CN114362607A - Motor driving device, driving assembly and electric tool - Google Patents
Motor driving device, driving assembly and electric tool Download PDFInfo
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- CN114362607A CN114362607A CN202210044280.0A CN202210044280A CN114362607A CN 114362607 A CN114362607 A CN 114362607A CN 202210044280 A CN202210044280 A CN 202210044280A CN 114362607 A CN114362607 A CN 114362607A
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Abstract
The invention relates to a motor driving device, a driving assembly and an electric tool, wherein the device comprises a three-phase motor, a three-phase full-bridge inverter, a voltage detection module, a driving module and a control module, wherein the three-phase full-bridge inverter comprises a first bridge arm, a second bridge arm and a third bridge arm, and each bridge arm comprises an upper bridge arm and a lower bridge arm; the driving module is used for sequentially outputting K driving signals in K continuous time periods in an initialization stage of starting the three-phase motor; the voltage detection module is used for detecting the voltage of the non-conducting phase of the three-phase motor when each driving signal acts in each time period; and the control module is used for determining the position of the rotor of the three-phase motor relative to the stator according to the magnitude relation of the voltage of the non-conducting phase in each time period. The embodiment of the disclosure can realize high-precision rotor positioning, so that the motor has larger torque at the initial stage of motor starting, and the running efficiency of the motor is improved.
Description
Technical Field
The disclosure relates to the technical field of motor control, in particular to a motor driving device, a driving assembly and an electric tool.
Background
The space vector modulation technology is already a mainstream mode of the dc brushless motor control, and for the dc brushless motor control without a position sensor, because the space vector position of the initial rotor relative to the stator is unknown, the control mode of the maximum permanent magnet torque, i.e. the stator and rotor magnetic field orthogonality, cannot be realized accurately. Therefore, the motor is positioned relative to the stator, the positioning precision is improved, and the motor control device has important significance for motor control, particularly heavy-load starting.
Disclosure of Invention
According to an aspect of the present disclosure, there is provided a motor driving apparatus including a three-phase motor, a three-phase full-bridge inverter, a voltage detecting module, a driving module, and a control module,
the three-phase full-bridge inverter comprises a first bridge arm, a second bridge arm and a third bridge arm, wherein each bridge arm comprises an upper bridge arm and a lower bridge arm, the upper bridge arm and the lower bridge arm of each bridge arm are respectively provided with a transistor, the three-phase full-bridge inverter is used for driving the three-phase motor, and the first bridge arm, the second bridge arm and the third bridge arm respectively correspond to a first phase, a second phase and a third phase of the three-phase motor;
the driving module is connected to each transistor of the three-phase full-bridge inverter and used for sequentially outputting K driving signals in K continuous time periods in an initialization stage of starting the three-phase motor, wherein each driving signal is used for driving any two phases of the three-phase motor to be conducted, and K is a positive integer;
the voltage detection module is connected between an upper bridge arm and a lower bridge arm of each bridge arm of the three-phase full-bridge inverter and is used for detecting the voltage of the non-conducting phase of the three-phase motor when each driving signal acts in each time period;
the control module is connected to the voltage detection module and the drive module and used for determining the position of the rotor of the three-phase motor relative to the stator according to the magnitude relation of the voltage of the non-conducting phase in each time period.
In a possible embodiment, the determining the position of the rotor of the three-phase motor relative to the stator according to the magnitude relation of the voltages of the non-conducting phases of the respective time periods includes:
determining a minimum voltage of voltages of the respective non-conducting phases;
determining a first position interval of the rotor relative to the stator according to the minimum voltage;
determining two adjacent target vectors of the first position interval in a sector corresponding to a motor space vector diagram, and determining a second position interval according to the voltage magnitude relation of a non-conducting phase corresponding to the target vectors, wherein the motor space vector diagram leads out a plurality of vectors from a central point, the plurality of vectors divide the motor space vector diagram into a plurality of sectors, each driving signal corresponds to a vector of the motor space vector diagram, and the target vectors are vectors corresponding to the driving signals;
and determining the position of the rotor of the three-phase motor relative to the stator according to the second position interval.
In a possible embodiment, the number of vectors is 12, the number of sectors is 12, and the determining a first position interval of the rotor relative to the stator according to the minimum voltage includes:
determining two sectors adjacent to a reverse vector of the vector corresponding to the minimum voltage as the first position interval; or
And determining a first position interval of the rotor relative to the stator according to the minimum voltage and a first mapping relation, wherein the first mapping relation comprises a corresponding relation between a non-conducting phase corresponding to the minimum voltage and a vector position interval.
In a possible implementation manner, the determining the second position interval according to the voltage magnitude relationship of the non-conducting phase corresponding to the target vector includes:
determining a first target vector corresponding to the voltage of a small non-conducting phase in the two target vectors;
determining a position interval which is close to the preset angle of the first target vector in the first position interval as a second position interval; or determining the sector of the first position interval close to the first target vector as a second position interval.
In one possible embodiment, the time lengths of the K time periods are equal.
In one possible embodiment, the duration of each time period is between 10 μ s and 30 μ s.
