Power conversion circuit of inverter device, inverter device, and control method thereof

Abstract

The present specification relates to an embodiment of a power conversion circuit, an inverter device, and a control method thereof, the power conversion circuit having changeovers switches provided between an N phase terminal and an L2 phase-N phase, which are outputted from an inverter to a load, so as to switch to a single-phase two-wire type through an L1 phase and an L2-N phase by opening the switch at the N phase terminal when operating in connection with a grid, and switch to a single-phase three-wire type through the L1 phase, the N phase, and the L2 phase by opening the switch between the L2 phase-N phase when operating separately from the grid.

Description

Power conversion circuit of inverter device, inverter device and control method thereof

[0001] The present invention relates to a power conversion circuit that converts supplied power into alternating current power, an inverter device including the same, and a method for controlling the same.

[0002] The technology that forms the background of the present invention relates to a power conversion circuit of an inverter device used in an ESS (Energy Storage System).

[0003] Typically, ESS is installed and operated to share peak power consumption, charging when load power consumption is low and discharging when it is high, and to reduce ripple power generated by renewable energy generation. When connected to the grid, ESS receives power from the grid to charge batteries or shares the power consumed by loads during peak loads. Furthermore, ESS is required to function as a distributed power source, independently supplying power to loads in the event of a grid failure (power outage) upon user request. This independent operation function is being applied not only as a replacement for emergency generators but also as a solution for establishing microgrids in isolated areas.

[0004] For residential ESS, single-phase products are the mainstream, except in countries where three-phase outlets are widely available. Topologies commonly used in single-phase ESS include H-Bridge, Totem-pole, and HERIC. As shown in Figure 1, residential ESS customers want to be able to use both 220V and 110V loads in their homes during a power outage. Therefore, ESS developers and manufacturers often configure their products with the Totem-pole topology, which simplifies the implementation of split-phase functionality.

[0005] Among these totem-pole topologies, a solution is being developed that can improve leakage current by connecting the L2 phase to the N phase. Figure 2 shows a previously proposed L2N phase totem-pole topology circuit. The L2N totem-pole has a hardware wiring characteristic in which the outputs of the phases with and without inductors are connected. Through this configuration, the phase with the inductor is operated when the grid voltage is in the area near 0 voltage, and the phase without the inductor is operated otherwise, and the area where leakage current issues occur in the existing totem-pole topology can be bypassed and operated through the phase with the inductor.

[0006] However, previously, there was no technology to switch between totem-pole and split-phase functions. Previously, two inverters, one dedicated to totem-pole and one dedicated to split-phase, were used selectively, but this method had limitations in that it increased the complexity and cost of the inverter circuit configuration. In other words, although circuits that can be universally used for both single-phase, two-wire and single-phase, three-wire systems have been proposed, a technology that easily switches between the two methods has not been proposed. Consequently, selective operation of single-phase, two-wire and single-phase, three-wire systems was not easily possible, and there were also limitations in responding to emergency power supply for two loads with different voltages. Furthermore, this difficulty in switching also limited response when connected to the grid or when operating independently.

[0007] The present invention aims to improve the limitations of the prior art as described above.

[0008] Accordingly, the present specification provides an embodiment that can selectively operate a single-phase two-wire system and a single-phase three-wire system.

[0009] In addition, it is intended to provide an embodiment that can easily respond to the transition between linked operation, which operates in conjunction with the system, and independent operation, which operates separately from the system.

[0010] In addition, we aim to provide an embodiment in which switching between linked operation and independent operation can be achieved with a simple circuit configuration.

[0011] In addition, an embodiment is provided in which two different voltages can be supplied during independent driving.

[0012] The present invention, which aims to solve the above-described problem, provides a plurality of changeover switches at the output terminal of an inverter, and, depending on whether or not it is connected to a grid, switches the inverter to a single-phase, two-wire system or a single-phase, three-wire system through the switching operation of the plurality of changeover switches.

[0013] Specifically, it is characterized by having a switching switch between the N-phase and L2-N-phase output from the inverter as a load, so that when operating in connection with the grid, the switch on the N-phase is opened to switch to a single-phase, two-wire system through the L1-phase and L2-N-phase, and when operating in isolation from the grid, the switch between the L2-phase and N-phase is opened to switch to a single-phase, three-wire system through the L1-phase, N-phase, and L2-phase.

[0014] Accordingly, single-phase 2-wire and single-phase 3-wire conversions can be easily achieved with a simple circuit configuration, and it becomes possible to easily respond to grid connection and independent operation conversion.

[0015] The above technical features can be applied and implemented to rectifier circuits, power conversion circuits, converter circuits, inverter circuits, power conversion devices, inverter devices, ESS (Energy Storage System) devices, emergency power devices, etc., and the present specification provides embodiments of a power conversion circuit, an inverter device, and a control method thereof using the above technical features as a means for solving a problem.

[0016] An embodiment of a power conversion circuit of an inverter device using the above technical features as a means for solving a problem includes a link unit for storing DC power, a first conversion unit for converting the DC power into a first power source and outputting it to a first load terminal of a supply target unit, a second conversion unit for converting the DC power into a second power source and outputting it to a second load terminal of the supply target unit, a third conversion unit for converting the DC power into a third power source and outputting it to a third load terminal of the supply target unit, a first conversion unit for connecting or disconnecting between an output terminal of the second conversion unit and an output terminal of the third conversion unit, and a second conversion unit for connecting or disconnecting between an output terminal of the second conversion unit and the second load terminal, wherein the first conversion unit and the second conversion unit operate differently depending on whether or not they are connected to a system.

[0017] The above power conversion circuit may be implemented in an embodiment that converts the power supply method to either a single-phase two-wire method or a single-phase three-wire method.

