KR20230165978A - Battery charge/discharge device including energy storage system and its charging method. - Google Patents

Abstract

This embodiment includes a battery; A charge/discharge regulator (CDR) that performs charging and discharging operations of the battery; An alternating current power supply (APC) that supplies power to the charge/discharge regulator; And an energy storage device (ESS) that supplies power to the charge/discharge regulator, wherein the AC power supply supplies a constant voltage (CV) to the charge/discharge regulator up to the rated current value, and in a range exceeding the rated current value. A battery charging and discharging device can be provided that replenishes insufficient current through the energy storage device (ESS) and supplies constant power (CP) to the charging and discharging regulator to charge the battery.

Description

Battery charge/discharge device using energy storage device and its charging method {BATTERY CHARGE/DISCHARGE DEVICE INCLUDING ENERGY STORAGE SYSTEM AND ITS CHARGING METHOD.}

This embodiment relates to a battery charging and discharging device using an energy storage device and a charging method thereof. More specifically, in the battery charging and discharging process through constant voltage, constant power, and full current, the battery charge and discharge process is performed using an energy storage system (ESS). It relates to a battery charging/discharging device that can replenish or consume power and a charging method using the same.

Battery Cell Formation refers to the process of performing the first charging and discharging operation in a battery cell.

In the process of charging and discharging battery cells for battery cell formation, the battery cells are charged and discharged by a converter - for example, a CF converter - and all converters are generally charged, discharged, or in standby operation at the same time.

If charging and discharging of all battery cells is performed simultaneously, a problem arises in which PS facility capacity becomes excessively large, which increases the cost of building power facilities. For example, it is necessary to expand contract capacity with power companies, switchgear facilities, PS facilities, etc.

According to the conventional charging and discharging method of battery cells, the power capacity in the PS equipment increases in charging or discharging mode, and even if regenerative braking is applied to the system when the battery is discharged, power loss occurs in proportion to the power capacity of the PS equipment. do. As a result, power usage in PS facilities increases during the charging and discharging process of battery cells, causing high operating costs.

Conventional battery cell charging and discharging methods do not obtain information on the characteristics of battery cells during the cell formation process, so they are stabilized by applying simple charging and discharging cycles to the battery cells, resulting in reduced power use efficiency.

Additionally, when charging or discharging existing battery cells, a problem occurs if the charging power or discharging power is greater than the existing PS (AC-DC power supply) power capacity.

When charging a battery, if the capacity of the PS (AC-DC power supply) is insufficient, the current flows to the maximum and then stops due to an overcurrent failure. When discharging the battery, the PS (AC-DC power supply) generates power toward the power source. If the capacity is insufficient, excessive current is supplied to the DC bus, causing the voltage to rise and causing a stoppage due to overvoltage failure.

Against this background, the purpose of this embodiment is to divide a pair of battery cells into a charging group and a discharging group and drive them simultaneously, balancing operation time, power, and amount of power to create an AC power system (APS). To provide a battery charging and discharging device that reduces the power capacity of PS equipment by minimizing the power capacity consumed and a battery charging method using the same.

In addition, the purpose of this embodiment is that when one group of charge-discharge regulators (CDR) completes the charge-discharge operation and is in standby mode, the charge-discharge regulator (CDR) of another group performs the charge-discharge operation. The aim is to provide a battery charge/discharge device that can increase the number of applied battery cells by minimizing the waiting time of the charge/discharge regulator (CDR) and a battery charging method using the same.

In addition, the purpose of this embodiment is to calculate the power loss of the charge/discharge regulator (CDR) and distribute the corresponding power through an alternating current power supply (APS) or energy storage system (ESS). The aim is to provide a device and a battery charging method using the same.

The purpose of this embodiment is to sequentially supply constant voltage (CV: Constant Voltage), constant power (CP: Constant Power), and constant current (CC) during charging, or supply constant voltage (CV), constant current (CC) during discharging. To provide a battery charging and discharging device that can sequentially supply power (CP) and constant voltage (CV) and a battery charging method using the same.

In order to achieve the above-described object, the first embodiment includes a plurality of batteries divided into a first group and a second group; A charge/discharge regulator (CDR) that performs charging and discharging operations of the plurality of batteries; and a DC bus electrically connected to the charging regulator and forming a direct current voltage, wherein the charging and discharging regulator simultaneously performs charging of the first group of batteries and discharging of the second group of batteries. A discharge device can be provided.

In the battery charging and discharging device, the charging and discharging regulator may control the timing of stopping charging and discharging of the first group or the second group of batteries by turning on and off a switch.

The battery charge/discharge device may further include an energy storage device (ESS) that supplies power corresponding to the power loss of the charge/discharge regulator through the DC bus.

