Pulse width modulation method and related device for six-phase motor with double Y windings shifted 30 degrees

Abstract

The present application discloses a pulse width modulation method and related device for a six-phase motor with a dual Y winding and a 30-degree shift, including: synthesizing a virtual voltage vector based on the voltage vector of the six-phase motor on the α-β plane; the voltage component of the virtual voltage vector on the x-y plane is zero, and the voltage component of the virtual voltage vector on the z1-z2 plane is zero; determining the virtual voltage vector and zero vector required to synthesize the target voltage vector based on the target voltage vector; calculating the action time of each voltage vector and the zero vector of the synthesized virtual voltage vector; and outputting the corresponding voltage vector and zero vector within the action time. This method is not only suitable for pulse width control of a six-phase motor with a dual Y winding and a 30-degree shift whose neutral points are not connected, but is also more suitable for pulse width control of a six-phase motor with a dual Y winding and a 30-degree shift whose neutral points are connected. It can simultaneously suppress the voltage components of the voltage of the six-phase motor with a dual Y winding and a 30-degree shift in the x-y plane and the z1-z2 plane, and make the voltage components of the voltage in the x-y plane and the z1-z2 plane zero within one switching cycle.

Description

Technical Field

[0001] The present application relates to the technical field of six-phase motors, and in particular to a pulse width modulation method for a six-phase motor with dual Y windings shifted 30 degrees; and also to a pulse width modulation device, equipment, and computer-readable storage medium for a six-phase motor with dual Y windings shifted 30 degrees. Background Art

[0002] Compared to three-phase motors, six-phase motors offer advantages such as high output power, low torque ripple, high efficiency, and good fault tolerance. Consequently, they are attracting increasing attention and application in the industrial sector. However, compared to three-phase motors, six-phase motors are more complex to control, primarily due to pulse-width modulation. Three-phase motors have only eight spatial voltage vectors, while six-phase motors have up to 64. After coordinate transformation, a six-phase motor with disconnected neutral points has not only voltage components in the α-β plane related to electromechanical energy conversion, but also voltage components in the xy plane, which are absent from three-phase motors. While the xy plane is unrelated to electromechanical energy conversion, the current components in the xy plane are directly related to the voltage in this plane and the motor's leakage inductance. The current components in the xy plane are reflected in the motor's stator current as significant current harmonics, so the voltage components in the xy plane need to be kept as small as possible. A six-phase motor with a connected neutral point has not only a voltage component in the xy plane but also a voltage component in the z1-z2 plane. The current component in the z1-z2 plane is directly related to the voltage in that plane and the motor's leakage inductance. This current component is also reflected in the motor's stator current. Therefore, it's necessary to minimize the voltage component in the z1-z2 plane to reduce the current component in that plane.

[0003] For the control of six-phase motors, existing research mainly focuses on six-phase motors with dual Y windings and a 30-degree shift in the neutral point. Four-vector space vector modulation is used in pulse width modulation to suppress the xy plane voltage component. This modulation scheme is not suitable for pulse width control of six-phase motors with dual Y windings and a 30-degree shift in the neutral point, which will result in a large voltage component in the z1-z2 plane.

[0004] Therefore, providing a pulse width control method suitable for a six-phase motor with a double Y winding connected and shifted 30 degrees at the neutral point, and solving the problem of large current harmonic content and uncontrolled current harmonics in the z1-z2 plane during pulse width control of the six-phase motor with a double Y winding connected and shifted 30 degrees at the neutral point has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this application is to provide a pulse width modulation method for a six-phase motor with a dual Y winding shifted by 30 degrees. This method is not only suitable for pulse width control of a six-phase motor with a dual Y winding shifted by 30 degrees and whose neutral points are not connected, but is also more suitable for pulse width control of a six-phase motor with a dual Y winding shifted by 30 degrees and whose neutral points are connected. It can simultaneously suppress the voltage components of the six-phase motor with a dual Y winding shifted by 30 degrees in the xy plane and the z1-z2 plane, and make the voltage components in the xy plane and the z1-z2 plane zero within one switching cycle. Another purpose of this application is to provide a pulse width modulation device, equipment, and computer-readable storage medium for a six-phase motor with a dual Y winding shifted by 30 degrees, all of which have the above-mentioned technical effects.

[0006] To solve the above technical problems, the present application provides a pulse width modulation method for a six-phase motor with dual Y windings shifted 30 degrees, comprising:

[0007] synthesizing a virtual voltage vector based on the voltage vector of the six-phase motor on the α-β plane; wherein the voltage component of the virtual voltage vector on the xy plane is zero, and the voltage component of the virtual voltage vector on the z1-z2 plane is zero;

[0008] determining the virtual voltage vector and the zero vector required to synthesize the target voltage vector according to the target voltage vector;

[0009] Calculating and synthesizing the action time of each of the voltage vectors and the zero vector that are determined to form the virtual voltage vector;

[0010] The corresponding voltage vector and the zero vector are output during the action time.

