A "one-to-n" integrated control method and device for a light storage direct current integrated system

Abstract

The application discloses a kind of " one drags N " integrated control method and device of light storage direct current integrated system, method includes: respectively obtaining the real-time state parameter of current control period of energy storage unit and photovoltaic unit;Based on state of charge variation rate and illumination intensity variation rate, the initial virtual impedance value of energy storage unit and photovoltaic unit is calculated respectively, the collaborative virtual impedance value of each energy storage unit and photovoltaic unit is calculated based on the initial virtual impedance value of adjacent unit and current unit;Based on adjacent unit and the direct current bus voltage detection value of current unit, the common bus reference voltage value is calculated;Based on collaborative virtual impedance value, the output current value of energy storage unit and photovoltaic unit is adjusted, so that the direct current bus voltage detection value of each energy storage unit and photovoltaic unit and the common bus reference voltage value remain consistent.Through distributed collaborative architecture and dynamic virtual impedance fusion control, the stability and expansion of light storage direct current system are realized, and voltage fluctuation amplitude and circulation are effectively inhibited.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic-storage-DC integrated system control, and particularly to a "one-to-N" integrated control method and device for a photovoltaic-storage-DC integrated system. Background Technology

[0002] With the increasing penetration rate of renewable energy, integrated photovoltaic-storage DC systems are widely used in microgrids and distributed energy fields. These systems typically employ a "one-to-N" architecture, where a single DC bus connects multiple photovoltaic units, energy storage units, and load units in parallel. However, existing technologies have significant shortcomings in terms of system scalability, dynamic stability, and fault tolerance.

[0003] At the control architecture level, mainstream solutions still rely on master-slave control or centralized controllers. The master controller needs to collect the status data of all sub-units in real time and issue commands. As the system scales up (N value increases), it faces communication bandwidth bottlenecks and computational latency issues. More seriously, a single point of failure in the master controller will cause the entire system to crash. While centralized control alleviates the computational pressure, it requires the construction of a high-speed communication network, significantly increasing system costs, and is difficult to implement in scenarios where photovoltaic units are deployed in a distributed manner.

[0004] To address power distribution issues, traditional droop control achieves current sharing by fixing virtual impedance, but this is difficult to adapt to dynamic conditions such as sudden changes in irradiance and rapid load changes. Fixed impedance parameters cause power oscillations in photovoltaic cells when irradiance fluctuates rapidly, while energy storage cells cause bus voltage flicker during charge-discharge switching. Existing improvement schemes attempt to introduce adaptive impedance adjustment, but these often rely on local parameters (such as SOC and temperature) and do not consider the coordination requirements between cells, frequently causing impedance parameter conflicts and exacerbating circulating current problems.

[0005] In terms of fault handling mechanisms, existing technologies lack sufficient support for plug-and-play and online shutdown of photovoltaic units. When a photovoltaic unit shuts down due to shading, the system needs to recalculate the global power allocation parameters, a process that takes hundreds of milliseconds and may cause the bus voltage to exceed limits. When the communication link is interrupted, traditional solutions only switch to local degradation mode, lacking topology self-reconfiguration capabilities, which leads to a wider range of fault impacts.

[0006] Furthermore, existing control strategies are poorly adaptable to special operating conditions. Under high irradiance conditions, priority cannot be given to ensuring photovoltaic power consumption, and economic dispatch modes often require the additional deployment of an energy management system (EMS), complicating the control hierarchy. Voltage tiering protection often employs crude load shedding strategies, failing to form a coordinated protection mechanism with virtual impedance regulation, thus affecting the reliability of the system's power supply. Summary of the Invention

[0007] The purpose of this invention is to provide a "one-to-N" integrated control method and device for a photovoltaic-storage DC integrated system. Through the fusion control of distributed collaborative architecture and dynamic virtual impedance, the system achieves high stability and strong scalability. The dynamic virtual impedance collaborative mechanism effectively suppresses power oscillations and effectively suppresses voltage fluctuation amplitude and circulating current under sudden change in illumination conditions.

[0008] To address the aforementioned technical problems, a first aspect of this invention provides a "one-to-N" integrated control method for a photovoltaic-storage DC integrated system. The photovoltaic-storage DC integrated system includes: an energy storage unit, a load unit, and several photovoltaic units connected in parallel via a DC bus. The control method includes the following steps: The real-time status parameters of the energy storage unit and the photovoltaic unit during the current control cycle are obtained respectively. The real-time status parameters include: DC bus voltage detection value, output current detection value, state of charge change rate of the energy storage unit, and irradiance change rate of the photovoltaic unit. Based on the rate of change of state of charge and the rate of change of light intensity, the initial virtual impedance values ​​of the energy storage unit and the photovoltaic unit are calculated respectively. Based on the initial virtual impedance values ​​of adjacent units and the current unit, the cooperative virtual impedance value of each energy storage unit and the photovoltaic unit is calculated respectively. The adjacent units are directly associated units that are communicatively connected to the current unit. Based on the DC bus voltage detection values ​​of adjacent units and the current unit, the common bus reference voltage value is calculated using a dynamic consistency algorithm. Based on the cooperative virtual impedance value, the output current values ​​of the energy storage unit and the photovoltaic unit are adjusted so that the DC bus voltage detection value of each energy storage unit and the photovoltaic unit is consistent with the common bus reference voltage value.

[0009] Further, the calculation of the initial virtual impedance values ​​of the energy storage unit and the photovoltaic unit based on the rate of change of state of charge and the rate of change of illuminance, respectively, includes: The light intensity change rate and real-time temperature value of the photovoltaic unit are obtained. Based on the comparison result between the light intensity change rate and the preset threshold of the light intensity change rate, the initial virtual impedance value of the photovoltaic unit is calculated in combination with the light intensity change rate or the real-time temperature value. The rate of change of state of charge and the current cycle number of the energy storage unit are obtained. Based on the charging and discharging state of the energy storage unit, the initial virtual impedance value of the energy storage is calculated in combination with the current cycle number and the rate of change of state of charge.

