JP2020162194A - Rotary electric machine winding switching device, rotary electric machine drive system, and electric apparatus - Google Patents

Abstract

To provide a winding switching device capable of inhibiting a drive system from being large-sized while enabling switching of connection states of windings of a rotary electric machine.SOLUTION: A winding switching device (9) for switching parallel connection and serial connection of a plurality of windings of a rotary electric machine comprises: a plurality of electrodes (22Us1, 22Us2, 22Ue1, 22Ue2) to which a plurality of windings (21U1, 21U2) and a power supply (U) are connected; a movable part (33) that is in contact with the plurality of electrodes and comprises a plurality of conductor parts (32a, 32b); and an actuator (31) that drives the movable part. Depending on a contact state between the plurality of electrodes and the plurality of conductor parts, the plurality of windings are connected in parallel at a first stop position of the movable part, the plurality of windings are opened at a second stop position of the movable part, and the plurality of windings are connected in series at a third stop position of the movable part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a winding switching device for switching a connection state of a rotary electric machine, a rotary electric machine drive system including a winding switching device, and an electric device driven by a rotary electric machine drive system including a winding switching device.

A technique for switching the connection state of windings is known in order to make the output characteristics of an electric motor, which is a rotary electric motor, different between a high speed range and a low speed range.

For example, the winding switching device described in Patent Document 1 includes a device main body including a plurality of electrodes to which end portions of a plurality of windings are connected, and a series connection circuit unit and a parallel connection circuit unit arranged in the switching direction. It has a movable portion including the above, and a drive device for operating the movable body in the switching direction. When the movable body is operated by the drive device and the electrodes of the device body come into contact with the electrodes of the series connection circuit section and the parallel connection circuit section movable body of the movable body, the windings of the electric motor are in series state and in parallel, respectively. Connected to the state.

Japanese Unexamined Patent Publication No. 2017-70112

Here, in a rotary electric drive system in which a mechanical load is driven at a variable speed by an electric motor, when the power supply source (for example, an inverter) to the electric motor is stopped, the electric motor is rotated by the inertia of the mechanical load and operates as a generator. Therefore, a breaker is provided to open the windings of the motor to protect the drive system. In such a rotary electric machine drive system, if the winding switching device according to the above-mentioned conventional technique is provided, there is a problem that the rotary electric machine drive system becomes large in size.

Therefore, the present invention relates to a winding switching device capable of switching the connection state of windings of a rotary electric machine while suppressing an increase in size of the drive system, a rotary electric machine drive system including a winding switching device, and a winding. Provided is an electric device driven by a rotary electric drive system including a switching device.

In order to solve the above problems, the winding switching device according to the present invention switches the parallel connection and the series connection of a plurality of windings of a rotary electric machine, and a plurality of electrodes to which the plurality of windings and a power supply are connected. A movable portion that comes into contact with a plurality of electrodes and has a plurality of conductor portions, and an actuator that drives the movable portion are provided, and the first movable portion is provided according to the contact state between the plurality of electrodes and the plurality of conductor portions. At the stop position of, a plurality of windings are connected in parallel, at the second stop position of the movable part, the plurality of windings are opened, and at the third stop position of the movable part, the plurality of windings are connected in series. To.

In order to solve the above problems, the rotary electric machine drive system according to the present invention includes a rotary electric machine and an inverter that supplies AC power to the rotary electric machine, and the winding switching device is the winding according to the present invention. It is a switching device.

In order to solve the above problems, the electric device according to the present invention is operated at a variable speed by the rotary electric machine drive system, and the rotary electric machine drive system is the rotary electric machine drive system according to the present invention.

According to the present invention, since the winding switching device can open the winding, it is possible to eliminate the need for a breaker for opening the winding of the electric motor.

Issues, configurations and effects other than those described above will be clarified by the description of the following embodiments.

It is a block diagram of the winding switching apparatus which is Example 1. FIG. It is a circuit diagram of the rotary electric machine drive system which is one Embodiment. It is a circuit diagram which shows the connection state of the three-phase winding of the three-phase AC electric motor in embodiment. It is a figure which shows an example of the relationship between the rotation speed of an electric motor, and the electric motor (motor) efficiency. It is a figure which shows an example of the current waveform when the same rectangular wave voltage is applied to the winding of a parallel connection and a series connection. It is a block diagram of the winding switching apparatus which is a comparative example with respect to Example 1. FIG. It is a block diagram of the winding switching apparatus which is Example 2. FIG. It is a block diagram of the winding switching apparatus which is Example 3. FIG. It is a block diagram of the electric railway vehicle which is one Embodiment.

First, a rotary electric machine drive system according to an embodiment of the present invention will be described with reference to FIG. 2-5.

FIG. 2 is a circuit diagram of a rotary electric machine drive system according to an embodiment of the present invention.

In the rotary electric machine drive system 1, the three-phase AC electric motor 2 is driven by the AC power from the inverter main circuit that converts DC power into AC power by the semiconductor switching element 5. As the three-phase AC motor 2, for example, a permanent magnet synchronous motor is applied.

The inverter main circuit includes a three-phase full bridge circuit including six semiconductor switching elements 5 and a recirculation diode 7 connected in antiparallel to each of the six semiconductor switching elements 5. In the present embodiment, the three-phase full bridge circuit is configured by connecting three power modules 6 in parallel. In one power module 6, two arms including a set of semiconductor switching elements 5 and a recirculation diode 7 are connected in series.

