WO2018047395A1 - Power conversion device - Google Patents

Power conversion device Download PDF

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Publication number
WO2018047395A1
WO2018047395A1 PCT/JP2017/014791 JP2017014791W WO2018047395A1 WO 2018047395 A1 WO2018047395 A1 WO 2018047395A1 JP 2017014791 W JP2017014791 W JP 2017014791W WO 2018047395 A1 WO2018047395 A1 WO 2018047395A1
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WO
WIPO (PCT)
Prior art keywords
power conversion
conversion device
power
conversion unit
longitudinal direction
Prior art date
Application number
PCT/JP2017/014791
Other languages
French (fr)
Japanese (ja)
Inventor
泰明 乗松
叶田　玲彦
馬淵　雄一
尊衛 嶋田
充弘 門田
祐樹 河口
瑞紀 中原
輝 米川
Original Assignee
株式会社日立製作所
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Application filed by 株式会社日立製作所 filed Critical 株式会社日立製作所
Publication of WO2018047395A1 publication Critical patent/WO2018047395A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/483—Converters with outputs that each can have more than two voltages levels
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/56—Power conversion systems, e.g. maximum power point trackers

Definitions

  • the power conversion device includes a plurality of power conversion devices that perform power conversion between DC power and AC power.
  • the power conversion device includes an insulating transformer and a power converter such as a DC / DC converter or an inverter. ing.
  • the loss can be further reduced by shortening the length of the DC wiring and low-voltage AC wiring.
  • the volume and weight of the outdoor-use solar PCS and interconnection transformer are large, and the solar panel Since the most recent arrangement is difficult due to the influence of the shade on the solar panel, it is generally arranged away from the solar panel.
  • Patent Document 1 is known as an example of arranging a power conversion device in association with a transformer panel when configuring the panel.
  • an input transformer 1 having a plurality of secondary windings, a transformer panel 10 that houses the input transformers 1, and a one-to-one connection to the secondary windings, as desired.
  • a three-phase inverter configured by Y-connecting a plurality of unit inverters 2 that serially connect a plurality of unit inverters 2 that output a single-phase AC voltage having a frequency of 5 and a converter panel 20 that houses the unit inverters 2 that constitute the three-phase inverter.
  • the converter panel 20 includes a plurality of support posts 22 made of an insulating material and a plurality of metal shelf plates 23 for fastening the support posts 22 adjacent to each other in the lateral direction.
  • the unit inverter 2 is mounted and fixed on the shelf plate 23, respectively.
  • the converter panel 20 has a high voltage for both input and output, it is necessary to take an insulation distance when taking a neutral point, and it is difficult to reduce the size of the power converter.
  • the outputs of the single-phase inverters of a plurality of power conversion units are connected in series.
  • a plurality of power conversion units constituting the power conversion unit group are formed by forming each phase of AC three-phase by three sets of power conversion unit groups housed in a power conversion device casing, The three power conversion unit groups arranged along the longitudinal direction of the device casing are arranged at the upper, middle, and lower levels in the height direction of the power conversion device casing, respectively.
  • One end side of the power conversion unit group is an output terminal of the three sets of power conversion unit groups, and the terminals of the three sets of power conversion unit groups are commonly connected to the other end side in the longitudinal direction of the power conversion device casing.
  • an air conditioner indoor unit is disposed on at least one of the left and right sides in the longitudinal direction inside the power conversion device housing
  • an air conditioner outdoor unit is disposed on at least one of the left and right sides in the longitudinal direction outside the power conversion device housing.
  • the inside of a power converter housing is cooled by cold air from the air.
  • FIG. 1 The figure which shows an example of the housing
  • FIG. 1 The figure which shows the other example of a connection of the several power conversion unit U in the power converter device housing
  • FIG. The figure which shows the structure of the electric circuit of the power converter device implement
  • FIG. 1 The figure which shows the mounting relationship of the power converter device housing
  • FIG. The figure which shows the flow of the inside air in the power converter device housing
  • FIG. The figure which shows the circuit structure of 2 in 1 unit supposing the case where input current is small about the circuit structure in the power conversion unit U.
  • FIG. The figure which shows the example comprised with IGBT about the circuit structure in the power conversion unit U.
  • FIG. 1 shows the example of a connection of the several power conversion unit U in the power converter device housing
  • FIG. 1 shows the structure which connected the transformer and the rectifier circuit in parallel about the circuit structure in the power conversion unit U.
  • FIG. 1 is a diagram showing a housing and arrangement positional relationship of a power conversion device according to the present invention.
  • the power conversion device casing 100 of the present invention is installed using a space formed between a solar panel PL and a base BB for mounting and supporting the solar panel PL. For this reason, it arrange
  • the box-shaped housing has a box shape extending in the longitudinal direction. Incidentally, the length of the casing is 2.5 (m), the length in the short direction is 0.9 (m), the height is 0.7 (m), for example, It can be placed in a shaded space formed by the solar panel PL and the gantry BB.
  • the power converter housing 100 and the outdoor units 101A and 101B are connected via pipes and the like.
  • the power converter housing 100 is provided with an air conditioner outdoor unit 101 at least at one end in the longitudinal direction thereof.
  • the power conversion device housing 100 includes air conditioner outdoor units 101 ⁇ / b> A and 101 ⁇ / b> B at both ends in the longitudinal direction.
  • FIG. 2 shows an example of a photovoltaic power generation site to which the power conversion device of the present invention is applied.
  • the photovoltaic power generation site in FIG. 2 is formed by a plurality of solar panels PL mounted and supported on the gantry B, and the DC output of each solar panel PL is obtained between the terminals TD1 and TD2.
  • the photovoltaic power generation site is provided with the power conversion device casing 100 of FIG. 1 that converts the direct current output of the solar panel PL into the three-phase alternating current of the power system using the lower space of the gantry BB.
  • the box-shaped power conversion device housing 100 houses a plurality of power conversion units U (U1 and U2 in the drawing), and each power conversion unit U is a DC output terminal of each solar panel PL.
  • DC input terminals TD1, TD2 connected to TL1, TL2 and AC output terminals TA1, TA2 are provided.
  • the direct current output terminals TL1, TL2 of the solar panel PL1 are connected in association with, for example, the direct current input terminals TD1, TD2 of the power conversion unit U1, and the direct current output terminals TL1, TL2 of the solar panel PL2 are, for example, the power conversion unit. They are connected in association with the DC input terminals TD1 and TD2 of U2.
  • the DC output terminals TL1 and TL2 of the plurality of solar panels PL are respectively connected in common and connected to the DC input terminals TD1 and TD2 of the power conversion unit U.
  • FIG. 3 shows a connection example of a plurality of power conversion units U in the power conversion device casing 100.
  • the external connection of the power conversion device housing 100 is connected to the DC input terminals TD1 and TD2 connected to the DC output terminals TL1 and TL2 of the plurality of solar panels PL and each phase of the high-voltage three-phase power system.
  • the three-phase AC output terminals TU, TV and TW are used.
  • a low voltage DC input is applied to the DC input terminals TD1, TD2, and a high voltage three phase output is applied from the three-phase AC output terminals TU, TV, TW.
  • the three-phase AC output is a Y-connection that is grounded at a neutral point N, and three-phase AC output terminals TU, TV, and TW are provided at one end in the longitudinal direction of the box-shaped power converter housing 100.
  • a neutral point N is arranged on the other end side in the longitudinal direction of the cubic power conversion device casing 100 in a centralized arrangement.
  • the arrangement positions of the DC input terminals TD1 and TD2 are not particularly limited, but the illustrated example shows an example of arrangement on the neutral point N side of the other end in the longitudinal direction of the box-shaped power converter housing 100. ing.
  • a DC circuit breaker MCCB is installed at the DC input terminals TD1 and TD2.
  • the DC output terminals TL1 and TL2 of the plurality of solar panels PL are connected in common and connected to the DC input terminals TD1 and TD2 provided in common in the power conversion unit U.
  • each phase between the three-phase AC output terminals TU, TV, TW and the neutral point N is configured by a plurality of power conversion units U.
  • each phase is composed of eight power conversion units U.
  • UWI, UW2, UW3, UW4, UW5, UW6, UW7, UW8 are arranged sequentially from the neutral point N side. is doing. This arrangement is the same for the other phases.
  • power conversion unit groups each of which is composed of eight power conversion units U are arranged in multiple stages in the height direction of the power conversion device casing 100.
  • the power conversion unit group of each phase of U, V, and W employs a three-stage stacked structure in which the U phase is disposed in the lower stage, the V phase is disposed in the intermediate stage, and the W phase is disposed in the upper stage.
  • FIG. 3 illustrates a configuration example of the UW 5 as a specific circuit configuration of the power conversion unit U. Since the other power conversion units U have the same configuration, only the configuration of UW5 will be described here.
  • the power conversion unit UW5 includes an LLC resonant converter LLC and an inverter IN.
  • the LLC resonant converter LLC includes an input side capacitor Ci, a full-bridge inverter circuit 11 composed of semiconductor elements Q1, Q2, Q3, and Q4, an exciting inductance 1, a leakage inductance 2, and a resonant capacitor 3 connected in series.
  • the isolated transformer 12 and the full-bridge rectifier circuit 13 composed of the diodes D1, D2, D3, and D4. After the direct current input from the solar panel PL is converted into a high frequency alternating current, the direct current is again generated. Has been converted.
  • the inverter IN is composed of a capacitor C and an inverter circuit 14 having a full bridge configuration composed of semiconductor elements Q5, Q6, Q7, and Q8.
  • an AC voltage is generated using the DC voltage Vd1 provided by the LLC resonant converter LLC as a power source.
  • the power conversion unit UW5 has a configuration in which the input is connected to the direct current from the solar panel PL and the output is connected to the high-voltage system side.
  • the power conversion unit UW5 connects the high voltage side terminal TA1 of the AC output terminals TA1 and TA2 to the AC output terminal TA2 of the adjacent high voltage side power conversion unit UW6 and the low voltage side terminal TA2 adjacent to the low voltage side.
  • the plurality of power conversion units U forming each phase share the high voltage of the power system by connecting the input side in parallel and connecting the output side in series.
  • FIG. 4 also shows an arrangement example of the power conversion unit U in the power conversion device casing 100, but is different from FIG. 3 only in that an AC circuit breaker is provided in each phase on the output side of the power conversion device. is doing.