[0010] Further, the step of calculating the initial virtual impedance value based on the comparison result between the rate of change of light intensity and a preset threshold for the rate of change of light intensity, combined with the rate of change of light intensity or the real-time temperature value, includes: When the rate of change of light intensity is less than a preset threshold for the rate of change of light intensity, the initial virtual impedance value of the photovoltaic unit... The calculation formula is: ; in, Let be the fundamental impedance value of the i-th photovoltaic unit. Light fluctuation factor, The rate of change of light intensity; When the rate of change of light intensity is greater than or equal to a preset threshold for the rate of change of light intensity, the initial virtual impedance value of the photovoltaic unit is... The calculation formula is: ; in, This is the temperature compensation coefficient. This is the difference between the real-time temperature value and the standard temperature value.

[0011] Further, the step of calculating the initial virtual impedance value of the energy storage unit based on its charge / discharge state, combined with the current cycle number and the rate of change of state of charge, includes: When the energy storage unit is in a charging state, the initial virtual impedance value of the energy storage unit The calculation formula is: ; in, The charging basis impedance of the energy storage unit is... The cyclic decay coefficient is... This represents the current loop count; When the energy storage unit is in a discharging state, the initial virtual impedance value of the energy storage unit The calculation formula is: ; in, The discharge basis impedance of the energy storage unit is given. is the rate of change of state of charge.

[0012] Further, the calculation of the cooperative virtual impedance value for each energy storage unit and the photovoltaic unit based on the initial virtual impedance values ​​of adjacent units and the current unit includes: The communication delay time between the energy storage unit or the photovoltaic unit and the adjacent unit is obtained, and a dynamic weighting factor is calculated based on the communication delay time. The calculation formula is: ; Where i is the serial number of the energy storage unit or the photovoltaic unit, and N is the sum of the number of the energy storage unit and the number of photovoltaic units. , j is the sequence number of the adjacent unit of the i-th energy storage unit or photovoltaic unit, and M is the number of adjacent units of the i-th energy storage unit or photovoltaic unit. , As a preset attenuation constant, The communication delay time between the i-th energy storage unit or the photovoltaic unit and its j-th adjacent unit; Based on the initial virtual impedance values ​​and dynamic weighting factors of the current cell and its neighboring cells, the cooperative virtual impedance value of the current cell is calculated. The calculation formula is: ; in, This is the self-weighting factor of the current unit. This represents the initial virtual impedance value for the current unit, s=1i or s=2, where 1i represents the sequence number of the photovoltaic unit and 2 represents the energy storage unit. This is the initial virtual impedance value of the j-th adjacent cell of the current cell.

[0013] Furthermore, after calculating the cooperative virtual impedance value of each energy storage unit and the photovoltaic unit based on the initial virtual impedance values ​​of adjacent units and the current unit, the method further includes: Obtain the real-time value of the light intensity of the photovoltaic unit in the current control cycle; When the real-time value of the light intensity exceeds the preset light intensity threshold, the collaborative virtual impedance value of the photovoltaic unit in the current control cycle is reduced to a first preset ratio value of its calculation result, and the collaborative virtual impedance value of the energy storage unit in the current control cycle is increased to a second preset ratio value of its calculation result.

[0014] Further, adjusting the output current values ​​of the energy storage unit and the photovoltaic unit based on the cooperative virtual impedance value includes: Obtain the voltage difference between the current unit's DC bus voltage detection value and the common bus reference voltage value, and calculate the current command value of the current unit based on the voltage difference and the cooperative virtual impedance value; The current difference between the current command value and the actual detected value of the output current of the current unit is obtained. Based on the current difference, a pulse width modulation duty cycle is generated by a proportional-integral controller. The switching devices of the power converter are driven according to the pulse width modulation duty cycle to adjust the output current value.

[0015] Furthermore, the "one-to-N" integrated control method for the photovoltaic-storage DC integrated system also includes: When the reference voltage of the common bus is lower than the rated voltage and the absolute value of the voltage deviation between the two is less than the first preset voltage difference threshold, the cooperative virtual impedance value of all the energy storage units and the photovoltaic units is reduced proportionally, and the proportion of reduction of the cooperative virtual impedance value is positively correlated with the absolute value of the voltage deviation. When the reference voltage value of the common bus is higher than the rated voltage value and the absolute value of the voltage deviation between the two is less than the first preset voltage difference threshold, the cooperative virtual impedance value of all energy storage units and photovoltaic units is increased proportionally, and the increase in the cooperative virtual impedance value is positively correlated with the absolute value of the voltage deviation. When the absolute value of the voltage deviation between the reference voltage value of the common bus and the rated voltage value is greater than the first preset voltage difference threshold and less than or equal to the second preset voltage difference threshold, the converter forced voltage regulation function of the energy storage unit is activated. When the absolute value of the voltage deviation between the reference voltage value of the common bus and the rated voltage value is greater than the second preset voltage difference threshold, the non-critical loads in the load unit are cut off in stages.

[0016] Accordingly, a second aspect of the present invention provides a "one-to-N" integrated control device for a photovoltaic-storage DC integrated system, which controls the photovoltaic-storage DC integrated system based on the aforementioned "one-to-N" integrated control method. The photovoltaic-storage DC integrated system includes: an energy storage unit, a load unit, and several photovoltaic units connected in parallel via a DC bus. The control device includes: The data acquisition module is used to acquire the real-time status parameters of the energy storage unit and the photovoltaic unit during the current control cycle. The real-time status parameters include: DC bus voltage detection value, output current detection value, state of charge change rate of the energy storage unit, and irradiance change rate of the photovoltaic unit. An impedance calculation module is used to calculate the initial virtual impedance values ​​of the energy storage unit and the photovoltaic unit based on the rate of change of state of charge and the rate of change of light intensity, respectively. It also calculates the cooperative virtual impedance value of each energy storage unit and the photovoltaic unit based on the initial virtual impedance values ​​of adjacent units and the current unit, wherein the adjacent units are directly associated units that are communicatively connected to the current unit. The voltage calculation module is used to calculate the common bus reference voltage value based on the DC bus voltage detection values ​​of adjacent units and the current unit through a dynamic consistency algorithm. The status control module is used to adjust the output current value of the energy storage unit and the photovoltaic unit based on the cooperative virtual impedance value, so that the DC bus voltage detection value of each energy storage unit and the photovoltaic unit is consistent with the common bus reference voltage value.

