A current compensation method, device, motor controller and storage medium

Abstract

The present application is applicable to the field of motor technology, and provides a current compensation method, device, motor controller and storage medium. The phase current at the v-phase comparison value moment is obtained according to two bus currents respectively sampled during the durations of the first effective vector and the second effective vector; the rotor angle at the uvw-phase comparison value moment of the k-th period is obtained according to the uvw-phase comparison values of the k-th period, the rotor angle at the current control moment, and the rotor angle at the current control moment of the (k-1)-th period; the second effective vector is obtained according to the bus voltage and the abc-phase comparison values; the phase current at the current control moment is obtained according to the duration of the second effective vector, the duration of the second zero vector, the phase current at the v-phase comparison value moment, the second effective vector, and the rotor angle at the uvw-phase comparison value moment, so as to achieve the effect of current delay compensation, improve the current control performance, and reduce current harmonics.

Description

Technical Field

[0001] This application belongs to the technical field of motors, and particularly relates to a current compensation method, device, motor controller, and storage medium. Background Art

[0002] The single-bus current detection technology is a technology for reducing the cost of current sensors. The single-bus current detection only detects the magnitude of the bus current on the DC bus in the motor controller, and determines the correlation between the bus current and the phase current of the motor according to the switching states of the three-phase bridge arms of the inverter, and then estimates the magnitude of the phase current of the motor. The single-bus current detection method only requires one current sensor, and the cost is greatly reduced. The reconstruction of the motor phase current based on the single-bus current detection technology provides a solution for a low-cost motor vector control system. During the reconstruction process of the motor phase current, it is necessary to sample the bus current twice continuously to convert it into two-phase current and calculate the third-phase current.

[0003] Since the bus current sampling operation needs to be completed within the duration of two effective voltage vectors, and the effective vector output during the operation of the motor continuously changes, the sampling moment of the bus current is variable relative to the carrier period. In the scope of low switching frequency control or high-speed motor control technology, since the change range of the electrical angle of the motor within the carrier period increases, the influence of the switching action on the current waveform is significantly increased. Within a single carrier period, due to the change of the applied voltage vector, the current change shows a stepwise change characteristic and the harmonics increase. The change of the bus current sampling moment has a significant impact on the accuracy of current sampling, and the single bus current sampling value may deviate from the current fundamental wave value. In addition, due to the change of the bus current sampling moment, the current delay effect is difficult to estimate. The existing single-bus current detection technology is difficult to effectively process current sampling in the scope of low switching frequency control or high-speed motor control technology, resulting in a reduction in current control performance and an increase in current harmonics. Summary of the Invention

[0004] The embodiments of this application provide a current compensation method, device, motor controller, and storage medium, aiming to solve the problem that the existing single-bus current detection technology is difficult to effectively process current sampling in the scope of low switching frequency control or high-speed motor control technology, resulting in a reduction in current control performance and an increase in current harmonics.

[0005] The first aspect of the embodiments of this application provides a current compensation method, including:

[0006] Based on the uvw phase comparison value in the k-th period, obtain the phase current at the moment of the v-phase comparison value in the k-th period according to two bus currents sampled respectively within the durations of the first effective vector and the second effective vector in the k-th period, and the uvw phase comparison value is obtained by arranging the abc phase comparison values in descending order;

[0007] Based on the uvw comparison value in the k-th period, the rotor angle at the current control moment, and the rotor angle at the current control moment in the (k - 1)-th period, obtain the rotor angle at the moment of the uvw comparison value in the k-th period;

[0008] Based on the bus voltage in the k-th period and the abc comparison value, obtain the second effective vector in the k-th period;

[0009] Based on the duration of the second effective vector in the k-th period, the duration of the second zero vector, the phase current at the moment of the v comparison value, the second effective vector, and the rotor angle at the moment of the uvw comparison value, obtain the phase current at the current control moment in the k-th period;

[0010] Wherein, the k-th period and the (k - 1)-th period are two adjacent half-carrier periods, and k is an integer greater than 1.

[0011] The second aspect of the embodiments of the present application provides a current compensation device, including:

[0012] A first phase current acquisition unit, configured to obtain the phase current at the moment of the v comparison value in the k-th period based on the uvw comparison value in the k-th period and two bus currents sampled respectively within the durations of the first effective vector and the second effective vector in the k-th period, and the uvw comparison value is obtained by arranging the abc comparison values in numerical descending order;

[0013] A rotor angle acquisition unit, configured to obtain the rotor angle at the moment of the uvw comparison value in the k-th period based on the uvw comparison value in the k-th period, the rotor angle at the current control moment, and the rotor angle at the current control moment in the (k - 1)-th period;

[0014] An effective vector calculation unit, configured to obtain the second effective vector in the k-th period based on the bus voltage in the k-th period and the abc comparison value;

[0015] A second phase current acquisition unit, configured to obtain the phase current at the current control moment in the k-th period based on the duration of the second effective vector in the k-th period, the duration of the second zero vector, the phase current at the moment of the v comparison value, the second effective vector, and the rotor angle at the moment of the uvw comparison value;

[0016] Wherein, the k-th period and the (k - 1)-th period are two adjacent half-carrier periods, and k is an integer greater than 1.

[0017] The third aspect of the embodiments of the present application provides a motor controller, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the current compensation method in the first aspect of the embodiments of the present application.

[0018] In the fourth aspect of the embodiments of the present application, a computer-readable storage medium is provided. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the current compensation method described in the first aspect of the embodiments of the present application are implemented.

[0019] The current compensation method provided in the first aspect of the embodiments of the present application is based on the uvw-phase comparison values obtained by sorting the abc-phase comparison values of the k-th period in descending order of numerical values. According to two busbar currents sampled respectively during the durations of the first effective vector and the second effective vector in the k-th period, the phase current at the moment of the v-phase comparison value in the k-th period is obtained; according to the uvw-phase comparison values of the k-th period, the rotor angle at the moment of the uvw-phase comparison value, and the rotor angle at the current control moment of the (k - 1)-th period, the rotor angle at the moment of the uvw-phase comparison value in the k-th period is obtained; according to the busbar voltage and the abc-phase comparison values of the k-th period, the second effective vector in the k-th period is obtained; according to the duration of the second effective vector in the k-th period, the duration of the second zero vector, the phase current at the moment of the v-phase comparison value, the second effective vector, and the rotor angle at the moment of the uvw-phase comparison value, the phase current at the current control moment in the k-th period is obtained, which can achieve the effect of current delay compensation and reduce the current control error caused by the sampling error of the busbar current. Therefore, the current control performance can be improved, the current harmonics can be reduced, and it can be applied to the field of low switching frequency control or high-speed motor control technology.

[0020] It can be understood that the beneficial effects of the above second aspect to the fourth aspect can be referred to the relevant descriptions in the above first aspect, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 is a schematic structural diagram of a motor controller provided by the embodiments of the present application;

[0023] Figure 2 is a calculation formula table of the three-phase comparison values of the target voltage vector in six sectors of the space vector plane provided by the embodiments of the present application;

[0024] Figure 3 is a schematic diagram of the waveforms of the triangular carrier, PWM signal, and busbar current within a half-carrier period provided by the embodiments of the present application;

[0025] Figure 4 It is the first schematic flowchart of the current compensation method provided by the embodiments of the present application;

[0026] Figure 5 It is a schematic diagram of the triangular carrier wave, PWM signal waveform, and bus current within a half-carrier period after redefining the abc phase sequence provided by the embodiments of the present application;

[0027] Figure 6 It is a schematic diagram of the relationship between the current change and the switch action moment (i.e., the uvw comparison value moment) within a half-carrier period provided by the embodiments of the present application;

[0028] Figure 7 It is the second schematic flowchart of the current compensation method provided by the embodiments of the present application;

[0029] Figure 8 It is a schematic diagram of the acquisition timing of the rotor angle, voltage, and current within a half-carrier period provided by the embodiments of the present application;

[0030] Figure 9 It is the third schematic flowchart of the current compensation method provided by the embodiments of the present application;

[0031] Figure 10 It is the fourth schematic flowchart of the current compensation method provided by the embodiments of the present application;

[0032] Figure 11 It is a schematic diagram of the structure of the current compensation device provided by the embodiments of the present application;

[0033] Figure 12 It is a schematic diagram of the structure of the motor controller provided by the embodiments of the present application. Detailed implementation manners

[0034] In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are presented to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0035] It should be understood that when used in the specification and appended claims of the present application, the term "comprising" indicates the presence of the described features, wholes, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0036] It should also be understood that the term "and / or" as used in the specification and appended claims of this application refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0037] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when", "once", "in response to determining", or "in response to detecting" depending on the context. Similarly, the phrase "if determined" or "if [the described condition or event] is detected" can be interpreted as meaning "once determined", "in response to determining", "once [the described condition or event] is detected", or "in response to detecting [the described condition or event]" depending on the context.