The battery charge/discharge device may further include a microprocessor unit (MPU) that determines the operation mode of the charge/discharge regulator and calculates the charge/discharge power amount and operation time of the charge/discharge regulator.

In the battery charging and discharging device, the microprocessor unit can monitor charging and discharging regulators in a standby state that do not perform charging and discharging operations of the battery, and determine which charging and discharging regulators will perform charging and discharging operations.

In the battery charging and discharging device, the microprocessor unit calculates the correlation between the open circuit voltage (OCV) and the state of charge (SOC) of the battery in the resting mode of the battery, and also supplies one or more pulses to obtain The correlation between the internal impedance value of the battery and the state of charge (SOC) can be calculated.

In the battery charge/discharge device, the charge/discharge regulator may supply a first pulse to measure the internal impedance value of the battery in a rest mode of the battery, and may recover a second pulse having the same area as the first pulse.

In order to achieve the above-mentioned object, the second embodiment includes: a pair of batteries that alternately perform charging and discharging; a plurality of charge/discharge regulators that control alternating charge/discharge of the battery; and a microprocessor unit that monitors the operating states of the plurality of charge/discharge regulators, wherein when the first group of charge/discharge regulators does not perform charge/discharge, the microprocessor unit simultaneously operates the second group of charge/discharge regulators. It is possible to provide a battery charging and discharging device that reduces charging and discharging waiting time by controlling charging and discharging.

In the battery charge/discharge device, the microprocessor unit may be set to alternate the charge/discharge timing of the first group of charge/discharge regulators and the charge/discharge timing of the second group of charge/discharge regulators.

In the battery charge/discharge device, the microprocessor unit calculates the power loss of the converter that occurs while the plurality of charge/discharge regulators charge and discharge a pair of batteries, and transmits the power to an energy storage device (ESS) through CAN communication. Loss amount information can be transmitted.

In a battery charging and discharging device, the plurality of charging and discharging regulators receive power from a unidirectional AC power supply, and the unidirectional AC power supply can supply constant voltage and then supply constant power.

It further includes a DC bus that supplies direct current voltage from the battery charge/discharge device, and the charge/discharge regulator can compensate for power loss by receiving power stored in an adjacent charge/discharge regulator that shares the DC bus.

To achieve the above-described object, a third embodiment includes a battery; A charge/discharge regulator (CDR) that performs charging and discharging operations of the battery; An alternating current power supply (APC) that supplies power to the charge/discharge regulator; And an energy storage device (ESS) that supplies power to the charge/discharge regulator, wherein the AC power supply supplies a constant voltage (CV) to the charge/discharge regulator up to the rated current value, and in a range exceeding the rated current value. A battery charging and discharging device can be provided that replenishes insufficient current through the energy storage device (ESS) and supplies constant power (CP) to the charging and discharging regulator to charge the battery.

In a battery charge/discharge device, the AC power supply may supply a constant current (CC) to the charge/discharge regulator when the maximum current value is reached.

The battery charge/discharge device is connected to the charge/discharge regulator, the AC power supply, and the energy storage device, and further includes a DC bus that supplies direct current voltage. Constant voltage, constant power, and constant current are sequentially supplied through the DC bus. It can be delivered.

In a battery charge/discharge device, the AC power supply supplies constant voltage (CV) to the charge/discharge regulator until the rated current value is reached, and when the rated current value is exceeded, the charger supplies constant power (CP) up to the maximum voltage value. It can be supplied to the discharge regulator.

In a battery charging and discharging device, the energy storage device can receive a voltage exceeding the maximum voltage value and store energy when the AC power device supplies constant power (CP).

In the battery charging and discharging device, the rated current value, maximum current value, and maximum voltage of the AC power supply device are determined. It may further include a microprocessor unit that stores related information and determines the status of the AC power device.

In the battery charging and discharging device, the microprocessor unit can generate an output current-output voltage map for battery charging or an output current-output voltage map for battery discharging and control the operation of the AC power supply device.

In the battery charging and discharging device, when the AC power device performs a constant power operation, the microprocessor unit can simultaneously generate a control signal that performs the operation of the energy storage device and transmit it to the energy storage device.

In the battery charging and discharging device, the batteries include a first group of batteries that perform charging; and a second group of batteries that perform discharging when the first group of battery cells perform charging.

In the battery charging and discharging device, the charging and discharging regulator may determine operation mode timing in which the first group of batteries and the second group of batteries are charged and discharged and standby mode timing in which cell stabilization is performed.

As described above, according to this embodiment, a pair of battery cells are divided into a charging group and a discharging group and driven simultaneously, and the operation time, power, and amount of power for charging and discharging the battery are balanced and consumed as an alternating current power supply (APS). Facility capacity can be reduced by minimizing the power capacity.

