Charge / discharge control system and charge / discharge control method
The charge/discharge control system uses power company meters to calculate average power consumption, addressing complex configurations and costs in electric vehicle charging by determining chargeable/dischargeable power, ensuring efficient and rapid charging without real-time surplus detection.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KYUDEN TECHNOSYST CORP
- Filing Date
- 2022-03-14
- Publication Date
- 2026-05-13
AI Technical Summary
Existing charging systems for electric vehicles require complex configurations and high costs due to the need for dedicated power conditioners and multiple power detection units, which complicate the management of power consumption and limit rapid charging.
A charge/discharge control system utilizing a power meter installed by the power company to calculate average power consumption over 30-minute intervals, determining chargeable/dischargeable power based on contract limits, allowing efficient control without real-time surplus power detection.
Enables efficient and cost-effective charging and discharging of electric vehicles by using existing power meters, preventing power contract exceedance and reducing the need for dedicated PCS, thereby facilitating rapid charging.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a device that charges and discharges electric power supplied from an electric power company to a charging target such as an in-vehicle battery of an electric vehicle. The present invention relates to a charge-discharge control system that enables management of demand power with a simple configuration using a metering power meter (maximum demand power meter) installed by an electric power company, and a charge-discharge control method using this system.
Background Art
[0002] In recent years, various electric vehicles (HV, EV, PHV) have been sold by various manufacturers. However, in order to popularize electric vehicles (EV) that are driven only by the power of the in-vehicle battery, infrastructure development such as the installation of charging stations is essential. Charging stations for electric vehicles installed in various commercial facilities, transportation facilities, public facilities, etc. have a load equipment and a charger for electric vehicles connected in parallel to a power supply line connected to a commercial power supply. The load equipment is a load owned by the installer of the charging station, and includes, for example, existing air conditioning equipment, lighting fixtures, electric motors, etc. to which commercial power is supplied. The charger for electric vehicles includes a power converter, performs power conversion according to the rated power value of the charger, outputs DC power, and charges the in-vehicle battery of an electric vehicle (EV).
[0003] When charging the in-vehicle battery, the sum of the power consumption value by the load equipment and the charging power value by the charger cannot exceed the contract power value between the electric power company and the installer of the charging station. Also, the power consumption by the load equipment is not always constant and varies depending on season, time zone, weather, etc. Since it is necessary to prioritize power supply to the load equipment, the charging power value to the electric vehicle will be used within a certain power value range set relatively low. Therefore, when there is little power available for charging, the charging time becomes long, resulting in the inconvenience that so-called rapid charging becomes impossible.
[0004] To address these inconveniences, a charging system has been proposed that focuses on the fact that power consumption by existing load equipment fluctuates, and by making maximum use of surplus power that fluctuates according to power consumption within the allowable power range that the load equipment can consume, thereby shortening the charging time (see Patent Document 1). [Prior art documents] [Patent Documents]
[0005] [Patent Document 1] WO2014 / 010025 [Overview of the project] [Problems that the invention aims to solve]
[0006] According to the charging system described above, a power detection unit and a power consumption measurement unit are installed to measure the power of the load in order to calculate surplus power in real time. Therefore, since individual power consumption measurements are performed for each charging system, it was necessary to install a dedicated PCS (power conditioner) equipped with measurement and control functions. Furthermore, when installing a dedicated PCS on-site for the power supply and power supply lines, depending on the situation, multiple power detection units and power consumption measurement units may be required (e.g., multiple branches of three-phase three-wire 200V), or a dedicated transformer may be required if the voltage is high, resulting in a complex configuration for calculating surplus power and increased equipment costs.
