Photovoltaic protocol conversion system and method for voltage regulation

Abstract

The invention provides a photovoltaic protocol conversion system and method for voltage regulation, and the system comprises a collection control unit, an inverter communication interaction unit and a self-adaptive voltage regulation unit, and the collection control unit is in bidirectional signal connection with the inverter communication interaction unit and the self-adaptive voltage regulation unit. The acquisition control unit generates a power generation data request message, and the inverter communication interaction unit transmits the power generation data request message to the photovoltaic inverter and receives a response message; after analysis, generating voltage regulation associated data, and transmitting the voltage regulation associated data to the self-adaptive voltage regulation unit; the self-adaptive voltage regulation unit obtains a reactive power regulation demand through a self-adaptive algorithm based on the voltage regulation associated data and returns the reactive power regulation demand; the acquisition control unit generates a reactive power regulation instruction message accordingly, and issues the reactive power regulation instruction message to the inverter through the interaction unit to drive the inverter to output or absorb corresponding reactive power so as to realize grid-connected point voltage regulation; according to the invention, reactive power is accurately controlled through cooperation of the units, and improvement of photovoltaic grid-connected voltage stability and power grid compatibility is facilitated.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic grid-connected control technology, and more specifically to a photovoltaic protocol conversion system and method for voltage regulation. Background Technology

[0002] Currently, with the large-scale grid connection of distributed photovoltaic (PV) power plants, the fluctuation in their output can easily cause the voltage at the grid connection point to deviate from the rated range, affecting grid security and power quality. Therefore, the voltage regulation capability of PV systems has become a core technical requirement. In current PV grid-connected control, the PV inverter, as the core of energy conversion, needs to interact efficiently with the control unit to achieve precise reactive power regulation, but existing technologies have many bottlenecks.

[0003] On the one hand, the communication protocols of photovoltaic inverters from different manufacturers vary greatly, and existing control equipment lacks a universal interactive unit, resulting in incomplete power generation data acquisition and delayed command response, failing to provide real-time and reliable data support for voltage regulation. On the other hand, voltage regulation largely relies on fixed threshold strategies, lacking adaptive algorithms based on real-time operating data, leading to low regulation accuracy and a tendency for "over-regulation" or "under-regulation." Furthermore, the data acquisition, communication, and regulation modules often operate independently, resulting in fragmented data flow and difficulty in forming a closed-loop control system of "data acquisition-analysis and calculation-command execution," leading to poor voltage fluctuation control at the grid connection point and hindering the grid compatibility of distributed photovoltaic systems. Summary of the Invention

[0004] To address the issues of incompatible photovoltaic inverter communication protocols, lack of adaptive adjustment algorithms based on real-time data, and insufficient coordination of functional modules during distributed photovoltaic grid connection, which lead to unreal-time power generation data acquisition, low voltage regulation accuracy, and voltage fluctuations at the grid connection point, this invention proposes a photovoltaic protocol conversion system for voltage regulation, comprising: an acquisition and control unit, an inverter communication interaction unit, and an adaptive voltage regulation unit.

[0005] The data acquisition and control unit is bidirectionally connected to the inverter communication interaction unit and the adaptive voltage regulation unit, respectively. It is used to generate a power generation data request message and send it to the inverter communication interaction unit. It is also used to parse the response message of the photovoltaic inverter returned by the inverter communication interaction unit to obtain voltage regulation related data. It is also used to generate a reactive power regulation command message adapted to the photovoltaic inverter according to the reactive power regulation requirements sent by the adaptive voltage regulation unit.

[0006] The inverter communication interaction unit is used to transmit the power generation data request message to the photovoltaic inverter; it is also used to receive the response message fed back by the photovoltaic inverter and send it back to the acquisition and control unit, and at the same time transmit the reactive power adjustment command message generated by the acquisition and control unit to the photovoltaic inverter.

[0007] The adaptive voltage regulation unit is used to obtain the voltage regulation correlation data from the acquisition and control unit, obtain the reactive power regulation requirement based on the voltage regulation correlation data using the adaptive voltage regulation algorithm, and transmit the reactive power regulation requirement to the acquisition and control unit.

[0008] After the data acquisition and control unit transmits the reactive power regulation command message to the photovoltaic inverter through the inverter communication interaction unit, the photovoltaic inverter outputs or absorbs the corresponding reactive power to the grid, thereby realizing grid connection point voltage regulation.

[0009] Optionally, the photovoltaic protocol conversion system further includes: a data center;

[0010] The data center is bidirectionally connected to the acquisition and control unit to store the voltage regulation correlation data generated by the acquisition and control unit, and to perform noise reduction and normalization preprocessing on the voltage regulation correlation data, and to provide the preprocessed voltage regulation correlation data to the adaptive voltage regulation unit.

[0011] Optionally, the adaptive voltage regulation unit, based on the voltage regulation correlation data, uses an adaptive voltage regulation algorithm to obtain the reactive power regulation requirement, including:

[0012] The difference between the real-time voltage at the grid connection point and the preset voltage threshold in the voltage regulation correlation data is calculated to obtain the difference calculation result;

[0013] When the calculated difference is less than or equal to the lower voltage threshold, an inductive reactive power regulation value is generated.

[0014] When the calculated difference is greater than or equal to the upper voltage threshold, a capacitive reactive power adjustment value is generated.