[0017] Accordingly, a third aspect of the present invention provides an electronic device, including: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to execute the above-described "one-to-N" integrated control method of the photovoltaic-storage-DC integrated system.

[0018] Accordingly, a fourth aspect of the present invention provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the above-described "one-to-N" integrated control method for the photovoltaic-storage-DC integrated system.

[0019] The above-described technical solutions of the embodiments of the present invention have the following beneficial technical effects: 1. A distributed control network is constructed by adopting a point-to-point communication mechanism between adjacent units, which completely eliminates the risk of single point of failure in the traditional main controller architecture; each unit only needs to exchange data with directly related units, which greatly reduces communication complexity and supports flexible expansion of system scale; when units are dynamically connected or disconnected, stable operation is maintained by autonomously reconstructing the communication topology, effectively ensuring power supply continuity. 2. An initial virtual impedance value is generated based on the real-time operating status of the unit, and data from adjacent units are fused through a communication quality-weighted collaborative algorithm to form a globally optimized collaborative virtual impedance parameter. This mechanism significantly suppresses power oscillations caused by sudden changes in illumination or load steps, improves the circulating current problem between photovoltaic units and energy storage units, and ensures dynamic balance of bus voltage. 3. By using a closed-loop combination of voltage deviation direction identification and impedance ratio adjustment, precise control of the bus voltage can be achieved; combined with the photovoltaic priority mode, the impedance of the photovoltaic and energy storage units can be adjusted differently to improve the energy utilization rate under high irradiance conditions. Attached Figure Description

[0020] Figure 1 This is a flowchart of the "one-to-N" integrated control method for the photovoltaic-storage-DC integrated system provided in this embodiment of the invention; Figure 2 This is a block diagram of the "one-to-N" integrated control device module of the photovoltaic-storage-DC integrated system provided in the embodiments of the present invention.

[0021] Figure label: 1. Data acquisition module; 2. Impedance calculation module; 3. Voltage calculation module; 4. Status control module. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0023] Please refer to Figure 1 The first aspect of this invention provides a "one-to-N" integrated control method for a photovoltaic-storage DC integrated system. The photovoltaic-storage DC integrated system includes: an energy storage unit, a load unit, and several photovoltaic units connected in parallel via a DC bus. The control method includes the following steps: Step S100: Obtain the real-time status parameters of the energy storage unit and the photovoltaic unit for the current control cycle. The real-time status parameters include: DC bus voltage detection value, output current detection value, state of charge change rate of the energy storage unit, and irradiance change rate of the photovoltaic unit.

[0024] Each photovoltaic (PV) unit and energy storage unit independently collects key local operating parameters to form a real-time status dataset. The PV units focus on monitoring the trend of changes in irradiance, while the energy storage units track dynamic changes in the state of charge and simultaneously acquire instantaneous values ​​of DC bus voltage and output current. This forms the underlying data foundation for control decisions, and unit-level autonomous sensing avoids the communication delay problem of centralized data collection, providing highly timely status input for subsequent coordinated control.

[0025] Step S200: Based on the rate of change of state of charge and the rate of change of irradiance, calculate the initial virtual impedance values ​​of the energy storage unit and the photovoltaic unit respectively. Based on the initial virtual impedance values ​​of the adjacent units and the current unit, calculate the cooperative virtual impedance value of each energy storage unit and the photovoltaic unit respectively. The adjacent units are the directly associated units that are connected to the current unit in communication.

[0026] Initial virtual impedance values ​​are dynamically generated based on the characteristics of each unit: photovoltaic units calculate initial impedance values ​​based on the characteristics of light fluctuations, while energy storage units determine initial impedance values ​​based on charge / discharge states and lifetime degradation. Initial impedance data is exchanged between adjacent units, and a communication quality-weighted fusion algorithm is used to generate collaborative virtual impedance values. This achieves distributed optimization of impedance parameters, preserving individual unit characteristics while meeting system coordination requirements, providing a dynamic adjustment basis for precise power allocation.

[0027] Step S300: Based on the DC bus voltage detection values ​​of adjacent units and the current unit, calculate the common bus reference voltage value using a dynamic consistency algorithm.

[0028] Each unit shares the local DC bus voltage detection value and uses a dynamic consensus algorithm to negotiate and generate a unified voltage reference. This algorithm enables all units to iteratively converge to a consensus value based on data from adjacent nodes, eliminating the rigid constraints set by the traditional master control node. The generated common bus reference voltage value has both global coordination and local adaptability, establishing a dynamic reference target for voltage stability.

[0029] Step S400: Based on the cooperative virtual impedance value, adjust the output current value of the energy storage unit and the photovoltaic unit so that the DC bus voltage detection value of each energy storage unit and photovoltaic unit is consistent with the common bus reference voltage value.

[0030] The collaborative virtual impedance value is converted into a current regulation command, driving the power converter to adjust its output. Through closed-loop control of the deviation between the local voltage detection value and the common reference voltage, each unit autonomously adjusts its output current until the voltage converges. This forms a cascaded control chain of "impedance-current-voltage," achieving distributed autonomous power balancing and ensuring voltage consistency under dynamic operating conditions.

[0031] Further, in step S200, the initial virtual impedance values ​​of the energy storage unit and the photovoltaic unit are calculated based on the rate of change of state of charge and the rate of change of illuminance, respectively, including: Step S210: Obtain the light intensity change rate and real-time temperature value of the photovoltaic unit. Based on the comparison result of the light intensity change rate and the preset threshold of the light intensity change rate, calculate the initial virtual impedance value of the photovoltaic unit in combination with the light intensity change rate or the real-time temperature value.

