Power conversion device

Abstract

A power conversion device according to an embodiment of the present invention comprises: a first switching unit that is turned on when a power failure occurs; a power failure signal generation unit that supplies auxiliary power to a power conversion unit when the first switching unit is turned on, and transmits a power failure signal; a control unit that requests power to be supplied from a vehicle and controls the power conversion unit; and the power conversion unit that converts power under the control of the control unit, wherein the power conversion unit receives power from the vehicle, and converts and outputs to a load.

Description

power conversion device

[0001] The present invention relates to a power conversion device.

[0002] Solar power generation is becoming widely adopted as an eco-friendly energy source, replacing conventional chemical and nuclear power generation. Solar power generation can be either standalone, with a battery connected to a converter, or grid-connected. Standalone systems typically consist of solar cells, storage batteries, and power conversion equipment, while grid-connected systems are connected to commercial power sources, enabling the exchange of power with load grid lines.

[0003] The power generated by solar panels cannot be directly supplied to the load or the power grid. Therefore, it is converted into usable power using a power conversion device such as an inverter. Furthermore, the power generated by solar panels can be stored in batteries, which can then be supplied to the load or the grid. A DC-DC converter controls the charging and discharging of the batteries. When multiple batteries are configured in parallel, the DC-DC converter, which converts the power of the batteries, performs voltage balancing between the batteries. Loads for the power conversion device may include home vehicle chargers.

[0004] Home vehicle charging devices utilize AC power from the grid to charge a vehicle's battery. When using AC power from the grid, power outages, etc., can make it difficult to charge the vehicle and even use the device in the home.

[0005] The technical challenge of the present invention is to provide a power conversion device capable of operating during a power outage. Furthermore, the present invention provides a power conversion device that controls multiple power conversion units connected in parallel. Furthermore, the present invention provides a power conversion device capable of initial operation through communication with an MLPE.

[0006] In order to solve the above technical problem, a power conversion device according to an embodiment of the present invention includes a first switching unit that is turned on during a power outage; a power outage signal generating unit that supplies auxiliary power to a power conversion unit and transmits a power outage signal when the first switching unit is turned on; a control unit that requests power supply to a vehicle according to the power outage signal and controls the power conversion unit; and a power conversion unit that performs power conversion according to the control of the control unit, wherein the power conversion unit receives power from the vehicle, converts the power, and outputs the converted power to a load.

[0007] In addition, the power supply unit includes a battery connected to the power supply signal generating unit, and the power supply signal generating unit can receive power from the battery and output it to the power conversion unit when the first switching unit is turned on.

[0008] In addition, the power failure signal generating unit includes a voltage receiving unit that receives a first voltage from the power conversion unit, and the power failure signal generating unit can transmit the power failure signal to the power conversion unit when the voltage receiving unit does not receive the first voltage when the first switching unit is turned on.

[0009] In addition, the static signal generating unit may not generate the static signal when the voltage receiving unit receives the first voltage when the first switching unit is turned on.

[0010] In addition, the power conversion unit can supply the first voltage to the power failure signal generation unit when power is supplied from the vehicle.

[0011] Additionally, the first switching unit may include a physical switch that is operated by an external force.

[0012] In addition, it may include a communication unit that operates using the auxiliary power source in the event of a power outage and transmits the power supply to the vehicle.

[0013] Additionally, the communication unit can receive status information of the vehicle's battery from the vehicle and transmit it to the control unit.

[0014] Additionally, the above load may include a domestic load.

[0015] In addition, the power conversion unit can convert power input from the grid and output it to the vehicle, and can convert power input from the vehicle and output it to the load.

[0016] In order to solve the above technical problem, a power conversion device according to a second embodiment of the present invention includes a first power conversion unit connected to a solar power generation module; a second power conversion unit connected to a grid; a DC link connected between the first power conversion unit and the second power conversion unit; and a plurality of third power conversion units connected to the DC link and connected to an energy storage device.

[0017] In addition, the plurality of third power conversion units may include a 3-1 power conversion unit and a 3-2 power conversion unit connected in parallel, and may include a switching element connecting an input / output terminal of the 3-1 power conversion unit and an input / output terminal of the 3-2 power conversion unit.

[0018] In addition, the plurality of third power conversion units may be connected to one energy storage device, the switching element may be turned on, and the third-first power conversion unit and the third-second power conversion unit may be connected to the one energy storage device.

[0019] In addition, the input / output terminal of the 3-1 power conversion unit may be connected to the energy storage device, and the input / output terminal of the 3-2 power conversion unit may be connected to the energy storage device through the switching element.

[0020] Additionally, the 3-1 power conversion unit and the 3-2 power conversion unit can be controlled in an interleaving manner.

[0021] In addition, the plurality of third power conversion units are connected to two energy storage devices, the switching element is turned off, and the third-first power conversion unit and the third-second power conversion unit can each be individually connected to one of the two energy storage devices.

[0022] Additionally, the 3-1 power conversion unit and the 3-2 power conversion unit can be independently controlled.

[0023] In addition, the control unit for controlling the third power conversion unit is included, and the control unit, when communication is connected with the energy storage device, turns off the switching element, measures the voltage of the 3-1 power conversion unit and the voltage of the 3-2 power conversion unit, and when only one of the voltage of the 3-1 power conversion unit and the voltage of the 3-2 power conversion unit is measured, turns on the switching element, and when both the voltage of the 3-1 power conversion unit and the voltage of the 3-2 power conversion unit are measured, turns off the switching element.

[0024] In addition, the control unit can control the 3-1 power conversion unit and the 3-2 power conversion unit in an interleaving manner after turning on the switching element.

[0025] Additionally, the first power conversion unit and the third power conversion unit may be DC-DC converters, and the second power conversion unit may be an inverter.

[0026] In order to solve the above technical problem, a power conversion device according to a third embodiment of the present invention includes a first power conversion unit connected to a solar power generation module; a second power conversion unit connected to a grid; a DC-link connected between the first power conversion unit and the second power conversion unit; an auxiliary power generation unit that generates auxiliary power using power of the DC-link; a communication unit that communicates with a control device of the solar power generation module; and a fifth power conversion unit that converts power of the DC-link and supplies the converted power to the communication unit, wherein the fifth power conversion unit converts the DC-link power and applies the converted power to the communication unit when the voltage of the DC-link is lower than or equal to a first voltage.

[0027] Additionally, if the voltage of the DC-link is greater than the first voltage, the fifth power conversion unit stops operating, and the auxiliary power generation unit can generate the auxiliary power using the DC-link voltage.

[0028] Additionally, the fifth power conversion unit may include a step-up converter.

[0029] In addition, the communication unit can receive power from the fifth power conversion unit and transmit an operation signal to the control device of the solar power generation module.

[0030] Additionally, when the control device of the solar power generation module operates in RSD (Rapid Shut Down) mode, the voltage of the DC link may become lower than the first voltage.

[0031] Additionally, the control device of the solar power generation module may include MLPE.

[0032] Additionally, the communication unit can perform power line communication with the control device of the solar power generation module.

[0033] In addition, the auxiliary power generation unit may include a third power conversion unit that converts direct current power of the DC-link; and a fourth power conversion unit that converts alternating current power of the grid into direct current power and applies the converted power to the third power conversion unit.

[0034] Additionally, the fourth power conversion unit can operate when the voltage of the DC link is lower than the second voltage.

[0035] In addition, the DC-link is electrically connected to an energy storage device, and the auxiliary power generation unit can generate the auxiliary power using power from any one of the solar power generation module, the energy storage device, and the grid applied to the DC-link. In order to solve the above technical problem, a power conversion device according to a fourth embodiment of the present invention includes a first power conversion unit connected to a solar power generation module; a second power conversion unit connected to a grid; a DC-link connected between the first power conversion unit and the second power conversion unit; an auxiliary power generation unit that generates auxiliary power using power of the DC-link; a communication unit that communicates with a control device of the solar power generation module; and a communication power supply unit that supplies power of the DC-link to the communication unit as power, wherein the communication power supply unit applies the DC-link power to the communication unit when a voltage of the DC-link is lower than or equal to a first voltage.

[0036] Additionally, if the voltage of the DC-link is greater than the first voltage, the communication power supply unit stops supplying the DC-link power as power to the communication unit, and the auxiliary power generation unit can generate the auxiliary power using the DC-link voltage.

[0037] Additionally, the communication power supply unit may include a bypass circuit.

