JP6286802B2 - Power converter - Google Patents

Description

  The present invention generally relates to a power converter, and more particularly to a power converter that converts DC power from a DC power source into AC power.

  In recent years, with the spread of residential solar power generation devices, fuel cells, power storage devices, and the like, various circuits have been proposed and provided as power conversion devices that convert the output of these DC power sources into AC. For example, Patent Literature 1 discloses a power conversion device that generates AC output converted from a DC voltage source into a plurality of voltage levels (output levels) (in Patent Literature 1, “multi-level power conversion device”).

  The power conversion device described in Patent Document 1 is a 5-level inverter that outputs a 5-level voltage, and includes two DC capacitors, two flying capacitors, and 16 switching elements. In this power converter, in the state where the DC voltage E is applied to the series circuit of two DC capacitors, the voltage across each DC capacitor is E / 2, and the voltage across each flying capacitor is E / 4. By controlling each switching element, a five-level voltage is output.

JP 2014-64431 A

  However, the above conventional example has a problem that the number of circuit components required to realize a desired number of output levels is increased.

  The present invention has been made in view of the above points, and an object thereof is to provide a power conversion device capable of reducing the number of circuit components necessary to realize a desired number of output levels. .

The power conversion device according to the present invention electrically connects the first input point and the second input point to which the main voltage source is electrically connected, the first output point and the second output point, and the voltage sources having different power supply voltages. N voltage control units connected to each other and four switches, and a conversion unit for generating an output voltage at the first output point and the second output point by inverting the polarity of the input DC voltage And a clamp unit that holds the output voltage at a predetermined voltage, the number N of voltage control units is an integer of 1 or more, and the N voltage control units are respectively A regenerative switch that opens and closes an electric circuit that connects either the positive electrode or the negative electrode of the voltage source and the conversion unit, and an electric circuit that connects either the positive electrode or the negative electrode of the main voltage source and the conversion unit Input switches for opening and closing the four switches. Said holding switch, the N by controlling the regenerative switch and the input switch in each of the voltage control unit further comprises a control unit for switching the output voltage to the 2N + 3 stages, wherein the control unit, the output voltage The power supply voltage of a voltage source electrically connected to an arbitrary voltage control unit, and when the power supply voltage is one step lower than the power supply voltage, the regenerative switch of the arbitrary voltage control unit is turned on. It is characterized by maintaining to .
The power conversion device according to the present invention electrically connects the first input point and the second input point to which the main voltage source is electrically connected, the first output point and the second output point, and the voltage sources having different power supply voltages. A voltage control unit connected in series, four switches, a conversion unit for inverting the polarity of the input DC voltage to generate output voltages at the first output point and the second output point, and holding A clamp unit that holds the output voltage at a predetermined voltage, and the voltage control unit opens and closes an electric circuit that connects either the positive electrode or the negative electrode of the voltage source and the conversion unit. A regenerative switch, and an input switch that opens and closes an electric circuit that connects either the positive electrode or the negative electrode of the main voltage source and the converter, and includes the four switches, the holding switch, and the voltage controller. Said regenerative switch in each And a control unit that switches the output voltage in five steps by controlling the input switch, and the control unit includes a case where the output voltage is a power supply voltage of the voltage source, and a case where the output voltage is in five steps. When the predetermined voltage is output from, the regenerative switch is turned on, and when the predetermined voltage is output from five levels of the output voltage, the four switches are further turned off.

  The present invention can reduce the number of circuit components required to achieve a desired number of output levels.

1 is a circuit diagram showing a basic configuration of a power conversion device according to Embodiment 1. FIG. 1 is a circuit diagram showing a basic configuration of a power conversion device according to Embodiment 1. FIG. 3A and 3B are circuit diagrams of the power conversion apparatus according to the first embodiment configured with 5-level inverters. It is a circuit diagram of the power converter device concerning Embodiment 1 comprised with the 5 level inverter. FIGS. 5A to 5C are operation explanatory diagrams of the power conversion apparatus according to the first embodiment configured with 5-level inverters. It is an output waveform diagram of the power converter concerning Embodiment 1 constituted with a 5-level inverter. It is a circuit diagram of the power converter concerning Embodiment 1 constituted by a 7 level inverter. 8A and 8B are operation explanatory diagrams of the power conversion device according to the first embodiment configured by 7-level inverters. FIG. 9A and FIG. 9B are operation explanatory diagrams of the power conversion apparatus according to the first embodiment configured by 7-level inverters. It is a circuit diagram which shows the power converter device which concerns on the comparative example comprised with the 5-level inverter. FIG. 11A to FIG. 11C are operation explanatory diagrams of a power conversion device according to a comparative example configured by 5-level inverters. It is operation | movement explanatory drawing of the power converter device which concerns on Embodiment 1 comprised with the 5-level inverter. FIG. 13A and FIG. 13B are operation explanatory diagrams of the power conversion device according to the first embodiment configured with 5-level inverters. It is operation | movement explanatory drawing of the power converter device which concerns on Embodiment 1 comprised with the 5-level inverter. FIG. 15A to FIG. 15C are operation explanatory diagrams of the power conversion device according to the first embodiment configured by 5-level inverters. FIG. 16A and FIG. 16B are operation explanatory diagrams of the power conversion device according to the first embodiment configured with 5-level inverters. It is the circuit diagram which changed a partial structure of the power converter device which concerns on Embodiment 1 comprised with the 5-level inverter. FIG. 18A is a diagram showing the control unit and each driver circuit before the change, and FIG. 18B is a diagram showing the control unit and each driver circuit after the change. FIG. 19A is a diagram illustrating the control unit and each driver circuit before the change, and FIG. 19B is a diagram illustrating the control unit and each driver circuit after the change. It is the schematic which shows the usage example of the power converter device which concerns on Embodiment 1. FIG. FIG. 9 is an operation explanatory diagram of the power conversion apparatus according to the second embodiment. In the power converter device which concerns on Embodiment 2, it is operation | movement explanatory drawing at the time of inverting the phase of a 1st carrier wave and a 4th carrier wave. 6 is an operation explanatory diagram of a power conversion apparatus according to Configuration Example 1 of Embodiment 2. FIG. 6 is an operation explanatory diagram of a power conversion device according to Configuration Example 2 of Embodiment 2. FIG. FIG. 9 is an operation explanatory diagram of the power conversion device according to Configuration Example 3 of Embodiment 2. 10 is an operation explanatory diagram of a power conversion device according to Configuration Example 4 of Embodiment 2. FIG. 10 is an operation explanatory diagram of a power conversion device according to Configuration Example 5 of Embodiment 2. FIG. FIG. 10 is an operation explanatory diagram of the power conversion apparatus according to Configuration Example 6 of Embodiment 2.

(Embodiment 1)
As shown in FIG. 1, the power conversion device 1 according to the first embodiment of the present invention includes a first input point 11 and a second input point 12, a first output point 13 and a second output point 14, and N pieces. The voltage control units 2 _{1 to} 2 _N , the conversion unit 3, the clamp unit 4, and the control unit 5 are provided. 'N' is an integer of 1 or more. A main voltage source VS _{N + 1} is electrically connected to the first input point 11 and the second input point 12. Voltage sources VS _{1 to} VS _N having different power supply voltages E _{1 to} E _N are electrically connected to the _N voltage control units 2 ₁ to 2 _N , respectively.

Voltage control unit _{2 M} includes a regeneration switch Q1 _M, an input switch Q2 _M. The regenerative switch Q1 _M opens and closes an electric circuit that connects either the positive electrode or the negative electrode of the voltage source VS _M (here, the positive electrode) and the conversion unit 3. The input switch Q2 _M opens and closes an electric circuit that connects either the positive electrode or the negative electrode (here, the positive electrode) of the main voltage source VS _{N + 1} and the conversion unit 3. 'M' is an integer of 1 or more and N or less.

  The conversion unit 3 is a full-bridge circuit that has four switches QB1 to QB4 and generates the output voltage V1 at the first output point 13 and the second output point 14 by inverting the polarity of the input DC voltage. is there. The clamp unit 4 includes holding switches QC1 and QC2, and holds the output voltage V1 at a predetermined voltage (here, 0 [V]).

Control unit 5 controls the four switches QB1～QB4, holding switch QC1, QC2, N pieces of the regenerative switch _Q1 in each of the voltage control unit ₂ 1 _{~2 N} 1 _{~Q1 N} and input switch _Q2 1 _{~Q2 N} . Thereby, the control part 5 switches the output voltage V1 to a '2N + 3' stage.

  Hereinafter, the power converter 1 of this embodiment is demonstrated in detail. However, the configuration described below is only an example of the present invention, and the present invention is not limited to the following embodiment, and the technical idea according to the present invention is not deviated from this embodiment. Various changes can be made in accordance with the design or the like as long as they are not.

First, the basic configuration of the power conversion device 1 of the present embodiment will be described. As shown in FIG. 1, the power conversion device 1 of this embodiment includes N voltage control units 2 ₁ to 2 _N , a conversion unit 3, a clamp unit 4, and a control unit 5. A main voltage source VS _{N + 1} is electrically connected to the first input point 11 and the second input point 12 of the power conversion device 1. In addition, for example, a system power supply 7 (see FIG. 19) and a load 8 (see FIG. 19) are electrically connected to the first output point 13 and the second output point 14 of the power conversion device 1. Then, the power converter 1, main voltage source VS N _{+ 1,} and outputs the converted AC voltage to a DC voltage input from any of the later-described voltage source VS ₁ ~VS _N. The voltage source _VS 1 _{~VS N} and the main voltage source _{VS N + 1} are different power supply voltage _{E 1 ~E N +} 1 from each other _{(E 1 <... <E N} + 1).

The voltage control units 2 _{1 to} 2 _N are electrically connected in series between the main voltage source VS _{N + 1} and the conversion unit 3. Hereinafter, an arbitrary voltage control unit 2 _M among the voltage control units 2 ₁ to 2 _N will be described. Voltage control unit _{2 M} includes a regeneration switch Q1 _M, an input switch Q2 _M. In the power conversion apparatus 1 of the present embodiment, the regenerative switch Q1 _M and the input switch Q2 _M are each IGBT: a (Insulated Gate Bipolar Transistor insulated gate bipolar transistor). Further, the regeneration switch Q1 _M and the input switch Q2 _M, recovery diode each is incorporated. Incidentally, the regenerative switch Q1 _M and the input switch Q2 _M may each be constituted by other semiconductor switching elements such as a bipolar transistor or a MOSFET (Metal-Oxide-Semiconductor Field -Effect Transistor).

Input switch Q2 _M has a collector electrically connected to the first input point 21 _M, the emitter is electrically connected to the output point 22 _M. The first input point 21 _M is electrically connected to the high potential point (positive electrode) of the main voltage source VS _{N + 1} via the first input point 11 (when M = N), or the voltage control unit 2 _{M + 1} Electrically connected to output point 22 _{M + 1} (when M ≠ N).

The input switch Q <b> 2 _M is opened / closed by the control unit 5 to open and close a part of the electric circuit between the first input point 11 and the first input point 31 of the conversion unit 3. That is, the input switch Q2 _M is one of the electrodes of the main voltage source VS N _{+ 1} of the positive electrode or the negative electrode (here, positive) for opening and closing an electrical path for connecting the conversion section 3.