[0038] In addition, in the description of the specification and appended claims of this application, the terms "first", "second", "third", etc. are only used for differential description and should not be construed as indicating or implying relative importance.

[0039] Reference to "one embodiment" or "some embodiments" or the like described in the specification of this application means that a specific feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of this application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in another way. The terms "comprising", "including", "having", and their variants all mean "including but not limited to", unless otherwise specifically emphasized in another way.

[0040] An embodiment of this application provides a current compensation method, which can be executed by a processor of a motor controller when running a corresponding computer program. During the motor control process, based on the phase current at the current sampling moment obtained by the current sampling technology, the phase current at the current control moment is obtained, which can achieve the current delay compensation effect and reduce the current control error caused by the bus current sampling error. Thus, the current control performance can be improved and the current harmonics can be reduced, and it can be applied to the field of low switching frequency control or high-speed motor control technology.

[0041] In application, the motor controller can be applied to air conditioners, fans, and washing machines to drive and control the motors of air conditioners, fans, and washing machines. Specifically, the motor controller can be an inverter.

[0042] As Figure 1 shown, a schematic structural diagram of the motor controller is exemplarily shown;

[0043] Among them, the motor controller includes a processor, a current sensor, and an inverter;

[0044] The current sensor is electrically connected to the negative pole of the DC bus and is used to detect the bus current on the DC bus. Figure 1 Exemplarily, it is shown that the current sensor is realized by a sampling resistor connected in series on the negative pole of the DC bus;

[0045] The first input terminal of the inverter is electrically connected to the positive pole of the DC bus, the second input terminal of the inverter is electrically connected to the negative pole of the DC bus, the six controlled terminals of the inverter are electrically connected to the processor, and the three output terminals of the inverter are respectively electrically connected to the three-phase current and phase voltage input terminals of the motor. Figure 1 Exemplarily, it is shown that the inverter includes three-phase bridge arms (a-phase bridge arm, b-phase bridge arm, and c-phase bridge arm), and each phase bridge arm includes two switching tubes (upper switching tube and lower switching tube). The input terminals of the upper switching tubes of the three-phase bridge arms are commonly connected to form the first input terminal of the inverter, the output terminals of the lower switching tubes of the three-phase bridge arms are commonly connected to form the second input terminal of the inverter 3, the controlled terminal of each switching tube forms a controlled terminal of the inverter, and the output terminal of the upper switching tube and the input terminal of the lower switching tube of each phase bridge arm are commonly connected to form an output terminal of the inverter;

[0046] The processor is used for:

[0047] According to the target rotor speed that the motor needs to reach, obtain the target phase voltages (a-phase voltage, b-phase voltage, and c-phase voltage) that need to be applied to the stator, so as to generate corresponding target phase currents (a-phase current ia, b-phase current ib, and c-phase current ic) in the stator;

[0048] Adopt the Space Vector Pulse Width Modulation (SVPWM) method. According to the rotor angle and the target phase voltage, determine the target voltage vector, and according to the amplitude and phase angle of the target voltage vector, obtain the three-phase comparison values through the comparison value calculation method based on the SVPWM method. Then, compare the triangular carrier wave with the calculated three-phase comparison values to generate the Pulse Width Modulation (PWM) signals used to drive the switching tubes of the corresponding phases, and control the on and off states of the six switching tubes of the three-phase bridge arms of the inverter, so as to output three-phase voltages to the motor.

[0049] According to the PWM signals, control the on and off states of the six switching tubes of the three-phase bridge arms of the inverter, so that the actual voltage of the bus voltage acting on the stator is equivalent to the target phase voltage. Correspondingly, the actual current of the bus current acting on the stator is equivalent to the target phase current, and further, the stator generates a corresponding magnetic field to drive the rotor to rotate at the target rotor speed;

[0050] To improve the motor control accuracy, it is necessary to collect the bus current on the DC bus through a current sensor to obtain the magnitude of the bus current on the DC bus, so that the magnitude of the actual phase current applied to the stator can be estimated according to the magnitude of the bus current. By comparing the actual phase current and the target phase current, the target phase current can be adjusted according to the deviation between the actual phase current and the target phase current. Based on the adjusted target phase current, the adjusted target phase voltage can be obtained. Combining with the space vector pulse width modulation method, the adjusted target voltage vector can be determined, and then the adjusted pulse width modulation signal can be generated according to the adjusted target voltage vector, and the on-off states of the six switching tubes of the three-phase bridge arm of the inverter can be controlled according to the adjusted pulse width modulation signal, and finally the feedback control of the motor can be realized.

[0051] In applications, the switching tube has the function of conducting or turning off under the trigger of an electrical signal (PWM signal) and is used to act as an electronic switch. Specifically, it can be an Insulated Gate Bipolar Transistor (IGBT), or it can also be a Bipolar Junction Transistor (BJT), a Field Effect Transistor (FET), a Thyristor, etc. The insulated gate bipolar transistor is a composite fully controlled voltage-driven power semiconductor device composed of a bipolar transistor and an insulated gate field effect transistor, and has the advantages of both the high input impedance of the insulated gate field effect transistor and the low conduction voltage drop of the bipolar transistor. The field effect transistor can specifically be a Metal-Oxide Semiconductor FET (MOS-FET for short).

[0052] In applications, a method for calculating the comparison value based on the SVPWM method will be introduced in detail below:

[0053] If the amplitude of the target voltage vector is Ur and the phase angle is θ1, the calculation method of the modulation coefficient m1 is:

[0054]

[0055] where Udc is the bus voltage;

[0056] If θ1 > 0 and θ1 ≤ 1 / 3 * π, the target voltage vector is located in the first sector of the space vector plane, and the angle θm relative to the first sector is θ1;

[0057] If θ1 > 1 / 3 * π and θ1 ≤ 2 / 3 * π, the target voltage vector is located in the second sector of the space vector plane, and the angle θm relative to the second sector is θ1 - 1 / 3 * π;

[0058] If θ1 > 2 / 3*π and θ1 ≤ 3 / 3*π, the target voltage vector is located in the third sector of the space vector plane, and the angle θm relative to the third sector is θm = θ1 - 2 / 3*π;

[0059] If θ1 > 3 / 3*π and θ1 ≤ 4 / 3*π, the target voltage vector is located in the fourth sector of the space vector plane, and the angle θm relative to the fourth sector is θm = θ1 - 3 / 3*π;

[0060] If θ1 > 4 / 3*π and θ1 ≤ 5 / 3*π, the target voltage vector is located in the fifth sector of the space vector plane, and the angle θm relative to the fifth sector is θm = θ1 - 4 / 3*π;

[0061] If θ1 > 5 / 3*π and θ1 ≤ 2*π, the target voltage vector is located in the sixth sector of the space vector plane, and the angle θm relative to the sixth sector is θm = θ1 - 5 / 3*π;

[0062] Calculate the duration ratios Tm1 and Tm2 of the two effective vectors within the carrier period based on m1 and θm:

[0063]

[0064]

[0065] where Tm is the maximum value of the carrier counter, that is, the maximum carrier period count value;

[0066] The calculation method for the duration ratio Tm0 of the zero vector is:

[0067] Tm0 = 0.5 * (1 - Tm1 - Tm2) * Tm

[0068] As Figure 2 shown, an exemplary calculation formula table of the three-phase comparison values of the target voltage vector in the six sectors of the space vector plane is shown; among them, the comparison value of phase a at the falling edge of the carrier is DDA0, and the comparison value at the rising edge of the carrier is DUA0; the comparison value of phase b at the falling edge of the carrier is DDB0, and the comparison value at the rising edge of the carrier is DUB0; the comparison value of phase c at the falling edge of the carrier is DDC0, and the comparison value at the rising edge of the carrier is DUC0. In the symmetric sampling mode, the comparison value at the falling edge of the carrier is the same as the comparison value at the rising edge of the carrier, that is, DDA0 = DUA0, DDB0 = DUB0, DDC0 = DUC0.

[0069] In an application, in the single-bus current sampling method based on SVPWM, within a half-carrier period, the voltage output by the inverter is divided into four segments. When the half-carrier period is the carrier falling-edge period, the four segments of voltage output by the inverter are: the first zero vector → the first effective vector → the second effective vector → the second zero vector; when the half-carrier period is the carrier rising-edge period, the four segments of voltage output by the inverter are: the second zero vector → the second effective vector → the first effective vector → the first zero vector.