Additionally, according to this embodiment, a pair of group states is divided into two parts: driving mode and standby mode. In the driving mode, one is charging, the other is discharging mode, and the standby mode can be applied at the same time. In this way, when a pair of cells in one group of charge/discharge regulators (CDR) is in standby mode after completing charge/discharge, the other pair of cells are charged/discharged to minimize the waiting time of the charge/discharge regulator, thereby reducing the number of applied cells. can be increased.

In addition, according to this embodiment, by simultaneously charging and discharging a pair of battery cells, additional power required to equal the power loss of the CF converter applied to each cell can be supplied through the alternating current power supply (APS), and here the energy storage device Since power can be shared using (ESS), the facility capacity of the alternating current power supply (APS) can be reduced.

In addition, according to this embodiment, the AC power supply (APS) charging operation control performs constant voltage (CV) operation when charging until the rated current is reached, and constant power (CP) operation when the rated current exceeds the rated current. When the maximum current is reached, constant current (CC) operation is possible. When the AC power supply (APS) enters the constant power operation area, the insufficient current can be supplemented through the energy storage system (ESS), and the problem of stopping is solved by allowing the AC power supply (APS) to flow only up to the rated current and maintain a constant voltage. It can be solved.

In addition, according to this embodiment, when controlling the discharge operation of the AC power supply (APS), constant voltage (CV) operation is performed until the rated current is reached, and constant power (CP) operation is performed when the rated current exceeds the rated current. When it reaches , constant voltage (CV) operation is possible. When entering the constant power operation range, the energy storage system (ESS) consumes as much voltage as the increased voltage, allowing the alternating current power supply (APS) to flow only up to the rated current and maintain a constant voltage, thereby solving the problem of stopping.

1 is a diagram explaining a conventional battery charging and discharging device.
Figure 2 is a diagram explaining a battery charging and discharging device according to this embodiment.
Figure 3 is a first example diagram explaining the operation of the battery charging and discharging device according to this embodiment.
Figure 4 is a second example diagram explaining the operation of the battery charging and discharging device according to this embodiment.
Figure 5 is a diagram comparing the state of charge (SOC) of each battery according to this embodiment.
Figure 6 is a diagram showing battery charging current according to this embodiment.
Figure 7 is a diagram showing the correlation between the state of charge (SOC) and internal impedance of the battery according to this embodiment.
Figure 8 is a diagram showing changes in the state of charge (SOC) of batteries at different times according to this embodiment.
Figure 9 is a diagram showing changes in output current and output voltage during the charging process of the power supply device according to this embodiment.
Figure 10 is a diagram showing the change in current over time during the charging process of the power supply and energy storage device according to this embodiment.
Figure 11 is a diagram showing changes in output current and output voltage during the discharging process of the power supply device according to this embodiment.
Figure 12 is a diagram showing the change in current over time during the discharge process of the power supply device and the energy storage device according to this embodiment.
Figure 13 is a diagram explaining constant current, constant voltage, and constant power driving of the DC bus according to this embodiment.
Figure 14 is a configuration diagram of a battery charging and discharging device according to this embodiment.
Figure 15 is a flowchart explaining the power sharing method in the battery charging and discharging process according to this embodiment.
Figure 16 is a flowchart explaining the charging process and discharging process of the battery according to this embodiment.

Hereinafter, some embodiments of the present invention will be described in detail through illustrative drawings. When adding reference numerals to components in each drawing, it should be noted that the same components are given the same reference numerals as much as possible even if they are shown in different drawings. Additionally, in describing the present invention, detailed descriptions of related known configurations or functions that are judged to be likely to obscure the gist of the present invention will be omitted.

Additionally, in describing the components of the present invention, terms such as first, second, a, and b may be used. These terms are only used to distinguish the component from other components, and the nature, order, or order of the component is not limited by the term. When a component is described as being “connected,” “coupled,” or “connected” to another component, that component may be directly connected or connected to that other component, but there is another component between each component. It will be understood that elements may be “connected,” “combined,” or “connected.”

1 is a diagram explaining a conventional battery charging and discharging device.

Referring to FIG. 1, a conventional battery charging and discharging device consists of a battery 10, a cell formation converter 20, and a bidirectional AC power supply device 30.

The battery 10 is connected by the cell formation converter 20 and can perform charging and discharging operations.

The cell formation converter 20 simultaneously charges or discharges all CF converters in three operation modes and performs standby operation. That is, the first CF converter 20-1, the second CF converter 20-2, the third CF converter 20-3, etc. are controlled to be charged or discharged at the same time and in standby operation at the same time.

