CN114142779B

CN114142779B - Phase current reconstruction method and device for single-resistance sampling permanent magnet synchronous motor

Info

Publication number: CN114142779B
Application number: CN202111460641.1A
Authority: CN
Inventors: 陈兰兰; 王玉石; 王颜章; 罗鹏
Original assignee: Gree Electric Appliances Inc of Zhuhai; Zhuhai Kaibang Motor Manufacture Co Ltd
Current assignee: Gree Electric Appliances Inc of Zhuhai; Zhuhai Kaibang Motor Manufacture Co Ltd
Priority date: 2021-12-02
Filing date: 2021-12-02
Publication date: 2023-10-10
Anticipated expiration: 2041-12-02
Also published as: CN114142779A

Abstract

The application relates to a phase current reconstruction method and device for a single-resistance sampling permanent magnet synchronous motor. The method comprises the following steps: acquiring a PWM signal to be sampled in a period to be sampled; determining a first phase current for sampling of the PWM signal to be sampled; determining a target insertion vector for inserting the PWM signal to be sampled under the condition that a target effective vector for sampling the first phase current does not exist in the PWM signal to be sampled or the continuous acting duration of the target effective vector is smaller than the minimum sampling duration, wherein the target insertion vector is consistent with the target effective vector; and inserting the target insertion vector into the PWM signal to be sampled according to the minimum sampling duration to obtain the reconstructed PWM signal. The method provided by the embodiment of the application can solve the problem of electromagnetic noise caused by the fact that the minimum sampling duration is ensured by carrying out phase shifting on the PWM signal.

Description

Phase current reconstruction method and device for single-resistance sampling permanent magnet synchronous motor

Technical Field

The application relates to the field of electromechanical control, in particular to a phase current reconstruction method and device for a single-resistance sampling permanent magnet synchronous motor.

Background

In the related art, since the single-resistance sampling circuit has the advantages of simple structure and low control cost, most of the current schemes still adopt a single-resistance sampling mode, but the following reasons are based:

1. dead time is usually set for preventing the upper bridge arm and the lower bridge arm of the inverter bridge from being directly connected;

2. the sampling and conversion of the chip AD require a certain time; the method comprises the following steps: the current acquisition process of the chip AD requires a certain time, and the time is required to be ensured to be larger than a minimum sampling time window, otherwise, the accuracy of sampling cannot be ensured;

3. the establishment of the direct-side current takes time.

Single resistance sampling therefore typically has a minimum sampling time window limit to ensure sampling accuracy, and the effective vector time is typically not as long as the minimum sampling time width is reached when the motor is at low speed or commutating

In the related art, a minimum sampling period is ensured by shifting the phase of each phase (i.e., U-phase, V-phase, and W-phase) sub-signal of the PWM signal, but this method causes electromagnetic noise to occur.

Aiming at the technical problems that the minimum sampling time length is ensured through phase shifting and electromagnetic noise is caused in the related technology, no effective solution is provided at present.

Disclosure of Invention

In order to solve the technical problem that electromagnetic noise can occur due to the fact that the minimum sampling time length is ensured through phase shifting, the application provides a phase current reconstruction method and device of a single-resistance sampling permanent magnet synchronous motor.

In a first aspect, an embodiment of the present application provides a phase current reconstruction method for a single-resistance sampling permanent magnet synchronous motor, including:

acquiring a PWM signal to be sampled in a period to be sampled;

determining a first phase current for sampling of the PWM signal to be sampled;

determining a target insertion vector for inserting the PWM signal to be sampled under the condition that a target effective vector for sampling the first phase current does not exist in the PWM signal to be sampled or the continuous acting time of the target effective vector is smaller than the minimum sampling time, wherein the target insertion vector is consistent with the target effective vector;

and inserting the target insertion vector into the PWM signal to be sampled according to the minimum sampling duration to obtain a reconstructed PWM signal.

Optionally, in the foregoing method, the inserting the target insertion vector into the PWM signal to be sampled according to the minimum sampling duration to obtain a reconstructed PWM signal includes:

determining a target action duration greater than or equal to the minimum sampling duration;

inserting the target insertion vector of the target acting duration into the PWM signal to be sampled to obtain an inserted PWM signal;

determining an adjusted acting time length corresponding to each remaining effective vector in the inserted PWM signal according to the target insertion vector of the target acting time length, wherein the remaining effective vectors are effective vectors except for the target insertion vector in the inserted PWM signal;

and obtaining the reconstructed PWM signal according to the inserted PWM signal and the adjusted acting time length corresponding to each residual effective vector.

