JP2022030152A - Power conversion device - Google Patents

Abstract

To provide a power conversion device that can simplify the configuration for supplying an AC voltage of a different voltage than an externally supplied AC voltage while converting the externally supplied AC voltage to a DC voltage.SOLUTION: A power conversion device 1 includes: a connection line connecting a first end t11 of an AC power source V1 and a first end t21 of an AC load V2; a shared half-bridge circuit 10c with upper-arm switching elements and lower-arm switching elements connected in series with a connection line at a neutral point; an AC/DC conversion circuit ct1 to which a second end t12 of the AC power supply V1 is connected and which converts a first AC voltage output from the AC power source V1 to a first DC voltage in cooperation with the shared half-bridge circuit 10c; and a DC/AC conversion circuit ct2 to which a second end t22 of an AC load V2 is connected and which converts a first DC voltage to a second AC voltage different from the first AC voltage in cooperation with the half-bridge circuit 10c.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power conversion device.

Conventionally, a power conversion device that converts an AC voltage supplied from an AC power supply into a DC voltage to charge a rechargeable battery or supplies an AC voltage to an external load has been known (for example, Patent Document 1). reference).

Japanese Unexamined Patent Publication No. 2019-92310

Here, in the power conversion device capable of supplying the AC voltage to the AC load in addition to the conversion from the AC voltage to the DC voltage, there is a concern that the configuration becomes complicated. In addition, the AC voltage supplied from the AC power supply may differ from the AC voltage required by the AC load.

The present invention has been made in view of the above problems, and is to convert an AC voltage supplied from an AC power supply into a DC voltage and to convert an AC voltage into an AC voltage different from the AC voltage supplied from the AC power supply. It is an object of the present invention to provide a power conversion device capable of supplying a voltage with a relatively simple configuration.

The power conversion device that achieves the above object includes a connection line connecting the first end of the AC power supply and the first end of the AC load, the first output line and the second output line, the first output line, and the above. A shared half-bridge circuit having an upper arm switching element and a lower arm switching element connected in series between the second output lines and the connection line connected to a neutral point, and the second end of the AC power supply. Is connected, the first AC voltage output from the AC power supply is converted into a first DC voltage in cooperation with the shared half bridge circuit, and the converted first DC voltage is converted into the first output line and the first. The AC / DC conversion circuit supplied to the two output lines and the second end of the AC load are connected, and the first DC voltage is different from the first AC voltage in cooperation with the shared half bridge circuit. It is provided with a DC / AC conversion circuit that converts the second AC voltage into the second AC voltage and outputs the converted second AC voltage to the AC load.

According to such a configuration, the power conversion device includes an AC / DC conversion circuit, so that the first AC voltage output from the AC power supply can be converted into the first DC voltage. Further, when the power conversion device includes a DC / AC conversion circuit, the first DC voltage can be converted into the second AC voltage. Further, a shared half-bridge circuit is used in both AC / DC conversion and DC / AC conversion. Therefore, the configuration can be simplified.

Regarding the power conversion device, the AC / DC conversion circuit has an upper arm switching element and a lower arm switching element connected in series between the first output line and the second output line, and is the first. The DC / AC conversion circuit has a first half-bridge circuit in which the second end of the AC power supply is connected to a neutral point via a coil, and the DC / AC conversion circuit is located between the first output line and the second output line. It has an upper arm switching element and a lower arm switching element connected in series, and has a second half bridge circuit in which the second end of the AC load is connected to a neutral point via a second coil. There may be.

According to this configuration, AC / DC conversion is performed by the first half-bridge circuit and the shared half-bridge circuit, and DC / AC conversion is performed by the second half-bridge circuit and the shared half-bridge circuit. In this case, the second AC voltage can be made different from the first AC voltage by adjusting the duty ratios of the upper arm switching element and the lower arm switching element of the second half bridge circuit. Further, the configuration can be simplified as compared with the configuration in which two half bridge circuits are provided for each of the AC / DC conversion circuit and the DC / AC conversion circuit.

The power conversion device further includes a switch for switching the connection to the neutral point of the second half-bridge circuit, and the switch is the neutral point of the second end of the AC load and the second half-bridge circuit. Is switched to the first switching state in which the AC power supply is connected, or the second switching state in which the second end of the AC power supply and the neutral point of the second half bridge circuit are connected. When the switch is in the first switching state, the first DC voltage is converted into the second AC voltage in cooperation with the shared half bridge circuit, and the converted second AC voltage is converted into the AC. While outputting to the load, when the switch is in the second switching state, the first AC voltage is converted into the first DC voltage in cooperation with the shared half bridge circuit, and the converted first DC is converted. The voltage may be supplied to the first output line and the second output line.