Regeneration switch Q1 _M has an emitter electrically connected to the second input point 23 _M, and the collector is electrically connected to the output point 22 _M. The second input point 23 _M is electrically connected to the high potential point (positive electrode) of the voltage source VS _M.

The regenerative switch Q1 _M is opened / closed by the control unit 5 so as to open and close a part of the electric circuit between the second input point _23M and the first input point 31 of the conversion unit 3. That is, the regenerative switch Q1 _M opens and closes an electric circuit that connects either the positive electrode or the negative electrode of the voltage source VS _M (here, the positive electrode) and the conversion unit 3.

  The conversion unit 3 is a full bridge inverter composed of four switches QB1 to QB4. In power converter 1 of this embodiment, switches QB1-QB4 are IGBTs, respectively. The switches QB1 to QB4 each have a built-in recovery diode. Switch elements QB1 to QB4 may each be composed of other semiconductor switch elements such as bipolar transistors and MOSFETs.

In the conversion unit 3, the series circuit of the first switch QB1 and the second switch QB2 and the series circuit of the third switch element QB3 and the fourth switch QB4 are electrically connected in parallel. The collectors of the switch elements QB1 and QB3 are electrically connected to the first input point 31 of the conversion unit 3. The first input point 31 of the conversion unit 3 is electrically connected to the first input point 11 via the voltage control units 2 ₁ to 2 _N. The emitters of the switch elements QB2 and QB4 are electrically connected to the second input point 32 of the conversion unit 3. Second input point 32 of the converter unit 3 is electrically connected to each of the low potential of the voltage source _VS 1 _{~VS N} (negative electrode), and the second input point 12. The connection point between the emitter of the first switch QB1 and the collector of the second switch QB2 and the connection point of the emitter of the third switch QB3 and the collector of the fourth switch QB4 are a pair of output points 33, 34. It has become.

  The clamp unit 4 is composed of a series circuit of a first holding switch QC1 and a second holding switch QC2. In power converter 1 of this embodiment, holding switches QC1 and QC2 are IGBTs, respectively. Each of the holding switches QC1 and QC2 includes a recovery diode. Note that the holding switches QC1 and QC2 may be composed of other semiconductor switch elements such as bipolar transistors and MOSFETs.

  The collector of the first holding switch QC <b> 1 is electrically connected to the first output point 33 of the conversion unit 3 and is electrically connected to the first output point 13. The collector of the second holding switch QC2 is electrically connected to the second output point 34 of the conversion unit 3 and electrically connected to the second output point 14. In addition, the emitter of the first holding switch QC1 and the emitter of the second holding switch QC2 are electrically connected. The clamp unit 4 includes holding switches QC1 and QC2, and holds the output voltage V1 at a predetermined voltage (here, 0 [V]).

The control unit 5 has, for example, a microcomputer as a main component, and executes various processes by executing a program stored in the memory. The program may be provided through a telecommunication line or may be provided by being stored in a storage medium. Control unit 5 gives the each drive signal regeneration switch _Q1 1 _{~Q1 N,} and input switch _Q2 1 _{~Q2 N} of the voltage control unit ₂ 1 to 2 _N, ON / OFF voltage control unit by switching the _{2 1} ~ 2 _N is controlled. Moreover, the control part 5 gives a drive signal to each of switch QB1-QB4 of the conversion part 3, and controls the conversion part 3 by switching on / off. Further, the control unit 5 gives a drive signal to each of the holding switches QC1 and QC2 of the clamp unit 4 and controls the clamp unit 4 by switching on / off. These drive signals are all PWM (Pulse Width Modulation) signals. The drive signal is not limited to a PWM signal, and may be, for example, a PFM (Pulse Frequency Modulation) signal or a PAM (Pulse Amplitude Modulation) signal.

Here, in the basic configuration of the power conversion apparatus 1 of the present embodiment, the configuration shown in FIG. 1, the voltage control unit 2 ₁ to 2 _N, are electrically connected to the positive pole of the voltage source VS ₁ ~VS _N However, other configurations may be used. That is, as shown in FIG. 2, the voltage control unit ₂ 1 to 2 _N can be electrically connected to the negative pole of the voltage source _VS 1 _{~VS N.} 3A, the regenerative switch Q1 _M is electrically connected to the negative electrode of the voltage source VS _M , and the input switch Q2 _M is electrically connected to the positive electrode of the main voltage source VS _{N + 1.} Also good. Furthermore, as shown in FIG. 3B, the regenerative switch Q1 _M is electrically connected to the positive electrode of the voltage source VS _M , and the input switch Q2 _M is electrically connected to the negative electrode of the main voltage source VS _{N + 1.} Also good. The example shown in FIGS. 3A and 3B is an electric power composed of a multi-level inverter (hereinafter referred to as “5-level inverter”) that switches the output voltage V1 in five stages (that is, N = 1, M = 1). The conversion device 1 is shown.

Hereinafter, an arbitrary voltage control unit 2 _M among the voltage control units 2 ₁ to 2 _N will be described with reference to FIG. 2.

Input switch Q2 _M has a collector electrically connected to the output point 22 _M, the emitter is electrically connected to the first input point 21 _M. The first input point 21 _M is electrically connected to the low potential point (negative electrode) of the main voltage source VS _{N + 1} via the second input point 12 (when M = N), or the voltage control unit 2 _{M + 1} Electrically connected to output point 22 _{M + 1} (when M ≠ N).

The input switch Q <b> 2 _M is opened / closed by the control unit 5 to open and close a part of the electric circuit between the second input point 12 and the second input point 32 of the conversion unit 3. That is, the input switch Q2 _M is one of the electrodes of the main voltage source VS N _{+ 1} of the positive electrode or the negative electrode (here, positive) for opening and closing an electrical path for connecting the conversion section 3.

Regeneration switch Q1 _M has an emitter electrically connected to the output point 22 _M, and the collector is electrically connected to the second input point 23 _M. The second input point 23 _M is electrically connected to the low potential point (negative electrode) of the voltage source VS _M.

Regeneration switch Q1 _M by the control unit 5 that is switched on / off, open and close the part of the electrical path between the second input point 23 _M and the second input point 32 of the converter unit 3. That is, the regenerative switch Q1 _M opens and closes an electric circuit that connects either the positive electrode or the negative electrode of the voltage source VS _M (here, the positive electrode) and the conversion unit 3.

Hereinafter, the operation of the basic configuration of the power conversion device 1 of the present embodiment will be described. In this basic configuration, the control unit 5 controls the switches of the _N voltage control units 2 ₁ to 2 _N , the conversion unit 3, and the clamp unit 4 according to the conditions shown in Table 1 below. That is, the control unit 5, four switches QB1～QB4, the holding switch QC1, QC2, N pieces of the regenerative switch _Q1 in each of the voltage control unit ₂ 1 _{~2 N} 1 _{~Q1 N} and input switch _Q2 1 _{~Q2 N} Control. Thus, this basic configuration operates as a multi-level inverter that switches the output voltage V1 to the '2N + 3' stage. That is, when the voltage source _VS 1 _{~VS N} supply voltages respectively _E 1 to E _N (V), the power supply voltage of the main voltage source _{VS N + 1} to _{E N + 1,} the basic structure is 0 V, ± _{E 1} [V],..., ± E _{N + 1 One} of the output voltages V1 of [V] is generated. In this basic configuration, the control unit 5 appropriately switches the output voltage V1 to output an AC voltage that changes between −E _{N + 1} [V] and E _{N + 1} [V] around 0 [V].

For example, when generating the output voltage V1 of the _{E M} V, control unit 5 switches the regenerative switch Q1 _M of the voltage control unit _{2 M} ON, the other voltage control unit ₂ 1 _{~2 M-1, 2} Switch _{M + 1} to _2N regeneration switch off. The control unit 5 switches the input switch _{Q2 1 ~Q2 M-1} of the voltage control unit _{2 1 ~2 M-1} is turned on, switch off the input switch of the other voltage control unit ₂ M to 2 _N. Then, the control unit 5 switches on the switches QB1 and QB4 of the conversion unit 3, switches off the switches QB2 and QB3, and switches off the holding switches QC1 and QC2 of the clamp unit 4.

When generating the output voltage V1 of −E _M [V], the control unit 5 may switch off the switches QB1 and QB4 of the conversion unit 3 and turn on the switches QB2 and QB3 in the above state. When the output voltage V1 is set to 0 [V], the control unit 5 switches off all the switches of the voltage control units 2 ₁ to 2 _N and the conversion unit 3 and holds the holding switch QC1, the clamp unit 4 What is necessary is just to switch QC2 on.

Hereinafter, as an example, the power conversion device 1 configured by a five-level inverter will be described. The power conversion apparatus 1, as shown in FIG. 4, a single voltage control section 2 _1. The second input point 23 ₁ of the voltage control unit 2 _1, the positive electrode voltage source VS ₁ are electrically connected. A main voltage source VS ₂ is electrically connected to the first input point 11 and the second input point 12. Here, it is assumed that the power source voltage of the voltage source VS ₁ is 1 [V] and the power source voltage of the main voltage source VS ₂ is 2 [V].

In this power conversion device 1, the control unit 5 controls the switches of the voltage control unit 2 ₁ , the conversion unit 3 and the clamp unit 4 according to the conditions shown in Table 2 below, thereby ± 2 [V], ± 1 [ V] and 0 [V] are generated in five stages of output voltage V1.

Hereinafter, it demonstrates concretely using FIG. 5A-FIG. 5C. In FIGS. 5A to 5C, switches surrounded by circles indicate an on state, and switches not surrounded by a circle indicate an off state. For example, when generating the output voltage V1 of 2 V, the control unit 5, on as shown in FIG. 5A, the input switch Q2 ₁ of the voltage control unit _{2 1,} switch QB1 of the conversion unit 3, and QB4 And switch off the other switches. When generating the output voltage V1 of −2 [V], the control unit 5 switches off the switches QB1 and QB4 of the conversion unit 3 and turns on the switches QB2 and QB3 in the above state.

To generate an output voltage V1 of 1 [V], the control unit 5, as shown in Figure 5B, switching the regenerative switch Q1 ₁ of the voltage control unit _{2 1,} switch QB1 of the conversion unit 3, and a QB4 ON Turn off the other switches. When generating the output voltage V1 of -1 [V], the control unit 5 switches off the switches QB1 and QB4 of the conversion unit 3 and switches on the switches QB2 and QB3 in the above state.

  When the output voltage V1 is set to 0 [V], the control unit 5 switches on the holding switches QC1 and QC2 of the clamp unit 4 and switches off the other switches as shown in FIG. 5C. And this power converter 1 changes between 2 [V]-2 [V] centering on 0 [V] by switching the output voltage V1 suitably by the control part 5, as shown in FIG. Output AC voltage (see thick solid line in the figure).

  Of course, the power conversion device 1 of the present embodiment is not limited to the five-level inverter described above, and can also be configured by a multi-level inverter that switches the output voltage V1 in multiple stages. For example, the power conversion device 1 of the present embodiment may be configured by a multi-level inverter (hereinafter referred to as “7-level inverter”) that switches the output voltage V1 in seven stages (that is, N = 2).

