Power control system and power control method for preventing countercurrent and overdemand

Abstract

The invention provides a power control system and a power control method for preventing countercurrent and overdemand, and the power control system comprises a power regulation unit, a power grid, and a power supply unit. The power regulation unit is connected with the power grid and is configured to obtain first grid side power of the power grid and determine whether countercurrent or over-demand exists or not based on the first grid side power; the power adjusting unit is connected with the power supply unit, and is further configured to obtain second network side power of the power grid and output power of the power supply unit under the condition of countercurrent or over-demand, and adjust the output power based on the second network side power; wherein the transmission delay of the second network side power is smaller than that of the first network side power. In this way, under the condition that demand exceeding or countercurrent is detected, the power adjusting unit can rapidly adjust the output power of the power supply unit to meet the actual demand of the load, and stable operation of the power grid is kept.

Description

Technical Field

[0001] The present disclosure relates to the field of power control, and in particular to a power control system and a power control method. Background Art

[0002] When the inverter is working normally, the load will increase and decrease continuously. The inverter needs to be operated by the operator and set the corresponding power according to the required power to adapt to the use of the load. If the operator fails to operate in time, the inverter output power will be greater than the load use and the excess power will flow to the power grid, causing unpredictable losses to the power grid. At the same time, the inverter output power may be less than the power required by the load. At this time, power will be obtained from the power grid to make up for it, which will cause huge economic losses to customers. The losses caused by these two situations will be huge or even immeasurable, and there will also be losses in manpower and energy.

[0003] At present, the time for energy storage scenarios to prevent backflow / over-demand strategies in the market is about 10-16 seconds. According to the latest anti-backflow indicators, it is impossible to complete the indicator certification. The anti-over-demand strategy does not have clear indicators, but it can still be completed within the required time like anti-backflow. Summary of the invention

[0004] In view of this, the embodiments of the present disclosure provide a power control system and a power control method for preventing backflow and over-demand, so as to improve the processing speed of the anti-backflow / anti-over-demand strategy.

[0005] The technical solution of the present invention is achieved in this way:

[0006] An embodiment of the present disclosure provides a power control system, including: a power regulation unit, a power grid and a power supply unit; wherein the power regulation unit is connected to the power grid, and is configured to obtain a first grid-side power of the power grid, and determine whether there is a reverse flow or over-demand based on the first grid-side power; the power regulation unit is connected to the power supply unit, and is also configured to obtain a second grid-side power of the power grid and an output power of the power supply unit when there is a reverse flow or over-demand, and adjust the output power based on the second grid-side power; wherein the transmission delay of the second grid-side power is less than that of the first grid-side power.

[0007] In the above solution, the power regulation unit is configured to obtain the redundant power of the power grid, and determine the adjustment range of the output power based on the redundant power of the power grid and the second grid-side power.

[0008] In the above scheme, the power supply unit includes: multiple power supply sub-units; wherein the power adjustment unit is connected to the multiple power supply sub-units, and is also configured to obtain the adjustment time and operating parameters of the multiple power supply sub-units, and set the power change curve of each power supply sub-unit based on the adjustment time, the operating parameters and the adjustment amplitude.

[0009] In the above scheme, the power control system includes: a first link and a second link; wherein the power regulation unit connects the power grid and the power supply unit through the first link and the second link; the transmission delay of the first link is smaller than that of the second link; the operating parameters, the output power and the second grid-side power are all transmitted through the first link; and the first grid-side power is transmitted through the second link.

[0010] In the above scheme, the redundant power includes: excess demand power and reverse flow power; the power adjustment unit is configured to adjust the adjustment amplitude to the difference between the reverse flow power and the second grid-side power when there is reverse flow; or, when there is excess demand, adjust the adjustment amplitude to the difference between the excess demand power and the second grid-side power.

[0011] In the above scheme, the adjustment time is less than 2S.

[0012] In the above scheme, the operating parameters include one or more of battery state of charge, battery temperature and battery health; and / or, the operating parameters include one or more of the number of photovoltaic modules, the number of channels at the maximum power point and the illuminance.