According to such a configuration, by putting the switch in the first switching state, AC / DC conversion and DC / AC conversion can be performed at the same time. Further, when the switch is in the second switching state, the second half-bridge circuit functions in cooperation with the shared half-bridge circuit to perform AC / DC conversion. As a result, when it is not necessary to supply the second AC voltage, the AC / DC conversion power can be increased by putting the switch in the second switching state.

The power conversion device has a transformer having a primary winding and a secondary winding, and converts the first DC voltage converted by the AC / DC conversion circuit into a second DC voltage and converts the second DC voltage. Is further provided with a DC / DC conversion circuit generated between the third output line and the fourth output line, the second end of the AC power supply is connected to the intermediate tap of the primary winding, and the AC /. The DC conversion circuit has an upper arm switching element and a lower arm switching element connected in series between the first output line and the second output line, and has a third coil and a first of the primary windings. A third half-bridge circuit in which the second end of the AC power supply is connected to a neutral point via an end and the intermediate tap, and the first output line and the second output line are connected in series. A fourth end having an upper arm switching element and a lower arm switching element, and the second end of the AC power supply connected to the neutral point via the fourth coil, the second end of the primary winding, and the intermediate tap. The DC / DC conversion circuit includes a half-bridge circuit, and has an upper arm switching element and a lower arm switching element connected in series between the first output line and the second output line. It may have a fifth half-bridge circuit in which the second end of the AC load is connected to the neutral point via the five coils.

According to such a configuration, since the shared half-bridge circuit is used for both AC / DC conversion and DC / AC conversion, the configuration can be simplified. Further, according to this configuration, the third half bridge circuit and the fourth half bridge circuit of the AC / DC conversion circuit are also used as a part of the DC / DC conversion circuit. This makes it possible to simplify the configuration.

According to one aspect of the present invention, the configuration for supplying an AC voltage having a voltage different from the AC voltage supplied from the outside while converting the AC voltage supplied from the outside into a DC voltage is simplified. can do.

The figure which shows an example of the structure of the power conversion apparatus 1 which concerns on 1st Embodiment. The figure which shows an example of the structure of the power conversion apparatus 2 which concerns on 2nd Embodiment.

<First Embodiment>
Hereinafter, the first embodiment will be described with reference to the drawings.
[overall structure]
The power conversion device 1 is, for example, a device mounted on a vehicle (for example, an electric vehicle). The electric vehicle is equipped with, for example, a rechargeable battery, and operates by driving a motor by the electric power stored in the rechargeable battery.

As shown in FIG. 1, the power conversion device 1 includes, for example, one or more half-bridge circuits 10, a control unit 20 that controls the operation of the half-bridge circuits 10, a first coil L1, and a second coil L2. It is equipped with a switch SW.

For example, an AC power supply V1 and an AC load V2 are connected to the power conversion device 1. The AC power supply V1 is, for example, a power supply provided in a charging device for charging a rechargeable battery. The AC power supply V1 is provided outside the vehicle. The AC power supply V1 outputs, for example, an AC voltage having a frequency of 60 [Hz] (or 50 [Hz]) and a voltage of 100 [V] or 200 [V]. The AC load V2 is, for example, a device connected to an outlet or the like provided in the vehicle interior, and is a device or the like that consumes AC power supplied from the power conversion device 1. The AC load V2 is, for example, AC power supplied from the power conversion device 1, and consumes AC power having a voltage of 100 [V].

In the following description, the AC voltage supplied by the AC power supply V1 to the power conversion device 1 is described as "first AC voltage", and the AC voltage supplied by the AC load V2 from the power conversion device 1 is referred to as "second AC voltage". It is described as. Hereinafter, a case where the first AC voltage and the second AC voltage are different voltages will be described. For example, it is assumed that the first AC voltage is 200 [V] and the second AC voltage is 100 [V]. That is, the second AC voltage is lower than the first AC voltage.

The AC power supply V1 includes a first end t11 and a second end t12. Further, the AC load V2 includes a first end t21 and a second end t22. The first ends t11 and t21 can be said to be the first terminals, and the second ends t12 and t22 can be said to be the second terminals. The first end t11 and the second end t12 of the AC power supply V1 are connected to the power conversion device 1, and the first end t21 and the second end t22 of the AC load V2 are connected to the power conversion device 1. ing.