As shown in FIG. 7, the power conversion device 1 configured with a seven-level inverter includes two voltage control units 2 ₁ and 2 ₂ . The second input point 23 ₁ of the voltage control unit 2 _1, the negative electrode of the voltage source VS ₁ are electrically connected. The _second voltage controller 2 ₂ of the second input point 23, the negative electrode of the voltage source VS ₂ are electrically connected. A main voltage source VS ₃ is electrically connected to the first input point 11 and the second input point 12. Here, it is assumed that the power source voltage of the voltage source VS ₁ is 1 [V], the power source voltage of the voltage source VS ₂ is 2 [V], and the power source voltage of the main voltage source VS ₃ is 3 [V].

In this power conversion device 1, the control unit 5 controls each switch of the voltage control units 2 ₁ and 2 ₂ , the conversion unit 3, and the clamp unit 4 according to the conditions shown in Table 3 below, so that ± 3 [V], A seven-stage output voltage V1 of ± 2 [V], ± 1 [V], and 0 [V] is generated.

Hereinafter, a specific description will be given with reference to FIGS. 8A, 8B, 9A, and 9B. In FIG. 8A, FIG. 8B, FIG. 9A, and FIG. 9B, a switch surrounded by a circle indicates an on state, and a switch that is not surrounded by a circle indicates an off state. For example, when the output voltage V1 of 3 [V] is generated, the control unit 5 includes the input switches Q2 ₁ and Q2 ₂ of the voltage control units 2 ₁ and 2 _{2 and} the switch of the conversion unit 3 as shown in FIG. 8A. QB1 and QB4 are switched on, and the other switches are switched off. When generating the output voltage V1 of −3 [V], the control unit 5 switches off the switches QB1 and QB4 of the conversion unit 3 and switches on the switches QB2 and QB3 in the above state.

To generate an output voltage V1 of 2 V, the control unit 5, as shown in FIG. 8B, on the regeneration switch Q1 ₂ of the voltage control unit _{2 2,} and an input switch Q2 ₁ of the voltage control unit _{2 1} Switch to. Further, the control unit 5 switches on the switches QB1 and QB4 of the conversion unit 3 and switches off the other switches. When generating the output voltage V1 of −2 [V], the control unit 5 switches off the switches QB1 and QB4 of the conversion unit 3 and turns on the switches QB2 and QB3 in the above state.

To generate an output voltage V1 of 1 [V], the control unit 5, as shown in FIG. 9A, switching the regenerative switch Q1 ₁ of the voltage control unit _{2 1,} switch QB1 of the conversion unit 3, and a QB4 ON Turn off the other switches. When generating the output voltage V1 of -1 [V], the control unit 5 switches off the switches QB1 and QB4 of the conversion unit 3 and switches on the switches QB2 and QB3 in the above state.

  When the output voltage V1 is set to 0 [V], the control unit 5 switches on the holding switches QC1 and QC2 of the clamp unit 4 and switches off the other switches as shown in FIG. 9B. And this power converter device 1 outputs the alternating voltage which changes between -3 [V]-3 [V] centering on 0 [V] by switching the output voltage V1 suitably by the control part 5. FIG.

  Here, a power conversion device 100 that is an NPC (Neutral-Point-Clamped) type five-level inverter will be described as a comparative example of the power conversion device 1 of the present embodiment. As shown in FIG. 10, in the power conversion apparatus 100, two voltage sources 105 and 106 are electrically connected in series between a first input point 101 and a second input point 102. Here, it is assumed that the power supply voltages of the voltage sources 105 and 106 are both 1 [V]. The connection point between the low potential point (negative electrode) of the voltage source 105 and the high potential point (positive electrode) of the voltage source 106 is a common potential point 107.

  Between the first input point 101 and the first output point 103, a series circuit of switches S1, S5 is electrically connected. A series circuit of switches S2 and S6 is electrically connected between the second input point 102 and the first output point 103. A series circuit of switches S3 and S7 is electrically connected between the first input point 101 and the second output point 104. Further, a series circuit of switches S4 and S8 is electrically connected between the second input point 102 and the second output point 104. The switches S1 to S8 are all IGBTs, and each has a built-in recovery diode.

  The collectors of the switches S1 and S3 are electrically connected to the first input point 101, and the emitters of the switches S2 and S4 are electrically connected to the second input point 102. The emitter of the switch S5 and the collector of the switch S6 are electrically connected to the first output point 103, and the emitter of the switch S7 and the collector of the switch S8 are electrically connected to the second output point 104.

  A series circuit of diodes D1 and D2 is electrically connected between the connection point of the emitter of the switch S1 and the collector of the switch S5 and the connection point of the collector of the switch S2 and the emitter of the switch S6. The connection point between the anode of the diode D1 and the cathode of the diode D2 is electrically connected to the common potential point 107. A series circuit of diodes D3 and D4 is electrically connected between the connection point of the emitter of the switch S3 and the collector of the switch S7 and the connection point of the collector of the switch S4 and the emitter of the switch S8. The connection point between the anode of the diode D3 and the cathode of the diode D4 is electrically connected to the common potential point 107.

  The switches S <b> 1 to S <b> 8 are switched on / off by receiving a drive signal that is a PWM signal from the control unit 200. In the power conversion device 100, the control unit 200 controls the switches S1 to S8 according to the conditions shown in Table 4 below, so that five stages of ± 2 [V], ± 1 [V], and 0 [V] are obtained. Output voltage V1 is generated.

  Hereinafter, it demonstrates concretely using FIG. 11A-FIG. 11C. In FIGS. 11A to 11C, switches surrounded by circles indicate an on state, and switches not surrounded by a circle indicate an off state. For example, when generating the output voltage V1 of 2 [V], the control unit 200 switches on the switches S1, S4, S5, and S8 and switches off the other switches as shown in FIG. 11A. When generating the output voltage V1 of −2 [V], the control unit 200 switches on the switches S2, S3, S6, and S7 and switches off the other switches.

  When generating the output voltage V1 of 1 [V], the control unit 200 switches on the switches S1, S5, and S8 and switches off the other switches as shown in FIG. 11B. When generating the output voltage V1 of −1 [V], the control unit 200 switches on the switches S2, S6, S7 and switches off the other switches.

  When the output voltage V1 is set to 0 [V], the control unit 200 switches on the switches S5 and S8 and switches off the other switches as shown in FIG. 11C. And this power converter device 100 outputs the alternating voltage which changes between -2 [V] -2 [V] centering on 0 [V] by switching the output voltage V1 suitably by the control part 200. FIG.

Here, the power conversion device 100 of the comparative example has a problem that the number of circuit components (switches, diodes, voltage sources) necessary to realize a desired number of output levels is increased. Therefore, in the power conversion apparatus 1 of the present embodiment, the regeneration of each of the N voltage control unit ₂ 1 to 2 _N switch _Q1 1 ～Q1 _N, and the control unit 5 to input switch _Q2 1 ～Q2 _N control Thus, the DC voltage input to the converter 3 is changed. Moreover, in the power converter device 1 of this embodiment, the control part 5 controls the switches QB1 to QB4 of the conversion part 3, thereby inverting the polarity of the output voltage V1. Further, in the power conversion device 1 of the present embodiment, the control unit 5 controls the holding switches QC1 and QC2 of the clamp unit 4, thereby holding the output voltage V1 at a predetermined voltage (here, 0 [V]). ing.

  The following table shows the results of comparing the number of components (switches, diodes (including a recovery diode), voltage source) of the power conversion device 1 of the present embodiment and the number of components of the power conversion device 100 of the comparative example. As shown in FIG. As described above, the power conversion device 1 of the present embodiment can reduce the number of circuit components necessary to realize a desired number of output levels, as compared with the power conversion device 100 of the comparative example. . Therefore, the power conversion device 1 of the present embodiment can reduce the cost because the number of components is small. In particular, since the power conversion device 1 according to the present embodiment requires only a small number of switches among the components, the control unit 5 that controls the switches can be simplified, and the cost can be further reduced. . In addition, since the power conversion device 1 of the present embodiment requires only a small number of components through which current flows, it is possible to reduce loss due to current flowing through the components.

Incidentally, the control unit 5 may control the regeneration switch _Q1 1 _{~Q1 N} ON / OFF of the voltage control unit ₂ 1 to 2 _N in accordance with the conditions shown in Table 6 below. Specifically, when the output voltage V1 is the power supply voltage E _M of the voltage source VS _M electrically connected to the arbitrary voltage control unit _2M , the control unit 5 determines the arbitrary voltage control unit _2M. the regeneration switch Q1 _M may be maintained in the oN state. Further, when the output voltage V1 is the power supply voltage E _M-1 that is one step lower than the power supply voltage E _M , the control unit 5 maintains the regenerative switch Q1 _M of any voltage control unit 2 _{M in} the on state. May be.

As an example, the case where the power converter device 1 of this embodiment is configured by a five-level inverter as shown in FIG. 4 will be described. In this case, the control unit 5, not only to generate the output voltage V1 of 1 V, as shown in FIG. 12, the voltage control unit 2 ₁ is also the case where the output voltage V1 and 0 [V] maintaining the regeneration switch Q1 ₁ in the oN state. In FIG. 12, switches surrounded by circles indicate an on state, and switches not surrounded by a circle indicate an off state.

In this configuration, there is no need to switch the regenerative switch _Q1 1 _{~Q1 N} ON / OFF of the voltage control unit ₂ 1 to 2 _N in a short time. Therefore, in this configuration, it is possible to use low-speed operating elements as the regenerative switches Q1 _{1 to} Q1 _N , so that the cost can be reduced.

  Further, the control unit 5 may control on / off of the holding switches QC1 and QC2 of the clamp unit 4 according to the conditions shown in Table 7 below. Specifically, the clamp unit 4 includes a series circuit of a pair of holding switches QC1 and QC2 that are electrically connected between the pair of output points 33 and 34 of the conversion unit 3. Then, the control unit 5 maintains the second holding switch QC2 of the pair of holding switches QC1 and QC2 in the ON state when the output voltage V1 is higher than a predetermined voltage (here, 0 [V]). You may control to. Further, the control unit 5 may perform control so that the first holding switch QC1 of the pair of holding switches QC1 and QC2 is maintained in the ON state when the output voltage is smaller than a predetermined voltage.

  As an example, the case where the power converter device 1 of this embodiment is configured by a five-level inverter as shown in FIG. 4 will be described. In this case, the control unit 5 generates either the output voltage V1 of 2 [V] as shown in FIG. 13A or the output voltage V1 of 1 [V] as shown in FIG. 13B. Also, the second holding switch QC2 of the clamp unit 4 is switched on. In FIGS. 13A and 13B, switches surrounded by a circle indicate an on state, and switches not surrounded by a circle indicate an off state.

  In this configuration, it is not necessary to switch on / off the holding switches QC1 and QC2 of the clamp unit 4 in a short period of time. Therefore, in this configuration, since the low-speed operation element can be used as the holding switches QC1 and QC2, the cost can be reduced.

  By the way, in the power converter device 1 of this embodiment, as shown in Table 1, the 1st switch QB1 and 4th switch QB4 of the conversion part 3 are switched on / off at the same timing mutually. Similarly, the second switch QB2 and the third switch QB3 of the conversion unit 3 can be switched on / off at the same timing.

  Therefore, in the power conversion device 1 of the present embodiment, the control unit 5 may control the switches QB1 to QB4 of the conversion unit 3 as follows. That is, the control unit 5 may drive the high-side switch QB1 of the first leg and the low-side switch QB4 of the second leg of the pair of legs of the conversion unit 3 with one drive signal. Good. Here, the first leg is a series circuit of switches QB1 and QB2, and the second leg is a series circuit of switches QB3 and QB4. However, the first leg and the second leg may be reversed. With this configuration, the number of signal lines for driving signals can be reduced. Further, in this configuration, it is possible to prevent the on / off timing from being shifted in the pair of switches driven by one drive signal.

