Compressor heating control method, control device and air conditioner of air conditioner
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- QINGDAO HAIER AIR CONDITIONING ELECTRONICS CO LTD
- Filing Date
- 2026-03-20
- Publication Date
- 2026-05-29
Smart Images
Figure CN122107545A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrical technology, and in particular to a compressor heating control method, control device, and air conditioner for an air conditioner. Background Technology
[0002] In air conditioning systems, if the compressor is shut down in a low-temperature environment, the viscosity of its internal lubricating oil will increase significantly, potentially leading to poor lubrication during the next startup, or even causing the compressor to seize or wear. To solve this problem, existing technologies typically employ a winding self-heating method, which uses an inverter to apply a pulse width modulation (PWM) signal to the compressor's motor windings, causing the windings to generate Joule heat as a resistive load, thereby achieving preheating.
[0003] Such heating control methods generally employ an open-loop control strategy. Specifically, the system sets a fixed PWM duty cycle based on experience or fixed operating conditions. When heating is required, it directly outputs a PWM signal with this duty cycle to drive the inverter, causing the windings to be continuously energized and heated. This duty cycle is typically calibrated based on the target power at the rated DC bus voltage and remains unchanged throughout the product's lifespan.
[0004] However, in practical applications, the DC bus voltage is often affected by factors such as grid fluctuations, rectifier circuit characteristics, and load changes, and frequently deviates from the rated value. For example, during peak electricity consumption periods, a drop in mains voltage can cause the bus voltage to fall below 300V; while in lightly loaded or high-voltage areas, the bus voltage may rise above 400V. Since the winding heating power is proportional to the square of the bus voltage, when the voltage deviates from the calibration conditions, the actual heating power will significantly deviate from the expected value. At low voltage, insufficient heating power cannot effectively raise the winding temperature, affecting the compressor's starting reliability; at high voltage, excessive heating power not only wastes energy but may also accelerate insulation aging due to localized overheating, or even trigger over-temperature protection and interrupt heating. Furthermore, the fixed duty cycle strategy cannot adapt to differences in heating requirements caused by different ambient temperatures, downtime, or compressor models, resulting in poor control flexibility and stability. Summary of the Invention
[0005] This invention provides a compressor heating control method, control device, and air conditioner for an air conditioner, addressing the shortcomings of existing technologies and achieving the following technical effects: By introducing a feedforward computing mechanism based on DC bus voltage compensation, the control accuracy and environmental adaptability of heating power are significantly improved. Compared to the traditional open-loop scheme with a fixed duty cycle, this method can automatically adjust the PWM duty cycle under bus voltage fluctuations, making the actual heating power stably approach the target value, thereby effectively ensuring reliable compressor start-up in low-temperature environments while avoiding energy waste and overheating risks.
[0006] In a first aspect, the present invention protects a compressor heating control method for an air conditioner, comprising: A pulse width modulation (PWM) signal is input to the inverter connected to the compressor to control the heating of the compressor's motor windings; Obtain the target heating power and the current DC bus voltage; Based on a pre-established functional relationship model between heating power, DC bus voltage, and PWM duty cycle, the target PWM duty cycle is calculated according to the target heating power and the current DC bus voltage. The PWM signal is generated according to the target PWM duty cycle to drive the inverter to heat the motor windings.
[0007] According to some embodiments of the present invention, after the step of generating the PWM signal according to the target PWM duty cycle, the method further includes: During the heating process, the instantaneous current of the motor windings is collected; The actual heating power is calculated based on the instantaneous current and the current DC bus voltage; The duty cycle of the PWM signal is adjusted based on the deviation between the actual heating power and the target heating power.
[0008] According to some embodiments of the present invention, the functional relationship model is established in the following manner: During the calibration phase, multiple PWM signals with different duty cycles are applied to the inverter, and the corresponding DC bus voltage, instantaneous current of the motor winding and actual heating power are collected respectively. Based on multiple sets of data on duty cycle, DC bus voltage, and actual heating power, a fitting algorithm is used to establish the functional relationship model.
[0009] According to some embodiments of the present invention, the step of feedback adjustment of the duty cycle of the PWM signal includes: The deviation is processed by PID control to generate a duty cycle correction value, which is then added to the target PWM duty cycle to obtain the final output PWM duty cycle.
[0010] According to some embodiments of the present invention, the step of feedback adjustment of the duty cycle of the PWM signal further includes: The final output PWM duty cycle is limited to between a preset minimum duty cycle and a maximum duty cycle.