[0038] In addition, the communication unit can receive power from the communication power supply unit and transmit an operation signal to the control device of the solar power generation module.

[0039] Additionally, when the control device of the solar power generation module operates in RSD (Rapid Shut Down) mode, the voltage of the DC link may become lower than the first voltage.

[0040] Additionally, the control device of the solar power generation module may include MLPE.

[0041] Additionally, the communication unit can perform power line communication with the control device of the solar power generation module.

[0042] In addition, the auxiliary power generation unit may include a third power conversion unit that converts direct current power of the DC-link; and a fourth power conversion unit that converts alternating current power of the grid into direct current power and applies the converted power to the third power conversion unit.

[0043] Additionally, the fourth power conversion unit can operate when the voltage of the DC link is lower than the second voltage.

[0044] In addition, the DC link is electrically connected to an energy storage device, and the auxiliary power generation unit can generate the auxiliary power using power from any one of the solar power generation module, the energy storage device, or the grid applied to the DC link.

[0045] According to embodiments of the present invention, operation is possible by configuring an auxiliary power source using a battery during a power outage. Furthermore, power can be supplied to household loads by linking with the vehicle's battery during stationary operation.

[0046] Additionally, one or more energy storage systems (ESS) can be connected, including multiple DC-DC converters that charge and discharge battery power. For one ESS, two DC-DC converters can operate interleavedly, reducing heat generation and distributing power consumption. By applying a separate DC-DC converter to each ESS, rapid charging and discharging can be performed without voltage balancing.

[0047] In addition, even if the MLPE is in RSD operation with no power from the grid and energy storage device and power supplied to the solar power generation module, the initial operation of the PV inverter is possible with a power switch configuration that enables PLC communication with a DC-link power of approximately 10 to 30 V.

[0048] Figure 1 is a block diagram of a power conversion device according to a first embodiment of the present invention.

[0049] Figures 2 to 4 are block diagrams of a power conversion device according to an embodiment of the present invention.

[0050] FIG. 5 and FIG. 6 are drawings for explaining a system configuration to which a power conversion device according to an embodiment of the present invention is applied.

[0051] Figure 7 is a drawing for explaining the operation of a power conversion device according to an embodiment of the present invention.

[0052] Figure 8 illustrates a system to which a power conversion device according to the second embodiment of the present invention is applied.

[0053] Figure 9 is a block diagram of a power conversion device according to a second embodiment of the present invention.

[0054] Figures 10 to 15 are drawings for explaining the configuration of a power conversion device according to the second embodiment of the present invention.

[0055] Figure 16 illustrates a system to which a power conversion device according to the third embodiment of the present invention is applied.

[0056] Figure 17 is a block diagram of a power conversion device according to a third embodiment of the present invention.

[0057] Figures 18 to 22 are drawings for explaining the configuration of a power conversion device according to a third embodiment of the present invention.

[0058] Figure 23 is a block diagram of a power conversion device according to the fourth embodiment of the present invention.

[0059] FIGS. 24 to 27 are drawings for explaining the configuration of a power conversion device according to the embodiment of FIG. 23.

[0060] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0061] However, the technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of ​​the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

[0062] In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which the present invention belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0063] Additionally, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention.

[0064] In this specification, the singular may also include the plural unless specifically stated otherwise in the phrase, and when it is described as “A and / or at least one (or more) of B, C”, it may include one or more of all combinations that can be combined with A, B, C.

[0065] Additionally, in describing components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and are not intended to limit the nature, order, or sequence of the components.

[0066] And, when a component is described as being 'connected', 'coupled', or 'connected' to another component, it may include not only cases where the component is 'connected', 'coupled', or 'connected' directly to the other component, but also cases where the component is 'connected', 'coupled', or 'connected' by another component between the component and the other component.

[0067] Additionally, when described as being formed or arranged "above" or "below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Furthermore, when expressed as "above" or "below," the meaning may include not only the upward direction but also the downward direction based on one component.

[0068] A variation according to the present embodiment may include some components of each embodiment and some components of other embodiments. That is, a variation may include one embodiment among various embodiments, but may omit some components and include some components of the corresponding other embodiment. Or, the opposite may be true. The features, structures, effects, etc. to be described in the embodiments are included in at least one embodiment, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by a person having ordinary skill in the art to which the embodiments belong. Therefore, the contents related to such combinations and modifications should be interpreted as being included within the scope of the embodiments.

[0069] Figure 1 is a block diagram of a power conversion device (100) according to one embodiment of the present invention.

[0070] A power conversion device (100) according to an embodiment of the present invention is composed of a power conversion unit (110), a first switching unit (120), a power failure signal generation unit (130), and a control unit (150), and may include a battery (140), a communication unit (160), a second switching unit (520), and a third switching unit (510). The power conversion device (100) according to an embodiment of the present invention may be a bidirectional EV charger, which is a vehicle charging device.

[0071] The power conversion unit (110) converts and outputs the input power. It can receive AC power from the grid (200), convert it into DC power, and output it to the vehicle (300). In addition to the grid, power can also be received from a DC power source such as a solar power generation module or a battery. The vehicle (300) includes a battery that is charged through the power conversion device (100), and may be an electric vehicle or a hybrid vehicle. In addition, the power conversion unit (110) can receive DC power from the vehicle (300), convert it into AC power, and output it to the load (400). The load (400) may include a household load. It may include a household load in which the power conversion device (100) is installed, such as a household light fixture or home appliance. The load (400) may operate by receiving power from the grid (200) or by receiving power output from the power conversion unit (110). The power conversion unit (110) may be a bidirectional AC-DC converter that converts power in both directions.

[0072] The first switching unit (120) is turned on in the event of a power outage. Here, a power outage refers to a state in which power is not supplied from the grid (200). If the power supply from the grid (200) is cut off, the operation of the power conversion unit (110) or the load (400) that was operating by receiving power from the grid (200) may stop. The first switching unit (120) may include a switch or relay that is turned off in a normal state and turned on in the event of a power outage.

[0073] The first switching unit (120) may include a physical switch that operates by an external force. The first switching unit (120) may operate when an external force is applied by a person or an external device in the event of a power outage. Alternatively, the first switching unit (120) may be turned on in response to an operation signal from an external device.

[0074] The power failure signal generation unit (130) supplies auxiliary power to the power conversion unit (110) when the first switching unit (120) is turned on and transmits a power failure signal. When the first switching unit (120) is turned on during a power failure, the power failure signal generation unit (130) transmits the power failure signal to the power conversion unit (110). At this time, the power failure signal generation unit (130) can provide auxiliary power to the power conversion unit (110) so that the power conversion unit (110) can operate.

[0075] The power failure signal generation unit (130) can operate when the first switching unit (120) is turned on, by forming a path for current flow. At this time, a power failure signal, such as an enable signal, can be transmitted to the power conversion unit (110) through a communication line or power line connected to the power failure signal generation unit (130) and the power conversion unit (110).

[0076] The battery (140) can be connected to the static signal generation unit (130), and the static signal generation unit (130) can receive power from the battery (140) when the first switching unit (120) is turned on and output the power to the power conversion unit (110). When the first switching unit (120) is turned on, power is connected to the battery (140) - static signal generation unit (130) - power conversion unit (110), so that the power of the battery (140) can be supplied as an auxiliary power source to the power conversion unit (110).

[0077] The power failure signal may be transmitted to the power conversion unit (110) through a separate communication line from the auxiliary power source. Alternatively, the power failure signal may be transmitted to the power conversion unit (110) through PLC communication, etc. together with the auxiliary power source.

[0078] The control unit (150) requests power supply to the vehicle (300) according to the power outage signal and controls the power conversion unit (110). The control unit (150) can control the power conversion unit (110) to convert power in both directions. That is, the control unit (150) can control the power conversion unit (110) to receive power from the grid (200), convert it, and output it to the vehicle (300), or control the power conversion unit (110) to receive power from the vehicle (300), convert it, and output it to the load (400). When the control unit (150) receives the power outage signal generated by the power outage signal generation unit (130) through the power conversion unit (110) or directly, it can request power supply to the vehicle (300) according to the power outage signal. The control unit (150) may be a controller that controls the power conversion unit (110). Alternatively, it may be a SECC (Supply Equipment Communication Controller) that controls communication of the power conversion device (100). The SECC is a supply equipment communication controller that communicates with the EVCC (Electric Vehicle Communication Controller), which is an electric vehicle communication controller of the vehicle, to control connection and charging between the charging device and the vehicle.

