Generator start-up control

Abstract

A control unit for controlling a power supply device configured for power supply between an energy store and a power grid supplying power to a connection point, the control unit being configured to receive first data indicating whether the energy store is connected to the power supply device, detecting first data that the energy store is connected to the power supply device, upon detecting that the energy store has been connected, obtaining second data indicative of the frequency and voltage of the exchanged power at the connection point during the observation period, it is determined whether the frequency has been maintained within a frequency limit and whether the voltage has been maintained within a voltage limit during the observation period, and a start-up control signal is provided to the power supply device indicating that the energy store is allowed to exchange power with the grid.

Description

Technical Field

[0001] This disclosure relates to a control unit and method for controlling a power supply device configured for power supply between an energy storage device and a power grid supplying power to a connection point. Background Technology

[0002] Power supply equipment should observe grid quality over a specific period before being allowed to feed power into the grid. This should occur each time the power supply equipment is started. Typical solar hybrid inverters and battery inverters remain in one place and are always connected to the grid. However, electric vehicles and / or other types of equipment with energy storage can be connected and disconnected several times a day, as users may use electric vehicles for transportation. Implementing this requirement in electric vehicles would result in a poorer charging experience for users, as they would have to wait for the function to be executed before being allowed to charge or discharge each time they connect the electric vehicle. This leads to a poorer charging experience for users. Summary of the Invention

[0003] According to one embodiment, a control unit is provided for controlling a power supply device configured for power exchange between an energy storage device and a power grid supplying power to a connection point. The control unit is configured to receive first data indicating whether the energy storage device is connected to the power supply device, use the first data to detect that the energy storage device is connected to the power supply device, obtain second data indicating the frequency and voltage of the power exchanged at the connection point during an observation period, use the second data to determine whether the frequency has been maintained within frequency limits and the voltage has been maintained within voltage limits during the observation period, and provide the power supply device with a start control signal instructing the energy storage device to allow the energy storage device to exchange power with the power grid.

[0004] If the voltage and frequency have been maintained within frequency and voltage limits during the observation period, this allows the energy storage device to begin exchanging power with the grid once connected to the power supply, thus avoiding the waiting time during energy storage connection, as the power supply device, which has been maintaining the connection, has already performed the observation. To detect the energy storage device's connection to the power supply device using the initial data, the power supply device can continuously monitor whether the energy storage device is plugged in. For example, whenever the energy storage device is plugged in, a specific signal should be received at the power supply device via the communication line between the energy storage device and the power supply device.

[0005] According to another embodiment, a method for controlling a power supply device configured for power exchange between an energy storage device and a power grid supplying power to a connection point is provided. The method includes: receiving first data indicating whether the energy storage device is connected to the power supply device; using the first data to detect that the energy storage device is connected to the power supply device; using the second data to determine whether the frequency has been maintained within a frequency limit and the voltage has been maintained within a voltage limit during an observation period; and providing the power supply device with a start control signal indicating that the energy storage device is permitted to exchange power with the power grid.

[0006] If the second data indicates that the grid frequency is not maintained within the frequency limit during the observation period, the start-up control signal can instruct the energy storage device to either supply power to the grid and not draw power from it during a first waiting period, or draw power from the grid and not supply power during a second waiting period. In other words, if the second data indicates that the grid is in an abnormal state and reinforcement (by adding load or generating power depending on the grid frequency) is needed to restore the grid frequency, the start-up control signal for the newly connected energy storage device can instruct the energy storage device to either supply power to the grid and not draw power from it, or draw power from the grid and not supply power until the grid frequency is restored.

[0007] In this way, the first and second waiting periods can be based on the time required to restore the power grid so that the frequency is once again within the frequency limits. For example, the control unit can continuously monitor the power grid, and when the control unit detects that the power grid frequency is once again within the frequency limits, the control unit can generate a start signal indicating that the energy storage device is allowed to exchange power with the power grid.

[0008] In this way, the energy storage device will be able to connect and start immediately to help the grid restore the frequency to within the frequency limits.

[0009] Based on multiple frequency and voltage measurements of the exchanged power obtained during the observation period, second data indicating the frequency and voltage of the exchanged power at the connection point used for observation can be obtained.

