CN115664296A - Stator winding reconfiguration switching topology and motor system - Google Patents

Abstract

The invention relates to the technical field of motors, and particularly discloses a stator winding reconstruction switching topology and a motor system. The stator winding reconstruction switching topology comprises a three-phase input end and three bus lines respectively connected with the three-phase input end. The output ends of the three bus lines are mutually connected, the three bus lines have the same structure, and each bus line is composed of a plurality of branch lines; the branch circuit is provided with a stator winding and at least one switch, when the main circuit comprises a plurality of branch circuits, a switch branch circuit is arranged between the stator windings of the adjacent branch circuits, the switch branch circuit is provided with at least one switch, and the number of the stator windings of the main circuit is adjusted through the on-off control of the switch. Each switch of this application accessible flexible operation, change the motor characteristic in order to satisfy complicated operating mode, make the operation of motor system can realize different rotational speeds, and then realize wide speed domain operation, improve motor drive system's operational reliability and fault tolerance simultaneously.

Description

Stator winding reconfiguration switching topology and motor system

Technical Field

The invention relates to the technical field of motors, in particular to a stator winding reconstruction switching topology and a motor system.

Background

With the development of the times, the electric vehicles are gradually popularized, and the motor system serving as a core unit of the electric vehicles also gradually enters the visual field of people. The motor system has the action principle that chemical energy stored in the battery is converted into mechanical rotary motion output by the rotating shaft through electromagnetic energy, and then the corresponding vehicle is driven. Taking an electric automobile as an example, a motor system of the electric automobile adopts a high-performance alternating current motor, the high-precision sensor is precisely controlled through algorithms such as vector control, direct torque control and the like, and the rotating speed and the torque output by a motor shaft are reduced through combination of amplification of a transmission ratio of a mechanical gearbox, so that the load requirement is met.

However, in most cases, the conventional high-performance motors, such as induction motors, permanent magnet synchronous motors, brushless dc motors, etc., have substantially constant stator electromagnetic structure parameters, which makes the output performance of the motors limited, for example, the motor system cannot operate in a wider speed range, cannot simultaneously meet the requirements of outputting large torque in a low-speed stage, and breaks through power limitation to continue to increase the speed in a high-speed stage, otherwise, the motors are designed to be large and bulky, and the power density is greatly reduced. Meanwhile, the current increase under partial conditions can cause great temperature rise of a controller, a motor and the like, the efficiency of the whole motor system is reduced, and the reliability is difficult to guarantee.

Secondly, because the direct output of the motor to the load can not meet the performance requirement, a mechanical transmission device such as a speed changer can be added to solve the problem generally. However, this type of device is composed of a large number of metal gears, occupies a large space and volume, and because of its heavy weight, the system additionally increases load, so that the friction between gears generates loss, which runs counter to the development direction of spacious, light-weighted and high-efficiency inside electric traffic.

In addition, in the actual operation process of the motor system, due to the problems of overvoltage, overcurrent and the like, the internal temperature rises, so that the turn-to-turn insulation of the motor winding fails, a short circuit fault is formed, the motor winding is burnt, and even electromagnetic force is generated to cause the motor winding to generate an open circuit fault. And the motor controller can act when detecting a corresponding fault signal, and the motor is braked emergently to prevent the further diffusion of the fault. However, this causes the motorized vehicle to stop working directly, which causes economic loss and even threatens personal safety. Although two motors can be adopted to drive the load, the reliability and the flexibility of the electric vehicle are greatly improved, but the defects of increased economic cost, multiple space occupation volume, reduced overall efficiency and the like are still unavoidable.

Therefore, how to improve the efficiency of the motor system, improve the endurance capacity of the motor system, and improve the fault tolerance and reliability of the motor system while the internal structure of the electric vehicle is compact and small is still urgent to solve.

Disclosure of Invention

The invention discloses a stator winding reconstruction switching topology and a motor system, which can flexibly switch reconstruction, realize wide-speed-range operation, occupy small space, have high operation efficiency and improve the operation reliability of the motor system.

In order to achieve the purpose, the invention provides the following technical scheme:

a stator winding reconfiguration switching topology comprising: the three-phase input end and the three bus lines are respectively connected with the three-phase input end;

the output ends of the three bus lines are mutually connected, the three bus lines have the same structure, and each bus line is composed of one or a plurality of branch lines;

the branch circuit is provided with a stator winding and at least one switch, when the main circuit comprises a plurality of branch circuits, a switch branch circuit is arranged between the stator windings of the adjacent branch circuits, the switch branch circuit is provided with at least one switch, and the number of the stator windings of the main circuit is adjusted through the on-off control of the switch.