[0079] In addition, it may include a communication unit (160) that is driven using the auxiliary power source during a power outage and transmits power supply to the vehicle (300). The communication unit (160) may communicate with the communication unit (330) of the vehicle to control the power conversion unit (110) and the power conversion unit (320) of the vehicle to be connected to each other and transmit power. Here, the communication unit (160) may be an SECC, and the communication unit (330) of the vehicle may be an EVCC. The communication unit (160) may be an SECC, and the control unit (150) may be a controller of the power conversion unit (110).

[0080] The vehicle (300) may include a vehicle communication unit (330) which is an EVCC, a vehicle battery (310), and a vehicle power conversion unit (320) which is a PDU (Power Distribution Unit) that receives power from a power conversion device (100) to charge the battery (310). Here, the vehicle power conversion unit (320) may be an HV junction box, and the vehicle battery (310) may be an HV battery. In addition, the vehicle (300) may include a VCU (Vehicle control unit) that drives the vehicle using power from the vehicle battery (310). The EVCC which is the vehicle communication unit (330) may perform control by performing CAN communication with the vehicle battery (310), the vehicle power conversion unit (320), and the VCU (not shown) or receive BMS (Battery Management System) data, etc.

[0081] The communication unit (160) can receive status information of the vehicle's battery (310) from the vehicle (300) and transmit it to the control unit (150). Here, the status information of the vehicle's battery (310) may be BMS data. The control unit (150) can control the power conversion unit (110) using the status information of the vehicle's battery (310).

[0082] When the control unit (150) receives a power outage signal, it can control the power conversion unit (110) to receive power from the vehicle (300), convert it, and output it to the load (400). The power conversion unit (110) can receive power from the battery (310) of the vehicle (300), convert it, and output it to the load (400). The power conversion unit (110) can convert DC power, which is the power source of the vehicle's battery (310), into AC power, and output it to the load (400).

[0083] The power failure signal generation unit (130) may include a voltage reception unit (131) that receives a first voltage from the power conversion unit (110). The power failure signal generation unit (130) may transmit the power failure signal to the power conversion unit (110) when the voltage reception unit (131) does not receive the first voltage when the first switching unit (120) is turned on. The power failure signal generation unit (130) may not generate the power failure signal when the voltage reception unit (131) receives the first voltage when the first switching unit (120) is turned on.

[0084] The voltage receiving unit (131) can receive the first voltage from the power conversion unit (110) in a normal state, not in a power outage state. When the first switching unit (120) is turned on and is not receiving the first voltage from the power conversion unit (110), it means that the operation of the power conversion unit (110) has stopped, and the power outage signal generating unit (130) can supply auxiliary power to the power conversion unit (110) and transmit a power outage signal. Through this, the power conversion unit (110) can receive power from the vehicle (300), convert it, and output it to the load (400). When the power conversion unit (110) receives power from the vehicle (300), it can supply the first voltage to the power outage signal generating unit (130) again. The power failure signal generation unit (130) serves to restart the power conversion unit (110) that has stopped operating due to a power failure, and when the power conversion unit (110) is operating normally, it stops generating the power failure signal by receiving the first voltage. Through this, the first switching unit (120) can be turned off again, and the auxiliary power supply to the battery (140) can be cut off, thereby reducing the power consumption of the battery (140).

[0085] When receiving the first voltage from the power conversion unit (110), it means that the power conversion unit (110) is operating, and even if the first switching unit (120) is turned on, the power failure signal generation unit (130) may not transmit the power failure signal or auxiliary power to the power conversion unit (110). Through this, malfunction of the first switching unit (120), etc., may be prevented. Alternatively, even if the first switching unit (120) is turned on, when receiving the first voltage from the power conversion unit (110), the power failure signal generation unit (130) may transmit the power failure signal but not supply auxiliary power.

[0086] The power conversion unit (110) may be connected to the grid (200) or the load (400) through a backup box (500). The backup box may include a second switching unit (520) connecting the load (400) and the power conversion unit (110) and a third switching unit (510) connecting the grid (200) and the power conversion unit (110). Here, the second switching unit (520) and the third switching unit (510) may include a relay.

[0087] In a normal state, the second switching unit (520) and the third switching unit (510) are turned on so that power from the grid (200) can be input to the power conversion unit (110) and supplied to the load (400). In the event of a power outage, the third switching unit (510) connected to the grid (200) is turned off so that the connection with the grid (200) is cut off, and the second switching unit (520) connected to the load (400) is turned on so that power output from the power conversion unit (110) can be supplied to the load (400).

[0088] A system to which a power conversion device (100) according to an embodiment of the present invention is applied may be configured as shown in FIGS. 5 and 6. The power conversion device (100) may be connected to a vehicle (300) and may be connected to a grid (200) and a household load (400) via a backup box (500). The power conversion device (100) may convert power input from the grid (200) via the backup box (500) and supply it to the vehicle (300) to charge the battery of the vehicle (300), and may convert power input from the battery of the vehicle (300) and supply it to the load (400) via the backup box (500). The backup box (500) may also supply power input from the grid (200) to the load (400).

[0089] The power conversion unit (110) of the power conversion device (100) may be a bidirectional AC-DC power module, the first switching unit (120) may be a push switch, and the battery (140) may be a 9 V battery. The control unit (150) or the communication unit (160) may be an SECC.

[0090] The power module can be connected to the grid and the backup box's grid relay, and to the household load and the backup box's load relay. The power module can be connected to the battery (HV battery) of an electric vehicle (EV) (300) through the PDU. The SECC can communicate with the vehicle's EVCC.

[0091] 12V is applied to the blackout signal generating unit in the power module, but if 12V is not applied during a blackout, when the push switch is pressed and turned on during a blackout, a blackout signal (blackout signal) is applied to the power module, and power from the 9V battery can be supplied to the power module as auxiliary power (aux). Through this, the power module operates, and the SECC also operates as an auxiliary power source to communicate with the EVCC of the vehicle, and the power module can receive power from the vehicle battery, convert it, and supply power to the load in the home.

[0092] When a power outage occurs, it can operate as shown in Fig. 7. When a power outage occurs, the grid relay is turned off, power supply from the grid is cut off, and the auxiliary power is also cut off. At this time, when the switch is manually turned on, the power outage signal and the power of the 9V battery are transmitted to the power module as the auxiliary power. The power module transmits the power outage signal to the SECC, and the SECC transmits a power supply signal to the EVCC of the vehicle. Here, the power supply request signal may include a request to turn on the connection relay (DC_Batt + / - relay) with the vehicle (300). The EVCC transmits the power supply signal to the PDU to supply power from the vehicle's battery to the power module. The EVCC transmits the connection status and battery status information to the SECC, and the SECC transmits it to the power module, so that the power module operates and can perform a V2H (Vehicle to Home Load) operation that supplies the power converted by the power module to the load in the home.

[0093] Through this, it is possible to operate by configuring an auxiliary power source using the battery during a power outage, and to supply power to household loads by linking with the vehicle's battery during a power outage.

[0094] Figure 8 illustrates a system to which a power conversion device according to the second embodiment of the present invention is applied.

[0095] The power conversion device (10) according to the second embodiment of the present invention can form a solar power generation system together with a solar power generation module (21), an energy storage device (23), a load (24), and a grid (22).

[0096] The solar power generation module (210) may include module-level power electronics (MLPE, 25) that control the solar cells to operate at the maximum power point (MPP), which is the operating point where the solar cells produce the maximum power under each condition. The MLPE (25) may be referred to as an optimizer. In solar power generation, depending on the characteristics of the relationship between current and voltage and the relationship between voltage and power, the maximum power may be the power when the maximum voltage is about 80% of the maximum voltage, not the maximum voltage. Since this maximum power point continuously changes depending on the magnitude of the voltage and current generated by the photovoltaic panel, the point where the maximum power point can be generated must be continuously searched. That is, in order to pursue the maximum power, not the maximum voltage, the magnitude of the voltage and current can be varied so as to achieve the maximum power. That is, the voltage can be reduced and the current can be increased in the direction of increasing power, or the voltage can be increased and the current can be reduced.

