Open-winding motor system and its method and device for detecting rotor magnetic pole position

Abstract

The present invention discloses an open-winding motor system, a method for detecting the rotor magnetic pole position thereof, and a detecting device. The method for detecting the rotor magnetic pole position of the open-winding motor comprises the following steps: obtaining the initial electrical angle of the rotor magnetic pole, the interval time for the main inverter and the auxiliary inverter to alternately output driving currents, the movement time of the rotor magnetic pole, and the discharge voltage of the bus capacitor; determining the Nth harmonic generated by the open-winding motor when driven by the corresponding driving current according to the discharge voltage; determining the electrical angle difference between any two adjacent preset electrical angle intervals according to the Nth harmonic and the discharge voltage of the bus capacitor; and determining the current position of the rotor magnetic pole according to the initial electrical angle of the rotor magnetic pole, the interval time for the main inverter and the auxiliary inverter to alternately output driving currents, the electrical angle difference, and the movement time of the rotor magnetic pole. The method for detecting the rotor magnetic pole position of the open-winding motor according to the present invention can detect the position of the rotating rotor magnetic pole in the open-winding motor.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and particularly relates to a method for detecting the rotor magnetic pole position of an open-winding motor, a device for detecting the rotor magnetic pole position of an open-winding motor, and an open-winding motor system. Background Art

[0002] Currently, in the industry, for an open-winding motor, a method of sending pulses and receiving responses is usually adopted to detect the initial electrical angle of its rotor magnetic poles. However, this method can only be used to judge the initial electrical angle of the magnetic poles before the motor is powered on, and cannot detect the position of the rotating rotor magnetic poles. In the industry, a method has also been proposed to judge the real-time position of the magnetic poles by overlapping high-order harmonics and respectively obtaining the differences between the direct-axis current and the quadrature-axis current in the motor before and after the overlap. However, this method will cause excessive iron loss in the overlapping high-order harmonics, which is not conducive to improving the motor efficiency. In summary, the industry cannot effectively detect the position of the rotating rotor magnetic poles in an open-winding motor. Summary of the Invention

[0003] The main object of the present invention is to provide a method for detecting the rotor magnetic pole position of an open-winding motor, aiming to detect the position of the rotating rotor magnetic poles in an open-winding motor.

[0004] To achieve the above object, the present invention proposes a method for detecting the rotor magnetic pole position of an open-winding motor. The method for detecting the rotor magnetic pole position of an open-winding motor includes the following steps:

[0005] Obtain the initial electrical angle of the rotor magnetic poles, the interval time for the main inverter and the auxiliary inverter to alternately output driving currents, the movement time of the rotor magnetic poles, and the discharge voltage of the bus capacitor;

[0006] Determine the Nth harmonic generated by the open-winding motor when driven by the corresponding driving current according to the discharge voltage;

[0007] Determine the electrical angle difference between any two adjacent preset electrical angle intervals according to the Nth harmonic and the discharge voltage of the bus capacitor; and

[0008] Determine the current position of the rotor magnetic poles according to the initial electrical angle of the rotor magnetic poles, the interval time for the main inverter and the auxiliary inverter to alternately output driving currents, the electrical angle difference, and the movement time of the rotor magnetic poles; where the movement time of the rotor magnetic poles is the time for the rotor magnetic poles to rotate from the initial electrical angle to the current position.

[0009] Optionally, the step of configuring the open-winding motor to generate the corresponding Nth harmonic when driven by the corresponding driving current is specifically:

[0010] The average width of the rotor teeth of the configured open-winding motor is less than the average width of the stator slots, so that when the open-winding motor is driven by a corresponding drive current, corresponding Nth harmonics are generated.

[0011] Optionally, when determining the Nth harmonics generated by the open-winding motor when driven by a corresponding drive current according to the discharge voltage, specifically:

[0012] Differentiate the discharge voltage, and use the calculation result as the Nth harmonics generated by the open-winding motor when driven by a corresponding drive current.

[0013] Optionally, the step of determining the electrical angle difference between any two adjacent preset electrical angle intervals according to the Nth harmonics and the discharge voltage of the bus capacitor includes:

[0014] Multiply the Nth harmonics by the discharge voltage of the bus capacitor and generate a first waveform signal according to the calculation result;

[0015] Perform edge detection on the first waveform signal to obtain the rising edge in the first waveform signal, and output a first edge signal according to the obtained result;

[0016] Perform edge detection on the discharge voltage of the bus capacitor to respectively obtain its rising edge and falling edge, and output a second edge signal according to the obtained result;

[0017] Perform a NAND logic operation on the inverted second edge signal and the first edge signal, and determine the electrical angle difference between any two adjacent preset electrical angle intervals according to the operation result.

[0018] Optionally, the step of performing edge detection on the first waveform signal to obtain the rising edge in the first waveform signal and outputting a first edge signal according to the obtained result specifically:

[0019] Perform edge detection on the first waveform signal to obtain the rising edge with an amplitude of zero therein, and output a first edge signal according to the obtained result.

