Permanent magnet synchronous motor topological structure and wide variable speed power generation method

Abstract

The invention belongs to the field of permanent magnet synchronous generators, and relates to a permanent magnet synchronous motor topological structure and a wide variable speed power generation method. The topological structure of the permanent magnet synchronous motor comprises three-phase windings, three winding switching devices, a three-phase uncontrolled rectifier bridge and a DC-DC converter, each winding in the three-phase windings is divided into two sub-windings which are connected in series, the negative ends of the three-phase windings are connected to serve as neutral points, one end of each winding switching device is connected with one bridge arm of the three-phase uncontrolled rectifier bridge, and the other end of each winding switching device is connected with the other bridge arm of the three-phase uncontrolled rectifier bridge. The other end of each winding switching device is connected with the positive end of the first sub-winding or the positive end of the second sub-winding of the corresponding phase, the output end of the three-phase uncontrolled rectifier bridge is connected with the input end of the DC-DC converter, and the output end of the DC-DC converter serves as output.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of permanent magnet synchronous generator, and relates to a permanent magnet synchronous motor topology structure and a wide variable-speed power generation method. BACKGROUND

[0002] The existing low-power permanent magnet synchronous motor direct-current power generation scheme is that the armature winding of the permanent magnet synchronous motor is rectified through a non-controlled rectification bridge and the required direct current is output through a subsequent DC / DC converter. The advantages of this scheme are as follows: the diode of the non-controlled rectification bridge has high reliability and low cost, and the short-circuit fault of the generator winding caused by rectification is greatly reduced; the system has high efficiency, simple control and fast response speed, and can meet the rapid changes of various loads. The disadvantages of this scheme are as follows: the power factor is low, the current harmonic of the motor side is large, and the applicable variable speed range is narrow. In order to obtain a wide variable speed range and high reliability conversion, the voltage withstand level of the DC / DC converter device needs to be improved, which significantly increases the size, weight and cost of the DC / DC converter. SUMMARY

[0003] The application aims to provide a permanent magnet synchronous motor topology structure and a wide variable-speed power generation method. By switching the number of turns of the armature winding of the permanent magnet synchronous motor in the low-speed and high-speed power generation stages, the applicable variable speed range can be widened by 2 times under the same voltage withstand level of the DC / DC converter.

[0004] TECHNICAL SCHEME A permanent magnet synchronous motor topology structure comprises three-phase windings, three winding switching devices, a three-phase non-controlled rectification bridge and a DC-DC converter. Each phase winding in the three-phase windings is divided into two series-connected sub-windings, and the negative terminal of the three-phase winding is connected as a neutral point. One end of each winding switching device is connected to one bridge arm of the three-phase non-controlled rectification bridge, and the other end of each winding switching device is connected to the positive terminal of the first sub-winding or the positive terminal of the second sub-winding of the corresponding phase. The output terminal of the three-phase non-controlled rectification bridge is connected to the input terminal of the DC-DC converter, and the output terminal of the DC-DC converter is used as an output.

[0005] Further, each phase winding in the three-phase windings is divided into two series-connected sub-windings according to the spatial position of the slot.

[0006] Further, the three-phase windings are in the form of concentrated windings.

[0007] Further, the three-phase windings are in the form of distributed windings.

[0008] Further, the first sub-windings of each phase winding in the three-phase windings are uniformly distributed in the stator slot.

[0009] Further, the three-phase windings are in the form of concentrated windings.

[0010] Further, the three-phase winding adopts circular wire or flat wire double-layer lap winding.

[0011] Further, the three-phase winding is 60° phase belt or 120° phase belt.

[0012] A wide variable speed power generation method, the method is executed by means of the permanent magnet synchronous motor topology structure described above, the method comprises: Low speed power generation stage, the other end of each winding switching device is connected with the positive end of the corresponding phase second sub-winding respectively, and the series number of the armature winding of each phase is 2N; High speed power generation stage, the other end of each winding switching device is connected with the positive end of the corresponding phase first sub-winding respectively, and the series number of the armature winding of each phase is N.

