KR102281978B1 - Electric power controlling system for minimizing electrical fee through optimal State of Charge control based on hierarchical Energy Storage System - Google Patents

Abstract

The present invention relates to a power control system, a power provider that supplies power to a power consumer and charges an electricity fee according to the power consumer's electricity usage, a main ESS that stores the power supplied from the power provider, a shiftable device, and a shift Impossible devices, PV (Photovoltaics) that converts sunlight into electrical energy to generate power, and control of the main ESS and sub ESS and sub ESS for supplying the power received from the PV to the shiftable device and the non-shiftable device Maintaining an optimal SoC of a hierarchical ESS consisting of one or more sub ESS modules and the main ESS and each sub ESS comprising a system and forming a hierarchical structure with the main ESS, and a main ESS control system for controlling the power supplier, the main ESS, and the one or more sub-ESS modules to minimize electricity charges. According to the present invention, there is an effect that the optimal SoC of the hierarchical ESS can be maintained by charging and discharging the main ESS and the sub ESS to each other using the hierarchical ESS (main ESS, sub ESS).

Description

{Electric power controlling system for minimizing electrical fee through optimal State of Charge control based on hierarchical Energy Storage System}

The present invention relates to a power control system having an Energy Storage System (ESS), and more particularly, to a power control system that minimizes electricity charges through hierarchical ESS-based optimal SoC control.

ESS (Energy Storage System) is a device that reduces variability in the power system and improves energy supply efficiency through a mechanism that stores surplus power in a storage device and supplies it when power is most needed.

The problem of a peak load, in which demand power is rapidly increased, has been dealt with for a long time. When a peak load occurs, it is difficult to respond with only supplied power, which causes problems such as power failure.

PV (Photovoltaics) is a power generation method that converts sunlight into direct current electricity to produce electricity. Solar power generation uses a solar panel with several solar cells attached.

Recently, interest in renewable power generation is increasing, and accordingly, the demand for PV (Photovoltaics), which is a type of renewable power generation, is increasing. Once the initial installation cost for installing PV is invested, there is an advantage that the power produced by PV can be used without charging. In addition, PV can be used as a response to peak loads because the amount of power generation increases during times of high power demand.

And, the load shift (load shift) is of interest as a method for coping with the peak load. A load shift classifies a device with a lower priority of power supply as a shiftable device, then minimizes the power delivery of the shiftable device when a peak load occurs, and powers the shiftable device with the shifted power when the load is stable. method of supply. In this regard, a device that can be shifted by power or time in power supply to the device is classified as a shiftable appliance, and a non-shiftable appliance is classified as a non-shiftable appliance, and the shift Capable of controlling the load on the device to avoid worst-case events such as power outages.

A shiftable appliance is a device that divides power supplied to electronic products and the like. As a driving method of a shiftable appliance, a time shift method and a power shift method are representative. In the time shift method, the supplied power is supplied later, and in the power shift method, the supplied power is lowered and supplied.

A non-shiftable appliance is the opposite of a shiftable appliance, and refers to a device that cannot divide and supply power supplied to electronic products.

The conventional method of controlling a shiftable device to respond to a peak load is basically to reduce the power supplied to the user, and the shifted power is supplied again at a time when there is room for power supply, but when the peak load occurs There is a problem in that the power supplied to the user is reduced in the time zone.

As such, a method of maintaining a constant power consumption peak load of a user receiving power from a power provider has been studied, but the existing method has to deal with the power consumption of numerous consumers every hour from the power provider, so the burden of central control is high. There is a problem. Therefore, there is a need for a system that controls the power supply in the area by applying the charging/discharging control method using the ESS.

In addition, since the SoC of the ESS changes according to the supply and demand of power, the SoC (State of Charge) may be lowered. In this case, since the response to the peak load may be insufficient, a system that can maintain the optimal SoC of the ESS by utilizing the hierarchical ESS is required.

In addition, when a peak load occurs, since the price of electricity is also increased, there is a problem in that the electricity cost to be borne by the consumer may increase exponentially. Therefore, there is a need for a method to minimize the electricity cost for the power purchased when a peak load occurs.

Republic of Korea Patent Publication No. 10-2016-0026622

The present invention has been devised to solve the above problems, and an object of the present invention is to provide a system in which hierarchical ESSs control each other's charging and discharging by utilizing hierarchical ESS (main ESS, sub-ESS).

In addition, another object of the present invention is to maintain the optimal SoC of the hierarchical ESS by supplying power to the hierarchical ESS by defining a criterion for determining the charge/discharge of the hierarchical ESS.

Another object of the present invention is to provide a method for minimizing electricity bills by purchasing power sufficient to maintain the optimal SoC of the hierarchical ESS from the power provider only when the optimal SoC of the hierarchical ESS cannot be maintained.

Objects of the present invention are not limited to the objects mentioned above, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

The power control system of the present invention for achieving the above object is a power provider that supplies power to a power consumer, and charges an electricity fee according to the electricity consumption of the power consumer, a main ESS that stores the power supplied from the power provider, a shift Capable devices, non-shiftable devices, PV (photovoltaics) that converts sunlight into electric energy to produce electric power, the main ESS and sub ESS for supplying the power received from the PV to the shiftable devices and the non-shiftable devices and a sub ESS control system, maintaining an optimal SoC of one or more sub ESS modules forming a hierarchical structure with the main ESS, and a hierarchical ESS comprising the main ESS and each sub ESS, from the power provider and a main ESS control system for controlling the power supplier, the main ESS, and the one or more sub-ESS modules so that electricity charges are minimized by minimizing the power supplied.