[0097] The power conversion device (10) according to an embodiment of the present invention is connected to the MLPE (25) of the solar power generation module (21), receives power output from the solar power generation module (21), converts the received power and supplies it to a load (24), transmits it to a grid (22), or charges an energy storage device (23). Alternatively, the power charged in the energy storage device (23) can be converted and supplied to a load (24), or power can be received from the grid (22) and supplied to a load (24) or converted and charged to an energy storage device (23). In order to transmit and receive power between each component, it must be converted into power suitable for each component. The power conversion device (10) according to an embodiment of the present invention is placed between each component and serves to convert power.

[0098] FIG. 9 is a block diagram of a power conversion device according to a second embodiment of the present invention, and FIGS. 10 to 15 are drawings for explaining the configuration of a power conversion device according to the second embodiment of the present invention.

[0099] A power conversion device (2100) according to an embodiment of the present invention is composed of a first power conversion unit (2110), a second power conversion unit (2120), a DC link (2130), and a third power conversion unit (2140), and may include a control unit (2150), a communication unit (not shown), etc.

[0100] The first power conversion unit (2110) is connected to a solar power generation module (2210). The first power conversion unit (2110) receives power from the solar power generation module (2210) and converts it. The solar power generation module (2210) may include an MLPE, and the first power conversion unit (2110) may receive power through the MLPE. The communication unit may perform power line communication (2PLC) with the MLPE. Here, the first power conversion unit (2110) may include a DC-DC converter. It may include a DC-DC converter that converts the voltage of the power of the solar power generation module (2210), which is DC power, into the voltage of the power to be output to the DC link (2130) and outputs it.

[0101] The second power conversion unit (2120) is connected to the grid (2220). The second power conversion unit (2120) may be connected to a load. The second power conversion unit (2120) may convert power input to the DC-link (2130) and output it from the grid (2220), or convert power input from the grid (2220) and output it to the DC-link (2130). Here, the first power conversion unit (2110) may include an inverter. It may include a bidirectional DC-AC inverter that converts power input to the DC-link (2130), which is DC power, from direct current to alternating current and outputs it to the grid (2220), or converts power input from the grid (2220) from alternating current to direct current and outputs it to the DC-link (2130).

[0102] The third power conversion unit (2140) is connected to the energy storage device (2230). The third power conversion unit (2140) can convert power input to the DC link (2130) and output it to the energy storage device (2230), or convert power input from the energy storage device (2230) and output it to the DC link (2130). Here, the third power conversion unit (2140) may include a DC-DC converter. It may include a DC-DC converter that converts the voltage of power input to the DC link (2130), which is DC power, into a voltage for charging the energy storage device (2230), or converts the voltage of power of the energy storage device (2230) and outputs it to the DC link (2130).

[0103] The DC link (2130) is connected between the first power conversion unit (2110) and the second power conversion unit (2120). The DC link (2130) is connected between the first power conversion unit (2110), the second power conversion unit (2120), and the third power conversion unit (2140), and serves to transfer power output from each power conversion unit to another power conversion unit. The DC link (2130) may include a DC-link capacitor. Power input to the DC-link may be stored in the DC-link capacitor and output through the DC-link capacitor.

[0104] The third power conversion unit (2140) may include a plurality of third power conversion units. The plurality of third power conversion units may include a 3-1 power conversion unit (2141) and a 3-2 power conversion unit (2142) connected in parallel, and may include a switching element (2143) connecting an input / output terminal of the 3-1 power conversion unit (2141) and an input / output terminal of the 3-2 power conversion unit (2142).

[0105] The 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) may have the same specifications. Alternatively, they may have different specifications depending on the connected energy storage device (2230), and either the 3-1 power conversion unit (2141) or the 3-2 power conversion unit (2142) may have a priority in being connected to the energy storage device (2230). The 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) may be bidirectional converters. Alternatively, either the 3-1 power conversion unit (2141) or the 3-2 power conversion unit (2142) may be a step-up converter and the other may be a step-down converter, or both may be step-up converters or both may be step-down converters. The switching element (2143) may include at least one of a relay, a mechanical switch, or an electronic switch.

[0106] As shown in Fig. 10, the plurality of third power conversion units may include two third power conversion units (2141, 2142) connected in parallel. The 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) may each include an input / output terminal connected to the outside. An energy storage device may be connected to the input / output terminal of the 3-1 power conversion unit (2141) and the input / output terminal of the 3-2 power conversion unit (2142). A switching element (2143) may be included between the input / output terminal of the 3-1 power conversion unit (2141) and the input / output terminal of the 3-2 power conversion unit (2142), thereby connecting or blocking the input / output terminal of the 3-1 power conversion unit (2141) and the input / output terminal of the 3-2 power conversion unit (2142).

[0107] In addition, as shown in FIG. 11, it may include three or more third power conversion units (2141, 2142, 2144) connected in parallel, and the number of switching elements (2143, 2145) connecting the input / output terminals of neighboring power conversion units may also include two or more, depending on the number of third power conversion units (2141, 2142, 2144).

[0108] The plurality of third power conversion units (2140) can be configured in various forms depending on the connection status with the energy storage device (22330).

[0109] A plurality of third power conversion units are connected to one energy storage device (2230), and the switching element (2143) is turned on so that the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) can be connected to one energy storage device (2230). As shown in FIG. 12, when one energy storage device (2230) is connected, the switching element (2143) can be turned on so that both the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) can be connected to the energy storage device (2230) to perform power conversion. The input / output terminal of the 3-1 power conversion unit (2141) can be directly connected to the energy storage device (2230), and the input / output terminal of the 3-2 power conversion unit (2142) can be connected to the energy storage device (2230) through the switching element (2143).

[0110] The switching element (2143), the 3-1 power conversion unit (2141), and the 3-2 power conversion unit (2142) can be controlled by the control unit (2150). The control unit (2150) can control the switching element (2143) so that the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) can be connected to one energy storage device (2230).

[0111] The control unit (2150) can control the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) connected together to one energy storage device (2230) in an interleaving manner. Since two power conversion units (2141, 2142) are connected to one energy storage device (2230) and convert power in an interleaving manner, power can be efficiently converted, and thereby heat generated during power conversion can be reduced. The power conversion device (2100) according to an embodiment of the present invention is configured with a first power conversion unit (2110), a second power conversion unit (2120), and a plurality of third power conversion units (2140) as a single device or module, which generates a lot of heat. However, since the plurality of third power conversion units (2140) operate in an interleaving manner, heat generation can be reduced, and a large number of power conversion units can be included.

[0112] The control unit (2150) controls the switching element (2143) so that the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) can be connected to one energy storage device (2230), but instead of interleaving, one power conversion unit is controlled to convert power, and the other power conversion unit can be used as a reserve for control in case a failure occurs or one power conversion unit has difficulty performing power conversion. In addition, control can be performed in various ways.

[0113] A plurality of third power conversion units are connected to two energy storage devices (2231, 2232) instead of one energy storage device (2230), and the switching element (2143) is turned off, so that the third-first power conversion unit (2141) and the third-second power conversion unit (2142) can be individually connected to one of the two energy storage devices (2231, 2232). As shown in Fig. 13, when two energy storage devices (2231, 2232) are connected, the switching element (2143) is turned off to disconnect the connection between the input / output terminal of the 3-1 power conversion unit (2141) and the input / output terminal of the 3-2 power conversion unit (2142), and the input / output terminal of the 3-1 power conversion unit (2141) and the input / output terminal of the 3-2 power conversion unit (2142) can be individually connected to one energy storage device (2231, 2232) each.

[0114] By connecting multiple energy storage devices, the amount of power that the energy storage devices can store can be increased, so that the entire system can operate stably. When multiple energy storage devices are connected in series, one energy storage device connected to the power conversion device (2100) and the third power conversion unit (2140) are connected, so that the switching element (2143) is turned on so that both the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) are connected to the corresponding energy storage device to perform power conversion.

[0115] Alternatively, when connecting multiple energy storage devices, the multiple energy storage devices may be connected in parallel. This can improve charging and discharging efficiency and speed compared to when connecting multiple energy storage devices in series. In this case, when multiple energy storage devices (2231, 2232) connected in parallel are connected to a single power conversion unit (2140), voltage balancing must be performed between the multiple energy storage devices (2231, 2232). If voltage balancing is not performed between the multiple energy storage devices (2231, 2232), efficient charging and discharging may not occur, and problems such as overcharging or overdischarging may occur.

[0116] The control unit (2150) can control the switching element (2143) so that the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) can be independently connected to one energy storage device (2231, 2232), respectively. In addition, the control unit (2150) can independently control the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142). Since the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) are each connected to one energy storage device and independently perform charging and discharging, efficient charging and discharging is possible even without performing voltage balancing between the energy storage devices (2231, 2232).

