Motor rotor position acquisition device and method, chip and electrical equipment

Abstract

The invention discloses a motor rotor position obtaining device and method, a chip and electrical equipment, the device is applied to an inverter, the inverter comprises multiple phases of bridge arms, each phase of bridge arm comprises an upper bridge arm and a lower bridge arm, the upper bridge arm comprises an upper bridge arm switch tube connected with a fly-wheel diode in parallel, and the lower bridge arm comprises a lower bridge arm switch tube connected with a fly-wheel diode in parallel. The device comprises an obtaining module used for obtaining the dead-zone voltage of a target bridge arm within the dead-zone time of the inverter, the target bridge arm being a bridge arm in which an upper bridge arm switch tube and a lower bridge arm switch tube are both disconnected within the dead-zone time, and the dead-zone voltage being the voltage generated on the corresponding bridge arm by the current flowing through a freewheeling diode within the dead-zone time; and the control module is used for determining the position of the motor rotor based on the dead-zone voltage. According to the device, a high-reliability motor rotor position acquisition function can be realized without a sensor, so that the control cost of the motor can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the field of chip design, and in particular to a device and method for obtaining the position of a motor rotor, a chip, and electrical equipment. Background Art

[0002] In chips involving motor control, sensors (such as Hall sensors, magnetic encoders, etc.) are usually used to monitor and feedback the motor rotor position, motor phase current and other operating parameters in real time, so as to control the motor current and direction, and then adjust the motor speed and position to achieve real-time control of the motor. In practical applications, due to the high cost of sensors, they cannot be widely used. Therefore, the related technology usually adopts the sliding film and Lomborg sensorless observer to obtain the motor rotor position. This method estimates the motor rotor position by measuring the motor's inductance, resistance, magnetic flux and other parameters to achieve the function of determining the motor rotor position.

[0003] The disadvantage of the above-mentioned related technologies is that the electronic rotor position determination method requires measuring multiple parameters such as the motor's magnetic flux, and requires complex arctan, sin and cos operations on these parameters. Therefore, the algorithm is relatively complex and requires high chip computing power, resulting in the corresponding motor control cost of this method is still high. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the first purpose of the present invention is to propose a motor rotor position acquisition device, which uses an acquisition module to acquire the target bridge arm dead zone voltage during the dead zone time of the inverter, and then determines the rotor position based on the dead zone voltage through a control module, thereby realizing the function of acquiring the motor rotor position without the need for a sensor. At the same time, the determination logic of the rotor position is simple, and there is no need to measure the inductance, flux linkage and other parameters of the motor, thereby effectively reducing the control cost of the motor and improving the reliability of the function of acquiring the motor rotor position.

[0005] The second objective of the present invention is to provide a chip.

[0006] The third object of the present invention is to provide an electrical device.

[0007] A fourth objective of the present invention is to provide a motor phase current sampling device.

[0008] A fifth object of the present invention is to provide a computer-readable storage medium.

[0009] To achieve the above-mentioned purpose, the first aspect of the embodiment of the present invention proposes a motor rotor position acquisition device, which is applied to an inverter, and the inverter includes a multi-phase bridge arm, each phase bridge arm includes an upper bridge arm and a lower bridge arm, the upper bridge arm includes an upper bridge arm switch tube connected in parallel with a freewheeling diode, and the lower bridge arm includes a lower bridge arm switch tube connected in parallel with a freewheeling diode. The device includes: an acquisition module, which is used to obtain the dead zone voltage of the target bridge arm within the dead zone time of the inverter, wherein the target bridge arm is a bridge arm in which the upper bridge arm switch tube and the lower bridge arm switch tube are both disconnected during the dead zone time, and the dead zone voltage is the voltage generated on the corresponding bridge arm by the current flowing through the freewheeling diode during the dead zone time; a control module, which is used to determine the motor rotor position based on the dead zone voltage.

[0010] According to the motor rotor position acquisition device of the embodiment of the present invention, the target bridge arm dead zone voltage is acquired by using the acquisition module during the dead zone time of the inverter, and then the rotor position is determined based on the dead zone voltage by the control module, thereby realizing the function of acquiring the motor rotor position without the need for a sensor. At the same time, the determination logic of the rotor position is simple, and there is no need to measure the inductance, magnetic flux and other parameters of the motor, thereby effectively reducing the control cost of the motor and improving the reliability of the function of acquiring the motor rotor position.

[0011] According to one embodiment of the present invention, the acquisition module includes an ADC sampling unit provided for each phase bridge arm of the corresponding inverter, and the ADC sampling unit is used to obtain the dead zone voltage of the corresponding phase bridge arm as the target bridge arm within the dead zone time.

[0012] According to an embodiment of the present invention, the ADC sampling unit obtains the dead-zone voltage of the corresponding bridge arm as the target bridge arm within the dead-zone time through a single-ended voltage sampling circuit.

[0013] According to an embodiment of the present invention, the control module is specifically configured to determine the motor rotor position at a rising edge or a falling edge of the dead zone voltage.

