KR20220158536A - An integrated electric vehicle charging system that uses an ESS module with a national power supply reserve ratio management function as the main power source and AC power as an auxiliary power source, and a distributed management method for the power supply reserve ratio - Google Patents

Abstract

The purpose of the present invention is to receive EV charging power by connection to an AC module at light load and supply the EV charging power to an electric vehicle by connection to an ESS power module at medium load and the maximum load. According to the present invention, an electric vehicle charging device comprises: a means of constituting a data security means (240) connected to a power supply reserve ratio control center server (250) through a communication network and a discharge command means (230) in an ESS module (140) and constituting a nighttime power grid (300) and an AC power grid (400) in an electric vehicle charging station; a means of charging the ESS module (140) through an ESS charging device (100); a means of converting power charged in the ESS module (140) to charging voltage required by an electric vehicle through the ESS power module (150); an AC power module (160); an EV charging power source switching unit (170); and an EV high-speed charger (190) charging the electric vehicle by EV charging power.

Description

An integrated electric vehicle charging system that uses the ESS module with the national power reserve management function as the main power source and AC power as the auxiliary power source, and a method for distributed management of the power supply reserve { An integrated electric vehicle charging system that uses an ESS module with a national power supply reserve ratio management function as the main power source and AC power as an auxiliary power source, and a distributed management method for the power supply reserve ratio }

With the spread of electric vehicles along with higher capacity electric vehicle batteries (20kWh -> around 100kWh) and lower battery prices (Tesla 2025 forecast 80 ~ 100$/kWh), power overload due to simultaneous charging of electric vehicles will be raised as an important industrial problem. Prospect. Current charging methods for electric vehicles consist of slow charging for 4 to 5 hours with a floor capacity of 3 to 7 kW and rapid charging within 30 minutes with a charging capacity of 50 kW. The rapid charging method is continuously increasing the charging capacity (400 ~ 700 kW for example), so the charging time is shortened, but difficulties are expected in the operation of the national power grid when many vehicles are charged simultaneously. Accordingly, the government sets electric vehicle charging station electricity rates for light load (23:00 to 09:00, minimum 56.4 won/kWh), medium load (maximum 113 won/kwh), maximum load (10:00 to 12:00, 13:00 to 17:00, 244 won) to encourage charging of electric vehicles at light loads.

In most countries, power supply and demand are managed by total power generation facility capacity, supply capacity, maximum power, average power, supply reserve, supply reserve ratio, and average utilization rate. Korea's total installed capacity in 2021 is 125,887 MW, but currently only around 80GW is generating power. The use of late-night power is encouraged to appropriately manage the reserve ratio between 10 and 50%. Korea’s late-night power system is a system to disperse power demand that is concentrated in a specific time zone and to increase the utilization rate of power generation facilities during late-night hours (11:00 p.m. to 9:00 a.m. the next day) when electricity demand is low. This is not a rate applied to all electricity used at midnight, but a rate system applied only to the amount of electricity used during the night of 'night power equipment', and the late-night rate, which is reduced to one-third of the daytime rate, is applied. 'Late-night power equipment' includes ▷ thermal storage heating and hot water equipment, ▷ thermal storage heating and cooling equipment (cold storage equipment), and ▷ ESS-type air conditioning and heating equipment. A separate late-night power meter is installed to read the amount used, and then the charge is charged separately from the general rate. Pumped-storage power plants (Cheongpyeong 400MW and 6 locations totaling 4,700MW) are being operated as another way to respond to peak load. A pumped storage generator is a facility that pumps and stores water from the lower dam to the upper dam during light load hours when electricity demand is low, and then pumps water back into the lower reservoir during peak load hours when electricity demand is high to produce electricity. In addition to being capable of storing large amounts of electricity, it is called the 'original ESS' because it handles peak loads, stabilizes the power system, and supplies start-up power to other generators in the event of a wide-area power outage. The 100MW Yecheon Pumped Storage Power Plant, completed in 2011, has an efficiency of 84%, and a construction cost of KRW 750 billion was invested. In the future, many difficulties are expected in stable national power operation and peak load management due to the increase in power demand due to the generalization of electric vehicles, base-load power plants other than nuclear power plants that are difficult to adjust output, and the volatility of new renewable energy such as solar and wind power.