[0011] Optionally, synthesizing a virtual voltage vector according to the voltage vector of the six-phase motor on the α-β plane includes:

[0012] The virtual voltage vector is synthesized according to the voltage vector with the largest amplitude of the six-phase motor on the α-β plane.

[0013] Optionally, synthesizing the virtual voltage vector according to the voltage vector of the six-phase motor having the largest amplitude on the α-β plane includes:

[0014] The three adjacent voltage vectors with the largest amplitudes on the α-β plane are grouped together to synthesize a candidate virtual voltage vector; the voltage component of the candidate virtual voltage vector on the xy plane is zero;

[0015] The virtual voltage vector is selected from the alternative virtual voltage vectors; the selected virtual voltage vector satisfies: the voltage component of one of the three adjacent voltage vectors with the largest amplitude of the synthetically selected virtual voltage vector on the z1-z2 plane is zero, and the voltage components of the other two voltage vectors on the z1-z2 plane are equal in magnitude and opposite in direction.

[0016] Optionally, the synthesizing the candidate virtual voltage vectors by taking the three adjacent voltage vectors with the largest amplitudes on the α-β plane as a group includes:

[0017] Calculating the action time of the three voltage vectors with the largest amplitudes in each group so that the composite voltage of the three voltage vectors with the largest amplitudes on the xy plane during the action time is zero;

[0018] The candidate virtual voltage vector is obtained by synthesizing the three voltage vectors with the largest amplitudes according to the action time.

[0019] Optionally, calculating the action time of the three voltage vectors with the largest amplitudes in each group so that the composite voltage of the three voltage vectors with the largest amplitudes on the xy plane is zero during the action time includes:

[0020] The action time of the three voltage vectors with the largest amplitudes in each group is calculated based on the total action time of the three voltage vectors with the largest amplitudes in each group and the angle between the three voltage vectors with the largest amplitudes and the x-coordinate axis on the xy plane, so that the composite voltage of the three voltage vectors with the largest amplitudes on the xy plane during the action time is zero.

[0021] Optionally, calculating and synthesizing the action time of each voltage vector of the determined virtual voltage vector includes:

[0022] calculating the action time of the determined virtual voltage vector;

[0023] The action time of each voltage vector used to synthesize the determined virtual voltage vector is calculated according to the action time of the virtual voltage vector.

[0024] Optionally, the action time of the virtual voltage vector and the zero vector determined by the calculation includes:

[0025] The determined virtual voltage vector and the action time of the zero vector are calculated according to the volt-second theorem of space vector modulation; the voltage components of the zero vector on the xy plane and on the z1-z2 plane are both zero.

[0026] To solve the above technical problems, the present application further provides a pulse width modulation device for a six-phase motor with dual Y windings shifted 30 degrees, comprising:

[0027] a synthesis module, configured to synthesize a virtual voltage vector based on the voltage vector of the six-phase motor on the α-β plane; wherein the voltage component of the virtual voltage vector on the xy plane is zero, and the voltage component of the virtual voltage vector on the z1-z2 plane is zero;

[0028] a determination module, configured to determine, according to a target voltage vector, the virtual voltage vector and the zero vector required to synthesize the target voltage vector;

[0029] a calculation module, configured to calculate the action time of each of the voltage vectors and the zero vector for synthesizing the determined virtual voltage vector;

[0030] An output module is used to output the corresponding voltage vector and the zero vector within the action time.

[0031] Optionally, the synthesis module is specifically configured to synthesize the virtual voltage vector based on the voltage vector with the largest amplitude of the six-phase motor on the α-β plane.

[0032] Optionally, the synthesis module includes:

[0033] a synthesis unit, configured to synthesize a candidate virtual voltage vector by grouping the three adjacent voltage vectors with the largest amplitudes on the α-β plane; wherein the voltage component of the candidate virtual voltage vector on the xy plane is zero;

[0034] A screening unit is used to screen out the virtual voltage vector from the alternative virtual voltage vectors; the screened virtual voltage vector satisfies: the voltage component of one of the three adjacent voltage vectors with the largest amplitude of the synthetically screened virtual voltage vector is zero on the z1-z2 plane, and the voltage components of the other two voltage vectors on the z1-z2 plane are equal in magnitude and opposite in direction.

[0035] Optionally, the synthesis unit includes:

[0036] a calculation subunit, configured to calculate the action time of the three voltage vectors with the largest amplitudes in each group, so that a composite voltage of the three voltage vectors with the largest amplitudes on the xy plane is zero within the action time;

[0037] A synthesis subunit is configured to synthesize the three voltage vectors with the largest amplitudes according to the action time to obtain the candidate virtual voltage vector.