[0070] As Figure 3 shown, an exemplary diagram shows the waveforms of the triangular carrier, PWM signal, and bus current within a half-carrier period; where Ta, Tb, and Tc are the comparison values of the abc phases, Tsh is the half-carrier period, the waveforms of phases a, b, and c are the waveforms of the PWM signals output to the three-phase bridge arms of the inverter, idc is the bus current, T1 is the duration of the first effective vector, T2 is the duration of the second effective vector, and Tad1 and Tad2 are the two bus current sampling moments.

[0071] In an application, the single-bus current sampling technology samples the bus current respectively within the durations of two adjacent effective vectors (i.e., the first effective vector and the second effective vector), and estimates the corresponding motor phase current. The relationship between the bus current sampling, phase current, and space voltage vector is as follows:

[0072] If the output voltage at the bus current sampling moment is the space voltage vector 100, then the bus current idc is equal to the phase-a current ia;

[0073] If the output voltage at the bus current sampling moment is the space voltage vector 110, then the bus current idc is equal to the negative phase-c current -ic;

[0074] If the output voltage at the bus current sampling moment is the space voltage vector 101, then the bus current idc is equal to the negative phase-b current -ib;

[0075] If the output voltage at the bus current sampling moment is the space voltage vector 010, then the bus current idc is equal to the phase-b current ib;

[0076] If the output voltage at the bus current sampling moment is the space voltage vector 011, then the bus current idc is equal to the negative phase-a current -ia;

[0077] If the output voltage at the bus current sampling moment is the space voltage vector 001, then the bus current idc is equal to the phase-c current ic.

[0078] As Figure 4 shown, an embodiment of the present application provides a current compensation method, including the following steps S401 to S406:

[0079] Step S401: Obtain the comparison values of phases a, b, and c in the k-th period according to the amplitude and phase angle of the target voltage vector in the k-th period.

[0080] In application, the comparison values of phases a, b, and c include the comparison value of phase a, the comparison value of phase b, and the comparison value of phase c. The comparison value of phase a, the comparison value of phase b, and the comparison value of phase c can be obtained by a comparison value calculation method based on the SVPWM method according to the amplitude and phase angle of the target voltage vector.

[0081] Step S402: Sort the comparison values of phases a, b, and c in the k-th period in descending order of numerical value to obtain the comparison values of phases u, v, and w in the k-th period.

[0082] In application, the comparison values of phases u, v, and w include the comparison value of phase u, the comparison value of phase v, and the comparison value of phase w. The comparison value of phase u, the comparison value of phase v, and the comparison value of phase w are obtained by sorting the comparison values of phases a, b, and c in descending order of numerical value (i.e., in the order from large to small) and renaming them. For example, if the comparison values of phases a, b, and c in descending order of numerical value are: comparison value of phase a > comparison value of phase b > comparison value of phase c, then after renaming, the comparison value of phase a becomes the comparison value of phase u, the comparison value of phase b becomes the comparison value of phase v, and the comparison value of phase c becomes the comparison value of phase w; if the comparison values of phases a, b, and c in descending order of numerical value are: comparison value of phase c > comparison value of phase b > comparison value of phase a, then after renaming, the comparison value of phase a becomes the comparison value of phase w, the comparison value of phase b becomes the comparison value of phase v, and the comparison value of phase c becomes the comparison value of phase u.

[0083] Step S403: Take the duration between the start time of the k-th period and the time of the comparison value of phase u as the duration of the first zero vector in the k-th period;

[0084] Step S404: Take the duration between the time of the comparison value of phase u and the time of the comparison value of phase v in the k-th period as the duration of the first effective vector in the k-th period;

[0085] Step S405: Take the duration between the time of the comparison value of phase v and the time of the comparison value of phase w in the k-th period as the duration of the second effective vector in the k-th period;

[0086] Step S406: Take the duration between the time of the comparison value of phase w and the end time in the k-th period as the duration of the second zero vector in the k-th period.

[0087] In application, based on the comparison values of phases u, v, and w obtained by sorting the comparison values of phases a, b, and c in descending order of numerical value and renaming them, the first zero vector, the first effective vector, the second effective vector, and the second zero vector within the half-carrier period are redefined, and the specific definitions are as follows:

[0088] The first zero vector is the output voltage from the start time of a half - carrier period to before the u - phase comparison value time, and the duration of the first zero vector is the duration between the start time of the half - carrier period and the u - phase comparison value time;

[0089] The first effective vector is the output voltage during the period from the u - phase comparison value time to the v - phase comparison value time, and the duration of the first effective vector is the duration between the u - phase comparison value time and the v - phase comparison value time;

[0090] The second effective vector is the output voltage during the period from the v - phase comparison value time to the w - phase comparison value time, and the duration of the second effective vector is the duration between the v - phase comparison value time and the w - phase comparison value time;

[0091] The second zero vector is the output voltage during the period from the w - phase comparison value time to the end time of the half - carrier period, and the duration of the second zero vector is the duration between the w - phase comparison value time and the end time of the half - carrier period.

[0092] As Figure 5 shown, an example shows the waveforms of the triangular carrier, PWM signal, and bus current within a half - carrier period after re - defining the abc phase sequence; where Tu, Tv, and Tw are the uvw - phase comparison values, Tsh is the half - carrier period, the waveforms of the u - phase, v - phase, and w - phase are the waveforms of the PWM signals output to the three - phase bridge arms of the inverter, idc is the bus current, T1 is the duration of the first effective vector, and T2 is the duration of the second effective vector.

[0093] In applications, in the application scenarios of controlling high - power motors, the switching frequency of the inverter is limited, that is, low - switching - frequency control needs to be achieved. In addition, in the field of high - speed motor control, the degree of change in the current phase within a single PWM period is large. Therefore, the equivalent switching frequency within the electrical period of the motor is reduced. In the above two application scenarios, due to the reduction of the switching frequency of the inverter, the harmonic components in the current increase, and the influence of the switching action on the current waveform cannot be ignored.

[0094] As Figure 6 shown, an example shows the schematic diagram of the relationship between the current change and the switching action time (i.e., the uvw - phase comparison value time) within a half - carrier period in the scope of low - switching - frequency control; where Tu, Tv, and Tw are the uvw - phase comparison values, Tsh is the half - carrier period, Tad1 is the current sampling time, and iu is the sampled bus current. Figure 6In this case, the u-phase current can be approximately regarded as a broken-line change within a half-carrier period, and the range of each broken line is the action range of different voltage vectors. The slopes of the current change segments under the action of different voltage vectors are different. Taking the current sampling moment Tad1 between the u-phase comparison value Tu and the v-phase comparison value Tv as an example, assuming that the bus current sampled at this time is equal to the u-phase current iu, it can be known that the sampled current iu at this time will deviate from the sine fundamental wave of the u-phase current at the current sampling moment Tad1, thereby reducing the subsequent current control effect. In addition, since the sampling position is affected by the occurrence moment of the carrier comparison action (i.e., the uvw-phase comparison value moment), and the uvw-phase comparison value continuously changes during the operation of the motor, therefore, the degree of influence of current sampling by harmonics is different during the operation of the motor, increasing the uncertainty of current control.

[0095] As Figure 7 shown, based on the above redefined uvw-phase sequence, the current compensation method provided by the embodiment of the present application further includes the following steps S701 to S704:

[0096] Step S701: Based on the uvw-phase comparison value in the k-th period, obtain the phase current at the v-phase comparison value moment in the k-th period according to the two bus currents sampled respectively within the durations of the first effective vector and the second effective vector in the k-th period.

[0097] In application, according to the single bus current detection technology, based on the uvw-phase sequence, sample the first bus current within the duration of the first effective vector and sample the second bus current within the duration of the second effective vector. On the basis of meeting the sampling required time, the two bus current sampling moments need to be close to the carrier comparison action moment between them, that is, the v-phase comparison value moment. Reconstruct the motor phase current from the first bus current and the second bus current and perform coordinate transformation to obtain the phase current in the two-phase stationary coordinate system as the phase current at the v-phase comparison value moment.

[0098] In one embodiment, step S701 includes:

[0099] Based on the single bus current detection technology, obtain the phase current in the three-phase stationary coordinate system in the k-th period according to the first bus current sampled within the first effective vector in the k-th period and the second bus current sampled within the duration of the second effective vector in the k-th period;

[0100] Perform coordinate transformation on the phase current in the three-phase stationary coordinate system in the k-th period to obtain the phase current in the two-phase stationary coordinate system in the k-th period as the phase current at the v-phase comparison value moment in the k-th period.

[0101] In one embodiment, the calculation formula for the phase current at the v-phase comparison value moment in the k-th period is:

[0102] iα = ia

[0103]

[0104] Wherein, iα and iβ respectively represent the α-axis component and β-axis component of the phase current in the two-phase stationary coordinate system of the k-th period (i.e., the α-axis component and β-axis component of the phase current in the two-phase stationary coordinate system at the v-phase comparison value moment of the k-th period), and ia, ib, and ic represent the phase currents in the three-phase stationary coordinate system of the k-th period.