[0007] The present invention was proposed in view of the above circumstances, and aims to provide a charge / discharge control system and charge / discharge control method that enables efficient charge / discharge control of charge / discharge targets (e.g., electric vehicles such as EVs) with a simple configuration and low cost by making it possible to use electricity meters such as electricity meters for trading installed by power companies. [Means for solving the problem]
[0008] To achieve the above objective, Claim 1 of the present invention provides a charge / discharge control system (1) comprising: a load equipment (4) connected to a power source (power system 2) that supplies demand power via a power meter (trading power meter 7) and consumes power; a charge / discharge device (6) connected to the power source and performs charging and discharging; and a control device (10) that detects the consumption state of the demand power using the power meter and controls the charging and discharging by the charge / discharge device (6), wherein While using a power meter installed by the power company for transactional purposes (maximum demand power meter) as the aforementioned power meter, The control device (10) is characterized by including the following configuration. An average power calculation unit (11) calculates the average power an for each period obtained by dividing the power consumption of the load equipment (4) over a certain 30-minute period into n equal parts, based on the power demand measured by the power meter. A charge / dischargeable power calculation unit (12) calculates the charge / dischargeable power bn, which is the difference between the target power Wtar, which is the maximum value of the demanded power during each of the above periods, and the average power an. The chargeable / dischargeable power bn is (n+1)th partition period A power charging / discharging unit (13) for charging and discharging.
[0009] In the charge / dischargeable power calculation unit (12), the value obtained by subtracting (an-a0) / n, which is calculated based on the average power an, from the target power Wtar is set as the actual target power value, and the charge / dischargeable power bn is calculated based on this target power value. It is characterized by the following.
[0010] Claim 2 is the same as Claim 1 In the charge / discharge control system described above, Let n be 30 and each of the periods be 1 minute. It is characterized by the following.
[0011] Claim 3 is Claim 1 or Claim 2 In the charge / discharge control system, Multiple chargers / dischargers are provided, and each charger / discharger can be connected to an electric vehicle. It is characterized by the following.
[0012] Claim 4 This is a control method for controlling the charging and discharging of load equipment that is connected to a power source that supplies power demand and consumes power, by detecting the power consumption state of the load equipment and controlling the charging and discharging of each charger / discharger when charging and discharging objects connected to the power source via a charger / discharger, Based on the measured value of the demand power by the power meter, a procedure for calculating the average power an of each period obtained by equally dividing the power consumption by the load equipment for a certain 30 minutes, and including a procedure for calculating the chargeable power bn obtained by subtracting the average power an from the target power Wtar which is the maximum value of the demand power in each period, Controlling to charge and discharge the chargeable power bn in the (n + 1)-th division period with the value obtained by subtracting (an - a0) / n calculated based on the average power an from the target power as the actual target power.
[0013] Claim 5 is the same as Claim 4 In the charge and discharge control method described in characterized in that n is 30 and each period is 1 minute. This is the feature.
[0014] Claim 6 is claim 4 or claim 5 In the charge and discharge control method described in characterized in that the charge and discharge object is an electric vehicle. This is the feature.
Effect of the Invention
[0015] According to the present invention, when detecting the power consumption state of the load equipment and controlling the charge and discharge to the charge and discharge object (electric vehicle (20) or storage battery) by the charger (6), it is controlled by the value calculated based on the average value of the power amount in the immediate past. Therefore, instead of obtaining the surplus power in real time, by using it as the difference (both positive and negative signs) with respect to the target power value, the charge and discharge control for the charge and discharge object connected to the charger (6) can be performed.
[0016] Also, by setting and calculating the chargeable power bn as the actual target power value by subtracting (an - a0) / n calculated based on the average power an from the target power set in the contract with the power company and supplying it in (n + 1) minutes, it is possible to prevent exceeding the contract power.
Brief Description of the Drawings
[0017] [Figure 1] It is a block diagram showing the configuration of the charge / discharge control system of the present invention. [Figure 2] It is a block diagram showing the configuration of the control device in the charge / discharge control system. [Figure 3] It is a model diagram showing the relationship among the measured value of the required power, the load equipment power, and the charge / discharge available power, where (a) shows the charging time and (b) shows the discharging time respectively. [Figure 4] It is a graph when calculating an (load equipment power) from the measurement of the amount of required power in units of 30 minutes. [Figure 5] It is a graph showing the amount of power (charge / discharge available power) bn which is the difference from the target power Wtar in FIG. 4. [Figure 6] It is a graph when adding the amount of power b(n - 1) to the amount of power an for n hours in FIG. 4. [Figure 7] It is a flowchart when performing charge / discharge control by the method of the present invention.