In one possible embodiment, the drive signals comprise at least two of a first drive signal, a second drive signal, a third drive signal, a fourth drive signal, a fifth drive signal, a sixth drive signal, wherein,
the first driving signal is used for driving the transistor of the upper bridge arm of the first bridge arm to be conducted and the transistor of the lower bridge arm of the third bridge arm to be conducted, and the non-conducting phase corresponding to the action time period of the first driving signal is a second phase;
the second driving signal is used for driving the transistor of the upper bridge arm of the second bridge arm to be conducted and the transistor of the lower bridge arm of the third bridge arm to be conducted, and the non-conducting phase corresponding to the action time period of the second driving signal is the first phase;
the third driving signal is used for driving the transistors of the upper bridge arm of the second bridge arm to be conducted and the transistors of the lower bridge arm of the first bridge arm to be conducted, and a non-conducting phase corresponding to a time period of action of the third driving signal is a third phase;
the fourth driving signal is used for driving the transistor of the upper bridge arm of the third bridge arm to be conducted and the transistor of the lower bridge arm of the first bridge arm to be conducted, and the non-conducting phase corresponding to the action time period of the fourth driving signal is a second phase;
the fifth driving signal is used for driving the transistors of the upper bridge arm of the third bridge arm to be conducted and the transistors of the lower bridge arm of the second bridge arm to be conducted, and the non-conducting phase corresponding to the action time period of the fifth driving signal is the first phase;
the sixth driving signal is used for driving the transistors of the upper bridge arm of the first bridge arm to be conducted and the transistors of the lower bridge arm of the second bridge arm to be conducted, and the non-conducting phase corresponding to the action time period of the sixth driving signal is the third phase.
In one possible embodiment, the voltage detection module includes a first voltage detection unit, a second voltage detection unit, and a third voltage detection unit, which are respectively connected between an upper bridge arm and a lower bridge arm of each phase of the three-phase full-bridge inverter, wherein each voltage detection unit includes a first detection resistor and a second detection resistor,
the first end of the first detection resistor is connected between the corresponding upper bridge arm and the corresponding lower bridge arm, and the second end of the first detection resistor is connected to the first end of the second detection resistor and used for outputting detection voltage;
the second end of the second detection resistor is grounded.
According to an aspect of the present disclosure, there is provided a drive assembly including the motor drive device.
According to an aspect of the present disclosure, there is provided a power tool including the drive assembly.
The motor driving device provided by the embodiment of the disclosure sequentially outputs K driving signals in K continuous time periods in the initialization stage of starting the three-phase motor through the driving module so as to drive any two phases of the three-phase motor to be conducted in each time period, and detects the voltage of the non-conducting phase of the three-phase motor when each driving signal in each time period acts through the voltage detecting module.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. Other features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments, which proceeds with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the disclosure.
Fig. 1 shows a block diagram of a motor driving apparatus according to an embodiment of the present disclosure.
Fig. 2 shows a flowchart of steps performed by a control module in a motor drive apparatus according to an embodiment of the present disclosure.
Fig. 3 shows a schematic view of a motor drive according to an embodiment of the present disclosure.
Fig. 4a shows a schematic diagram of magnetization curves of a motor stator core of a three-phase motor according to an embodiment of the present disclosure, and fig. 4B shows a schematic diagram of magnetization curves B-H and permeability curves μ -H of a ferromagnetic material used in the three-phase motor according to an embodiment of the present disclosure.
Fig. 4c is a schematic diagram illustrating the relationship between the variation of the electronic inductance of the three-phase motor and the included angle between the magnetic potential generated by the armature winding and the permanent magnetic potential according to an embodiment of the disclosure.
Fig. 5 shows a flowchart of steps performed by a control module in a motor drive apparatus according to an embodiment of the present disclosure.
Fig. 6 shows a motor space vector diagram according to an embodiment of the present disclosure.
Detailed Description
Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers can indicate functionally identical or similar elements. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
In the description of the present disclosure, it is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings, which is solely for the purpose of facilitating the description and simplifying the description, and does not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and, therefore, should not be taken as limiting the present disclosure.
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 implicitly indicating 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 disclosure, "a plurality" means two or more unless specifically limited otherwise.
In the present disclosure, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integral; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present disclosure can be understood by those of ordinary skill in the art as appropriate.
The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.
The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the term "at least one" herein means any one of a plurality or any combination of at least two of a plurality, for example, including at least one of A, B, C, and may mean including any one or more elements selected from the group consisting of A, B and C.
Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present disclosure. It will be understood by those skilled in the art that the present disclosure may be practiced without some of these specific details. In some instances, methods, means, elements and circuits that are well known to those skilled in the art have not been described in detail so as not to obscure the present disclosure.
Referring to fig. 1, fig. 1 shows a block diagram of a motor driving apparatus according to an embodiment of the present disclosure.
Referring to fig. 2, fig. 2 is a flowchart illustrating steps executed by a control module in a motor driving apparatus according to an embodiment of the disclosure.