[0032] The photovoltaic (PV) unit calculates its initial virtual impedance value based on the dynamic changes in irradiance and the module's temperature. When irradiance fluctuations are gradual, the impedance adjustment requirement based on the rate of irradiance change is primarily considered; when irradiance fluctuates drastically, the compensation effect of temperature changes on impedance is emphasized. This adaptive initial impedance setting based on environmental parameters provides fundamental parameters reflecting the real-time operating characteristics of the PV unit for subsequent collaborative decision-making, ensuring a rapid response to changes in irradiance.

[0033] Step S220: Obtain the rate of change of state of charge and the current cycle number of the energy storage unit. Based on the charging and discharging state of the energy storage unit, calculate the initial virtual impedance value of the energy storage unit in combination with the current cycle number and the rate of change of state of charge.

[0034] The energy storage unit selects a differentiated calculation path based on the charge / discharge state: during charging, the focus is on the impact of cycle life decay on impedance, while during discharging, the focus is on the impedance adjustment requirements of the rate of change of state of charge. By identifying the charge / discharge state, the impedance calculation strategy is dynamically switched, ensuring that the initial impedance value accurately matches the energy storage unit's operating mode, providing fundamental parameters that conform to battery characteristics for power coordination.

[0035] Further, step S210, which calculates the initial virtual impedance value based on the comparison result between the light intensity change rate and the preset light intensity change rate threshold, combined with the light intensity change rate or the real-time temperature value, includes: Step S211: When the rate of change of light intensity is less than a preset threshold for the rate of change of light intensity, the initial virtual impedance value of the photovoltaic unit is... The calculation formula is: .

[0036] in, Let be the fundamental impedance value of the i-th photovoltaic unit. Light fluctuation factor, The rate of change of light intensity.

[0037] In scenarios with gradual irradiance changes, such as morning / evening operation and seasonal transitions, this mechanism ensures smooth power transition through a dynamic irradiance response strategy. This strategy maps the rate of change in irradiance intensity to an impedance adjustment quantity, forming a virtual inertial element that adaptively adjusts with the irradiance gradient. It is typically applied to large-scale ground-mounted power plants during sunrise and sunset periods, resolving grid connection fluctuations caused by power ramp-up rate mismatch in traditional control systems, and providing the grid with rotational inertia characteristics similar to synchronous generator sets.

[0038] Step S212: When the rate of change of light intensity is greater than or equal to a preset threshold for the rate of change of light intensity, the initial virtual impedance value of the photovoltaic unit is... The calculation formula is: .

[0039] in, This is the temperature compensation coefficient. This is the difference between the real-time temperature value and the standard temperature value.

[0040] For highly dynamic scenarios such as sudden cloud formations at desert power plants and instantaneous changes in weather at coastal power plants, a temperature compensation strategy is activated. When satellite cloud images detect rapid movement of cumulonimbus clouds or precursors to sandstorms, the temperature deviation compensation model is invoked first. This is applicable to bifacial module power plants and BIPV (Building Integrated Photovoltaics) scenarios. Impedance negative feedback is used to suppress the "hot spot-power step" chain reaction caused by temperature differences in the glass substrate, thus avoiding malfunctions of string cascade protection.

[0041] Further, step S220, which calculates the initial virtual impedance value of the energy storage unit based on its charge / discharge state, combined with the current cycle number and the rate of change of state of charge, includes: Step S221: When the energy storage unit is in a charging state, the initial virtual impedance value of the energy storage unit... The calculation formula is: .

[0042] in, The charging impedance of the energy storage unit. The cyclic decay coefficient is... This represents the current loop count.

[0043] In charging scenarios such as off-peak electricity storage and redundant power absorption by wind and solar power, this mechanism extends battery life through a cyclic degradation compensation strategy. It converts the number of cycles along the charging path into impedance correction, constructing a virtual impedance layer that adaptively enhances with battery aging. This can be applied to joint frequency regulation systems in new energy power plants, solving the problem of accelerated capacity degradation caused by deep charging and shallow discharging in traditional control, and providing lifespan balance assurance for cascaded energy storage systems.

[0044] Step S222: When the energy storage unit is in a discharging state, the initial virtual impedance value of the energy storage unit... The calculation formula is: ; in, The discharge basis impedance of the energy storage unit. is the rate of change of state of charge.

[0045] To address high-power demand scenarios such as grid peak shaving and emergency backup power, this mechanism employs a dynamic state-of-charge (SOC) response strategy. It maps the rate of charge change during discharge to an impedance adjustment variable, forming a virtual impedance channel that dynamically contracts with power demand. This is particularly suitable for data center backup power systems and microgrid black-start scenarios, using impedance negative feedback to suppress the risk of lithium dendrite growth caused by high-current surges, thus ensuring battery safety boundaries under high-rate discharge conditions.

[0046] Further, in step S230, the cooperative virtual impedance value of each energy storage unit and photovoltaic unit is calculated based on the initial virtual impedance values ​​of adjacent units and the current unit, including: Step S231: Obtain the communication delay time between the energy storage unit or photovoltaic unit and adjacent units, and calculate a dynamic weighting factor based on the communication delay time. The calculation formula is: .

[0047] Where i is the serial number of the energy storage unit or photovoltaic unit, and N is the sum of the number of energy storage units and several photovoltaic units. , j is the index of the adjacent unit of the i-th energy storage unit or photovoltaic unit, and M is the number of adjacent units of the i-th energy storage unit or photovoltaic unit. , As a preset attenuation constant, Let be the communication delay time between the i-th energy storage unit or photovoltaic unit and its j-th adjacent unit.

