A method and controller for reverse power generation energy saving control of an air conditioner outdoor unit

Abstract

A method and controller for reverse power generation energy saving control of an outdoor air conditioning unit, relating to the field of air conditioning control technology, reduces the energy consumption of air conditioning operation by utilizing outdoor natural wind. In this method, before the entire air conditioning unit starts, the initial idling speed of the permanent magnet synchronous fan driven by natural wind is obtained; based on a preset speed-wind speed mapping relationship, the initial idling speed is converted into the initial natural wind speed; when the initial natural wind speed is greater than or equal to a preset wind speed threshold, the intelligent power module connected to the permanent magnet synchronous fan is controlled to conduct according to a preset timing sequence, causing the intelligent power module to switch to rectification mode, and the permanent magnet synchronous fan to be in reverse power generation mode; the AC power generated by the permanent magnet synchronous fan in reverse power generation mode is converted into DC power and fed back to the DC bus.

Description

Technical Field

[0001] This application relates to the field of air conditioning control technology, and in particular to a method and controller for reverse power generation energy saving control of an outdoor air conditioning unit. Background Technology

[0002] With the development of the air conditioning industry, all-DC inverter air conditioners have become the mainstream in the market. In this type of air conditioner, the outdoor unit is usually equipped with a permanent magnet synchronous fan. When the air conditioner is working, the controller drives the fan to run through the inverter circuit, forcing outdoor air to flow through the heat exchanger coil to complete the environmental heat exchange.

[0003] To further reduce the overall energy consumption of air conditioner operation, a reverse-generation mechanism for the outdoor fan has been introduced in related technologies. There are two main implementation methods for this reverse-generation mechanism: The first method involves using outdoor natural wind to rotate the fan impeller when the air conditioner is off, causing the fan motor to operate in reverse generation mode. An independent battery is also provided to store the electrical energy generated by the motor, achieving temporary energy storage. The second method involves controlling a specific circuit to direct the reverse-generated electrical energy from the motor directly to a heat dissipation resistor or protection circuit. This heat dissipation component converts the electrical energy into heat, preventing damage to components due to excessively high bus voltage.

[0004] However, when the air conditioner is in normal heat exchange mode and the outdoor natural wind intensity is sufficient to assist the heat exchanger in completing heat exchange, the relevant technology still outputs high-frequency current from the DC bus to drive the fan to rotate. At this time, the mechanical energy brought by the natural wind is difficult to be effectively utilized and will instead be converted into useless waste heat, which aggravates the heat load of the inverter module and the whole unit and increases the energy consumption of the air conditioner. Summary of the Invention

[0005] This application provides a reverse power generation energy-saving control method and controller for an outdoor air conditioning unit, which reduces the energy consumption of air conditioning operation by utilizing outdoor natural wind.

[0006] In a first aspect, a reverse power generation energy-saving control method for an outdoor unit of an air conditioner is provided. The method is characterized by being applied to a controller and includes: before the entire air conditioner is started, acquiring the initial idling speed of a permanent magnet synchronous fan driven by natural wind; converting the initial idling speed into an initial natural wind speed based on a preset speed-wind speed mapping relationship; when the initial natural wind speed is greater than or equal to a preset wind speed threshold, controlling the intelligent power module connected to the permanent magnet synchronous fan to conduct according to a preset timing sequence, causing the intelligent power module to switch to rectification mode, and the permanent magnet synchronous fan to be in reverse power generation mode; converting the AC power generated by the permanent magnet synchronous fan in reverse power generation mode into DC power and feeding it back to the DC bus.

[0007] By adopting the above technical solution, the controller can assess the outdoor natural wind speed by detecting the idling speed of the existing permanent magnet synchronous fan as a sensor before the air conditioner starts, without adding additional hardware costs. When the natural wind conditions are deemed suitable, the controller can actively switch the fan into reverse power generation mode, converting the natural wind energy that would otherwise be wasted into electrical energy and feeding it back to the DC bus for use by other components of the system. This reduces the energy consumption of the air conditioner without affecting the air conditioner startup process.

[0008] In conjunction with some embodiments of the first aspect, in some embodiments, after converting the alternating current generated by the permanent magnet synchronous fan in reverse power generation mode into direct current and feeding it back to the DC bus, the method further includes: during the reverse power generation mode, acquiring the real-time temperature of the outdoor unit coil; if the real-time temperature is greater than a preset temperature threshold, determining that the passive heat exchange capacity of the current air conditioning environment, which relies solely on natural airflow to complete heat exchange through the outdoor unit coil, does not meet the current heat exchange requirements of the air conditioning environment; controlling the intelligent power module to switch from rectification state to inverter state, stopping the reverse power generation mode, and driving the permanent magnet synchronous fan to operate by outputting current from the DC bus.

