Power conversion device

Abstract

A power conversion device according to an embodiment of the present invention comprises: a power conversion unit that converts and outputs input power; an auxiliary power unit receiving power from a first input / output terminal of the power conversion unit to generate auxiliary power of the power conversion unit; and a circuit breaker connected to the second input / output terminal of the power conversion unit, in which the auxiliary power unit operates when the circuit breaker is turned on and stops operating when the circuit breaker is turned off.

Description

Technical Field

[0001] Teachings according to exemplary and non-limiting embodiments of the present invention generally relate to a power conversion device, and more particularly, to a power conversion device capable of storing log information when a fault occurs, and to an energy storage device including the power conversion device. Background Art

[0002] As environmental awareness has increased in recent years, there has been a growing interest in ways to generate electricity that do not emit pollutants such as carbon dioxide. In particular, photovoltaic power generation systems are becoming increasingly popular as the cost of developing and installing them becomes cheaper due to technological advances.

[0003] In such a photovoltaic power generation system, a plurality of photovoltaic cells are gathered to form a plurality of photovoltaic modules, and the direct current (DC) electricity generated by the plurality of photovoltaic modules is converted into alternating current (AC) electricity that can be directly used in homes and industrial facilities through an inverter.

[0004] On the other hand, in the case of photovoltaic power generation, there are inevitably periods of insufficient power generation, such as at night when there is no sunlight or due to changes in weather conditions. Therefore, in order to compensate for these shortcomings, photovoltaic power generation systems must be equipped with batteries to ensure stable power supply.

[0005] A home solar (photovoltaic) system with batteries can be configured as follows Figure 1 As shown. The battery pack may include batteries, BMS and DC-DC converters. In this case, it is necessary to develop a technology to prevent the DC-DC converter inside the battery pack from burning or operating abnormally due to abnormal operation, so that normal operation can be achieved. Summary of the invention

[0006] Technical issues

[0007] The technical problem that the present invention attempts to solve is to provide a power conversion device and an energy storage device including the power conversion device, wherein the power conversion device can store log information when a failure occurs.

[0008] Technical Solution

[0009] In order to solve the above-mentioned technical challenges, a power conversion device according to an exemplary embodiment of the present invention may include: a power conversion unit, which converts input power and outputs it; an auxiliary power unit, which receives power from a first input / output terminal of the power conversion unit to generate auxiliary power of the power conversion unit; and a circuit breaker, which is connected to a second input / output terminal of the power conversion unit, wherein the auxiliary power unit operates when the circuit breaker is turned on, and stops operating after a predetermined time period when the circuit breaker is turned off.

[0010] Preferably, but not necessarily, the auxiliary power unit may include: a transformer for converting power from a first input / output terminal; a driving unit for driving the transformer in response to a first signal applied from the circuit breaker when the circuit breaker is turned on; and a controller for receiving the auxiliary power output from the transformer and controlling the driving unit to drive the transformer.

[0011] Preferably, but not necessarily, the driving unit may be capable of maintaining driving of the transformer in at least one of a case where the first signal is applied from the circuit breaker and a case where the driving unit is controlled by the controller to drive the transformer.

[0012] Preferably, but not necessarily, the controller may control the driving unit to maintain the driving of the transformer for a predetermined time when the circuit breaker is opened and the second signal is applied from the circuit breaker.

[0013] Preferably, but not necessarily, when the driving unit maintains driving of the transformer, the controller may store log information including at least one of previous operation information, a fault state, a fault type, and a fault location.

[0014] Preferably, but not necessarily, the auxiliary power unit may include: a first switch, one end of which is connected to the first input / output terminal; a transformer, which is connected to the other end of the first switch and converts power from the first input / output terminal; a driving unit, which is connected to the first (-) terminal of the transformer and drives the transformer according to a first signal applied from the circuit breaker when the circuit breaker is turned on; a capacitor, which is charged according to the output of the transformer to generate the auxiliary power unit; a second switch, which is connected to a first node between the circuit breaker and the driving unit at one end and the other end of the second switch is connected to a ground member; and a controller, which turns on the second switch when receiving the auxiliary power unit.

[0015] Preferably, but not necessarily, the first signal may have a potential corresponding to a ground, and when the second switch is turned on, the ground is connected to the first node, so that the driving unit drives the transformer.

[0016] Preferably, but not necessarily, the driving unit may maintain driving of the transformer in at least one of a case where the first signal is applied from the circuit breaker and a case where the second switch is turned on.

[0017] Preferably, but not necessarily, the first switch may be a MOSFET, and the gate may be connected to the first node.

[0018] In order to solve the above-mentioned technical challenges, an energy storage device according to an exemplary embodiment of the present invention may include: an energy storage unit, the energy storage unit including one or more batteries; a power conversion unit, the power conversion unit is used to convert the power stored in the energy storage unit and output it to the outside, or convert the power received from the outside and charge the energy storage unit; an auxiliary power unit, the auxiliary power unit is used to generate auxiliary power of the power conversion unit by receiving power from a first input / output terminal of the power conversion unit connected to the energy storage unit; and a circuit breaker, the circuit breaker is connected to a second input / output terminal of the power conversion unit connected to the outside, when the circuit breaker is turned on, the auxiliary power unit is driven, and when the circuit breaker is turned off, the auxiliary power unit stops driving after a predetermined time period.

[0019] Preferably, but not necessarily, the auxiliary power unit may include: a transformer for converting power from a first input / output terminal; a driving unit for driving the transformer according to a first signal applied from the circuit breaker when the circuit breaker is turned on; and a controller for receiving the auxiliary power output from the transformer and controlling the driving unit to drive the transformer, the driving unit being capable of maintaining driving of the transformer in at least one of a case where the first signal is applied from the circuit breaker and a case where the driving unit is controlled by the controller to drive the transformer.

[0020] Preferably, but not necessarily, the auxiliary power unit may include: a first switch, one end of which is connected to the first input / output terminal; a transformer, which is connected to the other end of the first switch to convert power from the first input / output terminal; a drive unit, which is connected to the first (-) terminal of the transformer and drives the transformer according to a first signal applied from the circuit breaker when the circuit breaker is turned on; a capacitor, which is charged according to the output of the transformer to generate auxiliary power; a second switch, one end of which is connected to a first node between the circuit breaker and the drive unit and to a ground at the other end; and a controller, which is used to apply auxiliary power and turn on the second switch, the first signal has a potential corresponding to the ground, and when the second switch is turned on, the ground is connected to the first node, the drive unit drives the transformer, and the drive unit is capable of maintaining the drive of the transformer in at least one of the cases when the first signal is applied from the circuit breaker and when the second switch is turned on.

[0021] In order to solve the above technical challenges, a power conversion device according to a second exemplary embodiment of the present invention may include at least one switch, which sets an identification number according to an on-off state and has an identification number different from other power conversion devices according to the state of the switch.