Optionally, the branch includes a first branch and a second branch, the first branch includes the stator winding and a switch, the second branch includes the stator winding and two switches, and the two switches are located on two sides of the stator winding respectively.

Optionally, a first end of the switching branch between the adjacent branches is disposed between the output end of the stator winding of one branch and the input end of the switch, and a second end of the switching branch is disposed between the input end of the stator winding of the other branch and the output end of the switch.

Optionally, the connection between the output ends of the three lines is a star connection or a delta connection.

Optionally, the stator winding is a one-phase stator winding.

A motor system comprises an inversion module and a stator winding reconstruction switching topology;

and the output end of the inversion module is connected with the three-phase input end.

Optionally, the inversion module selects a three-phase half-bridge topology.

The invention has the beneficial effects that:

(1) The invention can flexibly change the winding structure of the motor by controlling the switch state, thereby changing the characteristics of the motor to meet complex working conditions, and being equivalent to that a plurality of motors with different output characteristics can work selectively.

(2) The invention realizes the wide-speed-range operation, ensures that the motor outputs larger torque at low speed due to the increase of the number of the stator windings which can be connected in series, consumes less current when the output torque is the same, and reduces the problems of motor loss, irreversible demagnetization risk of the permanent magnet, short-time operation and the like.

(3) The invention changes the equivalent turns of the motor by changing the serial number of the stator windings, so that the same motor system has a plurality of rotating speeds to replace a mechanical gearbox, thereby achieving the effects of light weight, small occupied space and small friction loss of the metal gear.

(4) When the winding fails, the corresponding branch switch can be disconnected in time to remove the failure part, so that the operation reliability and fault tolerance of the motor driving system are improved.

Drawings

Fig. 1 is a schematic diagram of a stator winding reconfiguration switching topology according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a stator winding reconfiguration switching topology one-phase structure according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a motor system according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a motor system according to an embodiment of the present invention;

fig. 5A is a schematic diagram of a winding single-series connection structure according to an embodiment of the present invention;

fig. 5B is a schematic diagram of a winding double series connection structure according to an embodiment of the present invention;

fig. 5C is a schematic diagram of a winding three-series structure according to an embodiment of the present invention;

fig. 5D is a schematic diagram of a series connection structure of windings n according to an embodiment of the present invention;

fig. 6A is a schematic diagram of a single-parallel winding structure according to an embodiment of the present invention;

fig. 6B is a schematic diagram of a winding double parallel connection structure according to an embodiment of the present invention;

fig. 6C is a schematic diagram of a three-parallel connection structure of windings according to an embodiment of the present invention;

fig. 6D is a schematic diagram of a parallel connection structure of windings n according to an embodiment of the present invention;

FIG. 7A is a diagram of a single series winding state provided by an embodiment of the present invention;

FIG. 7B is a diagram of a dual series winding arrangement according to an embodiment of the present invention;

FIG. 7C is a diagram of a three-winding series state according to an embodiment of the present invention;

FIG. 7D is a diagram of a dual parallel winding arrangement according to an embodiment of the present invention;

FIG. 7E is a diagram of a three-parallel state of windings provided by an embodiment of the present invention;

fig. 7F is a diagram of a hybrid series-parallel state of windings according to an embodiment of the present invention.

Reference numerals:

11-a first branch; 12-a second branch; 13-switching the branch; 2-stator winding; 3-a first switch;

311-first input switch; 312-a second input switch; 321-a first output switch;

322-a second output switch; 4-a second switch; 41-first branch switch; 42-a second branch switch;

5-a direct current power supply; 6-direct current bus capacitor; 7-a freewheeling diode; 8-fully controlled device.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The application provides a stator winding reconfiguration switching topology and a motor system, as shown in fig. 1, the stator winding reconfiguration switching topology includes a three-phase input end and three bus lines respectively connected with the three-phase input end. The three-phase input end comprises an A-phase input end A, a B-phase input end B and a C-phase input end C which are connected in parallel, and each input end is correspondingly connected to the conventional inverter module. The input ends of the three main lines are respectively connected with an A-phase input end A, a B-phase input end B and a C-phase input end C, and the output ends of the three main lines are commonly connected to a neutral point N to be in star connection and also can be in angular connection according to actual conditions.