The power conversion device 1 of the present embodiment has a connection line cw1 that connects the first end t11 of the AC power supply V1 and the first end t21 of the AC load V2. The AC power supply V1 and the AC load V2 are connected to each other by the connection line cw1 in the power conversion device 1. The details of the connection mode of the second end t12 of the AC power supply V1 and the second end t22 of the AC load V2 in the power conversion device 1 will be described later.

Further, the power conversion device 1 includes a first output line OL1, a second output line OL2, and a capacitor C1. The positive electrode terminal of the capacitor C1 is connected to the first output line OL1, and the negative electrode terminal of the capacitor C1 is connected to the second output line OL2. The capacitor C1 smoothes the DC voltage, for example.

The potential generated in the first output line OL1 is the potential generated in the positive electrode terminal of the capacitor C1, and the potential generated in the second output line OL2 is the potential generated in the negative electrode terminal of the capacitor C1. Therefore, the first output line OL1 can be said to be a positive electrode potential portion having the same potential as the positive electrode terminal of the capacitor C1, and the second output line OL2 can be said to be a negative electrode potential portion having the same potential as the negative electrode of the capacitor C1. Further, the voltage generated between the first output line OL1 and the second output line OL2 is a voltage generated across the capacitor C1.

The power conversion device 1 of the present embodiment includes three half-bridge circuits 10 including a half-bridge circuit 10a, a half-bridge circuit 10b, and a half-bridge circuit 10c. The half-bridge circuit 10a is an example of a "first half-bridge circuit", the half-bridge circuit 10b is an example of a "second half-bridge circuit", and the half-bridge circuit 10c is an example of a "shared half-bridge circuit". Is.

In the following description, for the configuration included in the half-bridge circuit 10a, "a" is added to the end of the reference numeral, and for the configuration included in the half-bridge circuit 10b, "b" is added to the end of the reference numeral to form a half-bridge circuit. For the configuration included in 10c, "c" is added to the end of the code. Further, in the following description, when the half-bridge circuit 10a, the half-bridge circuit 10b, and the half-bridge circuit 10c are not distinguished from each other, they are simply described as "half-bridge circuit 10".

As shown in FIG. 1, the half-bridge circuit 10a, the half-bridge circuit 10b, and the half-bridge circuit 10c are connected in parallel between the first output line OL1 and the second output line OL2. The half-bridge circuit 10 has a similar configuration. Hereinafter, the configuration of the half-bridge circuit 10a among the half-bridge circuits 10 will be described, and the description of the configurations of the other two half-bridge circuits 10 will be omitted. Therefore, for the half-bridge circuit 10b and the half-bridge circuit 10c, the symbol at the end of the code may be replaced with "a" as "b" or "c".

The half-bridge circuit 10a includes, for example, a cell 11a and a cell 12a. The cell 11a and the cell 12a each include one or more switching elements and a diode according to the number of switching elements. The switching element is realized by, for example, an n-type power MOSFET (metal-oxide-semiconductor field-effect transistor) or an IGBT (Insulated Gate Bipolar Transistor). Hereinafter, a case where the cell 11a and the cell 12a are provided with one switching element and one diode each realized by the IGBT will be described. The switching element and the diode are connected in parallel with each other. Specifically, the collector of the switching element and the cathode of the diode are connected, and the emitter of the switching element and the anode of the diode are connected.

The cell 11a and the cell 12a are connected in series between the first output line OL1 and the second output line OL2. Specifically, the collector of the switching element included in the cell 11a and the cathode of the diode are connected to the first output line OL1. Further, the emitter of the switching element included in the cell 11a, the anode of the diode, the collector of the switching element included in the cell 12a, and the cathode of the diode are connected. Further, the emitter of the switching element included in the cell 12a and the anode of the diode are connected to the second output line OL2. In the following description, the connection point to which the cell 11a and the cell 12a are connected is also referred to as a “neutral point”. A connection line cw1 connecting the first end t11 of the AC power supply V1 and the first end t21 of the AC load V2 is connected to the neutral point of the half-bridge circuit 10c.

The power conversion device 1 of the present embodiment includes a first wiring wd1 for connecting the neutral point of the half-bridge circuit 10a and the second end t12 of the AC power supply V1, and the first coil L1 is on the first wiring wd1. It is provided. The AC / DC conversion circuit ct1 is configured by the first coil L1 and the half-bridge circuit 10a. That is, it can be said that the AC / DC conversion circuit ct1 includes a half-bridge circuit 10a.