The main ESS control system includes SoC information of the main ESS, load information of the main ESS, information on the amount of electricity supplied to the main ESS from the power provider, and SoC information of each sub ESS transmitted from each sub ESS system. Receive power information, calculate control information for the main ESS and control information for each sub ESS through the received power information, and transmit the calculated control information to each sub ESS control system, and the main ESS is charged It is possible to control the amount of power to be discharged and the amount of power to be discharged.

Each of the sub ESS control systems receives power information including SoC information of the sub ESS, power production information of PV, load information of shiftable devices, and load information of non-shiftable devices, and stores SoC information of the sub ESS into the main It is transmitted to the ESS control system, the control information of the sub ESS is calculated using the received power information, the load of the shiftable device is controlled using the calculated control information, and the load of the shiftable device is controlled by the sub ESS transmitted from the main ESS control system. It is possible to control the amount of power discharged from the sub ESS through the control information.

The main ESS control system includes SoC information of the main ESS, load information of the main ESS, power amount information supplied to the main ESS from the power provider, and SoC information of each sub ESS received from each sub ESS system. A first power information receiving unit for receiving power information, based on the power information received from the first power information receiving unit, comparing the SoC of the main ESS with the total load to determine whether the optimal SoC of the main ESS is maintained, and If it is determined that the main ESS maintains the optimal SoC, the sub ESS that currently needs power supply is searched for through the SoC information of the sub ESS that does not maintain the optimal SoC in the entire sub ESS, and the main ESS is supplied to the corresponding sub ESS. When it is determined that the control information that enables power to be supplied is calculated and it is determined that the optimal SoC cannot be maintained in the main ESS, the current discharge is performed through the SoC information of the sub ESS that has an amount of power exceeding the optimal SoC in the entire sub ESS. Search for possible sub ESSs, calculate control information to supply the power possessed by the discharging sub ESS to the main ESS, and if there is currently no discharging sub ESS, power is supplied from the power supplier to the main ESS In the first control information calculation unit for calculating the control information to be calculated, the control information transmission unit for transmitting the control information calculated by the first control information calculation unit to the main ESS and each sub-ESS control system, and the first control information calculation unit It may include a charge/discharge control unit that controls the amount of power charged from the power provider to the main ESS and the amount of power discharged from the main ESS to each sub-ESS by using the calculated control information.

Each sub ESS control system is configured to receive power information including power production information of each PV, SoC information of each sub ESS, load information of each shiftable device, and load information of each non-shiftable device. A receiver, a power information transmitter for transmitting SoC information of each sub ESS to the main ESS control system, and power production information of SoC of each sub ESS and each PV based on the power information received from the second power information receiver, each By comparing the load information of the shiftable device and the load information of each non-shiftable device, it is determined whether the optimal SoC can be maintained in each sub ESS, and if it is determined that the optimal SoC cannot be maintained in the sub ESS, the corresponding sub A second control information calculation unit that calculates control information for controlling the load of the corresponding shiftable device so that the optimal SoC is maintained in the ESS, and the load of the corresponding shiftable device according to the control information calculated by the second control information calculation unit A load control unit for controlling, a control information receiving unit for receiving control information from the main ESS control system, and a discharge control unit for controlling the amount of power discharged from each sub ESS to the main ESS according to the control information received from the control information receiving unit may be included.

은 단위 시간 t의 전기료라고 할 때, 상기 전력 공급자에게 구매하는 전력량을 최소화하여 전기료를 최소화하는 목적함수를,

(수학식 1)로 나타낼 수 있다.

is an objective function that minimizes the electricity cost by minimizing the amount of electricity purchased from the power supplier, when

It can be expressed by (Equation 1).

은 단위 시간 t에서 전력 공급자로부터 메인 ESS의 SoC를 유지하기 위해 공급받아야 할 전력량이고,

은 단위 시간 t에서 단위 전력 가격이라고 할 때, 단위 시간 t에서 전력 공급자로부터 들어오는 전력의 가격은 단위 시간 t에서 전력 공급자로부터 메인 ESS의 SoC를 유지하기 위해 공급받아야 할 전력과 단위 시간 t에서 단위 전력 가격을 곱한 값으로서,

(수학식 2)로 나타낼 수 있다.

is the amount of power that must be supplied from the power provider to maintain the SoC of the main ESS at unit time t,

is the unit power price at unit time t, the price of power coming from the power provider at unit time t is the power to be supplied from the power provider at unit time t to maintain SoC of the main ESS and unit power at unit time t multiplied by the price,

It can be expressed by (Equation 2).

은 단위 시간 t에서 메인 ESS의 최적 SoC를 유지하기 위해 필요로 하는 전력량이라고 할 때, 단위 시간 t에서 전력 공급자로부터 메인 ESS가 공급 받는 전력량은,

(수학식 3)의 조건식에 따라 결정될 수 있다.

is the amount of power required to maintain the optimal SoC of the main ESS at unit time t, the amount of power supplied by the main ESS from the power provider at unit time t is,

It may be determined according to the conditional expression of (Equation 3).

은 메인 ESS의 최적 SoC이고,

은 단위 시간 t에서 메인 ESS의 SoC이라고 할 때, 단위 시간 t에서 메인 ESS의 최적 SoC를 유지하기 위해 필요로 하는 전력량은 메인 ESS의 최적 SoC와 단위 시간 t에서 메인 ESS의 SoC 의해 결정되며, 이를

(수학식 4)로 나타낼 수 있다.

is the optimal SoC of the main ESS,

is the SoC of the main ESS at unit time t, the amount of power required to maintain the optimal SoC of the main ESS at unit time t is determined by the optimum SoC of the main ESS and SoC of the main ESS at unit time t,

It can be expressed by (Equation 4).

