KR102246252B1 - Electric vehicle charger applied fast demand response in ancillary service of electric power system, method and apparatus for controlling charging poser of the electric vehicle charger - Google Patents

Abstract

The present invention relates to an electric vehicle charger for high-speed demand response to respond to a change and intermittency in real time in a renewable energy-based power system. The electric vehicle charger according to an embodiment includes: a charging unit for supplying power to charge an electric vehicle; a frequency measuring unit that measures the frequency of an electric power system in real time during charging of the electric vehicle; and a power control unit that determines a step corresponding to the measured frequency based on a control criterion including a plurality of step-by-step charging power control ratios divided according to a preset frequency fluctuation range compared to a reference frequency, and automatically adjusts the charging rate of the electric vehicle according to the charging power control rate of the determined step.

Description

ELECTRIC VEHICLE CHARGER APPLIED FAST DEMAND RESPONSE IN ANCILLARY SERVICE OF ELECTRIC POWER SYSTEM, METHOD AND APPARATUS FOR CONTROLLING CHARGING POSER OF THE ELECTRIC VEHICLE CHARGER}

It relates to electric vehicle charger control technology to which Fast DR (Fast Demand Response) is applied to power system auxiliary services. More specifically, it relates to a method of controlling charging power of an electric vehicle charger for fast demand response based on renewable energy and the charger of the electric vehicle. To prepare for the volatility of new and renewable energy in the power system or strengthening the flexibility of the power system. For this purpose, it relates to a technology that controls the amount of charging power according to frequency fluctuations during charging of electric vehicles in real time.

Recently, as an energy policy target, the government proposed a target for the proportion of new and renewable energy generation by 2030 as 20%. Looking at the supply target for 2030, the total amount of generation of solar and wind power generations, which varies greatly among new and renewable energies, is from the total generation amount. It is expected to account for about 13%. As the supply of new and renewable energy increases, the necessity of securing the required amount of flexibility of the electric power system has emerged greatly. In order to secure the reserve power of the power system, various methods such as improvement of the power market system, improvement of power system operation, pumping power generation, energy storage system (ESS) for frequency control, demand response resource (DR), etc. are being implemented.

Power system operating institutions are securing reserves by participating in demand response resources, which are non-generator resources, as auxiliary services. The reserve power to which the demand-response resource participates is divided into frequency adjustment reserve, automatic power generation control reserve, and standby/substitute reserve, and it is classified according to the technical characteristics of the demand-response resource by presenting the required level of each reserve. It is being utilized as. In Korea, various studies are being conducted by applying mutatis mutandis that demand response resources are participating as auxiliary services, but the current system operation auxiliary service detailed operation standards only stipulate the operation of generators and electricity storage devices. There is a need for a system and plan for auxiliary services of demand-response resources, and a plan is needed to secure reserve power for the power system by participating as auxiliary services for resources that are expected to expand and demand such as electric vehicle chargers. .

There are about 80,000 electric vehicles in 2019, and over 20,000 electric vehicle chargers as of the end of 2019, and are increasing significantly every year. In addition, even if there is a problem with the flexibility of the power system due to the increase in new and renewable energy, the amount of power consumed by charging the electric vehicle is expected to consume about one thermal power plant, and the amount of power required will continue to increase with the increase of electric vehicles. It is judged to be. The technology currently being researched is V2G, and a method of securing the stability of the system is being studied by determining the amount of electric power by the demand management service provider and sending the electric power of the vehicle back to the grid. However, in reality, electric vehicle reverse transmission technology is in the technology development stage, and the government's policy on such reverse transmission has not been established.

Therefore, technology as an auxiliary service that secures the stability of the power system by efficiently controlling the charging power of electric vehicle chargers that require a lot of power demand in case of unbalanced power supply and demand due to the intermittentness of the power system due to the increase of new and renewable energy is urgently needed. Is being demanded.

