Motor rotor position observation method, device, rotor position observer and medium

Abstract

The present invention discloses a method, device, rotor position observer and medium for observing the rotor position of a motor. The method comprises: when injecting a high-frequency pulse into the D-axis of the motor, determining a reference value and determining six comparison values ​​of three-way modulation corresponding to the output voltage vector required under single resistor sampling; determining the difference between the reference value and the comparison value Act21 or Act22; adjusting the six comparison values ​​according to the difference, and adjusting the six comparison values ​​according to the adjusted comparison value Act21. New or Act22 New The first and second current sampling trigger values ​​are determined; the motor is controlled based on the adjusted six comparison values, and current sampling is performed on the motor based on the first and second current sampling trigger values ​​to obtain first and second sampled currents; and the rotor position of the motor is estimated based on the first and second sampled currents. This effectively improves the sampling current accuracy of single-resistance sampling, thereby improving the accuracy of motor rotor position observation.

Description

Technical Field

[0001] The present invention relates to the field of motor control technology, and in particular to a motor rotor position observation method, device, rotor position observer and medium. Background Art

[0002] A sensorless motor control method based on high-frequency injection is simple to implement, low-cost, and offers good control performance in low-speed ranges, enabling low-speed load startup of the motor. This method injects periodic positive and negative pulses into the d-axis, samples the high-frequency current response induced by the pulses, and feeds this high-frequency current response into a phase-locked loop (PLL) to estimate the motor's position. Traditional observer methods offer good performance in medium and high-speed ranges but fail to converge at low speeds, making high-frequency injection a valuable approach for practical applications.

[0003] The single-resistance sampling technology samples the current by using the sampling resistor on the DC negative bus. Sampling is required twice in one control cycle, and sampling is performed during the action time of two effective voltage vectors (i.e., non-zero voltage vectors). After sampling, the phase sequence to which the sampled current belongs is determined based on the voltage vector situation.

[0004] When sampling with a single resistor, both current samples require a certain amount of time. Sampling is typically performed around the time of the second or fifth switch activation, that is, within the time between the two effective voltage vectors. If the resultant voltage vector lies near a sector switching boundary, at least one of the effective voltage vectors may be too small. Therefore, to meet the sampling time requirement, phase shifting is required at the switch activation time to ensure the accuracy of the two current samples. However, this single resistor sampling can cause the sampling time to vary, especially near different sector switching regions. Differences in phase shifting methods can lead to significant differences in sampling time. Because the back EMF and resistor voltage drop are small when the motor is running at low speed, the controller output voltage is primarily a high-frequency injection voltage, which is injected periodically in positive and negative phases, with the corresponding sectors differing by 180°. This phase shift introduces significant sampling time errors, resulting in significant errors in the sampled q-axis high-frequency current response. Consequently, the estimated position obtained from this solution will also have significant errors, affecting the system's control performance. Summary of the Invention

[0005] The present invention aims to at least partially address one of the technical problems in the related art. To this end, a first object of the present invention is to provide a method for observing the position of a motor rotor that effectively improves the accuracy of current sampling using a single resistor, thereby improving the accuracy of observing the motor rotor position.

[0006] A second object of the present invention is to provide a computer-readable storage medium.

[0007] The third object of the present invention is to provide a rotor position observer.

[0008] A fourth object of the present invention is to provide a motor rotor position observation device.

[0009] To achieve the above-mentioned purpose, a first embodiment of the present invention proposes a method for observing the position of a motor rotor, comprising: when injecting a high-frequency pulse into the d-axis of the motor, determining a reference value, and determining six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 of three-way modulation corresponding to the output voltage vector required under single resistor sampling; determining the difference between the reference value and the comparison value Act21 or Act22; adjusting the six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 according to the difference, and adjusting the comparison value Act21 according to the adjusted comparison value Act21. New or Act22 New Determine the first current sampling trigger value and the second current sampling trigger value; according to the adjusted six comparison values ​​Act11 New Act21 New Act 31 New 、Act32 New Act 22 New Act 12 New The motor is controlled, and current sampling is performed on the motor according to the first current sampling trigger value and the second current sampling trigger value to obtain a first sampling current and a second sampling current; and the rotor position of the motor is estimated according to the first sampling current and the second sampling current.

[0010] According to the motor rotor position observation method of an embodiment of the present invention, the six comparison values ​​of the three-way modulation corresponding to the output required voltage vector under single resistor sampling are adjusted according to the difference between the reference value and the comparison value, and the first current sampling trigger value and the second current sampling trigger value are determined according to the adjusted comparison values, and the motor is controlled according to the adjusted six comparison values, and the motor current is sampled according to the first current sampling trigger value and the second current sampling trigger value to obtain the first sampling current and the second sampling current, and the rotor position of the motor is estimated according to the first sampling current and the second sampling current, which can effectively improve the sampling current accuracy of the single resistor sampling, thereby improving the accuracy of the motor rotor position observation.

[0011] According to one embodiment of the present invention, determining the reference value includes: obtaining a triangle wave carrier vertex count value; and determining the reference value according to the triangle wave carrier vertex count value.

[0012] According to an embodiment of the present invention, the reference value is greater than or equal to the difference between the comparison value Act22 and the comparison value Act11.

[0013] According to one embodiment of the present invention, the reference value is 0.5 times the vertex count value of the triangle wave carrier.