[0010] If the average of multiple frequency measurements is between a higher frequency threshold and a lower frequency threshold, or if a number of measurements are between a higher frequency threshold and a lower frequency threshold, then the frequency may have been maintained within the frequency limit.

[0011] If the average of multiple voltage measurements is between a higher voltage threshold and a lower voltage threshold, or if another number of voltage measurements is between a higher voltage threshold and a lower voltage threshold, then the voltage may have been maintained within the voltage limit.

[0012] If the average of multiple frequency measurements and / or at least one of the multiple frequency measurements is higher than a higher frequency threshold, the activation control signal instructs the energy storage device to draw power from the grid and not supply power to the grid during the second waiting period.

[0013] By drawing power from the grid, the energy storage device acts as a load on the grid, thereby helping to lower the grid frequency. When the frequency is above a higher frequency threshold, this allows the energy storage device to help restore the frequency at the grid.

[0014] If the average of the plurality of frequency measurements and / or at least one of the plurality of frequency measurements is below a lower frequency threshold, a start control signal instructs the energy storage device to supply power to the grid and not draw power from the grid during a first waiting period.

[0015] By supplying power from the energy storage unit to the grid, the energy storage unit helps to increase the grid frequency. When the frequency falls below a lower frequency threshold, this allows the energy storage unit to help restore the frequency of the power at the grid.

[0016] In this way, the power grid has the potential to reach a stable state more quickly, and once the power grid is stable again, the energy storage device will be allowed to exchange power with the power grid in any convenient way for the energy storage device.

[0017] Multiple frequency and voltage measurements can be performed by measuring devices connected to the connection point or by the power supply equipment.

[0018] The power supply equipment and / or measuring equipment can continuously measure the frequency and voltage of the exchanged power. For example, the power supply equipment and / or measuring equipment can perform frequency and voltage measurements every second or at any other suitable rate. If the measuring equipment is performing measurements, it sends these measurements to the power supply equipment. The power supply equipment can store the measured voltage and frequency in its internal memory, and when an energy storage device is detected connected to the power supply equipment, it can calculate, based on the stored measurements, whether the frequency and / or voltage have been maintained within frequency and / or voltage limits during the observation period prior to the energy storage device's connection. For example, if the observation period is 60 seconds and measurements are performed every second, the power supply equipment can store the last 60 measurements in its memory, such that when the energy storage device is detected connected, these 60 stored measurements will be used to detect whether the frequency and voltage are within the desired limits. For example, the average of these 60 measurements can be calculated, and if the average is within a higher and lower frequency threshold, the control unit of the power supply equipment will detect that the frequency of the exchanged power at the grid is within the frequency limits.

[0019] Instead of storing measurements, power supply equipment can update state variables stored in memory. For example, power supply equipment can change state variables based on whether the frequency and / or voltage are maintained within frequency and / or voltage limits.

[0020] The power supply equipment can be configured for bidirectional power supply between the energy storage device and the power grid, and if the frequency has been maintained within the frequency limit and the voltage has been maintained within the voltage limit during the observation period, the activation control signal indicates that the energy storage device is allowed to exchange power bidirectionally with the power grid.

[0021] The first and second waiting periods can be equal to the time required for the power grid to restore the frequency to within the frequency limit.

[0022] Energy storage devices can be installed in electric vehicles.

[0023] The observation period can include the time prior to detecting that the energy storage device is connected to the power supply equipment. The power supply equipment can maintain a connection to the power grid and can continuously monitor the grid. As long as the energy storage device is connected to the power supply equipment, a start control signal is sent to the energy storage device to indicate which action is permitted.

[0024] Higher frequency thresholds can be greater than lower frequency thresholds, and / or higher voltage thresholds can be greater than lower voltage thresholds.

[0025] According to another embodiment, an electric vehicle power supply device including a control unit is provided.

[0026] The higher frequency threshold can be between 65 Hz and 45 Hz, preferably between 52 Hz and 50 Hz. However, the higher frequency threshold can be any other suitable value.

[0027] The lower frequency threshold can be between 45 Hz and 65 Hz, preferably between 47 Hz and 50 Hz. However, the lower frequency threshold can be any other suitable value.

