Compressor frequency adjustment method, controller and multi-connected system of multi-connected system

Abstract

The application discloses a kind of compressor frequency adjustment method, controller and multi-connected system of multi-connected system, and the load index of each indoor unit is determined according to the indoor temperature of each indoor unit of multi-connected system, so as to adaptively reduce the initial frequency of compressor according to the load index of indoor unit and the current load rate of multi-connected system, so that the initial frequency of indoor unit load demand changes and makes compressor from the initial frequency of starting in the state of reaching temperature stop lower than default initial frequency, to meet the state of current small load demand of multi-connected system, more can match the load demand of indoor unit, avoid the problem that multi-connected system is trapped in vicious cycle of reaching temperature stop and cannot jump out due to the mutual influence between indoor units caused by starting compressor according to high initial frequency, compressor output capacity is too fierce finally, while also can improve the comfort of user using air conditioner, reduce the operating noise of compressor under small load demand.

Description

Technical Field

[0001] This application relates to the field of air conditioner control technology, and in particular to a compressor frequency adjustment method, controller and multi-split system for a multi-split air conditioning system. Background Technology

[0002] Multi-split air conditioning systems typically consist of one outdoor unit driving multiple indoor units. However, due to differences in room location and user needs, these indoor units can experience asynchronous loads and varying load requirements. Especially during the low-load, stable operation phase of a multi-split system, the compressor operates at a lower frequency. If indoor units experience alternating periods of load and no load, or if several indoor units experience alternating periods of load, the compressor's initial frequency will be calculated based on the formula used during high-load operation. This can lead to the compressor continuing to run at a higher frequency even when detecting changes in indoor unit load during low-load phases, resulting in excessive output. This can cause the operating indoor units to interfere with each other, leading to a vicious cycle of the system shutting down after reaching its operating temperature. For users, this is neither energy-efficient nor comfortable; frequent compressor starts and stops also generate noise, and the constant oscillations in the compressor's control system can shorten its lifespan. Summary of the Invention

[0003] This application provides a method for adjusting the compressor frequency of a multi-split air conditioning system, a controller, and a multi-split air conditioning system, which can reduce the initial frequency of the compressor and avoid frequent compressor start-stop.

[0004] In a first aspect, embodiments of this application provide a method for adjusting the compressor frequency of a multi-split air conditioning system, the multi-split air conditioning system including an outdoor unit and multiple indoor units connected to the outdoor unit; the compressor frequency adjustment method includes:

[0005] The load index of the indoor unit is determined based on the indoor temperature detected by the indoor unit, and the load index is used to characterize the load demand of the indoor unit.

[0006] The initial frequency of the compressor is reduced according to the load index and the load rate of the multi-split system. The initial frequency is the starting frequency at which the compressor restarts after reaching the temperature and stopping, due to changes in the load of the indoor unit.

[0007] In some embodiments, determining the load index of the indoor unit based on the indoor temperature detected by the indoor unit includes:

[0008] The temperature difference data of the indoor unit that is turned on within a preset time period is obtained. The temperature difference data is the difference between the indoor temperature of the corresponding indoor unit and the set temperature.

[0009] The load index of the indoor unit at the current moment is determined based on the temperature difference data.

[0010] In some embodiments, determining the load index of the indoor unit at the current moment based on the temperature difference data includes:

[0011] Determine the temperature difference function and weighting function within a preset time period. The temperature difference function represents the temperature difference data at different detection times within the preset time period, and the weighting function represents the weight value at different detection times within the preset time period.

[0012] The load index of the indoor unit at the current moment is determined based on the convolution integral result of the temperature difference function and the weighting function.

[0013] In some embodiments, the compressor frequency adjustment method further includes:

[0014] The load rate of the multi-split air conditioning system is determined based on the load requirements of the indoor units.

[0015] In some embodiments, determining the load rate of the multi-split system based on the load demand of the indoor unit includes:

[0016] Determine the total load demand of the indoor units that are turned on and the total rated capacity of all indoor units;

[0017] The load factor of the multi-split air conditioning system is determined based on the sum of the total load demand and the sum of the rated capacity.

[0018] In some embodiments, reducing the initial frequency of the compressor based on the load index and the load rate includes:

[0019] The correction coefficient is determined based on the load index of the indoor unit and the load rate of the multi-split air conditioning system;

[0020] The compressor's initial frequency is reduced by the correction factor to obtain a new initial frequency.

