JP2018050440A - Inverter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inverter device that is able to simplify power conversion when converting DC power into AC power.SOLUTION: According to the inverter device (100) in the present invention, an inverter (20) comprises a hybrid wave generating section (20a) and an output wave generating section (20b). A hybrid wave generating section (20a) generates a hybrid wave (Pm) from a DC power (Pdc), the hybrid wave (Pm) being a mixture of a first AC wave that periodically varies at a first frequency resulting from subtracting the output frequency of the inverter (20) from a predetermined frequency and a second AC wave that varies at a second frequency resulting from adding the output frequency of the inverter (20) to a predetermined frequency. The output wave generating section (20b) converts the component of a frequency that is twice the output frequency of the inverter (20) included in the hybrid wave (Pm) into the component of a frequency that is the same as the output frequency of the inverter (20), and generates from the hybrid (Pm) an output wave (Pout) that is output by the inverter (20).SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inverter device including an inverter that converts DC power into desired AC power.

  As an example of the above invention, the inventions described in Patent Document 1 and Patent Document 2 are cited. The solar power converter described in Patent Literature 1 includes a solar cell, an input-side inverter, an insulating transformer, a plurality of rectifier elements, and an output-side inverter. The DC power output from the solar cell is converted into AC power by the input side inverter and input to the primary side of the insulation transformer. The AC power output from the secondary side of the insulation transformer is converted into DC power by a plurality of rectifying elements, and is converted into desired AC power by an output-side inverter. Each of the input side inverter and the output side inverter includes four switching elements.

  The fuel cell power conversion device described in Patent Document 2 includes a fuel cell, a converter, a step-up transformer, a plurality of rectifying elements, and an inverter. The DC power output from the fuel cell is converted into AC power by the converter and input to the primary side of the step-up transformer. The AC power output from the secondary side of the step-up transformer is converted to DC power by a plurality of rectifier elements, and is converted to desired AC power by an inverter. The converter includes four switching elements. Although the number of switching elements of the inverter is not explicitly described in Patent Document 2, it is considered that the inverter includes four switching elements as in the converter.

JP-A-10-75580 JP 2010-22104 A

  However, the solar power converter described in Patent Document 1 converts the DC power output from the solar cell into AC power, and then returns it to DC power, and converts the DC power into AC power again. Thus, in the invention described in Patent Document 1, power conversion when converting DC power into AC power is complicated. For this reason, the output-side inverter described in Patent Document 1 needs to include a switching element having the same configuration as the input-side inverter, and it is difficult to simplify the output-side inverter. What has been described above for the invention described in Patent Document 1 can be similarly applied to the invention described in Patent Document 2.

  This invention is made | formed in view of such a situation, and makes it a subject to provide the inverter apparatus which can simplify the power conversion at the time of converting direct-current power into alternating current power.

  An inverter device according to the present invention is an inverter device comprising a DC power source, an inverter that converts DC power output from the DC power source into desired AC power, and a control device that drives and controls the inverter, The inverter periodically fluctuates at a first AC wave that fluctuates periodically at a first frequency obtained by subtracting the output frequency of the inverter from a predetermined frequency, and at a second frequency obtained by adding the output frequency of the inverter to the predetermined frequency. A hybrid wave generation unit that generates a hybrid wave that is a hybrid of the second AC wave from the DC power, and a frequency component that is twice the output frequency of the inverter included in the hybrid wave is the same as the output frequency of the inverter An output wave generating unit that converts the frequency component into a frequency component and generates an output wave output from the inverter from the hybrid wave.

  According to the inverter device of the present invention, the inverter includes a hybrid wave generation unit and an output wave generation unit. The hybrid wave generated by the hybrid wave generation unit includes a frequency component that is the same as the predetermined frequency and a frequency component that is twice the output frequency of the inverter. Therefore, the output wave generator easily converts the output wave output by the inverter from the hybrid wave by converting the frequency component twice the output frequency of the inverter included in the hybrid wave into the same frequency component as the output frequency of the inverter. Can be generated. Therefore, the inverter device according to the present invention converts DC power to AC power and then returns to DC power, and again converts DC power to AC power compared to converting DC power to AC power. Power conversion can be simplified.

1 is a configuration diagram illustrating an example of an inverter device 100 according to a first embodiment. It is a figure which shows an example of the time-dependent change of the alternating current concerning the 1st alternating current wave P1. It is a figure which shows an example of the time-dependent change of the alternating current concerning the 2nd alternating current wave P2. It is a figure which shows an example of the time-dependent change of the alternating current concerning the hybrid wave Pm. It is a figure which shows an example of the time-dependent change of the alternating current concerning the output wave Pout produced | generated from the hybrid wave Pm. 2 is a configuration diagram illustrating an example of a control device 30. FIG. 3 is a block diagram illustrating an example of a control block of a control device 30. FIG. 6 is a diagram illustrating an example of a relationship between a first modulated wave WM1, a carrier wave WC0, and a drive signal of one switching element of an input side switching element group 50. It is a figure which shows an example of the time-dependent change of the alternating current concerning the positive electrode side hybrid wave Pmp. It is a figure which shows an example of the time-dependent change of the alternating current concerning the negative electrode side hybrid wave Pmm. It is a figure which shows an example of the time-dependent change of the alternating current concerning the mixed wave Pf0 before filter. It is a block diagram which shows an example of the inverter apparatus 100 concerning 2nd embodiment. It is a block diagram which shows an example of the control block of the control apparatus 30 according to the second embodiment. FIG. 10 is a block diagram illustrating an example of a control block of a control device 30 according to a third embodiment. It is a block diagram which shows an example of the control block of the hybrid modulation wave generator 31f of FIG. It is a block diagram which shows an example of the inverter apparatus according to a modification. It is a figure which shows an example of the time-dependent change of the alternating current concerning the positive electrode side hybrid wave Pmp of FIG. It is a figure which shows an example of the time-dependent change of the alternating current concerning the negative electrode side mixed wave Pmm of FIG. It is a figure which shows an example of the time-dependent change of the alternating current concerning the mixed wave Pf0 before filter of FIG. It is a block diagram which shows another example of the inverter apparatus according to a modification. It is a block diagram which shows another example of the inverter apparatus according to a modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, common portions are denoted by common reference numerals for each embodiment, and redundant description is omitted in this specification. In addition, what has already been described in one embodiment can be appropriately applied to other embodiments. Further, the drawings are conceptual diagrams and do not define the dimensions of the detailed structure.

<First embodiment>
(Outline of the inverter device 100)
As shown in FIG. 1, the inverter device 100 includes a DC power supply 10, an inverter 20, and a control device 30. The inverter 20 includes a hybrid wave generation unit 20a and an output wave generation unit 20b. In the present embodiment, the hybrid wave generation unit 20 a includes a transformer 40 and an input side switching element group 50. In the present embodiment, the output wave generation unit 20 b includes a hybrid wave separator 60, an output side switching element group 70, and a filter 80.

(DC power supply 10)
The DC power supply 10 outputs DC power Pdc. The DC power supply 10 is not limited as long as it can output DC power Pdc. As the DC power source 10, for example, a power generation device such as a battery (lead storage battery), a lithium ion battery, or a fuel cell can be used. The fuel cell is a power generation device that generates power using fuel and an oxidant gas. For example, various fuel cells such as a known solid oxide fuel cell (SOFC) can be used.

  The DC power supply 10 can also use a power generation device other than a fuel cell (for example, a solar power generation device). Further, a gas engine generator or the like can be used as the DC power source 10. When a gas engine generator is used as the DC power source 10, the AC power output from the AC generator can be rectified by a known rectifier circuit such as a diode bridge and smoothed by a smoothing circuit to generate the DC power Pdc.

  As shown in FIG. 1, the DC power supply 10 includes a main body 11 and an electrolytic capacitor 12. The main body 11 schematically shows the main part of the DC power supply 10. One end side (positive electrode side) of the electrolytic capacitor 12 is connected to the positive electrode 10p side of the main body part 11, and the other end side (negative electrode side) of the electrolytic capacitor 12 is connected to the negative electrode 10n side of the main body part 11. . The DC power Pdc output from the main body 11 is smoothed by the electrolytic capacitor 12, and the ripple is reduced. The output state (information such as output power) of the DC power supply 10 is transmitted to the control device 30 described later.

(Inverter 20)
The inverter 20 converts the DC power Pdc output from the DC power supply 10 into desired AC power. As shown in FIG. 1, the inverter 20 includes a hybrid wave generator 20a and an output wave generator 20b. The hybrid wave generator 20a generates a hybrid wave Pm from the DC power Pdc. The hybrid wave Pm is an AC wave that is a mixture of the first AC wave P1 and the second AC wave P2. The first AC wave P1 refers to an AC wave that periodically fluctuates at a first frequency F1 obtained by subtracting the output frequency Fout of the inverter 20 from the predetermined frequency F0. The second AC wave P2 refers to an AC wave that periodically fluctuates at a second frequency F2 obtained by adding the output frequency Fout of the inverter 20 to the predetermined frequency F0.

  The predetermined frequency F0 needs to be set sufficiently higher or lower than the output frequency Fout of the inverter 20. In the present embodiment, the predetermined frequency F0 is set sufficiently higher than the output frequency Fout of the inverter 20. For example, when the output frequency Fout of the inverter 20 is several tens of hertz (for example, 50 Hz or 60 Hz), the predetermined frequency F0 can be set to several kilohertz to several hundred kilohertz. For example, the predetermined frequency F0 can be set to 1 kHz, 2 kHz, 10 kHz, 12 kHz, 20 kHz, 50 kHz, 100 kHz, or the like. Further, the predetermined frequency F0 can be set to a frequency higher than the upper limit value (for example, about 20 kHz) of the audible frequency band. In this case, noise during driving of the inverter 20 can be easily reduced.

