Air conditioner low-frequency operation control method and system

Abstract

The invention discloses an air conditioner low-frequency operation control method and system, relates to the technical field of air conditioner low-frequency operation control, and solves the technical problems that in the prior art, an air conditioner low-frequency operation decision cannot be synchronously analyzed according to the environment and environmental influence, and an air conditioner cannot be accurately controlled to enter a low-frequency operation state. The method specifically comprises the steps that a low-frequency operation decision-making unit conducts decision analysis on low-frequency operation of the air conditioner, decision-making information is obtained, air conditioner low-frequency operation decision-making coefficients are obtained according to a formula, whether low-frequency operation is executed currently or not is deduced through operation decision-making coefficient comparison, and meanwhile after low-frequency operation is executed through analysis, the low-frequency operation is executed. And the frequency conversion decision detection unit performs frequency conversion decision detection on the low-frequency operation time period of the air conditioner, acquires frequency conversion risk duration data and frequency conversion risk influence data in the operation time period, and deduces whether the frequency conversion decision detection is abnormal or not according to data comparison, if yes, regulation and control are performed, and if not, low-frequency operation is continuously performed.

Description

Technical Field

[0001] The present invention relates to the technical field of low-frequency operation control of air conditioners, and in particular to a method and system for controlling low-frequency operation of an air conditioner. Background Art

[0002] The low-frequency operation control of air conditioners is mainly to reduce energy consumption, reduce noise and improve comfort while meeting the indoor temperature regulation needs; the low-frequency operation of air conditioners is achieved by reducing the operating frequency of the compressor; the compressor is the core component of the air conditioner, and its operating frequency determines the cooling (heating) capacity and energy consumption; when the indoor temperature is close to the set temperature, the air conditioning control system will reduce the frequency of the compressor so that it runs at a lower power, thereby maintaining the stability of the indoor temperature.

[0003] The patent with announcement number CN105928145B provides a low-frequency operation control method for an air conditioner and an air conditioner, wherein the method includes: monitoring whether the operating condition meets the entry conditions for entering the low-frequency operation state, and if not, continuing to monitor; if satisfied, then: low-frequency operation and real-time monitoring of the operating condition to see whether it meets the exit conditions for exiting the low-frequency operation state, and if not, continuing to monitor; if satisfied, then: exiting the low-frequency operation state, and repeating the operation of monitoring whether the operating condition meets the entry conditions for entering the low-frequency operation state; using the method and air conditioner described in this article can: reduce the minimum operating frequency to as low as 8Hz; reduce energy consumption; and improve user comfort.

[0004] However, in the prior art, the decision on low-frequency operation of the air conditioner cannot be synchronously analyzed according to the environment and environmental impacts, and the air conditioner cannot be accurately controlled to enter a low-frequency operation state. At the same time, the frequency conversion decision cannot be detected in real time, so that although the temperature control requirements are met during low-frequency operation, the low-frequency operation increases the energy consumption of the air conditioner, thereby reducing the actual operating efficiency of the air conditioner.

[0005] In view of the above technical defects, a solution is now proposed. Summary of the invention

[0006] The purpose of the present invention is to solve the above-mentioned problems and to provide a method and system for controlling low-frequency operation of an air conditioner.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] An air conditioner low-frequency operation control system comprises an air conditioner operation control center, wherein the air conditioner operation control center is communicatively connected with a low-frequency operation decision unit, a frequency conversion decision detection unit and a frequency conversion fault prediction unit;

[0009] The low-frequency operation decision unit performs decision analysis on the low-frequency operation of the air conditioner, obtains decision information, and obtains the low-frequency operation decision coefficient of the air conditioner according to the formula. It infers whether low-frequency operation is currently being performed by comparing the operation decision coefficient. At the same time, after analyzing the execution of low-frequency operation, the variable frequency decision detection unit performs variable frequency decision detection on the low-frequency operation period of the air conditioner, collects the variable frequency risk duration data and variable frequency risk impact data during the operation period, and infers whether the variable frequency decision detection is abnormal based on data comparison. If yes, it will be regulated, otherwise, low-frequency operation will continue. During the low-frequency operation, the variable frequency fault prediction unit infers whether there is a fault risk of the air conditioner during the current variable frequency operation based on the operating status of the motor inside the compressor in the air conditioner. The variable frequency position parameters and low-frequency phase parameters are collected, and the fault risk is inferred based on parameter analysis. If there is a fault risk, the low-frequency operation is stopped, and if there is no fault, the low-frequency state is continued.

