CN114598214A - Motor rotor position observation method, device, rotor position observer and medium - Google Patents

Abstract

The invention discloses a method and a device for observing the position of a motor rotor, a rotor position observer and a medium, wherein the method comprises the following steps: when high-frequency pulses are injected into a d axis of the motor, a reference value is determined, and six comparison values of three paths of modulation corresponding to output required voltage vectors under single resistance sampling are determined; determining a difference between the reference value and the comparison value Act21 or Act 22; adjusting six comparison values according to the difference value, and adjusting the six comparison values according to the adjusted comparison value Act21_NewOr Act22_NewDetermining a first current sampling trigger value and a second current sampling trigger value; according to adjustedThe six comparison values control the motor, and current sampling is carried out 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 estimating the rotor position of the motor according to the first sampling current and the second sampling current. Therefore, the sampling current precision of single-resistor sampling can be effectively improved, and the motor rotor position observation precision is further improved.

Description

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

technical field

The invention relates to the technical field of motor control, and in particular, to a method and device for observing the rotor position of a motor, a rotor position observer and a medium.

Background technique

The motor position sensorless control method based on high frequency injection is simple to implement, low cost, has good control performance in the low speed region, and can realize the low speed load start of the motor. The method is to inject periodic positive and negative pulses in the d-axis, sample the high-frequency current response of the q-axis caused by the pulse, and send the high-frequency current response into a phase-locked loop to obtain the estimated position of the motor. The traditional observer method has good performance in the medium and high-speed region, but cannot converge in the low-speed region, so the high-frequency injection method has high practical application value.

The single-resistor sampling technology uses the sampling resistance on the DC negative bus to sample the current. It needs to be sampled twice in one control cycle, and the sampling is performed during the action time of the two effective voltage vectors (that is, the non-zero voltage vectors). After the end, according to the voltage vector situation, determine the phase sequence of the sampling current.

In the case of single-resistor sampling, both current samplings take a certain amount of time. Generally, the second or fifth switch tube is selected before and after the action time, that is, the two effective voltage vectors are used for sampling. If the combined voltage vector is located in the fan In the vicinity of the switching boundary of the region, there is at least one effective voltage vector that is too small. Therefore, in order to meet the sampling time requirements, it is necessary to perform phase-shift processing on the switching time of the switch to ensure the accuracy of the two current samplings. However, the sampling time of the single-resistor sampling will change in this way, especially in the vicinity of the switching area of different sectors, the difference of the phase shifting method will lead to a large difference in the sampling time. Since the back electromotive force and resistance voltage drop are small when the motor is running at low speed, the output voltage of the controller is mainly high-frequency injection voltage, and the high-frequency injection voltage is a positive and negative periodic injection, and the corresponding sectors differ by 180°, resulting in phase shift A large sampling time error is introduced, resulting in a large error in the q-axis high-frequency current response obtained by sampling, and a large error in the estimated position obtained by this solution, thus affecting the control performance of the system.

SUMMARY OF THE INVENTION

The present invention aims to solve one of the technical problems in the related art at least to a certain extent. Therefore, the first object of the present invention is to propose a method for observing the position of the motor rotor, which can effectively improve the sampling current accuracy of single-resistance sampling, thereby improving the accuracy of observing the rotor position of the motor.

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

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

The fourth object of the present invention is to provide a device for observing the rotor position of a motor.

In order to achieve the above object, the embodiment of the first aspect of the present invention proposes a method for observing the rotor position of a motor, which includes: when injecting high-frequency pulses into the d-axis of the motor, determining a reference value, and determining the required voltage vector output under single-resistance sampling. Corresponding three-way modulation six comparison values Act11, Act21, Act31, Act32, Act22, Act12; determine the difference between the reference value and the comparison value Act21 or Act22; according to the difference, compare the six comparison values Act11, Act21, Act31 , Act32, Act22, Act12 are adjusted, and the first current sampling trigger value and the second current sampling trigger value are determined according to the adjusted comparison value Act21 _New or Act22 _New ; according to the adjusted six comparison values Act11 _New , Act21 _New , Act31 _New , Act32 _New , Act22 _New , Act12 _New control the motor, and sample the current of 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; A sampled current and a second sampled current estimate the rotor position of the motor.

According to the method for observing the rotor position of the motor according to the embodiment of the present invention, the six comparison values of the three-way modulation corresponding to the output voltage vector required by the single-resistor sampling are adjusted according to the difference between the reference value and the comparison value, and according to The adjusted comparison value determines the first current sampling trigger value and the second current sampling trigger value, and controls the motor according to the adjusted six comparison values, and pairs the first current sampling trigger value and the second current sampling trigger value according to the adjusted comparison value. The motor performs current sampling, obtains 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, which can effectively improve the sampling current accuracy of single-resistance sampling, thereby improving the observation of the rotor position of the motor. accuracy.