In Korea, a system to sell the electricity stored in the battery of an electric vehicle or the electricity stored in the ESS (Energy Storage System) can be sold, going beyond charging the electric car. (V2G). To this end, technologies for transmitting electric vehicle battery power to the grid are expected to be additionally developed, such as an on-board charger for electric vehicles, a two-way slow charging system, and V2G (Vehicle To Grid: reverse transmission of electric vehicle power to the power grid) standard.

ESS refers to a device that collects surplus power and stores it in a physical device in preparation for a surge in power demand. In the meantime, electricity could not be sold because it was not recognized as a power plant, but as ESS was recognized as a power plant through the recent revision of the Electricity Business Act, it is now possible to sell stored electricity back to KEPCO. The government is also implementing a customized rate system that provides a 10% discount on the electricity unit price when charging during light load hours (23:00-09:00) so that consumers can shorten the payback period when installing ESS devices. Currently, the cost of ESS construction by public institutions is around 300 to 500 million won/MWh, but it is expected to continue to decrease with the development of ESS technology and large-scale commercialization.

Korean Registered Patent Publication No. 10-1972778 is a charging device equipped with an ESS module, which includes a power module that converts AC power into charging power directly input to an electric vehicle; a kiosk provided with a power line connected to the electric vehicle and connected to the power module; an ESS module connected to the power module and storing backup power provided to the electric vehicle; and a control module for controlling the power module, wherein the foreseeable power is converted into charging power by the power module and provided to the electric vehicle, and the control module selectively uses the ESS as the AC power or the reserve power. It was configured to be provided to the electric vehicle. This was limited to a method of using AC power as the main power source and using the ESS module as a reserve power for an electric vehicle charging station.

The concept of building an electric vehicle charging station by combining an ESS module and solar power generation is also known. Due to the nature of the ESS module, which cannot charge and discharge at the same time, it is limited to charging the ESS module during the day through solar power generation and using the ESS module at night. Although the above methods are configured to use the ESS module as the main power source, they do not provide a solution for charging the electric vehicle with the power of the ESS module while the ESS module is being charged with solar power generation. Accordingly, the present applicant uses Korean Patent Application Nos. 10-2020-0147196 and 10-2020-0167916 as a main power source for an ESS module that is automatically charged at a light load, and AC power at a light load or when the charging power of the ESS module is insufficient. Suggested how to use it as a reserve power when

Countries around the world are starting to build pumped-storage power generation in preparation for power load leveling and the expansion of renewable energy with high volatility. Germany is expanding from 8GW in 2013 to 12GW in 2025, China from 22GW to 120GW, and the United States from 23GW to 47GW. A pumped-storage power plant that builds a reservoir on a hill, pumps water into the reservoir with a motor pump using surplus power at night when power demand is low, and then drops the water from the reservoir to generate electricity, requires only 5 to 10 years of construction, so it has a short load time. It is being reviewed in a way that ESS handles the capacity and pumped-storage power generation handles the large capacity. In Korea, demand response policies are being expanded to manage peak loads in emergencies along with pumped-storage power generation. As companies reduce power operation when requested by the government, it is a kind of power demand reduction method that receives government subsidies. Although it is not a desirable power supply and demand measure, it is expanding as an alternative to peak load as it is difficult to build a power plant rapidly. It was announced that the scale would increase from 2GW in 2021 to 3.82GW in 2030.

The supply of electric vehicles is expected to reach 8 million by 2025. From 2025, some European countries will stop selling internal combustion locomotives, and from 2030, China, Germany and India will also stop selling them. Expansion of an efficient electric vehicle charging infrastructure is very important as many countries will stop selling internal combustion engine vehicles by 2040. The battery capacity of electric vehicles is also increasing from 20kWh to 100kWh in the early stages, and rapid charging technology is also developed, and it is expected that 700kW or higher, which can be charged within 10 minutes from the current 50kW, will become common. If 100,000 electric vehicles are charged at 700 kw at the same time, 70 GW of power is required. Compared to the domestic power supply capacity of 100GW, it is 70% of the maximum supply capacity, and it is impossible to fully expand electric vehicles and build charging infrastructure with the current base power generation capacity.

