Photovoltaic multi-split air conditioner control method and device, photovoltaic multi-split air conditioner and storage medium

Abstract

The invention relates to a photovoltaic multi-split air conditioner control method and device, a photovoltaic multi-split air conditioner and a storage medium. The method comprises the following steps: monitoring the photovoltaic output power of a photovoltaic module and the load demand quantity of the photovoltaic multi-split air conditioner; determining a compressor combination matched with the photovoltaic output power; under the condition that the currently determined compressor combination is different from the previously determined compressor combination, switching to the currently determined compressor combination and starting running; and in the process of running the currently determined compressor combination, the running number of the compressors in the currently determined compressor combination is adjusted according to the monitored photovoltaic output power and the load demand quantity. The appropriate compressor combination is automatically matched according to the photovoltaic output power and the load demand quantity, and the operation number of the compressors is adjusted according to the fluctuation of the photovoltaic output power, so that the fluctuation of the photovoltaic output power is dealt with, the system is enabled to stably operate under the optimal energy efficiency all the time, and the energy efficiency of the system is improved. And therefore, an energy-saving and efficient photovoltaic multi-split air conditioner control mode is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent control, and in particular to a control method and device of a photovoltaic multi-inverter, a photovoltaic multi-inverter and a storage medium. BACKGROUND

[0002] With the continuous development of renewable energy, the application scenarios of photovoltaic multi-inverters are increasingly widespread. However, in real scenarios, photovoltaic output power is greatly affected by factors such as light intensity and weather changes, and has significant volatility and uncertainty. In a traditional photovoltaic multi-inverter, a single specification compressor is usually used, and the compressor specifications in the photovoltaic multi-inverter may all be high-power compressors or may all be low-power compressors. When the photovoltaic output power is insufficient, the high-power compressors will not be able to operate normally due to insufficient photovoltaic output power, and even cause the photovoltaic multi-inverter system to shut down. When the photovoltaic output power is excessive, the low-power compressors will operate inefficiently, causing waste of photovoltaic energy. Therefore, the traditional photovoltaic multi-inverter will have reduced system operation stability due to the inability to cope with the fluctuations in photovoltaic output power. SUMMARY

[0003] The present application provides a control method and device of a photovoltaic multi-inverter, a photovoltaic multi-inverter and a storage medium to solve the problem of reduced system operation stability of the traditional photovoltaic multi-inverter due to the inability to cope with fluctuations in photovoltaic output power.

[0004] To solve the above technical problems, the technical solution of the present application is as follows: The present application provides a control method of a photovoltaic multi-inverter, comprising: monitoring photovoltaic output power of a photovoltaic module and load demand of a photovoltaic multi-inverter; determining a compressor combination matched with the photovoltaic output power; wherein the compressor combination comprises at least one compressor; the compressors in the same compressor combination have the same specifications; the compressors in different compressor combinations have different specifications; in the case that the currently determined compressor combination is different from the previously determined compressor combination, switching to the currently determined compressor combination and starting operation; in the process of operating the currently determined compressor combination, adjusting the number of compressors in operation in the currently determined compressor combination according to the monitored photovoltaic output power and load demand.

[0005] The determining the compressor combination matched with the photovoltaic output power comprises: determining a power interval corresponding to the photovoltaic output power; wherein a first power interval, a third power interval and a second power interval are sequentially preset in ascending order of end value; in a case where the photovoltaic output power corresponds to the first power interval, determining a first compressor combination corresponding to the first power interval as the compressor combination matched with the photovoltaic output power; wherein the first compressor combination comprises at least one compressor with a first rated power; in a case where the photovoltaic output power corresponds to the second power interval, determining a second compressor combination corresponding to the second power interval as the compressor combination matched with the photovoltaic output power; wherein the second compressor combination comprises at least one compressor with a second rated power; the first rated power is less than the second rated power; in a case where the photovoltaic output power corresponds to the third power interval, determining a compressor combination determined at a previous time as the compressor combination matched with the photovoltaic output power.

[0006] Before the determining the power interval corresponding to the photovoltaic output power, the method further comprises: determining a rated power of the first compressor combination; determining the second power interval according to the rated power of the first compressor combination and a preset first safety coefficient; wherein a minimum end value of the second power interval is greater than the rated power of the first compressor combination; determining a rated power of the second compressor combination; determining the first power interval according to the rated power of the second compressor combination and a preset second safety coefficient; wherein a maximum end value of the first power interval is less than the rated power of the second compressor combination.

[0007] The determining the power interval corresponding to the photovoltaic output power comprises: querying a power interval determined at a previous time and a hysteresis interval corresponding to the power interval; wherein the hysteresis interval refers to a substantial response interval corresponding to the power interval; in a case where the photovoltaic output power is in the hysteresis interval, determining the power interval corresponding to the photovoltaic output power as the power interval determined at the previous time; in a case where the photovoltaic output power is not in the hysteresis interval, determining the power interval corresponding to the photovoltaic output power as a power interval currently occupied by the photovoltaic output power.

[0008] The determining the compressor combination matched with the photovoltaic output power comprises: for each compressor combination, calculating a performance coefficient of the compressor combination according to the load demand and input power corresponding to the compressor combination; collecting a current ambient temperature; inputting the photovoltaic output power, the load demand, the ambient temperature, and the performance coefficient, rated power and compressor quantity corresponding to each compressor combination respectively into a pre-trained energy efficiency evaluation model, and obtaining the compressor combination matched with the photovoltaic output power output by the energy efficiency evaluation model.