[0048] In complex topology photovoltaic-storage systems, this mechanism quantifies network transmission reliability through communication delay and constructs a dynamic weight factor generation model. This model uses an exponential decay function to convert communication delay into the influence coefficient of neighboring nodes, ensuring that neighboring units with high transmission quality receive greater decision-making weights. It is typically applied in multi-hop communication scenarios such as island microgrids and mountain photovoltaic power stations, effectively solving communication asymmetry problems caused by terrain obstruction or heterogeneous equipment. Specifically for hybrid communication architectures combining 5G wireless private networks and power line carriers, it adaptively balances the delay differences between different transmission media through weighting, establishing a reliable data fusion foundation for collaborative control.

[0049] Step S232: Based on the initial virtual impedance values ​​and dynamic weighting factors of the current cell and its neighboring cells, calculate the cooperative virtual impedance value of the current cell. The calculation formula is: .

[0050] in, This is the self-weighting factor of the current unit. This represents the initial virtual impedance value for the current unit, s=1i or s=2, where 1i represents the sequence number of the photovoltaic unit and 2 represents the energy storage unit. This is the initial virtual impedance value of the j-th adjacent cell of the current cell.

[0051] An impedance fusion engine is constructed based on dynamic weighting factors, decoupling and reconstructing local characteristics from neighborhood states. This mechanism pioneers a unit type-aware self-weighting allocation strategy, allowing photovoltaic units to retain greater autonomy in response to sudden changes in illumination, while energy storage units enhance synergy to ensure system inertia support. In large-scale wind-solar-storage combined power plants, it can address impedance conflicts caused by differences in illumination between eastern and western regions; in cascaded battery energy storage clusters, it precisely harmonizes the impedance dispersion of new and old battery modules, avoiding accelerated capacity decay caused by circulating currents; and by establishing a balancing fulcrum, the system possesses both rapid response capabilities and global stability.

[0052] Furthermore, after calculating the cooperative virtual impedance value of each energy storage unit and photovoltaic unit based on the initial virtual impedance values ​​of adjacent units and the current unit in step S200, the process further includes: Step S241: Obtain the real-time value of the irradiance of the photovoltaic unit in the current control cycle.

[0053] In large-scale ground-mounted photovoltaic (PV) power plants, string-level intelligent sensor arrays capture the irradiance distribution in real time. Taking a 200MW PV power plant as an example, a radiometer deployed on a dual-axis tracking support samples at a frequency of 10Hz. When the irradiance difference between the east and west zones exceeds 150W / m², it automatically marks the high-irradiance subarray. Addressing the unique "cloud gap light" phenomenon in desert power plants, the system combines satellite cloud imagery prediction data to forecast irradiance spikes, completing a full-domain status scan within 500ms when the irradiance value exceeds the 800W / m² threshold. This overcomes the minute-level refresh bottleneck of traditional SCADA systems, providing a millisecond-level decision window for impedance coordination and effectively solving the DC bus oscillation problem caused by uneven irradiance between arrays.

[0054] Step S242: When the real-time value of the light intensity exceeds the preset light intensity threshold, the cooperative virtual impedance value of the photovoltaic unit in the current control cycle is reduced to the first preset ratio value of its calculation result, and the cooperative virtual impedance value of the energy storage unit in the current control cycle is increased to the second preset ratio value of its calculation result.

[0055] When high irradiance conditions are triggered, asymmetric impedance reconfiguration of the photovoltaic (PV) and energy storage (ESD) units is implemented: the PV unit impedance drops to 60%-70% of the calculated value (typically 70%), while the ESD unit impedance increases to 130%-150% (typically 140%). In a certain UHV power transmission base application, this mechanism increased the PV unit power output by 23%, while the ESD unit actively absorbed excess power by increasing its impedance, successfully suppressing DC bus voltage over-limit accidents during midday. To address the wave-focusing effect of floating power stations, a dynamic scaling factor is introduced: when the water surface reflection gain exceeds 25%, the PV impedance further decreases to 55%; when cloud cover is predicted, the ESD impedance drops in a stepwise manner to 110%. This dynamic reconfiguration mechanism maximizes the utilization of high irradiance resources while ensuring equipment safety, increasing the annual power generation of a single station by approximately 8.7%.

[0056] Further, in step S400, adjusting the output current values ​​of the energy storage unit and the photovoltaic unit based on the cooperative virtual impedance value includes: Step S410: Obtain the voltage difference between the current unit's DC bus voltage detection value and the common bus reference voltage value, and calculate the current command value of the current unit based on the voltage difference and the cooperative virtual impedance value.

[0057] A precise mapping channel from voltage deviation to current command is constructed, achieving scale adaptation of physical quantity conversion through collaborative virtual impedance values. When a deviation between the local DC bus voltage and the common reference voltage is detected, the voltage difference is divided by the collaborative virtual impedance value to generate a current command that conforms to the unit's power capability. This mechanism demonstrates its core value in a solar-fishery hybrid power station in Jiangsu: addressing regional voltage fluctuations caused by water surface reflection, it dynamically constrains the current command within the safe range of power devices through impedance self-adaptation, successfully solving the problem of string mismatch. Its technical essence lies in establishing a standardized conversion chain of "voltage error → impedance weighting → current distribution," preserving the flexibility of distributed decision-making while ensuring the consistency of system-level regulation.

[0058] Step S420 obtains the current difference between the current command value and the actual detected value of the output current of the current unit, generates a pulse width modulation duty cycle based on the current difference through a proportional-integral controller, drives the switching devices of the power converter according to the pulse width modulation duty cycle, and adjusts the output current value.

[0059] Based on the dynamic deviation between the current command value and the actual detected value, the proportional-integral (PI) controller is activated for precise modulation. The proportional element responds quickly to transient current fluctuations, while the integral element eliminates steady-state errors; together, they generate the optimal pulse width duty cycle. In a high-altitude photovoltaic project, this invention can handle extremely rapid cloud shadow conditions: when the illumination changes drastically by 40% within 0.5 seconds, the PI parameter adaptive algorithm compresses the adjustment time to within 100 milliseconds, improving the duty cycle resolution to 0.1%. The power device drive circuit adopts a three-level optimization strategy with dead-time compensation, maintaining nanosecond-level switching accuracy even in a -40℃ low-temperature environment, completely avoiding the risk of IGBT parallel current sharing failure.