Optionally, in the foregoing method, inserting the target insertion vector of the target acting duration into the PWM signal to be sampled to obtain an inserted PWM signal, including:

determining the middle time of the period to be sampled;

and inserting the target insertion vector of the target action duration into the PWM signal to be sampled according to the intermediate moment to obtain the inserted PWM signal, wherein in the first half period of the inserted PWM signal, the target insertion vector continuously acts for half the target action duration, and in the second half period of the inserted PWM signal, the target insertion vector continuously acts for the other half of the target action duration.

Optionally, in the foregoing method, the determining, according to the target insertion vector of the target acting duration, an adjusted acting duration corresponding to each remaining effective vector in the post-insertion PWM signal includes:

determining each candidate effective vector in the PWM signal to be sampled and candidate action duration corresponding to each candidate effective vector;

determining a target synthetic voltage vector of the PWM signal to be sampled based on candidate action time length corresponding to each candidate effective vector;

determining a sub-voltage vector according to the difference between the target synthesized voltage vector and the target insertion vector of the target acting time;

and determining the adjusted acting time length corresponding to each residual effective vector when the sub-voltage vectors are obtained according to the synthesis of each residual effective vector.

Optionally, in the foregoing method, the obtaining the reconstructed PWM signal according to the inserted PWM signal and the adjusted acting time period corresponding to each remaining effective vector includes:

and after the following steps are carried out on each residual effective vector traversal, the reconstructed PWM signal is obtained:

and adjusting the first half period action duration corresponding to the residual effective vector to be half of the adjusted action duration corresponding to the residual effective vector, and adjusting the second half period action duration corresponding to the residual effective vector to be half of the adjusted action duration corresponding to the residual effective vector.

Optionally, in the foregoing method, after the inserting the target insertion vector into the PWM signal to be sampled according to the minimum sampling duration, the method further includes:

and current sampling is carried out within the target action time length of the target insertion vector, and a first current value of the first phase current corresponding to the target insertion vector is obtained, wherein the target action time length is greater than or equal to the minimum sampling time length.

Optionally, in the foregoing method, after performing current sampling in the target acting duration of the target insertion vector and obtaining a first current value of a first phase current corresponding to the target insertion vector, the method further includes:

obtaining a second current value of a second phase current obtained by last measurement, wherein the second phase current is different from the first phase current;

and calculating a third current value of a third phase current according to the first current value and the second current value, wherein the third phase current is different from the second phase current and the first phase current.

In a second aspect, an embodiment of the present application provides a phase current reconstruction device for a single-resistance sampling permanent magnet synchronous motor, including:

the acquisition module is used for acquiring a PWM signal to be sampled in a period to be sampled;

a first determining module, configured to determine a first phase current used for sampling by the PWM signal to be sampled;

a second determining module, configured to determine a target insertion vector for inserting the PWM signal to be sampled, where the target insertion vector is consistent with the target effective vector, when the target effective vector for sampling the first phase current does not exist in the PWM signal to be sampled, or a continuous acting duration of the target effective vector is less than a minimum sampling duration;

and the reconstruction module is used for inserting the target insertion vector into the PWM signal to be sampled according to the minimum sampling time length to obtain a reconstructed PWM signal.

In a third aspect, an embodiment of the present application provides an electronic device, including: the device comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are communicated with each other through the communication bus;

the memory is used for storing a computer program;

the processor is configured to implement a method as claimed in any one of the preceding claims when executing the computer program.

In a fourth aspect, an embodiment of the present application provides a computer readable storage medium, the storage medium comprising a stored program, wherein the program when run performs a method according to any one of the preceding claims.

Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:

according to the method provided by the embodiment of the application, the target insertion vector is inserted into the PWM signal to be sampled according to the minimum sampling time length, so that the obtained reconstructed PWM signal is enabled to be identical to the target effective vector for sampling to obtain the first phase current, the reconstructed PWM signal can be enabled to be used for sampling to obtain the first phase current, and the problem of electromagnetic noise caused by the fact that the minimum sampling time length is ensured by phase shifting of the PWM signal can be solved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application.

In order to more clearly illustrate the embodiments of the application or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, and it will be obvious to a person skilled in the art that other drawings can be obtained from these drawings without inventive effort.