[0009] By adopting the above technical solution, the controller monitors the outdoor unit coil temperature, which is the core indicator of heat exchange effect, in real time. Once the temperature exceeds the preset safety range, indicating that insufficient heat exchange may affect the cooling or heating effect, the controller can immediately stop the power generation mode and switch to actively driving the fan, thereby ensuring the stability and reliability of air conditioning performance and achieving an intelligent balance between energy saving and performance.

[0010] In conjunction with some embodiments of the first aspect, in some embodiments, the step of converting the initial idling speed into the initial natural wind speed based on a preset speed-wind speed mapping relationship specifically includes: calling a preset speed-wind speed mapping relationship that matches the model parameters of the permanent magnet synchronous fan; substituting the initial idling speed into the preset speed-wind speed mapping relationship to obtain the initial natural wind speed.

[0011] By adopting the above technical solution, the controller can ensure that the conversion result is closer to the actual physical situation by calling the mapping relationship matched with the specific wind turbine model, thus improving the reliability of wind speed judgment.

[0012] In conjunction with some embodiments of the first aspect, in some embodiments, the step of determining that the passive heat exchange capacity of the current air conditioning system, which relies solely on natural airflow through the outdoor unit coil to complete heat exchange, does not meet the current environmental heat exchange requirements when the real-time temperature is greater than a preset temperature threshold, specifically includes: obtaining the outdoor ambient temperature; and determining that the passive heat exchange capacity of the current air conditioning system, which relies solely on natural airflow through the outdoor unit coil to complete heat exchange, does not meet the current environmental heat exchange requirements when the real-time temperature is greater than a preset temperature threshold and the difference between the real-time temperature and the outdoor ambient temperature is greater than a preset temperature difference threshold.

[0013] By employing the above technical solution, and comparing the difference between the coil temperature and the ambient temperature, the controller can distinguish whether the insufficient heat exchange is due to a high system load or simply a normal increase in coil temperature caused by an excessively high ambient temperature. This temperature difference-based judgment logic avoids misjudging heat exchange capacity in high-temperature environments and reduces unnecessary mode switching.

[0014] In conjunction with some embodiments of the first aspect, in some embodiments, while the permanent magnet synchronous wind turbine is in reverse power generation mode, the method further includes: real-time monitoring of the bus voltage of the DC bus; and, if the bus voltage exceeds a preset safety threshold, controlling the intelligent power module to adjust the rectification efficiency or temporarily stop reverse power generation to reduce the rectified output voltage and maintain the bus voltage within a safe range.

[0015] By adopting the above technical solution, the controller can promptly detect the risk of abnormal voltage rise caused by excessive power generation or sudden load drop by monitoring the DC bus voltage in real time. Once the voltage exceeds the safety threshold, the controller can immediately take measures such as adjusting the rectification efficiency or suspending power generation to intervene, preventing damage to expensive power components such as IPM, PFC circuit, and electrolytic capacitors caused by overvoltage, and improving the operational safety and reliability of the entire air conditioning electrical system.

[0016] In conjunction with some embodiments of the first aspect, in some embodiments, the method further includes: when the outdoor unit of the air conditioner is equipped with a wind speed detection module, during the reverse power generation mode, obtaining the real-time natural wind speed through the wind speed detection module; when the real-time natural wind speed is less than a preset wind speed threshold, controlling the intelligent power module to switch to inverter mode, driving the permanent magnet synchronous fan into active drive mode.

[0017] By adopting the above technical solution, during reverse power generation, the controller can use the wind speed detection module to obtain real-time, accurate natural wind speed unaffected by the rotation of the wind turbine itself. When the wind speed weakens to the point where it can no longer effectively support power generation, the controller can respond quickly and switch to active drive mode to ensure heat exchange effect, thus improving the sensitivity and accuracy of control.

[0018] In conjunction with some embodiments of the first aspect, in some embodiments, the method further includes: continuously monitoring the real-time natural wind speed and the temperature of the outdoor unit coil while the permanent magnet synchronous wind turbine is in active drive mode; and controlling the intelligent power module to switch back to rectification state when the real-time natural wind speed is detected to be greater than or equal to a preset wind speed threshold and the temperature is less than or equal to a preset temperature threshold, so that the permanent magnet synchronous wind turbine switches back to reverse power generation mode.

[0019] By adopting the above technical solution, when the system switches to active drive mode due to insufficient wind speed or heat exchange requirements, the controller does not terminate the energy-saving judgment, but continues to monitor wind speed and temperature conditions. Once it detects that the natural wind conditions become suitable again, the controller can switch back to reverse power generation mode, thereby realizing the dynamic capture and continuous utilization of favorable wind conditions, further improving the overall energy-saving effect of the air conditioning unit throughout the entire operating cycle.