The three bus lines are identical in structure, and each bus line is composed of at least one branch line. The branch circuit is provided with the stator winding 2 and at least one switch, the on-off of the stator winding 2 on the branch circuit can be changed by operating the on-off of the switch, the stator winding 2 cannot be used when the switch is turned off, and the stator winding 2 can be normally used in the main circuit when the switch is turned on. When the bus circuit comprises a plurality of branches, a switch branch is arranged between the stator windings of the adjacent branches, at least one switch is arranged on the switch branch, the stator windings 2 on the adjacent branches can be changed into a serial state by switching on the switch branch, and the stator windings 2 on the adjacent branches can be changed into a parallel state by switching off the switch on the switch branch. The structure of the stator winding 2 of the main circuit and the series-parallel connection relation between the stator windings 2 can be changed through the on-off control of the switches on each branch circuit and the switch branch circuits, along with the change of the structure of the stator winding 2 of the main circuit, the equivalent turn number of the motor is changed, and further the range of the operable rotating speed of the motor is influenced.

Specifically, the branch is composed of a first branch 11 and a second branch 12, and the first branch 11 is provided with a stator winding 2 and a first switch 3; the second branch 12 is provided with a stator winding 2 and two first switches 3, and the two first switches 3 are respectively arranged on one side of the input end and one side of the output end of the stator winding 2; when the bus line comprises a plurality of branches, the switch branch 13 is disposed between two adjacent branches connected in parallel, and at least one second switch 4 is disposed on the switch branch for controlling on/off of the switch branch. The first end of the first switch is arranged between the output end of the stator winding 2 of the previous branch and the input end of the first switch 3 at one side of the output end of the stator winding 2, and the second end of the first switch is arranged between the input end of the stator winding 2 of the next branch and the output end of the first switch 3 at one side of the input end of the stator winding 2. It should be understood that the sequence of the two ends of the switching branch 13 is not fixed, and may be changed according to the change of the branch group, as shown in fig. 2, the first end of the switching branch 13 may also be disposed between the input end of the stator winding 2 of the previous branch and the output end of the first switch 3 on the input end side of the stator winding 2, and the second end of the switching branch 13 may also be disposed between the output end of the stator winding 2 of the next branch and the input end of the first switch 3 on the output end side of the stator winding 2.

The number of the branches in the branch group is set to be n, and the total branches are different in structure when the number of the branches is different. When n =1, the bus is formed by one first branch 11; when n =2, the bus route is composed of two first branches 11 connected in parallel and one switching branch 13 connecting the two first branches 11; when n >2, the bus route is composed of two parallel first branches 11, n-2 second branches 12, and n-1 switch branches 13 connecting the branch groups. For example, when n =3, the bus route is composed of two first branches 11, one second branch 12, and two switching branches 13.

Referring to fig. 1 and 3, each branch group in each bus line is composed of n branches and n-1 switch branches 13, and the first switch 3 is divided, the first switch 3 on the input side of the stator winding 2 is divided into a first input switch 311, a second input switch 312, a first output switch 321, a second output switch 322, and a second switch 4 is divided into a first branch switch 41, a second branch switch 42, and the like. Each bus line comprises n-1 input switches, n-1 output switches and n-1 second switches 4, for a total of 3n-3 switches connecting the ends of the stator windings 2 together.

The stator windings 2 selected in the embodiment of the present application are all one-phase stator windings, but it should be noted that the multi-phase stator windings can also be applied in the embodiment of the present application, and the number of phases of the stator windings 2 on each branch in each bus line should be the same.

The application also provides a motor system, which comprises the stator winding reconstruction switching topology and the inversion module, wherein the output end of the inversion module is connected with the three-phase input end. In the embodiment of the present application, the topology structure adopted by the inverter module is a two-level three-phase half-bridge topology, and includes a dc current power supply 5, a dc bus capacitor 6, and a three-phase winding module, where the output end of the three-phase winding module is connected to the three-phase input end of the reconstructed switching topology of the stator winding, respectively. A freewheeling diode 7 and a full-control device 8 are arranged in the three-phase half-bridge topology, and other devices such as an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), and the like can be replaced according to actual conditions.

Specifically, the form of the line basic unit adopted by the inverter module is not limited to a two-level three-phase half-bridge topology, and multi-level inverter topology forms such as a three-level inverter topology, a five-level inverter topology, a seven-level inverter topology and the like can be adopted, so that the highest output voltage of the inverter module is increased under the condition that the withstand voltage grade of the used power device is not changed, and the withstand voltage grade of the used power device is reduced under the condition that the highest output voltage of the inverter module is not changed. The multi-level inversion topology can further improve the usable voltage level of each phase winding, so that the motor system can operate at high power density.

