Photovoltaic energy storage air conditioning device and centralized control method

Abstract

A kind of photovoltaic energy storage air conditioning device and centralized control method, including solar photovoltaic assembly, battery pack and commercial power grid and air conditioning unit, the air conditioning unit has drive compressor and the inverter of internal load operation, the inverter is electrically connected with DC bus by a capacitor;The battery pack has charging and discharging circuit module, battery management module and battery group, the charging and discharging circuit module is accessed DC bus to make solar photovoltaic assembly to battery group charging or by battery group to DC bus power supply.The present application concentrates control sunlight photovoltaic power supply, battery power supply or charging, AC commercial power grid power supply and the operation of air conditioner, does not need to be converted into AC power, reduces conversion power loss, in the case where not affecting user uses air conditioner, as far as possible uses photovoltaic green energy, reduces the consumption of chemical energy, and product initial investment reduces, is conducive to green energy product promotion.

Description

Technical Field

[0001] This invention relates to the field of control technology for photovoltaic energy storage air conditioning, and in particular to a photovoltaic energy storage air conditioning device and a centralized control method. Background Technology

[0002] Solar photovoltaic (PV) power generation, as a clean energy technology, has been widely applied. However, the power output of solar PV is intermittent and fluctuates, and user loads are constantly changing, resulting in a mismatch between PV power generation and user loads in off-grid conditions. To ensure system stability and operational efficiency, auxiliary energy equipment is necessary to supplement the system. Common methods include battery energy storage and power supply, and AC mains power supply in conjunction with PV. Battery energy storage and power supply typically uses batteries or other energy storage devices to store excess PV energy during the day and release it at night or on cloudy days for user loads. AC mains power supply in conjunction with PV involves measures based on the output of the PV cells and the load power relationship to achieve joint power supply from the mains and PV. In existing solutions, the circuitry of a hybrid PV, battery, and AC mains power supply system is complex and difficult to control; the system involves many loads, resulting in high equipment costs and large investments, which is not conducive to the application and promotion of clean energy.

[0003] Chinese patent CN107040034 discloses a photovoltaic energy storage air conditioning device and its control method. The air conditioning device includes: a photovoltaic power generation device, an energy storage device, an air conditioning unit, and an energy dispatch management device. The energy dispatch management device includes: a detection module for detecting the air conditioning operating status, the power supply and operating status of the photovoltaic power generation device and the energy storage device; and a dispatch module for controlling power supply and / or charging based on the air conditioning operating status, power supply and operating status, and set power supply and power consumption priorities. This patent does not implement centralized control; the photovoltaic and battery power supply to the air conditioning unit is AC power, which undergoes DC / AC conversion, resulting in significant power loss.

[0004] Chinese patent CN112310966 discloses a photovoltaic energy storage air conditioning power supply system, comprising: a photovoltaic system, an inverter power unit, a converter power unit, a control module, and an air conditioner. The air conditioner includes an air conditioning unit, an AC load, and a DC load. The DC load is connected to a DC bus provided by the photovoltaic energy storage system, and the AC load is connected to the mains power grid via AC wires. The inverter power unit is connected between the DC bus and the air conditioning unit, and the converter power unit is connected between the AC wires and the DC bus. The control module is used to control the operating mode of the photovoltaic energy storage air conditioning power supply system according to the state of the mains power grid. This patent lacks centralized coordination control and a control strategy that coordinates battery charging and discharging with the air conditioner, which is detrimental to the application and promotion of clean energy. Summary of the Invention

[0005] To address the problems of complex control, high equipment costs, and lack of centralized control in existing photovoltaic energy storage air conditioning systems, which hinder the application and promotion of clean energy, this invention provides a photovoltaic energy storage air conditioning device and a centralized control method. Based on the power required by the air conditioning unit and the power provided by the solar photovoltaic modules, the device coordinates and controls the power supply from the solar photovoltaic power grid, the power supply from the municipal power grid, and the charging and discharging of the battery, thus making full use of clean photovoltaic energy.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a photovoltaic energy storage air conditioning device, comprising a solar photovoltaic module, a battery module, a municipal power grid, and an air conditioning unit, wherein:

[0007] The air conditioning unit has an inverter that drives the compressor and internal load, and the inverter is electrically connected to the DC bus through a capacitor.

[0008] The solar photovoltaic module and the mains power grid respectively boost the output voltage to a preset voltage through a first boost boost circuit and a second boost boost circuit to supply power to the DC bus. The battery module has a charging and discharging circuit module, a battery management module and a battery pack. The charging and discharging circuit module is connected to the DC bus so that the solar photovoltaic module charges the battery pack or the battery pack supplies power to the DC bus.

[0009] Preferably, the solar photovoltaic module is electrically connected to the first Boost circuit via a first switch. The output DC voltage VDC1 and current I1 enter the first Boost circuit and are boosted to the output voltage VDC2 by the first Boost circuit. The first Boost circuit includes an inductor L1, a switch K1, and a diode D1. The diode D1 is connected to the positive terminal of the capacitor C. The voltage between the positive and negative terminals of the capacitor C is the DC bus voltage VDC5. The output voltage VDC2 is supplied to the DC bus voltage VDC5 by the diode D1, and the current is I2.

[0010] Preferably, the mains power grid is electrically connected to the second Boost circuit via a second switch and a rectifier bridge. The output AC power is rectified by the rectifier bridge into DC voltage VDC3 and current I3, which then enters the second Boost circuit and is boosted to the output voltage VDC4. The second Boost circuit includes an inductor L2, a switch K2, and a diode D2. The diode D2 is connected to the positive terminal of a capacitor C. The voltage between the positive and negative terminals of capacitor C is the DC bus voltage VDC5. The output voltage VDC4 is supplied to the DC bus voltage VDC5 by the diode D2, with a current of I4.

[0011] Preferably, the battery assembly is connected to the positive terminal of capacitor C through a charging and discharging circuit module, and the voltage between the positive and negative terminals of capacitor C is the DC bus voltage VDC5.

[0012] When the battery pack is discharging, the charging and discharging circuit module boosts the voltage of the battery pack to the DC bus voltage VDC5 to supply power to the DC bus voltage.

[0013] When the battery pack is charging, the charging and discharging circuit module steps down the DC bus voltage VDC5 to the battery pack voltage V. bat To charge the battery pack.

[0014] On the other hand, the present invention adopts the following technical solution: a centralized control method for a photovoltaic energy storage air conditioner, comprising the following steps:

[0015] The air conditioner is powered on, and after obtaining the status of each power supply component and determining the power supply status, it starts running.

[0016] When the air conditioner is running, the maximum output power P of the solar photovoltaic modules is used. pv The maximum output power P of the battery assembly batout The output power P of the municipal power grid ac Power required by the air conditioning unit P need Make a judgment to switch the power supply state, so that the total output power of the determined power supply state is greater than or equal to the power P required by the air conditioning unit. need .

[0017] Preferably, the method further includes the following steps:

[0018] When the air conditioner is powered on, the output DC voltage VDC1 of the solar photovoltaic module is obtained.

[0019] Determine if DC voltage VDC1 ≥ preset voltage value V st :

[0020] If VDC1≥V st If the output voltage of the solar photovoltaic module meets the power supply requirements, it is determined that the module will operate in the first power supply state with independent power supply.

[0021] If VDC1 < V st If the output voltage of the solar photovoltaic module fails to meet the power supply requirements, the status information of the battery module is obtained, and the power supply to the air conditioning unit is determined based on the status information.

[0022] If the conditions are met, the system will operate in the third power supply state, where the battery pack is independently powered.