[0038] Optionally, the calculation subunit is specifically used to calculate the action time of the three voltage vectors with the largest amplitudes in each group based on the total action time of the three voltage vectors with the largest amplitudes in each group and the angle between the three voltage vectors with the largest amplitudes and the x-coordinate axis on the xy plane, so that the synthetic voltage of the three voltage vectors with the largest amplitudes on the xy plane during the action time is zero.

[0039] Optionally, the calculation module includes:

[0040] a first calculation unit, configured to calculate the determined action time of the virtual voltage vector;

[0041] The second calculation unit is configured to calculate, according to the action time of the virtual voltage vector, the action time of each voltage vector that is synthesized to obtain the determined virtual voltage vector.

[0042] Optionally, the first calculation unit is specifically used to calculate the determined virtual voltage vector and the action time of the zero vector according to the volt-second theorem of space vector modulation; the voltage components of the zero vector on the xy plane and on the z1-z2 plane are both zero.

[0043] To solve the above technical problems, the present application also provides a pulse width modulation device for a six-phase motor with dual Y windings shifted 30 degrees, comprising:

[0044] memory for storing computer programs;

[0045] A processor is used to implement the steps of the pulse width modulation method of a six-phase motor with a dual Y winding shifted 30 degrees as described in any of the above items when executing the computer program.

[0046] In order to solve the above technical problems, the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the pulse width modulation method of a six-phase motor with a dual Y winding shifted 30 degrees as described in any of the above items are implemented.

[0047] The pulse width modulation method of a six-phase motor with a dual Y winding shifted 30 degrees provided in the present application includes: synthesizing a virtual voltage vector based on the voltage vector of the six-phase motor on the α-β plane; wherein the voltage component of the virtual voltage vector on the xy plane is zero, and the voltage component of the virtual voltage vector on the z1-z2 plane is zero; determining the virtual voltage vector and zero vector required to synthesize the target voltage vector based on the target voltage vector; calculating the action time of each of the voltage vectors and the zero vector of the synthesized determined virtual voltage vector; and outputting the corresponding voltage vector and the zero vector within the action time.

[0048] It can be seen that the pulse width modulation method of the six-phase motor with dual Y windings shifted by 30 degrees provided in the present application synthesizes a virtual voltage vector based on the voltage vector of the six-phase motor on the α-β plane, and the voltage components of the virtual voltage vector in the xy plane and on z1-z2 are all zero. Based on this virtual voltage vector, any required voltage vector can be synthesized by the virtual voltage vector. Since the voltage components of the virtual voltage vector in the xy plane and on z1-z2 are all zero, the voltage components in the xy plane and on z1-z2 can be suppressed for any required voltage vector, so that within one switching cycle, the voltage components in the xy plane and on z1-z2 are zero, which can greatly improve the control performance. This method is not only suitable for the pulse width control of the six-phase motor with dual Y windings shifted by 30 degrees whose neutral points are not connected, but is also more suitable for the pulse width control of the six-phase motor with dual Y windings shifted by 30 degrees whose neutral points are connected.

[0049] The pulse width modulation device, equipment and computer-readable storage medium of the six-phase motor with dual Y windings shifted 30 degrees provided in this application all have the above-mentioned technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the prior art and the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0051] Figure 1 A flow chart of a pulse width modulation method for a six-phase motor with dual Y windings shifted 30 degrees provided in an embodiment of the present application;

[0052] Figure 2 A schematic diagram of a six-phase motor stator winding with double Y windings connected at the neutral point and shifted 30 degrees provided in an embodiment of the present application;

[0053] Figure 3 A six-phase motor topology diagram with dual Y windings shifted 30 degrees and powered by a six-phase inverter provided in an embodiment of the present application;

[0054] Figure 4 A schematic diagram of an α-β plane voltage vector provided in an embodiment of the present application;

[0055] Figure 5 A schematic diagram of an xy plane voltage vector provided in an embodiment of the present application;

[0056] Figure 6 A schematic diagram of a voltage vector in the z1-z2 plane provided in an embodiment of the present application;

[0057] Figure 7 A distribution diagram of a voltage vector in the α-β plane provided in an embodiment of the present application;

[0058] Figure 8 A distribution diagram of a voltage vector in the xy plane provided in an embodiment of the present application;

[0059] Figure 9 A schematic diagram of a virtual voltage vector provided in an embodiment of the present application;

[0060] Figure 10 This is another schematic diagram of a virtual voltage vector provided in an embodiment of the present application. DETAILED DESCRIPTION

[0061] The core of this application is to provide a pulse width modulation method for a six-phase motor with a dual Y winding shifted 30 degrees. This method is not only suitable for pulse width control of a six-phase motor with a dual Y winding shifted 30 degrees whose neutral points are not connected, but is also more suitable for pulse width control of a six-phase motor with a dual Y winding shifted 30 degrees whose neutral points are connected. It can simultaneously suppress the voltage components of the six-phase motor with a dual Y winding shifted 30 degrees in the xy plane and the z1-z2 plane, and make the voltage components in the xy plane and the z1-z2 plane zero within one switching cycle. Another core of this application is to provide a pulse width modulation device, equipment, and computer-readable storage medium for a six-phase motor with a dual Y winding shifted 30 degrees, all of which have the above-mentioned technical effects.

