Apparatus for outputting alternating current power

Abstract

An apparatus for outputting alternating current power according to an embodiment of the present invention is an apparatus for outputting alternating current power from a plurality of batteries connected in series, and comprises: switching units connected to the plurality of batteries, respectively, and configured to turn on or off the electrical connection between a corresponding battery and the other battery according to an operation state; a filter unit configured to receive the output voltage of the plurality of batteries, adjust the polarity of the output voltage of the plurality of batteries according to an operation state, and output a voltage of the adjusted polarity; and a control unit configured to control the operation states of the switching units and the filter unit so that alternating current power is output from the plurality of batteries.

Description

AC power output device

[0001] This application claims priority to Korean Patent Application No. 10-2023-0102311, filed on August 4, 2023, the entire contents of which are disclosed in the specification and drawings of the said application are incorporated herein by reference.

[0002] The present invention relates to an alternating current power output device.

[0003] Conventionally, to output AC power from a battery pack composed of battery cells or modules, an inverter was installed in the battery pack to convert the direct current (DC) generated in the battery pack into alternating current (AC). For example, the inverter can convert the DC voltage of the battery pack into three-phase AC voltage, such as U, V, and W, using internal power semiconductors. This converted AC voltage is supplied to electric vehicles (EVs) and used as a driving source.

[0004] The present invention seeks to provide an AC power output device that generates and outputs AC power from batteries connected in series through switch control without using an inverter.

[0005] An AC power output device according to one aspect of the present invention is a device that outputs AC power from a plurality of batteries connected in series, and may include a switching unit connected to each of the plurality of batteries and configured to turn on and off electrical connection between a corresponding battery and another battery according to an operating state; a filter unit configured to receive output voltages of the plurality of batteries, adjust polarity of the output voltages of the plurality of batteries according to the operating state, and output voltages having adjusted polarity; and a control unit configured to control operating states of the switching unit and the filter unit so that AC power is output from the plurality of batteries.

[0006] The above control unit may be configured to control the operating state of the switching unit at each preset first cycle to change the number of batteries connected in series.

[0007] An AC power output device according to another aspect of the present invention may further include a measuring unit configured to measure battery information including at least one of voltage, current, and temperature of each of the plurality of batteries.

[0008] The control unit may be configured to determine priorities for the plurality of batteries based on battery information measured by the measurement unit, and to control the operating state of a corresponding switching unit according to the determined priorities.

[0009] The control unit may be configured to estimate the SOC of each of the plurality of batteries based on the battery information, and to set the priority to a higher value in the order of the estimated SOC.

[0010] The control unit may be configured to estimate the SOC and SOH of each of the plurality of batteries based on the battery information, and to set the priority to a higher value in the order of the estimated SOH and estimated SOC.

[0011] The control unit may be configured to estimate the SOC and SOH of each of the plurality of batteries based on the battery information, and to set the priority higher in the order of the estimated SOH being larger, and if the estimated SOHs are the same, to set the priority higher in the order of the estimated SOC being larger.

[0012] The control unit may be configured to select a corresponding number of batteries from among the plurality of batteries in the order of priority for each of the first cycles, and control the operation state of the switching unit corresponding to the selected batteries to be turned on so that only the selected batteries are connected in series.

[0013] The control unit may be configured to update the priorities for the plurality of batteries every first cycle.

[0014] The above control unit may be configured to control the operating state of the filter unit at every preset second cycle to reverse the polarity of the output voltage of the batteries connected in series.

[0015] The switching unit may be configured to include a first contact configured to be connected to one end of each of the plurality of batteries; a second contact configured to be connected to the other end of the batteries; and a third contact configured to be electrically connected to the first contact or the second contact when the operating state of the switching unit is turned on.

[0016] The above AC power source may be configured as a non-sinusoidal AC power source.

[0017] A battery pack according to another aspect of the present invention may include an AC power output device according to one aspect of the present invention.

[0018] A vehicle according to another aspect of the present invention may include an AC power output device according to one aspect of the present invention.

[0019] According to one aspect of the present invention, there is an advantage in that AC power can be generated and output through switch control without using an inverter.

[0020] In addition, according to one aspect of the present invention, since an inverter is not required, there is an advantage in that the circuit configuration of a battery pack including an AC power output device can be simplified and the production cost of the battery pack can be reduced.

[0021] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0022] The following drawings attached to this specification serve to further understand the technical idea of ​​the present invention together with the detailed description of the invention described below, and therefore the present invention should not be interpreted as being limited to the matters described in such drawings.

