KR102629348B1 - Energy storage device capacity measurement method and apparatus based on rated current for each service - Google Patents

Abstract

One embodiment includes a control circuit that controls charging and discharging of an energy storage device according to different rules for a plurality of services; a rated current determination circuit that determines a scheduled service to be provided in the next time period and determines a rated current according to the charging and discharging history of the scheduled service; and a capacity measurement circuit that measures the capacity of the energy storage device using the rated current.

Description

Energy storage device capacity measurement method and device based on rated current for each service {ENERGY STORAGE DEVICE CAPACITY MEASUREMENT METHOD AND APPARATUS BASED ON RATED CURRENT FOR EACH SERVICE}

This embodiment relates to a technology for measuring the capacity of an energy storage device.

The capacity of a battery can be measured by discharging a fully charged battery with a certain amount of current. For example, if the discharge current is 1A (ampere) and it takes 1 hour to discharge a fully charged battery to a full state, the capacity of the battery is evaluated as 1Ah.

In this measurement method, three factors are important: one is the fully charged state, the other is the fully charged state, and the other is the discharge current.

The full charge state generally refers to a state in which the charging current no longer flows when charging at a constant voltage with a voltage defined as the full charge voltage. Since it takes a long time to reach the state where the charging current no longer flows, it is generally used for a certain period of time through constant voltage charging. When this has elapsed or the charging current falls below a certain value, it is judged to be fully charged.

The full state means that the voltage of the battery, which is discharged with a certain amount of current, reaches a voltage defined as the full voltage.

The discharge current can generally be determined according to the rated current. For example, the discharge current can be determined as 1/25 times, 1/5 times, 1/2 times, 1 time, 2 times, etc. the rated current.

In this method of measuring battery capacity, if the three factors mentioned above are not appropriately determined, the capacity of the battery may be measured inappropriately or inaccurately. For example, if the full charge voltage is determined to be too low or the full discharge voltage is set to be too high, the battery capacity may be measured inappropriately or inaccurately.

Among the three factors mentioned above, in particular, if the discharge current is not properly determined, the battery capacity may be measured inappropriately or inaccurately. For example, if the capacity of a battery that is charged and discharged with a large current is measured with a small discharge current, the capacity value is difficult to use appropriately because it does not accurately represent the battery's capacity.

Against this background, the purpose of this embodiment is, in one aspect, to provide a technique for appropriately measuring the capacity of an energy storage device. In another aspect, the purpose of this embodiment is to provide a technology for measuring the capacity of an energy storage device to suit the characteristics of the service provided by the energy storage device. In another aspect, the purpose of this embodiment is to provide a technology for measuring the capacity of an energy storage device to suit the environmental conditions in which the energy storage device is operated.

In order to achieve the above-described object, one embodiment includes a control circuit that controls charging and discharging of the energy storage device according to different rules for each of the plurality of services; a rated current determination circuit that determines a scheduled service to be provided in the next time period and determines a rated current according to the charging and discharging history of the scheduled service; and a capacity measurement circuit that measures the capacity of the energy storage device using the rated current.

The energy storage device capacity measuring device further includes a memory that stores rated currents according to charge/discharge history for each service, and the rated current determination circuit may determine the rated current according to one of the rated currents.

The rated current determination circuit determines the basic rated current according to the charging and discharging history of the scheduled service, and determines the rated current to a value greater than the basic rated current to secure a margin for the capacity of the energy storage device. there is.

The rated current determination circuit may determine the rated current by adding a current margin value to the basic rated current.

The current margin value may be specified for each service.

The rated current determination circuit may determine the rated current by multiplying the basic rated current by a current margin ratio.

The control circuit determines the health of the energy storage device according to the capacity of the energy storage device, and the capacity measurement circuit measures the basic capacity of the energy storage device with the rated current and determines the environmental conditions of the energy storage device. To reflect this, the capacity of the energy storage device may be determined to be a value smaller than the basic capacity.

The capacity measurement circuit may determine the capacity of the energy storage device by adding an environmental margin value to the basic capacity.

The environmental margin value may be determined differently depending on at least one of charging conditions and temperature conditions.