[0062] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0063] Please refer to Figure 1 , Figure 1 A flow chart of a pulse width modulation method for a six-phase motor with a double Y winding shifted 30 degrees provided in an embodiment of the present application, with reference to Figure 1 As shown, the method includes:

[0064] S101: synthesizing a virtual voltage vector based on the voltage vector of the six-phase motor on the α-β plane; wherein the voltage component of the virtual voltage vector on the xy plane is zero, and the voltage component of the virtual voltage vector on the z1-z2 plane is zero;

[0065] In a specific embodiment, the method of synthesizing the virtual voltage vector based on the voltage vector of the six-phase motor on the α-β plane is:

[0066] A virtual voltage vector is synthesized according to the voltage vector with the largest amplitude of the six-phase motor on the α-β plane.

[0067] In a specific embodiment, the virtual voltage vector is synthesized according to the voltage vector with the largest amplitude on the α-β plane of the six-phase motor as follows:

[0068] The three adjacent voltage vectors with the largest amplitude on the α-β plane are grouped together to synthesize a candidate virtual voltage vector; the voltage component of the candidate virtual voltage vector on the xy plane is zero;

[0069] A virtual voltage vector is selected from the candidate virtual voltage vectors; the selected virtual voltage vector satisfies: the voltage component of one of the three adjacent voltage vectors with the largest amplitude that synthesize the selected virtual voltage vector on the z1-z2 plane is zero, and the voltage components of the other two voltage vectors on the z1-z2 plane are equal in magnitude and opposite in direction.

[0070] In addition, in a specific embodiment, the three adjacent voltage vectors with the largest amplitudes on the α-β plane are grouped together, and the method for synthesizing the candidate virtual voltage vectors is as follows:

[0071] Calculate the action time of the three voltage vectors with the largest amplitudes in each group so that the resultant voltage of the three voltage vectors with the largest amplitudes on the xy plane is zero during the action time;

[0072] The three voltage vectors with the largest amplitudes are synthesized according to the action time to obtain the candidate virtual voltage vector.

[0073] Specifically, the stator of a six-phase motor consists of two sets of three-phase windings, which are 30 electrical degrees apart in space. Both sets of windings are connected in a Y shape, denoted as ABC and XYZ respectively. The double Y windings connected at the neutral point are phase-shifted by 30 degrees. The windings of a six-phase motor are as follows: Figure 2 As shown, N is the connection point.

[0074] A six-phase voltage source inverter is usually used to drive a six-phase motor with dual Y windings and a 30-degree phase shift. The corresponding topology is as follows: Figure 3 As shown in the figure, each bridge arm of a six-phase voltage source inverter consists of two switches, one above and one below. The states of these two switches are complementary. When the upper switch is on, the lower switch is off; when the lower switch is on, the upper switch is off. A six-phase voltage source inverter has a total of 64 switching states, corresponding to 64 phase voltages. These 64 phase voltages form 64 space voltage vectors.

[0075] Through orthogonal coordinate transformation, the six phase voltages can be transformed into the α-β plane, xy plane, and z1-z2 plane. The coordinate transformation formula is as follows:

[0076]

[0077] In the above formula, u A 、u X 、u B 、u Y 、u C 、u Z Indicates six phase voltages, u α 、u β 、u x 、u y 、u z1 、u z2 Represents the result of orthogonal coordinate transformation.

[0078] The voltage vectors of the 64 phase voltages after coordinate transformation on the α-β plane, xy plane, and z1-z2 plane are as follows: Figure 4 、 Figure 5 as well as Figure 6 shown.

[0079] Since the current component on the xy plane is directly related to the voltage on the plane and the motor leakage inductance, the voltage on the xy plane should be as small as possible. Figure 4 and Figure 5 It can be seen that the vector with the maximum amplitude in the α-β plane has the minimum amplitude in the xy plane. For example, the maximum vector V in the α-β plane is 45 The amplitude in the xy plane is the smallest. Therefore, this embodiment selects the voltage vector with the largest amplitude in the α-β plane to minimize the voltage in the xy plane.

[0080] Select the voltage vector with the largest amplitude in the α-β plane to minimize the voltage in the xy plane, and also make the amplitude of the synthetic voltage vector of the six-phase motor in the xy plane zero. Figure 4 and Figure 5 It can be seen that every three adjacent voltage vectors with the largest amplitudes in the α-β plane are distributed nearly symmetrically in the xy plane. Therefore, by controlling the action time of each voltage vector, the synthetic voltage of the three adjacent voltage vectors in the xy plane can be made zero during the action time.