Republic of Korea Patent Publication No. 10-2015-0130568

The present invention is an electricity that plays the role of a frequency adjustment reserve in a fast demand response in order to adjust the demand of the power system in preparation for the volatility of new and renewable energy linked to the power system or a credible accident of the power system. An object of the present invention is to provide a vehicle charger and a method of controlling charging power of an electric vehicle.

According to one aspect, the electric vehicle charger to which Fast DR is applied to the power system auxiliary service is an electric vehicle charger to which Fast DR is applied to the power system auxiliary service, and a charging unit that charges the electric vehicle by supplying power, and the frequency of the power system during charging of the electric vehicle. A frequency measurement unit that measures in real time and a step corresponding to the measured frequency is determined based on a control criterion including a plurality of step-by-step charging power control ratios divided according to a preset frequency fluctuation compared to a reference frequency, and charging of the determined step It may include a power control unit that automatically adjusts the charging ratio of the electric vehicle according to the power control ratio.

At this time, the control standard is set to the same standard for all electric vehicle chargers, or is set differently for each electric vehicle type, electric vehicle charger group, or time slot, and the electric vehicle charger group is a demand management service provider, customers participating in high-speed demand response, and the installation location of the electric vehicle charger. It can be classified on the basis of at least one of.

When the charging rate of the electric vehicle is adjusted according to the measured frequency, the power control unit may maintain the adjusted charging rate for a predetermined time.

The charging power control device of the electric vehicle charger to which Fast DR is applied to the power system auxiliary service according to an aspect determines whether the electric vehicle charger is charged, and a charge determination unit that controls the frequency measurement of the frequency measurement unit according to whether the electric vehicle is charged, and the electric vehicle is charged. The step corresponding to the measured frequency is determined based on a control criterion including a frequency measuring unit that measures the frequency of the power system in real time and a plurality of step-by-step charging power control ratios divided according to a preset frequency fluctuation compared to the reference frequency, and And a power control unit that automatically adjusts the charging ratio of the electric vehicle according to the charging power control ratio of the determined step.

According to the present invention, first, when charging an electric vehicle, the electric vehicle charger detects the frequency of the power system and controls the amount of charging power according to the frequency, thereby performing the role of a frequency adjustment reserve that can quickly respond to the variability of new and renewable energy. In this way, it is possible to secure the flexibility of the power system to prepare for the volatility of new and renewable energy and the assumed accident of the power system. Currently, there is no market for auxiliary services for power systems in Korea, but it can be used to secure the frequency stability of the system through high-speed demand management resources when the market is opened in the future.

Second, it is possible to perform an auxiliary role of the frequency control ESS linked to the high-speed demand management project. As of 2019, there are more than 20,000 electric vehicle charging stations, and with an average of 5KW, there is an effect of frequency auxiliary service of about 100MW. It can be extended to an eco-friendly system that plays the role of a virtual power plant that is not affected by the amount of facilities and maintenance fees for the ESS of the frequency auxiliary service installed by the existing power agency.

Third, through the present invention, it is easy to install a power control and cut-off device through frequency measurement in a large amount of electric chargers currently installed and can be easily expanded because it operates on its own, so it is economical as an auxiliary service means responding to the volatility of new and renewable energy. It is possible to apply.

Fourth, through the present invention, it is possible to replace the existing ESS for frequency control by adding simple equipment in the electric vehicle charger, resulting in an economical effect. In addition, by adding power demand management products when charging electric vehicles, incentive benefits can be provided to electric vehicle charging stations and electric vehicle owners through power demand management.

1 is a diagram illustrating a high-speed demand response system including an electric vehicle charger to which Fast DR is applied to an auxiliary power system service.
2 is a block diagram of an electric vehicle charger according to an embodiment.
3 is a block diagram of an apparatus for controlling charging power of an electric vehicle charger according to an exemplary embodiment.
4 is a flowchart illustrating a method of controlling charging power in an electric vehicle charger according to an exemplary embodiment.
5 is a detailed flowchart of an electric vehicle charging power control step 420 according to an exemplary embodiment.

Details of other embodiments are included in the detailed description and drawings. Advantages and features of the described technology, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the drawings. The same reference numerals refer to the same elements throughout the specification.