[0021] In some embodiments, determining the correction coefficient based on the load index of the indoor unit and the load rate of the multi-split system includes:

[0022] The characteristic value is determined based on the load index of the indoor unit that is turned on;

[0023] A correction coefficient is determined based on the characteristic value and the load factor, wherein the correction coefficient is greater than 0 and less than 1.

[0024] In some embodiments, the multi-split system has multiple characteristic value ranges and multiple load rate ranges preset;

[0025] The step of determining the correction coefficient based on the characteristic value and the load factor includes:

[0026] The target load rate range of the characteristic value is determined based on the magnitude of the characteristic value, and the target load rate range of the load rate is determined based on the magnitude of the load rate.

[0027] The correction coefficient is determined based on the correspondence between the target load rate range and the target load rate range.

[0028] In a second aspect, embodiments of this application provide a controller including at least one processor and a memory for communicatively connecting to the at least one processor; the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the compressor frequency adjustment method as described in the second aspect.

[0029] Thirdly, embodiments of this application provide a multi-unit system including the controller described in the second aspect.

[0030] The compressor frequency adjustment method, controller, and multi-split air conditioning system of this application embodiment have at least the following beneficial effects: The multi-split air conditioning system determines the load index of each indoor unit based on the indoor temperature of each indoor unit, and then adaptively reduces the initial frequency of the compressor according to the load index of the indoor unit and the current load rate of the multi-split air conditioning system. This makes the initial frequency of the compressor starting from the temperature-reaching shutdown state lower than the default initial frequency when the load demand of the indoor unit changes, thus conforming to the current low load demand of the multi-split air conditioning system and better matching the load demand of the indoor units. This avoids the problem of mutual interference between indoor units due to starting the compressor at a high initial frequency and excessive compressor output capacity, which ultimately causes the multi-split air conditioning system to fall into a vicious cycle of temperature-reaching shutdown from which it cannot escape. At the same time, it can also improve the comfort of users using air conditioning and reduce the operating noise of the compressor under low load demand.

[0031] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description and the accompanying drawings. Attached Figure Description

[0032] Figure 1 This is an overall flowchart of a compressor frequency adjustment method provided in one embodiment of this application;

[0033] Figure 2 This is a flowchart of determining the load index based on temperature difference data provided in one embodiment of this application;

[0034] Figure 3 This is a flowchart illustrating the calculation of the load index based on convolution integral, provided in one embodiment of this application.

[0035] Figure 4 This is a flowchart of determining the correction coefficient and calculating the new initial frequency based on the load index and load rate, provided in one embodiment of this application;

[0036] Figure 5 This is a flowchart illustrating the determination of a correction factor based on characteristic values ​​and load factor, provided in one embodiment of this application.

[0037] Figure 6 This is a flowchart illustrating the determination of correction coefficients using an interval method, as provided in one embodiment of this application;

[0038] Figure 7 This is an overall flowchart of a compressor frequency adjustment method provided in an example of this application;

[0039] Figure 8 This is a schematic diagram of the controller provided in one embodiment of this application. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various implementations. Simultaneously, the steps or actions described in the method description can be rearranged or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various orders in the specification and drawings are merely for the clear description of a particular embodiment and do not imply a mandatory order, unless otherwise stated that a particular order must be followed.

[0041] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0042] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0043] In cooling mode, during the initial cooling phase, the compressor operates at a certain frequency to quickly lower the indoor temperature. After the rapid temperature reduction phase, the multi-split system enters a low-load stable operating phase, where the compressor operates at a lower frequency. At this time, some indoor units may not require cooling, while others may require it. If cooling demand and no cooling demand alternate, or if the cooling demand of multiple indoor units alternates, the compressor may switch back and forth between the states of reaching the temperature and stopping, and then restarting after stopping. Currently, the initial restart frequency of compressors in multi-split air conditioning systems is calculated based on formulas used during high-load demand, without adjusting for subtle changes in load requirements. Therefore, the initial restart frequency after reaching the set temperature and shutting off is relatively high. This causes the compressor to start at a higher frequency during low-load periods, resulting in excessive cooling output far exceeding the cooling capacity required by the indoor units. In this situation, the indoor units that are currently running will interfere with each other, easily entering a state with no cooling demand. Subsequently, as the load decreases, the multi-split system triggers the compressor's temperature-reaching shutdown again, leading to a vicious cycle of temperature-reaching shutdown. For users, this is neither energy-efficient nor comfortable; frequent compressor starts and stops also generate noise. For the compressor, the constant oscillations in its control system affect its lifespan.

