Power conversion device
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- LG INNOTEK CO LTD
- Filing Date
- 2023-06-23
- Publication Date
- 2026-06-30
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a power conversion device, and more specifically, to a power conversion device capable of storing log information at the time of a failure and an energy storage device including the same.
Background Art
[0002] Recently, as awareness of environmental protection has increased, interest in methods of generating electricity without emitting pollutants such as carbon dioxide has been growing. In particular, in the case of a power generation system using sunlight, with the development of technology, the development and installation costs of the technology have become lower, and the spread has been gradually expanding.
[0003] Such a solar power generation system is configured by a plurality of solar cells gathering to form a plurality of photovoltaic modules. However, the DC power generated by the plurality of photovoltaic modules is converted into AC power through an inverter and can be immediately used in homes and industrial facilities.
[0004] On the other hand, in the case of solar power generation, there is a power production blank period where sufficient power generation cannot be performed due to nighttime when sunlight is absent or weather changes. Therefore, in order to compensate for such disadvantages, a battery is essentially attached to the solar power generation system so that stable power supply can be achieved.
[0005] A household solar system including a battery can be configured as shown in FIG. 1. The inside of the battery pack can be composed of a battery, a BMS, and a DC-DC converter. At this time, it is necessary to develop a technology to prevent the DC-DC converter inside the battery pack from burning out or malfunctioning due to abnormal operation.
Summary of the Invention
Problems to be Solved by the Invention
[0006] The technical problem to be solved by the present invention is to provide a power conversion device capable of storing log information when a failure occurs, and an energy storage device including the same.
Means for Solving the Problem
[0007] In order to solve the above technical problem, a power conversion device according to an embodiment of the present invention includes a power conversion unit that converts input power and outputs it, an auxiliary power supply unit that receives the power at the first input / output terminal of the power conversion unit and generates an auxiliary power supply for the power conversion unit, and a circuit breaker connected to the second input / output terminal of the power conversion unit. The auxiliary power supply unit is driven when the circuit breaker is turned on and stops driving after a predetermined time when the circuit breaker is turned off.
[0008] Further, the auxiliary power supply unit may include a transformer that converts the power at the first input / output terminal, a drive unit that drives the transformer in response to a first signal applied from the circuit breaker when the circuit breaker is turned on, and a control unit that applies the auxiliary power supply output from the transformer and controls the drive unit to drive the transformer.
[0009] Further, the drive unit can maintain the drive of the transformer when either the first signal is applied from the circuit breaker or the control unit controls the transformer to be driven.
[0010] Further, when the circuit breaker is turned off and a second signal is applied from the circuit breaker, the control unit can control the drive unit to maintain the drive of the transformer for a predetermined time.
[0011] Further, while the drive unit maintains the drive of the transformer, the control unit can store log information including at least one of previous operation information, presence or absence of a failure, type of failure, and failure occurrence location.
[0012] Further, the auxiliary power supply unit may include a first switch having one end connected to the first input / output terminal, a transformer connected to the other end of the first switch for converting the power of the first input / output terminal, a driving unit connected to the primary side (-) terminal of the transformer for driving the transformer in response to a first signal applied from the circuit breaker when the circuit breaker is turned on, a capacitor charged by the output of the transformer to generate an auxiliary power supply, a second switch having one end connected to a first node between the circuit breaker and the driving unit and the other end connected to the ground, and a control unit to which the auxiliary power supply is applied to turn on the second switch.
[0013] Further, the first signal has a potential corresponding to the ground. When the second switch is turned on, the ground is connected to the first node, and the driving unit can drive the transformer.
[0014] Also, the driving unit can maintain the driving of the transformer when either one of the case where a first signal is applied from the circuit breaker and the case where the second switch is on occurs.
[0015] Further, the first switch may be a MOSFET, and its gate may be connected to the first node.
[0016] To solve the above technical problem, an energy storage device according to an embodiment of the present invention includes an energy storage unit including one or more batteries, a power conversion unit configured 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 supply unit configured to receive the power of the first input / output terminal of the power conversion unit connected to the energy storage unit and generate an auxiliary power supply for the power conversion unit, and a circuit breaker connected to the second input / output terminal of the power conversion unit connected to the outside. The auxiliary power supply unit is driven when the circuit breaker is turned on and stops driving after a predetermined time when the circuit breaker is turned off.
[0017] In addition, the auxiliary power supply unit includes a transformer that converts the power of the first input / output terminal, a driving unit that drives the transformer in response to a first signal applied from the circuit breaker when the circuit breaker is turned on, and a control unit that is applied with the auxiliary power output from the transformer and controls the driving unit to drive the transformer. The driving unit can maintain the driving of the transformer when either one of the case where a first signal is applied from the circuit breaker and the case where the control unit controls to drive the transformer occurs.
[0018] In addition, the auxiliary power supply unit includes a first switch whose one end is connected to the first input / output terminal, a transformer that is connected to the other end of the first switch and converts the power of the first input / output terminal, a driving unit that is connected to the primary side (-) terminal of the transformer and drives the transformer in response to a first signal applied from the circuit breaker when the circuit breaker is turned on, a capacitor that is charged by the output of the transformer to generate an auxiliary power supply, a second switch whose one end is connected to a first node between the circuit breaker and the driving unit and whose other end is connected to the ground, and a control unit that is applied with the auxiliary power supply and turns on the second switch. The first signal has a potential corresponding to the ground. When the second switch is turned on, the ground is connected to the first node, the driving unit drives the transformer, and the driving unit can maintain the driving of the transformer when either one of the case where a first signal is applied from the circuit breaker and the case where the second switch is on occurs.
[0019] To solve the above technical problem, the power conversion device according to the second embodiment of the present invention includes at least one switch that sets an identification number according to the on / off state, and has an identification number different from that of other power conversion devices according to the state of the switch.
[0020] The switch also includes a first switch and a second switch, a first resistor having one end connected to the first switch and the other end connected to ground, and a second resistor having one end connected to the second switch and the other end connected to ground. The first voltage is input to one end of the first switch, and the other end is connected to the first resistor. The first voltage is input to one end of the second switch, and the other end is connected to the second resistor. The nodes between the first switch and the first resistor and between the second switch and the second resistor can be connected to the control unit.
[0021] The power conversion device may also be connected in parallel with the other power conversion device.
[0022] The switch may also include a communication unit that communicates with the outside using an assigned identification number.
[0023] The power conversion device also includes a power conversion unit that converts and outputs the input power, and a housing in which the power conversion unit is disposed. The switch can be formed as a physical switch exposed outside the housing.