According to the circuit structure designed by the application, by controlling different switches, each bus circuit can form a plurality of stator winding series connection modes such as n-section series connection, n-1-section series connection of 8230, two-end series connection, single-section series connection and the like. Under the structure type, along with the increase of the number of the series sections of the stator winding 2, when the motor shaft outputs the same electromagnetic torque, the side line current of the inverter module required by the motor system is gradually reduced, and the equivalent turns of the motor are gradually increased. In addition, each bus line can also form n sections of parallel connection, n-1 sections of parallel connection, a plurality of stator winding 2 parallel connection modes such as 8230, two-end parallel connection, single-section parallel connection and the like. Along with the increase of the number of the parallel-connected sections of the stator winding 2, the equivalent impedance of each phase winding of the motor system is gradually reduced.

In addition, the switch can be flexibly adjusted according to the change of the actual working condition, the series connection structure and the parallel connection structure are combined to form a series-parallel connection structure, and the effects of reducing line current and reducing equivalent impedance are achieved at the same time. By changing the series connection mode, the parallel connection mode and the series-parallel connection mode among the stator windings, the equivalent turns of each phase of the motor winding can be changed in multiples, and corresponding inductance, resistance and flux linkage parameters are also changed; the basic speed of the motor is changed along with the switching reconstruction of the winding structure, so that the wide-speed-range speed regulation of a motor system is realized; the motor can output larger torque at low speed, and the consumed current is smaller when the output torque is the same, so that the loss is reduced.

Specifically, in the series structure, the number of windings that each phase of the stator winding 2 can be connected in series is set to S. Because the magnetic field intensity in the motor is approximately in direct proportion to the equivalent turns of the motor, the smaller the equivalent turns and the smaller the magnetic field intensity under the condition that the output of the inverter module is unchanged, the effect of weakening the magnetic field is achieved, and the speed increasing effect of weakening the magnetic field is achieved. That is, as the number S of windings that can be connected in series increases, the range of operable rotational speeds of the electric machine system is multiplied. For example, when S = N, the operable rotation speed range is N times the operable rotation speed range when S =1, and N-1 times the operable rotation speed range when S = 2. Under the condition of not considering other factors, as long as the number S of the series windings is large enough, the motor system can realize the operation of n times of wide speed range under the condition of single series winding.

When S = N, as shown in fig. 5A to 5D, the operable rotational speed of the electric machine system is multiplied as the number of stator windings actually connected in series per phase of the stator winding 2 is reduced. For example, the operable rotation speed in the case of a single-string winding structure is n times the operable rotation speed in the case of an n-string winding structure, the operable rotation speed in the case of a double-string winding structure is n-1 times the operable rotation speed in the case of an n-string winding structure, and the operable rotation speed in the case of a three-string winding structure is n-2 times the operable rotation speed in the case of an n-string winding structure.

Specifically, in the parallel structure, the number of stator windings that can be connected in parallel per phase of the stator winding 2 is set to P. When P = N, as shown in fig. 6A-6D, under the condition that the terminal voltage is not changed, as the number of actual parallel stator windings increases, since the equivalent turns of each phase winding is not changed, but the equivalent impedance is gradually reduced, the current density is continuously increased, and the motor system is gradually applied to the low-voltage high-current operation mode. Each voltage class has a suitable parallel winding configuration corresponding thereto, irrespective of other factors.

As further described with reference to fig. 3 and 6, the number of branches included in the branch group is set to 3, that is, when N =3, the states of the motor system in different cases are compared. By flexibly operating the switches, the stator winding 2 may include six winding states as shown in fig. 7A-7F, analyzed in conjunction with fig. 3 and 7A-7F, a winding single series configuration as shown in fig. 7A, a winding double series configuration as shown in fig. 7B, a winding triple series configuration as shown in fig. 7C, a winding double parallel configuration as shown in fig. 7D, a winding triple parallel configuration as shown in fig. 7E, and a winding hybrid series parallel configuration as shown in fig. 7F, respectively.