The capacity measurement circuit may determine the capacity of the energy storage device by multiplying the basic capacity by the environmental margin ratio.

Another embodiment is a method of measuring the capacity of an energy storage device in a system that controls charging and discharging of an energy storage device according to different rules for a plurality of services, the step of determining a service scheduled to be provided in the next time period. ; determining a rated current according to the charging and discharging history of the scheduled service; and measuring the capacity of the energy storage device using the rated current.

The energy storage device capacity measurement method determines the basic rated current according to the charging and discharging history of the scheduled service in the step of determining the rated current, and determines the basic rated current to secure a margin for the capacity of the energy storage device. The rated current can be determined with a larger value.

In the energy storage device capacity measurement method, in the step of determining the rated current, the rated current can be determined by adding a current margin value to the basic rated current.

In the energy storage device capacity measurement method, in the step of determining the rated current, the rated current can be determined by multiplying the basic rated current by the current margin ratio.

The energy storage device capacity measurement method measures the basic capacity of the energy storage device with the rated current in the step of measuring the capacity of the energy storage device, and measures the basic capacity more than the basic capacity to reflect the environmental conditions of the energy storage device. The capacity of the energy storage device can be determined with a small value.

As described above, according to this embodiment, the capacity of the energy storage device can be appropriately measured. And, according to this embodiment, it is possible to measure the capacity of the energy storage device to suit the characteristics of the service provided by the energy storage device. And, according to this embodiment, it is possible to measure the capacity of the energy storage device to suit the environmental conditions in which the energy storage device is operated.

1 is a configuration diagram of a power system according to an embodiment.
Figure 2 is a configuration diagram of a capacity measuring device according to an embodiment.
Figure 3a is a graph showing the charging and discharging history in the frequency control service.
Figure 3b is a graph showing the charging and discharging history in the electric vehicle charging service.
Figure 3c is a graph showing the charging and discharging history in the demand response service.
Figure 4 is an example graph showing battery capacity according to the size of discharge current.
Figure 5 is a flowchart of a capacity measurement method according to one embodiment.
Figure 6 is a flowchart of a health control method according to an 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 identical 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, 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 will be omitted.

Additionally, when describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, 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 configuration diagram of a power system according to an embodiment.

Referring to FIG. 1, the power system 100 may include an energy storage device 120, a charger/discharger 130, a load 140, and a capacity measurement device 110.

The energy storage device 120 may be a battery. Hereinafter, for convenience of explanation, the description will focus on an embodiment in which the energy storage device 120 is a battery.

The battery 120 may include at least one cell, and a sensor may be attached to measure current (Ib), voltage (Vb), temperature, etc. Here, current refers to the current input and output to the terminal of the battery 120, and voltage may refer to the terminal voltage of the battery 120. And, the temperature may mean the surface temperature of the battery 120.

The charger/discharger 130 can control the current (Ib) input and output to the battery 120 or the voltage of the battery 120. Through this, the charger/discharger 130 can charge the battery 120 or discharge the battery 120 to supply power to the load 140.

The charger/discharger 130 may receive a control signal (CTR) from the capacity measuring device 110 and control charging and discharging of the battery 120 according to the control signal (CTR). For example, the charger/discharger 130 may control the amount of charging current of the battery 120 or the amount of discharging current of the battery 120 according to the control signal (CTR). In this way, the capacity measuring device 110 can observe changes in the state of the battery 120 while inputting a desired current or voltage into the battery 120.

The capacity measuring device 110 can control charging and discharging of the battery 120 and measure the capacity of the battery 120.

The capacity measuring device 110 can provide multiple services using the battery 120. Additionally, the capacity measurement device 120 can measure the capacity of the battery differently for each service. For example, the capacity measuring device 110 can measure the capacity of the battery 120 as large in a service using low current, and measure the capacity of the battery 120 as small in a service using high current. .

Figure 2 is a configuration diagram of a capacity measuring device according to an embodiment.

Referring to FIG. 2, the capacity measurement device 110 may include a memory 210, a rated current determination circuit 220, a capacity measurement circuit 230, and a control circuit 240.