[0020] In a second aspect, embodiments of this application provide a controller comprising: one or more processors and a memory; the memory is coupled to the one or more processors and is used to store computer program code, the computer program code including computer instructions, wherein the one or more processors invoke the computer instructions to cause the controller to perform the method as described in the first aspect and any possible implementation thereof.

[0021] Thirdly, embodiments of this application provide a computer program product containing instructions that, when the computer program product is run on a controller, cause the controller to perform the method described in the first aspect and any possible implementation thereof.

[0022] Fourthly, embodiments of this application provide a computer-readable storage medium including instructions that, when executed on a controller, cause the controller to perform the method described in the first aspect and any possible implementation thereof.

[0023] Understandably, the controller provided in the second aspect, the computer program product provided in the third aspect, and the computer storage medium provided in the fourth aspect are all used to execute the methods provided in the embodiments of this application. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods, and will not be repeated here.

[0024] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0025] 1. The controller can use the existing permanent magnet synchronous fan as a sensor before the air conditioner starts, without adding extra hardware costs, to assess the outdoor natural wind speed by detecting its idling speed. When the natural wind conditions are deemed suitable, the controller can actively switch the fan into reverse power generation mode, converting the natural wind energy that would otherwise be wasted into electrical energy and feeding it back to the DC bus for use by other components in the system. This reduces the energy consumption of the air conditioner without affecting the air conditioner startup process.

[0026] 2. The controller monitors the outdoor unit coil temperature, which is a core indicator of heat exchange performance, in real time. Once the temperature exceeds the preset safety range, indicating insufficient heat exchange that may affect the cooling or heating effect, the controller can immediately stop the power generation mode and switch to actively driving the fan, thereby ensuring the stability and reliability of the air conditioner performance and achieving an intelligent balance between energy saving and performance.

[0027] 3. By comparing the difference between the coil temperature and the ambient temperature, the controller can distinguish whether the insufficient heat exchange is due to a high system load or simply a normal increase in coil temperature caused by an excessively high ambient temperature. This temperature difference-based judgment logic avoids misjudging heat exchange capacity in high-temperature environments and reduces unnecessary mode switching. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating a reverse power generation energy-saving control method for an outdoor air conditioning unit according to an embodiment of this application.

[0029] Figure 2 This is another schematic flowchart of an air conditioner outdoor unit reverse power generation energy-saving control method in the embodiments of this application.

[0030] Figure 3 This is a schematic diagram of the physical device structure of the controller in an embodiment of this application. Detailed Implementation

[0031] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0032] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0033] This application provides a reverse power generation energy-saving control method and controller for an outdoor air conditioning unit, which reduces the energy consumption of air conditioning operation by utilizing outdoor natural wind.

[0034] Please see Figure 1This is a flowchart illustrating a reverse power generation energy-saving control method for an outdoor air conditioning unit according to an embodiment of this application.

[0035] S101. Before the air conditioning unit starts, obtain the initial idling speed of the permanent magnet synchronous fan driven by natural wind.

[0036] An air conditioning unit refers to a complete air conditioning system with cooling or heating functions, typically including an indoor unit and an outdoor unit. "Before startup" indicates that the controller has received the user's or system's start-up command, but has not yet output drive power to the main drive circuits of the compressor, fan, and other major load components—a preparation or self-test phase. A permanent magnet synchronous fan is an outdoor unit fan that uses a permanent magnet synchronous motor as its power source. Its motor has energy reversibility; it can both consume electrical energy as a motor and be driven by external force to generate electrical energy. Natural wind refers to the airflow formed by non-artificial factors in the environment where the air conditioning outdoor unit is located. The initial idle speed is used to indicate the relatively stable rotational speed reached by the motor rotor of the permanent magnet synchronous fan when the impeller rotates freely only under the influence of natural wind during the specific period before startup, without any electric driving force.

[0037] Specifically, this step is performed during the brief interval between the controller responding to the power-on command and the formal operation of the drive system. During this phase, the controller intentionally keeps the intelligent power module (IPM) connected to the permanent magnet synchronous wind turbine in a high-resistance or non-drive state, meaning no drive current is applied to the wind turbine motor windings. Simultaneously, the controller monitors the back electromotive force (EMF) signal generated at both ends of the three-phase windings of the wind turbine motor due to the rotor rotating with the wind and cutting magnetic lines of force. Since the frequency and amplitude of the back EMF are proportional to the motor speed, the controller can calculate the current real-time speed of the motor by analyzing the period, frequency, or zero-crossing interval of the acquired back EMF signal. This speed measured in the unpowered drive state is recognized by the controller as the initial idle speed, objectively reflecting the driving capability of the current outdoor natural wind on the wind turbine impeller.