The two-way AC power device 30 forms a separate DC bus for each CF converter 20 and supplies power.

The conventional battery charging and discharging system performs charging and discharging of all battery cells (10-1, 10-2, and 10-3) simultaneously, resulting in excessively large PS facility capacity, contract capacity with the power company, and distribution panel facilities. , the cost of building power facilities increases due to the expansion of PS facilities.

In the conventional battery charging and discharging system, the power capacity of the PS is large in charging or discharging mode, so even if regenerative braking is performed through the system when the battery is discharged, power loss occurs in proportion to the PS power capacity. Therefore, PS power usage increases, resulting in high operating costs. I go in.

In addition, the conventional battery charging and discharging system performs cell formation by stabilizing the cells by applying simple charging and discharging cycles, so there is a limitation in that it cannot obtain information on the characteristics of the cells.

Figure 2 is a diagram explaining a battery charging and discharging device according to this embodiment.

Referring to FIG. 2, the battery charge/discharge device 100 may include a battery 110, a charge/discharge regulator 120, an AC power supply 130, an energy storage device 140, a microprocessor unit 150, etc. You can.

The battery 110 is capable of repeated charging and discharging and may include battery cells or battery modules.

The battery 110 is divided into a first group and a second group, so that the charging and discharging operations of the first group and the second group can be performed at the same time or at the same time, and the charging and discharging operations of each group are defined to alternate. It can be.

The charge-discharge regulator (CDR) 120 is electrically connected to the battery 110 and can control the charging or discharging operation of the battery 110.

The charge/discharge regulator 120 can be connected to a plurality of batteries and can individually control all or part of each battery. The charge/discharge regulator 120 can simultaneously charge the first group of batteries and discharge the second group of batteries.

The charge/discharge regulator 120 may control the timing of stopping charge/discharge of the first or second group of batteries by turning on and off the switch 111. For example, the operation of the first group of batteries performing a charging operation or the second group of batteries performing a discharging operation can be stopped by turning off the switch 111, and stabilization of the battery cells is achieved. You can switch to standby mode to run.

The charge/discharge regulator 120 may include a CF converter (not shown) for cell formation, and may be electrically connected to the DC bus 112 where a direct current voltage is formed. The DC bus 112 may connect each charge/discharge regulator 120, or connect each charge/discharge regulator 120, the AC power device 130, and the energy storage device 140.

The charge/discharge regulator 120 calculates the correlation between the open-circuit voltage and the state of charge of the battery in the rest mode of the battery 110, supplies a first pulse to measure the internal impedance value of the battery, and supplies the same pulse as the first pulse. An operation to recover the second pulse having an area may be performed.

The AC power system (APS) 130 may include a PPU, CPS, etc., and may be a unidirectional AC-DC power device. The AC power device 130 may be a device that supplies power to the battery 110 and the charge/discharge regulator 120.

The energy storage system (ESS) 140 can convert stored chemical energy into electrical energy and supply power to each battery 110 and the charge/discharge regulator 120. In addition, the energy storage device 140 may play an auxiliary role in supplying power corresponding to the power loss of the charge/discharge regulator 120 through the DC bus 112.

The microprocessor unit (MPU: Micro Processor Unit) 150 is an information processing device with computing capability, which determines the operation mode of the charge/discharge regulator 120 and determines the charge/discharge power amount and operating time of the charge/discharge regulator 120. It can be calculated.

The microprocessor unit 150 may monitor the charge/discharge regulator 120 in a standby state in which the battery 110 does not perform a charge/discharge operation, and determine the charge/discharge regulator 120 to perform a charge/discharge operation. A plurality of charge/discharge regulators 120 may form a group, some of which may exist in a standby state and some may exist in an operating state, with the charge/discharge regulator 120 in a standby state and the charge/discharge regulator 120 in an operating state. ) can alternately switch operations. In this case, the waiting time of the charge/discharge regulator 120 can be shortened.

The microprocessor unit 150 can calculate the correlation between the internal impedance value of the battery and the state of charge (SOC) obtained by supplying one or more pulses to the rest mode of the battery 110.

The microprocessor unit 150 may transmit a control signal to the charge/discharge regulator 120 through D-CAN communication or C-CAN communication.

Figure 3 is a first example diagram explaining the operation of the battery charging and discharging device according to this embodiment.

Figure 4 is a second example diagram explaining the operation of the battery charging and discharging device according to this embodiment.

Referring to FIGS. 3 and 4 , a pair of batteries C11 and C12 may alternately perform charging and discharging.

