KR20220060949A - Charging system, charging method, and charging station for charging electric vehicles mainly during mid-load and heavy-load periods with power automatically charged to the ESS during light load times - Google Patents

Abstract

In case of using only alternating current power of electric power companies as a charging infrastructure, in particular, charging many vehicles in a heavy-load period, the country's power reserve rate drops, which can cause fatal problems in the stable operation of the national power grid. As an alternative to this, a dedicated ESS or a method of mixing and using a standby ESS and alternating current power can be applied, but converting high power of 400 kW by relays, etc. is difficult, so more costs in forming a charging apparatus are required, and a risk like spark generation or the like in accordance with conversion between ESS and alternating current power is high. The present invention provides a charging station, in which power line is formed such that ESS power line is independent from alternating current power line and chargers are connected independent of each power line. Therefore, two chargers are provided in the same parking area, such that a user preferentially uses a main ESS charger, but when the remaining charging capacity of the ESS is insufficient or during light-load period (23:00 ~ 09:00), the user uses an auxiliary alternating current charger. The present invention is configured to automatically charge an ESS module in a light-load (midnight power) period and to charge an electric vehicle with the charging power of the ESS module mainly in the maximum-load period, thereby increasing the efficiency of the national power grid and enhancing power reserve rate.

Description

A charging system, charging method, and charging station for charging electric vehicles mainly during mid-load and full-load times with electric power automatically charged to the ESS during light load times. heavy-load periods with power automatically charged to the ESS during light load times}

As the spread of electric vehicles spread, electric vehicle battery capacity increased (30kWh -> 60kWh) and battery price fell (Tesla forecast 80 ~ 100$/KWh), and power overload caused by simultaneous charging of electric vehicles is being raised as an important industrial problem. The charging method for electric vehicles is also composed of a slow charging method that charges for 4 to 5 hours with a 3 to 7 kW layer capacity and a 50 kW charging capacity within 30 minutes. The rapid charging method continuously increases the charging capacity (for example, 400 kW), which shortens the charging time, but at the same time, it is expected that it will be difficult to operate a stable power grid when many vehicles are charging. Accordingly, at KEPCO, charging rates for electric vehicles are: light load (23:00 to 09:00, minimum 56.4 won/kWh), medium load (maximum KRW 113/kwh), and maximum load (10 a.m. to 12 noon, 13:00 to 17:00, up to 244 won).

The late-night power system is a system to disperse the power demand concentrated during a specific time period and to increase the utilization rate of power generation facilities during late-night hours (11 pm to 9 am the next day) when electricity demand is low. This is a rate system that applies only to the late-night power consumption of 'late-night power devices', not to all power consumption during the late night hours. 'Late night power equipment' includes ▷ heat storage-type heating/hot water equipment, ▷ heat storage-type heating and cooling equipment (cooling equipment) ▷ ESS-type heating and cooling equipment, etc. The late-night power rate is a rate system that is applied only to the late-night power consumption of late-night power devices, not to all the power used in the late night. This is billed separately from the normal rate after a late-night power meter is installed and metered.

In Korea, in order to resell the electricity charged in the electric vehicle battery or the electric power stored in the ESS (Energy Storage System), electric vehicles can not only charge electricity, but also sell the electric power charged in the electric vehicle's built-in battery. system was announced. According to the revision of the 'Guidelines on the Transaction of Small-scale New and Renewable Energy Generation Power, etc.', it is expected that electric vehicle users will be able to sell electric power charged at low rates at night at high prices during peak hours during the day. To this end, additional technologies for transmitting electric vehicle battery power to the electric grid are expected to be developed, such as on-board chargers for electric vehicles, two-way slow charging systems, and V2G (Vehicle To Grid: reverse transmission of electric vehicle power) standards. ESS refers to a device that collects excess power and stores it in a physical device in case the power demand surges. In the meantime, electricity could not be sold because it was not recognized as a power plant. As ESS is recognized as a power plant through the recent revision of the Electricity Business Act notice, the stored electricity can be resold to KEPCO in the future. In order to shorten the payback period when consumers install ESS devices, the government is also implementing a customized rate system in which the unit price of electricity is reduced by 10% compared to the current when charging during light load hours (23:00-09:00). Currently, the cost of building ESS for public institutions is around KRW 300 million/MWh, but it is expected to continue to decrease in line with technology development and large-scale commercialization.