[0013] An embodiment of the present disclosure also provides a power control method, including: obtaining a first grid-side power of a power grid, and determining whether there is a reverse flow or over-demand based on the first grid-side power; in the presence of a reverse flow or over-demand, obtaining a second grid-side power of the power grid and an output power of a power supply unit, and adjusting the output power based on the second grid-side power; wherein a transmission delay of the second grid-side power is less than that of the first grid-side power.

[0014] In the above scheme, adjusting the output power based on the second grid-side power includes: acquiring the redundant power of the grid, and determining the adjustment range of the output power based on the redundant power of the grid and the second grid-side power.

[0015] In the above scheme, the power supply unit includes: multiple power supply sub-units; the power control method also includes: obtaining the adjustment time and operating parameters of the multiple power supply sub-units, and setting the power change curve of each power supply sub-unit based on the adjustment time, the operating parameters and the adjustment amplitude.

[0016] The disclosed embodiment provides a power control system, including: a power regulating unit, a power grid and a power supply unit; wherein the power regulating unit is connected to the power grid, and is configured to obtain the first grid-side power of the power grid, and determine whether there is a reverse flow or over-demand based on the first grid-side power; the power regulating unit is connected to the power supply unit, and is also configured to obtain the second grid-side power of the power grid and the output power of the power supply unit in the presence of reverse flow or over-demand, and adjust the output power based on the second grid-side power; wherein the transmission delay of the second grid-side power is less than that of the first grid-side power. In this way, during the normal operation of the power control system, the delay of the first grid-side power is relatively large, so as to avoid generating a large amount of repeated or similar data in a short time, so that the power regulating unit collects and processes the first grid-side power, which will not cause a large amount of resource consumption, and prevent collapse or performance degradation due to overload.

[0017] At the same time, the power regulation unit uses the second grid-side power with a smaller delay to regulate the output power of the power supply unit, which can significantly improve the response speed of the power regulation unit's regulation process. Therefore, when over-demand or reverse flow is detected, the power regulation unit can quickly adjust the output power of the power supply unit to match the actual demand of the load and maintain the stable operation of the power grid.

[0018] In addition, the second grid-side power and output power with smaller delay can accurately reflect the real-time status of the power supply unit and the power grid, avoiding multiple adjustments by the power regulation unit, thereby reducing the regulation time of over-demand and reverse flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of the power control system provided in the embodiment of the present disclosure Figure 1 ;

[0020] Figure 2 A schematic diagram of the structure of the power control system provided in the embodiment of the present disclosure Figure 2 ;

[0021] Figure 3 A schematic diagram of the structure of the power control system provided in the embodiment of the present disclosure Figure 3 ;

[0022] Figure 4 A schematic diagram of the structure of the power control system provided in the embodiment of the present disclosure Figure 4 ;

[0023] Figure 5 A schematic diagram of the structure of the power control system provided in the embodiment of the present disclosure Figure 5 ;

[0024] Figure 6 A schematic diagram of the power control method provided in the embodiment of the present disclosure Figure 1 ;

[0025] Figure 7 A schematic diagram of the power control method provided in the embodiment of the present disclosure Figure 2 ;

[0026] Figure 8 A schematic diagram of the power control method provided in the embodiment of the present disclosure Figure 3 ;

[0027] Fig. 9 A schematic diagram of the power control method provided in the embodiment of the present disclosure Figure 4 ;

[0028] Fig.10 Schematic diagram of the power variation curve provided in the embodiment of the present disclosure Figure 1 ;

[0029] Fig.11 Schematic diagram of the power variation curve provided in the embodiment of the present disclosure Figure 2 . DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the technical solutions of the present disclosure are further elaborated in detail below in conjunction with the drawings and embodiments. The described embodiments should not be regarded as limiting the present disclosure. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0031] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0032] If similar descriptions of "first / second" appear in the application documents, the following description is added. In the following description, the terms "first / second / third" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It is understandable that "first / second / third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of the present disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. The terms used herein are only for the purpose of describing the embodiments of the present disclosure and are not intended to limit the present disclosure.