[0013] Beneficial effects: The original technology adopts a DC / DC converter with 2 times voltage withstand level, and is suitable for a permanent magnet machine with 2 times variable speed range; the present application adopts a DC / DC converter with 2 times voltage withstand level, and is suitable for a permanent magnet machine with 4 times variable speed range. Under the same voltage withstand level of the DC / DC converter, the present application can widen the variable speed range by 2 times, thereby reducing the system size, weight and cost. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a schematic diagram of embedded winding of three-phase winding of a 60° phase belt permanent magnet machine with 18 slots and double-layer lap winding; Figure 1 Figure 1 is a schematic diagram of embedded winding of three-phase winding of a 60° phase belt permanent magnet machine with 18 slots and double-layer lap winding; Figure 2 is a topological structure diagram of the permanent magnet generator working in a low speed (L) power generation stage; Figure 2 Figure 2 is a topological structure diagram of the permanent magnet generator working in a low speed (L) power generation stage; ~ Figure 3 is a topological structure diagram of the permanent magnet generator working in a high speed (H) power generation stage. Figure 3 is a topological structure diagram of the permanent magnet generator working in a high speed (H) power generation stage. Figure 3 Figure 3 is a topological structure diagram of the permanent magnet generator working in a high speed (H) power generation stage. ~ Figure 3 is a topological structure diagram of the permanent magnet generator working in a high speed (H) power generation stage. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the present application will be described in more detail below in combination with the drawings in the present application. In the drawings, the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application. The embodiments of the present application will be described in detail below in combination with the drawings.

[0016] In the description of the present application, it should be understood that the terms "center", "axial", "vertical", "upper", "lower", "upper end", "bottom end", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the present application.

[0017] The permanent magnet synchronous motor wide variable speed range direct current generation uncontrolled rectification topology comprises: a permanent magnet motor three-phase winding, a set of winding switching device, a three-phase uncontrolled rectification bridge and a DC / DC converter.

[0018] The permanent magnet motor three-phase winding is: the number of turns of each phase of the A-phase winding is 2N, the A-phase winding is equally divided into A1-phase winding and A2-phase winding, the number of turns of each phase of the A1-phase winding is N, the number of turns of each phase of the A2-phase winding is N, the A-phase winding is composed of the A1-phase winding and the A2-phase winding in series, wherein the "+" end of the A1-phase winding is connected with the "-" end of the A2-phase winding, the "+" end of the A-phase winding is the "+" end of the A2-phase winding, and the "-" end of the A-phase winding is the "-" end of the A1-phase winding; the number of turns of each phase of the B-phase winding is 2N, the B-phase winding is equally divided into B1-phase winding and B2-phase winding, the number of turns of each phase of the B1-phase winding is N, the number of turns of each phase of the B2-phase winding is N, the B-phase winding is composed of the B1-phase winding and the B2-phase winding in series, wherein the "+" end of the B1-phase winding is connected with the "-" end of the B2-phase winding, the "+" end of the B-phase winding is the "+" end of the B2-phase winding, and the "-" end of the B-phase winding is the "-" end of the B1-phase winding; the number of turns of each phase of the C-phase winding is 2N, the C-phase winding is equally divided into C1-phase winding and C2-phase winding, the number of turns of each phase of the C1-phase winding is N, the number of turns of each phase of the C2-phase winding is N, the C-phase winding is composed of the C1-phase winding and the C2-phase winding in series, wherein the "+" end of the C1-phase winding is connected with the "-" end of the C2-phase winding, the "+" end of the C-phase winding is the "+" end of the C2-phase winding, and the "-" end of the C-phase winding is the "-" end of the C1-phase winding; the three-phase winding is star-connected, and the "-" ends of the three-phase winding are connected, i.e. A1-, B1- and C1- are connected as a neutral point. The 3-pole 18-slot double-layer stacked 60° phase belt permanent magnet motor three-phase winding embedding winding schematic diagram is shown in the accompanying drawings. Figure 1

[0019] ​A winding switching device is used to selectively switch the number of series turns per phase of the armature winding, achieving 2N series turns per phase in the armature winding during low-speed power generation and N series turns per phase in the armature winding during high-speed power generation. The winding switching device includes three bidirectional contact switches: the first bidirectional contact switches are sequentially numbered 4-0#, 4-1#, and 4-2#; the second bidirectional contact switches are sequentially numbered 5-0#, 5-1#, and 5-2#; and the third bidirectional contact switches are sequentially numbered 6-0#, 6-1#, and 6-2#.

[0020] The connection method of the three-phase windings of the permanent magnet generator, a set of winding switching devices, a three-phase uncontrolled rectifier bridge, and the DC / DC converter is as follows: the "+" terminal of phase A winding (i.e., the "+" terminal of phase A2 winding) is connected to pin 4-1# of the first bidirectional contact switch, the "+" terminal of phase A1 winding is connected to pin 4-2# of the first bidirectional contact switch, and pin 4-0# of the first bidirectional contact switch is connected to one phase arm of the three-phase uncontrolled rectifier bridge; the "+" terminal of phase B winding (i.e., the "+" terminal of phase B2 winding) is connected to pin 5-1# of the second bidirectional contact switch, and the "+" terminal of phase B1 winding is connected to the second bidirectional contact bridge... Pin 5-2# of the first bidirectional contact switch and pin 5-0# of the second bidirectional contact switch are connected to one phase arm of the three-phase uncontrolled rectifier bridge; the "+" terminal of the C-phase winding, i.e., the "+" terminal of the C2-phase winding, is connected to pin 6-1# of the third bidirectional contact switch, and the "+" terminal of the C1-phase winding is connected to pin 6-2# of the third bidirectional contact switch. Pin 6-0# of the third bidirectional contact switch is connected to one phase arm of the three-phase uncontrolled rectifier bridge; the output terminal of the three-phase uncontrolled rectifier bridge is connected to the input terminal of the DC / DC converter, and the output terminal of the DC / DC converter is connected to the generator load to output the required DC power.