Fig. 1 is a schematic flow chart of a phase current reconstruction method of a single-resistance sampling permanent magnet synchronous motor provided by an embodiment of the application;

fig. 2 is a schematic flow chart of a phase current reconstruction method for a single-resistance sampling permanent magnet synchronous motor according to another embodiment of the present application;

fig. 3 is a schematic flow chart of a phase current reconstruction method of a single-resistance sampling permanent magnet synchronous motor according to another embodiment of the present application;

fig. 4 is a schematic flow chart of a phase current reconstruction method of a single-resistance sampling permanent magnet synchronous motor according to another embodiment of the present application;

fig. 5 is a schematic diagram of a PWM signal of a sector switching area according to an embodiment of the present application;

FIG. 6 is a schematic diagram of a phase current reconstruction method of a single-resistance sampling permanent magnet synchronous motor for the PWM signal shown in FIG. 5 according to the present application;

fig. 7 is a schematic diagram of a PWM signal in a low modulation region according to an embodiment of the present application;

FIG. 8 is a schematic diagram of a phase current reconstruction method of a single-resistance sampling permanent magnet synchronous motor according to the present application for PWM signals shown in FIG. 7;

FIG. 9 is a schematic diagram of another method for reconstructing phase current of a single-resistance sampling permanent magnet synchronous motor according to the present application for the PWM signal shown in FIG. 7;

fig. 10 is a block diagram of a phase current reconstruction device for a single-resistance sampling permanent magnet synchronous motor according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

According to one aspect of the embodiment of the application, a phase current reconstruction method of a single-resistance sampling permanent magnet synchronous motor is provided. Alternatively, in the present embodiment, the above-described phase current reconstruction method for a single-resistance sampling permanent magnet synchronous motor may be applied to a hardware environment constituted by a terminal and a server. The server is connected with the terminal through a network, and can be used for providing services (such as data processing services, data storage services and the like) for the terminal or the client installed on the terminal, and a database can be arranged on the server or independent of the server and used for providing data storage services for the server.

The network may include, but is not limited to, at least one of: wired network, wireless network. The wired network may include, but is not limited to, at least one of: a wide area network, a metropolitan area network, a local area network, and the wireless network may include, but is not limited to, at least one of: WIFI (Wireless Fidelity ), bluetooth. The terminal may not be limited to a PC, a mobile phone, a tablet computer, or the like.

The phase current reconstruction method of the single-resistance sampling permanent magnet synchronous motor can be executed by a server, a terminal or both. The method for reconstructing the phase current of the single-resistance sampling permanent magnet synchronous motor by the terminal can also be executed by a client mounted on the terminal.

Taking the method of reconstructing the phase current of the single-resistance sampling permanent magnet synchronous motor in the embodiment as an example, fig. 1 is a schematic flow chart of the method of reconstructing the phase current of the single-resistance sampling permanent magnet synchronous motor according to the embodiment of the present application, which includes the following steps:

step S101, obtaining a PWM signal to be sampled in a period to be sampled.

In a single resistance sampling circuit, the PWM signal to be sampled for each period can be obtained, where T0 is the active time of the inactive vector (000, or 111) in the figure as shown in fig. 5, and the rest of the time is complemented by the zero vector except for the non-zero vector active time during one T time (i.e., the total duration of one period).

The PWM signal to be sampled may be a PWM signal for collecting a certain phase current.

Step S102, determining a first phase current for sampling the PWM signal to be sampled.

After the PWM signal is obtained, the first phase current used for sampling by the PWM signal to be sampled may be determined, for example, when the PWM signal to be sampled includes an effective vector for sampling the first phase current, and a continuous acting duration of the effective vector reaches a minimum sampling duration, sampling the first phase current according to the effective vector of the continuous acting duration. Further, when the PWM signal sequentially includes a U-phase signal, a V-phase signal, and a W-phase signal, and the U-phase signal, the V-phase signal, and the W-phase signal in the effective vector I are respectively 0,1, then the PWM signal can be used to collect the U-phase current; the U-phase signal, the V-phase signal and the W-phase signal in the effective vector II are respectively 1,0 and 1, so that the method can be used for collecting V-phase current; the U-phase signal, the V-phase signal and the W-phase signal in the effective vector III are respectively 1,1 and 0, and can be used for collecting W-phase current.