[0105] Step S702: Obtain the rotor angle at the uvw-phase comparison value moment of the k-th period according to the uvw-phase comparison value of the k-th period, the rotor angle at the current control moment, and the rotor angle at the current control moment of the (k - 1)-th period.

[0106] In application, the rotor angle at the uvw-phase comparison value moment of the k-th period includes the rotor angle at the u-phase comparison value moment, the rotor angle at the v-phase comparison value moment, and the rotor angle at the w-phase comparison value moment, and can be calculated according to the uvw-phase comparison value of the k-th period, the rotor angle at the current control moment of the k-th period, and the rotor angle at the current control moment of the (k - 1)-th period. The meaning of the rotor angle is the angle within the electrical period pointed by the magnetic pole d-axis of the rotor permanent magnet. The rotor angle can be calculated from the induction signals of the angle sensor or speed sensor installed on the motor, or can be deduced by the rotor speed estimation technology based on sensorless.

[0107] In one embodiment, if the k-th period is a falling-edge period, the calculation formula for the rotor angle at the uvw-phase comparison value moment of the k-th period is:

[0108] θu = θ(k) - Tu / Tsh * [θ(k) - θ(k - 1)]

[0109] θv = θ(k) - Tv / Tsh * [θ(k) - θ(k - 1)]

[0110] θw = θ(k) - Tw / Tsh * [θ(k) - θ(k - 1)]

[0111] If the k-th period is a rising-edge period, the calculation formula for the rotor angle at the uvw-phase comparison value moment of the k-th period is:

[0112] θu = θ(k - 1) + Tu / Tsh * [θ(k) - θ(k - 1)]

[0113] θv = θ(k - 1) + Tv / Tsh * [θ(k) - θ(k - 1)]

[0114] θw = θ(k - 1) + Tw / Tsh * [θ(k) - θ(k - 1)]

[0115] Among them, θu, θv, and θw respectively represent the rotor angles at the u-phase comparison value moment, v-phase comparison value moment, and w-phase comparison value moment in the k-th period, θ(k) represents the rotor angle at the current control moment in the k-th period, θ(k - 1) represents the rotor angle at the current control moment in the (k - 1)-th period, Tu, Tv, and Tw respectively represent the u-phase comparison value, v-phase comparison value, and w-phase comparison value in the k-th period, and Tsh represents the half-carrier period.

[0116] As Figure 8 shown, an exemplary timing diagram of the acquisition of the rotor angle, voltage, and current within the half-carrier period is shown; among them, θ(k) represents the rotor angle at the current control moment in the k-th period, θ(k - 1) represents the rotor angle at the current control moment in the (k - 1)-th period, θu, θv, and θw respectively represent the rotor angles at the u-phase comparison value moment, v-phase comparison value moment, and w-phase comparison value moment in the k-th period, iα and iβ respectively represent the α-axis component and β-axis component of the phase current in the two-phase stationary coordinate system in the k-th period, uα(T1) and uβ(T1) respectively represent the α-axis component and β-axis component of the first effective vector in the two-phase stationary coordinate system in the k-th period, and uα(T2) and uβ(T2) respectively represent the α-axis component and β-axis component of the second effective vector in the two-phase stationary coordinate system in the k-th period.

[0117] Step S703: Obtain the second effective vector in the k-th period according to the bus voltage and the abc-phase comparison value in the k-th period.

[0118] In application, in the current delay compensation calculation, it is necessary to obtain the voltage applied to the motor between the bus current sampling moment and the current control moment. As Figure 5 shown, after the bus current sampling moment, it first passes through the duration T2 of the second effective vector, and then passes through the duration T02 of the second zero vector to reach the current control moment. The second effective vector is related to the sector where the target voltage vector is located in the space vector plane, that is, related to the magnitude of the abc-phase comparison value.

[0119] In application, within the scope of SVPWM, the second effective vector can be calculated according to the relationship between the duty ratio of the abc-phase comparison value and the bus voltage. When the bus current sampling moment is in the first half-carrier period (i.e., the falling edge period) and the second half-carrier period (i.e., the rising edge period), the calculation methods of the second effective vector are different.

[0120] In one embodiment, if the k-th period is the falling edge period, the calculation method of the second effective vector is as follows:

[0121] If the numerical values of the abc-phase comparison values are in descending order as a-phase comparison value > b-phase comparison value > c-phase comparison value, the second effective vector is:

[0122]

[0123] If the numerical values of the comparison values of a, b, and c are in descending order as the comparison value of b > the comparison value of a > the comparison value of c, the second effective vector is:

[0124]

[0125] If the numerical values of the comparison values of a, b, and c are in descending order as the comparison value of b > the comparison value of c > the comparison value of a, the second effective vector is:

[0126] uα(T2) = -2*Udc / 3, uβ(T2) = 0;

[0127] If the numerical values of the comparison values of a, b, and c are in descending order as the comparison value of c > the comparison value of b > the comparison value of a, the second effective vector is:

[0128] uα(T2) = -2*Udc / 3, uβ(T2) = 0;

[0129] If the numerical values of the comparison values of a, b, and c are in descending order as the comparison value of c > the comparison value of a > the comparison value of b, the second effective vector is:

[0130]

[0131] If the numerical values of the comparison values of a, b, and c are in descending order as the comparison value of a > the comparison value of c > the comparison value of b, the second effective vector is:

[0132]

[0133] Among them, uα(T2) and uβ(T2) respectively represent the α-axis component and β-axis component of the second effective vector in the two-phase stationary coordinate system of the k-th cycle, and Udc represents the bus voltage of the k-th cycle.

[0134] In one embodiment, if the k-th cycle is a rising-edge cycle, the calculation method of the second effective vector is as follows:

[0135] If the numerical values of the comparison values of a, b, and c are in descending order as the comparison value of a > the comparison value of b > the comparison value of c, the second effective vector is:

[0136] uα(T2) = 2*Udc / 3, uβ(T2) = 0;

[0137] If the numerical values of the comparison values of a, b, and c are in descending order as the comparison value of b > the comparison value of a > the comparison value of c, the second effective vector is:

[0138]

[0139] If the numerical values of the comparison values of a, b, and c are in descending order as the comparison value of b > the comparison value of c > the comparison value of a, the second effective vector is:

[0140]

[0141] If the numerical values of the a, b, and c comparison values are in descending order as c comparison value > b comparison value > a comparison value, the second effective vector is:

[0142]

[0143] If the numerical values of the a, b, and c comparison values are in descending order as c comparison value > a comparison value > b comparison value, the second effective vector is:

[0144]

[0145] If the numerical values of the a, b, and c comparison values are in descending order as a comparison value > c comparison value > b comparison value, the second effective vector is:

[0146] uα(T2) = 2*Udc / 3, uβ(T2) = 0;

[0147] Wherein, uα(T2) and uβ(T2) respectively represent the α-axis component and β-axis component of the second effective vector in the two-phase stationary coordinate system of the k-th period, and Udc represents the bus voltage of the k-th period.

[0148] Step S704: Obtain the phase current at the current control moment of the k-th period according to the duration of the second effective vector of the k-th period, the duration of the second zero vector, the phase current at the v comparison value moment, the second effective vector, and the rotor angle at the uvw comparison value moment.

[0149] In application, based on the permanent magnet machine mathematical model, linearize the action intervals of the second effective vector and the second zero vector, and calculate the current at the current control moment starting from the bus current sampling moment.

[0150] Such as Figure 9 shown, in one embodiment, step S704 includes the following steps S901 to S904:

[0151] Step S901: Obtain the phase current in the synchronous rotating coordinate system at the v comparison value moment of the k-th period according to the phase current in the two-phase stationary coordinate system at the v comparison value moment of the k-th period and the rotor angle at the v comparison value moment.

[0152] In application, calculate the d-axis current id(θv) and q-axis current iq(θv) in the synchronous rotating coordinate system at the v comparison value moment based on the phase current obtained by the bus current sampling technology.

[0153] In one embodiment, the calculation formulas for the phase currents \(i_d(\theta_v)\) and \(i_q(\theta_v)\) in the synchronous rotating coordinate system at the v-phase comparison value moment in the k-th cycle are as follows:

[0154] \(i_d(\theta_v)=i_{\alpha}(T_v)\cos(\theta_v)+i_{\beta}(T_v)\sin(\theta_v)\)

[0155] \(i_q(\theta_v)=i_{\beta}(T_v)\cos(\theta_v)-i_{\alpha}(T_v)\sin(\theta_v)\)

[0156] where \(i_d(\theta_v)\) and \(i_q(\theta_v)\) respectively represent the d-axis component and q-axis component of the phase current in the synchronous rotating coordinate system at the v-phase comparison value moment in the k-th cycle, \(i_{\alpha}(T_v)\) and \(i_{\beta}(T_v)\) respectively represent the α-axis component and β-axis component of the phase current in the two-phase stationary coordinate system at the v-phase comparison value moment in the k-th cycle, and \(\theta_v\) represents the rotor angle at the v-phase comparison value moment in the k-th cycle.