[0034] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0035] Figure 1 is a schematic diagram of a power control system 100 for preventing reverse flow and over-demand provided in an embodiment of the present disclosure, with reference to Figure 1 The power control system 100 includes a power conditioning unit 20, a power grid 10, and a power supply unit 30. The power supply unit 30 may include one or more of a photovoltaic device and an energy storage device.

[0036] In the embodiments of the present disclosure, reference Figure 1 , the power regulating unit 20 is connected to the power grid 10. The power regulating unit 20 is configured to obtain the first grid-side power of the power grid 10, and determine whether there is reverse flow or over-demand based on the first grid-side power. For example, the power grid 10 may be provided with a measuring device such as a grid-side electric meter, and the power regulating unit 20 may be connected to the measuring device such as the grid-side electric meter to obtain parameters such as the voltage and current of the power grid in real time, and obtain the grid-side power of the power grid by calculation.

[0037] It should be noted that the reference Figure 1 "Backflow" refers to the unexpected backflow of electric energy from the power generation system to the power grid. For example, when the power output of the power supply unit 30 such as a photovoltaic device or an energy storage device is greater than the power of the load 40, the excess electric energy will be sent to the power grid, causing "backflow". "Overdemand" means that the power demand of the load exceeds the power supply capacity of the power grid or the agreed power consumption. For example, when the power output of the power supply unit 30 such as a photovoltaic device or an energy storage device is less than the power of the load 40, the load 40 will obtain electric energy from the power grid, causing "overdemand". In other words, both "backflow" and "overdemand" will affect the stable operation of the power grid 10.

[0038] In the embodiments of the present disclosure, reference Figure 1 , the power adjustment unit 20 can determine whether there is reverse flow or over-demand according to the first grid-side power. For example, if the first grid-side power is a positive value (i.e., the power output of the power supply unit 30 is greater than the power of the load), the power control system 100 has a reverse flow phenomenon. If the first grid-side power is a negative value (i.e., the power output of the power supply unit 30 is less than the power of the load), the power control system 100 has an over-demand phenomenon.

[0039] In the embodiments of the present disclosure, reference Figure 1, the power regulating unit 20 is connected to the power supply unit 30. The power regulating unit 20 is also configured to obtain the second grid-side power of the power grid 10 and the output power of the power supply unit 30 in the presence of reverse flow or over-demand. The power regulating unit 20 is also configured to adjust the output power of the power supply unit 30 based on the second grid-side power. For example, in the case of reverse flow in the power control system 100, the reverse flow can be prevented by reducing the output power of the power supply unit 30, and the reduction in the output power of the power supply unit 30 can be equal to the second grid-side power. In the case of over-demand in the power control system 100, the over-demand can be prevented by increasing the output power of the power supply unit 30, and the increase in the output power of the power supply unit 30 can be equal to the second grid-side power.

[0040] In the embodiments of the present disclosure, reference Figure 1 , the regulation process of reverse flow and over-demand of the power control system 100 needs to respond quickly, otherwise it will affect the normal operation of the power grid 10 and cause losses. In the regulation process that requires a quick response, timely data collection is crucial. If data collection is not timely, it may not accurately reflect the actual state of the system, and the regulation strategy needs to be adjusted repeatedly, causing the regulation process to become lengthy and inefficient. For example, if there is a delay in the acquisition of the second grid-side power of the power grid 10, the regulation amplitude of the output power of the power supply unit 30 will deviate. The power supply unit 30 adjusts the output power according to the deviated regulation amplitude, so that the power control system 100 still has over-demand or reverse flow. Furthermore, the power regulation unit 20 needs to be adjusted repeatedly for multiple times to eliminate the over-demand or reverse flow of the power control system 100. In other words, data delays will affect the adjustment process of reverse flow and over-demand, and extend the adjustment time.

[0041] In the embodiments of the present disclosure, reference Figure 1 , the transmission delay of the second grid-side power is less than that of the first grid-side power. For example, the power adjustment unit 20 can establish dual channels with the grid 10 and the power supply unit 30, respectively, and sensitive data such as the second grid-side power is transmitted through the channel with a smaller delay, and data such as the first grid-side power is transmitted through the channel with a larger delay.