[0020] Optionally, the step of performing edge detection on the discharge voltage of the bus capacitor to respectively obtain its rising edge and falling edge and outputting a second edge signal according to the obtained result specifically:

[0021] Perform edge detection on the discharge voltage of the bus capacitor to respectively obtain the rising edge with an amplitude of zero and the falling edge with an amplitude of zero therein, and output a second edge signal according to the obtained result.

[0022] Optionally, the step of determining the current position of the rotor magnetic pole according to the initial electrical angle of the rotor magnetic pole, the interval time for the auxiliary inverter to alternately output drive currents, the electrical angle difference, and the movement time of the rotor magnetic pole includes:

[0023] Determining the electrical angle change frequency of the current rotor magnetic pole according to the electrical angle difference between any two adjacent preset electrical angle intervals and the interval time for the auxiliary inverter to alternately output drive currents;

[0024] Determining the current position of the rotor magnetic pole according to the initial electrical angle of the rotor magnetic pole, the electrical angle change frequency of the current rotor magnetic pole, and the movement time of the rotor magnetic pole.

[0025] The present invention also provides a detection device for the position of the rotor magnetic pole of an open winding motor, which is applied to an open winding motor system. The open winding motor system includes a dual-inverter unit and an open winding motor. The dual-inverter unit includes a main inverter and an auxiliary inverter. The main inverter and the auxiliary inverter are used to alternately output drive currents to the open winding motor within a preset electrical angle interval. The main inverter and the auxiliary inverter are respectively connected to the open winding motor through bus capacitors. When the open winding motor is driven by the corresponding drive current, it generates corresponding Nth harmonics. The bus capacitors are used to charge according to the drive current and the Nth harmonics. The detection device of the open winding motor includes:

[0026] A memory;

[0027] A processor; and

[0028] A detection program for the position of the rotor magnetic pole of the open winding motor stored on the memory and executable on the processor. When the processor executes the control program of the open winding motor, the detection method for the position of the rotor magnetic pole of the open winding motor as described above is implemented.

[0029] The present invention also provides an open winding motor system, and the open winding motor control system includes:

[0030] An open winding motor, which is used to generate corresponding Nth harmonics when driven by the corresponding drive current;

[0031] A sampling unit, which is used to sample the open winding motor and output corresponding sampling signals;

[0032] A dual-inverter unit, the dual-inverter unit includes a main inverter and an auxiliary inverter. The main inverter and the auxiliary inverter are used to alternately output drive currents to the open winding motor within a preset electrical angle interval. The main inverter and the auxiliary inverter are respectively connected to the open winding motor through bus capacitors; and the bus capacitors are used to charge according to the drive current and the Nth harmonics; and

[0033] The main control unit, which includes the detecting device for the rotor magnetic pole position of the open-winding motor as described above, is respectively connected to the sampling unit and the dual-inverter unit.

[0034] Optionally, the open-winding motor includes a stator and a rotor, and the rotor is accommodated in the stator; a plurality of stator slots are uniformly arranged on the inner surface side of the stator, and a plurality of rotor tooth parts are arranged on the outer surface side of the rotor corresponding to the plurality of stator slots.

[0035] Optionally, the average width of the rotor tooth part is less than the average width of the stator slot.

[0036] The method for detecting the rotor magnetic pole position of the open-winding motor according to the present invention obtains the initial electrical angle of the rotor magnetic pole, the interval time for the main inverter and the auxiliary inverter to alternately output driving currents, the movement time of the rotor magnetic pole, and the discharge voltage of the bus capacitor; and determines the Nth harmonic generated by the open-winding motor when driven by the corresponding driving current according to the discharge voltage; determines the electrical angle difference between any two adjacent preset electrical angle intervals according to the Nth harmonic and the discharge voltage of the bus capacitor; and determines the current position of the rotor magnetic pole according to the initial electrical angle of the rotor magnetic pole, the interval time for the main inverter and the auxiliary inverter to alternately output driving currents, the electrical angle difference, and the movement time of the rotor magnetic pole. The technical solution of the present invention configures the motor to generate harmonics when it is energized and running, without overlapping high-order harmonics and sending pulses. Therefore, while the position of the rotor magnetic pole can be detected in real time using harmonics, the iron loss of the motor can be reduced, and compared with the scheme of using a sensor for detection, the detection result is more stable and not affected by the waveform of the induced voltage. Description of the Drawings

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0038] Figure 1 It is a schematic flowchart of an embodiment of the method for detecting the rotor magnetic pole position of the open-winding motor according to the present invention;

[0039] Figure 2 It is a schematic flowchart of another embodiment of the method for detecting the rotor magnetic pole position of the open-winding motor according to the present invention;

[0040] Figure 3 It is a schematic flowchart of another embodiment of the method for detecting the rotor magnetic pole position of the open-winding motor according to the present invention;

[0041] Figure 4 It is a schematic flowchart of another embodiment of the method for detecting the rotor pole position of the open-winding motor of the present invention;