By dividing a pair of battery cells into a charging group and a discharging group and operating them simultaneously, the power capacity consumed by the alternating current power supply (APS) can be minimized by balancing the operation time, power, and amount of power, thereby reducing facility capacity. The driving mode of a pair of battery groups or a pair of charge/discharge regulator groups is one is charging and the other is discharging, and can be operated in standby mode at the same time. Ideally, APS can be operated so that the power consumed is zero.

The charge/discharge regulator 120 can control alternating charge/discharge of batteries, and a plurality of charge/discharge regulators 120 can be used to control charge and discharge operations of a plurality of battery pairs.

The microprocessor unit 150 can monitor the operating status of a plurality of charge/discharge regulators.

Additionally, the microprocessor unit 150 can control individual battery cells or modules, but can manage the charge/discharge regulator 120 as a group. When the first group of charging and discharging regulators 120 do not perform charging and discharging, the charging and discharging of the second group of regulators 120 can be controlled to perform charging and discharging at the same time, thereby reducing the charging and discharging waiting time. Through this, the charge/discharge operation of the battery pair (C11, C12) and the charge/discharge operation of the charge/discharge regulator (CDR #1, #2) can be linked and driven.

The microprocessor unit 150 may be set to alternate the charge/discharge timing of the first group of charge/discharge regulators and the charge/discharge timing of the second group of charge/discharge regulators.

The microprocessor unit 150 calculates the amount of power loss of the converter that occurs when a plurality of charge/discharge regulators charge and discharge a pair of batteries, and can transmit the amount of power loss information to the energy storage device (ESS) through CAN communication. there is.

The plurality of charge/discharge regulators 120 receive power from the one-way AC power device 130, and the one-way AC power device 130 can supply constant voltage and then supply constant power.

The battery charge/discharge device 100 further includes a DC bus that supplies direct current voltage, and the charge/discharge regulator 120 can compensate for power loss by receiving power stored in an adjacent charge/discharge regulator that shares the DC bus.

Figure 5 is a diagram comparing the state of charge (SOC) of each battery according to this embodiment.

Referring to FIG. 5, the state of charge (SOC) may vary for each battery.

The sum or difference in state of charge (SOC) may be different depending on the first battery pair (C11, C12), the second battery pair (C21, C22), and the third battery pair (C31, C32).

For example, the sum of the state of charge (a1) of the battery C11 and the state of charge (a2) of the battery C12 is the state of charge (b1) of the battery C21 and the state of charge (b2) of the battery C22. The sum may be different from the sum of the state of charge (c1) of the battery C31 and the state of charge (c2) of the battery C32.

In order to reduce the deviation of the state of charge (SOC) of the first battery pair (C11, C12) and the second battery pair (C21, C22), the battery charge/discharge device receives electrical energy from each battery cell or module from the energy storage system (ESS). can be supplied.

Figure 6 is a diagram showing battery charging current according to this embodiment.

Referring to FIG. 6, the battery charging and discharging device may charge the battery during the charging time (Tc) and stop charging the battery during the standby time (Tr).

Additionally, the battery charge/discharge device may discharge the battery during the discharge time (Tdc) and stop discharging the battery during the standby time (Tr).

In the process of repeating charging and discharging of a pair of batteries, the charging current and discharging current delivered to each battery may have the same size.

Referring to Figure 200A, the change in current supplied during the charging process of the battery can be illustratively shown. Current pulses (Pulse 1, 2) can be supplied to measure the internal impedance of the battery during the battery's standby time (Tr). In order to prevent changes in battery charging capacity caused by the first current pulse, a second current pulse of the same size can be recovered.

Referring to Figure 200B, a change in current supplied during the discharging process of the battery can be shown, and a current having a different phase from Figure 200A can be supplied.

Figure 7 is a diagram showing the correlation between the state of charge (SOC) and internal impedance of the battery according to this embodiment.

Referring to FIG. 7, it illustrates the correlation between the state of charge (SOC) of the battery and the internal impedance value, and may have a certain correlation as shown in the first graph (A) and the second graph (B).

The internal impedance of the battery can be measured at each point of the battery's state of charge (SOC) - for example, the point where the SOC remains constant in FIG. 8 - and stored in the form of a lookup table for use.

Here, the internal impedance value of the battery may be the average value integrated for each section of the pulse divided by the open circuit voltage (Voc) of the battery, and various measurement methods that are not limited to this can be used.

In the process of charging and discharging the battery, N pairs of current pulses (N is an integer greater than 1) are created, and the waiting time (minimum ), the internal impedance can be calculated by estimating the DCIR current. For example, the number of pairs of pulses is > It may be determined as N, but is not limited thereto.

Figure 8 is a diagram showing changes in the state of charge (SOC) of batteries at different times according to this embodiment.

Referring to FIG. 8, the state of charge (SOC) of the battery may change in response to pulses of current or voltage supplied to the battery.