[0038] S102. Based on the preset rotation speed and wind speed mapping relationship, convert the initial idling speed into the initial natural wind speed.

[0039] The preset rotational speed-wind speed mapping relationship refers to a set of data or mathematical formulas stored in the controller's memory that describe the correspondence between the idle rotational speed of a permanent magnet synchronous fan in a specific model of outdoor unit and the external natural wind speed. The initial natural wind speed represents a value estimated based on the initial idle rotational speed that can represent the current ambient wind intensity.

[0040] Specifically, after acquiring the initial idling speed value, the controller calls upon the internally stored preset speed-wind speed mapping relationship. This mapping relationship was determined during the product development phase through extensive wind tunnel experiments or fluid dynamics simulations, taking into account factors such as the aerodynamic characteristics of the turbine blades, motor damping, and bearing friction for a specific model. It establishes a mapping relationship between the electrically measurable parameter of motor idling speed and the environmental physical quantity of external natural wind speed. The controller uses the measured initial idling speed as an input variable, substitutes it into this mapping relationship, and calculates to obtain an initial natural wind speed value, for example, in meters per second (m / s).

[0041] In some embodiments, the conversion from engine speed to wind speed can be achieved in several ways: Optionally, the mapping relationship can be in the form of a lookup table. The controller internally stores a two-dimensional table, with one column representing discrete engine speed value ranges and the other column representing the corresponding wind speed values. The controller matches the measured initial idling engine speed with the engine speed ranges in the table, directly looking up or obtaining the corresponding initial natural wind speed value through linear interpolation. This method is simple to calculate and has a fast response. Optionally, the mapping relationship can also be a polynomial fitting function, such as V=aN. 2 The formula is: V = bN + c, where V is the wind speed, N is the rotational speed, and a, b, and c are pre-calibrated coefficients. The controller substitutes the measured initial idling speed N into this formula and directly calculates the initial natural wind speed V through floating-point or fixed-point arithmetic. Compared to the lookup table method, this method provides a smoother and more accurate continuous correspondence.

[0042] S103. When the initial natural wind speed is greater than or equal to the preset wind speed threshold, the intelligent power module connected to the permanent magnet synchronous wind turbine is controlled to be turned on according to the preset timing sequence, so that the intelligent power module is switched to the rectification state and the permanent magnet synchronous wind turbine is in the reverse power generation mode.

[0043] The preset wind speed threshold refers to a pre-set critical wind speed value used to determine whether the current natural wind speed is strong enough to ensure that the benefits of reverse power generation from the wind turbine outweigh its potential losses and meet certain heat exchange requirements. The intelligent power module is a power semiconductor module integrating power switching devices, drive circuits, and protection circuits, used to drive or control the motor. The preset timing sequence represents a specific sequence of gate drive control signals generated by the controller to enable the IPM to operate in rectification mode. Rectification mode means that the power devices inside the IPM are configured as an AC-DC converter, capable of converting the input AC power to DC power. Reverse power generation mode refers to the operating state of the permanent magnet synchronous wind turbine as a generator driven by natural wind.

[0044] Specifically, the controller compares the calculated initial natural wind speed with a preset wind speed threshold (e.g., 5 m / s) stored internally. If the initial natural wind speed is greater than or equal to this threshold, the controller determines that the current situation is valuable for energy-saving power generation using natural wind. Accordingly, the controller generates and sends a special set of PWM (Pulse Width Modulation) control signals to the IPM's control pins. The timing of these signals is completely different from the inverter timing for driving the motor; its purpose is to configure the power switching transistors (IGBTs) and their anti-parallel freewheeling diodes in the IPM's internal three-phase bridge circuit into a three-phase rectifier bridge. For example, this preset timing can be based on the detected zero-crossing signal of the wind turbine motor's back EMF to control the power transistors in the IPM to switch synchronously, achieving efficient synchronous rectification. Subsequently, as the natural wind continues to drive the wind turbine to rotate, the AC power generated by the wind turbine motor is rectified by the IPM, which is now in rectification mode, marking the permanent magnet synchronous wind turbine's entry into reverse power generation mode. Conversely, if the wind speed is less than the threshold, the controller will not enter the power generation mode, but will instead control the IPM to operate in the inverter state according to the normal procedure, actively driving the wind turbine to run.

[0045] S104. The AC power generated by the permanent magnet synchronous wind turbine in reverse generation mode is converted into DC power and fed back to the DC bus.

