Control methods, devices, air conditioning systems, and storage media for photovoltaic air conditioning systems

Abstract

This invention discloses a control method, device, system, and storage medium for a photovoltaic air conditioning system. The photovoltaic air conditioning system includes a photovoltaic array, a master unit, and two or more slave units. The method includes: determining the target output power of the photovoltaic array on the master unit side; determining the output power difference between each slave unit and the target output power of the photovoltaic array, and feeding it back to the master unit; controlling the output current of the slave unit on the master unit in conjunction with a control strategy; and adjusting the output current from the master unit to the slave units on the master unit side based on the output power differences of all slave units. This scheme, by controlling the output current of the slave units on the master unit side and adjusting the output current of all slave units, achieves coordination of the current output of different slave units, realizes balanced power distribution, and improves the utilization efficiency of photovoltaic energy.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic air conditioning technology, specifically relating to a control method, device, photovoltaic air conditioning system and storage medium for a photovoltaic air conditioning system, and particularly to a control method, device, photovoltaic air conditioning system and storage medium for the output current of a photovoltaic air conditioning system. Background Technology

[0002] To achieve the goals of carbon peaking and carbon neutrality, replacing existing energy sources with clean energy is an inevitable trend. Among these, photovoltaic (PV) energy is constantly improving in both cost and efficiency, with residential PV systems doubling in size annually. Local consumption of PV power generation will become an increasingly important aspect, leading to the development of PV-powered air conditioning.

[0003] Photovoltaic air conditioning systems are a green energy solution that uses solar energy to generate electricity and air conditioners to regulate indoor temperature. However, the photoelectric conversion efficiency of solar panels is only up to 30%, which makes the energy utilization efficiency of photovoltaic air conditioning systems low and unable to effectively leverage the advantages of photovoltaic energy generation.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a control method, device, system, and storage medium for a photovoltaic air conditioning system, in order to solve the problem of low energy utilization efficiency and inability to effectively leverage the advantages of photovoltaic energy generation in related technologies. This invention achieves the effect of coordinating the current output of different slave devices and achieving balanced power distribution by controlling the output current of the slave devices on the master side of the photovoltaic air conditioning system in a master-slave architecture and adjusting the output current of all slave devices, thereby improving the utilization efficiency of photovoltaic energy.

[0006] This invention provides a control method for a photovoltaic air conditioning system, the photovoltaic air conditioning system comprising: a photovoltaic array, a main unit, and two or more slave units; the power supply output terminal of the photovoltaic array is connected to the power supply input terminal of the main unit; the power supply distribution terminal of the main unit is respectively connected to the power supply input terminal of each of the two or more slave units; the method includes:

[0007] When the photovoltaic air conditioning system is operating, on the host side, the output voltage and output current of the photovoltaic array are acquired; on the slave side of any one of the two or more slave units, the output voltage and output current of the load of that slave unit are acquired; on the host side, the output power of the photovoltaic array is calculated based on the output voltage and output current of the photovoltaic array, and is taken as the target output power of the photovoltaic array; and the target output power of the photovoltaic array is sent to all the slave units; on the slave side of any slave unit, the actual output power of the load of that slave unit is determined based on the output voltage and output current of the load of that slave unit; the output power difference of that slave unit is determined based on the actual output power of the load of that slave unit and the target output power of the photovoltaic array, and the output power difference of that slave unit is fed back to the host; on the host side, upon receiving the output power difference of that slave unit fed back by that slave unit, the target output current of that slave unit is determined based on the output power difference of that slave unit and a preset control strategy; on the host side, the actual output current of that slave unit is adjusted based on the determined target output current of that slave unit.

[0008] In some implementations, on the host side, upon receiving the output power difference of any slave device as feedback, the target output current of the slave device is determined based on the output power difference and a preset control strategy. This includes: determining a control signal for controlling the target output current of the slave device based on the output power difference and the preset control strategy; and determining the target output current of the slave device based on the control signal for controlling the target output current of the slave device.

[0009] The preset control strategy is as follows:

[0010] I output =Kp*P2+Ki*∫P2dt;

[0011] Among them, I output P1 represents the target output current of any slave device; Kp is the proportional coefficient, Ki is the integral coefficient; P2 is the output power difference of any slave device.

[0012] In some implementations, on the host side, adjusting the actual output current of any slave device based on the determined target output current of any slave device includes: on the host side, determining the current regulation amount of any slave device based on the determined target output current of any slave device and the target output power of other slave devices among two or more slave devices; on the host side, determining the actual output current of any slave device as the sum of the target output current of any slave device and the current regulation amount of any slave device; on the host side, controlling the output current from the host side to any slave device according to the actual output current of any slave device; wherein, on the host side, determining the current regulation amount of any slave device based on the determined target output current of any slave device and the target output power of other slave devices among two or more slave devices includes: determining the current regulation amount of any slave device using a power balance algorithm based on the target output power of the photovoltaic array and the output power difference of other slave devices among two or more slave devices;

[0013] The power balancing algorithm is as follows:

[0014] ΔI=Kp1*(P0–P1)+Ki1*∫(P0-P1)dt;

[0015] Where ΔI is the current regulation amount of the actual output current of any slave device; Kp1 is the proportional coefficient, Ki1 is the integral coefficient; (P0–P1) is the output power difference; P0 is the target output power of the photovoltaic array, and P1 is the actual output power.

[0016] In some implementations, the method further includes: when the photovoltaic air conditioning system is operating, acquiring the outdoor light intensity and outdoor ambient temperature of the outdoor environment where the photovoltaic array is located on the host side; and determining the overcurrent protection threshold of the actual output current of any slave device based on the outdoor light intensity and the outdoor ambient temperature on the host side.

[0017] The specific method for determining the overcurrent protection threshold of the actual output current of any slave device is as follows:

[0018] It=Ib*(1+kt*(T0-Tb))*(1+kL*(L0-Lb))

[0019] Where It is the overcurrent protection threshold of the actual output current of any slave device; Ib is the reference current threshold; kt is the temperature compensation coefficient; T0 is the outdoor ambient temperature; Tb is the reference temperature; kL is the illumination compensation coefficient; L0 is the outdoor illumination intensity; Lb is the reference illumination intensity;

[0020] On the host side, the output current of any slave device or the operating status of the photovoltaic air conditioning system is controlled according to the actual output current of any slave device and the overcurrent protection threshold.

[0021] In some implementations, on the host side, the output current of any slave device or the operating state of the photovoltaic air conditioning system is controlled based on the actual output current of any slave device and the overcurrent protection threshold. This includes: if the actual output current of all slave devices among the two or more slave devices is less than or equal to the overcurrent protection threshold, then the photovoltaic air conditioning system is kept running normally; if the actual output current of any slave device among the two or more slave devices is greater than the overcurrent protection threshold and less than or equal to the product of the overcurrent protection threshold and a first preset ratio, then the actual output current of that slave device is reduced at a first preset rate; if the actual output current of any slave device among the two or more slave devices is greater than the product of the overcurrent protection threshold and the first preset ratio and less than or equal to the product of the overcurrent protection threshold and a second preset ratio, then the actual output current of that slave device is reduced at a second preset rate; if the actual output current of any slave device among the two or more slave devices is greater than the product of the overcurrent protection threshold and the second preset ratio, then the photovoltaic air conditioning system is shut down.