[0023] FIG. 1 is a schematic diagram illustrating an AC power output device according to one embodiment of the present invention.

[0024] FIG. 2 is a diagram schematically illustrating an exemplary configuration of an AC power output device according to one embodiment of the present invention.

[0025] FIG. 3 is a block diagram showing a hardware configuration that implements a control unit included in an AC power output device according to the present invention.

[0026] FIG. 4 is a schematic diagram illustrating an AC power source according to one embodiment of the present invention.

[0027] FIG. 5 is a schematic diagram illustrating an example of an AC power source according to one embodiment of the present invention.

[0028] FIG. 6 is a diagram schematically illustrating the priority and SOC of batteries at each time point in the embodiment of FIG. 5.

[0029] FIG. 7 is a schematic drawing of a vehicle according to another embodiment of the present invention.

[0030] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best possible manner.

[0031] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0032] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0033] Terms that include ordinal numbers, such as first, second, etc., are used to distinguish one of the various components from the rest, and are not used to limit the components by such terms.

[0034] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0035] Additionally, throughout the specification, when we say that a part is "connected" to another part, this includes not only cases where it is "directly connected" but also cases where it is "indirectly connected" with other elements in between.

[0036] Conventionally, when using secondary batteries that primarily generate DC power, a separate component called an inverter is required to output AC power. This increases the cost and size of the battery pack. For example, as the battery pack size increases, the inverter tends to also increase in size, which can lower the overall energy density of the battery pack. Furthermore, losses during the power switching process within the inverter itself can reduce output efficiency.

[0037] In consideration of such a situation, the present invention provides an AC power output device capable of generating and outputting AC power through switch control without using an inverter, and a battery pack and an electric vehicle including the same.

[0038]

[0039] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0040] FIG. 1 is a schematic diagram illustrating an AC power output device (100) according to one embodiment of the present invention. FIG. 2 is a schematic diagram illustrating an exemplary configuration of an AC power output device (100) according to one embodiment of the present invention.

[0041] An AC power output device (100) according to one embodiment of the present invention may be a device that outputs AC power from a plurality of batteries (B1, B2, B3, B4) connected in series. For example, the AC power output device (100) may convert DC power generated by a plurality of batteries (B1, B2, B3, B4) into AC power and output it without a configuration such as an inverter. Meanwhile, in the present embodiment, four batteries (B1, B2, B3, B4), including a first battery (B1), a second battery (B2), a third battery (B3), and a fourth battery (B4), were used, but the present invention is not limited thereto, and for example, a number of different batteries may be combined and used depending on needs and environments.

[0042] Here, each battery (B1, B2, B3, B4) has a negative terminal and a positive terminal and represents a physically separable independent cell. For example, a lithium ion battery or a lithium polymer battery may be considered as the battery in each battery (B1, B2, B3, B4). Furthermore, in the AC power output device (100) according to one embodiment of the present invention, the battery may also represent a battery module in which multiple cells are connected in series and / or in parallel. Hereinafter, for convenience of explanation, each battery (B1, B2, B3, B4) is described as representing a single independent cell.

[0043] Referring to FIG. 1, an AC power output device (100) may include a switching unit (110), a filter unit (120), a control unit (130), a measuring unit (140), and a storage unit (150).

[0044] The switching unit (110) can be configured to be connected to each of a plurality of batteries (B1, B2, B3, B4).

[0045] For example, in the embodiment of FIG. 2, a plurality of switching units (111, 112, 113, 114) may be provided to correspond to a plurality of batteries (B1, B2, B3, B4), respectively. A first switching unit (111) may be connected to a first battery (B1), and a second switching unit (112) may be connected to a second battery (B2). A third switching unit (113) may be connected to a third battery (B3), and a fourth switching unit (114) may be connected to a fourth battery (B4).

[0046] The switching unit (110) can be configured to turn on / off the electrical connection between the corresponding battery and another battery depending on the operating state.

[0047] According to one embodiment, the operating states of the switching unit (110) may include a first turn ON state, a second turn ON state, and a turn OFF state.

[0048] The turn-off state is a state in which the switching unit (110) is turned off. When the switching unit (110) is turned off, the switching unit (110) may be in a no-load state.

[0049] The first turn-on state is a state in which the switching unit (110) is controlled by the control unit (130) and connected to the corresponding battery. When the switching unit (110) is in the first turn-on state, the corresponding battery is electrically connected to another adjacent battery.

[0050] The second turn-on state is a state in which the switching unit (110) is controlled by the control unit (130) but is not connected to the corresponding battery. When the switching unit (110) is in the second turn-on state, the corresponding battery is not electrically connected to another battery. For example, when the switching unit (110) is in the second turn-on state, the corresponding battery is not electrically connected to another adjacent battery.