As shown in fig. 1, the apparatus includes a three-phase motor 10, a three-phase full-bridge inverter 20, a voltage detection module 30, a driving module 40 and a control module 50,
the three-phase full-bridge inverter 20 comprises a first bridge arm, a second bridge arm and a third bridge arm, each bridge arm comprises an upper bridge arm and a lower bridge arm, the upper bridge arm and the lower bridge arm of each bridge arm are provided with transistors, the three-phase full-bridge inverter 20 is used for driving the three-phase motor 10, and the first bridge arm, the second bridge arm and the third bridge arm respectively correspond to a first phase, a second phase and a third phase of the three-phase motor 10;
the driving module 40 is connected to each transistor of the three-phase full-bridge inverter 20, and configured to sequentially output K driving signals in K consecutive time periods in an initialization stage of starting the three-phase motor 10, where each driving signal is used to drive any two phases of the three-phase motor 10 to be turned on, and K is a positive integer;
the voltage detection module 30 is connected between an upper bridge arm and a lower bridge arm of each bridge arm of the three-phase full-bridge inverter 20, and configured to detect a voltage of a non-conducting phase of the three-phase motor 10 when each driving signal acts in each time period;
the control module 50 is connected to the voltage detection module 30 and the driving module 40, as shown in fig. 2, and configured to:
step S11, determining the position of the rotor of the three-phase motor 10 relative to the stator according to the magnitude relationship of the voltage of the non-conducting phase in each time segment.
The motor driving device provided by the embodiment of the disclosure sequentially outputs K driving signals in K continuous time periods in the initialization stage of starting the three-phase motor through the driving module so as to drive any two phases of the three-phase motor to be conducted in each time period, and detects the voltage of the non-conducting phase of the three-phase motor when each driving signal in each time period acts through the voltage detecting module.
It should be noted that each module and unit in the embodiments of the present disclosure may be implemented by a hardware circuit, or implemented by using a general hardware circuit in combination with related existing logic.
First, a possible implementation of the three-phase full-bridge inverter 20 is exemplarily described, and it should be noted that the implementation of the present disclosure is not limited to the possible implementation of the three-phase full-bridge inverter 20, and in other embodiments, the three-phase full-bridge inverter 20 may have other implementations.
The following is an exemplary description of possible implementations of the various modules.
Referring to fig. 3, fig. 3 is a schematic diagram illustrating a motor driving apparatus according to an embodiment of the disclosure.
As shown in fig. 3, the three-phase full-bridge inverter 20 may include a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a fifth transistor Q5, a sixth transistor Q6, the first transistor Q1 and the fourth transistor Q4 make up a first leg and the fourth transistor Q4 is a lower leg, the second transistor Q2 and the fifth transistor Q5 constitute a second leg and the fifth transistor Q5 is a lower leg, the third transistor Q3 and the sixth transistor Q6 constitute a third bridge arm and the sixth transistor Q6 is a lower bridge arm, one end of each winding of the three-phase motor 10 is electrically connected, and the other end of each winding is electrically connected between the first transistor Q1 and the fourth transistor Q4, between the second transistor Q2 and the fifth transistor Q5, and between the third transistor Q3 and the sixth transistor Q6.
In one possible implementation, the first Transistor Q1, the second Transistor Q2, the third Transistor Q3, the fourth Transistor Q4, the fifth Transistor Q5, and the sixth Transistor Q6 may be Metal-Oxide-Semiconductor Field-Effect transistors (MOSFETs), Insulated Gate Bipolar Transistors (IGBTs), wherein the transistors may be implemented based on SiC, GaN to improve performance.
In a possible implementation manner, as shown in fig. 3, the three-phase full-bridge inverter 20 may further include a plurality of first input resistors, a plurality of second input resistors, and a plurality of input capacitors to filter the input signals, the stator of the three-phase motor 10 includes a first winding a, a second winding B, and a third winding C, wherein the gates of the transistors of the three-phase full-bridge inverter 20 are electrically connected to the second ends of the first input resistors, the first ends of the second input resistors, and the first ends of the input capacitors, the sources of the transistors of the three-phase full-bridge inverter 20 are electrically connected to the second ends of the input capacitors, the second ends of the second input resistors, and the first ends of the first input resistors are used for inputting the control signals,
wherein the drain of the first transistor Q1, the drain of the second transistor Q2, and the drain of the third transistor Q3 are electrically connected, the source of the fourth transistor Q4, the source of the fifth transistor Q5, and the source of the sixth transistor Q6 are electrically connected,
the source of the first transistor Q1 is electrically connected to the drain of the fourth transistor Q4 and the first end of the first winding, the source of the second transistor Q2 is electrically connected to the drain of the fifth transistor Q5 and the first end of the second winding, the source of the third transistor Q3 is electrically connected to the drain of the sixth transistor Q6 and the first end of the third winding,
the second end of the first winding A, the second end of the second winding B and the second end of the third winding C are grounded.
In one example, as shown in fig. 3, the first input resistor may include a first resistor R1, a third resistor R3, a fifth resistor R5, a seventh resistor R7, a ninth resistor R9 and an eleventh resistor R11, the second input resistor may include a second resistor R2, a fourth resistor R4, a sixth resistor R6, an eighth resistor R8, a tenth resistor R10 and a twelfth resistor R12, and the input capacitor may include a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5 and a sixth capacitor C6.