[0015] The inductive reactive power adjustment value or the inductive reactive power adjustment value is taken as the reactive power adjustment requirement.

[0016] Optionally, the photovoltaic protocol conversion system further includes: a dual-mode communication interaction unit;

[0017] The dual-mode communication interaction unit is bidirectionally connected to the acquisition and control unit, and is used to convert the power grid operation data messages output by the acquisition and control unit into transmission signals adapted to the power line channel or wireless public network channel, and send them to the power grid dispatch master station; at the same time, it receives remote instructions from the power grid dispatch master station, converts them into signals that the acquisition and control unit can recognize, and then transmits them back.

[0018] Optionally, the acquisition and control unit is further configured to:

[0019] The inverter communication interaction unit sends multiple sets of reactive power test commands with different amplitudes to the photovoltaic inverter and reads the feedback execution data of the photovoltaic inverter in real time.

[0020] The maximum inductive reactive power output value and the maximum capacitive reactive power absorption value of the photovoltaic inverter are determined based on the feedback execution data.

[0021] The maximum inductive reactive power output value and the maximum capacitive reactive power absorption value are used as the maximum reactive power boundary values ​​of the photovoltaic inverter.

[0022] When the acquisition and control unit generates a reactive power adjustment command message, the adjustment power value in the reactive power adjustment command message does not exceed the maximum reactive power boundary value.

[0023] Optionally, the voltage regulation associated data includes one or more of the following: real-time voltage at the grid connection point, active power output of the photovoltaic inverter, reactive power output of the photovoltaic inverter, real-time current and power factor on the grid side.

[0024] Optionally, the reactive power adjustment command message includes a command identifier, an adjustment power value, and an execution time limit.

[0025] Optionally, the period for the acquisition and control unit to generate power generation data request messages is 1-5 minutes;

[0026] The power generation data request message contains a parameter type identifier to be collected, which includes one or more of the following: grid voltage, grid current, active power, reactive power, and power factor.

[0027] Optionally, the communication link of the inverter communication interaction unit is a wired communication link or a wireless communication link; the wired communication link adopts RS485 bus or power line carrier communication, and the wireless communication link adopts LoRa, WiFi or Bluetooth communication.

[0028] Based on the same inventive concept, the present invention also provides a photovoltaic protocol conversion method for voltage regulation, comprising:

[0029] The data acquisition and control unit generates a power generation data request message and notifies the inverter communication interaction unit to send it to the photovoltaic inverter.

[0030] The inverter communication interaction unit sends the power generation data request message generated by the acquisition and control unit to the photovoltaic inverter, and the photovoltaic inverter sends the response message back to the acquisition and control unit.

[0031] The control unit parses the response message and generates voltage regulation related data after data processing.

[0032] The reactive power regulation requirement is obtained by using the adaptive voltage regulation algorithm based on the voltage regulation correlation data by the adaptive voltage regulation unit.

[0033] The acquisition and control unit generates a reactive power regulation command message adapted to the photovoltaic inverter based on the reactive power regulation requirements, and transmits the reactive power regulation command message to the photovoltaic inverter to drive the photovoltaic inverter to output or absorb the corresponding reactive power to the grid, thereby realizing grid connection point voltage regulation.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] This invention provides a photovoltaic protocol conversion system and method for voltage regulation, comprising: a data acquisition and control unit, an inverter communication interaction unit, and an adaptive voltage regulation unit; the data acquisition and control unit is bidirectionally signal-connected to both the inverter communication interaction unit and the adaptive voltage regulation unit, and is used to generate a power generation data request message and send it to the inverter communication interaction unit, and also to parse the response message from the photovoltaic inverter returned by the inverter communication interaction unit to obtain voltage regulation related data; it is also used to generate a reactive power regulation command message adapted to the photovoltaic inverter based on the reactive power regulation demand sent by the adaptive voltage regulation unit; the inverter communication interaction unit is used to transmit the power generation data request message to the photovoltaic inverter; it is also used to receive the response message from the photovoltaic inverter and transmit it back to the data acquisition and control unit, and simultaneously transmit the reactive power regulation command message generated by the data acquisition and control unit to the photovoltaic inverter; the adaptive voltage regulation unit is used to obtain the voltage regulation related data from the data acquisition and control unit, and based on the voltage regulation related data, utilize adaptive... According to the voltage regulation algorithm, the reactive power regulation demand is obtained and transmitted to the acquisition and control unit. The acquisition and control unit transmits the reactive power regulation command message to the photovoltaic inverter through the inverter communication interaction unit, so that the photovoltaic inverter outputs or absorbs the corresponding reactive power to the grid, thereby realizing the grid connection point voltage regulation. This invention can adapt to the communication needs of different photovoltaic inverters through the inverter communication interaction unit, realize the smooth transmission of power generation data request and response messages, and avoid data acquisition delays or interruptions caused by protocol incompatibility. Based on the real-time generated voltage regulation correlation data, the adaptive voltage regulation unit accurately calculates the reactive power regulation demand through an adaptive algorithm, solving the problems of low accuracy and easy over-regulation or under-regulation of traditional fixed threshold regulation. The acquisition and control unit, as the central hub, integrates data parsing and command generation functions, so that data acquisition-analysis calculation-regulation command execution form a complete closed loop, ultimately realizing stable control of the grid connection point voltage, significantly improving the grid connection compatibility and grid operation safety of distributed photovoltaic systems, while reducing equipment losses and operation and maintenance costs caused by voltage fluctuations. Attached Figure Description

[0036] Figure 1 A schematic diagram of the framework of a photovoltaic protocol conversion system for voltage regulation provided by the present invention;

[0037] Figure 2 This is a schematic diagram of a traditional photovoltaic power generation system;

[0038] Figure 3 A schematic diagram illustrating the location and relationship of a photovoltaic protocol conversion system for voltage regulation in a low-voltage power distribution network, provided by the present invention.