[0014] According to one embodiment of the present invention, the six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 are adjusted according to the following formula:

[0015] Act11 New =Act11+DetaN;

[0016] Act21 New =Nref;

[0017] Act 31 New =Act31+DetaN;

[0018] Act32 New =Act32-DetaN;

[0019] Act22 New =Nref;

[0020] Act12 New =Act12-DetaN;

[0021] Among them, DetaN is the difference value and Nref is the reference value.

[0022] According to one embodiment of the present invention, when single-resistance sampling is performed during the rising phase of the triangle wave carrier, the first current sampling trigger value and the second current sampling trigger value are determined according to the following formula:

[0023] Trig1 New =Act21 New -Tsample;

[0024] Trig2 New =Act21 New +Tdead+Tup;

[0025] Among them, Trig1 New is the first current sampling trigger value, Trig2 New is the second current sampling trigger value, Tsample is the time required for hardware sampling, Tdead is the dead time, and Tup is the time it takes for the current to rise to a stable level.

[0026] According to one embodiment of the present invention, when single-resistance sampling is performed in the falling phase of the triangle wave carrier, the first current sampling trigger value and the second current sampling trigger value are determined according to the following formula:

[0027] Trig1 New =Act22New +Tsample;

[0028] Trig2 New =Act22 New -Tdead-Tup;

[0029] Among them, Trig1 New is the first current sampling trigger value, Trig2 New is the second current sampling trigger value, Tsample is the time required for hardware sampling, Tdead is the dead time, and Tup is the time it takes for the current to rise to a stable level.

[0030] To achieve the above objectives, a second embodiment of the present invention provides a computer-readable storage medium on which a motor rotor position observation program is stored. When the motor rotor position observation program is executed by a processor, the above-mentioned motor rotor position observation method is implemented.

[0031] According to the computer-readable storage medium of the embodiment of the present invention, based on the aforementioned motor rotor position observation method, the sampling current accuracy of single-resistance sampling can be effectively improved, thereby improving the accuracy of motor rotor position observation.

[0032] To achieve the above-mentioned purpose, an embodiment of the third aspect of the present invention proposes a rotor position observer, including a memory, a processor, and a motor rotor position observation program stored in the memory and executable on the processor. When the processor executes the motor rotor position observation program, the aforementioned motor rotor position observation method is implemented.

[0033] The rotor position observer according to the embodiment of the present invention, based on the aforementioned motor rotor position observation method, can effectively improve the sampling current accuracy of single-resistance sampling, thereby improving the accuracy of motor rotor position observation.

[0034] To achieve the above-mentioned purpose, a fourth embodiment of the present invention proposes a motor rotor position observation device, comprising: a first determination module for determining a reference value; a second determination module for determining six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 of three-way modulation corresponding to the output required voltage vector under single resistor sampling; an adjustment module for determining the difference between the reference value and the comparison value Act21 or Act22 when injecting a high-frequency pulse into the motor d-axis, and adjusting the six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 according to the difference; and a third determination module for adjusting the six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 according to the adjusted comparison value Act21. New or Act22 New Determine the first current sampling trigger value and the second current sampling trigger value; the control module is used to determine the first current sampling trigger value and the second current sampling trigger value according to the adjusted six comparison values ​​Act11New Act21 New Act 31 New 、Act32 New Act 22 New Act 12 New The motor is controlled, and current sampling is performed on the motor according to the first current sampling trigger value and the second current sampling trigger value to obtain the first sampling current and the second sampling current, and the rotor position of the motor is estimated according to the first sampling current and the second sampling current.

[0035] According to an embodiment of the present invention, a motor rotor position observation device adjusts the six comparison values ​​of the three-way modulation corresponding to the output required voltage vector under single resistor sampling according to the difference between the reference value and the comparison value, determines the first current sampling trigger value and the second current sampling trigger value according to the adjusted comparison value, controls the motor according to the adjusted six comparison values, samples the motor current according to the first current sampling trigger value and the second current sampling trigger value to obtain the first sampling current and the second sampling current, and estimates the rotor position of the motor according to the first sampling current and the second sampling current. This can effectively improve the sampling current accuracy of single resistor sampling, thereby improving the accuracy of motor rotor position observation.

[0036] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A diagram of a motor control system according to an embodiment of the present invention;

[0038] Figure 2 This is a diagram of a single resistor high frequency injection control system;

[0039] Figure 3a Schematic diagram of the voltage vector and the switch tube operation when a positive voltage pulse is injected at the 0° position according to one embodiment of the present invention;

[0040] Figure 3b Schematic diagram of the voltage vector and the switch tube operation when a negative voltage pulse is injected at the 0° position according to one embodiment of the present invention;

[0041] Figure 4 2 is a flow chart of a method for observing the position of a motor rotor according to an embodiment of the present invention;

[0042] Figure 5 For Figure 3a and Figure 3b The corresponding schematic diagram of the switch tube action after adjustment;

[0043] Figure 6 Schematic diagram of the structure of a motor rotor position observation device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The following describes embodiments of the present invention in detail, 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 are not to be construed as limiting the present invention.

[0045] In the process of motor position sensorless vector control, in order to obtain the motor rotor position, periodic positive and negative voltage pulses can be injected into the d-axis, and the high-frequency current response of the q-axis caused by the pulse is sampled. The high-frequency current response is then sent to the phase-locked loop to solve and obtain the motor rotor position. Due to cost considerations, single-resistance sampling technology is usually used to sample the high-frequency current response. The single-resistance sampling technology samples the current by using a sampling resistor on the DC negative bus, such as Figure 1 As shown in the figure, the current is sampled through the sampling resistor R on the DC negative bus. During sampling, sampling is required twice in one control cycle, and sampling is performed during the action time of two effective voltage vectors (i.e., non-zero voltage vectors). After the sampling is completed, the phase sequence of the sampled current is determined according to the voltage vector situation to obtain the two-phase current.