  By the way, in the power converter device 1 of this embodiment, as shown in Table 8 below, the control unit 5 may perform control so as to provide dead times DT1 to DT4 when the output voltage V1 is shifted. In the dead times DT1 to DT4, the control unit 5 switches all the switches off. By controlling in this way, it is possible to prevent a short circuit between the first input point 11 and the second input point 12 when the output voltage V1 is transitioned.

However, in the dead time DT1～DT4, as shown in FIG. 14, the switch _QB3, Q2 1, a current I1 in a path through QB2 recovery diode, and a main voltage source VS ₂ flows. Therefore, during the dead times DT1 to DT4, the power supply voltage E _{N + 1} [V] (here, 2 [V]) of the main voltage source VS _{N + 1 is} applied between the first input point 11 and the second input point 12. The Therefore, in this case, since the power supply voltage E _{N + 1} [V] of the main voltage source VS _{N + 1} may be applied to the switches constituting the voltage control units 2 ₁ to 2 _N at the maximum, a required withstand voltage is required. Is determined by the power supply voltage E _{N + 1} of the main voltage source VS _{N + 1} . For this reason, a high-breakdown-voltage element must be used for each switch constituting the voltage control units 2 ₁ to 2 _N, which may increase the cost.

Therefore, in the power conversion device 1 of the present embodiment, it is preferable that the control unit 5 controls as follows. That is, the control unit 5 controls each of the N voltage control units 2 ₁ to 2 _N , the conversion unit 3, and the clamp unit 4 so as to provide dead times DT 1 to DT 4 when the output voltage V 1 is transitioned. Then, in the dead times DT1 to DT4, the control unit 5 performs control so that the switch that is in the on state is maintained in the on state before and after the transition of the output voltage V1, and the other switches are switched off.

  As an example, the case where the power converter device 1 of this embodiment is configured by a five-level inverter as shown in FIG. 4 will be described. In the description, the path of the current I1 in each of the state in which the output voltage V1 of 2 [V] is generated, the state in which the output voltage V1 of 1 [V] is generated, and the state in which the output voltage V1 is 0 [V] is illustrated. 15A to FIG. 15C. Also, the path of the current I1 in each of the dead times DT1 and DT2 is shown in FIGS. 16A and 16B. In FIGS. 15A to 15C and FIGS. 16A and 16B, switches surrounded by circles indicate an on state, and switches not surrounded by a circle indicate an off state.

In this case, the control unit 5 controls the switches of the voltage control unit 2 ₁ , the conversion unit 3, and the clamp unit 4 according to the conditions shown in Table 9 below. For example, in the dead time DT1, the control unit 5 maintains the switches QB1, QB4, and QC2 that are in the on state before and after the transition of the output voltage V1 and switches off the other switches. Then, as shown in FIG. 16A, instead of applying the power supply voltage E ₂ [V] of the main voltage source VS ₂ to the first input point 11 and the second input point 12, the first input point 31 of the converter 3. The power source voltage E ₁ [V] of the voltage source VS ₁ is applied to the second input point 32.

Further, for example, the control unit 5 maintains the switches Q1 ₁ and QC2 that are in the on state before and after the transition of the output voltage V1 in the dead time DT2, and switches the other switches to the off state. Then, as shown in FIG. 16B, instead of applying the power supply voltage E ₂ [V] of the main voltage source VS ₂ to the first input point 11 and the second input point 12, the first output point 13 and the second output The voltage between the points 14 becomes 0 [V].

That is, in this configuration, the regenerative switch Q1 _M at any of the voltage control unit _{2 M,} and each minimum required withstand voltage of the input switch Q2 _M the following as shown in Table _{10 'E M + 1 -E M} ' [ V]. For example, it is assumed that the voltage difference between the main voltage source VS _{N + 1} and the voltage source VS _N and the voltage difference between an arbitrary voltage source VS _M and the voltage source VS _{M + 1} at the next stage are E ₁ [V]. . In this case, the minimum withstand voltage required for each of the regenerative switch Q1 _M and the input switch Q2 _{M in} the arbitrary voltage control unit _2M is E ₁ [V].

As described above, in this configuration, since the minimum withstand voltage required by each switch constituting the voltage control units 2 ₁ to 2 _N can be lowered, it is not necessary to use a high withstand voltage element, thereby reducing costs. can do. Moreover, the frequency in this configuration, switching between the regenerative switch _Q1 1 _{~Q1 N,} switch QB1~QB4 conversion unit 3, each of the on / off of the holding switch QC1, QC2 clamp portion 4 of the voltage control unit ₂ 1 to 2 _N Is less. For this reason, in this configuration, switching loss can be reduced.

Further, in the above configuration, the control unit 5, the voltage control unit 2 ₁ to 2 N so as to shift the output voltage V1 by one _step, conversion unit 3, it is preferable to control the respective switches of the clamping portion 4. That is, the control unit 5 includes the N voltage control units 2 ₁ to 2 _N , the conversion unit 3, and the clamp unit 4 so that the output voltage V 1 increases in order from the minimum value or decreases in order from the maximum value. Each switch is preferably controlled. As an example, the case where the power converter device 1 of this embodiment is configured by a five-level inverter as shown in FIG. 4 will be described. In this case, if the output voltage V1 is shifted from 2 [V] to 0 [V] without going through the state where the output voltage V1 is 1 [V], the first input point 11 and the second input point 12 in the dead time. In other words, the power supply voltage E ₂ [V] of the main voltage source VS ₂ is applied. Therefore, the minimum required withstand voltage of the switches QB1 to QB4 of the conversion unit 3 is determined by the power supply voltage E ₂ [V] of the main voltage source VS ₂ .

On the other hand, if the control unit 5 controls the output voltage V1 so as to transition one step at a time from 2 [V], 1 [V], and 0 [V], the minimum required withstand voltage of the switches QB1 to QB4 of the conversion unit 3 The power supply voltage E ₁ [V] of the voltage source VS ₁ is sufficient. For this reason, in this structure, it is not necessary to use a high voltage | pressure-resistant element for switch QB1-QB4 of the conversion part 3, and it can reduce cost.

  By the way, as shown in FIG. 18A, drive signals given to the switches QB1 and QB3 of the conversion unit 3 are drive signals GB1 and GB3, and drive signals given to the switches QC and QC2 of the clamp unit 4 are drive signals GC1 and GC2. To do. The drive signals GB1 and GB3 are buffered by the drive circuits 61 and 62, respectively, and then supplied to the switches QB1 and QB3 of the conversion unit 3. The drive signals GC1 and GC2 are buffered by the drive circuits 63 and 64, respectively, and then supplied to the holding switches QC1 and QC2 of the clamp unit 4. In order to drive the switch elements QB1 and QB3 and the holding switches QC1 and QC2, it is necessary to apply a voltage between the gate and the emitter. For this reason, the drive circuits 61 to 64 require a drive power supply that uses the emitter potentials of the switch elements QB1 and QB3 and the holding switches QC1 and QC2 as a reference potential.

  When the power conversion device 1 of the present embodiment is configured by the five-level inverter shown in FIG. 4, the emitter potentials of the holding switches QC1 and QC2 of the clamp unit 4 are the same. However, the emitter potential and the emitter potentials of the switches QB1 and QB3 of the conversion unit 3 are different from each other. Therefore, as shown in FIG. 18A, the drive circuits 61 to 64 cannot be driven unless three drive power supplies PS1 to PS3 having these emitter potentials as reference potentials are prepared.

  Therefore, in the power conversion device 1 of the present embodiment, any one of the switches QB1 to QB4 of the conversion unit 3 is electrically connected to any one of the holding switches QC1 and QC2 of the clamp unit 4. Good. Hereinafter, the case where the power converter device 1 of this embodiment is comprised with a 5-level inverter is demonstrated using FIG. In this configuration, as shown in FIG. 17, the emitter of the first switch QB1 of the conversion unit 3 is electrically connected to the emitter of the first holding switch QC1 of the clamp unit 4. The emitter of the third switch QB3 of the conversion unit 3 is electrically connected to the emitter of the second holding switch QC2 of the clamp unit 4.

  In this case, the emitter potentials of the first switch QB1 of the conversion unit 3 and the first holding switch QC1 of the clamp unit 4 are the common first emitter potential EP1. Further, the emitter potentials of the third switch QB3 of the conversion unit 3 and the second holding switch QC2 of the clamp unit 4 become the common second emitter potential EP2. Therefore, in this configuration, as shown in FIG. 18B, the first driver circuit 61 and the third driver circuit 63 can be driven by the first drive power source PS1 having the first emitter potential EP1 as a reference potential. Further, in this configuration, the second driver circuit 62 and the fourth driver circuit 64 can be driven by the second drive power source PS2 having the second emitter potential EP2 as a reference potential.

  As described above, with this configuration, the number of drive power supplies can be reduced to reduce the size of the circuit. Further, with this configuration, the number of drive power supplies can be reduced, so that the cost can also be reduced.

Further, in the power conversion apparatus 1 of this embodiment, with the configuration shown in FIG. 2, the switch QB2 of the conversion unit 3, and the emitter of the QB4, and the emitter of the regenerative switch Q1 ₁ of the voltage control unit 2 ₁ electrically Connected. The voltage control unit 2 ₁ is directly electrically connected to the converter 3. Similarly, the emitter of the input switch Q2 _M-1 of the arbitrary voltage control unit 2 _M-1 and the emitter of the regenerative switch Q1 _M of the voltage control unit 2 _{M at} the next stage are electrically connected. Therefore, a switch QB2, QB3 of the conversion unit 3, since the regenerative switch Q1 ₁ of the voltage control unit 2 ₁ is a common emitter voltage, can be driven by one common drive power source. Similarly, the input switch Q2 _M-1 of the arbitrary voltage control unit 2 _M-1 and the regenerative switch Q1 _M of the voltage control unit 2 _{M at} the next stage have a common emitter potential, so that one common drive power supply It is possible to drive with.

Hereinafter, the case where the power converter device 1 of this embodiment is comprised by the 7 level inverter shown in FIG. 7 is demonstrated. For example, as shown in FIG. 19A, the drive signal supplied to the converter 3 switch QB2 as a driving signal GB2, respectively driving signal a driving signal applied to input switch Q2 ₁ and the regenerative switch Q1 ₁ of the voltage control unit 2 ₁ Let G2 ₁ and G1 ₁ respectively. Further, the drive signal supplied to the regenerative switch Q1 ₂ of the voltage control unit _{2 2} and G1 _2. Drive signal GB2, G2 ₁ is given from the buffer in each drive circuit 65 and 66 to the switch QB2, Q2 _1. The drive signals G1 ₁ and G1 ₂ are buffered by drive circuits 67 and 68, respectively, and then supplied to the switches Q1 ₁ and Q1 ₂ .