[0022] In conjunction with the above method, another aspect of the present invention provides a control device for a photovoltaic air conditioning system, the photovoltaic air conditioning system comprising: a photovoltaic array, a main unit, and two or more slave units; the power supply output terminal of the photovoltaic array is connected to the power supply input terminal of the main unit; the power supply distribution terminal of the main unit is respectively connected to the power supply input terminal of each of the two or more slave units; the device comprises: an acquisition unit configured to, when the photovoltaic air conditioning system is operating, acquire the output voltage and output current of the photovoltaic array on the main unit side; acquire the output voltage and output current of the load of any slave unit on the slave side of any of the two or more slave units; and a control unit configured to, based on the output voltage and output current of the photovoltaic array, calculate the output power of the photovoltaic array as the target output power of the photovoltaic array; and transfer the photovoltaic... The target output power of the array is sent to all slave devices among two or more slave devices; the control unit is further configured to, on the slave side of any slave device, determine the actual output power of the load of any slave device based on the output voltage and output current of the load of that slave device; determine the output power difference of any slave device based on the actual output power of the load of that slave device and the target output power of the photovoltaic array, and feed back the output power difference of any slave device to the master device; the control unit is further configured to, on the master side, upon receiving the output power difference of any slave device fed back by any slave device, determine the target output current of any slave device based on the output power difference of any slave device and a preset control strategy; the control unit is further configured to, on the master side, adjust the actual output current of any slave device based on the determined target output current of any slave device.

[0023] In some embodiments, the control unit, on the host side, upon receiving the output power difference of any slave device fed back by that slave device, determines the target output current of that slave device based on the output power difference of that slave device and a preset control strategy, including: determining a control signal for controlling the target output current of that slave device based on the output power difference of that slave device and the preset control strategy; and determining the target output current of that slave device based on the control signal for controlling the target output current of that slave device.

[0024] The preset control strategy is as follows:

[0025] I output =Kp*P2+Ki*∫P2dt;

[0026] Among them, I output P1 represents the target output current of any slave device; Kp is the proportional coefficient, Ki is the integral coefficient; P2 is the output power difference of any slave device.

[0027] In some embodiments, the control unit, on the host side, adjusts the actual output current of any slave device according to a determined target output current of any slave device, including: on the host side, determining the current regulation amount of any slave device based on the determined target output current of any slave device and the target output power of other slave devices among two or more slave devices; on the host side, determining the actual output current of any slave device as the sum of the target output current of any slave device and the current regulation amount of any slave device; and on the host side, controlling the output current from the host side to any slave device according to the actual output current of any slave device; wherein, on the host side, determining the current regulation amount of any slave device based on the determined target output current of any slave device and the target output power of other slave devices among two or more slave devices includes: determining the current regulation amount of any slave device using a power balance algorithm based on the target output power of the photovoltaic array and the output power difference of other slave devices among two or more slave devices;

[0028] The power balancing algorithm is as follows:

[0029] ΔI=Kp1*(P0–P1)+Ki1*∫(P0-P1)dt;

[0030] Where ΔI is the current regulation amount of the actual output current of any slave device; Kp1 is the proportional coefficient, Ki1 is the integral coefficient; (P0–P1) is the output power difference; P0 is the target output power of the photovoltaic array, and P1 is the actual output power.

[0031] In some embodiments, the system further includes: the acquisition unit is specifically configured to, when the photovoltaic air conditioning system is operating, acquire, on the host side, the outdoor light intensity and outdoor ambient temperature of the outdoor environment where the photovoltaic array is located; the control unit is specifically configured to, on the host side, determine the overcurrent protection threshold of the actual output current of any slave device based on the outdoor light intensity and the outdoor ambient temperature; the specific method for determining the overcurrent protection threshold of the actual output current of any slave device is as follows:

[0032] It=Ib*(1+kt*(T0-Tb))*(1+kL*(L0-Lb))

[0033] Where It is the overcurrent protection threshold of the actual output current of any slave device; Ib is the reference current threshold; kt is the temperature compensation coefficient; T0 is the outdoor ambient temperature; Tb is the reference temperature; kL is the illumination compensation coefficient; L0 is the outdoor illumination intensity; Lb is the reference illumination intensity;

[0034] The control unit is further configured to, on the host side, control the output current of any slave device or the operating status of the photovoltaic air conditioning system based on the actual output current of any slave device and the overcurrent protection threshold.

[0035] In some embodiments, the control unit, on the host side, controls the output current of any slave device or the operating state of the photovoltaic air conditioning system based on the actual output current of any slave device and the overcurrent protection threshold, including: if the actual output current of all slave devices among the two or more slave devices is less than or equal to the overcurrent protection threshold, then the photovoltaic air conditioning system is kept running normally; if the actual output current of any slave device among the two or more slave devices is greater than the overcurrent protection threshold and less than or equal to the product of the overcurrent protection threshold and a first preset ratio, then the actual output current of that slave device is reduced at a first preset rate; if the actual output current of any slave device among the two or more slave devices is greater than the product of the overcurrent protection threshold and the first preset ratio and less than or equal to the product of the overcurrent protection threshold and a second preset ratio, then the actual output current of that slave device is reduced at a second preset rate; if the actual output current of any slave device among the two or more slave devices is greater than the product of the overcurrent protection threshold and the second preset ratio, then the photovoltaic air conditioning system is shut down.

[0036] In conjunction with the above-mentioned device, the present invention further provides a photovoltaic air conditioning system, including: the control device for the photovoltaic air conditioning system described above.

[0037] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device containing the storage medium controls the execution of the control method for the photovoltaic air conditioning system described above.

[0038] The present invention, in the operation of a photovoltaic air conditioning system with a master unit and multiple slave units, determines the target output power of the photovoltaic array on the master unit side based on the output voltage and output current of the photovoltaic array; on the slave unit side, it determines the actual output power of the load of any slave unit based on the output voltage and output current of the slave unit, and then determines the output power difference of any slave unit in combination with the target output power of the photovoltaic array, and feeds the output power difference back to the master unit; on the master unit side, it determines the target output current of any slave unit based on the output power difference and a preset control strategy, and adjusts the output current from the master unit side to the slave unit side in a balanced manner according to the output power differences of all slave units. Thus, by determining the target output current of any slave unit through the output power difference and the preset control strategy, and adjusting this output current, precise control of the slave unit's output current is achieved, coordinating the output current of multiple slave units, realizing balanced power distribution, and improving the energy utilization efficiency of photovoltaic power generation.

[0039] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0040] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0041] Figure 1 This is a flowchart illustrating an embodiment of the control method for the photovoltaic air conditioning system of the present invention;

[0042] Figure 2 This is a flowchart illustrating an embodiment of the method of the present invention for determining the target output current of any slave device on the host side;

[0043] Figure 3 This is a schematic flowchart of an embodiment of the method of the present invention, which involves adjusting the actual output current of any slave device on the host side.

[0044] Figure 4 This is a schematic flowchart of an embodiment of the method for overcurrent protection of a photovoltaic air conditioning system according to the present invention;

[0045] Figure 5 This is a schematic diagram of the structure of a control device for a photovoltaic air conditioning system according to an embodiment of the present invention;

[0046] Figure 6 This is a schematic diagram of the master and slave units and the photovoltaic array of the photovoltaic air conditioning system of the present invention;

[0047] Figure 7 This is a schematic diagram of the current transformer module of the photovoltaic air conditioning system of the present invention;

[0048] Figure 8 This is a flowchart illustrating the control principle of the photovoltaic air conditioning system of the present invention;

[0049] Figure 9 This is a flowchart illustrating an embodiment of the method for controlling the output current of a photovoltaic air conditioning system according to the present invention;

[0050] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0051] 102 - Acquisition unit; 104 - Control unit. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0053] In related solutions, photovoltaic air conditioning systems are configured with a master unit and slave units. How to control the current to improve the utilization efficiency of photovoltaic energy based on the master-slave architecture remains a challenge. Therefore, this invention provides a control method for a photovoltaic air conditioning system. By determining the output current of the slave unit in a master-slave architecture photovoltaic air conditioning system based on the output power difference and control strategy, and adjusting this output current, precise control of the output current of different slave units is achieved, resulting in balanced power distribution and improved energy utilization efficiency of the photovoltaic air conditioning system.