[0046] Alternating current (AC) refers to the alternating current output from the three-phase stator windings of a permanent magnet synchronous wind turbine during power generation, with a phase difference of 120 degrees. Direct current (DC) refers to the current whose direction and polarity remain essentially unchanged after rectification by an IPM (Integrated Power Regulator). Feedback refers to the process of returning the generated electrical energy to the common power node of the air conditioning system for reuse. The DC bus refers to the common high-voltage DC power bus in a variable frequency air conditioning electrical system that connects the PFC (Power Factor Correction) circuit, inverters (such as compressor drivers and fan drivers), and filter capacitors.

[0047] Specifically, when the permanent magnet synchronous fan enters reverse generation mode, the three-phase AC power induced in its stator windings is input into the IPM (Integrated Power Module), which has switched to rectification mode. The rectifier circuit inside the IPM converts this AC power into high-voltage DC power. The output of this DC power is directly connected to the DC bus inside the air conditioning system. Therefore, the DC power generated by the generator is directly injected into the DC bus, merging with the power supplied from the grid side through the PFC (Power Factor Correction) circuit, to charge the filter capacitors on the DC bus and increase the bus voltage. This fed-back power is preferentially consumed by other loads connected to the DC bus (mainly the running compressor and indoor unit fan), thereby directly reducing the power that the PFC circuit needs to absorb from the grid, achieving the energy-saving goal of reducing the total input power of the air conditioning system and improving the overall energy efficiency ratio of the system. During reverse power generation mode, the controller also monitors the DC bus voltage in real time. If the voltage exceeds a preset safety threshold (e.g., 380V) due to excessive power generation, the controller will immediately adjust the IPM's rectification efficiency (e.g., adjusting the switch duty cycle in synchronous rectification mode) or temporarily shut down the rectification function to protect the bus capacitor and other connected electrical components from overvoltage damage. Furthermore, in some embodiments equipped with a wind speed detection module, the controller also monitors the natural wind speed in real time during power generation. If the wind speed drops below a preset threshold, the controller will actively control the IPM to switch back to inverter mode, stop power generation, and start the active drive of the wind turbine to ensure heat exchange efficiency. When the wind speed subsequently rises above the threshold and the heat exchange conditions are met, the controller can again control the IPM to switch back to rectification mode, re-entering the reverse power generation mode, thus achieving dynamic cyclic switching of operating modes.

[0048] In some embodiments, power feedback and management can be achieved in several ways: Optionally, a direct parallel feedback method can be used. The positive and negative terminals of the IPM's DC output are directly connected to the positive and negative terminals of the DC bus. This method has the simplest circuit structure, the shortest energy transmission path, and high efficiency. The controller achieves basic overvoltage protection by monitoring the bus voltage. Optionally, a feedback method with buffering or voltage regulation can be used. A DC / DC converter consisting of an inductor, capacitor, and switching transistor can be added between the IPM's DC output and the DC bus. By controlling this converter, the controller can stabilize or regulate the DC voltage generated by the generator, making it better match the bus voltage, reducing the ripple of the injected current, and achieving finer power flow control, such as maximum power point tracking (MPPT).

[0049] In the above embodiments, the controller can use the existing permanent magnet synchronous fan as a sensor before the air conditioner starts, without adding extra hardware costs, to assess the outdoor natural wind speed by detecting its idling speed. When the natural wind conditions are deemed suitable, the controller can actively switch the fan into reverse power generation mode, converting the natural wind energy that would otherwise be wasted into electrical energy and feeding it back to the DC bus for use by other components of the system, thereby reducing the energy consumption of the air conditioner without affecting the air conditioner startup process.

[0050] However, in the above embodiments, after reverse power generation is initiated, for air conditioning systems without physical wind speed sensors, since the fan is already in power generation or driven mode, its rotational speed can no longer directly reflect the actual natural wind speed, and the controller loses its ability to sense changes in external wind speed in real time. In this situation, if the natural wind speed decreases during operation, but the coil temperature has not yet reached the trigger threshold, the system may continue to maintain power generation mode. At this time, the passive heat exchange capacity has actually decreased, and there is a potential risk of slow deterioration in the heat exchange effect. To solve this problem, a mechanism is needed to reliably assess the heat exchange effect and adjust the operating mode in a timely manner even without real-time wind speed data.

[0051] Please see Figure 2 This is another flowchart illustrating an air conditioner outdoor unit reverse power generation energy-saving control method in an embodiment of this application.

[0052] S201. Before the air conditioning unit is started, obtain the initial idling speed of the permanent magnet synchronous fan driven by natural wind.

[0053] S202. Based on the preset rotation speed and wind speed mapping relationship, the initial idling speed is converted into the initial natural wind speed.

[0054] S203. When the initial natural wind speed is greater than or equal to the preset wind speed threshold, the intelligent power module connected to the permanent magnet synchronous wind turbine is controlled to conduct according to the preset timing sequence, so that the intelligent power module switches to the rectification state and the permanent magnet synchronous wind turbine is in the reverse power generation mode.