[0022] Preferably, but not necessarily, the switch may include: a first switch and a second switch; a first resistor, one end of the first resistor being connected to the first switch and the other end of the first resistor being connected to a ground member; and a second resistor, one end of the second resistor being connected to the second switch and the other end of the second resistor being connected to a ground member, one end of the first switch being connected to a first voltage and the other end of the first switch being connected to the first resistor, one end of the second switch being connected to the first voltage and the other end of the second switch being connected to the second resistor, and a node between the first switch and the first resistor and a node between the second switch and the second resistor may be connected to a controller.

[0023] Preferably, but not necessarily, the power conversion device can be connected in parallel with other power conversion devices.

[0024] Preferably, but not necessarily, the power conversion device may include a communication unit for communicating with the outside using the identification number set by the switch.

[0025] Preferably, but not necessarily, the power conversion device may include: a power conversion unit, which converts input power to output power; and a shell, the power conversion unit is arranged inside the shell, and the switch can be formed as a physical switch exposed outside the shell.

[0026] Preferably, but not necessarily, it may include: when connected in parallel with other power conversion devices, a terminal switch unit that connects a terminal resistor in the case where the identification number is set to correspond to the terminal.

[0027] Preferably, but not necessarily, the terminal switch unit may include a plurality of switches which connect or disconnect the terminal resistance according to a communication method with the outside.

[0028] In order to solve the above-mentioned technical challenges, an energy storage device according to a second exemplary embodiment of the present invention may include: an energy storage unit, the energy storage unit including one or more batteries; a power conversion unit, the power conversion unit being used to convert the power stored in the energy storage unit and output it to the outside, or convert the power received from the outside and charge the energy storage unit; a controller, the controller being used to control the power conversion unit; at least one switch, the at least one switch being used to set an identification number according to an on-off state; and a communication unit, the communication unit being used to communicate with an inverter or the outside using an identification number, the identification number being different from other energy storage units connected in parallel according to the state of the switch.

[0029] Preferably, but not necessarily, the switch may include: a first switch and a second switch; a first resistor, one end of which is connected to the first switch and the other end of which is connected to a ground member; a second resistor, one end of which is connected to the second switch and the other end of which is connected to a ground member, one end of the first switch is input with a first voltage and the other end of the first switch is connected to the first resistor, the second switch is input with a first voltage at one end and is connected to the second resistor at the other end, and a node between the first switch and the first resistor and a node between the second switch and the second resistor are connected to a controller.

[0030] Preferably, but not necessarily, the switch may be formed as a physical switch exposed outside the housing of the energy storage device.

[0031] Preferably, but not necessarily, it may include: when connected in parallel with another energy storage device, one or more terminal switches are set to connect the terminal resistor when the terminal switch is set to an identification number corresponding to the terminal.

[0032] In order to solve the above technical challenges, an initial charging circuit according to a third embodiment of the present invention may include: a first switch, which is connected between a first input / output terminal and a second input / output terminal; and a PTC element, which is connected in series with the first switch, wherein the first switch is turned on until the voltage of the second input / output terminal corresponds to the voltage of the first input / output terminal.

[0033] Preferably, but not necessarily, when the current flowing through the first switch and the PTC element is higher than a threshold value, the PTC element may cut off the current.

[0034] Preferably, but not necessarily, the first input / output terminal may be connected to a battery and the second input / output terminal may be connected to an inverter or a DC-link terminal.

[0035] Preferably, but not necessarily, the initial charging circuit may further include a first capacitor connected to the second input / output terminal, and the first switch may be turned on until a voltage charged in the first capacitor is equal to a voltage of the battery.

[0036] Preferably, but not necessarily, the initial charging circuit may further include a second switch connected in parallel with the first switch and the PTC element, and when the voltage of the second input / output terminal corresponds to the voltage of the first input / output terminal, the first switch may be turned off and the second switch may be turned on.

[0037] In order to solve the above technical challenges, the energy storage device according to the third embodiment of the present invention may include: an energy storage unit, the energy storage unit including one or more batteries; a power conversion unit, the power conversion unit is used to convert the power stored in the energy storage unit and output it to the outside, or convert the power received from the outside and charge the energy storage unit; an initial charging circuit, the initial charging circuit is used to initially charge the voltage of the second input / output terminal connected to the outside, the initial charging circuit includes: a first switch, the first switch connects the energy storage unit and the second input / output terminal; and a PCT element, the PCT element is connected in series with the first switch, and the first switch is turned on until the voltage of the second input / output terminal corresponds to the voltage of the energy storage unit.

[0038] Preferably, but not necessarily, when the current flowing through the first switch and the PTC element is higher than a threshold value, the PTC element may cut off the current.

[0039] Preferably, but not necessarily, the second input / output terminal may be connected to an inverter or a DC-link stage.

[0040] Preferably, but not necessarily, the energy storage device may include a second switch connected in parallel with the first switch and the PTC element, and when the voltage of the second input / output terminal corresponds to the voltage of the energy storage unit, the first switch may be turned off and the second switch may be turned on.

[0041] Beneficial Effects

[0042] According to an exemplary embodiment of the present invention, by using a switch to set the identification number, the identification number can be changed after on-site installation, so that installation can be performed without restrictions on installation, and one type of product can be produced during production and the identification number can be set during installation, which improves the freedom of logistics management.

[0043] Furthermore, by configuring the initial charging circuit using a PTC element, when an overcurrent is applied due to an abnormal (short circuit) condition of the inverter, the temperature rises and the resistance value of the initial charging circuit increases, thereby preventing burnout of the initial charging circuit.

[0044] In addition, by enabling the auxiliary power unit to operate under the control of the circuit breaker and MCU, a separate auxiliary (SMPS) on / off switch can be removed, which reduces material costs, simplifies the operation sequence, and when the user manually disconnects the circuit breaker and the circuit breaker is disconnected due to a fault, the power of the auxiliary power circuit is maintained based on the MCU ORing circuit, preventing the product from burning due to irregular sequences and ensuring the log storage time. After completing the log storage, the MCUORing circuit is disconnected to switch the product to the minimum power mode, thereby preventing the battery from being over-discharged. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a diagram illustrating a photovoltaic power generation system having an insulation resistance measuring device according to an exemplary embodiment of the present invention.

[0046] Figure 2 is a block diagram of a power conversion apparatus according to an exemplary embodiment of the present invention.

[0047] Figure 3 is a block diagram of a power conversion apparatus according to a first exemplary embodiment of the present invention.

[0048] Figures 4 to 9 is a diagram showing a power conversion device according to a first exemplary embodiment of the present invention.

[0049] Fig.10 is a block diagram of an energy storage device according to a first exemplary embodiment of the present invention.

[0050] Fig.11 is a block diagram of a power conversion apparatus according to a second exemplary embodiment of the present invention.

[0051] Figure 12 to Figure 14 is a diagram showing a power conversion device according to a second embodiment of the present invention.

[0052] Fig.15 is a block diagram of an energy storage device according to a second exemplary embodiment of the present invention.