[0117] The control unit (2150) can determine the connected energy storage device (22330) and control the switching element (2143), the 3-1 power conversion unit (2141), and the 3-2 power conversion unit (2142) accordingly.

[0118] When the control unit (2150) is connected to the energy storage device (2230), the control unit (2150) turns off the switching element (2143) and measures the voltage of the 3-1 power conversion unit (2141) and the voltage of the 3-2 power conversion unit (2142). At this time, when only one of the voltages of the 3-1 power conversion unit (2141) and the voltage of the 3-2 power conversion unit (2142) is measured, the switching element can be turned on.

[0119] When the control unit (2150) performs communication with the energy storage device (2230) or the battery management system (BMS) of the energy storage device (2230), the control unit (2150) determines that it is connected to the energy storage device (2230), and first turns off the switching element (2143) to determine whether the energy storage device (2230) is connected to the input / output terminal of the 3-1 power conversion unit (2141) or the input / output terminal of the 3-2 power conversion unit (2142). Thereafter, the voltage of the 3-1 power conversion unit (2141) and the voltage of the 3-2 power conversion unit (2142) are measured, and if only one voltage is measured, the energy storage device (2230) is connected to the input / output terminal of the corresponding power conversion unit, and the switching element (2143) can be turned on to connect the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) to one energy storage device (2230). At this time, the control unit (2150) can control the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) in an interleaving manner.

[0120] Alternatively, the control unit (2150) turns on the switching element (2143) to connect the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) to one energy storage device (2230), but controls one power conversion unit to convert power instead of interleaving, and the other power conversion unit can be used as a reserve for control in case a failure occurs or one power conversion unit has difficulty performing power conversion. In addition, control can be performed in various ways.

[0121] Alternatively, if only one of the voltages of the 3-1 power conversion unit (2141) and the voltage of the 3-2 power conversion unit (2142) is measured, the control unit (2150) may connect only one power conversion unit to the energy storage device (2230) without turning on the switching element (2143).

[0122] When both the voltage of the 3-1 power conversion unit (2141) and the voltage of the 3-2 power conversion unit (2142) are measured, the control unit (2150) can control the switching element (2143) to turn off so that the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) can be independently connected to one energy storage device (2231, 2232), respectively. In addition, the control unit (2150) can independently control the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142). Since the 3-1 power conversion unit (2141) and the 3-2 power conversion unit (2142) are each connected to one energy storage device and independently perform charging and discharging, efficient charging and discharging is possible even without performing voltage balancing between the energy storage devices (2231, 2232).

[0123] As described above, efficient control suitable for each type is possible by controlling multiple power conversion units and switching elements according to the number of connected energy storage devices and their connection status.

[0124] A power conversion device (2100) according to an embodiment of the present invention may be implemented as a solar power generation hybrid inverter, as shown in FIGS. 14 and 15. A solar power generation panel (2210) and a DC-DC converter (2110) are connected, and a grid (2220) is connected through a relay (2160) and an inverter (2120), and an energy storage device ESS (2230) and a plurality of bidirectional DC-DC converters (2141, 2142), and the DC-DC converter (2110), the inverter (2120), and the plurality of bidirectional DC-DC converters (2141, 2142) are connected in parallel to a DC-link (2130), and may include a control unit (2150) which is a controller that controls each component.

[0125] As shown in Fig. 14, when one energy storage device (2230) is connected, the control unit (2150) can control charging and discharging by turning on the relay and then controlling multiple bidirectional DC-DC converters (2141, 2142) in an interleaving manner.

[0126] As shown in Fig. 15, when two energy storage devices (2231, 2232) are connected, the control unit (2150) turns off the relay and then independently controls a plurality of bidirectional DC-DC converters (2141, 2142) to independently control the charging and discharging of the two energy storage devices (2231, 2232).

[0127] By controlling multiple power conversion units and switching elements according to the number of connected energy storage devices and their connection status, efficient control suitable for each type is possible.

[0128] Figure 16 illustrates a system to which a power conversion device according to the third embodiment of the present invention is applied.

[0129] The power conversion device (10) according to the third embodiment of the present invention can form a solar power generation system together with a solar power generation module (21), an energy storage device (23), a load (24), and a grid (22).

[0130] The power conversion device (10) according to an embodiment of the present invention is connected to the MLPE (25) of the solar power generation module (21), receives power output from the solar power generation module (21), converts the received power and supplies it to a load (24), transmits it to a grid (22), or charges an energy storage device (23). Alternatively, the power charged in the energy storage device (23) can be converted and supplied to a load (24), or power can be received from the grid (22) and supplied to a load (24) or converted and charged to an energy storage device (23). In order to transmit and receive power between each component, it must be converted into power suitable for each component. The power conversion device (10) according to an embodiment of the present invention is placed between each component and serves to convert power.

[0131] The solar power generation module (21) may include module-level power electronics (MLPE, 25) that control the solar cells to operate at the maximum power point (MPP), which is the operating point where the power of the solar cells is maximum under each condition. The MLPE (25) may be referred to as an optimizer. In solar power generation, depending on the characteristics of the relationship between current and voltage and the relationship between voltage and power, the maximum power may be the power when the maximum voltage is about 80% or less than the maximum voltage, rather than the maximum voltage. Since this maximum power point continuously changes depending on the magnitude of the voltage and current generated by the photovoltaic panel, the point where the maximum power point can be generated must be continuously searched. That is, in order to pursue the maximum power rather than the maximum voltage, the magnitude of the voltage and current can be varied so as to achieve the maximum power. That is, the voltage can be reduced and the current can be increased in the direction of increasing power, or the voltage can be increased and the current can be reduced.

[0132] In the event of a fire or malfunction in the solar power generation module (21), the voltage of the solar power generation module must be rapidly reduced. This is called the RSP (Rapid Shut Down) function. In the event of a fire or malfunction, the MLPE (25) performs the RSD function to rapidly reduce the voltage of the solar power generation module (21). This allows workers inspecting or repairing the solar power generation module (21) to safely perform repair work.

[0133] An MLPE (25) is mounted on each output terminal of a plurality of solar power generation modules (21), and the plurality of MLPEs (25) are connected in series and can be connected to a power conversion device (10). Each MLPE (25) can perform monitoring and RSD functions for the solar power generation module (21).

[0134] In order for the power conversion device (10) to operate or perform power conversion, there must be auxiliary power, and the power conversion device (10) can generate auxiliary power by receiving power from at least one of a solar power generation module (21), an energy storage device (23), and a grid (22). The power input from the solar power generation module (21) can be used as the main power, and the energy storage device (23) or the grid (22) can be used as the secondary power, and the auxiliary power can be generated by receiving power from the outside according to various settings. If there is no power input from the energy storage device (23) or the grid (22), and the solar power generation module (21) is operated in RSD by the MLPE (25) so that the voltage of the power input to the power conversion device (10) is lower than the first voltage, it is difficult to generate auxiliary power, and thus the initial operation may not be performed.

[0135] A power conversion device according to an embodiment of the present invention can perform initial operation using a communication power supply unit. Hereinafter, the process of performing initial operation of a power conversion device according to an embodiment of the present invention will be described.

[0136] FIG. 17 is a block diagram of a power conversion device according to a third embodiment of the present invention, and FIGS. 18 to 22 are drawings for explaining the configuration of a power conversion device according to the third embodiment of the present invention.

[0137] A power conversion device (3100) according to a third embodiment of the present invention is composed of a first power conversion unit (3110), a second power conversion unit (3120), a DC link (3130), an auxiliary power generation unit (3140), a communication unit (3150), and a communication power supply unit (3160), and may include a control unit (3170).

[0138] The first power conversion unit (3110) is connected to a solar power generation module (3210). The first power conversion unit (3110) receives power from the solar power generation module (3210) and converts it. The solar power generation module (3210) may include an MLPE (3211), and the first power conversion unit (3110) may receive power through the MLPE (3211). The communication unit may perform power line communication (3PLC) with the MLPE. Here, the first power conversion unit (3110) may include a DC-DC converter. It may include a DC-DC converter that converts the voltage of the power of the solar power generation module (3210), which is DC power, into the voltage of the power to be output to the DC link (3130) and outputs the converted power.