The power conversion device 1 of the present embodiment includes a second wiring wd2 connected to the neutral point of the half-bridge circuit 10b, and a second coil L2 provided on the second wiring wd2. In the present embodiment, the DC / AC conversion circuit ct2 is configured by the second coil L2 and the half bridge circuit 10b. That is, it can be said that the DC / AC conversion circuit ct2 includes a half-bridge circuit 10b.

The switch SW includes a first end t31, a second end t32, and a third end t33. The first end t31 of the switch SW is connected to the first wiring wd1 (specifically, the portion of the first wiring wd1 that connects the first coil L1 and the AC power supply V1). The second end t32 of the switch SW is connected to the second end t12 of the AC power supply V1. The third end t33 of the switch SW is connected to the second wiring wd2. Therefore, the third end t33 is connected to the neutral point of the half-bridge circuit 10b via the second coil L2.

The switch SW switches the connection destination of the third end t33 to the first end t31 or the second end t32 based on the control of the control unit 20. Here, paying attention to the point that the third end t33 is connected to the neutral point of the half-bridge circuit 10c, the switch SW connects the connection destination of the neutral point of the half-bridge circuit 10b to the AC power supply V1 or AC. It switches to the load V2.

According to this configuration, when the connection destination of the third end t33 of the switch SW is the second end t32, the DC / AC conversion circuit ct2 is connected to the AC load V2. Specifically, the second end t22 of the AC load V2 is connected to the neutral point of the half-bridge circuit 10b via the second coil L2.

On the other hand, when the connection destination of the third end t33 of the switch SW is the first end t31, the second coil L2 and the half bridge circuit 10b are connected to the AC power supply V1. Specifically, the second end t12 of the AC power supply V1 is connected to the neutral point of the half-bridge circuit 10b via the second coil L2. In the following description, the state in which the second end t32 and the third end t33 are connected is referred to as a "first switching state". Further, the state in which the first end t31 and the third end t33 are connected is referred to as a "second switching state".

The control unit 20 is realized by, for example, at least one of one or more dedicated hardware circuits and one or more processors (control circuits) that operate according to a computer program (software). In other words, the control unit 20 can be said to be a control circuit. The control unit 20 controls the switch SW based on the state of the AC load V2. The control unit 20 sets the switch SW to the first switching state, for example, when it is necessary to supply the second AC voltage to the AC load V2. The control unit 20 sets the switch SW to the second switching state, for example, when it is not necessary to supply the second AC voltage to the AC load V2. The case where it is not necessary to supply the second AC voltage to the AC load V2 is, for example, the case where the device that consumes the AC power is not operating in the AC load V2, or the case where it is not necessary to operate these devices. ..

The control unit 20 controls PWM (Pulse Width Modulation) of the switching elements of the cells 11 and 12 included in the power conversion device 1. In the first switching state, the control unit 20 makes the AC / DC conversion circuit ct1 (specifically, the half-bridge circuit 10a) and the half-bridge circuit 10c cooperate with each other, and the first AC voltage output from the AC power supply V1. To a DC voltage. For example, the control unit 20 turns on the cell 11a and 12c while turning off the cell 12a and 11c, or turns off the cell 11a and 12c while turning the cell 12a and the cell 11c into an off state. Is turned on. As a result, the first AC voltage is converted into a DC voltage, and the DC voltage is supplied between both output lines (first output line OL1 and second output line OL2). In this case, the half-bridge circuit 10c is used to perform full-wave rectification of the first AC voltage. In the following description, the AC / DC conversion circuit ct1 and the half-bridge circuit 10c cooperate to convert the first AC voltage between both output lines (first output line OL1 and second output line OL2). The DC voltage supplied to is referred to as "first DC voltage".

In the first switching state, the control unit 20 converts the first DC voltage into the second AC voltage by coordinating the DC / AC conversion circuit ct2 (specifically, the half-bridge circuit 10b) and the half-bridge circuit 10c. do. For example, the control unit 20 turns on the cell 11b and 12c while turning off the cell 12b and 11c, or turns off the cell 11b and 12c while turning the cell 12b and the cell 11c into an off state. Is turned on. In this case, the control unit 20 operates the half-bridge circuit 10b (cells 11b, 12b) in correspondence with the operation of the half-bridge circuit 10c (cells 11c, 12c) operating in the AC / DC conversion. In this case, the half-bridge circuit 10c is used to invert the first DC voltage to a negative voltage in accordance with the frequency of the second AC voltage. As a result, the first AC voltage is converted into the second AC voltage while the first AC voltage is converted into the first DC voltage. That is, AC / DC conversion and DC / AC conversion are performed at the same time.