  A curve L11 in FIG. 2A shows an example of the change over time of the alternating current related to the first alternating wave P1. In the figure, the vertical axis represents current, and the horizontal axis represents time. The time t11 indicates one cycle of the alternating current of the curve L11, and the first frequency F1 that is the reciprocal number is also shown. The time t10 indicates one cycle of the output wave Pout output from the inverter 20, and the output frequency Fout that is the reciprocal number is also shown. A curve L12 in FIG. 2B shows an example of the change over time of the alternating current related to the second alternating wave P2. In the figure, the vertical axis represents current, and the horizontal axis represents time. The time t12 shows one cycle of the alternating current of the curve L12, and the second frequency F2 that is the reciprocal number is also shown. The time t10 and the output frequency Fout are the same as in FIG. 2A.

  For convenience of illustration and explanation, for example, the output frequency Fout of the inverter 20 is set to 50 Hz, and the predetermined frequency F0 is set to 1 kHz. In this case, the first frequency F1 is 950 Hz, and the second frequency F2 is 1050 Hz. As shown in FIG. 2A, assuming that one cycle (time t11) of the alternating current related to the first AC wave P1 is one wave, the wave number of one cycle of the output wave Pout output from the inverter 20 is 19 (= 950). / 50). Further, as shown in FIG. 2B, assuming that one cycle (time t12) of the alternating current related to the second AC wave P2 is one wave, the wave number of one cycle of the output wave Pout output by the inverter 20 is 21 ( = 1050/50). When the current waveform shown by the curve L11 in FIG. 2A and the current waveform shown by the curve L12 in FIG. 2B are superimposed (mixed), the current waveform shown by the curve L13 in FIG. 2C is obtained.

  A curve L13 in FIG. 2C shows an example of the change over time of the alternating current related to the hybrid wave Pm. In the figure, the vertical axis represents current, and the horizontal axis represents time. Time t13 indicates one cycle of the alternating current of the curve L13, and a predetermined frequency F0 that is the reciprocal number is also written. The time t10 and the output frequency Fout are the same as those in FIGS. 2A and 2B. A broken line curve L10 shows an example of a change with time of the alternating current related to the output wave Pout (frequency is the output frequency Fout) output from the inverter 20.

  As shown by a curve L13 in FIG. 2C, the alternating current related to the hybrid wave Pm has the same frequency component as the predetermined frequency F0 (in the example described above, a frequency component of 1 kHz) and a frequency twice the output frequency Fout of the inverter 20. Component (in the example described above, a frequency component of 100 Hz). In this way, a phenomenon in which two frequency components are newly generated by mixing (also referred to as mixing and synthesis) two waves having different frequencies (in this case, alternating current) is referred to as a “heterodyne phenomenon”. In addition, a phenomenon in which two waves having a small frequency difference (in this case, alternating current) interfere with each other and the amplitude of the hybrid wave Pm periodically varies is called “beat”.

  What has been described above can also be explained as follows. The alternating current related to the hybrid wave Pm can be expressed by the following formula 1. The first term on the left side shows the AC current (frequency is the first frequency F1) related to the first AC wave P1, and the second term on the left side is the AC current (frequency is related to the second AC wave P2). The second frequency F2) is shown. The right side shows an alternating current related to the hybrid wave Pm. The time is represented by time t. Thus, the alternating current related to the hybrid wave Pm includes the same frequency component as the predetermined frequency F0. Further, the alternating current related to the hybrid wave Pm includes a frequency component that is an integer multiple of two or more (mainly twice) the output frequency Fout of the inverter 20 with respect to the subharmonic. In addition, what was mentioned above about alternating current can be said similarly about alternating voltage. Hereinafter, in this specification, although an alternating current will be described as an example, the same applies to an alternating voltage.

  The output wave generation unit 20b converts a frequency component twice the output frequency Fout of the inverter 20 included in the hybrid wave Pm into the same frequency component as the output frequency Fout of the inverter 20, and the inverter 20 outputs the hybrid wave Pm. An output wave Pout is generated. A curve L10 in FIG. 2D shows an example of the change over time of the alternating current related to the output wave Pout generated from the hybrid wave Pm. In the figure, the vertical axis represents current, and the horizontal axis represents time. The time t10 and the output frequency Fout are the same as those in FIGS. 2A to 2C. The curve L10 in FIG. 2D matches the dashed curve L10 in FIG. 2C.

  As illustrated in FIG. 2C, the alternating current related to the hybrid wave Pm includes a frequency component that is twice the output frequency Fout of the inverter 20. Therefore, the output wave generation unit 20b converts the frequency component twice the output frequency Fout of the inverter 20 included in the hybrid wave Pm into the same frequency component as the output frequency Fout of the inverter 20, so that the hybrid wave Pm The output wave Pout output from 20 can be easily generated. In addition, in the curve L10 of FIG. 2D, the same frequency component as the predetermined frequency F0 included in the hybrid wave Pm is suppressed.

(Control device 30)
As shown in FIG. 3, the control device 30 includes a known central processing unit 30a, a storage device 30b, and an input / output interface 30c, which are electrically connected via a bus 30d. . The control device 30 can perform various arithmetic processes using these, and can exchange input / output signals with the external devices including the DC power supply 10 and the inverter 20.

  The central processing unit 30a is a CPU: Central Processing Unit, and can perform various arithmetic processes. The storage device 30b includes a first storage device 30b1 and a second storage device 30b2. The first storage device 30b1 is a volatile storage device (RAM) that can be read and written, and the second storage device 30b2 is a read-only nonvolatile storage device (ROM: Read Only Memory). is there. The input / output interface 30 c exchanges input / output signals with the external devices including the DC power supply 10 and the inverter 20.

  The control device 30 drives and controls at least the inverter 20. Specifically, the central processing unit 30a reads the drive control program for the inverter 20 stored in the second storage device 30b2 to the first storage device 30b1, and executes the drive control program. The central processing unit 30a generates a drive signal for the inverter 20 (drive signals for the hybrid wave generation unit 20a and the output wave generation unit 20b) based on the drive control program. The generated drive signal is given to the inverter 20 via the input / output interface 30c. In this way, the inverter 20 is driven and controlled by the control device 30. Further, in the inverter device 100 of the present embodiment, the DC power supply 10 is a fuel cell, and the inverter 20 is connected to a power system of a system power supply (not shown). The control device 30 controls the open / close relay (not shown) to open and close, so that the inverter 20 can be paralleled and disconnected from the power system of the system power supply.

  According to the inverter device 100 of the present embodiment, the inverter 20 includes the hybrid wave generation unit 20a and the output wave generation unit 20b. The hybrid wave Pm generated by the hybrid wave generation unit 20a includes the same frequency component as the predetermined frequency F0 and a frequency component twice the output frequency Fout of the inverter 20. Therefore, the output wave generation unit 20b converts the frequency component twice the output frequency Fout of the inverter 20 included in the hybrid wave Pm into the same frequency component as the output frequency Fout of the inverter 20, so that the hybrid wave Pm The output wave Pout output from 20 can be easily generated. Therefore, the inverter device 100 according to the present embodiment converts the DC power into AC power after converting the DC power into AC power and then converts the DC power back into DC power. The power conversion can be simplified.

(Transformer 40, input-side switching element group 50, and input-side switching element group controller 31)
The hybrid wave generator 20a only needs to be able to generate the hybrid wave Pm from the DC power Pdc, and its configuration is not limited. In the present embodiment, the hybrid wave generation unit 20 a includes a transformer 40 and an input side switching element group 50. In addition, the control device 30 includes an input side switching element group control unit 31.

  As shown in FIG. 1, the transformer 40 includes a primary side winding 41 and a secondary side winding 42. In the secondary side winding 42, a secondary side first winding 42a and a secondary side second winding 42b are connected in series, and the secondary side first winding 42a and the secondary side second winding 42b are connected. The neutral point is formed in the secondary side connection part 43 to which is connected. The primary side winding 41, the secondary side first winding 42a, and the secondary side second winding 42b are marked with black circles, and the black circles indicate the start of winding of each winding. The same applies to the other embodiments, and the black circle mark shown in the transformer 40 indicates the start of winding of each winding.

  As the transformer 40, a known power transformer (high-frequency transformer) can be used. The transformer 40 is preferably an insulating transformer in which the primary side and the secondary side are electrically insulated. Note that the turn ratio between the number of turns of the primary side winding 41 and the number of turns of the secondary side winding 42 is set according to the step-up ratio between the DC voltage on the primary side of the transformer 40 and the AC voltage on the secondary side. Yes. The number of turns of the secondary side first winding 42a and the number of turns of the secondary side second winding 42b are set to the same number.

  As shown in FIG. 1, the input side switching element group 50 includes two pairs of switching elements. In the figure, one of two pairs of switching elements is indicated by a pair of switching elements 50a, and the other of the two pairs of switching elements is indicated by a pair of switching elements 50b. Each of the two pairs of switching elements 50 a and 50 b includes a positive electrode side switching element 51, a negative electrode side switching element 52, and a connection portion 53. The positive electrode side switching element 51 is connected to the positive electrode 10 p side of the DC power supply 10, and the negative electrode side switching element 52 is connected to the negative electrode 10 n side of the DC power supply 10. Further, the positive electrode side switching element 51 and the negative electrode side switching element 52 are connected by a connection portion 53 and connected in series.

  In the present specification, when one of the two pairs of switching elements 50a and 50b is specified, the positive-side switching element 51a, the negative-side switching element 52a, and the connection portion 53a are used as appropriate. . Similarly, when specifying the other pair of switching elements 50b of the two pairs of switching elements 50a and 50b, the positive side switching element 51b, the negative side switching element 52b, and the connection portion 53b are used as appropriate.