[0046] When sampling with a single resistor, both current samplings require a certain amount of time. Generally, the sampling is performed before and after the second or fifth switch action, that is, within the action time of two effective voltage vectors. If the synthetic voltage vector is near the sector switching boundary, there is a situation where at least one effective voltage vector is too small. Therefore, in order to meet the sampling time requirements, the switch action moment needs to be phase-shifted to ensure the accuracy of the two current samplings. However, the sampling moment of the single resistor sampling will change, especially near different sector switching areas. The different phase shifting methods will lead to large differences in the sampling moments. Since the back electromotive force and the resistance voltage drop are small when the motor is running at low speed, such as Figure 2 As shown in the figure, the controller output voltage is mainly a high-frequency injection voltage, and the high-frequency injection voltage is positive and negative periodically injected, and the corresponding sectors differ by 180°. As a result, a large sampling time error is introduced due to the phase shift, resulting in a large error in the sampled q-axis high-frequency current response. The estimated position obtained by this solution will also have a large error, thereby affecting the control performance of the control system.

[0047] Specifically, the motor is at 0° position as an example. In the traditional method, when estimating the rotor position, a positive voltage pulse is first injected, referring to Figure 3aAs shown, the output synthetic voltage vector Uinj basically coincides with U4 (100). The action time t1 of the first effective voltage vector is large, and the action time t2 of the second effective voltage vector is small. Therefore, phase shifting is required. The current sampling time determined after phase shifting is close to the middle of the triangle wave carrier cycle, as shown in FIG. Figure 3a Trig1 and Trig2 are close to the middle of the triangle wave carrier cycle; after the positive voltage pulse ends, a negative voltage pulse is injected. Figure 3b As shown, the output synthetic voltage vector -Uinj is approximately 180° different from the synthetic voltage vector Uinj when the positive voltage pulse is injected, and basically coincides with U3 (011). The action time t1 of the first effective voltage vector is small, and the action time t2 of the second effective voltage vector is large. Phase shifting is also required, but the current sampling moment determined after phase shifting is close to the end of the triangle wave carrier cycle, as shown in Figure 3b Trig1 and Trig2 are close to the end of the triangle wave carrier cycle. Therefore, the current sampling time when a positive voltage pulse is injected is different from the current sampling time when a negative voltage pulse is injected. This leads to a large error in the high-frequency current response obtained by sampling, which in turn leads to a large error in the estimated position.

[0048] Based on this, in this application, a reference value can be first selected according to the triangular wave carrier cycle count value. Since the current sampling moment is calculated based on the second or fifth switch tube action moment, by aligning the second or fifth switch tube action moment with the reference value, it can be ensured that after the phase shift, the current sampling moment when the positive and negative voltage pulses are injected is the same, thereby reducing the current sampling error introduced by different current sampling moments, and thereby improving the estimation accuracy of the motor rotor position.

[0049] Figure 4 FIG. 1 is a flow chart of a method for observing the position of a motor rotor according to an embodiment of the present invention. Figure 4 As shown, the motor rotor position observation method may include the following steps:

[0050] In step S101 , when a high-frequency pulse is injected into the motor d-axis, a reference value is determined, and six comparison values ​​Act11 , Act21 , Act31 , Act32 , Act22 , and Act12 of three-way modulation corresponding to the output voltage vector required under single resistor sampling are determined.

[0051] Specifically, when high-frequency pulses, that is, positive and negative voltage pulses with a higher frequency, are injected into the d-axis of the motor, a reference value required to reduce the current sampling error introduced by different current sampling moments can be obtained, and the comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 of the various PWM (Pulse Width Modulation) signals required to control the motor are calculated based on single-resistance sampling, where Act11 represents the triangular wave carrier count value corresponding to the action moment of the first switch tube in the three-phase inverter bridge, Act21 represents the triangular wave carrier count value corresponding to the action moment of the second switch tube, Act31 represents the triangular wave carrier count value corresponding to the action moment of the third switch tube, Act32 represents the triangular wave carrier count value corresponding to the action moment of the fourth switch tube, Act22 represents the triangular wave carrier count value corresponding to the action moment of the fifth switch tube, and Act12 represents the triangular wave carrier count value corresponding to the action moment of the sixth switch tube. In the present application, the triangular wave carrier counting method is to increase first and then decrease, and accordingly Act11<Act21<Act31, Act32>Act22>Act12.