Step S103, determining a target insertion vector for inserting the PWM signal to be sampled under the condition that no target effective vector for sampling the first phase current exists in the PWM signal to be sampled or the continuous acting time of the target effective vector is smaller than the minimum sampling time, wherein the target insertion vector is consistent with the target effective vector.

Because the single-resistor sampling is usually limited by a minimum sampling time window to ensure sampling accuracy, if there is no target effective vector for sampling the first phase current in the PWM signal to be sampled, or if the continuous duration of the target effective vector is less than the minimum sampling duration, the first phase current cannot be acquired based on the effective vector in the PWM signal to be sampled. It is necessary to construct a target insertion vector that can be used for the first phase current acquisition.

And, the target insertion vector may be a vector determined according to the target effective vector of the first phase current and the minimum sampling duration, and the target insertion vector may be an effective vector existing in the PWM signal to be sampled, or may be an effective vector not existing in the PWM signal to be sampled, for example, the acting duration of the target insertion vector is consistent with the minimum sampling duration, and the target insertion vector is consistent with the target effective vector, that is, when the target effective vector is (0, 1) and the minimum sampling duration is Tmin, the target insertion vector is (0, 1) and the acting duration of the target insertion vector is Tmin.

Step S104, inserting the target insertion vector into the PWM signal to be sampled according to the minimum sampling duration to obtain the reconstructed PWM signal.

After the minimum sampling duration, the target insertion vector and the PWM signal to be sampled are obtained, at least the target insertion vector with the minimum sampling duration can be inserted into the PWM signal to be sampled, so that the target insertion vector with the action duration meeting the minimum sampling duration is constructed in the PWM signal to be sampled, and the first phase current corresponding to the target effective vector can be acquired within the action duration.

By inserting the target insertion vector into the PWM signal to be sampled according to the minimum sampling duration, the method in this embodiment may enable the obtained reconstructed PWM signal to have the same target insertion vector as the target effective vector used for sampling to obtain the first phase current, so that the reconstructed PWM signal may be used for sampling to obtain the first phase current, and further the problem of electromagnetic noise caused by ensuring the minimum sampling duration by phase shifting the PWM signal may be overcome.

As shown in fig. 2, as an alternative embodiment, the step S104 of inserting the target insertion vector into the PWM signal to be sampled according to the minimum sampling duration to obtain the reconstructed PWM signal according to the method described above includes the following steps:

step S201, determining a target acting duration greater than or equal to the minimum sampling duration.

After determining the minimum sampling time length, the minimum sampling time window meeting current sampling can be determined, and further, the action time length of the PWM signal to be sampled needs to be greater than or equal to the minimum sampling time length, so that the sampling process of the sampling chip on the phase current can meet the minimum sampling time window, otherwise, the accuracy of phase current sampling cannot be ensured. For example, in the case where the minimum sampling period is Tmin, the target action period Tg. Gtoreq.Tmin.

Step S202, inserting a target insertion vector of a target action duration into the PWM signal to be sampled to obtain an inserted PWM signal.

After determining the target action duration, a target insertion vector with continuous action duration being the target action duration can be inserted into the PWM signal to be sampled, so as to obtain an inserted PWM signal.

Alternatively, a phase (i.e., U-phase, V-phase, or W-phase) corresponding to a low level in the target insertion vector may be determined, and then a high level signal of the target duration of action in the signal of the phase may be modified to a low level signal of the target duration of action, to obtain the post-insertion PWM signal.

For example, when it is desired to detect a U-phase current, the target insertion vector 011 may be inserted into the inactive vector 111 (in turn: U-phase signal, V-phase signal, and W-phase signal), the insertion active vector of the target insertion vector 011 being to set the middle high level of PWM of the U-phase to a low level, and the time to set 0 being the target active period (e.g., the minimum time Tmin required for sampling). Thereby inserting a valid vector 011 whose time is the target duration of action. And then the inserted PWM signal is obtained.

Step S203, determining an adjusted active duration corresponding to each remaining active vector in the post-insertion PWM signal according to the target insertion vector of the target active duration, where the remaining active vectors are active vectors in the post-insertion PWM signal other than the target insertion vector.

Under the condition that the total composite voltage vector is unchanged, the adjusted acting time length corresponding to each residual effective vector in the inserted PWM signal can be determined based on the target insertion vector of the target acting time length.