  • FIG. 5 shows a configuration of an electric circuit of the power conversion device realized by connecting a plurality of units in the power conversion device casing 100 configured as shown in FIG. 3 or FIG.
  • the DC input terminals TD1 and TD2 of each power conversion unit U are connected in parallel, and the AC output terminals TA1 and TA2 of each power conversion unit U are connected in series, so that the voltage of the power system For example, the line voltage of 6.6 (kV) is achieved.
  • each phase shares a line voltage of 6.6 (kV) by eight power conversion units U, so each power conversion unit U outputs a voltage of about 800 (V).
  • the control apparatus 100 is controlling the ignition timing with respect to the semiconductor element in the some power conversion unit U of each phase.
  • the control device 100 can be housed in the power conversion device casing 100 illustrated in FIG.
  • a plurality of power conversion units are housed in the power conversion device casing 100 in FIG. 1, but the following measures are effective in order to realize an arrangement in a small space.
  • the power conversion unit U has an LLC resonant converter LLC and a single-phase inverter IN as main components as shown in FIG. Therefore, when these components are arranged, the lower substrate on which the components constituting the primary circuit of the LLC transformer 12 are mounted on the lower side and the secondary circuit on the upper side are arranged via the LLC transformer 12 and the insulating material.
  • the upper substrate on which the components to be mounted are mounted, the low voltage side and the high voltage side are separated, and the height direction of the power conversion unit U is shortened so that the structure suitable for the low-profile power converter housing 100 is obtained. Good.
  • the primary side substrate and the secondary side substrate are supported by a support member, and the LLC transformer 12 is appropriately fixed and arranged between the primary side substrate and the secondary side substrate.
  • the heat generated by the above can be discharged outside using the space formed between the upper and lower primary side substrates and the secondary side substrate.
  • a gradation configuration is realized by electrically connecting the left and right.
  • Eight units are one phase, and the U, V, and W phases are configured in the vertical direction of the power conversion device casing 100.
  • One side of the power conversion unit U group of each phase is a high-voltage three-phase output to the system, and the opposite side is a neutral point in the Y connection. The neutral point is grounded through a high resistance and becomes a low voltage potential.
  • the insulation distance can be shortened by arranging a DC input from sunlight and a breaker (MCCB) on the neutral point side.
  • MCCB breaker
  • a high-pressure air load switch (LBS) can be disposed on the high-pressure three-phase output side. It is good also as another structure without providing in the housing
  • the power conditioning system PCS having a transformer function that enables boosting and interconnection to a high voltage can be installed in the vicinity of the solar panel PL. Therefore, it is possible to reduce the wiring loss by shortening the DC wiring from the solar panel as compared with the conventional case.
  • the high-voltage output wiring is longer than the conventional one, since the high-voltage three-phase output is used, the increase in the high-voltage wiring loss can be suppressed to be sufficiently smaller than the reduction effect of the DC wiring loss.
  • the power conversion device casing 100 of the present invention shown in FIG. 1 can be installed under a solar panel, cooling against solar radiation that has been required to be considered in a conventional outdoor panel or container can be mitigated.
  • a heat exchanger is provided between the inside of the panel (inside the casing) and the outside of the panel (outside of the casing) in order to prevent the inside of the power converter casing 100 where the high-voltage terminal exists.
  • the insulation distance in the panel can be shortened by sealing with the outside air inside.
  • FIG. 7 is a diagram showing a mounting relationship between the power conversion device casing 100 and the internal three-phase power conversion unit group 1A.
  • the three-phase power conversion unit group 1A arranged inside the power conversion device casing 100 has a three-stage stacked structure in which the power conversion unit groups 1AU, 1AV, and 1AW of each phase are arranged in the height direction.
  • the three-phase power conversion unit group 1 ⁇ / b> A is arranged so as to form a space in the front, rear, left, and right with the power conversion device casing 100 that is an outer shell when housed in the power conversion device casing 100. .
  • the spaces formed at this time are a right space SPR, a left space SPL, a front space SPF, and a rear space SPB with respect to the longitudinal direction.
  • the upper space and the lower space may be appropriately formed.
  • FIG. 8 exemplifies the structure of the left-side space SPL among the cooling structures in the power conversion device casing 100 using these spaces.
  • the left space SPL, the front space SPF and the rear space SPB, and the left space SPL and the outdoor unit of the air conditioner are described separately.
  • the left-side space SPL houses the indoor unit 101I of the air conditioner, and the inside air WI that has been cooled and heated by the three-phase power conversion unit group 1A is guided from, for example, the front side space SPF to the indoor unit 101I.
  • the indoor unit 101I of the air conditioner is configured to include an expansion valve and a heat exchanger. In the heat exchanger, heat between the inside air WI and the refrigerant 121 from the outdoor unit 101O of the air conditioner. Exchange is performed, and the cooled inside air WI is delivered to, for example, the rear space SPB.
  • the flow may be a flow that is sucked from below and discharged from above.
  • the air conditioner outdoor unit 101O includes a compressor and a heat exchanger, and the refrigerant cooled by circulating the refrigerant between the indoor unit 101I and the outdoor unit 101O is used as an indoor unit. The heat of the refrigerant supplied to 101I and warmed by the indoor unit 101I is released to the outside.
  • FIG. 9 shows the flow of inside air in the power conversion device housing 100.
  • the inside air that has flowed into the rear space SPB cools the three-phase power conversion unit group 1A by flowing from the rear space SPB to the front space SPF between the three-phase power conversion unit group 1A that is the cooling target. Then, it becomes superheated air and is sent again to the indoor unit 101I of the air conditioner via the air passage in the left space.
  • the air may be appropriately forcedly circulated in order to efficiently circulate air from the rear space SPB through the three-phase power conversion unit group 1A to the front space SPF. Since the right space SPR is basically the same as the left space SPL, the disclosure is omitted.
  • the present invention proposes an internal cooling structure suitable for a low profile, in which the outdoor unit 101O of the air conditioner is arranged on at least one side in the longitudinal direction of the power conversion device casing 100.
  • a configuration is adopted in which the inside air obtained by air-cooling the three-phase power conversion unit group 1A is cooled by an end air conditioner and circulated.
  • WI wind direction may be opposite to the direction shown in FIG.
  • Example 1 the basic items of the power converter configuration of the present invention have been described as representative examples. In the second embodiment, further modifications of the configuration and specifications of the power conversion device will be described.
  • the power conversion device according to the present invention is preferably housed in the power conversion device casing 100 and configured as shown in FIGS. 3 and 4, but is further modified and used as follows. It may be.
  • FIGS. 3 and 4 is a configuration in which a single-phase inverter IN is applied to the subsequent stage of a full-bridge type LLC resonant converter LLC whose inputs are connected in parallel, and the single-phase inverter IN is used as a gradation configuration to output a high voltage. is there.
  • a Y-connection type is assumed, and the number of gradation levels is assumed to be eight, but is not limited thereto.
  • the neutral point N of the Y connection may be grounded or high resistance grounded, but is not limited thereto.
  • paragraph structure assumes 6.6kV output, you may make other voltages, such as changing the number of structures.
  • the DC voltage Vd1 provided by the full-bridge type LLC resonant converter LLC is a DC voltage of 1500 V or less, it is assumed that MOS FETs suitable for high frequency driving are applied as the semiconductor elements Q1, Q2, Q3, and Q4. .
  • the switching frequency is assumed to be several tens kHz to several hundreds kHz.
  • a SiC MOS FET suitable for high withstand voltage and high frequency switching may be applied, or other similar functions may be used.
  • the secondary side of the LLC resonant converter LLC is assumed to be a diode rectification and smoothing circuit.
  • Si-type Schottky barrier diodes or SiC Schottky barrier diodes may be applied to reduce conduction loss, or loss can be reduced by using SiC MOS FETs in synchronization. It is sufficient if it has other similar functions.
  • the LLC resonance type isolation transformer 12 has an insulating function with respect to the system voltage, and in order to achieve LLC resonance, a leakage inductance 2 and a resonance capacitor 3 that correspond to the excitation inductance 1 of the high frequency transformer are connected in series. is there.
  • the leakage inductance 2 is assumed to be integrated in the high-frequency transformer as a structure capable of adjusting the constant of the leakage magnetic flux in the high-frequency transformer, but is not limited thereto.
  • the resonant capacitor 3 is assumed to use a film capacitor or a ceramic capacitor, but may have any similar function.
  • the single-phase inverter IN following the LLC resonant converter LLC has a low switching frequency but is hard switching. Therefore, a MOS FET having a small switching loss is applied as the semiconductor elements Q5, Q6, Q7, and Q8. Is assumed.
  • the MOS FET to be used may be a SiC MOS FET suitable for high withstand voltage and high frequency switching, or may have an IGBT for high frequency driving or other similar functions.
  • FIGS. 10 to 12 various circuit configurations illustrated in FIGS. 10 to 12 can be adopted as the circuit configuration in the power conversion unit U.
  • this circuit configuration is a circuit configuration of a 2-in-1 unit assuming a case where the input current is small, such as when the input voltage is 1500V rated.
  • two primary-side insulating transformers 12 of a full-bridge type LLC resonant converter LLC whose inputs are connected in parallel are arranged in series, and the secondary side of the two insulating transformers 12 is connected in parallel two systems of rectifier circuit 13 and inverter circuit IN.
  • a single-phase inverter is applied to each subsequent stage of the rectifier circuit that receives the output of each isolation transformer, and two single-phase inverters are configured as one unit.
  • the structural members can be shared, and the unit structure can be reduced in size and weight.
  • the primary currents of the two isolation transformers are the same, variations in the power balance for the two stages can be kept small.
  • the circuit configuration in the power conversion unit U of FIG. 11 is a configuration in which two stages of single-phase inverters are three-level inverters, and the same effects as in FIG. 10 can be achieved.
  • the inverter drive frequency is 1/10 or less compared to the LLC resonant converter LLC, it is not a SiC MOS FET but a 3-level inverter MOS FET portion (Q5a, Q6a in FIG. 10) as shown in FIG. , Q7a, Q8a, Q5b, Q6b, Q7b, Q8b) can be IGBTs (H5a, H6a, H7a, H8a, H5b, H6b, H7b, H8b in FIG. 12).
  • a new three-level inverter configuration may be used if the semiconductor element can withstand twice the withstand voltage.
  • a connection example of a plurality of power conversion units U in the power conversion device housing 100 when the third embodiment is employed will be described with reference to FIG.