[0024] When connected in parallel with another power conversion device, if it corresponds to the identification number set for the terminal, a terminal switch unit for connecting a terminal resistor can be included.
[0025] The terminal switch unit may also include a plurality of switches that connect or disconnect the terminal resistor according to the communication method with the outside.
[0026] To solve the above technical problem, an energy storage device according to a second embodiment of the present invention includes an energy storage unit including one or more batteries, a power conversion unit configured to convert power stored in the energy storage unit and output the converted power to the outside, or convert power received from the outside and charge the energy storage unit, a control unit configured to control the power conversion unit, at least one switch configured to set an identification number according to an on / off state, and a communication unit configured to communicate with an inverter or the outside using the identification number. The energy storage device has an identification number different from that of another energy storage device connected in parallel according to the state of the switch.
[0027] Further, the switch includes a first switch and a second switch, and includes a first resistor having one end connected to the first switch and the other end connected to ground, and a second resistor having one end connected to the second switch and the other end connected to ground. The first switch has a first voltage input to one end and the first resistor connected to the other end, the second switch has a first voltage input to one end and the second resistor connected to the other end, and nodes between the first switch and the first resistor and between the second switch and the second resistor can be connected to the control unit.
[0028] Further, the switch can be formed of a physical switch exposed outside the housing of the energy storage device.
[0029] Further, when set to an identification number corresponding to a terminal when connected in parallel with another energy storage device, it can include one or more terminal switches for connecting a terminal resistor.
[0030] To solve the above technical problem, an initial charging circuit according to a third embodiment of the present invention includes a first switch connected between a first input / output terminal and a second input / output terminal; and a PTC element 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 first input / output terminal.
[0031] Also, when the current flowing through the first switch and the PTC element becomes equal to or higher than the critical value, the PTC element can cut off the current.
[0032] Also, the first input / output terminal can be connected to a battery, and the second input / output terminal can be connected to an inverter or a DC-link terminal.
[0033] Also, it includes a first capacitor connected to the second input / output terminal, and the first switch can be turned on until the voltage charged in the first capacitor becomes equal to the voltage of the battery.
[0034] Also, it includes a second switch connected in parallel with the first switch and the PTC element. If the voltage of the second input / output terminal corresponds to the voltage of the first input / output terminal, the first switch can be turned off and the second switch can be turned on.
[0035] To solve the above technical problem, the energy storage device according to the third embodiment of the present invention includes an energy storage unit including one or more batteries, a power conversion unit that converts the power stored in the energy storage unit and outputs it externally, or converts the power received from the outside and charges the energy storage unit, and an initial charging circuit that initially charges the voltage of the second input / output terminal to which the power conversion unit is connected to the outside. The initial charging circuit includes a first switch that connects 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.
[0036] Also, when the current flowing through the first switch and the PTC element becomes equal to or higher than the critical value, the PTC element can cut off the current.
[0037] Also, the second input / output terminal can be connected to an inverter or a DC-link terminal.
[0038] Also, it includes a second switch connected in parallel with the first switch and the PTC element. If the voltage at the second input / output terminal corresponds to the voltage of the energy storage unit, the first switch can be turned off and the second switch can be turned on.
Advantages of the Invention
[0039] According to the embodiment of the present invention, by using a switch to set an identification number, the identification number can be changed after the field installation, the installation can be carried out without installation constraints, the production can be carried out with one type of product during production, the identification number can be set during installation, and the freedom of logistics management can be improved.
[0040] Also, by using a PTC element to form an initial charging circuit, when an overcurrent is applied under abnormal conditions (SHORT) of the inverter, the temperature rises and the resistance value of the initial charging circuit increases, preventing the initial charging circuit from burning out.
[0041] Furthermore, the auxiliary power supply unit is made to operate under the control of a circuit breaker and an MCU, and a separate AUXILIARY (SMPS) ON / OFF switch can be removed, reducing material costs and simplifying the operation sequence (SEQUENCE). When the user turns off the circuit breaker MANUAL OFF and under the OFF condition due to a FAULT, the MCU ORING circuit maintains the power supply (POWER HOLDING) of the auxiliary power supply (AUXILIARY) circuit to prevent product burnout due to an irregular sequence and ensure the log storage time. After the log storage is completed, the MCU ORING circuit is turned off to switch to the minimum power mode of the product, and over-discharge of the battery can also be prevented.
Brief Description of the Drawings
[0042]
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Modes for Carrying Out the Invention
[0043] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0044] However, the technical idea of the present invention is not limited to the partial embodiments described, but can be implemented in various different forms. Within the scope of the technical idea of the present invention, one or more of the components can be selectively combined or replaced between the embodiments for use.
[0045] Also, the terms (including technical and scientific terms) used in the embodiments of the present invention can be interpreted in a meaning generally understood by those having ordinary knowledge in the technical field to which the present invention pertains, unless they are clearly defined and described specially. Terms generally used like those defined in a dictionary can have their meanings interpreted considering the meaning in the context of the related technology.
[0046] Also, the terms used in the embodiments of the present invention are for the purpose of explaining the embodiments and do not limit the present invention.
[0047] In this specification, the singular form can also include the plural form unless otherwise specifically mentioned in the text. When it is described as "at least one (or more) of A, B, and C", it can include one or more of all combinations formed by A, B, and C. Also, when explaining the components of the embodiments of the present invention, terms such as first, second, A, B, (A), (B), etc. can be used. These terms are for distinguishing the components from other components and are not limited to the essence, order, or sequence of the components by these terms.
[0048] And when a component is described as being "connected", "coupled", or "joined" to another component, that component can include not only the case where it is directly "connected", "coupled", or "joined" to the other component, but also the case where it is "connected", "coupled", or "joined" by another component between that component and the other component.
[0049] Also, when described as being formed or arranged "above (on top of)" or "below (beneath)" each component, "above (on top of)" or "below (beneath)" includes not only the case where two components are in direct contact with each other, but also the case where one or more other components are formed or arranged between the two components. Also, when expressed as "above (on top of)" or "below (beneath)", it can include not only the upward direction but also the downward direction with respect to one component.
[0050] The modified example according to this embodiment can include a part of the configurations of some of the embodiments and a part of the configurations of other embodiments. That is, the modified example includes one of the various embodiments, but a part of the configurations are omitted and can include a part of the configurations of the corresponding other embodiments. Or, vice versa may also be the case. The features, structures, effects, etc. described in the embodiments are included in at least one embodiment and are not necessarily limited to one embodiment. Furthermore, those skilled in the art to which the embodiments belong can implement the features, structures, effects, etc. illustrated in each embodiment by combining or modifying other embodiments. Therefore, the content related to such combinations and modifications should be interpreted as being included in the scope of the embodiments.