Incidentally, the control unit 20 modulates and controls the pulse width of the PWM control signal that controls the switching element of the half-bridge circuit 10b so that the second AC voltage becomes a voltage smaller than the first AC voltage. As a result, the second AC voltage, which is lower than the first AC voltage, is supplied to the AC load V2.

Further, in the second switching state, the control unit 20 causes the DC / AC conversion circuit ct2 (specifically, the half-bridge circuit 10b) and the half-bridge circuit 10c to cooperate with each other to change the first AC voltage to the first DC voltage. Convert to. The control unit 20 operates, for example, the half-bridge circuit 10a and the half-bridge circuit 10b in synchronization with each other to convert the first AC voltage into the first DC voltage. That is, in the second switching state, the DC / AC conversion circuit ct2 functions as an AC / DC conversion that converts the first AC voltage into the first DC voltage. In other words, the DC / AC conversion circuit ct2 is a bidirectional conversion circuit that performs AC / DC conversion or DC / AC conversion according to the state of the switch SW. Since the operation in which the half-bridge circuit 10a and the half-bridge circuit 10c cooperate in the second switching state is the same as the operation in the first switching state described above, the description thereof will be omitted.

In the above description, the control unit 20 has described a case where the half-bridge circuit 10b and the half-bridge circuit 10c are operated in cooperation with each other to convert the first AC voltage into the second AC voltage, but the present invention is limited to this. I can't. The control unit 20 operates in cooperation with the half-bridge circuit 10a and the half-bridge circuit 10c to convert the first AC voltage output from the AC power supply V1 into a DC voltage, and the half-bridge circuit 10b and the half-bridge The switching element with the circuit 10c may be operated as an interleave operation to operate as a power factor correction (PFC) circuit.

According to the first embodiment, the following effects can be obtained.
(1-1) The power conversion device 1 is connected to both the AC power supply V1 and the AC load V2, and has a first output line OL1 and a second output line OL2. The AC power supply V1 outputs a first AC voltage and has a first end t11 and a second end t22. The AC load V2 receives a second AC voltage having a voltage different from that of the first AC voltage, and has a first end t21 and a second end t22. The power conversion device 1 includes a connection line cw1 connecting the first end t11 of the AC power supply V1 and the first end t21 of the AC load V2, a shared half-bridge circuit (in this example, the half-bridge circuit 10c), and AC /. It includes a DC conversion circuit ct1 and a DC / AC conversion circuit ct2.

The half-bridge circuit 10c has an upper arm switching element (switching element of cell 11c) and a lower arm switching element (switching element of cell 12c) connected to the first output line OL1 and the second output line OL2 in a state of being connected in series with each other. ) And a neutral point to which the connecting line cw1 is connected. In the AC / DC conversion circuit ct1, the second end t12 of the AC power supply V1 is connected, and the first AC voltage output from the AC power supply V1 is converted into the first DC voltage in cooperation with the half bridge circuit 10c. The converted first DC voltage is supplied to both output lines (first output line OL1 and second output line OL2).

In the DC / AC conversion circuit ct2, the second end t22 of the AC load V2 is connected, the first DC voltage is converted into the second AC voltage in cooperation with the half bridge circuit 10c, and the converted second AC voltage is converted. Output to AC load V2.

According to such a configuration, both AC / DC conversion from the first AC voltage to the first DC voltage and DC / AC conversion from the first DC voltage to the second AC voltage can be performed. In this case, since the half-bridge circuit 10c is used in both the AC / DC conversion and the DC / AC conversion, the configuration can be simplified.

(1-2) The AC / DC conversion circuit ct1 includes a half-bridge circuit 10a as a first half-bridge circuit connected to both output lines (first output line OL1 and second output line OL2), and a first coil. It has L1 and. The half-bridge circuit 10a includes an upper arm switching element (switching element of cell 11a) and a lower arm switching element (switching element of cell 12a) connected in series with each other, and a second AC power supply V1 via the first coil L1. It has a neutral point to which the end t12 is connected.

The DC / AC conversion circuit ct2 has a half-bridge circuit 10b as a second half-bridge circuit connected to both output lines (first output line OL1 and second output line OL2), and a second coil L2. ing. The half-bridge circuit 10b includes an upper arm switching element (switching element of cell 11b) and a lower arm switching element (switching element of cell 12b) connected in series with each other, and a second AC load V2 via a second coil L2. It has a neutral point to which the end t22 is connected.

