Main control circuit of three-phase air conditioning unit, main control device of main control circuit and air conditioning system

Abstract

The utility model provides a main control circuit of a three-phase air conditioning unit, a main control device of the main control circuit and an air conditioning system. The main control circuit of the three-phase air conditioning unit comprises a common mode inductor; a first contact of the voltage detection module is electrically connected with a first output end of the common mode inductor, and a second contact of the voltage detection module is electrically connected with a second output end of the common mode inductor; the charge release module is electrically connected between the first output end of the common mode inductor and the second output end of the common mode inductor; and the first end of the current-limiting consumption module is electrically connected with the first output end of the common mode inductor, and the current-limiting consumption module is electrically connected with the first contact or the second contact. The problem that in a main control circuit of a three-phase air conditioning unit in an existing scheme, a resistor at the rear end of an X capacitor bears large voltage, power consumption is large, and consequently the resistor is damaged is solved.

Description

Technical Field

[0001] This application relates to the field of air conditioning unit technology, and more specifically, to a main control circuit, a main control device, and an air conditioning system for a three-phase air conditioning unit. Background Technology

[0002] Three-phase air conditioning units typically use three-phase electricity, requiring three live wires and one neutral wire to operate normally. The neutral wire is usually connected to the ground wire. However, in certain situations, such as in remote areas, older buildings, or special power usage scenarios, a neutral wire may not be available for the three-phase air conditioning unit, causing it to malfunction.

[0003] To address this issue, several methods exist to avoid using a neutral wire, such as employing a single-phase inverter to convert single-phase power to three-phase power. However, this method requires additional hardware and incurs higher costs, and its efficiency and performance are inferior to using three-phase power directly. Furthermore, single-phase inverters are susceptible to grid fluctuations, leading to unstable operation of the air conditioning unit.

[0004] Both the filter board and the main control board filter circuits utilize X capacitors. X capacitors quickly and safely release stored charge. After a power outage, to prevent electric shock hazards or equipment damage, a resistor is typically connected in parallel with the X capacitor to ensure rapid energy dissipation. In filter board circuit design, X capacitors are often placed between the live and neutral wires. These X capacitors are connected in parallel with a discharge resistor. Normally, there are no abnormalities in the unit's wiring. However, if the neutral wire at the unit's terminal block is unexpectedly disconnected, the resistors at the back of the X capacitors on the filter board and the main control board form a voltage divider, allowing the main control board to operate. Over time, the resistors at the back of the X capacitors, subjected to a large voltage and high power consumption, eventually fail, reducing the unit's reliability.

[0005] In the main control circuit of the existing three-phase air conditioning unit, the resistor downstream of capacitor X is damaged due to the large voltage it bears and the large power consumption. Utility Model Content

[0006] The main objective of this application is to provide a main control circuit, a main control device, and an air conditioning system for a three-phase air conditioning unit, so as to at least solve the problem that in the main control circuit of a three-phase air conditioning unit in the prior art, the resistor downstream of the X capacitor is damaged due to the large voltage it bears and the large power consumption.

[0007] To achieve the above objectives, according to one aspect of this application, a main control circuit for a three-phase air conditioning unit is provided. The main control circuit includes: a common-mode inductor, wherein a first input terminal of the common-mode inductor is electrically connected to any one of the three phase terminals of the main control circuit of the three-phase air conditioning unit, and a second input terminal of the common-mode inductor is electrically connected to the neutral terminal of the power supply; a voltage detection module, wherein a first detection terminal of the voltage detection module is electrically connected to the first input terminal of the common-mode inductor, a second detection terminal of the voltage detection module is electrically connected to the second input terminal of the common-mode inductor, a first contact of the voltage detection module is electrically connected to the first output terminal of the common-mode inductor, and a second contact of the voltage detection module is electrically connected to the second output terminal of the common-mode inductor; a charge release module, which is electrically connected between the first output terminal and the second output terminal of the common-mode inductor; and a current-limiting consumption module, wherein a first terminal of the current-limiting consumption module is electrically connected to the first output terminal of the common-mode inductor, and the current-limiting consumption module is electrically connected to either the first contact or the second contact.