Terms such as first and second may be used to describe various components, but the components should not be limited by terms. The terms are used only for the purpose of distinguishing one component from other components. Singular expressions include plural expressions unless the context clearly indicates otherwise. In addition, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary. In addition, terms such as "... unit" and "module" described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software.

Hereinafter, embodiments of an electric vehicle charger to which Fast DR is applied to a power system auxiliary service, a charging power control method of the electric vehicle charger, and a charging power control apparatus of the electric vehicle charger will be described with reference to the drawings.

1 is a diagram illustrating a high-speed demand response system including an electric vehicle charger to which Fast DR is applied to an auxiliary power system service.

As shown in FIG. 1, the production of power supply includes a generator with limited resources and renewable energy. The generators included in the domestic power system maintain a frequency of 60Hz±0.2Hz in generating and supplying electricity, but the renewable energy generation resources are weather conditions such as the location of the sun, wind strength, and weather. It is a resource that is very much affected by the power system, and due to the variability, it may be difficult to maintain the commercial frequency of the power system.

Accordingly, according to the present embodiments, when the power system is unstable while charging the electric vehicle (EV), the electric vehicle charger 10 controls the amount of electric vehicle charging power until the frequency is recovered, thereby improving the stability of the power system. .

Existing V2G (Vehicle To Grid) technology is a concept of connecting rechargeable eco-friendly vehicles such as electric vehicle battery vehicles and plug-in hybrid vehicles with the power grid to use the remaining power during parking.The electric vehicle is charged through the power grid and then the remaining electricity is transmitted back to the power grid. (Discharging) is a method that operates as an energy storage system (ESS·Energy Storage System) in which electric vehicles move.

However, these embodiments determine the frequency of the power system within the electric vehicle charger 10 itself to automatically cut off the charging power or control it at a predetermined ratio, and transmit the cutoff or controlled result to the demand management service provider 20 to obtain the corresponding result. It is different from the existing V2G technology in that it is a structure that receives compensation for. The technology through V2G is difficult to apply to high-speed demand management because it takes more than 30 minutes because the central center determines and controls power. This technology is installed in the electric vehicle charger to automatically shut off, and only the part of the set value that is automatically shut off can be controlled from the center. It is an advantage that the system can respond quickly, and it is a way to perform the role of the governor (GF) of the generator.

The electric vehicle charger 10 according to the present embodiment supplies power to the electric vehicle in response to a user's request for charging the electric vehicle. In addition, when charging the electric vehicle starts, the electric vehicle charger 10 may measure a frequency of the power system and control the charging power of the electric vehicle according to the measured frequency and a preset charging control standard. In this case, the charging control criterion may be set equally for all electric vehicle chargers. Alternatively, it may be set differently for each demand management service provider, for each customer, for each electric vehicle, for each electric vehicle group, for each time slot, for each electric vehicle target charging amount, remaining charging amount, remaining charging time, or a combination thereof.

For example, the charging control criterion may include a reference range, a control method, or a control time. The reference range is a frequency fluctuation width compared to a reference frequency (eg, 60Hz), and may be set in one or more steps. The control method may be a charging power cut-off, a step-by-step charging rate adjustment method, and/or a charging rate control. The control time is to adjust the blocking, charging rate and/or charging speed for a preset time (e.g. 30 seconds) according to the charging power control method, or to maintain the charging power control until the measurement frequency falls within the reference range. Can be.

As an example, the charging control criterion is to set the reference range to ±0.2Hz, and if the measurement frequency is out of the reference range compared to the reference frequency, the charging power supply is cut off in real time, such as within 3 seconds, and the cut off state is maintained for 30 seconds and then cut off Can be turned off automatically. Alternatively, it may be set to release the blocking when the frequency measured in real time again falls within the reference range after the supply of charging power is temporarily cut off.

