Control method, device and equipment of optical storage micro-grid system and medium
By determining whether photovoltaic equipment is transmitting power to transformer equipment in a photovoltaic-storage microgrid system, controlling the charging and discharging of energy storage equipment and adjusting the discharge power of photovoltaic equipment respectively, the problem of insufficient coordinated control between photovoltaic equipment and energy storage equipment is solved, improving the green electricity consumption rate and transformer load rate, and reducing operating costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN SKYWORTH ENERGY STORAGE TECH CO LTD
- Filing Date
- 2026-05-26
- Publication Date
- 2026-07-21
AI Technical Summary
In existing photovoltaic-storage microgrid systems, the coordinated control of photovoltaic equipment and energy storage equipment is insufficient, resulting in low green electricity consumption rate, large fluctuations in transformer load rate, and high cost and long cycle for traditional transformer capacity expansion.
By acquiring the low-voltage side power of the transformer, the photovoltaic discharge power of the photovoltaic equipment, and the load power consumption of the load, it is determined whether the photovoltaic equipment is transmitting power to the transformer. If power is being transmitted, the energy storage equipment is controlled to charge and the photovoltaic discharge is adjusted; if no power is being transmitted, the energy storage equipment is controlled to discharge and the photovoltaic discharge is adjusted, thus achieving coordinated operation of energy storage and photovoltaic.
It improved the efficiency of transformer capacity utilization, increased the self-consumption rate of green electricity, reduced basic electricity costs, and optimized the system's operating costs and stability.
Smart Images
Figure CN122437163A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photovoltaic-storage microgrid technology, and in particular to a control method, device, equipment and medium for a photovoltaic-storage microgrid system. Background Technology
[0002] With the continuous growth of industrial and commercial electricity load and the advancement of power market reform, photovoltaic-storage microgrid systems are widely used on the user side. In existing technologies, traditional solutions to address insufficient transformer capacity mainly rely on transformer capacity expansion, but this suffers from drawbacks such as high investment costs, long expansion cycles, and persistently high basic electricity costs after expansion. On the other hand, systems that have already deployed photovoltaic and energy storage devices typically focus on peak shaving and valley filling for energy storage devices, or on maximum power output for photovoltaic devices. These two aspects are independent of each other, lacking a mechanism for jointly regulating the charging and discharging of energy storage devices and photovoltaic power based on the power transmission status of the photovoltaic devices to the transformer equipment. Therefore, there is an urgent need for a photovoltaic-storage microgrid system control method that can control the charging and discharging of energy storage devices separately and synchronously adjust the discharge power of photovoltaic devices based on whether the photovoltaic system is transmitting power to the transformer equipment. Summary of the Invention
[0003] This invention provides a control method, device, equipment, and medium for a photovoltaic-storage microgrid system to address the problem of insufficient coordinated control between photovoltaic and energy storage devices in related technologies, which leads to low green electricity absorption rate and large fluctuations in transformer load rate.
[0004] In a first aspect, the present invention provides a control method for a photovoltaic-storage microgrid system, the photovoltaic-storage microgrid system comprising at least: a load, a transformer, a photovoltaic device, and an energy storage device, characterized in that it comprises: Obtain the low-voltage side power of the transformer equipment, the photovoltaic discharge power of the photovoltaic equipment, and the load power consumption of the load; Based on the low-voltage side power, determine whether the photovoltaic equipment is transmitting power to the transformer equipment; If the photovoltaic equipment transmits power to the transformer equipment, the energy storage charging power of the energy storage equipment is determined based on the load power consumption. Based on the energy storage charging power, the energy storage equipment is controlled to charge, and the photovoltaic discharge power is adjusted. If the photovoltaic equipment does not transmit power to the transformer equipment, the energy storage discharge power of the energy storage equipment is determined based on the low-voltage side power. Based on the energy storage discharge power, the energy storage equipment is controlled to discharge, and the photovoltaic discharge power is adjusted.
[0005] In some embodiments, determining whether a photovoltaic device is transmitting power to a transformer device based on the low-voltage side power includes: If the power on the low-voltage side is greater than or equal to zero, it is determined that the photovoltaic equipment is not transmitting power to the transformer equipment; If the power on the low-voltage side is less than zero, it is determined that the photovoltaic equipment is transmitting power to the transformer equipment.
[0006] In some embodiments, if the photovoltaic device supplies power to the transformer device, the energy storage charging power of the energy storage device is determined based on the load power consumption, and the energy storage device is controlled to charge based on the energy storage charging power, and the photovoltaic discharge power is adjusted, including: Obtain the state of charge of the energy storage device; Based on the difference between photovoltaic discharge power and load power consumption, the energy storage charging power is determined, and the energy storage device is charged according to the energy storage charging power. When the energy storage charging power is greater than or equal to the preset energy storage charging power threshold, the photovoltaic discharge power is reduced until the energy storage charging power is less than the preset energy storage charging power threshold. When the state of charge is greater than or equal to the preset upper limit threshold of charge, the photovoltaic discharge power is adjusted to equal the power consumed by the load.
[0007] In some embodiments, if the photovoltaic device does not supply power to the transformer device, the energy storage discharge power of the energy storage device is determined based on the low-voltage side power, and the energy storage device is controlled to discharge based on the energy storage discharge power, and the photovoltaic discharge power is adjusted, including: Adjust the photovoltaic discharge power to the maximum discharge power of the photovoltaic equipment; If the low-voltage side power is less than or equal to the preset expansion power value, the energy storage discharge power is determined to be zero, and the energy storage device is controlled to stop discharging. If the low-voltage side power is greater than the preset expansion power value, the energy storage discharge power is determined based on the difference between the load power consumption minus the photovoltaic discharge power and the preset expansion power value, and the energy storage device is controlled to discharge according to the energy storage discharge power.