A capacitor 4 is connected to the DC input side of the three-phase full bridge circuit. The capacitor 4 smoothes the input voltage from the DC power supply 3. The voltage of the DC power supplied from the DC power supply 3 is smoothed by the capacitor 4 and input to the three-phase full bridge circuit.

The semiconductor switching element 5 is on / off controlled by the gate control signal output by the control device 10 in FIG. 2, so that the inverter main circuit converts the DC power from the DC power supply into three-phase AC power. , Output from AC output terminals (U, V, W). In this embodiment, the series connection points of the two arms in the power module 6 serve as AC output terminals. The three-phase AC motor 2 is driven by the three-phase AC power output from the inverter main circuit.

The control device 10 in FIG. 2 creates a gate control signal in response to a control command from a higher-level control device (not shown). Therefore, by setting the control command as a speed command, the three-phase AC motor 2 is driven at a variable speed.

As shown in FIG. 2, a three-phase winding connection state is established between the AC output terminals (U, V, W) of the inverter main circuit and the three-phase winding terminal group 21 of the three-phase AC motor 2. The winding switching device 9 for switching is connected. The winding switching device 9 switches the connection state of the three-phase winding in response to the winding switching command from the control device 10. As will be described later, the control device 10 connects the windings in series when the speed is in the low speed range, and connects the windings in parallel when the speed is in the high speed range, depending on the speed of the three-phase AC motor 2. Connect. The control device 10 determines whether the speed of the three-phase AC motor 2 is in a predetermined low speed range or high speed range based on the control command (speed command) and the speed detection value (or speed estimation value). Then, a winding switching command is created according to the judgment result.

The winding switching device 9 in the present embodiment has a function of opening the three-phase winding of the three-phase AC motor 2, in addition to the function of switching the connection state of the winding as described above, that is, the three-phase winding and the inverter main. It has a function of cutting off the electrical connection with the circuit. As a result, when the operation of the inverter main circuit is stopped due to a failure or the like, the three-phase AC motor 2 rotates due to mechanical inertia to operate the generator, and a large current flows through the three-phase winding and the inverter main circuit. Can be prevented. Further, since the winding switching device 9 has a function of opening the three-phase winding, it is not necessary to provide a breaker between the three-phase winding and the main circuit of the inverter. Therefore, while providing the winding switching device 9. However, it is possible to suppress the increase in size of the electric motor drive system.

In the inverter main circuit of FIG. 2, an electrolytic capacitor or a film capacitor can be applied as the capacitor 4. Further, the capacitor 4 may be configured by connecting a plurality of small-capacity capacitors in parallel or in series in order to increase the capacity. In FIG. 2, an IGBT (Insulated Gate Bipolar Transistor) is applied as the semiconductor switching element 5, but the present invention is not limited to this, and a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or the like may be applied. Further, the recirculation diode 7 may be externally attached to or incorporated in the semiconductor switching element. When the semiconductor switching element 5 is a MOSFET, the body diode (parasitic diode) in the element may be used as the recirculation diode 7.

FIG. 3 is a circuit diagram showing a connection state of the three-phase windings of the three-phase AC motor 2 in the present embodiment.

The three-phase AC motor 2 includes a plurality of (two in FIG. 3) three-phase windings. That is, the three-phase AC motor 2 includes a _first three-phase winding composed of a U-phase winding 21U ₁ , a V-phase winding 21V _1, and a W-phase winding 21W ₁ , and a U-phase winding 21U _2. A second three-phase winding including a V-phase winding 21V ₂ and a W-phase winding 21W ₂ winding group is provided.

The upper figure of FIG. 3 shows the connection state of the windings in parallel, and the windings of each phase in the first three-phase winding and the windings of each phase in the second three-phase winding are connected in parallel. To. For example, for the U-phase, U-phase winding 21U ₁ at the winding start and _{U s1} and winding start _{U s2} of the U-phase winding 21U ₂ is connected and _{U e1} and U-phase winding end of the U-phase winding 21U ₁ and _{U e2} winding end of the winding 21U ₂ are connected. As a result, the U-phase winding 21U ₁ and the U-phase winding 21U ₂ are connected in parallel. The U-phase winding of the three-phase AC motor 2 is configured by connecting the U-phase winding 21U ₁ and the U-phase winding 21U ₂ in parallel.

As for the V phase and the W phase, as shown in the upper figure of FIG. 3, the V phase winding 21V ₁ and the V phase winding 21V ₂ are connected in parallel as in the U phase, and the V of the three-phase AC motor ₂ is connected. A phase winding is configured, and the W phase winding 21W ₁ and the W phase winding 21W ₂ are connected in parallel to form the W phase winding of the three-phase AC motor 2.

Of both ends of the U-phase winding, V-phase winding, and W-phase winding of the three-phase AC motor 2 configured in this way, the winding end side is connected to each other to form a neutral point. That is, the U-phase winding, the V-phase winding, and the W-phase winding of the three-phase AC motor 2 are star-connected (Y-connected). Further, among both ends of the U-phase winding, the V-phase winding, and the W-phase winding of the three-phase AC motor 2, the three-phase AC power supply 8 (in FIG. 2 shows the AC outputs U and V of the inverter main circuit) is the winding start side. , W).

In the figure, similarly to the symbols U _si and U _ei (i = 1, 2) described above, V _si and V _ei indicate the winding start and winding end of the V-phase winding 21V _i , respectively, and W _si and W _ei and W _ei indicates the winding start and winding end of the W phase winding 21W _i , respectively. Hereinafter, the winding start and winding end of each phase winding will be described by symbols only as appropriate.