[0044] Based on this, this application provides a compressor frequency adjustment method, controller, and multi-split air conditioning system. The multi-split air conditioning system determines the load index of each indoor unit based on the indoor temperature of each indoor unit. Then, based on the load index of the indoor units and the current load rate of the multi-split air conditioning system, it adaptively reduces the initial frequency of the compressor. This causes the initial frequency at which the compressor starts from the temperature-reaching shutdown state is lower than the default initial frequency, thus conforming to the current low-load demand of the multi-split air conditioning system. This better matches the load demand of the indoor units and avoids the problem of mutual interference between indoor units due to starting the compressor at a high initial frequency and excessive compressor output capacity, ultimately causing the multi-split air conditioning system to fall into a vicious cycle of temperature-reaching shutdown from which it cannot escape. At the same time, it also improves the user's comfort when using the air conditioner and reduces the operating noise of the compressor under low-load demand.

[0045] The following description, with reference to the accompanying drawings, explains the compressor frequency adjustment method, controller, and multi-split air conditioning system.

[0046] Reference Figure 1 As shown, a multi-split air conditioning system includes an outdoor unit and multiple indoor units connected to the outdoor unit. The compressor frequency adjustment method includes, but is not limited to, the following steps:

[0047] Step S110: Determine the load index of the indoor unit based on the indoor temperature detected by the indoor unit. The load index is used to characterize the load demand of the indoor unit.

[0048] Step S120: Reduce the initial frequency of the compressor according to the load index and the load rate of the multi-split system. The initial frequency is the starting frequency of the compressor after it stops at the set temperature and restarts due to changes in the load of the indoor unit.

[0049] A multi-split system connects multiple indoor units through at least one outdoor unit. The outdoor unit is equipped with a compressor, which is connected to each indoor unit through refrigerant pipes. By controlling the operating status of the compressor and the flow of refrigerant in the refrigerant pipes, the multi-split system can achieve functions such as cooling and heating of the indoor units. As previously known, when a compressor cools an indoor unit, it typically first goes through a rapid temperature reduction phase, followed by a phase where the indoor unit experiences low load demand. The compressor then reduces its operating frequency from a high to a low level, and can even stop operating when the indoor unit has no load demand. However, after the compressor stops, it needs to restart when the indoor unit experiences load demand, and then stops again after cooling is complete. Currently, the initial startup frequency of the compressor is too high, easily leading to a vicious cycle of stopping after reaching the set temperature. Therefore, this application's embodiment adjusts the compressor's initial frequency based on the indoor unit's load index and the current load rate of the multi-split system. This means adjusting the operating frequency used when the compressor restarts after stopping at the set temperature. This adjusted operating frequency is lower than the compressor's default initial frequency, thereby reducing the cooling output when the compressor restarts, meeting the cooling demand corresponding to low load requirements. This allows the indoor unit to output cooling output smoothly, avoiding frequent compressor stops and restarts.

[0050] The load index is used to indicate the load demand of the indoor units. In this embodiment of the multi-split air conditioning system, the load demand of the indoor unit is determined by detecting the indoor temperature of its corresponding room. The load index is then used to determine how to adjust the default initial frequency of the compressor based on the load index of each indoor unit. Additionally, the load rate of the outdoor unit is also considered when adjusting the initial frequency. The load rate represents the ratio of the current load demand of each indoor unit in the multi-split system to its full load, or the ratio of the current load demand of each indoor unit to the sum of the nominal capacity (rated capacity or rated cooling capacity) of all indoor units. By determining the load rate of the multi-split system, the number of indoor units currently in operation can be reflected, thereby determining how to adjust the default initial frequency of the compressor. In summary, this application embodiment determines how to adjust the default initial frequency of the compressor from two dimensions—the load index of the indoor unit and the load rate of the multi-split system—through the above-described step S120. This adjustment process considers the load demand of each indoor unit and the number of indoor units that are turned on, thus accurately adjusting the initial frequency to meet the current low load demand of the multi-split system. This ensures stable operation of the multi-split system and avoids frequent temperature-reaching shutdowns. Since the compressor no longer frequently oscillates back and forth, its service life is extended, improving energy efficiency. It also reduces the frequency of compressor start-up and shutdown noise, improving the user experience.