[0054] According to an embodiment of the present invention, a control method for a photovoltaic air conditioning system is provided. The photovoltaic air conditioning system includes: a photovoltaic array, a main unit, and two or more slave units; the power supply output terminal of the photovoltaic array is connected to the power supply input terminal of the main unit; the power supply distribution terminal of the main unit is respectively connected to the power supply input terminal of each of the two or more slave units; the photovoltaic air conditioner is a direct photovoltaic direct drive air conditioner. Figure 6 This is a schematic diagram of the master and slave units and the photovoltaic array of the photovoltaic air conditioning system of the present invention, as shown below. Figure 6As shown, the photovoltaic air conditioner includes a main unit and slave units. Multiple slave units can be set. Both the main unit and slave units are air conditioners, each with an indoor unit and an outdoor unit, capable of cooling and heating functions. The main unit and slave units are connected via the outdoor unit and exchange information and synchronize via the RS485 communication protocol. The outdoor units of the main unit and slave units are also connected to the photovoltaic array. The main unit is the processing and control center of the entire photovoltaic air conditioning system, responsible for overall system control and coordination, controlling the operation of the slave units, and possessing all the functions of the slave units. The slave units are controlled by the main unit and do not need to be directly connected to the photovoltaic array. They are mainly used to collect environmental information of their indoor and outdoor units and feed it back to the main unit in the form of pulse electrical signals (or WIFI, Bluetooth, etc.), including but not limited to the indoor and outdoor ambient temperature and humidity, outdoor ambient temperature and humidity, and the temperature of key nodes in the system. The slave units are also used to transmit user remote control signals. Figure 1 The diagram shows a flowchart of an embodiment of the method of the present invention. The control method of the photovoltaic air conditioning system may include steps S110 to S150.

[0055] In step S110, when the photovoltaic air conditioning system is in operation, the output voltage and output current of the photovoltaic array are obtained on the host side; and the output voltage and output current of the load of any one of the two or more slave units are obtained on the slave side of the slave unit.

[0056] Figure 7 This is a schematic diagram of the current transformer module of the photovoltaic air conditioning system of the present invention, as shown below. Figure 7 As shown, multiple current transformers are introduced into the photovoltaic main board and the outdoor unit main board. These current transformers are connected in parallel, specifically two current transformers of the main unit, two current transformers of slave unit 1, and two current transformers of slave unit 2. These three sets of transformers are then connected in parallel. This parallel connection allows for separate control of the main unit and slave units, enabling precise measurement and control of the slave unit current, improving measurement accuracy and response speed, and more effectively implementing overcurrent protection mechanisms. The rectified and filtered current generated by the photovoltaic array is first transmitted to the current transformers. The current transformers detect this current and determine whether it meets the current requirements of the main unit and slave units under the current conditions, ensuring the most efficient use of current. They can also monitor whether the current exceeds the limit, improving the overall reliability of the air conditioner. Since current control only occurs in the outdoor unit, the signal is sent to the indoor unit after the outdoor unit completes the control. The indoor unit only receives the signal and does not require a current transformer. The first preset current transformer module M1 is used to determine the value of the slave current input, and the second preset current transformer module M2 is used to determine the rate of change of the slave current input.

[0057] The multi-channel parallel current transformers are integrated onto the mainboard of the photovoltaic air conditioner. The current transformers are connected to the mainboard via corresponding current measurement circuits and connection interfaces. This installation location integrates current measurement and control with other functions of the mainboard, eliminating the need for separate current transformer placement, simplifying the system structure, and enhancing the reliability of the current transformers. A dedicated interface or slot for installing the current transformers is added to the outdoor unit's electrical box. The multi-channel current transformers can be connected to the outdoor unit's electrical box, and the current measurement signals are transmitted to the mainboard of the photovoltaic air conditioner for processing via parallel circuits. This installation location integrates current measurement with the existing electrical box structure of the main unit, reducing modifications to the mainboard.

[0058] In step S120, on the host side, the output power of the photovoltaic array is calculated based on the output voltage and output current of the photovoltaic array, and is used as the target output power of the photovoltaic array; and the target output power of the photovoltaic array is sent to all slave devices of the two or more slave devices.

[0059] Specifically, the host unit acquires voltage and current information of the photovoltaic array through sensors, and calculates the desired target output power P0 based on the maximum power point tracking algorithm.

[0060] P0 = f(V, I)

[0061] The host then sends the target output power P0 to the slave.

[0062] In step S130, on the slave side of any slave device, the actual output power of the load of any slave device is determined based on the output voltage and output current of the load of any slave device; the output power difference of any slave device is determined based on the actual output power of the load of any slave device and the target output power of the photovoltaic array, and the output power difference of any slave device is fed back to the host device.

[0063] Specifically, after receiving the target output power P0, the slave device first calculates the actual output power P1 based on the corresponding voltage and current information output by the slave device, and then subtracts the actual output power P1 from the target output power P0. 1， Calculate the output power difference P2:

[0064] P2 = P0 – P1

[0065] Where P2 is the output power difference.

[0066] In step S140, on the host side, upon receiving feedback from any slave device regarding the output power difference of that slave device, the target output current of that slave device is determined based on the output power difference of that slave device and a preset control strategy.

[0067] Figure 2 This is a flowchart illustrating an embodiment of the method of the present invention for determining the target output current of any slave device on the host side. In some embodiments, in step S140, on the host side, upon receiving the output power difference of any slave device as feedback, the specific process of determining the target output current of any slave device based on the output power difference of any slave device and a preset control strategy is as follows: Figure 2 As shown, it includes steps S210 and S220.

[0068] Step S210: Based on the output power difference of any slave device and the preset control strategy, determine the control signal for controlling the target output current of any slave device.

[0069] Step S220: Determine the target output current of any slave device according to the control signal controlling the target output current of any slave device.

[0070] The preset control strategy is as follows:

[0071] I output =Kp*P2+Ki*∫P2dt

[0072] Among them, I output I represents the target output current of any slave device; Kp is the proportional coefficient, Ki is the integral coefficient; P2 is the output power difference of any slave device. Specifically, I output The system uses a power regulator to control the current output of the slave device. Kp is directly adjusted based on the output power error, while Ki is adjusted based on the integral value of the output power error. ∫P2dt is the integral value of the output power error, used to compensate for the system's steady-state error. The values ​​of the proportional coefficient Kp and integral coefficient Ki are adjusted according to the characteristics of the photovoltaic array and the system load. The master device controls the current output of the slave device through a power regulator. Through experiments and simulation analysis, the control parameters are optimized and adjusted. The optimization goal is to achieve a fast system response, good stability, and to meet the accuracy requirements of current control.

[0073] Figure 8 This is a flowchart illustrating the control principle of the photovoltaic air conditioning system of the present invention. Figure 9 This is a flowchart illustrating an embodiment of the photovoltaic air conditioning system output current control method of the present invention, as shown below. Figure 8 , Figure 9 As shown, the control method of the photovoltaic air conditioning system of the present invention includes:

[0074] Step 1: After the photovoltaic air conditioning system is started and the master and slave units are running, the master unit calculates the target output power of the photovoltaic array according to the maximum power point algorithm and sends the target output power to all slave units, and then executes Step 2.

[0075] Step 2: The slave device calculates its actual output power based on the output voltage and output current. Based on the target power and the actual output power, it calculates the output power difference and feeds this difference back to the master device. The master device then determines the target output current I of the slave device based on the output power difference and the control strategy. output Then proceed to step 3.

[0076] The solution of this invention reduces the cost of whole-house photovoltaic air conditioning and expands the applicability of photovoltaic air conditioning by setting up a master and slave unit. At the same time, the target output power is determined according to the maximum power point tracking algorithm, and the output current of the slave unit is controlled according to the output power difference between the target output power and the current actual output power, thereby achieving precise control of the slave unit's output current and improving the utilization efficiency of solar energy.

[0077] In step S150, on the host side, the actual output current of any slave device is adjusted according to the determined target output current of any slave device, so that on the host side, the actual output current from the host side to any slave device is adjusted according to the target output power of the photovoltaic array and the actual output power of any slave device among the two or more slave devices, thereby achieving a balanced distribution of the actual output current of all slave devices among the two or more slave devices on the host side.