Korean Patent Publication No. 10-1972778 discloses a charging device equipped with an ESS module, comprising: a power module that converts AC power into charging power that is 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 reserve power provided to the electric vehicle; a control module for controlling the power module; wherein the predictive power is converted into the charging power by the power module and provided to the electric vehicle, and the control module selectively selects the ESS as the AC power or the reserve power It was configured to be provided to the electric vehicle. Alternatively, the concept of building an electric vehicle charging station using only the ESS module was presented.

The supply of electric vehicles in 2025 is expected to be 8 million units, and sales of internal combustion engine vehicles will be stopped in some European countries from 2025, and sales will also stop in China, Germany, and India from 2030. In 2040, the spread of efficient electric vehicle charging infrastructure is very important as sales are being held in many countries. The battery capacity of electric vehicles is also increasing from 20 kWh to 60 kWh at the beginning, and rapid charging technology is also developed, so it is expected that the current 50 kW class will become more common than the 400 kW class, which can be charged within 10 minutes. If 100,000 electric vehicles are rapidly charging 400 kW at the same time, 40 GW of power is required. Compared to 100GW, the maximum domestic electricity supply capacity is 40% of the maximum supply capacity, so it is impossible to build a full-scale electric vehicle expansion and charging infrastructure with the current power generation capacity.

Korean Patent Publication No. 10-1972778 discloses, for the first time, a charging device equipped with an ESS module, 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 reserve power provided to the electric vehicle; a control module for controlling the power module, wherein the reserve power is converted into the charging power by the power module and provided to the electric vehicle, and the control module selectively converts the AC power or the reserve electric power to the electric vehicle However, there is a problem in that 400kW of strong power is configured to open or close the electric circuit with a relay or a MCCB (Mold Case Current Breaker) circuit breaker. In addition, the stable operation of the national power grid cannot be guaranteed by using the ESS only as a backup power source.

As electric vehicle batteries are used, their charging capacity decreases to 80% or less, and their efficiency decreases, so they have no choice but to be replaced rather than installed in electric vehicles. . It is necessary to utilize this for electric vehicle charging infrastructure.

If the charging infrastructure uses only AC power from the power company, and if many vehicles are charging at the same time, the national power reserve ratio will drop, which may cause fatal problems in the stable operation of the national power grid. As an alternative to this, a method of using a mixture of ESS for standby power and AC power can be applied, but it is difficult to convert 400 kW of high power into a relay, etc. There is a high risk of sparks.

In the present invention, in order to solve this problem, an ESS (Energy Storage System) that automatically charges only during light load (midnight power) within the same charging parking area, the main ESS charger used during medium load and maximum load time with the power charged in the ESS, and auxiliary Independently compose two sets of chargers that use only AC power. Means to induce the use of an auxiliary AC power grid charger instead of the main ESS charger are included when the electric vehicle cannot be charged because the charging capacity of the ESS is exhausted or during the light load period. The appropriate capacity of the ESS is configured so that 100 cars/day per parking area can be charged by 50%. When charging an average of 30 kWh per electric vehicle, an ESS with a capacity of 3 MWh per charging area is required. In the case of a charging station with about six charging areas, an ESS with a capacity of 18MWh (ESS 80$/kWh, $1.4 million) is required. It is necessary to attach a late-night power meter for charging only with late-night power to the ESS module and automatically charge it during late-night hours. The average charging rate at light load is 60 won/kWh, so if 18MWh is sold at 240 won/kWh at maximum load, sales profit of 3.24 million won/day is expected.

In the charging station, the ESS power line and the AC power line are each independently of the power line, and the charger is independently configured in each power line. Therefore, there are two chargers in the same charging and parking area, and the user prefers to use the main ESS charger. It is configured to lead to an LED indicator light to use the power grid charger. In other words, compared to the existing method of using one charging device to use ESS reserve power and AC power together in the same charging area, the present invention, which consists of a main ESS charger and two auxiliary AC chargers, provides charging power to the ESS module. Even when the battery is exhausted, it has advantages in terms of construction cost as well as securing stability as well as guaranteeing charging.