은 단위 시간 t-1에서의 메인 ESS의 SoC이고,

은 단위 시간 t에서 서브 ESS들의 충방전량의 총합이라고 할 때, 단위 시간 t에서 메인 ESS의 SoC은 단위 시간 t-1에서 메인 ESS의 SoC, 단위 시간 t에서 전력 공급자로부터 메인 ESS가 공급 받는 전력량, 단위 시간 t에서 서브 ESS들의 충방전량의 총합에 의해 결정되며, 이를

(수학식 5)로 나타낼 수 있다.

is the SoC of the main ESS at unit time t-1,

is the sum of the charge/discharge amounts of sub ESSs at unit time t, SoC of the main ESS at unit time t is the SoC of the main ESS at unit time t-1, the amount of power supplied by the main ESS from the power supplier at unit time t It is determined by the sum of the charge/discharge amounts of sub ESSs at unit time t,

It can be expressed as (Equation 5).

은 단위 시간 t에서 n 번째의 서브 ESS 충방전량이고,

은 단위 시간 t에서 메인 ESS로부터 n번째 서브 ESS가 충전받는 전력량이고,

은 단위 시간 t에서 n번째의 서브 ESS로부터 메인 ESS가 충전받는 전력량이고,

은 단위 시간 t에서 n 번째의 서브 ESS의 최적 SoC를 유지하기 위해 필요한 전력량이라고 할 때, 단위 시간 t에서 n번째의 서브 ESS의 충방전량은,

(수학식 6)의 조건식에 따라 결정될 수 있다.

is the nth sub-ESS charge/discharge amount in unit time t,

is the amount of power the nth sub ESS receives from the main ESS at unit time t,

is the amount of power the main ESS receives from the nth sub ESS at unit time t,

is the amount of power required to maintain the optimal SoC of the nth sub ESS at a unit time t, the charge/discharge amount of the nth sub ESS at a unit time t is,

It may be determined according to the conditional expression of (Equation 6).

은 단위 시간 t에서 n 번째의 서브 ESS의 최적 SoC이고,

은 단위 시간 t에서 n 번째의 서브 ESS의 SoC이라고 할 때, 단위 시간 t에서 n 번째의 서브 ESS의 최적 SoC를 유지하기 위해 필요로 하는 전력량은 단위 시간 t에서 n 번째의 서브 ESS의 SoC와, n 번째의 서브 ESS의 최적 SoC에 의해 결정되며, 이를

(수학식 7)로 나타낼 수 있다.

is the optimal SoC of the nth sub-ESS at unit time t,

is the SoC of the nth sub ESS at unit time t, the amount of power required to maintain the optimal SoC of the nth sub ESS at unit time t is the SoC of the nth sub ESS at unit time t, It is determined by the optimal SoC of the nth sub ESS, and

It can be expressed as (Equation 7).

은 단위 시간 t-1에서 n 번째의 서브 ESS의 SoC이고,

은 단위 시간 t에서 n 번째의 PV에 의해 생산되는 전력량이고,

은 단위 시간 t에서 n 번째의 시프트 가능 기기의 로드이고,

은 단위 시간 t에서 n 번째의 시프트 불가능 기기의 로드라고 할 때, 단위 시간 t에서 n 번째의 서브 ESS의 SoC는 단위 시간 t-1에서 n 번째의 서브 ESS의 SoC, 단위 시간 t에서 n 번째의 서브 ESS의 충방전량, 단위 시간 t에서 n 번째의 PV에 의해 생산되는 전력량, 단위 시간 t에서 n 번째의 시프트 가능 기기의 로드, 단위 시간 t에서 n 번째의 시프트 불가능 기기의 로드에 의해 결정되며, 이를

(수학식 8)로 나타낼 수 있다.

is the SoC of the nth sub ESS at unit time t-1,

is the amount of power produced by the nth PV in unit time t,

is the load of the nth shiftable device in unit time t,

is the load of the nth non-shiftable device at unit time t, SoC of the nth sub ESS at unit time t is the SoC of the nth sub ESS at unit time t-1, the SoC of the nth sub ESS at unit time t It is determined by the charge/discharge amount of the sub ESS, the amount of power produced by the nth PV at unit time t, the load of the nth shiftable device at unit time t, and the load of the nth non-shiftable device at unit time t, this

It can be expressed as (Equation 8).

은 단위시간 t에서 n 번째의 서브 ESS가 필요한 전력량의 비율에 따라 서브 ESS의 최적 SoC를 유지하기 위해 필요한 전력량이고,

은 메인 ESS에서 방전할 수 있는 최대 전력량이고,

은 단위 시간 t에서 n번째의 서브 ESS의 최적 SoC를 유지하기 위해 필요한 전력량의 합이라고 할 때, 단위 시간 t에서 메인 ESS로부터 n 번째의 서브 ESS가 충전 받는 전력량은,

(수학식 9)의 조건식에 따라 결정될 수 있다.

is the amount of power required to maintain the optimal SoC of the sub ESS according to the ratio of the amount of power required by the nth sub ESS in unit time t,

is the maximum amount of power that can be discharged from the main ESS,

is the sum of the amount of power required to maintain the optimal SoC of the nth sub ESS at unit time t, the amount of power the nth sub ESS receives from the main ESS at unit time t is,

It may be determined according to the conditional expression of (Equation 9).

(수학식 10)으로 나타낼 수 있다. The amount of power required to maintain the optimal SoC of the sub ESS according to the ratio of the amount of power required by the nth sub ESS at the unit time t is the maximum amount of power that can be discharged from the main ESS, and the optimum amount of the nth sub ESS at the unit time t It is determined by the sum of the amount of power required to maintain the SoC and the amount of power required to maintain the optimal SoC of the nth sub ESS at unit time t.