[0009] The adjusting the number of compressors in operation in the compressor combination according to the monitored photovoltaic output power and the load demand comprises: determining a change rate of the photovoltaic output power of the photovoltaic module in each preset adjustment time period; in a case where the change rate of the photovoltaic output power is negative and the load demand is greater than a preset first demand threshold, determining a compressor adjustment amount according to the change rate of the photovoltaic output power, and reducing the number of compressors in operation in the compressor combination according to the compressor adjustment amount; in a case where the change rate of the photovoltaic output power is positive and the load demand is less than a preset second demand threshold, determining a compressor adjustment amount according to the change rate of the photovoltaic output power, and increasing the number of compressors in operation in the compressor combination according to the compressor adjustment amount.

[0010] The determining the compressor adjustment amount according to the change rate of the photovoltaic output power comprises: determining a change speed level to which the change rate of the photovoltaic output power belongs and determining an adjustment amount corresponding to the change speed level.

[0011] The application embodiment provides a control device of a photovoltaic multi-connected air conditioner, comprising: a monitoring unit configured to monitor a photovoltaic output power of a photovoltaic module and a load demand of the photovoltaic multi-connected air conditioner; a determining unit configured to determine a compressor combination matched with the photovoltaic output power; wherein the compressor combination comprises at least one compressor; the compressors in the same compressor combination have the same specifications; the compressors in different compressor combinations have different specifications; a switching unit configured to switch to the currently determined compressor combination and start running in a case where the currently determined compressor combination is different from a previously determined compressor combination; and an adjusting unit configured to adjust the number of compressors in operation in the currently determined compressor combination according to the monitored photovoltaic output power and the load demand in a process of running the currently determined compressor combination.

[0012] The embodiment of the present application provides a photovoltaic multi-inverter, comprising: at least one communication interface; at least one bus connected with the at least one communication interface; at least one processor connected with the at least one bus; at least one memory connected with the at least one bus, wherein the processor is configured to execute a control program of the photovoltaic multi-inverter stored in the memory to realize the control method of the photovoltaic multi-inverter.

[0013] The embodiment of the present application provides a computer readable storage medium, the computer readable storage medium stores computer executable instructions, the computer executable instructions are executed to realize the control method of the photovoltaic multi-inverter.

[0014] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art: the method provided by the embodiment of the present application can monitor the photovoltaic output power of the photovoltaic module and the load demand of the photovoltaic multi-inverter; determine a compressor combination matched with the photovoltaic output power; wherein the compressor combination comprises at least one compressor; the compressors in the same compressor combination are of the same specification; the compressors in different compressor combinations are of different specifications; in the case that the current determined compressor combination is different from the previous determined compressor combination, switch to the current determined compressor combination and start running; in the process of running the current determined compressor combination, adjust the number of compressors running in the current determined compressor combination according to the monitored photovoltaic output power and load demand. The embodiment of the present application automatically matches the appropriate compressor combination according to the photovoltaic output power and the load demand, and adjusts the number of compressors running according to the fluctuation of the photovoltaic output power, thereby coping with the fluctuation of the photovoltaic output power, so that the system always runs stably at the optimal energy efficiency, thereby realizing an energy-saving and efficient photovoltaic multi-inverter control mode. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings incorporated in and forming a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows, and obviously, other drawings can also be obtained by those skilled in the art without creative labor under the premise of these drawings.

[0017] One or more embodiments are illustrated by way of example in the drawings and described herein in connection with the appended drawings, which are not necessarily drawn to scale, wherein like references numerals refer to like elements, and in which, as a matter of

[0018] Figure 1 A flow chart of a control method of a photovoltaic multi-inverter according to an embodiment of the present application; Figure 2 A flow chart of a step of determining a compressor combination according to an embodiment of the present application; Figure 3 A flow chart of a step of determining a compressor combination according to another embodiment of the present application; Figure 4 A flow chart of a step of adjusting a number of compressors according to an embodiment of the present application; Figure 5 A structure diagram of a control device of a photovoltaic multi-inverter according to an embodiment of the present application; Figure 6 A structure diagram of a control device of a photovoltaic multi-inverter according to an embodiment of the present application. DETAILED DESCRIPTION

[0019] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, any other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0020] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplification, the components and arrangements of the specific examples are described in the following. Of course, they are only examples and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to the reference numerals and / or letters in different examples. Such repetition is for the purpose of simplification and clarity, and it does not indicate the relationship between the various embodiments and / or arrangements discussed.

[0021] The embodiments of the present application provide a control method of a photovoltaic multi-inverter. As shown in Figure 1 A flow chart of a control method of a photovoltaic multi-inverter according to an embodiment of the present application.

[0022] Step S110, monitoring a photovoltaic output power of a photovoltaic module and a load demand of the photovoltaic multi-inverter.

[0023] The photovoltaic output power refers to the instantaneous electric power generated by the photovoltaic module under the light condition. The photovoltaic output power can determine the available energy of the system.

[0024] The photovoltaic multi-in-one refers to an intelligent cold and heat supply system based on solar photovoltaic power generation.

[0025] The load demand refers to the rated power sum of the indoor units in the starting state in the photovoltaic multi-in-one. The rated power can also be referred to as the single-machine power.

[0026] In the embodiment of the present application, the photovoltaic output power of the photovoltaic module and the load demand of the photovoltaic multi-in-one can be monitored every preset monitoring period.