[0042] It can be understood that the embodiment of the present disclosure can determine whether there is over-demand and backflow in the power control system 100 through the first grid-side power. And, the output power of the power supply unit is adjusted using the second grid-side power with smaller delay. In this way, during the normal operation of the power control system 100, the delay of the first grid-side power is large, and the transmission frequency of the first grid-side power is reduced, thereby avoiding the generation of a large amount of repeated or similar data in a short period of time. Therefore, the power regulation unit 20 collects and processes the first grid-side power without causing a large amount of resource consumption, thereby preventing the power regulation unit 20 from crashing or performance degradation due to overload.

[0043] At the same time, the power regulating unit 20 uses the second grid-side power with a smaller delay to regulate the output power of the power supply unit 30, which can significantly improve the response speed of the regulation process of the power regulating unit 20. Therefore, when over-demand or reverse flow is detected, the power regulating unit 20 can quickly adjust the output power of the power supply unit 30 to match the actual demand of the load 40 and maintain the stable operation of the power grid 10.

[0044] In addition, the second grid-side power and output power with smaller delay can accurately reflect the real-time status of the power supply unit 30 and the power grid 10, avoiding multiple adjustments by the power regulation unit 20, thereby reducing the regulation time of over-demand and reverse flow.

[0045] Figure 2 It is a structural diagram of another optional power control system 100 provided in an embodiment of the present disclosure. It should be noted that the power regulation unit 20 may include a controller 210, and the controller 210 may be a processor such as a central processing unit (CPU). The controller 210 can monitor the first grid-side power and the second grid-side power of the power grid 10 through the grid-side electric meter 11. The power supply unit 30 may include one or more of an energy storage cabinet and a photovoltaic solar panel. The photovoltaic inverter (PV inverter) 301 is used to control the output power of the photovoltaic solar panel. The energy storage converter (PCS, Power Conversion System) 302 is used to control the output power of the energy storage cabinet. The controller 210 can also monitor and adjust the output power of the power supply unit 30 through the photovoltaic inverter 301 or the energy storage converter 302 in the power supply unit 30.

[0046] In some embodiments of the present disclosure, reference Figure 2 The power regulating unit 20 is configured to obtain the redundant power of the power grid 10 and determine the adjustment range of the output power based on the redundant power of the power grid 10 and the second grid-side power.

[0047] It should be noted that the output power of photovoltaic solar panels is affected by many factors such as light intensity and temperature. If the adjustment range is too large, the photovoltaic solar panels may not be able to adapt to these changes in time, resulting in unstable output. The energy storage cabinet generates heat during the charging and discharging process. When the power adjustment range of the energy storage cabinet is too large, the energy storage cabinet may not be able to dissipate heat in time, resulting in overheating or even damage, which may cause safety accidents such as battery short circuit and fire.

[0048] In the embodiments of the present disclosure, reference Figure 2, during the actual operation of the power grid 10, the power grid 10 will allow a smaller amount of reverse flow or over-demand. Therefore, the power regulation unit 20 determines the adjustment amplitude of the output power based on the redundant power of the power grid 10 and the second grid-side power. For example, in the presence of a reverse flow, the controller 201 can adjust the adjustment amplitude of the output power of the power supply unit 30 to the difference between the reverse flow power and the second grid-side power. In this way, the embodiment of the present disclosure can reduce the adjustment amplitude of the output power of the power supply unit 30 while ensuring that the reverse flow and over-demand that affect the normal operation of the power grid 10 can be handled in a timely manner, thereby avoiding damage to the power supply unit 30.

[0049] In some embodiments of the present disclosure, reference Figure 1 , the redundant power includes the excess power and the reverse flow power. The power regulating unit 20 is configured to adjust the regulation amplitude to the difference between the reverse flow power and the second grid side power when there is a reverse flow. For example, when there is a reverse flow, the power regulating unit 20 regulates the output power of the power supply unit 30 according to the following formula (1).

[0050] P final = P current - (P grid side - P allowed reverse flow) formula (1)

[0051] It should be noted that in formula (1), P grid side can be the second grid side power, and P current is the output power before the power supply unit 30 is adjusted. P final is the output power after the power supply unit 30 is adjusted, that is, the target power adjusted by the power supply unit 30. P allowed reverse flow is the reverse flow power. "P grid side - P allowed reverse flow" is the adjustment range of the output power of the power supply unit 30.

