Control method for automatic charging and discharging of industrial and commercial energy storage system

Abstract

The invention provides a control method for automatic charging and discharging of an industrial and commercial energy storage system. Relates to the technical field of automatic charging and discharging of industrial and commercial energy storage systems, and comprises the following steps: S1, starting a switch on an electric power storage device to enable a power grid to charge the electric power storage device, and turning on the electric power storage device to discharge; s2, acquiring and collecting the battery temperature of the energy storage battery pack, checking whether the battery temperature is normal or not, and if the temperature is too high, reducing or cutting off the power grid to charge the battery pack, and closing the battery pack to discharge so as to prevent the battery from being damaged; and S3, the output frequency of the power grid is acquired and collected, the change of the output frequency of the power grid is monitored in real time, and under the normal condition, the frequency of the power grid is generally kept at 50Hz or 60Hz (different national and regional standards may be different). When the power grid breaks down or the load changes greatly, the frequency deviates from the standard value, the output power of the generator can be adjusted at the moment, and the frequency of the power grid is stabilized.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic charging and discharging of industrial and commercial energy storage systems, and in particular to a control method for automatic charging and discharging of industrial and commercial energy storage systems. Background Art

[0002] As the world pays more attention to renewable energy and its application scale continues to expand, the proportion of intermittent renewable energy such as solar energy and wind energy connected to the power grid is increasing. The power generation of these renewable energy sources is volatile and uncertain. For example, solar energy depends on sunshine, and wind energy depends on wind speed and stability. This intermittency will cause power fluctuations in the power grid, affecting the stability of the power grid and the quality of power.

[0003] Some traditional control methods use relatively simple control strategies during the charge and discharge control process, such as timing control or simple threshold control. Timing control only charges and discharges according to the preset time and cannot be adjusted in real time according to the grid status and load demand. For example, under the time-of-use electricity price strategy, charging and discharging are only performed according to fixed time, resulting in missing the optimal charge and discharge time, and being unable to accurately fully charge when the electricity price is low, and effectively discharge when the electricity price is peak to reduce costs.

[0004] Practical Invention Content

[0005] The technical problem solved by the present invention is to provide a control method for automatic charging and discharging of an industrial and commercial energy storage system which can be adjusted in real time according to the state of the power grid and the load demand.

[0006] In order to solve the above technical problems, the present invention provides a control method for automatic charging and discharging of an industrial and commercial energy storage system, including: S1, starting the switch on the power storage device to enable the power grid to charge the power storage device, and at the same time turning on the power storage device for discharging; S2, obtaining and collecting the battery temperature of the energy storage battery pack, checking whether the battery temperature is normal, if the temperature is too high, reducing or cutting off the power grid charging the battery pack, and turning off the battery pack discharge to avoid battery damage; S3, obtaining and collecting the output frequency of the power grid, and monitoring the changes in the output frequency of the power grid in real time. Under normal circumstances, the power grid frequency is generally maintained at 50Hz or 60Hz (the standards in different countries and regions may be different). When the grid fails or the load changes significantly, the frequency will deviate from this standard value. At this time, the output power of the generator can be adjusted to stabilize the grid frequency; S4, obtain and collect the output voltage of the energy storage battery pack, evaluate the output voltage of the storage device, and determine whether the battery pack is within a reasonable voltage range. If the output voltage of the storage device is lower than the set lower limit (20%), charging needs to be considered; if the output voltage of the storage device is higher than the set upper limit (80%), charging needs to be stopped; S5, obtain and collect real-time electricity prices. When the grid is in peak power consumption, the real-time electricity price is higher than the preset discharge threshold electricity price (for example, 1. 0 yuan / kWh), and the remaining power of the battery pack is higher than 20% of its rated capacity (to ensure that there is enough power to be released and that excessive discharge does not affect the battery life), it is determined whether the user's real-time power load is close to or exceeds the upper limit of its power capacity contract. If there is a risk of peak load, or the grid frequency deviates and exceeds the allowable range (for example, 49.5-50.5Hz), and the voltage fluctuates greatly (the voltage deviation rate exceeds ±5%), it is determined that the discharge conditions are met at this time, and the energy storage system can discharge to the grid to relieve peak pressure, stabilize grid operation, directly supply power to the load of the storage equipment, reduce the amount of power drawn by the storage equipment from the grid, and reduce electricity costs.