  • the gradation configuration is realized by arranging the power conversion units of each phase in the horizontal direction of the panel and electrically connecting the single-phase inverter side on the left and right.
  • the power conversion unit 4 series is one phase, and the U, V, and W phases are configured in the height direction of the power conversion device housing 100. In this configuration, the number of power lines connected between unit cells and the number of connections outside the unit such as signal lines can be reduced.
  • FIG. 14 a circuit configuration example in the power conversion unit U is shown in FIG.
  • the circuit configuration of FIG. 14 is a unit circuit configuration that assumes a case where the input current is small, such as when the input voltage is 1500 V rated.
  • the rectifier circuit 13 is duplicated, but the inverter IN is common.
  • the transformers 12 of the full-bridge type LLC resonant converter LLC whose inputs are connected in parallel, are arranged in series on the primary side, the rectifier circuits 13 subsequent to the LLC transformers 12 are arranged in parallel, and the inverter IN is shared.
  • the power output for two transformers is made possible with one unit. According to this configuration, it is possible to increase the capacity, and it is possible to reduce the size and weight per capacity as an effect of increasing the capacity. In addition, since the primary currents of the two transformers are the same, variations in the power balance for the two stages can be kept small.
  • the single-phase inverter IN at the latter stage of the LLC resonant converter LLC is different from the LLC resonant converter LLC and has a low switching frequency but is hard switching. Therefore, it is assumed that a MOS FET having a small switching loss is applied.
  • a MOS FET having a small switching loss is applied as the MOS FET to be used.
  • a SiC MOS FET suitable for high withstand voltage and high frequency switching may be applied, or any IGBT having a high frequency driving IGBT or other similar function may be applied.
  • the panel structure of the power conversion device housing 100 is assumed to have an 8-unit configuration similar to that of the first embodiment, but is not limited thereto. Although many examples have been described above, the contents described in the examples may be used in combination depending on the application.

Abstract

The purpose of the present invention is to provide a power conversion device including a power conversion device case suitable for placement within a solar power generation site. Furthermore, the present invention aims to provide a structure for the power conversion device case that can be more compact and is designed for cooling because same is used in natural environmental conditions. A power conversion device having a power conversion unit comprising a single-phase inverter on a secondary side of a high-frequency resonant converter having DC input, said power conversion device characterized by: the output for the single-phase inverter for a plurality of power conversion units being connected in series and constituting a power conversion unit group; each phase for a three-phase alternating current being formed by using three sets of the power conversion unit groups housed inside the power conversion device case; the plurality of power conversion units constituting the power conversion unit group being arranged along the longitudinal direction of the power conversion device case; the three sets of power conversion unit groups being arranged on an upper level, middle level, and lower level, respectively, in the height direction of the power conversion device case; one end side of the power conversion device case in the longitudinal direction being an output terminal for the three sets of power conversion unit groups; the terminals of the three sets of power conversion unit groups having a common connection on the other end side of the power conversion device case in the longitudinal direction; an indoor unit for an air conditioner being arranged on at least either the right or left, in the longitudinal direction, inside the power conversion device case; an outdoor unit for an air conditioner being arranged on at least either the right or left, in the longitudinal direction, outside the power conversion device case; and the interior of the power conversion device case being cooled by cool air from the indoor unit of the air conditioner.

Description

電力変換装置Power converter
　本発明は、電力変換装置に関するものである。 The present invention relates to a power conversion device.
　太陽光発電や風力発電といった自然エネルギー利用の発電設備による電力を電力系統に連系するためには、電力系統の電圧及び周波数に変換する電力変換装置が使用される。電力変換装置は、直流電力と交流電力の間で電力変換を行う複数の電力変換装置により構成されており、電力変換装置は絶縁トランスおよびＤＣ／ＤＣコンバータやインバータといった電力変換器を備えて構成されている。 In order to connect the power from the power generation facility using natural energy such as solar power generation or wind power generation to the power system, a power converter that converts the voltage and frequency of the power system is used. The power conversion device includes a plurality of power conversion devices that perform power conversion between DC power and AC power. The power conversion device includes an insulating transformer and a power converter such as a DC / DC converter or an inverter. ing.
　一般に、例えば、大規模向け太陽光ＰＣＳの場合は太陽光発電設備からの直流が入力となり、４００Ｖ程度の三相電力を出力する。太陽光ＰＣＳから高圧系統（６．６ｋＶ，２２ｋＶ等）への昇圧出力には高圧絶縁トランスを使用しており、系統の周波数と同じ数十Ｈｚの低周波で駆動せざるを得ないため大型化する。また、大容量向けＰＣＳの屋外設置を実現するためにコンテナ内への太陽光ＰＣＳ格納や太陽光ＰＣＳ自体を屋外盤仕様にする必要があり、設備が大型化する。 Generally, for example, in the case of a large-scale solar PCS, direct current from a solar power generation facility is input and three-phase power of about 400 V is output. The high voltage insulation transformer is used for the step-up output from the solar PCS to the high voltage system (6.6 kV, 22 kV, etc.), and it must be driven at the same low frequency of several tens of Hz as the system frequency. To do. In addition, in order to realize the outdoor installation of the PCS for large capacity, it is necessary to store the solar PCS in the container or to make the solar PCS itself an outdoor panel specification, which increases the size of the equipment.
　また、直流配線や低圧交流配線の長さを短縮することで更なる低損失化が実現できるが、前述のように屋外仕様の太陽光ＰＣＳや連系トランスの体積・重量が大きく、太陽光パネル直近への配置は太陽光パネルへの日陰の影響から難しいため、太陽光パネルから離して配置することが一般的であった。 Furthermore, the loss can be further reduced by shortening the length of the DC wiring and low-voltage AC wiring. However, as described above, the volume and weight of the outdoor-use solar PCS and interconnection transformer are large, and the solar panel Since the most recent arrangement is difficult due to the influence of the shade on the solar panel, it is generally arranged away from the solar panel.
　なお電力変換装置を盤構成するに際し、変圧器盤と関連付けて配置した事例として特許文献１が知られている。 Note that Patent Document 1 is known as an example of arranging a power conversion device in association with a transformer panel when configuring the panel.
　特許文献１には、「複数個の２次巻線を有する入力変圧器１と、この入力変圧器１を収納する変圧器盤１０と、前記２次巻線に１対１で接続され、所望の周波数の単相交流電圧を出力する単位インバータ２を複数台直列接続した各相をＹ接続して構成した３相インバータと、前記３相インバータを構成する単位インバータ２を収納する変換器盤２０とを備え、前記変換器盤２０は、絶縁物からなる複数本の支柱２２と、この複数本の支柱２２の隣り合う支柱間を横方向に締結する複数個の金属製の棚板２３を有し、前記棚板２３上に前記単位インバータ２を夫々載置固定するように構成する。」ことが記載されている。 In Patent Document 1, “an input transformer 1 having a plurality of secondary windings, a transformer panel 10 that houses the input transformers 1, and a one-to-one connection to the secondary windings, as desired. A three-phase inverter configured by Y-connecting a plurality of unit inverters 2 that serially connect a plurality of unit inverters 2 that output a single-phase AC voltage having a frequency of 5 and a converter panel 20 that houses the unit inverters 2 that constitute the three-phase inverter. The converter panel 20 includes a plurality of support posts 22 made of an insulating material and a plurality of metal shelf plates 23 for fastening the support posts 22 adjacent to each other in the lateral direction. The unit inverter 2 is mounted and fixed on the shelf plate 23, respectively. "
特開２００４－３５７４３６号公報JP 2004-357436 A
　しかしながら、変換器盤２０は、入出力共に高圧であるので、中性点をとる場合絶縁距離を取る必要があり、電力変換装置の小型化を実現するのは困難である。 However, since the converter panel 20 has a high voltage for both input and output, it is necessary to take an insulation distance when taking a neutral point, and it is difficult to reduce the size of the power converter.
　以上のことから本発明においては、小型化を実現可能な電力変換装置を提供することを目的とする。 From the above, it is an object of the present invention to provide a power conversion device that can be miniaturized.
　以上のことから本発明においては、入力が直流である高周波共振型コンバータの２次側に単相インバータを備えた電力変換ユニットについて、複数の電力変換ユニットの単相インバータの出力を直列接続して電力変換ユニット群を構成し、電力変換装置筐体内に収納した３組の電力変換ユニット群により交流３相の各相を形成し、電力変換ユニット群を構成する複数の電力変換ユニットは、電力変換装置筐体の長手方向に沿って配置され、かつ３組の電力変換ユニット群は、電力変換装置筐体の高さ方向の上段、中段、下段にそれぞれ配置され、電力変換装置筐体の長手方向の一方端側が、３組の電力変換ユニット群の出力端子とされ、電力変換装置筐体の長手方向の他方端側で３組の電力変換ユニット群の端子が共通接続されているとともに、電力変換装置筐体内の長手方向左右の少なくとも一方にエアコンの室内機を配置し、電力変換装置筐体外の長手方向左右の少なくとも前記の一方にエアコンの室外機を配置し、エアコンの室内機からの冷風により電力変換装置筐体内を冷却することを特徴とする。 From the above, in the present invention, for a power conversion unit having a single-phase inverter on the secondary side of a high-frequency resonant converter whose input is DC, the outputs of the single-phase inverters of a plurality of power conversion units are connected in series. A plurality of power conversion units constituting the power conversion unit group are formed by forming each phase of AC three-phase by three sets of power conversion unit groups housed in a power conversion device casing, The three power conversion unit groups arranged along the longitudinal direction of the device casing are arranged at the upper, middle, and lower levels in the height direction of the power conversion device casing, respectively. One end side of the power conversion unit group is an output terminal of the three sets of power conversion unit groups, and the terminals of the three sets of power conversion unit groups are commonly connected to the other end side in the longitudinal direction of the power conversion device casing. In addition, an air conditioner indoor unit is disposed on at least one of the left and right sides in the longitudinal direction inside the power conversion device housing, and an air conditioner outdoor unit is disposed on at least one of the left and right sides in the longitudinal direction outside the power conversion device housing. The inside of a power converter housing is cooled by cold air from the air.
　本発明によれば、小型化を実現可能な電力変換装置を提供することができる。 According to the present invention, it is possible to provide a power converter that can be miniaturized.
