Air conditioning system

Abstract

This invention discloses an air conditioning system, including a three-phase power supply, a voltage divider circuit, and a controller. Each phase of the three-phase power supply is divided by the voltage divider circuit and then detected by the three ports of the controller. No isolation devices are used between the three-phase power supply and the controller, achieving both low cost and comprehensive detection signals, enabling full information detection of the input voltage. Since the air conditioning system's circuit ground is inherently a thermal ground design, it does not require isolation, ensuring safety. The three-phase power supply detection circuit is simple and reliable, extracting rich information, representing a minimalist and low-cost design solution for commercial air conditioning systems.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to an air conditioning system with low-cost three-phase power input voltage detection. Background Technology

[0002] Three-phase power supply is a very common power supply method in commercial air conditioning systems. The design of air conditioning systems is based on the balance of three-phase input voltages L1, L2, and L3. However, various problems may arise during the connection of the system to the power grid due to installation and operation issues. These problems include the absence of a phase L1 / L2 / L3, reversed three-phase sequence, different input frequencies for different markets (50Hz, 60Hz), and inability to obtain zero-crossing information of the input voltage, among others.

[0003] Currently, the industry and market for phase sequence detection and frequency detection typically employ analog signals that are stepped down by a resistor, or converted into digital signals using an analog-to-analog signal conversion circuit and a single-phase or bidirectional optocoupler. These digital signals are then sent to the MCU for level judgment and input information (such as...). Figure 1 , Figure 2 As shown, Figure 1 For half-wave period sampling, Figure 2 (This method uses full-wave cycle sampling). However, its detection has drawbacks, leading to the loss of certain signal information. This information is crucial in current variable frequency air conditioning systems. While the current circuit offers the advantage of input voltage signal isolation, this isolation characteristic is not essential in variable frequency air conditioning systems. Therefore, a low-cost, comprehensive input voltage information detection circuit for air conditioning systems is highly necessary.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0005] This invention proposes an air conditioning system that solves the technical problems of high cost and signal information loss caused by the isolation between the existing three-phase power supply and the controller.

[0006] To achieve the above-mentioned objectives, the present invention employs the following technical solution:

[0007] An air conditioning system, comprising:

[0008] Three-phase power supply, used to power the air conditioning system, including L1 phase, L2 phase and L3 phase;

[0009] The controller is used to sample the three-phase power supply;

[0010] The first voltage divider circuit is located between phase L1 and the controller's hot ground;

[0011] The second voltage divider circuit is located between phase L2 and the controller's hot ground;

[0012] The third voltage divider circuit is located between phase L3 and the controller's hot ground;

[0013] The controller includes:

[0014] The first port is used to receive the first voltage divider signal from the first voltage divider circuit.

[0015] The second port is used to receive the second voltage divider signal from the second voltage divider circuit.

[0016] The third port is used to receive the third voltage divider signal from the third voltage divider circuit;

[0017] No isolation device is installed between the three-phase power supply and the controller.

[0018] The above technical solution has the following advantages or beneficial effects: The air conditioning system includes a three-phase power supply, a voltage divider circuit, and a controller. Each phase of the three-phase power supply is divided by the voltage divider circuit and then detected by the three ports of the controller. No isolation devices are installed between the three-phase power supply and the controller, which achieves both low cost and comprehensive detection signals, enabling full information detection of the input voltage. Since the air conditioning system circuit ground itself is a thermal ground design, it does not require isolation design, ensuring safety. The three-phase power supply detection circuit design is simple and reliable, and can extract rich information, making it an extremely simple and low-cost design solution in the field of commercial air conditioning design.

[0019] In some embodiments, the controller is configured to:

[0020] When the signal at the first port is zero for a set period of time, it is determined that phase L1 is missing.

[0021] When the signal at the second port is zero for a set period of time, it is determined that phase L2 is missing.

[0022] When the signal at the third port is zero for a set period of time, it is determined that phase L3 is missing.