[0139] The second power conversion unit (3120) is connected to the grid (3220). The second power conversion unit (3120) may be connected to a load. The second power conversion unit (3120) may convert power input to the DC-link (3130) and output it from the grid (3220), or convert power input from the grid (3220) and output it to the DC-link (3130). Here, the first power conversion unit (3110) may include an inverter. It may include a bidirectional DC-AC inverter that converts power input to the DC-link (3130), which is DC power, from direct current to alternating current and outputs it to the grid (3220), or converts power input from the grid (3220) from alternating current to direct current and outputs it to the DC-link (3130).

[0140] The DC link (3130) is connected between the first power conversion unit (3110) and the second power conversion unit (3120). The DC link (3130) is connected between the first power conversion unit (3110) and the second power conversion unit (3120) and serves to transfer power output from each power conversion unit to another power conversion unit. The DC link (3130) may include a DC link capacitor. Power input to the DC link may be stored in the DC link capacitor and output through the DC link capacitor.

[0141] The DC link (3130) may be connected to an energy storage device (3230). At this time, the energy storage device (3230) may include a DC-DC converter that converts power input to the DC link (3130) and outputs it to the energy storage device (3230), or converts power input from the energy storage device (3230) and outputs it to the DC link (3130). The DC-DC converter may include a DC-DC converter that converts the voltage of power input to the DC link (3130), which is DC power, into a voltage for charging the energy storage device (3230), or converts the voltage of power of the energy storage device (3230) and outputs it to the DC link (3130). The DC-DC converter may be included in a power conversion device (3100) according to an embodiment of the present invention, rather than in the energy storage device (3230).

[0142] The auxiliary power generation unit (3140) generates auxiliary power using the power of the DC link (3130). The auxiliary power generation unit (3140) can generate auxiliary power including the power for driving the first power conversion unit (3110) and the second power conversion unit (3120) of the power conversion device (3100), the sensing power of the sensors, the control power of the control unit (3170), etc. Here, the auxiliary power may include a plurality of switches, and the first power conversion unit (3110) and the second power conversion unit (3120) may include a switch driving power or a gate power.

[0143] Power from a solar power generation module (3210), power from an energy storage device (3230), and power from a grid (3220) can be input to the DC link (3130), and an auxiliary power generation unit (3140) can generate auxiliary power using at least one of the power input to the DC link (3130). The auxiliary power generation unit (3140) can convert the power from the DC link (3130) into power required for the auxiliary power.

[0144] The communication unit (3150) communicates with the control device of the solar power generation module (3210). The control device of the solar power generation module (3210) may include an MLPE (3211). As shown in FIG. 18, the communication unit (3150) may transmit and receive status information, driving signals, RSD operation signals, etc. of the solar power generation module (3210) through communication with the MLPE (3211). At this time, the communication unit (3150) may perform power line communication (PLC) with the MLPE (3211). Communication may be performed using a power line connected to the first power conversion unit (3110) and the solar power generation module (3210). Alternatively, wired communication may be performed through a separate wire, or wireless communication may be performed. The communication unit (3150) may communicate not only with the MLPE (3211), but also with an external device such as a higher-level controller.

[0145] The communication unit (3150) can transmit a signal to release the RSD operation and allow power to be input from the solar power generation module (3210) when the MLPE (3211) performs the RSD operation and power is not supplied from the solar power generation module (3210). At this time, the communication unit (3150) requires an auxiliary power source to transmit the signal. When the MLPE (3211) performs the RSD operation, the output of the MLPE (3211) can be controlled to be 1 to 3 V, and the string voltage of the solar power generation module (3210) can be controlled to be less than a first voltage. Here, the first voltage can be 30 V.

[0146] When the MLPE (3211), which is a control device of the solar power generation module (3210), operates in RSD (Rapid Shut Down) mode, the voltage of the DC link may be lower than the first voltage. When there is no power input from the energy storage device (3230) or the grid (3220), and the voltage of the power input to the power conversion device (3100) is lower than the first voltage due to the solar power generation module (3210) being operated in RSD mode by the MLPE (3211), it is difficult for the auxiliary power generation unit (3140) to generate auxiliary power using the power of the DC link (3130).

[0147] To solve this, the power conversion device (3100) according to the embodiment of the present invention includes a communication power supply unit (3160) together with an auxiliary power generation unit (3140). The communication power supply unit (3160) supplies power of the DC-link (3130) as power to the communication unit (3150). When the voltage of the DC-link (3130) due to the power input from the solar power generation module (3210) is lower than the first voltage, it is difficult for the auxiliary power generation unit (3140) to generate auxiliary power, but the power required for the communication unit (3150) to perform communication with the MLPE (3211) may be sufficient. The communication power supply unit (3160) can directly apply power from the DC link (3130) to the communication unit (3150) rather than to the auxiliary power generation unit (3140), thereby enabling communication between the communication unit (3150) and the MLPE (3211). When power is supplied from the communication power supply unit (3160), the communication unit (3150) can transmit an RSD release signal or a driving signal to the MLPE (3211), thereby allowing normal power to be applied from the solar power generation module (3210). Through this, when the voltage of the DC link (3130) becomes greater than the first voltage, the auxiliary power generation unit (3140) operates to generate auxiliary power, thereby enabling the power conversion device (3100) to operate normally.

[0148] The communication power supply unit (3160) applies power of the DC link (3130) to the communication unit (3150) when the voltage of the DC link (3130) is lower than a first voltage. Here, the first voltage may be set to the minimum operating voltage at which the auxiliary power generation unit (3140) operates, or may be set lower than the minimum operating voltage, and may be set according to the specifications of the auxiliary power generation unit (3140) or may be set by the user. For example, the first voltage may be 30 V.

[0149] The communication power supply unit (3160) may include a bypass circuit (3161). As shown in FIG. 19, the communication power supply unit (3160) may be configured with a bypass circuit (3161), so that the power of the DC link (3130) is not input to the auxiliary power generation unit (3140), but is directly input to the communication unit (3150) through the bypass circuit (3161). The bypass circuit (3161) may include a switching element. When the switching element is turned on, a bypass path is formed, and when the switching element is turned off, the bypass path may be blocked. The switching element may include a MOSFET.

[0150] The communication unit (3150) receives power from the communication power supply unit (3160) and transmits an operation signal to the MLPE (3211), which is a control device of the solar power generation module (3210), so that power can be supplied from the solar power generation module (3210) to the DC link (3130).

[0151] If the voltage of the DC link (3130) is greater than the first voltage, the communication power supply unit (3160) may stop supplying power of the DC link (3130) to the communication unit (3150). The communication power supply unit (3160) may not operate if the voltage of the DC link (3130) is a normal voltage greater than the first voltage. At this time, the auxiliary power generation unit (3140) may generate auxiliary power using the power of the DC link (3130).

[0152] The auxiliary power generation unit (3140) may include a third power conversion unit (3141) and a fourth power conversion unit (3142). As shown in FIG. 20, the auxiliary power generation unit (3140) includes a third power conversion unit (3141) and a fourth power conversion unit (3142), and may supply auxiliary power generated by the third power conversion unit (3141) to the control unit (3170) or the communication unit (3150).

[0153] The third power conversion unit (3141) can generate auxiliary power by converting the direct current power of the DC-link (3130). The power and auxiliary power of the DC-link (3130) are direct current, and the direct current power of the DC-link (3130) can be converted to generate auxiliary power. The third power conversion unit (3141) can include a DC-DC converter.

[0154] The fourth power conversion unit (3142) can convert the AC power of the grid (3220) into DC power and supply it to the third power conversion unit (3141). The fourth power conversion unit (3142) can convert the AC power into DC power so that the AC power of the grid (3220) can be used to generate auxiliary power. The fourth power conversion unit (3142) can include an AC-DC converter that converts the AC power into DC power.

[0155] The fourth power conversion unit (3142) can operate when the voltage of the DC-link (3130) is lower than the second voltage. When the third power conversion unit (3141) generates auxiliary power using the power of the DC-link (3130), but the voltage of the DC-link (3130) is lower than the second voltage, and thus the auxiliary power cannot be generated using the power of the DC-link (3130) or cannot generate sufficient auxiliary power, the fourth power conversion unit (3142) can operate and supply power to the third power conversion unit (3141). Here, the second voltage may be set to the minimum operating voltage at which the third power conversion unit (3141) operates, or may be set lower than the minimum operating voltage, and may be set according to the specifications of the third power conversion unit (3141), or may be set by the user. The second voltage may be higher than the first voltage. For example, the second voltage may be 300 V. Alternatively, the second voltage can be set equal to the first voltage.