[0023] If the conditions are not met, the system will operate under the fifth power supply state, where the municipal power grid supplies power independently.

[0024] Preferably, the air conditioning unit, during operation, further includes the following steps:

[0025] When the air conditioning unit is operating in the first power supply state where the solar photovoltaic modules are independently powered:

[0026] Calculate the required power P of the air conditioning unit based on the target operating frequency of the variable frequency air conditioning compressor. need ;

[0027] The maximum power point tracking algorithm is run to control the switching frequency and duty cycle of the switching transistor K1 in the first Boost converter circuit, so that the solar photovoltaic module outputs power at the maximum power point. The maximum output power P of the solar photovoltaic module is calculated based on the output DC voltage VDC1 and current I1. pv ;

[0028] Compare P pv and P need :

[0029] When P pv ≥P need When the second switch on the mains power grid side is disconnected, the first power supply state is maintained. By controlling the switching frequency and duty cycle of the switch transistor K1, the DC voltage VDC1 is boosted to the output voltage VDC2. The output voltage VDC2 supplies power to the DC bus voltage through the diode D1.

[0030] When P pv <P need At that time, the status information of the battery pack is obtained, and the battery pack is used to determine whether it can supply power.

[0031] If the battery pack can supply power, the charging and discharging circuit module is controlled to discharge, entering a second power supply state where the solar photovoltaic module and battery module are simultaneously powered. The power supply current I6 of the charging and discharging circuit module is controlled to ensure that the power supply P... batout +P pv ≥P need ;

[0032] If the battery pack cannot supply power, the system enters a fourth power supply state where the solar photovoltaic modules and the mains grid supply power simultaneously. The switching frequency and duty cycle of switch K1 are controlled to ensure that the DC bus voltage VDC5 is higher than the rectified DC voltage VDC3 of the mains grid AC power. Then, the second switch on the mains grid side is closed, and the switching frequency and duty cycle of switch K2 are controlled to ensure that the second Boost circuit outputs a suitable output voltage VDC4. This output voltage VDC4 gradually increases the output current I4 on the mains grid side. By coordinating the switching frequencies and duty cycles of switch K1 and switch K2, the power supply P is increased. ac +Ppv ≥P need .

[0033] Preferably, the air conditioning unit, during operation, further includes the following steps:

[0034] When the air conditioning unit operates in the second power supply state, where both the solar photovoltaic modules and the battery modules are powered simultaneously, compare P pv and P need :

[0035] When P pv ≥P need When the battery module is not supplying power, the control charging and discharging circuit module does not work, and the system enters the first power supply state where the solar photovoltaic module is independently powered.

[0036] When P pv <P need At this time, the charging and discharging circuit module is in discharging operation, maintaining the second power supply state, so that the power P supplied by the battery pack to the air conditioner is... batout Satisfy P batout +P pv >P need .

[0037] Preferably, when the air conditioning unit is operating in the second power supply state, the following steps are further included:

[0038] Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st2 :

[0039] If VDC1 > V st2 It maintains operation in a second power supply state where both solar photovoltaic modules and battery modules are powered simultaneously.

[0040] If VDC1≤V st2 The system was determined to be unable to supply power due to insufficient output voltage from the solar photovoltaic modules. Based on the status information of the battery modules, it was determined whether the current battery pack could supply power independently.

[0041] When the current battery pack cannot supply power independently, it enters the sixth power supply state, where the battery pack and the mains power supply are simultaneously provided. The charging and discharging circuit module is controlled to ensure that the DC bus voltage VDC5 is higher than the rectified DC voltage VDC3 of the mains AC power. Then, the second switch on the mains side is closed, controlling the switching frequency and duty cycle of the switching transistor K2, causing the second Boost circuit to output a suitable output voltage VDC4. This output voltage VDC4 gradually increases the output current I4 on the mains side, thus increasing the power supply P. ac +P batout ≥P need ;

[0042] When the current battery pack is capable of independent power supply, the switching transistor K1 stops working, the first switch on the solar photovoltaic module side is disconnected, and the system enters the third power supply state where the battery pack is independently powered. The charging and discharging circuit module controls the output current I6 of the battery pack, thus increasing the power supply P. batout >P need .

[0043] Preferably, the air conditioning unit, during operation, further includes the following steps:

[0044] When the air conditioning unit operates in the third power supply state where the battery pack is independently powered:

[0045] Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st :

[0046] If VDC1 > V st If the solar photovoltaic module is ready to supply power, the first switch on the solar photovoltaic module side is closed. By controlling the switching frequency and duty cycle of the switch tube K1, the DC voltage VDC1 is boosted to the output voltage VDC2. The output voltage VDC2 supplies power to the DC bus voltage through the diode D1. The current I2 is increased by controlling VDC2. Within the allowable range, the power supply of the solar photovoltaic module is maximized. At this time, the second power supply state in which the solar photovoltaic module and the battery module supply power simultaneously is entered.

[0047] If VDC1≤V st The system was determined to be unable to supply power due to insufficient output voltage from the solar photovoltaic modules. Based on the status information of the battery modules, it was determined whether the current battery pack could supply power independently.

[0048] If the current battery pack can supply power independently, then maintain the third power supply state.

[0049] When the current battery pack cannot provide independent power, the charging and discharging circuit module is controlled to ensure that the DC bus voltage VDC5 is higher than the rectified DC voltage VDC3 of the AC power from the mains grid. Then, the second switch on the mains grid side is closed, controlling the switching frequency and duty cycle of the switching transistor K2, so that the second Boost circuit outputs a suitable output voltage VDC4. This output voltage VDC4 gradually increases the output current I4 on the mains grid side. The power output P of the mains power supply is calculated based on the DC voltage VDC3 and the current I3. ac By coordinating and controlling the switching frequency and duty cycle of the charging and discharging circuit module and the switching transistor K2, P... batout +P ac ≥P need At this point, it enters the sixth power supply state, where the battery pack and the mains grid supply power simultaneously.

[0050] Preferably, the air conditioning unit, during operation, further includes the following steps:

[0051] When the air conditioning unit operates in the fourth power supply state, where both solar photovoltaic modules and the mains power grid are simultaneously supplying power:

[0052] Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st2 :

[0053] If VDC1≤V st2 The system was determined to be unable to supply power due to insufficient output voltage from the solar photovoltaic modules. The status information of the battery modules was then used to determine whether the current battery pack could provide power.

[0054] When the battery pack is currently in a state where it can supply power, the charging and discharging circuit module is controlled to enter the discharging operation, boosting the output voltage to the DC bus voltage VDC5 to supply power to the DC bus, while simultaneously controlling the output current I6 to ensure that the power supply P... ac +P batout ≥P need Disconnect the first switch on the solar photovoltaic module side, and the solar photovoltaic module will no longer supply power, entering the sixth power supply state where the battery module and the mains grid supply power simultaneously;

[0055] When the current battery pack is unable to supply power, disconnect the first switch on the solar photovoltaic module side and stop the operation of the charging and discharging circuit module. Control the switching frequency and duty cycle of the switch transistor K2 to make the output of the second Boost boost circuit a suitable output voltage VDC4, so that the AC mains current I4 gradually increases and enters the fifth power supply state of independent power supply from the mains grid.

[0056] If VDC1 > V st2 Then compare P pv With P need :

[0057] If P pv ≥P need Disconnect the second switch on the mains power grid side and enter the first power supply state where the solar photovoltaic modules are independently powered;

[0058] If P pv <P need Based on the status information sent by the battery management module, it determines whether the battery pack can supply power: when the battery pack can supply power, it enters the second power supply state where the solar photovoltaic module and the battery module supply power simultaneously; when the battery pack cannot supply power, it maintains the fourth power supply state where the solar photovoltaic module and the mains grid supply power simultaneously.