Embodiments for Carrying Out the Invention
[0018] Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the charge / discharge control system according to the embodiment. This charge / discharge control system 1 is used, for example, in a charging stand that charges a plurality of electric vehicles 20. The electric vehicle 20 mentioned here is a vehicle equipped with an in-vehicle battery that can be charged via a plug, and EVs and PHVs are targeted.
[0019] The charge / discharge control system 1 is connected to a power supply system 2 which is a commercial power supply via a feeder line (power supply line) 3. The charge / discharge control system 1 includes a load equipment 4 that is connected to the power supply system 2 and consumes power, a plurality of chargers 6 that are connected to the feeder line 3 via a feeder line (power supply line) 5, and a control device 10 that controls the charging and discharging of the electric vehicle 20 by each charger 6 via a communication line. Each charger / discharger 6 is configured to be connected to an electric vehicle 20, allowing the onboard battery of the electric vehicle 20 to be charged and discharged under the control of the control device 10.
[0020] On the input side of the charge / discharge control system 1, a power meter such as the trading power meter 7, which is installed free of charge by the power company to manage the amount of electricity demanded, is connected, and the amount of electricity demanded supplied from the power system 2 to the power supply line 3 is measured. Although the user's maximum electricity demand is determined by their contract with the power company, the installation of the trading power meter 7 allows the power company to monitor whether the user is using electricity within this range and notifies the user of the need to renew their contract to increase their electricity usage if it is exceeded.
[0021] The specific configuration of the electricity meter 7 used for transactions involves, for example, an operation where a switch is momentarily turned ON when a certain amount of electricity (Wh) is accumulated (generating a service pulse in the high-voltage power receiving contract with the power company), thereby constantly monitoring the user's electricity consumption. In addition, the values measured by the electricity meter 7 used for transactions are obtained via communication means, including instantaneous power measurement values (W), cumulative energy measurement values (Wh), and the most recent 30-minute value (kWh). The 30-minute value (kWh) is the amount of energy accumulated over 30 minutes, from 00 minutes past the hour to 30 minutes past the hour, and from 30 minutes past the hour to 00 minutes past the hour.
[0022] A power meter 8 for charging and discharging the electric vehicle 20 is connected to the input side of the charge / discharge unit 6, and the measured value from the power meter 8 is output to the control device 10 via a measurement line. In this example, the charge / discharge unit 6 and the power meter 8 are configured separately, but it is also possible to configure the power meter to be built into the charge / discharge unit 6 and output the power amount to the control device 10 via a communication line.
[0023] Next, the detailed configuration of the control device 10 will be explained with reference to Figures 2 to 5. As shown in the block in Figure 2, the control device 10 includes an average power calculation unit 11 that calculates the load equipment power by measuring the power value consumed by the charge / discharge control system 1 as demand power (measured value in Figure 3), a charge / dischargeable power calculation unit 12 that calculates the power value that can be charged and discharged (chargeable power in Figure 3(a)) for the power value consumed by the load equipment 4 (load equipment power in Figure 3(a)), and a power charge / discharge unit 13 that notifies the charge / dischargeable power to the charge / discharge unit 6. The control device 10 is configured such that a control signal is sent to each charge / discharge unit 6 via a communication line after calculation processing is performed by a CPU or the like.
[0024] The average power calculation unit 11 calculates the average power an for each period obtained by dividing a certain 30-minute period of load equipment power in the charge / discharge control system 1 into n equal parts, using the demand power measured by the trading power meter 7 (measured value in Figure 3(a)) and the charge / discharge power measured by the charge / discharge power meter 8 (charging power in Figure 3(a)). In other words, as shown in Figure 4, when the demand for a given 30-minute period is set with a demand start time of 0:00 and a demand end time of 30:00, if the average power for each minute is an and the calculated 30-minute power is Wdem, then Wdem can be calculated using the formula in Equation 1.
[0025]
number
[0026] The charge / dischargeable power calculation unit 12 calculates the charge / dischargeable power bn from Equation 2, which is the difference between the target power Wtar (maximum power determined by the contract with the power company), which is the maximum power demand in each period, and the average power an.