[0052] For example, if Figure 3a-Figure 3b As shown, PWM1, PWM2 and PWM3 are Figure 1The PWM control signals of the upper-arm switching tubes VT1, VT3, and VT5 are shown (the PWM control signals of the lower-arm switching tubes VT4, VT6, and VT2 are 180° apart from the PWM control signals of the upper-arm switching tubes VT1, VT3, and VT5). When positive and negative voltage pulses are injected, when the voltage vector is in sector I, the comparison values ​​corresponding to PWM1 are Act11 and Act12, the comparison values ​​corresponding to PWM2 are Act21 and Act22, and the comparison values ​​corresponding to PWM3 are Act31 and Act32, that is, the duty cycle of PWM1 is the maximum value, the duty cycle of PWM2 is the middle value, and the duty cycle of PWM3 is the minimum value; when the voltage vector is in sector II, the comparison values ​​corresponding to PWM1 are Act21 and Act22, and the comparison values ​​corresponding to PWM2 are Act11 and Act22. Act12, the comparison values ​​corresponding to PWM3 are Act31 and Act32, that is, the duty cycle of PWM1 is the middle value, the duty cycle of PWM2 is the maximum value, and the duty cycle of PWW3 is the minimum value; when the voltage vector is in sector III, the comparison values ​​corresponding to PWM1 are Act31 and Act32, the comparison values ​​corresponding to PWM2 are Act11 and Act12, and the comparison values ​​corresponding to PWM3 are Act21 and Act22, that is, the duty cycle of PWM1 is the minimum value, the duty cycle of PWM2 is the maximum value, and the duty cycle of PWW3 is the minimum value. The ratio is the middle value; when the voltage vector is in sector IV, the comparison values ​​corresponding to PWM1 are Act31 and Act32, the comparison values ​​corresponding to PWM2 are Act21 and Act22, and the comparison values ​​corresponding to PWM3 are Act11 and Act12, that is, the duty cycle of PWM1 is the minimum value, the duty cycle of PWM2 is the middle value, and the duty cycle of PWM3 is the maximum value; when the voltage vector is in sector V, the comparison values ​​corresponding to PWM1 are Act21 and Act22, and the comparison values ​​corresponding to PWM2 are Act31 and Act32 , the comparison values ​​corresponding to PWM3 are Act11 and Act12, that is, the duty cycle of PWM1 is the middle value, the duty cycle of PWM2 is the minimum value, and the duty cycle of PWW3 is the maximum value; when the voltage vector is in sector VI, the comparison values ​​corresponding to PWM1 are Act11 and Act12, the comparison values ​​corresponding to PWM2 are Act31 and Act32, and the comparison values ​​corresponding to PWM3 are Act21 and Act22, that is, the duty cycle of PWM1 is the maximum value, the duty cycle of PWM2 is the minimum value, and the duty cycle of PWW3 is the middle value.

[0053] It should be noted that when determining the comparison value of each PWM signal, the determined comparison value is also phase-shifted to ensure that single-resistor sampling is performed within the effective voltage vector action time, ensuring the effectiveness and accuracy of current sampling. When performing the phase-shifting process, the corresponding comparison value is adjusted according to the current sampling phase, t1 / 2, and t2 / 2, so that the smaller value of t1 / 2 and t2 / 2 is greater than the minimum sampling time. For example, if Figure 3a As shown in the figure, when current sampling is performed during the falling phase of the triangular wave carrier cycle, t2 / 2 is small. At this time, the high level of PWM3 is shifted to the left, and the corresponding comparison value Act31 decreases and the comparison value Act32 increases. When current sampling is performed during the rising phase of the triangular wave carrier cycle, t2 / 2 is small. At this time, the high level of PWM3 is shifted to the right, and the corresponding comparison value Act31 increases and the comparison value Act32 decreases. Figure 3b As shown, when current sampling is performed in the falling phase of the triangular wave carrier cycle, t1 / 2 is small. At this time, the high level of PWM1 is shifted to the right, and the corresponding comparison value Act11 increases, while the comparison value Act12 decreases; when current sampling is performed in the rising phase of the triangular wave carrier cycle, t1 / 2 is small. At this time, the high level of PWM1 is shifted to the left, and the corresponding comparison value Act11 decreases, while the comparison value Act12 increases.

[0054] When obtaining the reference value, since the current sampling time is calculated based on the second or fifth switch tube action time, ensuring that the second or fifth switch tube action time is consistent can ensure the consistency of the current sampling time, such as Figure 3a-Figure 3b As shown, the fifth switch action moment is the moment corresponding to the comparison value Act22, and the moments corresponding to Trig1 and Trig2, i.e., the current sampling moments, are calculated based on the comparison value Act22, thus ensuring Figure 3a The comparison value Act22 in the corresponding time and Figure 3b The time corresponding to the comparison value Act22 is consistent to ensure Figure 3a The current sampling time and Figure 3b Considering that the triangle wave carrier cycle count value when injecting a positive voltage pulse is the same as the triangle wave carrier cycle count value when injecting a negative voltage pulse, a reference value can be selected based on the triangle wave carrier cycle count value, and the second or fifth switch tube action time is aligned with the reference value to ensure that the current sampling time when the positive and negative voltage pulses are injected after the phase shift is the same, as shown in the figure. Figure 3a The comparison value Act22 in the corresponding time and Figure 3b The time corresponding to the comparison value Act22 is aligned with the reference value to ensure Figure 3a The current sampling time and Figure 3b The current sampling moments in the circuit are consistent, thereby reducing the current sampling error introduced by different current sampling moments due to phase shift.

[0055] In some embodiments of the present invention, determining the reference value may include: obtaining a triangle wave carrier vertex count value; and determining the reference value according to the triangle wave carrier vertex count value.

[0056] Specifically, when injecting high-frequency pulses into the motor d-axis, a positive voltage pulse can be injected first. At this time, the triangle wave carrier vertex count value N corresponding to the positive voltage pulse is first determined. 1 / 2Period , and according to the triangle wave carrier vertex count value N 1 / 2Period Obtain the reference value Nref. After the positive voltage pulse ends, a negative voltage pulse is injected. Since the negative voltage pulse is in the opposite direction of the positive voltage pulse, the reference value Nref determined when the positive voltage pulse is injected can be directly used as the reference value Nref determined when the negative voltage pulse is injected. Of course, it can also be directly calculated.