[0028] The higher voltage threshold can be between 100% and 110% of the nominal voltage value. The lower voltage threshold can be between 50% and 100% of the nominal voltage value. For example, for a nominal voltage value such as 230V in Europe, the higher voltage threshold can be between 265.5V and 230V and / or the lower voltage threshold can be between 230V and 115V. However, the lower and / or higher voltage thresholds can be any other suitable values.

[0029] Those skilled in the art will understand that the above features can be combined in any way that is considered useful. Attached Figure Description

[0030] The present disclosure will now be described in more detail with reference to the accompanying drawings, which illustrate embodiments thereof:

[0031] Figure 1 This is a schematic diagram of a system for charging and / or discharging an energy storage device, according to at least one example of this disclosure.

[0032] Figure 2 This is a flowchart of a method for charging and / or discharging an energy storage device according to at least one example of this disclosure.

[0033] Figure 3 This is a schematic diagram of a system for a power supply device including a control unit, based on an example of this disclosure. Detailed Implementation

[0034] Embodiments of this disclosure will now be described herein with reference to the accompanying drawings. However, the embodiments of this disclosure are not limited to the specific embodiments and should be construed as including all modifications, alterations, equivalent devices and methods, and / or alternative embodiments of this disclosure.

[0035] As used herein, terms such as “first” and “second” may modify various elements regardless of the order and / or importance of the corresponding elements, and do not limit the corresponding elements. These terms may be used for the purpose of distinguishing one element from another. For example, without departing from the scope of the invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0036] The terminology used in describing the various embodiments of this disclosure is for the purpose of describing particular embodiments and is not intended to limit this disclosure. As used herein, singular forms are intended to include plural forms as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms used herein (including technical or scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. Terms defined in commonly used dictionaries should be interpreted as having the same or similar meaning as in the context of the related art and should not be interpreted as having an ideal or exaggerated meaning unless they are expressly defined herein. As appropriate, even terms defined in this disclosure should not be construed as excluding embodiments of this disclosure.

[0037] As used herein, the term "vehicle" refers to an object used for the transport of people or goods. Examples of vehicles include automobiles, cars, trucks, and buses. The term "vehicle" also includes electric vehicles (EVs) powered by an electric motor that draws electricity from an onboard energy storage device, such as a battery, which can be recharged from an external source, such as a residential or public power service or an onboard fuel-powered generator. An EV can be two or more wheeled vehicles manufactured for primary use on public streets and roads. EVs can be referred to as electric cars, electric sedans, electric road vehicles (ERVs), plug-in vehicles (PVs), plug-in electric vehicles (xEVs), etc., and xEVs can be classified as plug-in fully electric vehicles (BEVs), battery electric vehicles, plug-in electric vehicles (PEVs), hybrid electric vehicles (HEVs), hybrid plug-in electric vehicles (HPEVs), plug-in hybrid electric vehicles (PHEVs), etc.

[0038] Figure 1 This is a schematic diagram of a system 100 for charging an energy storage device 106, according to at least one example of the present disclosure.

[0039] Figure 1 The system 100 shows an electric vehicle 112 including an energy storage device 106. Figure 1 System 100 also illustrates a power supply device 104 connected to a power grid 108 via a connection point 110. The power grid 108 can be any type of power grid configured to supply power to one or more loads or generators. For example, the power grid 108 can be connected at connection point 110 of a house 124, and the house 124 can include the power supply device 104 and other loads and / or generators 122 belonging to the house 124, allowing power exchange in both directions between the power grid 108 and the house 124 to occur.

[0040] Energy storage device 106 can be connected to and disconnected from power supply device 104 via power cable 120. In this way, when energy storage device 106 is connected to power supply device 104, energy storage device 106 can supply power to grid 108 and consume power from grid 108.

[0041] The electric vehicle 112 may include a direct current (DC) to alternating current (AC) (and AC to DC) converter, for example, as part of the distribution board measurement circuit 130. In this way, the power supply device 104 can act as a switch and allow power to pass through it in both directions.

[0042] When the power grid 108 is under disturbance (meaning the frequency and voltage are outside the frequency and voltage limits imposed by the power grid supplier), the energy storage device 106 is not permitted to start. This is to ensure the safety of the power grid 108 and avoid negative consequences. With prior agreement from the power system operator, the control unit 102 will allow the energy storage device 106 to charge or discharge depending on the conditions of the power grid 108 to support grid recovery. For this purpose, the control unit 102 requires information on the voltage and frequency measurements of the power exchanged at connection point 110 of the power grid 108. This voltage and frequency can be internally measured by the distribution board measurement circuit 130 within the power supply equipment 104 or read from the measuring device 114.