Alternatively, for the post-insertion PWM signal, the remaining active vectors may correspond to one or more identical active vectors except for the target insertion vector, e.g., active vector 011 in the first half-cycle and active vector 011 in the second half-cycle of a normal PWM signal each correspond to the remaining active vector 011.

Step S204, obtaining a reconstructed PWM signal according to the inserted PWM signal and the adjusted acting time length corresponding to each residual effective vector.

Because the inserted PWM signal is a PWM signal after inserting the target insertion vector of the target action duration, after determining the adjusted action duration corresponding to each remaining effective vector, the action duration of each effective vector can be obtained, and further the reconstructed PWM signal can be obtained.

By the method in the embodiment, the target insertion vector can be inserted into the PWM signal to be sampled according to the minimum sampling time length to obtain the reconstructed PWM signal, so that the first phase current can be acquired with enough sampling time length in the later period.

As shown in fig. 3, as an alternative embodiment, the step S202 of inserting the target insertion vector of the target duration into the PWM signal to be sampled to obtain the post-insertion PWM signal, as the aforementioned method, includes the following steps:

step S301, determining an intermediate time of the period to be sampled.

Step S302, inserting a target insertion vector of a target action duration into the PWM signal to be sampled according to the intermediate moment to obtain an inserted PWM signal, wherein in the first half period of the inserted PWM signal, the target insertion vector continuously acts for half of the target action duration, and in the second half period of the inserted PWM signal, the target insertion vector continuously acts for the other half of the target action duration.

After the period to be sampled is determined, the intermediate time of the period to be sampled can be determined.

After the intermediate moment is determined, a target insertion vector of a target action duration is inserted into the PWM signal to be sampled according to the intermediate moment, an inserted PWM signal is obtained, in the inserted PWM signal, in the first half period of the inserted PWM signal, the target insertion vector continuously acts for half of the target action duration, and in the second half period of the inserted PWM signal, the target insertion vector continuously acts for the other half of the target action duration. Thus, in the post-insertion PWM signal, the signal of the target insertion vector within the target action period is symmetrical with respect to the intermediate timing. Since the PWM signal to be sampled is itself a signal symmetrical about the middle time, the inserted PWM signal is also a signal symmetrical about the middle time.

By the method in the embodiment, the signals symmetrical about the middle moment can be obtained, and then a basis can be provided for obtaining symmetrical reconstructed PWM signals in the later period.

As shown in fig. 4, as an alternative embodiment, the step S203 determines the adjusted active duration corresponding to each remaining active vector in the post-inserted PWM signal according to the target insertion vector of the target active duration, including the steps of:

step S401, determining each candidate effective vector in the PWM signal to be sampled and a candidate acting time length corresponding to each candidate effective vector.

After obtaining the PWM signal to be sampled, each candidate effective vector and a candidate action duration corresponding to each candidate effective vector may be determined.

The candidate active vector may be an active vector (any of 001, 010, 011, 100, 101, 110) in the PWM signal to be sampled.

The candidate acting duration is information which is uniquely corresponding to each candidate effective vector and is used for indicating the duration of the corresponding candidate effective vector in the PWM signal to be sampled. For example, the candidate active duration of the active vector 011 is T2.

Step S402, determining a target synthetic voltage vector of the PWM signal to be sampled based on the candidate action time length corresponding to each candidate effective vector.

After the candidate action duration corresponding to each candidate effective vector is determined, the sub-vectors obtained by the candidate effective vectors and the candidate action duration corresponding to each other can be calculated according to a PWM voltage vector sum calculation method, and then vector sum calculation is carried out on each sub-vector to determine the target synthesized voltage vector.

Step S403, determining a sub-voltage vector according to the difference between the target synthesized voltage vector and the target insertion vector of the target acting time.

After determining the target insertion vector for the target duration of action, a score vector A may be obtained based on an integration of the target duration of action and the target insertion vector; and then, carrying out difference calculation on the target synthesized voltage vector and the sub-vector A to obtain a sub-voltage vector.

Step S404, determining the adjusted acting time length corresponding to each residual effective vector when synthesizing the sub-voltage vectors according to each residual effective vector.

After all the remaining effective vectors and the sub-voltage vectors are determined, the adjusted acting time length corresponding to each remaining effective vector can be determined according to a vector synthesis method under the condition that the sub-voltage vector is obtained.