As another example, the charging control criterion is to set the charging power control ratio for each step by dividing the reference range into a plurality of steps by dividing the frequency fluctuation relative to the reference frequency, and charging the electric vehicle according to the charging power control ratio of the step corresponding to the measured frequency. It can be set to adjust the ratio. In this case, the charging rate control may be set to be maintained for a predetermined time, eg, 30 seconds, or the frequency measured in real time may be set to be adjusted in real time with the charging power control rate of a corresponding step. Table 1 below is an example of a preset step-by-step charging power control ratio, but is not limited thereto, and may be variously modified.

Measurement frequency range (Hz) Power control rate (%) Remark 60.20 or more 0 Maximum charge possible 59.80 ~ less than 60.20 5 5% power secured 59.70 ~ less than 59.80 10 Power control ratio adjustable 59.60 ~ less than 59.70 50 Power control ratio adjustable Less than 59.60 100 Block charger charging

As another example, the charging control criterion may be set to adjust the charging speed when the fluctuation range of the measurement frequency relative to the reference frequency is out of a reference range. The reason why the charger is set to be able to charge more than 100% of the power of the charger above 60.2Hz is to be able to prepare for the upper frequency of the system, and it is applied to a number of chargers by adjusting the ratio of the power amount of the charger to less than 59.8, the standard of auxiliary service. It can be simulated so that the demand management service provider can adjust it through the set value. Since a number of chargers are automatically adjusted step by step when the frequency of the system decreases, the inertia rate for the decrease in power can be increased, and the system can be set to respond effectively even when the system frequency is restored. The power control ratio can be dynamically set by the demand management service provider, and the power control operation can be set to operate through the charger's own control device.

As another example, the charging control criterion may be set by combining a fluctuation range of a measurement frequency, a target charging amount that the user wants to charge, an estimated remaining charging amount, and an estimated remaining charging time. For example, by combining the fluctuation of the measured frequency and the expected remaining charging time or remaining charge amount of the electric vehicle at the time of measuring the frequency, the measured frequency fluctuation is out of the reference range and at the same time, the remaining charging time or remaining charge exceeds a predetermined threshold. It can be set to cut off the power supply in case. According to this, even if the frequency fluctuation of the electric vehicle is outside the standard range and the charging power needs to be cut off, if charging can be completed within a short time at that point, charging can be continued without cutting off the power supply. Phosphorus response is possible.

Examples of the above-described charging control criteria are not particularly limited to any one, and two or more charging control criteria described above may be combined.

The electric vehicle charger 10 may transmit electric vehicle charging performance data, such as measured frequency data and controlled charging power amount data, to the demand management service provider 20 for incentive calculation.

The demand management service provider (20) is an organization that manages the Fast Demand Response business, recruiting customers to participate in Fast Demand Response, setting standards for fast demand response to customers, and responding to demand. You can manage performance, etc.

For example, the demand management service provider 20 manages apartments, charging stations, and public institutions that manage the electric vehicle charger 10 as customers who will participate in the high-speed demand response business, and the installation location of the electric vehicle charger 10 to participate for each customer. , The number of participants, charging control standards, etc. can be managed.

The demand management service provider 20 may communicate with the electric vehicle charger 10 and the power operating institution 30 and transmit and receive data on a high-speed demand response. For example, in order to calculate an incentive according to the performance of participation in high-speed demand response, performance data such as measured frequency data and controlled charging power amount may be received from the electric vehicle charger 10. In addition, by using the performance data of each electric vehicle charger 10, incentives may be calculated for each electric vehicle charger, each customer who manages the electric vehicle charger, or various other criteria.

The power operating institution 30 may be installed in a power system operating institution (ISO) such as Korea Electric Power (KEPCO) and the Korea Power Exchange (KPX). The power operating institution 30 is the contracted capacity of customers participating in the power management business, and It is possible to support stable operation of the power system by collecting information such as real-time power quantity and load blocking performance, and grasping the status of fast demand response in real time using the collected information.

The power operating institution 30 may collect the current status of the participating electric vehicle charger 10 in real-time usage capacity, controlled charging power amount, and the like. The power operating institution 30 can comprehensively analyze and monitor the collected data and, in connection with the power system 40, can grasp the power fluctuation trend of the participating electric vehicle charger 10 in real time and the status of the system frequency.