According to an embodiment of the present invention, determining the reference value includes: acquiring a triangular wave carrier vertex count value; and determining the reference value according to the triangular wave carrier vertex count value.

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.

According to an embodiment of the present invention, the reference value is 0.5 times the count value of the triangular wave carrier vertex.

According to one embodiment of the present invention, the six comparison values Act11, Act21, Act31, Act32, Act22, 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;

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

According to an embodiment of the present invention, when single-resistor sampling is performed in 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:

Trig1 _New = Act21 _New - Tsample;

Trig2 _New = Act21 _New + Tdead + Tup;

Wherein, 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 for the current to rise to a stable state.

According to an embodiment of the present invention, when single-resistor sampling is performed in the falling 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 formulas:

Trig1 _New = Act22 _New + Tsample;

Trig2 _New = Act22 _New -Tdead-Tup;

Wherein, 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 for the current to rise to a stable state.

In order to achieve the above object, the embodiment of the second aspect of the present invention provides a computer-readable storage medium on which a motor rotor position observation program is stored, and when the motor rotor position observation program is executed by a processor, the foregoing motor rotor position observation method is implemented. .

According to the computer-readable storage medium of the embodiment of the present invention, based on the foregoing method for observing the rotor position of the motor, the sampling current accuracy of single-resistance sampling can be effectively improved, thereby improving the accuracy of observing the rotor position of the motor.

In order to achieve the above object, the embodiment of the third aspect of the present invention provides a rotor position observer, which includes a memory, a processor, and a motor rotor position observation program stored in the memory and running on the processor, and the processor executes the motor rotor position. When observing the program, the aforementioned method of observing the rotor position of the motor is implemented.

According to the rotor position observer of the embodiment of the present invention, based on the aforementioned method for observing the rotor position of the motor, the sampling current accuracy of single-resistance sampling can be effectively improved, thereby improving the accuracy of observing the rotor position of the motor.

In order to achieve the above purpose, a fourth aspect of the present invention provides an apparatus for observing the rotor position of a motor, including: a first determination module for determining a reference value; a second determination module for determining a required output voltage under single-resistance sampling The six comparison values Act11, Act21, Act31, Act32, Act22, and Act12 of the three-way modulation corresponding to the vector; the adjustment module is used to determine the difference between the reference value and the comparison value Act21 or Act22 when injecting high-frequency pulses into the d-axis of the motor and adjust the six comparison values Act11, Act21, Act31, Act32, Act22, and Act12 according to the difference; the third determination module is used to determine the first current according to the adjusted comparison value Act21 _New or Act22 _New The sampling trigger value and the second current sampling trigger value; the control module is used to control the motor according to the adjusted six comparison values Act11 _New , Act21 _New , Act31 _New , Act32 _New , Act22 _New , Act12 _New , and according to the first The current sampling trigger value and the second current sampling trigger value perform current sampling on the motor, obtain the first sampling current and the second sampling current, and estimate the rotor position of the motor according to the first sampling current and the second sampling current.

According to the device for observing the rotor position of the motor according to the embodiment of the present invention, the six comparison values of the three-way modulation corresponding to the output required voltage vector under single-resistance sampling are adjusted according to the difference between the reference value and the comparison value, and according to The adjusted comparison value determines the first current sampling trigger value and the second current sampling trigger value, and controls the motor according to the adjusted six comparison values, and pairs the first current sampling trigger value and the second current sampling trigger value according to the adjusted comparison value. The motor performs current sampling, obtains 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, which can effectively improve the sampling current accuracy of single-resistance sampling, thereby improving the observation of the rotor position of the motor. accuracy.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

1 is a diagram of a motor control system according to an embodiment of the present invention;

Figure 2 is a diagram of a single-resistor high-frequency injection control system;

3a is a schematic diagram of the voltage vector of the injected positive voltage pulse and the operation of the switch tube at the 0° position according to an embodiment of the present invention;

3b is a schematic diagram of the voltage vector of the injected negative voltage pulse and the operation of the switch tube at the 0° position according to an embodiment of the present invention;

4 is a schematic flowchart of a method for observing a rotor position of a motor according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of the operation of the adjusted switch tube corresponding to FIG. 3a and FIG. 3b;

FIG. 6 is a schematic structural diagram of an apparatus for observing the rotor position of a motor according to an embodiment of the present invention.

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, and are intended to explain the present invention and should not be construed as limiting the present invention.