[0023] The above technical solution has the following advantages or beneficial effects: it can detect whether a phase is missing by checking if there is a signal at the port, and the detection method is simple and quick.

[0024] In some embodiments, the controller is configured to:

[0025] When the port signal remains above the set voltage value for a set period of time, a positive zero-crossing occurs when the trend of the port signal is above the set voltage value, and a negative zero-crossing occurs when the trend of the port signal is below the set voltage value.

[0026] The above technical solution has the following advantages or beneficial effects: by comparing the three port signals with the set voltage value and the voltage trend, the positive and negative zero crossing points of each phase of the three-phase power supply can be directly determined, and the detection method is simple and fast.

[0027] In some embodiments, the controller is configured with a flag bit that is 1 when the zero point crosses positively and 0 when the zero point crosses negatively; or, the flag bit is 1 when the zero point crosses negatively and 0 when the zero point crosses positively.

[0028] The above technical solution has the following advantages or beneficial effects: positive and negative zero-crossing points are marked by flag bits to facilitate the identification and statistics of zero-crossing points.

[0029] In some embodiments, the controller is configured to determine the input three-phase power supply voltage cycle based on the time interval between the positive and negative zero crossings.

[0030] The above technical solution has the following advantages or beneficial effects: the input three-phase power supply voltage cycle can be accurately determined by the time interval between the positive and negative zero crossings.

[0031] In some embodiments, the controller is configured to determine the three-phase power supply frequency based on the three-phase power supply voltage cycle.

[0032] The above technical solution has the following advantages or beneficial effects: the frequency of the three-phase power supply can be accurately determined by the three-phase power supply voltage cycle.

[0033] In some embodiments, the control module is configured to satisfy:

[0034] First port signal > 0, second port signal > 0, third port signal = 0;

[0035] First port signal > 0, second port signal = 0, third port signal > 0;

[0036] When the first port signal = 0, the second port signal = 0, and the third port signal > 0, the three-phase power supply phase sequence is normal; otherwise, the three-phase power supply phase sequence is abnormal.

[0037] The above technical solution has the following advantages or beneficial effects: the phase sequence of the three-phase power supply can be directly determined through three port signals, and the detection and determination method is simple and quick.

[0038] In some embodiments, the controller is configured to determine whether the input voltage is normal.

[0039] The above technical solution has the following advantages or beneficial effects: when the input voltage is confirmed to be normal, the air conditioning system is controlled to work normally and three-phase power supply is tested.

[0040] In some embodiments, it also includes:

[0041] The first filtering circuit is used to filter the first voltage divider signal and then transmit it to the first port.

[0042] The second filtering circuit is used to filter the second voltage divider signal and then transmit it to the second port.

[0043] The third filtering circuit is used to filter the third voltage divider signal before transmitting it to the third port.

[0044] The above technical solution has the following advantages or beneficial effects: the voltage divider signal is filtered by the filter circuit to reduce the noise entering the controller signal.

[0045] In some embodiments, it also includes:

[0046] The first voltage regulator circuit is used to regulate the first voltage divider signal and then transmit it to the first port;

[0047] The second voltage regulator circuit is used to regulate the second voltage divider signal and then transmit it to the second port.

[0048] The third voltage regulator circuit is used to regulate the third voltage divider signal before transmitting it to the third port.

[0049] The above technical solution has the following advantages or beneficial effects: the voltage divider signal is stabilized by the voltage regulator circuit to improve the detection accuracy.

[0050] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of the present 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 This section presents a sample circuit and waveform diagram for a half-cycle voltage signal in the prior art.

[0053] Figure 2 This section presents a full-cycle voltage signal sampling circuit and waveform diagram from existing technologies.

[0054] Figure 3 This is a block diagram illustrating the principle of three-phase power supply detection for an air conditioning system according to an embodiment.