[0008] Optionally, the voltage detection module is a relay, the first detection terminal of the relay is electrically connected to the first input terminal of the common mode inductor, and the second detection terminal of the relay is electrically connected to the second input terminal of the common mode inductor.

[0009] Optionally, the charge release module is a capacitor module, with a first terminal of the capacitor module electrically connected to the first output terminal of the common-mode inductor, and a second terminal of the capacitor module electrically connected to the second output terminal of the common-mode inductor.

[0010] Optionally, the capacitor module includes multiple capacitors connected in series or in parallel.

[0011] Optionally, the current limiting module is an NTC module, the first terminal of the NTC module is electrically connected to the first output terminal of the common mode inductor, and the NTC module is used to electrically connect to the first contact or the second contact.

[0012] Optionally, the NTC module includes multiple NTC resistors connected in series or in parallel.

[0013] Optionally, the main control circuit of the three-phase air conditioning unit further includes a rectifier bridge. The first output terminal and the second output terminal of the rectifier bridge are respectively used to be electrically connected to the main control board of the three-phase air conditioning unit. The first input terminal of the rectifier bridge is electrically connected to the second contact of the voltage detection module, and the second input terminal of the rectifier bridge is electrically connected to the first contact of the voltage detection module.

[0014] Optionally, the rectifier bridge is composed of four diodes connected in a bridge configuration.

[0015] According to another aspect of this application, a main control device for a three-phase air conditioning unit is provided, the main control device for the three-phase air conditioning unit including any of the main control circuits of the three-phase air conditioning unit described above.

[0016] According to another aspect of this application, an air conditioning system is provided, which includes the main control circuit of any of the three-phase air conditioning units and the three-phase air conditioning unit.

[0017] By applying the technical solution of this application and setting up a voltage detection module, a charge release module, and a current limiting and consumption module, the stability and safety of the main control circuit of a three-phase air conditioning unit can be significantly improved. Especially in abnormal situations such as unstable grid voltage or neutral wire disconnection, it can effectively protect the equipment from damage, extend the service life of the equipment, and ensure personnel safety and the EMC performance of the equipment. Compared with the existing solution, it will not damage the current limiting and consumption module, thus solving the problem that in the main control circuit of the existing three-phase air conditioning unit, the resistor after the X capacitor is damaged due to the large voltage and high power consumption. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0019] Figure 1 A schematic diagram of the structure of a three-phase power supply filter circuit provided in an embodiment of this application is shown;

[0020] Figure 2 A schematic diagram of a conventional single-phase motherboard filter circuit provided according to an embodiment of this application is shown;

[0021] Figure 3 A schematic diagram of the main control circuit of a first three-phase air conditioning unit according to an embodiment of this application is shown;

[0022] Figure 4 A schematic diagram of the main control circuit of a second type of three-phase air conditioning unit provided according to an embodiment of this application is shown.

[0023] The above figures include the following reference numerals:

[0024] 100. Common mode inductor; 200. Voltage detection module; 300. Charge release module; 400. Current limiting and consumption module; 500. Rectifier bridge. Detailed Implementation

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] As described in the background section, both the filter circuit on the filter board and the filter circuit on the main control board utilize X capacitors. X capacitors can quickly and safely release stored charge. After a power outage, to prevent electric shock hazards or equipment damage, a resistor is typically connected in parallel after the X capacitor to ensure the energy in the X capacitor is rapidly dissipated. In filter board circuit design, X capacitors are often placed between the live and neutral wires. These X capacitors are connected in parallel with a discharge resistor. Under normal wiring conditions, there are no abnormalities. However, when the neutral wire at the unit's terminal block is accidentally disconnected, the resistors at the back of the X capacitors on the filter board and the main control board form a voltage divider, allowing the main control board to operate. Over time, the resistors at the back of the X capacitors experience high voltage and high power consumption, leading to resistor damage and reduced unit reliability. To address the problem of resistor damage due to high voltage and high power consumption in the main control circuit of existing three-phase air conditioning units, embodiments of this application provide a main control circuit for a three-phase air conditioning unit, a main control device for a three-phase air conditioning unit, and an air conditioning system.