As many countries stop selling internal combustion engine vehicles from 2025, the spread of efficient electric vehicle charging infrastructure is very important. With the development of fast charging technology, it is expected that the current 50kW class will become more common than the 400kW class, which can be charged within 10 minutes. If the charging infrastructure uses only AC power from the power company, especially when many vehicles are charged during heavy load hours, the national power reserve ratio will drop, which may cause fatal problems in the stable operation of the national power grid. As an alternative to this, a method of using a dedicated ESS or a mixture of a spare ESS and AC power can be applied, but it is difficult to convert 400kW of high power into a relay, etc. There is a high risk of sparks caused by switching between the two. In the present invention, the power line of the charging station consists of an ESS power line and an AC power line independently, and a charger is independently connected to each power line. Therefore, there are two chargers in the same parking area, and the user prefers to use the main ESS charger. use. The present invention has the following effects.

First, by independently configuring the main ESS power line and auxiliary AC power line at the electric vehicle charging station, and independently configuring two chargers in each power line, the electric vehicle charging infrastructure can be operated stably even during the maximum load time.

Second, by configuring the ESS module to automatically charge during the light load (midnight power) time period, and by configuring the ESS module charging power to mainly charge the electric vehicle at the maximum load, the efficiency of the national grid can be improved and the power consumption ratio can be increased. .

Third, there is a main ESS power charger and an auxiliary AC power grid charger in the same charging parking area, so the ESS power line and AC power line are integrated by inducing the use of the auxiliary AC power grid charger when the remaining charging power of the ESS module is insufficient or light load. It can solve the problems of the existing method.

1 is an industrial electricity rate system for each light load, medium load, and maximum load time period operated in Korea.
2 is a table of electric vehicle charging rates in Korea and electricity rates supplied by electric charging service providers.
3 is a block diagram of a platform that integrates electric vehicles, electric vehicle charging stations and KEPCO's grid connection, payment system, and operation control system.
4 is a conceptual diagram of an ESS dedicated charging station composed of renewable energy and a power grid.
5 is a schematic diagram of a charging device (Korean Patent Registration No. 10-1972773) equipped with a spare ESS module.
6 is a configuration diagram of the ESS power line and the AC power line of the present invention independently configured, and the main ESS charger (including a kiosk) and the auxiliary AC power grid charger are connected to each power line.

If the charging infrastructure uses only AC power from the power company, and if many vehicles are charging at the same time, the national power reserve ratio will drop, which may cause fatal problems in the stable operation of the national power grid. As a passive alternative to this, a method of using a mixture of ESS for standby power and AC power can be applied, but it is difficult to convert 400 kW of high power into a relay, etc. There is a high risk of sparks caused by conversion.

In the present invention, in order to solve this problem, an ESS (Energy Storage System) module that automatically charges only at light load (midnight power from 23:00 to 9:00) within the same charging parking area, and the power charged in the ESS module is used during medium load and maximum load time It independently composes two sets of chargers that use only AC power as the main ESS charger and the auxiliary. Means to induce the use of an auxiliary AC power grid charger instead of the main ESS charger are included when the electric vehicle cannot be charged because the charging capacity of the ESS is exhausted or during the light load period. The appropriate capacity of the ESS is configured so that 100 cars/day per parking area can be charged by 50%. When charging an average of 30 kWh per electric vehicle, an ESS with a capacity of 3 MWh per charging area is required. In the case of a charging station with about six charging areas, an ESS with a capacity of 18MWh (ESS 80$/kWh, $1.4 million) is required. It is necessary to attach a late-night power meter for charging only with late-night power to the ESS module and automatically charge it during late-night hours.

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 the present specification and claims should not be construed as being limited to conventional or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention. Accordingly, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that there may be equivalents and variations.