[0010] As a preferred embodiment of the present invention, the decision information includes the floating span value of the numerical deviation between the ambient temperature of the air-conditioning coverage area and the air-conditioning set temperature during the current operating period of the air-conditioning, the maximum control speed proportion of the floating span increase speed after the corresponding numerical deviation floating span shows an increasing trend, the numerical floating frequency of the influencing parameters of the ambient temperature of the air-conditioning coverage area during the current operating period of the air-conditioning, and the operating time of temperature control equipment other than the air-conditioning when the temperature of the air-conditioning coverage area is adjusted to the air-conditioning set temperature during the current operating period of the air-conditioning, and corresponding labels SFK, SZB, FDP, and WKS are set.

[0011] As a preferred embodiment of the present invention, the formula is:

[0012] Among them, J is the decision coefficient of low-frequency operation of air conditioner during the operation period, mjk1, mjk2, mjk3, and mjk4 are preset proportional coefficients, and α is used as the error correction factor, with a value of 0.98.

[0013] As a preferred embodiment of the present invention, if the low-frequency operation decision coefficient of the air conditioner exceeds the operation decision coefficient threshold value during the operation period, a temporary non-execution signal is generated;

[0014] If the air conditioner low-frequency operation decision coefficient does not exceed the operation decision coefficient threshold during the operation period, a low-frequency execution signal is generated.

[0015] As a preferred embodiment of the present invention, the frequency conversion risk duration data and the frequency conversion risk impact data are respectively the overlapping duration of the air-conditioning compressor speed decrease phase and the air-conditioning coverage area temperature increase phase when the air-conditioning enters the low-frequency operation state during the current operating period, and the cumulative value of the proportion of the corresponding synchronously increased spans of the compressor speed decrease span and the air-conditioning coverage area temperature increase span during the corresponding stage overlapping duration.

[0016] As a preferred embodiment of the present invention, if the frequency conversion risk duration data exceeds the stage overlap duration threshold, or the frequency conversion risk impact data exceeds the synchronous increase span ratio cumulative value threshold, a frequency conversion decision risk signal is generated; if the frequency conversion risk duration data does not exceed the stage overlap duration threshold, and the frequency conversion risk impact data does not exceed the synchronous increase span ratio cumulative value threshold, a frequency conversion decision safety signal is generated.

[0017] As a preferred embodiment of the present invention, the variable frequency position parameter and the low-frequency phase parameter are respectively the distance deviation between the actual position of the motor rotor and the preset position during the motor adjustment stage inside the compressor during the variable frequency operation of the air conditioner, and the cumulative duration of the rotor speed being in a phase lag when the angle and speed of the motor rotor inside the compressor are in a fluctuating state when the air conditioner is in low-frequency operation.

[0018] As a preferred embodiment of the present invention, if the frequency conversion position parameter exceeds the distance deviation threshold, or the low-frequency phase parameter exceeds the cumulative duration threshold, a frequency conversion fault warning signal is generated; if the frequency conversion position parameter does not exceed the distance deviation threshold, and the low-frequency phase parameter does not exceed the cumulative duration threshold, a frequency conversion operation qualified signal is generated.

[0019] A low-frequency operation control method for an air conditioner, the specific operation control method steps are as follows:

[0020] Low-frequency operation decision: perform decision analysis on the low-frequency operation of the air conditioner, obtain decision information, obtain the low-frequency operation decision coefficient of the air conditioner according to the formula, and infer whether the low-frequency operation is currently being executed by comparing the operation decision coefficient;

[0021] Frequency conversion decision detection: after analyzing and executing low-frequency operation, frequency conversion decision detection is performed on the low-frequency operation period of the air conditioner. The frequency conversion risk duration data and frequency conversion risk impact data during the operation period are collected. Based on the data comparison, it is inferred whether the frequency conversion decision detection is abnormal. If yes, regulation is carried out; otherwise, low-frequency operation is continued.