[0051] FIG. 1 is a diagram for explaining a photovoltaic power generation system to which an insulation resistance measuring device according to an embodiment of the present invention is applied.
[0052] As shown in FIG. 1, the photovoltaic power generation system can include a solar power source 10, an inverter 20, a battery pack 30, and a load (LOAD) 50. However, those having ordinary knowledge in the relevant technical field can understand that in addition to the components illustrated in FIG. 1, other general-purpose components can be further included in the photovoltaic power generation system. For example, the photovoltaic power generation system can further include a grid (GRID) 40. Or, according to other embodiments, those having ordinary knowledge in the relevant technical field can understand that some of the components illustrated in FIG. 1 can be omitted.
[0053] The solar power supply 10 can be composed of a plurality of photovoltaic modules in which photovoltaic cells are assembled. The photovoltaic cell formed by joining a P-type semiconductor and an N-type semiconductor generates electricity from light. Specifically, when light shines on the photovoltaic cell, electrons and holes are generated inside. The generated charges move to the P electrode and the N electrode respectively, and due to this effect, a potential difference is generated between the P electrode and the N electrode. At this time, when a load is connected to the photovoltaic cell, an electric current flows. Here, the photovoltaic cell means the minimum unit for generating electricity. A plurality of photovoltaic cells gather to form a battery module, and the battery modules can also be connected in series / parallel to form an array to constitute the solar power supply 10.
[0054] The inverter 20 can convert the DC (direct current) power generated from the solar power supply 10 by the photovoltaic effect into AC (alternating current) power to supply power to the grid 40 or the load 50. Here, the grid 40 can mean a system for transmitting and distributing the power produced by the solar power generation system. On the other hand, the amount of power generated by the solar power supply 10 continues to change due to temporal factors such as sunrise and sunset and external factors such as weather. Therefore, the inverter 20 can control the voltage generated by the solar power supply 10 to search for the maximum power and supply it to the grid 40. At this time, when the power for operating the inverter is lower than the output power of the inverter, the inverter 20 can also consume the power of the grid 40 in reverse. Of course, in this case, the inverter can cut off the power flowing into the grid 40 and prevent the phenomenon of power reversal.
[0055] Various optimization (OPTIMIZER) control methods are applied to the photovoltaic power generation system to enable extraction of the maximum power from the photovoltaic power source 10. In the typical maximum power point tracking (MPP) method of the photovoltaic power source 10, there are the perturbation and observation (PO) method, the incremental conductance (IC) control method, the constant voltage (CV) control method, and the like. 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 tracking the MPP using the power value. The IC control method is a method of measuring the voltage and current generated from the photovoltaic power source 10 and controlling so that the change rate of the power with respect to the change in the terminal voltage operating point of the array becomes "0". The CV control method is a method of controlling with a constant reference voltage (REF V) regardless of the operating voltage or power of the array constituting the photovoltaic power source 10. By each optimization (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.
[0056] The load 50 can mean a product that utilizes the electrical form used in real life. For example, the inverter 20 can obtain AC power of a desired voltage and frequency through an appropriate conversion method, switching element, and control circuit and supply electricity to household appliances in a general household or machine products in an industrial facility. Also, in the case of photovoltaic power generation, there will be a blank period in power production where sufficient power generation cannot be performed due to the time at night when sunlight does not exist or weather changes. Therefore, in order to compensate for such drawbacks, a battery is essentially attached to the photovoltaic power generation system so that stable power supply can be achieved.
[0057] The battery pack 30 can include at least one of a DC-DC converter, a battery, a battery management system (BMS), an energy storage device (ESS), and a battery control circuit. The battery can be composed of a lithium-ion battery or a nickel-metal hydride battery, but is not necessarily limited to these configurations, and can mean a battery that can be used semi-permanently by charging. The DC-DC converter is a device that converts the DC power produced through the solar power source 10 into appropriate DC power for the battery or converts the power of the battery into appropriate power for the grid. Generally, the power can be converted by converting the DC power into AC power and then inverting the AC power back into DC power again. The battery management system (BMS) can provide a function for preventing misuse (PROTECTION) of the cells (CELLS) that make up the battery, equalization (BALANCING) between unit batteries, measurement of the remaining charge (SOC: STATE OF CHARGE), temperature maintenance management, or system monitoring function. Therefore, based on the sensor for measuring the state of the cell and the function of receiving the measured value of the sensor and transmitting it to the control system of the application product, when the temperature and charge state of the system exceed the set values, an abnormal signal is generated, and a circuit for blocking and releasing the power circuit between the cells can be constructed and controlled.
[0058] Figure 2 is a block diagram of a power conversion device according to an embodiment of the present invention.
[0059] A power conversion device 100 according to an embodiment of the present invention is composed of a power conversion unit 110, a first input / output terminal 120, and a second input / output terminal 130, and can include an identification number setting unit 140, a control unit 150, a communication unit 160, a termination resistance setting unit 170, an initial charging circuit 180, an auxiliary power supply unit 190, and the like.
[0060] The power conversion device 100 according to an embodiment of the present invention may be a DC-DC converter included in the battery pack 30, and may be a bidirectional converter in order to charge or discharge the battery inside the battery pack 30. The power conversion device 100 according to an embodiment of the present invention is composed of a module separate from the battery pack 30, is connected to the battery pack 30, and can also charge or discharge the battery inside the battery pack 30.
[0061] The power conversion unit 110 converts and outputs the input power and can operate in both directions. When power is input to the first input / output terminal 120, it is 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 battery of the energy storage unit 210 is connected to the first input / output terminal 120, and the second input / output terminal 130 can be connected to an inverter, a DC link terminal, or the outside.
[0062] The first input / output terminal 120 and the second input / output terminal 130 may include a (+) terminal and a (-) terminal.
[0063] FIG. 3 is a block diagram of the power conversion device according to the first embodiment of the present invention, and FIGS. 4 to 9 are diagrams for explaining the power conversion device according to the first embodiment of the present invention.
[0064] The power conversion device 101 according to the first embodiment of the present invention includes an identification number (ID) setting unit 140.