[0051] For example, in the embodiment of FIG. 2, each switching unit (111, 112, 113, 114) may include a first contact point (c1), a second contact point (c2), and a third contact point (c3). For example, in the switching unit (111) of the first battery (B1), the first contact point (c1) may be configured to be connected to one end of the first battery (B1), and the second contact point (c2) may be configured to be connected to the other end of the first battery (B1). In addition, the third contact point (c3) of the first battery (B1) may be configured to be connected to the other end of the adjacent second battery (B2). Through this connection, the third contact point (c3) of the first battery (B1) may be selectively connected to the first contact point (c1) or the second contact point (c2) as needed. For example, when the operating state of the switching unit (111) is the first turn-on state, the third contact point (c3) of the first battery (B1) is electrically connected to the first contact point (c1), so that the first battery (B1) is electrically connected to the adjacent second battery (B2). In addition, the third contact point (c3) of the first battery (B1) is electrically connected to the second contact point (c2) when the operating state of the switching unit (111) is the second turn-on state, so that in this case, the first battery (B1) is electrically disconnected from the adjacent second battery (B2).

[0052] In the embodiment of Fig. 2, an embodiment is shown in which each switching unit (111, 112, 113, 114) is positioned on the negative side of the corresponding battery (B1, B2, B3, B4). However, the connection position of the switching unit (110) is not limited by the embodiment of Fig. 2, and each switching unit (111, 112, 113, 114) may be positioned on the positive side of the corresponding battery (B1, B2, B3, B4). In this case, for example, the first contact (c1) of each battery may be connected to the positive pole of the battery, and the second contact (c2) may be connected to the negative pole of the battery. In addition, the third contact (c3) of each battery may be configured to be electrically connected selectively to the first contact or the second contact when the operating state of the switching unit (110) is turned on.

[0053] The filter unit (120) can be configured to receive output voltages of multiple batteries (B1, B2, B3, B4).

[0054] For example, the filter unit (120) can be connected to the high current path (L) of multiple batteries (B1, B2, B3, B4). That is, the DC voltage output from the multiple batteries (B1, B2, B3, B4) can be applied to the filter unit (120).

[0055] For example, in the embodiment of FIG. 2, the filter unit (120) can be connected to the high current path (L) of the plurality of batteries (B1, B2, B3, B4). That is, the DC voltage output from the plurality of batteries (B1, B2, B3, B4) can be input to the filter unit (120).

[0056] The filter unit (120) can be configured to control the polarity of the output voltage of multiple batteries (B1, B2, B3, B4) depending on the operating state.

[0057] For example, the filter unit (120) may be configured to reverse the polarity of the output voltage received from the plurality of batteries (B). For example, the filter unit (120) may adjust the polarity of the output voltage to plus (+) or minus (-) depending on the operating state. Alternatively, the filter unit (120) may adjust the polarity of the output voltage to plus (+) or minus (-) by separately using battery cells for plus voltage and battery cells for minus voltage, or by using a full-bridge or half-bridge method that applies plus voltage and minus voltage in a circuit.

[0058] The control unit (130) can be configured to control the operating states of the switching unit (110) and the filter unit (120) so that AC power is output from multiple batteries (B1, B2, B3, B4).

[0059] The control unit (130) can be connected to communicate with a plurality of switching units (111, 112, 113, 114) and a filter unit (120). In addition, the control unit (130) can control the operating states of each of the plurality of switching units (111, 112, 113, 114) and the operating state of the filter unit (120).

[0060] For example, in the embodiment of FIG. 2, the control unit (130) can be connected to a plurality of switching units (111, 112, 113, 114) and a filter unit (120), respectively.

[0061] According to one embodiment, the control unit (130) controls the switching unit (110) to control the number of batteries to be connected among the plurality of batteries (B1, B2, B3, B4), and can control the filter unit (120) to control the polarity of the output voltage of the plurality of batteries (B1, B2, B3, B4).

[0062] In one embodiment, the AC power may be configured as a non-sinusoidal AC power. That is, since the output voltages of the plurality of batteries (B1, B2, B3, B4) are DC voltages and the polarity of the output voltages is adjusted to AC by the filter unit (120), the AC power output by the AC power output device (100) may be a non-sinusoidal AC power.

[0063] FIG. 3 is a block diagram showing a hardware configuration that implements a control unit (130) included in an AC power output device (100) according to the present invention.