[0042] Figure 5 It is a schematic flowchart of another embodiment of the method for detecting the rotor pole position of the open-winding motor of the present invention;

[0043] Figure 6 It is a schematic structural diagram of the hardware operating environment of an embodiment of the device for detecting the rotor pole position of the open-winding motor of the present invention;

[0044] Figure 7 It is a schematic diagram of the functional modules of an embodiment of the open-winding motor system of the present invention;

[0045] Figure 8 It is a schematic diagram of the signal waveform of an embodiment of the method for detecting the rotor pole position of the open-winding motor of the present invention

[0046] Figure 9 It is a schematic diagram of the signal waveform of another embodiment of the method for detecting the rotor pole position of the open-winding motor of the present invention.

[0047] Explanation of the reference numerals in the drawings:

[0048] Label Name Label Name 101 Memory 20 Sampling unit 102 Processor 30 Dual-inverter unit 103 Communication bus 40 Master control unit 10 Open-winding motor

[0049] The realization of the purpose, functional features and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0051] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0052] In the present invention, unless otherwise clearly specified and defined, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0054] The present invention provides a method for detecting the rotor pole position of an open-winding motor.

[0055] The method for detecting the rotor pole position of an open-winding motor can be applied to an open-winding motor system and can be implemented by a detection device for the rotor pole position of the open-winding motor in the system. In the open-winding motor system, a dual-inverter unit and an open-winding motor can be provided. The dual-inverter unit can include a main inverter and an auxiliary inverter. The main inverter and the auxiliary inverter are used to alternately output drive current to the open-winding motor within a preset electrical angle range, and the main inverter and the auxiliary inverter are respectively connected to the open-winding motor through bus capacitors. The open-winding motor to be detected by this detection method can increase the pole difference by changing the structural configuration of its rotor and stator, so that when the motor is driven by the corresponding current, corresponding Nth harmonics can be generated; the bus capacitor can be used to charge according to the drive current and the Nth harmonics. In this embodiment, taking the Nth harmonics as the third harmonics and the preset electrical angle range as the electrical angle range in which the synthetic torque generated by the motor under the corresponding drive current is greater than a preset torque within the electrical angle corresponding to a pair of magnetic poles as an example for explanation,

[0056] Refer to Figure 1 , in an embodiment of the present invention, the method for detecting the rotor pole position of the open-winding motor includes the following steps:

[0057] Step S100: Obtain the initial electrical angle of the rotor pole, the interval time for the main inverter and the auxiliary inverter to alternately output drive current, the movement time of the rotor pole, and the discharge voltage of the bus capacitor;

[0058] Step S200: Determine the N - th harmonic generated by the open - winding motor when driven by the corresponding drive current according to the discharge voltage.

[0059] Step S300: Determine the electrical angle difference between any two adjacent preset electrical angle intervals according to the N - th harmonic and the discharge voltage of the bus capacitor; and

[0060] Step S400: Determine the current position of the rotor pole according to the initial electrical angle of the rotor pole, the interval time for the main inverter and the auxiliary inverter to alternately output drive current, the electrical angle difference, and the movement time of the rotor pole; where the movement time of the rotor pole is the time for the rotor pole to rotate from the initial electrical angle to the current position.

[0061] In this embodiment, the detection device for the position of the rotor pole of the open - winding motor can obtain the initial electrical angle of the rotor pole by sending a pulse to the open - winding motor and receiving a response before the detection starts. Since the dual - inverter unit can output drive current under the control of the detection device for the position of the rotor pole of the open - winding motor, the position of the rotor pole of the open - winding motor can, after the detection starts, use the integrated timer or software algorithm or program for timing in itself to obtain the interval time for the main inverter and the auxiliary inverter to alternately output drive current and the movement time of the rotor pole (the time for the rotor pole to rotate from the initial electrical angle to the current position) in real - time. And when the main inverter or the auxiliary inverter outputs drive current within the preset electrical angle interval, the detection device for the position of the rotor pole of the open - winding motor can control the main inverter and the auxiliary inverter to be turned on simultaneously at this time, so that the drive current output by one of them can flow into the bus capacitor on the side where the other is located through the voltage bus; and after the preset electrical angle interval, control the one that outputs the drive current to be turned off, while the other continues to be turned on, so that the drive current can all pass through the open - winding motor and then charge the bus capacitor, and after a preset time, control the other to be turned off as well and simultaneously control the bus capacitor to discharge. The detection device for the position of the rotor pole of the open - winding motor can obtain the discharge voltage of the bus capacitor through other functional units in the open - winding motor system, such as the sampling unit.

[0062] It can be understood that the charging current of the bus capacitor is provided by the drive current and the N - th harmonic generated when the drive current drives the motor to operate. Therefore, there is a corresponding mapping relationship between the discharge voltage of the bus capacitor and the N - th harmonic in its charging current. The position of the rotor pole of the open - winding motor can use a pre - stored corresponding algorithm or a pre - associated and stored corresponding database to inversely deduce the N - th harmonic component in its charging current from the discharge voltage of the bus capacitor, that is, the N - th harmonic generated by the open - winding motor when driven by the corresponding drive current.