[0052] In the embodiments of the present disclosure, reference Figure 1 In the case of excess demand, the power adjustment unit 20 can adjust the adjustment range to the difference between the excess demand power and the second grid-side power. For example, the power adjustment unit 20 adjusts the output power of the power supply unit 30 according to the following formula (2).

[0053] P final = P current - (P network side - P allowed excess demand) formula (2)

[0054] It should be noted that in formula (2), P grid side is the second grid side power, and P current is the output power before the power supply unit 30 is adjusted. P final is the output power after the power supply unit 30 is adjusted, that is, the target power adjusted by the power supply unit 30. P allowed reverse flow is the excess power. "P grid side - P allowed excess power" is the adjustment range of the output power of the power supply unit 30.

[0055] Figure 3 is an optional structural diagram of an optional power control system 100 provided in an embodiment of the present disclosure. It should be noted that: Figure 3The controller 210 , the photovoltaic inverter 301 and the energy storage rheostat 302 shown in FIG. 2 can be understood by referring to FIG. 2 . Figure 3 The controller 210 shown establishes a first link 51 and a second link 52 with the grid-side electric meter, the photovoltaic inverter 301 and the energy storage rheostat 302, respectively, that is, a first link 51 and a second link 52 are set between the power regulation unit and the grid and the power supply unit. A larger number of links can be set between the power regulation unit and the grid and the power supply unit, which is not limited here.

[0056] In some embodiments of the present disclosure, Figure 2 and Figure 3 The power control system 100 includes a first link 51 and a second link 52. The power adjustment unit 20 can connect the power grid 10 and the power supply unit 30 through the first link 51 and the second link 52. The transmission delay of the first link 51 is less than that of the second link 52.

[0057] It should be noted that, combined with Figure 2 and Figure 3 When the power regulating unit 20 collects data, it usually uses protocols such as the Modbus protocol for communication. However, due to the message length limitation of protocols such as the Modbus protocol, the power regulating unit 20 has a limited number of registers to query each time, and some data may not be collected and transmitted in time, which will cause delays in data collection.

[0058] In the present disclosure, Figure 2 and Figure 3 , the power regulating unit 20 can communicate with the power grid 10 and the power supply unit 30 through the TCP / IP protocol. The power regulating unit 20 can establish a first link 51 and a second link 52 with the power grid 10 and the power supply unit 30 respectively by creating multiple sockets. Furthermore, the power regulating unit 20 can communicate with the power grid 10 and the power supply unit 30 through the first link 51 and the second link 52.

[0059] In the present disclosure, Figure 2 and Figure 3 , the operating parameters, output power and second grid-side power are all transmitted through the first link 51. The first grid-side power is transmitted through the second link 52. In this way, the delay of the first grid-side power is large, the transmission frequency of the first grid-side power is reduced, and the power adjustment unit 20 collects and processes the first grid-side power without causing a large amount of resource consumption, thereby preventing the power adjustment unit 20 from crashing or performance degradation due to overload. The second grid-side power and output power with smaller delay can accurately reflect the real-time status of the power supply unit 30 and the power grid 10, avoiding multiple adjustments by the power adjustment unit 20, thereby reducing the adjustment time of over-demand and reverse flow.

[0060] It should be noted that the power regulating unit 20 can switch the communication protocol to increase the data acquisition speed during the over-demand or reverse flow strategy adjustment process. For example, the power regulating unit 20 can communicate with the measuring device of the power grid 10 through the IEC104 communication protocol, thereby increasing the transmission speed of the second grid-side power.

[0061] In some embodiments of the present disclosure, reference Figure 1 The power supply unit 30 includes a plurality of power supply sub-units. The power adjustment unit 20 is connected to the plurality of power supply sub-units and is further configured to obtain the adjustment time and the operating parameters of the plurality of power supply sub-units, and to set the power variation curve of each power supply sub-unit based on the adjustment time, the operating parameters and the adjustment amplitude.