For example, when a current pulse with a positive current value is delivered to the battery, the state of charge (SOC) of the battery may increase linearly or nonlinearly, and in the time period when the current pulse is not delivered, the state of charge (SOC) of the battery may increase (SOC). SOC) can be maintained.

In addition, when a current pulse with a negative current value is delivered to the battery - in this case, it can be understood that the direction of the current changes - the state of charge (SOC) of the battery may decrease linearly or non-linearly, and the current pulse The state of charge (SOC) of the battery can be maintained in the time period in which the is not transmitted.

Figure 9 is a diagram showing changes in output current and output voltage during the charging process of the power supply device according to this embodiment.

Figure 10 is a diagram showing the change in current over time during the charging process of the power supply and energy storage device according to this embodiment.

When charging or discharging existing battery cells in a conventional battery charging/discharging device, a problem occurs if the charging power or discharging power becomes greater than the power capacity of the existing PS (AC-DC power supply).

For example, when charging a battery, if the capacity of the existing PS (AC-DC power supply) is insufficient, the current flows to the maximum and then stops due to overcurrent failure. For this reason, the capacity of the AC-DC power supply must be sufficiently designed to prevent overcurrent failure in charging mode.

Referring to Figures 9 and 10, APS charging operation control may be performed in the following order: constant voltage - constant power - constant current. In the first stage of battery charging, constant voltage (CV) operation is performed until the rated current is reached, and in the second stage, when the rated current exceeds the rated current, constant power (CP) operation is performed until the maximum current is reached. Constant current (CC) operation is possible in three stages. In this case, when the AC power supply (APS) enters the constant power operation area, the insufficient current can be supplemented through the energy storage system (ESS), allowing the APS to flow only up to the rated current and maintain a constant voltage, thereby solving the problem of stopping.

From this perspective, the battery charging and discharging device includes: a battery; A charge/discharge regulator (CDR) that performs charging and discharging operations of the battery; An alternating current power supply (APC) that supplies power to the charge/discharge regulator; And an energy storage device (ESS) that supplies power to the charge/discharge regulator, wherein the AC power supply supplies a constant voltage (CV) to the charge/discharge regulator up to the rated current value, and in a range exceeding the rated current value. The battery can be charged by receiving insufficient current through the energy storage device (ESS) and supplying constant power (CP) to the charge/discharge regulator.

Additionally, in the battery charge/discharge device, the AC power supply may supply a constant current (CC) to the charge/discharge regulator when the maximum current value is reached.

In addition, the battery charge/discharge device may further include a DC bus that is connected to the charge/discharge regulator, the AC power device, and the energy storage device and supplies direct current voltage, and provides constant voltage, constant power, and constant current through the DC bus. can be delivered sequentially.

Figure 11 is a diagram showing changes in output current and output voltage during the discharging process of the power supply device according to this embodiment.

Figure 12 is a diagram showing the change in current over time during the discharge process of the power supply device and the energy storage device according to this embodiment.

When discharging a battery in a conventional battery charging/discharging device, if the existing PS (AC-DC power supply) does not have enough power generation capacity, excess current is supplied to the DC bus, causing the voltage to rise and stopping due to overvoltage failure. do. For this reason, the capacity of the AC-DC power supply must be sufficiently designed to prevent overvoltage failure in discharge mode.

Referring to Figures 11 and 12, APS discharge operation may be performed in the order of constant voltage - constant power - constant voltage. The first stage of discharging the battery is constant voltage (CV) operation until the rated current is reached, and the second stage is constant power (CP) operation until the maximum voltage is reached when the rated current exceeds the rated current. Stage 3 allows constant voltage (CV) operation. When entering the constant power operation area, the problem of stopping can be solved by consuming as much voltage as the increased voltage through the energy storage system (ESS), allowing the APS to flow only up to the rated current and maintain a constant voltage. In this way, the APS power capacity can be minimized and designed.

From this perspective, in a battery charge/discharge device, the AC power supply supplies constant voltage (CV) to the charge/discharge regulator until the rated current value is reached, and when the rated current value is exceeded, it supplies constant power (CP) up to the maximum voltage value. It can be supplied to the charge/discharge regulator.

Additionally, in a battery charging and discharging device, the energy storage device can receive a voltage exceeding the maximum voltage value and store energy when the AC power device supplies constant power (CP).

The battery charging and discharging device measures the rated current value, maximum current value, and maximum voltage of the AC power supply device. It may further include a microprocessor unit that stores related information and determines the status of the AC power device.

In the battery charging and discharging device, the microprocessor unit can generate an output current-output voltage map for battery charging or an output current-output voltage map for battery discharging and control the operation of the AC power supply device.

