JP5724567B2 - AC motor winding switching device and AC motor drive system - Google Patents

Description

  The present invention relates to an AC motor winding switching device and an AC motor drive system.

  2. Description of the Related Art Conventionally, AC motors that perform drive control with an AC variable frequency power source have been widely used as drive sources for machine tools and vehicles. This AC motor is provided with the same number of windings as the number of phases of the AC variable frequency power source as an armature, and there are, for example, a Y connection or a delta connection in the case of three phases. Further, in recent years, for the purpose of speed control and torque control of this AC motor, the AC motor has two sets of windings corresponding to the number of power supply phases therein, and the AC variable for these two sets of windings. A winding switching device has been proposed in which the field of the armature is changed stepwise by switching the connection with the frequency power supply.

  As an example of a conventional winding switching device, for example, there is one described in Patent Document 1. In the winding switching device described in Patent Document 1, an AC motor is provided with the above-described two sets of windings connected in series therein, and each output side (from an AC variable frequency power supply) of each set of windings. On the opposite side to the side to which power is supplied, the short-circuiting and shut-off of the wiring of each phase can be switched by switching two switches corresponding to each. The winding whose output side is short-circuited by the switch is connected by Y connection with the switch as a neutral point. In other words, depending on the combination of switching between the two switches, the Y-connection is made only with the winding closer to the AC variable frequency power source among the two sets of windings, and the Y-connection is made with the two sets of windings connected in series It becomes possible to switch to the state.

  In a Y-connected state with only one winding, since the impedance is low, a sufficient current can flow even in a high frequency region, which is suitable for high-speed operation. In addition, in the Y-connected state with the entire two windings connected in series, since the impedance is high, a sufficient voltage can be applied even in a low frequency region, and a large torque is generated with respect to the same current for low speed operation. Preferred.

Japanese Patent No. 3948209

  However, since the electrical connection between the two windings is always maintained in the above prior art configuration, when only one winding is used, the reactance or self-inductive action in the other winding is also used. There was a risk of affecting the operating performance under the influence of electric power.

  An object of the present invention is to provide an AC motor winding switching device and an AC motor drive system that can smoothly switch between two armature windings while preventing functional adverse effects on each armature winding. is there.

In order to achieve the above object, the first aspect of the invention is an AC that switches windings related to a plurality of first armature windings and second armature windings of an AC motor fed by an inverter. A winding switching device for an electric motor, wherein the first armature winding and the second armature winding in a connection conductive path connecting the first armature winding and the second armature winding in series Between the first armature winding and the second armature winding by interrupting the electrical connection between the first armature winding and the second armature winding. A first state in which power supplied from the inverter is guided to the first armature winding, and the first armature winding and the second armature winding electrically connected in series. Switchable between the second state for guiding the power supplied from the inverter to both the winding and the second armature winding A first semiconductor switch means, said inverter or the AC voltage induced between the second armature winding and the first armature winding can exceed the breakdown voltage of the first semiconductor switch means A voltage induced between the first armature winding and the second armature winding in response to an emergency switching control signal from the outside of the winding switching device corresponding to an abnormality detection state of the motor. Path switching means for forming a current path that protects the first semiconductor switch means from overvoltage as a minimum.

  In the first invention of the present application, in the first state in which the power supplied from the inverter is guided to the first armature winding to be operated, the first armature winding and the second armature winding are caused by the first semiconductor switch means. Break the electrical connection between. Thus, unlike the conventional structure that is affected by the other armature winding even when only one armature winding is used, the first armature winding is electrically affected by the second armature winding. It is possible to demonstrate the operating performance as rated without being affected. Further, in the second state in which the power supplied from the inverter is guided to both the first armature winding and the second armature winding to be operated, the first armature winding and the second electric machine are driven by the first semiconductor switch means. The child winding is electrically connected in series. Thereby, the operation performance of both armature windings can be exhibited as rated.

  In the first invention of the present application, the electrical connection between the first armature winding and the second armature winding and the switching between the armature winding are instantaneously performed by the first semiconductor switch means constituted by the semiconductor switch element. . This eliminates an electric shock such as chattering that occurs in the case of mechanical switch means, for example, and functionally cuts off the electromagnetic influence due to the reactance or self-dielectric electromotive force between the two armature windings. it can.

As a result, it is possible to smoothly switch between the two armature windings while preventing a functional adverse effect on each armature winding. In the first invention of the present application, each semiconductor switch means, in particular, the semiconductor switch means disposed between the two armature windings can be protected from overvoltage. As a result, the safety in the drive control of the AC motor can be improved.

  According to a second invention, in the first invention, the first semiconductor switch means includes a first electrical neutral point corresponding to the first state and the inverter of the first armature winding in the first state. A first switch means for connecting a first winding output terminal on the opposite side to the connected side, and cutting off the first electrical neutral point and the first winding output terminal in the second state. And in the second state, the first armature winding and the second armature winding are connected in series, and in the first state, the first armature winding and the second armature winding The second armature winding has a second winding output terminal opposite to the side connected to the second switch means corresponding to the second state. The second electrical neutral point is connected.

  The first semiconductor switch means is configured as described above, and the first state with respect to the Y connection using two armature windings by connecting the first electrical neutral point and the second electrical neutral point. And the second state can be realized with a simple wiring configuration. Further, in the first state where the power supplied from the inverter is guided to the first armature winding to be operated, the second switch means is electrically connected between the first armature winding and the second armature winding. By shutting off, the first armature winding can reliably exhibit the operating performance as rated without being affected by the electrical influence from the second armature winding. Further, when both the first armature winding and the second armature winding are housed in one housing to constitute one motor, the second electrical neutral point is inside the housing. By being formed at the winding end portion of the sub-winding, it is possible to eliminate the external wiring, facilitate the assembly of the AC motor, and improve the productivity.

  According to a third invention, in the second invention, the first semiconductor switch means further cuts off an electrical connection between the first armature winding and the second armature winding, and A third state in which power supplied from the inverter is guided to the armature winding, and the first armature winding and the first armature winding electrically connected in parallel to each other; A fourth state in which power supplied from the inverter is guided to both of the second armature windings can be switched, and the second state of the second armature windings in the third state and the fourth state can be switched. A third switch for connecting the second winding input terminal on the side connected to the switch means to the inverter and shutting off the second winding input terminal and the inverter in the first state and the second state; Means, and the first switch means is the fourth shape. The first electrical neutral point and the first armature winding are connected to each other, and the second switch means is connected to the first armature winding in both the third state and the fourth state. The second armature winding is cut off.

  In addition to the configuration of the second invention, the first semiconductor switch means is configured in this way, and the first electrical neutral point and the second electrical neutral point are connected, so that the second armature winding is connected. A third state in which the power supplied from the inverter is guided and operated, and a fourth state in which the power supplied from the inverter is guided and operated in parallel with both the first armature winding and the second armature winding are possible. Thus, switching of the above four states with respect to the Y connection using two armature windings can be realized with a simple wiring configuration. Further, in the third state in which the power supplied from the inverter is guided to the second armature winding to be operated, the second switch means is electrically connected between the first armature winding and the second armature winding. By shutting off, the second armature winding can exhibit the operating performance as rated without being affected by the electrical influence from the first armature winding.

  According to a fourth invention, in the second or third invention, each of the first switch means and the second switch means includes at least the same number of insulated gate bipolar transistor elements as the number of phases of the plurality of phases. Features.

  Thereby, the switching speed in each semiconductor switch means can be instantaneously performed, and electrical shocks such as torque loss and braking torque generated when the switching speed is slow can be greatly reduced.