[0065] 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 may be a DC-DC converter applied to an energy storage device (ENERGY STORAGE SYSTEM, ESS) such as a battery pack, and a plurality of energy storage devices can be added in parallel to increase the capacity of the energy storage device. At this time, in order to perform smooth communication with the inverter 20 that communicates so that a plurality of energy storage devices connected in parallel can operate, it is necessary to set respective communication IDs for the DC-DC converters, which are power conversion devices connected to each energy storage device. For example, when four energy storage devices, that is, four DC-DC converters are connected in parallel, communication IDs of MASTER(00), SLAVE(01), SLAVE2(10), and SLAVE3(11) can be set respectively. For this reason, the ID can be fixed and produced via a resistor inside the DC-DC converter. In this case, it is necessary to produce by distinguishing between the master and the slave, the production process is complicated, and it is impossible or difficult to exchange MASTER⇔SLAVE in the field.
[0066] The power conversion device 101 of the first embodiment of the present invention includes at least one switch that sets an identification number according to an on / off state, and has an identification number different from that of other power conversion devices according to the state of the corresponding switch.
[0067] The state of the switch is on or off, and can represent a state value of 0 or 1. Using such a state value, an identification number different from that of other power conversion devices can be obtained according to the state of the switch.
[0068] One switch has two state values of 0 or 1, and two switches can have four state values of 00, 01, 10, and 11.
[0069] The number of power conversion devices 101 for which identification numbers are to be set, that is, the number of power conversion devices 101 connected in parallel, can change the number of switches required. Hereinafter, an example in which two switches are used to set the identification numbers of four power conversion devices (101 to 101-N) will be described as a reference.
[0070] The identification number (ID) setting unit 140 can include two switches 141 and 142, and can have an identification number different from other power conversion devices depending on the states of the switches 141 and 142.
[0071] As shown in FIG. 5, resistors 143 having one end connected to switch 141 and the other end connected to ground (GND), and resistors 144 having one end connected to switch 142 and the other end connected to ground can be included so that the states of switches 141 and 142 can have state values of 0 or 1. Here, a first voltage 145 is input to one end of each of the switches 141 and 142, and each node between the switches and resistors connected to each other is connected to the control unit 150, and the state value can be transmitted to the control unit 150. Here, the first voltage can have a voltage value corresponding to the state value 1. The control unit 150 may be an MCU (MICRO CONTROL UNIT, microcontroller) in the power conversion device 101, or may be an MCU located outside.
[0072] When one switch 141 is off, the first voltage 145 is not transmitted to the control unit 150 via the node to which the corresponding switch 141 is connected, and the state value 0 corresponding to ground is transmitted to the control unit 150 via the resistor 143. When the switch 141 is turned on, the first voltage 145 is transmitted to the control unit 150 via the switch 141 and the node to which the corresponding switch 141 is connected, and the state value 1 corresponding to the first voltage is transmitted to the control unit 150.
[0073] When the other switch 142 is off, the first voltage 145 is not transmitted to the control unit 150 through the node to which the corresponding switch 142 is connected, and a state value of 0 corresponding to the ground through the resistor 144 is transmitted to the control unit 150. When the switch 142 is turned on, the first voltage 145 is transmitted to the control unit 150 through the switch 142 and the node to which the corresponding switch 142 is connected, and a state value of 1 corresponding to the first voltage is transmitted to the control unit 150.
[0074] Two state values are transmitted to the control unit 150 according to the on or off state of each of the switches 141 and 142. Here, the digit value of one switch 141 can be larger than the digit value of the other switch 142. Thereby, four identification numbers can be set.
[0075] The identification number can be set to 00 when the switch 141 is off and the switch 142 is off, 01 when the switch 141 is off and the switch 142 is on, 10 when the switch 141 is on and the switch 142 is off, and 11 when the switch 141 is on and the switch 142 is on. At this time, 00 can be set as the master, 01 as the slave 1, 10 as the slave 2, and 11 as the slave 3. The classification of the master and the slave may be different depending on the order of charging or discharging.
[0076] The states of the switches 141 and 142 can be set to be different for each of the (parallel-connected) power conversion devices (101 to 101-N) so that they have different identification numbers.
[0077] The identification number set as described above is used for communication, and the communication unit 160 can communicate with the outside using the set identification number. Here, the communication unit 160 can communicate through various communication methods. For example, various communication methods such as CAN communication and RS485 communication can be used.
[0078] The control unit 150 can communicate with an external device such as the inverter 20 through the set identification number, and control the power conversion unit 110 to convert power according to the operation control signal received from the external device.
[0079] The power conversion unit 110 includes a housing 111 disposed therein, and the switches 141 and 142 for setting the identification number can be formed by physical switches exposed outside the housing 111. When the switches 141 and 142 are formed inside the housing, it is difficult to change the identification number. Therefore, they are formed to be exposed outside the housing 111, and the switches 141 and 142 can be operated as needed to set or change the identification number.
[0080] When connected in parallel with other power conversion devices, if the identification number corresponding to the terminal is set, it can include a terminal resistance setting unit 170 for connecting the terminal resistance. When a plurality of power conversion devices are connected in parallel, a terminal resistance (ERMINATING RESISTANCE) needs to be connected to the power conversion device connected to the terminal. When a signal for communication passes through an impedance, a reflection phenomenon occurs, the signal becomes weak due to the reflection shape, noise is generated, and normal operation may become difficult. To solve such problems, a terminal resistance is connected to the terminal, and the reflection phenomenon can be reduced by circulating a constant current through the entire line, making it resistant to noise. This enables smooth communication. If the power conversion device connected to the terminal is fixed, the terminal resistance can be connected to the corresponding power conversion device. However, if a power conversion device with a changeable identification number and connectable to any position is set to the identification number corresponding to the terminal, the terminal resistance setting unit 170 connects the terminal resistance. As shown in FIG. 7, the terminal resistance is connected to the power conversion device (101-N) connected to the terminal.
[0081] When the terminal resistance setting unit 170 is connected in parallel with other power conversion devices and is set with an identification number corresponding to the terminal, it can include a terminal switch 171 for connecting the terminal resistance. The terminal switch 171 can be connected to the front end of the second input / output terminal 130. It can connect between the (+) terminal and the (-) terminal of the second input / output terminal 130.
[0082] The terminal switch 171 can include a plurality of switches for connecting or disconnecting the terminal resistance according to the communication method with the outside. Since the terminal resistance required may vary depending on the communication method, it includes a plurality of switches and the switches can be controlled in a state suitable for each communication method.
[0083] The terminal switch 171 can also be formed by a physical switch exposed outside the housing 111. When an identification number is set to 11 corresponding to the terminal by setting the switches 141 and 142 for setting the identification number, it is necessary to connect the terminal resistance, and the terminal switch 171 can be turned on to connect the terminal resistance. As shown in FIG. 9, the switch 140 for setting the identification number and the switch 170 for connecting or disconnecting the terminal resistance are formed outside the housing 111 and can be physically set by the operator.