[0043] The power supply device 104 includes a control unit 102. The control unit 102 is configured to receive first data indicating whether the power storage device 106 is connected to the power supply device 104. The control unit 102 is also configured to use the first data to detect that the power storage device 106 is connected to the power supply device 104.

[0044] For example, the control unit 102 can be connected to the energy storage device 106 via the communication line 226, so that the control unit 102 can receive signals via the communication line 226 as long as the energy storage device 106 is connected to the power supply device 104.

[0045] After detecting that the energy storage device 106 has just been connected to the power supply device 104, the control unit 102 can obtain second data indicating the frequency and voltage of the power exchanged at the connection point 110. The control unit 102 can use the second data to determine whether the frequency has been maintained within the frequency limit and whether the voltage has been maintained within the voltage limit during the observation period.

[0046] Based on multiple frequency and voltage measurements of the exchanged power obtained during the observation period, second data indicating the frequency and voltage of the exchanged power at the connection point used for observation can be obtained. The control unit can continuously monitor the power grid. For example, power supply equipment and / or measuring equipment can continuously measure the frequency and voltage of the exchanged power. The power supply equipment can store the measured voltage and frequency in its internal memory, and when an energy storage device is detected connected to the power supply equipment, it can calculate, based on the stored measurements, whether the frequency and / or voltage during the observation period prior to the energy storage device connection had been maintained within frequency and / or voltage limits.

[0047] If control unit 102 determines that the frequency and voltage have been maintained within the frequency limit and voltage limit during the observation period, control unit 102 will provide a start control signal to power supply device 104, indicating that power storage device 106 is permitted to exchange power with grid 108. Power supply device 104 can provide a start signal to electric vehicle 112 via communication line 226. Power storage device 106 can then begin charging power from grid 108 or discharging power into grid 108.

[0048] If the second data indicates that the frequency of the power grid 108 is not maintained within the frequency limit during the observation period, the control unit 102 will generate a start control signal indicating that the energy storage device 106 should supply power to the power grid 108 and not draw power from the power grid 108 during the first waiting period, or draw power from the power grid 108 and not supply power to the power grid 108 during the second waiting period.

[0049] Control unit 102 can obtain second data indicating the frequency and voltage of the exchanged power at connection point 110 during the observation period based on multiple frequency and voltage measurements of the exchanged power acquired during the observation period. These multiple frequency and voltage measurements can be performed by measuring device 114, which is connected to connection point 110 and transmitted to power supply device 104 via communication line 128. Alternatively, multiple frequency and voltage measurements of power supply device 104 can be performed using sensor 130.

[0050] Control unit 102 can detect that the frequency has been maintained within the frequency limit by determining the average of multiple frequency measurements taken during an observation period prior to connecting the energy storage device to the power supply device 104. If the calculated average is between a higher frequency threshold and a lower frequency threshold, control unit 102 can determine that the frequency has been maintained within the frequency limit.

[0051] Alternatively, the control unit 102 can detect that the frequency has been maintained within the frequency limit by determining that the number of multiple measurements performed during the observation period is between a higher frequency threshold and a lower frequency threshold.

[0052] Similarly, if the average of multiple voltage measurements is between a higher voltage threshold and a lower voltage threshold, or if another number of voltage measurements is between a higher voltage threshold and a lower voltage threshold, the control unit 102 can determine that the voltage has been maintained with the required voltage limit.

[0053] If the average of multiple frequency measurements and / or at least one of the multiple frequency measurements is higher than a higher frequency threshold, the control unit 102 may generate a start control signal indicating that the energy storage unit 106 should draw power from the grid 108 during a second waiting period and not supply power to the grid 108.

[0054] Similarly, if the average of multiple frequency measurements and / or at least one of the multiple frequency measurements is below a lower frequency threshold, the control unit 102 may generate a start control signal indicating that the energy storage unit 106 should supply power to the grid 108 during a first waiting period and not draw power from the grid 108.