[0059] Preferably, the air conditioning unit, during operation, further includes the following steps:

[0060] When the air conditioning unit is operating under the fifth power supply state of independent power supply from the municipal power grid:

[0061] Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st :

[0062] If VDC1 > V st If the solar photovoltaic module is ready to supply power, the first switch on the solar photovoltaic module side is closed. By controlling the switching frequency and duty cycle of the switch tube K1, the DC voltage VDC1 is boosted to the output voltage VDC2. The output voltage VDC2 supplies power to the DC bus voltage through the diode D1. The current I2 is increased by controlling VDC2. Within the allowable range, the power supply of the solar photovoltaic module is maximized. At this time, the fourth power supply state, in which the solar photovoltaic module and the mains grid supply power simultaneously, is entered.

[0063] If VDC1≤V st The system was determined to be unable to supply power due to insufficient output voltage from the solar photovoltaic modules. The status information of the battery modules was then used to determine whether the current battery pack could provide power.

[0064] If the battery pack can provide power, the charging and discharging circuit module is controlled to enter the discharging operation, boosting the output voltage of the battery pack to the DC bus voltage VDC5 and supplying power to the DC bus. Simultaneously, the power supply current I6 is controlled to ensure that the power supply P... batout +P ac ≥P need ;

[0065] If the battery pack is unable to supply power, it will continue to operate in the fifth power supply state, which is independently powered by the municipal power grid.

[0066] Preferably, the air conditioning unit, during operation, further includes the following steps:

[0067] When the air conditioning unit operates in the sixth power supply state, where both the battery pack and the mains power grid are powered simultaneously:

[0068] Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st :

[0069] If VDC1 > V stIf the solar photovoltaic module is ready to supply power, the first switch on the solar photovoltaic module side is closed. By controlling the switching frequency and duty cycle of the switch tube K1, the DC voltage VDC1 is boosted to the output voltage VDC2. The output voltage VDC2 supplies power to the DC bus voltage through the diode D1. The current I2 is increased by controlling VDC2. Within the allowable range, the power supply of the solar photovoltaic module is maximized. The second switch on the mains grid side is then disconnected, and the mains grid no longer supplies power. At this time, the system enters the second power supply state where the solar photovoltaic module and the battery module are powered simultaneously.

[0070] If VDC1≤V st If the solar photovoltaic module is determined to have insufficient output voltage and is unable to supply power, then the status information of the battery module is used to determine whether the current battery pack can continue to supply power.

[0071] If the battery pack can still provide power, then the sixth power supply state will be maintained.

[0072] When the battery pack can no longer supply power, the charging and discharging circuit modules will stop working and the system will enter the fifth power supply state, where it will be powered independently by the municipal power grid.

[0073] Preferably, the method further includes a step of the battery assembly entering a charging state:

[0074] When the battery management module of the battery pack detects that the battery pack needs charging and allows it to charge, it enters the charging state after one of the following conditions is met:

[0075] a: When the solar photovoltaic module is in an independent power supply state, and the power P that the solar photovoltaic module can provide is... pv > Power required by the air conditioner P need Then, the solar photovoltaic modules charge the battery, and the charging and discharging circuit module enters charging mode, reducing the DC bus voltage to the battery pack voltage to charge the battery pack, while controlling the charging current to ensure that the charging power P is sufficient. batin +P need <P pv ;

[0076] b: When the municipal power grid is in a period of low electricity price, the control charging and discharging circuit module enters charging mode, and supplies power to the battery pack while ensuring the normal operation of the air conditioning unit.

[0077] On the other hand, the present invention adopts the following technical solution: a centralized control device for a photovoltaic energy storage air conditioner, including a memory and a processor, wherein the processor executes a centralized control method for a photovoltaic energy storage air conditioner as described above by calling the control program stored in the memory.

[0078] On the other hand, the present invention adopts the following technical solution: a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes a centralized control method for a photovoltaic energy storage air conditioner as described above.

[0079] Compared with the prior art, the present invention has the following beneficial effects:

[0080] This invention proposes a household air conditioning circuit system that can be powered by a combination of solar photovoltaic power, a storage battery, and AC mains power, or by power supply separately, and can also charge the storage battery. Through the main control unit of the air conditioner, the solar photovoltaic power supply, the storage battery power supply or charging, the AC mains power supply, and the operation of the air conditioner are centrally controlled. Based on the power required by the air conditioning unit and the power that solar photovoltaic power can provide, the solar photovoltaic power supply, the AC mains power supply, and the charging and discharging of the storage battery are coordinated and controlled, giving priority to the use of photovoltaic power, then the use of storage battery power, and finally the use of AC mains power, so as to achieve the effect of fully utilizing clean photovoltaic energy.

[0081] This invention can also control the charging current of the battery module, so that excess solar photovoltaic power can be charged into the battery while ensuring the normal operation of the air conditioner. The solar photovoltaic module directly provides DC power to the air conditioner and battery, without the need for AC conversion, reducing conversion power loss. It maximizes the use of green photovoltaic energy and reduces the consumption of chemical energy without affecting the user's air conditioning use. Furthermore, the initial investment is lower, which is conducive to the promotion of green energy products. Based on the centralized control of the main control unit, photovoltaic, battery, and AC mains power can automatically and smoothly switch or supply power simultaneously without user intervention, without affecting the operation of the air conditioner or the user's comfort experience. Attached Figure Description

[0082] To more clearly illustrate the technical solution, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0083] Figure 1 This is a schematic diagram of the photovoltaic energy storage air conditioning circuit structure for implementing Case 1.

[0084] Figure 2 A flowchart illustrating the implementation of Case 2.

[0085] Figure 3 A schematic diagram of the workflow for the first power supply state in Case Study 3.

[0086] Figure 4 A schematic diagram of the workflow for implementing the second power supply state in Case 4.

[0087] Figure 5 A schematic diagram illustrating the workflow for implementing the third power supply state in Case Study 5.

[0088] Figure 6 A schematic diagram of the workflow for implementing the fourth power supply state in Case 6.

[0089] Figure 7 A schematic diagram of the workflow for implementing the fifth power supply state in Case 7.

[0090] Figure 8 A schematic diagram of the workflow for the sixth power supply state in Case 8. Detailed Implementation

[0091] In order to clearly and completely understand the technical solution, the present invention will be further described in conjunction with the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0092] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0093] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0094] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0095] Implementation Case 1:

[0096] like Figure 1 As shown, a photovoltaic energy storage air conditioning device includes solar photovoltaic modules, battery modules, a municipal power grid, and an air conditioning unit, wherein:

[0097] The air conditioning unit has an inverter 100 that drives the compressor and internal load. The inverter 100 is electrically connected to the DC bus through a capacitor C.

[0098] The solar photovoltaic module and the mains power grid respectively boost the output voltage to a preset voltage through the first Boost boost circuit 100 and the second Boost boost circuit 200 to supply power to the DC bus. The battery module has a charging and discharging circuit module, a battery management module and a battery pack. The charging and discharging circuit module is connected to the DC bus so that the solar photovoltaic module charges the battery pack or the battery pack supplies power to the DC bus.