[0064] A control unit (130) according to one embodiment disclosed in this document may include an MCU (132), a memory (134), a communication I / F (136), and an input / output I / F (138). The MCU (132) is a micro controller unit that executes various programs stored in the memory (134), processes various data used in these programs, and is a processor that performs the functions of the control unit (130).

[0065] The memory (134) can store operation data of various programs related to the operation of the lithium secondary battery system for the operation of the control unit (130). A plurality of such memories (134) may be provided as needed. The memory (134) may be a volatile memory or a non-volatile memory. As a volatile memory, the memory (134) may be a RAM, a DRAM, an SRAM, etc. As a non-volatile memory, the memory (134) may be a ROM, a PROM, an EAROM, an EPROM, an EEPROM, a flash memory, etc. The examples of the memories (134) listed above are merely examples and are not limited thereto.

[0066] The communication I / F (136) is a configuration capable of transmitting and receiving various data with the server, and may be various devices capable of supporting wired or wireless communication. For example, a program or various data for the operation of the control unit (130) may be transmitted and received from a separately provided external server via wired or wireless communication via the communication I / F (136). The input / output I / F (138) may provide an interface that connects an input device (not shown) such as a keyboard, mouse, or touch panel, an output device such as a display (not shown), and the MCU (132) to transmit and receive data.

[0067]

[0068] FIG. 4 is a schematic diagram illustrating an AC power source according to one embodiment of the present invention. For example, the embodiment of FIG. 4 is a schematic diagram illustrating an AC power source output from the battery pack (10) of FIG. 2.

[0069] In the embodiment of FIG. 4, the voltages v1, v2, v3, and v4 are voltages output by one, two, three, and four batteries, respectively. Furthermore, the positive voltage indicates a positive polarity, and the negative voltage indicates a negative polarity. Referring to FIGS. 2 and 4, a non-sinusoidal AC power source can be output from time t1 using multiple batteries (B1, B2, B3, and B4).

[0070] An AC power output device (100) according to one embodiment of the present invention has the advantage of being able to generate and output AC power from a plurality of batteries (B1, B2, B3, B4) without an inverter. Since an AC power output device (100) according to one embodiment of the present invention does not require an inverter, it has the advantage of being able to have a relatively simple circuit configuration.

[0071]

[0072] The control unit (130) can be configured to control the operating state of the switching unit (110) for each preset first cycle (T1) to change the number of batteries connected in series.

[0073] For example, the control unit (130) can control the operating state of the switching unit (110) for each first cycle (T1). Accordingly, the number of batteries connected in series can be changed for each first cycle (T1).

[0074] In the embodiment of FIG. 4, assuming that AC power is output from time t1, the number of batteries connected in series may change at each T1 cycle from time t1. At time t1, one battery may be connected to the filter unit (120). Therefore, at time t1, the v1 voltage may be output. Thereafter, the number of batteries connected at each T1 cycle may change by one. For example, at time t2, two batteries are connected and the v2 voltage is output, at time t3, three batteries are connected and the v3 voltage is output, and at time t4, four batteries are connected and the v4 voltage is output. In addition, at time t5, three batteries are connected again and the v3 voltage is output, at time t6, two batteries are connected and the v2 voltage is output, and at time t7, one battery is connected and the v1 voltage is output.

[0075] The control unit (130) can be configured to control the operating state of the filter unit (120) every preset second cycle (T2) to reverse the polarity of the output voltage of the batteries connected in series.

[0076] For example, the control unit (130) can control the operating state of the filter unit (120) every second cycle (T2). Accordingly, the polarity of the output voltage of the battery can be reversed every second cycle (T2).

[0077] In the embodiment of FIG. 4, the polarity of the output voltage may be reversed every T2 cycle from time point t1. That is, a positive voltage may be output at time point t1, and the polarity of the output voltage may be reversed at time point T2. For example, at time point t8, one battery is connected and a -v1 voltage is output, at time point t9, two batteries are connected and a -v2 voltage is output, at time point t10, three batteries are connected and a -v3 voltage is output, and at time point t11, four batteries are connected and a -v4 voltage is output. In addition, at time point t12, three batteries are connected again and a -v3 voltage is output, at time point t13, two batteries are connected and a -v2 voltage is output, and at time point t14, one battery is connected and a -v1 voltage is output.