[0057] It should be noted that when determining the reference value Nref, the reference value Nref can be determined based on the triangle wave carrier vertex count value N 1 / 2Period , the amplitude of the injected positive and negative voltage pulses is determined. For example, since the amplitude of the selected positive and negative voltage pulses when estimating the motor rotor position based on the high-frequency injection method generally does not exceed 50% of the DC bus voltage Udc, the reference value Nref can be 0.5 times the triangle wave carrier vertex count value, that is, the reference value Nref = (1 / 2) * N 1 / 2Period It should be noted that the reference value Nref is greater than or equal to the difference between the comparison value Act22 and the comparison value Act11.

[0058] Step S102 : determining the difference between the reference value and the comparison value Act21 or Act22 .

[0059] Specifically, when current sampling is performed during the rising phase of the triangular wave carrier, the corresponding comparison value is Act21, and the difference between the reference value and the comparison value Act21, DetaN, is calculated as Nref-Act21. When current sampling is performed during the falling phase of the triangular wave carrier, the corresponding comparison value is Act22, and the difference between the reference value Nref and the comparison value Act22, DetaN, is calculated as Nref-Act22. It is understood that when the triangular wave carrier counting method is to increase first and then decrease, and the comparison values ​​Act21 and Act22 are not phase-shifted during phase shifting, the two calculated differences DetaN are equal and do not need to be distinguished in subsequent use. However, in other cases, the two calculated differences DetaN may be unequal and need to be distinguished in subsequent use.

[0060] Step S103, adjusting the six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 according to the difference, and adjusting the comparison value Act21 according to the adjusted comparison value Act22. Newor Act22 New A first current sampling trigger value and a second current sampling trigger value are determined.

[0061] Specifically, after obtaining the difference DetaN, the six comparison values ​​can be adjusted based on the difference DetaN. The adjustment principle is that if t2 is a smaller value, the zero voltage vector U0 (000) is used to compensate the zero voltage vector U7 (111), that is, the duty cycle of PWM1, PWM2 and PWM3 is increased, that is, the high level time of PWM1, PWM2 and PWM3 is increased; if t1 is a smaller value, the zero voltage vector U7 (111) is used to compensate the zero voltage vector U0 (000), that is, the duty cycle of PWM1, PWM2 and PWM3 is reduced, that is, the high level time of PWM1, PWM2 and PWM3 is reduced.

[0062] For example, if Figure 3a As shown, t2 is a small value, and the zero voltage vector U0 (000) is used to compensate the zero voltage vector U7 (111). The adjusted PWM1, PWM2 and PWM3 are as follows: Figure 5 As shown in (a), compared with the PWM signal before adjustment, the high level of the adjusted PWM signal increases (i.e., expands); Figure 3b As shown, t1 is a small value, and the zero voltage vector U7 (111) is used to compensate the zero voltage vector U0 (000). The adjusted PWM1, PWM2 and PWM3 are as follows: Figure 5 As shown in (b), compared with the PWM signal before adjustment, the high level of the adjusted PWM signal is reduced (ie, contracted).

[0063] It should be noted that the purpose of setting the reference value Nref to be greater than or equal to the difference between the comparison value Act22 and the comparison value Act11 is to ensure that when t2 is a smaller value, the zero voltage vector U0 (000) is sufficient to supplement the zero voltage vector U7 (111), avoiding the zero voltage vector U0 (000) from not being able to supplement the zero voltage vector U7 (111) due to the zero voltage vector U0 (000) lasting too short, and when t1 is a smaller value, the zero voltage vector U7 (111) is sufficient to supplement the zero voltage vector U0 (000), avoiding the zero voltage vector U7 (111) from not being able to supplement the zero voltage vector U0 (000) due to the zero voltage vector U7 (111) lasting too short, thereby ensuring normal control of the motor.

[0064] Specifically, when the six comparison values ​​are adjusted according to the difference value DetaN, the six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 can be adjusted using the following formula (1):

[0065]

[0066] It should be noted that since the difference DetaN can be positive or negative, formula (1) is applicable to the above two cases. For example, the difference DetaN = Nref - Act22, if t2 is a small value, then the difference DetaN < 0, at this time the six adjusted comparison values ​​determined based on formula (1) are Figure 5 (a) is consistent; if t1 is a smaller value, the difference DetaN>0, then the six adjusted comparison values ​​determined based on formula (1) are consistent with Figure 5 (b) is consistent with the above.

[0067] After obtaining the adjusted six comparison values, based on the adjusted comparison values ​​Act21 New or Act22 New Determine the first current sampling trigger value and the second current sampling trigger value. Specifically, in one control cycle, current sampling can be performed before and after the second or fifth switch tube action moment, that is, at the comparison value Act21 New or Act22 New The current is sampled before and after the corresponding moment, so when the comparison value Act21 is obtained New and Act22 New After that, the first current sampling trigger value Trig1 and the second current sampling trigger value Trig2 can be obtained according to one of the two comparison values. For example, if the falling phase of the triangle wave carrier is selected for single resistor sampling, then according to the comparison value Act22 New Get the first current sampling trigger value Trig1 and the second current sampling trigger value Trig2; if the rising phase of the triangle wave carrier is selected for single resistor sampling, then according to the comparison value Act21 New A first current sampling trigger value Trig1 and a second current sampling trigger value Trig2 are obtained.