[0051] Reference Figure 2 As shown, in some embodiments, the step S110 above, which determines the load index of the indoor unit based on the indoor temperature detected by the indoor unit, includes:

[0052] Step S210: Obtain the temperature difference data of the indoor unit that is turned on within a preset time period. The temperature difference data is the difference between the indoor temperature of the corresponding indoor unit and the set temperature.

[0053] Step S220: Determine the load index of the indoor unit at the current moment based on the temperature difference data.

[0054] For any indoor unit, the indoor temperature changes over time during its operation. This embodiment records the difference between the indoor temperature detected by the indoor unit and the set temperature over a preset time period, i.e., temperature difference data. The larger the difference between the indoor temperature and the set temperature, the greater the current load demand of the indoor unit. Therefore, the load index at the current moment can be calculated based on the temperature difference data. To reflect the load changes of the indoor unit, the load index at the current moment is calculated based on multiple temperature difference data points within the preset time period. This load index reflects how the load of the indoor unit changes during its operation over the preset time period. According to control theory, the difference between the indoor temperature and the set temperature represents the system's control error. Taking into account the change of control error over time, the load index is obtained, reflecting the impact of accumulated control error on the load index during past operation. The calculated load index reflects the system's ability to achieve gradual and dynamic adjustment of the output of the corresponding set temperature.

[0055] Reference Figure 3 As shown, in some embodiments, the step S220 above, which determines the load index of the indoor unit at the current moment based on the temperature difference data, includes:

[0056] Step S310: Determine the temperature difference function and weighting function within the preset time period. The temperature difference function represents the temperature difference data at different detection times within the preset time period, and the weighting function represents the weight value at different detection times within the preset time period.

[0057] Step S320: Determine the load index of the indoor unit at the current moment based on the convolution integral result of the temperature difference function and the weighting function.

[0058] The indoor unit detects the indoor temperature at regular time intervals, and therefore the temperature difference data within the preset time period is also generated according to this time interval. To represent the change in temperature difference over time, this embodiment incorporates a temperature difference function, which can be expressed as ε(τ)=T1(τ)-T set (τ), where the temperature difference function ε(τ) represents the dynamic change of the load, T1(τ) represents the indoor temperature at time τ, and T set (τ) represents the set temperature at time τ. The operating state of the indoor unit may remain constant or change within the preset time period. For example, the indoor unit may continuously maintain cooling within the preset time period, or it may switch between cooling and off states within the preset time period. That is, the cooling state is not continuous. Therefore, this embodiment incorporates a weighting function, which is used to calculate the load index through convolution with the temperature difference function. This allows the load index to reflect the impact of accumulated control errors on the load index during past operation. The specific calculation formula is as follows:

[0059]

[0060] Where LDI(τ) represents the load index, α t-τ The weighting function represents the exponential decay of the control error's indicative effect on the load over time. In this embodiment, its value range is set to 0 to 1, and the integral interval 0-T represents the preset time period from time 0 to time T. It is worth noting that different values ​​can be considered for the weighting function under different control scenarios. For example, in the operation of a multi-split air conditioning system under the same mode, the weight value can change continuously with operation, change in segments, or remain fixed. Furthermore, the weight value can be different in different modes, and the weight value can even be adaptively learned based on the historical operating data of the air conditioner. Examples are not provided here.

[0061] It is understandable that the load index expression in the convolutional form described above means that the calculation of the load index at each moment takes into account the impact of accumulated control errors during past operation to a certain extent. The degree of this impact can be determined by different weighting indices. During cooling operation, the load index value gradually decreases as the multi-split system's capacity outputs; the smaller the value, the lower the load demand of the corresponding indoor unit. Simultaneously, because the calculation of the load index considers time-series factors, its value can indicate different stages of cooling. For example, a value greater than 0 indicates a high-load cooling stage; a value less than 0 but greater than a certain value (e.g., -1) indicates a wall temperature reduction stage; and a value below a certain value indicates a low-load stage for maintaining room temperature.

[0062] In some embodiments, the compressor frequency adjustment method of this application further includes:

[0063] Determine the load rate of the multi-split air conditioning system based on the load requirements of the indoor units.