本発明に係る電力変換装置の筐体と配置位置関係の一例を示す図。The figure which shows an example of the housing | casing and arrangement | positioning positional relationship of the power converter device which concerns on this invention. 本発明の電力変換装置が適用される太陽光発電サイトの一例を示す図。The figure which shows an example of the photovoltaic power generation site where the power converter device of this invention is applied. 電力変換装置筐体１００内における複数の電力変換ユニットＵの接続例を示す図。The figure which shows the example of a connection of the several power conversion unit U in the power converter device housing | casing 100. FIG. 電力変換装置筐体１００内における複数の電力変換ユニットＵの他の接続例を示す図。The figure which shows the other example of a connection of the several power conversion unit U in the power converter device housing | casing 100. FIG. 図３あるいは図４のように構成された電力変換装置筐体１００内の接続により実現される電力変換装置の電気回路の構成を示す図。The figure which shows the structure of the electric circuit of the power converter device implement | achieved by the connection in the power converter device housing | casing 100 comprised as FIG. 3 or FIG. 本発明に係る電力変換装置の筐体と配置位置関係の他の一例を示す図。The figure which shows another example of the housing | casing and arrangement | positioning positional relationship of the power converter device which concerns on this invention. 電力変換装置筐体１００と内部の三相電力変換ユニット群１Ａの実装関係を示す図。The figure which shows the mounting relationship of the power converter device housing | casing 100 and the internal three-phase power conversion unit group 1A. 電力変換装置筐体１００における冷却構造例を示す図。The figure which shows the example of a cooling structure in the power converter device housing | casing 100. FIG. 電力変換装置筐体１００における内気の流れを示す図。The figure which shows the flow of the inside air in the power converter device housing | casing 100. FIG. 電力変換ユニットＵ内の回路構成について、入力電流が小さい場合を想定した２ｉｎ１ユニットの回路構成を示す図。The figure which shows the circuit structure of 2 in 1 unit supposing the case where input current is small about the circuit structure in the power conversion unit U. 電力変換ユニットＵ内の回路構成について、単相インバータ２段分を３レベルインバータとした構成を示す図。The figure which shows the structure which made the single phase inverter 2 steps | paragraphs the 3-level inverter about the circuit structure in the power conversion unit U. FIG. 電力変換ユニットＵ内の回路構成について、ＩＧＢＴで構成した例を示す図。The figure which shows the example comprised with IGBT about the circuit structure in the power conversion unit U. FIG. 実施例３を採用する場合の電力変換装置筐体１００内における複数の電力変換ユニットＵの接続例を示す図。The figure which shows the example of a connection of the several power conversion unit U in the power converter device housing | casing 100 in the case of employ | adopting Example 3. FIG. 電力変換ユニットＵ内の回路構成について、トランスと整流回路を並列接続した構成を示す図。The figure which shows the structure which connected the transformer and the rectifier circuit in parallel about the circuit structure in the power conversion unit U.
　以下、本発明の電力変換装置について、図を用いて説明する。 Hereinafter, the power converter of the present invention will be described with reference to the drawings.
　　　　　　　
　図１は、本発明に係る電力変換装置の筐体と配置位置関係を示した図である。本発明の電力変換装置筐体１００は、太陽光パネルＰＬと、太陽光パネルＰＬを搭載、支持するための架台ＢＢの間に形成される空間を利用して設置される。このため直射日光を受けず、かつ風通しのよい位置に配置される。箱型の筐体は長手方向に延伸する箱型の形状とされている。因みに筐体は、長手方向の長さは例えば２．５（ｍ）、短手方向の長さは例えば０．９（ｍ）、高さが例えば０．７（ｍ）といった大きさであり、太陽光パネルＰＬと架台ＢＢにより形成される日陰空間に配置可能である。電力変換器筺体１００と室外機１０１Ａおよび１０１Ｂはパイプ等を介して接続されている。
FIG. 1 is a diagram showing a housing and arrangement positional relationship of a power conversion device according to the present invention. The power conversion device casing 100 of the present invention is installed using a space formed between a solar panel PL and a base BB for mounting and supporting the solar panel PL. For this reason, it arrange | positions in the position where it does not receive a direct sunlight, and has good ventilation. The box-shaped housing has a box shape extending in the longitudinal direction. Incidentally, the length of the casing is 2.5 (m), the length in the short direction is 0.9 (m), the height is 0.7 (m), for example, It can be placed in a shaded space formed by the solar panel PL and the gantry BB. The power converter housing 100 and the outdoor units 101A and 101B are connected via pipes and the like.
　また電力変換装置筐体１００は、その長手方向の少なくとも一方端にエアコンの室外機１０１を備えている。また図６に示すように、電力変換装置筐体１００は、その長手方向の両方の端部にエアコンの室外機１０１Ａ、１０１Ｂを備えている。 Moreover, the power converter housing 100 is provided with an air conditioner outdoor unit 101 at least at one end in the longitudinal direction thereof. As shown in FIG. 6, the power conversion device housing 100 includes air conditioner outdoor units 101 </ b> A and 101 </ b> B at both ends in the longitudinal direction.
　図２は、本発明の電力変換装置が適用される太陽光発電サイトの一例を示している。 FIG. 2 shows an example of a photovoltaic power generation site to which the power conversion device of the present invention is applied.
　図２の太陽光発電サイトは、架台Ｂ上に搭載、支持された複数の太陽光パネルＰＬにより形成されており、各太陽光パネルＰＬの直流出力は端子ＴＤ１、ＴＤ２間に得られている。またこの太陽光発電サイトには、架台ＢＢの下部空間を利用して太陽光パネルＰＬの直流出力を電力系統の三相交流に変換する図１の電力変換装置筐体１００が設置されている。後述するが、箱型形状の電力変換装置筐体１００は複数の電力変換ユニットＵ（図示ではＵ１、Ｕ２）を収納しており、各電力変換ユニットＵは、各太陽光パネルＰＬの直流出力端子ＴＬ１、ＴＬ２に接続される直流入力端子ＴＤ１、ＴＤ２と、交流出力端子ＴＡ１、ＴＡ２を備えている。なお、太陽光パネルＰＬ１の直流出力端子ＴＬ１、ＴＬ２は、例えば電力変換ユニットＵ１の直流入力端子ＴＤ１、ＴＤ２と対応付けて接続され、太陽光パネルＰＬ２の直流出力端子ＴＬ１、ＴＬ２は例えば電力変換ユニットＵ２の直流入力端子ＴＤ１、ＴＤ２と対応付けて接続される。あるいは複数の太陽光パネルＰＬの直流出力端子ＴＬ１、ＴＬ２がそれぞれ共通接続されて電力変換ユニットＵの直流入力端子ＴＤ１、ＴＤ２と接続される。 The photovoltaic power generation site in FIG. 2 is formed by a plurality of solar panels PL mounted and supported on the gantry B, and the DC output of each solar panel PL is obtained between the terminals TD1 and TD2. In addition, the photovoltaic power generation site is provided with the power conversion device casing 100 of FIG. 1 that converts the direct current output of the solar panel PL into the three-phase alternating current of the power system using the lower space of the gantry BB. As will be described later, the box-shaped power conversion device housing 100 houses a plurality of power conversion units U (U1 and U2 in the drawing), and each power conversion unit U is a DC output terminal of each solar panel PL. DC input terminals TD1, TD2 connected to TL1, TL2 and AC output terminals TA1, TA2 are provided. The direct current output terminals TL1, TL2 of the solar panel PL1 are connected in association with, for example, the direct current input terminals TD1, TD2 of the power conversion unit U1, and the direct current output terminals TL1, TL2 of the solar panel PL2 are, for example, the power conversion unit. They are connected in association with the DC input terminals TD1 and TD2 of U2. Alternatively, the DC output terminals TL1 and TL2 of the plurality of solar panels PL are respectively connected in common and connected to the DC input terminals TD1 and TD2 of the power conversion unit U.
　図３は、電力変換装置筐体１００内における複数の電力変換ユニットＵの接続例を示している。 FIG. 3 shows a connection example of a plurality of power conversion units U in the power conversion device casing 100.
　電力変換装置筐体１００についての対外部接続は、複数の太陽光パネルＰＬの直流出力端子ＴＬ１、ＴＬ２に接続された直流入力端子ＴＤ１、ＴＤ２と、高圧三相の電力系統の各相に接続される三相交流出力端子ＴＵ、ＴＶ、ＴＷで行われる。直流入力端子ＴＤ１、ＴＤ２には、低圧直流入力が印加され、三相交流出力端子ＴＵ、ＴＶ、ＴＷからは高圧三相出力が与えられる。 The external connection of the power conversion device housing 100 is connected to the DC input terminals TD1 and TD2 connected to the DC output terminals TL1 and TL2 of the plurality of solar panels PL and each phase of the high-voltage three-phase power system. The three-phase AC output terminals TU, TV and TW are used. A low voltage DC input is applied to the DC input terminals TD1, TD2, and a high voltage three phase output is applied from the three-phase AC output terminals TU, TV, TW.
　また三相交流出力は、中性点Ｎにおいてアース接続されるＹ結線とされ、箱型形状の電力変換装置筐体１００の長手方向の一方端側に三相交流出力端子ＴＵ、ＴＶ、ＴＷが集約配置され、立方体状の電力変換装置筐体１００の長手方向の他方端側に中性点Ｎが配置されている。なお直流入力端子ＴＤ１、ＴＤ２の配置位置について、特に限定をしないが、図示の例では箱型形状の電力変換装置筐体１００の長手方向の他方端の中性点Ｎ側に配置した例を示している。また図示の例では、直流入力端子ＴＤ１、ＴＤ２に直流遮断器ＭＣＣＢを設置した例を示している。また図示の例では、複数の太陽光パネルＰＬの直流出力端子ＴＬ１、ＴＬ２がそれぞれ共通接続されて、電力変換ユニットＵの共通に設けられた直流入力端子ＴＤ１、ＴＤ２と接続されている。 The three-phase AC output is a Y-connection that is grounded at a neutral point N, and three-phase AC output terminals TU, TV, and TW are provided at one end in the longitudinal direction of the box-shaped power converter housing 100. A neutral point N is arranged on the other end side in the longitudinal direction of the cubic power conversion device casing 100 in a centralized arrangement. The arrangement positions of the DC input terminals TD1 and TD2 are not particularly limited, but the illustrated example shows an example of arrangement on the neutral point N side of the other end in the longitudinal direction of the box-shaped power converter housing 100. ing. In the illustrated example, a DC circuit breaker MCCB is installed at the DC input terminals TD1 and TD2. In the illustrated example, the DC output terminals TL1 and TL2 of the plurality of solar panels PL are connected in common and connected to the DC input terminals TD1 and TD2 provided in common in the power conversion unit U.