  According to a fifth invention, in the fourth invention, the first switch means and the second switch means correspond to the three-phase first armature winding and the second armature winding of the AC motor. Each includes three insulated gate bipolar transistor elements.

  As a result, it can be applied to commonly used three-phase AC motors, and general-purpose specifications with relatively low withstand current values for the elements of each semiconductor switch connected individually corresponding to each phase. Insulated gate bipolar transistor elements can be used. As a result, heat generation can be suppressed and the manufacturing cost of the winding switching device can be suppressed.

  A sixth invention is the above-mentioned fifth invention, wherein the three insulated gate bipolar transistor elements of the first switch means and the three insulated gate bipolar transistor elements of the second switch means are one It is integrated as a semiconductor module.

  As a result, the six insulated gate bipolar transistor elements provided in the winding switching device as the first switch means and the second switch means can be constituted by a single general-purpose semiconductor module including the surrounding connection wiring. it can. As a result, the wiring in the entire winding switching device can be omitted, reduced in size, and reduced in weight, and the degree of freedom of the layout in a limited installation space, for example, when applied to an electric vehicle is improved.

  According to a seventh invention, in any one of the fourth to sixth inventions, the insulated gate bipolar transistor element of the first switch means is a normally-on type switch, and the insulated gate of the second switch means. The bipolar transistor element is a normally-off type switch.

  When switching between the first state and the second state by using a normally-on type on the first switch means side and a normally-off type opposite to the above on the second switch means side, the first switch means side And the second switch means can share the drive signal.

  According to an eighth invention, in any one of the fourth to sixth inventions, the insulated gate bipolar transistor element of the first switch means is a normally-off type switch, and the insulated gate type of the second switch means. The bipolar transistor element is a normally-on type switch.

  By using a normally-on type on the second switch means side and a normally-off type opposite to the above on the first switch means side, when switching between the first state and the second state, the first switch means side And the second switch means can share the drive signal.

  According to a ninth invention, in the first invention, the inverter is arranged in parallel to both the first armature winding and the second armature winding with respect to the inverter, and in the first state, The electrical connection between the second armature windings is cut off, and the connection to the inverter constituting the delta connection only by the first armature windings, and in the second state, the series connection It has 2nd semiconductor switch means which can switch the connection to the said inverter which comprises delta connection by both 1st armature winding and said 2nd armature winding.

  Thus, by combining the switching of the first semiconductor switch means and the second semiconductor switch means, in the first state, only the first armature winding constitutes a delta connection and is connected to the inverter, and in the second state is connected in series. Both the first armature winding and the second armature winding can form a delta connection and be connected to the inverter. In the first state, the first semiconductor switch means cuts off the serial electrical connection between the first armature winding and the second armature winding, and the second semiconductor switch means is connected to the inverter and the first armature winding. In order to cut off the electrical connection between the two armature windings, the first armature winding constituting the delta connection at this time is not affected by the electrical influence from the second armature winding, and is in accordance with the rating. Operational performance can be demonstrated.

  Also, the second semiconductor switch means constituted by the semiconductor switch element also instantaneously switches between electrical connection and disconnection between the inverter and the second armature winding, and therefore, similarly to the first semiconductor switch means, electromagnetic Functional effects can be blocked functionally.

  In a tenth aspect based on the ninth aspect, the first semiconductor switch means connects the first armature winding and the second armature winding in series in the second state, and The first armature winding and the second armature winding in a state are provided with a second switch means for cutting off the first armature winding, and the second semiconductor switch means is only the first armature winding in the first state. The first armature winding of the first armature winding is connected to the inverter on the opposite side of the first winding output terminal to the inverter so that the first armature winding is connected to the inverter. The fourth switch means for cutting off the first winding output terminal of the slave winding and the inverter, and opposite to the side connected to the second switch means of the second armature winding in the first state Side second winding output end And the inverter, and the first armature winding and the second armature winding connected in series in the second state form a delta connection so that the second armature winding 5th switch means which connects a 2nd coil | winding output terminal and the said inverter, It is characterized by the above-mentioned.

  Thus, the first semiconductor switch means and the second semiconductor switch means are configured and connected to the inverter, so that the switching between the first state and the second state for the delta connection using two armature windings is simplified. It can be realized with a simple wiring configuration. In the first state in which the power supplied from the inverter is guided to the first armature winding and operated, the second switch means is electrically connected between the first armature winding and the second armature winding. And the fifth switch means cuts off the electrical connection between the second winding output terminal of the second armature winding and the inverter, so that the first armature winding becomes the second armature winding. The rated operating performance can be achieved without being affected by electrical influences from the wires.

  In an eleventh aspect based on the tenth aspect, the first semiconductor switch means and the second semiconductor switch means are further electrically connected between the first armature winding and the second armature winding. And the third state in which the power supplied from the inverter is guided to the second armature winding and the first armature winding and the second armature winding are electrically connected in parallel. A fourth state in which power supplied from the inverter is guided to both the first armature winding and the second armature winding can be switched, and the first semiconductor switch means includes the third state and the fourth state. In the fourth state, a second winding input terminal connected to the second switch means of the second armature winding is connected to the inverter, and the second state in the first state and the margin 2 state is the second state. The second winding input terminal of the armature winding and the And a third switch means for shutting off the inverter, wherein the second switch means connects the first armature winding and the second armature winding in both the third state and the fourth state. The fourth switch means shuts off the first winding output terminal of the first armature winding and the inverter in the third state, and the first armature winding in the fourth state. The first winding output terminal of the first armature winding is connected to the inverter so as to form a delta connection only, and the fifth switch means is in either the third state or the fourth state. The second winding output terminal of the second armature winding is connected to the inverter so that a delta connection is formed only by the second armature winding.

  In addition to the structure of the tenth aspect of the present invention, the first semiconductor switch means and the second semiconductor switch means are configured as described above, and connected to the inverter to guide the power supplied from the inverter to the second armature winding. And a fourth state in which the power supplied from the inverter is guided and operated in parallel with both the first armature winding and the second armature winding. The above four states can be switched with respect to the used delta connection with a simple wiring configuration. In the third state in which the power supplied from the inverter is guided to the second armature winding to be operated, the second switch means is electrically connected between the first armature winding and the second armature winding. By shutting off, the second armature winding can exhibit the operating performance as rated without being affected by the electrical influence from the first armature winding.

A twelfth aspect of the invention is characterized in that, in any one of the ninth to eleventh aspects, the path switching unit also serves as at least one of the first semiconductor switch unit and the second semiconductor switch unit.

  Thereby, it is possible to protect the semiconductor switch means from overvoltage with a simple configuration without separately providing a dedicated switch for emergency.

A thirteenth aspect of the present invention is an AC motor drive system including the AC motor winding switching device according to any one of the first to twelfth aspects of the present invention, wherein the AC motor includes a plurality of armatures having the same number of turns in each phase. The winding switching device is capable of switching the plurality of electric coil windings to at least three winding states by appropriately combining conduction and blocking of the plurality of semiconductor switch elements, and the AC motor. And a switching control device that performs switching control of the winding switching device.

A fourteenth invention is the above-mentioned thirteenth invention, further comprising a sensor for detecting various abnormalities in the entire AC motor drive system or an application including the AC motor drive system, wherein the switching control device detects a detection signal of the sensor. The winding switching device is switch-controlled based on the above.

  Accordingly, the AC motor drive system or these can be applied to an application.

  According to the present invention, it is possible to smoothly switch between the two armature windings while preventing functional adverse effects on the armature windings.