[0014] According to one embodiment of the present invention, the control module is specifically used to determine the motor rotor position when the dead zone voltage is switched from the upper bridge arm voltage to the lower bridge arm voltage, or from the lower bridge arm voltage to the upper bridge arm voltage, wherein the upper bridge arm voltage is the voltage generated on the upper bridge arm by the current flowing through the freewheeling diode of the upper bridge arm during the dead zone time, and the lower bridge arm voltage is the voltage generated on the lower bridge arm by the current flowing through the freewheeling diode of the lower bridge arm during the dead zone time.

[0015] According to an embodiment of the present invention, the control module is further configured to generate and output an interrupt signal when the motor rotor position is determined, so as to control the motor based on the interrupt signal.

[0016] According to an embodiment of the present invention, the control module is further configured to generate a position signal and store it in a register when the position of the motor rotor is determined, so as to control the motor based on the position signal in the register.

[0017] According to an embodiment of the present invention, the control module is further configured to perform interpolation processing on the motor rotor position to obtain the interpolated motor rotor position.

[0018] According to an embodiment of the present invention, the control module is further configured to perform open-loop control on the motor using a constant voltage-frequency ratio or a constant current-frequency ratio.

[0019] To achieve the above-mentioned purpose, a second embodiment of the present invention provides a chip, including the aforementioned motor rotor position acquisition device.

[0020] According to the chip of the embodiment of the present invention, through the aforementioned motor rotor position acquisition device, the function of acquiring the motor rotor position can be realized when the motor is working without a sensor. At the same time, the logic for determining the rotor position is simple, and there is no need to measure the motor's inductance, magnetic flux and other parameters, thereby effectively reducing the control cost of the motor and improving the reliability of the function of acquiring the motor rotor position.

[0021] To achieve the above-mentioned purpose, a third aspect of the present invention provides an electrical device, including the aforementioned motor rotor position acquisition device, or the aforementioned chip.

[0022] According to the electrical equipment of the embodiment of the present invention, through the aforementioned motor rotor position acquisition device, or the aforementioned chip, the function of acquiring the motor rotor position can be realized when the motor is working without the need for a sensor. At the same time, the logic for determining the rotor position is simple, and there is no need to measure the motor's inductance, magnetic flux and other parameters, thereby effectively reducing the control cost of the motor and improving the reliability of the function of acquiring the motor rotor position.

[0023] To achieve the above-mentioned purpose, the fourth aspect of the present invention proposes a method for obtaining the position of a motor rotor, which is applied to an inverter. The inverter includes a multi-phase bridge arm, each phase bridge arm includes an upper bridge arm and a lower bridge arm, the upper bridge arm includes an upper bridge arm switch tube connected in parallel with a freewheeling diode, and the lower bridge arm includes a lower bridge arm switch tube connected in parallel with a freewheeling diode. The method includes: obtaining the dead zone voltage of the target bridge arm within the dead zone time of the inverter, wherein the target bridge arm is a bridge arm in which the upper bridge arm switch tube and the lower bridge arm switch tube are both disconnected within the dead zone time, and the dead zone voltage is the voltage generated on the corresponding bridge arm by the current flowing through the freewheeling diode within the dead zone time; based on the dead zone voltage, determining the position of the motor rotor.

[0024] According to the motor rotor position acquisition method of an embodiment of the present invention, the target bridge arm dead zone voltage is acquired within the dead zone time of the inverter, and then the rotor position is determined based on the dead zone voltage, thereby realizing the function of acquiring the motor rotor position without the need for a sensor. At the same time, the rotor position determination logic is simple, and there is no need to measure the motor's inductance, magnetic flux and other parameters, thereby effectively reducing the motor's control cost and improving the reliability of the motor rotor position acquisition function.

[0025] To achieve the above-mentioned purpose, a fifth aspect of the present invention provides a computer-readable storage medium having a program stored thereon, which implements the aforementioned method for obtaining the motor rotor position when executed by a processor.

[0026] According to the computer-readable storage medium of an embodiment of the present invention, through the aforementioned motor rotor position acquisition method, the function of acquiring the motor rotor position can be realized when the motor is working without the need for a sensor. At the same time, the logic for determining the rotor position is simple, and there is no need to measure the motor's inductance, magnetic flux and other parameters, thereby effectively reducing the control cost of the motor and improving the reliability of the function of acquiring the motor rotor position.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a structural schematic diagram of an inverter according to an embodiment of the present invention;

[0029] Figure 2 2 is a schematic diagram of the structure of a device for acquiring the position of a motor rotor according to an embodiment of the present invention;

[0030] Figure 3 is a control timing diagram of a target bridge arm according to an embodiment of the present invention;

[0031] Figure 4 A connection diagram of an ADC sampling unit according to an embodiment of the present invention;

[0032] Figure 5a to Figure 5b A schematic diagram of current direction of an inverter according to an embodiment of the present invention;

[0033] Figure 6 is a schematic diagram of a dead zone voltage and a phase current of an inverter according to an embodiment of the present invention;

[0034] Figure 7 is a waveform diagram of an interrupt signal according to an embodiment of the present invention;

[0035] Figure 8 is a schematic structural diagram of a chip according to an embodiment of the present invention;

[0036] Figure 9a to Figure 9b A schematic diagram of the structure of an electrical device according to an embodiment of the present invention;

[0037] Fig.10 The figure is a flow chart of a method for acquiring the motor rotor position according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0039] The following describes a motor rotor position acquisition device and method, a chip, an electrical device, and a computer-readable storage medium proposed in an embodiment of the present invention with reference to the accompanying drawings.