[0018] In addition, an embodiment of an inverter device using the above technical features as a means for solving a problem is an inverter device that supplies a single-phase, three-wire power source, including a link unit that stores DC power, a conversion unit that receives the DC power from the link unit and converts it into power to be supplied to a supply target unit, a switching unit that switches the connection between the conversion unit and the supply target unit according to an operation method of the inverter device, and a control unit that controls the conversion unit and the switching unit according to the operation method.

[0019] In an embodiment of the inverter device, the conversion unit includes a first conversion unit that converts the DC power into a first power and outputs it to a first load terminal of the supply target unit, a second conversion unit that converts the DC power into a second power and outputs it to a second load terminal of the supply target unit, and a third conversion unit that converts the DC power into a third power and outputs it to a third load terminal of the supply target unit, and the conversion unit includes a first conversion unit that switches an ON / OFF operation to connect or disconnect between an output terminal of the second conversion unit and an output terminal of the third conversion unit, and a second conversion unit that switches an ON / OFF operation to connect or disconnect between an output terminal of the second conversion unit and the second load terminal.

[0020] In the embodiment of the inverter device, the first switching unit and the second switching unit operate differently from each other.

[0021] Meanwhile, an embodiment of a control method of an inverter device using the above technical feature as a means for solving a problem comprises a method for controlling an inverter device, including a link unit storing DC power, a first conversion unit converting the DC power into a first power and outputting it to a first load terminal of a supply target unit, a second conversion unit converting the DC power into a second power and outputting it to a second load terminal of the supply target unit, and a third conversion unit converting the DC power into a third power and outputting it to a third load terminal of the supply target unit, a first conversion unit connecting between an output terminal of the second conversion unit and an output terminal of the third conversion unit when in an ON operation and separating between an output terminal of the second conversion unit and an output terminal of the third conversion unit when in an OFF operation, and a second conversion unit connecting between an output terminal of the second conversion unit and the second load terminal when in an ON operation and separating between an output terminal of the second conversion unit and the second load terminal when in an OFF operation, the method comprising the steps of starting an operation, a step of determining whether there is a connection between the inverter device and a system, a step of controlling the operation of the first conversion unit and the operation of the second conversion unit differently depending on the connection, and It includes a step of controlling the operation of the conversion unit according to the operation states of the first conversion unit and the second conversion unit.

[0022] The embodiments of the power conversion circuit, inverter device and control method thereof described above are not limited to those described above, and may include embodiments described in the specific description to be described below or embodiments that can be inferred / derived from the specific description.

[0023] A power conversion circuit, an inverter device and a control method thereof according to an embodiment have the effect of providing a plurality of changeover switches at an output terminal of an inverter, and switching the plurality of changeover switches depending on whether or not they are connected to a grid, thereby enabling switching to a single-phase, two-wire system or a single-phase, three-wire system.

[0024] Accordingly, there is an effect that allows for selective operation of single-phase 2-wire and single-phase 3-wire systems with one inverter circuit.

[0025] In addition, there is an effect that allows for easy switching between linked operation, which operates in conjunction with the system, and independent operation, which operates separately from the system, with a simple circuit configuration.

[0026] In addition, since switching between linked and independent operation is easily accomplished with a simple circuit configuration, not only does it facilitate response in an emergency, but it also has the effect of reducing the cost consumed in product manufacturing.

[0027] In addition, since it is easy to convert to a single-phase, three-wire system when driving independently, it has the effect of making it easy to supply two different voltages.

[0028] The effects according to the embodiments of the power conversion circuit, inverter device and control method thereof described above are not limited to those described above, and may also include effects described in the specific description to be described below or effects that can be inferred / derived from the specific description.

[0029] Figure 1 is a conceptual diagram showing the concept of supplying single-phase, three-wire power to respond to a power outage using an ESS inverter.

[0030] Figure 2 is a circuit diagram of a conventional L2N phase totem-pole topology.

[0031] Fig. 3 is a configuration diagram of a power conversion circuit and an inverter device including the same according to an embodiment.

[0032] Fig. 4 is a circuit diagram of a power conversion circuit according to an embodiment.

[0033] Fig. 5 is a circuit diagram showing an example of a modification of a power conversion circuit according to an embodiment.

[0034] Fig. 6 is an exemplary diagram showing an example of linked operation of a power conversion circuit according to an embodiment.

[0035] Fig. 7 is an exemplary diagram showing an example of independent operation of a power conversion circuit according to an embodiment.

[0036] Fig. 8 is a flowchart showing the control sequence of the control unit of the inverter device according to the embodiment.

[0037] Fig. 9 is a flowchart of a control method of an inverter device according to an embodiment.

[0038] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components are given the same reference numbers and redundant descriptions thereof are omitted. In addition, when describing embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, a detailed description thereof is omitted.

[0039] The power conversion circuit according to the embodiment (hereinafter referred to as the conversion circuit) means a power conversion module included in an inverter device that converts power.

[0040] Here, the inverter device may be an inverter used in a power supply device, a power control device, an emergency power device, a distributed power device, a renewable energy generation device, or an ESS (Energy Storage System).

[0041] The above conversion circuit may be a circuit included in the inverter device that converts power supplied from an external power source into AC power and outputs it to a supply target.

[0042] The above conversion circuit may be a circuit that includes a plurality of circuit elements and converts power through the plurality of circuit elements.

[0043] The above conversion circuit can be mounted on one substrate.

[0044] The above conversion circuit (100), as illustrated in FIG. 3, is a circuit included in an inverter device (1000) that converts power supplied from an external power supply source (P) into power to be supplied to a supply target portion (L) and supplies the converted power to the supply target portion (L), and includes a link portion (10), a conversion portion (20), and a switching portion (30).

[0045] The conversion circuit (100) including the link section (10), the conversion section (20) and the switching section (30) may correspond to the inverter section in the inverter device (1000).

[0046] Here, the power supply source (P) may be a battery or a source that supplies direct current power, and the supply target unit (L) may be a load of the inverter device (1000).