[0027] In step S120, a compressor combination matched with the photovoltaic output power is determined. The compressor combination includes at least one compressor. The compressors in the same compressor combination have the same specifications. The compressors in different compressor combinations have different specifications.

[0028] The compressor combination refers to a combination formed by at least one compressor.

[0029] The specification of the compressor refers to the rated power of the compressor. For example, one compressor combination includes multiple compressors with A power, and another compressor combination includes one compressor with B power.

[0030] In step S130, when the currently determined compressor combination is different from the previously determined compressor combination, the currently determined compressor combination is switched to and started to run.

[0031] The currently determined compressor combination is switched to and all the compressors or a part of the number of compressors in the compressor combination are run.

[0032] In step S140, during the running of the currently determined compressor combination, the number of the running compressors in the currently determined compressor combination is adjusted according to the monitored photovoltaic output power and the load demand.

[0033] The number of the running compressors refers to the number of the compressors in the starting state.

[0034] Since the photovoltaic output power changes with the change of the light, during the running of the compressor combination, the number of the compressors in the starting state in the compressor combination can be adjusted every preset adjustment period according to the monitored photovoltaic output power and the current load demand.

[0035] In the embodiment of the present application, the photovoltaic output power of the photovoltaic module and the load demand of the photovoltaic multi-inverter can be monitored; a compressor combination matching the photovoltaic output power is determined; wherein the compressor combination comprises at least one compressor; the compressors in the same compressor combination have the same specifications; the compressors in different compressor combinations have different specifications; in the case that the currently determined compressor combination is different from the previously determined compressor combination, the currently determined compressor combination is switched to and started to operate; in the process of operating the currently determined compressor combination, the number of operating compressors in the currently determined compressor combination is adjusted according to the monitored photovoltaic output power and load demand. The embodiment of the present application automatically matches the appropriate compressor combination according to the photovoltaic output power and load demand, and adjusts the number of operating compressors according to the fluctuation of the photovoltaic output power, so as to cope with the fluctuation of the photovoltaic output power, so that the system can always operate stably at the optimal energy efficiency, thereby realizing an energy-saving and efficient photovoltaic multi-inverter control mode.

[0036] In order to make the embodiment of the present application easier to understand, the control method of the photovoltaic multi-inverter of the embodiment of the present application is further described below.

[0037] The control method of the photovoltaic multi-inverter of the embodiment of the present application can be deployed in the photovoltaic multi-inverter.

[0038] The photovoltaic multi-inverter comprises a control unit, a monitoring unit, a photovoltaic module, an energy storage device, a plurality of indoor units, a plurality of compressors and a cold-heat exchange device. The plurality of compressors are compressors with different power specifications, such as a small compressor with a power of 3kW and a large compressor with a power of 10kW. The control unit is used to execute the control method of the photovoltaic multi-inverter of the embodiment of the present application.

[0039] The monitoring unit is used to monitor the photovoltaic output power of the photovoltaic module and the load demand of the photovoltaic multi-inverter under the control of the control unit. The monitoring unit comprises a plurality of sensors, which can comprise a photovoltaic monitoring sensor and a temperature sensor.

[0040] Although the photovoltaic multi-inverter comprises an energy storage device, the capacity of the energy storage device is limited, and the power required by the compressor with a large rated power is often much larger than the power that can be provided by the energy storage device, that is, the energy storage device cannot meet the starting demand of the large-power compressor. The current energy storage device does not have a dynamic matching and cooperative control logic, and when the energy storage device provides power, it can preferentially supply power to other loads outside the compressor, such as the main board, lighting circuit, etc., rather than preferentially supporting the compressor. The photovoltaic output power has fluctuation, and the energy provided by the energy storage device has a certain hysteresis, which will result in that the photovoltaic power cannot be quickly responded when it suddenly drops. Therefore, the embodiment of the present application adopts the mode of dynamically matching the compressor combination to cope with the fluctuation of the photovoltaic output power.

[0041] In the embodiments of the present application, in order to dynamically match compressors of different specifications to adapt to the output power of the photovoltaic system, increase the energy efficiency of the system, and avoid the problems of power surplus or power shortage, the output power of the photovoltaic module and the load demand of the photovoltaic multi-inverter can be monitored once every preset monitoring time period after the photovoltaic multi-inverter is started.

[0042] The length of the monitoring time period can be an empirical value or a value obtained through experiments.

[0043] In the embodiments of the present application, after the output power of the photovoltaic system and the load demand are monitored each time, a compressor combination matched with the output power of the photovoltaic system can be determined.

[0044] The compressor combination includes at least one compressor; the compressors in the same compressor combination have the same specifications; and the compressors in different compressor combinations have different specifications.

[0045] Two ways of determining the compressor combination matched with the output power of the photovoltaic system are provided below, and the way of determining the compressor combination matched with the output power of the photovoltaic system is not limited thereto.

[0046] In the first way, a plurality of power intervals are used to determine the compressor combination matched with the output power of the photovoltaic system.

[0047] Before the power interval corresponding to the output power of the photovoltaic system is determined, a first power interval, a third power interval, and a second power interval can be sequentially arranged from small to large according to the end value; the first power interval corresponds to a first compressor combination; the third power interval is a buffer interval and does not have a corresponding compressor combination; and the second power interval corresponds to a second compressor combination.