In one example, the three-phase full-bridge inverter 20 may further include a plurality of freewheeling diodes disposed between the source and drain of each transistor for providing a freewheeling path when the transistor is turned off to prevent the transistor from being damaged.
In one possible implementation, the three-phase motor 10 may be a three-phase dc brushless motor.
In one example, the embodiment of the present disclosure realizes a Y connection (or may be referred to as a star connection) of the three-phase motor 10 by electrically connecting one end of each winding of the stator and electrically connecting the other end of each winding between the first transistor Q1 and the fourth transistor Q4, between the second transistor Q2 and the fifth transistor Q5, and between the third transistor Q3 and the sixth transistor Q6.
In one example, as shown in fig. 3, the three-phase motor 10 may include a first winding a, a second winding B, and a third winding C (corresponding to the phase a, the phase B, and the phase C, respectively, and corresponding to the first arm, the second arm, and the third arm), wherein one end of the first winding a is electrically connected between the first transistor Q1 and the fourth transistor Q4, one end of the second winding B is electrically connected between the second transistor Q2 and the fifth transistor Q5, and one end of the third winding C is electrically connected between the third transistor Q3 and the sixth transistor Q6.
In one possible embodiment, as shown in fig. 3, the voltage detection module 30 includes a first voltage detection unit 310, a second voltage detection unit 320, and a third voltage detection unit 330, which are respectively connected between the upper bridge arm and the lower bridge arm of each phase of the three-phase full-bridge inverter 20, wherein each voltage detection unit includes a first detection resistor Re1 and a second detection resistor Re2,
the first end of the first detection resistor Re1 is connected between the corresponding upper bridge arm and the corresponding lower bridge arm, and the second end of the first detection resistor Re1 is connected to the first end of the second detection resistor Re2 and used for outputting a detection voltage Vde;
the second end of the second detection resistor Re2 is grounded.
In a possible implementation manner, the driving module 40 according to the embodiment of the present disclosure may be implemented by a dedicated motor driving chip, or may be built by a discrete device, which is not limited in the embodiment of the present disclosure.
The control module 50 of the disclosed embodiment may include processing components including, but not limited to, a single processor, or discrete components, or a combination of a processor and discrete components. The processor may comprise a controller having functionality to execute instructions in an electronic device, which may be implemented in any suitable manner, e.g., by one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), controllers, micro-controllers, microprocessors or other electronic components. Within the processor, the executable instructions may be executed by hardware circuits such as logic gates, switches, Application Specific Integrated Circuits (ASICs), programmable logic controllers, and embedded microcontrollers. The embodiment of the present disclosure does not limit the specific implementation manner of the control module 50.
The principle and possible implementation of the control module of the disclosed embodiment for positioning the rotor angle will be described in the following.
Referring to fig. 4a and 4B, fig. 4a is a schematic diagram illustrating magnetization curves of a stator core of a three-phase motor according to an embodiment of the present disclosure, and fig. 4B is a schematic diagram illustrating magnetization curves B-H and permeability curves μ -H of a ferromagnetic material used in the three-phase motor according to an embodiment of the present disclosure.
In one example, engineering to maximize the utilization of the core material, the no-load operating point of the motor is selected at a location where the rising slope of the magnetization curve is small, such as point a in fig. 4 b.
The nominal operating point of the motor core is not at its maximum permeability, but to the right of it, as shown by point a in fig. 4 b. When the armature winding of the stator is electrified, armature reaction caused by armature magnetic potential can cause the working point to shift, thereby causing the change of magnetic permeability.
In one example, the inductance of the motor stator armature winding can be given by equation 1:
further, equation 2 can be found:
according to the ampere-loop theorem, equation 2 can be transformed into equation 3:
wherein psiSRepresenting stator armature flux linkage, NSDenotes the number of turns of the stator armature winding, S denotes the cross-sectional area of the magnetic circuit, iSRepresenting stator armature winding current, L being the length of the magnetic circuit, RmψThe magnetic resistance of the main magnetic circuit of the motor is mainly composed of an iron core magnetic resistance and an air gap magnetic resistance, and B represents magnetic induction intensity.
The magnetic resistance of the main magnetic circuit of the motor can be obtained by formula 4:
wherein R isFeDenotes the core reluctance, RσDenotes air gap reluctance, LFeDenotes the core magnetic path length, μFeDenotes the core permeability, LσDenotes the air gap magnetic path length, μσIndicating the air gap permeability.
In one example, for a selected motor, the number of stator armature winding turns, NSIs a constant, and for surface-mounted brushless DC motors, the air gap length L isσIs constant, air gap permeability muσUnchanged, then the air gap reluctance RσIs constant; for the core reluctance with a long magnetic circuit, the magnetic potential generated by the armature winding will cause the magnetic field intensity H to change, thereby causing the magnetizing and demagnetizing effects to have different magnetic permeability muFe。
In one example, when the absolute value of the angle between the armature winding generated magnetic potential and the permanent magnetic potential is less than 90 °, the component of the armature magnetic potential on the d axis is a positive value, which results in a magnetizing effect, and as can be seen from fig. 4b, the magnetic permeability of the iron core will be reduced, and thus the stator inductance is reduced; when the absolute value of the included angle between the magnetic potential generated by the armature winding and the permanent magnetic potential is larger than 90 degrees, as shown in fig. 4b, the component of the armature magnetic potential on the d axis is a negative value, so that a demagnetization effect is caused, the magnetic conductivity of the iron core is increased, and the inductance of the stator is increased.