The present applicant filed a patent application for 'an integrated charging system and charging method using an ESS module charged during light load time as a main power source and AC power as an auxiliary power source'. If 10,000 electric vehicle charging stations with 10MW ESS modules are installed nationwide, the total capacity of ESS modules will reach 100GW. (National and public) It is necessary to establish a power supply reserve ratio adjustment center and configure each ESS module to be charged or discharged according to the supply reserve ratio. In other words, it is necessary to shift the government's power supply measures to the SR (Supply Response) market, which replaces the DR (Demand Response) market, in which the ESS module to be installed at the electric vehicle charging station is managed in a special situation by the power supply reserve adjustment center server. .

In order to cope with the peak load, there is a problem that the base power plant must be operated at all times and the efficiency of the generator can be secured only when the power generation utilization rate is maintained at 80% or more due to the nature of the base power plant. Currently, it is known that the supply reserve ratio of domestic power generation is operated at more than 40% during late-night hours due to lack of electricity demand. As much as there must be a load in order for electricity to flow, if the amount of power generation is insufficient compared to the amount of load, the power frequency deviates from 60Hz to the - direction, and if the amount of power generation is large, the power frequency deviates from 60Hz to the + direction. In the entire power plant, power is generated by adjusting the power plant output so that the AC frequency of generated electricity becomes 60 Hz. Therefore, the surplus power (supply reserve ratio) of power plants in operation means the amount of power that can be supplied, not all produced and discarded. Therefore, in order to secure the stable power generation efficiency (around 80%) and electricity quality (60Hz) of the power plant, if the ESS module of the electric vehicle charging station of the present invention is used like a pumped-storage generator operated in the middle of the night, countermeasures against peak loads and electricity quality are secured can do. ESS stacks batteries in a rack like modules and consists of BMS (Battery Management System), TMS (Thermal Management System), and PCS (Power Converting System) to control and manage them. EMS (Energy Management System) is in charge.

If the electric vehicle charging infrastructure uses only AC power from electric power companies and many vehicles are charged at the same time, the national power reserve rate drops, which can cause fatal problems in the stable operation of the national power grid. As an alternative to this, a method of mixing and using the ESS module and AC power can be applied, and a method of using AC power as the main power source and the ESS module as a backup power source has been proposed, but the above problem cannot be solved. Accordingly, the present applicant filed a patent application for 'an integrated charging system and charging method using an ESS module charged during light load time as the main power source and AC power as an auxiliary power source', The 'EV charging power source conversion unit' selected from AC power modules was provided either manually or automatically. First, at light load, it is connected to the AC power module to supply EV charging power to the electric vehicle. Second, it is connected to the ESS power module to supply EV charging power to the electric vehicle during medium and peak loads. Third, when the charging capacity of the ESS module is exhausted and the electric vehicle cannot be charged, it is converted to an AC power module to receive EV charging power. A late-night power meter for charging only at night is attached to the ESS module, and a means for automatically charging it in the middle of the night is configured. All power charged in the ESS module before light load time must be sold, but if there is surplus power, it is structured so that it can be connected to the national power grid and sold. To this end, the ESS module (10MWh as an example) is separated into a certain unit (1MWh as an example), and the upper unit is configured to charge the electric vehicle while the lower unit is connected to the grid to sell surplus power.

If 10,000 electric vehicle charging stations with 10MW ESS modules are installed nationwide, the total capacity of ESS modules will reach 100GW. Establish the 'National Power Supply Reserve Adjustment Center (tentative name)' to optimize the supply reserve ratio by configuring the ESS module of each electric vehicle charging station to be charged or discharged according to the supply reserve ratio. In the present invention, the 'charging and discharging command means' instructed through the 'national power supply reserve adjustment center server' is installed in the top-level EMS (Energy Management System) of the ESS module to be installed in the electric vehicle charging station to solve the above problems. do. Through this, the government can control the charging and discharging of a certain portion (around 30%) of the ESS capacity of the electric vehicle charging station to optimize the power reserve supply rate, thereby ensuring the quality of electricity while operating the minimum base power plant. Government's peak load countermeasures with SR (Supply Response) market that releases ESS power from electric vehicle charging stations by replacing the DR (Demand Response) market, which compulsorily reduces corporate power demand with subsidies for peak load response along with pumped-storage power generation can switch