For example, in the sector switching area, as shown in fig. 5, the candidate active duration of the candidate active vector 011 in the PWM signal to be sampled is T2, and the candidate active duration of the candidate active vector 001 in the PWM signal to be sampled is T1; the candidate effective vector 011 performs bus sampling at the time of each action T2/2 in the front and rear half cycles of the PWM signal, and the single resistance sampling is usually performed at the middle time of the action of the effective vector, because T2/2 is smaller than the minimum time Tmin required for sampling, in order to satisfy the minimum sampling time window, a target insertion vector 011 is inserted at the middle time of the PWM signal to be sampled and the action time thereof is made to be Tmin, and at the same time, in order to ensure that the total synthesized voltage vector is unchanged, the residual effective vector 011 needs to be reduced to T2-Tmin, that is, the action time of the effective vector 011 which is originally applied at each time T2/2 in the front and rear half cycles is reduced to T2/2-Tmin/2, so that the total time of the action of the effective vector 011 in the PWM cycle is still T2, and the residual effective vector 001 is still unchanged.

By the method in this embodiment, the adjusted acting time length corresponding to each remaining effective vector is determined by the method, so that the total synthesized voltage vector of the finally obtained reconstructed PWM signal is ensured to be the same as the target synthesized voltage vector of the PWM signal to be sampled.

As an alternative embodiment, the step S204 obtains a reconstructed PWM signal according to the inserted PWM signal and the adjusted duration of action corresponding to each remaining effective vector, including the steps of:

after the following steps are performed for each remaining active vector traversal, a reconstructed PWM signal is obtained:

For example, the adjusted acting duration of the remaining effective vector 011 needs to be reduced to T2-Tmin, and the adjusted acting duration of the remaining effective vector 001 is consistent with the candidate acting duration and is T1, so that only the candidate acting duration of the remaining effective vector 011 in half of each T2/2 of the front and rear half periods needs to be reduced to half of the adjusted acting duration T2/2-Tmin/2.

By means of the method in the embodiment, the final obtained reconstructed PWM signal still has symmetry and electromagnetic noise is not generated by adjusting the first half period action duration corresponding to the residual effective vector to be half of the adjusted action duration corresponding to the residual effective vector and adjusting the second half period action duration corresponding to the residual effective vector to be half of the adjusted action duration corresponding to the residual effective vector.

As an alternative embodiment, as in the foregoing method, after the step S104 inserts the target insertion vector into the PWM signal to be sampled according to the minimum sampling duration to obtain the reconstructed PWM signal, the method further includes the following steps:

After the reconstructed PWM signal is obtained, a target insertion vector having a target action duration is constructed, where the target insertion vector corresponds to the first phase current, and since the target action duration is greater than or equal to the minimum sampling duration, the current sampling may be performed on the target insertion vector having the target action duration, so as to obtain the first current value of the first phase current.

By the method in the embodiment, under the condition that the phase shift of the PWM signal to be sampled is not carried out, the acquisition of the current value of the phase current can still be completed, and the electromagnetic noise problem caused by current distortion can not be caused while the accuracy of current sampling can be ensured.

As an alternative embodiment, as in the foregoing method, after performing current sampling in the target duration of action of the target insertion vector in the step, and obtaining the first current value of the first phase current corresponding to the target insertion vector, the method further includes the following steps:

step S701, obtaining a second current value of a second phase current obtained by last measurement, wherein the second phase current is different from the first phase current;

in step S702, a third current value of a third phase current is calculated according to the first current value and the second current value, wherein the third phase current is different from the second phase current and the first phase current.

After the second current value obtained by the last measurement is obtained and based on the first current values obtained in steps S101 to S104, since the current values corresponding to the U-phase V-phase and W-phase are typically collected sequentially, and the current values of the U-phase V-phase and W-phase may be vector calculated by two of them to obtain the remaining one value, for example, the current value of the U-phase and the current value of the V-phase are calculated to obtain the current value of the W-phase, the third current value may be obtained based on the first current value and the second current value.

By the method in the embodiment, the third current value of the third phase current can be determined without measuring, and the measuring efficiency can be effectively improved.