[0029] like Figure 1 The diagram shows the structure of a three-phase power supply filter circuit. L1_IN, L2_IN, L3_IN, and N_IN are the inputs of the filter, and L1_OUT, L2_OUT, L3_OUT, and N_OUT are the outputs of the filter. C1, C2, and C3 are the X capacitors connected between L1, L2, and L3 and N, respectively. R1, R2, and R3 (with relatively large resistance values ​​of KΩ and MΩ) are the discharge resistors of C1, C2, and C3.

[0030] like Figure 2 As shown, the existing single-phase motherboard filter circuit is illustrated. C4 is the X capacitor connected between the live and neutral wires, R4 (with relatively large resistance values ​​of KΩ and MΩ) is the discharge resistor of the X capacitor, and R5 is the NTC resistor to prevent power-on surges.

[0031] When the neutral line N_IN of the three-phase filter board is disconnected, L3_OUT forms a voltage divider through R4, R2, and R3 (since the resistance values ​​of R4, R2, and R3 are all relatively large, the voltage across R4 after voltage division solves half of the line voltage), and the divided voltage allows the mainboard to work.

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0033] This application provides a main control circuit for a three-phase air conditioning unit, such as... Figure 3 As shown, the main control circuit of the three-phase air conditioning unit includes:

[0034] Common mode inductor 100, the first input terminal of the common mode inductor 100 is used to connect to any one of the three-phase terminals of the main control of the three-phase air conditioning unit. Figure 3 The content shown is related to Figure 1 In L3_OUT, this application is not limited to only being able to... Figure 1 The L3_OUT electrical connection can also be connected to... Figure 1 The L1_OUT or L2_OUT in the above-mentioned common mode inductor 100 is electrically connected to the neutral terminal N_OUT of the above-mentioned power supply.

[0035] A voltage detection module 200, wherein the first detection terminal of the voltage detection module 200 is electrically connected to the first input terminal of the common mode inductor 100, the second detection terminal of the voltage detection module 200 is electrically connected to the second input terminal of the common mode inductor 100, the first contact of the voltage detection module 200 is electrically connected to the first output terminal of the common mode inductor 100, and the second contact of the voltage detection module 200 is electrically connected to the second output terminal of the common mode inductor 100;

[0036] A charge release module 300 is electrically connected between the first output terminal and the second output terminal of the common mode inductor 100.

[0037] The current limiting module 400 has its first end electrically connected to the first output end of the common mode inductor 100, and its current limiting module 400 is electrically connected to the first contact or the second contact.

[0038] In the main control circuit of the aforementioned three-phase air conditioning unit, when the voltage detection module detects a broken neutral wire or abnormal voltage, it can respond promptly by controlling the state of the first and second contacts to trigger the protection mechanism. Specifically, when the voltage detection module detects a voltage flowing between the first and second input terminals of the common-mode inductor, it conducts the second contact to ensure the normal operation of the three-phase air conditioning module. At this time, the current-limiting consumption module plays a current-limiting role. When the voltage detection module detects no voltage flowing between the first and second input terminals of the common-mode inductor, it conducts the first contact to quickly consume and release the charge of the module. This solves the problem in the existing three-phase air conditioning unit main control circuit where the resistor downstream of the X capacitor is damaged due to the large voltage it bears and the high power consumption. By incorporating voltage detection, charge release, and current limiting modules, the stability and safety of the main control circuit of a three-phase air conditioning unit can be significantly improved. This is particularly effective in abnormal situations such as unstable grid voltage or a disconnected neutral wire, protecting the equipment from damage and extending its lifespan. It also ensures personnel safety and the equipment's EMC performance. Compared to existing solutions, this approach does not damage the current limiting module, thus solving the problem in existing three-phase air conditioning unit main control circuits where the resistor downstream of the X capacitor is damaged due to its high voltage and power consumption.