[0078] Referring to FIGS. 2 and 4, AC power having a maximum voltage of "v4[V]", a minimum voltage of "-v4[V]", and a cycle of "2×T2" can be output from an AC power output device (100) according to an embodiment of the present invention. In this way, the AC power output device (100) according to an embodiment of the present invention can output AC power having a required specification without a configuration such as an inverter by controlling the battery voltage from the step of generating voltage from the battery by appropriately controlling the number of connected batteries and the cycle, for example. In addition, by selectively connecting batteries used at each point in time, for example, battery cells used only in a peak state have a lower usage frequency, so that all battery cells can be used evenly, thereby effectively managing the battery lifespan.

[0079]

[0080] Below, an embodiment is described in which a control unit (130) controls a switching unit (110) to determine a battery connected in series among a plurality of batteries (B1, B2, B3, B4).

[0081] Referring back to FIG. 1, the AC power output device (100) may further include a measuring unit (140).

[0082] The measuring unit (140) may be configured to measure battery information including at least one of voltage, current, and temperature of each of the plurality of batteries (B1, B2, B3, B4).

[0083] For example, the measuring unit (140) may be connected to each of the plurality of batteries (B1, B2, B3, B4). In addition, the measuring unit (140) may be configured to measure the voltage and / or temperature of each of the plurality of batteries (B1, B2, B3, B4). In addition, the measuring unit (140) may be connected to the current path of each of the plurality of batteries (B1, B2, B3, B4) and may measure the current of each of the plurality of batteries (B1, B2, B3, B4).

[0084] In the embodiment of FIG. 2, the measuring unit (140) can measure the voltage of each of the first battery (B1), the second battery (B2), the third battery (B3), and the fourth battery (B4).

[0085] The measuring unit (140) can be connected to the control unit (130) to enable wired and / or wireless communication. In addition, the measuring unit (140) can transmit measured battery information to the control unit (130).

[0086] The control unit (130) may be configured to estimate the SOC (State of Charge) of each of the plurality of batteries (B1, B2, B3, B4) based on the battery information measured by the measurement unit (140).

[0087] For example, the control unit (130) can estimate SOC according to voltage information received from the measurement unit (140) based on a profile preset to indicate a correspondence between voltage and SOC.

[0088] As another example, the control unit (130) can estimate the SOC according to the voltage information and temperature information received from the measurement unit (140) based on a profile preset to indicate the correspondence between voltage, temperature, and SOC. That is, the control unit (130) can estimate the SOC of multiple batteries (B1, B2, B3, B4) using a profile in which the SOC corresponding to the voltage and temperature is set.

[0089] The control unit (130) may be configured to determine priorities for multiple batteries (B1, B2, B3, B4) based on the estimated SOC.

[0090] According to one embodiment, the control unit (130) may be configured to set priorities in ascending order of estimated SOC.

[0091] In addition, the control unit (130) can be configured to control the operating state of the corresponding switching unit (110) according to the determined priority.

[0092] For example, the control unit (130) can control the operating state of the corresponding switching unit (110) according to the priority determined for the batteries in order to preferentially discharge batteries with a high SOC. As a result, multiple batteries (B1, B2, B3, B4) can be evenly utilized in the process of outputting AC power.

[0093] That is, according to the AC power output device (100), since the batteries are discharged in order of priority based on the SOC, for example, multiple batteries (B1, B2, B3, B4) can be degraded evenly. That is, since deterioration imbalance of the multiple batteries (B1, B2, B3, B4) does not occur, the expected lifespan of the multiple batteries (B1, B2, B3, B4) can be improved.

[0094] Therefore, the AC power output device (100) according to one embodiment of the present invention has the advantage of preventing deterioration imbalance of multiple batteries (B) and further preventing capacity loss of multiple batteries (B) by controlling the switching unit (110) according to a priority based on SOC.

[0095]

[0096] FIG. 5 is a schematic diagram illustrating an example of an AC power source according to one embodiment of the present invention.

[0097] The embodiment of Fig. 5 is an embodiment in which AC power is output from the battery pack (10) according to the embodiment of Fig. 2 from time t1. For convenience of explanation, the illustration of the negative polarity output voltage is omitted.

[0098] The control unit (130) may be configured to select a corresponding number of batteries (B) from among a plurality of batteries in order of priority for each first cycle (T1).

[0099] In the embodiment of FIG. 5, the first battery (B1) may be selected from time t1 to time t2, and the second battery (B2) and the third battery (B3) may be selected from time t2 to time t3. From time t3 to time t4, the first battery (B1), the second battery (B2), and the fourth battery (B4) may be selected, and from time t4 to time t5, the first battery (B1), the second battery (B2), the third battery (B3), and the fourth battery (B4) may be selected. From time t5 to time t6, the first battery (B1), the third battery (B3), and the fourth battery (B4) may be selected, and from time t6 to time t7, the second battery (B2) and the third battery (B3) may be selected. From time t7 to time t8, the fourth battery (B4) may be selected.