In the process of motor position sensorless vector control, in order to obtain the rotor position of the motor, 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 pulses can be sampled, and the high-frequency current response can be sent to the Enter the phase-locked loop to solve the motor rotor position. Based on cost considerations, the high-frequency current response is usually sampled by the single-resistor sampling technique. The single-resistor sampling technique uses the sampling resistor on the DC negative bus to sample the current, as shown in Figure 1, through the sampling on the DC negative bus. The resistor R samples the current. When sampling, it needs to be sampled twice in one control cycle, and the sampling is performed during the action time of the two effective voltage vectors (that is, the non-zero voltage vectors). After the sampling, according to the voltage vector conditions, Determine the phase sequence to which the sampling current belongs, and obtain two-phase currents.

In the case of single-resistor sampling, both current samplings take a certain amount of time. Generally, the second or fifth switch tube is selected before and after the action time, that is, the two effective voltage vectors are used for sampling. If the combined voltage vector is located in the fan In the vicinity of the switching boundary of the region, there is at least one effective voltage vector that is too small. Therefore, in order to meet the sampling time requirements, it is necessary to perform phase-shift processing on the switching time of the switch to ensure the accuracy of the two current samplings. However, the sampling time of the single-resistor sampling will change in this way, especially in the vicinity of the switching area of different sectors, the difference of the phase shifting method will lead to a large difference in the sampling time. Since the back EMF and resistance voltage drop are small when the motor runs at low speed, as shown in Figure 2, the output voltage of the controller is mainly the high-frequency injection voltage, and the high-frequency injection voltage is positive and negative periodic injection, and the corresponding sector difference is 180 °, which will introduce a large sampling time error due to the phase shift, resulting in a large error in the high-frequency current response of the q-axis obtained by sampling, and the estimated position obtained by this solution will also have a large error, which will affect the control of the control system. performance.

Specifically, the description will be given by taking the motor at the 0° position as an example. In the traditional method, when estimating the rotor position, a positive voltage pulse is injected first. Referring to Figure 3a, the output synthetic voltage vector Uinj basically coincides with U4 (100), and the action time of the first effective voltage vector is t1 is large, the action time t2 of the second effective voltage vector is small, so it needs to be phase-shifted. Based on the current sampling time determined after the phase-shift, it is close to the middle of the triangular wave carrier cycle, as shown in Figure 3a, Trig1 and Trig2 are close to the middle of the triangular wave carrier cycle; After the positive voltage pulse ends, inject a negative voltage pulse. Referring to Figure 3b, the output composite voltage vector -Uinj is approximately 180° different from the composite voltage vector Uinj when the positive voltage pulse is injected, and it 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, and the phase shift is also required, but the current sampling time determined based on the phase shift is close to the end of the triangular wave carrier cycle, as shown in the figure Trig1 and Trig2 in 3b are near the tail of the triangular wave carrier period. Therefore, the current sampling time when the positive voltage pulse is injected is different from the current sampling time when the negative voltage pulse is injected, resulting in a large error in the high-frequency current response obtained by sampling, which in turn results in a large error in the estimated position.

Based on this, in the present application, the reference value can be selected according to the triangular wave carrier cycle count value. Since the current sampling time is calculated based on the operation time of the second or fifth switch tube, the second or fifth switch The tube action time is aligned with the reference value, which can ensure that the current sampling time during the injection of positive and negative voltage pulses is the same after the phase shift, thereby reducing the current sampling error caused by different current sampling time, thereby improving the estimation accuracy of the rotor position of the motor.

FIG. 4 is a schematic flowchart of a method for observing a rotor position of a motor according to an embodiment of the present invention. Referring to FIG. 4 , the method for observing the rotor position of the motor may include the following steps:

Step S101, when injecting high-frequency pulses into the d-axis of the motor, determine the reference value, and determine the six comparison values Act11, Act21, Act31, Act32, Act22, Act12.

Specifically, when injecting high-frequency pulses, that is, high-frequency positive and negative voltage pulses, into the d-axis of the motor, the reference value required to reduce the current sampling error caused by the different current sampling times can be obtained, and the sampled value based on the single resistance can be obtained. Calculate the comparison values Act11, Act21, Act31, Act32, Act22, and Act12 of each PWM (Pulse Width Modulation) signal required to control the motor, where Act11 represents the first switch tube in the three-phase inverter bridge The count value of the triangular wave carrier corresponding to the action time, Act21 represents the count value of the triangular wave carrier corresponding to the action time of the second switch, Act31 represents the count value of the triangular wave carrier corresponding to the action time of the third switch, and Act32 represents the action time of the fourth switch Corresponding triangular wave carrier count value, Act22 represents the triangular wave carrier count value corresponding to the action moment of the 5th switch tube, Act12 represents the triangular wave carrier count value corresponding to the 6th switch tube action moment. In the present application, the triangular wave carrier count method is an increase first and then a decrease method, correspondingly Act11<Act21<Act31, Act32>Act22>Act12.