[0039] The main function of a common-mode inductor is to suppress common-mode interference signals on the power line. This is especially important in three-phase power supply systems because it can effectively reduce electromagnetic interference from the power grid to the equipment, while also reducing electromagnetic pollution from the equipment to the power grid, thus improving the EMC (electromagnetic compatibility) performance of the entire system.

[0040] The voltage detection module is used to monitor the phase voltage and neutral voltage of the power supply in real time. Through the connection of the first and second detection terminals, it can detect the voltage state between the three phases and the neutral wire. When a neutral wire break or abnormal voltage is detected, it can respond promptly by controlling the state of the first and second contacts to trigger a protection mechanism, preventing the equipment from operating under abnormal voltage and protecting the main control circuit from damage. The main control circuit of the three-phase air conditioning unit is the core control part of the entire air conditioning system. It is responsible for monitoring, analyzing, and controlling the operating status of the air conditioner, ensuring that the system can operate efficiently and stably.

[0041] A charge release module rapidly releases the charge stored in the capacitors of a circuit when the power is lost or switched off. This is typically achieved through a discharge resistor or discharge circuit connected to the output of a common-mode inductor. Rapid charge release ensures that residual charge in the circuit does not pose a risk of electric shock to personnel during a power outage, while also protecting sensitive components in the circuit from residual voltage.

[0042] The current-limiting module can limit the current flowing through the main control circuit when the neutral wire is disconnected or the voltage is abnormal, preventing excessive voltage from overloading or damaging components in the circuit. The current-limiting module can be designed to activate only when the voltage detection module detects an abnormality, and through connection with the first or second contact, it can protect the main circuit.

[0043] The working principle of the main control circuit of the three-phase air conditioning unit is as follows: When the relay coil detects a voltage between the first and second input terminals of the common mode inductor, the second contact is turned on to ensure the normal operation of the main control circuit of the three-phase air conditioning module. At this time, the current limiting module plays a current limiting role. When the relay coil detects no voltage flowing between the first and second input terminals of the common mode inductor, the first contact is turned on to quickly consume and release the charge of the module.

[0044] In one embodiment of this application, such as Figure 4 As shown, the voltage detection module is a relay K1. The first detection terminal of the relay K1 is electrically connected to the first input terminal of the common mode inductor 100, and the second detection terminal of the relay K1 is electrically connected to the second input terminal of the common mode inductor 100.

[0045] Specifically, relays can quickly activate when an abnormal voltage is detected between the three-phase power supply and the neutral wire, such as a loose neutral wire. Through the switching of its contacts, the relay disconnects from the main control circuit, preventing excessive voltage or current from flowing into the main control circuit, thus avoiding potential circuit damage and personal injury, and improving system safety. Furthermore, as a mature electrical switching element, the relay possesses high reliability and stability. Compared to software-controlled detection mechanisms, the hardware characteristics of relays make them more reliable in extreme environments (such as electromagnetic interference and temperature changes), ensuring accurate voltage detection and timely response under various operating conditions. The relay's contact action provides electrical isolation between the power supply circuit and the main control circuit. Especially under abnormal voltage or large power fluctuations, this isolation effectively prevents interference from the power supply side from affecting the normal operation of the main control circuit, protecting the stability and data integrity of the main control circuit.

[0046] In one embodiment of this application, such as Figure 4 As shown, the charge release module is a capacitor module Cb. The first end of the capacitor module Cb is electrically connected to the first output terminal of the common mode inductor 100, and the second end of the capacitor module Cb is electrically connected to the second output terminal of the common mode inductor 100.

[0047] Specifically, capacitor modules store electrical charge in a circuit. When the power supply is working normally, the capacitor charges; when the power is off or fails, the capacitor quickly releases the stored charge, preventing residual charge from causing accidental injury to subsequent circuits or personnel. During power switching or failure, capacitors in the circuit may store some electrical energy. Without an effective charge release mechanism, this energy may remain at a sufficiently high voltage for an extended period, damaging sensitive components in the circuit, such as microprocessors and sensors. Capacitor modules can quickly release the charge to a safe level, protecting these components from damage. When maintaining or replacing circuit components, residual charge in the circuit may pose a risk of electric shock to operators. Capacitor modules can quickly release charge after the power is disconnected, reducing safety risks during maintenance.