[0060] Furthermore, the "one-to-N" integrated control method for photovoltaic-storage DC integrated systems also includes: Step S510: When the reference voltage value of the common bus is lower than the rated voltage value and the absolute value of the voltage deviation between the two is less than the first preset voltage difference threshold, the cooperative virtual impedance value of all energy storage units and photovoltaic units is reduced proportionally. The proportion of reduction of the cooperative virtual impedance value is positively correlated with the absolute value of the voltage deviation.

[0061] When the common bus reference voltage is detected to be lower than the rated value and the deviation is within the 5% threshold, the impedance proportional contraction strategy is triggered. Each unit synchronously reduces the cooperative virtual impedance value according to the voltage deviation amplitude, forming an equivalent system internal resistance compression effect. When a sudden drop in wind speed causes the DC bus voltage to drop by 3.2%, the impedance contraction enables the photovoltaic unit to automatically increase power injection by 15%, and the energy storage unit to release additional discharge capacity, achieving autonomous voltage recovery without the need for central dispatch instructions. A negative feedback path of "voltage deviation → inverse impedance adjustment → natural current growth" is constructed, avoiding the overshoot risk of traditional PID control through physical characteristic self-adjustment.

[0062] Step S520: When the reference voltage value of the common bus is higher than the rated voltage value and the absolute value of the voltage deviation between the two is less than the first preset voltage difference threshold, the cooperative virtual impedance value of all energy storage units and photovoltaic units is increased proportionally. The increase in the cooperative virtual impedance value is positively correlated with the absolute value of the voltage deviation.

[0063] When facing a positive voltage deviation, an impedance proportional expansion response should be initiated. The impedance increase ratio should be strictly matched with the voltage deviation. Impedance expansion is used to effectively enhance system damping: when the voltage exceeds the rated value by 2.8%, impedance expansion causes the energy storage unit to automatically switch to charging mode, and the photovoltaic unit achieves power-limited soft start-stop through impedance increase, avoiding the thermal management burden caused by traditional chopping energy consumption; and the voltage control is transformed into a continuous and gradual process in the impedance domain, eliminating the step impact caused by discrete control.

[0064] Step S530: When the absolute value of the voltage deviation between the common bus reference voltage value and the rated voltage value is greater than the first preset voltage difference threshold and less than or equal to the second preset voltage difference threshold, the converter forced voltage regulation function of the energy storage unit is activated.

[0065] When the voltage deviation exceeds the 5% safety boundary, it switches to an emergency voltage stabilization mode dominated by energy storage. The energy storage converter uses a voltage source control strategy to withstand an 80% voltage dip on the grid side within 0.2 seconds; it adopts a triple protection design: a nanosecond-level trigger circuit based on FPGA ensures a response delay of <50μs; dynamic priority management of battery SOC prevents over-discharge; a multi-module circulating current suppression algorithm maintains parallel current sharing accuracy of ±1.5%; by establishing a direct path between grid anomalies and energy storage response, it can overcome the multi-level transmission delay of traditional control architectures.

[0066] Step S540: When the absolute value of the voltage deviation between the common bus reference voltage value and the rated voltage value is greater than the second preset voltage difference threshold, non-critical loads in the load unit are cut off in stages.

[0067] In extreme cases where the voltage deviation exceeds 10%, a tiered load shedding strategy is activated. In one embodiment, the first level disconnects the landscape lighting and fresh air system (12% of the total load); the second level disconnects the backup charging pile (18% of the load); the third level isolates the non-critical server cluster (25% of the load); and the final protection disconnects the backup chiller unit (30% of the load). Each action is spaced 150ms apart, and the voltage prediction algorithm enables early intervention.

[0068] Accordingly, please refer to Figure 2The second aspect of this invention provides a "one-to-N" integrated control device for a photovoltaic-storage DC integrated system. Based on the aforementioned "one-to-N" integrated control method for the photovoltaic-storage DC integrated system, the device controls the photovoltaic-storage DC integrated system. The photovoltaic-storage DC integrated system includes: an energy storage unit, a load unit, and several photovoltaic units connected in parallel via a DC bus. The control device includes: Data acquisition module 1 is used to acquire the real-time status parameters of the energy storage unit and the photovoltaic unit during the current control cycle. The real-time status parameters include: DC bus voltage detection value, output current detection value, state of charge change rate of the energy storage unit and irradiance change rate of the photovoltaic unit. Impedance calculation module 2 is used to calculate the initial virtual impedance values ​​of the energy storage unit and the photovoltaic unit based on the rate of change of state of charge and the rate of change of irradiance, respectively. It also calculates the cooperative virtual impedance value of each energy storage unit and photovoltaic unit based on the initial virtual impedance values ​​of adjacent units and the current unit. The adjacent units are the directly associated units that are connected to the current unit in communication. Voltage calculation module 3 is used to calculate the common bus reference voltage value based on the DC bus voltage detection values ​​of adjacent units and the current unit through a dynamic consistency algorithm; The status control module 4 is used to adjust the output current value of the energy storage unit and the photovoltaic unit based on the cooperative virtual impedance value, so that the DC bus voltage detection value of each energy storage unit and photovoltaic unit is consistent with the common bus reference voltage value.

[0069] Accordingly, a third aspect of the present invention provides an electronic device, including: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to execute the "one-to-N" integrated control method of the above-described photovoltaic-storage-DC integrated system.

[0070] Accordingly, a fourth aspect of the present invention provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the above-described "one-to-N" integrated control method for the photovoltaic-storage-DC integrated system.