[0053] Fig.16 is a block diagram of a power conversion apparatus according to a third exemplary embodiment of the present invention.

[0054] Figures 17 to 21 is a diagram showing a power conversion device according to a third exemplary embodiment of the present invention.

[0055] Fig. 22 is a block diagram of an energy storage device according to a third exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0056] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0057] However, the present invention is not limited to the given exemplary embodiments described, but may be implemented in various different forms, and within the scope of the present invention, one or more of the components in the exemplary embodiments may be optionally combined or replaced between the embodiments.

[0058] In addition, unless explicitly and specifically defined and described, the terms (including technical and scientific terms) used in the embodiments of the present invention should be interpreted according to the meaning understood by ordinary technicians in the field to which the present invention belongs, and common terms (for example, terms defined in dictionaries) should be interpreted according to their contextual meanings in the relevant field.

[0059] Furthermore, the terms used in the embodiments of the present invention are intended to describe the embodiments but are not intended to limit the present invention.

[0060] In this specification, unless the context requires otherwise, the singular may include the plural, and the description of "at least one (or more) of A and (or) B and C" may include one or more of any combination of A, B and C that can be combined.

[0061] In addition, the terms first, second, A, B, (a) and (b), etc. may be used to describe the components of the embodiments of the present invention. These terms are intended to be used only to distinguish one component from another component, and are not intended to limit the nature, order or sequence of these components by these terms.

[0062] In addition, when a component is described as being “connected,” “coupled” or “attached” to another component, it can include the case where the component is directly “connected,” “coupled” or “attached” to the other component as well as the case where the component is “connected,” “coupled” or “attached” to another component located between the component and the other component.

[0063] Furthermore, when described as being formed or disposed “above” or “below” each component, “above” or “below” includes not only a case where two components are in direct contact with each other, but also a case where one or more other components are formed or disposed between the two components. Furthermore, when expressed as “above” or “below”, upward as well as downward meanings relative to a single component may be included.

[0064] Variations according to the present disclosure may include combinations of some configurations of each embodiment with some configurations of other embodiments, that is, variations may include one embodiment in various embodiments, but omit some configurations and include some configurations of corresponding other embodiments. Alternatively, the opposite may also be true. The features, structures, effects, etc. described in the embodiments are included in at least one embodiment and are not necessarily limited to any one embodiment. In addition, the features, structures, effects, etc. exemplified in each embodiment may be combined or modified in other embodiments by a person of ordinary skill in the art to which the embodiments belong. Therefore, such combinations and variations should be understood to be within the scope of the embodiments.

[0065] Figure 1is a diagram illustrating a photovoltaic power generation system having an insulation resistance measuring device according to an exemplary embodiment of the present invention.

[0066] like Figure 1 As shown, the photovoltaic (solar) power generation system may include a photovoltaic power source 10, an inverter 20, a battery bank 30 and a load 50. However, it will be understood by those skilled in the art that, in addition to Figure 1 In addition to the components shown, the photovoltaic power generation system may also include other common components. For example, the photovoltaic power generation system may also include a power grid (GRID40). Alternatively, according to other embodiments, a person skilled in the art will understand that Figure 1 Some of the components shown may be omitted.

[0067] The photovoltaic (solar) power source 10 may include a plurality of photovoltaic modules, each of which includes a plurality of photovoltaic cell monomers, wherein the photovoltaic cell monomers that join a P-type semiconductor and an N-type semiconductor together generate electricity using light. Specifically, when light is irradiated onto a solar cell, electrons and holes are generated inside the solar cell. The generated charges move toward the P pole and the N pole respectively, and this action generates a potential difference between the P pole and the N pole, and when a load is connected to the photovoltaic cell monomer, current flows. Here, the photovoltaic cell monomer is the smallest unit for power generation, and the photovoltaic cell monomers are assembled to form a cell monomer module, and the cell monomer module can be further connected in series / parallel to form an array, thereby forming a photovoltaic power source 10.

[0068] The inverter 20 can convert the DC electricity generated from the photovoltaic power source 10 by the photoelectric effect into AC electricity, and supply power to the grid 40 or the load 50. Here, the grid 40 may refer to a grid for transmitting and distributing the electricity generated by the photovoltaic power generation system. On the other hand, due to time factors such as sunrise and sunset or external factors such as weather, the amount of electricity generated by the photovoltaic power source 10 is constantly changing. Therefore, the inverter 20 can control the voltage generated by the photovoltaic power source 10 to find the maximum power and supply it to the grid 40. In this case, if the power required for the inverter to operate is lower than the output power of the inverter, the inverter 20 may reversely consume power from the grid 40. Of course, in this case, the inverter can prevent the phenomenon of power being reversed by cutting off the power entering the grid 40.

[0069] Various optimizer control methods are applied to the photovoltaic power generation system to extract the maximum power from the photovoltaic power source 10. Representative maximum power point (MPP) tracking methods of the photovoltaic power source 10 may include a PO (perturb and observe) method, an IC (incremental conductance) control method, and a CV (constant voltage) control method. Here, the PO method is a method of periodically measuring the voltage and current of the photovoltaic power source 10 to calculate the power and then using the power value to track the MPP. The IC control method is a method of measuring the voltage and current generated by the photovoltaic power source 10 and controlling it so that the rate of change of the power in response to the change of the terminal voltage operating point of the array is "0". The CV control method is a method of controlling a constant reference voltage (refV) regardless of the operating voltage or power of the array including the photovoltaic power source 10. According to each optimizer control method, the power source input from the photovoltaic power source 10 to the inverter can operate as a voltage source or a current source.

[0070] The load 50 may refer to a product that utilizes the form of electricity used in real life. For example, the inverter 20 may obtain AC electricity of the required voltage and frequency through an appropriate conversion method, a switching element, and a control circuit, and the control circuit supplies power to a machine in a household appliance or an industrial facility. In addition, in the case of photovoltaic power generation, there are inevitably nights without sunlight or power generation periods in which power generation is insufficient due to changes in weather conditions. Therefore, in order to compensate for these shortcomings, a battery pack 30 must be present in the photovoltaic power generation system to provide a stable power supply.

[0071] The battery pack 30 may include at least one of a DC-DC converter, a battery, a battery management system (BMS), an energy storage system (ESS), and a battery control circuit. The battery may include a lithium-ion battery or a nickel-metal hydride battery, but is not necessarily limited to these configurations, and the battery may refer to any battery that is semi-permanently available by charging. A DC-DC converter is a device that converts DC electricity generated by a photovoltaic power source 10 into DC electricity suitable for a battery, or converts power from a battery into power suitable for a grid, usually by converting DC electricity into AC electricity and then converting AC electricity back into DC electricity. A battery management system (BMS) may provide misuse protection for the battery cells that constitute the battery, as well as balance, state of charge (SOC), temperature management, or system monitoring. Therefore, based on the function of a sensor that measures the state of a battery cell and receives the measurement value of the sensor and transmits it to the control system of the application, a circuit may be constructed and controlled that generates an abnormal signal and shuts down or disconnects the power circuit between the battery cells when the temperature or state of charge of the system exceeds a set value.