[0011] According to some embodiments of the present invention, before obtaining the target heating power, the method further includes: Obtain at least one of the following: the current oil temperature of the lubricating oil in the compressor, the compressor's operating mode information before shutdown, and the ambient temperature. The target heating power is dynamically adjusted based on at least one of the current oil temperature, the operating mode information, and the ambient temperature.
[0012] According to some embodiments of the present invention, the step of dynamically adjusting the target heating power based on at least one of the current oil temperature, the operating mode information, and the ambient temperature includes: When the current oil temperature is lower than a preset oil temperature threshold, the target heating power is increased, and the target heating power increases as the current oil temperature decreases. If the operating mode before the shutdown is a high-load operating mode, increase the target heating power; When the ambient temperature is lower than a preset ambient temperature threshold, the target heating power is increased, and the target heating power increases as the ambient temperature decreases. When at least two of the above situations are triggered simultaneously, the highest determined target heating power is taken as the final target heating power.
[0013] According to some embodiments of the present invention, it further includes: After each heating process is completed, determine whether the heating has reached a steady state; Once the heating reaches a stable state, the stable PWM duty cycle, DC bus voltage, and actual heating power are recorded as valid data points. If the cumulative number of valid data points meets the preset conditions, the function relationship model is refitted based on the historical valid data points and the newly added valid data points, and the stored model parameters are updated with the refitted model parameters.
[0014] Secondly, the present invention also protects a compressor heating control device for an air conditioner, comprising: The first control module is used to input a pulse width modulation (PWM) signal to the inverter connected to the compressor in order to control the motor windings of the compressor to be heated. The first acquisition module is used to acquire the target heating power and the current DC bus voltage; The second acquisition module is used to calculate the target PWM duty cycle based on the target heating power and the current DC bus voltage, according to a pre-established functional relationship model between heating power, DC bus voltage and PWM duty cycle. The second control module is used to generate the PWM signal according to the target PWM duty cycle, so as to drive the inverter to heat the motor windings.
[0015] Thirdly, the present invention also protects an air conditioner, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the steps of the compressor heating control method for the air conditioner as described in the first aspect of the present invention.
[0016] In summary, the compressor heating control method provided by this invention significantly improves the control accuracy and environmental adaptability of heating power by introducing a feedforward computing mechanism based on DC bus voltage compensation. Compared with the traditional open-loop scheme with a fixed duty cycle, this method can automatically adjust the PWM duty cycle under bus voltage fluctuation conditions, making the actual heating power stably approach the target value, thereby effectively ensuring the reliable start-up of the compressor in low-temperature environments, while avoiding energy waste and overheating risks.
[0017] Specifically, this method utilizes a pre-established functional relationship model between heating power, DC bus voltage, and PWM duty cycle. During operation, it acquires the current bus voltage and target heating power in real time and dynamically calculates the target PWM duty cycle adapted to the current operating conditions. Since the model embeds the voltage-power influence law, the system can actively compensate for deviations caused by voltage changes without relying on power feedback. For example, when the bus voltage decreases, the controller automatically increases the duty cycle to maintain the required power; when the voltage increases, it decreases the duty cycle accordingly. This feedforward adaptive adjustment mechanism fundamentally overcomes the power inaccuracy problem caused by voltage fluctuations in open-loop control. Furthermore, this method does not rely on additional power sensors or complex closed-loop circuits; it only requires conventional voltage sampling to achieve high-precision control, balancing performance improvement with cost control. Therefore, this method significantly enhances the stability, energy efficiency, and start-up reliability of the heating system without changing the hardware architecture. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0019] Figure 1 This is one of the flowcharts illustrating the compressor heating control method for an air conditioner provided by the present invention.
[0020] Figure 2 This is the second flowchart of the compressor heating control method for air conditioners provided by the present invention.
[0021] Figure 3 This is a schematic diagram of the compressor heating control device for an air conditioner provided by the present invention.
[0022] Figure 4 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0024] The compressor heating control method, control device, and air conditioner of the present invention are described below with reference to the accompanying drawings. Before providing a detailed description of the embodiments of the present invention, the overall application scenario is first described. The compressor heating control method, control device, electronic device, and computer-readable storage medium of the air conditioner of the present invention can be applied locally to the air conditioner, to cloud platforms in the Internet field, or to other types of cloud platforms in the Internet field, or to third-party devices. These third-party devices may include various types such as mobile phones, tablets, laptops, in-vehicle computers, and other smart terminals.
[0025] The following description uses a compressor heating control method applicable to air conditioners as an example. It should be understood that the compressor heating control method of this invention can also be applied to cloud platforms and third-party devices. It should be noted that an air conditioner includes a compressor, which contains an oil sump. The control method of this invention is mainly used in the process of heating the oil sump before the compressor starts, that is, in the preheating stage of the oil sump inside the compressor before startup.