Expansion of an efficient electric vehicle charging infrastructure is very important as many countries will stop selling internal combustion engine vehicles from 2025. Rapid charging technology is also developed, and it is expected that more than 400kW class, which can be charged within 10 minutes, will become common. If many vehicles are charged during peak load hours with the current charging method, the national power reserve rate may drop, causing fatal problems in the stable operation of the national power grid. In order to respond to peak loads and secure electricity quality, the SR market is also operated to keep the supply reserve ratio high or forcibly reduce the contracted corporate power during peak loads. In the present invention, it is connected to the AC power module to receive EV charging power during light load, and is connected to the ESS power module to supply EV charging power to the electric vehicle during medium and peak loads. When the charging capacity of the ESS module is exhausted and the electric vehicle cannot be charged, it is converted to an AC power module and supplied with EV charging power. The government has installed a 'charge and discharge command means' in the ESS to control the charging and discharging of the ESS at the electric vehicle charging station. The present invention has the following effects.

First, the government (public) controls to release electric vehicle charging station ESS power during peak load and to charge the electric vehicle charging station ESS when the supply reserve ratio increases, thereby having an effect of coping with peak load and securing electricity quality. By operating this optimally, the operation of the base load power plant can be minimized.

Second, the present invention, instead of the current method of using AC power as the main power at the electric vehicle charging station, conversely configures the ESS module as the main power source and the AC power as the auxiliary power source, so that the electric vehicle charging infrastructure can be stably operated even during peak load times. can

Third, the ESS module is configured to automatically charge during light load (including high power reserve ratio and late-night power), and the ESS module charging power is configured to charge electric vehicles mainly at maximum load, thereby increasing the efficiency of the national power grid and increasing the supply reserve ratio can increase

Fourth, since the remaining charging power of the ESS module is not sufficient or it is converted to auxiliary AC power when the load is light, there is an effect that the electric vehicle charging station can be operated 24 hours a day.

Fifth, if charging power is expected to remain by configuring the ESS module in units, there is an effect that the power of a specific unit can be grid-connected and sold to the national power grid.

1 is an industrial electricity rate system for light load, medium load, and maximum load time zones operated in Korea.
2 is a table of electric vehicle charging rates and power rates supplied by electric charging companies in Korea.
3 is a block diagram of a platform that integrates electric vehicles, electric vehicle charging stations, grid connection, payment systems, and operation control systems of KEPCO.
4 is a conceptual diagram of an ESS-only charging station composed of renewable energy and a power grid.
5 is a schematic diagram of a charging device equipped with a spare ESS module (Korean Patent Registration No. 10-1972773).
6 is a configuration diagram in which an ESS power line and an AC power line filed by the present applicant as 10-2020-0147196 are independently configured and a main ESS charger and an auxiliary AC power network charger are connected to each power line.
7 is a configuration diagram of an electric vehicle charging station in which the electric vehicle is charged and discharged in conjunction with the power supply reserve ratio adjustment center server while charging the electric vehicle using the ESS of the present invention as the main power.

When only alternating current power of electric power companies is used as the charging infrastructure, when many vehicles are charged at the same time, a fatal problem may occur in the stable operation of the national power grid due to a decrease in the national power supply reserve ratio. As a passive alternative to this, a method of mixing and using an ESS for standby power and AC power may be applied, but the above problem cannot be solved because the ESS is used as a standby power source. Current power management has no alternative other than pumped-storage power plants that respond to peak loads (highest loads), so base load power plants maintain a high supply reserve ratio. Accordingly, it is also operating the SR (Supply Response) market, which provides subsidies instead of forcibly reducing the power of contracted companies during peak loads.

In the present invention, the 'charge and discharge command means' instructed through the 'power supply reserve ratio control center server' is installed in the top-level EMS (Energy Management System) stage of the ESS module to be installed in the electric vehicle charging station to solve the above problems. . ESS (Energy Storage System) module that automatically recharges electric vehicles at light loads (midnight power between 23:00 and 9:00), main ESS module and auxiliary ESS module used during medium and maximum load times with the power charged in the ESS module configured to use AC power. The 'EV charging power source conversion unit', which selects between an ESS power module and an AC power module as a power source, supplies EV charging power to electric vehicles by being connected to the AC power module during light loads. During medium and peak loads, it is connected to the ESS power module to supply EV charging power to electric vehicles. When the charging capacity of the ESS module is exhausted and the electric vehicle cannot be charged, it is converted to an AC power module and configured to receive EV charging power. All the power charged in the ESS module before the light load time must be sold, but if there is surplus power, it is necessary to configure it so that it can be connected to the national power grid and sold.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in this specification and claims should not be construed as being limited to ordinary or dictionary meanings, and the inventor appropriately uses the concept of terms in order to explain his/her invention in the best way. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical spirit of the present invention. Therefore, the embodiments described in this specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, so various alternatives can be made at the time of this application. It should be understood that there may be equivalents and variations.