[0055] Figure 4 This is a circuit diagram for three-phase power supply detection of an air conditioning system according to an embodiment;

[0056] Figure 5 This is a waveform diagram of the three-phase power supply detection of the air conditioning system according to an embodiment;

[0057] Figure 6 This is a flowchart of a three-phase power supply phase loss detection process for an air conditioning system according to an embodiment.

[0058] Figure 7 This is a flowchart of the three-phase power supply zero-crossing detection process for an air conditioning system according to an embodiment.

[0059] Figure 8 This is a flowchart of the three-phase power supply frequency detection process for an air conditioning system according to an embodiment.

[0060] Figure 9 This is a flowchart of the three-phase power supply phase sequence detection process for an air conditioning system according to an embodiment.

[0061] Figure 10 This is a flowchart illustrating the overall process of three-phase power supply detection for an air conditioning system according to an embodiment. Detailed Implementation

[0062] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0063] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0064] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0065] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0066] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0067] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0068] The air conditioning system disclosed in this application executes a refrigeration cycle using a compressor, condenser, throttling device, and evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation to cool or heat an indoor space.

[0069] Low-temperature, low-pressure refrigerant enters the compressor, which compresses it into a high-temperature, high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0070] The throttling device expands the high-temperature, high-pressure liquid refrigerant that condenses in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the expanded refrigerant in the throttling device, returning the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves its cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled. Throughout the cycle, the air conditioner regulates the temperature of the indoor space.

[0071] The outdoor unit of an air conditioning system refers to the part of the refrigeration cycle that includes the compressor and the outdoor heat exchanger. The throttling device is located in the outdoor unit.

[0072] The indoor unit of the air conditioning system includes an indoor heat exchanger. The air conditioning system includes at least two indoor units, and each indoor unit is equipped with an indoor expansion valve. The capacity of the indoor unit is adjusted by regulating the opening of the indoor expansion valve.

[0073] The indoor and outdoor heat exchangers function as either condensers or evaporators. When the indoor heat exchanger is used as a condenser, the air conditioner functions as a heater in heating mode; when the indoor heat exchanger is used as an evaporator, the air conditioner functions as a cooler in cooling mode.

[0074] The air conditioning system is powered by a three-phase power supply.

[0075] With the upgrading of inverter drivers in air conditioning systems and the increasing reliability requirements, the demand for input information from three-phase power supplies is growing. This includes phase sequence detection, incorrect phase sequence connection, missing phase sequence, and power frequency information. Furthermore, the air conditioning control algorithm requires the acquisition of zero-crossing times of the three-phase input voltages. However, current digital signal sampling circuits cannot simultaneously provide all of this information and are relatively expensive.

[0076] Therefore, based on the above requirements, a low-cost three-phase variable frequency air conditioner inverter drive input voltage detection circuit and method are proposed.

[0077] exist Figure 3 , 4 In the example, the air conditioning system includes a three-phase power supply, a controller IC1, and a voltage divider circuit.

[0078] Three-phase power supply is used to power the air conditioning system, including three phases: L1, L2, and L3.

[0079] Three-phase power supplies do not have an N-phase.

[0080] The controller IC1 is used to sample the L1, L2 and L3 phases of the three-phase power supply respectively.

[0081] The first voltage divider circuit is located between phase L1 and the controller IC1 hot ground.

[0082] The second voltage divider circuit is located between phase L2 and the controller IC1 hot ground.

[0083] The third voltage divider circuit is located between phase L3 and the controller IC1 hot ground.

[0084] The controller includes three ports for receiving voltage divider signals from the voltage divider circuit: port 1, port 2, and port 3.

[0085] The first port is used to receive the first voltage divider signal Signal1 from the first voltage divider circuit.

[0086] The second port is used to receive the second voltage divider signal Signal2 from the second voltage divider circuit.

[0087] The third port is used to receive the third voltage divider signal Signal3 from the third voltage divider circuit.