According to this configuration, AC / DC conversion is performed by the half-bridge circuit 10a and the half-bridge circuit 10c, and DC / AC conversion is performed by the half-bridge circuit 10b and the half-bridge circuit 10c. Thereby, in the power conversion device 1 of the present embodiment, the second AC voltage is referred to as the first AC voltage by adjusting the duty ratio of the switching element of the cell 11b of the half bridge circuit 10b and the switching element of the cell 12b. Can be different. Further, the power conversion device 1 of the present embodiment can be simplified as compared with a configuration in which two half bridge circuits are provided for each of the AC / DC conversion circuit ct1 and the DC / AC conversion circuit ct2. can.

(1-3) The power conversion device 1 includes a switch SW for switching the connection to the neutral point of the half-bridge circuit 10b as the second half-bridge circuit. The switch SW is in the first switching state in which the second end t22 of the AC load V2 and the neutral point of the half bridge circuit 10b are connected, or the second end t12 of the AC power supply V1 and the neutral point of the half bridge circuit 10b. It switches to the second switching state in which the point is connected. The DC / AC conversion circuit ct2 performs AC / DC conversion for converting the first AC voltage output from the AC power supply V1 into the first DC voltage in cooperation with the half bridge circuit 10c in the first switching state. Further, the DC / AC conversion circuit ct2 converts the first DC voltage into the second AC voltage in cooperation with the half bridge circuit 10c in the second switching state, and supplies the AC load V2.

According to such a configuration, AC / DC conversion and DC / AC conversion can be performed at the same time by setting the switch SW to the first switching state. Further, when the switch SW is in the second switching state, the half-bridge circuit 10b functions in cooperation with the half-bridge circuit 10c to perform AC / DC conversion. As a result, when the power conversion device 1 of the present embodiment does not need to supply the second AC voltage, the AC / DC conversion power is increased by setting the switch SW to the second switching state. Can be done.

In the above-described embodiment, the case where the power conversion device 1 includes the switch SW has been described, but the present invention is not limited to this. The power conversion device 1 does not have to include the switch SW. In this case, the second end t12 of the AC power supply V1 and the neutral point of the half bridge circuit 10a are connected by the first wiring wd1. Further, in this case, the second end t22 of the AC load V2 and the neutral point of the half bridge circuit 10b are connected by the second wiring wd2. By this connection, the power conversion device 1 of the present embodiment always operates in the above-mentioned first switching state.

As a result, the power conversion device 1 of the present embodiment performs AC / DC conversion and DC / AC conversion at the same time, and has two half-bridge circuits for each of the AC / DC conversion circuit ct1 and the DC / AC conversion circuit ct2. It is possible to simplify the configuration as compared with the configuration provided with the above.

<Second Embodiment>
Hereinafter, the second embodiment will be described with reference to the drawings. In the second embodiment, a case where the power converter 2 further includes a DC / DC converter will be described. The same components as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 2, the power conversion device 2 includes, for example, a half bridge circuit 10c which is a shared half bridge circuit, an AC / DC conversion circuit ct1, a DC / AC conversion circuit ct2, and a DC / DC conversion circuit ct3. Be prepared. The half-bridge circuit 10c of the present embodiment is connected to the first output line OL1 and the second output line OL2 as in the first embodiment, and the neutral point is connected to the connection line cw1. The DC / AC conversion circuit ct2 of the present embodiment has a half-bridge circuit 10b and a second coil L2 as in the first embodiment. The half-bridge circuit 10b is connected to the first output line OL1 and the second output line OL2. The neutral point of the half-bridge circuit 10b is connected to the second end t22 of the AC load V2 by the second wiring wd2, and the second coil L2 is provided on the second wiring wd2.

In the present embodiment, in the power conversion device 2, the AC / DC conversion circuit ct1 and the DC / DC conversion circuit ct3 are integrated. Specifically, the AC / DC conversion circuit ct1 includes a third coil L3, a fourth coil L4, a half-bridge circuit 10e, and a half-bridge circuit 10d. The DC / DC conversion circuit ct3 includes a half-bridge circuit 10d, a half-bridge circuit 10e, a third coil L3, a fourth coil L4, a transformer TR, a half-bridge circuit 10f, and a half-bridge circuit 10g. That is, in the present embodiment, the third coil L3, the fourth coil L4, the half-bridge circuit 10e, and the half-bridge circuit 10d are used in both the AC / DC conversion circuit ct1 and the DC / DC conversion circuit ct3. It is shared.

The half-bridge circuit 10d is an example of a "third half-bridge circuit", the half-bridge circuit 10e is an example of a "fourth half-bridge circuit", and the half-bridge circuit 10f and the half-bridge circuit 10g are "first". This is an example of "5 half bridge circuit".