[0099] The solar photovoltaic module is electrically connected to the first Boost circuit 100 via a first switch 10. The first switch 10 can be a DC contactor, DC relay, etc. The DC voltage VDC1 and current I1 output by the solar photovoltaic module enter the first Boost circuit 100 and are boosted to the output voltage VDC2 by the first Boost circuit 100. The first Boost circuit 100 includes an inductor L1, a switching transistor K1, and a diode D1. In this embodiment, the function of the first Boost circuit is to boost VDC1 to a suitable DC voltage VDC2 and simultaneously execute the maximum power point tracking algorithm. By controlling the duty cycle or switching frequency of the switching transistor K1, the voltage VDC1, current I1, voltage VDC2, and current I2 can be controlled. The diode D1 is connected to the positive terminal of the capacitor C. The voltage between the positive and negative terminals of the capacitor C is the DC bus voltage VDC5. The output voltage VDC2 is supplied by the diode D1 to the DC bus voltage VDC5, and the current is I2. Capacitor C serves as a voltage regulator, energy storage, and filter. The inverter is connected to capacitor C and is powered by the DC bus voltage VDC5, which drives the compressor. In this implementation, the DC bus voltage VDC5 supplies power to the air conditioning unit and its internal loads, such as the compressor, with a current of I5. The internal loads of the air conditioner include the compressor and fan motor. The air conditioning inverter typically uses an intelligent power module (IPM) to control the compressor, driving the compressor to operate at a variable frequency by controlling the switching transistors inside the inverter.

[0100] The municipal power grid is electrically connected to the second Boost converter 200 via the second switch 20 and the rectifier bridge 21. The output AC power is rectified by the rectifier bridge 21 into DC voltage VDC3 and current I3, which then enters the second Boost converter 200 and is boosted to the output voltage VDC4. The second Boost converter 200 includes an inductor L2, a switch K2, and a diode D2. In this embodiment, the function of the second Boost converter is to boost VDC3 to a suitable DC voltage VDC4. By controlling the duty cycle or switching frequency of the switch K2, the voltage VDC3, current I3, voltage VDC4, and current I4 can be controlled. The diode D2 is connected to the positive terminal of the capacitor C. The voltage between the positive and negative terminals of the capacitor C is the DC bus voltage VDC5. The output voltage VDC4 is supplied by the diode D2 to the DC bus voltage VDC5, with a current of I4.

[0101] The battery pack is connected to the positive terminal of capacitor C via a charging and discharging circuit module. The battery pack can store energy and release energy to power the load. A battery management module charges and discharges each cell within the battery pack. This module is connected to the DC bus via the charging and discharging circuit module. The charging and discharging circuit module can reduce the DC bus voltage to a suitable battery pack voltage to charge the battery pack; alternatively, it can boost the battery pack voltage to a suitable DC voltage to power the DC bus and drive the internal load of the air conditioner. When the battery pack is discharging, the charging and discharging circuit module boosts the battery pack voltage to the DC bus voltage VDC5 to power the DC bus. When the battery pack is charging, the charging and discharging circuit module reduces the DC bus voltage VDC5 to the battery pack voltage V. bat It charges the battery pack. The battery management module is integrated with the battery pack to manage the voltage, current, and temperature rise of each battery cell within the battery pack, and provides the battery pack's status information to the main control unit.

[0102] The main control unit is used to detect voltages VDC1, VDC2, VDC4, VDC5, and currents I1, I3, I5, and I6. It also receives battery pack status information from the battery management module. The main control unit controls the opening and closing of the first and second switches, the duty cycle or switching frequency of switching transistors K1 and K2, and the operation, shutdown, and state switching of the charging and discharging circuit modules through control methods and control logic.

[0103] This implementation case fully utilizes clean photovoltaic energy by coordinating and controlling the power supply of solar photovoltaic modules, the power supply of the municipal power grid, and the charging and discharging of the battery. Based on the centralized control of the main control unit, the solar photovoltaic, battery, and municipal power grid automatically and smoothly switch or supply power simultaneously without user intervention. It does not affect the operation of the air conditioner or the user's comfort experience. This implementation case also directly provides DC power to the air conditioner and battery without the need to convert it to AC power, reducing conversion power loss.

[0104] Implementation Case 2:

[0105] like Figure 2 As shown, a centralized control method for a photovoltaic energy storage air conditioner, based on the photovoltaic energy storage air conditioner device in Implementation Case 1, includes the following steps:

[0106] When the air conditioner is powered on, it acquires the status of each power supply component and determines the power supply status before starting operation, including: acquiring the output DC voltage VDC1 of the solar photovoltaic module;

[0107] Determine if DC voltage VDC1 ≥ preset voltage value V st :

[0108] If VDC1≥V st If the output voltage of the solar photovoltaic module meets the power supply requirements, it is determined that the module will operate in the first power supply state with independent power supply.

[0109] If VDC1 < V st If the output voltage of the solar photovoltaic module fails to meet the power supply requirements, the status information of the battery module is obtained, and the power supply to the air conditioning unit is determined based on the status information.

[0110] If the conditions are met, the system will operate in the third power supply state, where the battery pack is independently powered.

[0111] If the conditions are not met, the system will operate under the fifth power supply state, which is independently powered by the municipal power grid.

[0112] When the air conditioner is running, the maximum output power P of the solar photovoltaic modules is used. pv The maximum output power P of the battery assembly batout The output power P of the municipal power grid ac Power required by the air conditioning unit P need Make a judgment to switch the power supply state, so that the total output power of the determined power supply state is greater than or equal to the power P required by the air conditioning unit. need .

[0113] The power supply states described in this implementation case include: a first power supply state where the solar photovoltaic modules are powered independently; a second power supply state where the solar photovoltaic modules and the battery modules are powered simultaneously; a third power supply state where the battery modules are powered independently; a fourth power supply state where the solar photovoltaic modules and the municipal power grid are powered simultaneously; a fifth power supply state where the municipal power grid is powered independently; and a sixth power supply state where the battery modules and the municipal power grid are powered simultaneously.

[0114] This implementation case is based on the required power P of the air conditioning unit. need and the power P that solar photovoltaic modules can provide pv By coordinating and controlling the power supply from solar photovoltaic modules, the power supply from the municipal power grid, and the charging and discharging of battery modules, clean photovoltaic energy is fully utilized. The electricity from the solar photovoltaic modules is only supplied to the air conditioning unit and the battery module. When the power from the solar photovoltaic modules is insufficient, the battery module and the AC power grid can also provide power to the air conditioning unit. Therefore, it is not necessary to configure large-capacity photovoltaic panels, reducing cost investment. The battery module provides power to the air conditioning unit. When the battery is insufficient, the AC power grid can also provide power to the air conditioning unit. Therefore, it is not necessary to configure large-capacity batteries, reducing cost investment. Without affecting users' use of air conditioning, photovoltaic green energy is used as much as possible, reducing the consumption of chemical energy. Moreover, the initial investment of the product is lower, which is conducive to the promotion of green energy products.

[0115] Implementation Case 3:

[0116] like Figure 3 As shown, a centralized control method for a photovoltaic energy storage air conditioner is described, wherein the air conditioning unit operates in the first power supply state where the solar photovoltaic modules are independently powered:

[0117] Calculate the required power P of the air conditioning unit based on the target operating frequency of the variable frequency air conditioning compressor. need ;

[0118] The maximum power point tracking algorithm is run to control the switching frequency and duty cycle of the switching transistor K1 in the first Boost converter circuit, so that the solar photovoltaic module outputs power at the maximum power point. The maximum output power P of the solar photovoltaic module is calculated based on the output DC voltage VDC1 and current I1. pv ;

[0119] Compare P pv and P need :

[0120] When P pv ≥P needWhen the second switch on the mains power grid side is disconnected, the first power supply state is maintained. By controlling the switching frequency and duty cycle of the switch transistor K1, the DC voltage VDC1 is boosted to the output voltage VDC2. The output voltage VDC2 supplies power to the DC bus voltage through the diode D1.