Referring to fig. 4c, fig. 4c is a schematic diagram illustrating a relationship between a magnetic potential generated by an armature winding and an included angle between a permanent magnetic potential and an electronic inductance of a three-phase motor according to an embodiment of the present disclosure.
The ordinate in fig. 4c represents the variation of the stator inductance with the angle of the rotor relative to the stator, and when the angle of the rotor relative to the stator is less than 90 °, the stator inductance is greater than the original inductance, i.e., the stator inductance is over 100% of the original inductance.
In one example, as shown in fig. 4c, the smaller the armature magnetic potential angle to the permanent magnet magnetic potential, the larger the magnetizing effect, and the smaller the corresponding stator winding inductance.
In one example, the motor phase voltage of the dc brushless motor may be as shown in equation 5:
wherein u isa,b,cRepresenting phase voltages, R-meterPhase indicating resistance, LSRepresenting stator phase inductance, ia,b,cShows the phase current, ea,b,cRepresenting an opposite potential.
In one example, the counter-potential e is when the motor is at rest or at a low rotational speeda,b,cSmall, negligible; the phase resistance of the motor is usually small and the phase containing the resistance can be ignored, in which case equation 5 above can be simplified as:
it can be seen from equation 6 that the phase voltage is approximately proportional to the stator phase inductance when the motor speed is low. When the rotating speed is high, the voltage is considered to be counter potential phase voltage caused by the rotating speed, voltage drop on an inductor and a resistor is ignored, and when the rotating speed is low, the opposite is true, because the rotating speed is low, the counter potential and the rotating speed are related, and e is Ceφ n, where C is a constant and φ is a permanent magnet flux linkage, can also be considered to be constant, so that the back electromotive force of the motor is directly and positively correlated with the rotating speed, because for this reason, the current is large when the motor is started, the rotating speed is too low, the back electromotive force is too small, the voltage on the voltage basically acts on the inductance and the resistance of the motor, and therefore the starting current is large.
As can be seen from the above analysis, the stator inductance of the dc brushless motor is not always constant, and the stator inductance increases with the increasing of the stator current (as shown in fig. 4 a), but when the stator current reaches a certain value, the stator inductance reaches a saturation state; at the same time the rotor permanent magnets also have a large influence on the stator inductance, as shown in fig. 4 c.
Therefore, when the motor is in a static state, when the included angle between the magnetic field of the stator and the magnetic field of the rotor permanent magnet is smaller than 90 degrees, the rotor permanent magnet can play a role in increasing the magnetic field of the stator, and when the included angle between the magnetic field of the stator and the magnetic field of the rotor permanent magnet is larger than 90 degrees, the rotor permanent magnet can play a role in demagnetizing the magnetic field of the stator, so that a plurality of driving signals (including six vector pulses with the same width) which are not enough for the motor to rotate can be injected at the initial moment, and the stator vector sector where the rotor permanent magnet is located can be determined according to the magnitude relation of the non-conducting phase voltage obtained by injecting the six pulses.
The specific implementation manner of determining the position of the rotor of the three-phase motor 10 relative to the stator according to the magnitude relationship of the voltage of the non-conducting phase in each time period in step S11 is not limited in the embodiment of the present disclosure, and a person skilled in the art may implement the determination by using related technologies according to actual situations and needs, and the following describes an exemplary preferred embodiment.
Referring to fig. 5, fig. 5 is a flowchart illustrating steps executed by a control module in a motor driving apparatus according to an embodiment of the disclosure.
In one possible embodiment, as shown in fig. 5, the step S11 of determining the position of the rotor of the three-phase motor 10 relative to the stator according to the magnitude relation of the voltages of the non-conducting phases of the respective time periods may include:
step S111, determining the minimum voltage in the voltages of the non-conducting phases;
step S112, determining a first position interval of the rotor relative to the stator according to the minimum voltage;
step S113, determining two adjacent target vectors of the first position interval in a sector corresponding to a motor space vector diagram, and determining a second position interval according to the voltage magnitude relation of a non-conducting phase corresponding to the target vectors, wherein the motor space vector diagram leads out a plurality of vectors from a central point, the plurality of vectors divide the motor space vector diagram into a plurality of sectors, each driving signal corresponds to a vector of the motor space vector diagram, and the target vectors are vectors corresponding to the driving signals;
and step S114, determining the position of the rotor of the three-phase motor 10 relative to the stator according to the second position interval.
According to the embodiment of the disclosure, the minimum voltage in the voltages of the non-conducting phases is determined, the first position interval of the rotor relative to the stator is determined according to the minimum voltage, two adjacent target vectors of the first position interval in a sector corresponding to a motor space vector diagram are determined, and the second position interval is determined according to the voltage magnitude relation of the non-conducting phase corresponding to the target vectors, so that the position of the rotor relative to the stator can be determined quickly and accurately, and the determined position has higher precision.