[0078] Figure 3 This is a flowchart illustrating an embodiment of the method of the present invention, which adjusts the actual output current of any slave device on the host side. In some embodiments, in step S150, on the host side, the specific process of adjusting the actual output current of any slave device according to the determined target output current of the slave device is as follows: Figure 3 As shown, it includes steps S310 to S330.

[0079] Step S310: On the host side, based on the determined target output current of any slave device and in combination with the target output power of other slave devices among the two or more slave devices, determine the current regulation amount of any slave device.

[0080] Specifically, on the host side, based on the determined target output current of any slave device and combined with the target output power of the other slave devices among the two or more slave devices, the current regulation amount of any slave device is determined, including: based on the target output power of the photovoltaic array and the output power difference of the other slave devices among the two or more slave devices, the current regulation amount of any slave device is determined using a power balance algorithm.

[0081] The power balancing algorithm is as follows:

[0082] ΔI=Kp1*(P0–P1)+Ki1*∫(P0-P1)dt

[0083] Where ΔI is the current adjustment amount of the actual output current of any slave device; Kp1 is the proportional coefficient, Ki1 is the integral coefficient; (P0–P1) is the output power difference; P0 is the target output power of the photovoltaic array, and P1 is the actual output power; specifically, Kp1 is the proportional coefficient of power balance, used for direct adjustment based on the power error; Ki1 is the integral coefficient of power balance, used for adjustment based on the integral value of the power error; ∫(P0–P1)dt is the integral value of the power error, used to compensate for the steady-state error of the system. The control strategy in this power balance algorithm formula can be adjusted and optimized according to the requirements and characteristics of the actual system. The selection of adjustment parameters Kp1 and Ki1 needs to consider the system's response speed and stability. Through continuous experimentation and testing, the parameters are adjusted according to the actual situation to obtain the best power balance effect.

[0084] Step S320: On the host side, the sum of the target output current of any slave device and the current regulation amount of any slave device is determined as the actual output current of any slave device.

[0085] Step 330: On the host side, control the output current from the host side to the slave side according to the actual output current of the slave device.

[0086] Specifically, the current adjustment amount ΔI is obtained based on the power balance algorithm, and then adjusted based on the original output current I:

[0087] Ia=I+ΔI

[0088] Where Ia is the adjusted output current.

[0089] A power balancing algorithm is introduced into the master-slave communication protocol. This algorithm dynamically adjusts the output current of each slave device based on its current output, aiming to distribute the load as evenly as possible. The current adjustment amount can be calculated based on the difference between the actual output power and the target output power of each slave device, and then this adjustment amount is allocated to each slave device.

[0090] like Figure 8 , Figure 9 As shown, the control method of the photovoltaic air conditioning system of the present invention further includes:

[0091] Step 3: Determine the current regulation amount ΔI according to the power balance algorithm, and adjust the current regulation amount ΔI in step 2 accordingly. output The output current I of the slave device is adjusted, and the slave device outputs current according to the adjusted current Ia to achieve balanced distribution of load power.

[0092] The present invention determines the adjustment amount of the slave device's output current based on a power balance algorithm, and adjusts the slave device's output current according to the adjustment amount, thereby achieving precise control of the slave device's output current, balancing the load distribution, and maximizing the utilization of photovoltaic energy.

[0093] In some implementations, the process of providing overcurrent protection for the photovoltaic air conditioning system is also included. Figure 4 This is a schematic flowchart of an embodiment of the method for overcurrent protection of a photovoltaic air conditioning system according to the present invention, as shown below. Figure 4 As shown, the specific process of overcurrent protection for a photovoltaic air conditioning system includes steps S410 to S430.

[0094] Step S410: When the photovoltaic air conditioning system is in operation, the outdoor light intensity and outdoor ambient temperature of the outdoor environment where the photovoltaic array is located are obtained on the host side.

[0095] Step S420: On the host side, the overcurrent protection threshold of the actual output current of any slave device is determined based on the outdoor light intensity and the outdoor ambient temperature.

[0096] The specific method for determining the overcurrent protection threshold of the actual output current of any slave device is as follows:

[0097] It=Ib*(1+kt*(T0-Tb))*(1+kL*(L0-Lb))

[0098] Where It is the overcurrent protection threshold of the actual output current of any slave device; Ib is the reference current threshold; kt is the temperature compensation coefficient; T0 is the outdoor ambient temperature; Tb is the reference temperature; kL is the illumination compensation coefficient; L0 is the outdoor illumination intensity; Lb is the reference illumination intensity. Specifically, Ib represents the overcurrent protection threshold under standard operating conditions, kt represents the degree of influence of temperature on the overcurrent protection threshold, T0 is obtained by temperature sensor, Tb represents the temperature under standard operating conditions, kL represents the degree of influence of illumination on the overcurrent protection threshold, L0 is obtained by illumination sensor, and Lb represents the illumination intensity under standard operating conditions.

[0099] Considering the impact of ambient temperature on photovoltaic (PV) arrays, temperature compensation is incorporated into the overcurrent protection mechanism. The overcurrent protection threshold is adjusted by monitoring the PV array temperature and correcting it according to a temperature compensation coefficient. In high-temperature environments, the current characteristics of the PV array may be affected; therefore, the overcurrent protection threshold is increased to avoid false triggering. Changes in illuminance also affect the current output of the PV array; therefore, illuminance compensation is considered in the overcurrent protection mechanism, adjusting the overcurrent protection threshold based on real-time measured illuminance. Under low-illuminance conditions, the overcurrent protection threshold is decreased to accommodate changes in slave current output.

[0100] Step S430: On the host side, the output current of any slave device or the operating status of the photovoltaic air conditioning system is controlled according to the actual output current of any slave device and the overcurrent protection threshold.

[0101] In some implementations, step S430, on the host side, involves controlling the output current of any slave device or the operating state of the photovoltaic air conditioning system based on the actual output current of any slave device and the overcurrent protection threshold. This process includes:

[0102] If the actual output current of all slave devices in the two or more slave devices is less than or equal to the overcurrent protection threshold, the photovoltaic air conditioning system shall continue to operate normally.

[0103] If the actual output current of any of the two or more slave devices is greater than the overcurrent protection threshold and less than or equal to the product of the overcurrent protection threshold and the first preset ratio, then the actual output current of that slave device is reduced at the first preset rate.

[0104] If the actual output current of any of the two or more slave devices is greater than the product of the overcurrent protection threshold and the first preset ratio, and less than or equal to the product of the overcurrent protection threshold and the second preset ratio, then the actual output current of that slave device is reduced at the second preset rate.

[0105] If the actual output current of any of the two or more slave units exceeds the product of the overcurrent protection threshold and the second preset ratio, the photovoltaic air conditioning system will be shut down.

[0106] Specifically, the first preset ratio can be set to 105%, the second preset ratio can be set to 110%, the first preset rate can be set to 0.1A / s, and the second preset rate can be set to 0.3A / s. If the first preset current transformer module M1 detects that the output current Ia is less than the overcurrent protection threshold It, it controls the photovoltaic air conditioning system to operate normally and does not adjust the slave unit's output current; if it detects that the output current Ia is greater than the overcurrent protection threshold It, but less than or equal to 105%It, it controls the slave unit's output current to decrease at a rate of 0.1A / s until Ia is less than It; if it detects that the output current Ia is greater than 105%It, but less than or equal to 110%It, it controls the slave unit's output current to decrease at a rate of 0.3A / s until Ia is less than It; if it detects that the output current Ia is greater than 110%It, it disconnects the photovoltaic array's output circuit and shuts down the photovoltaic air conditioning system.

[0107] like Figure 8 , Figure 9 As shown, the control method of the photovoltaic air conditioning system of the present invention further includes:

[0108] Step 4: When the master and slave start running, acquire the outdoor environment light and ambient temperature information of the photovoltaic array. Based on the light and ambient temperature information and the preset protection strategy, determine the overcurrent protection threshold It of the slave's output current, and then execute step 5.