[0026] like Figure 1 and Figure 2 As shown, the compressor heating control method of an air conditioner according to a first aspect embodiment of the present invention includes: Step S1: Input a pulse width modulation (PWM) signal to the inverter connected to the compressor to control the heating of the compressor's motor windings.
[0027] In step S1, the controller outputs a square wave signal with a specific duty cycle to the inverter's drive circuit. The inverter then controls the switching of its power switching devices, applying an alternating voltage to the compressor's motor windings. This causes the windings to generate Joule heat due to resistance, thus achieving the heating function. The purpose of this step is to establish a path for converting electrical energy into thermal energy, serving as the basis for the entire heating control process. For example, when the compressor is off and the ambient temperature is low, the system can actively initiate this step to preheat the windings.
[0028] Step S2: Obtain the target heating power and the current DC bus voltage.
[0029] In this step, the controller can read the desired heating power value from the internal setting module or the external command interface, and detect the voltage value on the DC bus in real time through the voltage sampling circuit. The target heating power can be preset or dynamically adjusted according to the compressor's startup requirements, while the current DC bus voltage reflects the real-time status of the power supply system. This operation provides the necessary input parameters for subsequent duty cycle calculations, ensuring that control decisions are based on actual operating conditions.
[0030] Step S3: Based on the pre-established functional relationship model between heating power, DC bus voltage and PWM duty cycle, calculate the target PWM duty cycle according to the target heating power and the current DC bus voltage.
[0031] It is understandable that the aforementioned functional relationship model can be obtained through pre-establishment. For example, before product shipment or during system initialization, the mathematical mapping relationship between the three can be obtained through experimental calibration. This model can be a polynomial function, a lookup table, or other fitted expression. The controller uses this model, taking the current target heating power and the measured DC bus voltage as input variables, to calculate the required PWM duty cycle. Thus, based on the aforementioned functional relationship model, the specific magnitude of the PWM duty cycle can be precisely controlled, thereby achieving precise heating.
[0032] Step S4: Generate a PWM signal based on the target PWM duty cycle to drive the inverter to heat the motor windings.
[0033] In practice, step S4 specifically involves the controller converting its calculated duty cycle value into a specific pulse width and outputting the corresponding PWM waveform to the inverter according to a fixed carrier frequency. In this way, this step transforms the abstract control quantity into a physically executable electrical signal, completing the execution of the control command and driving the inverter to heat the motor windings.
[0034] In existing air conditioning systems, after the compressor stops and the environment is cold, the motor windings typically need to be preheated to reduce the viscosity of the lubricating oil and ensure the reliability of the next start-up. Traditional heating control methods often use an open-loop approach, which outputs a pulse width modulation (PWM) signal with a fixed duty cycle to the inverter to energize and heat the windings. However, this method does not consider the actual fluctuations in the DC bus voltage. Since the heating power of the windings is proportional to the square of the bus voltage, overheating is likely when the grid voltage is high, while insufficient heating occurs when the voltage is low. This power deviation not only affects starting performance but may also cause energy waste or safety hazards. Especially in different regions or during peak electricity consumption periods, the bus voltage fluctuates significantly, making it difficult for the fixed duty cycle strategy to meet precise heating requirements.
[0035] To address the technical deficiencies in the aforementioned related technologies, this invention proposes a compressor heating control method based on feedforward calculation. This method establishes a functional relationship model between heating power, DC bus voltage, and PWM duty cycle in advance, and dynamically calculates a target PWM duty cycle that is suitable for the current operating conditions by combining the target heating power and the current DC bus voltage obtained in real time during the operation phase, thereby achieving precise control of heating power.
[0036] Specifically, this invention incorporates bus voltage as a key compensation variable into the control decision. During the calibration phase, the system experimentally collects multiple sets of voltage, current, and corresponding power data under different duty cycles, fitting a mathematical model that reflects the coupling relationship among these three parameters. During operation, the controller no longer relies on fixed parameters but instead infers the required duty cycle based on the current voltage conditions. For example, when the bus voltage drops, the model automatically outputs a higher duty cycle to maintain the target power; conversely, it reduces the duty cycle to avoid overheating. This mechanism is essentially a voltage-adaptive feedforward control, which proactively adjusts the control input without waiting for power deviations, significantly improving response speed and control accuracy. Furthermore, because the model incorporates physical laws, high-stability heating can be achieved even in a pure feedforward mode without power feedback.