[0064] The load factor can be calculated in various ways. For example, in this embodiment, the multi-split system collects the load demand of all indoor units and then determines the load factor based on the load demand. Specifically, assuming that the sum of the load demand of all indoor units at the current moment is Q, and the number of indoor units connected to the outdoor unit is m, and the nominal capacity (rated capacity, or rated cooling capacity) of each indoor unit is n1, n2, ..., nm, then the load factor LR = Q / (n1 + n2 + ... + nm).

[0065] Reference Figure 4 As shown, in some embodiments, reducing the initial frequency of the compressor based on the load index and load rate in step S120 includes:

[0066] Step S410: Determine the correction coefficient based on the load index of the indoor unit and the load rate of the multi-split system;

[0067] Step S420: Reduce the compressor's initial frequency according to the correction factor to obtain the new initial frequency.

[0068] Based on the correlation between load index and load rate, different correction coefficients can be determined. Then, the compressor's default initial frequency is adjusted according to the correction coefficient. For example, when the load index and load rate are high, it means that the current load demand of the multi-split system connected to the indoor units is large and the number of connected indoor units is large. In this case, it is not appropriate to reduce the default initial frequency too much. In this case, the correction coefficient is larger (assuming the new initial frequency = correction coefficient * default initial frequency), and only the default initial frequency needs to be slightly reduced. On the other hand, when the load index and load rate are low, it means that the current load demand of the multi-split system connected to the indoor units is small and the number of connected indoor units is small. In this case, the correction coefficient can be smaller (assuming the new initial frequency = correction coefficient * default initial frequency), which can significantly reduce the default initial frequency to match the current low load demand scenario.

[0069] Reference Figure 5 As shown, in some embodiments, the step S410 above, which determines the correction coefficient based on the load index of the indoor unit and the load rate of the multi-split system, includes:

[0070] Step S510: Determine the characteristic value based on the load index of the indoor unit that is turned on;

[0071] Step S520: Determine the correction coefficient based on the characteristic value and load factor. The correction coefficient is greater than 0 and less than 1.

[0072] Based on the load indices of all activated indoor units, a representative characteristic value for the multi-split air conditioning system is calculated according to certain rules. For example, the maximum value of the load indices of all indoor units can be taken, or their average value can be taken, or the load index value of the indoor unit that the user deems most important can be selected as the characteristic value. Essentially, the purpose of this step is to obtain a representative load index to guide the operation of the outdoor units of the multi-split air conditioning system based on the load indices of different indoor units. The value of the correction factor is related to the calculation method of the new initial frequency obtained in step S420. In this embodiment, it is calculated as new initial frequency = correction factor * default initial frequency. Therefore, the correction factor is a positive decimal, and the new initial frequency after multiplication is lower than the default initial frequency.

[0073] Reference Figure 6 As shown, in some embodiments, the multi-split system has multiple preset characteristic value ranges and multiple load rate ranges;

[0074] The step S520 above, which determines the correction factor based on the characteristic value and the load factor, includes:

[0075] Step S610: Determine the target load rate range of the characteristic value based on the magnitude of the characteristic value, and determine the target load rate range of the load rate based on the magnitude of the load rate.

[0076] Step S620: Determine the correction coefficient based on the correspondence between the target load rate range and the target load rate range.

[0077] Multi-split air conditioning systems are divided into characteristic value intervals and load rate intervals. Each characteristic value interval and each load rate interval corresponds to a correction coefficient. Therefore, when determining the correction coefficient based on the characteristic value and load rate, it is necessary to find out which characteristic value interval the characteristic value belongs to and which load rate interval the load rate belongs to, thereby determining the corresponding correction coefficient. The calculated load correction coefficient is then multiplied by the compressor's default initial frequency (which can also be calculated based on the number of units required by the load demand) to obtain the corrected initial frequency, which is then sent to the compressor for execution.

[0078] In summary, this application provides a control method that adaptively adjusts the initial frequency of the compressor based on the load index of each activated indoor unit. This allows the compressor's starting frequency to better match the actual room load during low-load operation of the multi-split system. This solves the problems caused by the mutual influence between different indoor units in the existing control method, which results in an excessively high initial compressor frequency and excessive output capacity, leading to mutual influence between different indoor units, energy-inefficient operation, user discomfort, and loud compressor start-up and shutdown noise.