[0047] The above conversion circuit (100) may also further include a rectifier that rectifies the power supplied from the power supply source (P).

[0048] Each of the above link unit (10), the conversion unit (20), and the switching unit (30) may include one or more circuit elements.

[0049] For example, the link unit (10) may include a capacitor, the conversion unit (20) may include a switching module (SW), and the switching unit (30) may include a switching switch.

[0050] The specific circuit configuration of the above conversion circuit (100) may be as shown in FIG. 4.

[0051] The above-described conversion circuit (100) includes the link unit (10) for storing DC power as shown in FIGS. 3 and 4, the first conversion unit (21) for converting the DC power into a first power source and outputting it to a first load terminal (L1) of the supply target unit (L), the second conversion unit (22) for converting the DC power into a second power source and outputting it to a second load terminal (N) of the supply target unit (L), and the third conversion unit (23) for converting the DC power into a third power source and outputting it to a third load terminal (L2) of the supply target unit (L), and the conversion unit (30) including the first conversion unit (31) for connecting or disconnecting between an output terminal of the second conversion unit (22) and an output terminal of the third conversion unit (23), and the second conversion unit (32) for connecting or disconnecting between an output terminal of the second conversion unit (22) and the second load terminal (N).

[0052] In the above conversion circuit (100), the first conversion unit (31) and the second conversion unit (32) operate differently depending on whether they are connected to the system.

[0053] That is, the conversion circuit (100) can be operated by switching the connection with the supply target unit (L) by having the first switching unit (31) and the second switching unit (32) operate differently depending on whether or not they are connected to the system.

[0054] For example, when operating in conjunction with the system, the first switching unit (31) may operate ON, and when operating in isolation from the system, the first switching unit (31) may operate OFF.

[0055] In addition, when operating in conjunction with the system, the second switching unit (32) may operate OFF, and when operating separately from the system, the second switching unit (32) may operate ON.

[0056] The above link unit (10) includes a DC link capacitor, and can smooth and store the power received from the power supply source (P) through the DC link capacitor, and transmit the stored DC power to the conversion unit (20).

[0057] In this case, the DC power can be transmitted to each of the first conversion unit (21) to the third conversion unit (23).

[0058] The above conversion unit (20) may include the first conversion unit (21) connected to the L1 phase of the supply target unit (L), the second conversion unit (22) connected to the N phase of the supply target unit (L), and the third conversion unit (23) connected to the L2 phase of the supply target unit (L).

[0059] Each of the first conversion unit (21) to the third conversion unit (23) includes a plurality of switching modules (SW), and can convert the smooth power received from the link unit (10) into power to be supplied to the supply target unit (L) through the switching operation of the plurality of switching modules (SW) and apply the converted power to the supply target unit (L).

[0060] Here, the switching module may be a switching element included in a power conversion means such as an IGBT, BJT, JFET, or MOSFET.

[0061] The above plurality of switching modules (SW) can be divided into at least three pairs, and each can form the first conversion unit (21) to the third conversion unit (23).

[0062] That is, each of the first conversion unit (21) to the third conversion unit (23) may include at least one pair of switching modules (SW).

[0063] Meanwhile, one or more of the first conversion unit (21) to the third conversion unit (23) may include two pairs of switching modules (SW), as illustrated in FIG. 5.

[0064] That is, the above conversion unit (20) may be composed of four or more pairs of the above switching modules (SW).

[0065] In this case, as shown in Fig. 5, two pairs of switching modules (SW) are included in one converter (21), so that each output terminal can be connected in parallel to output one phase power.

[0066] Each of the first conversion unit (21) to the third conversion unit (23) can convert power of one of the three phases.

[0067] For example, the first conversion unit (21) can convert the first power corresponding to the L1 phase of the supply target unit (L), the second conversion unit (22) can convert the second power corresponding to the N phase of the supply target unit (L), and the third conversion unit (23) can convert the third power corresponding to the L2 phase of the supply target unit (L).

[0068] The first conversion unit (21) to the third conversion unit (23) can convert the DC power into a supply power by performing a switching operation according to an authorized control signal.

[0069] Here, the control signal may mean a PWM control signal.

[0070] The above control signal may be a signal that is applied to each of the switching modules (SW) included in the first conversion unit (21) to the third conversion unit (23) to control the switching operation of the switching module (SW).

[0071] The above first conversion unit (21) can be connected to the first load unit (L1) whose output terminal corresponds to the L1 phase of the supply target unit (L).

[0072] The output terminal of the first converter (21) may include one or more elements (21I) having an inductance component.

[0073] That is, the output terminal of the first conversion unit (21) can form a constant inductance corresponding to the element (21I).

[0074] The above element (21I) can be placed at the front end of the first load stage (L1).

[0075] By including one or more of the above elements (21I) in this way, the leakage current of the power output from the first converter (21) can be improved.

[0076] The output terminal of the first converter (21) may also include one or more capacitors or resistors.

[0077] The above second conversion unit (22) can be connected to the second load unit (N) whose output terminal corresponds to the N phase of the supply target unit (L).

[0078] The output terminal of the second converter (22) may include one or more elements (22I) having an inductance component.

[0079] That is, the output terminal of the second converter (22) can form a constant inductance corresponding to the element (22I).

[0080] The above element (22I) can be placed at one end of the first switching unit (31).

[0081] Here, one end of the first conversion unit (31) may be a contact point where the output terminal of the second conversion unit (22) and the first conversion unit (31) are connected.

[0082] Accordingly, inductance can be formed at the output terminal of the second conversion unit (22) regardless of whether the first conversion unit (31) is opened or closed.

[0083] By including one or more of the above elements (22I) in this way, the leakage current of the power output from the second converter (22) can be improved.

[0084] The output terminal of the second converter (22) may also include one or more capacitors or resistors.

[0085] The third conversion unit (23) can be connected to the third load unit (L2) whose output terminal corresponds to the L2 phase of the supply target unit (L).