[0072] Figure 2 is a block diagram of a power conversion apparatus according to an exemplary embodiment of the present invention.

[0073] According to one embodiment of the present invention, a power conversion device 100 includes a power conversion unit 110, a first input / output terminal 120, a second input / output terminal 130, and may include an identification number setting unit 140, a controller 150, a communication unit 160, a terminal resistance setting unit 170, an initial charging circuit 180, an auxiliary power unit 190, and the like.

[0074] The power conversion device 100 according to the embodiment of the present invention may be a DC-DC converter included in the battery pack 30, and may be a bidirectional converter for charging or discharging the battery inside the battery pack 30. The power conversion device 100 according to the embodiment of the present invention may include a module separated from the battery pack 30, and the module may be connected to the battery pack 30 to charge or discharge the battery inside the battery pack 30.

[0075] The power conversion unit 110 converts the input power and outputs it, and can operate bidirectionally. When power is input to the first input / output terminal 120, it can be converted and output to the second input / output terminal 130; when power is input to the second input / output terminal 130, it can be converted and output to the first input / output terminal 120. The first input / output terminal 120 can be connected to a battery, an energy storage unit 210, and the second input / output terminal 130 can be connected to an inverter, a DC link level, or the outside. The first input / output terminal 120 and the second input / output terminal 130 may include a (+) terminal and a (-) terminal.

[0076] Figure 3 is a block diagram of a power conversion apparatus according to a first exemplary embodiment of the present invention, Figures 4 to 9 is a diagram showing a power conversion device according to a first exemplary embodiment of the present invention.

[0077] The power conversion device 101 according to the first embodiment of the present invention includes an identification number (ID) setting unit 140 .

[0078] The power conversion device 101 according to the first embodiment of the present invention can be connected in parallel with other power conversion devices 101-1 to 101-n. As described above, the power conversion device 101 according to the first embodiment of the present invention can be a DC-DC converter applied to an energy storage system (ESS) such as a battery pack, and multiple energy storage devices (hereinafter, will be used equivalently to ESS) can be added in parallel to increase the capacity of the energy storage system. At this time, it is necessary to set a communication ID for each DC-DC converter (which is a power conversion device connected to each energy storage device) to facilitate communication with the inverter 20, which performs communication so that multiple energy storage devices connected in parallel can operate. For example, when four energy storage devices (i.e., four DC-DC converters) are connected in parallel, the communication IDs of the master device (00), slave device 1 (01), slave device 2 (10) and slave device 3 (11) can be set respectively. To this end, the ID can be fixed by a resistor inside the DC-DC converter. In this case, the master device and the slave device must be produced separately, which complicates the production process and cannot or is difficult to exchange on site.

[0079] The power conversion device 101 of the first exemplary embodiment of the present invention may include at least one switch which sets an identification number according to an ON-OFF state and has an identification number different from other power converters according to the state of the switch.

[0080] The state of the switch can represent the state value of on or off: 0 or 1. With these state (or condition) values, the switch can have an identification number different from other power conversion devices according to the state of the switch. One switch can have two state values ​​of 0 or 1, and two switches can have four state values ​​of 00, 01, 10, and 11.

[0081] The number of switches required may vary depending on the number of power conversion devices 101 for which identification numbers are set (ie, the number of power conversion devices 101 connected in parallel). Hereinafter, an example of setting identification numbers of four power conversion devices 101 to 101-n using two switches will be described.

[0082] The identification number (ID) setting unit 140 may include two switches 141 , 142 , and each of the switches 141 , 142 may have an identification number different from other power conversion devices according to a state of the switches 141 , 142 .

[0083] In order to enable the switches 141 and 142 to have a state value of 0 or 1 according to the states of the switches 141 and 142, the power conversion device may include a resistor 143 having one end connected to the switch 141 and the other end connected to the ground (GND) and a resistor 144 having one end connected to the switch 142 and the other end connected to the ground, as shown in FIG. Figure 5 As shown. Each of the switches 141, 142 may be connected to a first voltage 145, and each of the nodes between the interconnected switches and the resistor may be connected to the controller 150 to transmit the state value to the controller 150. Here, the first voltage may have a voltage value corresponding to the state value 1. The controller 150 may be a micro control unit (MCU) within the power conversion device 101, or may be an MCU located outside.

[0084] When one switch 141 is turned off, the first voltage 145 is not transmitted to the controller 150 through the node connected to the switch 141, and the state value 0 corresponding to the ground is transmitted to the controller 150 through the resistor (143). When the switch 141 is turned on, the first voltage 145 is transmitted to the controller 150 through the switch 141 and the node connected thereto, so that the state value 1 corresponding to the first voltage is transmitted to the controller 150.

[0085] When the other switch 142 is turned off, the first voltage 145 is not transmitted to the controller 150 through the node connected to the corresponding switch 142, and the state value 0 corresponding to the ground is transmitted to the controller 150 through the resistor 144. When the switch 142 is turned on, the first voltage 145 is transmitted to the controller 150 through the switch 142 and the node connected thereto, so that the state value 1 corresponding to the first voltage is transmitted to the controller 150.

[0086] According to the on or off state of each of the switches 141, 142, two state values ​​are transmitted to the controller 150. Here, the digital value of one switch 141 may be greater than the digital value of the other switch 142. This enables four different identification numbers to be set.

[0087] When the switch 141 is off and the switch 142 is off, the identification number may be set to 00; when the switch 141 is off and the switch 142 is on, the identification number may be set to 01; when the switch 141 is on and the switch 142 is off, the identification number may be set to 10; when the switch 141 is on and the switch 142 is on, the identification number may be set to 11. In this case, 00 may be set as the master device, 01 as the slave device 1, 10 as the slave device 2, and 11 as the slave device 3. Depending on the order of charging or discharging, the identification of the master device and the slave device may change.

[0088] For each of the power conversion devices 101 to 101 - n connected in parallel, the states of the switches 141 , 142 may be set differently so that they have different identification numbers.

[0089] The identification number set as described above is used to perform communication, and the communication unit 160 can use the identification number set as described above to perform communication with the outside. Here, the communication unit 160 can perform communication through various communication methods. For example, various communication methods such as CAN communication, RS485 communication, etc. can be used.

[0090] The controller 150 may communicate with the outside (eg, the inverter 20 ) via the above-set identification number to control the power conversion unit 110 to convert power according to an operation control signal received from the outside.

[0091] The power conversion unit 110 may include a housing 111 disposed inside, and switches 141, 142 for setting the identification number may be formed as physical switches exposed to the outside of the housing 111. If the switches 141, 142 are formed inside the housing, it may be difficult to change the identification number, so the switches 141, 142 may be formed to be exposed to the outside of the housing 111, so that the identification number can be set or changed by manipulating the switches 141, 142 as needed.