For example, as shown in Fig. 3a-Fig. 3b, PWM1, PWM2 and PWM3 are the PWM control signals of the upper-side switches VT1, VT3 and VT5 shown in Fig. 1 respectively (the lower-side switches VT4, VT6 and VT2) The PWM control signal corresponds to the PWM control signal of the upper bridge arm switch tubes VT1, VT3 and VT5, and the difference is 180°). When injecting positive and negative voltage pulses, 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 comparison values of PWM1 The duty cycle is the maximum value, the duty cycle of PWM2 is the middle value, and the duty cycle of PWW3 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 The comparison values corresponding to Act11 and Act12 and 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, and the duty cycle of PWM2 is the maximum value. The duty cycle of PWW3 is an intermediate 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, PWM1 The duty cycle of PWM2 is the minimum value, the duty cycle of PWM2 is the middle value, and the duty cycle of PWW3 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 For Act31 and Act32, the corresponding comparison values of 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 PWM1 corresponds to the comparison value of Act11 and Act12, PWM2 corresponds to the comparison value of Act31 and Act32, PWM3 corresponds to the comparison value of Act21 and Act22, that is, the duty cycle of PWM1 is the maximum value, and the duty cycle of PWM2 is the minimum value. , the duty cycle of PWW3 is an intermediate value.

It should be noted that when the comparison value of each PWM signal is determined, the determined comparison value is also phase-shifted to ensure single-resistor sampling within the effective voltage vector action time, and to ensure the validity and accuracy of current sampling. . During the phase-shift processing, the corresponding comparison value is adjusted according to the current sampling stage, 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, as shown in Fig. 3a, when the current sampling is performed during the period of the triangular wave carrier cycle, t2/2 is small. At this time, the high level of PWM3 is shifted to the left, the corresponding comparison value Act31 decreases, and the comparison value Act32 increases. When the current sampling is performed in 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, the corresponding comparison value Act31 increases, and the comparison value Act32 decreases. As shown in Figure 3b, when the current sampling is performed in the period of the triangular wave carrier cycle, t1/2 is small. At this time, the high level of PWM1 is shifted to the right, the corresponding comparison value Act11 is increased, and the comparison value Act12 is decreased; When the current sampling is performed in the rising phase of the carrier cycle, t1/2 is small. At this time, the high level of PWM1 is shifted to the left, the corresponding comparison value Act11 decreases, and the comparison value Act12 increases.

When obtaining the reference value, since the current sampling time is calculated based on the operating time of the second or fifth switch, the current sampling time can be guaranteed to be consistent by ensuring that the operating time of the second or fifth switch is consistent, as shown in the figure As shown in Fig. 3a-Fig. 3b, the action time of the fifth switch is the time corresponding to the comparison value Act22. The time corresponding to Trig1 and Trig2, that is, the current sampling time, is calculated according to the comparison value Act22. Therefore, it is guaranteed that the comparison value Act22 in Fig. 3a corresponds to the comparison value Act22. The timing of , and the timing corresponding to the comparison value Act22 in FIG. 3 b are consistent to ensure that the current sampling timing in FIG. 3 a is consistent with the current sampling timing in FIG. 3 b . Considering that the count value of the triangular wave carrier cycle when injecting a positive voltage pulse is the same as the count value of the triangular wave carrier cycle when injecting a negative voltage pulse, the reference value can be selected based on the count value of the triangular wave carrier cycle, and the second or fifth Alignment of the switching tube action time with the reference value can ensure that the current sampling time is the same when the positive and negative voltage pulses are injected after the phase shift. The time corresponding to the comparison value Act22 in Figure 3a and the time corresponding to the comparison value Act22 in Figure 3b are both Aligning with the reference value can ensure that the current sampling time in FIG. 3a is consistent with the current sampling time in FIG. 3b, thereby reducing the current sampling error caused by different current sampling time due to phase shift.

In some embodiments of the present invention, determining the reference value may include: acquiring a triangular wave carrier vertex count value; and determining the reference value according to the triangular wave carrier vertex count value.

Specifically, when injecting a high-frequency pulse into the d-axis of the motor, a positive voltage pulse can be injected first. At this time, the triangular wave carrier vertex count value N _1/2Period corresponding to the positive voltage pulse is determined first, and according to the triangular wave carrier vertex count value N _{1/ 2Period} obtains the reference value Nref. After the positive voltage pulse ends, inject the negative voltage pulse. Since the negative voltage pulse is a voltage pulse in the opposite direction to the positive voltage pulse, the reference value Nref determined when the positive voltage pulse is injected can be directly used as the reference determined when the negative voltage pulse is injected. The value Nref, of course, can also be calculated directly.