[0121] When P pv <P need At this time, the main control unit obtains the battery pack status information sent by the battery management module, and determines whether the battery pack can provide power based on the status information:

[0122] If the battery pack can provide power, the main control unit controls the charging and discharging circuit module to discharge, entering a second power supply state where the solar photovoltaic module and battery module are simultaneously powered. This controls the power supply current I6 of the charging and discharging circuit module, ensuring the power supply P... batout +P pv ≥P need ;

[0123] If the battery pack cannot supply power, the system enters a fourth power supply state where the solar photovoltaic modules and the mains grid supply power simultaneously. The switching frequency and duty cycle of switch K1 are controlled to ensure that the DC bus voltage VDC5 is higher than the rectified DC voltage VDC3 of the mains grid AC power. Then, the second switch on the mains grid side is closed, and the switching frequency and duty cycle of switch K2 are controlled to ensure that the second Boost circuit outputs a suitable output voltage VDC4. This output voltage VDC4 gradually increases the output current I4 on the mains grid side. By coordinating the switching frequencies and duty cycles of switch K1 and switch K2, the power supply P is increased. ac +P pv ≥P need .

[0124] Implementation Case 4:

[0125] like Figure 4 As shown, a centralized control method for a photovoltaic energy storage air conditioner is described, wherein the air conditioning unit operates in a second power supply state where both solar photovoltaic modules and battery modules are powered simultaneously:

[0126] Calculate the required power P of the air conditioning unit based on the target operating frequency of the variable frequency air conditioning compressor. need ;

[0127] The maximum power point tracking algorithm is run to control the switching frequency and duty cycle of the switching transistor K1 in the first Boost converter circuit, so that the solar photovoltaic module outputs power at the maximum power point. The maximum output power P of the solar photovoltaic module is calculated based on the output DC voltage VDC1 and current I1. pv ;

[0128] Compare P pv and Pneed :

[0129] When P pv ≥P need When the battery module is not supplying power, the control charging and discharging circuit module does not work, and the system enters the first power supply state where the solar photovoltaic module is independently powered.

[0130] When P pv <P need At the same time, it maintains a second power supply state where the solar photovoltaic modules and battery modules are simultaneously powered. The main control unit controls the charging and discharging circuit modules to discharge, so that the power P provided by the battery pack to the air conditioner is... batout Satisfy P batout +P pv >P need .

[0131] In this implementation case, the main control unit receives status information such as voltage, current, temperature rise, and charge of the battery pack from the battery management module. It then determines whether the battery pack can continue to supply power normally. If the battery pack can continue to supply power normally, it continues operating in the second power supply state. If the battery pack cannot continue to supply power, it needs to switch to the fourth power supply state, where the solar photovoltaic modules and the mains grid supply power simultaneously. The unit controls the switching frequency and duty cycle of switch K1 to make voltage VDC5 higher than the DC voltage VDC3 rectified from the AC mains grid. Then, it closes the second switch on the mains grid side and controls the switching frequency and duty cycle of switch K2, causing the second Boost circuit to output a suitable output voltage VDC4. This output voltage VDC4 gradually increases the output current I4 on the mains grid side. By coordinating the switching frequencies and duty cycles of switches K1 and K2, P... pv +P ac ≥P need ;

[0132] This implementation example also includes: comparing the DC voltage VDC1 of the solar photovoltaic module with a preset voltage value V. st2 :

[0133] If VDC1 > V st2 It maintains operation in a second power supply state where both solar photovoltaic modules and battery modules are powered simultaneously.

[0134] If VDC1≤V st2 The system was determined to be unable to supply power due to insufficient output voltage from the solar photovoltaic modules. Based on the status information of the battery modules, it was determined whether the current battery pack could supply power independently.

[0135] When the current battery pack cannot supply power independently, it enters the sixth power supply state, where the battery pack and the mains power supply are simultaneously provided. The charging and discharging circuit module is controlled to ensure that the DC bus voltage VDC5 is higher than the rectified DC voltage VDC3 of the mains AC power. Then, the second switch on the mains side is closed, controlling the switching frequency and duty cycle of the switching transistor K2, causing the second Boost circuit to output a suitable output voltage VDC4. This output voltage VDC4 gradually increases the output current I4 on the mains side, thus increasing the power supply P. ac +P batout ≥P need ;

[0136] When the current battery pack is capable of independent power supply, the switching transistor K1 stops working, the first switch on the solar photovoltaic module side is disconnected, and the system enters the third power supply state where the battery pack is independently powered. The main control unit controls the output current I6 of the battery pack through the charging and discharging circuit module, thereby increasing the power supply P. batout >P need .

[0137] Implementation Case 5:

[0138] like Figure 5 As shown, a centralized control method for a photovoltaic energy storage air conditioner is described, wherein the air conditioning unit operates in a third power supply state where the battery module provides independent power:

[0139] Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st To determine whether solar photovoltaic modules can supply power:

[0140] If VDC1 > V st If the solar photovoltaic module is ready to supply power, the first switch on the solar photovoltaic module side is closed. By controlling the switching frequency and duty cycle of the switch tube K1, the DC voltage VDC1 is boosted to the output voltage VDC2. The output voltage VDC2 supplies power to the DC bus voltage through the diode D1. The current I2 is increased by controlling VDC2. Within the allowable range, the power supply of the solar photovoltaic module is maximized. At this time, the second power supply state in which the solar photovoltaic module and the battery module supply power simultaneously is entered.

[0141] If VDC1≤V st The system was determined to be unable to supply power due to insufficient output voltage from the solar photovoltaic modules. Based on the status information of the battery modules, it was determined whether the current battery pack could supply power independently.

[0142] If the current battery pack can supply power independently, then maintain the third power supply state.

[0143] When the current battery pack cannot provide independent power, the charging and discharging circuit module is controlled to ensure that the DC bus voltage VDC5 is higher than the rectified DC voltage VDC3 of the AC power from the mains grid. Then, the second switch on the mains grid side is closed, controlling the switching frequency and duty cycle of the switching transistor K2, so that the second Boost circuit outputs a suitable output voltage VDC4. This output voltage VDC4 gradually increases the output current I4 on the mains grid side. The power output P of the mains power supply is calculated based on the DC voltage VDC3 and the current I3. ac By coordinating and controlling the switching frequency and duty cycle of the charging and discharging circuit module and the switching transistor K2, P... batout +P ac ≥P need At this point, it enters the sixth power supply state, where the battery pack and the mains grid supply power simultaneously.

[0144] Implementation Case Six:

[0145] like Figure 6 As shown, a centralized control method for a photovoltaic energy storage air conditioner is described, wherein the air conditioning unit operates in a fourth power supply state where solar photovoltaic modules and the municipal power grid are simultaneously powered:

[0146] First, determine if the solar photovoltaic module can still supply power by comparing its DC voltage VDC1 with the preset voltage value V. st2 :

[0147] ①If VDC1≤V st2 The system was determined to be unable to supply power due to insufficient output voltage from the solar photovoltaic modules. The status information of the battery modules was then used to determine whether the current battery pack could provide power.