[0037] In summary, by introducing a voltage-compensated functional relationship model, this invention achieves adaptive adjustment of heating power to bus voltage fluctuations, effectively overcoming the problems of large power deviation and poor adaptability in traditional open-loop control. Without increasing hardware costs, it significantly improves the reliability and energy efficiency of compressor low-temperature start-up.
[0038] Furthermore, based on the above basic working principle, the specific execution process of the control method of the present invention is as follows: In the scenario where the compressor needs to be preheated, the system first executes step S1, outputting an initial PWM signal to the inverter to start winding heating. Then, in step S2, the controller acquires the target heating power set for this heating task and simultaneously collects the current DC bus voltage. Next, in step S3, the controller calls a pre-stored function relationship model, using the target heating power and the current DC bus voltage as inputs, to calculate the PWM duty cycle required to achieve that power. Finally, in step S4, the controller generates a precise PWM signal based on this duty cycle and outputs it to the inverter, enabling the motor windings to stably output heating power close to the target value under the current voltage conditions. The entire process is completed in a feedforward manner, with a rapid response and effective compensation for power deviations caused by bus voltage fluctuations.
[0039] In summary, the compressor heating control method provided by this invention significantly improves the control accuracy and environmental adaptability of heating power by introducing a feedforward computing mechanism based on DC bus voltage compensation. Compared with the traditional open-loop scheme with a fixed duty cycle, this method can automatically adjust the PWM duty cycle under bus voltage fluctuation conditions, making the actual heating power stably approach the target value, thereby effectively ensuring the reliable start-up of the compressor in low-temperature environments, while avoiding energy waste and overheating risks.
[0040] Specifically, this method utilizes a pre-established functional relationship model between heating power, DC bus voltage, and PWM duty cycle. During operation, it acquires the current bus voltage and target heating power in real time and dynamically calculates the target PWM duty cycle adapted to the current operating conditions. Since the model embeds the voltage-power influence law, the system can actively compensate for deviations caused by voltage changes without relying on power feedback. For example, when the bus voltage decreases, the controller automatically increases the duty cycle to maintain the required power; when the voltage increases, it decreases the duty cycle accordingly. This feedforward adaptive adjustment mechanism fundamentally overcomes the power inaccuracy problem caused by voltage fluctuations in open-loop control. Furthermore, this method does not rely on additional power sensors or complex closed-loop circuits; it only requires conventional voltage sampling to achieve high-precision control, balancing performance improvement with cost control. Therefore, this method significantly enhances the stability, energy efficiency, and start-up reliability of the heating system without changing the hardware architecture.
[0041] like Figure 1 and Figure 2 As shown, according to some embodiments of the present invention, after the step of generating a PWM signal based on a target PWM duty cycle, the compressor heating control method for an air conditioner further includes: During the heating process, the instantaneous current of the motor windings is collected; The actual heating power is calculated based on the instantaneous current and the current DC bus voltage; The duty cycle of the PWM signal is adjusted based on the deviation between the actual heating power and the target heating power.
[0042] It is understood that this embodiment introduces a real-time feedback mechanism on the basis of feedforward control to improve the control accuracy of heating power. During the heating process, the system continuously acquires the instantaneous current of the motor windings. This current reflects the actual amount of current flowing through the windings and is typically obtained by sampling from the inverter output side or the DC bus circuit using a current sensor. Combined with the synchronously acquired current DC bus voltage, the controller can calculate the actual heating power of the windings based on the basic formula for electrical power.
[0043] Due to various disturbances in actual operating conditions, such as changes in winding resistance with increasing temperature, inverter switching losses, minor fluctuations in bus voltage, or model calibration deviations, feedforward calculations alone may not be able to ensure that the actual power is exactly equal to the target value. Therefore, the system compares the calculated actual heating power with the target heating power, generates a deviation signal, and dynamically adjusts the PWM duty cycle accordingly. For example, when the actual power is detected to be lower than the target value, the controller will appropriately increase the duty cycle to enhance the heating intensity; conversely, it will decrease the duty cycle to suppress overheating.
[0044] In this way, the aforementioned feedback adjustment mechanism effectively compensates for the limitations of the feedforward model, enabling the system to adapt to internal parameter drift and external disturbances. Its effect is to significantly improve the steady-state accuracy and robustness of the heating process, ensuring that the compressor windings can achieve stable and reliable preheating effects under different environmental and operating conditions.
[0045] According to some embodiments of the present invention, the functional relationship model is established in the following manner: During the calibration phase, multiple PWM signals with different duty cycles are applied to the inverter, and the corresponding DC bus voltage, instantaneous current of the motor windings and actual heating power are collected respectively. Based on multiple sets of duty cycle, DC bus voltage and actual heating power data, a functional relationship model is established using a fitting algorithm.