[0088] No isolation device is installed between the three-phase power supply and the controller IC1.

[0089] The air conditioning system includes a three-phase power supply, a voltage divider circuit, and a controller IC1. Each phase of the three-phase power supply is divided by the voltage divider circuit and then detected by the three ports of the controller IC1. No isolation devices are used between the three-phase power supply and the controller IC1, which achieves both low cost and comprehensive detection signals, enabling full information detection of the input voltage. Since the air conditioning system's circuit reference ground is a thermal ground design, it does not require isolation, ensuring safety. The three-phase power supply detection circuit design is simple and reliable, and can extract rich information, representing a minimalist and low-cost design solution in the field of commercial air conditioning design.

[0090] In some embodiments, controller IC1 is frequency converter driver IC1.

[0091] In a three-phase power supply, each phase (L1, L2, L3) is hot-grounded to sample signals from the inverter driver controller IC1. The hot-grounded inverter driver controller IC1 forms a virtual neutral point, ensuring electrical safety and eliminating the need for isolation devices.

[0092] The above technical solution has the following advantages or beneficial effects: when the input voltage is confirmed to be normal, the air conditioning system is controlled to work normally and three-phase power supply is tested.

[0093] In some embodiments, the air conditioning system further includes three filter circuits: a first filter circuit, a second filter circuit, and a third filter circuit.

[0094] Three filter circuits filter the three phases (L1 phase, L2 phase, and L3 phase) of the three-phase power supply respectively.

[0095] The first filter circuit is used to filter the first voltage divider signal and then transmit it to the first port of the controller IC1.

[0096] The second filter circuit is used to filter the second voltage divider signal and then transmit it to the second port of the controller IC1.

[0097] The third filter circuit is used to filter the third voltage divider signal and then transmit it to the third port of controller IC1.

[0098] The voltage divider signal is filtered by a filtering circuit to reduce noise entering the controller IC1 signal.

[0099] In some embodiments, the air conditioning system further includes three voltage regulator circuits: a first voltage regulator circuit, a second voltage regulator circuit, and a third voltage regulator circuit.

[0100] The three voltage regulator circuits regulate the voltage of the three phases (L1 phase, L2 phase, and L3 phase) of the three-phase power supply, respectively.

[0101] The first voltage regulator circuit is used to regulate the first voltage divider signal and then transmit it to the first port of the controller IC1.

[0102] The second voltage regulator circuit is used to regulate the second voltage divider signal and then transmit it to the second port of the controller IC1.

[0103] The third voltage regulator circuit is used to regulate the third voltage divider signal and then transmit it to the third port of controller IC1.

[0104] The voltage divider signal is stabilized by a voltage regulator circuit to improve the signal detection accuracy of controller IC1.

[0105] exist Figure 3 In the examples, the voltage divider circuit, filter circuit and voltage regulator circuit corresponding to each phase of the three-phase power supply are described respectively.

[0106] In phase L1, the first voltage divider circuit includes resistors R11-R16, where R11-R15 are voltage divider resistors and R16 is the input bias voltage Voffset setting resistor.

[0107] The first filter circuit consists of resistor R17 and capacitor C11, and is used as a voltage sampling signal input filter circuit.

[0108] The first voltage regulator circuit consists of Zener diodes D11 and D12, and serves as a voltage sampling signal input regulator circuit.

[0109] The first voltage divider signal will be directly sent to the first port (AD sampling port) of the controller IC1 based on the controller IC1 hot ground to complete the signal acquisition and reconstruction of the input voltage L1 phase and extract the corresponding information from it.

[0110] In phase L2, the second voltage divider circuit includes resistors R21-R26. Resistors R21-R25 are voltage divider resistors, and resistor R26 is the input bias voltage Voffset setting resistor.

[0111] The second filter circuit consists of resistor R27 and capacitor C21, and serves as the input filter circuit for the voltage sampling signal.