  As the positive electrode side switching element 51 and the negative electrode side switching element 52, known switching elements for electric power can be used. For example, the positive-side switching element 51 and the negative-side switching element 52 may use various switching elements such as a known field effect transistor (FET) and an insulated gate bipolar transistor (IGBT). it can.

  The positive side switching element 51 includes an input terminal 51c, an output terminal 51e, a control terminal 51g, and a reflux diode 51d. Here, a voltage applied between the control terminal 51g and the output terminal 51e is a positive control voltage. For example, when the positive-side control voltage is at a low level (voltage state equal to or lower than a predetermined voltage value), the input terminal 51c and the output terminal 51e are controlled to be in an open state where they are electrically disconnected. On the other hand, when the positive side control voltage is at a high level (a voltage state exceeding a predetermined voltage value), the input terminal 51c and the output terminal 51e are controlled to be in a closed state in which electrical connection is established.

  The body diode (parasitic diode) of the positive switching element 51 can be used as the freewheeling diode 51d. Instead of the body diode, a diode may be separately provided and connected in parallel between the input terminal 51c and the output terminal 51e. The free-wheeling diode 51d forms a current path from the output terminal 51e side to the input terminal 51c side when the positive side switching element 51 is in an open state. Thereby, the positive electrode side switching element 51 can be protected from the reverse current or the reverse voltage generated when the positive electrode side switching element 51 is opened and closed.

  What has been described above for the positive electrode side switching element 51 can be similarly applied to the negative electrode side switching element 52. That is, the negative side switching element 52 includes an input terminal 52c, an output terminal 52e, a control terminal 52g, and a free wheeling diode 52d. A voltage applied between the control terminal 52g and the output terminal 52e is defined as a negative side control voltage. For example, when the negative side control voltage is at a low level (a voltage state equal to or lower than a predetermined voltage value), the input terminal 52c and the output terminal 52e are controlled to be in an open state in which they are electrically disconnected. On the other hand, when the negative side control voltage is at a high level (a voltage state exceeding a predetermined voltage value), the closed state is established in which the input terminal 52c and the output terminal 52e are electrically connected. The free-wheeling diode 52 d has the same function as the free-wheeling diode 51 d of the positive-side switching element 51.

  As shown in FIG. 1, both the positive electrode side switching element 51 a and the positive electrode side switching element 51 b are connected to the positive electrode 10 p side of the DC power supply 10. Further, the negative electrode side switching element 52 a and the negative electrode side switching element 52 b are both connected to the negative electrode 10 n side of the DC power supply 10. Furthermore, one end portion 41 x of the primary winding 41 of the transformer 40 is connected to the connection portion 53 a of one pair of switching elements 50 a of the input side switching element group 50. The other end 41 y of the primary winding 41 is connected to the connection part 53 b of the other pair of switching elements 50 b in the input side switching element group 50. Thus, in the input side switching element group 50 of the present embodiment, four switching elements are connected by a full bridge.

  The control terminal 51g of the positive side switching element 51 is connected to the control device 30 via the input side drive circuit 30e. The control terminal 52g of the negative side switching element 52 is connected to the control device 30 via the input side drive circuit 30e. A known driver circuit (gate drive circuit) can be used for the input side drive circuit 30e. Specifically, the input-side drive circuit 30e generates the above-described positive-side control voltage and negative-side control voltage from the drive signal generated by the control device 30 (the drive signal of the hybrid wave generation unit 20a described above). Output. The control device 30 can change the duty ratio by, for example, pulse width modulation (PWM) control, and can control the opening and closing of each switching element of the input side switching element group 50 based on the duty ratio.

  The input side switching element group 50 converts the DC power Pdc output from the DC power supply 10 into AC power by alternately repeating the first state and the second state, and outputs the AC power to the secondary side of the transformer 40. be able to. The first state is a state in which both the positive electrode side switching element 51a and the negative electrode side switching element 52b are in a closed state, and both the positive electrode side switching element 51b and the negative electrode side switching element 52a are in an open state. The second state refers to a state where both the positive electrode side switching element 51a and the negative electrode side switching element 52b are in an open state, and both the positive electrode side switching element 51b and the negative electrode side switching element 52a are in a closed state.

  First, it is assumed that the secondary winding 42 of the transformer 40 outputs an alternating current similar to the alternating current that periodically fluctuates at the first frequency F1 shown in FIG. 2A. In this case, for example, the control device 30 performs pulse width modulation (PWM) control on the positive electrode side switching element 51a so that the alternating current (positive electrode side) shown in FIG. 2A is generated, and controls the negative electrode side switching element 52b. Control to the normally closed state (corresponding to the first state). Further, the control device 30 performs pulse width modulation (PWM) control on the negative side switching element 52a so that the alternating current (negative side) shown in FIG. 2A is generated, and the positive side switching element 51b is normally closed. (Corresponding to the second state). By alternately repeating the state corresponding to the first state and the state corresponding to the second state, the secondary side winding 42 of the transformer 40 is periodically provided at the first frequency F1 shown in FIG. 2A. An alternating current similar to a varying alternating current is output.

  Next, it is assumed that the secondary winding 42 of the transformer 40 outputs an alternating current similar to the alternating current that periodically varies at the second frequency F2 shown in FIG. 2B. In this case, for example, the control device 30 performs pulse width modulation (PWM) control on the negative side switching element 52b so that the alternating current (positive side) shown in FIG. 2B is generated, and controls the positive side switching element 51a. Control to the normally closed state (corresponding to the first state). Further, the control device 30 performs pulse width modulation (PWM) control on the positive electrode side switching element 51b so that the alternating current (negative electrode side) shown in FIG. 2B is generated, and the negative electrode side switching element 52a is normally closed. (Corresponding to the second state). By alternately repeating the state corresponding to the first state and the state corresponding to the second state, the secondary side winding 42 of the transformer 40 is periodically provided at the second frequency F2 shown in FIG. 2B. An alternating current similar to a varying alternating current is output.

  Next, it is assumed that the switching element controlled to be normally closed is subjected to pulse width modulation (PWM) control in the two cases described above. Specifically, the control device 30 generates a pair of switching elements 50a (positive electrode side) of the input-side switching element group 50 so that an alternating current that periodically fluctuates at the first frequency F1 illustrated in FIG. 2A is generated. The switching element 51a and the negative side switching element 52a) are subjected to pulse width modulation (PWM) control. Further, the control device 30 generates the other pair of switching elements 50b (positive electrode side switching elements 51b) of the input side switching element group 50 so that an alternating current that periodically fluctuates at the second frequency F2 illustrated in FIG. 2B is generated. And negative-side switching element 52b) are subjected to pulse width modulation (PWM) control. As a result, the current waveform indicated by the curve L11 in FIG. 2A and the current waveform indicated by the curve L12 in FIG. 2B are superimposed (hybridized) to generate the current waveform indicated by the curve L13 in FIG. 2C. The secondary side winding 42 of the transformer 40 can output an alternating current similar to the alternating current related to the hybrid wave Pm shown in FIG. 2C.

  As shown in FIG. 4, the control device 30 includes an input-side switching element group control unit 31 when viewed as a control block. The input side switching element group control unit 31 is not limited as long as it can perform the above-described pulse width modulation (PWM) control. The input-side switching element group control unit 31 can perform the above-described pulse width modulation (PWM) control using various known methods such as a triangular wave comparison method, for example. In the present embodiment, the input-side switching element group controller 31 includes a first modulated wave generator 31a, a second modulated wave generator 31b, a carrier wave generator 31c, a first comparator 31d, and a second comparator. 31e. The first modulated wave generator 31a generates a first modulated wave WM1 that periodically varies at the same frequency as the first frequency F1. The second modulated wave generator 31b generates a second modulated wave WM2 that periodically varies at the same frequency as the second frequency F2. In the present embodiment, the first modulated wave WM1 and the second modulated wave WM2 are both sine waves. In addition, the amplitudes of the first modulated wave WM1 and the second modulated wave WM2 are set in accordance with the modulation factor of pulse width modulation (PWM) control (a value obtained by dividing the command value by the DC voltage of the DC power supply 10).

  The carrier wave generator 31c generates a carrier wave WC0 for pulse width modulation (PWM) control. The carrier wave WC0 can use a triangular wave. The frequency of the carrier wave WC0 needs to be set sufficiently higher than the frequencies of the first modulated wave WM1 and the second modulated wave WM2. For example, when the predetermined frequency F0 is set to 1 kHz, the frequency of the carrier wave WC0 can be set to 10 kHz. For example, when the predetermined frequency F0 is set to 20 kHz, the frequency of the carrier wave WC0 can be set to 200 kHz. Thus, the frequency of the carrier wave WC0 can be set to a frequency that is ten times the predetermined frequency F0, for example. Further, when the output frequency Fout of the inverter 20 is variable, the carrier wave WC0 can be changed in frequency according to the output frequency Fout of the inverter 20, and is set to a constant frequency regardless of the output frequency Fout of the inverter 20. You can also

  The first comparator 31d compares the first modulated wave WM1 generated by the first modulated wave generator 31a with the carrier wave WC0 generated by the carrier wave generator 31c, and compares the magnitude with a low level (less than a predetermined voltage value). Voltage state) or high level (voltage state exceeding a predetermined voltage value) is output. The second comparator 31e compares the second modulated wave WM2 generated by the second modulated wave generator 31b with the carrier wave WC0 generated by the carrier wave generator 31c, and compares the magnitude with a low level (less than a predetermined voltage value). Voltage state) or high level (voltage state exceeding a predetermined voltage value) is output.