The lower part of FIG. 3 shows the connection state of the windings in series, and the windings of each phase in the first three-phase winding and the windings of each phase in the second three-phase winding are connected in series. .. For example, for the U-phase, and the winding start _{U s2} of the U-phase winding 21U ₁ of winding end _{U e1} and U-phase winding 21U ₂ are connected. As a result, the U-phase winding 21U ₁ and the U-phase winding 21U ₂ are connected in series. The U-phase winding of the three-phase AC motor 2 is configured by connecting the U-phase winding 21U ₁ and the U-phase winding 21U ₂ in series.

As for the V phase and the W phase, as shown in the upper figure of FIG. 3, the V phase winding 21V ₁ and the V phase winding 21V ₂ are connected in series as in the U phase, and the V of the three-phase AC motor ₂ is connected. A phase winding is configured, and the W phase winding 21W ₁ and the W phase winding 21W ₂ are connected in series to form the W phase winding of the three-phase AC motor 2.

Of both ends of the U-phase winding, V-phase winding, and W-phase winding of the three-phase AC motor 2 configured in this way, the winding end side is connected to each other to form a neutral point. That is, the U-phase winding, the V-phase winding, and the W-phase winding of the three-phase AC motor 2 are star-connected (Y-connected). Further, among both ends of the U-phase winding, the V-phase winding, and the W-phase winding of the three-phase AC motor 2, the three-phase AC power supply 8 (in FIG. 2 shows the AC outputs U and V of the inverter main circuit) is the winding start side. , W).

Next, the difference in the characteristics of the electric motor depending on the connection state of the windings will be described.

Harmonic loss W _h of the rotary electric machine is generated when the rectangular wave voltage inverter main circuit outputs are supplied to the rotary electric machine is expressed by the formula (2).

Here, K is n-order harmonic component of the proportional coefficient, V _n is a square wave voltage, the I _n is the n-order harmonic component of the current flowing in the windings. The V _n and _{I n} relation of equation (2).

Here, the impedance Zn is _expressed by the equation (3).

Here, R is the resistance of the winding of the rotating electric machine, L is the inductance of the winding of the rotating electric machine, and f _n is the frequency of the nth-order harmonic component.

Equation (4) is obtained by equations (1), (2) and (3).

Here, since R << 2πjf _n L, the equation (5) can be obtained by simplifying the equation (4).

Assuming that each inductance of the two windings whose connection state can be changed is L ₀ , the inductance L _{s of the} series connection and the inductance L _{p of the} parallel connection are represented by the equations (6) and (7), respectively.

Assuming that the harmonic losses in the case of parallel connection and series connection are W _hp and W _h , respectively, the voltage applied from the inverter main circuit is the same V _n. Therefore, in the equation (5), L = L _p , L = By using the formulas (6) and (7) as L _s , W _hp and W _{h s} are represented by the formulas (8) and (9), respectively.

Equation (8) and (9) shows, harmonic loss _{W hs} series connection is smaller than the high-frequency loss _{W hp} parallel connection.

Next, the result of the present inventor's study on the efficiency of the rotary electric machine based on such high frequency loss will be described.

FIG. 4 is a diagram showing an example of the relationship between the rotation speed of the electric motor and the electric motor (motor) efficiency.

As shown in FIG. 4, in the case of winding parallel (parallel connection), the efficiency is low in the low speed range, and the efficiency is high in the high speed range because the output can be increased. On the other hand, in the case of winding series (series connection), the efficiency is high in the low speed range, but the efficiency is low in the high speed range because the output is small.

FIG. 5 is a diagram showing an example of a current waveform when the same rectangular wave voltage is applied to the windings of the parallel connection and the series connection. Since the winding inductance of the series connection is larger than the inductance of the parallel connection as in the equations (6) and (7), as shown in FIG. 5, the harmonic component of the series connection is the harmonic component of the parallel connection. Less than.

Based on the difference in the generated loss due to the connection state of the windings as described above, the winding switching device makes a series connection in the low speed range of the rotating electric machine and a parallel connection in the high speed range of the rotating electric machine, so that the wide speed range , The rotating electric machine can be operated with high efficiency.

Hereinafter, the winding switching device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6-8 according to Examples 1 to 3 below. In each figure, those having the same reference number indicate the same constituent requirements or constituent requirements having similar functions.

FIG. 1 is a configuration diagram of a winding switching device according to a first embodiment of the present invention. In addition, FIG. 1 also shows the operation of the winding switching device. In order not to complicate the drawing, most of the symbols indicating each part of the winding switching device are shown only in the upper drawing of FIG.

As shown in the upper part of FIG. 1, the winding switching device 9 of the first embodiment has each phase winding (21U _i , 21V _i , 21W _i : i = 1, 2) constituting a plurality of three-phase windings. ) (U _si , V _si , W _si : i = 1, 2) and the end of winding (U _ei , V _ei , W _ei : i = 1, 2) are connected to a plurality of electrodes (22U _si , Movable with 22U _ei , 22V _si , 22V _ei , 22W _si , 22W _ei : i = 1, 2) and a plurality of conductor portions (32a to 32f) short-circuiting between two adjacent electrodes among these plurality of electrodes. A portion 33 and an actuator 31 for driving the movable portion 33 are provided.