As described below, an application example to which any of the foregoing embodiments is applied is provided:

in the sector switching area, as shown in fig. 5, the situation that the candidate effective vector 011 acts on each of T2/2 in the front and rear half cycles of PWM occurs, the single-resistor sampling generally performs bus sampling at the middle time of the effective vector acting, when T2/2 is smaller than the minimum time Tmin required for sampling, in order to meet the minimum sampling time window, a target insertion vector 011 is inserted at the middle time of the PWM signal to be sampled, as shown in fig. 6 (the dotted line is the PWM signal before reconstruction, the solid line is the PWM signal after reconstruction), and the acting time is set to Tmin, meanwhile, in order to ensure that the acting time of the effective vector 011 in the period is unchanged, the acting time of the remaining effective vector 011 originally acting on each of T2/2 in the front and rear half cycles is reduced to T2/2-Tmin/2, so that the total acting time of the effective vector 011 in the PWM period is still T2, the synthesized voltage vector is unchanged, and PWM symmetry is ensured.

In the low modulation region, the situation shown in fig. 7 occurs, and the active time of the candidate active vectors 001 and 011 of the PWM signal to be sampled in the first period to be sampled shown in fig. 7 is shorter, that is, neither T1/2 nor T2/2 satisfies the minimum sampling time, and then current sampling is performed in two consecutive PWM periods respectively. The candidate effective vector 011 is compensated in the first period, that is, the target insertion vector 011 is inserted in the middle of the PWM period to make the acting time be Tmin, as shown in fig. 8 (the dotted line is the PWM signal before reconstruction, the solid line is the PWM signal after reconstruction), and the current sampling is performed once in the middle of the vector acting to obtain a phase current, meanwhile, the residual effective vector 011 originally acting in each T2/2 time of the front and rear half periods needs to be reduced to T2/2-Tmin/2, so that the synthesized voltage vector remains unchanged, and because the PWM signal to be sampled in the period to be sampled only performs once current sampling, only one phase current can be obtained, and therefore, the other phase current can only be directly calculated by using the result of the last sampling. Then the next PWM signal to be sampled in the second period to be sampled compensates the 001 vector, inserts the effective vector 110 in the middle time of the PWM period to make the acting time be Tmin, as shown in fig. 9 (the dotted line is the PWM signal before reconstruction, the solid line is the PWM signal after reconstruction), and performs one-time current sampling in the middle time of the vector to obtain another phase current, and changes the acting time of the effective vector 001 originally acting in each T1/2 time of the front and rear half periods of PWM to each T1/2+tmin/2, so that the total synthetic voltage vector is ensured to be unchanged, and only one phase current can be obtained because only one-time current sampling is performed in the period, therefore the other phase current can only be directly calculated by using the result of the last sampling.

In the case of the above-mentioned low modulation ratio, it is also possible to select to insert the effective vector 011 in the PWM signal to be sampled in the first period to be sampled, and change the acting time of the effective vector 011 acting in the front and rear half periods to T2/2-Tmin/2. Then inserting an effective vector 101 in the second period, changing the action time of the front half cycle and the rear half cycle of 001 into T1/2-Tmin/2, and changing the action time of the front half cycle and the rear half cycle of 011 into T2/2+Tmin/2, thereby achieving the effects of unchanged synthetic vector and symmetrical PWM.

The effective vector insertion method can solve the problem that the minimum sampling time window of the commutation area and the low modulation ratio area is insufficient, ensure the symmetry of PWM signals and avoid electromagnetic noise.

As shown in fig. 10, according to an embodiment of another aspect of the present application, there is also provided a phase current reconstruction device for a single-resistance sampling permanent magnet synchronous motor, including:

the acquisition module 1 is used for acquiring a PWM signal to be sampled in a period to be sampled;

a first determining module 2, configured to determine a first phase current used for sampling by the PWM signal to be sampled;

a second determining module 3, configured to determine a target insertion vector for inserting the PWM signal to be sampled, where the target insertion vector is consistent with the target effective vector, when the target effective vector for sampling the first phase current does not exist in the PWM signal to be sampled, or when a continuous acting duration of the target effective vector is less than a minimum sampling duration;

and the reconstruction module 4 is used for inserting the target insertion vector into the PWM signal to be sampled according to the minimum sampling duration to obtain a reconstructed PWM signal.

In particular, the specific process of implementing the functions of each module in the apparatus of the embodiment of the present application may be referred to the related description in the method embodiment, which is not repeated herein.

According to another embodiment of the present application, there is also provided an electronic apparatus including: as shown in fig. 11, the electronic device may include: the device comprises a processor 1501, a communication interface 1502, a memory 1503 and a communication bus 1504, wherein the processor 1501, the communication interface 1502 and the memory 1503 are in communication with each other through the communication bus 1504.