[0086] The output terminal of the third conversion unit (23) can be formed to have a smaller inductance component than the first conversion unit (21) and the second conversion unit (22).

[0087] That is, the output terminal of the third converter (23) may not include an element having an inductance component.

[0088] The above switching unit (30) may include the first switching unit (31) that connects or separates between the second switching unit (22) and the third switching unit (23) and the second switching unit (32) that connects or separates between the second switching unit (22) and the second load stage (N).

[0089] The above first switching unit (31) and the above second switching unit (32) may be switches that switch between opening and closing by operating ON / OFF.

[0090] The above first switching unit (31) and the above second switching unit (32) may be switches that connect or disconnect two contact points by switching the ON / OFF operation.

[0091] The first switching unit (31) and the second switching unit (32) may be mechanical switches or electronic switches.

[0092] For example, it can be a POWER relay, MOSFET, IGBT, BJT, JFET, MAGNETIC CONTACTOR, or MCCB.

[0093] The above first switching unit (31) and the above second switching unit (32) may be A-contact switches that are closed when in the ON operation and open when in the OFF operation.

[0094] In addition, the first switching unit (31) and the second switching unit (32) may be B-contact switches that are closed when in the OFF operation and open when in the ON operation.

[0095] Hereinafter, for the convenience of explanation, the first switching unit (31) and the second switching unit (32) will be described with a focus on an example in which the first switching unit (31) and the second switching unit (32) are A-point switches. However, a specific embodiment of the conversion circuit (100) is based on the premise that the first switching unit (31) and the second switching unit (32) may be configured as B-point switches. In this case, whether the first switching unit (31) and the second switching unit (32) are opened or closed can be interpreted in reverse.

[0096] The first switching unit (31) and the second switching unit (32) can operate differently from each other.

[0097] The first switching unit (31) and the second switching unit (32) can operate in opposite directions to each other.

[0098] For example, if one operates ON, the other may operate OFF.

[0099] Accordingly, the first switching unit (31) and the second switching unit (32) can operate as an interlock.

[0100] The above first switching unit (31) and the above second switching unit (32) can operate differently depending on whether or not they are connected to the conversion circuit (100) and the system.

[0101] The above first conversion unit (31) can be placed between the output terminal of the second conversion unit (22) and one end of the second conversion unit (32).

[0102] Here, one end of the second switching unit (32) may be connected to the output terminal of the second conversion unit (22).

[0103] Accordingly, the first switching unit (31) can connect or disconnect the output terminal of the second switching unit (22) and the output terminal of the third switching unit (23) regardless of whether the second switching unit (32) is opened or closed.

[0104] The above first switching unit (31) can be closed when in the ON operation and opened when in the OFF operation.

[0105] The above first conversion unit (31) can connect between the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23) when the conversion circuit (100) is operated in conjunction with the system.

[0106] The above first conversion unit (31) is turned ON and closed when the conversion circuit (100) is operated in conjunction with the system, thereby connecting the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23).

[0107] That is, when the above conversion circuit (100) is operated in conjunction with the system, the first conversion unit (31) is turned ON so that the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23) can be connected.

[0108] In this case, the second switching unit (32) may operate in an OFF state opposite to the first switching unit (31) to separate the output terminal of the second conversion unit (22) and the second load terminal (N).

[0109] The above first conversion unit (31) can separate the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23) when the conversion circuit (100) is operated separately from the system.

[0110] The above first conversion unit (31) is opened by being turned OFF when the conversion circuit (100) is operated separately from the system, thereby separating the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23).

[0111] That is, when the conversion circuit (100) is operated separately from the system, the first switching unit (31) may be turned OFF to separate the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23).

[0112] In this case, the second switching unit (32) may operate in an ON state opposite to the first switching unit (31) to connect the output terminal of the second conversion unit (22) and the second load terminal (N).

[0113] The second switching unit (32) can be placed between one end of the first switching unit (31) and the second load end (N).

[0114] Here, one end of the first conversion unit (31) may be connected to the output terminal of the second conversion unit (22).

[0115] Accordingly, the second switching unit (32) can connect or disconnect the output terminal of the second conversion unit (22) and the second load terminal (N) depending on whether the first switching unit (31) is opened or closed.

[0116] The above second switching unit (32) can be closed when in the ON operation and opened when in the OFF operation.

[0117] The second conversion unit (32) can separate the output terminal of the second conversion unit (22) and the second load terminal (N) when the conversion circuit (100) is operated in conjunction with the system.

[0118] The second switching unit (32) can be opened by turning OFF when the conversion circuit (100) is operated in conjunction with the system, thereby separating the output terminal of the second conversion unit (22) and the second load terminal (N).

[0119] That is, when the conversion circuit (100) is operated in conjunction with the system, the second switching unit (32) may be turned OFF to separate the output terminal of the second conversion unit (22) and the second load terminal (N).

[0120] In this case, the first switching unit (31) may operate in an ON state opposite to the second switching unit (32) to connect the output terminal of the second switching unit (22) and the output terminal of the third switching unit (23).

[0121] The second conversion unit (32) can connect the output terminal of the second conversion unit (22) and the second load terminal (N) when the conversion circuit (100) is operated separately from the system.

[0122] The second switching unit (32) can be connected between the output terminal of the second switching unit (22) and the second load terminal (N) by being turned ON and closed when the conversion circuit (100) is operated separately from the system.

[0123] That is, when the conversion circuit (100) is operated separately from the system, the second switching unit (31) is turned ON so that the output terminal of the second conversion unit (22) and the second load terminal (N) can be connected.

[0124] In this case, the first switching unit (31) may operate in an OFF state opposite to the second switching unit (32) to separate the output terminal of the second switching unit (22) and the output terminal of the third switching unit (23).

[0125] In this way, when the above conversion circuit (100) is operated in conjunction with the system, as shown in FIG. 6, the first conversion unit (31) is turned ON to connect the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23), and the second conversion unit (32) is turned OFF to separate the output terminal of the second conversion unit (23) and the second load terminal (N).