[0046] This embodiment clarifies the process of establishing the functional relationship model, ensuring its engineering feasibility and physical accuracy. During the calibration phase, the system actively applies a series of PWM signals with different duty cycles to the inverter, covering typical values within the expected operating range. For each applied duty cycle, the system synchronously acquires the corresponding DC bus voltage and the instantaneous current of the motor windings, and calculates the actual heating power based on these two parameters, thus forming a set of three data points containing the duty cycle, bus voltage, and heating power. By traversing multiple duty cycles and recording the corresponding operating conditions, a sufficient amount of experimental data can be obtained.
[0047] Subsequently, the system utilizes these multiple sets of measured data and employs a mathematical fitting algorithm to construct a mapping relationship between heating power, DC bus voltage, and PWM duty cycle. The fitting algorithm can be least squares, polynomial regression, spline interpolation, or machine learning methods, with the goal of making the model output as close as possible to the measured results. The established functional model reflects the duty cycle required to achieve a specific heating power under different bus voltage conditions, thus providing a reliable basis for feedforward calculations during operation.
[0048] For example, in a laboratory environment, the duty cycle can be set sequentially to 20%, 40%, 60%, and 80%, and the stable bus voltage and winding current can be recorded under each setting to calculate the corresponding actual heating power. Finally, a two-dimensional function D = f(P, U) is fitted based on this data, where D is the duty cycle, P is the heating power, and U is the bus voltage. This modeling method is based on measured data, fully considers the nonlinear characteristics of the system, and effectively ensures the accuracy and generalization ability of the model in practical applications.
[0049] In some specific embodiments, the DC bus voltage, instantaneous motor winding current, actual heating power, and their corresponding PWM duty cycle data are shown in Table 1 below: Table 1 Current / mA Voltage / V Duty cycle Power / W 859.9 381 361 52.18 1749 381 1567 198.4 1367 305 1167 111.59 1334 457 839 113.35 According to some embodiments of the present invention, the step of feedback adjustment of the duty cycle of the PWM signal includes: The deviation is calculated using PID control to generate a duty cycle correction value, which is then added to the target PWM duty cycle to obtain the final output PWM duty cycle.
[0050] It is understood that this embodiment specifically defines the implementation method of feedback regulation, employing a classic proportional-integral-derivative (PID) control strategy to dynamically correct the duty cycle. Specifically, after obtaining the deviation between the actual heating power and the target heating power, the controller sends this deviation as an input signal to the PID calculation unit. The proportional term is used to quickly respond to the current deviation, the integral term is used to eliminate steady-state error, and the derivative term is used to suppress overshoot and improve the system's damping characteristics. The weighted combination of these three terms outputs a duty cycle correction.
[0051] This correction is then superimposed on the target PWM duty cycle calculated by the feedforward model to form the final PWM duty cycle used to drive the inverter. This structure achieves coordinated control of feedforward and feedback. The feedforward part provides the basic control quantity to deal with known disturbances (such as bus voltage changes), while the feedback part compensates for uncertainties not covered by the model through PID regulation, such as resistance changes caused by winding temperature rise, sensor noise, or load disturbances.
[0052] For example, when the resistance increases and the actual power decreases due to the rise in winding temperature, the deviation signal is negative. The PID controller outputs a positive correction value, so that the final duty cycle is slightly higher than the feedforward value, thereby maintaining power stability.
[0053] In summary, this method has a clear structure and mature parameter tuning, making it easy to implement in embedded control systems. It can effectively improve the tracking accuracy and dynamic response performance of heating power without significantly increasing the computational burden.
[0054] Furthermore, the step of feedback adjustment of the duty cycle of the PWM signal also includes: The final output PWM duty cycle is limited to between the preset minimum and maximum duty cycles.
[0055] This embodiment introduces a duty cycle limiting mechanism during feedback regulation to ensure the safety and reliability of system operation. It should be noted that after generating the duty cycle correction value through PID calculation and superimposing it onto the target PWM duty cycle, the final output value may exceed a reasonable range due to excessive deviation or integral accumulation. If the duty cycle is too low, it may lead to insufficient heating power, failing to effectively raise the winding temperature; if the duty cycle is too high, it may cause excessive winding current, resulting in inverter overload, excessive temperature rise of power devices, or damage to winding insulation.
[0056] To this end, the system sets a preset minimum and maximum duty cycle as safety boundaries. Before practical application, the final output PWM duty cycle needs to be limited. If the calculated value is lower than the minimum duty cycle, it is forcibly clamped to the lower limit; if it is higher than the maximum duty cycle, it is clamped to the upper limit. This limiting operation is usually performed at the end of the control cycle to ensure that all adjustment commands are within the controllable range.