[0092] When connected in parallel with another power conversion device, the power conversion device may include a terminal resistance setting unit 170 that connects the terminal resistance when it is set to an identification number corresponding to the terminal. When multiple power conversion devices are connected in parallel, the terminal resistance may be connected to the power conversion device connected to the terminal. When the signal used for communication passes through the impedance, a reflection phenomenon occurs, and the signal may be weakened and generate noise due to the reflection shape, making it difficult to operate normally. In order to solve these problems, a terminal resistance may be connected at the end of the line so that a constant current circulates throughout the line, reducing reflections and being more tolerant to noise. This enables smooth communication. If the power conversion device to be connected to the terminal is fixed, the terminal resistance may be connected to the power conversion device, but if the identification number can be changed so that the power conversion device that can be connected to any position can be set to an identification number corresponding to the terminal, the terminal resistance setting unit 170 connects the terminal resistance. As Figure 7 As shown, the terminal resistor is connected to the power conversion device 101 - n connected to the terminal.

[0093] When connected in parallel with another power conversion device, the terminal resistance setting unit 170 may include a terminal switch 171 that connects the terminal resistance when set to an identification number corresponding to the terminal. The terminal switch 171 may be connected to the front end of the second input / output terminal 130. The terminal switch 171 may be connected between the (+) terminal and the (-) terminal of the second input / output terminal 130.

[0094] The terminal switch 171 may include a plurality of switches that connect or disconnect the terminal resistor according to the communication method with the outside. Different communication methods may require different terminal resistors, and by including a plurality of switches, the switch can be controlled to a state suitable for each communication method.

[0095] The terminal switch 171 may also be formed as a physical switch exposed to the outside of the housing 111. When the identification number is set to 11 corresponding to the terminal according to the setting of the switches 141 and 142 for setting the identification number, the terminal resistor needs to be connected, and the terminal switch 171 may be turned on to connect the terminal resistor. Fig. 9 As shown, the switch 140 for setting the identification number and the switch 170 for connecting or disconnecting the terminal resistor may be formed outside the housing 111 to be physically set by an operator.

[0096] Here, the physical switch may be implemented by changing its position, for example by raising and lowering its position, or it may be implemented by pressing a button.

[0097] As described above, by using a switch to set the identification number, the identification number can be changed after on-site installation, so that installation can be performed without restrictions on installation, and one type of product can be produced during production and the identification number can be set during installation, which improves the freedom of logistics management.

[0098] Fig.10 is a block diagram of an energy storage device (aks ESS) according to a first exemplary embodiment of the present invention. Fig.10 The detailed description of each configuration in Figures 3 to 9 Corresponding to the detailed description of the power conversion device 101 in FIG. 1 , the energy storage device according to the first embodiment of the present invention will be described hereinafter, and redundant descriptions will be omitted.

[0099] According to the first embodiment of the present invention, the energy storage device 201 may include: an energy storage unit 210, the energy storage unit 210 includes one or more batteries; a power conversion unit 110, the power conversion unit 110 is used to convert the power stored in the energy storage unit 210 and output it to the external / inverter 301, or convert the power received from the external / inverter 301 and charge the energy storage unit; a controller 150, the controller 150 is used to control the power conversion unit 110; an identification number setting unit 140, the identification number setting unit 140 is used to set the identification number according to the on-off state; and a communication unit 160, the communication unit 160 is used to communicate with the inverter or the external / inverter 301 using the identification number, wherein the identification number has an identification number different from that of other energy storage devices connected in parallel.

[0100] Here, the identification number setting unit 140 may include at least one switch. The switch for setting the identification number may include two switches, and may include a resistor having one end connected to one of the switches and the other end connected to a grounding member, and a resistor having one end connected to the other switch and the other end connected to the grounding member. One switch and the other switch may each be connected to a first voltage at one end, and a node between the resistors connected to each switch may be connected to the controller 150.

[0101] The switch for setting the identification number may be formed as a physical switch exposed to the outside of the housing of the energy storage device. When connected in parallel with another energy storage device, one or more terminal switches may also be included to connect the terminal resistor when set to the identification number corresponding to the terminal.

[0102] Fig.11 is a block diagram of a power conversion apparatus according to a second exemplary embodiment of the present invention, Figure 12 to Figure 14 is a diagram showing a power conversion device according to a second exemplary embodiment of the present invention.

[0103] The power conversion device 102 according to the second embodiment of the present invention may include an initial charging circuit 180. As described above, the power conversion device 101 according to the first embodiment of the present invention may be a DC-DC converter applied to an energy storage system (ESS) such as a battery pack, and when the input terminal and the output terminal are connected to the inverter or the DC link terminal, initial charging is required to prevent the power conversion device from burning due to a sudden large current flow caused by the voltage difference. That is, before connecting the inverter, etc. to the second input / output terminal 130, the voltage of the second input / output terminal 130 must be charged using the voltage input to the first input / output terminal 120, and for this purpose, the initial charging circuit 180 is used. Here, the energy storage device may be a non-isolated energy storage device, and in the event of a short circuit in the inverter circuit, etc., the current may continue to flow from the initial charging circuit to the second input / output terminal, causing damage to the components of the initial charging circuit.

[0104] In order to prevent the current from continuously flowing in the initial charging circuit, the initial charging circuit 180 according to the second embodiment of the present invention may include a switch 181 connected between the first input / output terminal 120 and the second input / output terminal 130 and a PTC element 182 connected in series with the switch 181. Here, the switch 181 is turned on until the voltage of the second input / output terminal 130 corresponds to the voltage of the first input / output terminal 120. When the switch 181 is turned on, a path is formed between the first input / output terminal 120, the switch 181, and the second input / output terminal 130, and the current flows through the path, so that the voltage on the second input / output terminal 130 rises.

[0105] The first input / output terminal 120 can be connected to an energy storage unit (e.g., a battery) 210, and the second input / output terminal 130 can be connected to an inverter or a DC-link terminal 302, that is, the voltage on the second input / output terminal 130 is charged using the voltage of the energy storage unit (e.g., a battery) 210 so that the second input / output terminal 130 can be reliably connected to the inverter or the DC-link terminal 302.

[0106] The second input / output terminal 130 may include a capacitor 113 connected to the second input / output terminal 130, and the current flowing from the first input / output terminal 120 to the second input / output terminal 130 may charge the capacitor 113, thereby increasing the voltage at the second input / output terminal 130. The switch 181 may be turned on until the voltage charged in the capacitor 113 is equal to the voltage of the energy storage unit (e.g., battery) 210.

[0107] The switch 181 may include a switch 112 connected in parallel with the switch 181 and the PTC element 182 to form another path, and when the voltage of the second input / output terminal 130 corresponds to the voltage of the first input / output terminal 120, the initial charging is completed, the switch 181 is disconnected to stop the initial charging, and the switch 112 is turned on to enable the power conversion unit 110 to perform power conversion.