[0126] Accordingly, the power output from the second conversion unit (22) is induced to the output terminal of the third conversion unit (23) through the element (22I) and the first conversion unit (31), and power is not induced to the second load unit (N), so that power can be supplied to the first load unit (L1) and the third load unit (L2).

[0127] Accordingly, when the above-mentioned conversion circuit (100) is operated in conjunction with the system, single-phase, two-wire operation can be performed by operating the first load stage (L1) and the third load stage (L2).

[0128] In this case, the load can be driven by being connected to the first load stage (L1) and the third load stage (L2) and supplied with power.

[0129] Meanwhile, the voltage between the first load stage (L1) and the third load stage (L2) may correspond to 1.8 to 2.2 times the voltage between either the first load stage (L1) or the third load stage (L2) and the second load stage (N).

[0130] For example, if the voltage between one of the first load stage (L1) and the third load stage (L2) and the second load stage (N) is 110 V, the voltage between the first load stage (L1) and the third load stage (L2) may be 220 V.

[0131] That is, when the above conversion circuit (100) is operated in conjunction with the system, power can be supplied to a 220 V load in a single-phase, two-wire manner.

[0132] In addition, when the conversion circuit (100) is operated separately from the system, as shown in FIG. 7, the first conversion unit (31) is turned OFF to separate the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23), and the second conversion unit (32) is turned ON to connect the output terminal of the second conversion unit (23) and the second load terminal (N).

[0133] Accordingly, the power output from the second conversion unit (22) is induced to the second load stage (N) through the element (22I) and the second conversion unit (32), so that power can be supplied to the first load stage (L1), the second load stage (N), and the third load stage (L2).

[0134] Accordingly, when the above-mentioned conversion circuit (100) is operated separately from the system, single-phase, three-wire operation can be performed by operating the first load stage (L1), the second load stage (N), and the third load stage (L2).

[0135] In this case, the load can be driven by being connected to the first load stage (L1) and the second load stage (N), the second load stage (N) and the third load stage (L2), or the first load stage (L1) and the third load stage (L2).

[0136] Meanwhile, the voltage between the first load stage (L1) and the third load stage (L2) may correspond to 1.8 to 2.2 times the voltage between either the first load stage (L1) or the third load stage (L2) and the second load stage (N).

[0137] For example, if the voltage between one of the first load stage (L1) and the third load stage (L2) and the second load stage (N) is 110 V, the voltage between the first load stage (L1) and the third load stage (L2) may be 220 V.

[0138] That is, when the above conversion circuit (100) is operated in conjunction with the system, power can be supplied to a 110 V load and a 220 V load in a single-phase, three-wire manner.

[0139] Accordingly, in the case where the system is connected to the system and the system is operated while bearing a load of 110 V, and the system is operated separately from the system due to an abnormality in the system, the conversion circuit (100) may be converted to a single-phase, three-wire system and bear a load of 110 V.

[0140] In this way, the conversion circuit (100) can switch between single-phase two-wire and single-phase three-wire power supply by having the first conversion unit (31) and the second conversion unit (32) switch operations differently depending on whether or not they are connected to the system.

[0141] Accordingly, it becomes possible to selectively operate single-phase 2-wire and single-phase 3-wire in one inverter circuit, and with a simple circuit configuration, it becomes easy to switch between linked operation in which operation is performed in connection with the system and independent operation in which operation is performed separately from the system, and appropriate operation corresponding to each of the linked operation (single-phase 2-wire) and the independent operation (single-phase 3-wire) can be performed.

[0142] In this way, the conversion circuit (100) in which linked operation and independent operation are performed through the first switching unit (31) and the second switching unit (32) is included in the inverter device (1000) as shown in FIG. 3, and the switching of the linked operation and the independent operation can be controlled by the control unit (200) of the inverter device (1000).

[0143] The inverter device (1000) may be a device that supplies power to the supply target unit (L), including the conversion circuit (100) and the control unit (200), as shown in FIG. 3.

[0144] The inverter device (1000) includes an inverter device (100) (conversion circuit) including the link device (10) that stores DC power, the conversion device (20) that receives the DC power from the link device (10) and converts it into power to be supplied to the supply target device (L), and the switching device (30) that switches the connection between the conversion device (20) and the supply target device (L) according to the operation mode of the inverter device (1000), and the control device (200) that controls the conversion device (20) and the switching device (30) according to the operation mode.

[0145] Here, the conversion unit (20) includes the first conversion unit (21), the second conversion unit (22), and the third conversion unit (23), and the conversion unit (30) includes the first conversion unit (31) that switches the ON / OFF operation to connect or disconnect between the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23), and the second conversion unit (32) that switches the ON / OFF operation to connect or disconnect between the output terminal of the second conversion unit (22) and the second load terminal (N).

[0146] That is, the inverter unit (100) may be the conversion circuit (100) described above, and the inverter device (1000) may be a device including the inverter unit (100) and the control unit (200) that controls power conversion of the inverter unit (100).

[0147] The above control unit (200) may be a control device formed as a circuit module that is separable from the inverter unit (100).

[0148] That is, each of the inverter unit (100) and the control unit (200) can be formed in the form of separate modules.

[0149] The above control unit (200) may also be a control module included in the inverter unit (100).

[0150] The above control unit (200) can control the inverter unit (100) by applying a control signal to the inverter unit (100).

[0151] The above control unit (200) can control the inverter unit (100) by controlling the control signal applied to the inverter unit (100).

[0152] The control unit (200) controls the switching operation of the conversion unit (20) by applying a switching signal for controlling the switching operation to the conversion unit (20), and controls the switching operation of the conversion unit (30) by applying a switching signal for controlling the switching operation to the conversion unit (30), thereby controlling the power conversion and supply of the inverter unit (100).