1 is an industrial electricity rate system for each light load, medium load, and maximum load time period operated in Korea. For power generation efficiency of power plants, it is necessary to uniformly manage power demand at light load, medium load, and maximum load. In general, the electricity rate at light load is around 35% at full load. 2 is a table of electric vehicle charging rates in Korea and electricity rates supplied by electric charging service providers. 3 is a block diagram of a platform that integrates electric vehicles, electric vehicle charging stations and KEPCO's grid connection, payment system, and operation control system built so far.

4 is a conceptual diagram of an ESS dedicated charging station composed of renewable energy and a power grid. When the electric power charged in the ESS module is exhausted during light load, there is a contradiction in that electric power must be newly charged and used in the ESS module even at maximum load in order to charge the standby electric vehicle. Compared to charging an electric vehicle by converting alternating current to direct current, losses occur while charging the ESS module. 5 is a schematic diagram of a charging device (Korean Patent Registration No. 10-1972773) equipped with a spare ESS module. Since a one-type charging device is used, there is a problem in using a power module that must be used by switching between the spare ESS power and the main AC power. The DC output design cannot be optimized because the AC-DC converter has to supply the electric vehicle charging power while charging the spare ESS module when necessary.

6 is a configuration diagram of the ESS power line and the AC power line of the present invention independently configured, and a main ESS charger (including a kiosk) and an auxiliary AC power grid charger are connected to each power line. In the EV charging station, the main ESS power line and the auxiliary AC power line are independently configured, and two chargers are independently configured in each power line, so that the EV charging infrastructure can be operated stably even during the peak load time. It is configured to automatically charge the ESS module during the light load (midnight power) time period, and the ESS module charging power is mainly configured to charge the electric vehicle at the maximum load, thereby increasing the efficiency of the national power grid and increasing the power ratio. There is a main ESS power charger and an auxiliary AC power grid charger in the same charging parking area, so when the remaining charging power of the ESS module is insufficient or a light load, the use of the auxiliary AC power grid charger is restricted or induced. That is, at light load, the main ESS power charger is blocked and the auxiliary AC power grid charger is used. The charger of the ESS module is used at medium and maximum loads, but if the charging power is insufficient, the main ESS charger is cut off and an auxiliary AC network charger is used. It is efficient to use ESS power first at maximum load, so it can be configured to block the main ESS charger and use the auxiliary AC network charger even at medium load. In winter, the maximum load time is 10:00 to 12:00, 17:00 to 20:00, and 22:00 to 23:00, so it is necessary to conserve ESS power during intermediate load between 12:00 and 17:00.

An electric vehicle charging device comprising: means for configuring an electric vehicle charging station's midnight electric grid (2) and an AC electric power grid (1); The midnight power grid 2 includes means for charging the ESS module 4 through the light load ESS charging device 3 during the light load time (currently 23:00 to 09:00); means for converting the power charged in the ESS module 4 into a charging voltage required by the electric vehicle through the ESS power module 5 to form the main charging power 7 on the main power line; means for receiving the AC from the AC power grid 3 and converting it to a charging voltage required by the electric vehicle to form the auxiliary charging power 11 on the auxiliary power line; means for installing the main ESS charger 8 connected to the main charging power 7 and the auxiliary AC power grid charger 9 connected to the auxiliary charging power 11 in the same charging parking area 10, respectively; means for repeatedly installing a plurality of charging and parking areas (10); The electric vehicle 13 is configured to select and charge the main ESS charger 8 and the auxiliary AC power grid charger 9 . In other words, it provides an electric vehicle charging station for charging electric vehicles by installing two chargers in the same charging and parking area, and a main selling method and a charging method for the electric power charged in the ESS module at night time.

Inducing device for inducing the use of the auxiliary AC power grid charger 9 instead of the main ESS charger 8 when the remaining charging capacity of the ESS module 4 is insufficient or during the light load time (23:00 ~ 09:00) (12) is included. In order to use ESS power first at maximum load, it can be configured to cut off the main ESS charger and use an auxiliary AC network charger even at medium load. In particular, in winter, the maximum load is mainly from 10:00 to 12:00, 17:00 to 20:00, and 22:00 to 23:00, so it is necessary to efficiently manage the use of ESS modules in the morning. That is, an electric vehicle charging station using an ESS module charged during a light load time as main charging power, a charger equipped with a use inducing device, and a charging method are provided. The use inducement device 12 includes a passive means for indicating available (O) and impossible (X) and an active means for prohibiting use (eg, power off the charger kiosk).