[0108] However, if a fault occurs in the inverter circuit or the like, such as a short circuit, the short circuit may cause an overcurrent to continue to flow from the first input / output terminal 120 to the second input / output terminal 130 during initial charging. In this case, if the overcurrent continues to flow, the switch 181 for initial charging may burn out, and excessive voltage consumption of the battery may occur.

[0109] In this case, if the current flowing through the switch 181 and the PTC element 182 exceeds the threshold value (value), the PTC element 182 can cut off the current. The PTC element 182 is a passive element with a positive temperature coefficient (PTC) characteristic, which means that its resistance increases as the temperature of the element increases. When the temperature rises, the resistance increases to prevent overcurrent from flowing. Unlike the case of using a general resistor element that causes burning when an overcurrent flows, by connecting the PTC element 182 in series with the switch 181, the overcurrent can be blocked according to the characteristics of the PTC element 182.

[0110] If an overcurrent flows, as described above, the charging capacity of the capacitor 113 may be exceeded, which may cause the capacitor 113 to burn out. In order to interrupt the overcurrent before the capacitor 113 burns out, the specifications of the PTC element 182 may be determined, that is, the specifications of the PTC element 182 may be determined so that it can protect the capacitor according to the design specifications of the capacitor and match the capacity and type of the capacitor.

[0111] like Fig.14 As shown, the power conversion device according to the second exemplary embodiment may include a first input / output terminal 120 having a battery power interface (BPI) connected to a battery, a second input / output terminal 130 having an inverter power interface (IPI) connected to an inverter, a power conversion unit 110 that converts and outputs input power, and an initial charging circuit 180 that initially charges the second input / output terminal 130 with the voltage of the battery. In this case, the initial charging may be performed by charging the capacitor 113 in the power conversion unit.

[0112] The first input / output terminal 120 and the second input / output terminal 130 are connected in parallel with a path including a switch 181 and a PTC element 182 constituting an initial charging circuit 180 and a path including the switch 112, and a current flows in the path including the switch 181 and the PTC element 182 during initial charging. In the event of a fault, such as a short circuit between the (+) terminal and the (-) terminal on the inverter side, an overcurrent may flow, and depending on the characteristics of the PTC element 182, the overcurrent may cause a temperature rise and an increase in resistance, thereby blocking the overcurrent. A circuit breaker 131 may be connected to the second input / output terminal 130 to cut off the connection with the inverter in the event of a fault.

[0113] Fig.15 is a block diagram of an energy storage device according to a second exemplary embodiment of the present invention. Fig.15 The detailed description of each configuration in Figures 11 to 14 Corresponding to the detailed description of the power conversion device 102 in FIG. 1 , the energy storage device according to the second exemplary embodiment of the present invention will be described below, and redundant descriptions will be omitted.

[0114] The energy storage device 202 according to the second exemplary embodiment of the present invention may include: an energy storage unit 210, the energy storage unit 210 includes one or more batteries; a power conversion unit 110, the power conversion unit 110 is used to convert the power stored in the energy storage unit 210 and output it to the outside, or convert the power received from the outside and charge the energy storage unit; and an initial charging circuit 180, the initial charging circuit 180 is used to initially charge the voltage of the second input / output terminal 130 connected to the outside of the power conversion unit 110. The initial charging circuit 180 may include a switch 181 connecting the energy storage unit 210 and the second input / output terminal 130 and a PTC element 182 connected in series with the switch 181, and the switch 181 may be turned on until the voltage of the second input / output terminal 130 corresponds to the voltage of the energy storage unit 210.

[0115] Here, the second input / output terminal 130 may be connected to the inverter or DC-link terminal 302, and when the current flowing through the switch 181 and the PTC element 182 exceeds a threshold value, for example, when a short circuit occurs in the inverter 302, the temperature of the PTC element 182 may increase, causing the resistance value to increase and blocking the current. When the switch 181 and the PTC element 182 include a switch 112 connected in parallel with the switch 181 and the PTC element 182 and the voltage of the second input / output terminal 130 corresponds to the voltage of the energy storage unit 210, the switch 181 may be turned off and the second switch 112 may be turned on.

[0116] Fig.16 is a block diagram of a power conversion apparatus according to a third exemplary embodiment of the present invention, Figures 17 to 21 is a diagram showing a power conversion device according to a third embodiment of the present invention.

[0117] The power conversion device 103 of the third embodiment of the present invention may include an auxiliary power unit 190. As described above, the power conversion device 103 according to the third embodiment of the present invention may be a DC-DC converter applied to an energy storage system (ESS) such as a battery pack, and an auxiliary power supply is required to operate a switch that is switched when converting power, etc. If the energy storage device is not connected to the inverter, in order to prevent unnecessary power consumption, in addition to disconnecting the circuit breaker connected to the inverter, an auxiliary power on / off control switch may be applied to prevent the consumption of battery power to generate auxiliary power. In order to make the DC-DC converter operate normally, the auxiliary power is on / off controlled to turn on the switch, which brings inconvenience to the user, and when the switch is disconnected during normal operation, an irregular sequence may occur, resulting in damage to the internal components. In addition, when the circuit breaker is disconnected by a protective action, the auxiliary power is also disconnected immediately, and there is a problem that there is no time to save the log of the circuit breaker disconnection due to the DC-DC converter failure situation.

[0118] In order to solve this problem, in order to generate auxiliary power without an auxiliary power on / off control switch, and to prevent the auxiliary power from being immediately disconnected when the circuit breaker 131 is disconnected, the auxiliary power unit 190 is configured to start when the circuit breaker 131 is turned on, and stop operating after a predetermined period of time when the circuit breaker 131 is turned off.

[0119] The auxiliary power unit 190 receives power from the first input / output terminal 120 of the power conversion unit 110 that converts input power and outputs it to generate auxiliary power of the power conversion unit 110. The auxiliary power unit 190 may include a circuit breaker 131 connected to the second input / output terminal 130 of the power conversion unit 110, wherein when the circuit breaker 131 is turned on, the circuit breaker 131 is driven, and when the circuit breaker 131 is turned off, the circuit breaker 131 stops driving after a predetermined period of time.

[0120] The auxiliary power unit 190 may include: a transformer 191 that converts power from the first input / output terminal 120; a driving unit 192 that drives the transformer 191 according to a first signal applied from the circuit breaker 131 when the circuit breaker 131 is turned on; and a controller 150 that receives the auxiliary power output from the transformer 191 and controls the driving unit 192 to drive the transformer 191. Here, the transformer may be a transformer. The auxiliary power unit 190 may be as follows Fig.17 Configure as shown.

[0121] The drive unit 192 is connected to the circuit breaker 131 and receives a signal from the circuit breaker 131. When the circuit breaker 131 is turned on, the drive unit 192 may receive a first signal from the circuit breaker 131, and when the circuit breaker 131 is turned off, the drive unit 192 may receive a second signal. The first signal may be an enable signal for driving the drive unit 192, and the second signal may be a disable signal for stopping the drive unit 192. When the circuit breaker 131 is turned on, the power conversion unit 110 must be operated, and for this purpose, an auxiliary power source must be generated. When the circuit breaker 131 is turned on, the first signal is applied to the drive unit 192, and when the drive unit 192 is started, the power of the first input / output terminal 120 is applied to the transformer 191, and the auxiliary power is generated by the transformer 191. The auxiliary power unit 190 is operated by turning on the circuit breaker 131, so a separate switch is not required to turn the auxiliary power source on and off. This can reduce material costs, simplify the operating sequence, and eliminate the dangers associated with forced actuation of the auxiliary power on / off switch.