[0084] Here, the physical switch can be implemented in a way of changing positions such as raising and lowering, or can also be implemented in a button-pressing way.
[0085] As described above, by setting the identification number using the switch, the identification number can be changed after field installation, installation is possible without installation constraints, it is produced as one type of product during production, the identification number can be set during installation, and the degree of freedom in logistics management can be improved.
[0086] FIG. 10 is a block diagram of an energy storage device according to a first embodiment of the present invention. Since the detailed description of each configuration in FIG. 10 corresponds to the detailed description of the power conversion device 101 in FIGS. 3 to 9, the energy storage device according to the first embodiment of the present invention will be described below, and redundant descriptions will be omitted.
[0087] An energy storage device 201 according to a first embodiment of the present invention includes an energy storage unit 210 including one or more batteries, a power conversion unit 110 that converts the power stored in the energy storage unit 210 and outputs it to an external / inverter 301, or converts the power received from the external / inverter 301 and charges the energy storage unit, a control unit 150 that controls the power conversion unit 110, an identification number setting unit 140 that sets an identification number according to an on / off state, and a communication unit 160 that communicates with an inverter or an external / inverter 301 using the identification number. The identification number has an identification number different from that of other energy storage devices connected in parallel.
[0088] Here, the identification number setting unit 140 can include at least one or more switches. The switch for setting the identification number can include two switches, a resistor having one end connected to one switch and the other end connected to the ground, and a resistor having one end connected to the other switch and the other end connected to the ground. One of the switches and the other switch each have a first voltage input at one end, and the node between the resistors connected to each switch can be connected to the control unit 150.
[0089] The switch for setting the identification number can be formed of a physical switch exposed outside the housing of the energy storage device. Further, when set to an identification number corresponding to the termination when connected in parallel with other energy storage devices, it can include one or more termination switches for connecting a termination resistor.
[0090] FIG. 11 is a block diagram of a power conversion device according to a second embodiment of the present invention, and FIGS. 12 to 14 are diagrams for explaining the power conversion device according to the second embodiment of the present invention.
[0091] The power conversion device 102 according to the second embodiment of the present invention includes an initial charging circuit 180. As described above, the power conversion device 101 according to the first embodiment of the present invention is a DC-DC converter applied to an energy storage device (ENERGY STORAGE SYSTEM, ESS) such as a battery pack. When connected to an inverter at the input / output end or a DC link end, initial charging is required to prevent a suddenly large current from flowing due to a voltage difference and burning out the elements. That is, before connecting an inverter or the like to the second input / output end 130, the voltage of the second input / output end 130 must be charged using the voltage input to the first input / output end 120. Therefore, the initial charging circuit 180 is used. Here, the energy storage device may be a non-insulated energy storage device. When a short occurs in an inverter circuit or the like, current continuously flows through the initial charging circuit to the second input / output end, and there is a possibility that the elements of the initial charging circuit may be burned out.
[0092] To prevent current from continuously flowing through the initial charging circuit, the initial charging circuit 180 according to the second embodiment of the present invention can include a switch 181 connected between the first input / output end 120 and the second input / output end 130 and a PTC element 182 connected in series with the corresponding switch 181. Here, the switch 181 is turned on until the voltage of the second input / output end 130 corresponds to the voltage of the first input / output end 120. When the switch 181 is turned on, a path is formed through the first input / output end 120, the switch 181, and the second input / output end 130, current flows through the corresponding path, and the voltage of the second input / output end 130 increases.
[0093] The first input / output end 120 is connected to the battery 210, and the second input / output end 130 can be connected to an inverter or a DC-link end 302. That is, the voltage of the second input / output end 130 is charged so that the second input / output end 130 can be stably connected to the inverter or the DC-link end 302 using the battery 210 voltage.
[0094] It can include a capacitor 113 connected to the second input / output terminal 130. The current flowing from the first input / output terminal 120 to the second input / output terminal 130 charges the capacitor 113, thereby increasing the voltage of the second input / output terminal 130. The switch 181 can be turned on until the voltage charged in the capacitor 113 becomes the same as the voltage of the battery 210.
[0095] It can include a switch 112 connected in parallel with the switch 181 and the PTC element 182 to form another path. 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 turned off to stop the initial charging, and the switch 112 is turned on for the power conversion unit 110 to perform power conversion.
[0096] However, when a fault such as a short occurs in an inverter circuit or the like, due to the short, an overcurrent continuously flows from the first input / output terminal 120 to the second input / output terminal 130 during the initial charging. In this case, if the overcurrent continues to flow, there is a possibility that the switch 181 for the initial charging may burn out, and there may be a problem that the voltage of the battery is excessively consumed.
[0097] At this time, when the current flowing through the switch 181 and the PTC element 182 becomes equal to or higher than the critical value, the PTC element 182 can cut off the current. The PTC element 182 is a passive element having PTC (POSITIVE TEMPERATURE COFFICIENT) characteristics, and has the characteristic that the resistance increases as the temperature of the element increases. When the temperature rises, the resistance increases, and the overcurrent can be prevented from flowing. Different from the case where a general resistance element burns out when an overcurrent flows, by connecting the PTC element 182 in series with the switch 181, the overcurrent can be cut off according to the characteristics of the PTC element 182.
[0098] When an overcurrent flows and exceeds the charging capacity of the capacitor 113 described above, the capacitor 113 may be damaged by overheating. Before the capacitor 113 is damaged by overheating, the specifications of the PTC element 182 can be determined to cut off the overcurrent. That is, according to the design specifications of the capacitor, it can be protected, and the specifications of the PTC element 182 can be determined so as to be compatible with the capacitance and type of the capacitor.
[0099] As shown in FIG. 14, the power conversion device according to the second embodiment includes a first input / output terminal 120 of both terminals (BPI, BATTERY POWER INTERFACE) connected to the battery, a second input / output terminal 130 of both terminals (IPI, INVERTER POWER INTERFACE) connected to the inverter, a power conversion unit 110 that converts and outputs the input power, and an initial charging circuit 180 that initializes the charge of the second input / output terminal 130 using the voltage of the battery. At this time, the initial charge can be performed by charging the capacitor 113 in the power conversion device.