The plurality of electrodes (22U _si , 22U _ei , 22V _si , 22V _ei , 22W _si , 22W _ei : i = 1, 2) are separated from each other, and each phase winding is not connected and the movable portion 33 When not short-circuited by the conductor portions (32a to 32f), they are electrically insulated from each other. Further, the plurality of electrodes are fixed to a support (not shown). Further, the plurality of conductor portions (32a to 32f) in the movable portion 33 are separated from each other and fixed to the support 34, and the support 34 is electrically insulated from each other. In addition, in this Example 1, the support 34 is composed of an insulator (the same applies to other Examples and Comparative Examples).

A plurality of electrodes (22U _si , 22U _ei , 22V _si , 22V _ei , 22W _si , 22W _ei : i = 1, 2) are arranged side by side in a predetermined direction at intervals from each other. Further, the plurality of conductor portions (32a to 32f) are arranged side by side in the same direction as the direction in which the plurality of electrodes are lined up at intervals from each other. Since the movable portion 33 is in contact with a plurality of electrodes, when the movable portion 33 is slid along the direction in which the plurality of electrodes and the conductor portions are lined up by the actuator 31, a short-circuited state of the plurality of electrodes due to the plurality of conductor portions occurs. It changes sequentially. As a result, the connection state of the windings of the three-phase AC motor changes. In the first embodiment, the first position (upper view of FIG. 1), the second position (center view of FIG. 2) and the second position of the movable portion 33 (upper view of FIG. 1) and the second position of the movable portion 33 in ascending order of movement amount of the movable portion 33 from the actuator 31 side. At the position 3 (lower figure of FIG. 1), the connection state of each phase winding is the winding parallel (upper figure of FIG. 3) and the winding open (in FIG. 3 the winding and the three-phase AC power supply 8). (Cut off electrical connection) and winding in series (lower figure in FIG. 3).

The more detailed configuration and operation of the winding switching device of the first embodiment are as follows.

As shown in the upper part of FIG. 1, each phase winding of the first three-phase winding (21U ₁ , 21V ₁ , 21W ₁ ) and the second three-phase winding (21U ₂ , 21V ₂ , 21W ₂ ). 12 electrodes 22U _s1 , 22U _s2 , 22U _e1 , 22U _e2 , 22V _s1 , 22V _s2 , 22V _e1 , 22V _e2 , 22W _s1 , 22W _s2 , 22W _e1 , 22W _{e2, which} are equal to the total number of winding start and winding end. , In this order, they are arranged side by side in a predetermined direction, in the direction away from the actuator 31 side in the first embodiment, with mutual spacing. These electrodes _{22U s1,} the _{22U s2, 22U e1, 22U e2} , 22V s1, 22V s2, 22V e1, 22V e2, 22W s1, 22W s2, 22W e1, 22W e2 , respectively, of the U-phase winding 21U ₁ Winding start _Us1 , U-phase winding 21U ₂ winding start _Us2 , U-phase winding 21U ₁ winding end U _e1 , U-phase winding 21U ₂ winding end U _e2 , V-phase winding 21V ₁ winding start V _s1 , V-phase winding 21V ₂ winding start V _s2 , V-phase winding 21V ₁ winding end V _e1 , V-phase winding 21V ₂ winding end V _e2 , W-phase winding 21 W ₁ winding start W _s1 , W-phase winding 21W ₂ winding start W _s2 , W-phase winding 21W ₁ winding end We ₁ and W-phase winding 21 W ₂ winding end We ₂ are electrically connected.

Therefore, the V-phase winding 21V ₁ and 21V ₂ are connected to the U-phase winding connection electrode group consisting of the electrodes 22U _s1 , 22U _s2 , 22U _e1 and 22U _e2 that connect the U-phase windings 21U ₁ and 21U _2. It consists of a V-phase winding connection electrode group consisting of electrodes 22V _s1 , 22V _s2 , 22V _e1 and 22V _e2 , and electrodes 22W _s1 , 22W _s2 , 22W _e1 and 22W _e2 connecting W-phase windings 21W ₁ and 21W _2. The W-phase winding connection electrodes are arranged in this order in a direction away from the actuator 31 side. Of the electrodes (for example, 22U _s1 and 22U _e2 ) located at both ends of each electrode group, the electrode (22U _s1 ) located at one end on the actuator 31 side becomes the corresponding one phase (U phase) of the three-phase AC power supply. An electrode (22U _e2 ) connected and located at the other end constitutes a neutral point (N) in the star connection of the three-phase winding.

Further, the electrodes 22U _s1 , 22V _s1 , and 22W _s1 are electrically connected to the U-phase, V-phase, and W-phase of the three-phase AC power supply (inverter main circuit in FIG. 2, respectively). Further, the electrodes U _e2 , V _e2 , and We ₂ are electrically connected to each other to form a neutral point N of a star connection (Y connection).

Further, the six conductor portions 32a, 32b, 32c, 32d, 32e, 32f included in the movable portion 33 have electrodes 22U _s1 , 22U _s2 , 22U _e1 , 22U _e2 , 22V _s1 , 22V _s2 , and 22V _{e1 in} this order. , 22V _e2 , 22W _s1 , 22W _s2 , 22W _e1 , 22W _e2 are arranged side by side at the same predetermined direction as the line-up direction, and in the first embodiment, in the direction away from the actuator 31 side.

The movable portion 33 is moved by the actuator 31 along the direction in which the plurality of electrodes (22U _s1 , ...) And the conductor portions (32a, ...) Are lined up, that is, along the operating direction in FIG. At this time, the stop position of the movable portion 33 is the position shown in the upper figure of FIG. 1 (first position), the position shown in the central view of FIG. 1 (second position), and the position shown in the lower figure of FIG. It is one of the positions of 3).