[0062] Figure 4 and Figure 5 is an optional schematic diagram of a power control system 100 provided in an embodiment of the present disclosure. It should be noted that: Figure 4 and Figure 5 The grid-side electric meter 11 and the load 40 in the embodiment can be understood with reference to the above embodiments, and will not be described in detail here. Figure 5 The inverters 1 to n in the figure can respectively correspond to a power supply sub-unit. Figure 4 The energy storage cabinets 1 to n in the power supply unit 30 may correspond to a power supply sub-unit respectively. The multiple power supply sub-units in the power supply unit 30 may also be a combination of energy storage cabinets and photovoltaic solar panels. The photovoltaic total power meter 331 is used to collect the output power of the inverters 1 to n. The main control cabinet 320 is used to monitor and control the charging and discharging process of the energy storage cabinets 1 to n. Figure 1 The power regulation unit 20 can be set in the main control cabinet 320.

[0063] It should also be noted that since the reverse flow / over-demand regulation process is adjusted in real time according to the current system output power, load power, and grid-side power, further strategies need to be made in the allocation method to reduce system losses. For example, when the battery state of charge value of any energy storage cabinet is small, the battery health value is small, and the battery temperature is high, the output efficiency of the energy storage cabinet is low, and dispatching its high-power generation will cause a lot of waste and accelerate battery damage.

[0064] In the present disclosure, in combination Figure 1 and Figure 4, the power adjustment unit 20 can set the power change curve of each power supply subunit based on the adjustment time, operating parameters and adjustment amplitude. For example, in the case where the power supply subunit is an energy storage cabinet, the operating parameters include one or more of the battery state of charge (SOC), battery temperature and battery health (SOH). The power adjustment unit 20 can allocate different adjustment amplitudes according to the operating parameters of each energy storage cabinet. Taking the battery temperature as an example for the adjustment amplitude allocation, the specific allocation ratio can be understood by referring to the following Table 1:

[0065] Battery temperature Allocation ratio Tmax>Tbattery>Taverage 30％ Tmin < T battery ≤ T average 90％ T battery = Tmax 20％ T battery = Tmin 100％

[0066] Table 1

[0067] It should be noted that the power regulation unit 20 can allocate the power ratio by setting the average temperature (Taverage), the maximum temperature (Tmax) and the minimum temperature (Tmin). The allocation ratio is the ratio of the adjustment range of each energy storage cabinet to the total adjustment range. The battery state of charge (SOC) and battery health (SOH) can be understood with reference to the battery temperature and will not be repeated here.

[0068] In the present disclosure, in combination Figure 1 and Figure 5 In the case where the power supply unit is a photovoltaic solar panel, the operating parameters include one or more of the number of photovoltaic modules, the number of channels at the maximum power point, and the illuminance. The number of photovoltaic modules, the number of channels at the maximum power point, and the illuminance can be understood by referring to the battery state of charge (SOC), battery temperature, and battery health (SOH) of the energy storage cabinet, respectively, and will not be repeated here.

[0069] In some embodiments of the present disclosure, the adjustment time is less than 2S.

[0070] In the embodiments of the present disclosure, reference Figure 1 When the power generated by the power supply unit 30 exceeds the local load demand and is likely to flow back to the grid 10, if the backflow regulation time is less than 2 seconds, it helps to maintain the voltage and frequency stability of the grid 10 and avoid fluctuations in the grid 10 caused by the backflow. Thus, the equipment of the grid 10 is protected from damage to extend its service life.

[0071] Figure 6 is an optional flow chart of the power control method provided by the embodiment of the present disclosure, which will be combined with Figure 6 The steps shown are explained. Figure 6 The method shown in Figure 1 The power control system 100 shown is implemented.

[0072] S101. Obtain a first grid-side power of a power grid, and determine whether there is a reverse flow or over-demand based on the first grid-side power.

[0073] S102. In the presence of reverse flow or over-demand, obtain the second grid-side power of the power grid and the output power of the power supply unit, and adjust the output power based on the second grid-side power; wherein the transmission delay of the second grid-side power is less than that of the first grid-side power.

[0074] In the embodiments of the present disclosure, reference Figure 1 , the power regulation unit 20 can determine whether there is reverse flow or over-demand based on the first grid-side power.