It should be noted that, when determining the reference value Nref, it can be specifically determined according to the triangular wave carrier vertex count value N _1/2Period and the amplitude of the injected positive and negative voltage pulses. For example, since the amplitude of the selected positive and negative voltage pulses generally does not exceed 50% of the DC bus voltage Udc when estimating the rotor position of the motor based on the high-frequency injection method, the reference value Nref can be 0.5 times the count value of the triangular wave carrier vertex, That is, the reference value Nref=(1/2)*N _1/2Period . It should be noted that the reference value Nref is equal to or greater than the difference between the comparison value Act22 and the comparison value Act11.

Step S102, determining the difference between the reference value and the comparison value Act21 or Act22.

Specifically, when the current sampling is performed in 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 is DetaN=Nref-Act21; when the current sampling is performed in the falling phase of the triangular wave carrier, the corresponding comparison The value is Act22, and the difference between the reference value Nref and the comparison value Act22 is DetaN=Nref-Act22. It can be understood that when the triangular wave carrier count method is to increase first and then decrease, and the comparison values Act21 and Act22 are not phase-shifted during phase shifting, the calculated two difference values DetaN are equal, and will be used in subsequent use. In other cases, the two calculated differences DetaN may not be equal, and need to be distinguished in subsequent use.

Step S103, adjust the six comparison values Act11, Act21, Act31, Act32, Act22, and Act12 according to the difference, and determine the first current sampling trigger value and the second current sampling trigger according to the adjusted comparison value Act21 _New or Act22 _New value.

Specifically, after the difference value DetaN is obtained, the six comparison values can be adjusted based on the difference value DetaN. The adjustment principle is that if t2 is a small value, the zero voltage vector U0 (000) is used to compensate the zero voltage vector U7 (111), that is, increase the duty cycle of PWM1, PWM2 and PWM3, that is, increase the high level time of PWM1, PWM2 and PWM3; if t1 is a small value, use the zero-voltage vector U7 (111) to compensate the zero-voltage vector U0 (000), namely reducing the duty cycle of PWM1, PWM2 and PWM3, namely reducing the high level time of PWM1, PWM2 and PWM3.

For example, as shown in Figure 3a, when t2 is a small value, the zero voltage vector U0 (000) is used to compensate the zero voltage vector U7 (111), and the adjusted PWM1, PWM2 and PWM3 are shown in Figure 5(a) , compared with the PWM signal before adjustment, the high level of the adjusted PWM signal has increased (ie, expanded); as shown in Figure 3b, t1 is a small value, then the zero voltage vector U7 (111) is used to compensate for the zero voltage The vector U0 (000), the adjusted PWM1, PWM2 and PWM3 are shown in Fig. 5(b). Compared with the unadjusted PWM signal, the high level of the adjusted PWM signal is reduced (ie, indented).

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 small value, the zero-voltage vector U0 (000) is sufficient to supplement the zero-voltage vector U7 (111), Avoid that the zero voltage vector U7 (111) is not enough to be supplemented because the duration of the zero voltage vector U0 (000) is too short, and when t1 is a small value, the zero voltage vector U7 (111) is sufficient to supplement the zero voltage vector U0 (000), avoid Because the duration of the zero-voltage vector U7 (111) is too short to supplement the zero-voltage vector U0 (000), the normal control of the motor is ensured.

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

It should be noted that, since the difference DetaN has positive and negative points, the formula (1) is applicable to the foregoing two situations. For example, the difference value DetaN=Nref-Act22, if t2 is a small value, then the difference value DetaN<0, at this time, the adjusted six comparison values determined based on formula (1) are consistent with those shown in Figure 5(a) ; If t1 is a smaller value, the difference DetaN>0, and the six adjusted comparison values determined based on formula (1) are consistent with those shown in Figure 5(b).

After the adjusted six comparison values are obtained, the first current sampling trigger value and the second current sampling trigger value are determined based on the adjusted comparison value Act21 _New or Act22 _New . Specifically, in a control cycle, the current sampling can be performed before and after the second or fifth switching tube action time, that is, the current sampling is performed before and after the corresponding time of the comparison value Act21 _New or Act22 _New . After comparing the values Act21 _New and Act22 _New , 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 stage of the triangular wave carrier is selected for single-resistor sampling, the first current sampling trigger value Trig1 and the second current sampling trigger value Trig2 are obtained according to the comparison value Act22 _New ; if the single-resistance sampling is carried out in the rising stage of the triangular wave carrier, then The first current sampling trigger value Trig1 and the second current sampling trigger value Trig2 are acquired according to the comparison value Act21 _New .