It is the block diagram which showed typically the structure of the AC motor drive system provided with the coil | winding switching apparatus which concerns on embodiment of this invention. It is a figure which shows the circuit structure of a coil | winding switching device and a three-phase AC motor. It is a figure which shows the semiconductor module which integrated the 1st switch and the 2nd switch. It is a table which shows the content of the switching control which a switching control apparatus performs with respect to each switch of a coil | winding switching apparatus. It is a figure which shows the circuit structure of the coil | winding switching apparatus and 3-phase alternating current motor in a 1st modification. It is a table which shows the content of the switching control which the switching control apparatus in a 1st modification performs with respect to each switch of a coil | winding switching apparatus. It is a figure which shows the circuit structure of the coil | winding switching apparatus and 3 phase alternating current motor in a 2nd modification. It is a table which shows the content of the switching control which the switching control apparatus in a 2nd modification performs with respect to each switch of a coil | winding switching apparatus. It is a figure which shows the circuit structure of the coil | winding switching apparatus and 3 phase alternating current motor in a 3rd modification. It is a table which shows the content of the switching control which the switching control apparatus in a 3rd modification performs with respect to each switch of a coil | winding switching apparatus. It is a figure which shows the circuit structure of the coil | winding switching apparatus and 3 phase alternating current motor in a 4th modification. It is a table which shows the content of the switching control which the switching control apparatus in a 4th modification performs with respect to each switch of a coil | winding switching apparatus.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram schematically showing the configuration of an AC motor drive system including a winding switching device according to an embodiment of the present invention.

  In FIG. 1, an AC motor drive system 100 drives a three-phase AC motor 2, and includes an inverter 1, the three-phase AC motor 2 as an AC motor, a winding switching device 3, a sensor 4, and the like. The switching control device 5 is provided.

  In this example, the inverter 1 includes six switch elements SW made of a semiconductor, and is composed of a bridge in which two sets of switch elements SW connected in series are connected in parallel. Single-phase DC power is supplied to the entire bridge, and the six switch elements SW are repeatedly turned on and off in an appropriate order, thereby allowing three-phase AC power U from between two switch elements SW connected in series in each group. , V, W are output as inverter outputs.

  The three-phase AC motor 2 is a motor driven by the three-phase AC power source output from the inverter 1, and only the winding for performing field control is shown as an armature in the drawing. The three-phase AC motor 2 used in the present embodiment has two armature windings in which three windings having the same number of turns are arranged in parallel corresponding to the respective phases U, V, and W of the three-phase AC, that is, the first An armature winding 11 and a second armature winding 12 are provided. These two armature windings 11 and 12 are not electrically connected to each other in the three-phase AC motor 2, and input terminals and output terminals that can be electrically connected from the outside of the three-phase AC motor 2 are respectively provided. Is provided. The first armature winding 11 has a first input terminal (first winding input terminal) 11a (U1, V1, W1) and a first output terminal (first winding output terminal) to the outside of the three-phase AC motor 2. ) 11b (U2, V2, W2) can be electrically connected. The second armature winding 12 has a second input terminal (second winding input terminal) 12a (U3, V3, W3) and a second output terminal (second winding output terminal) to the outside of the three-phase AC motor 2. ) 12b (U4, V4, W4) can be electrically connected (however, as will be described later, there is an exception that the second output terminal 12b is not connected from the outside). The three-phase AC motor 2 can be applied to any of an induction type, a synchronous type, a rotary type, and a direct acting type. Although not particularly shown, the two armature windings 11 and 12 are classified into those types. Appropriately configured and arranged according to the difference.

  The winding switching device 3 includes a plurality of semiconductor switch elements as will be described in detail later. The inverter outputs U, V, W, the first input terminal 11a (U1, V1, W1), and the first output terminal 11b are switched by switching the conduction and interruption of the plurality of semiconductor switch elements in an appropriate combination. (U2, V2, W2), the second input terminal 12a (U3, V3, W3) and the second output terminal 12b (U4, V4, W4) are switched between conduction and interruption. The connection circuit configuration inside the winding switching device 3 is different between this embodiment and each modification described later (details will be described later).

  The sensor 4 includes the entire AC motor drive system 100 of the present embodiment including the inverter 1, the three-phase AC motor 2, and the winding switching device 3, and applications including the AC motor drive system 100 (for example, trains and electric vehicles). Various abnormalities in the entire vehicle, machine tool, etc.) are detected and a detection signal is output to the switching control device 5.

  The switching control device 5 includes a CPU, a RAM, a ROM, an A / D converter, and the like that are not particularly shown. This switching control device 5 conducts and cuts off each of the internal six switch elements SW so as to cause the inverter 1 to output three-phase AC power at an appropriate frequency based on a command from a host control device (not shown). Switching control is performed. At the same time, the switching control device 5 performs switching control of conduction and disconnection between the inverter output and the terminals 11a, 11b, 12a, 12b of the armature windings 11, 12 by the winding switching device 3. . In the present embodiment, the winding switching device 3 is configured to guide the inverter output only to the first armature winding 11 having the Y connection out of the first armature winding 11 and the second armature winding 12. The first state, the second state in which the first armature winding 11 and the second armature winding 12 are electrically connected in series as the Y connection, and the inverter output to both are detected, and an abnormality is detected from the sensor 4 In this case, the three states of the emergency state in which the voltage applied to each of the armature windings 11 and 12 is minimized are selectively switched (detailed later).

  FIG. 2 is a diagram illustrating a circuit configuration of the winding switching device 3 and the three-phase AC motor 2 in the present embodiment. In FIG. 2, the winding switching device 3 is connected so that the inverter output is directly input to the first input terminal 11a. The first output terminal 11b is connected to the first electrical neutral point 13 that short-circuits the wiring of each phase to one point via the first switch S1 as the first switch means, and as the second switch means. The second switch S2 is connected to the second input terminal 12a. In the present embodiment, with the exception described above, the second output terminal 12b of the second armature winding 12 is not connected to the winding switching device 3, and the wiring of each phase is directly provided inside the three-phase AC motor 2. It is connected to a second electrical neutral point 14 that is short-circuited to one point.

  Of these, the first switch S1 and the second switch S2 are each composed of a set of three semiconductor switch elements that electrically connect and disconnect the wirings corresponding to the three phases. That is, switching control is performed individually for each switch S1, S2 by switching control from the switching control device 5, and the three semiconductor switch elements in each of the switches S1, S2 perform the same switching operation collectively.

  In the present embodiment, each semiconductor switch element is composed of an IGBT (Insulated Gate Bipolar Transistor) element. As shown in FIG. 3, six IGBT elements 15A, 15B, 15C, 15D, 15E, and 15F, which are a combination of the first switch S1 and the second switch S2, are integrally provided as one semiconductor module 16A. Yes.

  In this semiconductor module 16A, two IGBT elements 15A, 15D (and 15B, 15E, and 15C, 15F) connected in series are arranged in parallel, and both ends of each set are connected in series with each other. The middle point can be connected as a module terminal. The semiconductor module 16A including the six IGBT elements 15A to 15F having such a wiring configuration is highly versatile because it can be used for circuit designs having various configurations, and is currently a semiconductor in which one or a plurality of the semiconductor modules 16A are incorporated. Packages are widely manufactured and distributed in general. As a result, the module unit cost can be made relatively low.

  In the present embodiment, among the two IGBT elements 15A and 15D (and 15B, 15E, and 15C and 15F) connected in series in each of the three sets, the three IGBT elements 15D, 15E, 15F can be used as the first switch S1, and the three IGBT elements 15A, 15B, and 15C corresponding to the other of the sets can be used as the second switch S2. Then, three module terminals of the corresponding combination (the intermediate point of the series connection in each set) can be connected to the first output terminal 11b, the second input terminal 12a, and the first electrical neutral point 13, respectively.