[0081] The method for calculating the action time of the three voltage vectors with the largest amplitudes in each group so that the composite voltage of the three voltage vectors with the largest amplitudes on the xy plane is zero during the action time is as follows:

[0082] According to the total action time of the three voltage vectors with the largest amplitude in each group and the angle between the three voltage vectors with the largest amplitude and the x-axis on the xy plane, the action time of the three voltage vectors with the largest amplitude in each group is calculated so that the synthetic voltage of the three voltage vectors with the largest amplitude on the xy plane during the action time is zero.

[0083] For example, the three adjacent maximum vectors V in the α-β plane 45 、V 44 、V 64 The distribution of these three voltage vectors in the α-β plane and the xy plane is nearly symmetrical. Figure 7 and Figure 8 As shown:

[0084] Let V 45 、V 44 、V 64 The total action time of these three vectors is T1, V 45 、V 44 、V 64 The action time of these three vectors is T 45 、T 44 、T 64 , in order to make the resultant vector in the xy plane equal to 0, we have:

[0085]

[0086] From this, the action times of the three voltage vectors can be calculated as follows:

[0087]

[0088] According to the above action time, V 45 、V 44 、V 64 These three vectors synthesize a virtual voltage vector in the α-β plane. The component of the virtual voltage vector in the xy plane is zero. The direction of the virtual voltage vector in the α-β plane is the same as V 44 The direction is consistent, and its amplitude is:

[0089]

[0090] Taking every three adjacent maximum vectors as a group to synthesize the virtual voltage vector, 12 alternative virtual voltage vectors V can be obtained. a1 ~V a12 , the distribution in the α-β plane is as follows Figure 9 These alternative virtual voltage vectors differ by 30 degrees in the α-β plane space, dividing the α-β plane into S1~S 12 For the 12 sectors, the voltage components of these alternative virtual voltage vectors in the xy plane are all zero.

[0091] Furthermore, for any given vector, the two most adjacent virtual voltage vectors and the zero vector in the sector where the given vector is located can be synthesized. Figure 9 As shown, V ref Can be Va1 and V a2 This method is feasible for six-phase motors with dual Y windings offset 30 degrees and unconnected neutral points. However, for six-phase motors with dual Y windings offset 30 degrees and connected neutral points, the z1-z2 plane still exists. This synthesis method will generate a large voltage component in the z1-z2 plane, resulting in large harmonic currents in the z1-z2 plane. Therefore, the voltage component in the z1-z2 plane also needs to be suppressed.

[0092] To this end, by analyzing Figure 4 and Figure 6 It can be seen that in the 12 largest voltage vectors V 44 ,V 64 ,V 66 ,V 26 ,V 22 ,V 32 ,V 33 ,V 13 ,V 11 ,V 51 ,V 55 ,V 45 In, V 44 ,V 66 ,V 22 ,V 33 ,V 11 ,V 55 The voltage component of the voltage vector in the z1-z2 plane is always 0. The voltage vector group V 64 -V 26 、V 26 -V 32 、V 32 -V 13 、V 13 -V 51 、V 51 -V 45 The voltage components of the two voltage vectors in the z1-z2 plane are equal in magnitude and opposite in direction. By controlling the action time of the two voltage vectors in the six voltage vector groups to be the same, the voltage component of the voltage vector group in the z1-z2 plane can be zero. Therefore, the above candidate virtual voltage vectors are screened and the V a2 , V a4 , V a6 , V a8 , V a10 , V a12 , retain the virtual voltage vector V a1 , V a3 , V a5 , V a7 , V a9 , V a11, thus reducing the number of sectors from 12 to 6 (S1-S6). For the retained virtual voltage vector, of the three adjacent maximum voltage vectors that form the virtual voltage vector, one voltage vector has a zero voltage on the z1-z2 plane, while the other two voltage vectors have equal magnitudes and opposite directions on the z1-z2 plane. Thus, the six retained virtual voltage vectors have zero voltage components on both the xy plane and the z1-z2 plane.

[0093] For example, Figure 10 Medium V ref By V a1 、V a3 and zero vector, that is, the maximum voltage vector V 45 ,V 44 ,V 64 ,V 66 ,V 26 and zero vector (V 00 or V 77 )synthesis.

[0094] It can be understood that in addition to selecting the three adjacent voltage vectors with the largest amplitudes on the α-β plane to synthesize the virtual voltage vector as mentioned above, voltage vectors with other amplitudes and numbers on the α-β plane can also be selected to synthesize the virtual voltage vector, as long as the voltage component of the synthesized virtual voltage vector on the xy plane is zero and the voltage component on the z1-z2 plane is zero.

[0095] S102: Determine a virtual voltage vector and a zero vector required to synthesize the target voltage vector according to the target voltage vector;

[0096] S103: Calculating the action time of each voltage vector and the zero vector of the synthesized determined virtual voltage vector;

[0097] S104: Outputting the corresponding voltage vector and the zero vector within the action time.