1 is an industrial electricity rate system for light load, medium load, and maximum load time zones operated in Korea. For the power generation efficiency of a power plant, it is necessary to uniformly manage power demand at light, medium, and maximum loads. In general, the electricity rate at light load is around 35% at maximum load. 2 is a table of electric vehicle charging rates and power rates supplied by electric charging companies in Korea. 3 is a block diagram of a platform that integrates and operates electric vehicles, electric vehicle charging stations, and KEPCO's grid connection, payment system, and operation control system that have been built up to now.

4 is a conceptual diagram of an ESS-only charging station composed of renewable energy and a power grid. During the week when the ESS is charged with renewable energy, it must be charged using other electricity. There is a contradiction in that solar power cannot receive enough power to rapidly charge an electric vehicle in real time, so it is necessary to charge the ESS module with separate power to charge the electric vehicle during the daytime. Compared to the method of directly charging an electric vehicle by converting AC to DC, losses (charging efficiency of around 92%) occur while charging the ESS module. Additional losses occur while converting power. 5 is a schematic diagram of a charging device equipped with a spare ESS module (Korean Patent Registration No. 10-1972773). Since a one-type charging device is used, there is a problem in using a power module that needs to switch between standby ESS power and main AC power. The DC output design cannot be optimized because the AC-DC converter must charge the spare ESS module when necessary and supply electric vehicle charging power. Lithium batteries such as ESS modules lose about 80% of their power capacity after being charged and discharged 300 to 500 times. Therefore, frequent charging and discharging is not desirable. In the dedicated ESS method, in which the ESS module is in charge of charging the electric vehicle, frequent charging and discharging inevitably occurs due to its configuration. Charging an electric vehicle while charging the ESS module can cause damage to the ESS module by generating heat. The reserve ESS method also has a structure in which the ESS module is frequently charged with a power module that converts AC to DC (connected to the primary DC power supply terminal). For a stable ESS module, it should be configured to charge at light load and charge at maximum and medium load. In this case, when the charging power of the ESS module is exhausted and when the electric vehicle is lightly loaded, there is a problem of how to charge the electric vehicle.

6 is a configuration diagram in which an ESS power line and an AC power line filed by the present applicant as 10-2020-0147196 are independently configured and a main ESS charger and an auxiliary AC power network charger are connected to each power line. 6 is a configuration diagram in which the ESS power line and the AC power line of the present application are independently configured and the main ESS charger (including the kiosk) and the auxiliary AC power grid charger are connected to each power line. In the electric vehicle charging station, the main ESS power line and the auxiliary AC power line are independently configured, and two chargers are independently configured on each power line, so that the electric vehicle charging infrastructure can be stably operated even during peak load hours.

7 is a configuration diagram of an electric vehicle charging station in which the electric vehicle is charged and discharged in conjunction with the power supply reserve ratio control center server while charging the electric vehicle using the ESS of the present invention as the main power. The power supply reserve ratio adjustment center is operated by the government or the public sector, but in countries where the electricity industry has been privatized (eg the United States), it can be operated by a private power company. The ESS module 140 includes a data security means 240 and a charge and discharge command means 230 connected to the power supply reserve ratio adjustment center server 250 and a communication network. ESS (Energy Storage System) module that automatically recharges only during light loads within the same charging parking area (hereinafter, including the forced charging command time and late-night hours of the power supply reserve control center server), medium load and maximum with the power charged in the ESS module Configured for use during load times. It is configured to include an 'EV charging power source switching unit' with a function of selecting an electric vehicle charging power source. The 'EV charging power source switching unit' that selects between an ESS power module and an AC power module as a power source can be provided manually or automatically. First, in principle, it is connected to the AC power module to supply EV charging power to the electric vehicle at light load. Second, it is connected to the ESS power module to supply EV charging power to the electric vehicle during medium and peak loads. Third, when the charging capacity of the ESS module is exhausted and the electric vehicle cannot be charged, it is converted to an AC power module and configured to receive EV charging power.