The memory 210 may store rated currents according to charge/discharge history for each service in a table (TBL).

Services may be frequency control services, electric vehicle charging services, demand response services, etc. The memory 210 may store the rated current value according to the charging/discharging history in each service in the form of a table (TBL). For example, the rated current of the frequency control service is 1A, the rated current of the electric vehicle charging service is 2A, and the rated current of the demand response service is 0.5A. The memory 210 can store the rated current value for each service.

In general, the size of the charging and discharging current used for each service may be different.

Figure 3 is a diagram showing an example of charge/discharge current for each service. FIG. 3A is a graph showing the charging and discharging history in the frequency control service, FIG. 3B is a graph showing the charging and discharging history in the electric vehicle charging service, and FIG. 3C is a graph showing the charging and discharging history in the demand response service.

As can be seen in FIG. 3, the magnitude of charge/discharge current used for each service may be different. At this time, the rated current may be determined differently depending on the charging and discharging history in each service.

The rated current may be determined, for example, as the average of the absolute values of the charging and discharging currents of each service. Alternatively, the rated current can be determined by the RMS (root mean square) value of the charging and discharging current of each service.

Referring again to FIG. 2, the memory 210 may store the rated current determined for each service as described above.

In addition, the rated current determination circuit 220 can determine the scheduled service to be provided in the next time period and determine the rated current according to the charging and discharging history of the scheduled service.

For example, if a frequency control service is provided in the current time period and an electric vehicle charging service is provided in the next time period, the rated current determination circuit 220 determines the electric vehicle charging service as a scheduled service, and the electric vehicle charging service is provided in the next time period. The rated current can be determined according to the charging and discharging history of the charging service. The rated current determination circuit 220 can check the scheduled service (SVC) from the control circuit 240.

The rated current determination circuit 220 can check the table (TBL) stored in the memory 210 and check the rated current corresponding to the scheduled service. For example, when the rated current value of the electric vehicle charging service stored in the table (TBL) is 2A, the rated current determination circuit 220 may determine the rated current of the scheduled service to be 2A.

As another example, when the memory 210 stores the charging and discharging history for each service, the rated current determination circuit 220 checks the charging and discharging history stored in the memory 210 and directly determines the rated current according to the charging and discharging history. It can be calculated.

The rated current determination circuit 220 can compensate for the rated current so that the measured capacity value has a certain margin.

The rated current determination circuit 220 determines the basic rated current according to the charging and discharging history for each service, and may determine the rated current to a value greater than the basic rated current to secure a margin for the capacity of the battery. For example, if the basic rated current according to the charging and discharging history of the electric vehicle charging service is 2A, the rated current decision circuit 220 can determine the rated current as 2.2A, which is the basic rated current plus a current margin value of 0.2A. there is.

The current margin value can be specified for each service. For example, the current margin value of the frequency control service may be 0.1A, the current margin value of the electric vehicle charging service may be 0.2A, and the current margin value of the demand response service may be 0.05A.

The rated current determination circuit 220 can determine the rated current by multiplying the basic rated current by the current margin ratio. For example, if the basic rated current according to the charging and discharging history of the electric vehicle charging service is 2A, the rated current decision circuit 220 determines 2.2A calculated by multiplying the basic rated current by the current margin ratio of 1.1 as the rated current. You can.

The current margin ratio can be specified for each service. For example, the current margin ratio of the frequency control service may be 1.1, the current margin ratio of the electric vehicle charging service may be 1.1, and the current margin ratio of the demand response service may be 1.05.

The current margin value may be a positive value or a negative value. And, the current margin ratio may be a value greater than 1 or a value between 0 and 1.

The capacity measurement circuit 230 can measure the capacity of the battery using the rated current.

Depending on the discharge current, the capacity of the battery can show different values.

Figure 4 is an example graph showing battery capacity according to the size of discharge current.

Referring to Figure 4, the capacity of the battery when discharged at 0.05C is 3.4Ah, but when discharged at 1C, it becomes 3.2Ah, and when discharged at 3C, the battery capacity drops to around 1.2Ah.