[0039] Figure 4 A schematic diagram of the overall framework of a photovoltaic protocol conversion system for voltage regulation provided by the present invention;

[0040] Figure 5 A schematic diagram illustrating the voltage regulation process of a photovoltaic protocol conversion system for voltage regulation provided by this invention;

[0041] Figure 6 This is a schematic flowchart of a photovoltaic protocol conversion method for voltage regulation provided by the present invention;

[0042] Figure 7 This is a schematic diagram of the collaborative hierarchical control of a photovoltaic protocol conversion system applied in a photovoltaic protocol conversion method for voltage regulation provided by the present invention. Detailed Implementation

[0043] This invention proposes a photovoltaic protocol conversion system and method for voltage regulation. The specific embodiments of this invention will be further described in detail below with reference to the accompanying drawings.

[0044] Example 1:

[0045] This invention provides a photovoltaic protocol conversion system for voltage regulation, the framework of which is shown in the schematic diagram below. Figure 1 As shown, it includes: a data acquisition and control unit, an inverter communication and interaction unit, and an adaptive voltage regulation unit;

[0046] The data acquisition and control unit is bidirectionally connected to both the inverter communication interaction unit and the adaptive voltage regulation unit. It is used to generate a power generation data request message and send it to the inverter communication interaction unit. It is also used to parse the response message from the photovoltaic inverter returned by the inverter communication interaction unit to obtain voltage regulation related data. Furthermore, it is used to generate a reactive power regulation command message adapted to the photovoltaic inverter based on the reactive power regulation requirements sent by the adaptive voltage regulation unit. The generation period for the data acquisition and control unit to generate the power generation data request message can be 1-5 minutes.

[0047] The inverter communication interaction unit is used to transmit the power generation data request message to the photovoltaic inverter; it is also used to receive the response message fed back by the photovoltaic inverter and send it back to the acquisition and control unit, and at the same time transmit the reactive power adjustment command message generated by the acquisition and control unit to the photovoltaic inverter.

[0048] The adaptive voltage regulation unit is used to obtain the voltage regulation correlation data from the acquisition and control unit, obtain the reactive power regulation requirement based on the voltage regulation correlation data using the adaptive voltage regulation algorithm, and transmit the reactive power regulation requirement to the acquisition and control unit.

[0049] After the acquisition and control unit transmits the reactive power regulation command message to the photovoltaic inverter through the inverter communication interaction unit, the photovoltaic inverter outputs or absorbs the corresponding reactive power to the grid, thereby realizing grid connection point voltage regulation.

[0050] For example, the reactive power adjustment command message may include a command identifier, an adjustment power value, and an execution time limit;

[0051] For example, the power generation data request message may contain a parameter type identifier to be collected, which includes one or more of the following: grid voltage, grid current, active power, reactive power, and power factor.

[0052] In one implementation, the photovoltaic protocol conversion system may further include: a data center;

[0053] The data center is bidirectionally connected to the acquisition and control unit to store voltage regulation correlation data generated by the acquisition and control unit. It also performs denoising and normalization preprocessing on this data, providing the preprocessed voltage regulation correlation data to the adaptive voltage regulation unit. In this implementation, the data center's denoising and normalization processing not only filters out abnormal fluctuations caused by instantaneous interference but also clears obstacles for the adaptive voltage regulation unit's algorithm calculation by unifying the data dimension, avoiding regulation deviations caused by messy raw data. Simultaneously, the data center's long-term data storage capacity can form voltage regulation data baselines for different time periods and operating conditions. This historical data can feed back into the adaptive algorithm optimization, i.e., by analyzing the "photovoltaic output - voltage" data in the historical data. The correlation between "fluctuation and regulation effect" upgrades the algorithm from passively responding to real-time voltage deviations to predicting voltage change trends based on historical baselines, generating more adaptable regulation strategies in advance. Simultaneously, in collaborative hierarchical control scenarios, the data center can act as a local data hub, providing the scheduling master station with fused data support of "real-time data + historical trends." This helps global regulation commands better align with the actual characteristics of local distribution areas, avoiding conflicts between one-size-fits-all commands in traditional collaborative control and local operating conditions. Furthermore, the long-accumulated preprocessed data can provide data support for system fault tracing and parameter optimization for different brand inverters, extending the photovoltaic protocol conversion system from a single voltage regulation device into a data-enabled core for distribution area photovoltaic management, significantly improving the system's adaptability and self-optimization capabilities in complex power grid environments.