[0109] Step 5: Obtain the slave current Ia output in Step 3 through the current monitor. Based on the comparison between the slave output current Ia and the overcurrent protection threshold It, determine the specific protection mechanism: When Ia ≤ It, maintain the normal operation of the photovoltaic air conditioning system; when It < Ia ≤ 105% It, slowly reduce the slave output current at a rate of 0.1 A / s until Ia ≤ It; when 105% It < Ia ≤ 110% It, rapidly reduce the slave output current at a rate of 0.3 A / s until Ia ≤ It; when Ia > 110% It, disconnect the slave output circuit and shut down the photovoltaic air conditioning system.

[0110] The present invention introduces an overcurrent protection mechanism into the master-slave control logic. When the slave's output current exceeds a set limit, measures are immediately taken to limit and adjust it to prevent system damage. Overcurrent protection is achieved by reducing the slave's output current or disconnecting the circuit, enabling current protection control according to different operating conditions and weather conditions, ensuring that the slave current remains stable within the set range.

[0111] By employing the technical solution of this embodiment, in the operation of a photovoltaic air conditioning system with a master unit and multiple slave units, the target output power of the photovoltaic array is determined on the master unit side based on the output voltage and output current of the photovoltaic array; on the slave unit side, the actual output power of the load of any slave unit is determined based on the output voltage and output current of the slave unit, and then the output power difference of any slave unit is determined in combination with the target output power of the photovoltaic array, and the output power difference is fed back to the master unit; on the master unit side, the target output current of any slave unit is determined based on the output power difference and a preset control strategy, and the output current from the master unit side to the slave unit side is adjusted evenly according to the output power differences of all slave units. Thus, by determining the target output current of any slave unit through the output power difference and the preset control strategy, and adjusting this output current, precise control of the slave unit's output current is achieved, coordinating the output current of multiple slave units, realizing balanced power distribution, and improving the energy utilization efficiency of photovoltaic power generation.

[0112] According to an embodiment of the present invention, a control device for a photovoltaic air conditioning system corresponding to a control method for a photovoltaic air conditioning system is also provided. The photovoltaic air conditioning system includes: a photovoltaic array, a main unit, and two or more slave units; the power supply output terminal of the photovoltaic array is connected to the power supply input terminal of the main unit; the power supply distribution terminal of the main unit is respectively connected to the power supply input terminal of each of the two or more slave units; the photovoltaic air conditioner is a direct photovoltaic direct-drive air conditioner. Figure 6 This is a schematic diagram of the master and slave units and the photovoltaic array of the photovoltaic air conditioning system of the present invention, as shown below. Figure 6 As shown, the photovoltaic air conditioner includes a main unit and slave units. Multiple slave units can be set. Both the main unit and slave units are air conditioners, each with an indoor unit and an outdoor unit, capable of cooling and heating functions. The main unit and slave units are connected via the outdoor unit and exchange information and synchronize via the RS485 communication protocol. The outdoor units of the main unit and slave units are also connected to the photovoltaic array. The main unit is the processing and control center of the entire photovoltaic air conditioning system, responsible for overall system control and coordination, controlling the operation of the slave units, and possessing all the functions of the slave units. The slave units are controlled by the main unit and do not need to be directly connected to the photovoltaic array. They are mainly used to collect environmental information of their indoor and outdoor units and feed it back to the main unit in the form of pulse electrical signals (or WIFI, Bluetooth, etc.), including but not limited to the indoor and outdoor ambient temperature and humidity, outdoor ambient temperature and humidity, and the temperature of key nodes in the system. The slave units are also used to transmit user remote control signals. See also... Figure 5 The diagram shows a structural schematic of an embodiment of the device of the present invention. The control device of the photovoltaic air conditioning system may include: an acquisition unit 102 and a control unit 104.

[0113] The acquisition unit 102 is configured to, when the photovoltaic air conditioning system is operating, acquire the output voltage and output current of the photovoltaic array on the host side; and acquire the output voltage and output current of the load of any one of the two or more slave units on the slave side. For the specific functions and processing of the acquisition unit 102, please refer to step S110.

[0114] Figure 7 This is a schematic diagram of the current transformer module of the photovoltaic air conditioning system of the present invention, as shown below. Figure 7 As shown, multiple current transformers are introduced into the photovoltaic main board and the outdoor unit main board. These current transformers are connected in parallel, specifically two current transformers of the main unit, two current transformers of slave unit 1, and two current transformers of slave unit 2. These three sets of transformers are then connected in parallel. This parallel connection allows for separate control of the main unit and slave units, enabling precise measurement and control of the slave unit current, improving measurement accuracy and response speed, and more effectively implementing overcurrent protection mechanisms. The rectified and filtered current generated by the photovoltaic array is first transmitted to the current transformers. The current transformers detect this current and determine whether it meets the current requirements of the main unit and slave units under the current conditions, ensuring the most efficient use of current. They can also monitor whether the current exceeds the limit, improving the overall reliability of the air conditioner. Since current control only occurs in the outdoor unit, the signal is sent to the indoor unit after the outdoor unit completes the control. The indoor unit only receives the signal and does not require a current transformer. The first preset current transformer module M1 is used to determine the value of the slave current input, and the second preset current transformer module M2 is used to determine the rate of change of the slave current input.

[0115] The multi-channel parallel current transformers are integrated onto the mainboard of the photovoltaic air conditioner. The current transformers are connected to the mainboard via corresponding current measurement circuits and connection interfaces. This installation location integrates current measurement and control with other functions of the mainboard, eliminating the need for separate current transformer placement, simplifying the system structure, and enhancing the reliability of the current transformers. A dedicated interface or slot for installing the current transformers is added to the outdoor unit's electrical box. The multi-channel current transformers can be connected to the outdoor unit's electrical box, and the current measurement signals are transmitted to the mainboard of the photovoltaic air conditioner for processing via parallel circuits. This installation location integrates current measurement with the existing electrical box structure of the main unit, reducing modifications to the mainboard.

[0116] The control unit 104 is configured to calculate the output power of the photovoltaic array based on its output voltage and output current, and use this output power as the target output power of the photovoltaic array; and to send the target output power of the photovoltaic array to all slave devices among the two or more slave devices. The specific functions and processing of this control unit 104 are described in step S120.

[0117] Specifically, the host unit acquires voltage and current information of the photovoltaic array through sensors, and calculates the desired target output power P0 based on the maximum power point tracking algorithm.

[0118] P0 = f(V, I)

[0119] The host then sends the target output power P0 to the slave.

[0120] The control unit 104 is further configured to, on the slave side of any slave device, determine the actual output power of the load of any slave device based on the output voltage and output current of the load of that slave device; determine the output power difference of any slave device based on the actual output power of the load of that slave device and the target output power of the photovoltaic array; and feed back the output power difference of any slave device to the master device. The specific functions and processing of the control unit 104 are described in step S130.

[0121] Specifically, after receiving the target output power P0, the slave device first calculates the actual output power P1 based on the corresponding voltage and current information output by the slave device, and then subtracts the actual output power P1 from the target output power P0. 1， Calculate the output power difference P2:

[0122] P2 = P0 – P1

[0123] Where P2 is the output power difference.

[0124] The control unit 104 is further configured to, on the host side, upon receiving the output power difference of any slave device fed back by the slave device, determine the target output current of the slave device based on the output power difference of the slave device and a preset control strategy; the specific functions and processing of the control unit 104 are described in step S140.

[0125] In some embodiments, the control unit 104, on the host side, upon receiving feedback from any slave device regarding the output power difference of that slave device, determines the target output current of that slave device based on the output power difference of that slave device and a preset control strategy, including:

[0126] Based on the output power difference of any slave device and the preset control strategy, a control signal for controlling the target output current of any slave device is determined; the specific functions and processing of the control unit 104 are described in step S210.