[0057] For example, in low-temperature startup scenarios, even if the PID controller continues to integrate due to prolonged insufficient power, its output will not cause the duty cycle to exceed the maximum allowed by the hardware, thus avoiding current surges. Similarly, as the target temperature approaches, the duty cycle will not drop below zero, maintaining basic heating capacity to prevent temperature drop.
[0058] In this way, the above measures effectively prevent the control quantity from becoming saturated or out of control, and enhance the stability and engineering practicality of the entire heating control system.
[0059] According to some embodiments of the present invention, before obtaining the target heating power, the compressor heating control method of the air conditioner further includes: Obtain at least one of the following: the current oil temperature of the lubricating oil inside the compressor, the compressor's operating mode information before shutdown, and the ambient temperature. The target heating power is dynamically adjusted based on at least one of the following: current oil temperature, operating mode information, and ambient temperature.
[0060] In this embodiment, before setting the target heating power, the method introduces environmental and operating condition parameters related to the compressor's thermal state and operating history, making the determination of heating demand more accurate. Specifically, the system can obtain at least one of the following: the current oil temperature of the lubricating oil in the compressor, the operating mode information of the compressor before shutdown, and the current ambient temperature. These parameters are all closely related to the lubrication conditions and heat load when the compressor starts.
[0061] The temperature of the lubricating oil directly affects its viscosity. The lower the oil temperature, the higher the viscosity, the greater the starting resistance, and the higher the required preheating intensity. The operating mode before shutdown reflects the heat accumulation state inside the compressor. For example, after a long period of high-load cooling operation, the windings and lubricating oil are still relatively hot, so the heating power can be appropriately reduced. However, after a short period of low-load operation, stronger heating may be required. The ambient temperature determines the heat dissipation rate during shutdown. Low-temperature environments accelerate heat loss, so the heating power needs to be increased to maintain effective preheating.
[0062] Based on at least one of the above parameters, the system dynamically adjusts the target heating power. For example, when the oil temperature is detected to be low or the ambient temperature is in a frigid range, the target heating power is automatically increased; when it is identified that the system was operating under high load before shutdown and the oil temperature is still high, the target value is appropriately reduced. This strategy avoids overheating or underheating problems caused by using a fixed heating power, ensuring that heating control matches actual physical needs.
[0063] As shown above, by fusing multi-source state information to make target power decisions, this method significantly improves the adaptability and energy efficiency of the heating strategy, and reduces unnecessary energy consumption while ensuring start-up reliability.
[0064] In some specific embodiments of the present invention, the step of dynamically adjusting the target heating power based on at least one of the current oil temperature, operating mode information, and ambient temperature includes: When the current oil temperature is lower than the preset oil temperature threshold, the target heating power is increased, and the target heating power increases as the current oil temperature decreases. Increase the target heating power when the operating mode before shutdown is high load operation mode; When the ambient temperature is lower than the preset ambient temperature threshold, the target heating power is increased, and the target heating power increases as the ambient temperature decreases.
[0065] When at least two of the above situations are triggered simultaneously, the highest determined target heating power is taken as the final target heating power.
[0066] It is understood that the above embodiments specify the dynamic adjustment logic of the target heating power and clarify the decision rules under multi-parameter conditions. The system first determines whether the current oil temperature is lower than the preset oil temperature threshold. If it is lower than the threshold, it indicates that the lubricating oil viscosity is high and the starting resistance is large. At this time, the target heating power is increased, and the lower the oil temperature, the greater the required heating intensity, and the target heating power is increased accordingly to ensure sufficient preheating.
[0067] Secondly, the system identifies the operating mode of the compressor before it stops. If it was in a high-load operating mode before stopping, such as long-term high-frequency cooling or heating, it means that a lot of heat has accumulated inside the compressor, and the temperature of the windings and lubricating oil is relatively high. Although the heating demand can be appropriately reduced at this time, considering that rapid cooling or refrigerant recirculation may occur after high-load shutdown, it is still necessary to maintain a high heating power to prevent local condensation or lubrication failure. Therefore, the system is set to increase the target heating power.
[0068] Next, the system checks whether the ambient temperature is lower than the preset ambient temperature threshold. In low-temperature environments, the compressor dissipates heat faster, and the winding temperature drops more easily. Therefore, the target heating power needs to be increased, and the lower the ambient temperature, the stronger the heating demand, and the greater the target heating power.