[0063] It can also be understood that the Nth harmonic is generated when the motor is driven by the drive current, representing the error component of the drive current due to the operation of the motor. This error component is generated due to the increase in its pole pitch. Therefore, the Nth harmonic may contain information related to the increased pole pitch within the preset electrical angle range. For example, the number of times the pole pitch increases within the preset electrical angle range. The discharge voltage of the bus capacitor may contain information about the overall operation of the motor within the preset electrical angle range. For example, the number of all pole pitches within the preset electrical angle range. The detection device for the rotor pole position of the open-winding motor can obtain the Nth harmonic and the discharge voltage within all preset electrical angle ranges up to the current time, and can also analyze the information contained in each of the Nth harmonic and the discharge voltage within all preset electrical angle ranges by running a software program or algorithm for analysis. Furthermore, the electrical angle difference between any two adjacent preset electrical angle ranges can be determined based on the information contained in both. It can be understood that the interval time between the alternating output of the drive current by the main inverter and the auxiliary inverter corresponds to the time between two adjacent preset electrical angle ranges. Therefore, the detection device can obtain the actual electrical angle change speed of the rotor pole based on the interval time and the electrical angle difference, and then can determine the current electrical angle of the rotor pole, that is, the current position of the rotor pole, based on the initial electrical angle of the rotor pole and the movement time of the rotor pole. It can be understood that since the rotor poles are evenly circumferentially distributed on the rotor, in practical applications, only the position of one rotor pole needs to be determined, and the positions of the remaining rotor poles can be deduced based on the angular relationship between the rotor poles.

[0064] It should be noted that those skilled in the art can use corresponding programming languages, such as computer programming languages like C language and M language, and traverse all combinations of preset electrical angle ranges and drive currents to associatively store various initial electrical angles of the rotor poles, various interval times of the alternating output of the drive current by the main inverter and the auxiliary inverter, various movement times of the rotor poles, various discharge voltages of the bus capacitors, and various finally obtained current positions. When it is necessary to detect the real-time position of the rotor pole of the open-winding motor subsequently, the corresponding data associatively stored can be directly called according to the relevant parameters to obtain the real-time position of the rotor pole of the open-winding motor.

[0065] The method for detecting the rotor pole position of the open-winding motor in the present invention obtains the initial electrical angle of the rotor pole, the interval time for the main inverter and the auxiliary inverter to alternately output driving currents, the movement time of the rotor pole, and the discharge voltage of the bus capacitor; and determines the Nth harmonic generated by the open-winding motor when driven by the corresponding driving current according to the discharge voltage; determines the electrical angle difference between any two adjacent preset electrical angle intervals according to the Nth harmonic and the discharge voltage of the bus capacitor; and determines the current position of the rotor pole according to the initial electrical angle of the rotor pole, the interval time for the main inverter and the auxiliary inverter to alternately output driving currents, the electrical angle difference, and the movement time of the rotor pole. The technical solution of the present invention configures the motor to generate harmonics when it is powered on and running, without overlapping high-order harmonics and sending pulses. Therefore, while the position of the rotor pole can be detected in real time using harmonics, the iron loss of the motor can be reduced, and compared with the scheme of using a sensor for detection, the detection result is more stable and not affected by the waveform of the induced voltage.

[0066] Referring to Figure 1 , in an embodiment of the present invention, the step of configuring the open-winding motor to generate the corresponding Nth harmonic when driven by the corresponding driving current specifically is:

[0067] Configure the average width of the rotor teeth of the open-winding motor to be less than the average width of the stator slots, so that the open-winding motor generates the corresponding Nth harmonic when driven by the corresponding driving current.

[0068] In this embodiment, the difference between the maximum and minimum values of the open-winding motor can be increased by changing the size relationship between the average width of the rotor teeth and the average width of the motor stator slots in the open-winding motor, so as to achieve the purpose of generating the corresponding Nth harmonic when the motor is driven to work. It can be understood that those skilled in the art can also achieve the same technical effect through other means, for example: grooving on the outer surface of the stator, which will not be elaborated here. The technical solution of the present invention overcomes the technical prejudice that the average widths of the rotor teeth and the motor stator slots in the motor design must correspond one by one, and actively introduces harmonic components to realize the detection of the rotor pole position.

[0069] Referring to Figure 2 , in an embodiment of the present invention, it is characterized in that the step S200 of determining the Nth harmonic generated by the open-winding motor when driven by the corresponding driving current according to the discharge voltage specifically is;

[0070] Perform differential calculation on the discharge voltage, and use the calculation result as the Nth harmonic generated by the open-winding motor when driven by the corresponding driving current.