The power operating agency 30 is provided by the demand management service provider (20), where the electric vehicle chargers (10) are installed by customers participating in the power management business, the number of electric vehicle chargers (10) to be participated, the time of use of the electric vehicle chargers, contracted capacity, and controlled charging power. Data such as capacity can be collected. In addition, the power operating institution 30 may classify and collect data collected from the demand management service provider 20 by electric vehicle charger 10, customer, electric vehicle charger group, or customer group. However, it is not limited thereto.

In addition, the power operating institution 30 calculates and calculates incentives according to the basic settlement amount of fast demand response resources for electric vehicle chargers and/or the controlled charging capacity of the electric vehicle charger 10 of customers participating in the high-speed demand response business. The incentive details can be transmitted to the demand management service provider (20).

2 is a block diagram of an electric vehicle charger according to an embodiment.

Referring to FIG. 2, the electric vehicle charger 200 includes a charging support unit 210, a charging unit 220, and a power control device 230.

The electric vehicle charger 200 may have a form including a separate body and a charging cable extending from the body and supplying power to the electric vehicle. In this case, the charging support unit 210, the charging unit 220, and the power control device 230 may be mounted in the main body. Alternatively, the electric vehicle charger 200 may have an outlet embedded in a wall such as a parking lot such as an apartment or building, and a charging cable connected from the outlet to supply power to the electric vehicle. At this time, some functions related to electric vehicle charging, such as a communication module and a power control device 230, may be mounted separately from other components on the charging cable.

The charging support unit 210 supports various operations related to electric vehicle charging. For example, the charging support unit 210 may include an interface that receives a charging request from a user and outputs charging-related guide information to the user.

The interface may include, for example, an RFID reader for recognizing a user's RFID card or an RFID tag attached to an electric vehicle. In addition, the charging support unit 210 may authenticate the user or the electric vehicle when the user contacts the RFID card or RFID tag with the RFID reader. However, the present invention is not limited thereto, and user authentication may be performed in various predefined ways, such as inputting registered user information and electric vehicle information such as an electric vehicle number. It is to provide incentives to users in the future by determining whether to participate in the high-speed demand management through user authentication.

When authentication is complete, the charging support unit 210 provides information on charging, such as connection of a charging cable, charging progress, charging completion, charging time, measurement frequency, charging control according to frequency fluctuations, charging cost, charging power amount according to charging control, etc. It may include a display that visually outputs a text or an icon to guide the information, a speaker module that outputs the information as a voice, and an LED warning light to guide that charging is being controlled.

The charging support unit 210 may also receive a target charging amount of the electric vehicle desired by the user through the interface. When the user authentication is completed and the target charging amount is received, the charging support unit 210 may transmit an operation signal to the charging unit 220.

When the user authentication is completed, the charging support unit 210 checks the type of electric vehicle registered for the user or the maximum chargeable power of the electric vehicle to be charged by performing direct communication with the electric vehicle, and determines the maximum power that can be charged to the charging unit 220 By sending it to

In addition, the charging support unit 210 is set so that, when the manager of the electric vehicle charger 200 sets or changes the charging control standard of the electric vehicle charger 200 through an interface, the power control device 230 can use it for charging power control. Alternatively, the changed charging control criterion may be received and stored in a memory (not shown). The memory refers to various devices that store data, and may include, but is not limited to, a flash memory, a RAM, an optical data device, and the like.

When an operation signal is received from the charging support unit 210, the charging unit 220 determines whether the charging cable is connected to the electric vehicle to determine whether the charging is possible, and when the charging is possible, can supply power to the electric vehicle.

In addition, when the charging amount of the electric vehicle reaches the target charging amount, the charging unit 220 may stop supplying power and transmit a charging completion signal to the charging support unit 220.

The power control device 230 monitors the variability of the power system based on renewable energy while charging the electric vehicle by the charging unit 220, and when instability of the power system occurs, the charging unit 220 controls the electric vehicle in real time. You can temporarily block charging, adjust the charging rate or adjust the charging speed according to the step-by-step charging power control rate.