It should be noted that when the first current sampling trigger value Trig1 and the second current sampling trigger value Trig2 are obtained according to the comparison value Act21 _New or Act22 _New , the time required for hardware sampling (such as the sampling time of the ADC converter), the dead time zone time (that is, when the PWM signal is output, in order to avoid the time reserved for the upper and lower switches of the same bridge arm to be turned on at the same time, for example, after the upper bridge arm switch tube is turned off and the dead time is delayed, the lower bridge arm switch tube can be turned on, or after the lower arm switch is turned off and the dead time is delayed, the upper arm switch can be turned on) and the current stabilization time after the switch is turned on (for example, after the switch is turned on, the current gradually rises Until the time corresponding to the stable state) is determined to ensure sufficient current sampling time, and avoid dead time and current instability time, ensuring the validity and accuracy of current sampling.

According to an embodiment of the present invention, when single-resistor sampling is performed in 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):

Wherein, 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 for the current to rise to a stable state.

According to an embodiment of the present invention, when single-resistor sampling is performed in the falling stage 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 (3):

Wherein, 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 for the current to rise to a stable state.

That is to say, the first current sampling is performed before the second or fifth switching tube action time, and the second current sampling is performed after that. Considering that the two sampling times are as close as possible to reduce the sampling time error, For the first current sampling, reserve a time Tsample required for hardware sampling, and for the second current sampling, reserve a dead time Tdead and a time Tup when the current rises to a stable state.

Step S104, control the motor according to the adjusted six comparison values Act11 _New , Act21 _New , Act31 _New , Act32 _New , Act22 _New , and Act12 _New , and control the motor according to the first current sampling trigger value and the second current sampling trigger value Perform current sampling to obtain a first sampling current and a second sampling current.

Specifically, after the adjusted six comparison values are obtained, the motor is also controlled according to the adjusted six comparison values, and during the control process, the first current sampling trigger value Trig1 and the second current sampling trigger value are triggered. The value Trig2 is current sampled, thereby obtaining the first sampled current and the second sampled current.

Take single-resistor sampling in the falling phase of the triangular wave carrier as an example. As shown in Figure 5(a)-Figure 5(b), after obtaining the adjusted six comparison values, if the timer count value is used to generate a triangular wave carrier, when the timer count value is equal to the comparison value Act11 _New , the control The upper bridge arm switch VT1 in Figure 1 is turned on, the lower bridge arm switches VT6 and VT2 are kept on, and the rest of the switches are turned off; when the timer count value is equal to the comparison value Act21 _New , the upper switch in Figure 1 is controlled The bridge arm switch VT3 is turned on, the upper bridge arm switch VT1 and the lower bridge arm switch VT2 are kept on, and the rest of the switches are turned off; when the timer count value is equal to the comparison value Act31 _New , control the upper The bridge arm switch VT5 is turned on, the upper bridge arm switch VT1 and VT3 remain on, and the rest of the switches are turned off; when the timer count value is equal to the comparison value Act32 _New , the lower bridge arm switch VT2 in Figure 1 is controlled to conduct When the timer count value is equal to the first current sampling trigger value Trig1, current sampling is performed through the sampling resistor R in Fig. 1 to obtain the first Sampling current; when the timer count value is equal to the comparison value Act22 _New , the lower arm switch VT6 in Figure 1 is controlled to be turned on, the upper arm switch VT1 and the lower arm switch VT2 are kept turned on, and the rest of the switches are Turn off; when the timer count value is equal to the second current sampling trigger value Trig2, the second sampling current is obtained by current sampling through the sampling resistor R in Figure 1; when the timer count value is equal to the comparison value Act12 _New , control Figure 1 The lower bridge arm switch tube VT4 in the middle is turned on, the lower bridge arm switch tubes VT2 and VT6 are kept on, and the rest of the switch tubes are turned off.

Therefore, based on the comparison value and the sampling trigger value, the control of the motor can be realized, and current sampling is performed during the control process. It should be noted that the process of performing single-resistance sampling in the rising phase of the triangular wave carrier is the same as the process of performing single-resistance sampling in the falling phase of the triangular wave carrier, which will not be described in detail here.

Step S105, the rotor position of the motor is estimated according to the first sampled current and the second sampled current.

Specifically, position observation can be performed according to the first sampled current and the second sampled current to obtain the rotor position of the motor, which can be realized by using the prior art, which will not be described here.

According to the method for observing the rotor position of the motor according to the embodiment of the present invention, the six comparison values of the three-way modulation corresponding to the output voltage vector required by the single-resistor sampling are adjusted according to the difference between the reference value and the comparison value, and according to The adjusted comparison value determines the first current sampling trigger value and the second current sampling trigger value, and controls the motor according to the adjusted six comparison values, and pairs the first current sampling trigger value and the second current sampling trigger value according to the adjusted comparison value. The motor performs current sampling, obtains 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, which can effectively improve the sampling current accuracy of single-resistance sampling, thereby improving the observation of the rotor position of the motor. High precision, simple algorithm and easy engineering application, thus achieving excellent control performance at low cost.