[0008] In some embodiments, after obtaining the low-voltage side power, photovoltaic discharge power, and load power consumption of the transformer, the method further includes: Obtain load function information of the load and state of charge of the energy storage device; Based on load function information, determine the trend of load power consumption variation; Based on the load power consumption trend, state of charge and photovoltaic discharge power, the predicted trend of low-voltage side power change is determined; The load is adjusted based on the predicted trend of low-voltage side power changes.
[0009] In some embodiments, load adjustment is performed based on predicted trends in low-voltage side power, including: Based on the predicted trend of low-voltage side power, the predicted time when the low-voltage side power is greater than or equal to the preset transformer safe power is determined. The load corresponding to the predicted time is classified into necessary load, adjustable load, and interruptible load. Based on predicted time, reduce the power consumption of adjustable loads and / or interrupt the operation of interruptible loads.
[0010] In some embodiments, it also includes: Obtain the state of charge of the energy storage device; If the current time is within the preset recharge period and the state of charge is lower than the preset recharge threshold, the energy storage device will be controlled to charge at the preset recharge power. During the charging process, if the state of charge reaches the preset stop threshold or the current time exceeds the recharge period, the charging of the energy storage device will be stopped.
[0011] Secondly, this disclosure provides a control device for a photovoltaic-storage microgrid system, the photovoltaic-storage microgrid system including at least: a load, a transformer, a photovoltaic device, and an energy storage device, including: The acquisition module is used to acquire the low-voltage side power of the transformer equipment, the photovoltaic discharge power of the photovoltaic equipment, and the load power consumption of the load. The judgment module is used to determine whether the photovoltaic equipment is transmitting power to the transformer equipment based on the low-voltage side power. The first adjustment module is used to determine the energy storage charging power of the energy storage device based on the load power consumption when the photovoltaic device transmits power to the transformer device, control the energy storage device to charge based on the energy storage charging power, and adjust the photovoltaic discharge power. The second adjustment module is used to determine the energy storage discharge power of the energy storage device based on the low-voltage side power if the photovoltaic device does not transmit power to the transformer device, control the energy storage device to discharge based on the energy storage discharge power, and adjust the photovoltaic discharge power.
[0012] Thirdly, the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the control method of the above-mentioned photovoltaic-storage microgrid system.
[0013] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the control method of the above-described photovoltaic-storage microgrid system.
[0014] The aforementioned control method, device, equipment, and medium for a photovoltaic-storage microgrid system utilize the following scheme: The low-voltage side power of the transformer, the photovoltaic discharge power of the photovoltaic equipment, and the load power consumption of the load are acquired. Based on the low-voltage side power, it is determined whether the photovoltaic equipment is supplying power to the transformer. If the photovoltaic equipment is supplying power, the energy storage charging power of the energy storage equipment is determined based on the load power consumption. Based on the energy storage charging power, the energy storage equipment is controlled to charge, and the photovoltaic discharge power is adjusted. If the photovoltaic equipment is not supplying power to the transformer, the energy storage discharge power of the energy storage equipment is determined based on the low-voltage side power. Based on the energy storage discharge power, the energy storage equipment is controlled to discharge, and the photovoltaic discharge power is adjusted. This method distinguishes between two operating conditions by determining whether the photovoltaic equipment is supplying power to the transformer, controlling the energy storage charging and discharging separately, and synchronously adjusting the photovoltaic discharge power. This achieves coordinated operation of energy storage and photovoltaics, improves transformer capacity utilization efficiency and green electricity self-consumption rate, and reduces basic electricity costs. Attached Figure Description
[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 This is a flowchart of a control method for a photovoltaic-storage microgrid system according to an embodiment of the present invention; Figure 2 This is another flowchart of the control method for a photovoltaic-storage microgrid system in one embodiment of the present invention; Figure 3 This is another flowchart of the control method for a photovoltaic-storage microgrid system in one embodiment of the present invention; Figure 4 This is another flowchart of the control method for a photovoltaic-storage microgrid system in one embodiment of the present invention; Figure 5 This is another flowchart of the control method for a photovoltaic-storage microgrid system in one embodiment of the present invention; Figure 6 This is another flowchart of the control method for a photovoltaic-storage microgrid system in one embodiment of the present invention; Figure 7 This is a schematic block diagram of the control device of a photovoltaic-storage microgrid system according to an embodiment of the present invention; Figure 8 This is a schematic block diagram of a computer device according to an embodiment of the present invention. Detailed Implementation
[0017] As an example, such as Figure 1As shown, a control method for a photovoltaic-storage microgrid system is provided. The photovoltaic-storage microgrid system includes at least: a load, a transformer, a photovoltaic device, and an energy storage device, and includes the following steps: S101, obtain the low-voltage side power of the transformer equipment, the photovoltaic discharge power of the photovoltaic equipment, and the load power consumption of the load; S102, based on the low-voltage side power, determines whether the photovoltaic equipment is transmitting power to the transformer equipment; S103, If the photovoltaic equipment transmits power to the transformer equipment, the energy storage charging power of the energy storage equipment is determined based on the load power consumption, and the energy storage equipment is controlled to charge based on the energy storage charging power, and the photovoltaic discharge power is adjusted. S104 If the photovoltaic equipment does not transmit power to the transformer equipment, the energy storage discharge power of the energy storage equipment is determined based on the low-voltage side power. Based on the energy storage discharge power, the energy storage equipment is controlled to discharge, and the photovoltaic discharge power is adjusted.