[0055] In this manner, the control unit 102 of the power supply device 104 determines the permissible operation of the energy storage device 106 of the electric vehicle 112 based on the second data. The power supply device 104 can communicate the permissible operation to the electric vehicle 112 via the communication line 226 and using communication protocols such as ISO 15118-2, ISO 15118-20, IEC 61851, or DIN 70121. However, any other communication standard can be used to communicate possible / permissible operations such as wireless, Bluetooth, etc.

[0056] As already explained, based on the second data received, indicating the frequency and voltage of the power exchanged at connection point 110, control unit 102 can determine the following operations of electric vehicle 112.

[0057] If the control unit 102 determines that the power grid 108 is operating under normal conditions, meaning that the voltage and frequency of the power exchanged at connection point 110 are within permissible limits, then the control unit 102 will provide the power supply device 104 with a start control signal indicating that the energy storage device 106 is permitted to exchange power bidirectionally with the power grid 108. In this way, if the voltage and frequency are within permissible ranges during the past observation period (i.e., charging or discharging is permitted), the electric vehicle 112 is permitted to operate as needed immediately after being plugged into the power supply device 104.

[0058] If control unit 102 determines that the power grid 108 is operating under interference conditions, meaning that the frequency of the power exchanged at connection point 110 is not within permissible limits, control unit 102 will provide a start control signal to power supply equipment 104 indicating the following:

[0059] If the frequency is on the higher side of the nominal value (and the voltage is within the permissible range), the control unit 102 should provide a start control signal that allows the electric vehicle 112 to immediately charge the energy storage 106, which will help the grid 108 reduce its frequency by adding a load to the grid 102. That is, if the first data indicates that the frequency of the grid 108 is higher than the higher frequency threshold, the start control signal instructs the energy storage 106 to draw power from the grid 108 and not supply power to the grid 108 during a second waiting period, thereby allowing the energy storage 106 of the electric vehicle 112 to charge, but delaying the discharge of the energy storage 106.

[0060] When the frequency is on the lower side of the nominal value (and the voltage is within the permissible range), the control unit 102 should provide a start control signal that allows the electric vehicle 112 to immediately discharge the energy storage 106. This will help the grid 108 increase its frequency by adding power generation to the grid 108. That is, if the first data indicates that the frequency of the grid 108 is below the lower frequency threshold, the start control signal instructs the energy storage 106 to supply power to the grid 108 and not draw power from the grid 108 during a first waiting period, thereby allowing the energy storage 106 of the electric vehicle 112 to discharge but delaying the charging of the energy storage 106.

[0061] Even when the electric vehicle 112 is not connected, the power supply device 104 can continuously monitor the voltage and frequency of the exchanged power at the connection point 110 from the moment the power supply device 104 is powered on.

[0062] The control unit may take into account other disturbance conditions of the power grid 108, such that the control unit 102 should provide a start control signal to the power supply equipment 104 based on the following Table I:

[0063]

[0064] Table I

[0065] The first column of Table I corresponds to the frequency of the power grid 108, the second column corresponds to the voltage of the power grid 108, and the third column shows the operations permitted by the start-up control signal generated by the combination of frequency and voltage corresponding to the corresponding row. For example, if both the frequency and voltage of the power grid 108 are higher than a higher frequency threshold and a higher voltage threshold, respectively, the control unit 102 can generate a start-up control signal that allows the energy storage device 106 to charge from the power grid 108 but not to discharge. However, if the frequency of the power grid 108 is lower than a lower frequency threshold and the voltage of the power grid 108 is higher than a higher voltage threshold, the control unit 102 can generate a start-up control signal that does not allow the energy storage device 106 to charge from or discharge from the power grid 108.

[0066] Table II below provides some examples of the ranges for observation periods, higher frequency thresholds, lower frequency thresholds, higher voltage thresholds, and lower voltage thresholds, as well as possible default settings. However, these ranges and values ​​are not limiting, and any other suitable values ​​and ranges can be used.

[0067]

[0068] Table II

[0069] The frequency range, voltage range, and observation period should be adjustable within the range specified in column 2 of Table I. If the grid operator has not specified any settings, the default settings for connection or start-up of power generation due to normal operation or activity are specified in column 3 of Table I. Un is the nominal voltage, which for the European Union (EU) is 230Vac (i.e., 230V refers to 100% UV).