[0068] It should be noted that, according to the comparison value Act21 New or Act22 New When obtaining the first current sampling trigger value Trig1 and the second current sampling trigger value Trig2, they can be determined based on the time required for hardware sampling (such as the sampling time of the ADC converter), the dead time (that is, the time reserved to avoid simultaneous conduction of the upper and lower switches of the same bridge arm when the PWM signal is output, such as the lower arm switch tube can be turned on only after the upper arm switch tube is turned off and the dead time is delayed, or the upper arm switch tube can be turned on only after the lower arm switch tube is turned off and the dead time is delayed), and the current stabilization time after the switch tube is turned on and off (such as the time corresponding to the current gradually rising until it reaches a stable state after the switch tube is turned on), so as to ensure sufficient current sampling time, avoid the dead time and current unstable time, and ensure the effectiveness and accuracy of current sampling.

[0069] According to one embodiment of the present invention, when single-resistance sampling is performed during the rising phase of the triangular wave carrier, the first current sampling trigger value and the second current sampling trigger value are determined according to the following formula (2):

[0070]

[0071] Among them, Trig1 New is the first current sampling trigger value, Trig2 New is the second current sampling trigger value, Tsample is the time required for hardware sampling, Tdead is the dead time, and Tup is the time it takes for the current to rise to a stable level.

[0072] According to one embodiment of the present invention, when single-resistance sampling is performed in the falling phase of the triangle wave carrier, the first current sampling trigger value and the second current sampling trigger value are determined according to the following formula (3):

[0073]

[0074] Among them, Trig1 New is the first current sampling trigger value, Trig2 New is the second current sampling trigger value, Tsample is the time required for hardware sampling, Tdead is the dead time, and Tup is the time it takes for the current to rise to a stable level.

[0075] That is, the first current sampling is performed before the second or fifth switch actuation moment, and the second current sampling is performed thereafter. Considering that the two sampling moments should be as close as possible to reduce sampling time error, for the first current sampling, a time Tsample required for hardware sampling is reserved. For the second current sampling, a dead time Tdead and the time Tup for the current to rise to stability are reserved.

[0076] Step S104: according to the adjusted six comparison values ​​Act11 New Act21 New Act 31 New 、Act32 New Act 22 New Act 12 New The motor is controlled, and current sampling is performed on the motor according to the first current sampling trigger value and the second current sampling trigger value to obtain a first sampling current and a second sampling current.

[0077] Specifically, after obtaining the adjusted six comparison values, the motor is controlled according to the adjusted six comparison values, and during the control process, current sampling is performed according to the first current sampling trigger value Trig1 and the second current sampling trigger value Trig2, thereby obtaining the first sampling current and the second sampling current.

[0078] Take the single resistor sampling in the falling phase of the triangle wave carrier as an example. Figure 5 (a)- Figure 5 As shown in (b), after obtaining the adjusted six comparison values, if the timer count value is used to generate a triangular wave carrier, then when the timer count value is equal to the comparison value Act11 New When controlling Figure 1 The upper arm switch tube VT1 is turned on, the lower arm switch tubes VT6 and VT2 remain turned on, and the other switch tubes are turned off; when the timer count value is equal to the comparison value Act21 New When controlling Figure 1 The upper arm switch tube VT3 is turned on, the upper arm switch tube VT1 and the lower arm switch tube VT2 remain turned on, and the other switch tubes are turned off; when the timer count value is equal to the comparison value Act31 New When controlling Figure 1 The upper arm switch VT5 is turned on, the upper arm switch VT1 and VT3 remain on, and the other switch tubes are turned off; when the timer count value is equal to the comparison value Act32 New When controlling Figure 1 The lower bridge arm switch tube VT2 is turned on, the upper bridge arm switch tubes VT1 and VT3 remain turned on, and the other switch tubes are turned off; when the timer count value is equal to the first current sampling trigger value Trig1, Figure 1 The sampling resistor R in the circuit samples the current to obtain the first sampling current; when the timer count value is equal to the comparison value Act22 New When controlling Figure 1 The lower bridge arm switch tube VT6 is turned on, the upper bridge arm switch tube VT1 and the lower bridge arm switch tube VT2 remain turned on, and the other switch tubes are turned off; when the timer count value is equal to the second current sampling trigger value Trig2, Figure 1 The sampling resistor R in the circuit samples the current to obtain the second sampling current; when the timer count value is equal to the comparison value Act12 New When controlling Figure 1 The lower bridge arm switch tube VT4 is turned on, the lower bridge arm switch tubes VT2 and VT6 remain turned on, and the other switch tubes are turned off.

[0079] Thus, based on the comparison value and the sampling trigger value, the motor can be controlled and current sampling can be performed during the control process. It should be noted that the process of performing single-resistance sampling during the rising phase of the triangular wave carrier is the same as the process of performing single-resistance sampling during the falling phase of the triangular wave carrier, and the details will not be detailed here.

[0080] Step S105 : estimating the rotor position of the motor according to the first sampled current and the second sampled current.

[0081] Specifically, position observation can be performed based on the first sampled current and the second sampled current to obtain the rotor position of the motor. This can be achieved using existing technologies, which will not be detailed here.