[0148] When the battery pack is currently in a state where it can supply power, the charging and discharging circuit module is controlled to enter the discharging operation, boosting the output voltage to the DC bus voltage VDC5 to supply power to the DC bus, while simultaneously controlling the output current I6 to ensure that the power supply P... ac +P batout ≥P need Disconnect the first switch on the solar photovoltaic module side, and the solar photovoltaic module will no longer supply power, entering the sixth power supply state where the battery module and the mains grid supply power simultaneously;

[0149] When the current battery pack is unable to supply power, disconnect the first switch on the solar photovoltaic module side and stop the operation of the charging and discharging circuit module. Control the switching frequency and duty cycle of the switch transistor K2 to make the output of the second Boost boost circuit a suitable output voltage VDC4, so that the AC mains current I4 gradually increases and enters the fifth power supply state of independent power supply from the mains grid.

[0150] ②If VDC1>V st2Then, the maximum power point tracking algorithm is used to control the switching frequency and duty cycle of the switch K1 so that the solar photovoltaic module outputs power at the maximum power point. The maximum output power P of the solar photovoltaic module is calculated based on VDC1 and I1. pv Compare P pv With P need :

[0151] If P pv ≥P need Disconnect the second switch on the mains power grid side and enter the first power supply state where the solar photovoltaic modules are independently powered;

[0152] If P pv <P need The system determines whether the battery pack can provide power based on the status information sent by the battery management module.

[0153] When the battery pack can provide power, the main control unit controls the charging and discharging circuit module to discharge, raising the battery pack voltage to the DC bus voltage and supplying power to the DC bus. Simultaneously, it controls the supply current I6, thereby increasing the power supply P. batout +P pv >P need Disconnect the second switch on the mains power grid side, and the AC mains power grid will no longer supply power, entering a second power supply state where the solar photovoltaic modules and battery modules are powered simultaneously.

[0154] When the battery pack cannot supply power, the fourth power supply state is maintained, in which the solar photovoltaic modules and the mains grid supply power simultaneously.

[0155] Implementation Case Seven:

[0156] like Figure 7 As shown, a centralized control method for a photovoltaic energy storage air conditioner is described, wherein the air conditioning unit operates in the fifth power supply state where it is independently powered by the municipal power grid:

[0157] Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st :

[0158] If VDC1 > V st If the solar photovoltaic module is ready to supply power, the first switch on the solar photovoltaic module side is closed. By controlling the switching frequency and duty cycle of the switch tube K1, the DC voltage VDC1 is boosted to the output voltage VDC2. The output voltage VDC2 supplies power to the DC bus voltage through the diode D1. The current I2 is increased by controlling VDC2. Within the allowable range, the power supply of the solar photovoltaic module is maximized. At this time, the fourth power supply state, in which the solar photovoltaic module and the mains grid supply power simultaneously, is entered.

[0159] If VDC1≤V stThe system was determined to be unable to supply power due to insufficient output voltage from the solar photovoltaic modules. The status information of the battery modules was then used to determine whether the current battery pack could provide power.

[0160] If the battery pack can provide power, the main control unit controls the charging and discharging circuit module to enter the discharging operation, boosting the output voltage of the battery pack to the DC bus voltage VDC5 and supplying power to the DC bus, while controlling the supply current I6 to ensure that the supply power P batout +P ac ≥P need It enters the sixth power supply state, where the battery pack and the mains power grid supply power simultaneously;

[0161] If the battery pack is unable to supply power, it will continue to operate in the fifth power supply state, which is independently powered by the municipal power grid.

[0162] Implementation Case 8:

[0163] like Figure 8 As shown, a centralized control method for a photovoltaic energy storage air conditioner is described, wherein the air conditioning unit operates in the sixth power supply state, where the battery module and the mains power grid are simultaneously powered:

[0164] Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st :

[0165] If VDC1 > V st If the solar photovoltaic module is ready to supply power, the first switch on the solar photovoltaic module side is closed. By controlling the switching frequency and duty cycle of the switch tube K1, the DC voltage VDC1 is boosted to the output voltage VDC2. The output voltage VDC2 supplies power to the DC bus voltage through the diode D1. The current I2 is increased by controlling VDC2. Within the allowable range, the power supply of the solar photovoltaic module is maximized. The second switch on the mains grid side is then disconnected, and the mains grid no longer supplies power. At this time, the system enters the second power supply state where the solar photovoltaic module and the battery module are powered simultaneously.

[0166] If VDC1≤V st If the solar photovoltaic module is determined to have insufficient output voltage and is unable to supply power, then the status information of the battery module is used to determine whether the current battery pack can continue to supply power.

[0167] If the battery pack can still provide power, then the sixth power supply state will be maintained.

[0168] When the battery pack can no longer supply power, the charging and discharging circuit modules will stop working and the system will enter the fifth power supply state, where it will be powered independently by the municipal power grid.

[0169] Implementation Case Nine:

[0170] like Figure 3As shown, a centralized control method for a photovoltaic energy storage air conditioner includes the following steps for the battery module to enter the charging state during the operation of the air conditioning unit in various power supply states as described in the above implementation example:

[0171] When the battery management module of the battery pack detects that the battery pack needs charging and allows it to charge, it enters the charging state after one of the following conditions is met:

[0172] ① When the solar photovoltaic module is in an independent power supply state, and the power P that the solar photovoltaic module can provide is... pv > Power required by the air conditioner P need Comparison of power P pv and the preset power value P st When P pv >P st At this time, the solar photovoltaic modules charge the battery, and the charging and discharging circuit module enters the charging operation, reducing the DC bus voltage to the battery pack voltage to charge the battery pack, while controlling the charging current to ensure that the charging power P is sufficient. batin +P need <P pv ;

[0173] ② When the municipal power grid is in a period of low electricity price, the control charging and discharging circuit module enters charging mode to supply power to the battery pack while ensuring the normal operation of the air conditioning unit.

[0174] This invention proposes a household air conditioning circuit system that can be powered by a combination of solar photovoltaic power, a storage battery, and AC mains power, or by power supply separately, and can also charge the storage battery. Through the main control unit of the air conditioner, the solar photovoltaic power supply, the storage battery power supply or charging, the AC mains power supply, and the operation of the air conditioner are centrally controlled. Based on the power required by the air conditioning unit and the power that solar photovoltaic power can provide, the solar photovoltaic power supply, the AC mains power supply, and the charging and discharging of the storage battery are coordinated and controlled, giving priority to the use of photovoltaic power, then the use of storage battery power, and finally the use of AC mains power, so as to achieve the effect of fully utilizing clean photovoltaic energy.

[0175] This invention can also control the charging current of the battery module, so that excess solar photovoltaic power can be charged into the battery while ensuring the normal operation of the air conditioner. The solar photovoltaic module directly provides DC power to the air conditioner and battery, without the need for AC conversion, reducing conversion power loss. It maximizes the use of green photovoltaic energy and reduces the consumption of chemical energy without affecting the user's air conditioning use. Furthermore, the initial investment is lower, which is conducive to the promotion of green energy products. Based on the centralized control of the main control unit, photovoltaic, battery, and AC mains power can automatically and smoothly switch or supply power simultaneously without user intervention, without affecting the operation of the air conditioner or the user's comfort experience.

[0176] On the other hand, the present invention also provides the following implementation example: a centralized control device for a photovoltaic energy storage air conditioner, including a memory and a processor, wherein the processor executes a centralized control method for a photovoltaic energy storage air conditioner as described above by calling a control program stored in the memory.

[0177] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor such that the processor can read and write information to / from the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside as discrete components in the user terminal.

[0178] On the other hand, the present invention also provides the following embodiment: a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to execute a centralized control method for a photovoltaic energy storage air conditioner as described in the above embodiment.

[0179] Computer-readable media includes both computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. Storage media can be any available medium accessible to a computer. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a computer. Any connection is also properly referred to as computer-readable media.