[0157] Step S902: Obtain the second effective vector in the synchronous rotating coordinate system in the k-th cycle according to the second effective vector in the two-phase stationary coordinate system in the k-th cycle and the rotor angle at the vw-phase comparison value moment.

[0158] In application, perform coordinate transformation on the voltage within the action interval of the second effective vector to obtain the d-axis voltage \(u_d(T_2)\) and q-axis voltage \(u_q(T_2)\) in the synchronous rotating coordinate system, where \(\theta_{T_2}\) is the central angle within the duration \(T_2\) of the second effective vector.

[0159] In one embodiment, the calculation formula for the second effective vector in the synchronous rotating coordinate system in the k-th cycle is as follows:

[0160] \(u_d(T_2)=u_{\alpha}(T_2)\cos(\theta_{T_2})+u_{\beta}(T_2)\sin(\theta_{T_2})\)

[0161] \(u_q(T_2)=u_{\beta}(T_2)\cos(\theta_{T_2})-u_{\alpha}(T_2)\sin(\theta_{T_2})\)

[0162] \(\theta_{T_2}=(\theta_v+\theta_w) / 2\)

[0163] where \(u_d(T_2)\) and \(u_q(T_2)\) respectively represent the d-axis component and q-axis component of the second effective vector in the synchronous rotating coordinate system in the k-th cycle, \(u_{\alpha}(T_2)\) and \(u_{\beta}(T_2)\) respectively represent the α-axis component and β-axis component of the second effective vector in the two-phase stationary coordinate system in the k-th cycle, and \(\theta_w\) represents the rotor angle at the w-phase comparison value moment in the k-th cycle.

[0164] Step S903: Obtain the phase current in the synchronous rotating coordinate system at the w-phase comparison value moment of the k-th period based on the duration of the second effective vector in the k-th period, the second effective vector in the synchronous rotating coordinate system, and the phase current in the synchronous rotating coordinate system at the v-phase comparison value moment.

[0165] In applications, according to the motor state equation, calculate the d-axis current id(θw) and q-axis current iq(θw) in the synchronous rotating coordinate system at the w-phase comparison value moment from the sampled currents id(θv) and iq(θv) at the v-phase comparison value moment.

[0166] In one embodiment, the calculation formula for the phase current in the synchronous rotating coordinate system at the w-phase comparison value moment of the k-th period is:

[0167]

[0168]

[0169] where id(θw) and iq(θw) respectively represent the d-axis component and q-axis component of the phase current in the synchronous rotating coordinate system at the w-phase comparison value moment of the k-th period, T2 represents the duration of the second effective vector in the k-th period, Ld and Lq respectively represent the d-axis component and q-axis component of the inductance of the motor in the synchronous rotating coordinate system, R represents the resistance of the motor, ωe represents the electrical angular velocity of the motor, and ψf represents the magnetic flux of the motor.

[0170] Step S904: Obtain the phase current in the synchronous rotating coordinate system at the current control moment of the k-th period based on the duration of the second zero vector in the k-th period and the phase current in the synchronous rotating coordinate system at the w-phase comparison value moment.

[0171] In applications, since the voltage is zero within the zero vector action interval, estimate the current at the current control moment from the current at the bus current sampling moment to achieve the current compensation effect.

[0172] In one embodiment, the calculation formula for the phase current in the synchronous rotating coordinate system at the current control moment of the k-th period is:

[0173]

[0174]

[0175] where id(k) and iq(k) respectively represent the d-axis component and q-axis component of the phase current in the synchronous rotating coordinate system at the current control moment of the k-th period, and T02 represents the duration of the second zero vector in the k-th period.

[0176] Such as Figure 10As shown, in one embodiment, step S704 includes the following steps S1001 to S1004:

[0177] Step S1001, obtaining the phase current in the synchronous rotating coordinate system at the v phase comparison value moment of the kth cycle according to the phase current in the two-phase stationary coordinate system at the v phase comparison value moment of the kth cycle and the rotor angle at the v phase comparison value moment.

[0178] In the application, step S1001 and Figure 9 Step S901 in the corresponding embodiment is the same and will not be repeated here.

[0179] Step S1002: Obtain an average voltage vector in the two-phase stationary coordinate system of the kth period according to the duration of the second effective vector of the kth period, the duration of the second zero vector and the second effective vector in the two-phase stationary coordinate system.

[0180] In the application, the voltage average values ​​uα(avg) and uβ(avg) between the bus current sampling moment and the current control moment are calculated, that is, the average effect of the second effective vector and the second zero vector.

[0181] In one embodiment, the calculation formula of the average voltage vector in the two-phase stationary coordinate system of the kth period is:

[0182] uα(avg)=T2*uα(T2) / (T2+T02)

[0183] uβ(avg)=T2*uβ(T2) / (T2+T02)

[0184] Among them, uα(avg) and uβ(avg) respectively represent the α-axis component and β-axis component of the average voltage vector in the two-phase stationary coordinate system of the kth period, uα(T2) and uβ(T2) respectively represent the α-axis component and β-axis component of the second effective vector in the two-phase stationary coordinate system of the kth period, T2 represents the duration of the second effective vector of the kth period, and T02 represents the duration of the second zero vector of the kth period.

[0185] Step S1003, obtaining the average voltage vector in the synchronous rotating coordinate system of the kth period according to the average voltage vector in the two-phase stationary coordinate system of the kth period, the rotor angle at the v-phase comparison value moment and the rotor angle at the current control moment.

[0186] In the application, the coordinate transformation is performed on the voltage average values ​​uα(avg) and uβ(avg) to obtain the d-axis voltage average value ud(avg) and the q-axis voltage average value uq(avg) in the synchronous rotating coordinate system.

[0187] In one embodiment, the calculation formula for the average voltage vector in the synchronous rotating coordinate system of the k-th period is as follows:

[0188] ud(avg) = uα(avg) * cos(θavg) + uβ(avg) * sin(θavg)

[0189] uq(avg) = uβ(avg) * cos(θavg) - uα(avg) * sin(θavg)

[0190] θavg = [θv + θ(k)] / 2

[0191] where ud(avg) and uq(avg) respectively represent the d-axis component and q-axis component of the average voltage vector in the synchronous rotating coordinate system of the k-th period, and θ(k) represents the rotor angle at the current control moment of the k-th period.

[0192] Step S1004: Obtain the phase current in the synchronous rotating coordinate system at the current control moment of the k-th period according to the phase current in the synchronous rotating coordinate system at the v-phase comparison value moment of the k-th period, the duration of the second effective vector, the duration of the second zero vector, and the average voltage vector in the synchronous rotating coordinate system.

[0193] In application, according to the motor state equation, calculate the d-axis current id(k) and q-axis current iq(k) in the synchronous rotating coordinate system corresponding to the current control moment.

[0194] In one embodiment, the calculation formula for the phase current in the synchronous rotating coordinate system at the current control moment of the k-th period is as follows:

[0195]

[0196]

[0197] where id(k) and iq(k) respectively represent the d-axis component and q-axis component of the phase current in the synchronous rotating coordinate system at the current control moment of the k-th period, Ld and Lq respectively represent the d-axis component and q-axis component of the inductance of the motor in the synchronous rotating coordinate system, R represents the resistance of the motor, ωe represents the electrical angular velocity of the motor, and ψf represents the magnetic flux of the motor.

[0198] In application, Figure 10 What the corresponding embodiment provides is a simplified current compensation method, compared with Figure 9The difference between the corresponding embodiments lies in that in the current delay compensation calculation of S1002, by averaging the voltages in the action intervals of the second effective vector and the second zero vector, the current at the current control moment can be calculated only by solving the motor state equation once, which simplifies the calculation process and thus can effectively improve the current control efficiency of the motor.

[0199] In the application, the k-th period and the (k - 1)-th period are two adjacent half-carrier periods, k is an integer greater than 1, the k-th period can be the current half-carrier period, and correspondingly, the (k - 1)-th period can be the previous half-carrier period.

[0200] The embodiment of the present application also provides a current compensation device, which is applied to a motor controller and is used to execute the steps in the above method embodiment. This device can be a virtual appliance in the motor controller, run by the processor of the motor controller, or the motor controller itself.

[0201] As Figure 11 shown, the current compensation device 100 provided by the embodiment of the present application includes:

[0202] The first-phase current acquisition unit 101 is used to obtain the phase current at the moment of the v-phase comparison value in the k-th period based on the uvw-phase comparison value in the k-th period and two bus currents sampled respectively within the durations of the first effective vector and the second effective vector in the k-th period.