[0054] In one implementation, the photovoltaic protocol conversion system may further include: a dual-mode communication interaction unit;

[0055] The dual-mode communication interaction unit is bidirectionally connected to the acquisition and control unit, and is used to convert the power grid operation data messages output by the acquisition and control unit into transmission signals adapted to the power line channel or the wireless public network channel, and send them to the power grid dispatch master station; at the same time, it receives remote commands from the power grid dispatch master station, converts them into signals that the acquisition and control unit can recognize, and then transmits them back. In this implementation, the introduction of the dual-mode communication interaction unit, through the automatic protocol conversion and intelligent channel switching mechanism, can dynamically allocate transmission resources according to service priority. For example, high-priority remote adjustment commands are transmitted first through the power line channel, while low-priority historical data is uploaded in batches through the wireless public network. At the same time, when a certain channel is interrupted, millisecond-level seamless switching is achieved and interrupted data is cached, ensuring the data continuity required for observability and measurability and the command accuracy required for adjustability and controllability. This completely solves the data packet loss or command delay problems of traditional single-channel communication in power grid congestion and signal shielding scenarios, thereby realizing full-scenario adaptation of data transmission and command interaction between the photovoltaic protocol conversion system and the dispatch master station.

[0056] Generally, photovoltaic protocol conversion systems are electrical communication devices that support both the standard protocol of the power grid cloud master station and the custom protocol of the photovoltaic inverter. This enables the distributed photovoltaic system to achieve the "four capabilities" (observable, measurable, adjustable, and controllable) of the power grid. As the core grid-connected interface of the photovoltaic power generation system, the control strategy of the photovoltaic inverter has a significant impact on the safe and stable operation of the power grid. A schematic diagram of a traditional photovoltaic power generation system is shown below. Figure 2 As shown, when the user end of the grid connection point is in peak electricity consumption, most of the equipment operating during peak hours (such as air conditioners, refrigerators, washing machines, fans, etc.) are inductive loads. Inductive loads will cause the power factor (which can be represented by cosφ) to decrease (φ angle increases, sinφ increases), according to the following formula:

[0057] ;

[0058] ;

[0059] in, This represents the voltage lost during power transmission. Indicates the mains current; Indicates the equivalent resistance of a power grid line or system; Indicates the power factor of the load; Indicates the inductive reactance of an inductor; This refers to the reactive electrical energy used to stabilize the magnetic field; Indicates the user's voltage; This represents the system-side voltage; according to the above formula, during peak electricity consumption, the voltage in the formula... This term becomes very large, thus Increase, user voltage A drop in voltage, or frequent undervoltage operation of electrical equipment, can lead to decreased performance, difficulty in starting, or even burnout.

[0060] According to the following formula:

[0061] ;

[0062] ;

[0063] in, Indicates capacitive reactive power; Indicates the system's equivalent susceptance; Indicates the user's voltage; This represents the voltage lost during power transmission. R represents the active power output of the photovoltaic system; R represents the equivalent resistance of the power grid line or system. X represents the reactive power output of the photovoltaic system; X represents the equivalent reactance of the grid line or system; U represents the rated voltage of the grid; according to this formula, when the user end of the grid connection point is in an unloaded or lightly loaded state, the active power consumption P=0. Negative value Negative value, voltage Increased voltage and frequent overvoltage operation of electrical equipment can cause overvoltage in user equipment, accelerate equipment aging, cause overheating, and make the equipment more susceptible to damage.

[0064] To address the undervoltage problem, existing technologies typically employ parallel capacitors to boost the voltage; to address the overvoltage problem, existing technologies typically employ parallel reactors to reduce the voltage; or they use large-scale dedicated reactive power regulation equipment such as static var compensators (SVCs) and static var generators (SVGs).

[0065] These devices all share the following common problems:

[0066] 1) Huge fixed asset investment and operation and maintenance costs;

[0067] 2) The voltage regulation system of the power grid is cumbersome and rigid.

[0068] Furthermore, the application of photovoltaic (PV) inverters in low-voltage networks is increasing daily. However, current PV inverter grid connection primarily employs the following method: the DC power generated by the PV modules is entirely converted into active power and injected into the grid with unity power factor (i.e., zero reactive power output). This "active power-first" operating mode simply treats distributed PV as a passive energy source, failing to fully utilize its potential grid support capacity. A schematic diagram illustrating the location and relationship of PV conversion equipment in a low-voltage distribution network is shown below. Figure 3 As shown, the photovoltaic (PV) inverter transmits the grid-required data to the dispatching master station via smart meters and concentrators, enabling the master station to monitor and flexibly control the PV inverter. It also communicates with the PV inverter and reads the grid-required data, serving as a crucial link between the PV inverter and the dispatching master station. Existing PV conversion systems primarily monitor, request, and flexibly control PV inverter data at the dispatching master station, without regulating the voltage at the user side / grid connection point. To address these issues, this invention proposes a PV protocol conversion system that supports adaptive voltage adjustment. The overall framework structure is illustrated in the diagram below. Figure 4 As shown, it includes: a dual-mode communication interaction unit, a data center, an adaptive voltage regulation unit, a data acquisition and control unit, and an inverter communication interaction unit, specifically:

[0069] The dual-mode communication interaction unit is mainly used to convert the messages sent to the master station in the photovoltaic protocol conversion system into signals and send them to the power line or wireless channel.