As shown in the upper part of FIG. 1, at the first position, the electrode 22U _s1 and the electrode 22 _s2 are short-circuited by the conductor portion 32a, and the electrode 22U _e1 and the electrode 22U _e2 are short-circuited by the conductor portion 32b. Accordingly, the winding start _{U s1} and winding end _{U e1} of the U-phase winding 21U ₁ is electrically connected to the winding start _{U s2} and winding end _{U e2} of the U-phase winding 21U ₂ respectively. That is, the U-phase winding 21U ₁ and the U-phase winding 21U ₂ are connected in parallel.

Further, in the first position, the electrode 22V _s1 and the electrode 22V _s2 are short-circuited by the conductor portion 32c, and the electrode 22V _e1 and the electrode 22V _e2 are short-circuited by the conductor portion 32d. Accordingly, the winding start _{V s1} and winding end _{V e1} of the V-phase winding 21V ₁ is electrically connected to the winding start _{V s2} and winding end _{V e2} of the V-phase winding 21V ₂ respectively. That is, the V-phase winding 21V ₁ and the V-phase winding 21V ₂ are connected in parallel.

Further, in the first position, the electrode 22W _s1 and the electrode 22W _s2 are short-circuited by the conductor portion 32e, and the electrode 22W _e1 and the electrode 22W _e2 are short-circuited by the conductor portion 32f. Accordingly, the winding start _{W s1} and winding end _{W e1} of the W-phase winding 21W ₁ is electrically connected to the winding start _{W s2} and winding end _{W e2} of the W-phase winding 21W ₂ respectively. That is, the W-phase winding 21W ₁ and the W-phase winding 21W ₂ are connected in parallel.

As described above, at the first position of the movable portion 33, the connection state of each phase winding of the three-phase AC motor is the winding parallel as shown in the upper figure of FIG.

As shown in the central view of FIG. 1, at the second position, the electrode 22U _s2 and the electrode 22U _e2 are in contact with the conductor portion 32a and the conductor portion 32b, respectively, but the electrode 22U _s1 and the electrode 22U _e1 are respectively conductors. Although they are adjacent to the portion 32a and the conductor portion 32b, they are both in non-contact with these conductor portions. At the second position, the electrode 22U _s1 and the electrode 22U _e1 are in contact with only the support 34 among the conductor portions and the support 34 electrically insulated from the conductor portions. .. The electrode 22U _s1 contacts the support 34 between the conductor portion 32a and the actuator 31, and the electrode 22U _e1 contacts the support 34 between the conductor portion 32a and the conductor portion 32b. As a result, the U-phase winding 21U ₁ and the U-phase winding 21U ₂ are opened.

Here, in the present embodiment 1, the plurality of electrodes and a plurality of directions in which the conductor portions are arranged, the distance of the electrodes _{22U s1} and the electrode _{22U e1,} in Figure 1, the end portion and the electrode of the electrode _{22U s1} which are opposite to each other _{22U e1} The distance L ₁ between the ends of the conductor portion 32b is set to a value larger than the width L ₂ of the conductor portion 32b (the same applies to the other conductor portions) (L ₁ > L ₂ ). As a result, at the second position, a non-contact state between the electrode 22U _s1 and the electrode 22U _e1 and the conductor portion as described above, that is, an open state of the U-phase winding 21U ₁ and the U-phase winding 21U ₂ is brought about.

Further, as shown in the central view of FIG. 1, at the second position, the electrode 22V _s2 and the electrode 22V _e2 are in contact with the conductor portion 32c and the conductor portion 32d, respectively, but the electrode 22V _s1 and the electrode 22V _e1 are Although they are adjacent to the conductor portion 32c and the conductor portion 32d, respectively, they are not in contact with these conductor portions. At the second position, the electrode 22V _s1 and the electrode 22V _e1 are in contact with only the support 34 among the conductor portions and the support 34 electrically insulated from the conductor portions. .. The electrode 22V _s1 contacts the support 34 between the conductor portion 32b and the conductor portion 32c, and the electrode 22V _e1 contacts the support 34 between the conductor portion 32c and the conductor portion 32d. As a result, the V-phase winding 21V ₁ and the V-phase winding 21V ₂ are opened.

Here, in the present embodiment 1, the plurality of electrodes and a plurality of directions in which the conductor portions are arranged, the distance of the electrode _{22V s1} and the electrode _{22V e1,} in Figure 1, the end portion and the electrode of the electrode _{22V s1} which are opposite to each other _{22V e1} The distance L ₁ between the ends of the conductor portion 32d is set to a value larger than the width L ₂ of the conductor portion 32d (the same applies to the other conductor portions) (L ₁ > L ₂ ). As a result, at the second position, the non-contact state of the electrode 22V _s1 and the electrode 22V _e1 and the conductor portion as described above, that is, the open state of the V-phase winding 21V ₁ and the V-phase winding 21V ₂ is brought about.

Further, as shown in the central view of FIG. 1, at the second position, the electrode 22W _s2 and the electrode 22W _e2 are in contact with the conductor portion 32e and the conductor portion 32f, respectively, but the electrode 22W _s1 and the electrode 22W _e1 are Although they are adjacent to the conductor portion 32e and the conductor portion 32f, respectively, they are not in contact with these conductor portions. At the second position, the electrode 22W _s1 and the electrode 22W _e1 are in contact with only the support 34 among the conductor portions and the support 34 electrically insulated from the conductor portions. .. The electrode 22W _s1 contacts the support 34 between the conductor portion 32d and the conductor portion 32e, and the electrode 22W _e1 contacts the support 34 between the conductor portion 32e and the conductor portion 32f. As a result, the W-phase winding 21W ₁ and the W-phase winding 21W ₂ are opened.