It can be expressed as (Equation 10).

According to the present invention, there is an effect that the optimal SoC of the hierarchical ESS can be maintained by charging and discharging the main ESS and the sub ESS to each other using the hierarchical ESS (main ESS, sub ESS).

In addition, according to the present invention, a PV is installed in the sub ESS to control the load of shiftable and non-shiftable devices, and when a peak load occurs, by controlling the load of the shiftable device, it is possible to control the peak load and supply stable power. there is an effect that

In addition, according to the present invention, only when it is impossible to maintain the optimal SoC of the hierarchical ESS, electricity can be minimized by purchasing power sufficient to maintain the optimal SoC of the hierarchical ESS from the power provider.

1 is an overall configuration diagram of a power control system through an optimal SoC (State of Charge) control based on a hierarchical energy storage system (ESS) of the present invention.
2 is a block diagram showing the configuration of the main ESS control system of the present invention.
3 is a block diagram showing the configuration of a sub-ESS control system of the present invention.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

In addition, in the description with reference to the accompanying drawings, the same components are assigned the same reference numerals regardless of the reference numerals, and the overlapping description thereof will be omitted. In describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

1 is an overall configuration diagram of a power control system through an optimal SoC (State of Charge) control based on a hierarchical energy storage system (ESS) of the present invention.

Referring to FIG. 1 , the power control system of the present invention includes a power provider 100 , a main ESS 110 , a sub ESS module 200 , and a main ESS control system 120 .

The power provider 100 supplies power to the power consumer through a power grid, etc., but charges an electricity fee according to the electricity consumption of the power consumer.

The main ESS 110 stores power supplied from the power provider 100 .

The sub ESS module 200 includes the main ESS 110 and the sub ESS forming a hierarchical structure, and one or more are provided.

The sub ESS module 200 includes a shiftable device 160 , a non-shiftable device 170 , a PV (Photovoltaics) 140 that converts sunlight into electrical energy to generate electricity, and the main ESS 110 and PV 140 ) and a sub ESS 130 and a sub ESS control system 150 for supplying the power received from the shiftable device 160 and the non-shiftable device 170 .

The main ESS control system 120 maintains the optimal SoC of the hierarchical ESS consisting of the main ESS 110 and each sub ESS 130 , but minimizes the power supplied from the power provider 100 to minimize the electricity cost. 100 , the main ESS 110 and one or more sub ESS modules 200 are controlled.

The main ESS control system 120 includes SoC information of the main ESS 110 , load information of the main ESS 110 , information on the amount of electricity supplied to the main ESS 110 from the power provider 100 , and each sub ESS system. At 150 , power information including SoC information of each sub ESS 150 is received.

Then, the main ESS control system 120 calculates control information for the main ESS 110 and control information for each sub ESS 130 through the received power information.

Then, the main ESS control system 120 transmits the calculated control information to each sub ESS control system 150 , and controls the amount of electric power charged and discharged by the main ESS 110 .

Each sub ESS control system 150 is a power including SoC information of the sub ESS 130 , power production information of the PV 140 , load information of the shiftable device 160 , and load information of the non-shiftable device 170 . receive information

Then, each sub ESS control system 150 calculates control information of the sub ESS 130 using the received power information, and controls the load 160 of the shiftable device using the calculated control information.

In addition, each sub ESS control system 150 controls the amount of electric power discharged from the sub ESS 130 through the control information on the sub ESS 130 transmitted from the main ESS control system 120 .

In FIG. 1 , the present invention stores the power produced in the PV 140 in the sub ESS 130 in order to minimize the price of the power coming from the power provider 100 , and the power of the sub ESS 130 . to maintain the optimal SoC of the main ESS 110 and, if the optimal SoC of the main ESS 110 cannot be maintained, receive power from the power provider 100, thereby minimizing the electricity cost.

The main ESS control system 120 includes SoC information of the main ESS 110 , load information of the main ESS 110 , information on the amount of power supplied by the main ESS 110 from the power provider 100 , and sub (Sub) Receives SoC information of the sub ESS 130 , which is power information transmitted from the ESS control system 150 .

Then, the control information of the main ESS 110 and the control information of the sub ESS 130 are calculated through the received information.

Then, the calculated information is transmitted to the sub ESS control system 150 and the amount of electric power charged and discharged by the main ESS 110 is controlled.

The sub ESS control system 150 receives SoC information of the sub ESS 130 , power production information of the PV 140 , load information of the shiftable device 160 , and load information of the non-shiftable device 170 . do.

Then, the sub ESS control system 150 transmits the SoC information of the sub ESS 130 to the main ESS control system 120 .

Then, the sub ESS control system 150 calculates the control information of the sub ESS 130 through the received information, and controls the load of the shiftable device 160 through the calculated information.

In addition, the sub ESS control system 150 controls the amount of electric power discharged from the sub ESS 130 through the sub ESS 130 control information transmitted from the main ESS control system 120 .

2 is a block diagram showing the configuration of the main ESS control system of the present invention.

That is, Figure 2 collects power information, calculates control information of the main ESS 110, transmits the calculated information to the sub ESS control system 150, and discharges the amount of power charged and discharged by the main ESS 110 It is a block diagram of the main ESS control system 120 for controlling the amount of power.

In the present invention, the control system 120 of the main ESS includes a first power information receiver 121 , a first control information calculator 122 , a control information transmitter 123 , and a charge/discharge controller 124 .