[0022] Inverter fault prediction: During low-frequency operation, the operating status of the motor inside the compressor of the air conditioner is analyzed to infer whether the air conditioner has a fault risk during the current variable frequency operation. The variable frequency position parameters and low-frequency phase parameters are collected, and the fault risk is inferred based on parameter analysis. If there is a fault risk, the low-frequency operation is stopped. If there is no fault, the low-frequency state is continued.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. In the present invention, a decision analysis is performed on the low-frequency operation of the air conditioner, and whether the air conditioner is suitable for low-frequency operation is inferred through environmental analysis and real-time environmental impact analysis, so that the air conditioner can accurately perform low-frequency operation during actual operation, and avoid unreasonable low-frequency adjustment timing during the air conditioner operation stage, which causes the low frequency of the air conditioner to fail to meet the current environmental requirements, so that the low-frequency operation of the air conditioner is converted into high-frequency operation, which increases the energy consumption of the air conditioner and reduces the energy saving efficiency brought by the low-frequency operation;

[0025] Perform variable frequency decision detection on the low-frequency operation period of the air conditioner, and infer whether the current low-frequency operation meets the actual demand based on the low-frequency operation analysis of the air conditioner, so as to avoid the situation where the regional temperature control demand cannot be met during low-frequency operation, and the situation where the low-frequency operation meets the temperature control demand but increases the energy consumption of the air conditioner, thereby reducing the efficiency of the variable frequency decision execution; through real-time variable frequency decision detection, it can also be inferred in real time whether the low-frequency operation of the air conditioner needs to be executed, so as to facilitate timely variable frequency regulation, ensuring the regional temperature control efficiency while ensuring the regional air conditioning energy consumption and energy-saving control.

[0026] 2. In the present invention, fault prediction is performed during the variable frequency operation of the air conditioner. According to the operating state of the motor inside the compressor of the air conditioner, it is inferred whether there is a fault risk of the air conditioner during the current variable frequency operation, so as to timely predict the variable frequency operation of the air conditioner, reduce the variable frequency of the air conditioner and operate the compressor in time, so as to avoid the air conditioner in the non-variable frequency state failing to meet the temperature control requirements of the actual coverage area, resulting in a decrease in the operating efficiency of the air conditioner;

[0027] Evaluate the low-frequency operation efficiency of the air conditioner, and infer whether there are risks in the current low-frequency operation state of the air conditioner through efficiency evaluation, so as to adjust the low-frequency operation state in time to reduce the risk of frequency conversion failure. It can also be adjusted in time during low-efficiency operation to minimize the energy consumption of the air conditioner and play a role in energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0029] Figure 1 This is a principle block diagram of Embodiment 1 of the present invention;

[0030] Figure 2 This is a principle block diagram of the second embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0033] Embodiment 1

[0034] This embodiment performs intelligent control analysis on low-frequency operation of air conditioners. Figure 1 As shown, an air conditioner low-frequency operation control system includes an air conditioner operation control center, wherein the air conditioner operation control center is communicatively connected to a low-frequency operation decision unit, a frequency conversion decision detection unit, and a frequency conversion fault prediction unit;

[0035] The air-conditioning operation control center generates a low-frequency operation decision signal and sends the low-frequency operation decision signal to the low-frequency operation decision unit. After receiving the low-frequency operation decision signal, the low-frequency operation decision unit performs decision analysis on the low-frequency operation of the air-conditioning, and infers whether the air-conditioning is suitable for low-frequency operation through environmental analysis and real-time environmental impact analysis, so that the air-conditioning can accurately perform low-frequency operation during actual operation, and avoid unreasonable low-frequency adjustment timing during the air-conditioning operation stage, which causes the low frequency of the air-conditioning to fail to meet the current environmental requirements, so that the low-frequency operation of the air-conditioning is converted into high-frequency operation, which increases the energy consumption of the air-conditioning, but reduces the energy saving efficiency brought by the low-frequency operation;