[0100] In addition, the control unit (130) can be configured to control the operating state of the switching unit (110) corresponding to the selected battery to the first turn-on state so that only these selected batteries are connected in series.

[0101] For example, in the embodiment of FIG. 5, the first battery (B1) may be discharged from time t1 to time t2. To this end, the control unit (130) may control the first switching unit (111) to a first turn-on state from time t1 to time t2, and control the second switching unit (112), the third switching unit (113), and the fourth switching unit (114) to a second turn-on state.

[0102] From time t2 to time t3, the second battery (B2) and the third battery (B3) can be connected in series and discharged. To this end, the control unit (130) can control the second switching unit (112) and the third switching unit (113) to a first turn-on state from time t2 to time t3, and control the first switching unit (111) and the fourth switching unit (114) to a second turn-on state.

[0103] From time t3 to time t4, the first battery (B1), the second battery (B2), and the fourth battery (B4) can be connected in series and discharged. To this end, the control unit (130) can control the first switching unit (111), the second switching unit (112), and the fourth switching unit (114) to a first turn-on state from time t3 to time t4, and control the third switching unit (113) to a second turn-on state.

[0104] From time t4 to time t5, the first battery (B1), the second battery (B2), the third battery (B3), and the fourth battery (B4) can be connected in series and discharged. To this end, the control unit (130) can control the first switching unit (111), the second switching unit (112), the third switching unit (113), and the fourth switching unit (114) to the first turn-on state from time t4 to time t5.

[0105] From time t5 to time t6, the first battery (B1), the third battery (B3), and the fourth battery (B4) can be connected in series and discharged. To this end, the control unit (130) can control the first switching unit (111), the third switching unit (113), and the fourth switching unit (114) to a first turn-on state from time t5 to time t6, and control the second switching unit (112) to a second turn-on state.

[0106] From time t6 to time t7, the second battery (B2) and the third battery (B3) can be connected in series and discharged. To this end, the control unit (130) can control the second switching unit (112) and the third switching unit (113) to the first turn-on state from time t6 to time t7, and control the first switching unit (111) and the fourth switching unit (114) to the second turn-on state.

[0107] From time t7 to time t8, the fourth battery (B4) may be discharged. To this end, the control unit (130) may control the fourth switching unit (114) to the first turn-on state from time t7 to time t8, and control the first switching unit (111), the second switching unit (112), and the third switching unit (113) to the second turn-on state.

[0108]

[0109] Meanwhile, the control unit (130) may be configured to update the priorities for multiple batteries (B) every first cycle (T1).

[0110] For example, if the priorities for multiple batteries (B1, B2, B3, B4) are not updated, a degradation imbalance of the multiple batteries (B1, B2, B3, B4) may occur. Therefore, the control unit (130) may update the priorities every first cycle (T1) to prevent a degradation imbalance of the multiple batteries (B1, B2, B3, B4). Here, the control unit (130) may estimate the SOC of the multiple batteries (B1, B2, B3, B4) every first cycle (T1) and update the priorities of the multiple batteries (B1, B2, B3, B4) based on the estimated SOC.

[0111] FIG. 6 is a diagram schematically illustrating the priorities and SOCs of batteries at each time point in the embodiment of FIG. 5. In the embodiment of FIG. 6, it is assumed that the initial SOCs of the first battery (B1), the second battery (B2), the third battery (B3), and the fourth battery (B4) are all 100%, and that the SOCs of the batteries being discharged decrease by 10% for each first cycle (T1). For convenience of explanation, if the SOCs of two or more batteries are the same, the priority of the battery with a lower reference number is set higher.

[0112] Referring to FIG. 6, the control unit (130) can adjust the number of batteries connected in series for each first cycle (T1) to output AC power. In this process, since the SOCs of the plurality of batteries (B1, B2, B3, B4) may differ, the control unit (130) can update the priorities of the plurality of batteries (B1, B2, B3, B4) according to the SOCs for each first cycle (T1). Then, the control unit (130) can select the batteries to be connected in series in the next cycle based on the updated priorities. According to one embodiment, the control unit (130) can select the batteries to be connected in series in the next cycle in the order of highest updated priorities.

[0113] In the embodiment of FIG. 6, since the priorities are updated every first cycle (T1), the SOCs of the first battery (B1), the second battery (B2), the third battery (B3), and the fourth battery (B4) at time t8 can be equal to 60%. Accordingly, the priority update can prevent unbalanced degradation of the multiple batteries (B1, B2, B3, B4). Thereafter, from time t8, the polarity of the output voltage is reversed by the filter unit (120), so that negative-polarity AC power can be output.