Hereinafter, embodiments of the power control device 230 will be described in more detail with reference to FIG. 3.

3 is a block diagram of an apparatus for controlling charging power of an electric vehicle charger according to an exemplary embodiment. The power control device according to an embodiment may be integrally formed in the form of a control circuit inside the electric vehicle charger 200 described above. In addition, the power control device may be manufactured as a separate small module and mounted on a device that remotely controls an electric vehicle charger. Alternatively, the power control device itself may be formed as a separate hardware device to be electrically connected to the electric vehicle charger or to control the electric vehicle charger through a wireless communication connection.

Referring to FIG. 3, the power control device 300 may include a charge determination unit 310, a frequency measurement unit 320, a power control unit 330, and a communication unit 340.

Referring to FIGS. 2 and 3, the charging determination unit 310 may monitor whether the charging unit 220 is in progress in real time, and when charging starts, a signal for starting the frequency measurement to the frequency measurement unit 320 may be transmitted. . When the charging of the charging unit 220 is completed, the charging determination unit 310 may transmit a signal for terminating the frequency measurement to the frequency measurement unit 320.

The frequency measurement unit 320 may include a meter, and when a measurement signal is received from the charging determination unit 310, it measures a real-time power system frequency and transmits the measured frequency to the power control unit 330. The frequency measurement unit 320 may terminate the power system frequency measurement when a measurement termination signal is received from the charging determination unit 310.

When the measurement frequency data is received from the frequency measurement unit 320, the power control unit 330 determines whether the measurement frequency corresponds to a preset control criterion by referring to the charging control criterion stored in the memory, and if it corresponds to the control criterion, the charging unit 220 ) To control the charging power of the electric vehicle.

For example, when the control criterion is set to cut off the power supply when the measurement frequency is outside the range of ±0.2 compared to the rated frequency 60Hz, and release the cutoff when the frequency falls within the range of ±0.2 compared to the rated frequency 60Hz, the power control unit 330 When the measurement frequency is less than 59.8Hz, power supply may be temporarily cut off by controlling the charging unit 220. After the power supply is temporarily cut off, if the measured frequency received from the frequency measurement unit 320 in real time is within 59.8Hz to 60Hz, the power supply cutoff may be released.

As another example, when the control criterion is set to cut off the power supply for 30 seconds when the measurement frequency falls below the rated frequency 59.8Hz, the power control unit 330 generates a power cutoff signal within 3 seconds when the measurement frequency is 59.78Hz, and The cutoff can be automatically released when the power supply cutoff is maintained for 30 seconds and the cutoff is automatically released after 30 seconds, or if the frequency of the system is recovered as a result of the judgment by judging the frequency recovery status of the system, the cutoff can be released.

As another example, as shown in Table 1 above, when the charging power control ratio is set differently in a plurality of steps divided by the frequency fluctuation width unit, the power control unit 330 is Electric vehicle charging can be controlled by applying a power control ratio. For example, when the measurement frequency is 59.85Hz, referring to Table 1 above, the charging power control ratio is 5%. In this case, the power control unit 330 may control the electric vehicle to be charged at 95% of the target charging power by applying a power control ratio of 5% to the original target charging power amount of the electric vehicle set by the user. In this way, until the frequency is stabilized, the risky level of the frequency is applied step by step to induce the effect of reducing the power demand. The embodiments of the electric vehicle charging power control have been described above, but the present invention is not limited thereto.

According to another example, when the charging control criterion is set to a rapid charging method if the charging control criterion is within 59.8 Hz, and a slow charging method when the charging control standard is out of 59.8 Hz, the power control unit 330 sets the electric vehicle charging method rapidly or slowly according to the measured frequency. It can be controlled variably.