[0070] The data center is mainly used as a storage and processing unit for electrical data (such as voltage, current, active power, reactive power, power factor, etc.) collected and controlled in real time or at regular intervals in the system.

[0071] The data acquisition and control unit is mainly used for real-time monitoring and control of digital information such as grid voltage, real-time active power, and real-time reactive power.

[0072] The inverter communication interaction unit is mainly used to receive digital signals transmitted by the inverter or to send digital signals that the photovoltaic inverter can recognize. For example, the communication link of the inverter communication interaction unit can be a wired communication link or a wireless communication link. The wired communication link can use RS485 bus or power line carrier communication, and the wireless communication link can use LoRa, WiFi or Bluetooth communication.

[0073] The adaptive voltage regulation unit is mainly used to calculate the reactive power output or absorption value of the photovoltaic inverter according to the adaptive voltage regulation algorithm, thereby realizing bidirectional, flexible and precise regulation of the grid connection point voltage.

[0074] Through the coordinated operation of the aforementioned units, the system can achieve adaptive voltage adjustment of the photovoltaic protocol conversion system.

[0075] In one implementation, the process by which the adaptive voltage regulation unit obtains the reactive power regulation demand based on the voltage regulation correlation data and using an adaptive voltage regulation algorithm may include:

[0076] The difference between the real-time voltage at the grid connection point and the preset voltage threshold in the voltage regulation correlation data is calculated to obtain the difference calculation result;

[0077] When the calculated difference is less than or equal to the lower voltage threshold, an inductive reactive power regulation value is generated.

[0078] When the calculated difference is greater than or equal to the upper voltage threshold, a capacitive reactive power adjustment value is generated.

[0079] The inductive reactive power adjustment value or the inductive reactive power adjustment value is taken as the reactive power adjustment requirement;

[0080] For example, the voltage regulation associated data may include one or more of the following: real-time voltage at the grid connection point, active power output of the photovoltaic inverter, reactive power output of the photovoltaic inverter, real-time current and power factor on the grid side;

[0081] In this implementation, the dual-threshold discrimination logic enables the same algorithm to seamlessly adapt to both excessively low and high voltage conditions. It achieves bidirectional regulation without the need for additional hardware such as reactors or capacitors, which reduces equipment investment and maintenance costs. Furthermore, the software-defined regulation mode enhances system deployment flexibility. The direct correlation between the difference calculation result and the reactive power regulation value allows the regulation amount to dynamically adapt to the voltage deviation, avoiding over-regulation or under-regulation problems caused by traditional fixed-step regulation. Simultaneously, this precise difference-driven mechanism can be deeply integrated with the collaborative hierarchical control architecture, providing millisecond-level regulation basis for local rapid response and precise local operating condition data support for global optimization by the dispatch master station. This, in turn, improves the stability and economy of voltage control in distributed photovoltaic grid-connected scenarios.

[0082] In one implementation, the acquisition and control unit can also be used for:

[0083] The inverter communication interaction unit sends multiple sets of reactive power test commands with different amplitudes to the photovoltaic inverter and reads the feedback execution data of the photovoltaic inverter in real time.

[0084] The maximum inductive reactive power output value and the maximum capacitive reactive power absorption value of the photovoltaic inverter are determined based on the feedback execution data.

[0085] The maximum inductive reactive power output value and the maximum capacitive reactive power absorption value are used as the maximum reactive power boundary values ​​of the photovoltaic inverter.

[0086] When the acquisition and control unit generates a reactive power adjustment command message, the adjustment power value in the reactive power adjustment command message does not exceed the maximum reactive power boundary value.

[0087] In this implementation, the control unit actively issues multiple sets of reactive power test commands and reads feedback data in real time to dynamically obtain the actual maximum inductive reactive power output value and the maximum capacitive reactive power absorption value of the photovoltaic inverter. These values ​​are then used as dynamically updated maximum reactive power boundary values. This approach avoids the risk of redundancy or overload caused by equipment aging and changes in operating conditions due to traditional fixed boundaries. It also maximizes the utilization of idle reactive power regulation potential of each inverter, making the available resources for voltage regulation more aligned with the real-time performance of the equipment. Furthermore, this measured boundary determination method eliminates the need for manual configuration of reactive power parameters for different brands and models of inverters, significantly improving the compatibility and adaptability of the photovoltaic protocol conversion system with inverters from multiple manufacturers. In collaborative hierarchical control scenarios, the actual maximum reactive power boundary data of each inverter can be uploaded to the dispatch master station through the concentrator, providing accurate equipment capability data for global reactive power allocation. This avoids the collaborative conflicts caused by insufficient regulation and overload of some inverters in traditional global regulation due to a lack of understanding of the actual potential of local equipment. This maximizes the efficiency of voltage regulation within safe boundaries, which is beneficial for ensuring the long-term stable operation of the equipment.