[0055] S204. The AC power generated by the permanent magnet synchronous wind turbine in reverse generation mode is converted into DC power and fed back to the DC bus.

[0056] Step S201 is similar to step S101, step S202 is similar to step S102, step S203 is similar to step S103, and step S204 is similar to step S104, so they will not be repeated here.

[0057] S205. During reverse power generation mode, obtain the real-time temperature of the outdoor unit coil.

[0058] The reverse power generation mode refers to the entire period from when the controller puts the IPM into rectification mode, the fan starts generating electricity, until the mode is terminated. The outdoor unit coil is the core heat exchange component in the outdoor unit of the air conditioner; it is typically a copper tube covered with heat dissipation fins, where the refrigerant undergoes a phase change to exchange heat with the outside air. Real-time temperature refers to the value that the controller continuously or periodically collects through temperature sensors, reflecting the current surface temperature of the coil in real time.

[0059] Specifically, once successfully entering reverse power generation mode, the controller initiates a continuous performance monitoring subtask. The core of this task is real-time acquisition of the outdoor unit coil temperature. The controller accomplishes this through temperature sensors (typically negative temperature coefficient thermistors, NTCs) connected to key locations on the outdoor unit coil (e.g., the middle or outlet section of the heat exchanger). The controller periodically (e.g., several times per second) provides an excitation signal to the temperature sensor and reads its feedback voltage or resistance value, then converts it to a Celsius or Fahrenheit temperature value using an internally stored temperature-resistance / voltage characteristic curve or formula.

[0060] In some embodiments, coil temperature acquisition and processing can be achieved in several ways: Optionally, single-point temperature sampling can be used. The controller deploys only one temperature sensor at a single predetermined point on the coil. This point is typically selected in the area that best represents the overall heat exchange state or is most prone to extreme temperatures. The controller makes judgments based on this single-point temperature, resulting in simple control logic. Optionally, multi-point weighted average temperature sampling can be used. The controller deploys multiple temperature sensors in different areas of the coil (such as the upper, middle, and lower parts, or the inlet and outlet areas) and collects the temperature at each point in real time. The controller performs a weighted average of these multi-point temperatures according to preset weighting coefficients to obtain a comprehensive temperature value that better reflects the overall thermal state of the coil. This method can avoid misjudgments caused by uneven local airflow or sensor position deviations, making the judgment more reliable.

[0061] S206. When the real-time temperature is greater than the preset temperature threshold, it is determined that the passive heat exchange capacity, which relies solely on natural airflow through the outdoor unit coil to complete heat exchange, does not meet the current environmental heat exchange requirements of the air conditioner.

[0062] The preset temperature threshold refers to an upper limit (during cooling) or lower limit (during heating) of the coil temperature set according to the air conditioner's operating mode (cooling / heating), load size, and environmental conditions. Exceeding this range indicates insufficient heat exchange. Passive heat exchange capacity refers to the heat that can be carried away or brought in by natural wind passing over the coil fins without active forced ventilation by a fan. The current environmental heat exchange demand of the air conditioner refers to the heat that the high-temperature, high-pressure refrigerant discharged by the compressor (during cooling) needs to discharge to the outside to maintain the set indoor temperature.

[0063] Specifically, during its continuous performance monitoring cycle, the controller compares the real-time coil temperature with a preset temperature threshold (e.g., 50°C in cooling mode). If the real-time coil temperature consistently exceeds this threshold, the controller determines that passive heat exchange via natural wind alone is insufficient to dissipate the heat carried by the refrigerant into the air in a timely and adequate manner. This situation leads to an abnormal increase in refrigerant temperature and pressure within the heat exchanger, thereby reducing cooling efficiency, increasing compressor power consumption, and potentially triggering high-pressure protection, resulting in a shutdown. Therefore, once this condition is met, the controller will make a decision to interrupt or exit the reverse power generation mode. In a more refined control strategy, the controller considers not only the absolute temperature of the coil but also the ambient outdoor temperature. A judgment of insufficient heat exchange is only made when the real-time coil temperature exceeds the preset temperature threshold, and the difference between this real-time temperature and the ambient outdoor temperature exceeds a preset temperature difference threshold (e.g., 15°C). Introducing temperature difference judgment eliminates the possibility of a normally high coil temperature due to extremely high ambient outdoor temperatures, making the judgment more accurate.