  A curve L21 in FIG. 5 shows an example of a change with time of the first modulated wave WM1 generated by the first modulated wave generator 31a. A curve L22 shows an example of a change over time of the carrier wave WC0 generated by the carrier wave generator 31c. A curve L23 shows an example of a change with time of the output of the first comparator 31d. The output of the first comparator 31d corresponds to the drive signal A of one switching element (for example, the positive side switching element 51a) of the input side switching element group 50. The open state in the figure indicates that the switching element is controlled to be in the open state when the output of the first comparator 31d is at a low level (voltage state equal to or lower than a predetermined voltage value). The closed state in the figure indicates that the switching element is controlled to be closed when the output of the first comparator 31d is at a high level (a voltage state exceeding a predetermined voltage value).

  When the first modulated wave WM1 indicated by the curve L21 is smaller than the carrier wave WC0 indicated by the curve L22, the output of the first comparator 31d is at a low level (voltage state equal to or lower than a predetermined voltage value), and the positive-side switching element 51a is It is controlled to be in an open state (for example, a section indicated by time t21 in the figure). On the other hand, when the first modulated wave WM1 indicated by the curve L21 is larger than the carrier wave WC0 indicated by the curve L22, the output of the first comparator 31d is at a high level (voltage state exceeding a predetermined voltage value), and the positive-side switching element 51a is controlled to be in a closed state (for example, a section indicated by time t22 in the figure). By repeating this, the drive signal A for the positive switching element 51a indicated by the curve L23 is generated. When the dead time is ignored, the drive signal A for the negative side switching element 52a becomes a drive signal obtained by inverting the open state and the closed state of the drive signal A for the positive side switching element 51a.

  The drive signal B for the positive switching element 51b can be generated in the same manner. Specifically, when the second modulated wave WM2 is smaller than the carrier wave WC0, the output of the second comparator 31e is at a low level (voltage state equal to or lower than a predetermined voltage value), and the positive-side switching element 51b is in the open state. Be controlled. On the other hand, when the second modulation wave WM2 is larger than the carrier wave WC0, the output of the second comparator 31e is at a high level (voltage state exceeding a predetermined voltage value), and the positive-side switching element 51b is controlled to be closed. The By repeating this, the drive signal B of the positive side switching element 51b is generated. If the dead time is ignored, the drive signal B of the negative side switching element 52b becomes a drive signal that is an inversion of the open state and the closed state of the drive signal B of the positive side switching element 51b. When the frequencies of the first modulated wave WM1 and the second modulated wave WM2 are set high (for example, 20 kHz or higher), the drive signal A and the drive signal B are generated in advance, for example, the second shown in FIG. It may be stored in the storage device 30b2. And the input side switching element group control part 31 can read the drive signal A and the drive signal B which are memorize | stored in the 2nd memory | storage device 30b2 to the 1st memory | storage device 30b1, and can output it. The same can be said for the drive signal D described later.

  According to the inverter device 100 of the present embodiment, the hybrid wave generation unit 20a includes the transformer 40 and the input side switching element group 50. One end 41x of the primary side winding 41 of the transformer 40 is connected to the connection portion 53a of one pair of switching elements 50a of the input side switching element group 50, and the other end of the primary side winding 41 is connected. 41y is connected to the connection part 53b of the other pair of switching elements 50b of the input side switching element group 50. Further, the control device 30 includes an input side switching element group control unit 31. The input-side switching element group control unit 31 uses the first modulated wave WM1 that periodically fluctuates at the same frequency as the first frequency F1, and uses one pair of switching elements 50a (a positive-side switching element 51a and a negative-side switching element 52a). ) Is subjected to pulse width modulation (PWM) control, and the second pair of switching elements 50b (the positive side switching element 51b and the negative side switching element) using the second modulated wave WM2 that periodically varies at the same frequency as the second frequency F2. 52b) is subjected to pulse width modulation (PWM) control to output the hybrid wave Pm to the secondary winding 42 of the transformer 40. Thus, the inverter device 100 of the present embodiment can easily generate the hybrid wave Pm from the DC power Pdc.

(Hybrid wave separator 60, output side switching element group 70, filter 80, and output side switching element group control unit 32)
The output wave generation unit 20b converts a frequency component twice the output frequency Fout of the inverter 20 included in the hybrid wave Pm into the same frequency component as the output frequency Fout of the inverter 20, and the inverter 20 outputs the hybrid wave Pm. The configuration is not limited as long as the output wave Pout can be generated. In the present embodiment, the output wave generation unit 20 b includes a hybrid wave separator 60, an output side switching element group 70, and a filter 80. In addition, the control device 30 includes an output side switching element group control unit 32.

  The hybrid wave separator 60 separates the hybrid wave Pm into a positive electrode side hybrid wave Pmp and a negative electrode side hybrid wave Pmm. The positive-side hybrid wave Pmp is a hybrid wave Pm in which the passage of the positive-side component of the hybrid wave Pm is allowed and the passage of the negative-side component is restricted. The negative-side hybrid wave Pmm is a hybrid wave Pm in which the passage of the negative-side component of the hybrid wave Pm is permitted and the passage of the positive-side component is restricted. As shown in FIG. 1, in the present embodiment, the hybrid wave separator 60 includes a plurality (two) of rectifying elements (a first rectifying element 61 and a second rectifying element 62). As the first rectifying element 61 and the second rectifying element 62, a known power rectifying element (for example, a diode) can be used.

  The first rectifying element 61 includes an input side electrode 61a and an output side electrode 61b. When a diode is used as the first rectifying element 61, the input side electrode 61a corresponds to an anode electrode, and the output side electrode 61b corresponds to a cathode electrode. The second rectifying element 62 includes an input side electrode 62a and an output side electrode 62b. When a diode is used as the second rectifying element 62, the input side electrode 62a corresponds to an anode electrode, and the output side electrode 62b corresponds to a cathode electrode.

  The output side switching element group 70 includes a pair of switching elements 70a in which an output side first switching element 71 and an output side second switching element 72 are connected in series. The output-side first switching element 71 outputs a positive-side hybrid wave Pmp as a positive-side component of the output wave Pout output from the inverter 20. The output-side second switching element 72 outputs the negative-side hybrid wave Pmm as the negative-side component of the output wave Pout output from the inverter 20.

  The output-side first switching element 71 and the output-side second switching element 72 are controlled to open and close in synchronization with the output frequency Fout of the inverter 20. In the present embodiment, the output frequency Fout of the inverter 20 is set sufficiently lower than the predetermined frequency F0. Therefore, the output-side first switching element 71 and the output-side second switching element 72 can use low-speed switching elements as compared with the switching elements of the input-side switching element group 50. A switching element for low speed (for example, a thyristor) has a gap between an input terminal and an output terminal in a closed state as compared with a switching element for high speed (for example, an insulated gate bipolar transistor (IGBT) described above). Can be reduced, and loss due to the switching element can be reduced. The output-side first switching element 71 and the output-side second switching element 72 may use switching elements such as the insulated gate bipolar transistor (IGBT) described above, and various switching elements can be used.

  The output side first switching element 71 includes an input terminal 71c, an output terminal 71e, a control terminal 71g, and a reflux diode 71d. The output-side second switching element 72 includes an input terminal 72c, an output terminal 72e, a control terminal 72g, and a free wheeling diode 72d. These terminals and freewheeling diodes are the same as the terminals and freewheeling diodes already described in the positive electrode side switching element 51 and the negative electrode side switching element 52, and redundant description is omitted.

  The filter 80 includes a positive-side hybrid wave Pmp output through the output-side first switching element 71 and a negative-side hybrid wave Pmm output through the output-side second switching element 72 (hereinafter referred to as pre-filter mixed wave Pf0). .)), The same frequency component as the predetermined frequency F0 is reduced. In the present embodiment, the predetermined frequency F0 is set sufficiently higher than the output frequency Fout of the inverter 20. Therefore, the filter 80 allows passage of the same frequency component as the output frequency Fout of the inverter 20 included in the pre-filter hybrid wave Pf0, and restricts passage of the same frequency component as the predetermined frequency F0 included in the pre-filter hybrid wave Pf0. A low pass filter can be used.

  The filter 80 may be a bandpass filter that allows passage of the same frequency component as the output frequency Fout of the inverter 20 included in the pre-filter hybrid wave Pf0. The positive-side hybrid wave Pmp and the negative-side hybrid wave Pmm (hereinafter referred to as post-filter hybrid wave) after passing through the filter 80 correspond to the output wave Pout output from the inverter 20.

  The filter 80 only needs to be able to reduce the same frequency component as the predetermined frequency F0 included in the pre-filter hybrid wave Pf0, and its configuration is not limited. In the present embodiment, the filter 80 includes a reactor 81 and a capacitor 82, and a low-pass filter is configured. As the reactor 81 and the capacitor 82, known power elements can be used. Further, the inductance of the reactor 81 and the capacitance of the capacitor 82 are set such that the cutoff frequency of the filter 80 is higher than the output frequency Fout of the inverter 20 and lower than the predetermined frequency F0. The higher the predetermined frequency F0 is set, the higher the cutoff frequency of the filter 80 can be set. When the cutoff frequency of the filter 80 is set high, the inductance of the reactor 81 and the capacitance of the capacitor 82 can be reduced, and thus the reactor 81 and the capacitor 82 can be easily downsized.

  As shown in FIG. 1, the input side electrode 61a of the first rectifying element 61 is one end portion 42x of the secondary side winding 42 and the side on which the secondary side first winding 42a is provided. It is connected to the end on the same side. The output side electrode 61 b of the first rectifying element 61 is connected to the input terminal 71 c of the output side first switching element 71. The output side electrode 62b of the second rectifying element 62 is the other end portion 42y of the secondary side winding 42 and is the same end as the side where the secondary side second winding 42b is provided. It is connected to the. The input side electrode 62 a of the second rectifying element 62 is connected to the output terminal 72 e of the output side second switching element 72.