The first power information receiving unit 121 includes information on the amount of power supplied to the main ESS 110 from the SoC of the main ESS 110 , the load of the main ESS 110 , and each sub-ESS system 150 ). SoC information of each sub ESS 130 received from

The first control information calculating unit 122 compares the SoC of the main ESS 110 with the total load based on the power information received from the first power information receiving unit 121 to determine whether the optimal SoC of the main ESS 110 is maintained. judge

And, when it is determined that the main ESS 110 maintains the optimal SoC, the first control information calculating unit 122 determines that the current power supply is reduced through the SoC information of the sub ESS that does not maintain the optimal SoC in the entire sub ESS. The necessary sub ESS is searched for, and control information for supplying power of the main ESS 110 to the corresponding sub ESS is calculated.

In addition, if it is determined that the first control information calculating unit 122 does not maintain the optimal SoC in the main ESS 110 , the SoC information of the sub ESS that has an amount of power exceeding the optimal SoC in the entire sub ESS is used. The current discharging sub ESS is searched for, and control information for supplying the power held in the discharging sub ESS to the main ESS 110 is calculated. At this time, if there is no sub-ESS capable of being discharged at present, control information for supplying power from the power provider 100 to the main ESS 110 is calculated.

The control information transmission unit 123 transmits the control information calculated by the first control information calculation unit 122 to the main ESS 110 and each sub-ESS control system 150 .

The charging/discharging control unit 124 uses the control information calculated by the first control information calculation unit 122 to determine the amount of power charged from the power provider 100 to the main ESS 110 , and each sub-ESS from the main ESS 110 . Controls the amount of power discharged to 130.

3 is a block diagram showing the configuration of a sub-ESS control system of the present invention.

That is, FIG. 3 shows that power information is collected, load control information is calculated, a load of a shiftable appliance 160 is controlled, and the collected power information is transferred to the main ESS control system 120 . It is a block diagram of a sub ESS control system that controls the amount of discharge of each sub ESS 130 through the transmitted and received control information of the sub ESS 130 .

In FIG. 3 , the sub ESS control system 150 of the present invention includes a second power information receiving unit 151 , a power information transmitting unit 152 , a second control information calculating unit 153 , a load controlling unit 154 , and a control information receiving unit ( 155), and a discharge control unit 156.

The second power information receiving unit 151 may include power production information of each PV 140 , SoC information of each sub ESS 130 , load information of each shiftable device 160 , and load information of each non-shiftable device 170 . It serves to receive power information including

The power information transmitter 152 serves to transmit SoC information of each sub ESS 130 to the power information receiver 121 of the main ESS control system 120 .

The second control information calculating unit 153 is based on the power information received from the second power information receiving unit 151, the SoC of each sub ESS 130 and the power production information of each PV 140, and each shiftable device ( 160) and the load information of each non-shiftable device 170 are compared to determine whether the optimal SoC can be maintained in each sub ESS 130 , and the optimal SoC cannot be maintained in the sub ESS 130 . Accordingly, control information for controlling the load of the corresponding shiftable device 160 is calculated so that the optimal SoC is maintained in the corresponding sub ESS 130 .

The load control unit 154 controls the load of the corresponding shiftable device 160 according to the control information calculated by the second control information calculation unit 153 .

The control information receiving unit 155 serves to receive control information of the main ESS control system 120 .

The discharge control unit 156 controls the amount of power discharged from each sub ESS 130 to the main ESS 110 through the control information received from the control information receiving unit 155 .

The parameters constituting the equation of the present invention are summarized as follows.

은 단위 시간 t의 전기료이고,

은 단위 시간 t에서 전력 공급자로부터 메인 ESS의 SoC를 유지하기 위해 공급받아야 할 전력량이고,

은 단위 시간 t에서 단위 전력 가격이다.

is the electricity cost per unit time t,

is the amount of power that must be supplied from the power provider to maintain the SoC of the main ESS at unit time t,

is the unit power price at unit time t.

은 단위 시간 t에서 메인 ESS의 최적 SoC를 유지하기 위해 필요로 하는 전력량이고,

은 메인 ESS의 최적 SoC이고,

은 단위 시간 t에서 메인 ESS의 SoC이고,

은 단위 시간 t-1에서의 메인 ESS의 SoC이고,

은 단위 시간 t에서 서브 ESS들의 충방전량의 총합이다. And,

is the amount of power required to maintain the optimal SoC of the main ESS at unit time t,

is the optimal SoC of the main ESS,

is the SoC of the main ESS at unit time t,

is the SoC of the main ESS at unit time t-1,

is the sum of the charge/discharge amounts of sub-ESSs at unit time t.

은 단위 시간 t에서 n 번째의 서브 ESS 충방전량이고,

은 단위 시간 t에서 메인 ESS로부터 n번째 서브 ESS가 충전 받는 전력량이고,

은 단위 시간 t에서 n번째의 서브 ESS로부터 메인 ESS가 충전 받는 전력량이고,

은 단위 시간 t에서 n 번째의 서브 ESS의 최적 SoC를 유지하기 위해 필요한 전력량이다. And,

is the nth sub-ESS charge/discharge amount in unit time t,

is the amount of power the nth sub ESS receives from the main ESS at unit time t,

is the amount of power the main ESS receives from the nth sub ESS at unit time t,

is the amount of power required to maintain the optimal SoC of the n-th sub ESS at unit time t.

은 단위 시간 t에서 n 번째의 서브 ESS의 최적 SoC이고,

은 단위 시간 t에서 n 번째의 서브 ESS의 SoC이고,

은 단위 시간 t-1에서 n 번째의 서브 ESS의 SoC이고,

은 단위 시간 t에서 n 번째의 PV에 의해 생산되는 전력량이고,

은 단위 시간 t에서 n 번째의 시프트 가능 기기의 로드이고,

은 단위 시간 t에서 n 번째의 시프트 불가능 기기의 로드이다. And,

is the optimal SoC of the nth sub-ESS at unit time t,

is the SoC of the nth sub-ESS at unit time t,

is the SoC of the nth sub ESS at unit time t-1,

is the amount of power produced by the nth PV in unit time t,

is the load of the nth shiftable device in unit time t,

is the load of the nth non-shiftable device at unit time t.