In the configuration shown in FIG. 19A, and a switch _{QB2, Q2 1, Q1 1,} Q1 2 drive power PS4~PS7 individually to drive. On the other hand, in the configuration shown in FIG. 19B, since the emitter and the regeneration switch Q1 ₁ emitter of switch QB2 are at the same potential, and drive switch QB2, Q1 ₁ with one driving power source PS4. Similarly, the emitter of the input switch Q2 ₁ and the emitter of the regenerative switch Q1 ₂ is at the same potential, is driving the switch _Q2 1, Q1 ₂ in one driving power source PS5. That is, the configuration illustrated in FIG. 19B can reduce the number of drive power supplies compared to the configuration illustrated in FIG. 19A.

As described above, with this configuration, the number of drive power supplies can be reduced to reduce the size of the circuit. Specifically, if the power conversion device 1 of the present embodiment is configured to include N voltage control units 2 ₁ to 2 _N , the drive power supply is compared with the case where the drive power supply is individually provided for each switch. N can be reduced. Further, with this configuration, the number of drive power supplies can be reduced, so that the cost can also be reduced. Note that whether or not to adopt the configuration is arbitrary.

Further, in the power conversion apparatus 1 of the present embodiment, any of the voltage source VS _M that is electrically connected to the voltage control unit 2 _M, the power supply voltage E _M is the main voltage source VS N _{+ 1} power supply voltage E _{N + 1} ' M / (N + 1) ′ is preferred. In other words, the M-th voltage controller 2 _M counted from the voltage control unit 2 ₁ is directly electrically connected to the converter unit 3, the power supply voltage E _M is the main voltage source VS N _{+ 1} power supply voltage E _{N + 1} ' preferably, M / (N + 1) voltage source VS _M is a 'are electrically connected.

For example, it is assumed that the power conversion device 1 of the present embodiment is configured with a 7-level inverter (that is, N = 2). In this case, the voltage source VS ₁ electrically connected to the voltage control unit 2 ₁ (that is, M = 1) has the power supply voltage E ₁ that is 1/3 of the output voltage E ₃ of the main voltage source VS _3. It is preferable. Similarly, the voltage source VS ₂ electrically connected to the voltage control unit 2 ₂ (that is, M = 2) has a power supply voltage E ₂ that is 2/3 of the output voltage E ₃ of the main voltage source VS _3. It is preferable.

In this configuration, the voltage difference between the main voltage source VS _{N + 1} and the voltage source VS _N, and the voltage difference between the arbitrary voltage source VS _M and the voltage source VS _{M + 1} of the next stage are respectively “E _{N + 1} / (N + 1)”. [V]. Therefore, as shown in Table 11 below, the minimum necessary breakdown voltage of each switch can be lowered. For example, 7-level inverter such as a power conversion device 1 of the present embodiment shown in FIG. 7 (i.e., N = 2) in the case of a configuration using, minimum required withstand voltage of each switch, E _3/3 = E ₁ [ V] is enough. For this reason, in this configuration, the breakdown voltage required for each switch can be lowered, so that it is not necessary to use a high breakdown voltage element, and the cost can be reduced. Also, with this configuration, the limitation on the insulation distance that should be taken into account when each switch is mounted on the substrate is relaxed. Further, in this configuration, since the same type of element can be used for each switch, the cost can be further reduced.

  Hereinafter, the usage example which used the power converter device 1 of this embodiment for the power conditioner is demonstrated. As shown in FIG. 20, this usage example includes the power conversion device 1 of the present embodiment and a disconnector 9. The disconnector 9 is electrically connected between the first output point 13 and the second output point 14 and the system power supply 7. Specifically, the first output point 13 and the second output point 14 of the power conversion device 1 are electrically connected to the interconnection breaker provided in the distribution board via the disconnector 9, It is electrically connected to the system power supply 7. A load 8 is electrically connected between the disconnector 9 and the system power supply 7.

  The circuit breaker 9 is electrically connected between the first contact point 91 electrically connected between the first output point 13 and the system power supply 7, and between the second output point 14 and the system power supply 7. And a second contact portion 92. However, the circuit breaker 9 only needs to be electrically connected between at least one of the first output point 13 and the second output point 14 and the system power supply 7, and the first contact point portion 91 and the second contact point portion. Any of 92 may be omitted.

In this usage example, grid connection operation is performed in a steady state, DC power input from the main voltage source VS _{N + 1} and the voltage sources VS _{1 to} VS _N is converted into AC power by the power converter 1, and the system power source 7 and Output to load 8.

In this usage example, the control unit 5 includes the voltage control units 2 ₁ to 2 _N , the conversion unit 3, and the clamp unit so that the phase of the output AC voltage is opposite to the phase of the power supply voltage of the system power supply 7. Each of the four switches may be controlled. In this configuration, the charging and discharging directional inverter both are possible in the main voltage source VS N _{+ 1} and the voltage source VS ₁ ~VS _N, may use power conversion apparatus 1 of the present embodiment.

In this usage example, the control unit 5 may have a function of measuring the power supply frequency of the system power supply 7. The control unit 5 controls each switch of the voltage control units 2 ₁ to 2 _N , the conversion unit 3, and the clamp unit 4 so that the phase of the output AC voltage is shifted from the phase of the power supply voltage of the system power supply 7. Also good.

  In this configuration, reactive power can be injected into the system power supply 7 by controlling as described above. When an abnormality such as a power failure occurs in the system power supply 7, the power supply frequency of the system power supply 7 varies due to the injection of reactive power. Therefore, the control unit 5 can determine whether or not an abnormality such as a power failure has occurred in the system power supply 7 by measuring the power supply frequency of the system power supply 7. It can be determined whether or not the vehicle is driving.

(Embodiment 2)
Hereinafter, the power converter device 1 which concerns on Embodiment 2 of this invention is demonstrated using FIG. The power conversion device 1 of the present embodiment has a circuit configuration itself that is the same as that of the power conversion device 1 of the first embodiment, and the operation of the control unit 5 is different from that of the power conversion device 1 of the first embodiment. In addition, in the power converter device 1 of this embodiment, description is abbreviate | omitted suitably about the component in common with the power converter device 1 of Embodiment 1. FIG. Below, the case where the power converter device 1 of this embodiment is comprised with a 5-level inverter as shown in FIG. 4 is demonstrated. Further, it is assumed that the power source voltage of the voltage source VS ₁ is E ₁ [V] and the power source voltage of the main voltage source VS ₂ is E ₂ [V]. Of course, it is not the meaning which limits the power converter device 1 of this embodiment to a 5-level inverter.

In the power conversion device 1 of the present embodiment, the control unit 5 switches each of the voltage control unit 2 ₁ , the conversion unit 3, and the clamp unit 4 according to the comparison result between the four carrier waves CW1 to CW4 and the target signal OS1. To control.

The first carrier wave CW1 is a triangular wave having a minimum voltage value of 0 [V] and a maximum voltage value of E ₁ / L [V]. The second carrier wave CW2 is a triangular wave having a minimum voltage value of E ₁ / L [V] and a maximum voltage value of E ₂ / L [V]. The third carrier wave CW3 is a triangular wave having a minimum voltage value of −E ₁ / L [V] and a maximum voltage value of 0 [V]. The fourth carrier wave CW4 is a triangular wave having a minimum voltage value of −E ₂ / L [V] and a maximum voltage value of −E ₁ / L [V]. The carriers CW1 to CW4 are synchronized with each other. 'L' is an integer of 1 or more.

The target signal OS1 is a signal corresponding to a desired AC voltage command value output from the power converter 1. In the power conversion device 1 of the present embodiment, the target signal OS1 has the same voltage value as the command value, a sine wave having a minimum voltage value of −E ₂ / L [V] and a maximum voltage value of E ₂ / L [V]. become. 'L' is an integer of 1 or more.

The control unit 5 compares the carrier waves CW1 to CW4 with the target signal OS1 and generates a voltage control unit 2 ₁ , a conversion unit 3, and a clamp unit 4 so as to generate an output voltage V 1 according to the conditions shown in Table 12 below. Control each switch. When the target signal OS1 is equal to any of the carrier waves CW1 to CW4 (for example, OS1 = CW1 etc.), the conditions are not limited to those shown in Table 12, and may be defined as appropriate.

For example, when the voltage value of the target signal OS1 is between the third carrier CW3 and the fourth carrier CW4, the control unit 5 uses the first holding switch QC1 of the clamp unit 4, the switches QB2 and QB3 of the conversion unit 3, the voltage switching the regeneration switch Q1 ₁ of the control unit _{2 1} is turned on. In addition, the control unit 5 switches off the remaining switches. Thereby, the power converter device 1 of this embodiment generates the output voltage V1 of −E ₁ [V].

As described above, in the power conversion device 1 of the present embodiment, the control unit 5 includes the voltage control unit 2 ₁ and the conversion unit according to the comparison result between the four synchronized carriers CW1 to CW4 and the target signal OS1. 3. Control each switch of the clamp unit 4. Thus, the power conversion device 1 of the present embodiment, by switching the output voltage V1 appropriately by the control unit 5 varies between 0 [V] -E ₂ (V) to E ₂ V to about the Outputs AC voltage.

In addition, when the power conversion device 1 of the present embodiment includes _N voltage control units 2 ₁ to 2 _N , the control unit 5 includes 'N × 2 + 2' synchronized carriers and the target signal OS1. The switches of the voltage control units 2 ₁ to 2 _N , the conversion unit 3, and the clamp unit 4 are controlled according to the comparison result. Thus, the power conversion device 1 of the present embodiment, by switching the output voltage V1 appropriately by the control unit 5 varies between 0 V -E N _{+ 1} [V] to E N _{+ 1} [V] around the Outputs AC voltage.

  Therefore, the power conversion device 1 according to the present embodiment has a small number of transitions of the output voltage V1 in order to output a desired AC voltage, so that the number of times each switch is turned on / off is small, and switching loss is reduced. Can do.

By the way, in the power converter device 1 of this embodiment, as shown in FIG. 22, the phases of the first carrier wave CW1 and the fourth carrier wave CW1 may be reversed. Also in this case, the control unit 5 compares the carrier waves CW1 to CW4 with the target signal OS1 and generates the output voltage V1 in accordance with the conditions shown in Table 12, so that the voltage control unit 2 ₁ , the conversion unit 3, the clamp Each switch of the unit 4 is controlled.

That is, the control unit 5 determines the voltage control unit according to the comparison result between the target signal OS1 and the “N + 1” carriers, and the “N + 1” carriers whose phases are inverted from those of the “N + 1” carriers. 2 ₁ to 2 _N, converter 3, it may control the switch of the clamping portion 4. In this configuration, since the number of times the output voltage V1 is transitioned to output a desired AC voltage is constant, it is possible to output an AC voltage with less distortion.

(Configuration example 1)
Hereinafter, the power converter 1 which concerns on the structural example 1 of this embodiment is demonstrated using FIG. In the power conversion device 1 of the present configuration example, the control unit 5 converts the voltage control unit 2 ₁ , the conversion according to the comparison result between the two carrier waves CW1 and CW2 and the target signal OS1 and the determination result of the positive / negative command value. Each switch of the part 3 and the clamp part 4 is controlled.