According to another example, when the control criterion is set to cut off the power supply when the control criterion falls below 59.8 Hz and the estimated remaining charging time or the remaining charging amount exceeds a predetermined threshold, the power control unit 330 If is 59.75Hz, the estimated remaining charging time or remaining charging amount information is received from the charging unit 220, and when the estimated remaining charging time or remaining charging exceeds a threshold, power supply may be cut off, and if it is within the threshold, the power supply may not be cut off. .

Meanwhile, the charging control criteria illustrated above may be combined with each other. In addition, a standard for controlling the charging speed may be set differently by combining one or more of a charging speed preferred by the user, a charging time period, and the like.

The communication unit 340 may communicate with an electric vehicle, a terminal of an electric vehicle user, an electric vehicle charger management server, a terminal of an electric vehicle charger manager, or a demand management service provider. At this time, the communication unit 340 includes Bluetooth communication, BLE (Bluetooth Low Energy) communication, near field communication (NFC), WLAN communication, Zigbee communication, infrared (Infrared Data Association, IrDA) communication. , Wi-Fi Direct (WFD) communication, ultra-wideband (UWB) communication, Ant+ communication, WIFI communication, RFID (Radio Frequency Identification) communication, 3G communication, 4G communication and 5G communication, etc., but are not limited thereto. .

For example, the communication unit 340 may communicate with the electric vehicle to receive information such as the type of the electric vehicle and the maximum charging power of the electric vehicle. In addition, when charging is completed, the communication unit 340 transmits information such as charging date and time, charging power amount, charging control amount, and charging cost to the electric vehicle to be stored in the memory of the electric vehicle. You can apply to make information easier to check. In addition, the communication unit 340 may transmit charging-related information, such as whether charging is completed, charging cost, charging power amount, and charging control amount, to a terminal of a pre-registered electric vehicle user.

In addition, the communication unit 340 transmits the authenticated user information according to the user's charging request, and the charging-related information when charging of the electric vehicle is completed, to a management server such as an electric vehicle charger management office, such as a management office such as an apartment, or a public institution. It can be used for settlement of expenses, such as billing.

In addition, the communication unit 340 may transmit data such as measured frequency data and controlled charging power amount of the electric vehicle charger to the demand management service provider to calculate an incentive according to the power control performance of the electric vehicle charger.

4 is a flowchart of a method of controlling charging power in an electric vehicle charger according to an exemplary embodiment. 5 is a detailed flowchart of an electric vehicle charging power control step 420 according to an exemplary embodiment. 4 and 5 may be performed by the electric vehicle charger 200 according to the embodiment of FIG. 2.

Referring to FIG. 4, when an electric vehicle charging request is received from a user, the electric vehicle charger 200 may charge the electric vehicle by supplying power to the electric vehicle (410). The user performs user authentication through various predefined methods, such as RFID card recognition, user information input, electric vehicle information, such as electric vehicle number, etc., through the interface of the electric vehicle charger 200, and inputs a target charge amount when user authentication is completed. By doing so, you can enter a charge request. When a charging request is input, the electric vehicle charger 200 guides information necessary for charging, such as connection of a charging cable, and when the charging cable is connected to the electric vehicle, it may start supplying power to the electric vehicle. In addition, the electric vehicle charger 200 may output information about charging, charging completion, charging cost, charging amount, and the like to the user.

Then, in step 410, whether charging of the electric vehicle starts, and when charging of the electric vehicle starts, the electric vehicle charging power may be controlled (420).

Referring to FIG. 5, the charging determination unit of the electric vehicle charger may monitor whether the electric vehicle is charged in real time (510). The charging determination unit of the electric vehicle charger may control frequency measurement according to whether the electric vehicle is charged. For example, when charging of the electric vehicle starts, an operation signal for measuring the frequency of the power system may be transmitted to the frequency measuring unit, and an operation signal for ending the frequency measurement when the electric vehicle is finished charging may be transmitted.

Then, when the frequency measurement operation signal of the electric vehicle charger is received, the frequency measurement unit may perform frequency measurement and transmit the measured frequency data to the power control unit (520 ).

Then, the power control unit of the electric vehicle charger may determine whether the measurement frequency corresponds to the control criterion (530 ). For example, the control criterion may be variously set based on the variation width of the measurement frequency compared to the reference frequency, as described above.