[0036] The floating span value of the numerical deviation between the ambient temperature of the air-conditioning coverage area and the air-conditioning set temperature during the current operation period of the air-conditioning and the maximum control speed ratio of the floating span increase speed after the corresponding numerical deviation floating span shows an increasing trend are obtained, wherein the maximum control speed ratio is expressed as the maximum speed value that can control the speed reduction in the floating span increase speed, and the floating span value of the numerical deviation between the ambient temperature of the air-conditioning coverage area and the air-conditioning set temperature during the current operation period of the air-conditioning and the maximum control speed ratio of the floating span increase speed after the corresponding numerical deviation floating span shows an increasing trend are marked as SFK and SZB respectively; the numerical floating frequency of the influencing parameter of the ambient temperature of the air-conditioning coverage area during the current operation period of the air-conditioning is obtained, and the numerical floating frequency of the influencing parameter of the ambient temperature of the air-conditioning coverage area during the current operation period of the air-conditioning is marked as FDP, wherein the influencing parameter is expressed as an environmental parameter that affects the ambient temperature, such as ventilation volume and the number of heat sources added. This application uses the influencing parameter values ​​for unified calibration, and any environmental influencing parameter can be substituted into this system according to the actual usage scenario;

[0037] The operation time of the temperature control equipment other than the air conditioner when the temperature of the air conditioner coverage area is adjusted to the air conditioner set temperature during the current operation period of the air conditioner is obtained, and the operation time of the temperature control equipment other than the air conditioner when the temperature of the air conditioner coverage area is adjusted to the air conditioner set temperature during the current operation period of the air conditioner is marked as WKS, where the temperature control equipment is represented by an electric fan, an air conditioning fan, and other equipment in the prior art;

[0038] The above collected data are uniformly marked as decision information and substituted into the formula to obtain the decision coefficient of low-frequency operation of the air conditioner during the operation period, where the formula is: Among them, J is the decision coefficient of low-frequency operation of air conditioner in the operation period, mjk1, mjk2, mjk3, and mjk4 are preset proportional coefficients, and α is used as the error correction factor, with a value of 0.98;

[0039] Compare the low-frequency operation decision coefficient of the air conditioner within the operation period with the operation decision coefficient threshold:

[0040] If the low-frequency operation decision coefficient of the air conditioner during the operation period exceeds the operation decision coefficient threshold, it is inferred that the air conditioner is not suitable for low-frequency operation during the operation period, and a temporary suspension signal is generated and sent to the air conditioner operation control center. After receiving the temporary suspension signal, the air conditioner operation control center continuously monitors the ambient temperature of the current air conditioner coverage area and monitors the parameters affecting the ambient temperature. At the same time, the operation time of temperature control equipment other than the air conditioner in the air conditioner coverage area is reduced or turned off;

[0041] If the air conditioner low-frequency operation decision coefficient during the operation period does not exceed the operation decision coefficient threshold, it is inferred that the air conditioner is suitable for low-frequency operation during the air conditioner operation period, and a low-frequency execution signal is generated and sent to the air conditioner operation control center;

[0042] After receiving the low-frequency operation execution signal, the air-conditioning operation control center records the execution time and continuously monitors the ambient temperature of the air-conditioning coverage area during the execution process;

[0043] At the same time, a variable frequency decision detection signal is generated and sent to the variable frequency decision detection unit. After receiving the variable frequency decision detection signal, the variable frequency decision detection unit performs a variable frequency decision detection on the low-frequency operation period of the air conditioner, and infers whether the current low-frequency operation meets the actual demand based on the low-frequency operation analysis of the air conditioner, so as to avoid the failure to meet the regional temperature control demand during low-frequency operation, and also avoid the low-frequency operation increasing the energy consumption of the air conditioner although the temperature control demand is met, thereby reducing the efficiency of the variable frequency decision execution; through real-time variable frequency decision detection, it can also be inferred in real time whether the low-frequency operation of the air conditioner needs to be executed, so as to facilitate timely variable frequency regulation, ensure the regional temperature control efficiency while ensuring the energy consumption and energy-saving control of the regional air conditioner;