[0098] Specifically, for a desired voltage vector, or target voltage vector, the virtual voltage vector and zero vector required to synthesize the target voltage vector are first determined. Determining the virtual voltage vector required to synthesize the target voltage vector also determines the voltage vector required to synthesize the target voltage vector. Furthermore, after determining the virtual voltage vector required to synthesize the target voltage vector, the application time of each voltage vector in the desired virtual voltage vector and the application time of the zero vector are calculated. Finally, by controlling the on and off states of the switches on the relevant bridge arms of the six-phase inverter, the voltage vector is output within the application time corresponding to the voltage vector, thereby achieving pulse width modulation.

[0099] In a specific embodiment, the action time of each voltage vector for synthesizing the determined virtual voltage vector is calculated as follows:

[0100] calculating the action time of the determined virtual voltage vector;

[0101] According to the action time of the virtual voltage vector, the action time of each voltage vector for synthesizing the determined virtual voltage vector is calculated.

[0102] The method for calculating the action time of the determined virtual voltage vector and the zero vector may be:

[0103] The determined virtual voltage vector and the action time of the zero vector are calculated according to the volt-second theorem of space vector modulation; the voltage components of the zero vector on the xy plane and on the z1-z2 plane are both zero.

[0104] Specifically, the action times of the virtual voltage vector and the zero vector can be calculated based on the volt-second theorem, similar to the principle of space vector modulation for three-phase motors. This application will not be further elaborated herein, and reference will be made to existing related art. Based on the calculated action time of the virtual voltage vector, the action times of each voltage vector of the synthesized virtual voltage vector are calculated based on the action time of the virtual voltage vector.

[0105] For example, suppose two adjacent virtual voltage vectors V a1 and V a3 The action time of the zero vector is T0, and the synthetic virtual voltage vector V a1 The three largest vectors (V 45 ,V 44 ,V 64 ) Action time:

[0106]

[0107] Synthesized virtual voltage vector V a3 The three largest vectors (V 64 ,V 66 ,V 26 ) Action time:

[0108]

[0109] Therefore, the 5 maximum voltage vectors V 45 ,V 44 ,V 64 ,V 66 ,V 26 The action time and a zero vector (V 00 or V 77 ) Action time:

[0110]

[0111] In summary, the pulse width modulation method of the six-phase motor with dual Y windings shifted by 30 degrees provided in the present application synthesizes a virtual voltage vector based on the voltage vector of the six-phase motor on the α-β plane, and the voltage components of the virtual voltage vector in the xy plane and on z1-z2 are all zero. Based on this virtual voltage vector, any required voltage vector can be synthesized by the virtual voltage vector. Since the voltage components of the virtual voltage vector in the xy plane and on z1-z2 are all zero, the voltage components in the xy plane and on z1-z2 can be suppressed for any required voltage vector, so that within one switching cycle, the voltage components in the xy plane and on z1-z2 are zero, which can greatly improve the control performance. This method is not only suitable for the pulse width control of the six-phase motor with dual Y windings shifted by 30 degrees whose neutral points are not connected, but is also more suitable for the pulse width control of the six-phase motor with dual Y windings shifted by 30 degrees whose neutral points are connected.

[0112] This application also provides a pulse width modulation device for a six-phase motor with dual Y windings shifted 30 degrees. The device described below can be used in conjunction with the method described above. The device includes:

[0113] a synthesis module, configured to synthesize a virtual voltage vector based on the voltage vector of the six-phase motor on the α-β plane; wherein the voltage component of the virtual voltage vector on the xy plane is zero, and the voltage component of the virtual voltage vector on the z1-z2 plane is zero;

[0114] a determination module, configured to determine, according to a target voltage vector, the virtual voltage vector and the zero vector required to synthesize the target voltage vector;

[0115] a calculation module, configured to calculate the action time of each of the voltage vectors and the zero vector for synthesizing the determined virtual voltage vector;

[0116] An output module is used to output the corresponding voltage vector and the zero vector within the action time.

[0117] On the basis of the above embodiment, optionally, the synthesis module is specifically configured to synthesize the virtual voltage vector according to the voltage vector of the six-phase motor having the largest amplitude on the α-β plane.

[0118] Based on the above embodiment, optionally, the synthesis module includes:

[0119] a synthesis unit, configured to synthesize a candidate virtual voltage vector by grouping the three adjacent voltage vectors with the largest amplitudes on the α-β plane; wherein the voltage component of the candidate virtual voltage vector on the xy plane is zero;

[0120] A screening unit is used to screen out the virtual voltage vector from the alternative virtual voltage vectors; the screened virtual voltage vector satisfies: the voltage component of one of the three adjacent voltage vectors with the largest amplitude of the synthetically screened virtual voltage vector is zero on the z1-z2 plane, and the voltage components of the other two voltage vectors on the z1-z2 plane are equal in magnitude and opposite in direction.