[0018] As an example, in step S101, the low-voltage side power of the transformer equipment can be collected in real time by a smart meter installed on the low-voltage side of the transformer equipment. Simultaneously, the photovoltaic discharge power of the photovoltaic equipment can be obtained through the communication interface of the photovoltaic inverter or a smart meter, and the real-time load power consumption of the load can be obtained through a smart meter or power monitoring module on the load side. It should be understood that the sampling period for the above power data can be configured according to system response requirements, for example, sampling once every 100 milliseconds, or it can be set to second-level or minute-level sampling according to the transformer capacity and load fluctuation characteristics. This disclosure does not limit this, nor does it limit the specific method of obtaining the above power data.
[0019] In one embodiment, an industrial IoT gateway or data acquisition terminal can establish a communication connection with various power monitoring devices using protocols such as Modbus, IEC 61850, or MQTT to synchronously acquire low-voltage side power, photovoltaic discharge power, and load power consumption. These three power data points can be timestamped to ensure time alignment.
[0020] In one embodiment, the transformer can be a distribution transformer connected to the power grid on the user side, used to convert high-voltage grid power into low-voltage power to supply the load; the photovoltaic equipment can be a power generation unit composed of photovoltaic modules and inverters, used to convert solar energy into AC power; the energy storage equipment can be an energy storage unit composed of battery packs and energy storage converters, used to realize the charging, discharging and storage of electrical energy; the load can be all electrical equipment consuming power in the user park, including production equipment, lighting, air conditioning, etc. This disclosure does not limit the specific types and structures of the transformer, photovoltaic equipment, energy storage equipment and load.
[0021] As an example, in step S102, the direction of power transmission between the photovoltaic equipment and the transformer equipment can be determined based on the real-time acquired low-voltage side power value.
[0022] In one embodiment, the positive and negative meanings of low-voltage side power are predefined: when the low-voltage side power is positive, it indicates that electrical energy flows from the power grid to the user side via the transformer; when the low-voltage side power is negative, it indicates that electrical energy flows from the user side (i.e., the photovoltaic equipment) to the power grid via the transformer. Based on this definition, the transmission direction of the photovoltaic equipment can be determined by comparing the magnitude of the low-voltage side power with zero.
[0023] It should be understood that the above definition of positive and negative power is merely illustrative and is not intended to limit the scope of this disclosure. In other embodiments, other numerical identification methods may be used to distinguish different directions of power transmission, as long as it is possible to clearly determine whether the photovoltaic equipment is transmitting power to the transformer equipment.
[0024] As an example, in step S103, when it is determined that the photovoltaic equipment is transmitting power to the transformer equipment, it means that there is surplus green electricity on the user side. The system will prioritize starting the energy storage equipment for charging and dynamically adjust the photovoltaic discharge power to match the power consumed by the load to avoid backfeeding power to the grid.
[0025] Specifically, the energy storage charging power of the energy storage device can be calculated based on the current load power consumption and photovoltaic discharge power. Then, a corresponding charging control command is sent to the energy storage device to control it to charge according to the energy storage charging power. At the same time, a power adjustment command is sent to the photovoltaic device to dynamically adjust the photovoltaic discharge power of the photovoltaic device.
[0026] In one embodiment, the energy storage charging power can be determined based on the difference between the photovoltaic discharge power and the load power consumption, so as to prioritize the consumption of excess electrical energy generated by the photovoltaic device. The charging control of the energy storage device can be achieved by adjusting the output current, voltage or power command of the inverter in the energy storage device; the adjustment of the photovoltaic discharge power can be achieved by adjusting the inverter operating parameters of the photovoltaic device or by directly issuing a power limiting command.
[0027] As an example, in step S104, when it is determined that the photovoltaic equipment is not transmitting power to the transformer equipment, it means that the green electricity on the user side is insufficient to meet the load demand. The system will prioritize scheduling the energy storage equipment to discharge and make up for the shortfall, and simultaneously increase the photovoltaic discharge power to its maximum discharge power to maximize the utilization of green electricity.
[0028] Specifically, the energy storage discharge power of the energy storage device can be calculated based on the current low-voltage side power, combined with the load power consumption and photovoltaic discharge power. Then, a corresponding discharge control command is sent to the energy storage device to control it to discharge according to the energy storage discharge power. At the same time, a power adjustment command is sent to the photovoltaic device to dynamically adjust the photovoltaic discharge power of the photovoltaic device.
[0029] In one embodiment, the energy storage discharge power can be determined based on the low-voltage side power calculation to maintain the low-voltage side power of the transformer equipment within a preset reasonable operating range. The discharge control of the energy storage equipment can be achieved by adjusting the output current, voltage, or power command of the converter in the energy storage equipment; when adjusting the photovoltaic discharge power, it can be increased to the maximum power currently achievable by the photovoltaic equipment to ensure that green electricity is prioritized for load operation, thereby minimizing grid power consumption.
[0030] In summary, this disclosure proposes a control method for a photovoltaic-storage microgrid system. The system includes at least a load, a transformer, a photovoltaic device, and an energy storage device. The method includes: acquiring the low-voltage side power of the transformer, the photovoltaic discharge power of the photovoltaic device, and the load power consumption of the load; determining whether the photovoltaic device is supplying power to the transformer based on the low-voltage side power; if the photovoltaic device is supplying power to the transformer, determining the energy storage charging power of the energy storage device based on the load power consumption, controlling the energy storage device to charge based on the charging power, and adjusting the photovoltaic discharge power; if the photovoltaic device is not supplying power to the transformer, determining the energy storage discharge power of the energy storage device based on the low-voltage side power, controlling the energy storage device to discharge based on the discharge power, and adjusting the photovoltaic discharge power. This method distinguishes between two operating conditions by determining whether the photovoltaic device is supplying power to the transformer, controlling the energy storage charging and discharging separately, and synchronously adjusting the photovoltaic discharge power, thus achieving coordinated operation of energy storage and photovoltaics, improving transformer capacity utilization efficiency and green electricity self-consumption rate, and reducing basic electricity costs.