[0088] In summary, this invention addresses the problems of incompatible photovoltaic inverter communication protocols, lack of adaptive adjustment algorithms based on real-time data, and insufficient coordination of functional modules in distributed photovoltaic grid-connected systems. These problems lead to issues such as unreal-time power generation data acquisition, low voltage regulation accuracy, and volatile grid connection point voltage. The invention proposes a photovoltaic protocol conversion system for voltage regulation. This system is centered on a data acquisition and control unit, complemented by an inverter communication interaction unit, an adaptive voltage regulation unit, and a dual-mode communication interaction unit. The data acquisition and control unit has bidirectional signal connections with the other units. The inverter communication interaction unit enables protocol adaptation and data relay between the photovoltaic inverter and the system. The adaptive voltage regulation unit is based on the acquired grid connection point voltage, power, and other related data. The system generates precise reactive power regulation requirements through an adaptive algorithm. It can also be integrated into a collaborative hierarchical control architecture, linking the concentrator with the dispatch master station to form a "local rapid response + regional collaborative optimization" management and control mode. Through the photovoltaic protocol conversion system of this invention, the investment costs of traditional capacitors and reactors can be reduced by relying on existing grid equipment. It achieves bidirectional regulation of both high and low voltage using the same system, utilizing the characteristics of power electronic devices to achieve precise regulation at the second level, smooth and continuous. It supports local autonomy for rapid response to voltage changes and can participate in regional coordination to achieve optimal control of the distribution area. Simultaneously, it solves inverter protocol compatibility issues to ensure real-time data acquisition, ultimately effectively improving the voltage stability and regulation accuracy at the grid connection point.

[0089] Example 2:

[0090] The present invention provides a photovoltaic protocol conversion system for voltage regulation applied to a single grid-connected point, illustrated by a specific embodiment. The process flow diagram is shown below. Figure 5As shown, the specific steps include:

[0091] Step S1: Obtain the maximum reactive power boundary value of the photovoltaic inverter by issuing different reactive power values ​​and reading them in real time. Subsequent reactive power control results... condition: |< ; This indicates the upper limit threshold for reactive power control;

[0092] Step S2: Monitor electrical data in real time, such as real-time voltage.

[0093] Step S3: By comparing the current voltage With high voltage starting voltage Low-voltage start-up voltage Choosing different processing strategies, specifically step S3, includes:

[0094] Step S31: When the current voltage is higher than the high voltage starting voltage, determine... Does it fall under the high voltage starting voltage? With high voltage threshold voltage Between; when Then output ; Then perform linear calculations to obtain... The adaptive voltage regulation unit notifies the acquisition and control unit to send a signal to the photovoltaic inverter. When a photovoltaic inverter absorbs inductive reactive power, the voltage drops; Adjust slowly The value, until .

[0095] Step S32: When the current voltage is lower than the low-voltage start-up voltage, determine... Does it fall under the low-voltage start-up voltage? With low voltage threshold voltage Between, when Then output ;when Then perform linear calculations to obtain... The adaptive voltage regulation unit notifies the acquisition and control unit to send a signal to the photovoltaic inverter. The photovoltaic inverter generates inductive reactive power, causing the voltage to rise; when Adjust slowly The value, until ;

[0096] This specific embodiment illustrates that the present invention, based on actively measured maximum reactive power boundary values ​​of photovoltaic inverters, abandons the conservative approach of setting adjustment upper limits solely based on equipment nameplate parameters. This method not only helps to accurately pinpoint the safe operating boundaries of the equipment but also maximizes the exploitation of the idle reactive power adjustment potential of each photovoltaic inverter, thereby avoiding the waste of adjustment capacity or the risk of equipment overload due to the disconnect between parameters and actual operating conditions. Furthermore, step S3, based on a graded processing strategy for voltage ranges, subdivides voltage fluctuations into scenarios such as "high voltage critical, high voltage non-critical, low voltage critical, and low voltage non-critical," and generates differentiated adjustment values ​​through a combination of threshold judgment and linear calculation. This approach can address voltage fluctuations when they reach critical thresholds (…). , At maximum reactive power (±) This design achieves rapid voltage control, avoids overcompensation through linear adjustment in the non-critical range, and prevents secondary voltage fluctuations caused by sudden changes in the adjustment value through a slow zeroing operation after the voltage returns to the normal range. This upgrades the voltage regulation of a single grid-connected point from coarse switching control to refined linear control. This process design does not require additional compensation hardware. It can maximize the efficiency of the photovoltaic inverter in a single grid-connected point within the safety boundary through software strategy optimization. This not only ensures the operational reliability of user equipment such as air conditioners and refrigerators in a stable voltage environment, but also transforms the photovoltaic system of a single grid-connected point from a passive grid-connected load into a flexible resource that actively supports the grid voltage. This significantly improves the grid adaptability and voltage control economy of photovoltaic grid connection in single grid-connected point scenarios.

[0097] Example 3:

[0098] Based on the same inventive concept, this invention also provides a photovoltaic protocol conversion method for voltage regulation, as illustrated in the flowchart below. Figure 6 As shown, it includes:

[0099] Step 1: Generate a power generation data request message through the acquisition and control unit, and notify the inverter communication interaction unit to send it to the photovoltaic inverter;

[0100] Step 2: The inverter communication interaction unit sends the power generation data request message generated by the acquisition and control unit to the photovoltaic inverter, and sends the response message of the photovoltaic inverter back to the acquisition and control unit;

[0101] Step 3: The control unit parses the response message and generates voltage regulation related data after data processing;

[0102] Step 4: Based on the voltage regulation correlation data, the adaptive voltage regulation unit calculates the reactive power regulation requirement using the adaptive voltage regulation algorithm.