In the electric vehicle charging device, the ESS module 140 is composed of a data security means 240 and a charge and discharge command means 230 connected to the power supply reserve ratio adjustment center server 250 through a communication network, and basically late at night at an electric vehicle charging station Means for configuring the power grid 300 and the AC power grid 400; ESS module 140 through light load ESS charging device 100 to late-night power grid 300 at light-load time (hereinafter, power supply reserve ratio control center server's forced charging command time and late-night power time zone 23:00 to 09:00) means for charging; Means for converting the power charged in the ESS module 140 into a charging voltage required by the electric vehicle through the ESS power module 150; An AC/DC converter 130 that receives AC from the AC power grid 400 as an auxiliary and converts it into DC, and an AC power module 160 that converts it into a charging voltage required by an electric vehicle; an EV charging power source switching unit 170 that selects between the ESS power module 150 and the AC power module 160 to generate EV charging power 180 for charging the electric vehicle; The EV charging power 180 is provided as an EV rapid charger 190 for charging an electric vehicle. Through this, it is possible to build a system and charging method for charging electric vehicles with the ESS module as the main power source and AC power as auxiliary, and electric vehicle charging stations.

If stable power supply is difficult due to a decrease in the national power supply reserve ratio, the national power supply reserve ratio control center server 250 instructs the ESS module 400 to discharge power in a designated scale through the charging and discharging parallel means 230 doing; The corresponding ESS module 400 is configured to emit power in a specified scale. Conversely, when the supply reserve ratio of national electricity increases, the server 250 of the National Electricity Supply Reserve Adjustment Center charges the ESS module 400 to the specified scale in order to maintain the stable power generation and electricity quality of the base station at 60Hz. and instructing the discharge parallel age means 230; The corresponding ESS module 400 is configured to charge power in a designated scale. Through this, we intend to provide an electric vehicle charging system, charging method, and electric vehicle charging station with a national power management function. By participating in the national power management function, electric vehicle charging stations with ESS as the main power source can serve as a substitute for pumped-storage power plants that take a long time for new construction and unfair DR (Demand Response) markets that block corporate electricity use with subsidies.

In this case, EV charging through the AC power grid 400 and the AC power module 160 instead of the ESS module 140 charging power during the light load period or when the remaining charging capacity of the ESS module 140 is insufficient The EV charging power source switching unit 170 is configured to switch to the AC power module 160 to supply power 180 . In other words, it consists of a system and charging method for charging an electric vehicle using AC power at light load and when the charging power of the ESS module is insufficient, and an electric vehicle charging station. Means for manually and automatically operating the EV charging power source switching unit 170; Means configured in the same form as a manual electric circuit breaker in the case of manual operation; Means of construction in the form of high voltage relays in the case of automatic; Means for indicating the selected power source to the management station and charger; When the EV charging power source conversion unit 170 is operated, a means for prohibiting the use of the entire EV fast charger 190 must be included. Through this, it is possible to provide a system for charging an electric vehicle by selecting the ESS module charging power and AC power, a charging method, and an electric vehicle charging station. In this case, the means for operating the EV charging power source switching unit 170; prohibiting use of the entire EV fast charger 190; Step of turning off (OFF) and blocking the power source currently used; Setting a standby time for stably switching a power source; It should be configured with the steps of turning on and connecting the power source to be used. When switching the power source, a certain amount of standby and initialization time (several to tens of seconds) is required, and the use of the entire charger must be temporarily blocked. When the charging power of the ESS module 140 is expected to be insufficient at maximum load, the power of the ESS module 140 is preferentially used for charging the electric vehicle at the maximum load. That is, the EV charging power source switching unit 170 is limited to use the auxiliary AC power module 160 instead of the ESS power module 150 during a medium load. An object of the present invention is to provide an electric vehicle charging system, a charging method, and an electric vehicle charging station that preferentially use ESS module charging power during maximum load.