In the battery charging and discharging device, when the AC power device performs a constant power operation, the microprocessor unit can simultaneously generate a control signal that performs the operation of the energy storage device and transmit it to the energy storage device.

In the battery charging and discharging device, the batteries include a first group of batteries that perform charging; and a second group of batteries that perform discharging when the first group of battery cells perform charging.

In the battery charging and discharging device, the charging and discharging regulator may determine operation mode timing in which the first group of batteries and the second group of batteries are charged and discharged and standby mode timing in which cell stabilization is performed.

Figure 13 is a diagram explaining constant current, constant voltage, and constant power driving of the DC bus according to this embodiment.

The conventional battery charging and discharging device measures and manages constant voltage, constant current and constant power based on the battery cell, but the battery charging and discharging device according to this embodiment measures the DC bus to have constant voltage, constant current and constant power at the same time, as shown in FIG. 13. You can control it.

Figure 14 is a configuration diagram of a battery charging and discharging device according to this embodiment.

Referring to FIG. 14, the battery charge/discharge device 300 may include a battery 310, a sensor 320, a microprocessor unit 330, etc.

The sensor 320 may be a sensor for measuring the charging voltage and charging current of the battery 310, and measuring the state of charge (SOC), internal impedance value, etc. based on this.

The microprocessor unit 330 includes a battery cell mode management circuit 331, a battery charge state calculation circuit 332, a charge/discharge regulator waiting time calculation circuit 333, a charge/discharge regulator power loss calculation circuit 334, and an AC power supply. It may include a state control circuit 335, an energy storage device state control circuit 336, etc.

The battery cell mode management circuit 331 can manage the battery state by dividing the driving mode of the battery cell into an operation mode that performs a charging or discharging operation and a standby mode that performs cell stabilization after charging and discharging are completed.

The battery SOC calculation circuit 332 may be a circuit that calculates and stores the state of charge (SOC) of the battery based on the voltage and current of the battery measured by the sensor 320.

The charging/discharging regulator waiting time calculation circuit 333 may be a circuit that checks the charging or discharging status of a battery pair or a charging/discharging regulator pair, and calculates a waiting time for transmitting and receiving power to minimize the waiting time.

The charging/discharging regulator power loss calculation circuit 334 may be a circuit that calculates the power lost waiting for the power standard value of a plurality of charging/discharging regulators, and provides information on the shortfall to an alternating current power supply (APS) or energy storage system (ESS). It may be a transmitting circuit.

The AC power device status control circuit 335 may be a circuit for controlling the output of the AC power device or for selecting a battery or charge/discharge regulator to be transmitted.

The energy storage device status control circuit 336 may be a device for transferring energy stored in an energy storage device (ESS) to a battery or charge/discharge regulator, or receiving excess energy from a battery or charge/discharge regulator to store energy.

Figure 15 is a flowchart explaining the power sharing method in the battery charging and discharging process according to this embodiment.

Referring to FIG. 15, the power sharing method 400 includes a battery cell group selection step (S410), a step of simultaneously charging and discharging a pair of battery cells (S420), and a step of measuring the standby time of the charge and discharge regulator. (S430), measuring the power loss of the charge/discharge regulator (S440), and performing power sharing through the APS and ESS (S450).

The battery cell group selection step (S410) may be a step of selecting a plurality of batteries to be charged and discharged. Here, the plurality of batteries may include a plurality of battery pairs that alternately perform charging and discharging.

The step of simultaneously charging and discharging a pair of battery cells (S420) may be a step of charging one battery and discharging the other battery at the same time.

The step of measuring the waiting time of the charge/discharge regulator (S430) may be a step of measuring the charge/discharge time of one group of charge/discharge regulators (CDRs) and the standby time of the charge/discharge regulators (CDRs) of another group. By measuring the waiting time of the charge/discharge regulator (CDR), the operation of the charge/discharge regulator (CDR) can be controlled sequentially and alternately without time delay.

The step of measuring the power loss of the charge/discharge regulator (S440) may be a step of measuring and managing the power loss by combining the state of charge (SOC), internal impedance, and power usage of a plurality of charge/discharge regulators (CDRs). Power loss can be monitored to improve the variation in charging capacity of battery cells or modules.

The step of performing power sharing through the APS and ESS (S450) may be a step in which the APS or ESS supplies the shortfall in response to the power loss of the charge/discharge regulator (CDR). The limit value of the power capacity of the APS can be measured in advance, and the ESS can make up for the shortfall. Alternatively, the energy of the ESS can be utilized preferentially and the ESS energy shortfall can be supplemented through the APS, but is not limited to this.