[0153] The above control unit (200) can control each of the first conversion unit (21) to the third conversion unit (23) included in the conversion unit (20).

[0154] That is, the control unit (200) can control the switching operation of each of the first conversion unit (21) to the third conversion unit (23) by applying a switching signal to each of the first conversion unit (21) to the third conversion unit (23).

[0155] The above control unit (200) can also control each of the first switching unit (31) and the second switching unit (32) included in the switching unit (30).

[0156] That is, the control unit (200) can control the switching operation of each of the first switching unit (31) and the second switching unit (23) by applying a switching signal to each of the first switching unit (31) and the second switching unit (32).

[0157] In this way, in the inverter device (1000) including the inverter unit (100) and the control unit (200), the first switching unit (31) and the second switching unit (32) can operate differently from each other.

[0158] The first switching unit (31) and the second switching unit (32) can operate in an OFF state when one of them is in an ON state.

[0159] That is, when the first switching unit (31) operates ON, the second switching unit (32) operates OFF, and when the first switching unit (31) operates OFF, the second switching unit (32) operates ON.

[0160] The above control unit (200) can control the operation of each of the first switching unit (31) and the second switching unit (32) so that the first switching unit (31) and the second switching unit (32) operate differently from each other.

[0161] For example, when an ON operation signal is applied to the first switching unit (31), an OFF operation signal is applied to the second switching unit (32), so that the first switching unit (31) and the second switching unit (32) can be controlled to operate in opposite directions.

[0162] The above control unit (200) can control the operation of the conversion unit (20) and the switching unit (30) differently when the driving method corresponds to linked driving in which the driving method is operated in conjunction with the system and when the driving method corresponds to independent driving in which the driving method is operated separately from the system.

[0163] For example, when the above-mentioned linked operation is applicable, the operation control of the conversion unit (20) and the switching unit (30) may be controlled in mode A, and when the above-mentioned independent operation is applicable, the operation control of the conversion unit (20) and the switching unit (30) may be controlled in mode B, which is different from mode A.

[0164] The above control unit (200) can control the operation of the conversion unit (20) in the first control mode while the driving method corresponds to the linked driving.

[0165] Here, the first control mode may be any type of PWM control mode that controls the switching operation of the conversion unit (20).

[0166] The above first control mode may be, for example, an L2N PWM control mode.

[0167] The above control unit (200) can control the operation of the conversion unit (20) in a second control mode different from the first control mode while the driving method corresponds to the independent driving.

[0168] Here, the second control mode may be any one type of the PWM control mode except the first control mode.

[0169] The second control mode may be, for example, a Split Phase PWM control mode.

[0170] Accordingly, the switching operation of the above-mentioned conversion unit (20) during the linked operation and the switching operation during the independent operation can be performed differently from each other.

[0171] That is, the above conversion unit (20) can perform different switching operations depending on whether the above linked operation or the above independent operation is performed.

[0172] The above control unit (200) can control the operation of the first conversion unit (31) to ON while the driving method corresponds to the linked driving, thereby connecting the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23).

[0173] That is, in the case of the linked operation, the control unit (200) can control the first switching unit (31) to operate ON as shown in FIG. 6.

[0174] The above control unit (200) can separate the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23) by controlling the operation of the first conversion unit (31) to OFF while the driving method corresponds to the independent driving.

[0175] That is, in the case of the independent operation, the control unit (200) can control the first switching unit (31) to operate OFF as shown in Fig. 7.

[0176] Accordingly, the first conversion unit (31) can be turned ON as shown in FIG. 6 when the inverter device (1000) is operated in the linked operation to connect the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23), and can be turned OFF as shown in FIG. 7 when the inverter device (1000) is operated in the independent operation to separate the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23).

[0177] The above control unit (200) can separate the output terminal of the second conversion unit (22) and the second load terminal (N) by controlling the operation of the second switching unit (32) to OFF while the driving method corresponds to the linked driving.

[0178] That is, in the case of the linked operation, the control unit (200) can control the second switching unit (32) to operate OFF as shown in FIG. 6.

[0179] The above control unit (200) can control the operation of the second switching unit (32) to ON while the driving method corresponds to the independent driving, thereby connecting the output terminal of the second conversion unit (22) and the second load terminal (N).

[0180] That is, in the case of the independent operation, the control unit (200) can control the second switching unit (32) to operate ON as shown in FIG. 7.

[0181] Accordingly, the second switching unit (32) is turned OFF as shown in FIG. 6 when the inverter device (1000) is operated in the linked operation, thereby separating the output terminal of the second switching unit (22) and the second load terminal (N), and is turned ON as shown in FIG. 7 when the inverter device (1000) is operated in the independent operation, thereby connecting the output terminal of the second switching unit (22) and the second load terminal (N).

[0182] The specific control process of the above control unit (200) may be as shown in FIG. 8.

[0183] As illustrated in Fig. 8, when the operation of the inverter device (1000) starts (SS), the control unit (200) determines whether it is connected to the system (S10), and can control the conversion unit (20) and the switching unit (30) differently (S20 and S30) depending on whether it is connected.

[0184] The above control unit (200) can control (S21) the first switching unit (31) to operate ON and the second switching unit (32) to operate OFF, as shown in FIG. 6, in the case of the above-described linked operation that operates in conjunction with the above-described system.

[0185] In this case, the control unit (200) can apply different signals to each of the first switching unit (31) and the second switching unit (32).

[0186] For example, an ON operation signal can be applied to the first switching unit (31), and an OFF operation signal can be applied to the second switching unit (32).

[0187] The above control unit (200) can control (S21) the first switching unit (31) to operate ON and the second switching unit (32) to operate OFF, and then control (S23) the conversion unit (20) in the first control mode.

[0188] That is, if the result of determining whether or not there is a linkage (S10) is the linked operation, the control unit (200) controls the first switching unit (31) to operate ON and the second switching unit (32) to operate OFF as shown in FIG. 6 (S21), and then controls the conversion unit (20) according to the first control mode (S31) to control the operation performance (SE) of the inverter device (1000).