[0156] A power conversion device (3100) according to an embodiment of the present invention can be implemented as shown in FIG. 21. A solar power generation module (PV module) 3210 is connected to a DC-link (3130) through an MLPE (3211) and a boost DC-DC converter, which is a first power conversion unit (3110). The DC-link (3130) is connected to a grid (3220) through an inverter, which is a second power conversion unit (3120), and can be connected to an energy storage device (ESS, 3230). A DC Aux generation unit, which is a third power conversion unit (3141) of an auxiliary power generation unit (3140), converts the power of the DC-link to supply sensing / control power, switch / gate power, and can supply communication power for performing PLC communication with the MLPE, which is a power source of a communication unit (3150), and external communication power for performing communication with an external upper controller. The AC Aux generation unit, which is the fourth power conversion unit (3142) of the auxiliary power generation unit (3140), can convert the AC power of the grid (3220) into DC power and supply it to the DC Aux generation unit, which is the third power conversion unit (3141). The AC Aux generation unit can operate when the DC-link voltage is 300 V or less. The bypass circuit, which is a communication power supply unit (3160), is configured with a power switch that enables PLC communication with a DC-link power of about 10 to 30 V even when the RSD of the MLPE (3211) is in operation when there is no power from the grid (3220) and the energy storage device (3230) and the power is supplied to the solar power generation module (3210), thereby enabling PLC communication with the MLPE (3211), and through this, the power conversion device (3100) can be initially operated using the power of the solar power generation module (3210). At this time, when the DC-link (3130) voltage is applied at 120 V or higher through the power of the solar power generation module (3210) after the RSD of the MLPE (3211) is disabled, the power conversion device (3100) can be initially operated.

[0157] In contrast, in the case of the power conversion device according to the comparative example of Fig. 22, to which the communication power supply unit (3160) is not applied, if there is no power from the grid and the energy storage device (3ESS) and the MLPE RSD is operated in the solar power generation module (PV module), the device does not operate when the DC-DC input from the solar power generation module is less than 30 V.

[0158] FIG. 23 is a block diagram of a power conversion device according to a fourth embodiment of the present invention, and FIGS. 24 to 27 are drawings for explaining the configuration of a power conversion device according to the embodiment of FIG. 23.

[0159] A power conversion device (4000) according to a fourth embodiment of the present invention is composed of a first power conversion unit (3110), a second power conversion unit (3120), a DC link (3130), an auxiliary power generation unit (3140), a communication unit (3150), and a fifth power conversion unit (3180), and may include a control unit (3170).

[0160] The first power conversion unit (3110) is connected to a solar power generation module (3210). The first power conversion unit (3110) receives power from the solar power generation module (3210) and converts it. The solar power generation module (3210) may include an MLPE (3211), and the first power conversion unit (3110) may receive power through the MLPE (3211). The communication unit may perform power line communication (3PLC) with the MLPE. Here, the first power conversion unit (3110) may include a DC-DC converter. It may include a DC-DC converter that converts the voltage of the power of the solar power generation module (3210), which is DC power, into the voltage of the power to be output to the DC link (3130) and outputs the converted power.

[0161] The second power conversion unit (3120) is connected to the grid (3220). The second power conversion unit (3120) may be connected to a load. The second power conversion unit (3120) may convert power input to the DC-link (3130) and output it from the grid (3220), or convert power input from the grid (3220) and output it to the DC-link (3130). Here, the first power conversion unit (3110) may include an inverter. It may include a bidirectional DC-AC inverter that converts power input to the DC-link (3130), which is DC power, from direct current to alternating current and outputs it to the grid (3220), or converts power input from the grid (3220) from alternating current to direct current and outputs it to the DC-link (3130).

[0162] The DC link (3130) is connected between the first power conversion unit (3110) and the second power conversion unit (3120). The DC link (3130) is connected between the first power conversion unit (3110) and the second power conversion unit (3120) and serves to transfer power output from each power conversion unit to another power conversion unit. The DC link (3130) may include a DC link capacitor. Power input to the DC link may be stored in the DC link capacitor and output through the DC link capacitor.

[0163] The DC link (3130) may be connected to an energy storage device (3230). At this time, the energy storage device (3230) may include a DC-DC converter that converts power input to the DC link (3130) and outputs it to the energy storage device (3230), or converts power input from the energy storage device (3230) and outputs it to the DC link (3130). The DC-DC converter may include a DC-DC converter that converts the voltage of power input to the DC link (3130), which is DC power, into a voltage for charging the energy storage device (3230), or converts the voltage of power of the energy storage device (3230) and outputs it to the DC link (3130). The DC-DC converter may be included in a power conversion device (4000) according to an embodiment of the present invention, rather than in the energy storage device (3230).

[0164] The auxiliary power generation unit (3140) generates auxiliary power using the power of the DC link (3130). The auxiliary power generation unit (3140) can generate auxiliary power including the power for driving the first power conversion unit (3110) and the second power conversion unit (3120) of the power conversion device (4000), the sensing power of the sensors, the control power of the control unit (3170), etc. Here, the auxiliary power may include a plurality of switches, and the first power conversion unit (3110) and the second power conversion unit (3120) may include a switch driving power or a gate power.

[0165] Power from a solar power generation module (3210), power from an energy storage device (3230), and power from a grid (3220) can be input to the DC link (3130), and an auxiliary power generation unit (3140) can generate auxiliary power using at least one of the power input to the DC link (3130). The auxiliary power generation unit (3140) can convert the power from the DC link (3130) into power required for the auxiliary power.

[0166] The communication unit (3150) communicates with the control device of the solar power generation module (3210). The control device of the solar power generation module (3210) may include an MLPE (3211). As shown in FIG. 24, the communication unit (3150) may transmit and receive status information, driving signals, RSD operation signals, etc. of the solar power generation module (3210) through communication with the MLPE (3211). At this time, the communication unit (3150) may perform power line communication (PLC) with the MLPE (3211). Communication may be performed using a power line connected to the first power conversion unit (3110) and the solar power generation module (3210). Alternatively, wired communication may be performed through a separate wire, or wireless communication may be performed. The communication unit (3150) may communicate not only with the MLPE (3211), but also with an external device such as a higher-level controller.

[0167] The communication unit (3150) can transmit a signal to release the RSD operation and allow power to be input from the solar power generation module (3210) when the MLPE (3211) performs the RSD operation and power is not supplied from the solar power generation module (3210). At this time, the communication unit (3150) requires an auxiliary power source to transmit the signal. When the MLPE (3211) performs the RSD operation, the output of the MLPE (3211) can be controlled to be 1 to 3 V, and the string voltage of the solar power generation module (3210) can be controlled to be less than a first voltage. Here, the first voltage can be 30 V.

[0168] When the MLPE (3211), which is a control device of the solar power generation module (3210), operates in RSD (Rapid Shut Down) mode, the voltage of the DC link may be lower than the first voltage. When there is no power input from the energy storage device (3230) or the grid (3220), and the voltage of the power input to the power conversion device (4000) is lower than the first voltage due to the solar power generation module (3210) being operated in RSD mode by the MLPE (3211), it is difficult for the auxiliary power generation unit (3140) to generate auxiliary power using the power of the DC link (3130).

[0169] To solve this, the power conversion device (4000) according to the embodiment of the present invention includes a fifth power conversion unit (3180) together with an auxiliary power generation unit (3140). The fifth power conversion unit (3180) converts the power of the DC-link (3130) and supplies it as power to the communication unit (3150). When the voltage of the DC-link (3130) due to the power input from the solar power generation module (3210) is lower than the first voltage, it is difficult for the auxiliary power generation unit (3140) to generate auxiliary power, but the fifth power conversion unit (3180) may be sufficient to convert the power required for the communication unit (3150) to communicate with the MLPE (3211). The fifth power conversion unit (3180) can convert the power of the DC link (3130) and apply it to the communication unit (3150) instead of the auxiliary power generation unit (3140), thereby enabling communication between the communication unit (3150) and the MLPE (3211). When power is supplied from the fifth power conversion unit (3180), the communication unit (3150) can transmit an RSD release signal or a driving signal to the MLPE (3211), thereby allowing normal power to be applied from the solar power generation module (3210). Through this, when the voltage of the DC link (3130) becomes greater than the first voltage, the auxiliary power generation unit (3140) operates to generate auxiliary power, thereby enabling the power conversion device (4000) to operate normally.