[0070] Figure 1 The electric vehicle 112 includes an energy storage unit 106 and a vehicle control unit 130. The vehicle control unit 130 is configured to receive a start control signal generated by the control unit 102 of the power supply equipment 104 when the electric vehicle 112 has just been connected to the power supply equipment 104, and to control the energy storage unit 106 based on the start control signal. The start control signal can instruct the energy storage unit 106 to: begin exchanging power with the grid in any direction, supply power to the grid and not draw power from the grid during a first waiting period, or draw power from the grid and not supply power to the grid during a second waiting period. The first and second waiting periods correspond to the amount of time required for the grid to restore its frequency to within frequency limits.

[0071] Figure 2 A flowchart is shown of a method for controlling a power supply device 104, which is configured to supply power between an energy storage device 106 and a power grid 108 that supplies power to a connection point 110.

[0072] In step 202, Figure 2 The method receives first data indicating whether the energy storage device 106 is connected to the power supply device 104. In step 204, Figure 2 The method uses the first data to detect that the energy storage device 106 is connected to the power supply device 104.

[0073] After detecting in step 204 that the energy storage device 106 is connected to the power supply device 104, the method proceeds to step 206 and obtains second data indicating the frequency and voltage of the power exchanged at the connection point 110 during the observation period.

[0074] In step 208, the method uses the second data to determine whether the frequency has been maintained within the frequency limit and whether the voltage has been maintained within the voltage limit during the observation period.

[0075] Based on multiple frequency and voltage measurements of the exchanged power obtained during the observation period, second data indicating the frequency and voltage of the exchanged power at the connection point used for observation can be obtained. Figure 2 One method could be continuous monitoring of the power grid. For example, Figure 2 The method can continuously measure the frequency and / or voltage of the exchanged power, or continuously receive measurements of the frequency and / or voltage of the exchanged power. The measured voltage and frequency can be stored in internal memory, and when the energy storage device is detected to be connected to the power supply device, the method in step 208 can determine, based on the stored measurements, whether the frequency and / or voltage have been maintained within frequency and / or voltage limits during the observation period prior to the connection of the energy storage device.

[0076] After determining in step 208 that the frequency has been maintained within the frequency limit and the voltage has been maintained within the voltage limit during the observation period, the method proceeds to step 210 and sends a start control signal to the power supply device 104 to allow the energy storage device 106 to exchange power with the power grid 108.

[0077] If the method determines in step 208 that the frequency is not maintained within the frequency limit, the method proceeds to step 212 and generates a start control signal indicating that the energy storage device 106 should supply power to the grid 108 and not draw power from the grid 108 during a first waiting period, or draw power from the grid 108 and not supply power to the grid 108 during a second waiting period.

[0078] Figure 3 A block diagram of a device 302 for a power supply device 104 is shown, the device including components configured to perform... Figure 2 The method includes a control unit 102. The device 302 may include a control unit 102, a memory 306, and a communication unit 310. The control unit 102 may include a central processing unit (CPU) connected to the memory 306 and the communication unit 310.

[0079] The memory 306 may include any suitable known memory device to store data and / or instructions to be executed on the control unit 102, and may include any known type of volatile and non-volatile memory device, RAM and ROM type memory, etc. The memory may be used to store multiple measurements that will be used to determine whether the frequency and / or voltage of the power grid are within frequency and / or voltage limits.

[0080] Communication unit 310b is configured to send signals to and receive signals from devices external to control unit 102, such as electric vehicle 112 or measuring device 114. Any known and suitable transceiver device can be used for this purpose using any known or still-developing (standard) communication technology, including 2G, 3G, 4G, 5G, Wi-Fi, Bluetooth, NFC, etc. For this purpose, communication unit 310b can be connected to a network and an antenna.

[0081] While this disclosure has been described with reference to exemplary embodiments, those skilled in the art will understand that various changes can be made and elements can be substituted with equivalents without departing from the scope of this disclosure. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of this disclosure without departing from the basic scope of this disclosure. Therefore, it is intended that this disclosure be limited to the specific embodiments disclosed, but rather that this disclosure will include all embodiments falling within the scope of the appended claims.