At light load time (23:00 ~ 09:00), the ESS charging device (3) connected to the late-night power grid (2) of the power company includes a late-night power meter; and means for converting alternating current to direct current (AC-DC converter), and is configured to automatically charge the ESS module 4 . An electric vehicle charging station that uses the ESS module charged during the light load time as the main charging power is configured. The power charged in the ESS module (4) is set to the charging voltage (300V ~ 400V) required by the electric vehicle, so that the main charging power (7) is provided to the main power line even if a separate ESS power module (5) is not used. can do. One high-capacity AC power module 6 can be used, but it can also be obtained by including the small-capacity AC power module 6 in each auxiliary AC power grid charger 9 .

1: AC power grid 2: midnight power grid
3: ESS charging device under light load 4: ESS module
5: ESS power module 6: AC power module
7: main charging power 8: main ESS charger
9: auxiliary AC power grid charger 10: charging parking area
11: auxiliary charging power 12: use induction device
13: electric car

Claims (7)

In the electric vehicle charging device,
means for configuring the midnight power grid (2) and the AC power grid (1) of the electric vehicle charging station;
means for charging the ESS module 4 through the light load ESS charging device 3 during the light load time (currently 23:00 to 09:00) to the late-night power grid 2 ;
means for converting the power charged in the ESS module (4) into a charging voltage required by the electric vehicle through the ESS power module (5) to form the main charging power (7) in the main power line;
means for receiving the AC from the AC power grid 3 and converting it into a charging voltage required by the electric vehicle to form the auxiliary charging power 11 on the auxiliary power line;
means for installing the main ESS charger 8 connected to the main charging power 7 and the auxiliary AC power grid charger 9 connected to the auxiliary charging power 11 in the same charging parking area 10, respectively; means for repeatedly installing the charging parking area 10 in a plurality of cases;
In the electric vehicle 13, two chargers are installed in the same charging parking area, characterized in that the main ESS charger 8 and the auxiliary AC power grid charger 9 are selected and charged. How to sell the power charged in the ESS module as main, how to charge
According to claim 1,
Inducing device for inducing the use of the auxiliary AC grid charger 9 instead of the main ESS charger 8 when the remaining charging capacity of the ESS module 4 is insufficient, or during light load time (23:00 ~ 09:00) An electric vehicle charging station that uses the ESS module charged during the light load time period comprising (12) as the main charging power and a charger equipped with an induction device and charging method
According to claim 1,
When the shortage of charging power of the ESS module 4 is expected at maximum load;
In order to preferentially use the main ESS power at the maximum load, the ESS module charging power is preferentially charged at the maximum load, characterized in that the main ESS charger (8) is cut off and the auxiliary AC network charger (9) is used even at an intermediate load. Charging stations for electric vehicles used, chargers equipped with use-inducing devices, and charging methods
According to claim 2,
As the use guide device (12),
A charger and charging method equipped with a use inducement device comprising passive means for indicating available (O) and unavailable (X) and active means such as turning off the power of the charger
According to claim 1,
At light load hours (23:00 to 09:00)
The ESS charging device (3) connected to the power company’s late-night power grid (2) has
late night electricity meter; and
means for converting alternating current to direct current (AC-DC converter);
Electric vehicle charging station using the ESS module charged during the light load time, characterized in that it is configured to charge the ESS module (4) as the main charging power
According to claim 1,
The power charged in the ESS module (4) is set to the charging voltage required by the electric vehicle, and the main charging power (7) is provided to the main power line even if a separate ESS power module (5) is not used. An electric vehicle charging station that uses the ESS module charged in the
According to claim 1,
Auxiliary AC network charger, characterized in that instead of one high-capacity AC power module (6), a small-capacity AC power module is included in each auxiliary AC power grid charger (9)

Images