　電力変換装置筐体１００内では、三相交流出力端子ＴＵ、ＴＶ、ＴＷと中性点Ｎの間の各相をそれぞれ複数の電力変換ユニットＵで構成している。図の例では各相は８台の電力変換ユニットＵで構成されており、Ｗ相で例示すると、中性点Ｎ側から順次ＵWI、ＵＷ２、ＵＷ３、ＵＷ４、ＵＷ５、ＵＷ６、ＵＷ７、ＵＷ８を配置している。この配置は他の相も同じである。 In the power converter housing 100, each phase between the three-phase AC output terminals TU, TV, TW and the neutral point N is configured by a plurality of power conversion units U. In the example shown in the figure, each phase is composed of eight power conversion units U. In the case of W phase, UWI, UW2, UW3, UW4, UW5, UW6, UW7, UW8 are arranged sequentially from the neutral point N side. is doing. This arrangement is the same for the other phases.
　また電力変換装置筐体１００内では、各相が８台の電力変換ユニットＵで構成された電力変換ユニット群が、電力変換装置筐体１００の高さ方向に多段配置されている。図示の例では、Ｕ、Ｖ、Ｗの各相の電力変換ユニット群について、Ｕ相を下段、Ｖ相を中間段、Ｗ相を上段に配置した３段重ね構造を採用している。 Further, in the power conversion device casing 100, power conversion unit groups each of which is composed of eight power conversion units U are arranged in multiple stages in the height direction of the power conversion device casing 100. In the illustrated example, the power conversion unit group of each phase of U, V, and W employs a three-stage stacked structure in which the U phase is disposed in the lower stage, the V phase is disposed in the intermediate stage, and the W phase is disposed in the upper stage.
　図３では、電力変換ユニットＵの具体的な回路構成としてＵＷ５の構成例を例示している。他の電力変換ユニットＵも同じ構成であるので、ここではＵＷ５の構成のみ説明する。電力変換ユニットＵＷ５は、ＬＬＣ共振コンバータＬＬＣと、インバータＩＮにより構成されている。 FIG. 3 illustrates a configuration example of the UW 5 as a specific circuit configuration of the power conversion unit U. Since the other power conversion units U have the same configuration, only the configuration of UW5 will be described here. The power conversion unit UW5 includes an LLC resonant converter LLC and an inverter IN.
　このうちＬＬＣ共振コンバータＬＬＣは、入力側コンデンサＣｉと、半導体素子Ｑ１、Ｑ２、Ｑ３、Ｑ４で構成されたフルブリッジ構成のインバータ回路１１と、励磁インダクタンス１とリーケージインダクタンス２と共振コンデンサ３が直列接続された絶縁トランス１２と、ダイオードＤ１、Ｄ２、Ｄ３、Ｄ４で構成されたフルブリッジ構成の整流回路１３とで構成され、太陽光パネルＰＬからの直流入力を高周波数の交流に変換した後に再度直流に変換している。 Among these, the LLC resonant converter LLC includes an input side capacitor Ci, a full-bridge inverter circuit 11 composed of semiconductor elements Q1, Q2, Q3, and Q4, an exciting inductance 1, a leakage inductance 2, and a resonant capacitor 3 connected in series. The isolated transformer 12 and the full-bridge rectifier circuit 13 composed of the diodes D1, D2, D3, and D4. After the direct current input from the solar panel PL is converted into a high frequency alternating current, the direct current is again generated. Has been converted.
　インバータＩＮは、コンデンサＣと半導体素子Ｑ５、Ｑ６、Ｑ７、Ｑ８で構成されたフルブリッジ構成のインバータ回路１４とで構成されている。これによりＬＬＣ共振コンバータＬＬＣが与える直流電圧Ｖｄ１を電源として交流電圧を発生する。このように、電力変換ユニットＵＷ５は、その入力が太陽光パネルＰＬからの直流に接続され、その出力が高圧系統側に接続される構成である。 The inverter IN is composed of a capacitor C and an inverter circuit 14 having a full bridge configuration composed of semiconductor elements Q5, Q6, Q7, and Q8. Thus, an AC voltage is generated using the DC voltage Vd1 provided by the LLC resonant converter LLC as a power source. Thus, the power conversion unit UW5 has a configuration in which the input is connected to the direct current from the solar panel PL and the output is connected to the high-voltage system side.
　また電力変換ユニットＵＷ５は、その交流出力端子ＴＡ１、ＴＡ２のうち高圧側の端子ＴＡ１を隣接する高圧側の電力変換ユニットＵＷ６の交流出力端子ＴＡ２に接続し、低圧側の端子ＴＡ２を隣接する低圧側の電力変換ユニットＵＷ４の交流出力端子ＴＡ１に接続する。かくして、各相を形成する複数の電力変換ユニットＵは、その入力側は並列接続され、出力側は直列接続されることで電力系統の高電圧を分担負担している。 The power conversion unit UW5 connects the high voltage side terminal TA1 of the AC output terminals TA1 and TA2 to the AC output terminal TA2 of the adjacent high voltage side power conversion unit UW6 and the low voltage side terminal TA2 adjacent to the low voltage side. To the AC output terminal TA1 of the power conversion unit UW4. Thus, the plurality of power conversion units U forming each phase share the high voltage of the power system by connecting the input side in parallel and connecting the output side in series.
　電力変換装置筐体１００内には、図３に例示したような構成の電力変換ユニットＵが複数、相毎に３段重ね構造を採用して配置されている。図４もまた、電力変換装置筐体１００内における電力変換ユニットＵの配置例を示しているが、電力変換装置の出力側の各相に交流遮断器を設けている点でのみ図３と相違している。 In the power conversion device casing 100, a plurality of power conversion units U configured as illustrated in FIG. 3 are arranged by adopting a three-stage stacked structure for each phase. FIG. 4 also shows an arrangement example of the power conversion unit U in the power conversion device casing 100, but is different from FIG. 3 only in that an AC circuit breaker is provided in each phase on the output side of the power conversion device. is doing.
　図５は、図３あるいは図４のように構成された電力変換装置筐体１００内の複数ユニットの接続により実現される電力変換装置の電気回路の構成を示している。この構成によれば、各電力変換ユニットＵの直流入力端子ＴＤ１、ＴＤ２は並列に接続され、各電力変換ユニットＵの交流出力端子ＴＡ１、ＴＡ２は直列に接続されることで、電力系統の電圧として例えば線間電圧の６．６（ｋＶ）を達成している。この例では、各相は８台の電力変換ユニットＵにより線間電圧の６．６（ｋＶ）を分担しているので、各電力変換ユニットＵは８００（Ｖ）程度の電圧を出力していることになる。なお、制御装置１００は、各相の複数の電力変換ユニットＵ内の半導体素子に対する点弧タイミングを制御している。図２に図示した電力変換装置筐体１００内には、複数の電力変換ユニットＵとともに、制御装置１００も収納することができる。 FIG. 5 shows a configuration of an electric circuit of the power conversion device realized by connecting a plurality of units in the power conversion device casing 100 configured as shown in FIG. 3 or FIG. According to this configuration, the DC input terminals TD1 and TD2 of each power conversion unit U are connected in parallel, and the AC output terminals TA1 and TA2 of each power conversion unit U are connected in series, so that the voltage of the power system For example, the line voltage of 6.6 (kV) is achieved. In this example, each phase shares a line voltage of 6.6 (kV) by eight power conversion units U, so each power conversion unit U outputs a voltage of about 800 (V). It will be. In addition, the control apparatus 100 is controlling the ignition timing with respect to the semiconductor element in the some power conversion unit U of each phase. In addition to the plurality of power conversion units U, the control device 100 can be housed in the power conversion device casing 100 illustrated in FIG.
　図１の電力変換装置筐体１００内には、複数の電力変換ユニットを収納するが、小スペースでの配置を実現するために以下の対策が有効である。 1, a plurality of power conversion units are housed in the power conversion device casing 100 in FIG. 1, but the following measures are effective in order to realize an arrangement in a small space.
　まず電力変換ユニットＵ自体を小型化することに関して、電力変換ユニットＵは図３などに示したようにＬＬＣ共振コンバータＬＬＣと単相インバータＩＮを主要な部品としている。このことからこれらの部品を配置するに際して、ＬＬＣトランス１２と絶縁材を介し、下側にＬＬＣトランス１２の１次側回路を構成する部品を搭載した下側基板、上側に２次側回路を構成する部品を搭載した上側基板とすることで低圧側と高圧側を分離し、電力変換ユニットＵの高さ方向を短縮して低背型の電力変換装置筐体１００に適した構造とするのがよい。この構成では、１次側基板と２次側基板の間は支持部材により支持し、ＬＬＣトランス１２は１次側基板と２次側基板の間に適宜固定御配置されることで、これらの部品により発生した熱は、上下の１次側基板と２次側基板の間に形成された空間を利用して外部排出することが可能である。 First, regarding the miniaturization of the power conversion unit U itself, the power conversion unit U has an LLC resonant converter LLC and a single-phase inverter IN as main components as shown in FIG. Therefore, when these components are arranged, the lower substrate on which the components constituting the primary circuit of the LLC transformer 12 are mounted on the lower side and the secondary circuit on the upper side are arranged via the LLC transformer 12 and the insulating material. By using the upper substrate on which the components to be mounted are mounted, the low voltage side and the high voltage side are separated, and the height direction of the power conversion unit U is shortened so that the structure suitable for the low-profile power converter housing 100 is obtained. Good. In this configuration, the primary side substrate and the secondary side substrate are supported by a support member, and the LLC transformer 12 is appropriately fixed and arranged between the primary side substrate and the secondary side substrate. The heat generated by the above can be discharged outside using the space formed between the upper and lower primary side substrates and the secondary side substrate.