[0048] The first power interval is a low-power interval, which corresponds to the power range of small compressors. The second power interval is a high-power interval, which corresponds to the power range of large compressors. The third power interval is a transition interval, which is located between the first power interval and the second power interval. In the transition interval, the system maintains the compressor combination of the previous state. For example, the first power interval is , the third power interval is , and the second power interval is .

[0049] The first compressor combination is a small compressor combination composed of one or more compressors with small rated power. The second compressor combination is a large compressor combination composed of one or more compressors with large rated power.

[0050] Further, the rated power of the first compressor combination can be determined; and the second power interval can be determined according to the rated power of the first compressor combination and a preset first safety coefficient; wherein the minimum end value of the second power interval is greater than the rated power of the first compressor combination.

[0051] The rated power of the first compressor combination is the sum of the rated power of each compressor in the first compressor combination.

[0052] The first safety coefficient is a coefficient for providing power margin. Through the first safety coefficient, the minimum end value of the second power interval can be slightly higher than the total power (rated power) of the first compressor combination, ensuring that the second compressor combination starts when the photovoltaic power is sufficient and avoiding overloading of the first compressor combination.

[0053] For example, the second power interval is The boundary value D of the second power interval can be calculated according to the following formula: D=A×(1+first safety coefficient); wherein A is the rated power of the first compressor combination. For example, the rated power A of the small compressor combination is 3kW, and the first safety coefficient is 10%, so D=6.6kW. The boundary value refers to the end value of the interval.

[0054] Further, the rated power of the second compressor combination can be determined; and the first power interval can be determined according to the rated power of the second compressor combination and a preset second safety coefficient; wherein the maximum end value of the first power interval is less than the rated power of the second compressor combination.

[0055] The rated power of the second compressor combination is the sum of the rated power of each compressor in the second compressor combination.

[0056] The second safety coefficient is also a coefficient for providing power margin. Through the second safety coefficient, the maximum end value of the first power interval can be slightly lower than the rated power of the second compressor combination, ensuring that the second compressor combination will not be shut down due to insufficient photovoltaic output power. The second safety coefficient and the first safety coefficient are the same or different.

[0057] For example, the first power interval is The boundary value C of the first power interval can be calculated according to the following formula: C=B×(1-second safety coefficient); wherein B is the rated power of the second compressor combination; for example, if the rated power B of the large compressor combination is 10kW, and the second safety coefficient is 10%, then C=9kW.

[0058] After the boundary values of the first power interval and the second power interval are determined, the boundary values of the third power interval can be determined.

[0059] Figure 2 This is a flowchart illustrating the steps of determining a compressor assembly according to an embodiment of this application.

[0060] Step S210: Determine the power range corresponding to the photovoltaic output power; wherein, a first power range, a third power range, and a second power range are pre-set in ascending order of terminal value.

[0061] The power range corresponding to photovoltaic output power refers to the power range in which the photovoltaic output power is located or is equivalent to the power range in which it is located. The power range in which the photovoltaic output power is equivalent to the power range in which it is located refers to the power range corresponding to the hysteresis range in which the photovoltaic output power is located.

[0062] The hysteresis range refers to the actual response range corresponding to a power range. Different hysteresis ranges can be set for different power ranges. The first and second power ranges use narrow hysteresis to ensure fast response. The third power range uses wide hysteresis to avoid frequent switching. Narrow hysteresis means the power range includes the hysteresis range. Wide hysteresis means the hysteresis range includes the power range.

[0063] For example: first power range Second power range Both are low fluctuation ranges. The hysteresis width can be set to ±0.5kW and the hysteresis type to narrow hysteresis. Therefore, with C=9kW, the hysteresis range corresponding to the first power range is... (Unit: kW), with D = 10kW, the hysteresis interval corresponding to the second power range is: (Unit: kW).

[0064] For example: the third power range For the high fluctuation range, the hysteresis width can be set to ±1kW and the hysteresis type to wide hysteresis. Then, with C=9kW and D=10kW, the hysteresis range corresponding to the third power range is... (Unit: kW) Thus, when the photovoltaic output power is... When fluctuations occur, the system maintains its current operating state.

[0065] Further, query the previously determined power range and its corresponding hysteresis range; wherein, the hysteresis range refers to the actual response range corresponding to the power range; if the photovoltaic output power is within the hysteresis range, determine the power range corresponding to the photovoltaic output power as the previously determined power range; if the photovoltaic output power is not within the hysteresis range, determine the power range corresponding to the photovoltaic output power as the power range in which the photovoltaic output power is currently located.

[0066] In the embodiment of the present application, different hysteresis intervals are set for different power intervals. After it is determined that the photovoltaic output power is in a power interval, subsequent monitoring of the photovoltaic output power can be performed. As long as it is determined that the current photovoltaic output power is in the hysteresis interval corresponding to the power interval, it can be considered that the current photovoltaic output power is still in the power interval, thereby maintaining the original state and avoiding frequent switching of the compressor combination. The problem of frequent oscillation start and stop of the compressor combination caused by slight fluctuation of the photovoltaic output power is eliminated, the system stability is improved, and the mechanical life of the equipment is prolonged.

[0067] In step S220, it is determined whether the photovoltaic output power corresponds to the first power interval. If yes, step S230 is performed; if no, step S240 is performed.

[0068] In step S230, in a case where it is determined that the photovoltaic output power corresponds to the first power interval, it is determined that the first compressor combination corresponding to the first power interval is the compressor combination matched with the photovoltaic output power (for example, a small compressor combination).