[0071] In this embodiment, those skilled in the art can configure a pre-experiment stage before the formal detection stage. In this stage, those skilled in the art can directly obtain the third harmonic component generated in the open-winding motor when driven by the corresponding drive current through the zero-sequence current compensation module, and obtain the discharge voltage under this drive current. And based on the obtained results, the differential relationship between the two can be analyzed, and the corresponding differential algorithm can be stored in the detection device of the rotor magnetic pole position of the open-winding motor. So that when the detection device in the formal detection stage obtains the discharge voltage of the bus capacitor, the corresponding Nth harmonic can be directly obtained by running this differential algorithm. With such a setting, when detecting the position of the rotor magnetic pole, the corresponding Nth harmonic can be automatically generated directly according to the obtained discharge voltage without repeatedly obtaining it through the detection module.

[0072] Referring to Figures 3 to 4 and Figures 8 to 9 , in an embodiment of the present invention, the step S300 of determining the electrical angle difference between any two adjacent preset electrical angle intervals according to the Nth harmonic and the discharge voltage of the bus capacitor includes:

[0073] Step S310: Perform a multiplication operation on the Nth harmonic and the discharge voltage of the bus capacitor and generate a first waveform signal according to the calculation result;

[0074] Step S320: Perform edge detection on the first waveform signal to obtain the rising edge in the first waveform signal, and output a first edge signal according to the obtained result;

[0075] Step S330: Perform edge detection on the discharge voltage of the bus capacitor to respectively obtain its rising edge and falling edge, and output a second edge signal according to the obtained result;

[0076] Step S340: Perform a logical AND operation on the inverted second edge signal and the first edge signal, and determine the electrical angle difference between any two adjacent preset electrical angle intervals according to the operation result.

[0077] Further, the step S320 of performing edge detection on the first waveform signal to obtain the rising edge in the first waveform signal and output a first edge signal according to the obtained result is specifically:

[0078] Perform edge detection on the first waveform signal to obtain the rising edge with zero amplitude therein, and output a first edge signal according to the obtained result.

[0079] Further, the step S330 of performing edge detection on the discharge voltage of the bus capacitor to respectively obtain its rising edge and falling edge and output a second edge signal according to the obtained result is specifically:

[0080] Perform edge detection on the discharge voltage of the bus capacitor to respectively obtain the rising edge with an amplitude of zero and the falling edge with an amplitude of zero, and output a second edge signal according to the obtained results.

[0081] In this embodiment, since both the Nth harmonic and the discharge voltage of the bus capacitor have a mapping relationship with each preset electrical angle interval, the real-time values of both the Nth harmonic and the discharge voltage correspond to an electrical angle. The detection device for the rotor pole position of the open-winding motor can send the Nth harmonic and the discharge voltage obtained in all preset electrical angle intervals during the movement time of the rotor pole to the multiplier integrated in itself or directly run an algorithm for performing multiplication calculation to generate a first waveform signal, and can perform edge detection on the first waveform signal after digital-to-analog conversion through the ADC circuit by running an edge detection program to obtain the rising edge (i.e., the part where the waveform shows an upward trend) therein, and output a first edge signal representing the electrical angle of the rising edge. In an alternative embodiment, the point where the derivative value in the first waveform signal is greater than 0 and the signal amplitude is 0 is selected for detection.

[0082] Meanwhile, the detection device for the rotor magnetic pole position of the open-winding motor can directly run the edge detection program to perform edge detection on the discharge voltages corresponding to all preset electrical angle intervals during the movement time of the rotor magnetic pole, so as to simultaneously obtain the rising edge and the falling edge therein (falling edge: the part where the waveform shows a downward trend), and output a second edge signal that simultaneously characterizes the rising-edge electrical angle and the falling-edge electrical angle. In another alternative embodiment, the points where the derivative value in the detected discharge voltage is greater than 0 and the signal amplitude is 0, and the points where the derivative value is less than 0 and the signal amplitude is 0 are selected. The detection device for the rotor magnetic pole position of the open-winding motor is further configured to perform an inversion operation on the second edge signal (at this time, the original rising edge is converted into a falling edge, and the original falling edge is converted into a rising edge), and perform an AND logic operation on the result of the inversion operation and the first edge signal (at this time, when the electrical angle of the rising edge (i.e., the original falling edge) in the second edge signal is the same as the electrical angle of the rising edge in the first edge signal, it is output, and in other cases, it is not output). In practical applications, the result of the AND logic operation can be sent to a pulse generator. When the electrical angle of the rising edge in the first edge signal is the same, the pulse generator outputs a high level, and for other electrical angles, it outputs a low level. And it can be understood that since the selected preset electrical angle interval is the electrical angle interval in which the synthetic torque generated by the motor under the corresponding drive current is greater than a preset torque among the electrical angles corresponding to a pair of magnetic poles, therefore, when the rotor magnetic pole rotates through a pair of magnetic poles, that is, through an electrical angle of 360°, the pulse generator can output a high level, and the electrical angle between any two adjacent high-level signals output by the pulse generator corresponds to the electrical angle difference between any two adjacent preset electrical angle intervals. The technical solution of the present invention can obtain the electrical angle difference between any two adjacent preset electrical angle intervals through the Nth harmonic and the discharge voltage of the bus capacitor, and then can achieve various fine cooperative calculations with the preset electrical angle interval. For example, when there are multiple preset electrical angle intervals among the electrical angles corresponding to a pair of magnetic poles, it is beneficial to improve the detection accuracy of the rotor magnetic pole position, and there is no need to perform complex calculations using multiple parameters.