  In addition, an end portion 81 x on one end side of the reactor 81 of the filter 80 is connected to the secondary side connection portion 43 (neutral point) of the transformer 40. The other end 81 y of the reactor 81 is connected to one end 82 x of the capacitor 82 of the filter 80 and is connected to the output terminal 90 b of the inverter 20. An end 82y on the other end side of the capacitor 82 is connected to a connection portion 73 to which the output side first switching element 71 and the output side second switching element 72 are connected, and is connected to the output terminal 90a of the inverter 20. Yes.

  Furthermore, the control terminal 71g of the output side first switching element 71 is connected to the control device 30 via the output side drive circuit 30f. The control terminal 72g of the output-side second switching element 72 is connected to the control device 30 via the output-side drive circuit 30f. A known driver circuit (gate drive circuit) can be used for the output side drive circuit 30f. Specifically, the output side drive circuit 30f generates a control voltage to be applied to the control terminal 71g and the control terminal 72g from the drive signal generated by the control device 30 (the drive signal of the output wave generation unit 20b described above). And output. Control device 30 controls opening and closing of output-side first switching element 71 and output-side second switching element 72 of output-side switching element group 70 in synchronization with output frequency Fout of inverter 20.

  As illustrated in FIG. 4, the control device 30 includes an output-side switching element group control unit 32 when viewed as a control block. When the output side switching element group control unit 32 outputs the positive side component of the output wave Pout, the output side first switching element 71 is closed and the output side second switching element 72 is opened. Specifically, the output-side switching element group control unit 32 determines that the control voltage applied between the control terminal 71g and the output terminal 71e of the output-side first switching element 71 is at a high level (a voltage state exceeding a predetermined voltage value). And a drive signal C is generated in which the control voltage applied between the control terminal 72g and the output terminal 72e of the output-side second switching element 72 is low level (voltage state equal to or lower than a predetermined voltage value).

  In this case, the secondary side first winding 42 a of the transformer 40, the first rectifying element 61, the output side first switching element 71, the connection portion 73, the end 82 y on the other end side of the capacitor 82, the load 90, and the capacitor 82 A current path that passes through the end portion 82x on one end side, the reactor 81, and the secondary side connection portion 43 (neutral point) is formed. At this time, the first rectifying element 61 allows passage of the positive-side component of the hybrid wave Pm, and the second rectifying element 62 restricts passage of the positive-side component of the hybrid wave Pm.

  A curve L31 in FIG. 6A shows an example of the change over time of the alternating current related to the positive-side hybrid wave Pmp. The vertical axis of the figure shows the current flowing through the first rectifying element 61, and the horizontal axis shows the time. The time t13, the predetermined frequency F0, the time t10, the output frequency Fout, and the curve L10 are the same as those in FIG. 2C. As shown in FIG. 6A, the positive-side hybrid wave Pmp is output as the positive-side component of the output wave Pout. Note that the AC current related to the positive-side hybrid wave Pmp after passing through the filter 80 has the same frequency component as the predetermined frequency F0 included in the positive-side hybrid wave Pmp suppressed by the filter 80, and the curve L10 (positive electrode) in FIG. Side)).

  When the output side switching element group control unit 32 outputs the negative side component of the output wave Pout, the output side first switching element 71 is opened and the output side second switching element 72 is closed. Specifically, the output side switching element group control unit 32 is configured such that the control voltage applied between the control terminal 71g and the output terminal 71e of the output side first switching element 71 is at a low level (voltage state equal to or lower than a predetermined voltage value). And a drive signal C is generated in which the control voltage applied between the control terminal 72g and the output terminal 72e of the output-side second switching element 72 becomes high level (voltage state exceeding a predetermined voltage value).

  In this case, the secondary side second winding 42b of the transformer 40, the secondary side connection portion 43 (neutral point), the reactor 81, the end portion 82x on one end side of the capacitor 82, the load 90, and the other end side of the capacitor 82 are provided. A current path that passes through the end 82y, the connecting portion 73, the output-side second switching element 72, and the second rectifying element 62 in this order is formed. At this time, the second rectifying element 62 allows passage of the negative electrode side component of the hybrid wave Pm, and the first rectifying element 61 restricts passage of the negative electrode side component of the hybrid wave Pm.

  A curve L32 in FIG. 6B shows an example of the change over time of the alternating current related to the negative-side hybrid wave Pmm. The vertical axis of the figure shows the current flowing through the second rectifying element 62, and the horizontal axis shows the time. The time t13, the predetermined frequency F0, the time t10, the output frequency Fout, and the curve L10 are the same as those in FIG. 2C. As shown in FIG. 6B, the negative electrode side mixed wave Pmm is output as the negative electrode side component of the output wave Pout. Note that the AC current related to the negative-side hybrid wave Pmm after passing through the filter 80 has the same frequency component as the predetermined frequency F0 contained in the negative-side hybrid wave Pmm suppressed by the filter 80, and the curve L10 (negative electrode in FIG. Side)).

  A curve L33 in FIG. 6C shows an example of the change over time of the alternating current related to the pre-filter hybrid wave Pf0. In the figure, the vertical axis represents current, and the horizontal axis represents time. The time t13, the predetermined frequency F0, the time t10, the output frequency Fout, and the curve L10 are the same as those in FIG. 2C. It can be said that the current waveform indicated by the curve L33 in FIG. 6C is a current waveform obtained by superimposing the current waveform indicated by the curve L31 in FIG. 6A and the current waveform indicated by the curve L32 in FIG. 6B. As shown in FIG. 6C, the output-side switching element group control unit 32 alternately outputs the positive-side hybrid wave Pmp and the negative-side hybrid wave Pmm in synchronization with the output frequency Fout of the inverter 20, The wave Pf0 is output. Note that the AC current related to the post-filter hybrid wave (the output wave Pout output from the inverter 20) after passing through the filter 80 has the same frequency component as the predetermined frequency F0 included in the pre-filter hybrid wave Pf0 suppressed by the filter 80. Thus, the current waveform is the same as that of the curve L10 in FIG. 2D.

  In the inverter device 100 of the present embodiment, the inverter 20 is linked to the power system of the system power supply. When the inverter 20 is linked to the power system of the system power supply, it is necessary to synchronize the phase of the alternating current related to the output wave Pout output from the inverter 20 and the phase of the alternating current of the system power supply. Therefore, in this embodiment, the output side switching element group control part 32 is provided with the phase synchronizer (not shown). For example, a known PLL circuit (Phase Locked Loop Circuit) can be used as the phase synchronizer. The PLL circuit can generate an output signal synchronized with the input signal (in this case, the phase of the alternating current of the system power supply).

  The first modulated wave generator 31a of the input side switching element group control unit 31 generates the first modulated wave WM1 in synchronization with the output signal of the phase synchronizer (the phase of the alternating current of the system power supply). The second modulated wave generator 31b of the input side switching element group controller 31 generates the second modulated wave WM2 in synchronization with the output signal of the phase synchronizer (phase of AC current of the system power supply). As a result, the zero cross timing of the frequency component twice the output frequency Fout of the inverter 20 included in the hybrid wave Pm can be matched with the zero cross timing of the AC current of the system power supply, and the inverter 20 outputs. The phase of the alternating current related to the output wave Pout is synchronized with the phase of the alternating current of the system power supply.

  Further, the output-side switching element group control unit 32 determines the wave number of the first modulated wave WM1 generated by the first modulated wave generator 31a or the wave number of the second modulated wave WM2 generated by the second modulated wave generator 31b. The timing at which the polarity (positive polarity or negative polarity) of the alternating current related to the output wave Pout output from the inverter 20 is switched can be obtained (similar to the relationship between the period and the wave number in FIGS. 2A to 2D). In addition, when the inverter 20 supplies power to the load 90 alone (for example, when the inverter 20 and the power system of the system power supply are not linked), the above-described restriction on phase synchronization does not occur. However, in this case as well, the output-side switching element group control unit 32 determines the AC current related to the output wave Pout output from the inverter 20 from the wave number of the first modulated wave WM1 or the second modulated wave WM2, as in the case described above. The timing at which the polarity (positive polarity or negative polarity) is switched can be obtained.

  According to the inverter device 100 of the present embodiment, the output wave generation unit 20 b includes the hybrid wave separator 60, the output side switching element group 70, and the filter 80. In addition, the control device 30 includes an output side switching element group control unit 32. When the output side switching element group control unit 32 outputs the positive side component of the output wave Pout, the output side first switching element 71 is closed and the output side second switching element 72 is opened. On the other hand, when the output side switching element group control unit 32 outputs the negative side component of the output wave Pout, the output side first switching element 71 is opened and the output side second switching element 72 is closed. To do. The output side switching element group control unit 32 can output the positive side hybrid wave Pmp and the negative side hybrid wave Pmm alternately by repeating these steps. Therefore, the inverter device 100 of the present embodiment can easily convert the frequency component twice the output frequency Fout of the inverter 20 included in the hybrid wave Pm into the same frequency component as the output frequency Fout of the inverter 20. The output wave Pout output from the inverter 20 can be easily generated from the wave Pm.

  Further, according to the inverter device 100 of the present embodiment, the output side switching element group 70 includes two switching elements (the output side first switching element 71 and the output side second switching element 72). Therefore, the inverter apparatus 100 of this embodiment is compared with the power converter device of patent document 1 and patent document 2 (henceforth the conventional power converter device) provided with four switching elements in the secondary side of a transformer. The number of switching elements on the secondary side of the transformer 40 can be halved, and loss due to the switching elements (switching loss) can be reduced.