[0040] It should be noted that the motor rotor position acquisition device of the embodiment of the present invention can be applied to Figure 1 In the inverter shown, reference Figure 1 As shown, the inverter 100 includes a three-phase bridge arm, which is respectively a U-phase bridge arm, a W-phase bridge arm and a V-phase bridge arm, so as to be connected to the U-phase, W-phase and V-phase of the motor M. Each phase bridge arm includes an upper bridge arm and a lower bridge arm, and the upper bridge arm of the three-phase bridge arm is connected to the DC bus power supply VBUS, and the lower bridge arm of the three-phase bridge arm is grounded GND. The upper bridge arm also includes an upper bridge arm switch tube QU connected in parallel with a freewheeling diode, and the lower bridge arm also includes a lower bridge arm switch tube QD connected in parallel with a freewheeling diode. By controlling the on-off of the six switch tubes of the three-phase bridge arm, the inverter 100 can convert the DC power provided by the DC bus power supply VBUS into three-phase AC power, and then control the rotation of the motor M. The control logic can be a variety of control logics such as two-by-two conduction and three-by-three conduction. The specific control logic is not expanded here.

[0041] Figure 2 FIG. 1 is a schematic diagram of a motor rotor position acquisition device according to an embodiment of the present invention. Figure 2 As shown, the device 200 includes: an acquisition module 210 and a control module 220.

[0042] Among them, the acquisition module 210 is used to obtain the dead zone voltage of the target bridge arm within the dead zone time of the inverter 100, wherein the target bridge arm is the bridge arm in which the upper bridge arm switch tube and the lower bridge arm switch tube are both disconnected during the dead zone time, and the dead zone voltage is the voltage generated on the corresponding bridge arm by the current flowing through the freewheeling diode during the dead zone time; the control module 220 is used to determine the motor rotor position based on the dead zone voltage.

[0043] Specifically, in the control process of the inverter 100, in order to realize the phase switching function of the motor M, a phase in the three-phase bridge arm needs to switch the upper bridge arm switch tube and the lower bridge arm switch tube. At this time, the phase bridge arm is the target bridge arm. In order to avoid the upper and lower bridge arm switches of the target bridge arm being turned on at the same time, causing damage to the inverter 100, it is necessary to set a period as a dead zone period before switching on, such as Figure 3 In the time period t0-t1 and the time period t2-t3 shown, it is ensured that the upper bridge arm switch tube and the lower bridge arm switch tube in the phase bridge arm are both disconnected, and then the conduction switching function is performed to protect the safety of the inverter 100. From the above analysis, it can be seen that during the dead time of the inverter 100, the bridge arm in which the upper bridge arm switch tube and the lower bridge arm switch tube are both disconnected is the target bridge arm.

[0044] After determining the target bridge arm of the current dead time, refer to Figure 1 As shown, taking the U-phase bridge arm as the target bridge arm as an example, during the dead time of the U-phase bridge arm, although the upper bridge arm switch tube QU and the lower bridge arm switch tube QD are both turned off, since both switch tubes have freewheeling diodes, different freewheeling circuits will be generated in the U-phase bridge arm at this time according to the magnitude of the phase voltage of the U-phase, and the voltage generated on the upper bridge arm or the lower bridge arm by the current flowing through the freewheeling diode at this time can be obtained in a variety of ways, and this voltage is the dead zone voltage. At the same time, since the dead zone voltage can explain the magnitude of the U-phase phase voltage at this time, and then determine the current commutation moment of the motor M, and in the control logic of the motor M, the motor rotor position corresponding to the fixed commutation moment is also fixed, therefore, the control module 220 can determine the corresponding motor rotor position according to the dead zone voltage.

[0045] As can be seen from the above, the acquisition device 200 of the embodiment of the present invention can determine the rotor position of the motor M by detecting the dead zone voltage of the target bridge arm in the inverter 100. Compared with the method of using sliding film and Lomborg sensorless observer to determine the motor rotor position in the related art, the acquisition device 200 of the embodiment of the present invention only involves the dead zone voltage as a measurement parameter, and does not need to measure the inductance and resistance and flux parameters of the motor M; at the same time, the logic of the acquisition process of the motor rotor position by the acquisition device 100 is relatively simple, and neither complex arctan, sin and cos operations nor floating point data are required. Therefore, the acquisition device 200 has low requirements on the computing power and performance of the chip, and the error probability is also low. As a result, the acquisition device of the embodiment of the present invention has the advantages of simple logic, high reliability and low error probability. In addition, compared with the method of using sensors to obtain the motor rotor position, the acquisition device of the embodiment of the present invention also has the advantage of low cost.