[0170] The fifth power conversion unit (3180) converts the power of the DC link (3130) and applies it to the communication unit (3150) when the voltage of the DC link (3130) is lower than the first voltage. Here, the first voltage may be set to the minimum operating voltage at which the auxiliary power generation unit (3140) operates, or may be set lower than the minimum operating voltage, and may be set according to the specifications of the auxiliary power generation unit (3140) or may be set by the user. For example, the first voltage may be 30 V.

[0171] The fifth power conversion unit (3180) may include a DC-DC converter. Here, the DC-DC converter may be a boost converter (3181). As shown in FIG. 25, the fifth power conversion unit (3180) is configured with a boost converter (3181), so that the power of the DC-link (3130) is not input to the auxiliary power generation unit (3140), but is input to the communication unit (3150) as power boosted through the boost converter (3181). The fifth power conversion unit (3180) may include a boost converter (3181), a switching element, and a control unit that senses a DC-link voltage and controls the switching element. When the DC-link voltage becomes lower than a first voltage, the switching element of the fifth power conversion unit (3180) may be turned on, and when the DC-link voltage is higher than the first voltage, the switching element of the fifth power conversion unit (3180) may be turned off. When the switching element is turned on, a path to the step-up converter (3181) may be formed, and when the switching element is turned off, the path to the step-up converter (3181) may be blocked. The switching element may include a MOSFET.

[0172] The communication unit (3150) can receive power from the fifth power conversion unit (3180) and transmit an operation signal to the MLPE (3211), which is a control device of the solar power generation module (3210), so that power can be supplied from the solar power generation module (3210) to the DC link (3130).

[0173] If the voltage of the DC link (3130) is greater than the first voltage, the fifth power conversion unit (3180) may stop converting the power of the DC link (3130) and supplying it as power to the communication unit (3150). The fifth power conversion unit (3180) may not operate if the voltage of the DC link (3130) is a normal voltage greater than the first voltage. At this time, the auxiliary power generation unit (3140) may generate auxiliary power using the power of the DC link (3130).

[0174] The auxiliary power generation unit (3140) may include a third power conversion unit (3141) and a fourth power conversion unit (3142). As shown in Fig. 26, the auxiliary power generation unit (3140) includes a third power conversion unit (3141) and a fourth power conversion unit (3142), and may supply auxiliary power generated by the third power conversion unit (3141) to the control unit (3170) or the communication unit (3150).

[0175] The third power conversion unit (3141) can generate auxiliary power by converting the direct current power of the DC-link (3130). The power and auxiliary power of the DC-link (3130) are direct current, and the direct current power of the DC-link (3130) can be converted to generate auxiliary power. The third power conversion unit (3141) can include a DC-DC converter.

[0176] The fourth power conversion unit (3142) can convert the AC power of the grid (3220) into DC power and supply it to the third power conversion unit (3141). The fourth power conversion unit (3142) can convert the AC power into DC power so that the AC power of the grid (3220) can be used to generate auxiliary power. The fourth power conversion unit (3142) can include an AC-DC converter that converts the AC power into DC power.

[0177] The fourth power conversion unit (3142) can operate when the voltage of the DC-link (3130) is lower than the second voltage. When the third power conversion unit (3141) generates auxiliary power using the power of the DC-link (3130), but the voltage of the DC-link (3130) is lower than the second voltage, and thus the auxiliary power cannot be generated using the power of the DC-link (3130) or cannot generate sufficient auxiliary power, the fourth power conversion unit (3142) can operate and supply power to the third power conversion unit (3141). Here, the second voltage may be set to the minimum operating voltage at which the third power conversion unit (3141) operates, or may be set lower than the minimum operating voltage, and may be set according to the specifications of the third power conversion unit (3141), or may be set by the user. The second voltage may be higher than the first voltage. For example, the second voltage may be 300 V. Alternatively, the second voltage can be set equal to the first voltage.

[0178] A power conversion device (4000) according to an embodiment of the present invention can be implemented as shown in FIG. 27. A solar power generation module (PV module) 3210 is connected to a DC-link (3130) through a boost DC-DC converter, which is an MLPE (3211) and a first power conversion unit (3110). The DC-link (3130) is connected to a grid (3220) through an inverter, which is a second power conversion unit (3120), and can be connected to an energy storage device (ESS, 3230). A DC Aux generation unit, which is a third power conversion unit (3141) of an auxiliary power generation unit (3140), converts the power of the DC-link to supply sensing / control power, switch / gate power, and can supply communication power for performing PLC communication with the MLPE, which is the power of the communication unit (3150), and external communication power for performing communication with an external upper controller. The AC Aux generation unit, which is the fourth power conversion unit (3142) of the auxiliary power generation unit (3140), can convert the AC power of the grid (3220) into DC power and supply it to the DC Aux generation unit, which is the third power conversion unit (3141). The AC Aux generation unit can operate when the DC-link voltage is 300 V or lower. The boost converter, which is the fifth power conversion unit (3180), can boost the DC-link power at a level of about 10 to 30 V even when the RSD operation of the MLPE (3211) is in progress if there is no power from the grid (3220) and the energy storage device (3230) and the power is supplied to the solar power generation module (3210), thereby enabling PLC communication with the MLPE (3211). Through this, when the DC-link (3130) voltage is applied at 120 V or higher through the power of the solar power generation module (3210) after the RSD of the MLPE (3211) is disabled, the power conversion device (4000) can be initially operated.

[0179] A variation according to the present embodiment may include some components of one of the first or second embodiments along with some components of the other embodiment. For example, a variation may include the first embodiment, but may omit some components of the first embodiment and include some components of the corresponding second embodiment. Alternatively, a variation may include the second embodiment, but may omit some components of the second embodiment and include some components of the corresponding first embodiment. A third or fourth embodiment may also include corresponding components.

[0180] The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by those skilled in the art to which the embodiments pertain. Therefore, the contents related to such combinations and modifications should be construed as being included within the scope of the embodiments.

[0181] As described above, the present invention has been described with specific details such as specific components and limited examples and drawings, but these are provided only to help a more general understanding of the present invention, and the present invention is not limited to the above examples, and those with ordinary knowledge in the field to which the present invention pertains can make various modifications and variations from this description.

[0182] Therefore, the idea of ​​the present invention should not be limited to the described embodiments, and all things that are equivalent or equivalent to the following claims as well as the claims are considered to fall within the scope of the idea of ​​the present invention.

Claims

1. A first switching unit that turns on during a power outage; A power failure signal generating unit that supplies auxiliary power to the power conversion unit when the first switching unit is turned on and transmits a power failure signal; A control unit that requests power supply to the vehicle according to the above-mentioned power failure signal and controls the power conversion unit; and Includes a power conversion unit that performs power conversion under the control of the above control unit, The above power conversion unit, A power conversion device that receives power from the above vehicle, converts it, and outputs it to a load.

2. In paragraph 1, Includes a battery connected to the above static signal generating unit, The above-mentioned static signal generating unit is a power conversion device that receives power from the battery when the first switching unit is turned on and outputs it to the power conversion unit.

3. In paragraph 1, The above-mentioned static signal generating unit includes a voltage receiving unit that receives a first voltage from the power conversion unit, The above static signal generating unit is, A power conversion device that transmits the power failure signal to the power conversion unit when the voltage receiving unit does not receive the first voltage when the first switching unit is turned on.

4. In paragraph 3, The above static signal generating unit is, A power conversion device that does not generate the power failure signal when the voltage receiving unit receives the first voltage when the first switching unit is turned on.

5. In paragraph 3, The above power conversion unit, A power conversion device that supplies the first voltage to the power failure signal generating unit when receiving power from the vehicle.

6. In paragraph 1, The above first switching unit, A power conversion device comprising a physical switch that is operated by an external force.

7. In paragraph 1, A power conversion device that is driven using the auxiliary power source during a power outage and includes a communication unit that transmits the power supply to the vehicle.

8. In paragraph 7, The above communication department, A power conversion device that receives status information of a vehicle's battery from the vehicle and transmits it to the control unit.

9. In paragraph 1, The above load is a power conversion device including a household load.

10. In paragraph 1, The above power conversion unit, Converts the power input from the grid and outputs it to the vehicle, A power conversion device that converts power input from the vehicle and outputs it to the load.

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