In FIG. 23, the first determination signal DS1 is a signal indicating whether the command value is positive or negative. The first determination signal DS1 is 'L' if the command value is positive and 'H' if the command value is negative. Note that the determination signal DS1 when the command value is zero may be appropriately defined. The target signal OS1 is a signal adjusted so as to fall between the minimum value and the maximum value of a plurality of carrier waves (carrier waves CW1, CW2) based on the positive / negative determination result of the command value. In the power conversion device 1 of this configuration example, the target signal OS1 is a signal to which a predetermined voltage value is added during a period in which the command value is negative. Here, the predetermined voltage value is a difference between the minimum value of the first carrier CW1 and the maximum value of the second carrier CW2. That is, as shown in FIG. 23, the target signal OS1 shows the same voltage value as the command value while the first determination signal DS1 indicates “L”, and the command value when the first determination signal DS1 becomes “H”. Represents a voltage value obtained by adding 'E ₂ / L' [V].

The control unit 5 controls the voltage so as to generate the output voltage V1 according to the conditions shown in Table 13 below according to the comparison result between the carrier waves CW1 and CW2 and the target signal OS1 and the first determination signal DS1. The switches of the unit 2 ₁ , the conversion unit 3, and the clamp unit 4 are controlled. When the target signal OS1 is equal to one of the carrier waves CW1 and CW2 (for example, OS1 = CW1 etc.), the conditions are not limited to those shown in Table 13, and may be defined as appropriate.

For example, a case where the voltage value of the target signal OS1 is between the first carrier wave CW1 and the second carrier wave CW2 will be described. In this case, if the first determination signal DS1 is 'L', the control unit 5, second hold switch QC2 clamp portion 4, the switch QB1 of the conversion unit 3, QB4, regeneration switch Q1 of the voltage controller _{2 1 1} Switch on and switch off the remaining switches. Thereby, the power converter device 1 of this configuration example generates the output voltage V1 of E ₁ [V]. Further, if the first determination signal DS1 is 'H', the control unit 5, the first holding switch QC1 of the clamping portion 4, the switch QB2, QB3 of the conversion unit 3, the regeneration switch Q1 ₁ of the voltage control unit _{2 1} Switch on and switch off the remaining switches. Thereby, the power converter device 1 of this configuration example generates the output voltage V1 of −E ₁ [V].

As described above, in the power conversion device 1 of the present configuration example, the control unit 5 determines the comparison result between the two synchronized carriers CW1 and CW2 and the target signal OS1 and the determination result of the command value positive / negative. The switches of the voltage control unit 2 ₁ , the conversion unit 3, and the clamp unit 4 are controlled. Thus, the power conversion device 1 of the present configuration example, by switching the output voltage V1 appropriately by the control unit 5 varies between 0 [V] -E ₂ (V) to E ₂ V to about the Outputs AC voltage.

Further, when the power conversion device 1 of this configuration example includes N voltage control units 2 ₁ to 2 _N , the control unit 5 performs the following control. That is, the control unit 5 determines the voltage control units 2 ₁ to 2 _N , the conversion unit 3, the clamp according to the comparison result between the “N + 1” synchronized carriers and the target signal OS 1, and the positive / negative determination result of the command value. Each switch of the unit 4 is controlled. Thus, the power conversion device 1 of the present embodiment, by switching the output voltage V1 appropriately by the control unit 5 varies between 0 V -E N _{+ 1} [V] to E N _{+ 1} [V] around the Outputs AC voltage.

  Therefore, since the power conversion device 1 of this configuration example requires a small number of carrier waves, the software and hardware necessary for generating the carrier waves can be simplified, and the cost can be reduced. In addition, in the power converter device 1 of this structural example, although the control part 5 is performing the addition process with respect to command value in target signal OS1, another structure may be sufficient. That is, the addition process may be executed by an adder provided separately from the control unit 5.

(Configuration example 2)
Hereinafter, the power converter device 1 according to the configuration example 2 of the present embodiment will be described with reference to FIG. In the power conversion device 1 of this configuration example, unlike the power conversion device 1 of the configuration example 1, the phase of the first carrier wave CW1 is inverted. The target signal OS1 is a signal adjusted so as to fall between the minimum value and the maximum value of a plurality of carrier waves (carrier waves CW1, CW2) based on the positive / negative determination result of the command value. In the power conversion device 1 according to the present configuration example, unlike the power conversion device 1 according to the configuration example 1, the target signal OS1 is a signal obtained by inverting the sign of the command value in a period in which the command value is negative. That is, as shown in FIG. 24, the target signal OS1 indicates the same voltage value as the command value while the first determination signal DS1 indicates “L”, and the command value when the first determination signal DS1 becomes “H”. Indicates the voltage value obtained by reversing the positive and negative signs.

The control unit 5 controls the voltage so as to generate the output voltage V1 according to the conditions shown in Table 14 below according to the comparison result between the carrier waves CW1 and CW2 and the target signal OS1 and the first determination signal DS1. The switches of the unit 2 ₁ , the conversion unit 3, and the clamp unit 4 are controlled. When the target signal OS1 is equal to one of the carrier waves CW1 and CW2 (for example, OS1 = CW1 etc.), the conditions are not limited to those shown in Table 14, and may be defined as appropriate.

For example, a case where the voltage value of the target signal OS1 is larger than the second carrier wave CW2 will be described. In this case, if the first determination signal DS1 is 'L', the control unit 5, second hold switch QC2 clamp portion 4, the switch QB1 of the conversion unit 3, QB4, input switch Q2 ₁ of the voltage control unit _{2 1} Switch on and switch off the remaining switches. Thereby, the power converter device 1 of the present configuration example generates the output voltage V1 of E ₂ [V]. Further, if the first determination signal DS1 is 'H', the control unit 5, the first holding switch QC1 of the clamping portion 4, the conversion unit 3 of the switch QB2, QB3, an input switch Q2 ₁ of the voltage control unit _{2 1} Switch on and switch off the remaining switches. Thereby, the power converter device 1 of this configuration example generates the output voltage V1 of −E ₂ [V].

As described above, in the power conversion device 1 of this configuration example, the control unit 5 compares the second carrier wave CW2, the first carrier wave CW1 whose phase is inverted with the target signal OS1, and the positive / negative determination result of the command value. Accordingly, the switches of the voltage control unit 2 ₁ , the conversion unit 3, and the clamp unit 4 are controlled. Thus, the power conversion device 1 of the present configuration example, by switching the output voltage V1 appropriately by the control unit 5 varies between 0 [V] -E ₂ (V) to E ₂ V to about the Outputs AC voltage.

Further, when the power conversion device 1 of this configuration example includes N voltage control units 2 ₁ to 2 _N , the control unit 5 performs the following control. That is, the control unit 5 determines each of the voltage control units 2 ₁ to 2 _N , the conversion unit 3, and the clamp unit 4 according to the comparison result between the plurality of carrier waves and the target signal OS 1 and the determination result of the positive / negative command value. Control the switch. The plurality of carrier waves are “[(N + 1) / 2]” carrier waves and “[(N + 1) / 2]” carrier waves whose phase is inverted from the “[(N + 1) / 2]” carrier waves. It is. Thus, the power conversion device 1 of the present embodiment, by switching the output voltage V1 appropriately by the control unit 5 varies between 0 V -E N _{+ 1} [V] to E N _{+ 1} [V] around the Outputs AC voltage.

  Note that “[]” in “[(N + 1) / 2]” is a Gaussian symbol. For example, when X is a real number, [X] is an integer and satisfies the relationship of “X−1 ≦ [X] <X”. Therefore, '[(N + 1) / 2]' represents the maximum integer that does not exceed '(N + 1) / 2'.

  Therefore, since the power conversion device 1 of this configuration example requires a small number of carrier waves, the software and hardware necessary for generating the carrier waves can be simplified, and the cost can be reduced. In addition, in the power converter device 1 of this structural example, although the control part 5 is performing the process which reverses the positive / negative of command value in target signal OS1, other structures may be sufficient. That is, a process of inverting the sign of the command value may be executed by a multiplier provided separately from the control unit 5.

(Configuration example 3)
Hereinafter, the power converter 1 which concerns on the structural example 3 of this embodiment is demonstrated using FIG. In the power conversion device 1 of the present configuration example, the control unit 5 includes the voltage control units 2 ₁ , 2, and 2 according to the comparison result between the two carrier waves CW1 and CW3 and the target signal OS1 and the comparison result between the command value and the threshold value. The switches of the conversion unit 3 and the clamp unit 4 are controlled. Here, 'E ₁ / L' [V], which is the maximum value of the first carrier CW1, is set as the first threshold, and '-E ₁ / L' [V], which is the minimum value of the third carrier CW3, is set as the threshold. Two threshold values are set.

In FIG. 25, the second determination signal DS2 is a signal indicating a comparison result between the command value and the threshold value. The second determination signal DS2 is' H1 'if the command value exceeds the first threshold (' E ₁ / L '[V]), and' 2 if the command value falls below the second threshold ('-E ₁ / L' [V]). “H2”, otherwise “L”. Further, the target signal OS1 is a signal adjusted to fall between the minimum value and the maximum value of a plurality of carrier waves (carrier waves CW1, CW3) based on the comparison result between the command value and the threshold value. In the power conversion device 1 of this configuration example, the target signal OS1 is obtained by subtracting the first threshold value from the command value during the period when the command value exceeds the first threshold value, and from the command value during the period when the command value is less than the second threshold value. A signal obtained by subtracting two threshold values. That is, as shown in FIG. 25, the target signal OS1 indicates the same voltage value as the command value while the second determination signal DS2 indicates “L”, and the command value when the second determination signal DS2 becomes “H1”. The voltage value obtained by subtracting 'E ₁ / L' [V] from the value is shown. Further, the target signal OS1 indicates a voltage value obtained by subtracting “−E ₁ / L” [V] from the command value when the second determination signal DS2 becomes “H2”.

The control unit 5 controls the voltage so as to generate the output voltage V1 according to the conditions shown in Table 15 below according to the comparison result between the carrier waves CW1 and CW3 and the target signal OS1 and the second determination signal DS2. The switches of the unit 2 ₁ , the conversion unit 3, and the clamp unit 4 are controlled. When the target signal OS1 is equal to one of the carrier waves CW1 and CW3 (for example, OS1 = CW1 etc.), the conditions are not limited to those shown in Table 15, and may be defined as appropriate.

For example, a case where the voltage value of the target signal OS1 is between the first carrier wave CW1 and the third carrier wave CW3 will be described. In this case, if the second determination signal DS2 is 'L', the control unit 5, the holding switch QC1 of the clamping portion 4, QC2, switches the regeneration switch Q1 ₁ of the voltage control unit _{2 1} is turned on, the remaining switches Switch off. Thereby, the power converter device 1 of this structural example sets the output voltage V1 to 0 [V]. Further, if the second determination signal DS2 is 'H1', the control unit 5, second hold switch QC2 clamp portion 4, the switch QB1, QB4 in the conversion section 3, a regenerative switch Q1 ₁ of the voltage control unit _{2 1} Switch on and switch off the remaining switches. Thereby, the power converter device 1 of this configuration example generates the output voltage V1 of E ₁ [V]. Further, if the second determination signal DS2 is 'H2', the control unit 5, the first holding switch QC1 of the clamping portion 4, the switch QB2, QB3 of the conversion unit 3, the regeneration switch Q1 ₁ of the voltage control unit _{2 1} Switch on and switch off the remaining switches. Thereby, the power converter device 1 of this configuration example generates the output voltage V1 of −E ₁ [V].