[0075] The judgment and treatment process of backflow can be referred to Figure 7 To understand the steps in:

[0076] S1101. Start.

[0077] S1102. Detect grid-side power.

[0078] S1103: Detect that the grid-side power exceeds the permissible reverse flow value.

[0079] S1104. Execute anti-backflow strategy.

[0080] In the present disclosure, in combination Figure 1 and Figure 7 The power control unit 20 can detect the grid-side power (e.g., the first grid-side power) of the grid 10. If it is found that the grid-side power of the grid 10 exceeds the allowable reverse flow range (i.e., the grid-side power is greater than the power value corresponding to the reverse flow control line), the reverse flow prevention strategy is immediately executed. Fig.10 The power change curve is set according to the power of the second grid side.

[0081] The judgment and processing process of excess demand can be referred to Figure 8 To understand the steps in:

[0082] S2101, start.

[0083] S2102. Detect the grid-side power.

[0084] S2103: Detect whether the grid-side power exceeds the allowed value.

[0085] S2104. Implement strategies to prevent over-demand.

[0086] In the present disclosure, in combination Figure 1 and Figure 8The power control unit 20 can detect the grid-side power (e.g., the first grid-side power) of the grid 10. If it is found that the grid-side power of the grid 10 exceeds the reverse flow allowable range (i.e., the grid-side power is less than the power value corresponding to the over-demand prevention control line), the over-demand prevention strategy is immediately executed. Fig.10 The power change curve is set according to the second grid side power.

[0087] The judgment and processing process of callback can refer to Fig. 9 To understand the steps in:

[0088] S3101, start.

[0089] S3102. Detect the grid-side power.

[0090] S3103: Detect that the grid-side power is neither reverse-flow nor over-demand.

[0091] S3104. Execute the callback strategy.

[0092] In the present disclosure, in combination Figure 1 and Fig. 9 The power control unit 20 can detect the grid-side power (e.g., the first grid-side power) of the grid 10. If it is found that the grid-side power of the grid 10 is neither reverse nor over-demand (i.e., the grid-side power is between the power values ​​corresponding to the over-demand prevention control line and the reverse flow prevention control line), the callback strategy is immediately executed. The execution process of the callback strategy is referred to in Fig.10 The power change curve is set according to the second grid side power.

[0093] In the embodiments of the present disclosure, reference Figure 1 In the energy storage scenario (i.e., the power supply unit only includes the energy storage cabinet), the power conditioning unit 20 can be Fig.10 In the scenario of photovoltaic storage (i.e., the power supply unit only includes photovoltaic solar panels and energy storage cabinets), since the energy storage backflow prevention is executed faster than the photovoltaic backflow prevention, the power adjustment unit 20 can adjust the output power of the energy storage cabinet and the like. Fig.11 In the photovoltaic application scenario (i.e., the power supply unit only includes photovoltaic solar panels), after a period of stabilization without reverse flow and without over-demand, the control method of the power control unit 20 can refer to Fig.10 Please understand and I will not elaborate on it here.

[0094] In some embodiments of the present disclosure, S201 can also be used to implement Figure 6 In S102, each step will be described in combination.

[0095] S201. Obtain redundant power of a power grid, and determine an adjustment range of output power based on the redundant power of the power grid and the second grid-side power.

[0096] In the embodiments of the present disclosure, reference Figure 1 , the power regulating unit 20 can determine the adjustment amplitude of the output power based on the redundant power of the power grid and the second grid-side power. For example, in the presence of reverse flow, the power regulating unit 20 can adjust the adjustment amplitude of the output power of the power supply unit 30 to the difference between the excess power and the second grid-side power. In this way, the embodiment of the present disclosure can reduce the adjustment amplitude of the output power of the power supply unit 30 while avoiding the influence of reverse flow and excess demand on the normal operation of the power grid 10, thereby avoiding damage to the power supply unit 30.

[0097] In some embodiments of the present disclosure, S301 can also be used to implement Figure 6 In S102, each step will be described in combination.