[0082] According to the motor rotor position observation method of an embodiment of the present invention, the six comparison values ​​of the three-way modulation corresponding to the output required voltage vector under single resistor sampling are adjusted according to the difference between the reference value and the comparison value, and the first current sampling trigger value and the second current sampling trigger value are determined according to the adjusted comparison values. The motor is controlled according to the adjusted six comparison values, and the motor current is sampled according to the first current sampling trigger value and the second current sampling trigger value to obtain the first sampling current and the second sampling current, and the rotor position of the motor is estimated according to the first sampling current and the second sampling current. This can effectively improve the sampling current accuracy of single resistor sampling, thereby improving the accuracy of motor rotor position observation. The algorithm is simple and easy to apply in engineering, thereby achieving excellent control performance at a low cost advantage.

[0083] In an embodiment of the present invention, a computer-readable storage medium is further provided, on which a motor rotor position observation program is stored. When the motor rotor position observation program is executed by a processor, the motor rotor position observation method described above is implemented.

[0084] According to the computer-readable storage medium of the embodiment of the present invention, based on the aforementioned motor rotor position observation method, the sampling current accuracy of single-resistance sampling can be effectively improved, thereby improving the accuracy of motor rotor position observation.

[0085] In an embodiment of the present invention, a rotor position observer is also provided, comprising a memory, a processor, and a motor rotor position observation program stored in the memory and executable on the processor. When the processor executes the motor rotor position observation program, the aforementioned motor rotor position observation method is implemented.

[0086] The rotor position observer according to the embodiment of the present invention, based on the aforementioned motor rotor position observation method, can effectively improve the sampling current accuracy of single-resistance sampling, thereby improving the accuracy of motor rotor position observation.

[0087] Figure 6is a schematic diagram of a motor rotor position observation device according to an embodiment of the present invention, with reference to Figure 6 As shown, the motor rotor position observation device may include: a first determination module 10 , a second determination module 20 , an adjustment module 30 , a third determination module 40 , and a control module 50 .

[0088] Among them, the first determination module 10 is used to determine the reference value; the second determination module 20 is used to determine the six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 of the three-way modulation corresponding to the output voltage vector required under single resistor sampling; the adjustment module 30 is used to determine the difference between the reference value and the comparison value Act21 or Act22 when injecting a high-frequency pulse into the motor d axis, and adjust the six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 according to the difference; the third determination module 40 is used to determine the six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 according to the adjusted comparison value Act21 New or Act22 New Determine the first current sampling trigger value and the second current sampling trigger value; the control module 50 is used to determine the first current sampling trigger value and the second current sampling trigger value according to the adjusted six comparison values ​​Act11 New Act21 New Act 31 New 、Act32 New Act 22 New Act 12 New The motor is controlled, and current sampling is performed on the motor according to the first current sampling trigger value and the second current sampling trigger value to obtain the first sampling current and the second sampling current, and the rotor position of the motor is estimated according to the first sampling current and the second sampling current.

[0089] According to an embodiment of the present invention, the first determining module 10 is specifically configured to: obtain a triangle wave carrier vertex count value; and determine a reference value according to the triangle wave carrier vertex count value.

[0090] According to an embodiment of the present invention, the reference value is greater than or equal to the difference between the comparison value Act22 and the comparison value Act11.

[0091] According to one embodiment of the present invention, the reference value is 0.5 times the vertex count value of the triangle wave carrier.

[0092] According to one embodiment of the present invention, the adjustment module 30 is specifically configured to adjust the six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 according to the following formula:

[0093] Act11 New =Act11+DetaN;

[0094] Act21 New =Nref;

[0095] Act 31 New =Act31+DetaN;

[0096] Act32 New =Act32-DetaN;

[0097] Act22 New =Nref;

[0098] Act12 New =Act12-DetaN;

[0099] Among them, DetaN is the difference value and Nref is the reference value.

[0100] According to one embodiment of the present invention, the third determining module 40 is specifically configured to determine the first current sampling trigger value and the second current sampling trigger value according to the following formula when single resistor sampling is performed during the rising phase of the triangle wave carrier:

[0101] Trig1 New =Act21 New -Tsample;

[0102] Trig2 New =Act21 New +Tdead+Tup;

[0103] Among them, Trig1 New is the first current sampling trigger value, Trig2 New is the second current sampling trigger value, Tsample is the time required for hardware sampling, Tdead is the dead time, and Tup is the time it takes for the current to rise to a stable level.

[0104] According to one embodiment of the present invention, the third determining module 40 is specifically configured to determine the first current sampling trigger value and the second current sampling trigger value according to the following formula when single resistor sampling is performed in the falling phase of the triangular wave carrier:

[0105] Trig1 New =Act22 New +Tsample;

[0106] Trig2 New =Act22 New -Tdead-Tup;

[0107] Among them, Trig1 New is the first current sampling trigger value, Trig2 Newis the second current sampling trigger value, Tsample is the time required for hardware sampling, Tdead is the dead time, and Tup is the time it takes for the current to rise to a stable level.

[0108] It should be noted that, for the description of the motor rotor position observation device in this application, please refer to the description of the motor rotor position observation method in this application, and the details will not be repeated here.

[0109] According to an embodiment of the present invention, a motor rotor position observation device adjusts the six comparison values ​​of the three-way modulation corresponding to the output required voltage vector under single resistor sampling according to the difference between the reference value and the comparison value, determines the first current sampling trigger value and the second current sampling trigger value according to the adjusted comparison value, controls the motor according to the adjusted six comparison values, samples the motor current according to the first current sampling trigger value and the second current sampling trigger value to obtain the first sampling current and the second sampling current, and estimates the rotor position of the motor according to the first sampling current and the second sampling current. This can effectively improve the sampling current accuracy of single resistor sampling, thereby improving the accuracy of motor rotor position observation.