[0046] In the above embodiment, the target bridge arm dead zone voltage is obtained by using the acquisition module within the dead zone time of the inverter, and then the rotor position is determined based on the dead zone voltage by the control module, thereby realizing the function of obtaining the motor rotor position without the need for a sensor. At the same time, the determination logic of the rotor position is simple, and there is no need to measure the motor's inductance, magnetic flux and other parameters, thereby effectively reducing the control cost of the motor and improving the reliability of the function of obtaining the motor rotor position.

[0047] In some embodiments, reference Figure 4 As shown, the acquisition module 210 includes an ADC (analog to digital converter) sampling unit 211 set corresponding to each phase bridge arm of the inverter 100, and the ADC sampling unit 211 is used to obtain the dead zone voltage of the corresponding phase bridge arm as the target bridge arm within the dead zone time.

[0048] Furthermore, the ADC sampling unit 211 obtains the dead-zone voltage of the corresponding bridge arm as the target bridge arm within the dead-zone time through the single-ended voltage sampling circuit 300 .

[0049] Specifically, in the control cycle of the motor M, each of the three-phase bridge arms will serve as a target bridge arm at a certain switching moment. Therefore, a single-ended voltage sampling circuit 300 can be set at the output end of the three-phase AC power of the inverter 100. When the corresponding bridge arm serves as the target bridge arm, the circuit can collect the dead zone voltage of the target bridge arm and transmit it to the ADC sampling unit 111. The ADC sampling unit 111 can convert the collected dead zone voltage from an analog signal into a digital signal for transmission or storage, so as to be queried and used by the control module 220.

[0050] Optionally, the single-ended voltage sampling circuit 300 may be as follows: Figure 4 As shown, reference Figure 4As shown, the single-ended voltage sampling circuit 300 may include three identical single-ended sampling sub-circuits 310, and the three sampling ends of the single-ended sampling sub-circuit 310 are respectively connected to the JU, JW, and JV nodes of the inverter 100, wherein the JU, JW, and JV nodes are the output ends of the corresponding phase AC power of the inverter 100, and the three sampling points of the single-ended sampling sub-circuit 310 are respectively connected to the ADC sampling unit. The circuit structures of the three single-ended sampling sub-circuits 310 are the same. Taking the single-ended sampling sub-circuit 310 of the U-phase bridge arm as an example, the circuit 310 includes a first resistor to a third resistor R1~R3 ​​and a capacitor C, wherein one end of the first resistor R1 is grounded GND, and the other end of the first resistor R1 is connected to one end of the second resistor R2 and one end of the third resistor R3 respectively; the other end of the second resistor R2 is connected to the node JU as a sampling end; the other end of the third resistor R3 is connected to one end of the capacitor C and serves as the voltage sampling point Vbemf of the single-ended voltage sampling circuit 300, and the other end of the capacitor C is grounded GND. The circuit mainly collects the upper bridge arm or lower bridge arm voltage of the U-phase bridge arm as the dead zone voltage according to the voltage division principle of the first resistor R1 and the second resistor R2. At the same time, the capacitor C has a voltage stabilizing effect, and the third resistor R3 has a current limiting effect to avoid excessive current in the single-ended voltage sampling circuit 300.

[0051] When the single-ended voltage sampling circuit 300 is Figure 4 As shown, the process of obtaining the dead zone voltage of the target bridge arm of the inverter 100 is as follows: when the U-phase bridge arm is the target bridge arm, according to the high or low phase voltage of the U-phase of the motor M, there are two situations in the freewheeling circuit on the U-phase bridge arm. In the first situation, the U-phase voltage is high, and there is current in the upper bridge arm of the U-phase bridge arm. At this time, the current path in the single-ended voltage sampling circuit 300 is as follows: Figure 5a As shown, one current path starts from the JU node, passes through the second resistor R2 and the first resistor R1 to the ground terminal GND, and the other current path starts from the JU node, passes through the second resistor R2 and the third resistor R3 to the ADC sampling unit 211. At this time, according to the voltage division principle, the following formula (1) can be obtained:

[0052] Vbemf=VU*R1 / (R2+R2) (1)

[0053] Wherein, Vbemf is the sampling voltage collected by the single-ended voltage sampling circuit 300, VU is the voltage generated in the upper bridge arm by the current flowing through the freewheeling diode, that is, the dead zone voltage, R1 is the resistance value of the first resistor R1, and R2 is the resistance value of the second resistor R2. The dead zone voltage VU of the U-phase bridge arm at this time can be obtained by the above formula (1).

[0054] Alternatively, in the second case, the U phase voltage is low, and there is current in the lower bridge arm of the U phase bridge arm. At this time, the current path in the single-ended voltage sampling circuit 300 is as follows: Figure 5bAs shown, one current path starts from the ground terminal GND, passes through the first resistor R1 and the second resistor R2 to the JU node, and the other current path starts from the ground terminal GND, passes through the first resistor R1 and the third resistor R3 to the ADC sampling unit 211. At this time, the dead zone voltage VU at this time can also be calculated according to the above formula (1). At this time, the measured dead zone voltage is a negative value.