[0112] The second voltage regulator circuit consists of Zener diodes D21 and D22, and serves as the voltage sampling signal input voltage regulator circuit.

[0113] The second voltage divider signal will be directly sent to the second port (AD sampling port) of the controller IC1 based on the controller IC1 hot ground to complete the signal acquisition and reconstruction of the input voltage L2 phase and extract the corresponding information from it.

[0114] In phase L3, the third voltage divider circuit includes resistors R31-R36. Resistors R31-R35 are voltage divider resistors, and resistor R36 is the input bias voltage Voffset setting resistor.

[0115] The third filter circuit consists of resistor R37 and capacitor C31, and serves as the input filter circuit for the voltage sampling signal.

[0116] The third voltage regulator circuit consists of Zener diodes D31 and D32, and serves as a voltage sampling signal input regulator circuit.

[0117] The third voltage divider signal will be directly sent to the third port (AD sampling port) of the controller IC1 based on the controller IC1 hot ground to complete the signal acquisition and reconstruction of the input voltage L1 phase and extract the corresponding information from it.

[0118] The circuit design is simple and reliable, and the algorithm can extract a wealth of information, making it a minimalist and low-cost design solution for the commercial air conditioning design field.

[0119] For basic judgment information regarding information extraction, please refer to [link / reference]. Figure 10 The three-phase voltage input information extraction control logic performs input voltage detection after the air conditioner inverter driver is powered on and the system self-tests to confirm that it can work normally. This includes voltage anomaly detection, phase loss detection, zero-crossing detection, frequency detection, and phase sequence detection.

[0120] In some embodiments, the controller is configured to determine whether the input voltage is normal.

[0121] If the input voltage is confirmed to be normal, the air conditioning system will operate normally and a three-phase power supply test will be performed; otherwise, an abnormal alarm will be triggered.

[0122] When the input voltage is normal, perform phase loss detection.

[0123] In some embodiments, the controller is configured to:

[0124] When the signal at the first port is zero for a set period of time, it is determined that phase L1 is missing.

[0125] When the signal at the second port is zero for a set period of time, it is determined that phase L2 is missing.

[0126] When the signal at the third port is zero for a set period of time, it is determined that phase L3 is missing.

[0127] Phase loss can be detected by checking if there is a signal at the port; the detection method is simple and quick.

[0128] exist Figure 6 In this example, the procedure for detecting a phase loss in a three-phase power supply is as follows:

[0129] S1, Begin.

[0130] S2. The controller obtains the first voltage divider signal Signal1 at the first port, the second voltage divider signal Signal2 at the second port, and the third voltage divider signal Signal3 at the third port.

[0131] If Signal1 = 0 and the set time is maintained, proceed to step S3; if Signal2 = 0 and the set time is maintained, proceed to step S4; if Signal3 = 0 and the set time is maintained, proceed to step S5.

[0132] Phases S3 and L1 are missing.

[0133] Phases S4 and L2 are missing.

[0134] Phases S5 and L3 are missing.

[0135] Zero-crossing detection is performed when there is no phase loss in the three-phase power supply.

[0136] exist Figure 5 In this example, the controller is configured as follows:

[0137] When the port signal remains above the set voltage value for a set period of time, a positive zero-crossing occurs when the trend of the port signal is above the set voltage value, and a negative zero-crossing occurs when the trend of the port signal is below the set voltage value.

[0138] By comparing the signals from the three ports with the set voltage value and observing the voltage trend, the positive and negative zero-crossing points of each phase of the three-phase power supply can be directly determined, making the detection method simple and quick.

[0139] In some embodiments, the controller is configured with a flag bit that is 1 when the zero point is crossed positively and 0 when the zero point is crossed negatively; or, the flag bit is 1 when the zero point is crossed negatively and 0 when the zero point is crossed positively.

[0140] Positive and negative zero-crossing points are marked by flags to facilitate the identification and statistical analysis of zero-crossing points.