[0110] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, 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 it in another suitable manner if necessary, and then storing it in a computer memory.

[0111] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0112] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0113] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0114] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0115] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for observing the position of a motor rotor, characterized in that: include: When injecting a high-frequency pulse into the d-axis of the motor, a reference value is determined, and six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 of the three-way modulation corresponding to the output required voltage vector under single-resistance sampling are determined, wherein Act11 represents the triangular wave carrier count value corresponding to the action moment of the first switch tube in the three-phase inverter bridge, Act21 represents the triangular wave carrier count value corresponding to the action moment of the second switch tube, Act31 represents the triangular wave carrier count value corresponding to the action moment of the third switch tube, Act32 represents the triangular wave carrier count value corresponding to the action moment of the fourth switch tube, Act22 represents the triangular wave carrier count value corresponding to the action moment of the fifth switch tube, and Act12 represents the triangular wave carrier count value corresponding to the action moment of the sixth switch tube; determining a difference between the reference value and the comparison value Act21 or Act22; The six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 are adjusted according to the difference, and the adjusted comparison value Act21 is used as the comparison value. New or Act22 New Determine a first current sampling trigger value and a second current sampling trigger value; According to the adjusted six comparison values ​​Act11 New Act21 New Act 31 New 、Act32 New Act 22 New Act 12 New Controlling the motor and sampling the current of the motor according to the first current sampling trigger value and the second current sampling trigger value to obtain a first sampling current and a second sampling current; The rotor position of the motor is estimated according to the first sampling current and the second sampling current.

2. The method according to claim 1, characterized in that Determine baseline values, including: Get the triangle wave carrier vertex count value; The reference value is determined according to the triangle wave carrier vertex count value.

3. The method according to claim 2, characterized in that The reference value is greater than or equal to the difference between the comparison value Act22 and the comparison value Act11.

4. The method according to claim 2, characterized in that The reference value is 0.5 times the vertex count value of the triangle wave carrier.

5. The method according to any one of claims 1 to 4, characterized in that The six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 are adjusted according to the following formula: Act11 New =Act11+DetaN; Act21 New =Nref; Act31 New =Act31+DetaN; Act32 New =Act32-DetaN; Act22 New =Nref; Act12 New =Act12-DetaN; Wherein, DetaN is the difference value, and Nref is the reference value.

6. The method according to claim 1, characterized in that When single-resistance sampling is performed during the rising phase of the triangle wave carrier, the first current sampling trigger value and the second current sampling trigger value are determined according to the following formula: Trig1 New =Act21 New -Tsample; Trig2 New =Act21 New +Tdead+Tup; Among them, Trig1 New is the first current sampling trigger value, Trig2 New is the second current sampling trigger value, Tsample is the time required for hardware sampling, Tdead is the dead time, and Tup is the time it takes for the current to rise to a stable state.

7. The method according to claim 1, characterized in that When single-resistance sampling is performed in the falling phase of the triangle wave carrier, the first current sampling trigger value and the second current sampling trigger value are determined according to the following formula: Trig1 New =Act22 New +Tsample; Trig2 New =Act22 New -Tdead-Tup; Among them, Trig1 New is the first current sampling trigger value, Trig2 New is the second current sampling trigger value, Tsample is the time required for hardware sampling, Tdead is the dead time, and Tup is the time it takes for the current to rise to a stable state.

8. A computer-readable storage medium, characterized in that A motor rotor position observation program is stored thereon, and when the motor rotor position observation program is executed by a processor, a motor rotor position observation method according to any one of claims 1 to 7 is implemented.

9. A rotor position observer, characterized in that: The method comprises a memory, a processor and a motor rotor position observation program stored in the memory and executable on the processor. When the processor executes the motor rotor position observation program, the motor rotor position observation method according to any one of claims 1 to 7 is implemented.

10. A motor rotor position observation device, characterized in that: include: A first determining module, configured to determine a reference value; a second determination module, configured to determine six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 of three-way modulation corresponding to the output required voltage vector under single resistor sampling, wherein Act11 represents the triangular wave carrier count value corresponding to the first switch tube action moment in the three-phase inverter bridge, Act21 represents the triangular wave carrier count value corresponding to the second switch tube action moment, Act31 represents the triangular wave carrier count value corresponding to the third switch tube action moment, Act32 represents the triangular wave carrier count value corresponding to the fourth switch tube action moment, Act22 represents the triangular wave carrier count value corresponding to the fifth switch tube action moment, and Act12 represents the triangular wave carrier count value corresponding to the sixth switch tube action moment; an adjustment module, configured to determine a difference between the reference value and the comparison value Act21 or Act22 when injecting a high-frequency pulse into the motor d-axis, and adjust the six comparison values ​​Act11, Act21, Act31, Act32, Act22, and Act12 according to the difference; The third determining module is configured to determine the value of Act21 according to the adjusted comparison value New or Act22 New Determine a first current sampling trigger value and a second current sampling trigger value; Control module, used to adjust the six comparison values ​​Act11 New Act21 New Act 31 New 、Act32 New Act 22 New Act 12 New The motor is controlled, and current sampling is performed on the motor according to the first current sampling trigger value and the second current sampling trigger value to obtain a first sampling current and a second sampling current, and the rotor position of the motor is estimated according to the first sampling current and the second sampling current.

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