　また、図３において、各相を形成する複数の電力変換ユニットＵについて電力変換装置筐体１００の水平方向に配置し、かつ相毎に３段に高さ方向に配置し、単相インバータ側を左右で電気的に接続することで階調構成を実現する。８ユニットを１相とし、電力変換装置筐体１００の縦方向にＵ、Ｖ、Ｗ相を構成する。各相の電力変換ユニットＵ群の片側が系統への高圧三相出力、逆側がＹ接続における中性点となる。中性点は高抵抗を介して接地し、低圧の電位となる。中性点側に太陽光からの直流入力とブレーカ（ＭＣＣＢ）を配置することで絶縁距離の短縮が可能となる。図４に示すように高圧三相出力側には高圧気中負荷開閉器（ＬＢＳ）を配置することが可能であるが、図３のように高圧気中負荷開閉器（ＬＢＳ）を電力変換装置筐体１００内に備えず別構造としても良い。 Moreover, in FIG. 3, about the several power conversion unit U which forms each phase, arrange | position in the horizontal direction of the power converter device housing | casing 100, and arrange | position to the height direction in three steps | paragraphs for every phase, A gradation configuration is realized by electrically connecting the left and right. Eight units are one phase, and the U, V, and W phases are configured in the vertical direction of the power conversion device casing 100. One side of the power conversion unit U group of each phase is a high-voltage three-phase output to the system, and the opposite side is a neutral point in the Y connection. The neutral point is grounded through a high resistance and becomes a low voltage potential. The insulation distance can be shortened by arranging a DC input from sunlight and a breaker (MCCB) on the neutral point side. As shown in FIG. 4, a high-pressure air load switch (LBS) can be disposed on the high-pressure three-phase output side. It is good also as another structure without providing in the housing | casing 100. FIG.
　以上の構成を採用することにより、図１に示すように太陽光パネルＰＬの下に設置可能な低背型の盤構造を実現することができる。図１の構成を採用する本発明に係るパワーコンディショニングシステムＰＣＳによれば、高圧への昇圧と連系を可能とするトランスの機能を備えたパワーコンディショニングシステムＰＣＳが太陽光パネルＰＬ近傍に設置可能となるため、従来と比較して太陽光パネルからの直流配線の短縮による配線の損失低減が実現できる。高圧出力配線は従来よりも長くなるが、高圧三相出力であるため高圧配線損失の上昇は直流配線損失の低減効果と比較して十分に小さく抑えることができる。 By adopting the above configuration, it is possible to realize a low-profile panel structure that can be installed under the solar panel PL as shown in FIG. According to the power conditioning system PCS according to the present invention adopting the configuration of FIG. 1, the power conditioning system PCS having a transformer function that enables boosting and interconnection to a high voltage can be installed in the vicinity of the solar panel PL. Therefore, it is possible to reduce the wiring loss by shortening the DC wiring from the solar panel as compared with the conventional case. Although the high-voltage output wiring is longer than the conventional one, since the high-voltage three-phase output is used, the increase in the high-voltage wiring loss can be suppressed to be sufficiently smaller than the reduction effect of the DC wiring loss.
　図１に示す本発明の電力変換装置筐体１００は、太陽光パネルの下に設置可能であるため、従来の屋外盤やコンテナで考慮が必要であった日射に対する冷却は緩和可能となる。 Since the power conversion device casing 100 of the present invention shown in FIG. 1 can be installed under a solar panel, cooling against solar radiation that has been required to be considered in a conventional outdoor panel or container can be mitigated.
　本発明では屋外設置であることからさらに、高圧端子が存在する電力変換装置筐体１００内の汚損を防ぐために盤内（筐体内）と盤外（筐体外）との熱交換器を設け、盤内の外気との密閉を実現することで盤内の絶縁距離の短縮を実現する。 In the present invention, since it is installed outdoors, a heat exchanger is provided between the inside of the panel (inside the casing) and the outside of the panel (outside of the casing) in order to prevent the inside of the power converter casing 100 where the high-voltage terminal exists. The insulation distance in the panel can be shortened by sealing with the outside air inside.
　図７は、電力変換装置筐体１００と内部の三相電力変換ユニット群１Ａの実装関係を示した図である。電力変換装置筐体１００の内部に配置される三相電力変換ユニット群１Ａは、各相の電力変換ユニット群１ＡＵ、１ＡＶ、１ＡＷを高さ方向に配置した３段重ね構造のものである。三相電力変換ユニット群１Ａは、電力変換装置筐体１００内に収納された時に、外殻である電力変換装置筐体１００との間で、前後左右に空間を形成するように配置されている。この時に形成される空間は長手方向に対して右側空間ＳＰＲ、左側空間ＳＰＬ、前側空間ＳＰＦ、後側空間ＳＰＢである。なお上側空間、下側空間を形成することは適宜行われてよい。 FIG. 7 is a diagram showing a mounting relationship between the power conversion device casing 100 and the internal three-phase power conversion unit group 1A. The three-phase power conversion unit group 1A arranged inside the power conversion device casing 100 has a three-stage stacked structure in which the power conversion unit groups 1AU, 1AV, and 1AW of each phase are arranged in the height direction. The three-phase power conversion unit group 1 </ b> A is arranged so as to form a space in the front, rear, left, and right with the power conversion device casing 100 that is an outer shell when housed in the power conversion device casing 100. . The spaces formed at this time are a right space SPR, a left space SPL, a front space SPF, and a rear space SPB with respect to the longitudinal direction. The upper space and the lower space may be appropriately formed.
　図８は、これらの空間を利用した電力変換装置筐体１００における冷却構造のうち、左側空間ＳＰＬの構造例を中心にして例示している。また説明の都合上、左側空間ＳＰＬと前側空間ＳＰＦおよび後側空間ＳＰＢの間、および左側空間ＳＰＬとエアコンの室外機の間を離して記述している。 FIG. 8 exemplifies the structure of the left-side space SPL among the cooling structures in the power conversion device casing 100 using these spaces. For convenience of explanation, the left space SPL, the front space SPF and the rear space SPB, and the left space SPL and the outdoor unit of the air conditioner are described separately.
　図８において、左側空間ＳＰＬにはエアコンの室内機１０１Ｉを収納しており、三相電力変換ユニット群１Ａを冷却して加熱された内気ＷＩが例えば前側空間ＳＰＦから室内機１０１Ｉに導かれている。よく知られているように、エアコンの室内機１０１Ｉは、膨張弁や熱交換器を含んで構成されており、熱交換器において内気ＷＩとエアコンの室外機１０１Ｏからの冷媒１２１の間での熱交換が行われて、冷却された内気ＷＩが例えば後側空間ＳＰＢに送出される。なお、エアコンの室内機１０１Ｉの吸い込み口と吹き出し口の位置関係によっては、下から吸い込んで、上から吐き出す流れのものであってもよい。 In FIG. 8, the left-side space SPL houses the indoor unit 101I of the air conditioner, and the inside air WI that has been cooled and heated by the three-phase power conversion unit group 1A is guided from, for example, the front side space SPF to the indoor unit 101I. . As is well known, the indoor unit 101I of the air conditioner is configured to include an expansion valve and a heat exchanger. In the heat exchanger, heat between the inside air WI and the refrigerant 121 from the outdoor unit 101O of the air conditioner. Exchange is performed, and the cooled inside air WI is delivered to, for example, the rear space SPB. Depending on the positional relationship between the suction port and the blowout port of the indoor unit 101I of the air conditioner, the flow may be a flow that is sucked from below and discharged from above.
　またよく知られているように、エアコン室外機１０１Ｏは圧縮機や熱交換器を含んで構成されており、室内機１０１Ｉと室外機１０１Ｏの間に冷媒を循環させることで冷えた冷媒を室内機１０１Ｉに供給し、室内機１０１Ｉで暖められた冷媒の熱を外部放出している。 As well known, the air conditioner outdoor unit 101O includes a compressor and a heat exchanger, and the refrigerant cooled by circulating the refrigerant between the indoor unit 101I and the outdoor unit 101O is used as an indoor unit. The heat of the refrigerant supplied to 101I and warmed by the indoor unit 101I is released to the outside.
　図９は、電力変換装置筐体１００における内気の流れを示している。後側空間ＳＰＢに流れた内気は、その後後側空間ＳＰＢから冷却対象である三相電力変換ユニット群１Ａの間を前側空間ＳＰＦに向かって流れることで三相電力変換ユニット群１Ａを冷却するとともに、過熱空気となって再度左側空間の風路を経由してエアコンの室内機１０１Ｉに送られる。ここでは図示していないが、後側空間ＳＰＢから三相電力変換ユニット群１Ａの間を通して前側空間ＳＰＦに空気を効率的に循環させるために適宜強制循環させるものであってもよい。
なお右側空間ＳＰＲは基本的に左側空間ＳＰＬと同じであるので開示を省略している。 FIG. 9 shows the flow of inside air in the power conversion device housing 100. The inside air that has flowed into the rear space SPB cools the three-phase power conversion unit group 1A by flowing from the rear space SPB to the front space SPF between the three-phase power conversion unit group 1A that is the cooling target. Then, it becomes superheated air and is sent again to the indoor unit 101I of the air conditioner via the air passage in the left space. Although not shown here, the air may be appropriately forcedly circulated in order to efficiently circulate air from the rear space SPB through the three-phase power conversion unit group 1A to the front space SPF.
Since the right space SPR is basically the same as the left space SPL, the disclosure is omitted.
　このように本発明においては、エアコンの室外機１０１Ｏを電力変換装置筐体１００の長手方向の少なくとも一方側に配置する構造とし、低背型に適した盤内冷却構造を提案している。三相電力変換ユニット群１Ａを空冷した内気が端部のエアコンで冷却されて循環する構成を採用している。 As described above, the present invention proposes an internal cooling structure suitable for a low profile, in which the outdoor unit 101O of the air conditioner is arranged on at least one side in the longitudinal direction of the power conversion device casing 100. A configuration is adopted in which the inside air obtained by air-cooling the three-phase power conversion unit group 1A is cooled by an end air conditioner and circulated.
　なおＷＩの風向は図９に示した方向と逆方向であってもよい。 Note that the WI wind direction may be opposite to the direction shown in FIG.
　実施例１では、本発明の電力変換装置構成について基本的な事項を代表事例として説明した。実施例２では、電力変換装置の構成や仕様についてのさらなる変形事例について説明する。 In Example 1, the basic items of the power converter configuration of the present invention have been described as representative examples. In the second embodiment, further modifications of the configuration and specifications of the power conversion device will be described.
　本発明に係る電力変換装置は、電力変換装置筐体１００内に収納されて図３、図４のような構成例とされるのがよいが、さらに以下のように変更され、使用されるものであってもよい。 The power conversion device according to the present invention is preferably housed in the power conversion device casing 100 and configured as shown in FIGS. 3 and 4, but is further modified and used as follows. It may be.