The transformer TR has a primary winding and a secondary winding. The second end t12 of the AC power supply V1 is connected to the intermediate tap of the primary winding of the transformer TR. The half-bridge circuit 10d is connected to the first output line OL1 and the second output line OL2. The neutral point of the half-bridge circuit 10d is connected to the first end of the primary winding of the transformer TR via the third coil L3. That is, the neutral point of the half-bridge circuit 10d is connected to the second end t12 of the AC power supply V1 via the third coil L3, the first end of the primary winding of the transformer TR, and the intermediate tap. In the present embodiment, the third coil L3 and the fourth coil L4 are examples of the "fifth coil".

The half-bridge circuit 10e is connected to the first output line OL1 and the second output line OL2. The neutral point of the half-bridge circuit 10e is connected to the second end of the primary winding of the transformer TR via the fourth coil L4. That is, the neutral point of the half-bridge circuit 10e is connected to the second end t12 of the AC power supply V1 via the fourth coil L4, the second end of the primary winding of the transformer TR, and the intermediate tap.

The power conversion device 2 has a third output line OL3 and a fourth output line OL4. The half-bridge circuit 10f and the half-bridge circuit 10g are connected in parallel to each other between the third output line OL3 and the fourth output line OL4. The neutral point of the half-bridge circuit 10f is connected to the first end of the secondary winding of the transformer TR. Further, the neutral point of the half-bridge circuit 10g is connected to the second end of the secondary winding of the transformer TR.

The power conversion device 2 includes a capacitor C2. The capacitor C2 is provided between the half-bridge circuit 10b and the half-bridge circuit 10d. The capacitor C2 smoothes the first DC voltage converted by the AC / DC conversion circuit ct1. The power conversion device 2 includes a capacitor C3. The capacitor C3 smoothes the second DC voltage converted by the DC / DC conversion circuit ct3.

In the above description, the control unit 20 has described a case where the half-bridge circuit 10b and the half-bridge circuit 10c are operated in cooperation with each other to convert the first AC voltage into the second AC voltage, but the present invention is limited to this. I can't. The control unit 20 operates the half-bridge circuits 10c, 10d, and 10e in cooperation with each other to convert the first AC voltage output from the AC power supply V1 into a DC voltage, and the half-bridge circuit 10b and the half-bridge circuit 10c. The switching element with and may be operated as an interleave operation to operate as a power factor correction (PFC) circuit.

The control unit 20 converts the first AC voltage into the first DC voltage by operating the AC / DC conversion circuit ct1 (specifically, the half-bridge circuits 10d and 10e) and the half-bridge circuit 10c in cooperation with each other. .. In this case, the half-bridge circuit 10c functions as a full-wave rectifier of the first AC voltage. Further, the control unit 20 converts the first DC voltage into the second DC voltage by operating the DC / DC conversion circuit ct3 (specifically, the half-bridge circuits 10d, 10e, 10f, 10g) in cooperation with each other. ..

Further, the control unit 20 converts the first AC voltage into the second AC voltage by operating the DC / AC conversion circuit ct2 (specifically, the half-bridge circuit 10b) and the half-bridge circuit 10c in cooperation with each other.

According to the second embodiment, the following effects can be obtained.
(2-1) The power conversion device 2 has a transformer TR having a primary winding and a secondary winding, and converts the first DC voltage converted by the AC / DC conversion circuit ct1 into the second DC voltage and converts it. The DC / DC conversion circuit ct3 for generating the second DC voltage between the third output line OL3 and the fourth output line OL4 is further provided. The DC / DC conversion circuit ct3 includes a half-bridge circuit 10d, a half-bridge circuit 10e, a third coil L3, a fourth coil L4, a transformer TR, a half-bridge circuit 10f, and a half-bridge circuit 10g. Further, the AC / DC conversion circuit ct1 of the power conversion device 2 includes a third coil L3, a fourth coil L4, a half-bridge circuit 10e, and a half-bridge circuit 10d.

According to this configuration, a shared half-bridge circuit (specifically, a half-bridge circuit 10c) is used for both AC / DC conversion and DC / AC conversion, and further, a third coil L3, a fourth coil L4, and a half-bridge circuit. The 10e and the half-bridge circuit 10d are shared by both the AC / DC conversion circuit ct1 and the DC / DC conversion circuit ct3. This makes it possible to simplify the configuration.