[0071] The embodiments of the present invention aim to protect a "one-to-N" integrated control method and device for a photovoltaic-storage DC integrated system, which has the following effects: 1. A distributed control network is constructed by adopting a point-to-point communication mechanism between adjacent units, which completely eliminates the risk of single point of failure in the traditional main controller architecture; each unit only needs to exchange data with directly related units, which greatly reduces communication complexity and supports flexible expansion of system scale; when units are dynamically connected or disconnected, the system maintains stable operation by autonomously reconstructing the communication topology, effectively ensuring power supply continuity. 2. An initial virtual impedance value is generated based on the real-time operating status of the unit, and data from adjacent units are fused through a communication quality-weighted collaborative algorithm to form a globally optimized collaborative virtual impedance parameter. This mechanism significantly suppresses power oscillations caused by sudden changes in illumination or load steps, improves the circulating current problem between photovoltaic units and energy storage units, and ensures dynamic balance of bus voltage. 3. By using a closed-loop combination of voltage deviation direction identification and impedance ratio adjustment, precise control of the bus voltage can be achieved; combined with the photovoltaic priority mode, the impedance of the photovoltaic and energy storage units can be adjusted differently to improve the energy utilization rate under high irradiance conditions.

[0072] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0073] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0074] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0075] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A "one-to-N" integrated control method for a photovoltaic-storage-DC integrated system, characterized in that, The photovoltaic-storage DC integrated system comprises: an energy storage unit, a load unit, and several photovoltaic units connected in parallel via a DC bus. The control method includes the following steps: The real-time status parameters of the energy storage unit and the photovoltaic unit during the current control cycle are obtained respectively. The real-time status parameters include: DC bus voltage detection value, output current detection value, state of charge change rate of the energy storage unit, and irradiance change rate of the photovoltaic unit. Based on the rate of change of state of charge and the rate of change of light intensity, the initial virtual impedance values ​​of the energy storage unit and the photovoltaic unit are calculated respectively. Based on the initial virtual impedance values ​​of adjacent units and the current unit, the cooperative virtual impedance value of each energy storage unit and the photovoltaic unit is calculated respectively. The adjacent units are directly associated units that are communicatively connected to the current unit. Based on the DC bus voltage detection values ​​of adjacent units and the current unit, the common bus reference voltage value is calculated using a dynamic consistency algorithm. Based on the cooperative virtual impedance value, the output current values ​​of the energy storage unit and the photovoltaic unit are adjusted so that the DC bus voltage detection value of each energy storage unit and photovoltaic unit is consistent with the common bus reference voltage value. The step of adjusting the output current values ​​of the energy storage unit and the photovoltaic unit based on the cooperative virtual impedance value includes: Obtain the voltage difference between the current unit's DC bus voltage detection value and the common bus reference voltage value, and divide the voltage difference by the cooperative virtual impedance value to obtain the current command value of the current unit; The calculation of the cooperative virtual impedance value for each energy storage unit and the photovoltaic unit based on the initial virtual impedance values ​​of adjacent units and the current unit includes: The communication delay time between the energy storage unit or the photovoltaic unit and the adjacent unit is obtained, and a dynamic weighting factor is calculated based on the communication delay time. The calculation formula is: ； Where i is the serial number of the energy storage unit or the photovoltaic unit, and N is the sum of the number of the energy storage unit and the plurality of photovoltaic units. , j is the sequence number of the adjacent unit of the i-th energy storage unit or photovoltaic unit, and M is the number of adjacent units of the i-th energy storage unit or photovoltaic unit. , As a preset attenuation constant, The communication delay time between the i-th energy storage unit or the photovoltaic unit and its j-th adjacent unit; Based on the initial virtual impedance values ​​and dynamic weighting factors of the current cell and its neighboring cells, the cooperative virtual impedance value of the current cell is calculated. The calculation formula is: ； in, This is the self-weighting factor of the current unit. This represents the initial virtual impedance value for the current unit, s=1i or s=2, where 1i represents the sequence number of the photovoltaic unit and 2 represents the energy storage unit. This is the initial virtual impedance value of the j-th adjacent cell of the current cell.

2. The "one-to-N" integrated control method for the photovoltaic-storage-DC integrated system according to claim 1, characterized in that, The calculation of the initial virtual impedance values ​​of the energy storage unit and the photovoltaic unit based on the rate of change of state of charge and the rate of change of illuminance, respectively, includes: The light intensity change rate and real-time temperature value of the photovoltaic unit are obtained. Based on the comparison result between the light intensity change rate and the preset threshold of the light intensity change rate, the initial virtual impedance value of the photovoltaic unit is calculated in combination with the light intensity change rate or the real-time temperature value. The rate of change of state of charge and the current cycle number of the energy storage unit are obtained. Based on the charge and discharge state of the energy storage unit, the initial virtual impedance value of the energy storage unit is calculated by combining the current cycle number and the rate of change of state of charge.

3. The "one-to-N" integrated control method for the photovoltaic-storage DC integrated system according to claim 2, characterized in that, The calculation of the initial virtual impedance value of the photovoltaic unit based on the comparison result between the rate of change of light intensity and a preset threshold for the rate of change of light intensity, combined with the rate of change of light intensity or the real-time temperature value, includes: When the rate of change of light intensity is less than a preset threshold for the rate of change of light intensity, the initial virtual impedance value of the photovoltaic unit... The calculation formula is: ； in, Let be the fundamental impedance value of the i-th photovoltaic unit. The light fluctuation factor, The rate of change of light intensity; When the rate of change of light intensity is greater than or equal to a preset threshold for the rate of change of light intensity, the initial virtual impedance value of the photovoltaic unit is... The calculation formula is: ； in, This is the temperature compensation coefficient. This is the difference between the real-time temperature value and the standard temperature value.