[0055] It should be noted that the motor rotor position acquisition device of the embodiment of the present invention may also adopt other types of single-ended voltage sampling circuits 300. Figure 4 The single-ended voltage sampling circuit 300 shown is exemplary and is not intended to limit the present application.

[0056] In some embodiments, the control module 220 is specifically configured to determine the motor rotor position at a rising edge or a falling edge of the dead zone voltage.

[0057] Furthermore, the control module 220 is specifically used to determine the motor rotor position when the dead zone voltage switches from the upper bridge arm voltage to the lower bridge arm voltage, or switches from the lower bridge arm voltage to the upper bridge arm voltage, wherein the upper bridge arm voltage is the voltage generated on the upper bridge arm by the current flowing through the freewheeling diode of the upper bridge arm during the dead zone time, and the lower bridge arm voltage is the voltage generated on the lower bridge arm by the current flowing through the freewheeling diode of the lower bridge arm during the dead zone time.

[0058] Specifically, the dead zone voltage obtained by the acquisition module 210 can be divided into an upper bridge arm voltage and a lower bridge arm voltage according to the voltage acquisition method, wherein the upper bridge arm voltage is the voltage generated on the upper bridge arm by the current flowing through the freewheeling diode of the upper bridge arm during the dead zone time. At this time, the freewheeling circuit in the inverter is as follows: Figure 5a As shown, the freewheeling loop starts from the JU node, passes through the freewheeling diode of the upper bridge arm switch tube, and reaches the DC bus power supply VBUS. At this time, according to the voltage division principle, the following formula (2) can be obtained:

[0059] VU=Vbus+Vd (2)

[0060] Among them, VU is the upper bridge arm voltage, which can be Figure 4 The single-ended voltage sampling circuit 300 shown in FIG. 1 is obtained, VBUS is the DC bus voltage of the inverter 100, which can be obtained by real-time detection; Vd is the diode conduction voltage, which can be obtained by obtaining the diode parameters. It can be seen that when the dead zone voltage is the upper bridge arm voltage, the dead zone voltage is a positive value. Considering the measurement error, the obtained dead zone voltage VU should be around Vbus+Vd.

[0061] The voltage of the lower bridge arm is the voltage generated on the lower bridge arm by the current flowing through the freewheeling diode of the lower bridge arm during the dead time. At this time, the freewheeling circuit in the inverter is as follows Figure 5bAs shown in FIG. 1 , the freewheeling loop starts from the ground terminal GND, passes through the freewheeling diode of the lower bridge arm switch tube, and reaches the JU node. At this time, the following formula (3) can be obtained according to the voltage division principle:

[0062] VU=0-Vd (3)

[0063] Among them, VU is the upper bridge arm voltage, which can be Figure 4 The single-ended voltage sampling circuit 300 shown in the figure is obtained, Vd is the diode conduction voltage, which can be obtained by obtaining the diode parameters. It can be seen that when the dead zone voltage is the lower bridge arm voltage, the dead zone voltage is a negative value and should be around -Vd. It can be seen that during the dead zone time, the dead zone voltage of the target bridge arm will only jump between the two levels of Vbus+Vd and -Vd (hereinafter referred to as high level and low level, respectively).

[0064] Subsequently, after the voltage value of the dead zone voltage is determined, the variation curve of the dead zone voltage can be determined in combination with the control logic of the motor M. For example, when the motor is controlled in a three-phase-three-phase conduction mode, the three-phase current of the motor M and the generated dead zone voltage can be as follows: Figure 6 As shown, Figure 6 Taking the U-phase bridge arm shown in the figure as an example, when the dead zone voltage of the U-phase bridge arm switches between high level and low level, it means that the bridge arm switch tube of the phase bridge arm is switched, so that the motor M is switched. During the switching, the phase current of the U-phase bridge arm passes through the zero point. In the control logic of the motor, the motor rotor position corresponding to the zero point of the phase current of the three-phase bridge arm is determined. For example, refer to Figure 6 As shown, six commutations are required in one control cycle of the inverter, one every 60°. At this time, the two zero crossings corresponding to the U-phase current are the second and fifth, respectively. The corresponding motor rotor positions should be 60° and 240°. Figure 6 It can be seen that the motor rotor position corresponding to the falling edge of the U-phase dead zone voltage is 60°, and the rotor position corresponding to the rising edge of the U-phase dead zone voltage is 240°, and the motor rotor positions of the remaining phases are similar. It can be seen that the motor rotor position corresponding to the rising and falling edges of the dead zone phase voltage of the U-phase bridge arm is determined.