[0098] S103, obtaining the adjustment time and the operating parameters of the plurality of power supply subunits, and setting the power variation curve of each power supply subunit based on the adjustment time, the operating parameters and the adjustment amplitude.

[0099] In the embodiments of the present disclosure, reference Figure 1 The power adjustment unit 20 can adjust the power change curve of each power supply subunit according to the operating parameters, adjustment amplitude and adjustment time. In this way, the adjustment amplitude of each power supply subunit can match the change of the operating parameters, thereby reducing the fluctuation and instability of the system. Thus, the collapse of the entire system caused by the failure or abnormality of a single unit can be prevented.

[0100] The serial numbers of the embodiments of the present disclosure are for description only and do not represent the advantages and disadvantages of the embodiments. The methods disclosed in the several method embodiments provided by the present disclosure can be arbitrarily combined without conflict to obtain new method embodiments. The features disclosed in the several product embodiments provided by the present disclosure can be arbitrarily combined without conflict to obtain new product embodiments. The features disclosed in the several method or device embodiments provided by the present disclosure can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0101] The above description is only a specific implementation mode of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure.

Claims

1. A power control system for preventing backflow and over-demand, characterized in that: include: Power conditioning unit, power grid and power supply unit; wherein, The power regulating unit is connected to the power grid and is configured to obtain a first grid-side power of the power grid and determine whether there is a reverse flow or over-demand based on the first grid-side power; The power regulation unit is connected to the power supply unit, and is also configured to obtain the second grid-side power of the power grid and the output power of the power supply unit in the presence of reverse flow or overdemand, and adjust the output power based on the second grid-side power; wherein the transmission delay of the second grid-side power is less than that of the first grid-side power.

2. The power control system according to claim 1, characterized in that: The power regulation unit is configured to obtain the redundant power of the power grid, and determine the regulation amplitude of the output power based on the redundant power of the power grid and the second grid-side power.

3. The power control system according to claim 2, characterized in that: The power supply unit comprises: a plurality of power supply sub-units; wherein, The power regulating unit is connected to a plurality of the power supply sub-units, and is also configured to obtain the regulating time and the operating parameters of the plurality of the power supply sub-units, and to set the power variation curve of each of the power supply sub-units based on the regulating time, the operating parameters and the regulating amplitude.

4. The power control system according to claim 3, characterized in that: The power control system comprises: a first link and a second link; wherein, The power regulating unit connects the power grid and the power supply unit through the first link and the second link; the transmission delay of the first link is smaller than that of the second link; The operating parameter, the output power and the second network-side power are all transmitted through the first link; and the first network-side power is transmitted through the second link.

5. The power control system according to claim 2, characterized in that: The redundant power includes: excess power and reverse power; The power regulation unit is configured to adjust the regulation amplitude to the difference between the reverse flow power and the second grid-side power when there is reverse flow; or to adjust the regulation amplitude to the difference between the excess demand power and the second grid-side power when there is excess demand.

6. The power control system according to claim 3, characterized in that: The adjustment time is less than 2S.

7. The power control system according to claim 3, characterized in that: The operating parameters include one or more of a battery state of charge, a battery temperature, and a battery health; and / or, the operating parameters include one or more of a number of photovoltaic modules, a number of channels at a maximum power point, and illuminance.

8. A power control method for preventing backflow and over-demand, characterized in that: include: Acquire a first grid-side power of the power grid, and determine whether there is reverse flow or over-demand based on the first grid-side power; In the presence of reverse flow or over-demand, the second grid-side power of the power grid and the output power of the power supply unit are obtained, and the output power is adjusted based on the second grid-side power; wherein the transmission delay of the second grid-side power is less than that of the first grid-side power.

9. The power control method according to claim 8, characterized in that: Adjusting the output power based on the second network-side power includes: The redundant power of the power grid is obtained, and based on the redundant power of the power grid and the second grid-side power, an adjustment range of the output power is determined.

10. The power control method according to claim 9, characterized in that: The power supply unit comprises: a plurality of power supply sub-units; The power control method further comprises: The adjustment time and the operating parameters of the plurality of power supply subunits are acquired, and based on the adjustment time, the operating parameters and the adjustment amplitude, a power variation curve of each power supply subunit is set.

Images