[0100] The first input / output terminal 120 and the second input / output terminal 130 are connected in parallel with a path composed of the switch 181 and the PTC element 182 constituting the initial charging circuit 180 and a path composed of the switch 112. During the initial charging, current flows through the path composed of the switch 181 and the PTC element 182. At this time, when a failure such as a short circuit occurs between the inverter side (+) terminal and the (-) terminal, an overcurrent may flow. However, when the overcurrent flows due to the characteristics of the PTC element 182, the temperature rises, thereby increasing the resistance and cutting off the overcurrent. A circuit breaker 131 that cuts off the connection with the inverter may be connected to the second input / output terminal 130 side when a failure occurs.
[0101] FIG. 15 is a block diagram of an energy storage device according to the second embodiment of the present invention. Since the detailed description of each component in FIG. 15 corresponds to the detailed description of the power conversion device 102 in FIGS. 11 to 14, the energy storage device according to the second embodiment of the present invention will be described below, and redundant descriptions will be omitted.
[0102] The energy storage device 202 according to the second embodiment of the present invention includes an energy storage unit 210 including one or more batteries, a power conversion unit 110 that converts the power stored in the energy storage unit 210 and outputs it externally, or converts the power received from the outside and charges the energy storage unit, and an initial charging circuit 180 that initially charges the voltage of the second input / output terminal to which the power conversion unit 110 is connected to the outside. Here, the initial charging circuit 180 includes a switch 181 that connects the energy storage unit 210 and the second input / output terminal 130, and a PTC element 182 that is connected in series with the switch 181, and the switch 181 can be turned on until the voltage of the second input / output terminal 130 corresponds to the voltage of the energy storage unit 210.
[0103] Here, the second input / output terminal 130 can be connected to an inverter or a DC-link terminal 302. When a short circuit occurs in the inverter 302, for example, and the current flowing through the switch 181 and the PTC element 182 exceeds a critical value, the temperature of the PTC element 182 rises and the resistance value increases, and the current can be cut off. It includes a switch 112 connected in parallel with the switch 181 and the PTC element 182. When the voltage of the second input / output terminal 130 corresponds to the voltage of the energy storage unit 210, the switch 181 is turned off and the second switch 112 can be turned on.
[0104] FIG. 16 is a block diagram of a power conversion device according to a third embodiment of the present invention, and FIGS. 17 to 21 are diagrams for explaining the power conversion device according to the third embodiment of the present invention.
[0105] The power conversion device 103 according to the third embodiment of the present invention includes an auxiliary power supply 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 device (ENERGY STORAGE SYSTEM, ESS) such as a battery pack, and an auxiliary power supply (AUXILIARY) for operating a switch or the like that performs a switching operation during power conversion is required. When the energy storage device is not connected to the inverter, in order to prevent unnecessary power consumption, in addition to a circuit breaker that cuts off the connection to the inverter, an auxiliary power supply on / off control switch can be applied to prevent battery power from being consumed to generate the auxiliary power supply. In order for the DC-DC converter to operate normally, the auxiliary power supply on / off control switch is turned on and operated, but this causes inconvenience to the user. If the corresponding switch is turned off during normal operation, an irregular sequence (SEQUENCE) may occur, and there is a possibility of burnout in internal components and the like. Also, when the circuit breaker is turned off due to a protection operation, the auxiliary power supply is also immediately turned off, and there is a problem that it is not possible to secure a time for storing a log at the time when the circuit breaker is turned off due to the occurrence of a DC-DC converter fault (FAULT) situation.
[0106] To solve this problem, the auxiliary power supply unit 190 is configured to be driven when the circuit breaker 131 is turned on and stop driving after a predetermined time when the circuit breaker 131 is turned off, so that the auxiliary power supply can be generated even without an auxiliary power supply on / off control switch and the auxiliary power supply does not immediately turn off when the circuit breaker is turned off.
[0107] The auxiliary power supply unit 190 receives the power at the first input / output terminal 120 of the power conversion unit 110 that converts the input power and outputs it, and generates the auxiliary power supply of the power conversion unit 110. Although it includes a circuit breaker 131 connected to the second input / output terminal 130 of the power conversion unit 110, the auxiliary power supply unit 190 is driven when the circuit breaker 131 is turned on and stops driving after a predetermined time when the circuit breaker 131 is turned off.
[0108] The auxiliary power supply unit 190 can include a transformer 191 that converts the power of the first input / output terminal 120, a driving unit 192 that drives the transformer 191 in response to a first signal applied from the circuit breaker 131 when the circuit breaker 131 is turned on, and a control unit 150 that is applied with the auxiliary power supply 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 supply unit 190 can be configured as shown in FIG. 17.
[0109] The driving unit 192 is connected to the circuit breaker 131 and receives a signal from the circuit breaker 131. The circuit breaker 131 can receive a first signal from the circuit breaker 131 when it is turned on and a second signal when it is turned off. The first signal can be an ENABLE signal that the driving unit 192 drives, and the second signal can be a DISABLE signal that the driving unit 192 stops. When the circuit breaker 131 is turned on, the power conversion unit 110 must operate, and for this purpose, an auxiliary power supply must be generated. When the circuit breaker 131 is turned on, the first signal is applied to the driving unit 192, and when the driving unit 192 is driven, the power of the first input / output terminal 120 is applied to the transformer 191, and an auxiliary power supply is generated through the transformer 191. Since the auxiliary power supply unit 190 operates when the circuit breaker 131 is turned on, a separate switch for turning the auxiliary power supply on and off is not required. Thereby, the material cost can be saved, the operation sequence can be simplified, and the risk due to the forced operation of the auxiliary power supply on / off switch can be removed.
[0110] When the auxiliary power supply is generated, the auxiliary power supply is applied to the control unit 150, and when the auxiliary power supply is applied, the control unit 150 can apply a control signal to the driving unit 192 to control the driving unit 192 to drive the transformer 191. At this time, a signal corresponding to the first signal can be applied to the driving unit 192 under the control of the control unit 150.
[0111] When a first signal is applied from the circuit breaker 131 or when it is controlled by the control unit 150 to drive the transformer, the driving unit 192 can maintain the driving of the transformer. The driving unit 192 has a first signal applied from the circuit breaker 131, and a signal corresponding to the first signal is applied by the control operation of the control unit 150. That is, the driving unit 192 is maintained in driving by an enable signal applied via the circuit breaker 131 or the control unit 150, and maintains the driving of the transformer. That is, even if a second signal instead of the first signal is applied from the circuit breaker 131, the driving can be maintained by the signal applied via the control unit 150. In this way, an ORING circuit structure that drives when at least one of two types of conditions is satisfied can be configured.