[0065] In one control cycle, Figure 6 In the range of 0° to 360° shown in the figure, the U-phase bridge arm has undergone two high-low level switchings, and the falling edge or rising edge of the switching is the dead time. During the dead time, when the dead zone voltage of the U-phase bridge arm switches from a high level to a low level, the freewheeling current in the U-phase of the motor will be Figure 5a The direction shown becomes Figure 5bIn the direction shown, the dead zone voltage measured at this time will switch from the upper bridge arm voltage to the lower bridge arm voltage. Therefore, in actual operation, when the control module 220 detects that the dead zone voltage of the U-phase bridge arm switches from the upper bridge arm voltage to the lower bridge arm voltage, it indicates that the commutation time of the motor M has arrived. Figure 6 Similarly, when the control module 220 detects that the dead zone voltage of the U-phase bridge arm switches from the lower bridge arm voltage to the upper bridge arm voltage during actual operation, it indicates that the commutation time of the motor M has arrived. Figure 6 As shown in the figure, the rising edge position of the U-phase dead zone voltage. As can be seen from the above, the falling edge and the rising edge of the U-phase dead zone voltage of the motor M correspond to specific motor rotor positions. After determining whether the dead zone voltage of the motor M is at the rising edge or the falling edge at this time, the control module 220 can obtain the motor rotor position at this time by looking up a table or the like. As a result, the control module realizes the function of determining the motor rotor position according to the rising edge and the falling edge of the dead zone voltage.

[0066] It should be noted that, since the acquisition device 200 in the embodiment of the present invention only works within the dead time of the inverter, the sampling frequency of the acquisition device 200 can be set based on the dead time of the inverter 100. Figure 6 When the three-three conduction mode is used for control, each phase bridge arm performs two phase changes in a single control cycle. Therefore, the sampling frequency of the acquisition device 200 can be set to twice the control frequency. For example, when the control frequency of the inverter 100 is 16KHZ, the sampling frequency of the acquisition device 200 can be 32KHZ, which can achieve the effect of determining the motor rotor position within the dead time.

[0067] In some embodiments, the control module 220 is further configured to generate and output an interrupt signal when the motor rotor position is determined, so as to control the motor based on the interrupt signal.

[0068] Specifically, when the motor rotor position is determined, the control module 220 may assume part of the control function of the motor M, that is, provide an interrupt signal to the external controller of the motor. The generated interrupt signal may be as follows: Figure 7 As shown, reference Figure 7 As shown, within one cycle, the control module 220 can generate 6 interrupt signals according to the motor rotor position, and output them in the form of increasing square waves, corresponding to Figure 7 In the examples shown in Figures 0 to 5, the external controller can determine the current motor rotor position based on the interrupt signal and perform six commutation operations to achieve the control function of the motor, thereby further reducing the control cost of the motor.

[0069] In some embodiments, the control module 220 is further configured to generate a position signal and store it in a register when the position of the motor rotor is determined, so as to control the motor based on the position signal in the register.

[0070] Specifically, when determining the motor rotor position, the control module 220 can also generate a position signal based on the determined rotor position and store it in a register. The register has the characteristics of easy storage and reading. Therefore, the external controller of the motor M can easily read the position signal from the register to control the motor M based on the position signal in the register, thereby further reducing the control cost of the motor.

[0071] In some embodiments, the control module 220 is further configured to perform interpolation processing on the motor rotor position to obtain the interpolated motor rotor position.

[0072] Specifically, interpolation processing refers to processing multiple sets of motor rotor position data using interpolation method. The motor rotor position after interpolation processing can reduce the error in the process of determining the motor rotor position, thereby improving the accuracy of the determined motor rotor position.

[0073] In some embodiments, the control module 220 is further configured to perform open-loop control on the motor using a constant voltage-frequency ratio or a constant current-frequency ratio.

[0074] Specifically, the constant voltage-frequency ratio and the constant current-frequency ratio are both VF open-loop control modes. In the stable state of VF open-loop control, the current phase difference of the inverter 100 has a stable relationship with the phase difference of the rotor position. At this time, determining the rotor position by detecting the current zero-crossing point can make the determined rotor position more accurate. Therefore, when the motor is open-loop controlled using a constant voltage-frequency ratio or a constant current-frequency ratio, the motor rotor position determined by the acquisition device of the embodiment of the present invention is more accurate, thereby improving the accuracy of the acquisition device.

[0075] It should be noted that the motor rotor position acquisition device 200 of the aforementioned multiple invention embodiments can be integrated into a chip, so that the chip can integrate the motor rotor position acquisition function and has the advantages of low control cost and high reliability, thereby optimizing the chip design.

[0076] In summary, according to the motor rotor position acquisition device of the embodiment of the present invention, the target bridge arm dead zone voltage is acquired by using the ADC sampling unit in the acquisition module during the dead zone time of the inverter, and then the rotor position is determined based on the dead zone voltage by the control module, thereby realizing the function of acquiring the motor rotor position without the need for a sensor. At the same time, the determination logic of the rotor position is simple, and there is no need to measure the inductance, magnetic flux and other parameters of the motor. In addition, the control module can also send an interrupt signal or generate a position signal and write it to a register when determining the motor rotor position, so that the external controller of the motor can acquire the rotor position of the motor, thereby effectively reducing the control cost of the motor and improving the reliability of the function of acquiring the motor rotor position.