[0007] Preferably, the charging device includes a battery pack and a charge and discharge switch, and the charge and discharge switch is used to control the power grid to charge the power storage device and discharge the battery pack.

[0008] Preferably, S2 includes: a temperature sensor for detecting the battery temperature when the battery pack is discharged; a first control module, and a charge and discharge switch for controlling the grid to charge the power storage device and discharge the battery pack.

[0009] Preferably, S3 includes: a frequency sensor, which is a sensor based on the principle of electromagnetic induction, used to detect the output frequency of the power grid. The frequency sensor mainly measures the power grid frequency based on the periodic characteristics of the electrical signal. It can sense the periodic changes of the alternating current in the power grid. When the alternating current in the power grid passes through the induction coil of the sensor, it will generate an induced electromotive force related to the frequency. By measuring and processing the signal of this induced electromotive force, the frequency of the power grid can be obtained; a second control module, used to control the output frequency of the power grid to the storage device and the output voltage of the power grid.

[0010] Preferably, S4 includes: a voltage sensor for detecting the battery voltage when the battery pack is discharging; and a third control module for controlling the charging state of the battery pack by the power grid so that the battery pack maintains a stable output voltage.

[0011] Preferably, the S5 includes: an intelligent networking acquisition module for querying real-time electricity prices; and a fourth control module for controlling the load of the power storage device or adjusting its operating state so as to charge when the electricity price is low and discharge when the electricity price is high.

[0012] Preferably, the first control module, the second control module, the third control module and the fourth control module are connected in series and can be remotely controlled via a wireless transmission module, thus avoiding conflicts between them.

[0013] Preferably, S2 further includes: a power detection module for obtaining the remaining power of the battery pack; and a display module for automatically displaying the remaining power of the battery pack on the body when the remaining power of the battery pack reaches a predetermined value.

[0014] Compared with the related art, the control method for automatic charging and discharging of the industrial and commercial energy storage system provided by the present invention has the following beneficial effects:

[0015] The present invention provides a control method for automatic charging and discharging of an industrial and commercial energy storage system. By acquiring and collecting the output frequency of the power grid, the change of the output frequency of the power grid is monitored in real time. Under normal circumstances, the power grid frequency is generally maintained at 50Hz or 60Hz (the standards in different countries and regions may be different). When a fault occurs in the power grid or a large change occurs in the load, the frequency will deviate from this standard value. At this time, the output power of the generator can be adjusted to stabilize the power grid frequency; S4, acquiring and collecting the output voltage of the energy storage battery pack, evaluating the output voltage of the power storage device, and judging whether the battery pack is within a reasonable voltage range, if the output voltage of the power storage device is lower than the set lower limit (20%), charging needs to be considered; if the output voltage of the power storage device is higher than the set upper limit (80%), charging needs to be stopped to ensure that the output voltage of the battery pack is always within a reasonable voltage range, so that the battery pack can maintain a long-term effective voltage output. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A flowchart of the method for controlling automatic charging and discharging of an industrial and commercial energy storage system provided by the present invention. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0018] Please refer to Figure 1 In the present invention, the control method for automatic charging and discharging of the industrial and commercial energy storage system includes:

[0019] S1, start the switch on the power storage device to allow the power grid to charge the power storage device, and at the same time turn on the power storage device to discharge;

[0020] S2. Obtain and collect the battery temperature of the energy storage battery pack, check whether the battery temperature is normal, and if the temperature is too high, reduce or cut off the power grid to charge the battery pack, and turn off the battery pack discharge to avoid battery damage;