The number of the driving signals is not limited in the embodiments of the present disclosure, and those skilled in the art can set the driving signals according to actual conditions and needs.
The specific implementation manner of determining the first position interval of the rotor relative to the stator according to the minimum voltage in step S112 is not limited in the embodiment of the present disclosure, and those skilled in the art may implement the determination in a suitable manner according to actual situations and needs, which is described in the following exemplary description.
Referring to fig. 6, fig. 6 shows a motor space vector diagram according to an embodiment of the present disclosure.
In a possible embodiment, the number OF said vectors may be 12 (OA/OK/OY/OH/OC/OG/OX/OF/OB/OE/OZ/OD), and the number OF said sectors (minimum sectors) may be 12 (OAD/ODZ, etc.), wherein the vectors OA, OB, OC correspond to the three-phase vector positions OF the motor, respectively, with a mutual spatial difference OF 120 °, each minimum sector corresponding to 30 °.
In a possible implementation, as shown in fig. 5, the step S112 of determining a first position interval of the rotor relative to the stator according to the minimum voltage may include:
step S1121, determining two sectors adjacent to a reverse vector of the minimum voltage corresponding vector as the first position interval.
For example, if the non-conducting phase voltage corresponding to the OD vector is the minimum, the reverse vector of the OD vector is determined to be OG, and two adjacent sectors of the OD vector are OXG and OGC.
In a possible embodiment, as shown in fig. 5, the step S112 of determining a first position interval of the rotor relative to the stator according to the minimum voltage includes:
step S1121, determining a first position interval of the rotor relative to the stator according to the minimum voltage and a first mapping relationship, where the first mapping relationship includes a correspondence between a non-conducting phase corresponding to the minimum voltage and a vector position interval.
For example, the corresponding relationship between the vector corresponding to the minimum voltage and the vector position interval may be established in advance, as shown in table 1.
TABLE 1
For example, as shown in fig. 6 and table 1, if the minimum voltage is determined to be OD, the first location interval may be determined to be the sector OXC.
The specific implementation manner of determining the second position interval according to the voltage magnitude relationship of the non-conducting phase corresponding to the target vector in step S113 is not limited in the embodiment of the present disclosure, and those skilled in the art may implement the determination in an appropriate manner according to actual situations and needs, which is described in the following exemplary description.
In a possible implementation manner, as shown in fig. 5, the determining, in step S113, the second position interval according to the voltage magnitude relationship of the non-conducting phase corresponding to the target vector may include:
step S1131, determining a first target vector corresponding to the voltage of the small non-conducting phase in the two target vectors;
step S1132, determining a position interval, which is close to the preset angle of the first target vector, in the first position interval as a second position interval; or determining the sector of the first position interval close to the first target vector as a second position interval.
For example, as shown in fig. 6, if the first location interval is determined as sector OXC, and the vector corresponding to the driving signal includes OD/OE/OF/OG/OH/OK, the target vectors adjacent to the first location interval may be determined as vector OF and vector OH, in which case, the disclosed embodiment may compare the magnitudes OF the voltages OF the non-conducting phases corresponding to vector OF and vector OH, and determine the smaller voltage as the first target vector.
For example, as shown in fig. 6, if it is determined that the voltage OF the non-conducting phase corresponding to the vector OF is less than the voltage OF the non-conducting phase corresponding to the vector OH, a position interval close to the vector OF by a preset angle in the first position interval OXC may be determined as the second position interval, and if the preset angle is 30 degrees, the second position interval may be determined as the sector OXG.
For example, as shown in fig. 6, the embodiment OF the present disclosure may also determine the sector OF the first location interval close to the first target vector as the second location interval, for example, the sector OXC includes two minimum sectors OXG and OGC, and the sector OF close to the vector is OXG, and then the embodiment OF the present disclosure may determine the second location interval as the sector OXG.
Of course, the above description of step S1132 is exemplary and should not be construed as limiting the embodiments of the present disclosure.
The driving signals of the embodiments of the present disclosure are exemplarily described below.
In one possible embodiment, the time lengths of the K time periods are equal.
In one possible embodiment, the duration of each time segment is between 10 μ s and 30 μ s, for example, the duration of each time segment may be 20 μ s.
The embodiment of the disclosure can support setting each time period to be 10-30 mus, and compared with a setting mode of more than 60 mus in the related art, the mute property of the motor operation can be greatly improved.
In a possible embodiment, assuming that the number of time periods and the number of driving signals are both 6, and assuming that the driving signals include at least two of the first driving signal, the second driving signal, the third driving signal, the fourth driving signal, the fifth driving signal, and the sixth driving signal, the corresponding relationship between the driving signals, the vectors, and the corresponding non-conducting phases is shown in table 2.
TABLE 2
A, B, C indicates each phase of the three-phase motor (which may be referred to as a first phase or a phase, a second phase or B phase, a third phase or C phase), "up" indicates that the transistor of the upper arm is on, "down" indicates that the transistor of the lower arm is on, and, for example, a up, C, and down indicate that the transistor of the upper arm of the first arm corresponding to a is on and the transistor of the lower arm of the third arm corresponding to C is on, as will be described in the following exemplary description.