[0121] Based on the above embodiment, optionally, the synthesis unit includes:

[0122] a calculation subunit, configured to calculate the action time of the three voltage vectors with the largest amplitudes in each group, so that a composite voltage of the three voltage vectors with the largest amplitudes on the xy plane is zero within the action time;

[0123] A synthesis subunit is configured to synthesize the three voltage vectors with the largest amplitudes according to the action time to obtain the candidate virtual voltage vector.

[0124] Based on the above embodiment, optionally, the calculation subunit is specifically used to calculate the action time of the three voltage vectors with the largest amplitudes in each group based on the total action time of the three voltage vectors with the largest amplitudes in each group and the angle between the three voltage vectors with the largest amplitudes and the x-coordinate axis on the xy plane, so that the synthetic voltage of the three voltage vectors with the largest amplitudes on the xy plane during the action time is zero.

[0125] Based on the above embodiment, optionally, the calculation module includes:

[0126] a first calculation unit, configured to calculate the determined action time of the virtual voltage vector;

[0127] The second calculation unit is configured to calculate, according to the action time of the virtual voltage vector, the action time of each voltage vector that is synthesized to obtain the determined virtual voltage vector.

[0128] Based on the above embodiment, optionally, the first calculation unit is specifically used to calculate the determined virtual voltage vector and the action time of the zero vector according to the volt-second theorem of space vector modulation; the voltage components of the zero vector on the xy plane and on the z1-z2 plane are both zero.

[0129] The present application also provides a pulse width modulation device for a six-phase motor with dual Y windings shifted 30 degrees, the device including a memory and a processor.

[0130] memory for storing computer programs;

[0131] The processor is configured to execute a computer program to implement the following steps:

[0132] A virtual voltage vector is synthesized based on the voltage vector of the six-phase motor on the α-β plane; wherein the voltage component of the virtual voltage vector on the xy plane is zero, and the voltage component of the virtual voltage vector on the z1-z2 plane is zero; the virtual voltage vector and the zero vector required to synthesize the target voltage vector are determined based on the target voltage vector; the action time of each of the voltage vectors and the zero vector of the synthesized determined virtual voltage vector is calculated; and the corresponding voltage vector and the zero vector are output within the action time.

[0133] For an introduction to the equipment provided in this application, please refer to the above method embodiments, and this application will not go into details here.

[0134] The present application also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the following steps can be implemented:

[0135] A virtual voltage vector is synthesized based on the voltage vector of the six-phase motor on the α-β plane; wherein the voltage component of the virtual voltage vector on the xy plane is zero, and the voltage component of the virtual voltage vector on the z1-z2 plane is zero; the virtual voltage vector and the zero vector required to synthesize the target voltage vector are determined based on the target voltage vector; the action time of each of the voltage vectors and the zero vector of the synthesized determined virtual voltage vector is calculated; and the corresponding voltage vector and the zero vector are output within the action time.

[0136] The computer-readable storage medium may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes.

[0137] For an introduction to the computer-readable storage medium provided in this application, please refer to the above method embodiment, and this application will not go into details here.

[0138] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. References to the common and similar parts between the various embodiments are sufficient. The devices, apparatuses, and computer-readable storage media disclosed in the embodiments are described briefly because they correspond to the methods disclosed in the embodiments. For relevant details, refer to the description of the methods.

[0139] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0140] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0141] The above is a detailed introduction to the technical solution provided by the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only intended to help understand the method and core ideas of the present application. It should be pointed out that, for those skilled in the art, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A pulse width modulation method for a six-phase motor with dual Y windings shifted 30 degrees, characterized in that: include: According to the six-phase motor The voltage vector on the plane synthesizes a virtual voltage vector; wherein the virtual voltage vector is The voltage component on the plane is zero, and the virtual voltage vector The voltage component on the plane is zero; determining the virtual voltage vector and the zero vector required to synthesize the target voltage vector according to the target voltage vector; Calculating and synthesizing the action time of each of the voltage vectors and the zero vector that are determined to form the virtual voltage vector; Outputting the corresponding voltage vector and the zero vector within the action time; The six-phase motor The voltage vector on the plane synthesizes the virtual voltage vector including: According to the six-phase motor The voltage vector with the largest amplitude on the plane is synthesized into the virtual voltage vector; The six-phase motor is The voltage vector with the largest amplitude on the plane synthesizes the virtual voltage vector, which includes: As mentioned The three adjacent voltage vectors with the largest amplitude on the plane are grouped together to form a candidate virtual voltage vector; the candidate virtual voltage vector is The voltage component on the plane is zero; The virtual voltage vector is selected from the candidate virtual voltage vectors; the selected virtual voltage vector satisfies: one of the three adjacent voltage vectors with the largest amplitudes of the synthesized selected virtual voltage vector is selected; The voltage component on the plane is zero, and the other two voltage vectors are in the The voltage components on the plane are equal in magnitude and opposite in direction.