[0064] In some embodiments, the determination of insufficient heat exchange capacity can be achieved in several ways: Optionally, a fixed threshold comparison method can be used. The controller selects a fixed temperature threshold for comparison based on the current macroscopic operating mode (such as cooling or heating). For example, the threshold is 50°C in cooling mode and -5°C in heating mode. This method is simple to implement but has poor adaptability. Optionally, a dynamic threshold adjustment method can be used. The preset temperature threshold is not a fixed value, but is dynamically calculated by the controller based on other operating parameters. For example, this threshold can be related to parameters such as the compressor's operating frequency and the indoor-outdoor temperature difference. When the compressor is running at high frequency, the system's heat dissipation demand is high, and the threshold will be lowered accordingly, making the control more sensitive. Conversely, when running at low frequency, the threshold can be appropriately relaxed. This adaptive threshold strategy can better balance energy saving effect and system performance.

[0065] S207 controls the intelligent power module to switch from rectification to inverter mode, stops the reverse power generation mode, and drives the permanent magnet synchronous wind turbine to operate by outputting current from the DC bus.

[0066] In the inverter mode, the power devices inside the IPM are configured as a DC-AC converter, capable of converting the DC power from the DC bus into three-phase AC power with controllable frequency and amplitude to drive the motor. The current output from the DC bus indicates that the energy flows from the DC bus to the IPM, and then from the IPM to the wind turbine motor, which is exactly the opposite of the energy flow in reverse generation.

[0067] Specifically, once the controller determines, based on the judgment in step S206, that the reverse power generation mode needs to be terminated, it immediately executes a state switching operation. First, the controller stops sending control timing signals for rectification to the IPM, causing all power transistors inside the IPM to turn off, thereby instantly cutting off the energy feedback path of reverse power generation. Next, the controller seamlessly switches to the conventional fan drive logic, calculating a target speed based on the heat exchange required by the current air conditioning system. Subsequently, the controller generates a standard three-phase SPWM (Sinusoidal Pulse Width Modulation) or SVPWM (Space Vector Pulse Width Modulation) signal corresponding to the target speed and sends it to the IPM. Upon receiving the new inverter control signal, the IPM's internal power switches begin high-speed switching according to a preset inverter timing sequence, inverting the high-voltage DC power from the DC bus into three-phase AC power, driving the permanent magnet synchronous fan to actively rotate to the target speed. This process marks the system's switch from a passive energy-saving mode utilizing natural wind to a performance-assured mode of active forced ventilation, ensuring the stable and efficient operation of the air conditioning system.

[0068] In some embodiments, the state switching from rectification to inversion can be achieved in several ways: Optionally, a hard switching method with a stop-start mechanism can be used. The controller first completely stops rectification control and waits for a very short delay (e.g., a few milliseconds) to ensure that the circuit state is completely stable. Then, the inverter control logic is started, driving the fan to accelerate to the target speed from zero. This method has clear logic and can avoid instantaneous conflicts between the control signals of the two modes. Optionally, a soft switching method with a smooth transition can be used. During the switching process, the controller implements a transition algorithm. For example, while stopping rectification, the controller immediately starts inverter control, but the initial output drive voltage or current is very small. Then, the drive force is smoothly increased over a preset time (e.g., hundreds of milliseconds) until the fan reaches the target speed. This method can reduce the current surge and mechanical vibration at the moment of switching, improving the user experience and system reliability.

[0069] In the above embodiments, after entering reverse power generation mode, the controller uses the real-time temperature of the outdoor unit coil as the core monitoring indicator. By comparing this real-time temperature with a preset temperature threshold, and even with the temperature difference from the outdoor ambient temperature, the controller can more accurately determine whether the passive heat exchange capacity of natural wind alone still meets the actual heat exchange requirements of the air conditioner. Once it is determined that the heat exchange is insufficient, the controller will stop power generation and switch to actively driving the fan, thereby placing the protection of air conditioner performance as the highest priority.

[0070] The above describes a reverse power generation energy-saving control method for an outdoor air conditioner unit in the embodiments of this application. The exemplary controller 300 provided in the embodiments of this application is described below.

[0071] Figure 3This is a schematic diagram of an exemplary hardware structure of the controller 300 provided in an embodiment of this application. In some embodiments, the controller 300 is a computer device. The computer device includes a processor, a memory, and a network interface connected via a system bus. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database of the computer device is used to store data. The network interface of the computer device is used to communicate with other external terminals or servers via a network connection. In some embodiments, the network interface can be a wired network interface; in some embodiments, the network interface can also be a wireless network interface. When the computer program is executed by the processor, it implements an air conditioner outdoor unit reverse power generation energy-saving control method according to an embodiment of this application.

[0072] Those skilled in the art will understand that Figure 3 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0073] In some embodiments of this application, a computer-readable storage medium is also provided, including instructions that, when executed on the controller 300, cause the controller 300 to perform an air conditioner outdoor unit reverse power generation energy-saving control method according to an embodiment of this application.