[0077] Corresponding to the above embodiment, the embodiment of the present invention further provides a chip, referring to Figure 8 As shown, the chip 1000 includes the aforementioned motor rotor position acquisition device 200 .

[0078] According to the chip of the embodiment of the present invention, through the aforementioned motor rotor position acquisition device, it is possible to realize the function of acquiring the motor rotor position when the motor is working without the need for a sensor. At the same time, the logic for determining the rotor position is simple, and there is no need to measure the motor's parameters such as inductance and magnetic flux. In addition, when determining the motor rotor position, an interrupt signal can be sent or a position signal can be generated and written into a register to control the motor, thereby effectively reducing the control cost of the motor and improving the reliability of the function of acquiring the motor rotor position.

[0079] Corresponding to the above embodiment, the embodiment of the present invention further provides an electrical device, referring to Figure 9a to Figure 9b As shown, the electrical device 10000 includes the aforementioned motor rotor position acquisition device 200, or the aforementioned chip 1000.

[0080] The electrical equipment according to the embodiments of the present invention comprises the motor rotor position acquisition device or chip in any of the above embodiments, wherein the electrical equipment may be various equipment such as air conditioners, refrigerators, compressors, etc. These electrical equipment can, through the aforementioned motor rotor position acquisition device or the aforementioned chip, realize the function of acquiring the motor rotor position when the motor is working without the need for a sensor, and the logic for determining the rotor position is simple, and there is no need to measure the inductance, magnetic flux and other parameters of the motor; in addition, when determining the motor rotor position, an interrupt signal can be issued or a position signal can be generated and written into a register to control the motor, thereby effectively reducing the control cost of the motor and improving the reliability of the function of acquiring the motor rotor position.

[0081] Corresponding to the above embodiment, the embodiment of the present invention further provides a method for obtaining the position of a motor rotor, which is applied to Figure 1The inverter 100 shown in FIG. 1 includes a multi-phase bridge arm, each phase bridge arm includes an upper bridge arm and a lower bridge arm, the upper bridge arm includes an upper bridge arm switch tube connected in parallel with a freewheeling diode, and the lower bridge arm includes a lower bridge arm switch tube connected in parallel with a freewheeling diode. Fig.10 As shown, the method includes:

[0082] S11, obtaining the dead zone voltage of the target bridge arm during the dead zone of the inverter, wherein the target bridge arm is the bridge arm in which both the upper bridge arm switch tube and the lower bridge arm switch tube are disconnected during the dead zone, and the dead zone voltage is the voltage generated on the corresponding bridge arm by the current flowing through the freewheeling diode during the dead zone.

[0083] S12, determining the motor rotor position based on the dead zone voltage.

[0084] According to an embodiment of the present invention, the method further includes: acquiring, by an ADC sampling unit, a dead zone voltage of a corresponding phase bridge arm as a target bridge arm within a dead zone time.

[0085] According to an embodiment of the present invention, the method further includes: acquiring the dead-zone voltage of the corresponding bridge arm as the target bridge arm within the dead-zone time by means of a single-ended voltage sampling circuit.

[0086] According to an embodiment of the present invention, the method further includes: determining the motor rotor position at a rising edge or a falling edge of the dead zone voltage.

[0087] According to one embodiment of the present invention, the method also includes: when the dead zone voltage switches from the upper bridge arm voltage to the lower bridge arm voltage, or switches from the lower bridge arm voltage to the upper bridge arm voltage, determining the motor rotor position, wherein the upper bridge arm voltage is the voltage generated on the upper bridge arm by the current flowing through the freewheeling diode of the upper bridge arm during the dead zone time, and the lower bridge arm voltage is the voltage generated on the lower bridge arm by the current flowing through the freewheeling diode of the lower bridge arm during the dead zone time.

[0088] According to an embodiment of the present invention, the method further includes: when the motor rotor position is determined, generating an interrupt signal and outputting the interrupt signal to the outside, so as to control the motor based on the interrupt signal.

[0089] According to an embodiment of the present invention, the method further comprises: when the position of the motor rotor is determined, generating a position signal and storing it in a register, so as to control the motor based on the position signal in the register.

[0090] According to an embodiment of the present invention, the method further includes: performing interpolation processing on the motor rotor position to obtain the interpolated motor rotor position.

[0091] According to an embodiment of the present invention, the method further comprises: performing open-loop control on the motor by adopting a constant voltage-frequency ratio or a constant current-frequency ratio.

[0092] It should be noted that, for the description of the motor rotor position acquisition method in the present application, please refer to the description of the motor rotor position acquisition device in the present application, and the details will not be repeated here.