  As described above, between the first armature winding 11 and the second armature winding 12 in the connection conductive path that connects the first armature winding 11 and the second armature winding 12 in series. The first switch S1 and the second switch S2 that are arranged and configured by semiconductor switch elements constitute the first semiconductor switch means described in the claims.

  FIG. 4 is a table showing the contents of the switching control performed by the switching control device 5 on the switches S1 and S2 of the winding switching device 3 in the present embodiment.

  As described above, in the present embodiment, the winding switching device 3 includes the first state in which the inverter output is guided to the first armature winding 11 having the Y connection, the first armature winding 11 and the second armature. A second state in which the entire output of the windings 12 electrically connected in series is Y-connected and the inverter output is led to both, and the voltage applied to the armature windings 11 and 12 when an abnormality is detected from the sensor 4 is minimized. The three states of the emergency state to be switched selectively.

  Specifically, as shown in FIG. 4, when realizing the first state, the switching control device 5 turns on the first switch S1 of the winding switching device 3 (conduction; the same applies hereinafter), and the second switch S2 is set to OFF (blocking; the same applies hereinafter). As a result, only the first armature winding 11 connected to the first electrical neutral point 13 and Y-connected is connected to the inverter 1, in other words, the first armature winding 11 and the second electric machine. The electrical connection with the child winding 12 is interrupted, and the supply power from the inverter 1 is guided only to the first armature winding 11, and the first state is switched. At this time, since the impedance is low, a sufficient current can flow even in the high frequency region, and a state suitable for driving the three-phase AC motor 2 at high speed is obtained.

  When realizing the second state, the switching control device 5 turns off the first switch S1 of the winding switching device 3 and turns on the second switch S2. Thereby, the 1st armature winding 11 and the 2nd armature winding 12 are connected in series, and the whole becomes a Y connection via the 2nd electrical neutral point 14, and is connected to inverter 1 In other words, the first armature winding 11 and the second armature winding 12 are electrically connected in series, and both the first armature winding 11 and the second armature winding 12 are connected to the inverter 1 from the inverter 1. Switching to the second state, in which the supplied power is guided. At this time, since the impedance is high, a sufficient voltage can be applied even in a low frequency region, and a large torque can be generated in the three-phase AC motor 2 with respect to the same current, which is suitable for low-speed driving. Become.

  The switching between the first state and the second state described above may be performed by switching to the first state when the rotational speed of the three-phase AC motor 2 is faster than a predetermined threshold speed, and to the second state when it is slow, for example. Alternatively, switching may be performed according to the relationship between the induced voltage and the DC voltage.

  When an abnormality is detected from the sensor 4, the switching control device 5 turns on the first switch S1 and turns off the second switch S2 of the winding switching device 3, whereby the two armature windings are turned on. 11 and 12 can be switched to the emergency state in which the voltage applied to each of them can be minimized. At this time, the detection signal output from the sensor 4 that has detected the abnormality constitutes an emergency switching control signal described in each claim, and the first switch S1 and the second switch S2 constitute path switching means.

  As described above, in the present embodiment, in the first state in which the power supplied from the inverter 1 is guided only to the first armature winding 11 to operate, the second switch S2 and the first armature winding 11 The electrical connection with the second armature winding 12 is cut off. Thus, unlike the conventional structure that is affected by the other armature winding even when only one armature winding is used, the first armature winding 11 has the reactance and The operation performance as rated can be exhibited without being affected by electrical effects such as self-induced electromotive force. Further, in the second state in which the power supplied from the inverter 1 is guided to both the first armature winding 11 and the second armature winding 12 to be operated, the first armature winding 11 and the second armature winding 11 are The second armature winding 12 is electrically connected in series. Thereby, the operation performance of both the armature windings 11 and 12 can be exhibited as rated.

  In addition, the electrical switch between the first armature winding 11 and the second armature winding 12 is instantaneously switched between the first armature winding 11 and the second armature winding 12 by the second switch S2 formed of a semiconductor switch element. As a result, for example, an electric shock such as chattering that occurs in the case of a mechanical switch means is eliminated, and the electromagnetic influence due to the reactance or self-dielectric electromotive force is functionally cut off between the two armature windings 11 and 12. can do. As a result, in the present embodiment, the two armature windings 11 and 12 can be smoothly switched while preventing functional adverse effects on the armature windings 11 and 12.

  In this embodiment, in particular, switching between the first state and the second state for the Y connection using the two armature windings 11 and 12 can be realized with a simple wiring configuration. Note that, in the first state where the power supplied from the inverter 1 is guided only to the first armature winding 11 and operated, the second switch S2 is connected between the first armature winding 11 and the second armature winding 12. By interrupting the electrical connection between the first armature winding 11 and the second armature winding 12, the first armature winding 11 can reliably exhibit the operating performance as rated without being affected by the electrical effect. Further, if both the first armature winding 11 and the second armature winding 12 are accommodated in one housing to constitute one three-phase AC motor 2, the second armature is formed inside the housing. Since the electrical neutral point 14 is formed at the winding end portion of the second armature winding 12, the external wiring is omitted, the assembly of the three-phase AC motor 2 is facilitated, and the productivity is improved. is there.

  In this embodiment, in particular, each of the first switch S1 and the second switch S2 corresponds to the three-phase first armature winding 11 and the second armature winding 12 of the three-phase AC motor 2, respectively. The same number of phases, that is, three IGBT elements 15A to 15C (or 15D to 15F) are provided. As a result, the switching speeds of the switches S1 and S2 can be instantaneously performed, and electrical shocks such as torque loss and braking torque generated when the switching speed is slow can be greatly reduced. Moreover, it can be applied to a commonly used three-phase AC motor 2, and each semiconductor switch element connected individually corresponding to each phase has a general specification with a relatively low withstand current value. An IGBT element can be used. As a result, heat generation can be suppressed and the manufacturing cost of the winding switching device 3 can be suppressed.

  In this embodiment, in particular, the three IGBT elements 15D, 15E, 15F of the first switch S1 and the three IGBT elements 15A, 15B, 15C of the second switch S2 are integrated as one semiconductor module 16B. ing. As a result, the six IGBT elements 15A to 15F included in the winding switching device 3 as the first switch S1 and the second switch S2 can be configured by a single general-purpose semiconductor module 16B including the surrounding connection wiring. As a result, wiring in the entire winding switching device 3 can be omitted, reduced in size, and reduced in weight, and the degree of freedom of layout in a limited installation space, for example, when applied to an electric vehicle is improved. To do.

  Further, for example, when the winding switching device 3 is in the second state (low-speed compatible state) during the high-speed rotation of the three-phase AC motor 2, the voltage induced between the two armature windings 11 and 12 May exceed the breakdown voltage of the semiconductor switch element. As a countermeasure, in the present embodiment, the first switch S1 and the second switch S2 are provided with the first armature according to the detection signal from the sensor 4 corresponding to the abnormality detection state of the inverter 1 or the three-phase AC motor 2. A current path that minimizes the voltage applied to the winding 11 and the second armature winding 12 is formed. That is, when an abnormality is detected from the sensor 4, that is, for example, a failure of a speed detector (not shown) such as a rotary encoder provided in the three-phase AC motor 2, disconnection of various signal lines, or a speed calculator When an abnormality relating to speed detection such as malfunction of the winding is detected, it is considered as an emergency, and the switching control device 5 turns on the first switch S1 of the winding switching device 3 and turns off the second switch S2. To do. As a result, the voltage applied to each of the two armature windings 11 and 12 is minimized to protect each semiconductor switch element, in particular, the second switch S2 disposed between the two armature windings 11 and 12 from overvoltage. can do.