[0074] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application 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. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0075] As used in the above embodiments, depending on the context, the term "when..." can be interpreted as meaning "if...", "after...", "in response to determining...", or "in response to detecting...". Similarly, depending on the context, the phrase "when determining..." or "if (the stated condition or event) is interpreted as meaning "if determining...", "in response to determining...", "when (the stated condition or event) is detected", or "in response to detecting (the stated condition or event)".

[0076] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state drive), etc.

[0077] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for controlling energy saving by reverse power generation in an outdoor air conditioning unit, characterized in that, Applied to a controller, the method includes: Before the air conditioning unit is started, the initial idling speed of the permanent magnet synchronous fan driven by natural wind is obtained; Based on the preset rotation speed-wind speed mapping relationship, the initial idling speed is converted into the initial natural wind speed; When the initial natural wind speed is greater than or equal to a preset wind speed threshold, the intelligent power module connected to the permanent magnet synchronous wind turbine is controlled to be turned on according to a preset timing sequence, so that the intelligent power module is switched to the rectification state and the permanent magnet synchronous wind turbine is in the reverse power generation mode. The AC power generated by the permanent magnet synchronous wind turbine in reverse generation mode is converted into DC power and then fed back to the DC bus.

2. The method according to claim 1, characterized in that, After the step of converting the alternating current generated by the permanent magnet synchronous wind turbine in reverse generation mode into direct current and feeding it back to the DC bus, the method further includes: During the reverse power generation mode, the real-time temperature of the outdoor unit coil is acquired; If the real-time temperature is greater than the preset temperature threshold, it is determined that the passive heat exchange capacity of the outdoor unit coil, which relies solely on natural airflow to complete heat exchange, does not meet the current environmental heat exchange requirements of the air conditioner. The intelligent power module is controlled to switch from the rectification state to the inverter state, the reverse power generation mode is stopped, and the permanent magnet synchronous wind turbine is driven to operate by outputting current from the DC bus.

3. The method according to claim 1, characterized in that, The step of converting the initial idling speed into the initial natural wind speed based on the preset speed-wind speed mapping relationship specifically includes: Invoke the preset rotational speed and wind speed mapping relationship that matches the model parameters of the permanent magnet synchronous fan; Substituting the initial idling speed into the preset speed-wind speed mapping relationship, the initial natural wind speed is obtained.

4. The method according to claim 2, characterized in that, The step of determining that, when the real-time temperature is greater than a preset temperature threshold, the passive heat exchange capacity relying solely on natural airflow through the outdoor unit coil is insufficient to meet the current environmental heat exchange requirements of the air conditioner specifically includes: Obtain the outdoor ambient temperature; The step of determining that the passive heat exchange capacity of the outdoor unit coil, which relies solely on natural airflow to complete heat exchange, does not meet the current environmental heat exchange requirements of the air conditioner when the real-time temperature is greater than a preset temperature threshold and the difference between the real-time temperature and the outdoor ambient temperature is greater than a preset temperature difference threshold.

5. The method according to claim 1, characterized in that, During the period when the permanent magnet synchronous wind turbine is in the reverse power generation mode, the method further includes: Real-time monitoring of the bus voltage of the DC bus; If the bus voltage exceeds a preset safety threshold, the intelligent power module is controlled to adjust the rectification efficiency or temporarily stop reverse power generation to reduce the rectified output voltage and keep the bus voltage within a safe range.

6. The method according to claim 1, characterized in that, The method further includes: When the outdoor unit of the air conditioner is equipped with a wind speed detection module, the real-time natural wind speed is obtained through the wind speed detection module during the reverse power generation mode. When the real-time natural wind speed is less than the preset wind speed threshold, the intelligent power module is controlled to switch to inverter mode, driving the permanent magnet synchronous fan into active drive mode.

7. The method according to claim 6, characterized in that, The method further includes: During the active drive mode of the permanent magnet synchronous fan, the real-time natural wind speed and the temperature of the outdoor unit coil are continuously monitored; If the real-time natural wind speed is detected to be greater than or equal to the preset wind speed threshold again, and the temperature is less than or equal to the preset temperature threshold, the intelligent power module is controlled to switch back to the rectification state, so that the permanent magnet synchronous wind turbine switches back to the reverse power generation mode.

8. A controller, characterized in that, The controller includes: one or more processors and a memory; the memory is coupled to the one or more processors, the memory being used to store computer program code, the computer program code including computer instructions, and the one or more processors invoking the computer instructions to cause the controller to perform the method as described in any one of claims 1-7.

9. A computer program product containing instructions, characterized in that, When the computer program product is run on the controller, the controller performs the method as described in any one of claims 1-7.

10. A computer-readable storage medium comprising instructions, characterized in that, When the instructions are executed on the controller, the controller causes the controller to perform the method as described in any one of claims 1-7.

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