Since the capacity of the battery shows different values depending on the discharge current, the capacity measurement circuit measures the battery capacity with a different discharge current for each service according to the rated current determined by the rated current determination circuit.

Referring again to FIG. 2, the capacity measurement circuit 230 can check the rated current determined by the rated current determination circuit 220 and measure the capacity of the battery with a discharge current corresponding to a certain multiple of the rated current. Here, the constant multiple is a predetermined value and may be 1/25 times, 1/5 times, 1/2 times, 1 times, 2 times, etc.

The capacity measurement circuit 230 may correct the measured capacity value to reflect the environmental conditions under which the battery is used. Specifically, the capacity measurement circuit 230 may measure the basic capacity of the battery using the rated current and determine the capacity of the battery as a value smaller than the basic capacity to reflect the environmental conditions of the battery.

For example, the capacity measurement circuit 230 can determine the capacity (CPT) of the battery by adding the environmental margin value to the basic capacity. Alternatively, the capacity measurement circuit 230 can determine the capacity (CPT) of the battery by multiplying the basic capacity by the environmental margin ratio.

Here, the environmental margin value or environmental margin ratio may be determined differently depending on at least one of the charging conditions and temperature conditions.

As an example, when the charging condition is rapid charging, the environmental margin value may be a negative value. Or, if the charging condition is rapid charging, the environmental margin ratio may be a value between 0 and 1. As another example, when the charging condition is slow charging, the environmental margin value may be a positive value. Or, if the charging condition is slow charging, the environmental margin ratio may be a value of 1 or more.

Regarding temperature conditions, as an example, if the usage temperature of the battery is much higher or lower than the temperature at which battery capacity is measured, the environmental margin value may be a negative value or the environmental margin ratio may be a value between 0 and 1.

The control circuit 240 can control charging and discharging of the battery according to different rules for each service. In addition, the control circuit 240 may determine the health of the battery - for example, remaining life capacity - according to the battery capacity (CPT) determined by the capacity measurement circuit 230. Additionally, the control circuit 240 may apply different control processes depending on the health of the battery.

Figure 5 is a flowchart of a capacity measurement method according to one embodiment.

Referring to FIG. 5, the capacity measurement device can determine the service scheduled to be provided in the next time period (S502).

The capacity measuring device can control charging and discharging of the battery according to different rules for each service. At this time, the capacity measurement device can determine the service in the current time section and the scheduled service in the next time section.

The time interval may be a month or a quarter.

The capacity measuring device can determine the rated current according to the charging and discharging history of the scheduled service (S504).

In the step of determining the rated current (S504), the capacity measuring device determines the basic rated current according to the charging and discharging history of the scheduled service, and sets the rated current to a value greater than the basic rated current to secure a margin for the capacity of the battery. You can decide.

In the step of determining the rated current (S504), the capacity measuring device can determine the rated current by adding the current margin value to the basic rated current.

In the step of determining the rated current (S504), the capacity measuring device can determine the rated current by multiplying the basic rated current by the current margin ratio.

The capacity measuring device can measure the capacity of the battery using the rated current (S506).

In the step of measuring the capacity of the battery (S506), the basic capacity of the battery can be measured using the rated current, and the capacity of the battery can be determined as a value smaller than the basic capacity to reflect the environmental conditions of the battery.

Figure 6 is a flowchart of a health control method according to an embodiment.

Referring to FIG. 6, the control device - for example, a capacity measurement device - can determine the service scheduled to be provided in the next time period (S502).

And, the control device can determine the rated current according to the charging and discharging history of the scheduled service (S504).

And, the control device can measure the capacity of the battery using the rated current (S506).

Then, the control device compares the capacity with the reference value (S608), and if the capacity is less than the reference value (NO in S608), it can perform a control process according to the maintenance/repair algorithm (S612).

And, if the capacity is greater than the reference value (YES in S608), the control device can perform a control process according to the control/operation algorithm (S610).

As described above, according to this embodiment, the capacity of the energy storage device can be appropriately measured. And, according to this embodiment, it is possible to measure the capacity of the energy storage device to suit the characteristics of the service provided by the energy storage device. And, according to this embodiment, it is possible to measure the capacity of the energy storage device to suit the environmental conditions in which the energy storage device is operated.