For example, an algorithm can be performed to balance the amount of charge and discharge in a pair of groups with the same initial SOC state. For example, in an initial 20% SOC state, an algorithm can be performed that sends half to SOC 0% and the other half to SOC 100%.

Figure 15 is intended to illustrate a power sharing method in the battery charging and discharging process, and may include various modified embodiments such as some of the steps being omitted or the order of some steps being changed.

Figure 16 is a flowchart explaining the charging process and discharging process of the battery according to this embodiment.

Referring to Figure 16, the charging and discharging processes for each battery charging mode can be compared.

The battery charging and discharging process 500 may include determining the driving mode (S510), performing APS charging (S520), and performing APS discharging (S530).

The step of determining the driving mode (S510) may be a step of determining whether the battery cell or module is charged and, if so, checking the driving mode for charging or discharging.

The step of performing APS charging (S520) is a step of sequentially performing constant voltage (CV) operation, constant power (CP) operation, and constant current (CC) operation when the battery charging mode is confirmed in the operation mode determination step (S510). It can be.

The step of performing APS charging (S520) is a step of constant voltage (CV) operation until the rated current is reached (S522), a step of constant power (CP) operation when the rated current exceeds the rated current (S522), and the step of performing constant voltage (CP) operation until the rated current is reached (S522). Once reached, it is divided into a constant current (CC) operation step (S523) and the charging operation can be performed. When the APS enters the constant power operation area, the insufficient current can be supplemented through the ESS to allow the APS to flow only up to the rated current and maintain a constant voltage, thereby solving the problem of stopping.

The step of performing APS discharge (S530) is a step of sequentially performing constant voltage (CV) operation, constant power (CP) operation, and constant voltage (CV) operation when it is confirmed that the battery discharge mode is in the operation mode determination step (S510). It can be.

The step of performing APS discharge (S530) is a step of constant voltage (CV) operation until the rated current is reached (S531), a step of constant power (CP) operation when the rated current is higher than the rated current (S532), and the step of performing constant voltage (CP) operation until the rated current is reached (S532). Once reached, it is divided into a constant voltage (CV) operation step (S533) and a discharge operation can be performed. When entering the constant power operation area, the problem of stopping can be solved by consuming as much voltage as the increased voltage through the ESS, allowing the APS to flow only up to the rated current and maintain a constant voltage.

FIG. 16 is for illustrating a battery charging and discharging process, and may include various modified embodiments such as some of the steps being omitted or the order of some steps being changed.

Claims (10)

battery;
A charge/discharge regulator (CDR) that performs charging and discharging operations of the battery;
An alternating current power supply (APC) that supplies power to the charge/discharge regulator; and
Includes an energy storage system (ESS) that supplies power to the charge/discharge regulator,
The AC power supply supplies a constant voltage (CV) to the charge/discharge regulator up to the rated current value, and in the range exceeding the rated current value, the insufficient current is supplemented through the energy storage device (ESS) and supplied to the charge/discharge regulator. A battery charging and discharging device that supplies power (CP) to charge the battery. According to claim 1,
A battery charging and discharging device wherein the AC power supply supplies a constant current (CC) to the charging and discharging regulator when the maximum current value is reached. According to claim 1,
It is connected to the charge/discharge regulator, the AC power device, and the energy storage device, and further includes a DC bus that supplies a direct current voltage,
A battery charging and discharging device in which constant voltage, constant power, and constant current are sequentially transmitted through the DC bus. According to claim 1,
The AC power supply supplies constant voltage (CV) to the charge/discharge regulator until it reaches the rated current value, and when it exceeds the rated current value, supplies constant power (CP) to the charge/discharge regulator up to the maximum voltage value. , battery charging and discharging device. According to claim 4,
The energy storage device is a battery charging and discharging device that stores energy by receiving a voltage exceeding a maximum voltage value when the AC power supply supplies constant power (CP). According to claim 1,
The rated current value, maximum current value, and maximum current value of the AC power supply device? A battery charging and discharging device further comprising a microprocessor unit that stores related information and determines the state of the AC power device. According to claim 6,
The microprocessor unit generates an output current-output voltage map for battery charging or an output current-output voltage map for battery discharging, and controls the operation of the AC power supply device. According to claim 6,
The microprocessor unit, when the AC power device performs a constant power operation, simultaneously generates a control signal that performs the operation of the energy storage device and transmits it to the energy storage device. According to claim 1,
The batteries include a first group of batteries that perform charging; and
A battery charging and discharging device comprising a second group of batteries that perform discharging when the first group of battery cells perform charging. According to clause 9,
The charge/discharge regulator determines a driving mode timing in which the first group of batteries and the second group of batteries are charged and discharged and a standby mode timing in which cell stabilization is performed.