  Furthermore, according to the inverter device 100 of the present embodiment, the two switching elements on the secondary side of the transformer 40 (the output-side first switching element 71 and the output-side second switching element 72) have the output frequency Fout of the inverter 20. The opening and closing is controlled in synchronization. In the present embodiment, the output frequency Fout of the inverter 20 is set sufficiently lower than the predetermined frequency F0. Therefore, the inverter device 100 of the present embodiment can reduce the speed of the two switching elements on the secondary side of the transformer 40 and use a switching element for low speed as compared with the conventional power conversion device. The switching element for low speed can reduce the inter-terminal voltage between the input terminal and the output terminal in the closed state as compared with the switching element for high speed provided in the conventional power conversion device. Loss can be reduced.

  Further, according to the inverter device 100 of the present embodiment, the hybrid wave separator 60 includes a plurality (two) of rectifier elements (first rectifier element 61 and second rectifier element 62). One rectifying element (first rectifying element 61) of the plural (two) rectifying elements permits passage of the positive-side component of the hybrid wave Pm and restricts passage of the negative-side component of the hybrid wave Pm. To do. The other rectifying element (second rectifying element 62) of the plurality (two) of rectifying elements allows passage of the negative electrode side component of the hybrid wave Pm and also positive electrode side component of the hybrid wave Pm. Restrict the passage of. Therefore, the inverter device 100 of the present embodiment can easily separate the hybrid wave Pm into the positive-side hybrid wave Pmp and the negative-side hybrid wave Pmm.

<Second embodiment>
The present embodiment is mainly different from the first embodiment in the hybrid wave generation unit 20a. Hereinafter, a description will be given focusing on differences from the first embodiment.

  As shown in FIG. 7, the hybrid wave generation unit 20 a includes a transformer 40 and an input side switching element group 50. The transformer 40 includes a primary side winding 41 and a secondary side winding 42. In the present embodiment, the primary side winding 41 of the transformer 40 includes a primary side first winding 41a and a primary side second winding 41b, which are connected in series. The number of turns of the primary side first winding 41a and the number of turns of the primary side second winding 41b are set to the same number. The input side switching element group 50 includes an input side first switching element 54 and an input side second switching element 55.

  The input-side first switching element 54 includes one end 41x of the primary-side winding 41, the same end as the side where the primary-side first winding 41a is provided, and the negative electrode 10n of the DC power supply 10. It is provided in the electric circuit between. The input-side second switching element 55 includes the other end 41 y of the primary-side winding 41, the same end as the side where the primary-side second winding 41 b is provided, and the negative electrode 10 n of the DC power supply 10. It is provided in the electric circuit between. The positive electrode 10p of the DC power supply 10 is connected to a primary side connection portion 44 to which a primary side first winding 41a and a primary side second winding 41b are connected.

  As the input-side first switching element 54 and the input-side second switching element 55, known power switching elements can be used. For example, as the input side first switching element 54 and the input side second switching element 55, various switching elements such as a known field effect transistor (FET) and an insulated gate bipolar transistor (IGBT) can be used. The input side first switching element 54 includes an input terminal 54c, an output terminal 54e, a control terminal 54g, and a reflux diode 54d. The input-side second switching element 55 includes an input terminal 55c, an output terminal 55e, a control terminal 55g, and a free wheeling diode 55d. These terminals and freewheeling diodes are the same as the terminals and freewheeling diodes already described in the positive electrode side switching element 51 and the negative electrode side switching element 52 of the first embodiment, and redundant description is omitted.

  As shown in FIG. 8, the input-side switching element group control unit 31 of the control device 30 includes a first modulated wave generator 31a, a second modulated wave generator 31b, and a carrier wave generator, as in the first embodiment. 31c, a first comparator 31d, and a second comparator 31e. In the present embodiment, the output (drive signal A) of the first comparator 31d is output to the input-side first switching element 54. The output (drive signal B) of the second comparator 31 e is output to the input-side second switching element 55. That is, the input side switching element group control unit 31 performs pulse width modulation (PWM) control on the input side first switching element 54 using the first modulated wave WM1. Further, the input side switching element group control unit 31 performs pulse width modulation (PWM) control on the input side second switching element 55 using the second modulated wave WM2. As a result, as in the first embodiment, the input side switching element group control unit 31 can output the hybrid wave Pm to the secondary side winding 42 of the transformer 40. Therefore, also in the present embodiment, it is possible to obtain the same operational effects as those described in the first embodiment.

  In the present embodiment, the above can be explained as follows. The alternating current related to the hybrid wave Pm can be expressed by the following formula 2. The first term on the left side shows the AC current (frequency is the first frequency F1) related to the first AC wave P1, and the second term on the left side is the AC current (frequency is related to the second AC wave P2). The second frequency F2) is shown. The right side shows an alternating current related to the hybrid wave Pm. The time is represented by time t. Also in the present embodiment, the alternating current related to the hybrid wave Pm includes the same frequency component as the predetermined frequency F0. Further, the alternating current related to the hybrid wave Pm includes a frequency component that is an integer multiple of two or more (mainly twice) the output frequency Fout of the inverter 20 with respect to the subharmonic.

<Third embodiment>
The present embodiment mainly differs from the first embodiment in the input-side switching element group control unit 31. Hereinafter, a description will be given focusing on differences from the first embodiment.

  As shown in FIG. 9, the input side switching element group control unit 31 includes a hybrid modulation wave generator 31f, a carrier wave generator 31g, and a third comparator 31h. As shown in FIG. 10, the hybrid modulation wave generator 31f includes a predetermined frequency generator 31f1, an output frequency generator 31f2, and a multiplier 31f3. The predetermined frequency generation unit 31f1 generates and outputs a first signal (in this embodiment, a sine wave) that periodically varies at the same frequency as the predetermined frequency F0. The output frequency generation unit 31f2 generates and outputs a second signal (in this embodiment, a sine wave) that periodically varies at the same frequency as the output frequency Fout of the inverter 20. The multiplier 31f3 multiplies the first signal (predetermined frequency F0) output from the predetermined frequency generation unit 31f1 and the second signal (output frequency Fout) output from the output frequency generation unit 31f2 to generate the hybrid modulated wave WMM. Is generated and output.

  As shown in Equation 1 described in the first embodiment, when the first signal (predetermined frequency F0) and the second signal (output frequency Fout) are multiplied, the first modulated wave WM1 and the second modulated wave WM2 are obtained. A hybrid mixed modulation wave WMM can be generated. As described above, the first modulated wave WM1 is a modulated wave that periodically varies at the same frequency as the first frequency F1 (a frequency obtained by subtracting the output frequency Fout of the inverter 20 from the predetermined frequency F0). The second modulation wave WM2 is a modulation wave that periodically fluctuates at the same frequency as the second frequency F2 (a frequency obtained by adding the output frequency Fout of the inverter 20 to the predetermined frequency F0). That is, the hybrid modulated wave WMM can be said to be a modulated wave that changes with time similarly to the alternating current related to the hybrid wave Pm shown by the curve L13 in FIG. 2C.

  In this way, the hybrid modulation wave generator 31f can generate the hybrid modulation wave WMM. The carrier wave generator 31g generates a pulse width modulation (PWM) controlled carrier wave WC0 in the same manner as the carrier wave generator 31c described in the first embodiment. Also in this embodiment, the carrier wave WC0 can use a triangular wave. In addition, the frequency of the carrier wave WC0 needs to be set sufficiently higher than the frequency of the predetermined frequency F0. The specific frequency of the carrier wave WC0 can be set similarly to the carrier wave generator 31c.

  The third comparator 31h compares the hybrid modulation wave WMM generated by the hybrid modulation wave generator 31f with the carrier wave WC0 generated by the carrier wave generator 31g, and compares the magnitude with a low level (a voltage state equal to or lower than a predetermined voltage value). ) Or high level (a voltage state exceeding a predetermined voltage value) is output. That is, the input side switching element group control unit 31 uses each of the switching elements (positive side switching) of the input side switching element group 50 by using the hybrid modulation wave WMM instead of the first modulation wave WM1 shown by the curve L21 in FIG. Drive signal D of each of element 51a, negative electrode side switching element 52a, positive electrode side switching element 51b, and negative electrode side switching element 52b). As a result, an alternating current related to the hybrid wave Pm indicated by the curve L13 in FIG. 2C is generated in the secondary winding 42 of the transformer 40.

  According to the inverter device 100 of the present embodiment, the input side switching element group control unit 31 uses the hybrid modulation wave WMM to switch each switching element (positive side switching element 51a, negative side switching element) of the input side switching element group 50. 52a, each of the positive electrode side switching element 51b and the negative electrode side switching element 52b) are subjected to pulse width modulation (PWM) control, and the hybrid wave Pm is output to the secondary winding 42 of the transformer 40. Therefore, also in the present embodiment, it is possible to obtain the same operational effects as those described in the first embodiment.

  In addition, what was mentioned above is applicable similarly also about the inverter apparatus 100 of 2nd embodiment. In this case, the input-side switching element group control unit 31 performs pulse width modulation (PWM) control of the input-side first switching element 54 and the input-side second switching element 55 using the hybrid modulation wave WMM, and A hybrid wave Pm is output to the secondary winding 42. Also in this case, the same effects as those already described in the first embodiment can be obtained.

<Others>
The present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within a range not departing from the gist. For example, in the above-described embodiment, the inverter 20 generates and outputs a single-phase output wave Pout. However, the output of the inverter 20 is not limited to a single phase. The output of the inverter 20 can be multiphase (for example, three phases). In this case, the hybrid wave generation unit 20a may include, for example, the transformers 40 for the number of phases and a pair of switching elements for a number (number of sets) that is one more than the number of phases.