[0069] When two or more of the above conditions are met simultaneously, the system calculates the corresponding target heating power based on each condition and selects the highest value as the final target heating power to be executed. This "highest value" strategy ensures sufficient heating capacity even under the most demanding operating conditions, avoiding start-up failures due to conservative estimations. For example, when the oil temperature is extremely low and the ambient temperature is also frigid, even if the system was in high-load mode before shutdown, the system will still prioritize the higher heating demand corresponding to either the oil temperature or the ambient temperature. This mechanism balances safety and adaptability, ensuring that heating control is neither overly conservative nor underheating.
[0070] According to some embodiments of the present invention, the compressor heating control method for an air conditioner further includes: After each heating process is completed, determine whether the heating has reached a steady state; Once the heating reaches a stable state, the stable PWM duty cycle, DC bus voltage, and actual heating power are recorded as valid data points. If the cumulative number of valid data points meets the preset conditions, the functional relationship model is refitted based on the historical valid data points and the newly added valid data points, and the stored model parameters are updated with the refitted model parameters.
[0071] Specifically, after each heating process, the system first determines whether the heating has reached a steady state. A steady state means that the actual heating power fluctuates around the target value without a significant trend change, indicating that the control has entered a steady state, and the recorded data at this time is representative.
[0072] If the state is determined to be stable, the corresponding stable PWM duty cycle, DC bus voltage, and actual heating power are stored as a set of valid data points. This data point truly reflects the mapping relationship between the three under the current hardware conditions and can effectively capture the effects of slowly changing factors such as changes in winding resistance due to long-term use, inverter efficiency degradation, or sensor zero-point drift.
[0073] When the cumulative number of valid data points reaches a preset condition, such as meeting the minimum sample size requirement, the system initiates the model update process. This process uses both historical valid data points and newly added data points as the training set, recalculates the parameters of the functional relationship model using the same fitting algorithm as the initial modeling, and replaces the originally stored model parameters with the new parameters. For example, after long-term operation, the winding resistance may increase slightly due to oxidation, resulting in a decrease in actual power at the same duty cycle. The new data points will reflect this change, and the refitted model will automatically adjust the duty cycle output strategy to compensate for this deviation.
[0074] In this way, by periodically updating the model using real operating data, the method achieves online adaptation of the control strategy, effectively maintains the accuracy of feedforward calculation, extends the effective service life of the system, and improves the reliability of heating control throughout its entire life cycle.
[0075] The compressor heating control device for an air conditioner provided by the present invention will be described below. The compressor heating control device for an air conditioner described below can be referred to in correspondence with the compressor heating control method for an air conditioner described above.
[0076] like Figure 3 As shown, the compressor heating control device for an air conditioner according to a second aspect embodiment of the present invention includes: The first control module 110 is used to input a pulse width modulation (PWM) signal to the inverter connected to the compressor to heat the motor windings of the compressor. The first acquisition module 120 is used to acquire the target heating power and the current DC bus voltage; The second acquisition module 130 is used to calculate the target PWM duty cycle based on the pre-established functional relationship model between heating power, DC bus voltage and PWM duty cycle, according to the target heating power and the current DC bus voltage. The second control module 140 is used to generate a PWM signal according to the target PWM duty cycle to drive the inverter to heat the motor windings.
[0077] Thirdly, the present invention also protects an air conditioner, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the compressor heating control method of the air conditioner as described in the first aspect of the present invention.
[0078] Figure 4 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 4 As shown, the electronic device may include a processor 810, a communication interface 820, a memory 830, and a communication bus 840. The processor 810, communication interface 820, and memory 830 communicate with each other via the communication bus 840. The processor 810 can call logic instructions in the memory 830 to execute a compressor heating control method for an air conditioner, including: inputting a pulse width modulation (PWM) signal to an inverter connected to the compressor to heat the motor windings of the compressor; acquiring the target heating power and the current DC bus voltage; calculating the target PWM duty cycle based on a pre-established functional relationship model between the heating power, DC bus voltage, and PWM duty cycle, according to the target heating power and the current DC bus voltage; and generating a PWM signal according to the target PWM duty cycle to drive the inverter to heat the motor windings.
[0079] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0080] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions, and when the program instructions are executed by the computer, the computer can execute the compressor heating control method for an air conditioner provided by the above methods, including: inputting a pulse width modulation (PWM) signal to an inverter connected to the compressor to heat the motor windings of the compressor; obtaining a target heating power and a current DC bus voltage; calculating a target PWM duty cycle based on a pre-established functional relationship model between the heating power, the DC bus voltage, and the PWM duty cycle, according to the target heating power and the current DC bus voltage; and generating a PWM signal according to the target PWM duty cycle to drive the inverter to heat the motor windings.