[0189] In this case, the power supply method to the supply target unit (L) may be a single-phase, two-wire system consisting of the first load unit (L1) and the third load unit (L2).

[0190] The above control unit (200) can control (S22) so that the first switching unit (31) operates OFF and the second switching unit (32) operates ON, as shown in FIG. 7, in the case of the separate operation that operates separately from the system.

[0191] In this case, the control unit (200) can apply different signals to each of the first switching unit (31) and the second switching unit (32).

[0192] For example, an OFF operation signal can be applied to the first switching unit (31), and an ON operation signal can be applied to the second switching unit (32).

[0193] The above control unit (200) can control the first switching unit (31) to operate OFF and the second switching unit (32) to operate ON (S22), and then control the conversion unit (20) to the second control mode (S32).

[0194] That is, if the control unit (200) determines (S10) that the connection is established and that the operation is separate, as shown in FIG. 7, the first switching unit (31) is controlled (S22) to operate OFF and the second switching unit (32) is controlled (S32) to operate ON, and then the conversion unit (20) is controlled (S32) according to the second control mode to control the operation performance (SE) of the inverter device (1000).

[0195] In this case, the power supply method to the supply target unit (L) may be a single-phase, three-wire system consisting of the first load unit (L1), the second load unit (N), and the third load unit (L2).

[0196] In this way, the embodiment of the inverter device (1000) in which the control unit (200) controls the inverter unit (100) to perform switching between single-phase two-wire and single-phase three-wire, or the linked operation and the independent operation, may also be implemented as an embodiment of a control method of the inverter device (hereinafter, referred to as a control method).

[0197] The above control method can also be implemented as an operating method of the inverter device (1000).

[0198] In addition, the above control method may be implemented in a way that the control unit (200) of the inverter device (1000) controls the inverter unit (100).

[0199] The control method is a method of controlling the inverter device (1000) including the link unit (10), the conversion unit (20) including the first conversion unit (21) to the third conversion unit (23), and the first conversion unit (31) which connects the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23) when the ON operation is on and separates the output terminal of the second conversion unit (22) and the output terminal of the third conversion unit (23) when the OFF operation is on, and the second conversion unit (32) which connects the output terminal of the second conversion unit (22) and the second load terminal (N) when the ON operation is on and separates the output terminal of the second conversion unit (22) and the second load terminal (N) when the OFF operation is on, and the step (S10) of determining whether there is a connection between the inverter device (1000) and the system after starting operation, as shown in FIG. 9, It includes a step (S20) of controlling the operation of the first switching unit (31) and the operation of the second switching unit (32) differently depending on whether or not the first switching unit (31) and the second switching unit (32) are in operation, and a step (S30) of controlling the operation of the conversion unit (20) depending on the operation status of the first switching unit (31) and the second switching unit (32).

[0200] That is, the control unit (200) can control the inverter unit (1000) in the following order: after the inverter device (1000) starts operation (SS), determines whether there is a connection between the inverter device (1000) and the system (S10), controls the operation of the first switching unit (31) and the operation of the second switching unit (32) differently depending on whether there is a connection (S20), and controls the operation of the conversion unit (20) depending on the operation states of the first switching unit (31) and the second switching unit (32) (S30).

[0201] Here, at least one of the first conversion unit (21) and the second conversion unit (22) may include at least one element having an inductance component.

[0202] The control method, which includes a step (S10) of determining whether or not there is a linkage, a step (S20) of controlling the operation of the first switching unit (31) and the operation of the second switching unit (32) differently from each other, and a step (S30) of controlling the operation of the conversion unit (20), may be performed in the order shown in FIG. 8.

[0203] The step (S20) of controlling the operation of the first switching unit (31) and the operation of the second switching unit (32) differently from each other can, as a result of determining whether or not there is a linkage (S10), if it is linked to the system, turn the first switching unit (31) ON and turn the second switching unit (32) OFF (S21), as shown in FIG. 6.

[0204] The step (S20) of controlling the operation of the first switching unit (31) and the operation of the second switching unit (32) differently from each other can, as shown in Fig. 7, turn the first switching unit (31) OFF and turn the second switching unit (32) ON (S22) if the system is separated as a result of determining whether or not it is connected (S10).

[0205] The step (S30) of controlling the operation of the above conversion unit (20) can control the operation of the above conversion unit (20) in the first control mode (S31) when the above first conversion unit (31) is in the ON operation (S21).

[0206] The step (S30) of controlling the operation of the above conversion unit (20) can control the operation of the above conversion unit (20) in the second control mode (S32) which is different from the first control mode when the second switching unit (32) is in the ON operation (S22).

[0207] So far, the above-described conversion circuit (100), the above-described inverter device (1000), and the above-described control method have been described in detail, but the described embodiments may be modified in various ways without departing from the scope of the present invention. The scope of the present invention should not be limited to the described embodiments, but should be determined by the claims described below as well as equivalents thereof.

Claims

1. In the power conversion circuit of the inverter device, Link unit that stores DC power; A first conversion unit that converts the DC power into a first power source and outputs it to a first load terminal of a supply target unit; A second conversion unit that converts the DC power into a second power and outputs it to a second load terminal of the supply target unit; A third conversion unit that converts the DC power into a third power source and outputs it to a third load terminal of the supply target unit; A first switching unit that connects or disconnects the output terminal of the second switching unit and the output terminal of the third switching unit; and It includes a second switching unit that connects or disconnects between the output terminal of the second switching unit and the second load terminal, The above first switching unit and the above second switching unit, A power conversion circuit of an inverter device characterized by different operations depending on whether it is connected to a grid.

2. In paragraph 1, The output terminal of the above first converter is, A power conversion circuit of an inverter device characterized by including an element having an inductance component.