[0203] The rotor angle acquisition unit 102 is used to obtain the rotor angle at the moment of the uvw-phase comparison value in the k-th period according to the uvw-phase comparison value in the k-th period, the rotor angle at the current control moment in the k-th period, and the rotor angle at the current control moment in the (k - 1)-th period.

[0204] The effective vector calculation unit 103 is used to obtain the second effective vector in the k-th period according to the bus voltage and the abc-phase comparison value in the k-th period.

[0205] The second-phase current acquisition unit 104 is used to obtain the phase current at the current control moment in the k-th period according to the duration of the second effective vector in the k-th period, the duration of the second zero vector, the phase current at the moment of the v-phase comparison value, the second effective vector, and the rotor angle at the moment of the uvw-phase comparison value in the k-th period.

[0206] In one embodiment, the current compensation device further includes:

[0207] The comparison value acquisition unit is used to obtain the abc-phase comparison value in the k-th period according to the amplitude and phase angle of the target voltage vector in the k-th period.

[0208] A phase sequence mapping unit, configured to sort the comparison values of the abc phases in the k-th period in descending order of numerical value to obtain the comparison values of the uvw phases in the k-th period;

[0209] A first time acquisition unit, configured to use the duration between the start moment of the k-th period and the moment of the u-phase comparison value as the duration of the first zero vector in the k-th period;

[0210] A second time acquisition unit, configured to use the duration between the moment of the u-phase comparison value and the moment of the v-phase comparison value in the k-th period as the duration of the first effective vector in the k-th period;

[0211] A third time acquisition unit, configured to use the duration between the moment of the v-phase comparison value and the moment of the w-phase comparison value in the k-th period as the duration of the second effective vector in the k-th period;

[0212] A fourth time acquisition unit, configured to use the duration between the moment of the w-phase comparison value and the end moment in the k-th period as the duration of the second zero vector in the k-th period.

[0213] In one embodiment, the first phase current acquisition unit includes:

[0214] A current sampling sub-unit, configured to obtain the phase currents in the three-phase stationary coordinate system in the k-th period based on the single-bus current detection technology according to the first bus current sampled within the first effective vector in the k-th period and the second bus current sampled within the duration of the second effective vector in the k-th period;

[0215] A coordinate transformation sub-unit, configured to perform coordinate transformation on the phase currents in the three-phase stationary coordinate system in the k-th period to obtain the phase currents in the two-phase stationary coordinate system in the k-th period as the phase currents at the moment of the v-phase comparison value in the k-th period.

[0216] In one embodiment, a coordinate transformation unit is configured to calculate the phase currents at the moment of the v-phase comparison value in the k-th period according to the following formula:

[0217] iα = ia

[0218]

[0219] wherein, iα and iβ respectively represent the α-axis component and β-axis component of the phase currents in the two-phase stationary coordinate system in the k-th period (i.e., the α-axis component and β-axis component of the phase currents in the two-phase stationary coordinate system at the moment of the v-phase comparison value in the k-th period), and ia, ib, and ic represent the phase currents in the three-phase stationary coordinate system in the k-th period.

[0220] In one embodiment, the rotor angle acquisition unit is configured to:

[0221] If the k-th period is a falling-edge period, calculate the rotor angle at the uvw comparison value moment of the k-th period according to the following calculation formula:

[0222] θu = θ(k) - Tu / Tsh * [θ(k) - θ(k - 1)]

[0223] θv = θ(k) - Tv / Tsh * [θ(k) - θ(k - 1)]

[0224] θw = θ(k) - Tw / Tsh * [θ(k) - θ(k - 1)]

[0225] If the k-th period is a rising-edge period, calculate the rotor angle at the uvw comparison value moment of the k-th period according to the following calculation formula:

[0226] θu = θ(k - 1) + Tu / Tsh * [θ(k) - θ(k - 1)]

[0227] θv = θ(k - 1) + Tv / Tsh * [θ(k) - θ(k - 1)]

[0228] θw = θ(k - 1) + Tw / Tsh * [θ(k) - θ(k - 1)]

[0229] Among them, θu, θv, and θw respectively represent the rotor angles at the u-phase comparison value moment, v-phase comparison value moment, and w-phase comparison value moment of the k-th period, θ(k) represents the rotor angle at the current control moment of the k-th period, θ(k - 1) represents the rotor angle at the current control moment of the k - 1-th period, Tu, Tv, and Tw respectively represent the u-phase comparison value, v-phase comparison value, and w-phase comparison value of the k-th period, and Tsh represents the half-carrier period.

[0230] In one embodiment, the effective vector calculation unit is used to calculate the second effective vector through the following calculation method:

[0231] If the k-th period is a falling-edge period, the calculation method of the second effective vector is as follows:

[0232] If the numerical order of the abc comparison values is a-phase comparison value > b-phase comparison value > c-phase comparison value, the second effective vector is:

[0233]

[0234] If the numerical order of the abc comparison values is b-phase comparison value > a-phase comparison value > c-phase comparison value, the second effective vector is:

[0235]

[0236] If the numerical order of the abc comparison values is b-phase comparison value > c-phase comparison value > a-phase comparison value, the second effective vector is:

[0237] uα(T2) = -2*Udc / 3, uβ(T2) = 0;

[0238] If the numerical descending order of the comparison values of phases a, b, and c is c-phase comparison value > b-phase comparison value > a-phase comparison value, the second effective vector is:

[0239] uα(T2) = -2*Udc / 3, uβ(T2) = 0;

[0240] If the numerical descending order of the comparison values of phases a, b, and c is c-phase comparison value > a-phase comparison value > b-phase comparison value, the second effective vector is:

[0241]

[0242] If the numerical descending order of the comparison values of phases a, b, and c is a-phase comparison value > c-phase comparison value > b-phase comparison value, the second effective vector is:

[0243]

[0244] Among them, uα(T2) and uβ(T2) respectively represent the α-axis component and β-axis component of the second effective vector in the two-phase stationary coordinate system of the k-th period, and Udc represents the bus voltage of the k-th period.

[0245] In one embodiment, in one embodiment, the effective vector calculation unit is used to calculate the second effective vector through the following calculation method:

[0246] If the k-th period is a rising-edge period, the calculation method of the second effective vector is as follows:

[0247] If the numerical descending order of the comparison values of phases a, b, and c is a-phase comparison value > b-phase comparison value > c-phase comparison value, the second effective vector is:

[0248] uα(T2) = 2*Udc / 3, uβ(T2) = 0;

[0249] If the numerical descending order of the comparison values of phases a, b, and c is b-phase comparison value > a-phase comparison value > c-phase comparison value, the second effective vector is:

[0250]

[0251] If the numerical descending order of the comparison values of phases a, b, and c is b-phase comparison value > c-phase comparison value > a-phase comparison value, the second effective vector is:

[0252]

[0253] If the numerical descending order of the comparison values of phases a, b, and c is c-phase comparison value > b-phase comparison value > a-phase comparison value, the second effective vector is:

[0254]

[0255] If the numerical values of the comparison values of a, b, and c are in descending order as the comparison value of phase c > the comparison value of phase a > the comparison value of phase b, the second effective vector is:

[0256]

[0257] If the numerical values of the comparison values of a, b, and c are in descending order as the comparison value of phase a > the comparison value of phase c > the comparison value of phase b, the second effective vector is:

[0258] uα(T2) = 2*Udc / 3, uβ(T2) = 0;

[0259] Wherein, uα(T2) and uβ(T2) respectively represent the α-axis component and β-axis component of the second effective vector in the two-phase stationary coordinate system at the k-th period, and Udc represents the bus voltage at the k-th period.

[0260] In one embodiment, the second-phase current acquisition unit includes:

[0261] The first current acquisition subunit is configured to obtain the phase current in the synchronous rotating coordinate system at the v-phase comparison value moment of the k-th period according to the phase current in the two-phase stationary coordinate system at the v-phase comparison value moment of the k-th period and the rotor angle at the v-phase comparison value moment;

[0262] The vector acquisition subunit is configured to obtain the second effective vector in the synchronous rotating coordinate system at the k-th period according to the second effective vector in the two-phase stationary coordinate system at the k-th period and the rotor angle at the vw-phase comparison value moment;

[0263] The second current acquisition subunit is configured to obtain the phase current in the synchronous rotating coordinate system at the w-phase comparison value moment of the k-th period according to the duration of the second effective vector at the k-th period, the second effective vector in the synchronous rotating coordinate system, and the phase current in the synchronous rotating coordinate system at the v-phase comparison value moment;

[0264] The third current acquisition subunit is configured to obtain the phase current in the synchronous rotating coordinate system at the current control moment of the k-th period according to the duration of the second zero vector at the k-th period and the phase current in the synchronous rotating coordinate system at the w-phase comparison value moment.