[0031] As an example, in step S102, the determination of whether the photovoltaic equipment is transmitting power to the transformer equipment can be completed by comparing the value of the low-voltage side power with a threshold. Specifically, if the low-voltage side power is greater than or equal to zero, it is determined that the photovoltaic equipment is not transmitting power to the transformer equipment; if the low-voltage side power is less than zero, it is determined that the photovoltaic equipment is transmitting power to the transformer equipment.
[0032] In other words, when the power on the low-voltage side is greater than or equal to zero, it indicates that there is a positive power flow on the low-voltage side of the transformer equipment, meaning that the power consumed by the load is not completely covered by the photovoltaic discharge power of the photovoltaic equipment. At this time, it can be determined that the photovoltaic equipment is not transmitting power to the transformer equipment. When the power on the low-voltage side is less than zero, it indicates that the power generated by the photovoltaic equipment has exceeded the local load demand, meaning that the power consumed by the load has been completely covered by the photovoltaic discharge power. At this time, it can be determined that the photovoltaic equipment is transmitting power to the transformer equipment, and the excess power flows back into the grid through the low-voltage side.
[0033] As an example, such as Figure 2 As shown, in step S103, if the photovoltaic equipment transmits power to the transformer equipment, the energy storage charging power of the energy storage device is determined based on the load power consumption. Based on the energy storage charging power, the energy storage device is controlled to charge, and the photovoltaic discharge power is adjusted, including: S201, Obtain the state of charge of the energy storage device; S202, Based on the difference between photovoltaic discharge power and load power consumption, determine the energy storage charging power, and control the charging of the energy storage device according to the energy storage charging power; S203, when the energy storage charging power is greater than or equal to the preset energy storage charging power threshold, reduce the photovoltaic discharge power until the energy storage charging power is less than the preset energy storage charging power threshold. S204 When the state of charge is greater than or equal to the preset upper limit threshold of the charge, adjust the photovoltaic discharge power to be equal to the power consumed by the load.
[0034] As an example, in step S201, the state of charge (SOC) data of the energy storage device is acquired in real time. This SOC data is used to determine the remaining power capacity of the energy storage device, providing a basis for subsequent charging control and photovoltaic power regulation.
[0035] In one embodiment, state of charge (SOC) data can be directly obtained through the communication interface of the battery management system (BMS) of the energy storage device, or the voltage and current data of the battery pack can be indirectly collected and the SOC calculated through the converter of the energy storage device.
[0036] In one optional embodiment, the sampling period for the state of charge is consistent with the sampling periods for the low-voltage side power, photovoltaic discharge power, and load power consumption, and is accompanied by a unified timestamp to ensure data synchronization.
[0037] As an example, in step S202, the difference between the photovoltaic discharge power and the load consumption power at the current moment can be calculated as the energy storage charging power, and a corresponding charging control command can be sent to the energy storage device to control the energy storage device to charge according to the power.
[0038] In one embodiment, when the photovoltaic discharge power is greater than the load power, the difference between the two is positive, and this positive value is the target charging power of the energy storage device. At this time, all the excess electricity generated by the photovoltaic is used to charge the energy storage device. When the photovoltaic discharge power is less than or equal to the load power, the difference between the two is zero or negative, and at this time, the energy storage device does not charge.
[0039] In one optional embodiment, a charging reserve value and a maximum demand value can be preset. The maximum value of the energy storage charging power does not exceed the difference between the preset maximum demand value and the charging reserve value, so as to ensure that the grid side has sufficient power margin to cope with sudden load growth and avoid overload of transformer equipment.
[0040] The charging reserve space value is the power margin set on the low-voltage side of the transformer equipment. It is used to reserve sufficient power margin during the charging process of the energy storage equipment to cope with sudden load increases or sudden drops in photovoltaic output, and to prevent instantaneous overload of the transformer equipment. The maximum demand value is the maximum output power allowed on the low-voltage side of the transformer equipment. It is used to constrain the maximum upper limit of the energy storage charging power to avoid overloading of the transformer equipment or exceeding the electricity demand declared by the user. It should be understood that the maximum demand can be a fixed value or a dynamic value that changes over time. This disclosure does not limit it in this way.
[0041] As an example, in step S203, the value of the energy storage charging power can be monitored in real time. When the value reaches or exceeds the preset energy storage charging power threshold, the photovoltaic discharge power of the photovoltaic equipment is gradually reduced until the energy storage charging power falls back below the preset energy storage charging power threshold.
[0042] In one embodiment, the preset energy storage charging power threshold can be set as the rated maximum charging power of the energy storage device to prevent damage to the energy storage device due to excessive charging power. The reduction of photovoltaic discharge power can be achieved through a step-by-step adjustment, decreasing the preset power step size each time until the power requirement is met.
[0043] In an optional embodiment, the preset energy storage charging power threshold can also be dynamically adjusted according to the maximum demand. When the maximum demand decreases, the preset energy storage charging power threshold is simultaneously lowered to adapt to the load change.
[0044] As an example, in step S204, when the state of charge of the energy storage device reaches or exceeds the preset upper limit threshold of the charge, it indicates that the energy storage device is fully charged and cannot continue to store electrical energy. At this time, the system adjusts the photovoltaic discharge power of the photovoltaic device to make it completely equal to the current load power consumption.