[0112] When the circuit breaker 131 is turned off and a second signal is applied from the circuit breaker 131, the control unit 150 can control the driving unit 192 to maintain the driving of the transformer 191 for a predetermined time. When the circuit breaker 131 is turned off, a second signal instead of the first signal is applied, but the signal applied to the driving unit 192 by the control unit 150 can be made to maintain the enable signal. Without immediately stopping the auxiliary power generation when the circuit breaker 131 is turned off, the control unit 150 can control the driving unit 192 to maintain the driving of the transformer 191 for the time necessary for stable stop and log storage. The time for which the control unit 150 controls the driving unit 192 to maintain the driving of the transformer 191 is the time necessary for storing the log and can be set by the user. Alternatively, in the case of a temporary failure where the circuit breaker 131 is turned on again immediately after the circuit breaker 131 is interrupted, it may be a time preset to maintain the auxiliary power supply, the time for maintaining the auxiliary power supply.
[0113] While the drive unit 192 maintains the drive of the transformer 191, the control unit 150 can store log information including at least one of previous operation information, presence or absence of a failure, type of failure, and failure occurrence location. It is necessary to store log information for storing history information or failure occurrence information so that repair or replacement of the product can be performed. The control unit 150 can maintain the auxiliary power supply even when the circuit breaker 131 is turned off, can secure the time for storing the log information, and can also store the log information. The control unit 150 can include one or more memories. Alternatively, it can be stored in a separate memory or the log information can be transmitted externally.
[0114] The auxiliary power supply unit 190 includes a first switch 194 whose one end is connected to the first input / output terminal 120, a transformer 191 connected to the other end of the first switch 194 and converting the power of the first input / output terminal 120, a driving unit 192 connected to the primary side (-) terminal of the transformer and driving 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 charged by the output of the transformer 191 to generate an auxiliary power supply, a second switch 195 whose one end is connected to a first node between the circuit breaker 131 and the driving unit 192 and whose other end is connected to the ground, and a control unit 150 to which the auxiliary power supply is applied and which turns on the second switch 195. As shown in FIG. 18, when a first signal is applied from the circuit breaker 131 to the driving unit 192, the driving unit 192 becomes ENABLE. The first switch 194 is a MOSFET, and its gate can be connected to the first node. A current flows through the first input / output terminal 120, the first switch 194, the primary side of the transformer 191, and the driving unit 192, and a current is output to the secondary side of the transformer 191, and the capacitor 196 can be charged to generate an auxiliary power supply. Here, the first signal applied from the circuit breaker 131 can have a potential corresponding to the ground. For example, it may be 0V. In this way, the generated auxiliary power supply is used to operate the power conversion unit 110. The auxiliary power supply is also transmitted to the control unit 150, and the control unit 150 can control the power conversion unit 110 to operate. In addition, the control unit 150 can turn on the second switch 195 so that the driving unit 192 is connected to the ground through the second switch 195. As described above, since the ENABLE signal of the driving unit 192 is a signal corresponding to the ground, when it is connected to the ground through the second switch 195, the ENABLE is maintained even if the first signal is not received from the circuit breaker 131. That is, the ENABLE signal for the driving unit 192 can have an ORING circuit structure.
[0115] The driving unit 192 can maintain the driving of the transformer 191 when either one of the case where a first signal is applied from the circuit breaker 131 and the case where the second switch is on occurs.
[0116] Even if the breaker 131 is turned off and the second signal is applied instead of the first signal, the control unit 150 can maintain the turn-on of the second switch 195 and maintain the connection of the drive unit 192 to the ground. As a result, it is possible to prevent the drive unit 192 from maintaining drive and the auxiliary power supply from stopping. By securing the time to store the log information using the continuously generated auxiliary power supply, it is possible to prevent burnout due to a sudden stop of the auxiliary power supply.
[0117] When the log storage is completed, the control unit 150 turns off the second switch 195 to cut off the connection between the drive unit 192 and the ground, and cuts off the application of the enable signal to the drive unit 192, thereby stopping the generation of the auxiliary power supply and switching to the minimum power mode. As a result, over-discharge of the battery 210 connected to the first input / output terminal 120 can be prevented.
[0118] The power conversion device according to the third embodiment of the present invention can be implemented as shown in FIG. 19. The CONTROL IC of the drive unit 192 is connected to receive an ENABLE signal from a circuit breaker (CIRCUIT BREAKER) 131 connected to one end of the bidirectional converter of the power conversion unit 131. A first switch 194 is 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 the drive unit 192 is connected to the primary side of the transformer 191. The gate of the first switch 194 is connected to the node between the breaker 131 and the drive unit 192. A diode and a capacitor 196 are connected to the secondary side of the transformer 191, and an auxiliary power supply is generated by being charged. The capacitor 196 is connected to the output terminal to the MCU which is the control unit 150, and the MCU transmits a control signal for turning off the second switch 195 in response to the application of the auxiliary power supply. One end of the second switch 195 is connected to the drive unit 192, and the other end is connected to the ground.
[0119] In the circuit as described above, as shown in FIG. 20, when the breaker 131 is turned on, a 0V signal is applied from the breaker 131 to the drive unit 192. The enable signal of the drive unit 192 is 0V, whereby the drive unit 192 is driven, current flows through the drive unit 192, current flows through the first switch 194 and the transformer 191, the capacitor 196 on the secondary side of the transformer 191 is charged, and an auxiliary power supply is generated. The auxiliary power supply is applied to the control unit 150, the second switch 195 is turned on, and an OR condition of the enable signal for the drive unit 192 is formed together with the breaker 131.
[0120] After that, as shown in FIG. 21, when the breaker 131 is turned off, a floating signal instead of 0V is applied from the breaker 131 to the drive unit 192. At this time, it can float at a voltage corresponding to the battery voltage. When a DISABLE signal is applied from the breaker 131, due to the previously formed OR condition, the enable signal of the drive unit 192 still maintains 0V, and the generation of the auxiliary power supply is maintained. When the breaker 131 is turned off, the corresponding information is transmitted to the control unit 150, and the control unit 150 maintains the auxiliary power supply and performs HOUSE-KEEPING for storing the logs of the power conversion device and the battery. It stores log information including the presence or absence of a fault, the type of fault, and fault occurrence information. When the storage is completed, the control unit 150 turns off the second switch 195 to stop the generation of the auxiliary power supply and switches to the minimum power consumption mode for preventing over-discharge of the battery.