[0127] The target output current of any slave device is determined according to the control signal that controls the target output current of any slave device; the specific functions and processing of the control unit 104 are described in step S220.

[0128] The preset control strategy is as follows:

[0129] I output =Kp*P2+Ki*∫P2dt

[0130] Among them, I output I represents the target output current of any slave device; Kp is the proportional coefficient, Ki is the integral coefficient; P2 is the output power difference of any slave device. Specifically, I output The system uses a power regulator to control the current output of the slave device. Kp is directly adjusted based on the output power error, while Ki is adjusted based on the integral value of the output power error. ∫P2dt is the integral value of the output power error, used to compensate for the system's steady-state error. The values ​​of the proportional coefficient Kp and integral coefficient Ki are adjusted according to the characteristics of the photovoltaic array and the system load. The master device controls the current output of the slave device through a power regulator. Through experiments and simulation analysis, the control parameters are optimized and adjusted. The optimization goal is to achieve a fast system response, good stability, and to meet the accuracy requirements of current control.

[0131] Figure 8 This is a flowchart illustrating the control principle of the photovoltaic air conditioning system of the present invention. Figure 9 This is a flowchart illustrating an embodiment of the photovoltaic air conditioning system output current control method of the present invention, as shown below. Figure 8 , Figure 9 As shown, the control method of the photovoltaic air conditioning system of the present invention includes:

[0132] Step 1: After the photovoltaic air conditioning system is started and the master and slave units are running, the master unit calculates the target output power of the photovoltaic array according to the maximum power point algorithm and sends the target output power to all slave units, and then executes Step 2.

[0133] Step 2: The slave device calculates its actual output power based on the output voltage and output current. Based on the target power and the actual output power, it calculates the output power difference and feeds this difference back to the master device. The master device then determines the target output current I of the slave device based on the output power difference and the control strategy. output Then proceed to step 3.

[0134] The solution of this invention reduces the cost of whole-house photovoltaic air conditioning and expands the applicability of photovoltaic air conditioning by setting up a master and slave unit. At the same time, the target output power is determined according to the maximum power point tracking algorithm, and the output current of the slave unit is controlled according to the output power difference between the target output power and the current actual output power, thereby achieving precise control of the slave unit's output current and improving the utilization efficiency of solar energy.

[0135] The control unit 104 is further configured to, on the host side, adjust the actual output current of any slave device according to the determined target output current of any slave device.

[0136] In some embodiments, the control unit 104 is further configured, on the host side, to adjust the actual output current of any slave device based on a determined target output current of that slave device, including:

[0137] On the host side, based on the target output current of any slave device and in combination with the target output power of other slave devices among the two or more slave devices, the current regulation amount of any slave device is determined; the specific functions and processing of the control unit 104 are described in step S310.

[0138] Specifically, on the host side, based on the determined target output current of any slave device and combined with the target output power of the other slave devices among the two or more slave devices, the current regulation amount of any slave device is determined, including: based on the target output power of the photovoltaic array and the output power difference of the other slave devices among the two or more slave devices, the current regulation amount of any slave device is determined using a power balance algorithm.

[0139] The power balancing algorithm is as follows:

[0140] ΔI=Kp1*(P0–P1)+Ki1*∫(P0-P1)dt

[0141] Where ΔI is the current adjustment amount of the actual output current of any slave device; Kp1 is the proportional coefficient, Ki1 is the integral coefficient; (P0–P1) is the output power difference; P0 is the target output power of the photovoltaic array, and P1 is the actual output power; specifically, Kp1 is the proportional coefficient of power balance, used for direct adjustment based on the power error; Ki1 is the integral coefficient of power balance, used for adjustment based on the integral value of the power error; ∫(P0–P1)dt is the integral value of the power error, used to compensate for the steady-state error of the system. The control strategy in this power balance algorithm formula can be adjusted and optimized according to the requirements and characteristics of the actual system. The selection of adjustment parameters Kp1 and Ki1 needs to consider the system's response speed and stability. Through continuous experimentation and testing, the parameters are adjusted according to the actual situation to obtain the best power balance effect.

[0142] On the host side, the sum of the target output current of any slave device and the current regulation amount of any slave device is determined as the actual output current of any slave device. The specific functions and processing of the control unit 104 are described in step S320.

[0143] On the host side, the output current from the host side to the slave device is controlled according to the actual output current of the slave device. For the specific functions and processing of the control unit 104, please refer to step S330.

[0144] Specifically, the current adjustment amount ΔI is obtained based on the power balance algorithm, and then adjusted based on the original output current I:

[0145] Ia=I+ΔI

[0146] Where Ia is the adjusted output current.

[0147] A power balancing algorithm is introduced into the master-slave communication protocol. This algorithm dynamically adjusts the output current of each slave device based on its current output, aiming to distribute the load as evenly as possible. The current adjustment amount can be calculated based on the difference between the actual output power and the target output power of each slave device, and then this adjustment amount is allocated to each slave device.

[0148] Specifically, the current adjustment amount ΔI is obtained based on the power balance algorithm, and then adjusted based on the original output current I:

[0149] Ia=I+ΔI

[0150] Where Ia is the adjusted output current.

[0151] A power balancing algorithm is introduced into the master-slave communication protocol. This algorithm dynamically adjusts the output current of each slave device based on its current output, aiming to distribute the load as evenly as possible. The current adjustment amount can be calculated based on the difference between the actual output power and the target output power of each slave device, and then this adjustment amount is allocated to each slave device.

[0152] like Figure 8 , Figure 9 As shown, the control method of the photovoltaic air conditioning system of the present invention further includes:

[0153] Step 3: Determine the current regulation amount ΔI according to the power balance algorithm, and adjust the current regulation amount ΔI in step 2 accordingly. output The output current I of the slave device is adjusted, and the slave device outputs current according to the adjusted current Ia to achieve balanced distribution of load power.

[0154] The present invention determines the adjustment amount of the slave device's output current based on a power balance algorithm, and adjusts the slave device's output current according to the adjustment amount, thereby achieving precise control of the slave device's output current, balancing the load distribution, and maximizing the utilization of photovoltaic energy.

[0155] In some embodiments, the acquisition unit 102 is further configured to acquire, on the host side, the outdoor light intensity and outdoor ambient temperature of the outdoor environment where the photovoltaic array is located when the photovoltaic air conditioning system is running; the specific functions and processing of the acquisition unit 102 are described in step S410.

[0156] The control unit 104 is further configured to determine the overcurrent protection threshold of the actual output current of any slave device on the host side based on the outdoor light intensity and the outdoor ambient temperature; the specific functions and processing of the control unit 104 are described in step S420.

[0157] The specific method for determining the overcurrent protection threshold of the actual output current of any slave device is as follows:

[0158] It=Ib*(1+kt*(T0-Tb))*(1+kL*(L0-Lb))

[0159] Where It is the overcurrent protection threshold of the actual output current of any slave device; Ib is the reference current threshold; kt is the temperature compensation coefficient; T0 is the outdoor ambient temperature; Tb is the reference temperature; kL is the illumination compensation coefficient; L0 is the outdoor illumination intensity; Lb is the reference illumination intensity. Specifically, Ib represents the overcurrent protection threshold under standard operating conditions, kt represents the degree of influence of temperature on the overcurrent protection threshold, T0 is obtained by temperature sensor, Tb represents the temperature under standard operating conditions, kL represents the degree of influence of illumination on the overcurrent protection threshold, L0 is obtained by illumination sensor, and Lb represents the illumination intensity under standard operating conditions.