　まず図３、図４に図示の例は、入力が並列接続となるフルブリッジ型ＬＬＣ共振コンバータＬＬＣの後段に単相インバータＩＮを適用し、単相インバータＩＮを階調構成として高圧出力する構成である。階調構成としてはＹ接続型を想定しており、階調段数は８段を想定しているがそれに限るものではない。Ｙ接続の中性点Ｎは接地または高抵抗接地しても良いし、これに限るものではない。また、８段階調構成による高圧出力は６．６ｋＶ出力を想定しているが、構成数を変更する等その他の電圧にしてもよい。 First, the example shown in FIGS. 3 and 4 is a configuration in which a single-phase inverter IN is applied to the subsequent stage of a full-bridge type LLC resonant converter LLC whose inputs are connected in parallel, and the single-phase inverter IN is used as a gradation configuration to output a high voltage. is there. As the gradation configuration, a Y-connection type is assumed, and the number of gradation levels is assumed to be eight, but is not limited thereto. The neutral point N of the Y connection may be grounded or high resistance grounded, but is not limited thereto. Moreover, although the high voltage output by 8 step | paragraph structure assumes 6.6kV output, you may make other voltages, such as changing the number of structures.
　フルブリッジ型のＬＬＣ共振コンバータＬＬＣが与える直流電圧Ｖｄ１は１５００Ｖ以下の直流電圧であるため、半導体素子Ｑ１、Ｑ２、Ｑ３、Ｑ４としては高周波駆動に適したＭＯＳ　ＦＥＴを適用することを想定している。スイッチング周波数は数十ｋＨｚから数百ｋＨｚを想定している。使用するＭＯＳ　ＦＥＴには高耐圧・高周波スイッチングに適したＳｉＣ　ＭＯＳ　ＦＥＴを適用してもよいし、その他同様の機能を有するものであってもよい。ＬＬＣ共振コンバータＬＬＣの２次側は、ダイオードによる整流、平滑回路を想定している。Ｓｉダイオードの他に、導通損失を低減させるためにＳｉ型のショットキーバリアダイオードやＳｉＣ　ショットキーバリアダイオードを適用してもよいし、ＳｉＣ　ＭＯＳ　ＦＥＴを同期させて使用することで損失低減させてもよいし、その他同様の機能を有するものであればよい。 Since the DC voltage Vd1 provided by the full-bridge type LLC resonant converter LLC is a DC voltage of 1500 V or less, it is assumed that MOS FETs suitable for high frequency driving are applied as the semiconductor elements Q1, Q2, Q3, and Q4. . The switching frequency is assumed to be several tens kHz to several hundreds kHz. As the MOS FET to be used, a SiC MOS FET suitable for high withstand voltage and high frequency switching may be applied, or other similar functions may be used. The secondary side of the LLC resonant converter LLC is assumed to be a diode rectification and smoothing circuit. In addition to Si diodes, Si-type Schottky barrier diodes or SiC Schottky barrier diodes may be applied to reduce conduction loss, or loss can be reduced by using SiC MOS FETs in synchronization. It is sufficient if it has other similar functions.
　ＬＬＣ共振型の絶縁トランス１２は系統電圧との絶縁機能を有し、ＬＬＣ共振とするために高周波トランスの励磁インダクタンス１に共振対応させたリーケージインダクタンス２と共振コンデンサ３とが直列接続される構成である。リーケージインダクタンス２は高周波トランス内の漏れ磁束の定数の調整が可能となる構造として高周波トランス内で一体化した構成を想定しているがそれに限るものではない。共振コンデンサ３はフィルムコンデンサやセラミックコンデンサを使用することを想定しているが、同様の機能を有するものであればよい。 The LLC resonance type isolation transformer 12 has an insulating function with respect to the system voltage, and in order to achieve LLC resonance, a leakage inductance 2 and a resonance capacitor 3 that correspond to the excitation inductance 1 of the high frequency transformer are connected in series. is there. The leakage inductance 2 is assumed to be integrated in the high-frequency transformer as a structure capable of adjusting the constant of the leakage magnetic flux in the high-frequency transformer, but is not limited thereto. The resonant capacitor 3 is assumed to use a film capacitor or a ceramic capacitor, but may have any similar function.
　ＬＬＣ共振コンバータＬＬＣの後段の単相インバータＩＮは、ＬＬＣ共振コンバータＬＬＣとは異なり、スイッチング周波数は低いがハードスイッチングであるため、半導体素子Ｑ５、Ｑ６、Ｑ７、Ｑ８としてスイッチング損失の小さいＭＯＳ　ＦＥＴの適用を想定している。使用するＭＯＳ　ＦＥＴは高耐圧・高周波スイッチングに適したＳｉＣ　ＭＯＳ　ＦＥＴを適用してもよいし、高周波駆動用のＩＧＢＴやその他同様の機能を有するものであってもよい。 Unlike the LLC resonant converter LLC, the single-phase inverter IN following the LLC resonant converter LLC has a low switching frequency but is hard switching. Therefore, a MOS FET having a small switching loss is applied as the semiconductor elements Q5, Q6, Q7, and Q8. Is assumed. The MOS FET to be used may be a SiC MOS FET suitable for high withstand voltage and high frequency switching, or may have an IGBT for high frequency driving or other similar functions.
　さらに実施例３として、電力変換ユニットＵ内の回路構成については、図１０から図１２に例示する各種の回路構成を採用することが可能である。 Furthermore, as the third embodiment, various circuit configurations illustrated in FIGS. 10 to 12 can be adopted as the circuit configuration in the power conversion unit U.
　まず図１０の電力変換ユニットＵ内の回路構成について、この回路構成は入力電圧が１５００Ｖ定格時のように入力電流が小さい場合を想定した２ｉｎ１ユニットの回路構成である。 First, regarding the circuit configuration in the power conversion unit U of FIG. 10, this circuit configuration is a circuit configuration of a 2-in-1 unit assuming a case where the input current is small, such as when the input voltage is 1500V rated.
　ここでは、入力が並列接続となるフルブリッジ型のＬＬＣ共振コンバータＬＬＣの１次側絶縁トランス１２を２直列とし、２つの絶縁トランス１２の二次側を並列２系統の整流回路１３及びインバータ回路ＩＮとしたものである。具体的には、それぞれの絶縁トランスの出力を受ける整流回路の後段にそれぞれ単相インバータを適用し、単相インバータ２段分を１つのユニットとした構成である。この回路構成によれば、構造部材の共通化が可能となり、ユニット構造の小型・軽量化が可能となる。また、２つの絶縁トランスの１次側電流が同一となるため、２段分の電力バランスのばらつきも小さく抑えられる。 Here, two primary-side insulating transformers 12 of a full-bridge type LLC resonant converter LLC whose inputs are connected in parallel are arranged in series, and the secondary side of the two insulating transformers 12 is connected in parallel two systems of rectifier circuit 13 and inverter circuit IN. It is what. Specifically, a single-phase inverter is applied to each subsequent stage of the rectifier circuit that receives the output of each isolation transformer, and two single-phase inverters are configured as one unit. According to this circuit configuration, the structural members can be shared, and the unit structure can be reduced in size and weight. In addition, since the primary currents of the two isolation transformers are the same, variations in the power balance for the two stages can be kept small.
　図１１の電力変換ユニットＵ内の回路構成について、この回路構成は単相インバータ２段分を３レベルインバータとした構成であり、図１０と同様の効果を奏することが可能となる。また、インバータの駆動周波数はＬＬＣ共振コンバータＬＬＣと比較して１／１０以下であるため、ＳｉＣ　ＭＯＳ　ＦＥＴではなく、図１２に示すように３レベルインバータのＭＯＳ　ＦＥＴの部分（図１０のＱ５ａ、Ｑ６ａ、Ｑ７ａ、Ｑ８ａ、Ｑ５ｂ、Ｑ６ｂ、Ｑ７ｂ、Ｑ８ｂ）にＩＧＢＴ（図１２のＨ５ａ、Ｈ６ａ、Ｈ７ａ、Ｈ８ａ、Ｈ５ｂ、Ｈ６ｂ、Ｈ７ｂ、Ｈ８ｂ）を使用することができる。また、半導体素子が２倍の耐圧に耐えられるならば新３レベルインバータ構成を使用してもよい。 The circuit configuration in the power conversion unit U of FIG. 11 is a configuration in which two stages of single-phase inverters are three-level inverters, and the same effects as in FIG. 10 can be achieved. In addition, since the inverter drive frequency is 1/10 or less compared to the LLC resonant converter LLC, it is not a SiC MOS FET but a 3-level inverter MOS FET portion (Q5a, Q6a in FIG. 10) as shown in FIG. , Q7a, Q8a, Q5b, Q6b, Q7b, Q8b) can be IGBTs (H5a, H6a, H7a, H8a, H5b, H6b, H7b, H8b in FIG. 12). Also, a new three-level inverter configuration may be used if the semiconductor element can withstand twice the withstand voltage.
　実施例３を採用する場合の電力変換装置筐体１００内における複数の電力変換ユニットＵの接続例について、図１３を用いて説明する。この場合には、各相の電力変換ユニットを盤水平方向に配置し、単相インバータ側を左右で電気的に接続することで階調構成を実現する。このため２ｉｎ１ユニットを適用する実施例３では、実施例１とは異なり、電力変換ユニット４直列を１相とし、電力変換装置筐体１００の高さ方向にＵ、Ｖ、Ｗ相を構成する。ユニットセル間のパワー線の接続数や信号線等のユニットの外の接続数を低減可能な構成である。 A connection example of a plurality of power conversion units U in the power conversion device housing 100 when the third embodiment is employed will be described with reference to FIG. In this case, the gradation configuration is realized by arranging the power conversion units of each phase in the horizontal direction of the panel and electrically connecting the single-phase inverter side on the left and right. For this reason, in the third embodiment in which the 2 in 1 unit is applied, unlike the first embodiment, the power conversion unit 4 series is one phase, and the U, V, and W phases are configured in the height direction of the power conversion device housing 100. In this configuration, the number of power lines connected between unit cells and the number of connections outside the unit such as signal lines can be reduced.
