surface of the According to said i _calcbuseve And said i _buseve Determining a correction proportion P; correcting the i respectively according to the P _U Said i _V The i _W Obtaining the target three-phase current.
2. The three-phase current correction circuit according to claim 1, wherein the first current collection unit comprises a first NMOS tube, a second NMOS tube, a third NMOS tube, a fourth NMOS tube, a fifth NMOS tube, and a sixth NMOS tube;
the drain electrode of the first NMOS tube, the drain electrode of the second NMOS tube and the drain electrode of the third NMOS tube are respectively and electrically connected with the bus;
the gates of the first NMOS tube, the second NMOS tube, the third NMOS tube, the fourth NMOS tube, the fifth NMOS tube and the sixth NMOS tube are respectively and electrically connected with the first end of the control unit;
the source electrode of the fourth NMOS tube, the source electrode of the fifth NMOS tube and the source electrode of the sixth NMOS tube are respectively and electrically connected with the first end of the second current acquisition unit;
the source electrode of the first NMOS tube is electrically connected with the drain electrode of the fourth NMOS tube, the source electrode of the second NMOS tube is electrically connected with the drain electrode of the fifth NMOS tube, and the source electrode of the third NMOS tube is electrically connected with the drain electrode of the sixth NMOS tube.
3. The three-phase current correction circuit according to claim 2, wherein the first current collection unit further comprises a first operational amplifier, a second operational amplifier, and a third operational amplifier;
the input end of the first operational amplifier is connected with the fourth NMOS tube in parallel, the input end of the second operational amplifier is connected with the fifth NMOS tube in parallel, and the input end of the third operational amplifier is connected with the sixth NMOS tube in parallel;
the output ends of the first operational amplifier, the second operational amplifier and the third operational amplifier are respectively and electrically connected with the second end of the control unit.
4. The three-phase current correction circuit according to claim 3, wherein the second current collection unit includes a bus resistor, a fourth operational amplifier, a filter capacitor, and a filter resistor;
the first end of the bus resistor is electrically connected with the source electrode of the fourth NMOS tube, the source electrode of the fifth NMOS tube and the source electrode of the sixth NMOS tube respectively;
the input end of the fourth operational amplifier is connected with the bus resistor in parallel, and the output end of the fourth operational amplifier is electrically connected with the first end of the filter resistor;
the second end of the filter resistor is electrically connected with the third end of the control unit and the first end of the filter capacitor respectively;
and the second end of the bus resistor is grounded, and the second end of the filter capacitor is grounded.
5. The three-phase current correction circuit of claim 4, wherein the source of the first NMOS transistor, the source of the second NMOS transistor, and the source of the third NMOS transistor are electrically connected to different phases of the motor, respectively.
6. A three-phase current correction method, characterized by being applied to a three-phase current correction circuit, the method comprising:
the first current acquisition unit acquires a first phase current i _U Second phase current i _V Third phase current i _W ；
The second current acquisition unit acquires a second effective value i of the bus current _buseve ；
The control unit is based on the i _U Said i _V The i _W Determining a first effective value i of the bus current _calcbuseve The method comprises the steps of carrying out a first treatment on the surface of the According to said i _calcbuseve And said i _buseve Determining a correction proportion P; correcting the i respectively according to the P _U Said i _V The i _W Obtaining the target three-phase current.
7. The method according to claim 6, wherein the first current acquisition unit acquires a first phase current i _U Second phase current i _V Third phase current i _W Comprising:
the control unit sends a control signal to the first current acquisition unit;
the first current acquisition unit determines the i according to the control signal _U Said i _V The i _W 。
8. The three-phase current correction method according to claim 7, wherein the current correction is performed in accordance with the i _U Said i _V The i _W Determining a first effective value i of the bus current _calcbuseve Comprising:
the control unit acquires a period T PWM In, the conduction time T of the fourth NMOS tube U Conduction time T of fifth NMOS tube V Conduction time T of sixth NMOS tube W ；
According to said i _U Said i _V Said i _W Said T PWM Said T U Said T V The T is W Determining the i _calcbuseve The calculation formula is as follows:
9. the three-phase current correction method according to claim 8, wherein the current correction is performed in accordance with the i _calcbuseve And said i _buseve The correction ratio P is determined, and the calculation formula is as follows:
10. the three-phase current correction method according to claim 9, wherein said i is corrected according to said P, respectively _U Said i _V The i _W Obtaining a target three-phase current, comprising:
respectively correcting the i _U Said i _V The i _W Obtaining corrected first phase current i' _U Corrected second phase current i' _V Corrected third phase current i' _W The calculation formula is as follows:
i' _x ＝P×i _x
wherein x is U, V or W;
the i' _U 、i′ _V I's' _W And determining the three-phase current as a target three-phase current.
CN202311408082.9A 2023-10-26 2023-10-26 Three-phase current correction circuit and method Pending CN117554678A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202311408082.9A CN117554678A (en) 2023-10-26 2023-10-26 Three-phase current correction circuit and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202311408082.9A CN117554678A (en) 2023-10-26 2023-10-26 Three-phase current correction circuit and method

Publications (1)

Publication Number Publication Date
CN117554678A true CN117554678A (en) 2024-02-13

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN202311408082.9A Pending CN117554678A (en) 2023-10-26 2023-10-26 Three-phase current correction circuit and method

Country Status (1)

Country Link
CN (1) CN117554678A (en)

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