With the proper capacity of the ESS module, it can be configured to charge about 50% of 100 cars/day per parking area. When charging an average of 30kWh per electric vehicle, ESS with a capacity of 3MWh per charging zone is required. In the case of a charging station with about 6 charging zones, an ESS with a capacity of 18MWh ($1.4 million for an ESS of 80$/kWh) is required. It is necessary to attach a late-night power meter to the ESS module for charging only with late-night power and automatically charge it in the late-night time zone. Basically, at light load time (23:00 to 09:00), the ESS charging device 110 at light load connected to the late-night power grid 300 of the electric power company includes a late-night power meter; And, it is configured to automatically charge the ESS module 140 by including a means (AC-DC converter) for converting alternating current to direct current. That is, an electric vehicle charging system and method using an ESS module charged during light load time as main charging power are provided. All the power charged in the ESS module before the light load time must be sold, but if there is surplus power, it is necessary to configure it so that it can be connected to the national power grid and sold. That is, means for predicting that the power charged in the ESS module 140 is not consumed until the light load time (23:00 in Korea); Means for controlling the EV charging power source switching unit 170 to use the auxiliary AC power module 160 instead of the power of the ESS module 140 at the maximum load time closest to the light load time; The surplus charging power of the ESS module 140 may be configured to be sold (V2G) in connection with the power grid 100 through the inverter 120. It provides an electric vehicle charging system and method, and an electric vehicle charging station that sells the surplus charging power of the ESS module through grid connection. If the ESS module (eg 10MWh) is separated into a certain unit (1MWh as an example), the upper unit can be configured to charge the electric vehicle while the lower unit connects to the grid and sells surplus power. That is, means for configuring the entire ESS module 140 by dividing it by a certain power capacity; Means for variably operating the ESS module 140 as a grid-connected ESS unit 210 connected to the electric vehicle charging ESS unit 220 and the inverter 120; Means for predicting that the electric power charged in electric vehicle charging will not be exhausted until light load time (23:00 in Korea); means for determining the grid-connected ESS unit 210 according to the amount of surplus charging power; Means for selling (V2G) the charging power of the grid-connected ESS unit 210 through the inverter 120 through the grid-connected power grid 100 at the maximum load time closest to the light-load time; The charging power of the electric vehicle charging ESS unit 220 is configured to be used as electric vehicle charging power.

When it is predicted that there will be remaining charging power in the ESS module, it is economically advantageous to charge the ESS module at light load by selling the charging power to the electric power company at mid-load and peak-load hours in connection with the grid and leaving around 10% in the ESS module. Measuring the remaining charging capacity of the remaining ESS modules for this purpose; Calculating the remaining time until light load; Calculating the expected number of electric vehicles to be charged for the remaining time; It consists of a step of deciding to sell the remaining charge to the electric power company, a step of turning off the use of the main ESS module and turning on the use of the auxiliary AC power module. The ESS module of the electric vehicle charging station is composed of not only charging the electric vehicle but also selling the charging power to the electric power company when necessary, through which stable base generation (24-hour continuous operation is the part that forms the basis of power generation, and the cost of generation is the lowest power generation by nuclear power and coal) can be operated. Currently, power companies are operating a passive industrial electricity demand control policy (DR market) that costs a lot of money.

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In general, if charging is 20kw per electric vehicle, ESS module needs 1MWh of capacity to charge 50 electric vehicles. In the near future, the battery price is expected to be less than 100 USD per kW, and since used batteries for electric vehicles can also be applied to ESS modules, ESS at electric vehicle charging stations is inevitable. As it is not possible to limit the electric vehicle charging at maximum load, the present invention is a business model that charges the electric vehicle at maximum load by charging the ESS module using base power at light load or resells surplus charging power to the electric power company at maximum load. to be implemented through In addition, by optimally controlling the charging and discharging functions of the ESS electric vehicle charging station connected to the power grid from the center (power supply reserve ratio control center server), even if the operation of the base power plant is minimized, it is possible to respond to peak loads and secure electricity quality, thereby reducing the earth's It can contribute to solving environmental problems.