  At this time, particularly in the present embodiment, the first switch S1 and the second switch S2 form the current path that minimizes the voltage applied to the first armature winding 11 and the second armature winding 12. Thus, each semiconductor switch element can be protected from overvoltage with a simple configuration without separately providing a dedicated switch for emergency.

  As shown in the table of FIG. 4 above, in both the first state and the second state, the first switch S1 and the second switch S2 are in the opposite ON / OFF state, and the first state It can be seen that the first switch S1 and the second switch S2 are switched to the opposite ON / OFF states in accordance with the switching of the second state. Focusing on this point, the first switch S1 is composed of a normally-on type IGBT element, the second switch S2 is composed of a normally-off type IGBT element, and both switches are controlled to be switched by a common control line. It is good.

  In this case, in a normal state where a drive signal is not output on the common control line, the normally-on type first switch S1 is turned on and the normally-off type second switch S2 is turned off. Switch to the first state. In a non-normal state in which a drive signal is output on the common control line, the normally-on type first switch S1 is turned off and the normally-off type second switch S2 is turned on. Switch to 2 state. Thereby, the wiring between the switching control device 5 and the winding switching device 3 can be omitted, and the configuration of the entire system can be simplified. On the contrary, the first switch S1 may be a normally-off type and the second switch S2 may be a normally-on type. In this case, switching between output / non-output of the drive signal on the common control line is reversed. The first state and the second state are switched.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and technical idea of the present invention. Hereinafter, such modifications will be described in order. In addition, about the part equivalent to the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified suitably.

(1) When switching to a state other than the first and second states (third state and fourth state) in the Y connection In the above embodiment, the first state in which only the first armature winding 11 is used in the Y connection. The first armature winding 11 and the second armature winding 12 connected in series are switched to only the two states of the second state using the Y connection, but the present invention is not limited to this. . For example, a third state in which only the second armature winding 12 is used in the Y connection, and a fourth state in which both the first armature winding 11 and the second armature winding 12 are used in parallel as the Y connection, respectively. It may be configured to be switchable to the state.

  FIG. 5 is a diagram showing a circuit configuration of the winding switching device 3A and the three-phase AC motor 2A (in this example, the same configuration as that of the three-phase AC motor 2) in the first modified example. In FIG. 5, in the winding switching device 3A, in addition to the configuration shown in FIG. 2 of the above embodiment, the second input terminal 12a is connected to the inverter 1 via a third switch S3 as third switch means. ing. Although not particularly shown, the third switch S3 is also composed of a semiconductor switch element as described above, and constitutes a first semiconductor switch means together with the first switch S1 and the second switch S2.

  FIG. 6 is a table showing the contents of the switching control performed by the switching control device 5 for each switch S1 to S3 of the winding switching device 3A in this modification.

  As described above, in this modification, the winding switching device 3A includes the third state in which only the second armature winding 12 is used in the Y connection in addition to the first state, the second state, and the emergency, The five states of the fourth state in which both the first armature winding 11 and the second armature winding 12 are respectively used in parallel as Y connections are selectively switched.

  Specifically, as shown in the table of FIG. 6, when the first state is realized, the switching control device 5 turns off the third switch S3 of the winding switching device 3A, and the first switch S1 is turned on and the second switch S2 is turned off. Thereby, it switches to the said 1st state. When realizing the second state, the switching control device 5 turns off the first switch S1 and turns on the second switch S2 with the third switch S3 of the winding switching device 3A turned off. To do. Thereby, it switches to the said 2nd state.

  Further, when realizing the third state, the switching control device 5 turns off the first switch S1 of the winding switching device 3A, turns off the second switch S2, and turns on the third switch S3. Thereby, only the second armature winding 12 connected to the second electrical neutral point 14 and Y-connected is connected to the inverter 1, in other words, the first armature winding 11 and the second electric machine. The electrical connection with the child winding 12 is interrupted, and the power supplied from the inverter 1 is guided only to the second armature winding 12, and the third state is switched. At this time, since the impedance is as low as that in the first state, a sufficient current can flow even in the high frequency region, and the state is suitable for driving the three-phase AC motor 2A at high speed.

  When realizing the fourth state, the switching control device 5 turns on the first switch S1 of the winding switching device 3A, turns off the second switch S2, and turns on the third switch S3. As a result, both the first armature winding 11 and the second armature winding 12 Y-connected are connected to the inverter 1 in parallel, in other words, the first armature winding 11 and the second armature winding 11. The armature winding 12 is electrically connected in parallel so that the power supplied from the inverter 1 is led to both the first armature winding 11 and the second armature winding 12, and the fourth state is switched. At this time, since the impedance is as low as that in the first state, a sufficient current can flow even in the high frequency region, and the state is suitable for driving the three-phase AC motor 2A at high speed.

  If an abnormality is detected from the sensor 4, the switching control device 5 turns on the first switch S1 of the winding switching device 3A, turns off the second switch S2, and turns on the third switch S3. Thus, the state can be switched to the emergency state in which the voltage applied to each of the two armature windings 11 and 12 can be minimized. At this time, each switch S1-S3 comprises a path | route switching means.

  Also by this modified example described above, the same effect as the above embodiment is obtained. Further, in the present modification, in addition to the first state and the second state of the above-described embodiment, a third state in which the power supplied from the inverter 1 is guided and operated only to the second armature winding 12; A fourth state in which the power supplied from the inverter 1 is guided and operated in parallel with both the armature winding 11 and the second armature winding 12 becomes possible. Thereby, the switching of the four states with respect to the Y connection using the two armature windings 11 and 12 can be realized with a simple wiring configuration. In the third state in which the power supplied from the inverter 1 is guided only to the second armature winding 12, the second switch S2 is connected between the first armature winding 11 and the second armature winding 12. By interrupting the electrical connection between the second armature winding 12 and the first armature winding 11, the second armature winding 12 can exhibit the operating performance as rated without being affected by the electrical effect.

  In the above embodiment, the combination of the first switch S1 and the second switch S2 constitutes one semiconductor module 16A shown in FIG. 3, but in this modification, the combination of the second switch S2 and the third switch S3. A single semiconductor module can also be configured.

(2) When switching between the first state and the second state by the delta connection In the above embodiment, the armature windings 11 and 12 are used for the Y connection in the first state and the second state, respectively. Is not limited to this. For example, the armature windings 11 and 12 may be used in delta connection in the first state and the second state, respectively.

  FIG. 7 is a diagram illustrating a circuit configuration of the winding switching device 3B and the three-phase AC motor 2B in the second modified example. In FIG. 7, the winding switching device 3B is connected so that the inverter output is directly input to the first input terminal 11a. The first output terminal 11b is connected to the second input terminal 12a via the second switch S2 as the second switch means and connected to the inverter 1 via the fourth switch S4 as the fourth switch means. Has been. The second output terminal 12b is connected to the inverter 1 via a fifth switch S5 as fifth switch means.

  Here, with respect to the connection between the first output terminal 11b and the inverter 1 via the fourth switch S4, the wirings of the corresponding phases are not connected to each other, but the U phase of the first output terminal 11b (U2 in the figure). ) Is connected to the V phase (V in the figure) of the inverter 1, the V phase (V2 in the figure) of the first output terminal 11b is connected to the W phase (W in the figure) of the inverter 1, and the first output The W phase (W2 in the figure) of the terminal 11b is connected to the U phase (U in the figure) of the inverter 1. Thus, when the fourth switch S4 is connected, only the first armature winding 11 forms a delta connection. The same applies to the connection between the second output terminal 12b and the inverter 1 via the fifth switch S5.