[0069] The first compressor combination includes at least one compressor with a first rated power.

[0070] In step S240, it is determined whether the photovoltaic output power corresponds to the second power interval. If yes, step S250 is performed; if no, step S260 is performed.

[0071] In step S250, in a case where it is determined that the photovoltaic output power corresponds to the second power interval, it is determined that the second compressor combination corresponding to the second power interval is the compressor combination matched with the photovoltaic output power (for example, a large compressor combination).

[0072] The second compressor combination includes at least one compressor with a second rated power; the first rated power is less than the second rated power.

[0073] In step S260, in a case where it is determined that the photovoltaic output power corresponds to the third power interval, it is determined that the compressor combination determined last time is the compressor combination matched with the photovoltaic output power.

[0074] In order to avoid the problem of frequent switching of the compressor combination, resulting in unstable system and affecting the service life of the equipment, the embodiment of the present application provides a rapid decision based on the power interval and the hysteresis interval. According to the power interval in which the photovoltaic output power is located and in combination with the hysteresis logic, it is quickly determined whether the small compressor or the large compressor is used, or the original state is maintained. In this way, the basic stability and response speed of the system can be ensured.

[0075] The second mode is to use a pre-trained energy efficiency evaluation model to determine the compressor combination matched with the photovoltaic output power.

[0076] As shown in the flow chart of the determination step of the compressor combination according to another embodiment of the present application. Figure 3

[0077] In step S310, for each compressor combination, the coefficient of performance (COP) of the compressor combination is calculated according to the load demand and the input power corresponding to the compressor combination.

[0078] The input power corresponding to the compressor combination refers to the sum of the input powers of the compressors in each starting state in the compressor combination.

[0079] The load demand can be divided by the input power corresponding to the compressor combination, and the quotient obtained is taken as the coefficient of performance of the compressor combination.

[0080] In step S320, the current ambient temperature is collected. Currently, this step can also be performed before step S310.

[0081] In step S330, the photovoltaic output power, the load demand, the ambient temperature, and the coefficients of performance, rated powers, and compressor numbers corresponding to each compressor combination are input into a pre-trained energy efficiency evaluation model, and the compressor combination matched with the photovoltaic output power output by the energy efficiency evaluation model is obtained.

[0082] Because the conventional photovoltaic multi-inverter lacks an effective response mechanism for photovoltaic output power fluctuations, it cannot realize intelligent matching of the operating state of the compressor, resulting in a low overall energy efficiency of the system and a low energy utilization rate. Therefore, an energy efficiency evaluation model for determining the compressor combination matched with the photovoltaic output power is provided in the embodiments of the present application. The objective function of the energy efficiency evaluation unit is to maximize the system energy efficiency, so that the system obtains the optimal energy efficiency under the premise of stable operation, and meets the load demand while obtaining the optimal energy efficiency. In this way, the energy efficiency evaluation model is introduced, and multiple factors such as power, load, and ambient temperature are comprehensively considered to select the optimal energy efficiency scheme from multiple selectable compressor combinations, so as to maximize the economic operation level of the system.

[0083] In the embodiments of the present application, after the compressor combination matched with the photovoltaic output power is determined, the currently determined compressor combination can be compared with the previously determined compressor combination. In the case where the currently determined compressor combination is different from the previously determined compressor combination, the currently determined compressor combination is switched to and starts to operate. ​When it is determined that the current photovoltaic output power is in the first power interval, it can be determined that the compressor combination matched with the photovoltaic output power is changed to the first compressor combination, at this time, the second compressor combination can be closed, and the first compressor combination with smaller rated power is operated, so as to avoid that the compressors in the second compressor combination with larger rated power are stopped due to insufficient photovoltaic output power.

[0084] When it is determined that the current photovoltaic output power is in the second power interval, it can be determined that the compressor combination matched with the photovoltaic output power is changed to the second compressor combination, at this time, the first compressor combination can be closed, and the second compressor combination with larger rated power is operated, so as to switch to the second compressor combination with larger rated power when the photovoltaic output power is sufficient, and then the system energy efficiency can be improved.

[0085] In the embodiments of the present application, after switching to the currently determined compressor combination and starting to operate, the number of operating compressors in the currently determined compressor combination can be adjusted according to the monitored photovoltaic output power and the load demand during the operation of the currently determined compressor combination.

[0086] As shown in FIG. 5, it is a flow chart of the step of adjusting the number of operating compressors according to an embodiment of the present application. Figure 4

[0087] Step S410, every preset adjustment time period, determine the change rate of the photovoltaic output power of the photovoltaic module in the adjustment time period.

[0088] The change rate of the photovoltaic output power of the photovoltaic module in the adjustment time period can be determined at the end of each adjustment time period.

[0089] The change rate of the photovoltaic output power of the current adjustment time period = (the photovoltaic output power at the end of the current adjustment time period - the photovoltaic output power at the beginning of the current adjustment time period) ÷ the time length of the current adjustment time period. That is, the change rate = (the photovoltaic output power at the end of the current adjustment time period - the photovoltaic output power at the beginning of the current adjustment time period) ÷ the time length of the current adjustment time period. .

[0090] Step S420, judge whether the change rate of the photovoltaic output power is negative and the load demand is greater than the first demand threshold; if yes, execute step S430; if no, execute step S440.