[0045] In one embodiment, a preset upper limit threshold for charge is set, for example, to 95% to 98% of the rated capacity of the energy storage device, to prevent overcharging and extend the lifespan of the energy storage device. Furthermore, by adjusting the power limiting command of the photovoltaic device's inverter, the photovoltaic discharge power can be controlled at a level consistent with the load power consumption. At this point, the low-voltage side power of the transformer is maintained near zero, preventing both power draw from the grid and backfeeding to the grid.
[0046] In one optional embodiment, the low-voltage side power can be monitored in real time. When the low-voltage side power shows a trend of being less than zero, the photovoltaic discharge power can be adjusted in advance to ensure that the low-voltage side power is always not less than zero, so as to prevent reverse power transmission to the transformer equipment.
[0047] As an example, such as Figure 3 As shown, step S104, i.e., if the photovoltaic equipment does not transmit power to the transformer equipment, then based on the low-voltage side power, the energy storage discharge power of the energy storage equipment is determined, and based on the energy storage discharge power, the energy storage equipment is controlled to discharge, and the photovoltaic discharge power is adjusted, including: S301, adjusts the photovoltaic discharge power to the maximum discharge power of the photovoltaic equipment; S302, if the low-voltage side power is less than or equal to the preset expansion power value, then the energy storage discharge power is determined to be zero, and the energy storage device is controlled to stop discharging; S303 If the low-voltage side power is greater than the preset expansion power value, the energy storage discharge power is determined based on the difference between the load power consumption minus the photovoltaic discharge power and the preset expansion power value, and the energy storage device is controlled to discharge according to the energy storage discharge power.
[0048] As an example, in step S301, the photovoltaic discharge power of the photovoltaic equipment can be adjusted to the maximum discharge power under the current environmental conditions in order to maximize the consumption of green electricity and reduce the amount of electricity drawn from the grid.
[0049] In one embodiment, the maximum discharge power of the photovoltaic device can be determined based on the current light intensity and temperature conditions. In other words, the maximum discharge power of the photovoltaic device can change in real time with environmental conditions, and the value can be recalculated and updated for each sampling period.
[0050] In one optional embodiment, when the photovoltaic equipment malfunctions or requires maintenance, its maximum discharge power can be temporarily limited to ensure the safe and stable operation of the system.
[0051] As an example, in step S302, the low-voltage side power of the transformer can be monitored in real time. When the low-voltage side power does not exceed the preset expansion power value, it indicates that the transformer is within the safe operating range and there is no need for the energy storage device to discharge and replenish energy. At this time, the energy storage device is controlled to stop discharging and the stored energy is reserved for subsequent peak load periods.
[0052] In one embodiment, the preset expansion power value is a low-voltage side safe operating power threshold set for the transformer equipment, and its value is, for example, 80%-90% of the rated capacity of the transformer equipment.
[0053] In one optional embodiment, a power fluctuation threshold can be set. Taking a power fluctuation threshold of 5kW as an example, the energy storage device will stop discharging only when the low-voltage side power is lower than the preset expansion power value of 5kW; the energy storage device will start discharging only when the low-voltage side power is higher than the preset expansion power value of 5kW, so as to avoid frequent start-stop of the energy storage device due to small load fluctuations.
[0054] As an example, in step S303, when the power on the low-voltage side exceeds the preset expansion power value, it indicates that the transformer equipment has approached or exceeded the safety limit. At this time, the energy storage device is started to discharge, making up for the power consumption gap of the load and realizing the auxiliary capacity expansion of the transformer equipment.
[0055] In one embodiment, the energy storage discharge power can be the difference between the load power consumption minus the photovoltaic discharge power and the preset expansion power value. This calculation method can ensure that the low-voltage side power of the transformer equipment is always maintained at the preset expansion power value and there will be no overload. The adjustment accuracy of the energy storage discharge power is consistent with the sampling period and can be dynamically adjusted in real time according to the fluctuations of the load and photovoltaic equipment.
[0056] In one embodiment, the calculated energy storage discharge power shall not exceed the maximum discharge power of the energy storage device. If the calculated value exceeds the upper limit, the energy storage device shall discharge according to its maximum discharge power.
[0057] In one optional embodiment, a discharge reserve space value can be preset. During the discharge process of the energy storage device, the low-voltage side power of the transformer device must not be lower than the discharge reserve space value, so as to reserve sufficient grid power margin to cope with sudden situations such as sudden drop in photovoltaic device discharge and prevent power reverse flow.
[0058] As an example, such as Figure 4 As shown, after step S101, the method further includes: obtaining the load function information of the load and the state of charge of the energy storage device; S401, based on load function information, determine the load power consumption change trend of the load; S402, based on the load power consumption trend, state of charge and photovoltaic discharge power, determine the predicted trend of low-voltage side power. S403 adjusts the load based on the predicted trend of low-voltage side power changes.
[0059] As an example, in step S401, the operating patterns and power variation characteristics of each load can be analyzed based on the acquired load function information to determine the load power consumption trend over a future period. The load function information includes, but is not limited to, the load's device type, operating period, power level, start / stop schedule, and real-time operating status.
[0060] In one optional embodiment, a load prediction model can be established based on relevant historical load data, and combined with current load function information, the load power consumption change curve for a future period of time (e.g., 15 minutes to 4 hours) can be output.
[0061] In one optional embodiment, the system can be connected to a production management system, building automation system, or energy management system to obtain more accurate load operation plan data, such as production line scheduling plans, air conditioning temperature control plans, and lighting timed switching plans, thereby further improving the prediction accuracy of load power consumption change trends.
[0062] As an example, in step S402, the predicted trend of power change on the low-voltage side of the transformer can be calculated by combining the load power consumption trend, the state of charge of the energy storage device, and the predicted value of photovoltaic discharge power of the photovoltaic device.