Here, in the first embodiment, the distance between the electrodes 22W _s1 and the electrodes 22W _{e1 in} the direction in which the plurality of electrodes and the plurality of conductors are arranged, and in FIG. 1, the ends of the electrodes 22W _s1 facing each other and the electrodes 22W _e1 The distance L ₁ between the ends of the conductor portion 32f is set to a value larger than the width L ₂ of the conductor portion 32f (the same applies to the other conductor portions) (L ₁ > L ₂ ). As a result, at the second position, the non-contact state between the electrode 22W _s1 and the electrode 22W _e1 and the conductor portion as described above, that is, the open state of the W-phase winding 21W ₁ and the W-phase winding 21W ₂ is brought about.

As described above, at the second position of the movable portion 33, the connection state of each phase winding of the three-phase AC motor is in the open state.

As shown in the lower part of FIG. 1, at the third position, the electrode 22U _s1 is not in contact with the conductor portion and the electrode 22U _e2 is in contact with the conductor portion 32b, as in the second position. Further, the electrode 22U _s2 and the electrode 22U _e1 are short-circuited by the conductor portion 32a. Accordingly, the winding start _{U s2} of the U-phase winding 21U ₁ of winding end _{U e1} and U-phase winding 21U ₂ are electrically connected. That is, the U-phase winding 21U ₁ and the U-phase winding 21U ₂ are connected in series.

Further, in the third position, as in the second position, the electrode 22V _s1 is not in contact with the conductor portion, and the electrode 22V _e2 is in contact with the conductor portion 32d. Further, the electrode 22V _s2 and the electrode 22V _e1 are short-circuited by the conductor portion 32c. Accordingly, the winding start _{V s2} of the winding end _{V e1} of the V-phase winding 21V ₁ V-phase winding 21V ₂ are electrically connected. That is, the V-phase winding 21V ₁ and the V-phase winding 21V ₂ are connected in series.

Further, in the third position, as in the second position, the electrode 22W _s1 is not in contact with the conductor portion, and the electrode 22W _e2 is in contact with the conductor portion 32f. Further, the electrode 22W _s2 and the electrode 22W _e1 are short-circuited by the conductor portion 32e. Accordingly, the winding start _{W s2} of _W winding end of the W-phase winding 21W _{1 e1} and W-phase winding 21W ₂ are electrically connected. That is, the W-phase winding 21W ₁ and the W-phase winding 21W ₂ are connected in series.

As described above, at the third position of the movable portion 33, the connection state of each phase winding of the three-phase AC motor is the winding series shown in the lower figure of FIG.

The actuator 31 is driven by a drive control device (not shown). This drive control device sets the stop position of the movable portion 33 to any of the above-mentioned first to third positions by driving the actuator 31 in response to the winding switching command shown in FIG.

FIG. 6 is a configuration diagram of a winding switching device which is a comparative example with respect to the first embodiment. In addition, in FIG. 6, the operation of the winding switching device is also shown in the same manner as in FIG.

In this comparative example, unlike Example 1 (FIG. 1), the distance between the electrodes 22U _s1 and the electrodes 22U _{e1 in} the direction in which the plurality of electrodes and the plurality of conductor portions are lined up, and in FIG. 6, the electrodes 22U _s1 facing each other. The distance L ₁ between the end of the electrode 22U _e1 and the end of the electrode 22U _e1 is set to a value smaller than the width L ₂ of the conductor portions (32a to 32f) (L ₁ <L ₂ ). In this case, as shown in the middle diagram of FIG. 6, in the second position of the movable portion 33, unlike Example 1, the electrode _{22U s1} that winding start _{U s1} of the U-phase winding 21U ₁ is connected, and electrodes _{22U e1} of winding end _{U e1} of the U-phase winding 21U ₁ is connected is in contact with the conductor portion of the movable portion 33. Therefore, the U-phase winding 21U ₁ and the U-phase winding 21U ₂ are not in the open state. Similarly, the V-phase winding 21V ₁ and the V-phase winding 21V ₂ , and the W-phase winding 21W ₁ and the W-phase winding 21W ₂ are not in the open state. Note that “L ₃ ” in FIG. 6 will be referred to in the description of Example 2 described later.

As described above, according to the first embodiment, the winding switching device can switch the connection state of the winding of the electric motor between the series connection and the parallel connection, and can open the winding. This makes it possible to switch the connection state of the windings of the electric motor, while suppressing the increase in size of the electric motor drive system. Further, in the first embodiment, in order to equip the winding switching device with the winding opening function, at a predetermined position (the above-mentioned second position) within the moving range of the movable portion 33 for switching the connection state. The winding start and winding end of each phase winding (21U ₁ , 21V ₁ , 21W _{1 in} FIG. 1) are prevented from contacting the conductor portion in the movable portion 33. As a result, although the winding switching device has the winding opening function, the configuration of the winding switching device is not complicated, and the winding switching device itself is not enlarged. Further, since the movable portion 33 is linearly driven by the actuator 31 to switch the winding connection, the dimension in the width direction of the winding switching device can be reduced. Therefore, even if there are restrictions on the width dimension when installing the winding switching device in the electric motor drive system, it can be installed.