[0083] Referring to Figure 5 , in an embodiment of the present invention, the step S400 of determining the current position of the rotor magnetic pole according to the initial electrical angle of the rotor magnetic pole, the interval time for the auxiliary inverter to alternately output drive currents, the electrical angle difference, and the movement time of the rotor magnetic pole includes:

[0084] Step S410, determining the electrical angle change frequency of the current rotor magnetic pole according to the electrical angle difference between any two adjacent preset electrical angle intervals and the interval time for the main inverter and the auxiliary inverter to alternately output drive currents;

[0085] Step S420: Determine the current position of the rotor pole according to the initial electrical angle of the rotor pole, the electrical angle change frequency of the current rotor pole, and the movement time of the rotor pole.

[0086] In this embodiment, when the open-winding motor runs at a constant speed, the electrical angle difference between any two adjacent preset electrical angle intervals and the interval time for the dual-inverter unit to alternately output drive current can be selected, and the electrical angle difference is divided by the interval time. The calculation result can be characterized as the electrical angle change frequency of the current rotor pole. When the open-winding motor runs in acceleration / deceleration, the electrical angle difference and the corresponding interval time between the two adjacent preset electrical angle intervals closest to the current position of the rotor pole can be selected; alternatively, the electrical angle difference and the corresponding interval parameters between the next two adjacent preset electrical angle intervals can also be estimated according to the acceleration / deceleration trend of the open-winding motor. It can be understood that the product of the electrical angle change frequency and the movement time of the rotor pole represents the electrical angle rotated by the rotor pole during this movement time, and the sum of this product result and the initial electrical angle of the rotor pole is the current electrical angle of the rotor pole. The technical solution of the present invention determines the real-time position of the rotor pole by determining the electrical angle change frequency of the current rotor pole, without sending pulses to the motor or overlapping high-order harmonics, reducing the motor loss while also reducing the complexity of the detection system.

[0087] The present invention also proposes a detection device for the position of the rotor pole of an open-winding motor, which is applied to an open-winding motor system. The open-winding motor system includes a dual-inverter unit and an open-winding motor. The dual-inverter unit includes a main inverter and an auxiliary inverter. The main inverter and the auxiliary inverter are used to alternately output drive current to the open-winding motor within a preset electrical angle interval. The main inverter and the auxiliary inverter are respectively connected to the open-winding motor through bus capacitors; when the open-winding motor is driven by the corresponding drive current, it generates corresponding Nth harmonics; the bus capacitors are used to charge according to the drive current and the Nth harmonics.

[0088] Refer to Figure 6 , in an embodiment of the present invention, the detection device of the open-winding motor includes:

[0089] Memory 101;

[0090] Processor 102; and

[0091] A detection program for the position of the rotor pole of an open-winding motor stored on the memory 101 and executable on the processor 102. When the processor 102 executes the control program of the open-winding motor, the detection method for the position of the rotor pole of the open-winding motor as described above is implemented.

[0092] In this embodiment, the memory 101 can be a high-speed RAM memory or a stable memory (non-volatile memory), such as a disk memory. Optionally, the memory 101 can also be a storage device independent of the aforementioned control device; the processor 102 can be a CPU. The memory 101 and the processor 102 are connected by a communication bus 103, and the communication bus 103 can be a UART bus or an I2C bus. It can be understood that other relevant programs can also be set in the detection device to drive other functional units in the open-winding motor system to work.

[0093] The present invention also proposes an open-winding motor system.

[0094] Referring to Figure 7 , in an embodiment of the present invention, the open-winding motor control system includes:

[0095] An open-winding motor 10, configured to generate corresponding Nth harmonics when driven by a corresponding drive current;

[0096] A sampling unit 20, configured to sample the open-winding motor 10 and output a corresponding sampling signal;

[0097] A dual-inverter unit 30, the dual-inverter unit includes a main inverter and an auxiliary inverter. The main inverter and the auxiliary inverter are configured to alternately output drive current to the open-winding motor 10 within a preset electrical angle range. The main inverter and the auxiliary inverter are respectively connected to the open-winding motor 10 via bus capacitors; and, the bus capacitors are configured to charge according to the drive current and the Nth harmonics;

[0098] A main control unit 40, the main control unit 40 includes a detection device for the rotor magnetic pole position of the open-winding motor as described above, and the main control unit 40 is respectively connected to the sampling unit 20 and the dual-inverter unit 30.

[0099] In this embodiment, the open-winding motor 10 can be a permanent magnet synchronous motor, which is used to generate corresponding Nth harmonics when powered on and running.