As described above, in the power conversion device 1 of this configuration example, the control unit 5 responds to the comparison result between the two synchronized carriers CW1 and CW3 and the target signal OS1 and the comparison result between the command value and the threshold value. The switches of the voltage control unit 2 ₁ , the conversion unit 3, and the clamp unit 4 are controlled. Thus, the power conversion device 1 of the present configuration example, by switching the output voltage V1 appropriately by the control unit 5 varies between 0 [V] -E ₂ (V) to E ₂ V to about the Outputs AC voltage.

Further, when the power conversion device 1 of this configuration example includes N voltage control units 2 ₁ to 2 _N , the control unit 5 performs the following control. That is, the control unit 5 determines whether the voltage control units 2 ₁ to 2 _N , the conversion unit 3, the comparison result between the “N + 1” synchronized carriers and the target signal OS 1, and the comparison result between the command value and the threshold value. Each switch of the clamp part 4 is controlled. Thus, the power conversion device 1 of the present embodiment, by switching the output voltage V1 appropriately by the control unit 5 varies between 0 V -E N _{+ 1} [V] to E N _{+ 1} [V] around the Outputs AC voltage.

  Therefore, since the power conversion device 1 of this configuration example requires a small number of carrier waves, the software and hardware necessary for generating the carrier waves can be simplified, and the cost can be reduced. In the power conversion device 1 of this configuration example, the control unit 5 performs the subtraction process on the command value in the target signal OS1, but other configurations may be used. That is, the subtraction process may be executed by a subtracter provided separately from the control unit 5.

(Configuration example 4)
Hereinafter, the power converter device 1 according to the configuration example 4 of the present embodiment will be described with reference to FIG. In the power conversion device 1 of this configuration example, unlike the power conversion device 1 of the configuration example 3, the phase of the third carrier wave CW3 is inverted. Further, the target signal OS1 is a signal adjusted to fall between the minimum value and the maximum value of a plurality of carrier waves (carrier waves CW1, CW3) based on the comparison result between the command value and the threshold value. In the power conversion device 1 of the present configuration example, unlike the power conversion device 1 of the configuration example 3, the target signal OS1 has a difference between the command value and the first threshold value during the period in which the command value exceeds the first threshold value. The signal is subtracted from the threshold value. Further, the target signal OS1 is a signal obtained by subtracting the difference between the command value and the second threshold value from the second threshold value during the period when the command value is less than the second threshold value. That is, as shown in FIG. 26, the target signal OS1 indicates the same voltage value as the command value while the second determination signal DS2 indicates “L”, and the command value when the second determination signal DS2 becomes “H1”. And “E ₁ / L” [V] is subtracted from “E ₁ / L” [V]. The target signal OS1 is a voltage obtained by subtracting the difference between the command value and “−E ₁ / L” [V] from “−E ₁ / L” [V] when the second determination signal DS2 becomes “H2”. Indicates the value.

The control unit 5 controls the voltage so as to generate the output voltage V1 according to the conditions shown in Table 16 below according to the comparison result between the carrier waves CW1 and CW3 and the target signal OS1 and the second determination signal DS2. The switches of the unit 2 ₁ , the conversion unit 3, and the clamp unit 4 are controlled. When the target signal OS1 is equal to one of the carrier waves CW1 and CW3 (for example, OS1 = CW1 etc.), the conditions are not limited to those shown in Table 16, and may be defined as appropriate.

For example, a case where the voltage value of the target signal OS1 is between the first carrier wave CW1 and the third carrier wave CW3 will be described. In this case, if the second determination signal DS2 is 'L', the control unit 5, the holding switch QC1 of the clamping portion 4, QC2, switches the regeneration switch Q1 ₁ of the voltage control unit _{2 1} is turned on, the remaining switches Switch off. Thereby, the power converter device 1 of this structural example sets the output voltage V1 to 0 [V]. Further, if the second determination signal DS2 is 'H1', the control unit 5, second hold switch QC2 clamp portion 4, the conversion unit 3 of the switch QB1, QB4, an input switch Q2 ₁ of the voltage control unit _{2 1} Switch on and switch off the remaining switches. Thereby, the power converter device 1 of the present configuration example generates the output voltage V1 of E ₂ [V]. Further, if the second determination signal DS2 is 'H2', the control unit 5, the first holding switch QC1 of the clamping portion 4, the conversion unit 3 of the switch QB2, QB3, an input switch Q2 ₁ of the voltage control unit _{2 1} Switch on and switch off the remaining switches. Thereby, the power converter device 1 of this configuration example generates the output voltage V1 of −E ₂ [V].

As described above, in the power conversion device 1 of this configuration example, the control unit 5 determines the voltage according to the comparison result between the two carrier waves CW1 and CW3 and the target signal OS1 and the comparison result between the command value and the threshold value. The switches of the control unit 2 ₁ , the conversion unit 3, and the clamp unit 4 are controlled. Thus, the power conversion device 1 of the present configuration example, by switching the output voltage V1 appropriately by the control unit 5 varies between 0 [V] -E ₂ (V) to E ₂ V to about the Outputs AC voltage.

Further, when the power conversion device 1 of this configuration example includes N voltage control units 2 ₁ to 2 _N , the control unit 5 performs the following control. That is, the control unit 5 determines each of the voltage control units 2 ₁ to 2 _N , the conversion unit 3, and the clamp unit 4 according to the comparison result between the plurality of carrier waves and the target signal OS 1 and the comparison result between the command value and the threshold value. Control the switch. The plurality of carrier waves are “[(N + 1) / 2]” carrier waves and “[(N + 1) / 2]” carrier waves whose phase is inverted from the “[(N + 1) / 2]” carrier waves. It is. Thus, the power conversion device 1 of the present embodiment, by switching the output voltage V1 appropriately by the control unit 5 varies between 0 V -E N _{+ 1} [V] to E N _{+ 1} [V] around the Outputs AC voltage.

  Therefore, since the power conversion device 1 of this configuration example requires a small number of carrier waves, the software and hardware necessary for generating the carrier waves can be simplified, and the cost can be reduced. In the power conversion device 1 of this configuration example, the control unit 5 performs the subtraction process on the command value in the target signal OS1, but other configurations may be used. That is, the subtraction process may be executed by a subtracter provided separately from the control unit 5.

(Configuration example 5)
Hereinafter, the power converter device 1 according to the configuration example 5 of the present embodiment will be described with reference to FIG. In the power conversion device 1 of the present configuration example, the control unit 5 determines the voltage according to the comparison result between the first carrier wave CW1 and the target signal OS1, the determination result of the command value positive / negative, and the comparison result between the command value and the threshold value. The switches of the control unit 2 ₁ , the conversion unit 3, and the clamp unit 4 are controlled.

  In the power conversion device 1 of this configuration example, the second determination signal DS2 is “H1” if the command value exceeds the first threshold when the first determination signal DS1 is “L”, and the first determination signal DS1 is “H”. In the case of “,” the command value is “H2” if it falls below the second threshold, and “L” otherwise.

  Further, the target signal OS1 falls between the minimum value and the maximum value of one carrier wave (first carrier wave CW1) based on the result of the positive / negative determination of the command value and the comparison result between the command value and the threshold value. The signal is adjusted as follows. In the power conversion device 1 of this configuration example, the target signal OS1 is a signal obtained by subtracting the first threshold value from the command value in a period in which the command value is positive and exceeds the first threshold value. The target signal OS1 is a signal obtained by adding the first threshold value to the command value during the period when the command value is negative. Further, the target signal OS1 is a signal in which the first threshold value is further added to the command value after the addition in a period in which the command value is negative and falls below the second threshold value.

That is, as shown in FIG. 27, the target signal OS1 shows the same voltage value as the command value while the first determination signal DS1 is 'L' and the second determination signal DS2 is 'L'. Then, the target signal OS1 indicates a voltage value obtained by subtracting “E ₁ / L” [V] from the command value when the second determination signal DS2 becomes “H1”. Further, the target signal OS1 indicates a voltage value obtained by adding “E ₁ / L” [V] to the command value while the first determination signal DS1 indicates “H” and the second determination signal DS2 indicates “L”. . Then, the target signal OS1, the second when the determination signal DS2 is _{'H2', 'E 1 /} L' (V) further command value is added to 'E _{1 /} L' adding the voltage value (V) Indicates.

The control unit 5 sets the output voltage V1 according to the conditions shown in Table 17 below according to the comparison result between the first carrier wave CW1 and the target signal OS1, the first determination signal DS1, and the second determination signal DS2. The switches of the voltage control unit 2 ₁ , the conversion unit 3, and the clamp unit 4 are controlled so as to be generated. When the target signal OS1 is equal to the carrier wave CW1, the conditions are not limited to those shown in Table 17, and may be defined as appropriate.

For example, a case where the voltage value of the target signal OS1 is larger than the first carrier wave CW1 and the first determination signal DS1 is 'L' will be described. In this case, if the second determination signal DS2 is 'L', the control unit 5, second hold switch QC2 clamp portion 4, the switch QB1 of the conversion unit 3, QB4, regeneration switch Q1 of the voltage controller _{2 1 1} Switch on and switch off the remaining switches. Thereby, the power converter device 1 of this configuration example generates the output voltage V1 of E ₁ [V]. Further, if the second determination signal DS2 is 'H1', the control unit 5, second hold switch QC2 clamp portion 4, the conversion unit 3 of the switch QB1, QB4, an input switch Q2 ₁ of the voltage control unit _{2 1} Switch on and switch off the remaining switches. Thereby, the power converter device 1 of the present configuration example generates the output voltage V1 of E ₂ [V].

As described above, in the power conversion device 1 of the present configuration example, the control unit 5 compares the comparison result between the single carrier wave CW1 and the target signal OS1, the determination result of the command value positive / negative, and the comparison between the command value and the threshold value. Depending on the result, each switch of the voltage control unit 2 ₁ , the conversion unit 3, and the clamp unit 4 is controlled. Thus, the power conversion device 1 of the present configuration example, by switching the output voltage V1 appropriately by the control unit 5 varies between 0 [V] -E ₂ (V) to E ₂ V to about the Outputs AC voltage.

Further, when the power conversion device 1 of this configuration example includes N voltage control units 2 ₁ to 2 _N , the control unit 5 performs the following control. That is, the control unit 5 determines the voltage control units 2 ₁ to 2 _N according to the comparison result between one carrier wave CW1 and the target signal OS1, the determination result of the positive / negative command value, and the comparison result between the command value and the threshold value. The switches of the conversion unit 3 and the clamp unit 4 are controlled. Thus, the power conversion device 1 of the present embodiment, by switching the output voltage V1 appropriately by the control unit 5 varies between 0 V -E N _{+ 1} [V] to E N _{+ 1} [V] around the Outputs AC voltage.

  Therefore, since the power conversion device 1 of this configuration example requires only one carrier wave, the software and hardware necessary for generating the carrier wave can be simplified and the cost can be reduced. . Moreover, since the power converter device 1 of this structural example uses one carrier wave, it is not necessary to synchronize a plurality of carrier waves. In addition, in the power converter device 1 of this structural example, although the control part 5 is performing the addition process and the subtraction process with respect to command value in target signal OS1, another structure may be sufficient. That is, the addition process may be executed by an adder provided separately from the control unit 5 and the subtraction process may be executed by a subtractor provided separately from the control unit 5.