[0141] In some embodiments, the voltage value is set to the bias voltage Offset_Value.

[0142] State_V_LX=signalS_Value>Offset_Value, X represents 1, 2, 3.

[0143] exist Figure 7 In this example, the zero-crossing detection process for a three-phase power supply is as follows:

[0144] S1, Begin.

[0145] S2, the three ports of the controller respectively obtain the voltage divider signal.

[0146] S3. Voltage divider signal > bias voltage Offset_Value, for a set duration. If the trend is higher than the set voltage value, proceed to step S4; if the trend is lower than the set voltage value, proceed to step S5.

[0147] S4, positive zero crossing, State_V_Pole = 1.

[0148] S5, negative zero crossing, State_V_Pole = 0.

[0149] Each time a positive or negative zero-crossing occurs, State_Zero_Counter is incremented by 1.

[0150] In some embodiments, the controller is configured to determine the input three-phase power supply voltage cycle based on the time interval between the positive and negative zero crossings.

[0151] The cycle of the input three-phase power supply voltage can be accurately determined by the time interval between the positive and negative zero crossings.

[0152] In some embodiments, the controller is configured to determine the three-phase power supply frequency based on the three-phase power supply voltage cycle.

[0153] The frequency of a three-phase power supply can be accurately determined by the voltage cycle of the three-phase power supply.

[0154] The three-phase power supply voltage period Tp = T_State_Current - |_State_Before.

[0155] In some embodiments, 9ms <Tp<11mS,FrequenCy=50HZ;7ms<Tp<9mS,Frequency=60HZ。

[0156] exist Figure 8In the example, the three-phase power supply frequency detection process is as follows:

[0157] S1. Start.

[0158] S2. The three ports of the controller respectively obtain the voltage division signals.

[0159] S3. Determine the positive zero-crossing point and the negative zero-crossing point.

[0160] S4. Determine the time interval Tp between the positive zero-crossing point and the negative zero-crossing point. When 9ms < Tp < 11mS, go to step S5; when 7ms < Tp < 9mS, go to step S6.

[0161] S5. Frequency = 50HZ.

[0162] S6. FrequenCy = 60HZ.

[0163] In some embodiments, the control module is configured to satisfy:

[0164] The signal of the first port > 0, the signal of the second port > 0, the signal of the third port = 0;

[0165] The signal of the first port > 0, the signal of the second port = 0, the signal of the third port > 0;

[0166] When the signal of the first port = 0, the signal of the second port = 0, and the signal of the third port > 0, the three-phase power supply phase sequence is normal; otherwise, the three-phase power supply phase sequence is abnormal.

[0167] State_V_L1 = signals1_Value > 0,

[0168] State_V_L2 = signals2_Value > 0,

[0169] State_V_L3 = signals3_Value = 0.

[0170] State_V_L1 = signals1_Value > 0,

[0171] State_V_L2 = signals2_Value = 0,

[0172] State_V_L3 = signals_3Value > 0.

[0173] State_V_L1 = signals1_Value = 0,

[0174] State_V_L2 = signals2_Value > 0,

[0175] State_V_L3=signals3_Value>0.

[0176] The phase sequence of a three-phase power supply can be directly determined using signals from three ports, making the detection and determination method simple and quick.

[0177] exist Figure 9 In this example, the three-phase power supply phase sequence detection process is as follows:

[0178] S1, Begin.

[0179] S2, the three ports of the controller respectively obtain the voltage divider signal.

[0180] S3. Does the voltage divider signal meet the normal phase sequence condition? If yes, proceed to step S4; otherwise, proceed to step S5.

[0181] The normal phase sequence conditions are:

[0182] First port signal > 0, second port signal > 0, third port signal = 0.

[0183] State_V_L1=signals1_Value>0、

[0184] State_V_L2=signals2_Value>0、

[0185] State_V_L3=signals3_Value=0.

[0186] First port signal > 0, second port signal = 0, third port signal > 0.