[0265] In one embodiment, the second-phase current acquisition unit includes:

[0266] The first current acquisition subunit is configured to obtain the phase current in the synchronous rotating coordinate system at the v-phase comparison value moment of the k-th period according to the phase current in the two-phase stationary coordinate system at the v-phase comparison value moment of the k-th period and the rotor angle at the v-phase comparison value moment;

[0267] The first vector acquisition subunit is configured to obtain the average voltage vector in the two-phase stationary coordinate system of the k-th period according to the duration of the second effective vector, the duration of the second zero vector, and the second effective vector in the two-phase stationary coordinate system in the k-th period;

[0268] The second vector acquisition subunit is configured to obtain the average voltage vector in the synchronous rotating coordinate system of the k-th period according to the average voltage vector in the two-phase stationary coordinate system of the k-th period, the rotor angle at the v-phase comparison value moment, and the rotor angle at the current control moment;

[0269] The second current acquisition subunit is configured to obtain the phase current in the synchronous rotating coordinate system at the current control moment of the k-th period according to the phase current in the synchronous rotating coordinate system at the v-phase comparison value moment of the k-th period, the duration of the second effective vector, the duration of the second zero vector, and the average voltage vector in the synchronous rotating coordinate system.

[0270] In applications, each component in the above device can be a software program unit, can also be implemented by different logic circuits integrated in the processor or independent physical components connected to the processor, and can also be implemented by multiple distributed processors.

[0271] The current compensation device provided in the embodiment of the present application can obtain the phase current at the current control moment according to the phase current at the current sampling moment obtained based on the current sampling technology, can achieve the current delay compensation effect, and reduce the current control error caused by the bus current sampling error, so as to improve the current control performance, reduce the current harmonics, and can be applicable to the low switching frequency control or high-speed motor control technology field.

[0272] As Figure 12 shown, the embodiment of the present application further provides a motor controller 200, including: at least one processor 201 ( Figure 12 only one processor is shown in the figure), a memory 202, and a computer program 203 stored in the memory 202 and executable on at least one processor 201. When the processor 201 executes the computer program 203, the steps in the above various method embodiments are implemented.

[0273] In applications, the motor controller may include, but is not limited to, a processor and a memory, and may also include Figure 1 the current sensor and inverter shown in the figure, and / or may also include a filter, a PWM driver, an analog-to-digital converter, etc. Those skilled in the art can understand, Figure 12This is only an example of the motor controller and does not constitute a limitation on the motor controller. It may include more or fewer components than those shown in the figure, or combine certain components, or different components. For example, it may also include input / output devices, network access devices, etc. The input / output devices may include the aforementioned human-machine interaction devices and may also include a display screen for displaying the operating parameters of the motor controller. The network access device may include a communication module for communicating between the motor controller and the client.

[0274] In an application, the processor may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0275] In an application, in some embodiments, the memory may be an internal storage unit of the motor controller, such as the hard disk or memory of the motor controller. In other embodiments, the memory may also be an external storage device of the motor controller, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the motor controller. The memory may also include both the internal storage unit and the external storage device of the motor controller. The memory is used to store the operating system, application programs, boot loaders, data, and other programs, such as the program code of computer programs. The memory may also be used to temporarily store the data that has been output or will be output.

[0276] In an application, the display may be a thin film transistor liquid crystal display (TFT-LCD), a liquid crystal display (LCD), an organic electroluminesence display (OLED), a quantum dot light emitting diodes (QLED) display, a seven-segment or eight-segment digital tube, etc.

[0277] In an application, the communication module can be set as any device capable of directly or indirectly performing long-distance wired or wireless communication with a client according to actual needs, so that a user can, by operating the client, use the motor controller to control the working state of a motor, and further control the working states of devices such as air conditioners, fans, and washing machines applied by the motor. The communication module can provide communication solutions applied to network devices, including wireless local area networks (WLANs) (such as Wi-Fi networks), Bluetooth, Zigbee, mobile communication networks, global navigation satellite systems (GNSSs), frequency modulation (FM), near field communication (NFC), infrared technology (IR), etc. The communication module can include an antenna, and the antenna can have only one element or can be an antenna array including multiple elements. The communication module can receive electromagnetic waves through the antenna, perform frequency modulation and filtering processing on the electromagnetic wave signals, and send the processed signals to the processor. The communication module can also receive signals to be sent from the processor, perform frequency modulation and amplification on them, and convert them into electromagnetic waves through the antenna for radiation.

[0278] It should be noted that for the information interaction, execution process, etc. between the above-mentioned devices / modules, since they are based on the same concept as the method embodiment of this application, for their specific functions and the technical effects brought, reference can be specifically made to the method embodiment part, and details will not be elaborated here.

[0279] Those skilled in the art can clearly understand that, for the sake of convenience and simplicity of description, only the above division of each functional module is used for illustration. In actual applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. Each functional module in the embodiment can be integrated into a processing module, or each module can exist physically alone, or two or more modules can be integrated into one module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. In addition, the specific names of each functional module are only for the convenience of mutual distinction and do not limit the protection scope of this application. The specific working process of the modules in the above system can refer to the corresponding process in the foregoing method embodiment, and details will not be elaborated here.

[0280] The embodiments of the present application also provide a computer-readable storage medium. A computer program is stored in the computer-readable storage medium. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0281] The embodiments of the present application provide a computer program product. When the computer program product runs on a motor controller, the motor controller can implement the steps in the above-mentioned method embodiments.

[0282] If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, to implement all or part of the processes in the above-mentioned method embodiments of the present application, a computer program can be used to instruct relevant hardware to complete. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable medium can at least include: any entity or device that can carry the computer program code to the motor controller, recording medium, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal, and software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disc, etc.

[0283] In the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0284] Those of ordinary skill in the art can realize that the modules and algorithm steps of the examples described in combination with the embodiments disclosed in this document can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0285] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or modules can be in electrical, mechanical or other forms.

[0286] The modules described as separate components may or may not be physically separated. The components shown as modules may or may not be physical modules, that is, they can be located in one place or distributed to multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0287] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A current compensation method, characterized in that Including: Based on the uvw comparison value in the k-th period, obtain the phase current at the v-phase comparison value moment in the k-th period according to two busbar currents sampled respectively during the durations of the first effective vector and the second effective vector in the k-th period. The uvw comparison value is obtained by arranging the abc comparison values in descending order of magnitude; Obtain the rotor angle at the uvw comparison value moment in the k-th period according to the uvw comparison value in the k-th period, the rotor angle at the current control moment in the k-th period, and the rotor angle at the current control moment in the (k - 1)-th period; Obtain the second effective vector in the k-th period according to the busbar voltage and the abc comparison value in the k-th period; Obtain the phase current at the current control moment in the k-th period according to the duration of the second effective vector in the k-th period, the duration of the second zero vector, the phase current at the v-phase comparison value moment, the second effective vector, and the rotor angle at the uvw comparison value moment in the k-th period; Wherein, the k-th period and the (k - 1)-th period are two adjacent half-carrier periods, and k is an integer greater than 1.

2. The current compensation method according to claim 1, wherein If the k-th period is a falling-edge period, the calculation formula for the rotor angle at the uvw comparison value moment in the k-th period is: θu = θ(k) - Tu / Tsh * [θ(k) - θ(k - 1)] θv = θ(k) - Tv / Tsh * [θ(k) - θ(k - 1)] θw = θ(k) - Tw / Tsh * [θ(k) - θ(k - 1)] If the k-th period is a rising-edge period, the calculation formula for the rotor angle at the uvw comparison value moment in the k-th period is: θu = θ(k - 1) + Tu / Tsh * [θ(k) - θ(k - 1)] θv = θ(k - 1) + Tv / Tsh * [θ(k) - θ(k - 1)] θw = θ(k - 1) + Tw / Tsh * [θ(k) - θ(k - 1)] Wherein, θu, θv, and θw respectively represent the rotor angles at the u-phase comparison value moment, the v-phase comparison value moment, and the w-phase comparison value moment in the k-th period, θ(k) represents the rotor angle at the current control moment in the k-th period, θ(k - 1) represents the rotor angle at the current control moment in the (k - 1)-th period, Tu, Tv, and Tw respectively represent the u-phase comparison value, the v-phase comparison value, and the w-phase comparison value in the k-th period, and Tsh represents the half-carrier period.