  As described above, between the first armature winding 11 and the second armature winding 12 in the connection conductive path that connects the first armature winding 11 and the second armature winding 12 in series. The second switch S2, which is arranged and is constituted by a semiconductor switch element, constitutes the first semiconductor switch means described in each claim. Further, a fourth switch S4 and a fifth switch S5, which are arranged in parallel to both the first armature winding 11 and the second armature winding 12 with respect to the inverter 1 and are composed of semiconductor switch elements, are provided. The second semiconductor switch means described in the claims is configured.

  FIG. 8 is a table showing the contents of the switching control performed by the switching control device 5 for each switch S2, S4, S5 of the winding switching device 3B in this modification.

  As described above, in this modification, the winding switching device 3B is configured such that the first state in which the inverter output is guided only to the first armature winding 11 having the delta connection, the first armature winding 11 and the second armature winding. The second state in which the entire output is electrically connected in series with the wire 12 as a delta connection and the inverter output is led to both, and when an abnormality is detected from the sensor 4, the voltage applied to the armature windings 11 and 12 is minimized. In an emergency, the three states are selectively switched.

  Specifically, as shown in the table of FIG. 8, when realizing the first state, the switching control device 5 turns off the second switch S2 of the winding switching device 3B and turns on the fourth switch S4. Then, the fifth switch S5 is turned OFF. As a result, the electrical connection between the inverter 1 and the second armature winding 12 is cut off, and only the first armature winding 11 forms a delta connection and is connected to the inverter 1 in the first state. Can be switched. At this time, since the impedance is low, a sufficient current can flow even in the high frequency region, and the state is suitable for driving the three-phase AC motor 2B at high speed.

  When realizing the second state, the switching control device 5 turns on the second switch S2 of the winding switching device 3B, turns off the fourth switch S4, and turns on the fifth switch S5. As a result, the first armature winding 11 and the second armature winding 12 connected in series constitute a delta connection and is switched to the second state, which is connected to the inverter 1. At this time, since the impedance is high, a sufficient voltage can be applied even in a low frequency region, and a large torque can be generated in the three-phase AC motor 2B with respect to the same current. Become.

  Note that the switching between the first state and the second state described above may be switched to the first state when the rotational speed of the three-phase AC motor 2B is faster than a predetermined threshold speed, and to the second state when it is slow, for example. However, the switching may be performed according to the relationship between the induced voltage and the DC voltage.

  When an abnormality is detected from the sensor 4, the switching control device 5 turns off the second switch S2 of the winding switching device 3B, turns on the fourth switch S4, and turns off the fifth switch S5. Thus, the state can be switched to the emergency state in which the voltage applied to each of the two armature windings 11 and 12 can be minimized. At this time, the second switch S2, the fourth switch S4, and the fifth switch S5 constitute path switching means.

  As described above, in this modification, by combining the switching of the second switch S2, the fourth switch S4, and the fifth switch S5, in the first state, the delta connection is made only by the first armature winding 11. The first armature winding 11 and the second armature winding 12 connected in series in the second state can be connected to the inverter 1 by configuring the delta connection in the second state. In the first state, the second switch S2 cuts off the serial electrical connection between the first armature winding 11 and the second armature winding 12, and the fifth switch S5 is connected to the inverter 1. The electrical connection with the second armature winding 12 is cut off. Thereby, the 1st armature winding 11 which comprises a delta connection at this time exhibits the operation performance as rated without receiving the electrical influence from the 2nd armature winding 12, like the said embodiment. Can do. In addition, the electric switch between the inverter 1 and the second armature winding 12 is instantaneously switched between the first armature winding 12 and the fifth switch S5 formed of a semiconductor switch element. Thereby, the electromagnetic influence can be cut off functionally as described above.

  In this modification, in particular, switching between the first state and the second state for the delta connection using the two armature windings 11 and 12 can be realized with a simple wiring configuration. Note that, in the first state where the power supplied from the inverter 1 is guided only to the first armature winding 11 and operated, the second switch S2 is connected between the first armature winding 11 and the second armature winding 12. And the fifth switch S5 cuts off the electrical connection between the second output terminal 12b of the second armature winding 12 and the inverter 1, whereby the first armature winding 11 is cut off. However, it is possible to exhibit the operating performance as rated without being affected by the electrical effect from the second armature winding 12.

  In the present modification, a single semiconductor module as shown in FIG. 3 can also be configured by combining the fourth switch S4 and the fifth switch S5.

(3) When switching between the third state and the fourth state by delta connection In the second modified example, the first state in which only the first armature winding 11 is used in the delta connection and the first armature connected in series. The configuration is such that the winding 11 and the second armature winding 12 as a whole are switched in only two ways, that is, in the second state in which the delta connection is used. However, the present invention is not limited to this. For example, the third state where only the second armature winding 12 is used in the delta connection, and the fourth state where both the first armature winding 11 and the second armature winding 12 are used in parallel as the delta connection, respectively. It may be configured to be switchable to the state.

  FIG. 9 is a diagram showing a circuit configuration of the winding switching device 3C and the three-phase AC motor 2C in the third modified example. In FIG. 9, in the winding switching device 3C, in addition to the configuration shown in FIG. 7 of the second modification, the second input terminal 12a is connected to the inverter 1 via the third switch S3 as third switch means. It is connected to the. The third switch S3 is also composed of a semiconductor switch element, and constitutes a first semiconductor switch means together with the second switch S2.

  FIG. 10 is a table showing the contents of the switching control performed by the switching control device 5 on the switches S2 to S5 of the winding switching device 3C in this modification.

  As described above, in this modification, the winding switching device 3C includes the third state in which only the second armature winding 12 is used in the delta connection in addition to the first state, the second state, and the emergency state, The five states of the fourth state in which both the first armature winding 11 and the second armature winding 12 are respectively used in parallel as delta connections are selectively switched.

  Specifically, as shown in the table of FIG. 10, when realizing the first state, the switching control device 5 turns off the second switch S2 of the winding switching device 3C and turns off the third switch S3. The fourth switch S4 is turned on and the fifth switch S5 is turned off. Thereby, it switches to the said 1st state. When realizing the second state, the second switch S2 is turned on, the third switch S3 is turned off, the fourth switch S4 is turned off, and the fifth switch S5 is turned on. Thereby, it switches to the 2nd state.

  Further, when realizing the third state, the switching control device 5 turns off the second switch S2 of the winding switching device 3C, turns on the third switch S3, turns off the fourth switch S4, and turns off the fifth switch. S5 is turned ON. As a result, only the second armature winding 12 that is delta-connected is connected to the inverter 1, in other words, the electrical connection between the first armature winding 11 and the second armature winding 12 is interrupted. Thus, only the second armature winding 12 is switched to the third state in which the power supplied from the inverter 1 is guided. At this time, although depending on the number of turns of the second armature winding 12, since the impedance is as low as that in the first state, a sufficient current can flow even in the high frequency region, and the three-phase AC motor 2C is driven at high speed. It becomes a suitable state to do.