[0044] The overlapping time of the air conditioner compressor speed reduction phase and the air conditioner coverage area temperature increase phase when the air conditioner enters the low-frequency operation state in the current operation period is obtained, and at the same time, the corresponding synchronous increase span ratio of the compressor speed reduction span and the air conditioner coverage area temperature increase span in the corresponding stage overlap time is obtained, where the synchronous increase span ratio is expressed as the ratio of the compressor speed or temperature value floating span to the speed or temperature value of the corresponding type of data itself; and the overlapping time of the air conditioner compressor speed reduction phase and the air conditioner coverage area temperature increase phase when the air conditioner enters the low-frequency operation state in the current operation period, and the corresponding synchronous increase span ratio of the compressor speed reduction span and the air conditioner coverage area temperature increase span in the corresponding stage overlap time are marked as variable frequency risk duration data and variable frequency risk impact data, and compared with the stage overlap duration threshold and the synchronous increase span ratio cumulative value threshold respectively:

[0045] If the overlapping time of the air-conditioning compressor speed reduction stage and the air-conditioning coverage area temperature increase stage when the air-conditioning enters the low-frequency operation state during the current operation period exceeds the stage overlapping time threshold, or the corresponding synchronous increase span proportion cumulative value of the compressor speed reduction span and the air-conditioning coverage area temperature increase span during the corresponding stage overlapping time exceeds the synchronous increase span proportion cumulative value threshold, it is inferred that the current frequency conversion decision detection is abnormal, and a frequency conversion decision risk signal is generated and sent to the air-conditioning operation control center. After receiving the frequency conversion decision risk signal, the air-conditioning operation control center changes and slows down the air-conditioning frequency conversion decision, controls the frequency reduction speed, and monitors the temperature fluctuation of the air-conditioning coverage area in real time, and restores the frequency reduction speed when there is no abnormality in the temperature fluctuation, stops the frequency conversion decision when the temperature fluctuation rising trend continues to increase, and restores to the operating frequency that controls the temperature of the air-conditioning coverage area to the set temperature;

[0046] If the overlapping time of the air-conditioning compressor speed reduction stage and the air-conditioning coverage area temperature increase stage when the air-conditioning enters the low-frequency operation state during the current operation period does not exceed the stage overlapping time threshold, and the corresponding synchronous increase span proportion cumulative value of the compressor speed reduction span and the air-conditioning coverage area temperature increase span during the corresponding stage overlapping time does not exceed the synchronous increase span proportion cumulative value threshold, it is inferred that the current variable frequency decision detection is normal, and a variable frequency decision safety signal is generated and sent to the air-conditioning operation control center. After receiving the variable frequency decision safety signal, the air-conditioning operation control center puts the air-conditioning into the low-frequency operation state, and records various parameters of the low-frequency operation period in real time, such as the compression speed floating value and the ambient temperature floating value at the corresponding moment;

[0047] During the continuous variable frequency operation of the air conditioner at high frequency and low frequency, the air conditioner operation control center generates a variable frequency fault prediction signal and sends the variable frequency fault prediction signal to the variable frequency fault prediction unit;

[0048] After receiving the frequency conversion fault prediction signal, the frequency conversion fault prediction unit predicts the fault of the frequency conversion operation process of the air conditioner, and infers whether there is a fault risk of the air conditioner during the current frequency conversion operation according to the running state of the motor inside the compressor of the air conditioner, so as to timely predict the frequency conversion operation of the air conditioner, reduce the frequency conversion frequency of the air conditioner and operate the compressor in time, so as to avoid the air conditioner in the non-frequency conversion state failing to meet the temperature control requirements of the actual coverage area, resulting in a decrease in the operating efficiency of the air conditioner;

[0049] The distance deviation between the actual position of the motor rotor and the preset position in the motor adjustment stage of the compressor during the variable frequency operation of the air conditioner is obtained, and at the same time, the accumulated duration of the motor speed being in a phase lag when the angle and speed of the motor rotor in the compressor are in a fluctuating state when the air conditioner is in low frequency operation is obtained. The distance deviation between the actual position of the motor rotor and the preset position in the motor adjustment stage of the compressor during the variable frequency operation of the air conditioner and the accumulated duration of the rotor speed being in a phase lag when the angle and speed of the motor rotor in the compressor are in a fluctuating state when the air conditioner is in low frequency operation are marked as variable frequency position parameters and low frequency phase parameters, and are compared with the distance deviation threshold and the accumulated duration threshold respectively:

[0050] If the distance deviation between the actual position of the motor rotor and the preset position during the motor adjustment stage of the compressor during the variable frequency operation of the air conditioner exceeds the distance deviation threshold, or the angle and speed of the motor rotor in the compressor are in a fluctuating state when the air conditioner is in low-frequency operation, and the cumulative duration of the rotor speed in a phase lag exceeds the cumulative duration threshold, it is inferred that the compressor motor is in an inefficient operating state during the variable frequency operation of the air conditioner, and a variable frequency fault warning signal is generated and sent to the air conditioner operation control center. After receiving the variable frequency fault warning signal, the air conditioner operation control center performs performance debugging on the compressor and internal motor in the air conditioner and simulates the variable frequency operation state. The position and operating parameters of each component are counted under the simulated variable frequency operation state, so as to facilitate operation monitoring under real-time variable frequency operation state and timely warning in case of abnormality;

[0051] If the distance deviation between the actual position of the motor rotor and the preset position during the motor adjustment stage of the compressor during the variable frequency operation of the air conditioner does not exceed the distance deviation threshold, and the cumulative duration of the rotor speed being in a phase lag in the fluctuating angle and speed of the motor rotor in the compressor when the air conditioner is in low frequency operation does not exceed the cumulative duration threshold, it is inferred that the compressor motor is in a normal operating state during the variable frequency operation of the air conditioner, and a variable frequency operation qualified signal is generated and sent to the air conditioner operation control center;

[0052] Embodiment 2

[0053] The previous embodiment monitors and controls the low-frequency operation of the air conditioner to ensure the rationality and stability of operation. Figure 2 As shown, this embodiment adds a low-frequency operation efficiency evaluation unit on the basis of the previous embodiment, so as to facilitate the operation efficiency evaluation when entering the low-frequency operation state;

[0054] After the frequency conversion decision detection is normal and the air conditioner enters the low-frequency state, a low-frequency operation efficiency evaluation signal is generated and sent to the low-frequency operation efficiency evaluation unit. After receiving the low-frequency operation efficiency evaluation signal, the low-frequency operation efficiency evaluation unit evaluates the low-frequency operation efficiency of the air conditioner. Through the efficiency evaluation, it is inferred whether there is a risk in the current low-frequency operation state of the air conditioner, so as to timely adjust the low-frequency operation state to reduce the risk of frequency conversion failure. It can also be adjusted in time during low-efficiency operation to minimize the energy consumption of the air conditioner, thereby playing a role in energy saving and emission reduction;

[0055] The corresponding numerical ratio of the continuous operation time of high-low frequency fault-free conversion in the low-frequency operation state of the air conditioner and the control accuracy of the ambient temperature of the air conditioner coverage area within the corresponding continuous operation time is obtained. At the same time, the corresponding time numerical ratio of the set temperature control time and the set temperature maintenance time when the air conditioner enters the low-frequency state at different starting ambient temperatures in the low-frequency operation period of the air conditioner is obtained. The corresponding numerical ratio of the continuous operation time of high-low frequency fault-free conversion in the low-frequency operation state of the air conditioner and the control accuracy of the ambient temperature of the air conditioner coverage area within the corresponding continuous operation time, and the corresponding time numerical ratio of the set temperature control time and the set temperature maintenance time when the air conditioner enters the low-frequency state at different starting ambient temperatures in the low-frequency operation period of the air conditioner are marked as low-frequency operation data and low-frequency state data, respectively, and compared with the duration accuracy numerical ratio threshold and the time consumption numerical ratio threshold, respectively:

[0056] If the continuous operation time of high-low frequency fault-free conversion in the low-frequency operation state of the air conditioner and the corresponding numerical ratio of the control accuracy of the ambient temperature in the area covered by the air conditioner during the corresponding continuous operation time do not exceed the time accuracy numerical ratio threshold, or the corresponding time numerical ratio of the set temperature regulation time and the set temperature maintenance time when the air conditioner enters the low-frequency state at different starting ambient temperatures during the low-frequency operation period of the air conditioner exceeds the time numerical ratio threshold, it is inferred that the low-frequency operation efficiency evaluation of the air conditioner is abnormal, and a low-frequency operation inefficiency signal is generated and sent to the air-conditioning operation control center. After receiving the low-frequency operation inefficiency signal, the air-conditioning operation control center performs an air-conditioning state self-inspection for the period when the air conditioner is in the low-frequency operation state. If the self-inspection and debugging cannot be successful, the low-frequency operation time of the current operation period is reduced, and the performance debugging of the equipment itself is completed before the start of the adjacent operation period.