Then, as a result of determination in step 530, if the measurement frequency corresponds to the control criterion, the electric vehicle charging power may be controlled (540). For example, the power supply can be cut off when the variation of the measurement frequency relative to the reference frequency exceeds 0.2 Hz. As another example, the charging power may be controlled according to the charging power control ratio set in the step in which the measurement frequency corresponds. Since this has been described in detail above, a detailed description will be omitted below.

If the real-time frequency measured in step 520 does not correspond to the frequency control criterion after the charging power is cut off or the charging rate is adjusted in step 540 (530), that is, the frequency of the power system is restored to a stable state. If so, the temporary blocking state may be canceled or charged at a normal charging rate (550).

According to the embodiments of the present invention disclosed above, it is possible to immediately respond to real-time frequency fluctuations in a power system based on renewable energy, thereby increasing the flexibility of the power system. In particular, even if there is a problem with the flexibility of the current renewable energy-based power system, the amount of power consumed by electric vehicle charging is very large, but the V2G technology currently being researched to solve this problem is still in the early stage of technology and government policy is also Not established. In addition, the V2G technology is fundamentally different from the embodiments of the present invention. According to the disclosed embodiments, it is possible to effectively solve the power system stability problem caused by electric vehicle charging in a renewable energy-based power system due to the spread of electric vehicles expected to increase rapidly in the future.

Meanwhile, the embodiments may be implemented as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes all types of recording devices that store data that can be read by a computer system.

Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tapes, floppy disks, optical data storage devices, and the like. Includes. Further, the computer-readable recording medium is distributed over a computer system connected by a network, so that computer-readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the embodiments can be easily inferred by programmers in the technical field to which the present invention belongs.

Those of ordinary skill in the art to which the present disclosure pertains will appreciate that it may be implemented in other specific forms without changing the disclosed technical idea or essential features. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects.

200: electric vehicle charger 210: charging support unit
220: charging unit 230,300: power control device
310: charging determination unit 320: frequency measurement unit
330: power control unit 340: communication unit

Claims (4)

In the electric vehicle charger to which Fast DR is applied to the power system auxiliary service,
A charging unit for charging the electric vehicle by supplying electric power;
A frequency measurement unit that measures a frequency of a power system during charging of the electric vehicle in real time; And
A step corresponding to the measured frequency is determined based on a control criterion including a plurality of step-by-step charging power control ratios divided according to a preset frequency fluctuation compared to a reference frequency, and the electric vehicle is Includes a power control unit that automatically adjusts the charging rate,
The above control criteria are
All electric vehicle chargers are set with the same standard, or differently for each electric vehicle type, electric vehicle charger group, or time slot,
The electric vehicle charger group is
Electric vehicle chargers with Fast DR applied to power system auxiliary services classified on the basis of at least one of a demand management service provider, a customer participating in high-speed demand response, and an installation location of an electric vehicle charger. delete The method of claim 1,
The power control unit
When the charging rate of the electric vehicle is adjusted according to the measured frequency, Fast DR is applied to a power system auxiliary service that maintains the adjusted charging rate for a predetermined time. A charging determination unit determining whether the electric vehicle charger is charged, and controlling a frequency measurement of the frequency measurement unit according to whether or not the electric vehicle charger is charged;
A frequency measurement unit that measures a frequency of a power system during charging of the electric vehicle in real time; And
A step corresponding to the measured frequency is determined based on a control criterion including a plurality of step-by-step charging power control ratios divided according to a preset frequency fluctuation compared to a reference frequency, and the electric vehicle is Includes a power control unit that automatically adjusts the charging rate,
The above control criteria are
All electric vehicle chargers are set with the same standard, or differently for each electric vehicle type, electric vehicle charger group, or time slot,
The electric vehicle charger group is
A charging power control device for electric vehicle chargers with Fast DR applied to power system auxiliary services classified based on at least one of a demand management service provider, a customer participating in high-speed demand response, and an electric vehicle charger installation location.

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