3. In paragraph 1, The output terminal of the above second converter is A power conversion circuit of an inverter device, characterized in that it includes an element having an inductance component at one end of the first switching section.

4. In paragraph 1, The output terminal of the third converter is A power conversion circuit of an inverter device characterized in that the inductance component is formed smaller than that of the first conversion unit and the second conversion unit.

5. In paragraph 1, The above first switching unit is, A power conversion circuit of an inverter device, characterized in that it is arranged between the output terminal of the second conversion unit and one end of the second conversion unit.

6. In paragraph 1, The above first switching unit is, A power conversion circuit of an inverter device characterized in that the power conversion circuit connects the output terminal of the second conversion unit and the output terminal of the third conversion unit when the power conversion circuit is operated in conjunction with the system.

7. In paragraph 1, The above first switching unit is, A power conversion circuit of an inverter device characterized in that the output terminal of the second conversion unit and the output terminal of the third conversion unit are separated when the power conversion circuit is operated separately from the system.

8. In paragraph 1, The above second switching unit is, A power conversion circuit of an inverter device, characterized in that it is arranged between one end of the first switching unit and the second load end.

9. In paragraph 1, The above second switching unit is, A power conversion circuit of an inverter device characterized in that the output terminal of the second conversion unit and the second load terminal are separated when the power conversion circuit is operated in conjunction with a system.

10. In paragraph 1, The above second switching unit is, A power conversion circuit of an inverter device characterized in that the power conversion circuit is connected between the output terminal of the second conversion unit and the second load terminal when the power conversion circuit is operated separately from the system.

11. In the inverter device, Link unit that stores DC power; A conversion unit that receives the DC power from the link unit and converts it into power to be supplied to the supply target unit; A switching unit that switches the connection between the conversion unit and the supply target unit according to the operation method of the inverter device; and In an inverter device including a control unit that controls the conversion unit and the switching unit according to the above driving method, The above conversion part, A first conversion unit that converts the DC power into a first power source and outputs it to a first load terminal of the supply target unit; A second conversion unit that converts the DC power into a second power and outputs it to the second load terminal of the supply target unit; and Includes a third conversion unit that converts the DC power into a third power source and outputs it to a third load terminal of the supply target unit, The above switching part is, A first switching unit that connects or disconnects the output terminal of the second conversion unit and the output terminal of the third conversion unit by switching the ON / OFF operation; and Includes a second switching unit that switches ON / OFF operation to connect or disconnect between the output terminal of the second converter unit and the second load terminal, The above first switching unit and the above second switching unit, An inverter device characterized by operating differently from each other.

12. In paragraph 11, The above first switching unit and the above second switching unit, An inverter device characterized in that when one of the devices is turned on, the other device is turned off.

13. In paragraph 11, The above control unit, An inverter device characterized in that the operation control of the conversion unit and the switching unit is different when the above operation method corresponds to linked operation in which the operation is performed in conjunction with the system and when the above operation method corresponds to independent operation in which the operation is performed separately from the system.

14. In paragraph 13, The above control unit, While the above driving method corresponds to the above linked driving, Control the operation of the above conversion unit in the first control mode, While the above driving method corresponds to the above independent driving, An inverter device characterized in that the operation of the above-mentioned conversion unit is controlled in a second control mode different from the first control mode.

15. In paragraph 13, The above control unit, While the above driving method corresponds to the above linked driving, Controlling the operation of the first conversion unit to ON to connect the output terminal of the second conversion unit and the output terminal of the third conversion unit, While the above driving method corresponds to the above independent driving, An inverter device characterized in that the operation of the first conversion unit is controlled to OFF to separate the output terminal of the second conversion unit and the output terminal of the third conversion unit.

16. In paragraph 13, The above control unit, While the above driving method corresponds to the above linked driving, By controlling the operation of the second switching unit to OFF, the output terminal of the second switching unit and the second load terminal are separated, While the above driving method corresponds to the above independent driving, An inverter device characterized in that the operation of the second switching unit is controlled to ON to connect the output terminal of the second switching unit and the second load terminal.

17. Link section for storing DC power; A first conversion unit that converts the DC power into a first power source and outputs it to a first load terminal of a supply target unit; A second conversion unit that converts the DC power into a second power and outputs it to the second load terminal of the supply target unit; and A conversion unit including a third conversion unit that converts the DC power into a third power and outputs it to a third load terminal of the supply target unit; A first switching unit that connects the output terminal of the second conversion unit and the output terminal of the third conversion unit when in the ON operation, and separates the output terminal of the second conversion unit and the output terminal of the third conversion unit when in the OFF operation; and A control method for an inverter device including a second switching unit that connects the output terminal of the second conversion unit and the second load terminal when in an ON operation and separates the output terminal of the second conversion unit and the second load terminal when in an OFF operation, After starting operation, a step of determining whether there is a connection between the inverter device and the grid; A step of controlling the operation of the first switching unit and the operation of the second switching unit differently depending on whether the above linkage is established; and A control method for an inverter device, characterized in that it comprises a step of controlling the operation of the conversion unit according to the operating states of the first conversion unit and the second conversion unit.

18. In paragraph 17, At least one of the first conversion unit and the second conversion unit, A control method for an inverter device, characterized in that it includes an element having an inductance component.

19. In paragraph 17, The step of controlling the operation of the first switching unit and the operation of the second switching unit differently from each other is: If linked to the above system, Turning the first switching unit ON and turning the second switching unit OFF, If separated from the above system, A control method for an inverter device characterized by turning the first switching unit OFF and turning the second switching unit ON.

20. In paragraph 17, The step of controlling the operation of the above conversion unit is: When the above first switching unit is in ON operation, Control the operation of the above conversion unit in the first control mode, When the above second switching unit is in ON operation, A control method for an inverter device, characterized in that the operation of the above-mentioned conversion unit is controlled in a second control mode different from the first control mode.

Images