  For example, in the case of three phases, the hybrid wave generator 20a may include three transformers 40 and four pairs of switching elements. A pair of switching elements (a common pair of switching elements) out of the four pairs of switching elements and a pair of other switching elements (a first pair of the four pairs of switching elements) The first mixed wave Pm1, which is the reference mixed wave Pm, is output to the secondary winding 42 of one of the three transformers 40 using a pair of switching elements). In addition, a pair of switching elements (a common pair of switching elements) out of the four pairs of switching elements, and another pair of switching elements (a first pair of the four pairs of switching elements). And a pair of switching elements), the mixed wave Pm whose phase is advanced by 120 ° relative to the secondary side winding 42 of the other one of the three transformers 40 relative to the first hybrid wave Pm1. The second hybrid wave Pm2 is output. Furthermore, a pair of switching elements (a common pair of switching elements) out of the four pairs of switching elements, and a remaining pair of switching elements (a first pair of the four pairs of switching elements) And a pair of switching elements), the mixed wave Pm whose phase is advanced by 120 ° in the secondary winding 42 of the remaining one of the three transformers 40 compared to the second hybrid wave Pm2. The third hybrid wave Pm3 is output. The output wave generator 20b generates a three-phase output wave Pout from the first hybrid wave Pm1, the second hybrid wave Pm2, and the third hybrid wave Pm3.

(Hybrid wave separator 60)
As shown in FIG. 11, the hybrid wave separator 60 can also include a first rectifier element 61, a second rectifier element 62, a positive electrode side capacitor 63, and a negative electrode side capacitor 64. One end side of the positive electrode side capacitor 63 is connected to an electric circuit between the output side electrode 61 b of the first rectifying element 61 and the input terminal 71 c of the output side first switching element 71. The other end side of the positive electrode side capacitor 63 is connected to an electric circuit between the secondary side connection portion 43 (neutral point) of the transformer 40 and an end portion 81 x on one end side of the reactor 81 of the filter 80. Further, one end side of the negative electrode side capacitor 64 is connected to an electric circuit between the input side electrode 62 a of the second rectifying element 62 and the output terminal 72 e of the output side second switching element 72. The other end side of the negative electrode side capacitor 64 is connected to an electric circuit between the secondary side connection portion 43 (neutral point) of the transformer 40 and an end portion 81 x on one end side of the reactor 81 of the filter 80.

  A curve L41 in FIG. 12A shows an example of the change over time of the alternating current related to the positive-side hybrid wave Pmp in FIG. FIG. 12A corresponds to FIG. 6A, and the curve L31 in FIG. 6A is indicated by a broken line. As shown by a curve L41 in FIG. 12A, the hybrid wave separator 60 includes the positive capacitor 63, and thus can reduce fluctuations in the same frequency component as the predetermined frequency F0 included in the positive hybrid wave Pmp.

  A curve L42 in FIG. 12B shows an example of the change over time of the alternating current related to the negative-side hybrid wave Pmm in FIG. FIG. 12B corresponds to FIG. 6B, and the curve L32 in FIG. 6B is indicated by a broken line. As illustrated by a curve L42 in FIG. 12B, the hybrid wave separator 60 includes the negative electrode side capacitor 64, and thus can reduce the fluctuation of the same frequency component as the predetermined frequency F0 included in the negative electrode side hybrid wave Pmm.

  A curve L43 in FIG. 12C shows an example of the change over time of the alternating current related to the pre-filter hybrid wave Pf0 in FIG. FIG. 12C corresponds to FIG. 6C, and the curve L33 in FIG. 6C is indicated by a broken line. As shown by a curve L43 in FIG. 12C, the hybrid wave separator 60 includes a positive electrode side capacitor 63 and a negative electrode side capacitor 64, whereby a predetermined frequency F0 included in the positive electrode side hybrid wave Pmp and the negative electrode side hybrid wave Pmm. The fluctuation of the same frequency component can be reduced. As a result, the current waveform of the alternating current related to the pre-filter hybrid wave Pf0 is an AC waveform related to the post-filter hybrid wave (the output wave Pout output from the inverter 20) after passing through the filter 80, as compared with the embodiment described above. It becomes close to the current waveform of the current (current waveform shown by the curve L10 in FIG. 2D).

  As shown in FIG. 13, the hybrid wave separator 60 can also include a plurality (eight) rectifying elements (a first rectifying element group 65 and a second rectifying element group 66). The first rectifying element group 65 includes a plurality (four) of rectifying elements (rectifying element 65a, rectifying element 65b, rectifying element 65c, and rectifying element 65d), and these rectifying elements are connected in a full bridge. The second rectifier element group 66 includes a plurality (four) of rectifier elements (rectifier element 66a, rectifier element 66b, rectifier element 66c, and rectifier element 66d), and these rectifier elements are connected in a full bridge. As these rectifying elements, similarly to the first rectifying element 61 and the second rectifying element 62, known rectifying elements for electric power can be used.

  The input side terminal 65i1 of the first rectifying element group 65 is one end portion 42x of the secondary side winding 42 of the transformer 40 and is on the same side as the side where the secondary side first winding 42a is provided. Connected to the end. The input side terminal 65i2 of the first rectifying element group 65 is connected to the secondary side connection portion 43 (neutral point) of the transformer 40. The output side terminal 65 o 1 of the first rectifying element group 65 is connected to the input terminal 71 c of the output side first switching element 71. The output-side terminal 65 o 2 of the first rectifying element group 65 is connected to the end 81 x on one end side of the reactor 81 of the filter 80.

  The input side terminal 66i1 of the second rectifying element group 66 is the other end 42y of the secondary side winding 42 of the transformer 40, and is on the same side as the side where the secondary side second winding 42b is provided. Connected to the end. The input side terminal 66i2 of the second rectifying element group 66 is connected to the secondary side connection portion 43 (neutral point) of the transformer 40. The output side terminal 66 o 1 of the second rectifying element group 66 is connected to the output terminal 72 e of the output side second switching element 72. The output-side terminal 66 o 2 of the second rectifying element group 66 is connected to the end 81 x on one end side of the reactor 81 of the filter 80.

  According to the inverter device 100 of this modification, the hybrid wave separator 60 includes a plurality (eight) rectifier elements (first rectifier element group 65 and second rectifier element group 66). A plurality (four) of rectifying elements (first rectifying element group 65) among the plurality (eight) rectifying elements allow passage of the positive-side component of the hybrid wave Pm, as with the first rectifying element 61. And the passage of the negative electrode side component of the hybrid wave Pm is regulated. Further, among the plural (eight) rectifying elements, the other plural (four) rectifying elements (second rectifying element group 66) are, as in the second rectifying element 62, the negative-side component of the hybrid wave Pm. The passage is allowed and the passage of the positive-side component of the hybrid wave Pm is restricted. Therefore, also in the inverter apparatus 100 of this modification, the same operation effect as the operation effect already described in the first embodiment can be obtained.

(Modulated wave)
In the embodiment described above, the first modulated wave WM1 and the second modulated wave WM2 are sine waves. As a result, the alternating current related to the hybrid wave Pm includes a frequency component that changes with time in a sine wave shape (FIG. 2C). Further, the alternating current related to the positive-side hybrid wave Pmp, the alternating current related to the negative-side hybrid wave Pmm, and the alternating current related to the pre-filter mixed wave Pf0 include frequency components that change over time in a sine wave (half wave) form. (FIGS. 6A-6C). Similarly, the hybrid modulated wave WMM obtained by hybridizing the first modulated wave WM1 that is a sine wave and the second modulated wave WM2 that is a sine wave also becomes a sine wave, and the above can be said similarly.

  However, the first modulated wave WM1 and the second modulated wave WM2 are not limited to sine waves. The first modulated wave WM1 and the second modulated wave WM2 can be rectangular waves, for example. In this case, the alternating current related to the hybrid wave Pm includes a frequency component that changes with time in a rectangular wave shape. Further, the alternating current related to the positive-side hybrid wave Pmp, the alternating current related to the negative-side hybrid wave Pmm, and the alternating current related to the pre-filter mixed wave Pf0 include a frequency component that changes with time in a rectangular wave shape. Also, the hybrid modulated wave WMM obtained by hybridizing the first modulated wave WM1 that is a rectangular wave and the second modulated wave WM2 that is a rectangular wave is also a rectangular wave, and the above can be said similarly.

  Thus, it is preferable that the first modulated wave WM1 and the second modulated wave WM2 are rectangular waves or sine waves. Both the rectangular wave and the sine wave can be easily generated, and the input-side switching element group control unit 31 can be easily simplified. Further, as will be described later, when the first modulated wave WM1 and the second modulated wave WM2 are rectangular waves, distortion of the lower order (the same frequency component as the output frequency Fout of the inverter 20) is compared with the case of the sine wave. This is likely to occur, and the filter 80 may be enlarged. Therefore, from the viewpoint of downsizing the filter 80, the first modulated wave WM1 and the second modulated wave WM2 are preferably sine waves. On the other hand, when the first modulated wave WM1 and the second modulated wave WM2 are sine waves, the control is likely to be complicated compared to the case of a rectangular wave. Therefore, from the viewpoint of simplifying the control, it is preferable that the first modulated wave WM1 and the second modulated wave WM2 are rectangular waves.