[0027]
number
[0028] Since bn is the difference from the target power Wtar, it can be said that it represents the rechargeable power that can be charged without exceeding the target power Wtar during that time (see Figure 5). When the control device 10 controls charging, if it issues a command for bn minutes, the value of bn will be determined after n minutes have elapsed, so the control will be performed for bn minutes from n minutes to (n+1) minutes (see Figure 6).
[0029] Assuming that the charging output is controlled in this way, the actual measured power demand W can be calculated using Equation 3.
[0030]
number
[0031] Comparing this demand power W with the target power Wtar, the difference between the two can be calculated using Equation 4.
[0032]
number
[0033] As shown in Figure 6, the above difference may cause the demand to be exceeded. Therefore, it is preferable to design the target power with a margin from the actual target power Wtar, and if the above difference is 0, there is no risk of exceeding the demand. In other words, by taking a margin of the difference (a30-a0) from the target power Wtar, it is possible to avoid exceeding the demand. Assuming that the difference (a30-a0) is approximately the same as the target power, it is estimated that a margin of approximately 3% (a30-a0) / 30 would reduce the risk of exceeding the demand.
[0034] Therefore, the power charging / discharging unit 13 controls the charger / discharger 6 to charge / discharge the electric vehicle 20 over (n+1) minutes, using the chargeable / dischargeable power bn calculated using the target power value, which is obtained by subtracting (a30-a0) / 30 calculated based on the average power an.
[0035] In the above example, we described the case where the electric vehicle 20 is charged by the charger / discharger 6. However, in the same configuration, if the value of the difference W-Wtar between the demand power W and the target power Wtar becomes negative, the charge / discharge system 1 will control the discharge from the onboard battery of the electric vehicle 20. In the case of discharge control, the relationship between the power value (measured value) consumed by the charge / discharge control system 1 as demand power, the load equipment power, and the power required for discharge is as shown in Figure 3(b).
[0036] The charging and discharging operation of the charging and discharging control system described above will be explained below with reference to the flowchart in Figure 7. Assume that each charger / discharger 6 of the charging and discharging control system 1 is connected to the onboard battery of the electric vehicle 20.
[0037] The amount of electricity demanded (corresponding to the measured value in Figure 3) is obtained from the electricity meter 7 used for trading, and the average power consumption over the past minute is calculated (Step 51). The charge / discharge power (corresponding to the charging power and discharging power in Figure 3) is obtained from the charge / discharge power meter 8, and the average power over the past minute is calculated (Step 52).
[0038] Calculate the load equipment power (measured value - charging (discharging) power, which corresponds to the average power an) when the electric vehicle 20 is connected (Step 53).
[0039] Compare the target power with the load equipment power (Step 54). If the load equipment power is less than the target power, a charging command (for the next minute) is issued to each charger / discharger 6 to charge the onboard battery of the electric vehicle 20 (step 55). If the load equipment power is greater than the target power, a discharge command (for the next minute) is issued to each charger / discharger 6 to discharge the onboard battery of the electric vehicle 20 (step 56).
[0040] In the charge / discharge control system 1 described above, the maximum demand power (demand value) based on the contract with the power company is calculated by the trading power meter 7 using the average power from 00 minutes to 30 minutes (30 minutes to 00 minutes). Based on the average power an calculated from the measurement by the trading power meter 7, the charge / dischargeable power bn is calculated. (n+1)th partition period By supplying power in this way, it is possible to control the average value of power demand over a 30-minute period so that it is below the contracted power. Furthermore, when calculating the chargeable / dischargeable power bn based on the average power an, the actual target power value can be set by subtracting (an-a0) / n, which is calculated based on the average power an, from the target power set in the contract with the power company, thereby preventing exceeding the contracted power.
[0041] In the charge / discharge control system 1 described above, control was performed with n=30, but control may also be performed with integers such as n=15, 45, 60, etc. The larger the number of n, the closer the control becomes to real-time control. Also, as n decreases, the value of (an-a0) / n, which is the difference between demand power and target power, becomes larger, so a larger margin is needed to avoid exceeding the demand, relative to the target power Wtar calculated from the contracted power.
[0042] In the example described above, an example of applying the charge / discharge control system 1 of the present invention to a charging station was explained. However, by connecting a power meter with a configuration similar to the power meter 7 used for transactions installed by power companies, it is also possible to install it in a private home. In addition, the charger / discharger 6 may be connected to other devices to be charged or discharged, such as a battery storage device, in addition to the electric vehicle 20.