[0180] The above disclosures are merely one or more preferred embodiments of the present invention, used to help understand the inventive concept of the technical solution, and are not intended to limit the present invention in any other way. Any other equivalent or conventional substitution schemes made by those skilled in the art based on the features defined by the present invention shall still fall within the scope of the present invention.

Claims

1. A centralized control method for a photovoltaic energy storage air conditioner, characterized in that, Includes the following steps: After the air conditioner is powered on, it acquires the status of each power supply component and determines the power supply status before starting operation. It acquires the output DC voltage VDC1 of the solar photovoltaic module and determines whether the DC voltage VDC1 is greater than or equal to the preset voltage value V. st : If VDC1≥V st It is determined that the system will operate in the first power supply state, with the photovoltaic modules providing independent power. If VDC1 < V st Obtain the status information of the battery pack and determine whether the power supply to the air conditioning unit is sufficient based on the status information: If the conditions are met, the system will operate in the third power supply state, where the battery pack is independently powered. If the conditions are not met, the system will operate under the fifth power supply state, which is independently powered by the municipal power grid. When the air conditioner is running, the maximum output power P of the solar photovoltaic modules is used. pv The maximum output power P of the battery assembly batout The output power P of the municipal power grid ac Power required by the air conditioning unit P need Make a judgment to switch the power supply state, so that the total output power of the determined power supply state is greater than or equal to the power P required by the air conditioning unit. need ; When the air conditioning unit is running in the first power supply state, compare P pv and P need : When P pv ≥P need At that time, maintain operation in the first power supply state; When P pv <P need At that time, the status information of the battery pack is obtained, and the battery pack is used to determine whether it can supply power. If the battery pack can supply power, it enters the second power supply state where the solar photovoltaic modules and the battery pack supply power simultaneously; if the battery pack cannot supply power, it enters the fourth power supply state where the solar photovoltaic modules and the mains grid supply power simultaneously. When the air conditioning unit is operating in the second power supply state, the following steps are also included: Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st2 : If VDC1 > V st2 It maintains operation in a second power supply state where both solar photovoltaic modules and battery modules are powered simultaneously. If VDC1≤V st2 The system was determined to be unable to supply power due to insufficient output voltage from the solar photovoltaic modules. Based on the status information of the battery modules, it was determined whether the current battery pack could supply power independently. When the current battery pack cannot supply power independently, it enters the sixth power supply state, in which the battery pack and the mains power grid supply power simultaneously. When the current battery pack is capable of supplying power independently, it enters the third power supply state where the battery pack supplies power independently.

2. The centralized control method for a photovoltaic energy storage air conditioner according to claim 1, characterized in that, The air conditioning unit, during operation, also includes the following steps: When the air conditioning unit is operating in the first power supply state where the solar photovoltaic modules are independently powered: Calculate the required power P of the air conditioning unit based on the target operating frequency of the variable frequency air conditioning compressor. need ; The maximum power point tracking algorithm is run to control the switching frequency and duty cycle of the switching transistor K1 in the first Boost converter circuit, so that the solar photovoltaic module outputs power at the maximum power point. The maximum output power P of the solar photovoltaic module is calculated based on the output DC voltage VDC1 and current I1. pv ; Compare P pv and P need : When P pv ≥P need When the second switch on the mains power grid side is disconnected, the first power supply state is maintained. By controlling the switching frequency and duty cycle of the switch transistor K1, the DC voltage VDC1 is boosted to the output voltage VDC2. The output voltage VDC2 supplies power to the DC bus voltage through the diode D1. When P pv <P need At that time, the status information of the battery pack is obtained, and the battery pack is used to determine whether it can supply power. If the battery pack can supply power, the charging and discharging circuit module is controlled to discharge, entering a second power supply state where the solar photovoltaic module and battery module are simultaneously powered. The power supply current I6 of the charging and discharging circuit module is controlled to ensure that the power supply P... batout +P pv ≥P need ; If the battery pack cannot supply power, the system enters a fourth power supply state where the solar photovoltaic modules and the mains grid supply power simultaneously. The switching frequency and duty cycle of switch K1 are controlled to ensure that the DC bus voltage VDC5 is higher than the rectified DC voltage VDC3 of the mains grid AC power. Then, the second switch on the mains grid side is closed, and the switching frequency and duty cycle of switch K2 are controlled to ensure that the second Boost circuit outputs a suitable output voltage VDC4. This output voltage VDC4 gradually increases the output current I4 on the mains grid side. By coordinating the switching frequencies and duty cycles of switch K1 and switch K2, the power supply P is increased. ac +P pv ≥P need .

3. The centralized control method for a photovoltaic energy storage air conditioner according to claim 2, characterized in that, The air conditioning unit, during operation, also includes the following steps: When the air conditioning unit operates in the second power supply state, where both the solar photovoltaic modules and the battery modules are powered simultaneously, compare P pv and P need : When P pv ≥P need When the battery module is not supplying power, the control charging and discharging circuit module does not work, and the system enters the first power supply state where the solar photovoltaic module is independently powered. When P pv <P need At this time, the charging and discharging circuit module is in discharging operation, maintaining the second power supply state, so that the power P supplied by the battery pack to the air conditioner is... batout Satisfy P batout +P pv >P need .

4. The centralized control method for a photovoltaic energy storage air conditioner according to claim 1, characterized in that, The air conditioning unit also includes the following steps during operation: When the air conditioning unit operates in the third power supply state where the battery pack is independently powered: Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st : If VDC1 > V st If the solar photovoltaic module is ready to supply power, the first switch on the solar photovoltaic module side is closed. By controlling the switching frequency and duty cycle of the switch tube K1, the DC voltage VDC1 is boosted to the output voltage VDC2. The output voltage VDC2 supplies power to the DC bus voltage through the diode D1. The current I2 is increased by controlling VDC2. Within the allowable range, the power supply of the solar photovoltaic module is maximized. At this time, the second power supply state in which the solar photovoltaic module and the battery module supply power simultaneously is entered. If VDC1≤V st The system was determined to be unable to supply power due to insufficient output voltage from the solar photovoltaic modules. Based on the status information of the battery modules, it was determined whether the current battery pack could supply power independently. If the current battery pack can supply power independently, then maintain the third power supply state. When the current battery pack cannot provide independent power, the charging and discharging circuit module is controlled to ensure that the DC bus voltage VDC5 is higher than the rectified DC voltage VDC3 of the AC power from the mains grid. Then, the second switch on the mains grid side is closed, controlling the switching frequency and duty cycle of the switching transistor K2, so that the second Boost circuit outputs a suitable output voltage VDC4. This output voltage VDC4 gradually increases the output current I4 on the mains grid side. The power output P of the mains power supply is calculated based on the DC voltage VDC3 and the current I3. ac By coordinating and controlling the switching frequency and duty cycle of the charging and discharging circuit module and the switching transistor K2, P... batout +P ac ≥P need At this point, it enters the sixth power supply state, where the battery pack and the mains grid supply power simultaneously.