[0081] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the compressor heating control method of the air conditioner provided above, including: inputting a pulse width modulation (PWM) signal to an inverter connected to the compressor to heat the motor windings of the compressor; acquiring a target heating power and a current DC bus voltage; calculating a target PWM duty cycle based on a pre-established functional relationship model between the heating power, the DC bus voltage, and the PWM duty cycle, according to the target heating power and the current DC bus voltage; and generating a PWM signal according to the target PWM duty cycle to drive the inverter to heat the motor windings.
[0082] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.
[0083] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of various embodiments or some parts of embodiments.
[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for controlling the heating of an air conditioner compressor, characterized in that, include: A pulse width modulation (PWM) signal is input to the inverter connected to the compressor to control the heating of the compressor's motor windings; Obtain the target heating power and the current DC bus voltage; Based on a pre-established functional relationship model between heating power, DC bus voltage, and PWM duty cycle, the target PWM duty cycle is calculated according to the target heating power and the current DC bus voltage. The PWM signal is generated according to the target PWM duty cycle to drive the inverter to heat the motor windings.
2. The compressor heating control method for an air conditioner according to claim 1, characterized in that, After the step of generating the PWM signal according to the target PWM duty cycle, the method further includes: During the heating process, the instantaneous current of the motor windings is collected; The actual heating power is calculated based on the instantaneous current and the current DC bus voltage; The duty cycle of the PWM signal is adjusted based on the deviation between the actual heating power and the target heating power.
3. The compressor heating control method for an air conditioner according to claim 2, characterized in that, The functional relationship model is established in the following way: During the calibration phase, multiple PWM signals with different duty cycles are applied to the inverter, and the corresponding DC bus voltage, instantaneous current of the motor winding and actual heating power are collected respectively. Based on multiple sets of data on duty cycle, DC bus voltage, and actual heating power, a fitting algorithm is used to establish the functional relationship model.
4. The compressor heating control method for an air conditioner according to claim 2, characterized in that, The step of feedback adjustment of the duty cycle of the PWM signal includes: The deviation is processed by PID control to generate a duty cycle correction value, which is then added to the target PWM duty cycle to obtain the final output PWM duty cycle.
5. The compressor heating control method for an air conditioner according to claim 4, characterized in that, The step of feedback adjustment of the duty cycle of the PWM signal further includes: The final output PWM duty cycle is limited to between a preset minimum duty cycle and a maximum duty cycle.
6. The compressor heating control method for an air conditioner according to any one of claims 1 to 5, characterized in that, Before obtaining the target heating power, the process also includes: Obtain at least one of the following: the current oil temperature of the lubricating oil in the compressor, the compressor's operating mode information before shutdown, and the ambient temperature. The target heating power is dynamically adjusted based on at least one of the current oil temperature, the operating mode information, and the ambient temperature.
7. The compressor heating control method for an air conditioner according to claim 6, characterized in that, The step of dynamically adjusting the target heating power based on at least one of the current oil temperature, the operating mode information, and the ambient temperature includes: When the current oil temperature is lower than a preset oil temperature threshold, the target heating power is increased, and the target heating power increases as the current oil temperature decreases. If the operating mode before the shutdown is a high-load operating mode, increase the target heating power; When the ambient temperature is lower than a preset ambient temperature threshold, the target heating power is increased, and the target heating power increases as the ambient temperature decreases. When at least two of the above situations are triggered simultaneously, the highest determined target heating power is taken as the final target heating power.
8. The compressor heating control method for an air conditioner according to any one of claims 1 to 5, characterized in that, Also includes: After each heating process is completed, determine whether the heating has reached a steady state; Once the heating reaches a stable state, the stable PWM duty cycle, DC bus voltage, and actual heating power are recorded as valid data points. If the cumulative number of valid data points meets the preset conditions, the function relationship model is refitted based on the historical valid data points and the newly added valid data points, and the stored model parameters are updated with the refitted model parameters.
9. A compressor heating control device for an air conditioner, characterized in that, include: The first control module is used to input a pulse width modulation (PWM) signal to the inverter connected to the compressor in order to control the motor windings of the compressor to be heated. The first acquisition module is used to acquire the target heating power and the current DC bus voltage; The second acquisition module is used to calculate the target PWM duty cycle based on the target heating power and the current DC bus voltage, according to a pre-established functional relationship model between heating power, DC bus voltage and PWM duty cycle. The second control module is used to generate the PWM signal according to the target PWM duty cycle, so as to drive the inverter to heat the motor windings.
10. An air conditioner, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the compressor heating control method for an air conditioner as described in any one of claims 1 to 8.