Claims

1. A control unit (102) for controlling a power supply device (104), the power supply device (104) being configured for power supply between an energy storage device (106) and a power grid (108) supplying power to a connection point (110), the control unit (102) being configured to: • Receive first data indicating whether the energy storage device (106) is connected to the power supply device (104); • Using the first data, detect that the energy storage device is connected to the power supply equipment (104). • Obtain second data indicating the frequency and voltage of the power exchanged at the connection point (110) during the observation period; • Using the second data, determine whether the frequency has been maintained within the frequency limit and whether the voltage has been maintained within the voltage limit during the observation period; as well as • A start control signal is sent to the power supply equipment (104) to instruct the energy storage device (106) to exchange power with the power grid (108).

2. A method for controlling a power supply device (104), the power supply device (104) being configured for power supply between an energy storage device (106) and a power grid (108) supplying power to a connection point (110), the method comprising: • Receive (202) first data indicating whether the energy storage device (106) is connected to the power supply device (104); • Using the first data, detect (204) that the energy storage device is connected to the power supply device (104). • Obtain (206) second data indicating the frequency and voltage of the power exchanged at the connection point (110) during the observation period; • Using the second data, determine (208) whether the frequency has been maintained within the frequency limit and whether the voltage has been maintained within the voltage limit during the observation period; as well as • Provide the power supply equipment (104) with a start control signal (210) indicating that the energy storage device (106) is allowed to exchange power with the power grid (108).

3. The control unit (102) according to claim 1 or the method according to claim 2, wherein, If the second data indicates that the frequency of the power grid (108) is not maintained within the frequency limit during the observation period, the start control signal indicates that the energy storage device (106) should supply power to the power grid (108) and not draw power from the power grid (108) during the first waiting period, or draw power from the power grid (108) and not supply power to the power grid (108) during the second waiting period.

4. The control unit (102) or method according to claim 3, wherein, The second data, which indicates the frequency and voltage of the power exchanged at the connection point (110) during the observation period, is obtained based on multiple frequency and voltage measurements of the power exchanged during the observation period.

5. The control unit (102) or method according to claim 4, wherein, If the average of the plurality of frequency measurements is between a higher frequency threshold and a lower frequency threshold, or if a number of the plurality of measurements is between the higher frequency threshold and the lower frequency threshold, then the frequency has been maintained within the frequency limit, and / or if the average of the plurality of voltage measurements is between a higher voltage threshold and a lower voltage threshold, or if another number of the plurality of voltage measurements is between the higher voltage threshold and the lower voltage threshold, then the voltage has been maintained within the voltage limit.

6. The control unit (102) or method according to claim 5, wherein, If the average of the plurality of frequency measurements and / or at least one of the plurality of frequency measurements is higher than the higher frequency threshold, the start control signal instructs the energy storage device (106) to draw power from the grid (108) and not supply power to the grid (108) during the second waiting period.

7. The control unit (102) or method according to claim 5, wherein, If the average value of the plurality of frequency measurements and / or at least one of the plurality of frequency measurements is lower than the lower frequency threshold, the start control signal instructs the energy storage device (106) to supply power to the grid (108) and not to draw power from the grid (108) during the first waiting period.

8. The control unit (102) or method according to claim 4, wherein, The multiple frequency and voltage measurements are obtained by a measuring device (114) connected to the connection point (110) or by the power supply device (104).

9. The control unit (102) or method according to any one of the preceding claims, wherein, The power supply device (104) is configured for bidirectional power supply between the energy storage device (106) and the power grid (108), and if the frequency has been maintained within the frequency limit and the voltage has been maintained within the voltage limit during the observation period, the start control signal indicates that the energy storage device (106) is allowed to exchange power bidirectionally with the power grid (108).

10. The control unit (102) or method according to any one of claims 3-9, wherein, The first waiting period and the second waiting period are based on the amount of time required for the power grid to restore the frequency to the frequency limit.

11. The control unit (102) or method according to any one of the preceding claims, wherein, The energy storage device (106) is located at the electric vehicle (112).

12. The control unit (102) or method according to any one of the preceding claims, wherein, The observation period includes the time before the energy storage device (106) is detected to be connected to the power supply device (104).

13. The control unit (102) or method according to claim 5, wherein, The higher frequency threshold is greater than the lower frequency threshold and / or the higher voltage threshold is greater than the lower voltage threshold.

14. An electric vehicle power supply device (104) comprising a control unit (102) according to any one of claims 1 or 3-13.

Images