  When the first modulated wave WM1 and the second modulated wave WM2 are rectangular waves, the alternating current related to the hybrid wave Pm includes a harmonic component that is an integer multiple of two or more of the predetermined frequency F0. As a result, the output wave Pout output from the inverter 20 includes a harmonic component that is an integer multiple of two or more of the output frequency Fout of the inverter 20 (the low-order distortion described above). For example, when the predetermined frequency F0 is 20 kHz, the alternating current related to the hybrid wave Pm includes harmonic components such as 40 kHz, 60 kHz, and 80 kHz. As a result, for example, when the output frequency Fout of the inverter 20 is 50 Hz, the output wave Pout output from the inverter 20 includes harmonic components such as 100 Hz, 150 Hz, and 200 Hz. Therefore, the filter 80 may be increased in size in order to remove harmonic components contained in the output wave Pout output from the inverter 20.

  Therefore, as shown in FIG. 14, the filter 80 preferably includes a first filter 80a and a second filter 80b. The first filter 80a includes a reactor 81 and a capacitor 82, and is the same as the filter already described in the first embodiment. The 2nd filter 80b should just be able to suppress that the harmonic component of two or more integral multiples of the predetermined frequency F0 mentioned above contains in the hybrid wave Pm, The structure is not limited. In the figure, the second filter 80b includes a reactor 83 and a capacitor 84, and a low-pass filter is configured.

  Specifically, an end portion 83 x on one end side of the reactor 83 is connected to a connection portion 53 a of one pair of switching elements 50 a in the input side switching element group 50. The other end 83 y of the reactor 83 is connected to one end 84 x of one end of the capacitor 84, and is connected to one end 41 x of the primary side winding 41 of the transformer 40. The other end 84 y of the capacitor 84 is connected to the connection portion 53 b of the other pair of switching elements 50 b of the input side switching element group 50 and connected to the other end 41 y of the primary side winding 41 of the transformer 40. Has been.

  As the reactor 83 and the capacitor 84, a known power element can be used. Further, the inductance of the reactor 83 and the capacitance of the capacitor 84 are such that the cutoff frequency of the second filter 80b is higher than the second frequency F2 (a frequency obtained by adding the output frequency Fout of the inverter 20 to the predetermined frequency F0), and The frequency is set to be lower than twice the predetermined frequency F0. Thereby, the alternating current concerning the 1st alternating current wave P1 which changes to a rectangular wave shape is made into a sine wave, and the alternating current concerning the 2nd alternating current wave P2 which changes to a rectangular wave shape is made into a sine wave. As a result, harmonic components that are integer multiples of two or more of the predetermined frequency F0 are reduced from the alternating current related to the hybrid wave Pm. Further, from the output wave Pout output from the inverter 20, harmonic components that are an integer multiple of two or more of the output frequency Fout of the inverter 20 are reduced.

10: DC power supply, 10p: positive electrode, 10n: negative electrode,
20: Inverter, 20a: Hybrid wave generator, 20b: Output wave generator,
30: Control device,
31: input-side switching element group control unit, 32: output-side switching element group control unit,
40: Transformer
41: primary winding, 41x: one end, 41y: the other end,
41a: primary side first winding, 41b: primary side second winding,
42: secondary winding, 44: primary side connection,
50: input side switching element group, 50a, 50b: a pair of switching elements,
51: Positive side switching element, 52: Negative side switching element, 53: Connection part,
54: input side first switching element, 55: input side second switching element,
60: Hybrid wave separator,
61: first rectifying element, 62: second rectifying element,
65: first rectifier element group, 66: second rectifier element group,
70: output side switching element group, 70a: a pair of switching elements,
71: Output side first switching element, 72: Output side second switching element,
80: filter,
100: Inverter device,
F0: predetermined frequency, F1: first frequency, F2: second frequency, Fout: output frequency,
WM1: first modulated wave, WM2: second modulated wave, WMM: hybrid modulated wave,
Pdc: DC power, P1: first AC wave, P2: second AC wave, Pm: hybrid wave,
Pmp: positive mixed wave, Pmm: negative mixed wave, Pout: output wave.

Claims (8)

An inverter device comprising a DC power source, an inverter that converts DC power output from the DC power source into desired AC power, and a control device that drives and controls the inverter,
The inverter is
A first AC wave that periodically varies at a first frequency obtained by subtracting the output frequency of the inverter from a predetermined frequency, and a second AC that periodically varies at a second frequency obtained by adding the output frequency of the inverter to the predetermined frequency. A hybrid wave generating unit that generates a hybrid wave that is a hybrid of waves from the DC power;
An output wave that converts a frequency component that is twice the output frequency of the inverter included in the hybrid wave into a frequency component that is the same as the output frequency of the inverter, and generates an output wave that the inverter outputs from the hybrid wave A generator,
An inverter device comprising: The hybrid wave generator is
A transformer comprising a primary winding and a secondary winding;
Two pairs of switching elements in which a positive side switching element connected to the positive side of the DC power source and a negative side switching element connected to the negative side of the DC power source are connected at a connecting portion and connected in series. An input side switching element group comprising:
Comprising
One end of the primary side winding of the transformer is connected to the connection part of one pair of switching elements of the input side switching element group, and the other end of the primary side winding is the input Connected to the connection portion of the other pair of switching elements of the side switching element group,
The control device performs pulse width modulation control on the one pair of switching elements using a first modulated wave that periodically varies at the same frequency as the first frequency, and periodically at the same frequency as the second frequency. An input-side switching element group control unit that performs pulse width modulation control on the other pair of switching elements using a second modulated wave that fluctuates and outputs the mixed wave to the secondary winding of the transformer. The inverter device according to Item 1. The hybrid wave generator is
A transformer comprising a primary side winding in which a primary side first winding and a primary side second winding are connected in series, and a secondary side winding;
The input side provided in the electric circuit between one end of the primary side winding and the same side as the side where the primary first winding is provided and the negative electrode of the DC power supply An electric circuit between the first switching element and the other end of the primary side winding on the same side as the side where the primary second winding is provided and the negative electrode of the DC power supply An input-side switching element group comprising an input-side second switching element provided in
Comprising
The positive electrode of the DC power source is connected to a primary side connection portion to which the primary side first winding and the primary side second winding are connected,
The control device performs pulse width modulation control on the input-side first switching element using a first modulated wave that periodically varies at the same frequency as the first frequency, and periodically at the same frequency as the second frequency. The input-side switching element group control part which carries out pulse width modulation control of the said input side 2nd switching element using the 2nd modulated wave which fluctuates, and outputs the said mixed wave to the said secondary side winding of the said transformer is provided. The inverter device according to Item 1. The hybrid wave generator is
A transformer comprising a primary winding and a secondary winding;
Two pairs of switching elements in which a positive side switching element connected to the positive side of the DC power source and a negative side switching element connected to the negative side of the DC power source are connected at a connecting portion and connected in series. An input side switching element group comprising:
Comprising
One end of the primary side winding of the transformer is connected to the connection part of one pair of switching elements of the input side switching element group, and the other end of the primary side winding is the input Connected to the connection portion of the other pair of switching elements of the side switching element group,
The control device uses a hybrid modulated wave obtained by hybridizing a first modulated wave that periodically varies at the same frequency as the first frequency and a second modulated wave that periodically varies at the same frequency as the second frequency. The input side switching element group control part which carries out pulse width modulation control of each switching element of the said input side switching element group, and outputs the said mixed wave to the said secondary side winding of the said transformer is provided. Inverter device. The hybrid wave generator is
A transformer comprising a primary side winding in which a primary side first winding and a primary side second winding are connected in series, and a secondary side winding;
The input side provided in the electric circuit between one end of the primary side winding and the same side as the side where the primary first winding is provided and the negative electrode of the DC power supply An electric circuit between the first switching element and the other end of the primary side winding on the same side as the side where the primary second winding is provided and the negative electrode of the DC power supply An input-side switching element group comprising an input-side second switching element provided in
Comprising
The positive electrode of the DC power source is connected to a primary side connection portion to which the primary side first winding and the primary side second winding are connected,
The control device uses a hybrid modulated wave obtained by hybridizing a first modulated wave that periodically varies at the same frequency as the first frequency and a second modulated wave that periodically varies at the same frequency as the second frequency. And an input-side switching element group controller that performs pulse width modulation control on the input-side first switching element and the input-side second switching element, and outputs the mixed wave to the secondary-side winding of the transformer. The inverter device according to Item 1.   The inverter device according to any one of claims 2 to 5, wherein the first modulation wave and the second modulation wave are a rectangular wave or a sine wave. The output wave generator is
The positive-side mixed wave in which the positive-side component of the hybrid wave is allowed to pass and the negative-side component is restricted from passing, and the negative-side hybrid in which the negative-side component of the hybrid wave is allowed to pass and the positive-side component is restricted from passing A hybrid wave separator for separating the hybrid wave into a wave;
An output-side first switching element that outputs the positive-side hybrid wave as a positive-side component of the output wave output from the inverter, and an output-side second switching element that outputs the negative-side hybrid wave as a negative-side component of the output wave Output side switching element group comprising a pair of switching elements connected in series,
The same frequency component as the predetermined frequency contained in the positive-side hybrid wave output via the output-side first switching element and the negative-side hybrid wave output via the output-side second switching element is reduced. Filters,
Comprising
The control device closes the output-side first switching element and outputs the output-side second switching element when the positive-side component of the output wave is output, and the negative-side component of the output wave When the output side first switching element is opened and the output side second switching element is closed, the positive side hybrid wave and the negative side hybrid wave are alternately output. The inverter apparatus as described in any one of Claims 1-6 provided with a side switching element group control part. The hybrid wave separator includes a plurality of rectifying elements,
One or more rectifying elements of the plurality of rectifying elements allow passage of the positive-side component of the hybrid wave and restrict passage of the negative-side component of the hybrid wave, and the plurality of rectifying elements 8. The inverter device according to claim 7, wherein the other rectifying element or the plurality of rectifying elements allow passage of the negative-side component of the hybrid wave and restrict passage of the positive-side component of the hybrid wave.

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