FIG. 7 is a configuration diagram of a winding switching device according to a second embodiment of the present invention. Note that FIG. 7 also shows the operation of the winding switching device. In order not to complicate the drawing, most of the symbols indicating each part of the winding switching device are shown only in the upper drawing of FIG. 7.

Hereinafter, the differences from the first embodiment will be mainly described.

In the second embodiment, as shown in the upper part of FIG. 7, the electrodes (22U _si , 22U _ei , 22V _si , 22V _ei , 22W _si , 22W _{ei) to which} the winding start and winding end of each phase winding are connected are connected. : The arrangement of i = 1, 2) is different. That is, in the second embodiment, the 12 electrodes 22U _s1 , 22U _s2 , 22U _e1 , 22U _e2 , 22V _e2 , 22V _e1 , 22V _s2 , 22V _s1 , 22W _e2 , 22W _e1 , 22W _s2 , 22W _s1 In this order, they are arranged side by side in a predetermined direction, in the direction away from the actuator 31 side in the second embodiment, with mutual spacing.

Thus, between the U-phase coil connection electrode group and the V-phase coil connection electrode group, the electrodes _{22U e2} that winding end _{U e2} of the U-phase winding 21U ₂ are connected, the V-phase winding 21V ₂ The electrode 22V _e2 to which the winding end V _e2 is connected is arranged adjacent to the electrode 22V _e2 . As described above, since the electrodes 22U _e2 and 22V _{e2 form} the neutral point N, they are always at the same potential. Therefore, without compromising the electrical reliability, reducing the distance of the electrodes _{22U e2} and electrode _{22V e2,} 7, the distance _{L 4} between the end portions of the electrode _{22V e2} electrode _{22U e2} facing each other can do. For example, L ₄ is based on the distance between the V-phase winding connection electrode group and the W-phase winding connection electrode group in the above-mentioned comparative example (FIG. 6), that is, the distance L ₃ between the electrode 22V _e2 and the electrode 22W _s1. Can also be set to a small value. Therefore, the size of the winding switching device 9 can be reduced.

In the second embodiment, the arrangement of each electrode in the V-phase winding connection electrode group is different from that in the first embodiment (FIG. 1), and the arrangement of each electrode in the V-phase winding connection electrode group is different. Is also different. Therefore, between the V-phase winding connection electrode group and the W-phase winding connection electrode group, the electrode 22V _s1 to which the winding start V _s1 of the V-phase winding 21V ₁ is connected and the W-phase winding 21W ₂ The electrode 22W _e2 to which the winding end _Wee2 is connected is arranged adjacent to the electrode 22W _e2 . The electrode 22V _s1 is connected to the V phase of the three-phase AC power supply, and the electrode 22W _e2 constitutes the neutral point N. Therefore, the electrical state between the V-phase winding connection electrode group and the W-phase winding connection electrode group is the same as in Example 1 (FIG. 1) and Comparative Example (FIG. 6), and for V-phase winding connection. The distance between the electrode group and the W-phase winding connection electrode group can be the same as in Example 1 (FIG. 1) and Comparative Example (FIG. 6). Therefore, in the second embodiment, L ₄ is the distance between the V-phase winding connection electrode group and the W-phase winding connection electrode group, that is, the distance between the electrode 22V _s1 and the electrode 22W _e2 (“L ₃ ” in FIG. Corresponds to)) is set to a smaller value. That is, in the second embodiment, it is effective that the neutral point N is formed between the adjacent electrode groups and the electrodes having the same potential at all times are adjacent to each other in order to reduce the size of the winding switching device 9. It works. As a result, the size of the winding switching device can be reliably reduced.

In the second embodiment, the configuration other than the above is the same as that of the first embodiment, including the relationship between L ₁ and L ₂ (L ₁ > L ₂ ) shown in FIG.

As described above, according to the second embodiment, the winding switching device can open the windings of the electric motor and can reduce the size of the winding switching device.

FIG. 8 is a configuration diagram of a winding switching device according to a third embodiment of the present invention. Note that FIG. 8 also shows the operation of the winding switching device. In order not to complicate the drawing, most of the symbols indicating each part of the winding switching device are shown only in the upper drawing of FIG. In addition, a cross-sectional view taken along the line AA'is also shown in FIG.

Hereinafter, the differences from the first embodiment will be mainly described.

As shown in the cross-sectional view taken along the line AA', the winding switching device 9 of the third embodiment has a substantially cylindrical outer shape. The electrodes (22U _si , 22U _ei , 22V _si , 22V _ei , 22W _si , 22W _ei : i = 1, 2) connecting the phase windings are arranged inside a substantially cylindrical case. Further, the movable portion 33 having the conductor portions (32a to 32f) has a substantially cylindrical shape.

Since the electrodes connecting the phase windings are arranged inside the case having a substantially cylindrical shape, even if the electrodes are misaligned or the center position of the movable portion 33 is displaced, the electrodes are evenly applied to the movable portion 33. Contact. As a result, the life of the electrode and the conductor portion is extended, and the replacement cycle of the electrode and the conductor portion or the winding switching device itself can be extended.

In the third embodiment, the relationship between L ₁ and L ₂ shown in FIG. 1 (L ₁ > L ₂ ) is included (in FIG. 8, the relationship between L _t and L _s (L _t > L _s )), other than those described above. The configuration of is the same as that of the first embodiment.

As described above, according to the third embodiment, the winding switching device 9 can open the winding of the electric motor, and the reliability and maintainability of the winding switching device 9 are improved.