[0063] In one embodiment, the predicted value of the low-voltage side power can be calculated by subtracting the predicted photovoltaic discharge power from the predicted load power consumption trend, and then subtracting the predicted energy storage charge and discharge power. The predicted energy storage charge and discharge power can be determined by combining the current state of charge of the energy storage device with a preset charge and discharge control strategy.
[0064] In one optional embodiment, weather forecast data can be incorporated to correct the predicted value of photovoltaic discharge power. For example, the discharge prediction of the photovoltaic equipment can be adjusted based on future light intensity, temperature, cloud cover, etc., thereby improving the accuracy of low-voltage side power prediction.
[0065] As an example, in step S403, the load can be proactively adjusted in advance based on the predicted trend of low-voltage power changes to avoid instantaneous overload of the transformer equipment and ensure its safe and stable operation. Compared with passive overload protection, proactive load regulation can achieve smoother power control and reduce the impact on users' production and operation.
[0066] As an example, such as Figure 5 As shown, step S404, which involves adjusting the load based on the predicted trend of low-voltage side power changes, includes: S501, based on the predicted change trend of low-voltage side power, determine the prediction time when the low-voltage side power is greater than or equal to the preset transformer safe power. S502, classify the load corresponding to the predicted time to obtain necessary load, adjustable load and interruptible load; S503, based on predicted time, reduces the power consumption of adjustable loads and / or interrupts the operation of interruptible loads.
[0067] As an example, in step S501, the predicted trend of the low-voltage side power can be compared with the preset transformer safety power to determine the intersection time of the two. This time is the predicted time when the low-voltage side power will exceed the safety threshold.
[0068] In one embodiment, the preset safe power of the transformer can be the rated capacity of the transformer equipment, which is the maximum power limit that allows the transformer equipment to operate safely for a long period of time. Furthermore, an advance warning time can be set, for example, issuing a warning signal 15 minutes before the predicted time and initiating the load regulation process.
[0069] In one optional embodiment, the preset transformer safety power value can be dynamically adjusted according to the actual operating status and aging degree of the transformer equipment to ensure safe operation of the equipment.
[0070] As an example, in step S502, loads that are in operation within the predicted time can be classified according to their importance and interruptibility, providing a basis for subsequent load adjustment.
[0071] In one embodiment, essential loads are critical loads that cannot be interrupted, such as core equipment of the production line, fire protection system, server room, etc., and their power supply is given priority; adjustable loads are loads that can reduce power according to system instructions, such as central air conditioning, lighting system, some auxiliary production equipment, etc.; interruptible loads are loads that can be temporarily stopped, such as non-essential office equipment, charging piles, landscape lighting, etc.
[0072] In one optional embodiment, the classification criteria and priority order of the load can be customized according to production and operation needs, and then the load adjustment can be performed according to the rules set by the user.
[0073] As an example, in step S503, the adjustable load and interruptible load can be adjusted in advance according to the determined prediction time to ensure that the total load power consumption is controlled within a safe range before the low-voltage side power reaches the preset transformer safe power.
[0074] In one embodiment, the power consumption of the adjustable load can be reduced first, for example, by raising the set temperature of the central air conditioner or reducing the brightness of the public area lighting; if the power consumption of the adjustable load still exceeds the preset safe power of the transformer after reducing the adjustable load, the operation of the interruptible loads is interrupted in a preset order.
[0075] In an optional embodiment, once the low-voltage side power drops below the safety threshold, the power supply to the interruptible load and the operating power of the adjustable load can be gradually restored in the reverse order of adjustment to reduce the impact on the user's normal production.
[0076] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.
[0077] As an example, during the execution of steps S101-S104, the steps are executed either before or after step S104. Figure 6 As shown, it includes: S601, Obtain the state of charge of the energy storage device; S602, if the current time is within the preset recharge period and the state of charge is lower than the preset recharge threshold, then control the energy storage device to charge at the preset recharge power. S603: During the charging process, if the state of charge reaches the preset stop threshold or the current time exceeds the recharge period, the charging of the energy storage device will be stopped.
[0078] As an example, in step S601, the state of charge of the energy storage device can be obtained in real time. This state of charge is used to determine whether the remaining power of the energy storage device can meet the operational requirements of subsequent dynamic expansion, photovoltaic consumption and other functions, and is the basis for starting and stopping SOC recharge.
[0079] In one embodiment, the state of charge (SOC) data can be directly obtained through the communication interface of the battery management system (BMS) of the energy storage device, or the voltage and current data of the battery pack can be indirectly collected through the energy storage converter and the SOC data can be calculated. This disclosure does not limit the scope of the invention.
[0080] As an example, in step S602, the current time and energy storage charge state can be judged simultaneously. When the current time and energy storage charge state simultaneously meet the preset recharge conditions, the recharge process of the energy storage device is started to actively replenish the stored energy.
[0081] In one embodiment, the preset recharge time period is typically set to the off-peak electricity hours of the user's campus, such as the midday production break or the low-load period at night, to avoid the recharge process consuming grid power resources and affecting the user's normal production electricity consumption. The preset recharge threshold is the minimum amount of electricity required to ensure that the energy storage device can respond to dynamic capacity expansion needs at any time, for example, set to 60%–80% of the rated capacity of the energy storage device.
[0082] In one optional embodiment, the preset recharge power can be set according to the maximum demand on the grid side and the user's electricity demand. For example, a higher recharge power can be set during periods when the grid electricity price is low, and a lower recharge power can be set during periods when the grid load is high.
[0083] As an example, in step S603, the energy storage charge status and the current time can be monitored in real time during the recharge process. When either the energy storage charge status or the current time meets the preset stop condition, the recharge process of the energy storage device is immediately terminated.