[0091] Step S430, in the case that the change rate of the photovoltaic output power is negative and the load demand is greater than the preset first demand threshold, determine the compressor adjustment amount according to the change rate of the photovoltaic output power, and reduce the number of operating compressors in the compressor combination according to the compressor adjustment amount.

[0092] ​​The rate of change of the photovoltaic output power being negative indicates that the photovoltaic output power is decreasing in the current adjustment time period. The load demand being greater than the first demand threshold indicates that the load demand is large in the current adjustment time period. Based on this, in the case that the rate of change of the photovoltaic output power is negative and the load demand is greater than the preset first demand threshold, the photovoltaic output power continues to change, and the energy source can not be able to support the currently running compressors, so that, when the next adjustment time period arrives, the number of the compressors running is reduced in advance, and the upcoming energy shortage is actively adapted to.

[0093] The compressor adjustment amount is determined according to the rate of change of the photovoltaic output power, including: determining a change speed level to which the rate of change of the photovoltaic output power belongs and determining an adjustment amount corresponding to the change speed level.

[0094] The change speed level includes but is not limited to rapid change and slow change. An adjustment amount and a range of the rate of change of the photovoltaic output power can be set in advance for each change speed level. The adjustment amount refers to the number of the compressors to be adjusted. For example, the adjustment amount corresponding to the rapid change is 2, and the adjustment amount corresponding to the slow change is 1.

[0095] In step S440, it is judged whether the rate of change of the photovoltaic output power is positive and the load demand is less than the second demand threshold. If yes, step S450 is executed; if no, step S460 is executed.

[0096] The first demand threshold and the second demand threshold can be the same or different values. If the first demand threshold and the second demand threshold are different values, the first demand threshold is greater than the second demand threshold.

[0097] In step S450, in the case that the rate of change of the photovoltaic output power is positive and the load demand is less than the preset second demand threshold, a compressor adjustment amount is determined according to the rate of change of the photovoltaic output power, and the number of the compressors running in the compressor combination is increased according to the compressor adjustment amount.

[0098] The rate of change of the photovoltaic output power being positive indicates that the photovoltaic output power is increasing in the current adjustment time period. The load demand being less than the second demand threshold indicates that the load demand is small in the current adjustment time period. Based on this, in the case that the rate of change of the photovoltaic output power is positive and the load demand is less than the second demand threshold, the current photovoltaic output power is already sufficient to meet the running compressors, the photovoltaic output power continues to change, and the trend of energy surplus will appear, so that, when the next adjustment time period arrives, the number of the compressors running is increased in advance, and the waste of photovoltaic energy and the improvement of system energy efficiency are avoided.

[0099] The compressor adjustment amount is determined according to the rate of change of the photovoltaic output power, including: determining a change speed level to which the rate of change of the photovoltaic output power belongs, and determining an adjustment amount corresponding to the change speed level.

[0100] In step S460, the current number of operating compressors in the compressor combination is maintained.

[0101] In the case that the rate of change of the photovoltaic output power is zero, or the rate of change of the photovoltaic output power is negative and the load demand amount is less than a first demand amount threshold, or the rate of change of the photovoltaic output power is positive and the load demand amount is greater than a second demand amount threshold, the current number of operating compressors in the compressor combination is maintained.

[0102] In the embodiments of the present application, a dynamic fine-tuning method based on fuzzy logic is provided. During the operation of the compressor combination, the number of operating compressors is adjusted in a forward-looking and small-amplitude manner according to the change trend (rate of change) of the photovoltaic output power and the load demand amount, so as to improve the smoothness and adaptive ability of the system in response to power fluctuations.

[0103] In the embodiments of the present application, different specifications of compressor combinations can be set to adapt to the change of the photovoltaic output power, so that the system can still operate efficiently under limited photovoltaic output power, and the phenomenon of mismatch between the photovoltaic output power and the required power of the compressor can be avoided; the hysteresis interval can be set to avoid frequent switching of the compressor at the critical power point, and the stability of the system can be improved; the operation strategy can be optimized by using multiple compressors, so that the COP value of the system can be improved by 15%-25%, and the technical effects of energy saving and efficient operation can be achieved.

[0104] The embodiments of the present application also provide a control device of a photovoltaic multi-split air conditioner. As shown in Figure 5 Fig. 1 is a structural diagram of a control device of a photovoltaic multi-split air conditioner according to an embodiment of the present application.

[0105] The control device of the photovoltaic multi-split air conditioner includes: A monitoring unit 510 is configured to monitor the photovoltaic output power of a photovoltaic module and the load demand amount of the photovoltaic multi-split air conditioner.

[0106] A determination unit 520 is configured to determine a compressor combination matched with the photovoltaic output power, wherein the compressor combination includes at least one compressor, the compressors in the same compressor combination have the same specification, and the compressors in different compressor combinations have different specifications.

[0107] A switching unit 530 is configured to switch to the currently determined compressor combination and start operation in the case that the currently determined compressor combination is different from the previously determined compressor combination. The adjusting unit 540 is configured to, in a process of running the currently determined compressor combination, adjust the number of compressors running in the currently determined compressor combination according to the monitored photovoltaic output power and the monitored load demand.

[0108] The functions of the apparatus described in the embodiments of the present application have been described in the foregoing method embodiments, and thus the descriptions of the embodiments of the present application are not elaborated herein.