[0079] The compressor frequency adjustment method of this application will be described in detail below with an example.

[0080] A multi-split air conditioning system connects an outdoor unit to multiple indoor units, and performs corresponding operating frequency control through the following steps:

[0081] S1. During the operation of the multi-split system, the load index of the multiple indoor units in operation is calculated and collected, denoted as LDI_i, where i represents the label of the different indoor units. A load index can be calculated for each indoor unit at any time after the system is turned on. The calculation method is as follows:

[0082] For a running indoor unit (denoted as the i-th indoor unit), the start-up time of the indoor unit is denoted as time t0. Starting from time t0, its control error ε is calculated at intervals ΔT:

[0083] ε=T1-T set

[0084] Where T1 is the current indoor temperature, T set Set the temperature for the user.

[0085] At any time j, based on the control error ε of the indoor unit at the current time and the load index of previous times, calculate its load index LDI(τ) from the start time to the current time according to the following formula:

[0086] ε(τ)=T1(τ)-T set (τ)

[0087]

[0088] The above formula calculates the real-time load index of the indoor unit, which represents the convolution of the error function ε(τ) and the weighting function α(τ), where the error function ε(τ) represents the dynamic difference between load and capacity, and the weighting function α(τ) = α t-τ This indicates that the indicative effect of the error on the load decays exponentially over time, and the integral expresses the slow dynamic characteristics of the load.

[0089] Under this convolution formula, the calculation of the load index LDI(τ) at the current moment takes into account the decay of the control error ε(τ) over time. For the assignment of α, different values ​​can be considered under different control scenarios. For example, during the operation of the system in the same mode, it can be continuously changing with the operation, or it can be segmented, or it can be fixed. In addition, the value of α can be different in different modes, and the value of α can even be adaptively learned based on the historical operation data of the air conditioner.

[0090] Essentially, the load index expression using convolutional methods aims to convey that the calculation of the load index at each moment takes into account, to some extent, the impact of accumulated control errors during past operation. The degree of this impact can be determined by different weighting indices. During cooling operation, the value of LDI(τ) gradually decreases as the air conditioning system's output capacity increases; the smaller the value, the lower the load demand of the corresponding indoor unit. Simultaneously, because its calculation method considers time-series factors, its value can indicate different stages of cooling. For example, a value greater than 0 indicates a high-load cooling stage; a value less than 0 but greater than a certain value (e.g., -1) indicates a wall temperature reduction stage; and a value below a certain value indicates a low-load stage for maintaining room temperature.

[0091] S2. Determine the correction coefficient for the compressor initialization frequency based on the load index of all currently active indoor units and the load rate of the current multi-split system.

[0092] Based on the load index LDI_i of all activated indoor units, calculate the representative characteristic value LDI_flag of the multi-split system's LDI according to certain rules. For example, the maximum value of the load index of all indoor units can be taken, or their average value can be taken, or the load index value of the indoor unit that the user deems most important can be selected as the representative load index value. Essentially, the purpose of this step is to obtain a representative load index LDI_flag that guides the operation of the outdoor unit based on the load indices of different indoor units.

[0093] Based on the value of LDI_flag and the value of load factor LR, the correction coefficient K_cool for the compressor's initial frequency is obtained by referring to the table below. LDI_cool_a is the partition threshold of LDI, which can be specified according to requirements. The calculation of load factor LR is explained in the following example: The sum of the current indoor unit's load demand is Q, the number of all indoor units connected to this outdoor unit is m, and the nominal capacity of each indoor unit is n1, n2, ... nm, then the load factor LR = Q / (n1 + n2 + ... + nm).

[0094] Table 1: Characteristic Values ​​of Load Index and Corresponding Correction Factors for Load Rate

[0095]

[0096] The columns in the table above represent different load index ranges, which in turn characterize different stages of the load over time. For example, it could indicate whether the system is in a high-load, rapid cooling phase, a slow cooling phase, or a final low-load maintenance phase. Theoretically, the smaller the value, the lower the actual load demand from users. In short, this value represents the phased characteristics of the load over time. The rows in the table represent the load percentage of the total system capacity currently running (e.g., the load rate differs depending on whether one or two indoor units are in demand). By combining these row and column queries, refined load adjustments can be achieved.