[0100] The sampling unit 20 can be one or a combination of current and / or voltage type sensor devices, speed sensing devices, torque detection devices, etc. for collecting working parameters of the open-winding motor 10, so as to detect various working parameters of the open-winding motor 10 and output corresponding types of sampling signals.

[0101] Both the main inverter unit and the auxiliary inverter unit in the dual-inverter unit 30 can be constructed by one or a combination of switching devices such as MOS transistors, triodes, IGBTs, or thyristors. Each inverter unit is used to invert the input direct current into alternating current according to the on-off states of the switching devices and then output it to the open-winding motor 10 to drive the open-winding motor 10 to operate electrically.

[0102] The main control unit 40 can be a host computer or a PLC, which can integrate corresponding hardware circuits and software programs or algorithms, and can be connected to other functional units in the open-winding motor system through ports and wiring. By running the hardware circuits and software programs or algorithms, and calling the corresponding parameter data, corresponding control signals are output to each functional unit to control its working state, and various signals fed back by each functional unit during operation can be received, thereby realizing the overall monitoring of the open-winding motor system. Since the main control unit 40 includes the detection device for the rotor magnetic pole position of the open-winding motor; the detailed structure of the detection device for the rotor magnetic pole position of the open-winding motor 10 can refer to the above-mentioned embodiment and will not be elaborated here; it can be understood that since the detection device for the rotor magnetic pole position of the open-winding motor 10 is used in the main control unit 40, therefore, the embodiment of the main control unit 40 includes all the technical solutions of all the embodiments of the detection device for the rotor magnetic pole position of the open-winding motor 10, and the achieved technical effects are also exactly the same and will not be elaborated here. The main control unit 40 can also use the detection method for the rotor magnetic pole position of the open-winding motor 10 as described above. The detection method for the rotor magnetic pole position of the open-winding motor 10 has been described above and will not be elaborated here either.

[0103] Refer to Figures 1 to 2 , in an embodiment of the present invention, the open-winding motor 10 includes a stator and a rotor, and the rotor is accommodated in the stator; a plurality of stator slots are uniformly provided on the inner surface side of the stator, and a plurality of rotor tooth portions are provided on the outer surface side of the rotor corresponding to the plurality of stator slots.

[0104] Furthermore, the average width of the rotor tooth portions is less than the average width of the stator slots.

[0105] In this embodiment, the stator may be nearly cylindrical, and the rotor may be nearly cylindrical; both can be formed by stamping and stacking a plurality of silicon steel sheets. The side of the stator close to the rotor is the inner surface side, on which a plurality of identical stator teeth may be evenly provided, and a stator slot may be formed between any two adjacent stator teeth; a plurality of rotor teeth may be evenly provided on the outer surface side of the rotor corresponding to each stator slot, and the average width of each rotor tooth is less than the average width of the stator slot. It can be understood that the number of stator slots and the number of rotor teeth only need to be matched, and no limitation is made here. With such a setting, the pole difference in the open-winding motor 10 can be increased, so that when it works, a reluctance torque with a corresponding magnitude and an electromagnetic torque with a corresponding magnitude can be generated.

[0106] The above are only alternative embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A method for detecting the rotor pole position of an open-winding motor, which is applied to an open-winding motor system. Characterized in that, The open-winding motor system includes a dual-inverter unit and an open-winding motor. The dual-inverter unit includes a main inverter and an auxiliary inverter. The main inverter and the auxiliary inverter are used to alternately output drive currents to the open-winding motor within a preset electrical angle range. The main inverter and the auxiliary inverter are respectively connected to the open-winding motor via bus capacitors. Configure the open-winding motor to generate corresponding Nth harmonics when driven by the corresponding drive current; the bus capacitor is used to charge according to the drive current and the Nth harmonics; when the rotor pole is in the preset electrical angle range, the resultant torque generated by the open-winding motor under the drive current is greater than a preset torque. The method for detecting the rotor pole position of the open-winding motor includes the following steps: Obtain the initial electrical angle of the rotor pole, the interval time for the main inverter and the auxiliary inverter to alternately output drive currents, the movement time of the rotor pole, and the discharge voltage of the bus capacitor. Determine the Nth harmonics generated by the open-winding motor when driven by the corresponding drive current according to the discharge voltage. Determine the electrical angle difference between any two adjacent preset electrical angle ranges according to the Nth harmonics and the discharge voltage of the bus capacitor; and Determine the current position of the rotor pole according to the initial electrical angle of the rotor pole, the interval time for the main inverter and the auxiliary inverter to alternately output drive currents, the electrical angle difference, and the movement time of the rotor pole; wherein, the movement time of the rotor pole is the time for the rotor pole to rotate from the initial electrical angle to the current position.

2. The method for detecting the rotor pole position of the open-winding motor according to claim 1, Characterized in that, The step of configuring the open-winding motor to generate corresponding Nth harmonics when driven by the corresponding drive current is specifically: Configure the average width of the rotor teeth of the open-winding motor to be less than the average width of the stator slots, so that the open-winding motor generates corresponding Nth harmonics when driven by the corresponding drive current.