A memory 1503 for storing a computer program;

the processor 1501 is configured to execute the program stored in the memory 1503, thereby implementing the steps of the method embodiment described above.

The buses mentioned for the above electronic devices may be peripheral component interconnect standard (Peripheral Component Interconnect, PCI) buses or extended industry standard architecture (Extended Industry Standard Architecture, EISA) buses, etc. The bus may be classified as an address bus, a data bus, a control bus, etc. For ease of illustration, the figures are shown with only one bold line, but not with only one bus or one type of bus.

The communication interface is used for communication between the electronic device and other devices.

The Memory may include random access Memory (Random Access Memory, RAM) or may include Non-Volatile Memory (NVM), such as at least one disk Memory. Optionally, the memory may also be at least one memory device located remotely from the aforementioned processor.

The processor may be a general-purpose processor, including a central processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), etc.; but also digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

The embodiment of the application also provides a computer readable storage medium, wherein the storage medium comprises a stored program, and the program executes the method steps of the method embodiment.

It should be noted that in this document, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is only a specific embodiment of the application to enable those skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The phase current reconstruction method for the single-resistance sampling permanent magnet synchronous motor is characterized by comprising the following steps of:

acquiring a PWM signal to be sampled in a period to be sampled;

determining a first phase current for sampling of the PWM signal to be sampled;

inserting the target insertion vector into the PWM signal to be sampled according to the minimum sampling duration to obtain a reconstructed PWM signal, wherein the method comprises the following steps: determining a target action duration greater than or equal to the minimum sampling duration; determining the middle time of the period to be sampled; inserting the target insertion vector of the target action duration into the PWM signal to be sampled according to the intermediate moment to obtain an inserted PWM signal, wherein in the first half period of the inserted PWM signal, the target insertion vector continuously acts for half of the target action duration, and in the second half period of the inserted PWM signal, the target insertion vector continuously acts for the other half of the target action duration; determining an adjusted acting time length corresponding to each remaining effective vector in the inserted PWM signal according to the target insertion vector of the target acting time length, wherein the remaining effective vectors are effective vectors except for the target insertion vector in the inserted PWM signal; and obtaining the reconstructed PWM signal according to the inserted PWM signal and the adjusted acting time length corresponding to each residual effective vector.

2. The method of claim 1, wherein said determining an adjusted active duration in the post-insertion PWM signal corresponding to each remaining active vector in accordance with the target insertion vector for the target active duration comprises:

3. The method according to claim 2, wherein said obtaining the reconstructed PWM signal according to the inserted PWM signal and the adjusted active duration corresponding to each remaining active vector comprises:

4. The method according to claim 1, wherein after said inserting the target insertion vector into the PWM signal to be sampled according to the minimum sampling duration, the method further comprises:

5. The method of claim 4, wherein, during the target duration of action of the target insertion vector, current sampling is performed, and wherein after obtaining a first current value of a first phase current corresponding to the target insertion vector, the method further comprises:

6. The utility model provides a single resistance sampling PMSM phase current reconstruction device which characterized in that includes:

the reconstruction module is configured to insert the target insertion vector into the PWM signal to be sampled according to the minimum sampling duration to obtain a reconstructed PWM signal, and includes: determining a target action duration greater than or equal to the minimum sampling duration; determining the middle time of the period to be sampled; inserting the target insertion vector of the target action duration into the PWM signal to be sampled according to the intermediate moment to obtain an inserted PWM signal, wherein in the first half period of the inserted PWM signal, the target insertion vector continuously acts for half of the target action duration, and in the second half period of the inserted PWM signal, the target insertion vector continuously acts for the other half of the target action duration; determining an adjusted acting time length corresponding to each remaining effective vector in the inserted PWM signal according to the target insertion vector of the target acting time length, wherein the remaining effective vectors are effective vectors except for the target insertion vector in the inserted PWM signal; and obtaining the reconstructed PWM signal according to the inserted PWM signal and the adjusted acting time length corresponding to each residual effective vector.

7. An electronic device, comprising: the device comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are communicated with each other through the communication bus;

the memory is used for storing a computer program;

the processor being adapted to implement the method of any one of claims 1 to 5 when executing the computer program.

8. A computer readable storage medium, characterized in that the storage medium comprises a stored program, wherein the program when run performs the method of any of the preceding claims 1 to 5.