은 단위시간 t에서 n 번째의 서브 ESS가 필요한 전력량의 비율에 따라 서브 ESS의 최적 SoC를 유지하기 위해 필요한 전력량이고,

은 메인 ESS에서 방전할 수 있는 최대 전력량이고,

은 단위 시간 t에서 n번째의 서브 ESS의 최적 SoC를 유지하기 위해 필요한 전력량의 합이다. And,

is the amount of power required to maintain the optimal SoC of the sub ESS according to the ratio of the amount of power required by the nth sub ESS in unit time t,

is the maximum amount of power that can be discharged from the main ESS,

is the sum of the amount of power required to maintain the optimal SoC of the nth sub ESS at unit time t.

[Equation 1]

The objective function of the model aims to minimize the electricity cost by minimizing the amount of power coming from the power supplier.

은 단위 시간 t의 전기료이다.

is the electricity cost per unit time t.

[Equation 2]

은 단위 시간 t에서 전력 공급자로부터 메인 ESS의 SoC를 유지하기 위해 공급받아야 할 전력량이다.

is the amount of power to be supplied from the power provider to maintain the SoC of the main ESS at unit time t.

은 단위 시간 t에서 단위 전력 가격이다.

is the unit power price at unit time t.

The price of power coming from the power provider at unit time t is the product of the power to be supplied from the power provider at unit time t to maintain the SoC of the main ESS at unit time t multiplied by the unit power price at unit time t.

[Equation 3]

은 단위 시간 t에서 메인 ESS의 최적 SoC를 유지하기 위해 필요로 하는 전력량이다.

is the amount of power required to maintain the optimal SoC of the main ESS at unit time t.

The amount of power supplied to the main ESS from the power provider at unit time t is determined according to the conditional expression.

The conditional expression is an expression that determines the amount of power required to maintain the optimal SoC of the main ESS at unit time t. If the amount of power required by the main ESS at unit time t is greater than or equal to 0, the main ESS receives power from the power provider at unit time t.

[Equation 4]

은 메인 ESS의 최적 SoC이다.

is the optimal SoC for the main ESS.

은 단위 시간 t에서 메인 ESS의 SoC이다.

is the SoC of the main ESS at unit time t.

The amount of power required to maintain the optimal SoC of the main ESS at unit time t is determined by the optimal SoC of the main ESS and the SoC of the main ESS at unit time t.

[Equation 5]

은 단위 시간 t-1에서의 메인 ESS의 SoC이다.

is the SoC of the main ESS at unit time t-1.

은 단위 시간 t에서 서브 ESS들의 충/방전량의 총합이다.

is the sum of charge/discharge amounts of sub ESSs at unit time t.

The SoC of the main ESS at unit time t is determined by the sum of the SoC of the main ESS at unit time t-1, the amount of power supplied to the main ESS from the power provider at unit time t, and the charge/discharge amount of the sub-ESSs at unit time t do.

[Equation 6]

은 단위 시간 t에서 n 번째의 서브 ESS 충/방전량이다.

is the nth sub-ESS charge/discharge amount in unit time t.

은 단위 시간 t에서 메인 ESS로부터 n번째 서브 ESS가 충전 받는 전력량이다.

is the amount of power the nth sub ESS receives from the main ESS at unit time t.

은 단위 시간 t에서 n번째의 서브 ESS로부터 메인 ESS가 충전 받는 전력량이다.

is the amount of power the main ESS receives from the nth sub ESS at unit time t.

은 단위 시간 t에서 n 번째의 서브 ESS의 최적 SoC를 유지하기 위해 필요한 전력량이다.

is the amount of power required to maintain the optimal SoC of the n-th sub ESS at unit time t.

The amount of charge/discharge of the nth sub ESS at unit time t is determined according to the conditional expression.

The conditional expression is an expression for determining charge/discharge for the purpose of maintaining the optimal SoC of the nth sub ESS at unit time t. If the amount of power required by the nth sub ESS at unit time t is 0 or more, the amount of power the nth sub ESS receives from the main ESS at unit time t is less than 0, the main ESS from the nth sub ESS at unit time t is the amount of power being charged.

[Equation 7]

은 단위 시간 t에서 n 번째의 서브 ESS의 최적 SoC이다.

is the optimal SoC of the nth sub-ESS at unit time t.

은 단위 시간 t에서 n 번째의 서브 ESS의 SoC이다.

is the SoC of the nth sub ESS at unit time t.

The amount of power required to maintain the optimal SoC of the n-th sub ESS at unit time t is determined by the SoC of the n-th sub ESS and the optimal SoC of the n-th sub ESS at the unit time t.

[Equation 8]

은 단위 시간 t-1에서 n 번째의 서브 ESS의 SoC이다.

is the SoC of the nth sub ESS at unit time t-1.

은 단위 시간 t에서 n 번째의 PV에 의해 생산되는 전력량이다.

is the amount of power produced by the nth PV at unit time t.

은 단위 시간 t에서 n 번째의 시프트 가능 기기의 로드이다.

is the load of the nth shiftable device at unit time t.

은 단위 시간 t에서 n 번째의 시프트 불가능 기기의 로드이다.

is the load of the nth non-shiftable device at unit time t.