In one example, as shown in fig. 3 and table 2, the first driving signal (a up, C down) is used to drive the transistors of the upper arm of the first arm to be turned on and the transistors of the lower arm of the third arm to be turned on, and the non-conducting phase corresponding to the time period of action of the first driving signal is the second phase;
in one example, as shown in fig. 3 and table 2, the second driving signal (B, up, C, and down) is used to drive the transistors of the upper arm of the second arm to be turned on and the transistors of the lower arm of the third arm to be turned on, and the non-conducting phase corresponding to the acting time period of the second driving signal is the first phase;
in one example, as shown in fig. 3 and table 2, the third driving signal (B up, a down) is used to drive the transistors of the upper arm of the second arm to be turned on and the transistors of the lower arm of the first arm to be turned on, and the non-conducting phase corresponding to the acting time period of the third driving signal is a third phase;
in one example, as shown in fig. 3 and table 2, the fourth driving signal (C up, a down) is used to drive the transistors of the upper arm of the third arm to be conductive and the transistors of the lower arm of the first arm to be conductive, and a non-conductive phase corresponding to a period of action of the fourth driving signal is a second phase;
in an example, as shown in fig. 3 and table 2, the fifth driving signal (C up, B down) is used to drive the transistors of the upper arm of the third arm to be turned on and the transistors of the lower arm of the second arm to be turned on, and a non-conducting phase corresponding to a time period during which the fifth driving signal acts is a first phase;
in one example, as shown in fig. 3 and table 2, the sixth driving signal (a up, B down) is used to drive the transistors of the upper arm of the first arm to be conductive and the transistors of the lower arm of the second arm to be conductive, and the non-conductive phase corresponding to the time period in which the sixth driving signal is applied is the third phase.
The sequence of the driving signals injected into the inverter is not limited in the embodiments of the present disclosure, and taking six driving signals as an example, the six driving signals may be injected into the three-phase full-bridge inverter according to any sequence, and the acting time length of each driving signal is the preset time length.
The embodiment of the present disclosure does not limit the specific implementation manner of determining the position of the rotor of the three-phase motor 10 relative to the stator according to the second position interval in step S114, and the specific implementation manner of controlling the three-phase motor according to the position of the rotor relative to the stator, and a person skilled in the art may select an appropriate implementation manner according to actual conditions and needs.
The motor driving device provided by the embodiment of the disclosure sequentially outputs K driving signals in K continuous time periods in the initialization stage of starting the three-phase motor through the driving module so as to drive any two phases of the three-phase motor to be conducted in each time period, and detects the voltage of the non-conducting phase of the three-phase motor when each driving signal in each time period acts through the voltage detecting module.
It is understood that the above-mentioned method embodiments of the present disclosure can be combined with each other to form a combined embodiment without departing from the logic of the principle, which is limited by the space, and the detailed description of the present disclosure is omitted. Those skilled in the art will appreciate that in the above methods of the specific embodiments, the specific order of execution of the steps should be determined by their function and possibly their inherent logic.
Having described embodiments of the present disclosure, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
Claims (10)
1. A motor driving device is characterized by comprising a three-phase motor, a three-phase full-bridge inverter, a voltage detection module, a driving module and a control module,
the three-phase full-bridge inverter comprises a first bridge arm, a second bridge arm and a third bridge arm, wherein each bridge arm comprises an upper bridge arm and a lower bridge arm, the upper bridge arm and the lower bridge arm of each bridge arm are respectively provided with a transistor, the three-phase full-bridge inverter is used for driving the three-phase motor, and the first bridge arm, the second bridge arm and the third bridge arm respectively correspond to a first phase, a second phase and a third phase of the three-phase motor;
the driving module is connected to each transistor of the three-phase full-bridge inverter and used for sequentially outputting K driving signals in K continuous time periods in an initialization stage of starting the three-phase motor, wherein each driving signal is used for driving any two phases of the three-phase motor to be conducted, and K is a positive integer;
the voltage detection module is connected between an upper bridge arm and a lower bridge arm of each bridge arm of the three-phase full-bridge inverter and is used for detecting the voltage of the non-conducting phase of the three-phase motor when each driving signal acts in each time period;
the control module is connected to the voltage detection module and the drive module and used for determining the position of the rotor of the three-phase motor relative to the stator according to the magnitude relation of the voltage of the non-conducting phase in each time period.
2. The apparatus of claim 1, wherein determining the position of the rotor relative to the stator of the three-phase motor according to the magnitude relationship of the voltage of the non-conducting phase of each time period comprises:
determining a minimum voltage of voltages of the respective non-conducting phases;
determining a first position interval of the rotor relative to the stator according to the minimum voltage;
determining two adjacent target vectors of the first position interval in a sector corresponding to a motor space vector diagram, and determining a second position interval according to the voltage magnitude relation of a non-conducting phase corresponding to the target vectors, wherein the motor space vector diagram leads out a plurality of vectors from a central point, the plurality of vectors divide the motor space vector diagram into a plurality of sectors, each driving signal corresponds to a vector of the motor space vector diagram, and the target vectors are vectors corresponding to the driving signals;
and determining the position of the rotor of the three-phase motor relative to the stator according to the second position interval.