[0114]

[0115] Meanwhile, the control unit (130) can estimate the SOC and SOH (State of health) of each of the multiple batteries (B1, B2, B3, B4) based on the battery information.

[0116] For example, the control unit (130) can estimate the SOC and SOH of each of the plurality of batteries (B1, B2, B3, B4) based on the battery information received from the measurement unit (140). Here, the method by which the control unit (130) estimates the SOH of the plurality of batteries (B1, B2, B3, B4) based on the battery information received from the measurement unit (140) can be, for example, a conventional SOH estimation method.

[0117] The control unit (130) can set the priority of each of the plurality of batteries (B1, B2, B3, B4) by considering the SOC and SOH of the plurality of batteries (B1, B2, B3, B4). For example, the control unit (130) can set the priority to be higher in the order of the estimated SOH and estimated SOC.

[0118] Meanwhile, the control unit (130) can set the priority of batteries in order of the highest estimated SOH. Among the multiple batteries (B1, B2, B3, B4), batteries with the same estimated SOH can be set to a higher priority in order of the highest estimated SOC.

[0119] That is, the control unit (130) can estimate the SOC and SOH of each of the plurality of batteries (B1, B2, B3, B4) based on the battery information, and set the priority to be higher in the order of the estimated SOH. In addition, if the estimated SOH for some of the plurality of batteries (B1, B2, B3, B4) is the same, the control unit (130) can set the priority to be higher in the order of the estimated SOC.

[0120] For example, the control unit (130) may set priorities for the plurality of batteries (B1, B2, B3, B4) by first considering the estimated SOH and second considering the estimated SOC. According to one embodiment, among the plurality of batteries (B1, B2, B3, B4), batteries with the same estimated SOH and estimated SOC may be set to have a higher priority for a battery with a lower reference number. In addition, the control unit (130) may be configured to control the operating state of the corresponding switching unit (110) according to the determined priority.

[0121] In addition, the control unit (130) may be configured to update the priorities based on the SOC and SOH of the plurality of batteries (B1, B2, B3, B4) for each first cycle (T1). Similar to the previous embodiment, in order to prevent the plurality of batteries (B1, B2, B3, B4) from being degraded unevenly, the control unit (130) may estimate the SOC and SOH of the plurality of batteries (B1, B2, B3, B4) for each first cycle (T1). In addition, the control unit (130) may update the priorities of the plurality of batteries (B1, B2, B3, B4) for each first cycle (T1) based on the estimated SOC and the estimated SOH.

[0122] The AC power output device (100) can prevent the multiple batteries (B1, B2, B3, B4) from being unbalancedly degraded during the process of outputting AC power by updating the priority in consideration of the SOC and SOH of the multiple batteries (B1, B2, B3, B4).

[0123]

[0124] In addition, the AC power output device (100) may further include a storage unit (150). The storage unit (150) may store, separately from the memory (134) of the control unit (130), data or programs required for each component of the AC power output device (100) to perform operations and functions, or data generated in the process of performing operations and functions. The storage unit (150) is not particularly limited in type as long as it is a known information storage means known to be capable of recording, erasing, updating, and reading data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, etc. In addition, the storage unit (150) may store program codes defining processes executable by the control unit (130).

[0125] For example, the storage unit (150) can store the voltage of each of the plurality of batteries (B1, B2, B3, B4) measured by the measurement unit (140). In addition, the storage unit (150) can store the SOC of each of the plurality of batteries (B1, B2, B3, B4) estimated by the control unit (130). In addition, the storage unit (150) can store the SOH of each of the plurality of batteries (B1, B2, B3, B4) estimated by the control unit (130). In addition, the storage unit (150) can store the priority for the plurality of batteries (B1, B2, B3, B4) determined by the control unit (130).

[0126]

[0127] The AC power output device (100) according to the present invention can be applied to a BMS (Battery Management System). That is, the BMS according to the present invention can include the above-described AC power output device (100). In this configuration, at least some of the components of the AC power output device (100) can be implemented by supplementing or adding the functions of the components included in a conventional BMS. For example, the switching unit (110), filter unit (120), control unit (130), measurement unit (140), and storage unit (150) of the AC power output device (100) can be implemented as components of the BMS.