[0187] State_V_L1=signals1_Value>0、

[0188] State_V_L2=signals2_Value=0,

[0189] State_V_L3=signalS_3Value>0.

[0190] First port signal = 0, second port signal = 0, third port signal > 0.

[0191] State_V_L1=signals1_Value=0,

[0192] State_V_L2=signals2_Value>0、

[0193] State_V_L3=signals3_Value>0.

[0194] S4. The phase sequence of the three-phase power supply is normal.

[0195] S5, abnormal phase sequence of three-phase power supply.

[0196] Air conditioning systems have the following advantages:

[0197] 1-Solve the problem of low design cost of input voltage sampling circuit.

[0198] 2- It can fully reflect the system input information such as phase loss, phase reversal, frequency, and zero crossing of the required input voltage.

[0199] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0200] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An air conditioning system, comprising: Three-phase power supply, used to power the air conditioning system, including L1 phase, L2 phase and L3 phase; The controller is used to sample the three-phase power supply; Its characteristic is that it further includes: The first voltage divider circuit is located between phase L1 and the controller's hot ground; The second voltage divider circuit is located between phase L2 and the controller's hot ground; The third voltage divider circuit is located between phase L3 and the controller's hot ground; The controller includes: The first port is used to receive the first voltage divider signal from the first voltage divider circuit. The second port is used to receive the second voltage divider signal from the second voltage divider circuit. The third port is used to receive the third voltage divider signal from the third voltage divider circuit; No isolation device is installed between the three-phase power supply and the controller.

2. The air conditioning system according to claim 1, characterized in that, The controller is configured as follows: When the signal at the first port is zero for a set period of time, it is determined that phase L1 is missing. When the signal at the second port is zero for a set period of time, it is determined that phase L2 is missing. When the signal at the third port is zero for a set period of time, it is determined that phase L3 is missing.

3. The air conditioning system according to claim 1, characterized in that, The controller is configured as follows: When the port signal remains above the set voltage value for a set period of time, a positive zero-crossing occurs when the trend of the port signal is above the set voltage value, and a negative zero-crossing occurs when the trend of the port signal is below the set voltage value.

4. The air conditioning system according to claim 3, characterized in that, The controller is configured with a flag bit, which is 1 when the zero point crosses positively and 0 when the zero point crosses negatively; or, the flag bit is 1 when the zero point crosses negatively and 0 when the zero point crosses positively.

5. The air conditioning system according to claim 3, characterized in that, The controller is configured to determine the input three-phase power supply voltage cycle based on the time interval between the positive and negative zero crossings.

6. The air conditioning system according to claim 3, characterized in that, The controller is configured to determine the three-phase power frequency based on the three-phase power voltage cycle.

7. The air conditioning system according to claim 1, characterized in that, The control module is configured to satisfy: First port signal > 0, second port signal > 0, third port signal = 0; First port signal > 0, second port signal = 0, third port signal > 0; When the first port signal = 0, the second port signal = 0, and the third port signal > 0, the three-phase power supply phase sequence is normal; otherwise, the three-phase power supply phase sequence is abnormal.

8. The air conditioning system according to claim 1, characterized in that, The controller is configured to determine whether the input voltage is normal.

9. The air conditioning system according to any one of claims 1-8, characterized in that, Also includes: The first filtering circuit is used to filter the first voltage divider signal and then transmit it to the first port. The second filtering circuit is used to filter the second voltage divider signal and then transmit it to the second port. The third filtering circuit is used to filter the third voltage divider signal before transmitting it to the third port.

10. The air conditioning system according to any one of claims 1-8, characterized in that, Also includes: The first voltage regulator circuit is used to regulate the first voltage divider signal and then transmit it to the first port; The second voltage regulator circuit is used to regulate the second voltage divider signal and then transmit it to the second port. The third voltage regulator circuit is used to regulate the third voltage divider signal before transmitting it to the third port.

Images