3. The apparatus of claim 2, wherein the number of vectors is 12, the number of sectors is 12, and the determining the first position interval of the rotor relative to the stator according to the minimum voltage comprises:
determining two sectors adjacent to a reverse vector of the vector corresponding to the minimum voltage as the first position interval; or
And determining a first position interval of the rotor relative to the stator according to the minimum voltage and a first mapping relation, wherein the first mapping relation comprises a corresponding relation between a non-conducting phase corresponding to the minimum voltage and a vector position interval.
4. The apparatus of claim 2, wherein the determining the second position interval according to the voltage magnitude relationship of the non-conducting phase corresponding to the target vector comprises:
determining a first target vector corresponding to the voltage of a small non-conducting phase in the two target vectors;
determining a position interval which is close to the preset angle of the first target vector in the first position interval as a second position interval; or determining the sector of the first position interval close to the first target vector as a second position interval.
5. The apparatus of claim 1, wherein the duration of each of the K time periods is equal.
6. The apparatus of claim 5, wherein the duration of each time period is between 10 μ s and 30 μ s.
7. The apparatus of claim 1, wherein the drive signals comprise at least two of a first drive signal, a second drive signal, a third drive signal, a fourth drive signal, a fifth drive signal, and a sixth drive signal, wherein,
the first driving signal is used for driving the transistor of the upper bridge arm of the first bridge arm to be conducted and the transistor of the lower bridge arm of the third bridge arm to be conducted, and the non-conducting phase corresponding to the action time period of the first driving signal is a second phase;
the second driving signal is used for driving the transistor of the upper bridge arm of the second bridge arm to be conducted and the transistor of the lower bridge arm of the third bridge arm to be conducted, and the non-conducting phase corresponding to the action time period of the second driving signal is the first phase;
the third driving signal is used for driving the transistors of the upper bridge arm of the second bridge arm to be conducted and the transistors of the lower bridge arm of the first bridge arm to be conducted, and a non-conducting phase corresponding to a time period of action of the third driving signal is a third phase;
the fourth driving signal is used for driving the transistor of the upper bridge arm of the third bridge arm to be conducted and the transistor of the lower bridge arm of the first bridge arm to be conducted, and the non-conducting phase corresponding to the action time period of the fourth driving signal is a second phase;
the fifth driving signal is used for driving the transistors of the upper bridge arm of the third bridge arm to be conducted and the transistors of the lower bridge arm of the second bridge arm to be conducted, and the non-conducting phase corresponding to the action time period of the fifth driving signal is the first phase;
the sixth driving signal is used for driving the transistors of the upper bridge arm of the first bridge arm to be conducted and the transistors of the lower bridge arm of the second bridge arm to be conducted, and the non-conducting phase corresponding to the action time period of the sixth driving signal is the third phase.
8. The apparatus of claim 1, wherein the voltage detection module comprises a first voltage detection unit, a second voltage detection unit and a third voltage detection unit respectively connected between an upper bridge arm and a lower bridge arm of each phase of the three-phase full-bridge inverter, wherein each voltage detection unit comprises a first detection resistor and a second detection resistor,
the first end of the first detection resistor is connected between the corresponding upper bridge arm and the corresponding lower bridge arm, and the second end of the first detection resistor is connected to the first end of the second detection resistor and used for outputting detection voltage;
the second end of the second detection resistor is grounded.
9. A drive assembly, characterized in that the drive assembly comprises a motor drive according to any one of claims 1-8.
10. A power tool comprising the drive assembly of claim 9.
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| CN101174811A (en) * | 2007-10-19 | 2008-05-07 | 奇瑞汽车有限公司 | Electric motor control method and device adopting space vector pulse width modulation |
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| US20190229668A1 (en) * | 2018-01-19 | 2019-07-25 | Huazhong University Of Science And Technology | Open-winding motor drive topology and modulation method thereof |
| CN214480347U (en) * | 2021-04-09 | 2021-10-22 | 上海晟矽微电子股份有限公司 | Motor driving device, driving assembly and electric tool |
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| CN101174811A (en) * | 2007-10-19 | 2008-05-07 | 奇瑞汽车有限公司 | Electric motor control method and device adopting space vector pulse width modulation |
| JP2009284630A (en) * | 2008-05-21 | 2009-12-03 | Toyota Motor Corp | Charge controller and vehicle with the same |
| WO2018108040A1 (en) * | 2016-12-15 | 2018-06-21 | 上海理工大学 | Electric driving device, electric equipment, inverter and multiphase alternating current motor |
| US20190229668A1 (en) * | 2018-01-19 | 2019-07-25 | Huazhong University Of Science And Technology | Open-winding motor drive topology and modulation method thereof |
| CN214480347U (en) * | 2021-04-09 | 2021-10-22 | 上海晟矽微电子股份有限公司 | Motor driving device, driving assembly and electric tool |
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