[0128] In addition, the AC power output device (100) according to the present invention may be provided in a battery pack (10). That is, the battery pack (10) according to the present invention may include the above-described AC power output device (100) and one or more batteries. In addition, the battery pack (10) may further include electrical components (relays, fuses, etc.) and a case, etc.

[0129] Referring to FIG. 2, a battery pack (10) according to one embodiment of the present invention may include a plurality of batteries (B1, B2, B3, B4) and an AC power output device (100). In addition, the battery pack (10) may output AC power through the AC power output device (100) without a separate inverter.

[0130]

[0131] FIG. 7 is a schematic drawing of a vehicle (700) according to another embodiment of the present invention.

[0132] An AC power output device (100) according to an embodiment of the present invention may be included in a vehicle (700) such as an electric vehicle (EV) or a hybrid vehicle (HV).

[0133] For example, in the embodiment of FIG. 7, the vehicle (700) may include a battery pack (710) and an AC power output device (100). According to one embodiment, the AC power output device (100) may be included in the battery pack (710). The AC power output through the AC power output device (100) may be applied to the motor of the vehicle (700).

[0134] That is, the automobile (700) can be driven by applying AC power to the motor of the automobile (700) through the AC power output device (100).

[0135]

[0136] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0137] In addition, the present invention described above is not limited to the above-described embodiments and the attached drawings, and all or part of each embodiment may be selectively combined and configured so that various modifications can be made, as those skilled in the art can make various substitutions, modifications, and changes within the scope of the technical idea of ​​the present invention.

[0138] (Explanation of symbols)

[0139] 10: Battery pack

[0140] 100: AC power output device

[0141] 110: Switching section

[0142] 120: Filter section

[0143] 130: Control unit

[0144] 140: Measurement section

[0145] 150: Storage

Claims

1. In a device that outputs AC power from multiple batteries connected in series, A switching unit connected to each of the plurality of batteries and configured to turn on and off the electrical connection between the corresponding battery and another battery according to the operating state; A filter unit configured to receive the output voltages of the plurality of batteries, adjust the polarity of the output voltages of the plurality of batteries according to the operating state, and output a voltage of the adjusted polarity; and An AC power output device characterized by including a control unit configured to control the operating states of the switching unit and the filter unit so that AC power is output from the plurality of batteries.

2. In paragraph 1, The above control unit, An AC power output device characterized in that it is configured to change the number of batteries connected in series by controlling the operating state of the switching unit at each preset first cycle.

3. In paragraph 2, Further comprising a measuring unit configured to measure battery information including at least one of voltage, current, and temperature of each of the plurality of batteries, The above control unit, An AC power output device characterized in that it determines priorities for the plurality of batteries based on battery information measured by the measuring unit, and controls the operating state of a corresponding switching unit according to the determined priorities.

4. In paragraph 3, The above control unit, An AC power output device characterized in that it is configured to estimate the SOC of each of the plurality of batteries based on the battery information and to set the priority to a higher order in the order of the estimated SOC.

5. In paragraph 3, The above control unit, An AC power output device characterized in that it is configured to estimate the SOC and SOH of each of the plurality of batteries based on the battery information, and to set the priority to a higher order in the order of the estimated SOH and estimated SOC.

6. In paragraph 3, The above control unit, Based on the above battery information, the SOC and SOH of each of the plurality of batteries are estimated, and the priority is set to be high in the order of the estimated SOH. An AC power output device configured to set the priority higher in the order of the estimated SOC when the estimated SOH is the same.

7. In paragraph 3, The above control unit, An AC power output device characterized in that it is configured to select a corresponding number of batteries from among the plurality of batteries in the order of priority for each of the first cycles, and to control the operating state of the switching unit corresponding to the selected batteries to a turn-on state so that only the selected batteries are connected in series.

8. In paragraph 3, The above control unit, An AC power output device characterized in that it is configured to update the priorities for the plurality of batteries at each of the first cycles.

9. In paragraph 2, The above control unit, An AC power output device characterized in that it is configured to control the operating state of the filter unit at every preset second cycle to reverse the polarity of the output voltage of the battery connected in series.

10. In paragraph 1, The above switching unit, A first contact configured to be connected to one end of the battery; a second contact configured to be connected to the other terminal of the battery; and An AC power output device characterized in that it comprises a third contact configured to be electrically connected to the first contact or the second contact when the operating state of the switching unit is turned on.

11. In paragraph 1, The above AC power supply is, An AC power output device characterized by being composed of a non-sinusoidal AC power source.

12. A battery pack comprising an AC power output device according to any one of claims 1 to 11.

13. A vehicle including an AC power output device according to any one of paragraphs 1 to 11.

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