[0057] If the continuous operation time of high-low frequency fault-free conversion in the low-frequency operation state of the air conditioner and the corresponding numerical ratio of the control accuracy of the ambient temperature in the air-conditioning coverage area during the corresponding continuous operation time exceed the time accuracy numerical ratio threshold, and the corresponding time numerical ratio of the set temperature regulation time and the set temperature maintenance time when the air conditioner enters the low-frequency state at different starting ambient temperatures during the low-frequency operation period of the air conditioner does not exceed the time numerical ratio threshold, it is inferred that the low-frequency operation efficiency evaluation of the air conditioner is normal, a low-frequency operation high-efficiency signal is generated and sent to the air-conditioning operation control center;

[0058] A low-frequency operation control method for an air conditioner, the specific operation control method steps are as follows:

[0059] Low-frequency operation decision: perform decision analysis on the low-frequency operation of the air conditioner, obtain decision information, obtain the low-frequency operation decision coefficient of the air conditioner according to the formula, and infer whether the low-frequency operation is currently being executed by comparing the operation decision coefficient;

[0060] Frequency conversion decision detection: after analyzing and executing low-frequency operation, frequency conversion decision detection is performed on the low-frequency operation period of the air conditioner. The frequency conversion risk duration data and frequency conversion risk impact data during the operation period are collected. Based on the data comparison, it is inferred whether the frequency conversion decision detection is abnormal. If yes, regulation is carried out; otherwise, low-frequency operation is continued.

[0061] Inverter fault prediction: During low-frequency operation, the operating status of the motor inside the compressor of the air conditioner is analyzed to infer whether the air conditioner has a fault risk during the current variable frequency operation. The variable frequency position parameters and low-frequency phase parameters are collected, and the fault risk is inferred based on parameter analysis. If there is a fault risk, the low-frequency operation is stopped, and if there is no fault, the low-frequency state is continued;

[0062] The above formulas are obtained by collecting a large amount of data and performing software simulation, and a formula close to the actual value is selected. The coefficients in the formula are set by technicians in this field according to actual conditions;

[0063] When the present invention is in use, the low-frequency operation decision unit performs decision analysis on the low-frequency operation of the air conditioner, obtains decision information, obtains the low-frequency operation decision coefficient of the air conditioner according to the formula, and infers whether the low-frequency operation is currently being performed by comparing the operation decision coefficient. At the same time, after analyzing the execution of the low-frequency operation, the frequency conversion decision detection unit performs frequency conversion decision detection on the low-frequency operation period of the air conditioner, collects the frequency conversion risk duration data and the frequency conversion risk impact data in the operation period, and infers whether the frequency conversion decision detection is abnormal based on the data comparison. If yes, regulation is performed, otherwise, low-frequency operation is continued. During the low-frequency operation, the frequency conversion fault prediction unit infers whether there is a fault risk of the air conditioner during the current variable frequency operation based on the operating status of the motor inside the compressor in the air conditioner, collects the frequency conversion position parameters and the low-frequency phase parameters, and infers the fault risk based on the parameter analysis. If there is a fault risk, the low-frequency operation is stopped, and if there is no fault, the low-frequency state is continued.