[0021] No-load back EMF of permanent magnet synchronous generator , of which The fundamental magnetic flux per pole. For rotational speed, Where W is the number of pole pairs and W is the number of turns in series per phase. Because it is the fundamental winding factor, therefore the no-load back EMF is... With rotational speed It is directly proportional to the number of turns W in series per phase. To simplify the analysis, the armature winding resistance and leakage reactance of the permanent magnet synchronous motor after the load are ignored. Therefore, the output voltage after the load is... .

[0022] Permanent magnet synchronous motor with wide speed range ( ~ The methods for generating electricity are as follows: 1) When the permanent magnet generator is operating at low speed ( ~ During the power generation phase, the topology is as shown in the attached diagram. Figure 2As shown, pin 4-0# of the first bidirectional contact switch is connected to pin 4-1# via a contact, pin 5-0# of the second bidirectional contact switch is connected to pin 5-1# via a contact, and pin 6-0# of the third bidirectional contact switch is connected to pin 6-1# via a contact. Therefore, the three-phase windings A, B, and C, each with 2N turns in series, are rectified and output through a three-phase uncontrolled rectifier bridge module. ~ DC current, ( ~ The DC power is converted into a stable DC power output through a DC / DC converter.

[0023] 2) When the permanent magnet generator operates at high speed ( ~ During the power generation phase, the topology is as shown in the attached diagram. Figure 3 As shown, pin 4-0# of the first bidirectional contact switch is connected to pin 4-2# via a contact, pin 5-0# of the second bidirectional contact switch is connected to pin 5-2# via a contact, and pin 6-0# of the third bidirectional contact switch is connected to pin 6-2# via a contact. Therefore, the three-phase windings A1, B1, and C1, each with N turns in series, are rectified and output through a three-phase uncontrolled rectifier bridge module. ~ DC current, ( ~ The DC power is converted into a stable DC power output through a DC / DC converter.

[0024] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A permanent magnet synchronous motor topology, characterized in that, The application relates to a three-phase winding, three winding switching devices, a three-phase uncontrolled rectifier bridge and a DC-DC converter, wherein each phase winding of the three-phase winding is divided into two series-connected sub-windings, the negative end of the three-phase winding is connected as a neutral point, one end of each winding switching device is connected with one bridge arm of the three-phase uncontrolled rectifier bridge, the other end of each winding switching device is connected with the positive end of the first sub-winding or the positive end of the second sub-winding of the corresponding phase, the output end of the three-phase uncontrolled rectifier bridge is connected with the input end of the DC-DC converter, and the output end of the DC-DC converter is used as an output. Each phase winding of the three-phase winding is divided into two series-connected sub-windings according to the spatial position of the slots.

2. The permanent magnet synchronous machine topology of claim 1, wherein, The three-phase winding is in a concentrated winding distribution form.

3. The permanent magnet synchronous machine topology of claim 2, wherein, The three-phase winding is in a distributed winding distribution form.

4. The permanent magnet synchronous machine topology of claim 3, wherein, The first sub-winding of each phase winding of the three-phase winding is uniformly distributed in the stator slots.

5. The permanent magnet synchronous machine topology of claim 4, wherein, The three-phase winding adopts circular wire or flat wire lap winding.

6. The permanent magnet synchronous machine topology of claim 5, wherein, The three-phase winding adopts circular wire or flat wire double-layer lap winding.

7. The permanent magnet synchronous machine topology of claim 6, wherein, The three-phase winding is a 60-degree phase belt or a 120-degree phase belt.

8. The permanent magnet synchronous machine topology of claim 7, wherein, The method is executed by means of the permanent magnet synchronous motor topology structure in any one of claims 1-8, and the method comprises the following steps:

9. A method of generating power over a wide range of speeds, characterized by In the low-speed power generation stage, the other end of each winding switching device is connected with the positive end of the second sub-winding of the corresponding phase, and the series-connected turn number of each phase of the armature winding is 2N; In the high-speed power generation stage, the other end of each winding switching device is connected with the positive end of the first sub-winding of the corresponding phase, and the series-connected turn number of each phase of the armature winding is N. ​

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