[0097] S3. The system will operate at the initial frequency as described above when it detects a change in the number of indoor unit load requirements.

[0098] The calculated load correction factor K_cool is multiplied by the compressor initial frequency F_ini calculated based on the number of units required for the load, and the corrected initial frequency F_load_ini = K_cool * F_ini is sent to the compressor for execution.

[0099] like Figure 8 As shown, Figure 8 This is a schematic diagram of a controller 1000 provided in one embodiment of this application.

[0100] The controller 1000 in this embodiment includes one or more processors 1001 and a memory 1002. Figure 8 The example uses a processor 1001 and a memory 1002.

[0101] Processor 1001 and memory 1002 can be connected via a bus or other means. Figure 8 Taking the example of a connection between China and Israel via a bus.

[0102] Memory 1002, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory 1002 may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory 1002 may optionally include memory 1002 remotely located relative to processor 1001, and these remote memories can be connected to controller 1000 via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0103] Those skilled in the art will understand that Figure 8 The device structure shown does not constitute a limitation on the controller 1000 and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0104] This application also provides a multi-unit system, including the controller 1000 described above.

[0105] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0106] The non-transient software program and instructions required to implement the control method of the air conditioning system in the above embodiments are stored in the memory and are executed by the processor when the above embodiments are executed.

[0107] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network nodes. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0108] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0109] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0110] In the several embodiments provided in this application, it should be understood that the disclosed systems, instruments, and methods can be implemented in other ways. For example, the instrument embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between instruments or units may be electrical, mechanical, or other forms. Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0111] It should also be understood that the various implementation methods provided in this application can be combined arbitrarily to achieve different technical effects.

[0112] The above is a detailed description of the preferred embodiments of this application. However, this application is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for adjusting the compressor frequency of a multi-split air conditioning system, characterized in that, The multi-split air conditioning system includes an outdoor unit and multiple indoor units connected to the outdoor unit; the compressor frequency adjustment method includes: The load index of the indoor unit is determined based on the indoor temperature detected by the indoor unit, and the load index is used to characterize the load demand of the indoor unit. The initial frequency of the compressor is reduced according to the load index and the load rate of the multi-split system. The initial frequency is the starting frequency at which the compressor restarts after reaching the temperature and stopping, due to changes in the load of the indoor unit. The step of determining the load index of the indoor unit based on the indoor temperature detected by the indoor unit includes: The temperature difference data of the indoor unit that is turned on within a preset time period is obtained. The temperature difference data is the difference between the indoor temperature of the corresponding indoor unit and the set temperature. Determine the temperature difference function and weighting function within a preset time period. The temperature difference function represents the temperature difference data at different detection times within the preset time period, and the weighting function represents the weight value at different detection times within the preset time period. The load index of the indoor unit at the current moment is determined based on the convolution integral result of the temperature difference function and the weighting function; The multi-split air conditioning system has multiple preset characteristic value ranges and multiple load rate ranges; the step of reducing the initial frequency of the compressor based on the load index and the load rate of the multi-split air conditioning system includes: The characteristic value is determined based on the load index of the indoor unit that is turned on; The target load rate range of the characteristic value is determined based on the magnitude of the characteristic value, and the target load rate range of the load rate is determined based on the magnitude of the load rate. A correction coefficient is determined based on the correspondence between the target load factor range and the target load factor range, wherein the correction coefficient is greater than 0 and less than 1; The compressor's initial frequency is reduced by the correction factor to obtain a new initial frequency.

2. The compressor frequency adjustment method according to claim 1, characterized in that, The compressor frequency adjustment method further includes: The load rate of the multi-split air conditioning system is determined based on the load requirements of the indoor units.

3. The compressor frequency adjustment method according to claim 2, characterized in that, Determining the load rate of the multi-split air conditioning system based on the load demand of the indoor units includes: Determine the total load demand of the indoor units that are turned on and the total rated capacity of all indoor units; The load factor of the multi-split air conditioning system is determined based on the sum of the total load demand and the sum of the rated capacity.

4. A controller, characterized in that, It includes at least one processor and a memory for communicatively connecting with said at least one processor; The memory stores instructions executable by the at least one processor to enable the at least one processor to perform the compressor frequency adjustment method as described in any one of claims 1 to 3.

5. A multi-split air conditioning system, characterized in that, Includes the controller as described in claim 4.

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