[0084] In one embodiment, the preset stop threshold is, for example, 80%-90% of the rated capacity of the energy storage device. This ensures that the energy storage device has sufficient power reserves while reserving some charging space for absorbing subsequent surplus photovoltaic power. When the recharge period ends, recharge will stop regardless of whether the energy storage state of charge has reached the preset stop threshold, thus avoiding the occupation of grid power during peak electricity consumption periods.
[0085] In one optional embodiment, if other control logic such as discharging or charging of the energy storage device is triggered during the recharging process, the recharging process is automatically paused or stopped, and other control actions are executed first. If the recharging conditions are still met after the other control actions are completed, the recharging can be resumed.
[0086] In one embodiment, a control device for a photovoltaic-storage microgrid system is provided, which corresponds one-to-one with the control method for the photovoltaic-storage microgrid system described in the above embodiments. For example... Figure 7 As shown, the control device of this photovoltaic-storage microgrid system includes an acquisition module 701, a judgment module 702, a first adjustment module 703, and a second adjustment module 704. Detailed descriptions of each functional module are as follows: The acquisition module 701 is used to acquire the low-voltage side power of the transformer equipment, the photovoltaic discharge power of the photovoltaic equipment, and the load power consumption of the load; The judgment module 702 is used to determine whether the photovoltaic equipment is transmitting power to the transformer equipment based on the low-voltage side power. The first adjustment module 703 is used to determine the energy storage charging power of the energy storage device based on the load power consumption when the photovoltaic device transmits power to the transformer device, control the energy storage device to charge based on the energy storage charging power, and adjust the photovoltaic discharge power. The second adjustment module 704 is used to determine the energy storage discharge power of the energy storage device based on the low-voltage side power if the photovoltaic device does not transmit power to the transformer device, control the energy storage device to discharge based on the energy storage discharge power, and adjust the photovoltaic discharge power.
[0087] In one embodiment, the determination module 702 is further configured to determine that the photovoltaic equipment is not transmitting power to the transformer equipment if the low-voltage side power is greater than or equal to zero. If the power on the low-voltage side is less than zero, it is determined that the photovoltaic equipment is transmitting power to the transformer equipment.
[0088] In one embodiment, the first adjustment module 703 is further configured to acquire the state of charge of the energy storage device; Based on the difference between photovoltaic discharge power and load power consumption, the energy storage charging power is determined, and the energy storage device is charged according to the energy storage charging power. When the energy storage charging power is greater than or equal to the preset energy storage charging power threshold, the photovoltaic discharge power is reduced until the energy storage charging power is less than the preset energy storage charging power threshold. When the state of charge is greater than or equal to the preset upper limit threshold of charge, the photovoltaic discharge power is adjusted to equal the power consumed by the load.
[0089] In one embodiment, the second adjustment module 704 is further configured to adjust the photovoltaic discharge power to the maximum discharge power of the photovoltaic device; If the low-voltage side power is less than or equal to the preset expansion power value, the energy storage discharge power is determined to be zero, and the energy storage device is controlled to stop discharging. If the low-voltage side power is greater than the preset expansion power value, the energy storage discharge power is determined based on the difference between the load power consumption minus the photovoltaic discharge power and the preset expansion power value, and the energy storage device is controlled to discharge according to the energy storage discharge power.
[0090] In one embodiment, the second adjustment module 704 is further configured to acquire load function information of the load and state of charge of the energy storage device. Based on load function information, determine the trend of load power consumption variation; Based on the load power consumption trend, state of charge and photovoltaic discharge power, the predicted trend of low-voltage side power change is determined; The load is adjusted based on the predicted trend of low-voltage side power changes.
[0091] In one embodiment, the second adjustment module 704 is further configured to determine, based on the predicted change trend of the low-voltage side power, the predicted time when the low-voltage side power is greater than or equal to the preset transformer safe power. The load corresponding to the predicted time is classified into necessary load, adjustable load, and interruptible load. Based on predicted time, reduce the power consumption of adjustable loads and / or interrupt the operation of interruptible loads.
[0092] In one embodiment, the second adjustment module 704 is further configured to acquire the state of charge of the energy storage device; If the current time is within the preset recharge period and the state of charge is lower than the preset recharge threshold, the energy storage device will be controlled to charge at the preset recharge power. During the charging process, if the state of charge reaches the preset stop threshold or the current time exceeds the recharge period, the charging of the energy storage device will be stopped.
[0093] This invention provides a control device for a photovoltaic-storage microgrid system, comprising: an acquisition module for acquiring the low-voltage side power of a transformer, the photovoltaic discharge power of a photovoltaic device, and the load power consumption of a load; a judgment module for determining whether the photovoltaic device is supplying power to the transformer based on the low-voltage side power; a first adjustment module for determining the energy storage charging power of the energy storage device based on the load power consumption if the photovoltaic device is supplying power to the transformer, controlling the energy storage device to charge based on the energy storage charging power, and adjusting the photovoltaic discharge power; and a second adjustment module for determining the energy storage discharge power of the energy storage device based on the low-voltage side power if the photovoltaic device is not supplying power to the transformer, controlling the energy storage device to discharge based on the energy storage discharge power, and adjusting the photovoltaic discharge power. This device distinguishes between two operating conditions by determining whether the photovoltaic device is supplying power to the transformer, controlling the energy storage charging and discharging separately and synchronously adjusting the photovoltaic discharge power, thus achieving coordinated operation of energy storage and photovoltaics, improving transformer capacity utilization efficiency and green electricity self-consumption rate, and reducing basic electricity costs.
[0094] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 8 As shown, the computer device includes a processor, memory, network interface, and database connected via a system bus. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and database. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database is used for data employed in the control method of the photovoltaic-storage microgrid system. The network interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it can implement a control method for a photovoltaic-storage microgrid system.