[0093] According to the motor rotor position acquisition method of the embodiment of the present invention, by acquiring the target bridge arm dead zone voltage within the dead zone time of the inverter, and then determining the rotor position based on the dead zone voltage, the function of acquiring the motor rotor position is realized without the need for a sensor. At the same time, the rotor position determination logic is simple, and there is no need to measure the inductance, magnetic flux and other parameters of the motor. In addition, by issuing an interrupt signal or generating a position signal and writing it into a register when determining the motor rotor position, the external controller of the motor can acquire the rotor position of the motor, thereby effectively reducing the control cost of the motor and improving the reliability of the function of acquiring the motor rotor position.

[0094] Corresponding to the above embodiment, an embodiment of the present invention further provides a computer-readable storage medium on which a program is stored. When the program is executed by a processor, the above-mentioned method for obtaining the motor rotor position is implemented.

[0095] According to the computer-readable storage medium of an embodiment of the present invention, through the aforementioned motor rotor position acquisition method, the function of acquiring the motor rotor position can be realized when the motor is working without a sensor, and the logic for determining the rotor position is simple, and there is no need to measure the motor's inductance, magnetic flux and other parameters; in addition, when determining the motor rotor position, an interrupt signal can be issued or a position signal can be generated and written into a register to control the motor, thereby effectively reducing the control cost of the motor and improving the reliability of the function of acquiring the motor rotor position.

[0096] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0097] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0098] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0099] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0100] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0101] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A motor rotor position acquisition device, characterized in that: Applied to an inverter, the inverter includes a multi-phase bridge arm, each phase bridge arm includes an upper bridge arm and a lower bridge arm, the upper bridge arm includes an upper bridge arm switch tube connected in parallel with a freewheeling diode, the lower bridge arm includes a lower bridge arm switch tube connected in parallel with a freewheeling diode, and the device includes: An acquisition module, used for acquiring a dead zone voltage of a target bridge arm within a dead zone of the inverter, wherein the target bridge arm is a bridge arm in which both an upper bridge arm switch tube and a lower bridge arm switch tube are disconnected within the dead zone, and the dead zone voltage is a voltage generated on the corresponding bridge arm by a current flowing through the freewheeling diode within the dead zone; The control module is used to determine the motor rotor position based on the dead zone voltage.

2. The device according to claim 1, characterized in that The acquisition module comprises an ADC sampling unit arranged corresponding to each phase bridge arm of the inverter, and the ADC sampling unit is used for acquiring the dead zone voltage of the corresponding phase bridge arm as the target bridge arm within the dead zone time.

3. The device according to claim 2, characterized in that The ADC sampling unit acquires the dead zone voltage of the corresponding bridge arm as the target bridge arm within the dead zone time through a single-ended voltage sampling circuit.

4. The device according to any one of claims 1 to 3, characterized in that: The control module is specifically used to determine the motor rotor position at the rising edge or the falling edge of the dead zone voltage.

5. The device according to any one of claims 1 to 3, characterized in that: The control module is specifically used to determine the motor rotor position when the dead zone voltage is switched from the upper bridge arm voltage to the lower bridge arm voltage, or from the lower bridge arm voltage to the upper bridge arm voltage, wherein the upper bridge arm voltage is the voltage generated on the upper bridge arm by the current flowing through the freewheeling diode of the upper bridge arm during the dead zone time, and the lower bridge arm voltage is the voltage generated on the lower bridge arm by the current flowing through the freewheeling diode of the lower bridge arm during the dead zone time.

6. The device according to claim 1, characterized in that The control module is further configured to generate and output an interrupt signal when the motor rotor position is determined, so as to control the motor based on the interrupt signal.

7. The device according to claim 1, characterized in that The control module is further configured to generate a position signal and store the position signal in a register when the position of the motor rotor is determined, so as to control the motor based on the position signal in the register.

8. The device according to claim 1, characterized in that The control module is also used to perform interpolation processing on the motor rotor position to obtain the interpolated motor rotor position.

9. The device according to claim 1, characterized in that The control module is also used to perform open-loop control on the motor using a constant voltage-frequency ratio or a constant current-frequency ratio.

10. A chip, characterized in that: It comprises the motor rotor position acquisition device according to any one of claims 1-9.

11. An electrical device, characterized in that: It comprises the motor rotor position acquisition device according to any one of claims 1 to 9, or the chip according to claim 10.

12. A method for obtaining a motor rotor position, characterized in that: Applied to an inverter, the inverter includes a multi-phase bridge arm, each phase bridge arm includes an upper bridge arm and a lower bridge arm, the upper bridge arm includes an upper bridge arm switch tube connected in parallel with a freewheeling diode, the lower bridge arm includes a lower bridge arm switch tube connected in parallel with a freewheeling diode, and the method includes: Acquire a dead zone voltage of a target bridge arm during a dead zone of the inverter, wherein the target bridge arm is a bridge arm in which both an upper bridge arm switch tube and a lower bridge arm switch tube are disconnected during the dead zone, and the dead zone voltage is a voltage generated on the corresponding bridge arm by a current flowing through the freewheeling diode during the dead zone; Based on the dead-band voltage, a motor rotor position is determined.

13. A computer-readable storage medium, characterized in that: A program is stored thereon, and when the program is executed by a processor, the method for obtaining the motor rotor position according to claim 12 is implemented.

Images