[0048] Preferably, the capacitor module includes multiple capacitors connected in series or in parallel.

[0049] When capacitors are connected in parallel, the total capacitance of the circuit equals the sum of the individual capacitor values. This means that by connecting multiple capacitors in parallel, the total capacitance of the capacitor module can be effectively increased, thereby improving the circuit's filtering capability, energy storage capacity, or power supply stability. When capacitors are connected in series, each capacitor withstands a portion of the total voltage, thus increasing the overall voltage tolerance of the capacitor module. In high-voltage power supply circuits, using series capacitors ensures that each capacitor does not exceed its rated voltage, preventing damage due to overvoltage. By connecting multiple capacitors in parallel or series, the heat generated during capacitor operation can be distributed, reducing the thermal stress on individual capacitors, thereby improving the thermal stability and lifespan of the entire capacitor module.

[0050] In one embodiment of this application, such as Figure 4 As shown, the current limiting module is an NTC module Rb. The first end of the NTC module Rb is electrically connected to the first output end of the common mode inductor 100. The NTC module Rb is used to electrically connect to the first contact or the second contact.

[0051] Specifically, the NTC module can limit sudden current surges during the initial power-on phase. Because NTC resistors have high resistance at low temperatures, their resistance gradually decreases as the resistive element heats up (e.g., due to self-heating caused by current flow during power-on). This characteristic provides instantaneous current limiting during power-on, protecting other components in the circuit from the impact of power-on surges. In the main control circuit of a three-phase air conditioning unit, if the neutral wire is accidentally disconnected, the NTC module can connect to the relay contacts to limit current. Due to the resistance characteristics of the NTC module, it automatically increases its resistance under high current conditions, thereby limiting the current flowing through the relay contacts, preventing the main control circuit from experiencing excessive voltage and current, and protecting it from damage. The NTC module can automatically increase its resistance under overheating or overcurrent conditions to limit current, but once conditions return to normal (e.g., current decreases or temperature drops), its resistance will return to its initial state without manual intervention, thus achieving automatic protection and recovery functions for the circuit. NTC modules can reduce the impact of power fluctuations or faults on circuits, especially sensitive microcontrollers and signal circuits. This protection mechanism can significantly improve the reliability of the entire system and reduce maintenance and fault recovery time.

[0052] Preferably, the NTC module includes multiple NTC resistors connected in series or in parallel.

[0053] Whether connected in series or parallel, the multiple resistors in the NTC module provide redundancy in the circuit design. If a single NTC resistor fails, the other resistors in the series circuit can still limit the current, while the other resistors in the parallel circuit can share the current, ensuring that the basic function of the circuit is not affected.

[0054] In one embodiment of this application, such as Figure 4 As shown, the main control circuit of the three-phase air conditioning unit also includes a rectifier bridge 500. The first output terminal and the second output terminal of the rectifier bridge 500 are respectively used to be electrically connected to the main control board of the three-phase air conditioning unit. The first input terminal of the rectifier bridge 500 is electrically connected to the second contact of the voltage detection module 200, and the second input terminal of the rectifier bridge 500 is electrically connected to the first contact of the voltage detection module 200.

[0055] Specifically, the function of the rectifier bridge is to convert alternating current (AC) to direct current (DC), providing a stable DC power supply to the downstream circuits. By connecting the first input terminal of the rectifier bridge to the second contact of the voltage detection module, and vice versa, it can be ensured that the rectifier bridge can receive the correct three-phase AC input and perform effective rectification under normal voltage conditions. The voltage detection module, connected to the rectifier bridge input terminal through its contacts, enables real-time monitoring of the input voltage in the circuit. Once an abnormal voltage is detected (such as voltage fluctuations caused by a broken neutral wire), the contacts can be quickly disconnected to cut off the input power to the rectifier bridge, preventing overvoltage or undervoltage damage to the circuit and providing effective circuit protection. This connection method allows the voltage detection module to respond quickly to voltage changes and control the power input state of the rectifier bridge in a timely manner. In cases such as a broken neutral wire, the voltage detection module ensures that the rectifier bridge does not operate under unstable input voltage by controlling the disconnection of the contacts, avoiding potential failure risks.