100: grid 110: ESS charging device at light load
120: inverter 130: AC/DC converter
140: ESS module 150: ESS power module
160: AC power module 170: EV charging power source conversion unit
180: EV charging power 190: EV fast charger
200: ESS module 210: grid-connected ESS unit
220: electric vehicle charging ESS unit
230: charge and discharge command means
240: data security means
250: power supply reserve ratio control center server

Claims (7)

In the electric vehicle charging device,
It consists of a data security means 240 and a charge and discharge command means 230 connected to the ESS module 140 with the power supply reserve ratio adjustment center server 250 and a communication network,
Means for configuring an electric vehicle charging station with a late-night power grid 300 and an AC power grid 400;
Means for charging the ESS module 140 through the ESS charging device 100 at light load time (currently 23:00 to 09:00) with the late-night power grid 300;
Means for converting the power charged in the ESS module 140 into a charging voltage required by the electric vehicle through the ESS power module 150;
An AC/DC converter 130 that receives AC from the AC power grid 400 as an auxiliary and converts it into DC, and an AC power module 160 that converts it into a charging voltage required by an electric vehicle;
an EV charging power source switching unit 170 that selects between the ESS power module 150 and the AC power module 160 and generates EV charging power 180 for charging the electric vehicle;
A system and charging method for charging an electric vehicle with an ESS module as a main power source and AC power as an auxiliary, characterized by being provided by an EV rapid charger (190) that charges an electric vehicle with EV charging power (180), and an electric vehicle charging station
According to claim 1,
When it is difficult to supply stable electricity due to a decrease in the national electricity supply reserve ratio,
Instructing the charging and discharging parallel means 230 to discharge power from the corresponding ESS module 400 in a specified scale in the power supply reserve ratio adjustment center server 250;
An electric vehicle charging system and charging method with a national power management function, characterized in that the ESS module (400) is configured to emit power in a specified scale, and an electric vehicle charging station
According to claim 1,
In order to maintain the quality of electricity when the supply reserve ratio of national electricity increases,
Instructing the charging and discharging parallel means 230 to charge the power in the corresponding ESS module 400 to a specified scale in the power supply reserve ratio adjustment center server 250
An electric vehicle charging system and charging method with a national power management function characterized in that the ESS module (400) is configured to charge power in a specified scale, and an electric vehicle charging station
According to claim 1,
In the case of charging by the late-night power time (23:00 ~ 09:00) and the charging instruction command (forced charging) of the national power supply reserve adjustment center server 250,
In the ESS charging device 110 connected to the late-night power grid 300 of the power company,
late-night power and forced charging meters; and
comprising means for converting alternating current to direct current (AC-DC converter);
An electric vehicle charging system and method using the ESS module charged as the main charging power during light load time period and forcible charging for adjusting the power supply reserve ratio, characterized in that the ESS module 140 is configured to automatically charge
According to claim 1,
Measuring the remaining charging capacity of the remaining ESS modules;
Calculating the remaining time until light load;
Calculating the expected number of electric vehicles to be charged for the remaining time;
Determining to sell the remaining charging power to the power company;
Electric vehicle charging system and method for selling surplus charging power of the ESS module by grid connection, characterized by comprising the step of turning off the use of the ESS module 140 and turning on the use of the auxiliary AC power module
According to claim 1,
means for predicting that the power charged in the ESS module 140 will not be consumed until the light load time (23:00 in Korea);
Means for controlling the EV charging power source switching unit 170 to use the auxiliary AC power module 160 instead of the power of the ESS module 140 at the maximum load time closest to the light load time;
The surplus charging power of the ESS module 140 is sold in connection with the power grid 100 through the inverter 120 (V2G) An electric vehicle charging system that sells the surplus charging power of the ESS module in connection with the grid and Method, EV charging station
According to claim 1,
Means for configuring the entire ESS module 200 by dividing it by a certain power capacity;
Means for variably operating the ESS module 200 as a grid-connected ESS unit 210 connected to the electric vehicle charging ESS unit 220 and the inverter 120;
Means for predicting that the electric power charged in electric vehicle charging will not be exhausted until light load time (23:00 in Korea);
means for determining the grid-connected ESS unit 210 according to the amount of surplus charging power;
Means for selling (V2G) the charging power of the grid-connected ESS unit 210 through the inverter 120 through the grid-connected power grid 100 at the maximum load time closest to the light-load time;
An electric vehicle charging system and method that sells surplus charging power of an ESS module in a grid-connected manner, characterized in that the charging power of the electric vehicle charging ESS unit (220) is used as electric vehicle charging power, and an electric vehicle charging station

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