[0122] When the auxiliary power is generated, the auxiliary power is applied to the controller 150, and the controller 150 may apply a control signal to the driving unit 192 to control the driving unit 192 to drive the transformer 191 when the auxiliary power is applied. At this time, a signal corresponding to the first signal may be applied to the driving unit 192 through the control of the controller 150.

[0123] The driving unit 192 can maintain the driving of the transformer in at least one of a case where a first signal is applied from the circuit breaker 131 and a case where the controller 150 is controlled to drive the transformer. When the first signal is applied from the circuit breaker 131 and a signal corresponding to the first signal is applied by the control operation of the controller 150, the driving unit 192 is started. In other words, the driving unit 192 maintains the driving by the enable signal applied by the circuit breaker 131 or the controller 150, thereby maintaining the driving of the transformer. In other words, even if a second signal is applied from the circuit breaker 131 instead of the first signal, the driving unit 192 can maintain the driving by the signal applied by the controller 150. In this way, the Qring circuit structure can be configured to operate when at least one of the two conditions is met.

[0124] When the circuit breaker 131 is disconnected and the second signal is applied from the circuit breaker 131, the controller 150 may control the drive unit 192 to maintain the drive of the transformer 191 for a predetermined period of time. When the circuit breaker 131 is disconnected, the second signal is applied instead of the first signal, but the signal applied by the controller 150 to the drive unit 192 may be controlled to maintain the enable signal. When the circuit breaker 131 is disconnected, instead of immediately stopping the generation of auxiliary power, the drive unit 192 may be controlled to keep the transformer 191 running for the time required to reliably stop and store the log. The time that the drive unit 192 controls the transformer 191 to keep running may be the time required to store the log, which may be set by the user. Alternatively, the time may be a preset time to maintain the auxiliary power in the case of a transient fault in which the circuit breaker 131 is immediately reconnected after the circuit breaker 131 is disconnected.

[0125] The controller 150 can store log information when the drive unit 192 keeps the transformer 191 running, and the log information includes at least one of the following information: previous operation information, fault state, fault type and fault location. It is necessary to store log information to store historical information or fault occurrence information so that the product can be repaired or replaced. Even if the circuit breaker 131 is disconnected, the controller 150 can also maintain auxiliary power so that there is time to store log information, and the log information can be stored. The controller 150 may include one or more memories. Alternatively, the log information may be stored in a separate memory or transmitted to the outside.

[0126] The auxiliary power unit 190 may include: a first switch 194, one end of which is connected to the first input / output terminal 120; a transformer 191, which is connected to the other end of the first switch 194 to convert power of the first input / output terminal 120; a drive unit 192, which is connected to the primary (-) terminal of the transformer and drives the transformer 191 according to a first signal applied from the circuit breaker 131 when the circuit breaker 131 is turned on; a capacitor 196, which is charged according to the output of the transformer 191 to generate an auxiliary power supply; a second switch 195, one end of which is connected to a first node between the circuit breaker 131 and the drive unit 192, and the other end of the second switch 195 is connected to a ground member; and a controller 150, which receives the auxiliary power supply and turns on the second switch 195.

[0127] like Fig.18As shown, when a first signal is applied from the circuit breaker 131 to the drive unit 192, the drive unit 192 is enabled. The first switch 194 may be a MOSFET, the gate may be connected to the first node, the current may flow through the first input / output terminal 120, the first switch 194, the primary side of the transformer 191 and the drive unit 192, and the current may be output to the secondary side of the transformer 191 to charge the capacitor 196 and generate auxiliary power. Here, the first signal applied from the circuit breaker 131 may have a potential corresponding to the grounding member. For example, the potential may be 0V. In this way, the auxiliary power generated is used to operate the power conversion unit 110. The auxiliary power is also delivered to the controller 150, and the controller 150 may control the power conversion unit 110 to operate.

[0128] In addition, the controller 150 may turn on the second switch 195 so that the driving unit 192 is connected to the ground via the second switch 195. As described above, the enable signal for the driving unit 192 is a signal corresponding to the ground, and therefore, when connected to the ground via the second switch 195, it remains enabled even if the first signal is not received from the circuit breaker 131. In other words, the enable signal for the driving unit 192 may have an Oring circuit structure.

[0129] The driving unit 192 may maintain driving of the transformer 191 in at least one of a case where the first signal is applied from the circuit breaker 131 and a case where the second switch is turned on.

[0130] Even if the circuit breaker 131 is disconnected and the second signal is applied instead of the first signal, the controller 150 can keep the second switch 195 turned on to keep the drive unit 192 connected to the ground, thereby keeping the drive unit 192 running and preventing the auxiliary power from stopping. The continuously generated auxiliary power can be used to provide time to store log information and prevent the log from burning information due to a sudden auxiliary power interruption.

[0131] The controller 150 may stop the generation of auxiliary power to switch to the minimum power mode by disconnecting the second switch 195 when the log storage is completed, thereby disconnecting the connection between the drive unit 192 and the ground to prevent the enable signal from being applied to the drive unit 192. This prevents excessive discharge of the energy storage unit 210 connected to the first input / output terminal 120.

[0132] The power conversion device according to the third exemplary embodiment of the present invention may be as follows Fig.19As shown. The control IC as the drive unit 192 is connected to receive an enable signal from the circuit breaker 131, and the circuit breaker 131 is connected to one end of the bidirectional converter as the power conversion unit. A first switch 194 connected to the other end of the power conversion unit 110, a transformer 191 whose primary side is connected to the first switch 194 and a drive unit 192 connected to the primary side of the transformer 191 are connected. The gate of the first switch 194 is connected to the node between the circuit breaker 131 and the drive unit 192. A diode and a capacitor 196 are connected to the secondary side of the transformer 191 to generate an auxiliary power supply by charging it. The capacitor 196 is connected to the output end of the controller 150, and the controller 150, i.e., the MCU, transmits a control signal to disconnect the second switch 195 in response to the application of the auxiliary power. One end of the second switch 195 is connected to the drive unit 192, and the other end of the second switch 195 is connected to the ground.

[0133] In the above circuit, if Fig. 20 As shown, when the circuit breaker 131 is turned on, a 0V signal is applied from the circuit breaker 131 to the drive unit 192. The enable signal of the drive unit 192 is 0V, so that the drive unit 192 is driven, so that current flows through the drive unit 192, the current flows through the first switch 194 and the transformer 191, and the capacitor 196 on the secondary side of the transformer 191 is charged to generate auxiliary power. The auxiliary power is applied to the controller 150, and the second switch 195 is turned on, thereby forming an OR state for the enable signal of the drive unit 192 together with the circuit breaker 131.