[0043] According to the charging and discharging system described above, by utilizing the power meter 7 installed by the power company for transactions, the system detects the power consumption status of the load and controls the charging and discharging of the electric vehicle 20 by the charger / discharger 6. The system calculates and controls the chargeable power value based on the average value of the most recent past power consumption. Therefore, instead of calculating surplus power in real time and adjusting the instantaneous peak power, it uses the difference (both positive and negative) relative to the target power, enabling charging and discharging operations for the electric vehicle 20 connected to the charger / discharger 6 without using a dedicated PCS measuring instrument. As a result, when measuring power values and calculating the available power for charging, the power meter 7 installed by the power company is used, eliminating the need for calibration of measurement values, and making it possible to manage the amount of available power for charging with inexpensive equipment.
[0044] Furthermore, by measuring the amount of electricity using the average power calculation unit 11 in the control device 10 in 30-minute increments, the contracted power value (power company measurement value), which is calculated using the average value over a 30-minute period, becomes the same as the contracted power value (power company measurement value), enabling control using the same type of measurement. Furthermore, because the system uses the measurements from the power meter 7 installed by the power company, the measurement error between the power value known to the entire system and the contracted power with the power company is the same, which makes it easier to achieve the result of "not exceeding the contracted power." [Explanation of Symbols]
[0045] 1. Charge / Discharge Control System 2 Power system (commercial power supply) 3 Power line 4 Load equipment 5 Power line 6 Charger / discharger 7. Electricity meter for commercial use 8 Charge / discharge power meter 10 Control device 11 Average power calculation section 12 Chargeable and dischargeable power calculation section 13 Power charging / discharging section 20 Electric Vehicles (EVs)
Claims
1. A charge / discharge control system comprising: a power source that supplies demand power via a power meter; load equipment that consumes power by being connected to the power source; a charge / discharge device that is connected to the power source and performs charging and discharging; and a control device that detects the power consumption status of the demand power using the power meter and controls the charging and discharging by the charge / discharge device, wherein As the aforementioned electricity meter, a trading electricity meter (maximum demand electricity meter) installed by the power company is used. The control device is An average power calculation unit calculates the average power an for each period obtained by dividing the power consumption of the load equipment over a certain 30-minute period into n equal parts, based on the power demand measured by the power meter. A charge / dischargeable power calculation unit calculates the charge / dischargeable power bn, which is the difference between the target power Wtar, which is the maximum value of the demanded power during each of the above periods, and the average power an. The system includes a power charging and discharging unit that charges and discharges the chargeable power bn during the (n+1)th divided period, A charge / discharge control system characterized by setting the value obtained by subtracting (an - a0) / n, calculated based on the average power an, from the target power Wtar as the actual target power value, and calculating the charge / dischargeable power bn based on this target power value.
2. The charge / discharge control system according to claim 1, wherein n is 30 and each of the periods is 1 minute.
3. The charge / discharge control system according to claim 1 or claim 2, wherein a plurality of charge / discharge units are provided, and an electric vehicle can be connected to each charge / discharge unit.
4. In a control method for charging and discharging load equipment connected to a power source that supplies power demand and consumes power, where the power consumption status of the load equipment is detected and the charging and discharging of each charger / discharger is controlled when charging and discharging objects connected to the power source via chargers / dischargers, A procedure for calculating the average power an for each period obtained by dividing the power consumption of the load equipment over a certain 30-minute period into n equal parts, based on the power demand measured by a power meter (maximum demand power meter) installed by the power company, The procedure includes calculating the rechargeable power bn by subtracting the average power an from the target power Wtar, which is the maximum value of the demanded power during each period, The actual target power is calculated by subtracting (an - a0) / n, which is calculated based on the average power an, from the target power, and the charge / dischargeable power bn is controlled to be charged and discharged during the (n+1)th division period. A charge / discharge control method characterized by the following:
5. The charge / discharge control method according to claim 4, wherein n is 30 and each of the periods is 1 minute.
6. The charge / discharge control method according to claim 4 or 5, wherein the object to be charged and discharged is an electric vehicle.