[0021] S3. Obtain and collect the output frequency of the power grid, and monitor the changes in the output frequency of the power grid in real time. Under normal circumstances, the power grid frequency is generally maintained at 50Hz or 60Hz (the standards in different countries and regions may be different). When the power grid fails or the load changes significantly, the frequency will deviate from this standard value. At this time, the output power of the generator can be adjusted to stabilize the power grid frequency;

[0022] S4, obtaining and collecting the output voltage of the energy storage battery pack, evaluating the output voltage of the power storage device, and judging whether the output voltage of the battery pack is within a reasonable voltage range. If the output voltage of the power storage device is lower than the set lower limit (20%), charging needs to be considered; if the output voltage of the power storage device is higher than the set upper limit (80%), charging needs to be stopped;

[0023] S5. Obtain and collect real-time electricity prices. When the power grid is in the peak period of electricity consumption, the real-time electricity price is higher than the preset discharge threshold electricity price (for example, 1.0 yuan / kWh), and the remaining power of the battery pack is higher than 20% of its rated capacity (to ensure that there is enough power to be released and that excessive discharge does not affect the battery life), determine whether the user's real-time power load is close to or exceeds the upper limit of its power capacity contract. If there is a risk of peak load, or the grid frequency deviates and exceeds the allowable range (for example, 49.5-50.5Hz), and the voltage fluctuates greatly (the voltage deviation rate exceeds ±5%), it is determined that the discharge conditions are met at this time. The energy storage system can discharge to the grid to relieve peak pressure and stabilize grid operation, directly supply power to the load of the storage equipment, reduce the amount of electricity drawn by the storage equipment from the grid, and reduce electricity costs.

[0024] The frequency sensor is a sensor based on the principle of electromagnetic induction, which is used to detect the output frequency of the power grid. The frequency sensor mainly measures the power grid frequency based on the periodic characteristics of electrical signals. It can sense the periodic changes of the alternating current in the power grid. When the alternating current in the power grid passes through the induction coil of the sensor, it will generate an induced electromotive force related to the frequency. The frequency of the power grid can be obtained by measuring and processing the signal of this induced electromotive force. In conjunction with the second control module, it is used to control the output frequency of the power grid to the power storage device and the output voltage of the power grid, so as to maintain a stable output frequency of the power storage device and ensure the safety of charging and discharging.

[0025] Compared with the related art, the control method for automatic charging and discharging of the industrial and commercial energy storage system provided by the present invention has the following beneficial effects:

[0026] The present invention provides a control method for automatic charging and discharging of an industrial and commercial energy storage system. By acquiring and collecting the output frequency of the power grid, the change of the output frequency of the power grid is monitored in real time. Under normal circumstances, the power grid frequency is generally maintained at 50Hz or 60Hz (the standards in different countries and regions may be different). When a fault occurs in the power grid or a large change occurs in the load, the frequency will deviate from this standard value. At this time, the output power of the generator can be adjusted to stabilize the power grid frequency; S4, acquiring and collecting the output voltage of the energy storage battery pack, evaluating the output voltage of the power storage device, and judging whether the battery pack is within a reasonable voltage range, if the output voltage of the power storage device is lower than the set lower limit (20%), charging needs to be considered; if the output voltage of the power storage device is higher than the set upper limit (80%), charging needs to be stopped to ensure that the output voltage of the battery pack is always within a reasonable voltage range, so that the battery pack can maintain a long-term effective voltage output.