[0109] The embodiments of the present application further provide a control device of a photovoltaic multi-split air conditioner, as shown in Figure 6 The control device of the photovoltaic multi-split air conditioner according to an embodiment of the present application is shown in the structural diagram of the control device of the photovoltaic multi-split air conditioner.

[0110] The control device of the photovoltaic multi-split air conditioner includes a processor 610, a communication interface 620, a memory 630 and a communication bus 640. The processor 610, the communication interface 620 and the memory 630 communicate with each other through the communication bus 640.

[0111] The memory 630 is configured to store a computer program.

[0112] In an embodiment of the present application, the processor 610 is configured to, when executing the program stored in the memory 630, implement the control method of the photovoltaic multi-split air conditioner provided in any one of the foregoing method embodiments, including: monitoring a photovoltaic output power of a photovoltaic module and a load demand of the photovoltaic multi-split air conditioner; determining a compressor combination matched with the photovoltaic output power; wherein the compressor combination includes at least one compressor; the compressors in the same compressor combination have the same specifications; the compressors in different compressor combinations have different specifications; in a case where the currently determined compressor combination is different from a previously determined compressor combination, switching to the currently determined compressor combination and starting to run; in a process of running the currently determined compressor combination, adjusting the number of compressors running in the currently determined compressor combination according to the monitored photovoltaic output power and the monitored load demand.

[0113] The determination of the compressor combination matched with the photovoltaic output power comprises: determining a power interval corresponding to the photovoltaic output power; the first power interval, the third power interval and the second power interval are sequentially preset in ascending order of end value; in a case where the photovoltaic output power corresponds to the first power interval, a first compressor combination corresponding to the first power interval is determined as the compressor combination matched with the photovoltaic output power; the first compressor combination comprises at least one compressor with a first rated power; in a case where the photovoltaic output power corresponds to the second power interval, a second compressor combination corresponding to the second power interval is determined as the compressor combination matched with the photovoltaic output power; the second compressor combination comprises at least one compressor with a second rated power; the first rated power is less than the second rated power; in a case where the photovoltaic output power corresponds to the third power interval, the compressor combination determined in the previous time is determined as the compressor combination matched with the photovoltaic output power.

[0114] Before the determination of the power interval corresponding to the photovoltaic output power, the method further comprises: determining a rated power of the first compressor combination; determining the second power interval according to the rated power of the first compressor combination and a preset first safety coefficient; the minimum end value of the second power interval is greater than the rated power of the first compressor combination; determining a rated power of the second compressor combination; determining the first power interval according to the rated power of the second compressor combination and a preset second safety coefficient; the maximum end value of the first power interval is less than the rated power of the second compressor combination.

[0115] The determination of the power interval corresponding to the photovoltaic output power comprises: querying a power interval determined in the previous time and a hysteresis interval corresponding to the power interval; the hysteresis interval refers to a substantial response interval corresponding to the power interval; in a case where the photovoltaic output power is in the hysteresis interval, the power interval corresponding to the photovoltaic output power is determined as the power interval determined in the previous time; in a case where the photovoltaic output power is not in the hysteresis interval, the power interval corresponding to the photovoltaic output power is determined as a power interval currently occupied by the photovoltaic output power.

[0116] The determining the compressor combination matched with the photovoltaic output power comprises: for each compressor combination, calculating a performance coefficient of the compressor combination according to the load demand and input power corresponding to the compressor combination; collecting a current environment temperature; inputting the photovoltaic output power, the load demand, the environment temperature, and the performance coefficient, rated power and compressor quantity corresponding to each compressor combination into a pre-trained energy efficiency evaluation model respectively, and obtaining the compressor combination matched with the photovoltaic output power output by the energy efficiency evaluation model.

[0117] The adjusting the number of compressors in operation in the compressor combination according to the monitored photovoltaic output power and the load demand comprises: determining a change rate of the photovoltaic output power of the photovoltaic module in each preset adjustment time period; in a case where the change rate of the photovoltaic output power is negative and the load demand is greater than a preset first demand threshold, determining a compressor adjustment amount according to the change rate of the photovoltaic output power, and reducing the number of compressors in operation in the compressor combination according to the compressor adjustment amount; in a case where the change rate of the photovoltaic output power is positive and the load demand is less than a preset second demand threshold, determining a compressor adjustment amount according to the change rate of the photovoltaic output power, and increasing the number of compressors in operation in the compressor combination according to the compressor adjustment amount.

[0118] The determining the compressor adjustment amount according to the change rate of the photovoltaic output power comprises: determining a change speed level to which the change rate of the photovoltaic output power belongs and determining an adjustment amount corresponding to the change speed level. The embodiment of the application further provides a computer readable storage medium, which has a computer program stored thereon, and the computer program is executed by a processor to realize the steps of the control method of the photovoltaic multi-connected machine provided by any one of the foregoing method embodiments. Since the control method of the photovoltaic multi-connected machine has been described in detail above, the description of the embodiment is not described in detail, and the related description in the foregoing embodiments can be referred to, which is not repeated here.

[0119] The apparatus embodiments described above are only schematic, wherein the units shown as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, can be located in one place or distributed on a plurality of network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment scheme.