[0134] Then, if Fig.21 As shown, when the circuit breaker 131 is disconnected, a non-zero floating signal is applied from the circuit breaker 131 to the drive unit 192. This can be a floating voltage corresponding to the battery voltage. Even if a disable signal is applied from the circuit breaker 131, the enable signal of the drive unit 192 remains at 0V according to the OR condition established previously, and auxiliary power generation is maintained. When the circuit breaker 131 is disconnected, the information is passed to the controller 150, which maintains the auxiliary power and performs housekeeping to store logs of the power conversion device and the battery. After storing the log information (including whether a fault has occurred, the type of fault, and the cause of the fault), the controller 150 disconnects the second switch 195 to stop generating auxiliary power, and switches to the minimum power consumption mode to prevent excessive discharge of the battery.

[0135] Fig. 22 is a block diagram of an energy storage device according to a third exemplary embodiment of the present invention. Fig. 22 The detailed description of each configuration in Figures 16 to 21Corresponding to the detailed description of the power conversion device 103 in FIG. 1 , the energy storage device according to the third exemplary embodiment of the present invention will be described below, and redundant descriptions will be omitted.

[0136] The energy storage device 203 according to the third embodiment of the present invention may include: an energy storage unit 210, which includes one or more batteries; a power conversion unit 110, which converts the power stored in the energy storage unit 210 and outputs it to the outside, or converts the power received from the outside and charges the energy storage unit 210; an auxiliary power unit 190, which is used to generate auxiliary power of the power conversion unit 110 by receiving power from the first input / output terminal 120 of the power conversion unit 110 connected to the energy storage unit 210; and a circuit breaker 131, which is connected to the second input / output terminal 130 of the power conversion device 110 connected to the outside. When the circuit breaker 131 is turned on, the auxiliary power unit 190 can be driven, and when the circuit breaker 131 is turned off, the auxiliary power unit 190 can stop driving after a predetermined period of time.

[0137] The auxiliary power unit 190 may include: a transformer 191, which is used to convert power of the first input / output terminal 120; a driving unit 192, which is used to drive the transformer 191 according to a first signal applied from the circuit breaker 131 when the circuit breaker 131 is turned on, and apply auxiliary power output from the transformer 191; and a controller 150, which controls the driving unit 192 to drive the transformer 191, and the driving unit 192 is capable of maintaining the driving of the transformer 191 in at least one of the cases where the first signal is applied from the circuit breaker 131 and the case where the controller 150 controls the driving unit 192 to drive the transformer 191.

[0138] In addition, the auxiliary power unit 190 may include: a first switch 194, one end of which is connected to the first input / output terminal 120; a transformer 191, which is connected to the other end of the first switch 194 to convert the power of the first input / output terminal 120; a driving unit 192, which is connected to the primary side (-) terminal of the transformer 191 to drive the transformer 191 according to the first signal applied from the circuit breaker 131 when the circuit breaker 131 is turned on; a capacitor 196, which is charged according to the output of the transformer 191 to generate auxiliary power; a second switch 195, one end of which is connected to the first node between the circuit breaker 131 and the driving unit 192 and the other end of the second switch 195 is connected to the ground member; and a controller 150, which receives the auxiliary power and turns on the second switch 195.

[0139] Here, the first signal has a potential corresponding to the grounding member, and when the second switch 195 is turned on, the grounding member is connected to the first node, so that the driving unit 192 drives the transformer 191, and the driving unit 192 can maintain the driving of the transformer 191 in at least one of the cases where the first signal is applied from the circuit breaker 131 and the case where the second switch 195 is turned on.

[0140] Variations according to this embodiment may include all configurations of the first embodiment to the third embodiment. Variations may also include some configurations of the first embodiment, some configurations of the second embodiment, or some configurations of the third embodiment. Variations may also include some configurations of the first embodiment and some configurations of the second embodiment, some configurations of the first embodiment and some configurations of the third embodiment, or some configurations of the second embodiment and some configurations of the third embodiment.

[0141] The features, structures, effects, etc. described above in the embodiments are included in at least one embodiment and are not necessarily limited to any one embodiment. In addition, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by a person of ordinary skill in the art to which the embodiments belong. Therefore, such combinations and modifications should be understood to be within the scope of the present embodiment.

[0142] It will be appreciated by those skilled in the art that the present embodiment can be implemented in a modified form without departing from the essential features of the above-mentioned materials. Therefore, the disclosed method should be considered from an illustrative rather than a restrictive perspective. The scope of the present invention is shown in the claims of this patent rather than in the preceding description, and all differences within the scope should be interpreted as being included in the present invention.

Claims

1. An initial charging circuit, comprising: a first switch connected between the first input / output terminal and the second input / output terminal; as well as A PTC element connected in series with the first switch, The first switch is turned on until the voltage of the second input / output terminal corresponds to the voltage of the first input / output terminal.

2. The initial charging circuit according to claim 1, wherein: When the current flowing through the first switch and the PTC element is higher than a threshold value, the PTC element cuts off the current.

3. The initial charging circuit according to claim 1, wherein: The first input / output terminal is connected to a battery and the second input / output terminal is connected to an inverter or a DC-link terminal.

4. The initial charging circuit according to claim 3, comprising: a first capacitor connected to the second input / output terminal, The first switch is turned on until the voltage charged in the first capacitor is equal to the voltage of the battery.

5. The initial charging circuit according to claim 1, comprising: a second switch connected in parallel with the first switch and the PTC element, When the voltage of the second input / output terminal corresponds to the voltage of the first input / output terminal, the first switch is turned off and the second switch is turned on.

6. An energy storage device comprising: An energy storage unit, the energy storage unit comprising one or more batteries; a power conversion unit configured to convert the power stored in the energy storage unit and output the power to the outside, or convert the power received from the outside and charge the energy storage unit; an initial charging circuit configured to initially charge a voltage of a second input / output terminal connected to the outside, Wherein, the initial charging circuit comprises: a first switch, the first switch connecting the energy storage unit and the second input / output terminal; and A PTC element connected in series with the first switch, The first switch is turned on until the voltage of the second input / output terminal corresponds to the voltage of the energy storage unit.

7. The energy storage device according to claim 6, wherein: When the current flowing through the first switch and the PTC element is higher than a threshold value, the PTC element cuts off the current.

8. The energy storage device according to claim 6, wherein: The second input / output terminal is connected to an inverter or a DC-link terminal.

9. The energy storage device according to claim 6, comprising: a first capacitor connected to the second input / output terminal, The first switch is turned on until the voltage charged in the first capacitor is equal to the voltage of the battery.

10. The energy storage device according to claim 6, comprising: a second switch connected in parallel with the first switch and the PTC element, When the voltage of the second input / output terminal corresponds to the voltage of the energy storage unit, the first switch is turned off and the second switch is turned on.

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