3. The current compensation method according to claim 1, characterized in that The obtaining of the phase current at the current control moment in the k-th period according to the duration of the second effective vector in the k-th period, the duration of the second zero vector, the phase current, the second effective vector, and the rotor angle at the uvw comparison value moment in the k-th period includes: Obtain the phase current in the synchronous rotating coordinate system at the v-phase comparison value moment in the k-th period according to the phase current in the two-phase stationary coordinate system at the v-phase comparison value moment in the k-th period and the rotor angle at the v-phase comparison value moment; Obtain the second effective vector in the synchronous rotating coordinate system in the k-th period according to the second effective vector in the two-phase stationary coordinate system in the k-th period and the rotor angle at the vw comparison value moment; Obtain the phase current in the synchronous rotating coordinate system at the w - phase comparison value moment of the k - th period based on the duration of the second effective vector in the k - th period, the second effective vector in the synchronous rotating coordinate system, and the phase current in the synchronous rotating coordinate system at the v - phase comparison value moment; Obtain the phase current in the synchronous rotating coordinate system at the current control moment of the k - th period based on the duration of the second zero vector in the k - th period and the phase current in the synchronous rotating coordinate system at the w - phase comparison value moment.

4. The current compensation method according to claim 3, characterized in that, The calculation formula for the phase current in the synchronous rotating coordinate system at the v - phase comparison value moment of the k - th period is: id(θv) = iα(Tv) * cos(θv) + iβ(Tv) * sin(θv) iq(θv) = iβ(Tv) * cos(θv) - iα(Tv) * sin(θv) The calculation formula for the second effective vector in the synchronous rotating coordinate system of the k - th period is: ud(T2) = uα(T2) * cos(θT2) + uβ(T2) * sin(θT2) uq(T2) = uβ(T2) * cos(θT2) - uα(T2) * sin(θT2) θT2 = (θv + θw) / 2 The calculation formula for the phase current in the synchronous rotating coordinate system at the w - phase comparison value moment of the k - th period is: The calculation formula for the phase current in the synchronous rotating coordinate system at the current control moment of the k - th period is: Where, id(θv) and iq(θv) respectively represent the d - axis component and q - axis component of the phase current in the synchronous rotating coordinate system at the v - phase comparison value moment of the k - th period, iα(Tv) and iβ(Tv) respectively represent the α - axis component and β - axis component of the phase current in the two - phase stationary coordinate system at the v - phase comparison value moment of the k - th period, and θv represents the rotor angle at the v - phase comparison value moment of the k - th period; ud(T2) and uq(T2) respectively represent the d - axis component and q - axis component of the second effective vector in the synchronous rotating coordinate system of the k - th period, uα(T2) and uβ(T2) respectively represent the α - axis component and β - axis component of the second effective vector in the two - phase stationary coordinate system of the k - th period, and θw represents the rotor angle at the w - phase comparison value moment of the k - th period; id(θw) and iq(θw) respectively represent the d - axis component and q - axis component of the phase current in the synchronous rotating coordinate system at the w - phase comparison value moment of the k - th period, T2 represents the duration of the second effective vector in the k - th period, Ld and Lq respectively represent the d - axis component and q - axis component of the inductance of the motor in the synchronous rotating coordinate system, R represents the resistance of the motor, ωe represents the electrical angular velocity of the motor, and ψf represents the magnetic flux of the motor; id(k) and iq(k) respectively represent the d - axis component and q - axis component of the phase current in the synchronous rotating coordinate system at the current control moment of the k - th period, and T02 represents the duration of the second zero vector in the k - th period.

5. The current compensation method according to claim 1, characterized in that, The obtaining of the phase current at the current control moment of the k - th period based on the duration of the second effective vector, the duration of the second zero vector, the phase current, the second effective vector, and the rotor angle at the uvw - phase comparison value moment of the k - th period includes: Obtain the phase current in the synchronous rotating coordinate system at the v-phase comparison value moment of the k-th period based on the phase current in the two-phase stationary coordinate system at the v-phase comparison value moment of the k-th period and the rotor angle at the v-phase comparison value moment. Obtain the average voltage vector in the two-phase stationary coordinate system of the k-th period based on the duration of the second effective vector, the duration of the second zero vector, and the second effective vector in the two-phase stationary coordinate system of the k-th period. Obtain the average voltage vector in the synchronous rotating coordinate system of the k-th period based on the average voltage vector in the two-phase stationary coordinate system of the k-th period, the rotor angle at the v-phase comparison value moment, and the rotor angle at the current control moment. Obtain the phase current in the synchronous rotating coordinate system at the current control moment of the k-th period based on the phase current in the synchronous rotating coordinate system at the v-phase comparison value moment of the k-th period, the duration of the second effective vector, the duration of the second zero vector, and the average voltage vector in the synchronous rotating coordinate system.

6. The current compensation method according to claim 5, characterized in that The calculation formula for the phase current in the synchronous rotating coordinate system at the v-phase comparison value moment of the k-th period is: id(θv) = iα(Tv) * cos(θv) + iβ(Tv) * sin(θv) iq(θv) = iβ(Tv) * cos(θv) - iα(Tv) * sin(θv) The calculation formula for the average voltage vector in the two-phase stationary coordinate system of the k-th period is: uα(avg) = T2 * uα(T2) / (T2 + T02) uβ(avg) = T2 * uβ(T2) / (T2 + T02) The calculation formula for the average voltage vector in the synchronous rotating coordinate system of the k-th period is: ud(avg) = uα(avg) * cos(θavg) + uβ(avg) * sin(θavg) uq(avg) = uβ(avg) * cos(θavg) - uα(avg) * sin(θavg) θavg = [θv + θ(k)] / 2 The calculation formula for the phase current in the synchronous rotating coordinate system at the current control moment of the k-th period is: Wherein, id(θv) and iq(θv) respectively represent the d-axis component and q-axis component of the phase current in the synchronous rotating coordinate system at the v-phase comparison value moment of the k-th period, iα(Tv) and iβ(Tv) respectively represent the α-axis component and β-axis component of the phase current in the two-phase stationary coordinate system at the v-phase comparison value moment of the k-th period, and θv represents the rotor angle at the v-phase comparison value moment of the k-th period; uα(avg) and uβ(avg) respectively represent the α-axis component and β-axis component of the average voltage vector in the two-phase stationary coordinate system of the k-th period, uα(T2) and uβ(T2) respectively represent the α-axis component and β-axis component of the second effective vector in the two-phase stationary coordinate system of the k-th period, T2 represents the duration of the second effective vector of the k-th period, and T02 represents the duration of the second zero vector of the k-th period; ud(avg) and uq(avg) respectively represent the d-axis component and q-axis component of the average voltage vector in the synchronous rotating coordinate system of the k-th period, and θ(k) represents the rotor angle at the current control moment of the k-th period; id(k) and iq(k) respectively represent the d-axis component and q-axis component of the phase current in the synchronous rotating coordinate system at the current control moment of the k-th period. Ld and Lq respectively represent the d-axis component and q-axis component of the inductance of the motor in the synchronous rotating coordinate system. R represents the resistance of the motor. ωe represents the electrical angular velocity of the motor. ψf represents the magnetic flux of the motor.

7. The current compensation method according to any one of claims 1 to 6, characterized in that Before obtaining the phase current at the v-phase comparison value moment of the k-th period based on the uvw-phase comparison value of the k-th period and two bus currents sampled respectively during the durations of the first effective vector and the second effective vector of the k-th period, it includes: Obtaining the abc-phase comparison value of the k-th period according to the amplitude and phase angle of the target voltage vector of the k-th period; Sorting the abc-phase comparison values of the k-th period in descending order of values to obtain the uvw-phase comparison value of the k-th period.

8. A current compensation device, characterized in that, It includes: A first phase current acquisition unit, configured to obtain the phase current at the v-phase comparison value moment of the k-th period based on the uvw-phase comparison value of the k-th period and two bus currents sampled respectively during the durations of the first effective vector and the second effective vector of the k-th period, where the uvw-phase comparison value is obtained by sorting the abc-phase comparison values in descending order of values; A rotor angle acquisition unit, configured to obtain the rotor angle at the uvw-phase comparison value moment of the k-th period according to the uvw-phase comparison value of the k-th period, the rotor angle at the current control moment of the k-th period, and the rotor angle at the current control moment of the (k - 1)-th period; An effective vector calculation unit, configured to obtain the second effective vector of the k-th period according to the bus voltage of the k-th period and the abc-phase comparison value; A second phase current acquisition unit, configured to obtain the phase current at the current control moment of the k-th period according to the duration of the second effective vector of the k-th period, the duration of the second zero vector, the phase current at the v-phase comparison value moment, the second effective vector, and the rotor angle at the uvw-phase comparison value moment of the k-th period; Wherein, the k-th period and the (k - 1)-th period are two adjacent half-carrier periods, and k is an integer greater than 1.

9. A motor controller, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the current compensation method according to any one of claims 1 to 7.

10. A computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the steps of the current compensation method according to any one of claims 1 to 7.

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