[0027] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A control method for automatic charging and discharging of an industrial and commercial energy storage system, characterized in that: The steps include: S1, start the switch on the power storage device to allow the power grid to charge the power storage device, and at the same time turn on the power storage device to discharge; S2. Obtain and collect the battery temperature of the energy storage battery pack, check whether the battery temperature is normal, and if the temperature is too high, reduce or cut off the power grid to charge the battery pack, and turn off the battery pack discharge to avoid battery damage; S3. Obtain and collect the output frequency of the power grid, and monitor the changes in the output frequency of the power grid in real time. Under normal circumstances, the power grid frequency is generally maintained at 50Hz or 60Hz (the standards in different countries and regions may be different). When the power grid fails or the load changes significantly, the frequency will deviate from this standard value. At this time, the output power of the generator can be adjusted to stabilize the power grid frequency; S4, obtaining and collecting the output voltage of the energy storage battery pack, evaluating the output voltage of the power storage device, and judging whether the output voltage of the battery pack is within a reasonable voltage range. If the output voltage of the power storage device is lower than the set lower limit (20%), charging needs to be considered; if the output voltage of the power storage device is higher than the set upper limit (80%), charging needs to be stopped; S5. Obtain and collect real-time electricity prices. When the power grid is in the peak period of electricity consumption, the real-time electricity price is higher than the preset discharge threshold price (for example, 1.0 yuan / kWh), and the remaining power of the battery pack is higher than 20% of its rated capacity (to ensure that there is enough power to be released and that excessive discharge does not affect the battery life), determine whether the user's real-time power load is close to or exceeds the upper limit of its power capacity contract. If there is a risk of peak load, or the grid frequency deviates and exceeds the allowable range (for example, 49.5-50.5Hz), and the voltage fluctuates greatly (the voltage deviation rate exceeds ±5%), it is determined that the discharge conditions are met at this time. The energy storage system can discharge to the grid to relieve peak pressure and stabilize grid operation, directly supply power to the load of the storage equipment, reduce the amount of power drawn by the storage equipment from the grid, and reduce electricity costs.

2. The control method for automatic charging and discharging of an industrial and commercial energy storage system according to claim 1, characterized in that: The charging device comprises a battery pack and a charge and discharge switch, wherein the charge and discharge switch is used to control the power grid to charge the power storage device and discharge the battery pack.

3. The control method for automatic charging and discharging of an industrial and commercial energy storage system according to claim 2, characterized in that: Said S2 includes: A temperature sensor, used to detect the battery temperature when the battery pack is discharged; The first control module, the charge and discharge switch is used to control the power grid to charge the power storage device and discharge the battery pack.

4. The control method for automatic charging and discharging of an industrial and commercial energy storage system according to claim 3 is characterized in that: Said S3 includes: The frequency sensor is a sensor based on the principle of electromagnetic induction. It is used to detect the output frequency of the power grid. The frequency sensor mainly measures the power grid frequency based on the periodic characteristics of the electrical signal. It can sense the periodic changes of the alternating current in the power grid. When the alternating current in the power grid passes through the induction coil of the sensor, it will generate an induced electromotive force related to the frequency. By measuring this induced electromotive force and processing the signal, the frequency of the power grid can be obtained. The second control module is used to control the output frequency of the power grid to the power storage device and the output voltage of the power grid.

5. The control method for automatic charging and discharging of an industrial and commercial energy storage system according to claim 4, characterized in that: In said S4, including: A voltage sensor for detecting the battery voltage when the battery pack is discharged; The third control module is used to control the charging state of the battery pack by the power grid so that the battery pack maintains a stable output voltage.

6. The control method for automatic charging and discharging of an industrial and commercial energy storage system according to claim 5, characterized in that: In said S5, including: Intelligent networking collection module, used to query real-time electricity prices; The fourth control module is used to control the load of the power storage device or adjust its operating state so as to charge when the electricity price is low and discharge when the electricity price is high.

7. The control method for automatic charging and discharging of an industrial and commercial energy storage system according to claim 6, characterized in that: The first control module, the second control module, the third control module and the fourth control module are connected in series and can be remotely controlled through a wireless transmission module, so that conflicts between them can be avoided.

8. The control method for automatic charging and discharging of an industrial and commercial energy storage system according to claim 7, characterized in that: The S2 also includes: A power detection module, used to obtain the remaining power of the battery pack; The display module is used to automatically display the remaining power of the battery pack on the body when the remaining power of the battery pack reaches a preset value.

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