In an embodiment of the present invention, there is also provided a computer-readable storage medium on which a motor rotor position observation program is stored, and when the motor rotor position observation program is executed by a processor, the foregoing motor rotor position observation method is implemented.

According to the computer-readable storage medium of the embodiment of the present invention, based on the foregoing method for observing the rotor position of the motor, the sampling current accuracy of single-resistance sampling can be effectively improved, thereby improving the accuracy of observing the rotor position of the motor.

In an embodiment of the present invention, a rotor position observer is also provided, which includes a memory, a processor, and a motor rotor position observation program stored in the memory and running on the processor. When the processor executes the motor rotor position observation program , to realize the aforementioned method for observing the rotor position of the motor.

According to the rotor position observer of the embodiment of the present invention, based on the aforementioned method for observing the rotor position of the motor, the sampling current accuracy of single-resistance sampling can be effectively improved, thereby improving the accuracy of observing the rotor position of the motor.

FIG. 6 is a schematic diagram of a motor rotor position observation device according to an embodiment of the present invention. Referring to FIG. 6 , the motor rotor position observation device may include: a first determination module 10 , a second determination module 20 , an adjustment module 30 , and a first determination module 10 . Three determination module 40, control module 50.

Wherein, 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 of the three-way modulation corresponding to the output required voltage vector under single resistance sampling , Act12; the adjustment module 30 is used to determine the difference between the reference value and the comparison value Act21 or Act22 when injecting high-frequency pulses into the d-axis of the motor, and to compare the six comparison values Act11, Act21, Act31, Act32 according to the difference , Act22 and Act12 are adjusted; the third determination module 40 is used for determining the first current sampling trigger value and the second current sampling trigger value according to the adjusted comparison value Act21 _New or Act22 _New ; the control module 50 is used for according to the adjusted six The comparison values Act11 _New , Act21 _New , Act31 _New , Act32 _New , Act22 _New , and Act12 _New control the motor, and perform current sampling on the motor according to the first current sampling trigger value and the second current sampling trigger value, and obtain the first sampling current and the second sampled current, and the rotor position of the motor is estimated from the first sampled current and the second sampled current.

According to an embodiment of the present invention, the first determination module 10 is specifically configured to: acquire the count value of the triangular wave carrier vertex; and determine the reference value according to the triangular wave carrier vertex count value.

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.

According to an embodiment of the present invention, the reference value is 0.5 times the count value of the triangular wave carrier vertex.

According to an 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:

Act11 _New = Act11 + DetaN;

Act21 _New = Nref;

Act31 _New = Act31 + DetaN;

Act32 _New = Act32-DetaN;

Act22 _New = Nref;

Act12 _New = Act12-DetaN;

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

According to an embodiment of the present invention, the third determination 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-resistance sampling is performed in the rising phase of the triangular wave carrier:

Trig1 _New = Act21 _New - Tsample;

Trig2 _New = Act21 _New + Tdead + Tup;

Wherein, 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 for the current to rise to a stable state.

According to an embodiment of the present invention, the third determination module 40 is specifically configured to determine the first current sampling trigger value and the second current sampling trigger value according to the following formulas when single-resistor sampling is performed in the falling stage of the triangular wave carrier:

Trig1 _New = Act22 _New + Tsample;

Trig2 _New = Act22 _New -Tdead-Tup;

Wherein, 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 for the current to rise to a stable state.

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 details are not repeated here.

According to the device for observing the rotor position of the motor according to the embodiment of the present invention, the six comparison values of the three-way modulation corresponding to the output required voltage vector under single-resistance sampling are adjusted according to the difference between the reference value and the comparison value, and according to The adjusted comparison value determines the first current sampling trigger value and the second current sampling trigger value, and controls the motor according to the adjusted six comparison values, and pairs the first current sampling trigger value and the second current sampling trigger value according to the adjusted comparison value. The motor performs current sampling, obtains 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, which can effectively improve the sampling current accuracy of single-resistance sampling, thereby improving the observation of the rotor position of the motor. accuracy.