  When the fourth state is realized, the switching control device 5 turns off the second switch S2 of the winding switching device 3C, turns on the third switch S3, turns on the fourth switch S4, and turns on the fifth switch. S5 is turned ON. As a result, both the first armature winding 11 and the second armature winding 12 connected in delta connection are connected to the inverter 1 in parallel, in other words, the first armature winding 11 and the second armature. The winding 12 is electrically connected in parallel so that the power supplied from the inverter 1 is led to both the first armature winding 11 and the second armature winding 12, and the fourth state is switched. At this time, although depending on the number of turns of the armature windings 11 and 12, since the impedance is as low as in the first state, a sufficient current can flow even in the high frequency region, and the three-phase AC motor 2C can be operated at high speed. It is in a state suitable for driving.

  When an abnormality is detected from the sensor 4, the switching control device 5 turns off the second switch S2 of the winding switching device 3C, and the other third switch S3, fourth switch S4, and fifth switch S5. By turning ON both of these, the state applied to the emergency state in which the voltage applied to each of the two armature windings 11 and 12 can be minimized can be switched. At this time, the second switch S2, the third switch S3, the fourth switch S4, and the fifth switch S5 constitute path switching means.

  Also in this modification, the effect similar to the said embodiment is acquired similarly to the said 2nd modification. In the present modification, as described above, in addition to the first state and the second state of the second modification, the power supplied from the inverter 1 is guided only to the second armature winding 12 to be operated. The third state and the fourth state in which the power supplied from the inverter 1 is guided and operated in parallel to both the first armature winding 11 and the second armature winding 12 are possible, and two armature windings are possible. The above four states can be switched with respect to the delta connection using 11 and 12 with a simple wiring configuration. In the third state in which the power supplied from the inverter 1 is guided only to the second armature winding 12, the second switch S2 is connected between the first armature winding 11 and the second armature winding 12. By interrupting the electrical connection between the second armature winding 12 and the first armature winding 11, the second armature winding 12 can exhibit the operating performance as rated without being affected by the electrical effect.

  In this modification, in addition to the combination of the second switch S2 and the third switch S3, the combination of the third switch S3 and the fourth switch S4, or the combination of the fourth switch S4 and the fifth switch S5 is also described above. One semiconductor module as shown in FIG.

(4) When switching to the first to fourth states in Y connection and delta connection respectively In the above embodiment and each modification, only one of Y connection or delta connection is used in the armature windings 11 and 12. However, the present invention is not limited to this. For example, the Y connection and the delta connection may be configured to be switchable.

  FIG. 11 is a diagram showing a circuit configuration of the winding switching device 3D and the three-phase AC motor 2D (in this example, the same configuration as the above-described three-phase AC motor 2C) in the fourth modified example. In FIG. 11, in addition to the configuration shown in FIG. 9 of the third modified example, the winding switching device 3D has a first output terminal 11b connected to the first electric power via a first switch S1 as a first switch means. The second output terminal 12b is connected to the second electrical neutral point 14 via the sixth switch S6 as the sixth switch means. The sixth switch S6 is also composed of a semiconductor switch element.

  FIG. 12 is a table showing the contents of the switching control performed by the switching control device 5 on the switches S1 to S6 of the winding switching device 3D in this modification.

  Basically, the winding switching device 3D in the present modification includes all the switches included in the embodiment and each modification, and the first to fourth states in the Y connection and the delta depending on the combination of the switching, A total of nine states including the first to fourth states in connection and the emergency state are selectively switched.

  Specifically, as shown in the table of FIG. 12, first, when realizing the first state in the Y connection, the switching control device 5 turns on the first switch S1 of the winding switching device 3D, and the second to second 6 All switches S2 to S6 are turned OFF. As a result, only the first armature winding 11 that is Y-connected is switched to the first state in which the inverter 1 is connected.

  Further, when realizing the second state in the Y connection, the first switch S1 is turned OFF, the second switch S2 is turned ON, the third to fifth switches S3 to S5 are turned OFF, and the sixth switch S6 is turned ON. To do. As a result, the first armature winding 11 and the second armature winding 12 are connected in series, and the whole is connected to the inverter 1 as a Y connection via the second electrical neutral point 14. It is switched to the second state.

  When realizing the third state in the Y connection, the first and second switches S1 and S2 are turned off, the third switch S3 is turned on, the fourth to fifth switches S4 to S5 are turned off, and the sixth switch S6 is turned ON. As a result, only the second armature winding 12 Y-connected is switched to the third state in which the inverter 1 is connected.

  Further, when the fourth state is realized in the Y connection, the first switch S1 is turned on, the second switch S2 is turned off, the third switch S3 is turned on, and the fourth to fifth switches S4 to S5 are turned off. The sixth switch S6 is turned on. Thereby, both the 1st armature winding 11 and the 2nd armature winding 12 which were each Y-connected are switched to the said 4th state connected to the inverter 1 in parallel.

  Further, when realizing the first state in the delta connection, the first to third switches S1 to S3 are turned off, the fourth switch S4 is turned on, and the fifth to sixth switches S5 to S6 are turned off. As a result, only the first armature winding 11 that is delta-connected is switched to the first state in which the inverter 1 is connected.

  When realizing the second state in the delta connection, the first to second switches S1 to S2 are turned off, the third switch S3 is turned on, the fourth switch S4 is turned off, and the fifth switch S5 is turned on. And the sixth switch S6 is turned OFF. As a result, the first armature winding 11 and the second armature winding 12 are connected in series, and the entirety thereof becomes a delta connection and is switched to the second state where it is connected to the inverter 1.

  Further, when realizing the third state in the delta connection, the first and second switches S1 and S2 are turned off, the third switch S3 is turned on, the fourth switch S4 is turned off, and the fifth switch S5 is turned on. Then, the sixth switch S6 is turned OFF. As a result, only the second armature winding 12 that is delta-connected is switched to the third state in which the inverter 1 is connected.

  Further, when realizing the fourth state in the delta connection, the first and second switches S1 and S2 are turned off, the third to fifth switches S3 to S5 are turned on, and the sixth switch S6 is turned off. As a result, both the first armature winding 11 and the second armature winding 12 respectively connected in delta connection are switched to the fourth state in which the inverter 1 is connected in parallel.

  When an abnormality is detected from the sensor 4, the switching control device 5 turns on only the first switch S1 and the second switch S2 of the winding switching device 3D, and the other third to sixth switches S3 to S6. Is switched to an emergency state in which the voltage applied to each of the two armature windings 11 and 12 can be minimized. At this time, all the first to sixth switches S1 to S6 constitute a path switching means.

  Also in this modification, the same effect as the above embodiment is obtained. Further, as described above, it is possible to realize a wiring configuration that selectively switches a total of eight states including the first to fourth states in the Y connection and the first to fourth states in the delta connection.

(5) Others In the above, any of the switches S1 to S6 also serves as the path switching unit, but is not limited thereto. That is, a path switching unit separate from the switches S1 to S6 may be provided to form a current path that minimizes the voltage applied to the plurality of armature windings.

  In the above description, the AC motor drive system that drives and controls the three-phase AC motors 2 and 2A to 2D has been described as an example, but the present invention is not limited thereto. That is, a system that drives and controls a multiphase AC motor having four or more phases may be used. In this case, the same effect can be obtained. Moreover, you may apply to the alternating current motor provided with the 3 or more armature winding, and the same effect can be acquired also in that case.

  Moreover, each switch S1-S6 should just be comprised with the semiconductor switch element at least, and semiconductor switch elements other than the said IGBT element may be sufficient as it. Also in this case, the original effect of smoothly switching between the two armature windings can be obtained while preventing the functional adverse effect on each armature winding.