[0120] Those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general hardware platform, and of course can be implemented by hardware. Based on such an understanding, the technical solutions described above essentially or in other words make contributions to the related art, and can be embodied in a software product form, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, or an optical disk, and includes a plurality of instructions to cause a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0121] It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their occurrence in the particular order

[0122] The above description is merely that of specific embodiments of the present application, and thus is not intended to limit the present application. Based on the general principles described herein, various modifications can be made to the application by those skilled in the art. Therefore, the present application is not limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method of a photovoltaic multi-inverter, characterized by, include: Monitor the photovoltaic output power of photovoltaic modules and the load demand of photovoltaic multi-split systems; Determine a compressor combination that matches the photovoltaic output power; wherein the compressor combination includes at least one compressor; the compressors in the same compressor combination have the same specifications; the compressors in different compressor combinations have different specifications; If the currently determined compressor combination is different from the previously determined compressor combination, switch to the currently determined compressor combination and start operation; During the operation of the currently determined compressor combination, the number of compressors operating in the currently determined compressor combination is adjusted according to the monitored photovoltaic output power and the load demand.

2. The method of claim 1, wherein, The determination of the compressor combination matching the photovoltaic output power includes: Determine the power range corresponding to the photovoltaic output power; wherein, a first power range, a third power range, and a second power range are pre-set in ascending order of their endpoint values; When it is determined that the photovoltaic output power corresponds to the first power range, the first compressor combination corresponding to the first power range is determined to be a compressor combination that matches the photovoltaic output power; wherein, the first compressor combination includes at least one compressor with a first rated power; When the photovoltaic output power corresponds to the second power range, the second compressor combination corresponding to the second power range is determined to be a compressor combination that matches the photovoltaic output power; wherein, the second compressor combination includes at least one compressor with a second rated power; the first rated power is less than the second rated power; If the photovoltaic output power corresponds to the third power range, the previously determined compressor combination is determined to be a compressor combination that matches the photovoltaic output power.

3. The method of claim 2, wherein, Before determining the power range corresponding to the photovoltaic output power, the method further includes: The rated power of the first compressor assembly is determined; the second power range is determined based on the rated power of the first compressor assembly and a preset first safety factor; wherein the minimum value of the second power range is greater than the rated power of the first compressor assembly. The rated power of the second compressor assembly is determined; the first power range is determined based on the rated power of the second compressor assembly and a preset second safety factor; wherein the maximum value of the first power range is less than the rated power of the second compressor assembly.

4. The method of claim 2, wherein, Determining the power range corresponding to the photovoltaic output power includes: Query the previously determined power range and its corresponding hysteresis range; wherein, the hysteresis range refers to the actual response range corresponding to the power range; When the photovoltaic output power is within the hysteresis range, the power range corresponding to the photovoltaic output power is determined to be the previously determined power range; If the photovoltaic output power is not in the hysteresis interval, the power interval corresponding to the photovoltaic output power is determined as the power interval in which the photovoltaic output power is currently located.

5. The method of claim 1, wherein, The determination of the compressor combination matching the photovoltaic output power includes: For each compressor combination, a coefficient of performance of the compressor combination is calculated according to the load demand and an input power corresponding to the compressor combination; An ambient temperature is acquired; The photovoltaic output power, the load demand, the ambient temperature, and the coefficient of performance, the rated power, and the number of compressors corresponding to each compressor combination are input into a pre-trained energy efficiency evaluation model, and a compressor combination matching the photovoltaic output power output by the energy efficiency evaluation model is acquired.

6. The method of claim 1, wherein, The adjusting the number of compressors operating in the compressor combination according to the monitored photovoltaic output power and the load demand comprises: Every preset adjustment time period, a change rate of the photovoltaic output power of the photovoltaic module in the adjustment time period is determined; In a case where the change rate of the photovoltaic output power is negative and the load demand is greater than a preset first demand threshold, a compressor adjustment amount is determined according to the change rate of the photovoltaic output power, and the number of compressors operating in the compressor combination is reduced by the compressor adjustment amount; In a case where the change rate of the photovoltaic output power is positive and the load demand is less than a preset second demand threshold, a compressor adjustment amount is determined according to the change rate of the photovoltaic output power, and the number of compressors operating in the compressor combination is increased by the compressor adjustment amount.

7. The method of claim 6, wherein, The determining the compressor adjustment amount according to the change rate of the photovoltaic output power comprises: Determining a change speed level to which the change rate of the photovoltaic output power belongs and determining an adjustment amount corresponding to the change speed level.

8. A control device of a photovoltaic multi-inverter, characterized by, Comprise: A monitoring unit configured to monitor a photovoltaic output power of a photovoltaic module and a load demand of a photovoltaic multi-connected air conditioner; A determining unit configured to determine a compressor combination matching the photovoltaic output power, wherein the compressor combination comprises at least one compressor, compressors in a same compressor combination have the same specification, and compressors in different compressor combinations have different specifications; A switching unit configured to, in a case where a currently determined compressor combination is different from a previously determined compressor combination, switch to the currently determined compressor combination and start operation; An adjusting unit configured to, in a process of operating the currently determined compressor combination, adjust a number of compressors operating in the currently determined compressor combination according to the monitored photovoltaic output power and the load demand.

9. A photovoltaic multi, characterized in that, Comprise: At least one communication interface; At least one bus connected to the at least one communication interface; and at least one processor connected to the at least one bus; At least one memory connected to the at least one bus, wherein the processor is configured to execute a control program of the photovoltaic multi-connected air conditioner stored in the memory to implement the control method of the photovoltaic multi-connected air conditioner according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer executable instructions, and the computer executable instructions are executed to implement the control method of the photovoltaic multi-connected air conditioner according to any one of claims 1-7.

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