In addition, in this Example 3, the arrangement of the electrode in Example 2 may be applied. Thereby, the dimension of the columnar winding switching device 9 in the longitudinal direction can be reduced.

FIG. 9 is a configuration diagram of an electric railway vehicle according to an embodiment of the present invention.

The electric railway vehicle shown in FIG. 9 is driven by a rotary electric drive system 1 including a three-phase AC motor 2 (M). As the rotary electric machine drive system 1, one embodiment of the present invention shown in FIG. 2 is applied. Further, electric power is supplied to the rotary electric machine drive system 1 from the overhead wire 11 via a current collector. The overhead wire 11 may be either a DC overhead wire or an AC overhead wire. In the case of an AC overhead line, an AC / DC converter is mounted on the electric railway vehicle as a DC power source (“3” in FIG. 2). The electric ground in the electric railway vehicle is grounded via the wheels 13 and the rails 12.

The three-phase AC motor 2 is driven at a variable speed by the three-phase AC power from the inverter main circuit in the rotary electric machine drive system 1. The three-phase AC electric motor 2 is mechanically connected to the axle of the electric railway vehicle, and the running of the electric railway vehicle is controlled by the three-phase AC electric motor 2.

Any of Examples 1 to 3 is applied as the winding switching device included in the rotary electric machine drive system.

According to the above embodiment, the electric railway vehicle can be operated with high efficiency by switching the winding connection state of the three-phase AC motor 2 by the winding switching device. Further, since the winding switching device is provided with the winding opening function, the increase in the size of the motor driving system is suppressed even though the motor driving system is provided with the winding switching device. Therefore, an electric motor drive system including a winding switching device can be easily mounted on an electric railway vehicle.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

For example, as a rotary electric motor, in addition to a permanent magnet synchronous motor, a winding field synchronous motor, an induction motor, a switched reluctance motor, and the like can be applied.

In addition to electric railway vehicles, the rotary electric drive system can be applied to electric equipment that operates at variable speeds, such as electric vehicles, hybrid vehicles, and construction machinery.

1 rotary electric drive system, 2 three-phase AC motor, 3 DC power supply, 4 capacitors,
5 semiconductor switching elements, 6 power modules, 7 recirculation diodes,
8 three-phase AC power supply, 9 winding switching device, 10 control device, 11 overhead line,
12 rails, 13 wheels, 21 three-phase winding terminals,
21U _1, 21U ₂ U-phase winding,
21V _1, 21V ₂ V-phase winding,
21W _1, 21W ₂ W-phase winding,
22U _s1 , 22U _s2 , 22U _e1 , 22U _e2 electrodes,
22V _s1 , 22V _s2 , 22V _e1 , 22V _e2 electrodes,
22W _s1 , 22W _s2 , 22W _e1 , 22W _e2 electrodes,
31 Actuator, 32a to 32f conductor part, 33 movable part

Claims (9)

In a winding switching device that switches between parallel connection and series connection of multiple windings of a rotary electric machine,
With the plurality of electrodes to which the plurality of windings and the power supply are connected,
A movable part that comes into contact with the plurality of electrodes and has a plurality of conductor parts,
The actuator that drives the movable part and
With
Depending on the contact state between the plurality of electrodes and the plurality of conductors,
At the first stop position of the movable portion, the plurality of windings are connected in parallel.
At the second stop position of the movable portion, the plurality of windings are released.
A winding switching device characterized in that a plurality of windings are connected in series at a third stop position of the movable portion. In the winding switching device according to claim 1,
The plurality of electrodes
The winding start of the winding is connected, and the first electrode connected to the power supply is connected.
With the second electrode to which the winding end of the winding is connected,
Including
A winding switching device characterized in that the distance between the end of the first electrode and the end of the second electrode is larger than the width of the conductor. In the winding switching device according to claim 1,
The position of the movable part is
In the high-speed range of the rotary electric machine, it is the first stop position.
When the power supply is stopped, it is the second stop position.
A winding switching device characterized in that it is the third stop position in the low speed range of the rotary electric machine. In the winding switching device according to claim 1,
The winding switching device, wherein the second stop position is between the first stop position and the third stop position. In the winding switching device according to claim 1,
The plurality of electrodes
Of the plurality of windings, the first electrode to which the winding for the first phase of the rotary electric machine is connected and
Of the plurality of windings, the second electrode to which the winding for the second phase of the rotary electric machine is connected and
Including
A winding switching device characterized in that the first electrode and the second electrode are adjacent to each other and form a neutral point. In the winding switching device according to claim 5,
The plurality of electrodes
Of the plurality of windings, the third electrode to which the winding for the third phase of the rotary electric machine is connected and
Of the plurality of windings, a fourth electrode to which the winding for the second phase of the rotary electric machine is connected and
Including
The third electrode and the fourth electrode are adjacent to each other and
The third electrode constitutes the neutral point and
A winding switching device characterized in that the power supply is connected to the fourth electrode. In the winding switching device according to claim 1,
A winding switching device characterized by having a cylindrical outer shape. With a rotary electric machine
An inverter that supplies AC power to the rotary electric machine,
In a rotary electric drive system equipped with
A winding switching device for switching parallel connection and series connection of a plurality of windings of the rotary electric machine is connected between the rotary electric machine and the output of the inverter.
The rotary electric machine drive system, wherein the winding switching device is the winding switching device according to claim 1. In electric equipment operated at variable speed by a rotary electric drive system
An electric device according to claim 8, wherein the rotary electric drive system is the rotary electric drive system.

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