  In addition to those already described above, the methods according to the above-described embodiments and modifications may be used in appropriate combination.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

1 Inverter 2 3-phase AC motor (AC motor)
2A-D 3-phase AC motor (AC motor)
3 Winding Switching Device 3A to D Winding Switching Device 4 Sensor 5 Switching Control Device 11 First Armature Winding 11a First Input Terminal 11b First Output Terminal 12 Second Armature Winding 12a Second Input Terminal 12b Second Output terminal 13 1st electrical neutral point 14 2nd electrical neutral point 15A-15F IGBT element 16A, 16B Semiconductor module 100 AC motor drive system S1 1st switch S2 2nd switch S3 3rd switch S4 4th switch S5 5th switch S6 6th switch SW switch element

Claims (14)

A winding switching device for an AC motor that performs winding switching related to a first armature winding and a second armature winding of a plurality of phases provided in an AC motor fed by an inverter,
The first armature winding and the second armature winding are disposed between the first armature winding and the second armature winding in a connection conductive path that connects the first armature winding and the second armature winding in series. The inverter is connected to the first armature winding of the first armature winding and the second armature winding by cutting off the electrical connection between the child winding and the second armature winding. A first state in which power supplied from the first armature winding and the first armature winding and the second armature winding are electrically connected in series, and the first armature winding and the second armature winding A first semiconductor switch means capable of switching between a second state in which the power supplied from the inverter is guided to both,
Corresponding to an abnormality detection state of the inverter or the AC motor in which the voltage induced between the first armature winding and the second armature winding may exceed the withstand voltage of the first semiconductor switch means The first semiconductor switch means minimizes the voltage induced between the first armature winding and the second armature winding in response to an emergency switching control signal from the outside of the winding switching device. A path switching means for forming a current path that protects against overvoltage ;
A winding switching device for an AC motor, comprising: In the AC motor winding switching device according to claim 1,
The first semiconductor switch means includes:
In the first state, the first electrical neutral point corresponding to the first state is connected to the first winding output terminal on the opposite side to the side connected to the inverter of the first armature winding. A first switch means for cutting off the first electrical neutral point and the first winding output terminal in the second state;
The first armature winding and the second armature winding are connected in series in the second state, and the first armature winding and the second armature winding are connected in the first state. A second switch means for blocking,
The second armature winding is:
A winding of an AC motor, wherein a second winding output terminal opposite to the side connected to the second switch means is connected to a second electrical neutral point corresponding to the second state. Switching device. In the AC motor winding switching device according to claim 2,
The first semiconductor switch means includes:
A third state in which electrical connection between the first armature winding and the second armature winding is interrupted to supply power supplied from the inverter to the second armature winding; A first armature winding and a second armature winding are electrically connected in parallel to guide the power supplied from the inverter to both the first armature winding and the second armature winding. 4 states can be switched,
In the third state and the fourth state, a second winding input terminal connected to the second switch means of the second armature winding is connected to the inverter, and the first state and the second state A third switch means for shutting off the second winding input terminal and the inverter in two states;
The first switch means connects the first electrical neutral point and the first armature winding in the fourth state;
The second switch means cuts off the first armature winding and the second armature winding in both the third state and the fourth state;
A winding switching device for an AC electric motor. In the AC motor winding switching device according to claim 2 or claim 3,
Each of the first switch means and the second switch means includes:
An AC motor winding switching apparatus comprising at least the same number of insulated gate bipolar transistor elements as the number of phases of the plurality of phases. In the AC motor winding switching device according to claim 4,
Corresponding to the first armature winding and the second armature winding of the three-phase AC motor,
Each of the first switch means and the second switch means is
A winding switching device for an AC motor, comprising three insulated gate bipolar transistor elements. In the AC motor winding switching device according to claim 5,
The three insulated gate bipolar transistor elements of the first switch means and the three insulated gate bipolar transistor elements of the second switch means are integrated as one semiconductor module. AC motor winding switching device. In the winding switching device for an AC motor according to any one of claims 4 to 6,
The insulated gate bipolar transistor element of the first switch means is a normally-on type switch,
The winding switching device for an AC motor, wherein the insulated gate bipolar transistor element of the second switch means is a normally-off type switch. In the winding switching device for an AC motor according to any one of claims 4 to 6,
The insulated gate bipolar transistor element of the first switch means is a normally-off type switch,
The winding switching device for an AC motor, wherein the insulated gate bipolar transistor element of the second switch means is a normally-on type switch. In the AC motor winding switching device according to claim 1,
Arranged in parallel to both the first armature winding and the second armature winding with respect to the inverter, and in the first state, between the inverter and the second armature winding. Connection to the inverter that forms a delta connection with only the first armature winding by cutting off the electrical connection, and in the second state, the first armature winding and the second electric machine connected in series A winding switching device for an AC motor comprising second semiconductor switch means capable of switching between connection to the inverter constituting a delta connection with both of the child windings. In the winding switching device for an AC motor according to claim 9,
The first semiconductor switch means includes:
The first armature winding and the second armature winding are connected in series in the second state, and the first armature winding and the second armature winding are connected in the first state. A second switch means for shutting off;
The second semiconductor switch means includes
In the first state, the first winding output terminal on the side opposite to the side connected to the inverter of the first armature winding is connected to the inverter so that a delta connection is formed only by the first armature winding. A fourth switch means for connecting and disconnecting the first winding output terminal of the first armature winding and the inverter in the second state;
In the first state, the second winding output terminal opposite to the side connected to the second switch means of the second armature winding and the inverter are shut off, and the second state is connected in series in the second state. A fifth switch that connects the second winding output terminal of the second armature winding and the inverter so that both the first armature winding and the second armature winding form a delta connection. A winding switching device for an AC electric motor. In the AC motor winding switching device according to claim 10,
The first semiconductor switch means and the second semiconductor switch means are:
A third state in which electrical connection between the first armature winding and the second armature winding is interrupted to supply power supplied from the inverter to the second armature winding; A first armature winding and a second armature winding are electrically connected in parallel to guide the power supplied from the inverter to both the first armature winding and the second armature winding. 4 states can be switched,
The first semiconductor switch means includes:
In the third state and the fourth state, the second winding input terminal on the side connected to the second switch means of the second armature winding is connected to the inverter, and the first state and the proxy are connected. A third switch means for shutting off the second winding input terminal of the second armature winding and the inverter in two states;
The second switch means interrupts the first armature winding and the second armature winding in both the third state and the fourth state,
The fourth switch means shuts off the first winding output terminal of the first armature winding and the inverter in the third state, and deltas only in the first armature winding in the fourth state. Connecting the first winding output terminal of the first armature winding to the inverter so as to form a connection;
The fifth switch means outputs the second winding output of the second armature winding so that a delta connection is formed only by the second armature winding in both the third state and the fourth state. Connect the terminal to the inverter,
A winding switching device for an AC electric motor. In the winding switching device for an AC motor according to any one of claims 9 to 11,
The route switching means is
A winding switching device for an AC motor, which serves also as at least one of the first semiconductor switch means and the second semiconductor switch means. An AC motor drive system comprising the AC motor winding switching device according to any one of claims 1 to 12,
The AC motor is
Comprising a plurality of armature windings with the same number of turns in each phase;
The winding switching device is
The plurality of electric coil windings can be switched to at least three winding states by appropriately combining conduction and blocking of a plurality of semiconductor switch elements,
And,
An AC motor drive system comprising an inverter that drives the AC motor and a switching control device that performs switching control of the winding switching device. The AC motor drive system according to claim 13,
A sensor for detecting various abnormalities in the entire AC motor drive system or an application including the AC motor drive system;
The switching control device is
An AC motor drive system that controls switching of the winding switching device based on a detection signal of the sensor.

Images