[0160] Considering the impact of ambient temperature on photovoltaic (PV) arrays, temperature compensation is incorporated into the overcurrent protection mechanism. The overcurrent protection threshold is adjusted by monitoring the PV array temperature and correcting it according to a temperature compensation coefficient. In high-temperature environments, the current characteristics of the PV array may be affected; therefore, the overcurrent protection threshold is increased to avoid false triggering. Changes in illuminance also affect the current output of the PV array; therefore, illuminance compensation is considered in the overcurrent protection mechanism, adjusting the overcurrent protection threshold based on real-time measured illuminance. Under low-illuminance conditions, the overcurrent protection threshold is decreased to accommodate changes in slave current output.

[0161] The control unit 104 is further configured to, on the host side, control the output current of any slave device or the operating status of the photovoltaic air conditioning system based on the actual output current of any slave device and the overcurrent protection threshold. The specific functions and processing of this control unit 104 are described in step S430.

[0162] In some embodiments, the control unit 104 is further configured to, on the host side, control the output current of any slave device or the operating state of the photovoltaic air conditioning system based on the actual output current of any slave device and the overcurrent protection threshold, including:

[0163] If the actual output current of all slave devices in the two or more slave devices is less than or equal to the overcurrent protection threshold, the photovoltaic air conditioning system shall continue to operate normally.

[0164] If the actual output current of any of the two or more slave devices is greater than the overcurrent protection threshold and less than or equal to the product of the overcurrent protection threshold and the first preset ratio, then the actual output current of that slave device is reduced at the first preset rate.

[0165] If the actual output current of any of the two or more slave devices is greater than the product of the overcurrent protection threshold and the first preset ratio, and less than or equal to the product of the overcurrent protection threshold and the second preset ratio, then the actual output current of that slave device is reduced at the second preset rate.

[0166] If the actual output current of any of the two or more slave units exceeds the product of the overcurrent protection threshold and the second preset ratio, the photovoltaic air conditioning system will be shut down.

[0167] Specifically, the first preset ratio can be set to 105%, the second preset ratio can be set to 110%, the first preset rate can be set to 0.1A / s, and the second preset rate can be set to 0.3A / s. If the first preset current transformer module M1 detects that the output current Ia is less than the overcurrent protection threshold It, it controls the photovoltaic air conditioning system to operate normally and does not adjust the slave unit's output current; if it detects that the output current Ia is greater than the overcurrent protection threshold It, but less than or equal to 105%It, it controls the slave unit's output current to decrease at a rate of 0.1A / s until Ia is less than It; if it detects that the output current Ia is greater than 105%It, but less than or equal to 110%It, it controls the slave unit's output current to decrease at a rate of 0.3A / s until Ia is less than It; if it detects that the output current Ia is greater than 110%It, it disconnects the photovoltaic array's output circuit and shuts down the photovoltaic air conditioning system.

[0168] like Figure 8 , Figure 9 As shown, the control method of the photovoltaic air conditioning system of the present invention further includes:

[0169] Step 4: When the master and slave start running, acquire the outdoor environment light and ambient temperature information of the photovoltaic array. Based on the light and ambient temperature information and the preset protection strategy, determine the overcurrent protection threshold It of the slave's output current, and then execute step 5.

[0170] Step 5: Obtain the slave current Ia output in Step 3 through the current monitor. Based on the comparison between the slave output current Ia and the overcurrent protection threshold It, determine the specific protection mechanism: When Ia ≤ It, maintain the normal operation of the photovoltaic air conditioning system; when It < Ia ≤ 105% It, slowly reduce the slave output current at a rate of 0.1 A / s until Ia ≤ It; when 105% It < Ia ≤ 110% It, rapidly reduce the slave output current at a rate of 0.3 A / s until Ia ≤ It; when Ia > 110% It, disconnect the slave output circuit and shut down the photovoltaic air conditioning system.

[0171] The present invention introduces an overcurrent protection mechanism into the master-slave control logic. When the slave's output current exceeds a set limit, measures are immediately taken to limit and adjust it to prevent system damage. Overcurrent protection is achieved by reducing the slave's output current or disconnecting the circuit, enabling current protection control according to different operating conditions and weather conditions, ensuring that the slave current remains stable within the set range.

[0172] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0173] By employing the technical solution of this embodiment, in the operation of a photovoltaic air conditioning system with a master unit and multiple slave units, the target output power of the photovoltaic array is determined on the master unit side based on the output voltage and output current of the photovoltaic array; on the slave unit side, the actual output power of the load of any slave unit is determined based on the output voltage and output current of the slave unit, and then the output power difference of any slave unit is determined in combination with the target output power of the photovoltaic array, and the output power difference is fed back to the master unit; on the master unit side, the target output current of any slave unit is determined based on the output power difference and a preset control strategy, and the output current from the master unit side to the slave unit side is adjusted evenly according to the output power differences of all slave units. Thus, by determining the target output current of any slave unit through the output power difference and the preset control strategy, and adjusting this output current, precise control of the slave unit's output current is achieved, coordinating the output current of multiple slave units, realizing balanced power distribution, and improving the energy utilization efficiency of photovoltaic power generation.

[0174] According to an embodiment of the present invention, a photovoltaic air conditioning system corresponding to a control device for a photovoltaic air conditioning system is also provided. This photovoltaic air conditioning system may include: the control device for the photovoltaic air conditioning system described above.

[0175] Since the processing and functions implemented by the photovoltaic air conditioner in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned devices, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0176] By employing the technical solution of this embodiment, in the operation of a photovoltaic air conditioning system with a master unit and multiple slave units, the target output power of the photovoltaic array is determined on the master unit side based on the output voltage and output current of the photovoltaic array; on the slave unit side, the actual output power of the load of any slave unit is determined based on the output voltage and output current of the slave unit, and then the output power difference of any slave unit is determined in combination with the target output power of the photovoltaic array, and the output power difference is fed back to the master unit; on the master unit side, the target output current of any slave unit is determined based on the output power difference and a preset control strategy, and the output current from the master unit side to the slave unit side is adjusted evenly according to the output power differences of all slave units. Thus, by determining the target output current of any slave unit through the output power difference and the preset control strategy, and adjusting this output current, precise control of the slave unit's output current is achieved, coordinating the output current of multiple slave units, realizing balanced power distribution, and improving the energy utilization efficiency of photovoltaic power generation.

[0177] According to an embodiment of the present invention, a storage medium corresponding to a control method for a photovoltaic air conditioning system is also provided. The storage medium includes a stored program, wherein the program controls the device where the storage medium is located to execute the control method for the photovoltaic air conditioning system described above when it is running.

[0178] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0179] By employing the technical solution of this embodiment, in the operation of a photovoltaic air conditioning system with a master unit and multiple slave units, the target output power of the photovoltaic array is determined on the master unit side based on the output voltage and output current of the photovoltaic array; on the slave unit side, the actual output power of the load of any slave unit is determined based on the output voltage and output current of the slave unit, and then the output power difference of any slave unit is determined in combination with the target output power of the photovoltaic array, and the output power difference is fed back to the master unit; on the master unit side, the target output current of any slave unit is determined based on the output power difference and a preset control strategy, and the output current from the master unit side to the slave unit side is adjusted evenly according to the output power differences of all slave units. Thus, by determining the target output current of any slave unit through the output power difference and the preset control strategy, and adjusting this output current, precise control of the slave unit's output current is achieved, coordinating the output current of multiple slave units, realizing balanced power distribution, and improving the energy utilization efficiency of photovoltaic power generation.

[0180] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0181] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A control method for a photovoltaic air conditioning system, characterized in that, The photovoltaic air conditioning system includes: a photovoltaic array, a main unit, and two or more slave units; the power output terminal of the photovoltaic array is connected to the power input terminal of the main unit; the power distribution terminal of the main unit is respectively connected to the power input terminal of each of the two or more slave units; the method includes: When the photovoltaic air conditioning system is in operation, the output voltage and output current of the photovoltaic array are obtained on the host side; the output voltage and output current of the load of any one of the two or more slave units are obtained on the slave side of that slave unit. On the host side, the output power of the photovoltaic array is calculated based on the output voltage and output current of the photovoltaic array, and is taken as the target output power of the photovoltaic array; and the target output power of the photovoltaic array is sent to all slave devices of the two or more slave devices; On the slave side of any slave device, the actual output power of the load of any slave device is determined based on the output voltage and output current of the load of that slave device; the output power difference of any slave device is determined based on the actual output power of the load of that slave device and the target output power of the photovoltaic array, and the output power difference of any slave device is fed back to the master device; On the master side, upon receiving feedback from any slave device regarding the output power difference of that slave device, the target output current of that slave device is determined based on the output power difference of that slave device and a preset control strategy. On the host side, the actual output current of any slave device is adjusted according to the target output current of that slave device.