[0064] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. An air conditioner low frequency operation control system, characterized in that: It includes an air-conditioning operation control center, wherein the air-conditioning operation control center is communicatively connected with a low-frequency operation decision unit, a variable frequency decision detection unit, and a variable frequency fault prediction unit; The low-frequency operation decision unit performs decision analysis on the low-frequency operation of the air conditioner, obtains decision information, and obtains the low-frequency operation decision coefficient of the air conditioner according to the formula. It infers whether low-frequency operation is currently being performed by comparing the operation decision coefficient. At the same time, after analyzing the execution of low-frequency operation, the variable frequency decision detection unit performs variable frequency decision detection on the low-frequency operation period of the air conditioner, collects the variable frequency risk duration data and variable frequency risk impact data during the operation period, and infers whether the variable frequency decision detection is abnormal based on data comparison. If yes, it will be regulated, otherwise, low-frequency operation will continue. During the low-frequency operation, the variable frequency fault prediction unit infers whether there is a fault risk of the air conditioner during the current variable frequency operation based on the operating status of the motor inside the compressor in the air conditioner. The variable frequency position parameters and low-frequency phase parameters are collected, and the fault risk is inferred based on parameter analysis. If there is a fault risk, the low-frequency operation is stopped, and if there is no fault, the low-frequency state is continued.

2. The air conditioner low frequency operation control system according to claim 1, characterized in that: The decision information includes the floating span value of the numerical deviation between the ambient temperature of the area covered by the air conditioner and the set temperature of the air conditioner during the current operating period of the air conditioner, the maximum control speed proportion of the floating span increase speed after the corresponding numerical deviation floating span shows an increasing trend, the numerical floating frequency of the influencing parameters of the ambient temperature of the area covered by the air conditioner during the current operating period of the air conditioner, and the operating time of the temperature control equipment other than the air conditioner when the temperature of the area covered by the air conditioner is adjusted to the set temperature of the air conditioner during the current operating period of the air conditioner, and the corresponding setting labels SFK, SZB, FDP, and WKS.

3. The air conditioner low frequency operation control system according to claim 2, characterized in that: The formula is: Among them, J is the decision coefficient of low-frequency operation of air conditioner during the operation period, mjk1, mjk2, mjk3, and mjk4 are preset proportional coefficients, and α is used as the error correction factor, with a value of 0.

98.

4. The air conditioner low frequency operation control system according to claim 3, characterized in that: If the low-frequency operation decision coefficient of the air conditioner during the operation period exceeds the operation decision coefficient threshold, a temporary non-execution signal is generated; if the low-frequency operation decision coefficient of the air conditioner during the operation period does not exceed the operation decision coefficient threshold, a low-frequency execution signal is generated.

5. The air conditioner low frequency operation control system according to claim 1, characterized in that: The frequency conversion risk duration data and frequency conversion risk impact data are respectively the overlapping time of the air-conditioning compressor speed decrease phase and the air-conditioning coverage area temperature increase phase when the air-conditioning enters the low-frequency operation state during the current operating period, and the cumulative value of the proportion of the corresponding synchronous increase spans of the compressor speed decrease span and the air-conditioning coverage area temperature increase span during the corresponding overlapping time periods.

6. The air conditioner low frequency operation control system according to claim 5, characterized in that: If the frequency conversion risk duration data exceeds the stage overlap duration threshold, or the frequency conversion risk impact data exceeds the cumulative value threshold of the synchronous increase span ratio, a frequency conversion decision risk signal is generated; if the frequency conversion risk duration data does not exceed the stage overlap duration threshold, and the frequency conversion risk impact data does not exceed the cumulative value threshold of the synchronous increase span ratio, a frequency conversion decision safety signal is generated.

7. The air conditioner low frequency operation control system according to claim 1, characterized in that: The variable frequency position parameter and low-frequency phase parameter are respectively the distance deviation between the actual position of the motor rotor and the preset position during the motor adjustment stage inside the compressor during the variable frequency operation of the air conditioner, and the cumulative duration of the rotor speed in the phase lag when the angle and speed of the motor rotor inside the compressor are in a fluctuating state when the air conditioner is in low-frequency operation.

8. The air conditioner low frequency operation control system according to claim 7, characterized in that: If the frequency conversion position parameter exceeds the distance deviation threshold, or the low-frequency phase parameter exceeds the cumulative duration threshold, a frequency conversion fault warning signal is generated; if the frequency conversion position parameter does not exceed the distance deviation threshold, and the low-frequency phase parameter does not exceed the cumulative duration threshold, a frequency conversion operation qualified signal is generated.

9. A method for controlling low-frequency operation of an air conditioner, characterized in that: An air conditioner low-frequency operation control system as described in any one of claims 1 to 8 is adopted.

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