[0103] Step 5: The acquisition and control unit generates a reactive power regulation command message adapted to the photovoltaic inverter according to the reactive power regulation requirements, and transmits the reactive power regulation command message to the photovoltaic inverter to drive the photovoltaic inverter to output or absorb the corresponding reactive power to the grid, thereby realizing grid connection point voltage regulation.

[0104] In one implementation, when the adaptive voltage regulation unit in step 4 above detects that the voltage is higher than a threshold, it generates a capacitive reactive power value (for example, it can use...). (This is to be displayed), and the data acquisition control unit is notified again;

[0105] For example, the aforementioned reactive power regulation requirements may include: inductive reactive power value or capacitive reactive power value; the acquisition and control unit generates a reactive power regulation command message recognizable by the photovoltaic inverter based on the inductive or capacitive reactive power value, and notifies the inverter communication interaction unit to send it to the photovoltaic inverter; the inverter identifies the voltage and outputs inductive reactive power to the grid (for example, it can use...). (to be represented) or to absorb reactive power from the grid ( ).

[0106] Its collaborative hierarchical control diagram can be as follows: Figure 7 As shown (each grid connection point is configured with a dedicated photovoltaic protocol conversion system and photovoltaic inverter, forming a bottom-level unit of "one grid connection point, one conversion system, and one inverter"), all three bottom-level units communicate bidirectionally with the concentrator in the middle layer. The concentrator then establishes a data interaction link with the top-level dispatch master station, forming a hierarchical and collaborative control network. The specific steps include:

[0107] (1) The photovoltaic protocol conversion system periodically reports the electrical data of the photovoltaic inverter at the corresponding grid connection point, such as voltage, current, active power, reactive power, power factor, etc.

[0108] (2) The dispatching master station collects electrical data of inverters in each zone through the concentrator and performs overall data analysis;

[0109] (3) Based on the data analysis results, the dispatching master station notifies each grid-connected point in the area of ​​the expected voltage value of the photovoltaic protocol conversion system;

[0110] (4) The photovoltaic protocol conversion system determines the direction, magnitude, and adjustment strategy of reactive power adjustment based on the desired voltage value;

[0111] (5) The photovoltaic protocol conversion system sends the corresponding reactive power value to the inverter to smoothly adjust the voltage at the grid connection point;

[0112] Specifically, the information interaction process may include: each underlying photovoltaic inverter first collects its own output power, current, and real-time voltage data of the corresponding grid connection point, and transmits it to the photovoltaic protocol conversion system in the same unit. The protocol conversion system completes data parsing, protocol adaptation (such as converting the inverter's custom protocol to a concentrator-compatible protocol), and preprocessing, and then summarizes the data to the concentrator. The concentrator integrates and analyzes the voltage and power data of the three underlying units, forms a global grid voltage status report, and uploads it to the dispatch master station. The dispatch master station determines whether the voltage of each grid connection point exceeds the standard based on the global data (such as the voltage of grid connection point 1 being too low and the voltage of grid connection point 3 being too high), and generates a coordinated dispatch report. The global command is sent to the concentrator; the concentrator decomposes the global command into local adjustment tasks adapted to each underlying unit and sends them to the corresponding photovoltaic protocol conversion system; the conversion system further converts the adjustment task into a reactive power adjustment signal that the photovoltaic inverter can execute, driving the inverter to output or absorb the corresponding reactive power to stabilize the voltage at the grid connection point, and at the same time feeds back the adjustment execution results (such as the actual reactive power output value of the inverter and the corrected grid connection point voltage data) to the dispatch master station via the concentrator, realizing coordinated hierarchical voltage regulation from global control to local execution and then to the closed loop of results, avoiding grid voltage fluctuations or regulation conflicts caused by independent regulation of a single unit;

[0113] In this embodiment, the concentrator's integrated analysis of data from multiple grid-connected points and the global assessment by the dispatching master station enable adjustment commands to move beyond the local voltage demand of a single grid-connected point. Instead, they generate collaborative strategies based on the overall grid voltage status. For example, in the contradictory scenario of low voltage at grid-connected point 1 and high voltage at grid-connected point 3, differentiated regulation is achieved through command decomposition, where "the former outputs inductive reactive power, and the latter absorbs inductive reactive power." This fundamentally avoids regional voltage fluctuations or grid reactive power flow disturbances that may be caused by independent adjustment of a single unit. The closed-loop design, where the adjustment execution results are fed back to the dispatching master station through the entire link, not only ensures the validity verification of command execution but also allows the dispatching master station to dynamically correct subsequent strategies. This upgrades voltage regulation from a passive response to an intelligent mode of "global prediction - precise matching - continuous optimization." At the same time, this hierarchical collaborative mechanism transforms distributed photovoltaic systems from individual power generation units into flexible support resources that can be precisely dispatched by the grid. This significantly improves the voltage stability and overall operating efficiency of the grid in scenarios with a high proportion of distributed photovoltaic access, providing an efficient management and control path for the large-scale grid connection of distributed energy.

[0114] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention 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.

[0115] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. 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 illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0116] 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.

[0117] 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.

[0118] 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 its scope of protection. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present invention, they can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the application, but these changes, modifications or equivalent substitutions are all within the scope of protection of the claims pending approval.