It should be noted that the logic and/or steps represented in the flowcharts or otherwise described herein, for example, may be considered as an ordered listing of executable instructions for implementing the logical functions, and may be embodied in any computer readable medium for use by an instruction execution system, apparatus, or device (such as 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), or in combination with these used to execute a system, device or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport the program for use by or in connection with an instruction execution system, apparatus, or apparatus. More specific examples (non-exhaustive list) of computer readable media include the following: electrical connections with one or more wiring (electronic devices), portable computer disk cartridges (magnetic devices), random access memory (RAM), Read Only Memory (ROM), Erasable Editable Read Only Memory (EPROM or Flash Memory), Fiber Optic Devices, and Portable Compact Disc Read Only Memory (CDROM). In addition, the computer readable medium may even be paper or other suitable medium on which the program may be printed, as the paper or other medium may be optically scanned, for example, followed by editing, interpretation, or other suitable medium as necessary process to obtain the program electronically and then store it in computer memory.

It should be understood that various parts of the present invention may be implemented in hardware, software, firmware or a combination thereof. In the above-described embodiments, various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one or a combination of the following techniques known in the art: Discrete logic circuits, application specific integrated circuits with suitable combinational logic gates, Programmable Gate Arrays (PGA), Field Programmable Gate Arrays (FPGA), etc.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature 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 particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between the two elements, unless otherwise specified limit. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims (10)

1. A method for observing the position of a rotor of an electric motor, comprising:

when high-frequency pulses are injected into a d axis of the motor, a reference value is determined, and six comparison values Act11, Act21, Act31, Act32, Act22 and Act12 of three-way modulation corresponding to the output required voltage vector under single resistance sampling are determined;

determining a difference between the reference value and a comparison value Act21 or Act 22;

adjusting six comparison values Act11, Act21, Act31, Act32, Act22 and Act12 according to the difference values, and adjusting the six comparison values according to the adjusted comparison values Act21_NewOr Act22_NewDetermining a first current sampling trigger value and a second current sampling trigger value;

according to the adjusted six comparison values Act11_New、Act21_New、Act31_New、Act32_New、Act22_New、Act12_NewControlling a 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;

and estimating the rotor position of the motor according to the first sampling current and the second sampling current.

2. The method of claim 1, wherein determining a reference value comprises:

acquiring a triangular wave carrier peak count value;

and determining the reference value according to the triangular wave carrier peak count value.

3. The method according to claim 2, wherein the reference value is equal to or greater than the difference between the comparison value Act22 and the comparison value Act 11.

4. The method according to claim 2, wherein the reference value is 0.5 times the triangular carrier vertex count value.

5. Method according to any of claims 1-4, characterized in that the six comparison values Act11, Act21, Act31, Act32, Act22, 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；

where DetaN is the difference value and Nref is the reference value.

6. The method of claim 1, wherein the first current sampling trigger value and the second current sampling trigger value are determined according to the following equations when single resistance sampling is performed during the rise phase of a triangular carrier wave:

Trig1_New＝Act21_New-Tsample；

Trig2_New＝Act21_New+Tdead+Tup；

wherein, the Trig1_NewSampling a trigger value, Trig2, for the first current_NewAnd sampling the trigger value for the second current, wherein Tsample is the time required by hardware sampling, Tdead is the dead time, and Tup is the time for the current to rise to be stable.

7. The method of claim 1, wherein the first current sampling trigger value and the second current sampling trigger value are determined according to the following equations when single resistance sampling is performed during a falling phase of a triangular carrier wave:

Trig1_New＝Act22_New+Tsample；

Trig2_New＝Act22_New-Tdead-Tup；

wherein, the Trig1_NewSampling a trigger value, Trig2, for the first current_NewAnd sampling the trigger value for the second current, wherein Tsample is the time required by hardware sampling, Tdead is the dead time, and Tup is the time for the current to rise to be stable.

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

9. A rotor position observer, comprising a memory, a processor and an electric machine rotor position observation program stored on the memory and executable on the processor, when executing the electric machine rotor position observation program, implementing the electric machine rotor position observation method according to any one of claims 1-7.

10. An electric motor rotor position observation device, comprising:

a first determination module for determining a reference value;

the second determination module is used for determining six comparison values Act11, Act21, Act31, Act32, Act22 and Act12 of three-way modulation corresponding to the voltage vector required by the single-resistor sampling output;

the adjusting module is used for determining the difference value between the reference value and the comparison value Act21 or Act22 when high-frequency pulses are injected into the d shaft of the motor, and adjusting six comparison values Act11, Act21, Act31, Act32, Act22 and Act12 according to the difference value;

a third determination module for determining the adjusted comparison value Act21_NewOr Act22_NewDetermining a first current sampling trigger value and a second current sampling trigger value;

a control module for adjusting six comparison values Act11_New、Act21_New、Act31_New、Act32_New、Act22_New、Act12_NewControlling a motor, sampling the current of the motor according to the first current sampling trigger value and the second current sampling trigger value, obtaining a first sampling current and a second sampling current, and estimating the position of a rotor of the motor according to the first sampling current and the second sampling current.

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