[0121] FIG. 22 is a block diagram of an energy storage device according to the third embodiment of the present invention. Since the detailed description of each configuration in FIG. 22 corresponds to the detailed description of the power conversion device 103 in FIGS. 16 to 21, hereinafter, the energy storage device according to the third embodiment of the present invention will be described, and repeated descriptions will be omitted.
[0122] The energy storage device 203 according to the third embodiment of the present invention includes an energy storage unit 210 including one or more batteries, a power conversion unit 110 that 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 supply unit 190 that receives the power at the first input / output terminal 120 of the power conversion unit 110 connected to the energy storage unit 210 and generates an auxiliary power supply for the power conversion unit 110, and a circuit breaker 131 connected to the second input / output terminal 130 of the power conversion unit 110 connected to the outside. The auxiliary power supply unit 190 can be driven when the circuit breaker 131 is turned on and stop driving after a predetermined time when the circuit breaker 131 is turned off.
[0123] The auxiliary power supply unit 190 includes a transformer 191 that converts the power at the first input / output terminal 120, a driving unit 192 that drives the transformer 191 in response to a first signal applied from the circuit breaker 131 when the circuit breaker 131 is turned on, and a control unit 150 that applies the auxiliary power supply output from the transformer 191 and controls the driving unit 192 to drive the transformer 191. The driving unit 192 can maintain the driving of the transformer 191 when either one of the cases where a first signal is applied from the circuit breaker 131 and the case where the control unit 150 controls the transformer 191 to be driven occurs.
[0124] Also, the auxiliary power supply unit 190 includes a first switch 194 having one end connected to the first input / output terminal 120, a transformer 191 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 connected to the primary side (-) terminal of the transformer 191 and driving the transformer 191 in response to a first signal applied from the circuit breaker 131 when the circuit breaker 131 is turned on, a capacitor 196 charged by the output of the transformer 191 to generate an auxiliary power supply, a second switch 195 having one end connected to a first node between the circuit breaker 131 and the driving unit 192 and the other end connected to the ground, and a control unit 150 to which the auxiliary power supply is applied to turn on the second switch 195. Here, the first signal has a potential corresponding to the ground. When the second switch 195 is turned on, the ground is connected to the first node, and the driving unit 192 drives the transformer 191. The driving unit 192 can maintain the driving of the transformer 191 when either the first signal is applied from the circuit breaker 131 or the second switch 195 is on.
[0125] The modification according to this embodiment can include all the configurations of the first to third embodiments. Further, it can include a part of the configuration of the first embodiment, a part of the configuration of the second embodiment, and a part of the configuration of the third embodiment. Also, it can include a part of the configurations of the first and second embodiments, a part of the configurations of the first and third embodiments, or a part of the configurations of the second and third embodiments.
[0126] As described above, the features, structures, effects, etc. described in the embodiments are included in at least one embodiment and are not necessarily limited to one embodiment. Further, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified for other embodiments by those with ordinary knowledge in the field to which the embodiments belong. Therefore, the content related to these combinations and modifications should be interpreted as being included in the scope of the embodiments.
[0127] Those skilled in the art in the technical field related to this embodiment will be able to understand that it can be implemented in a modified form without departing from the essential characteristics of the above-described description. Therefore, the disclosed method should be considered from an illustrative perspective rather than a limiting one. The scope of the present invention is shown not in the foregoing description but in the claims, and all differences within the equivalent scope thereof should be construed as being included in the present invention.
Claims
1. A first switch connected between the first input / output terminal and the second input / output terminal, The first switch includes a PTC element connected in series with the first switch, An initial charging circuit in which the first switch is turned on until the voltage at the second input / output terminal corresponds to the voltage at the first input / output terminal.
2. The initial charging circuit according to claim 1, wherein the PTC element interrupts the current when the current flowing through the first switch and the PTC element exceeds a critical value.
3. The first input / output terminal is connected to the battery, The initial charging circuit according to claim 1, wherein the second input / output terminal is connected to an inverter or a DC-link terminal.
4. Includes a first capacitor connected to the second input / output terminal, The initial charging circuit according to claim 3, wherein the first switch is turned on until the voltage charged to the first capacitor is equal to the voltage of the battery.
5. The system includes the first switch and a second switch connected in parallel with the PTC element, The initial charging circuit according to claim 1, wherein when the voltage at the second input / output terminal corresponds to the voltage at the first input / output terminal, the first switch is turned off and the second switch is turned on.
6. An energy storage unit including one or more batteries, A power conversion unit that converts the power stored in the energy storage unit and outputs it to the outside, or converts power received from the outside and charges the energy storage unit, The power conversion unit includes an initial charging circuit that initially charges the voltage of the second input / output terminal connected to the outside, An auxiliary power supply unit that receives power from the first input / output terminal of the power conversion unit and generates an auxiliary power supply for the power conversion unit, The power conversion unit includes a circuit breaker connected to the second input / output terminal, The auxiliary power supply unit is driven when the circuit breaker is turned on, and stops being driven after a predetermined time when the circuit breaker is turned off. The initial charging circuit described above is The first switch connects the energy storage unit and the second input / output terminal, The first switch includes a PTC element connected in series with the first switch, An energy storage device in which the first switch is turned on until the voltage at the second input / output terminal corresponds to the voltage of the energy storage unit.
7. The energy storage device according to claim 6, wherein the PTC element interrupts the current when the current flowing through the first switch and the PTC element exceeds a critical value.
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. Includes a first capacitor connected to the second input / output terminal, The energy storage device according to claim 6, wherein the first switch is turned on until the voltage charged to the first capacitor is equal to the voltage of the battery.
10. The system includes the first switch and a second switch connected in parallel with the PTC element, The energy storage device according to claim 6, wherein when the voltage at 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.
11. The aforementioned auxiliary power supply unit is A transformer that converts the power at the first input / output terminal, The circuit breaker includes a drive unit that drives the transformer in response to a first signal applied from the circuit breaker when the circuit breaker is turned on, The energy storage device according to claim 6, further comprising: a control unit which receives an auxiliary power output from the transformer and controls the drive unit to drive the transformer.
12. The aforementioned drive unit is The energy storage device according to claim 11, which maintains the drive of the transformer in either case when a first signal is applied from the circuit breaker or when the control unit controls the transformer to drive.
13. The control unit, The energy storage device according to claim 11, wherein when the circuit breaker is turned off and a second signal is applied from the circuit breaker, the drive unit is controlled to maintain the drive of the transformer for a predetermined time.
14. The control unit, The energy storage device according to claim 13, wherein while the drive unit maintains the drive of the transformer, log information including at least one of previous operation information, whether or not there was a fault, the type of fault, and the location where the fault occurred.