(2-2) In the power conversion device 2, the half-bridge circuit 10d and the half-bridge circuit 10e are electrically isolated from the half-bridge circuit 10f and the half-bridge circuit 10g by the transformer TR. Thereby, in the power conversion device 2 of the present embodiment, the half-bridge circuit 10d and the half-bridge circuit 10e can suppress the influence of the current generated by the high voltage generated by the half-bridge circuit 10f and the half-bridge circuit 10g.

Each of the above embodiments may be changed as follows. Further, each of the above embodiments and the following alternative examples may be appropriately combined within a range that does not cause a technical contradiction.
○ The specific configuration of the AC / DC conversion circuit ct1 is arbitrary. Similarly, the specific configuration of the DC / AC conversion circuit ct2 is arbitrary.

○ The target on which the power conversion devices 1 and 2 are mounted is not limited to the electric vehicle, but is arbitrary.

1, 2 ... Power converter, 10, 10a, 10b, 10c, 10d, 10f, 10g, 10e ... Half-bridge circuit, 11, 11a, 11b, 11c, 12, 12a, 12b, 12c ... Cell, 20 ... Control unit , C1, C2, C3 ... Condenser, L1 ... 1st coil, L2 ... 2nd coil, L3 ... 3rd coil, L4 ... 4th coil, V1 ... AC power supply, V2 ... AC load, OL1 ... 1st output line, OL2 ... 2nd output line, ct1 ... AC / DC conversion circuit, ct2 ... DC / AC conversion circuit, ct3 ... DC / DC conversion circuit.

Claims (4)

A connection line connecting the first end of the AC power supply and the first end of the AC load,
The first output line and the second output line,
A shared half-bridge circuit having an upper arm switching element and a lower arm switching element connected in series between the first output line and the second output line, and the connection line connected to a neutral point.
The second end of the AC power supply is connected, the first AC voltage output from the AC power supply is converted into a first DC voltage in cooperation with the shared half bridge circuit, and the converted first DC voltage is converted into the first DC voltage. An AC / DC conversion circuit supplied to the first output line and the second output line,
The second end of the AC load is connected, and in cooperation with the shared half-bridge circuit, the first DC voltage is converted into a second AC voltage having a voltage different from the first AC voltage, and the second end is converted. A DC / AC conversion circuit that outputs AC voltage to the AC load,
A power converter equipped with. The AC / DC conversion circuit has an upper arm switching element and a lower arm switching element connected in series between the first output line and the second output line, and is neutral via the first coil. It has a first half-bridge circuit to which the second end of the AC power supply is connected at a point.
The DC / AC conversion circuit has an upper arm switching element and a lower arm switching element connected in series between the first output line and the second output line, and is neutral via a second coil. It has a second half-bridge circuit to which the second end of the AC load is connected to the point.
The power conversion device according to claim 1. Further equipped with a switch for switching the connection to the neutral point of the second half-bridge circuit,
The switch is in the first switching state in which the second end of the AC load and the neutral point of the second half bridge circuit are connected, or in the second end of the AC power supply and the second half bridge circuit. It switches to the second switching state in which the sex points are connected.
The DC / AC conversion circuit is
When the switch is in the first switching state, the first DC voltage is converted into the second AC voltage in cooperation with the shared half bridge circuit, and the converted second AC voltage is used as the AC load. While outputting
When the switch is in the second switching state, the first AC voltage is converted into the first DC voltage in cooperation with the shared half-bridge circuit, and the converted first DC voltage is converted into the first output. Supplying to the wire and the second output wire,
The power conversion device according to claim 2. It has a transformer having a primary winding and a secondary winding, converts the first DC voltage converted by the AC / DC conversion circuit into a second DC voltage, and converts the converted second DC voltage into a third output line. Further equipped with a DC / DC conversion circuit generated between the fourth output line and
The second end of the AC power supply is connected to the intermediate tap of the primary winding.
The AC / DC conversion circuit is
It has an upper arm switching element and a lower arm switching element connected in series between the first output line and the second output line, and has a third coil, the first end of the primary winding, and the intermediate tap. A third half-bridge circuit in which the second end of the AC power supply is connected to the neutral point via
It has an upper arm switching element and a lower arm switching element connected in series between the first output line and the second output line, and has a fourth coil, a second end of the primary winding, and the intermediate tap. A fourth half-bridge circuit in which the second end of the AC power supply is connected to the neutral point via
Equipped with
The DC / DC conversion circuit has an upper arm switching element and a lower arm switching element connected in series between the first output line and the second output line, and is neutral via a fifth coil. It has a fifth half-bridge circuit to which the second end of the AC load is connected to the point.
The power conversion device according to claim 1.

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