3. The method for detecting the rotor pole position of the open-winding motor according to claim 1, Characterized in that, The step of determining the Nth harmonics generated by the open-winding motor when driven by the corresponding drive current according to the discharge voltage is specifically: Perform differential calculation on the discharge voltage, and use the calculation result as the Nth harmonics generated by the open-winding motor when driven by the corresponding drive current.

4. The method for detecting the rotor pole position of the open-winding motor according to claim 3, Characterized in that, The step of determining the electrical angle difference between any two adjacent preset electrical angle ranges according to the Nth harmonics and the discharge voltage of the bus capacitor includes: Perform a product operation on the Nth harmonics and the discharge voltage of the bus capacitor and generate a first waveform signal according to the calculation result; Perform edge detection on the first waveform signal to obtain the rising edge in the first waveform signal, and output a first edge signal according to the obtained result. Perform edge detection on the discharge voltage of the bus capacitor to respectively obtain its rising edge and falling edge, and output a second edge signal according to the obtained result; Perform a logical AND operation on the second edge signal after inverting it and the first edge signal, and determine the electrical angle difference between any two adjacent preset electrical angle intervals according to the operation result.

5. The method for detecting the rotor pole position of an open-winding motor according to claim 4, characterized in that, The step of performing edge detection on the first waveform signal to obtain the rising edge in the first waveform signal and outputting a first edge signal according to the obtained result is specifically: Perform edge detection on the first waveform signal to obtain the rising edge with zero amplitude therein, and output a first edge signal according to the obtained result.

6. The method for detecting the rotor pole position of an open-winding motor according to claim 4, characterized in that, The step of performing edge detection on the discharge voltage of the bus capacitor to respectively obtain its rising edge and falling edge, and outputting a second edge signal according to the obtained result is specifically: Perform edge detection on the discharge voltage of the bus capacitor to respectively obtain the rising edge with zero amplitude and the falling edge with zero amplitude therein, and output a second edge signal according to the obtained result.

7. The method for detecting the rotor pole position of an open-winding motor according to claim 1, characterized in that, The step of determining the current position of the rotor pole according to the initial electrical angle of the rotor pole, the interval time for the auxiliary inverter to alternately output drive current, the electrical angle difference, and the movement time of the rotor pole includes: Determine the electrical angle change frequency of the current rotor pole according to the electrical angle difference between any two adjacent preset electrical angle intervals and the interval time for the auxiliary inverter to alternately output drive current; Determine the current position of the rotor pole according to the initial electrical angle of the rotor pole, the electrical angle change frequency of the current rotor pole, and the movement time of the rotor pole.

8. A device for detecting the rotor pole position of an open-winding motor, applied to an open-winding motor system, characterized in that, The open-winding motor system includes a dual-inverter unit and an open-winding motor. The dual-inverter unit includes a main inverter and an auxiliary inverter. The main inverter and the auxiliary inverter are used to alternately output drive current to the open-winding motor within a preset electrical angle interval. The main inverter and the auxiliary inverter are respectively connected to the open-winding motor through a bus capacitor; Configure the open-winding motor to generate corresponding Nth harmonics when driven by the corresponding drive current; The bus capacitor is used to charge according to the drive current and the Nth harmonics. The detection device of the open-winding motor includes: A memory; A processor; and A detection program for the rotor pole position of an open-winding motor stored on the memory and executable on the processor. When the processor executes the control program of the open-winding motor, the method for detecting the rotor pole position of the open-winding motor according to any one of claims 1-7 is implemented.

9. An open-winding motor system, characterized in that, The open-winding motor control system includes: An open-winding motor, which is used to generate corresponding Nth harmonics when driven by the corresponding drive current; A sampling unit, configured to sample the open-winding motor and output corresponding sampling signals; A dual-inverter unit, the dual-inverter unit includes a main inverter and an auxiliary inverter, the main inverter and the auxiliary inverter are configured to alternately output drive currents to the open-winding motor within a preset electrical angle range, the main inverter and the auxiliary inverter are respectively connected to the open-winding motor via bus capacitors; and, the bus capacitors are configured to be charged according to the drive currents and the Nth harmonics; and A main control unit, the main control unit includes a detecting device for the rotor magnetic pole position of the open-winding motor as claimed in claim 8, the main control unit is respectively connected to the sampling unit and the dual-inverter unit.

10. The open-winding motor system as claimed in claim 9, characterized in that the open-winding motor includes a stator and a rotor, the rotor is accommodated in the stator; a plurality of stator slots are uniformly arranged on the inner surface side of the stator, and a plurality of rotor tooth portions corresponding to the plurality of stator slots are arranged on the outer surface side of the rotor.

11. The open-winding motor system as claimed in claim 10, characterized in that the average width of the rotor tooth portions is less than the average width of the stator slots.

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