The SoC of the nth sub ESS at unit time t is determined by the SoC of the nth sub ESS at unit time t-1, the charge/discharge amount of the nth sub ESS at unit time t, and the PV of the nth at unit time t. It is determined by the amount of power produced, the load of the n-th non-shiftable device at unit time t, and the load of the n-th non-shiftable device at unit time t.

[Equation 9]

은 단위시간 t에서 n 번째의 서브 ESS가 필요한 전력량의 비율에 따라 서브 ESS의 최적 SoC를 유지하기 위해 필요한 전력량이다.

is the amount of power required to maintain the optimal SoC of the sub ESS according to the ratio of the amount of power required by the nth sub ESS in unit time t.

은 메인 ESS에서 방전 할 수 있는 최대 전력량이다.

is the maximum amount of power that can be discharged from the main ESS.

은 단위 시간 t에서 n번째의 서브 ESS의 최적 SoC를 유지하기 위해 필요한 전력량의 합이다.

is the sum of the amount of power required to maintain the optimal SoC of the nth sub ESS at unit time t.

The amount of power the nth sub ESS receives from the main ESS at unit time t is determined according to the conditional expression.

The conditional expression is an expression that determines the amount of power charged by the nth sub ESS from the main ESS at unit time t. If the maximum amount of power that can be discharged from the main ESS is greater than the sum of the amount of power required to maintain the optimal SoC of the nth sub ESS in the unit time t, the optimal SoC of the sub ESS is maintained according to the nth ratio in the unit time t If it is small, it is the amount of power required to maintain the optimal SoC of the nth sub ESS at unit time t.

[Equation 10]

According to the ratio of the amount of power required by the nth sub ESS at unit time t, the amount of power required to maintain the optimal SoC of the sub ESS is the maximum amount of power that can be discharged from the main ESS, and the optimal SoC of the nth sub ESS at unit time t It is determined by the sum of the amount of power required to maintain , and the amount of power required to maintain the optimal SoC of the nth sub ESS at unit time t.

[Equation 11]

은 단위 시간 t에서 사용자 n의 PV에 의해 생산되는 최대 전력량이다.

is the maximum amount of power produced by PV of user n at unit time t.

The amount of power produced by the PV of user n at unit time t is limited to the case where there is no production and the maximum amount of power produced.

[Equation 12]

은 단위 시간 t에서 n번째의 시프트 가능 기기의 로드이다.

is the load of the nth shiftable device at unit time t.

는 단위 시간 당 시프트 가능 기기에 공급되어야 할 최대 전력량이다.

is the maximum amount of power that must be supplied to the shiftable device per unit time.

At a unit time t, the load of the shiftable device is limited to the case where it is not supplied and the maximum amount of power that must be supplied according to the shiftable device.

Although the present invention has been described above using several preferred embodiments, these examples are illustrative and not restrictive. Those of ordinary skill in the art to which the present invention pertains will understand that various changes and modifications can be made without departing from the spirit of the present invention and the scope of the appended claims.

100 Power supply 110 Main ESS
120 Main ESS Control System 130 Sub ESS
140 PV 150 Sub ESS Control System
160 Shiftable units 170 Non-shiftable units
121 Power information receiver 122 Control information calculator
123 Control information transmitter 124 Charge/discharge controller
151 Power information receiver 152 Power information transmitter
153 Control information calculation unit 154 Load control unit
155 Control information receiver 156 Discharge controller

Claims (15)

A power provider that supplies power to power consumers, but charges an electricity fee according to the power consumer's electricity usage;
a main ESS for storing power supplied from the power provider;
Shiftable device, non-shiftable device, PV (photovoltaics) that converts sunlight into electric energy to produce electric power, and a sub for supplying power received from the main ESS and the PV to the shiftable device and the non-shiftable device one or more sub-ESS modules, comprising an ESS and a sub-ESS control system, and forming a hierarchical structure with the main ESS; and
Maintaining the optimal SoC of the hierarchical ESS consisting of the main ESS and each sub-ESS, but controlling the power provider, the main ESS, and the one or more sub-ESS modules to minimize the electricity cost by minimizing the power supplied from the power provider including the main ESS control system;
The main ESS control system includes SoC information of the main ESS, load information of the main ESS, information on the amount of electricity supplied to the main ESS from the power provider, and SoC information of each sub ESS transmitted from each sub ESS system. Receive power information, calculate control information for the main ESS and control information for each sub ESS through the received power information, and transmit the calculated control information to each sub ESS control system, and the main ESS is charged Controls the amount of power being discharged and the amount of power discharged,
Each of the sub ESS control systems receives power information including SoC information of the sub ESS, power production information of PV, load information of shiftable devices, and load information of non-shiftable devices, and transmits SoC information of the sub ESS to the main ESS transmit to the control system, calculate the control information of the sub ESS using the received power information, control the load of the shiftable device using the calculated control information, and control the load of the shiftable device by using the calculated control information. Control the amount of power discharged from the sub ESS through control information,
The main ESS control system,
First for receiving power information including SoC information of the main ESS, load information of the main ESS, information on the amount of power supplied to the main ESS from the power provider, and SoC information of each sub ESS received from each sub-ESS system 1 power information receiving unit;
Based on the power information received from the first power information receiver, it is determined whether the optimal SoC of the main ESS is maintained by comparing the SoC of the main ESS and the total load, and when it is determined that the main ESS maintains the optimal SoC , through the SoC information of the sub ESS that does not maintain the optimal SoC in the entire sub ESS, search for the sub ESS that currently needs power supply, and calculate control information to supply the power of the main ESS to the sub ESS, If it is determined that the main ESS does not maintain the optimal SoC, the currently discharging sub ESS is searched through the SoC information of the sub ESS that has an amount of power exceeding the optimal SoC in the entire sub ESS, and in the sub ESS that can be discharged A first control information calculation unit that calculates control information for supplying retained power to the main ESS, and calculates control information for supplying power from the power supplier to the main ESS if there is no sub-ESS capable of being discharged at present ;
a control information transmission unit for transmitting the control information calculated by the first control information calculation unit to the main ESS and each sub-ESS control system; and
A charge/discharge control unit for controlling the amount of power charged from the power provider to the main ESS and the amount of power discharged from the main ESS to each sub ESS by using the control information calculated by the first control information calculation unit; ,
Each sub ESS control system is
a second power information receiver configured to receive power information including power production information of each PV, SoC information of each sub ESS, load information of each shiftable device, and load information of each non-shiftable device;
a power information transmitter for transmitting SoC information of each sub ESS to the main ESS control system;
Based on the power information received from the second power information receiving unit, the power production information of SoC and each PV of each sub ESS, load information of each shiftable device, and load information of each non-shiftable device are compared, and in each sub ESS It is determined whether the optimal SoC can be maintained, and if it is determined that the optimal SoC cannot be maintained in the sub ESS, control information for controlling the load of the shiftable device is calculated so that the optimal SoC is maintained in the corresponding sub ESS. a second control information calculating unit;
a load control unit configured to control a load of the corresponding shiftable device according to the control information calculated by the second control information calculation unit;
a control information receiving unit for receiving control information from the main ESS control system; and
and a discharge control unit for controlling the amount of electric power discharged from each sub ESS to the main ESS according to the control information received from the control information receiving unit,