[0056] Preferably, the rectifier bridge is composed of four diodes connected in a bridge configuration.

[0057] Bridge rectifier circuits convert alternating current (AC) to direct current (DC) using full-wave rectification. This means that a positive DC voltage can be output regardless of whether the AC power supply is in its positive or negative half-cycle, improving rectification efficiency and making the power supply more stable and efficient. Compared to half-wave rectifier circuits, bridge rectifier circuits can make fuller use of the AC power supply voltage, with the output DC voltage approaching 0.9 times the peak AC voltage. This is particularly important in applications requiring high-voltage DC power.

[0058] Therefore, this application omits resistor R4 and adds a single-pole double-throw relay K1, whose coil is controlled by single-phase electricity. When the wiring of the three-phase filter board is normal and powered on, the NTC module Rb is connected to the second contact of the relay. After the coil of relay K1 is energized, the relay blade is connected to the first contact, ensuring the normal operation of the main board. When the neutral line N_IN of the three-phase filter board is disconnected, the impedance of the NTC module Rb is at the Ω level, resulting in a very small voltage drop. Furthermore, the NTC module has a positive temperature coefficient, meaning its impedance decreases as the temperature increases, leading to an even smaller voltage drop. This confirms that the main board does not operate when the neutral line N_IN of the three-phase filter board is disconnected, thus improving the reliability of the unit.

[0059] When the unit experiences a power outage, if L3_OUT and N_OUT are lower than the relay coil's disconnection voltage, the relay contacts will switch from the first contact to the second contact. At this time, the NTC module Rb and the capacitor module Cb are connected in parallel. When the power supply is completely lost, Rb quickly discharges to Cb to ensure that the energy in the X capacitor is quickly dissipated.

[0060] This application also provides a main control device for a three-phase air conditioning unit, which includes any of the above-mentioned main control circuits for three-phase air conditioning units. By setting up a voltage detection module, a charge release module, and a current limiting and consumption module, the stability and safety of the main control circuit of the three-phase air conditioning unit can be significantly improved. Especially in abnormal situations such as unstable grid voltage or neutral wire disconnection, it can effectively protect the equipment from damage, extend the service life of the equipment, and ensure personnel safety and the EMC performance of the equipment. Compared with existing solutions, it does not damage the current limiting and consumption module, thus solving the problem in the existing solutions where the resistor downstream of the X capacitor in the main control circuit of the three-phase air conditioning unit is damaged due to the large voltage it bears and the large power consumption.

[0061] This application also provides an air conditioning system, which includes the main control circuit of any of the above-mentioned three-phase air conditioning units and the three-phase air conditioning unit itself. By setting up a voltage detection module, a charge release module, and a current limiting and consumption module, the stability and safety of the main control circuit of the three-phase air conditioning unit can be significantly improved. Especially in abnormal situations such as unstable grid voltage or neutral wire disconnection, it can effectively protect the equipment from damage, extend the service life of the equipment, and ensure personnel safety and the EMC performance of the equipment. Compared with existing solutions, it does not damage the current limiting and consumption module, thus solving the problem in the existing solutions where the resistor after the X capacitor in the main control circuit of the three-phase air conditioning unit is damaged due to the large voltage it bears and the large power consumption.

[0062] It should be noted that the above electrical connection can be a direct electrical connection or an indirect electrical connection. A direct electrical connection means that two devices are directly connected, while an indirect electrical connection means that there are other devices such as capacitors and resistors connected between the connected A and B.