Terms such as “include,” “comprise,” or “have,” as used above, mean that the corresponding component may be included, unless specifically stated to the contrary, and do not exclude other components. It should be interpreted that it may further include other components. All terms, including technical or scientific terms, unless otherwise defined, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains. Commonly used terms, such as terms defined in a dictionary, should be interpreted as consistent with the meaning in the context of the related technology, and should not be interpreted in an idealized or overly formal sense unless explicitly defined in the present invention.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

Claims (15)

A control circuit that controls charging and discharging of the energy storage device according to different rules for each service;
a rated current determination circuit that determines a scheduled service to be provided in the next time period and determines a rated current according to the charging and discharging history of the scheduled service; and
A capacity measurement circuit that measures the capacity of the energy storage device using the rated current.
Energy storage device capacity measuring device including. ◈Claim 2 was abandoned upon payment of the setup registration fee.◈ According to paragraph 1,
It further includes a memory that stores rated currents according to the charging and discharging history for each service,
The rated current determining circuit is,
An energy storage device capacity measuring device that determines the rated current according to one of the rated currents. According to paragraph 1,
The rated current determining circuit is,
An energy storage device capacity measuring device that determines the basic rated current according to the charging and discharging history of the scheduled service and determines the rated current to a value greater than the basic rated current to secure a margin for the capacity of the energy storage device. According to paragraph 3,
The rated current determining circuit is,
An energy storage device capacity measuring device that determines the rated current by adding a current margin value to the basic rated current. According to paragraph 4,
The current margin value is an energy storage device capacity measurement device specified for each service. According to paragraph 3,
The rated current determining circuit is,
An energy storage device capacity measuring device that determines the rated current by multiplying the basic rated current by the current margin ratio. According to paragraph 1,
The control circuit determines the health of the energy storage device according to the capacity of the energy storage device,
The capacity measurement circuit measures the basic capacity of the energy storage device with the rated current, and determines the capacity of the energy storage device to a value smaller than the basic capacity to reflect the environmental conditions of the energy storage device. Capacity measuring device. In clause 7,
The capacity measurement circuit is,
An energy storage device capacity measuring device that determines the capacity of the energy storage device by adding an environmental margin value to the basic capacity. According to clause 8,
An energy storage device capacity measuring device in which the environmental margin value is determined differently depending on at least one of charging conditions and temperature conditions. In clause 7,
The capacity measurement circuit is,
An energy storage device capacity measuring device that determines the capacity of the energy storage device by multiplying the basic capacity by the environmental margin ratio. In a method of measuring the capacity of the energy storage device in a system that controls charging and discharging of the energy storage device according to different rules for a plurality of services,
Determining the service scheduled to be provided in the next time period;
determining a rated current according to the charging and discharging history of the scheduled service; and
Measuring the capacity of the energy storage device using the rated current
Energy storage device capacity measurement method including. ◈Claim 12 was abandoned upon payment of the setup registration fee.◈ According to clause 11,
In the step of determining the rated current,
A method of measuring the capacity of an energy storage device for determining the basic rated current according to the charging and discharging history of the scheduled service, and determining the rated current to a value greater than the basic rated current to secure a margin for the capacity of the energy storage device. ◈Claim 13 was abandoned upon payment of the setup registration fee.◈ According to clause 12,
In the step of determining the rated current,
An energy storage device capacity measurement method that determines the rated current by adding a current margin value to the basic rated current. ◈Claim 14 was abandoned upon payment of the setup registration fee.◈ According to clause 12,
In the step of determining the rated current,
An energy storage device capacity measurement method that determines the rated current by multiplying the basic rated current by the current margin ratio. ◈Claim 15 was abandoned upon payment of the setup registration fee.◈ According to clause 11,
In the step of measuring the capacity of the energy storage device,
An energy storage device capacity measurement method for measuring the basic capacity of the energy storage device with the rated current and determining the capacity of the energy storage device as a value smaller than the basic capacity to reflect the environmental conditions of the energy storage device.

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