4. The "one-to-N" integrated control method for the photovoltaic-storage-DC integrated system according to claim 2, characterized in that, The calculation of the initial virtual impedance value of the energy storage unit based on its charge / discharge state, combined with the current cycle number and the rate of change of state of charge, includes: When the energy storage unit is in a charging state, the initial virtual impedance value of the energy storage unit The calculation formula is: ； in, The charging basis impedance of the energy storage unit is... The cyclic decay coefficient is... This represents the current loop count; When the energy storage unit is in a discharging state, the initial virtual impedance value of the energy storage unit The calculation formula is: ; in, The discharge basis impedance of the energy storage unit is given. is the rate of change of state of charge.

5. The "one-to-N" integrated control method for the photovoltaic-storage DC integrated system according to claim 1, characterized in that, After calculating the cooperative virtual impedance value of each energy storage unit and the photovoltaic unit based on the initial virtual impedance values ​​of adjacent units and the current unit, the method further includes: Obtain the real-time value of the light intensity of the photovoltaic unit in the current control cycle; When the real-time value of the light intensity exceeds the preset light intensity threshold, the collaborative virtual impedance value of the photovoltaic unit in the current control cycle is reduced to a first preset ratio value of its calculation result, and the collaborative virtual impedance value of the energy storage unit in the current control cycle is increased to a second preset ratio value of its calculation result.

6. The "one-to-N" integrated control method for the photovoltaic-storage-DC integrated system according to claim 1, characterized in that, The step of adjusting the output current values ​​of the energy storage unit and the photovoltaic unit based on the cooperative virtual impedance value further includes: The current difference between the current command value and the actual detected value of the output current of the current unit is obtained. Based on the current difference, a pulse width modulation duty cycle is generated by a proportional-integral controller. The switching devices of the power converter are driven according to the pulse width modulation duty cycle to adjust the output current value.

7. The "one-to-N" integrated control method for the photovoltaic-storage-DC integrated system according to any one of claims 1-6, characterized in that, Also includes: When the reference voltage of the common bus is lower than the rated voltage and the absolute value of the voltage deviation between the two is less than the first preset voltage difference threshold, the cooperative virtual impedance value of all the energy storage units and the photovoltaic units is reduced proportionally, and the proportion of reduction of the cooperative virtual impedance value is positively correlated with the absolute value of the voltage deviation. When the reference voltage value of the common bus is higher than the rated voltage value and the absolute value of the voltage deviation between the two is less than the first preset voltage difference threshold, the cooperative virtual impedance value of all energy storage units and photovoltaic units is increased proportionally, and the increase in the cooperative virtual impedance value is positively correlated with the absolute value of the voltage deviation. When the absolute value of the voltage deviation between the reference voltage value of the common bus and the rated voltage value is greater than the first preset voltage difference threshold and less than or equal to the second preset voltage difference threshold, the converter forced voltage regulation function of the energy storage unit is activated. When the absolute value of the voltage deviation between the reference voltage value of the common bus and the rated voltage value is greater than the second preset voltage difference threshold, the non-critical loads in the load unit are cut off in stages.

8. A "one-to-N" integrated control device for a photovoltaic-storage DC integrated system, characterized in that, The photovoltaic-storage DC integrated system is controlled based on the "one-to-N" integrated control method described in any one of claims 1-7. The photovoltaic-storage DC integrated system comprises: an energy storage unit, a load unit, and several photovoltaic units connected in parallel via a DC bus. The control device includes: The data acquisition module is used to acquire the real-time status parameters of the energy storage unit and the photovoltaic unit during the current control cycle. The real-time status parameters include: DC bus voltage detection value, output current detection value, state of charge change rate of the energy storage unit, and irradiance change rate of the photovoltaic unit. An impedance calculation module is used to calculate the initial virtual impedance values ​​of the energy storage unit and the photovoltaic unit based on the rate of change of state of charge and the rate of change of light intensity, respectively. It also calculates the cooperative virtual impedance value of each energy storage unit and the photovoltaic unit based on the initial virtual impedance values ​​of adjacent units and the current unit, wherein the adjacent units are directly associated units that are communicatively connected to the current unit. The calculation of the cooperative virtual impedance value for each energy storage unit and the photovoltaic unit based on the initial virtual impedance values ​​of adjacent units and the current unit includes: The communication delay time between the energy storage unit or the photovoltaic unit and the adjacent unit is obtained, and a dynamic weighting factor is calculated based on the communication delay time. The calculation formula is: ； Where i is the serial number of the energy storage unit or the photovoltaic unit, and N is the sum of the number of the energy storage unit and the plurality of photovoltaic units. , j is the sequence number of the adjacent unit of the i-th energy storage unit or photovoltaic unit, and M is the number of adjacent units of the i-th energy storage unit or photovoltaic unit. , As a preset attenuation constant, The communication delay time between the i-th energy storage unit or the photovoltaic unit and its j-th adjacent unit; Based on the initial virtual impedance values ​​and dynamic weighting factors of the current cell and its neighboring cells, the cooperative virtual impedance value of the current cell is calculated. The calculation formula is: ； in, This is the self-weighting factor of the current unit. This represents the initial virtual impedance value for the current unit, s=1i or s=2, where 1i represents the sequence number of the photovoltaic unit and 2 represents the energy storage unit. This is the initial virtual impedance value of the j-th adjacent cell of the current cell; The voltage calculation module is used to calculate the common bus reference voltage value based on the DC bus voltage detection values ​​of adjacent units and the current unit through a dynamic consistency algorithm. A state control module is used to adjust the output current values ​​of the energy storage unit and the photovoltaic unit based on the cooperative virtual impedance value, so that the DC bus voltage detection value of each energy storage unit and the photovoltaic unit is consistent with the common bus reference voltage value; the adjustment of the output current values ​​of the energy storage unit and the photovoltaic unit based on the cooperative virtual impedance value includes: obtaining the voltage difference between the DC bus voltage detection value of the current unit and the common bus reference voltage value, and dividing the voltage difference by the cooperative virtual impedance value to obtain the current command value of the current unit.

9. An electronic device, characterized in that, include: At least one processor; And a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to perform the "one-to-N" integrated control method of the photovoltaic-storage-DC integrated system as described in any one of claims 1-7.

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