　さらに実施例４として、電力変換ユニットＵ内の回路構成例を図１４に示す。図１４の回路構成は、入力電圧が１５００Ｖ定格時のように入力電流が小さい場合を想定したユニットの回路構成である。 Further, as a fourth embodiment, a circuit configuration example in the power conversion unit U is shown in FIG. The circuit configuration of FIG. 14 is a unit circuit configuration that assumes a case where the input current is small, such as when the input voltage is 1500 V rated.
　図１４では、整流回路１３を二重化しているが、インバータＩＮは共通としている。この場合には、入力が並列接続となるフルブリッジ型ＬＬＣ共振コンバータＬＬＣのトランス１２をその一次側で２直列とし、それぞれのＬＬＣトランス１２後段の整流回路１３を並列構成とし、インバータＩＮは共通とることで、１ユニットでトランス２つ分の電力出力を可能とした構成である。この構成によれば、大容量化が可能となり、大容量化の効果として容量当たりの小型・軽量化が可能となる。また、２つのトランスの１次側電流が同一となるため、２段分の電力バランスのばらつきも小さく抑えられる。 In FIG. 14, the rectifier circuit 13 is duplicated, but the inverter IN is common. In this case, the transformers 12 of the full-bridge type LLC resonant converter LLC, whose inputs are connected in parallel, are arranged in series on the primary side, the rectifier circuits 13 subsequent to the LLC transformers 12 are arranged in parallel, and the inverter IN is shared. Thus, the power output for two transformers is made possible with one unit. According to this configuration, it is possible to increase the capacity, and it is possible to reduce the size and weight per capacity as an effect of increasing the capacity. In addition, since the primary currents of the two transformers are the same, variations in the power balance for the two stages can be kept small.
　なおＬＬＣ共振コンバータＬＬＣの後段の単相のインバータＩＮは、ＬＬＣ共振コンバータＬＬＣとは異なり、スイッチング周波数は低いがハードスイッチングであるため、スイッチング損失の小さいＭＯＳ　ＦＥＴの適用を想定している。使用するＭＯＳ　ＦＥＴには高耐圧・高周波スイッチングに適したＳｉＣ　ＭＯＳ　ＦＥＴを適用してもよいし、高周波駆動用のＩＧＢＴやその他同様の機能を有するものであれば適用可能である。 Note that the single-phase inverter IN at the latter stage of the LLC resonant converter LLC is different from the LLC resonant converter LLC and has a low switching frequency but is hard switching. Therefore, it is assumed that a MOS FET having a small switching loss is applied. As the MOS FET to be used, a SiC MOS FET suitable for high withstand voltage and high frequency switching may be applied, or any IGBT having a high frequency driving IGBT or other similar function may be applied.
　電力変換装置筐体１００の盤構造は、実施例１と同様の８ユニット構成を想定しているが、これに限るものではない。以上、多くの実施例を挙げて説明したが、用途に応じて前記実施例に記述した内容を組み合わせて使用してもよい。 The panel structure of the power conversion device housing 100 is assumed to have an 8-unit configuration similar to that of the first embodiment, but is not limited thereto. Although many examples have been described above, the contents described in the examples may be used in combination depending on the application.
１：励磁インダクタンス，２：リーケージインダクタンス，３：共振コンデンサ，１１：インバータ回路，１２：絶縁トランス，１３：整流回路，１４：インバータ回路，１００：電力変換装置筐体，１０１Ｉ：エアコンの室内機，１０１Ｏ：エアコンの室外機，１２１：冷媒，Ｂ、ＢＢ：架台，Ｃ：コンデンサ，Ｃｉ：入力側コンデンサ，Ｄ１、Ｄ２、Ｄ３、Ｄ４：ダイオード，ＩＮ：インバータ，ＬＬＣ：ＬＬＣ共振コンバータ，ＰＬ：太陽光パネル，Ｑ１、Ｑ２、Ｑ３、Ｑ４、Ｑ５、Ｑ６、Ｑ７、Ｑ８：半導体素子，ＳＰＲ、ＳＰＬ、ＳＰＦ、ＳＰＢ：空間，ＴＤ１、ＴＤ２：直流入力端子，ＴＬ１、ＴＬ２：直流出力端子，ＴＡ１、ＴＡ２：交流出力端子，ＴＵ、ＴＶ、ＴＷ：三相交流出力端子，Ｕ：電力変換ユニット，ＷＩ：内気 1: Excitation inductance, 2: Leakage inductance, 3: Resonance capacitor, 11: Inverter circuit, 12: Insulation transformer, 13: Rectifier circuit, 14: Inverter circuit, 100: Power converter housing, 101I: Indoor unit of air conditioner, 101O: outdoor unit of air conditioner, 121: refrigerant, B, BB: mount, C: capacitor, Ci: input side capacitor, D1, D2, D3, D4: diode, IN: inverter, LLC: LLC resonant converter, PL: sun Optical panel, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8: Semiconductor element, SPR, SPL, SPF, SPB: Space, TD1, TD2: DC input terminal, TL1, TL2: DC output terminal, TA1, TA2: AC output terminal, TU, TV, TW: Three-phase AC output terminal, U: Power conversion unit, WI: Inside air

Claims (8)

  1. 　入力が直流である高周波共振型コンバータの２次側に単相インバータを備えた電力変換ユニットについて、複数の電力変換ユニットの前記単相インバータの出力を直列接続して電力変換ユニット群を構成し、電力変換装置筐体内に収納した３組の前記電力変換ユニット群により交流３相の各相を形成し、
    　前記電力変換ユニット群を構成する複数の前記電力変換ユニットは、前記電力変換装置筐体の長手方向に沿って配置され、かつ３組の前記電力変換ユニット群は、前記電力変換装置筐体の高さ方向の上段、中段、下段にそれぞれ配置され、
    　前記電力変換装置筐体の長手方向の一方端側が、３組の前記電力変換ユニット群の出力端子とされ、前記電力変換装置筐体の長手方向の他方端側で３組の前記電力変換ユニット群の端子が共通接続されているとともに、
    　前記電力変換装置筐体内の長手方向左右の少なくとも一方にエアコンの室内機を配置し、前記電力変換装置筐体外の長手方向左右の少なくとも前記の一方にエアコンの室外機を配置し、前記エアコンの室内機からの冷風により前記電力変換装置筐体内を冷却することを特徴とする電力変換装置。     For a power conversion unit including a single-phase inverter on the secondary side of a high-frequency resonant converter whose input is DC, a power conversion unit group is configured by connecting the outputs of the single-phase inverters of a plurality of power conversion units in series. Each of the three phases of alternating current is formed by the three sets of the power conversion units housed in the power converter housing,
    The plurality of power conversion units constituting the power conversion unit group are arranged along the longitudinal direction of the power conversion device casing, and three sets of the power conversion unit groups are arranged at a height of the power conversion device casing. Placed in the upper, middle and lower tiers,
    One end side in the longitudinal direction of the power conversion device casing serves as an output terminal of the three sets of power conversion unit groups, and three sets of power conversion unit groups on the other end side in the longitudinal direction of the power conversion device casings Are connected in common,
    An indoor unit of an air conditioner is disposed on at least one of the left and right in the longitudinal direction inside the power conversion device casing, and an outdoor unit of the air conditioner is disposed on at least one of the left and right in the longitudinal direction outside the casing of the power conversion device. A power converter, wherein the inside of the power converter casing is cooled by cold air from a machine.
  2. 　請求項１記載の電力変換装置であって、
    　前記電力変換ユニットの直流入力側に直流遮断器を有することを特徴とする電力変換装置。     The power conversion device according to claim 1,
    A power converter having a DC circuit breaker on a DC input side of the power conversion unit.
  3. 　請求項１に記載の電力変換装置であって、
    　前記電力変換ユニット群の出力端子側に高圧気中負荷開閉器を有することを特徴とする電力変換装置。     The power conversion device according to claim 1,
    A power converter having a high-pressure air load switch on an output terminal side of the power conversion unit group.
  4. 　請求項１に記載の電力変換装置であって、
    　前記高周波共振型コンバータは、共振トランスを備えており、２組の共振トランスの１次側を直列接続していることを特徴とする電力変換装置。     The power conversion device according to claim 1,
    The high-frequency resonant converter includes a resonant transformer, and the primary side of two sets of resonant transformers are connected in series.
  5. 　請求項４に記載の電力変換装置であって、
    　２組の前記共振トランスの２次側にそれぞれ単相インバータを備え、２段分の階調接続としたことを特徴とする電力変換装置。     The power conversion device according to claim 4,
    A power conversion device characterized in that a single-phase inverter is provided on each secondary side of the two sets of resonant transformers, and gradation connection for two stages is made.
  6. 　請求項４に記載の電力変換装置であって、
    　前記共振トランスの２次側をそれぞれダイオード整流した後段を直列接続とし、その後段に３レベルインバータを備えたことを特徴とする電力変換装置。     The power conversion device according to claim 4,
    A power conversion device comprising a series connection at a subsequent stage of diode rectification of the secondary side of the resonant transformer, and a three-level inverter at the subsequent stage.
  7. 　請求項４に記載の電力変換装置であって、
    　前記共振トランス２次側をそれぞれダイオード整流した後段を並列接続したことを特徴とする電力変換装置。     The power conversion device according to claim 4,
    A power conversion device characterized in that subsequent stages of diode rectification of the secondary side of the resonant transformer are connected in parallel.
  8. 　請求項１に記載の電力変換装置であって、
    　前記電力変換装置筐体は、太陽光発電サイトに設置され、架台に支持された太陽光パネルの日陰に配置可能な低背型構造としたことを特徴とする電力変換装置。     The power conversion device according to claim 1,
    The power converter device has a low-profile structure that can be placed in the shade of a solar panel that is installed at a photovoltaic power generation site and supported by a gantry.
PCT/JP2017/014791 2016-09-06 2017-04-11 Power conversion device WO2018047395A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11220887A (en) * 1998-01-30 1999-08-10 Toshiba Corp Power converter
JP2013243867A (en) * 2012-05-21 2013-12-05 Daihen Corp Transformation facility unit
WO2015079586A1 (en) * 2013-11-29 2015-06-04 東芝三菱電機産業システム株式会社 Electric equipment housing

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11220887A (en) * 1998-01-30 1999-08-10 Toshiba Corp Power converter
JP2013243867A (en) * 2012-05-21 2013-12-05 Daihen Corp Transformation facility unit
WO2015079586A1 (en) * 2013-11-29 2015-06-04 東芝三菱電機産業システム株式会社 Electric equipment housing

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