[0095] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement a control method for a photovoltaic-storage microgrid system.
[0096] In one embodiment, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program that, when executed by a processor, implements a control method for a photovoltaic-storage microgrid system.
[0097] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), IAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.
[0098] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.
[0099] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.
Claims
1. A control method for a photovoltaic-storage microgrid system, wherein the photovoltaic-storage microgrid system comprises at least: Loads, transformers, photovoltaic equipment, and energy storage equipment, characterized in that they include: The low-voltage side power of the transformer equipment, the photovoltaic discharge power of the photovoltaic equipment, and the load power consumption of the load are obtained. Based on the low-voltage side power, determine whether the photovoltaic equipment is transmitting power to the transformer equipment; If the photovoltaic device supplies power to the transformer device, the energy storage charging power of the energy storage device is determined based on the power consumed by the load. Based on the energy storage charging power, the energy storage device is controlled to charge, and the photovoltaic discharge power is adjusted. If the photovoltaic device does not supply power to the transformer device, the energy storage discharge power of the energy storage device is determined based on the low-voltage side power. Based on the energy storage discharge power, the energy storage device is controlled to discharge, and the photovoltaic discharge power is adjusted.
2. The method according to claim 1, characterized in that, The step of determining whether the photovoltaic equipment is transmitting power to the transformer equipment based on the low-voltage side power includes: If the low-voltage side power is greater than or equal to zero, it is determined that the photovoltaic equipment is not transmitting power to the transformer equipment; If the low-voltage side power is less than zero, it is determined that the photovoltaic equipment is transmitting power to the transformer equipment.
3. The method according to claim 1, characterized in that, If the photovoltaic device supplies power to the transformer device, then based on the load power consumption, the energy storage charging power of the energy storage device is determined; based on the energy storage charging power, the energy storage device is controlled to charge, and the photovoltaic discharge power is adjusted, including: Obtain the state of charge of the energy storage device; Based on the difference between the photovoltaic discharge power and the load power consumption, the energy storage charging power is determined, and the energy storage device is charged according to the energy storage charging power. When the energy storage charging power is greater than or equal to a preset energy storage charging power threshold, the photovoltaic discharge power is reduced until the energy storage charging power is less than the preset energy storage charging power threshold. When the state of charge is greater than or equal to a preset upper limit threshold for charge, the photovoltaic discharge power is adjusted to equal the power consumed by the load.
4. The method according to claim 1, characterized in that, If the photovoltaic device does not supply power to the transformer device, then based on the low-voltage side power, the energy storage discharge power of the energy storage device is determined; based on the energy storage discharge power, the energy storage device is controlled to discharge, and the photovoltaic discharge power is adjusted, including: Adjust the photovoltaic discharge power to the maximum discharge power of the photovoltaic device; If the low-voltage side power is less than or equal to the preset expansion power value, then the energy storage discharge power is determined to be zero, and the energy storage device is controlled to stop discharging. If the low-voltage side power is greater than the preset expansion power value, the energy storage discharge power is determined based on the difference between the load power consumption minus the photovoltaic discharge power and the preset expansion power value, and the energy storage device is controlled to discharge according to the energy storage discharge power.
5. The method according to claim 1, characterized in that, After obtaining the low-voltage side power of the transformer, the photovoltaic discharge power, and the load power consumption, the method further includes: Obtain the load function information of the load and the state of charge of the energy storage device; Based on the load function information, determine the load power consumption change trend of the load; Based on the load power consumption change trend, the state of charge, and the photovoltaic discharge power, the predicted change trend of the low-voltage side power is determined; The load is adjusted based on the predicted trend of the low-voltage side power.
6. The method according to claim 5, characterized in that, The adjustment of the load based on the predicted trend of the low-voltage side power includes: Based on the predicted change trend of the low-voltage side power, the predicted time when the low-voltage side power is greater than or equal to the preset transformer safe power is determined. The loads corresponding to the predicted times are classified into necessary loads, adjustable loads, and interruptible loads. Based on the predicted time, reduce the power consumption of the adjustable load and / or interrupt the operation of the interruptible load.
7. The method according to claim 1, characterized in that, Also includes: Obtain the state of charge of the energy storage device; If the current time is within a preset recharge period and the state of charge is lower than a preset recharge threshold, then the energy storage device is controlled to charge at a preset recharge power. During the charging process, if the state of charge reaches a preset stop threshold or the current time exceeds the recharge time period, the charging of the energy storage device will be stopped.
8. A control device for a photovoltaic-storage microgrid system, wherein the photovoltaic-storage microgrid system comprises at least: Loads, transformers, photovoltaic equipment, and energy storage equipment, characterized in that they include: The acquisition module is used to acquire the low-voltage side power of the transformer equipment, the photovoltaic discharge power of the photovoltaic equipment, and the load power consumption of the load; The judgment module is used to determine whether the photovoltaic equipment is transmitting power to the transformer equipment based on the low-voltage side power. The first adjustment module is used to determine the energy storage charging power of the energy storage device based on the load power consumption when the photovoltaic device transmits power to the transformer device, control the energy storage device to charge based on the energy storage charging power, and adjust the photovoltaic discharge power. The second adjustment module is used to determine the energy storage discharge power of the energy storage device based on the low-voltage side power if the photovoltaic device does not supply power to the transformer device, control the energy storage device to discharge based on the energy storage discharge power, and adjust the photovoltaic discharge power.
9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the control method for the photovoltaic-storage microgrid system as described in any one of claims 1 to 7.
10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the control method for the photovoltaic-storage microgrid system as described in any one of claims 1 to 7.