Specifically, in fig. 7A, to form a winding single series configuration, the first output terminal switch 321 may be turned on, and the remaining switches may be turned off; or the first input switch 311 and the second output switch 322 are switched on, and the other switches are switched off; or turn on the second input switch 312 and turn off the remaining switches. In fig. 7B, to form the winding double series structure, the first branch switch 41 and the second output terminal switch 322 may be turned on, and the remaining switches may be turned off; or the first input terminal switch 311 and the second branch switch 42 are turned on, and the remaining switches are turned off. In fig. 7C, to form a winding three-series configuration, the first branch switch 41 and the second branch switch 42 may be turned on, and the remaining switches may be turned off. In fig. 7D, to form the winding double parallel structure, the first output switch 321, the second output switch 322 and the first input switch 311 can be turned on, and the rest of the switches can be turned off; or turn on the first input terminal switch 311, the second input terminal switch 312, and the second output terminal switch 322; or turns on the first input terminal switch 311 and the first output terminal switch 321. In fig. 7E, to form a winding triple parallel structure, the first input terminal switch 311, the second input terminal switch 312, the first output terminal switch 321, and the second output terminal switch 322 may be turned on. In fig. 7F, to form the winding hybrid series-parallel structure, the first bypass switch 41, the second output terminal switch 322, and the second input terminal switch 312 may be turned on. It should be understood that the manner of operation of the switch is not limited thereto, and as the number of branches increases, the manner of operation of the switch is more versatile.

In addition, because the connection modes of the motor windings are different, the parameters of the motor system are changed, so that the output performance is different. The embodiment provides three series connection modes, corresponding to three different equivalent turns of the motor, namely corresponding to three different rotation speed levels, and the electromagnetic torque changes accordingly, which is equivalent to the effect of a transmission. For example, the rated rotation speed and the rated torque of the winding three-series structure in fig. 7C are set to 2000r/min and 30Nm; the rated rotation speed of the winding double series connection structure and the mixed series-parallel connection structure in the figures 7B and 7F is 3000r/min, and the rated torque is 20Nm; the rated rotating speed of the winding single series connection structure, the winding double parallel connection structure and the winding triple parallel connection structure in the rest of the drawings A, D and E is 6000r/min, and the rated torque is 10Nm. It should be noted that the winding structure may have the same rated rotation speed and rated torque, but the parameters are different except that the equivalent turns are the same, and the winding structure can be applied to different voltage levels according to the size of the equivalent impedance.

In the practical application process, when a part of windings have faults, the connection of the fault part can be cut off by disconnecting or removing the switch after the position of the fault winding is detected, other windings can continue to operate without being influenced, the fault-tolerant operation without stopping is realized, and the reliability of a motor system is enhanced.

It will be apparent to those skilled in the art that various changes and modifications may be made in the embodiments of the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims (8)

1. A stator winding reconfiguration switching topology comprising: the three-phase input end and the three bus lines are respectively connected with the three-phase input end;

the output ends of the three bus lines are mutually connected, the three bus lines have the same structure, and each bus line is composed of a plurality of parallel branches;

the stator winding and the at least one switch are arranged on the branch circuit, a switch branch circuit is arranged between the stator windings of the adjacent branch circuits, the switch branch circuit is provided with the at least one switch, and the stator winding structure of the main circuit is changed through the on-off control of each switch.

2. The stator winding reconfiguration switching topology according to claim 1, wherein said legs comprise a first leg and a second leg, said first leg comprising said stator winding and a switch, said second leg comprising said stator winding and two switches, said two switches being located on either side of said stator winding.

3. The stator winding reconfiguration switching topology according to claim 2, wherein a first end of said switching leg between adjacent said legs is disposed between an output of said stator winding of one of said legs and an input of said switch, and a second end of said switching leg is disposed between an input of said stator winding of another of said legs and an output of said switch.

4. The stator winding reconfiguration switching topology according to claim 3, characterized in that the number of said branches constituting said total line is n;

when n =2, the bus is formed by two of the first branches and one of the switch branches;

when n >2, the bus is composed of two first branches, n-2 second branches and n-1 switch branches.

5. The stator winding reconfiguration switching topology according to claim 1, wherein the connections between the outputs of said three lines are star-connected or delta-connected.

6. The stator winding reconfiguration switching topology according to claim 1, wherein said stator winding is a one-phase stator winding.

7. An electric machine system comprising an inverter module and a stator winding reconstruction switching topology according to any of claims 1-6;

and the output end of the inversion module is connected with the three-phase input end.

8. The electric machine system of claim 7, wherein the inverter module selects a three-phase half-bridge topology.

Images