2. The pulse width modulation method according to claim 1, wherein: The above The three adjacent voltage vectors with the largest amplitudes on the plane are grouped together, and the synthesized candidate virtual voltage vectors include: Calculate the action time of the three voltage vectors with the largest amplitudes in each group so that the three voltage vectors with the largest amplitudes are within the action time. The resultant voltage on the plane is zero; The candidate virtual voltage vector is obtained by synthesizing the three voltage vectors with the largest amplitudes according to the action time.

3. The pulse width modulation method according to claim 2, characterized in that: The action time of the three voltage vectors with the largest amplitudes in each group is calculated so that the three voltage vectors with the largest amplitudes in the action time are within the range of The resultant voltage on the plane is zero including: According to the total action time of the three voltage vectors with the largest amplitudes in each group and the The angles between the three voltage vectors with the largest amplitudes on the plane and the x-axis are calculated to obtain the action time of the three voltage vectors with the largest amplitudes in each group, so that the three voltage vectors with the largest amplitudes are within the action time. The resultant voltage on the plane is zero.

4. The pulse width modulation method according to claim 1, wherein: Calculating and synthesizing the action time of each of the voltage vectors of the determined virtual voltage vector includes: calculating the action time of the determined virtual voltage vector; The action time of each voltage vector used to synthesize the determined virtual voltage vector is calculated according to the action time of the virtual voltage vector.

5. The pulse width modulation method according to claim 4, characterized in that: The action time of the virtual voltage vector and the zero vector determined by the calculation includes: The virtual voltage vector and the action time of the zero vector are determined by calculating the volt-second theorem of space vector modulation; the zero vector is in the On the plane and in the The voltage components on the plane are all zero.

6. A pulse width modulation device for a six-phase motor with double Y windings shifted 30 degrees, characterized in that: include: Synthesis module for the six-phase motor The voltage vector on the plane synthesizes a virtual voltage vector; wherein the virtual voltage vector is The voltage component on the plane is zero, and the virtual voltage vector The voltage component on the plane is zero; a determination module, configured to determine, according to a target voltage vector, the virtual voltage vector and the zero vector required to synthesize the target voltage vector; a calculation module, configured to calculate the action time of each of the voltage vectors and the zero vector for synthesizing the determined virtual voltage vector; An output module, configured to output the corresponding voltage vector and the zero vector within the action time; The synthesis module is specifically used to The voltage vector with the largest amplitude on the plane is synthesized into the virtual voltage vector; The synthesis module includes: Synthetic unit for The three adjacent voltage vectors with the largest amplitude on the plane are grouped together to form a candidate virtual voltage vector; the candidate virtual voltage vector is The voltage component on the plane is zero; A screening unit is configured to screen out the virtual voltage vector from the candidate virtual voltage vectors; the screened virtual voltage vector satisfies: one of the three adjacent voltage vectors with the largest amplitudes of the synthesized screened virtual voltage vector is in the The voltage component on the plane is zero, and the other two voltage vectors are in the The voltage components on the plane are equal in magnitude and opposite in direction.

7. The pulse width modulation device according to claim 6, characterized in that The synthesis unit comprises: The calculation subunit is used to calculate the action time of the three voltage vectors with the largest amplitudes in each group, so that the three voltage vectors with the largest amplitudes in the action time are within the range of The resultant voltage on the plane is zero; A synthesis subunit is configured to synthesize the three voltage vectors with the largest amplitudes according to the action time to obtain the candidate virtual voltage vector.

8. The pulse width modulation device according to claim 7, characterized in that: The calculation subunit is specifically configured to calculate the total action time of the three voltage vectors with the largest amplitudes in each group and the The angles between the three voltage vectors with the largest amplitudes on the plane and the x-axis are calculated to obtain the action time of the three voltage vectors with the largest amplitudes in each group, so that the three voltage vectors with the largest amplitudes are within the action time. The resultant voltage on the plane is zero.

9. The pulse width modulation device according to claim 6, characterized in that The calculation module includes: a first calculation unit, configured to calculate the determined action time of the virtual voltage vector; The second calculation unit is configured to calculate, according to the action time of the virtual voltage vector, the action time of each voltage vector that is synthesized to obtain the determined virtual voltage vector.

10. The pulse width modulation device according to claim 9, characterized in that: The first calculation unit is specifically used to calculate the determined virtual voltage vector and the action time of the zero vector according to the volt-second theorem of space vector modulation; the zero vector is in the On the plane and in the The voltage components on the plane are all zero.

11. A pulse width modulation device for a six-phase motor with dual Y windings shifted 30 degrees, characterized in that: include: memory for storing computer programs; A processor is configured to implement the steps of the pulse width modulation method for a six-phase motor with a dual Y winding shifted 30 degrees as described in any one of claims 1 to 5 when executing the computer program.

12. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the pulse width modulation method of a six-phase motor with a dual Y winding shifted 30 degrees as claimed in any one of claims 1 to 5.

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