Claims

1. A photovoltaic protocol conversion system for voltage regulation, characterized by, include: The system includes a data acquisition and control unit, an inverter communication and interaction unit, and an adaptive voltage regulation unit. The data acquisition and control unit is bidirectionally connected to the inverter communication interaction unit and the adaptive voltage regulation unit, respectively. It is used to generate a power generation data request message and send it to the inverter communication interaction unit. It is also used to parse the response message of the photovoltaic inverter returned by the inverter communication interaction unit to obtain voltage regulation related data. It is also used to generate a reactive power regulation command message adapted to the photovoltaic inverter according to the reactive power regulation requirements sent by the adaptive voltage regulation unit. The inverter communication interaction unit is used to transmit the power generation data request message to the photovoltaic inverter; it is also used to receive the response message fed back by the photovoltaic inverter and send it back to the acquisition and control unit, and at the same time transmit the reactive power adjustment command message generated by the acquisition and control unit to the photovoltaic inverter. The adaptive voltage regulation unit is used to obtain the voltage regulation correlation data from the acquisition and control unit, obtain the reactive power regulation requirement based on the voltage regulation correlation data using the adaptive voltage regulation algorithm, and transmit the reactive power regulation requirement to the acquisition and control unit. After the data acquisition and control unit transmits the reactive power regulation command message to the photovoltaic inverter through the inverter communication interaction unit, the photovoltaic inverter outputs or absorbs the corresponding reactive power to the grid, thereby realizing grid connection point voltage regulation.

2. The system of claim 1, wherein, Also includes: Data center; The data center is bidirectionally connected to the acquisition and control unit to store the voltage regulation correlation data generated by the acquisition and control unit, and to perform noise reduction and normalization preprocessing on the voltage regulation correlation data, and to provide the preprocessed voltage regulation correlation data to the adaptive voltage regulation unit.

3. The system of claim 1, wherein, The adaptive voltage regulation unit, based on the voltage regulation correlation data, uses an adaptive voltage regulation algorithm to obtain the reactive power regulation demand, including: The difference between the real-time voltage at the grid connection point and the preset voltage threshold in the voltage regulation correlation data is calculated to obtain the difference calculation result; When the calculated difference is less than or equal to the lower voltage threshold, an inductive reactive power regulation value is generated. When the calculated difference is greater than or equal to the upper voltage threshold, a capacitive reactive power adjustment value is generated. The inductive reactive power adjustment value or the inductive reactive power adjustment value is taken as the reactive power adjustment requirement.

4. The system of claim 1, wherein, Also includes: Dual-mode communication interaction unit; The dual-mode communication interaction unit is bidirectionally connected to the acquisition and control unit, and is used to convert the power grid operation data messages output by the acquisition and control unit into transmission signals adapted to the power line channel or wireless public network channel, and send them to the power grid dispatch master station; at the same time, it receives remote instructions from the power grid dispatch master station, converts them into signals that the acquisition and control unit can recognize, and then transmits them back.

5. The system of claim 1, wherein, The acquisition and control unit is also used for: The inverter communication interaction unit sends multiple sets of reactive power test commands with different amplitudes to the photovoltaic inverter and reads the feedback execution data of the photovoltaic inverter in real time. determine a maximum inductive reactive output value and a maximum capacitive reactive absorption value of the photovoltaic inverter based on the feedback; use the maximum inductive reactive output value and the maximum capacitive reactive absorption value as the maximum reactive boundary value of the photovoltaic inverter; when the collection control unit generates a reactive power adjustment instruction message, the adjustment power value in the reactive power adjustment instruction message does not exceed the maximum reactive boundary value.

6. The system of claim 1, wherein, The voltage adjustment associated data includes one or more of the following: real-time voltage at the grid connection point, photovoltaic inverter output active power, photovoltaic inverter output reactive power, grid-side real-time current and power factor.

7. The system of claim 1, wherein, The reactive power adjustment instruction message includes instruction identification, adjustment power value and execution time limit.

8. The system of claim 1, wherein, The period of generating the power generation data request message by the collection control unit is 1-5 minutes; The power generation data request message includes parameter type identification to be collected, and the parameter type identification includes one or more of the following: grid voltage, grid current, active power, reactive power and power factor.

9. The system of claim 1, wherein, The communication link of the inverter communication interaction unit is a wired communication link or a wireless communication link; the wired communication link uses RS485 bus or power line carrier communication, and the wireless communication link uses LoRa, WiFi or Bluetooth communication.

10. A photovoltaic protocol conversion method for voltage regulation, characterized by, The method comprises: generating a power generation data request message by a collection control unit and notifying an inverter communication interaction unit to send to a photovoltaic inverter; sending the power generation data request message generated by the collection control unit to the photovoltaic inverter by the inverter communication interaction unit and returning the response message of the photovoltaic inverter to the collection control unit; analyzing the response message by the collection control unit and generating voltage adjustment associated data after data processing; using an adaptive voltage adjustment algorithm based on the voltage adjustment associated data by an adaptive voltage adjustment unit to calculate a reactive power adjustment requirement; generating a reactive power adjustment instruction message adapted to the photovoltaic inverter by the collection control unit according to the reactive power adjustment requirement, transmitting the reactive power adjustment instruction message to the photovoltaic inverter, driving the photovoltaic inverter to output or absorb corresponding reactive power to the grid, and realizing grid connection point voltage adjustment.

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