(Configuration example 6)
Hereinafter, the power converter device 1 according to the configuration example 6 of the present embodiment will be described with reference to FIG. In the power conversion device 1 according to the present configuration example, unlike the power conversion device 1 according to the configuration example 5, the target signal OS1 is a signal value between the command value and the first threshold value in a period in which the command value is positive and exceeds the first threshold value. The difference is a signal obtained by subtracting from the first threshold value. The target signal OS1 is a signal obtained by inverting the sign of the command value during the period when the command value is negative. Furthermore, the target signal OS1 is a signal obtained by subtracting the difference between the command value after inversion and the first threshold value from the first threshold value during a period in which the command value is negative and less than the second threshold value.

That is, as shown in FIG. 28, the target signal OS1 shows the same voltage value as the command value while the first determination signal DS1 is “L” and the second determination signal DS2 is “L”. Then, when the second determination signal DS2 becomes 'H1', the target signal OS1 has a voltage value obtained by subtracting the difference between the command value and 'E ₁ / L' [V] from 'E ₁ / L' [V]. Show. The target signal OS1 indicates a voltage value obtained by inverting the sign of the command value while the first determination signal DS1 is “H” and the second determination signal DS2 is “L”. The target signal OS1 is a voltage obtained by subtracting the difference between the inverted command value and 'E ₁ / L' [V] from 'E ₁ / L' [V] when the second determination signal DS2 becomes 'H2'. Indicates the value.

The control unit 5 sets the output voltage V1 according to the conditions shown in Table 18 below according to the comparison result between the first carrier wave CW1 and the target signal OS1, the first determination signal DS1, and the second determination signal DS2. The switches of the voltage control unit 2 ₁ , the conversion unit 3, and the clamp unit 4 are controlled so as to be generated. When the target signal OS1 is equal to the carrier wave CW1, the conditions are not limited to those shown in Table 18 and may be defined as appropriate.

For example, a case where the voltage value of the target signal OS1 is smaller than the first carrier wave CW1 and the first determination signal DS1 is 'L' will be described. In this case, if the second determination signal DS2 is 'L', the control unit 5, the holding switch QC1 of the clamping portion 4, QC2, switches the regeneration switch Q1 ₁ of the voltage control unit _{2 1} is turned on, the remaining switches Switch off. Thereby, the power converter device 1 of this structural example sets the output voltage V1 to 0 [V]. Further, if the second determination signal DS2 is 'H1', the control unit 5, second hold switch QC2 clamp portion 4, the conversion unit 3 of the switch QB1, QB4, an input switch Q2 ₁ of the voltage control unit _{2 1} Switch on and switch off the remaining switches. Thereby, the power converter device 1 of the present configuration example generates the output voltage V1 of E ₂ [V].

  The power conversion device 1 of this configuration example can achieve the same effects as the power conversion device 1 of the configuration example 5. In the power conversion device 1 of the present configuration example, the control unit 5 executes the processing for inverting the sign of the command value and the subtraction processing for the command value in the target signal OS1, but even in other configurations, Good. That is, a process of inverting the sign of the command value may be executed by a multiplier provided separately from the control unit 5, and a subtraction process may be executed by a subtractor provided separately from the control unit 5.

1 power converter 11 first input point 12 second input point 13 first output point 14 second output point 2 ₁ to 2 _N voltage control unit 3 converting portion 4 clamp unit 5 control unit Q1 ₁ ~Q1 _N regeneration switch Q2 ₁ ~ Q2 _N input switch VS ₁ ~ VS _N voltage source VS _{N + 1} main voltage source

Claims (18)

A first input point and a second input point to which the main voltage source is electrically connected;
A first output point and a second output point;
N voltage controllers that are electrically connected to different voltage sources, respectively,
A conversion unit having four switches and inverting the polarity of the input DC voltage to generate an output voltage at the first output point and the second output point;
A holding switch, and a clamp part for holding the output voltage at a predetermined voltage,
The number N of voltage control units is an integer greater than or equal to 1,
Each of the N voltage control units includes a regenerative switch that opens and closes an electric circuit connecting either the positive electrode or the negative electrode of the voltage source and the conversion unit, and either the positive electrode or the negative electrode of the main voltage source. An input switch that opens and closes an electrical circuit connecting the electrode and the conversion unit,
A control unit that switches the output voltage in 2N + 3 stages by controlling the regenerative switch and the input switch in each of the four switches, the holding switch, and the N voltage control units ;
When the output voltage is a power source voltage of a voltage source electrically connected to an arbitrary voltage control unit, and when the output voltage is a power source voltage one step lower than the power source voltage, the control unit A power conversion device, wherein the regenerative switch of the control unit is maintained in an on state. The clamp part is composed of a series circuit of a pair of switches electrically connected between a pair of output points of the conversion part,
The control unit maintains a second switch of the pair of switches in an on state when the output voltage is greater than the predetermined voltage, and the pair of switches when the output voltage is smaller than the predetermined voltage. 2. The power conversion device according to claim 1 , wherein the first switch among the switches is controlled to be kept in an on state . The control unit includes the four switches, the holding switch, and the N voltage controls according to a comparison result between N × 2 + 2 synchronized carrier waves and a target signal corresponding to a command value of a desired AC voltage. The power conversion device according to claim 1 or 2, wherein the regenerative switch and the input switch in each of the units are controlled . In accordance with a comparison result between the N + 1 carrier waves, N + 1 carrier waves whose phases are inverted from the N + 1 carrier waves, and a target signal corresponding to a command value of a desired AC voltage, The power converter according to claim 1 or 2 , wherein the switch, the holding switch, and the regenerative switch and the input switch in each of the N voltage control units are controlled . The control unit includes the four switches according to a comparison result of a plurality of N + 1 synchronized carrier waves and a target signal according to a command value of a desired AC voltage, and a determination result of whether the command value is positive or negative. Controlling the holding switch, the regenerative switch and the input switch in each of the N voltage control units,
The target signal is based on the positive or negative determination result of the command value, according to claim 1 or 2, characterized in that the adjusted signal to fit in between the minimum and maximum values of said plurality of carriers power converter according to. The control unit includes a plurality of carriers, a comparison result of a target signal corresponding to a command value of a desired AC voltage, and a positive / negative determination result of the command value, the four switches, the holding switch, Controlling the regenerative switch and the input switch in each of the N voltage control units;
The plurality of carriers are [(N + 1) / 2] carriers and [(N + 1) / 2] carriers whose phases are reversed from the [(N + 1) / 2] carriers.
The target signal is based on the positive or negative determination result of the command value, according to claim 1 or 2, characterized in that the adjusted signal to fit in between the minimum and maximum values of said plurality of carriers power converter according to. The control unit includes the four switches according to a comparison result between a plurality of N + 1 synchronized carrier waves and a target signal according to a command value of a desired AC voltage, and a comparison result between the command value and a threshold value. , Controlling the holding switch, the regenerative switch and the input switch in each of the N voltage control units,
The target signal, based on a result of comparison between the command value and the threshold value, according to claim 1, characterized in that the adjusted signal to fit in between the minimum and maximum values of said plurality of carriers Or the power converter device of 2. The control unit includes a plurality of carriers, a comparison result of a target signal corresponding to a command value of a desired AC voltage, and a comparison result of the command value and a threshold value, the four switches, the holding switch, Controlling the regenerative switch and the input switch in each of the N voltage control units;
The plurality of carriers are [(N + 1) / 2] carriers and [(N + 1) / 2] carriers whose phases are reversed from the [(N + 1) / 2] carriers.
The target signal, based on a result of comparison between the command value and the threshold value, according to claim 1, characterized in that the adjusted signal to fit in between the minimum and maximum values of said plurality of carriers Or the power converter device of 2. The control unit according to a comparison result between one carrier wave and a target signal corresponding to a desired AC voltage command value, a positive / negative determination result of the command value, and a comparison result between the command value and a threshold value Controlling the regenerative switch and the input switch in each of the four switches, the holding switch, and the N voltage control units,
The target signal is adjusted to fall between the minimum value and the maximum value of the one carrier wave based on the result of the positive / negative determination of the command value and the comparison result between the command value and the threshold value. It is a signal, The power converter device of Claim 1 or 2 characterized by the above-mentioned. Wherein the control unit of claim 1 to 9, wherein the driving by one driving signal low-side switches of the switch and the second leg of the high side of the first leg of the pair of legs of the converter section The power converter of any one of Claims. The control unit controls the regenerative switch and the input switch in each of the four switches, the holding switch, and the N voltage control units so as to provide a dead time when transitioning the output voltage; and 11. The control according to claim 1 , wherein, in the dead time, a switch that is in an on state is maintained in an on state before and after a transition of the output voltage, and other switches are switched off . The power converter of any one of Claims. The control unit controls the regenerative switch and the input switch in each of the four switches, the holding switch, and the N voltage control units so as to transition the output voltage step by step. The power conversion device according to claim 11 . Each of the four switches and the holding switch is an insulated gate bipolar transistor,
Either the emitter of the four switches, the power conversion apparatus according to any one of claims 1 to 12, characterized in that it is electrically connected to the emitter of the holding switch. The regenerative switch and the input switch in each of the four switches and the N voltage control units are insulated gate bipolar transistors, respectively.
Any one of the emitters of the four switches and the emitter of the regenerative switch of the voltage control unit that is electrically connected directly to the conversion unit are electrically connected,
The emitter of the input switch of an arbitrary voltage control unit and the emitter of the regenerative switch of the voltage control unit of the next stage are electrically connected to each other. The power converter described. Assuming that an integer from 1 to N is represented by M,
A voltage source whose power supply voltage is M / (N + 1) of the power supply voltage of the main voltage source is electrically connected to the Mth voltage control unit counted from the voltage control unit directly electrically connected to the conversion unit. power converter according to any one of claims 1 to 14, characterized in that it is connected. A system power supply is electrically connected to the first output point and the second output point,
The control unit is configured to output the AC voltage in the four switches, the holding switch, and the N voltage control units so that the phase of the output AC voltage is opposite to the phase of the power supply voltage of the system power supply. The power conversion device according to any one of claims 1 to 15, wherein the regenerative switch and the input switch are controlled . A system power supply is electrically connected to the first output point and the second output point,
The control unit has a function of measuring a power supply frequency of the system power supply,
In addition, the regenerative switch and the input switch in each of the four switches, the holding switch, and the N voltage control units are controlled so that the phase of the output AC voltage is shifted from the phase of the power supply voltage of the system power supply. The power conversion device according to claim 1, wherein the power conversion device is a power conversion device. A first input point and a second input point to which the main voltage source is electrically connected;
A first output point and a second output point;
A voltage control unit that is electrically connected to different voltage sources each having a power supply voltage;
A conversion unit having four switches and inverting the polarity of the input DC voltage to generate an output voltage at the first output point and the second output point;
A holding switch, and a clamp part for holding the output voltage at a predetermined voltage,
The voltage control unit includes a regenerative switch that opens and closes an electric circuit that connects either the positive electrode or the negative electrode of the voltage source and the converter, the positive electrode or the negative electrode of the main voltage source, and the An input switch for opening and closing an electric circuit connecting the conversion unit,
A control unit that switches the output voltage in five stages by controlling the regenerative switch and the input switch in each of the four switches, the holding switch, and the voltage control unit;
The control unit turns on the regenerative switch when the output voltage is a power supply voltage of the voltage source, and when the predetermined voltage is output from the output voltage in five stages,
If from the output voltage out of 5 outputs a predetermined voltage, further the four you wherein power conversion device to turn off the switch.

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