2. The control method for a photovoltaic air conditioning system according to claim 1, characterized in that, On the master side, upon receiving feedback from any slave device regarding the output power difference of that slave device, the target output current of that slave device is determined based on the output power difference of that slave device and a preset control strategy, including: Based on the output power difference of any slave device and the preset control strategy, determine the control signal for controlling the target output current of any slave device; The target output current of any slave device is determined based on the control signal that controls the target output current of any slave device; The preset control strategy is as follows: I output =Kp*P2+Ki*∫P2dt; Among them, I output P1 represents the target output current of any slave device; Kp is the proportional coefficient, Ki is the integral coefficient; P2 is the output power difference of any slave device.

3. The control method for the photovoltaic air conditioning system according to claim 1, characterized in that, On the host side, based on the determined target output current of any slave device, the actual output current of that slave device is adjusted, including: On the master side, based on the target output current of any slave device and in combination with the target output power of other slave devices among two or more slave devices, the current regulation amount of any slave device is determined. On the host side, the sum of the target output current of any slave device and the current regulation amount of any slave device is determined as the actual output current of any slave device. On the master side, the output current from the master side to the slave side is controlled according to the actual output current of the slave device; On the master side, based on the determined target output current of any slave device and in conjunction with the target output power of the other slave devices among two or more slave devices, the current regulation amount of any slave device is determined, including: Based on the target output power of the photovoltaic array and the output power difference of other slave devices among two or more slave devices, the current regulation amount of any slave device is determined using a power balancing algorithm. The power balancing algorithm is as follows: ΔI=Kp1*(P0–P1)+Ki1*∫(P0-P1)dt; Where ΔI is the current regulation amount of the actual output current of any slave device; Kp1 is the proportional coefficient, Ki1 is the integral coefficient; (P0–P1) is the output power difference; P0 is the target output power of the photovoltaic array, and P1 is the actual output power.

4. The control method for the photovoltaic air conditioning system according to any one of claims 1-3, characterized in that, Also includes: When the photovoltaic air conditioning system is in operation, the outdoor light intensity and outdoor ambient temperature of the outdoor environment where the photovoltaic array is located are obtained on the host side. On the host side, the overcurrent protection threshold of the actual output current of any slave device is determined based on the outdoor light intensity and the outdoor ambient temperature. The specific method for determining the overcurrent protection threshold of the actual output current of any slave device is as follows: It=Ib*(1+kt*(T0-Tb))*(1+kL*(L0-Lb)) Where It is the overcurrent protection threshold of the actual output current of any slave device; Ib is the reference current threshold; kt is the temperature compensation coefficient; T0 is the outdoor ambient temperature; Tb is the reference temperature; kL is the illumination compensation coefficient; L0 is the outdoor illumination intensity; Lb is the reference illumination intensity; On the host side, the output current of any slave device or the operating status of the photovoltaic air conditioning system is controlled according to the actual output current of any slave device and the overcurrent protection threshold.

5. The control method for the photovoltaic air conditioning system according to claim 4, characterized in that, On the master side, based on the actual output current of any slave device and the overcurrent protection threshold, the output current of any slave device or the operating status of the photovoltaic air conditioning system is controlled, including: If the actual output current of all slave devices in the two or more slave devices is less than or equal to the overcurrent protection threshold, the photovoltaic air conditioning system shall continue to operate normally. If the actual output current of any of the two or more slave devices is greater than the overcurrent protection threshold and less than or equal to the product of the overcurrent protection threshold and the first preset ratio, then the actual output current of that slave device is reduced at the first preset rate. If the actual output current of any of the two or more slave devices is greater than the product of the overcurrent protection threshold and the first preset ratio, and less than or equal to the product of the overcurrent protection threshold and the second preset ratio, then the actual output current of that slave device is reduced at the second preset rate. If the actual output current of any of the two or more slave units exceeds the product of the overcurrent protection threshold and the second preset ratio, the photovoltaic air conditioning system will be shut down.

6. A control device for a photovoltaic air conditioning system, characterized in that, The photovoltaic air conditioning system includes: a photovoltaic array, a main unit, and two or more slave units; the power output terminal of the photovoltaic array is connected to the power input terminal of the main unit; the power distribution terminal of the main unit is respectively connected to the power input terminal of each of the two or more slave units; the device includes: The acquisition unit is configured to, when the photovoltaic air conditioning system is in operation, acquire the output voltage and output current of the photovoltaic array on the host side; and acquire the output voltage and output current of the load of any one of the two or more slave units on the slave side. The control unit is configured to calculate the output power of the photovoltaic array based on the output voltage and output current of the photovoltaic array, as the target output power of the photovoltaic array; and to send the target output power of the photovoltaic array to all slave devices among two or more slave devices; The control unit is further configured to, on the slave side of any slave device, determine the actual output power of the load of any slave device based on the output voltage and output current of the load of any slave device; determine the output power difference of any slave device based on the actual output power of the load of any slave device and the target output power of the photovoltaic array; and feed back the output power difference of any slave device to the host device. The control unit is further configured to, on the host side, upon receiving the output power difference of any slave device fed back by the slave device, determine the target output current of the slave device based on the output power difference of the slave device and a preset control strategy. The control unit is further configured to, on the host side, adjust the actual output current of any slave device based on the determined target output current of any slave device.

7. The control device for the photovoltaic air conditioning system according to claim 6, characterized in that, The control unit, on the host side, upon receiving the output power difference from any slave device, determines the target output current of that slave device based on the output power difference and a preset control strategy, including: Based on the output power difference of any slave device and the preset control strategy, determine the control signal for controlling the target output current of any slave device; The target output current of any slave device is determined based on the control signal that controls the target output current of any slave device; The preset control strategy is as follows: I output =Kp*P2+Ki*∫P2dt; Among them, I output P1 represents the target output current of any slave device; Kp is the proportional coefficient, Ki is the integral coefficient; P2 is the output power difference of any slave device.

8. The control device for the photovoltaic air conditioning system according to claim 6, characterized in that, The control unit, on the host side, adjusts the actual output current of any slave device according to the determined target output current of any slave device, including: On the master side, based on the target output current of any slave device and in combination with the target output power of other slave devices among two or more slave devices, the current regulation amount of any slave device is determined. On the host side, the sum of the target output current of any slave device and the current regulation amount of any slave device is determined as the actual output current of any slave device. On the master side, the output current from the master side to the slave side is controlled according to the actual output current of the slave device; On the master side, based on the determined target output current of any slave device and in conjunction with the target output power of the other slave devices among two or more slave devices, the current regulation amount of any slave device is determined, including: Based on the target output power of the photovoltaic array and the output power difference of other slave devices among two or more slave devices, the current regulation amount of any slave device is determined using a power balancing algorithm. The power balancing algorithm is as follows: ΔI=Kp1*(P0–P1)+Ki1*∫(P0-P1)dt; Where ΔI is the current regulation amount of the actual output current of any slave device; Kp1 is the proportional coefficient, Ki1 is the integral coefficient; (P0–P1) is the output power difference; P0 is the target output power of the photovoltaic array, and P1 is the actual output power.

9. A photovoltaic air conditioning system, characterized in that, include: The control device for the photovoltaic air conditioning system as described in any one of claims 6 to 8.

10. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the control method of the photovoltaic air conditioning system according to any one of claims 1 to 5.

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