is the electricity cost per unit time t,
An objective function to minimize the electricity cost by minimizing the amount of power purchased from the power supplier,

(Equation 1)
Power control system, characterized in that it can be represented as.
delete delete delete delete delete The method according to claim 1,

is the amount of power that must be supplied from the power provider to maintain the SoC of the main ESS at unit time t,

is the unit power price at unit time t,
The price of power coming from the power provider at unit time t is the product of the power to be supplied from the power provider at unit time t to maintain the SoC of the main ESS at unit time t and the unit power price at unit time t,

(Equation 2)
Power control system characterized in that it can be represented as.
8. The method of claim 7,

is the amount of power required to maintain the optimal SoC of the main ESS at unit time t,
The amount of power supplied by the main ESS from the power provider at unit time t is,

(Equation 3)
Power control system, characterized in that determined according to the conditional expression of.
9. The method of claim 8,

is the optimal SoC of the main ESS,

is the SoC of the main ESS at unit time t,
The amount of power required to maintain the optimal SoC of the main ESS at unit time t is determined by the optimal SoC of the main ESS and the SoC of the main ESS at unit time t,

(Equation 4)
Power control system characterized in that it can be represented as.

10. The method of claim 9,

is the SoC of the main ESS at unit time t-1,

is the sum of the charge/discharge amounts of sub ESSs at unit time t,
The SoC of the main ESS at unit time t is determined by the sum of the SoC of the main ESS at unit time t-1, the amount of power supplied by the main ESS from the power provider at unit time t, and the charge/discharge amount of the sub-ESSs at unit time t, this,

(Equation 5)
Power control system characterized in that it can be represented as.
11. The method of claim 10,

is the nth sub-ESS charge/discharge amount in unit time t,

is the amount of power the nth sub ESS receives from the main ESS at unit time t,

is the amount of power the main ESS receives from the nth sub ESS at unit time t,

is the amount of power required to maintain the optimal SoC of the nth sub ESS at unit time t,
The charge/discharge amount of the nth sub ESS in unit time t is,

(Equation 6)
Power control system, characterized in that determined according to the conditional expression of.
12. The method of claim 11,

is the optimal SoC of the nth sub-ESS at unit time t,

is the SoC of the nth sub ESS at unit time t,
The amount of power required to maintain the optimal SoC of the n-th sub ESS at unit time t is determined by the SoC of the n-th sub ESS and the optimal SoC of the n-th sub ESS at the unit time t,

(Equation 7)
Power control system characterized in that it can be represented as.
13. The method of claim 12,

is the SoC of the nth sub ESS at unit time t-1,

is the amount of power produced by the nth PV in unit time t,

is the load of the nth shiftable device in unit time t,

is the load of the nth non-shiftable device in unit time t,
The SoC of the nth sub ESS at unit time t is produced by the SoC of the nth sub ESS at unit time t-1, the charge/discharge amount of the nth sub ESS at unit time t, and the nth PV at unit time t It is determined by the amount of power used, the load of the nth shiftable device in unit time t, and the load of the nth non-shiftable device in unit time t, which is

(Equation 8)
Power control system characterized in that it can be represented as.
14. The method of claim 13,

is the amount of power required to maintain the optimal SoC of the sub ESS according to the ratio of the amount of power required by the nth sub ESS in unit time t,

is the maximum amount of power that can be discharged from the main ESS,

is the sum of the amount of power required to maintain the optimal SoC of the nth sub ESS at unit time t,
The amount of power the nth sub ESS receives from the main ESS at unit time t is,

(Equation 9)
Power control system, characterized in that determined according to the conditional expression of.
15. The method of claim 14,
The amount of power required to maintain the optimal SoC of the sub ESS according to the ratio of the amount of power required by the nth sub ESS at the unit time t is the maximum amount of power that can be discharged from the main ESS, and the optimal amount of the nth sub ESS at the unit time t The amount of power required to maintain SoC is determined by the sum of the amount of power required to maintain the optimal SoC of the nth sub ESS at unit time t,

(Equation 10)
Power control system, characterized in that it can be represented as.

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