5. The centralized control method for a photovoltaic energy storage air conditioner according to claim 1, characterized in that, The air conditioning unit, during operation, also includes the following steps: When the air conditioning unit operates in the fourth power supply state, where both solar photovoltaic modules and the mains power grid are simultaneously supplying power: Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st2 : If VDC1≤V st2 The system was determined to be unable to supply power due to insufficient output voltage from the solar photovoltaic modules. The status information of the battery modules was then used to determine whether the current battery pack could provide power. When the battery pack is currently in a state where it can supply power, the charging and discharging circuit module is controlled to enter the discharging operation, boosting the output voltage to the DC bus voltage VDC5 to supply power to the DC bus, while simultaneously controlling the output current I6 to ensure that the power supply P... ac +P batout ≥P need Disconnect the first switch on the solar photovoltaic module side, and the solar photovoltaic module will no longer supply power, entering the sixth power supply state where the battery module and the mains grid supply power simultaneously; When the current battery pack is unable to supply power, disconnect the first switch on the solar photovoltaic module side and stop the operation of the charging and discharging circuit module. Control the switching frequency and duty cycle of the switch transistor K2 to make the output of the second Boost boost circuit a suitable output voltage VDC4, so that the AC mains current I4 gradually increases and enters the fifth power supply state of independent power supply from the mains grid. If VDC1 > V st2 Then compare P pv With P need : If P pv ≥P need Disconnect the second switch on the mains power grid side and enter the first power supply state where the solar photovoltaic modules are independently powered; If P pv <P need Based on the status information sent by the battery management module, it determines whether the battery pack can supply power: when the battery pack can supply power, it enters the second power supply state where the solar photovoltaic module and the battery module supply power simultaneously; when the battery pack cannot supply power, it maintains the fourth power supply state where the solar photovoltaic module and the mains grid supply power simultaneously.

6. The centralized control method for a photovoltaic energy storage air conditioner according to claim 1, characterized in that, The air conditioning unit, during operation, also includes the following steps: When the air conditioning unit is operating under the fifth power supply state of independent power supply from the municipal power grid: Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st : If VDC1 > V st If the solar photovoltaic module is ready to supply power, the first switch on the solar photovoltaic module side is closed. By controlling the switching frequency and duty cycle of the switch tube K1, the DC voltage VDC1 is boosted to the output voltage VDC2. The output voltage VDC2 supplies power to the DC bus voltage through the diode D1. The current I2 is increased by controlling VDC2. Within the allowable range, the power supply of the solar photovoltaic module is maximized. At this time, the fourth power supply state, in which the solar photovoltaic module and the mains grid supply power simultaneously, is entered. If VDC1≤V st The system was determined to be unable to supply power due to insufficient output voltage from the solar photovoltaic modules. The status information of the battery modules was then used to determine whether the current battery pack could provide power. If the battery pack can provide power, the charging and discharging circuit module is controlled to enter the discharging operation, boosting the output voltage of the battery pack to the DC bus voltage VDC5 and supplying power to the DC bus. Simultaneously, the power supply current I6 is controlled to ensure that the power supply P... batout +P ac ≥P need ; If the battery pack is unable to supply power, it will continue to operate in the fifth power supply state, which is independently powered by the municipal power grid.

7. The centralized control method for a photovoltaic energy storage air conditioner according to claim 1, characterized in that, The air conditioning unit also includes the following steps during operation: When the air conditioning unit operates in the sixth power supply state, where both the battery pack and the mains power grid are powered simultaneously: Compare the DC voltage VDC1 of the solar photovoltaic module with the preset voltage value V. st : If VDC1 > V st If the solar photovoltaic module is ready to supply power, the first switch on the solar photovoltaic module side is closed. By controlling the switching frequency and duty cycle of the switch tube K1, the DC voltage VDC1 is boosted to the output voltage VDC2. The output voltage VDC2 supplies power to the DC bus voltage through the diode D1. The current I2 is increased by controlling VDC2. Within the allowable range, the power supply of the solar photovoltaic module is maximized. The second switch on the mains grid side is then disconnected, and the mains grid no longer supplies power. At this time, the system enters the second power supply state where the solar photovoltaic module and the battery module are powered simultaneously. If VDC1≤V st If the solar photovoltaic module is determined to have insufficient output voltage and is unable to supply power, then the status information of the battery module is used to determine whether the current battery pack can continue to supply power. If the battery pack can still provide power, then the sixth power supply state will be maintained. When the battery pack can no longer supply power, the charging and discharging circuit modules will stop working and the system will enter the fifth power supply state, where it will be powered independently by the municipal power grid.

8. The centralized control method for a photovoltaic energy storage air conditioner according to claim 1, characterized in that, It also includes the steps for the battery assembly to enter the charging state: When the battery management module of the battery pack detects that the battery pack needs charging and allows it to charge, it enters the charging state after one of the following conditions is met: a: When the solar photovoltaic module is in an independent power supply state, and the power P that the solar photovoltaic module can provide is... pv > Power required by the air conditioner P need Then, the solar photovoltaic modules charge the battery, and the charging and discharging circuit module enters charging mode, reducing the DC bus voltage to the battery pack voltage to charge the battery pack, while controlling the charging current to ensure that the charging power P is sufficient. batin +P need <P pv ; b: When the municipal power grid is in a period of low electricity price, the control charging and discharging circuit module enters charging mode, and supplies power to the battery pack while ensuring the normal operation of the air conditioning unit.

9. A centralized control device for a photovoltaic energy storage air conditioner, characterized in that, A centralized control method for implementing a photovoltaic energy storage air conditioner as described in any one of claims 1-8, wherein the photovoltaic energy storage air conditioner includes a solar photovoltaic module, a battery module, a municipal power grid, and an air conditioning unit; The air conditioning unit has an inverter that drives the compressor and internal load, and the inverter is electrically connected to the DC bus through a capacitor. The solar photovoltaic module and the mains power grid respectively boost the output voltage to a preset voltage through a first boost boost circuit and a second boost boost circuit to supply power to the DC bus. The battery module has a charging and discharging circuit module, a battery management module and a battery pack. The charging and discharging circuit module is connected to the DC bus so that the solar photovoltaic module charges the battery pack or the battery pack supplies power to the DC bus.

10. A centralized control device for a photovoltaic energy storage air conditioner according to claim 9, characterized in that: The solar photovoltaic module is electrically connected to the first Boost circuit via a first switch. The output DC voltage VDC1 and current I1 enter the first Boost circuit and are boosted to the output voltage VDC2 by the first Boost circuit. The first Boost circuit includes an inductor L1, a switch K1, and a diode D1. The diode D1 is connected to the positive terminal of the capacitor C. The voltage between the positive and negative terminals of the capacitor C is the DC bus voltage VDC5. The output voltage VDC2 is supplied by the diode D1 to the DC bus voltage VDC5, and the current is I2.

11. The centralized control device for a photovoltaic energy storage air conditioner according to claim 9, characterized in that: The mains power grid is electrically connected to the second Boost circuit via a second switch and a rectifier bridge. The output AC power is rectified by the rectifier bridge into DC voltage VDC3 and current I3, which then enters the second Boost circuit and is boosted to the output voltage VDC4. The second Boost circuit includes an inductor L2, a switch K2, and a diode D2. The diode D2 is connected to the positive terminal of a capacitor C. The voltage between the positive and negative terminals of capacitor C is the DC bus voltage VDC5. The output voltage VDC4 is supplied by diode D2 to the DC bus voltage VDC5, with a current of I4.

12. The centralized control device for a photovoltaic energy storage air conditioner according to claim 9, characterized in that: The battery assembly is connected to the positive terminal of capacitor C through a charging and discharging circuit module. The voltage between the positive and negative terminals of capacitor C is the DC bus voltage VDC5. When the battery pack is discharging, the charging and discharging circuit module boosts the voltage of the battery pack to the DC bus voltage VDC5 to supply power to the DC bus voltage. When the battery pack is charging, the charging and discharging circuit module steps down the DC bus voltage VDC5 to the battery pack voltage V. bat To charge the battery pack.

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