[0063] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0064] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0065] 1) The main control circuit of the three-phase air conditioning unit of this application, by setting a voltage detection module, a charge release module and a current limiting consumption module, can significantly improve the stability and safety of the main control circuit of the three-phase air conditioning unit. Especially in the case of abnormal conditions such as unstable grid voltage or neutral wire disconnection, it can effectively protect the equipment from damage, extend the service life of the equipment, and ensure personnel safety and the EMC performance of the equipment. Compared with the existing solution, it will not damage the current limiting consumption module, thus solving the problem that the resistor after the X capacitor in the main control circuit of the existing three-phase air conditioning unit is damaged due to the large voltage and high power consumption.

[0066] 2) The main control device of the three-phase air conditioning unit of this application, by setting a voltage detection module, a charge release module and a current limiting consumption module, can significantly improve the stability and safety of the main control circuit of the three-phase air conditioning unit. Especially in abnormal situations such as unstable grid voltage or neutral wire disconnection, it can effectively protect the equipment from damage, extend the service life of the equipment, and ensure personnel safety and the EMC performance of the equipment. Compared with the existing solution, it will not damage the current limiting consumption module, thus solving the problem that the resistor after the X capacitor in the main control circuit of the existing three-phase air conditioning unit is damaged due to the large voltage and high power consumption.

[0067] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A main control circuit of a three-phase air conditioning unit, characterized by comprising: Comprises: A common mode inductor, a first input end of the common mode inductor is used for electrical connection with any one of the three-phase ends of the main control of the three-phase air conditioning unit, and a second input end of the common mode inductor is used for electrical connection with a zero line end of a power supply; A voltage detection module, a first detection end of the voltage detection module is electrically connected with the first input end of the common mode inductor, a second detection end of the voltage detection module is electrically connected with the second input end of the common mode inductor, a first contact of the voltage detection module is electrically connected with a first output end of the common mode inductor, and a second contact of the voltage detection module is electrically connected with a second output end of the common mode inductor; A charge release module, the charge release module is electrically connected between the first output end of the common mode inductor and the second output end of the common mode inductor; A current-limiting consumption module, a first end of the current-limiting consumption module is electrically connected with the first output end of the common mode inductor, and the current-limiting consumption module is electrically connected with the first contact or the second contact.

2. The main control circuit of a three-phase air conditioning unit according to claim 1, wherein The voltage detection module is a relay, a first detection end of the relay is electrically connected with the first input end of the common mode inductor, and a second detection end of the relay is electrically connected with the second input end of the common mode inductor.

3. The main control circuit of a three-phase air conditioning unit according to claim 1, wherein The charge release module is a capacitor module, a first end of the capacitor module is electrically connected with the first output end of the common mode inductor, and a second end of the capacitor module is electrically connected with the second output end of the common mode inductor.

4. The main control circuit of a three-phase air conditioning unit according to claim 3, wherein The capacitor module comprises a plurality of series or parallel capacitors.

5. The main control circuit of a three-phase air conditioning unit according to claim 1, wherein The current-limiting consumption module is an NTC module, a first end of the NTC module is electrically connected with the first output end of the common mode inductor, and the NTC module is used for electrical connection with the first contact or the second contact.

6. The main control circuit of a three-phase air conditioning unit according to claim 5, wherein The NTC module comprises a plurality of series or parallel NTC resistors.

7. The main control circuit of a three-phase air conditioning unit according to claim 1, wherein The main control circuit of the three-phase air conditioning unit further comprises a rectifier bridge, a first output end of the rectifier bridge and a second output end of the rectifier bridge are respectively used for electrical connection with a main control board of the three-phase air conditioning unit, a first input end of the rectifier bridge is electrically connected with the second contact of the voltage detection module, and a second input end of the rectifier bridge is electrically connected with the first contact of the voltage detection module.

8. The main control circuit of a three-phase air conditioning unit according to claim 7, wherein The rectifier bridge is formed by four diodes in a bridge connection.

9. A master control device of a three-phase air conditioning unit, characterized by, Comprises: The main control circuit of the three-phase air conditioning unit according to any one of claims 1 to 8.

10. An air conditioning system, characterised in that, Comprises: The main control circuit of the three-phase air conditioning unit according to any one of claims 1 to 8 and the three-phase air conditioning unit.

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