Control system of DC28V and DC600V dual-power-supply air conditioner

Abstract

The utility model discloses a control system of a DC28V and DC600V double-power-supply air conditioner. The control system comprises a signal detection element, a compressor pre-charging element, a control device and a protection device. The controller is electrically connected with an evaporation fan, a condensation fan and a compressor in the air conditioner; the signal detection element is used for detecting temperature and refrigerating system pressure; the compressor is connected with the power supply bus through the high-voltage connector and the pre-charging circuit, and the controller controls the pre-charging circuit. The control device comprises a plurality of groups of high-voltage direct-current relays, the normally open contacts are closed to enable the power supply ends of the evaporation fan, the condensation fan, the compressor and the PTC electric heater to be connected to a DC600V power supply circuit, and coils of each group of high-voltage direct-current relays are electrically connected with a control signal interface of the controller; the protection device comprises a high-voltage direct-current fuse, a high-voltage direct-current circuit breaker and a temperature relay, the protection device is electrically connected with the controller detection interface, a perfect protection function is provided for the dual-power-supply air conditioner, and the safety and reliability of the air conditioner equipment are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to air conditioning control system field, specifically a control system of DC28V and DC600V dual power air conditioner. BACKGROUND

[0002] With the successful application of high voltage direct current drive technology in the combat unit integrated pilot construction, the DC28V and DC600V dual power air conditioner has become a new temperature regulation requirement equipment of weapon system. The core components of the refrigeration system of the DC28V and DC600V dual power air conditioner adopt advanced high voltage direct current electric scroll compressor and high voltage direct current circulating fan and condensing fan of stepless speed regulation, replace the fixed frequency compressor and alternating current variable frequency compressor commonly used in air conditioning equipment. The core components of the heating system adopt high voltage direct current PTC electric heater arranged in the heating mode of return air outlet, rely on the physical property change of PTC material itself, adjust the heating power of PTC electric heater, replace the heating mode of constant heating power metal electric heating tube embedded in evaporator commonly used in military refrigeration equipment. Therefore, a control system is needed to control according to the technical characteristics of high voltage direct current electric scroll compressor and high voltage direct current circulating fan and high voltage direct current PTC electric heater, ensure that the temperature in the space of weapon system does not fluctuate sharply and improve the safety, reliability and service life of air conditioning equipment. CONTENT OF THE UTILITY MODEL

[0003] The utility model provides a control system of DC28V and DC600V dual power air conditioner to guarantee that air conditioning equipment provides comfortable working environment for equipment adopting high voltage direct current drive technology and improves the safety, reliability and service life of air conditioning equipment.

[0004] In order to achieve the above purpose, the technical scheme adopted by the utility model is:

[0005] A control system of DC28V and DC600V dual power air conditioner, the evaporative fan, condensing fan, compressor and PTC electric heater in the dual power air conditioner are powered by DC600V power supply, and the controller is powered by DC28V power supply, characterized by comprising signal detection element, compressor pre-charging element, controller device and protector device.

[0006] The controller is electrically connected with the evaporative fan, condensing fan and compressor in the dual power air conditioner.

[0007] The signal detection element comprises temperature sensor and pressure sensor and is used for detecting the temperature and pressure in the dual power air conditioner, and the signal detection element is electrically connected with the signal detection interface of the controller.

[0008] The compressor pre-charging element comprises a high-voltage connector and a pre-charging circuit, and a control module of the compressor is connected to a DC 600V power supply circuit through the high-voltage connector and the pre-charging circuit; the compressor pre-charging element is electrically connected to a control signal interface of the controller;

[0009] The control device comprises a plurality of high-voltage DC relays, and the closing of the moving contact points connects the power supply ends of the evaporative fan, the condensing fan, the compressor and the electric heater to the DC 600V power supply circuit; the coils of the high-voltage DC relays are electrically connected to the control signal interface of the controller;

[0010] The protection device comprises two groups of high-voltage DC circuit breakers, one group of the high-voltage DC circuit breakers is connected to the evaporative fan and the DC 600V power supply bus positive line, and the other group of the high-voltage DC circuit breakers is connected to the condensing fan and the DC 600V power supply bus positive line; the auxiliary contact points of the two groups of high-voltage DC circuit breakers are electrically connected to the overload signal detection port of the controller;

[0011] Further, the signal detection element comprises three groups of temperature sensors for detecting the return air temperature, the coil temperature and the exhaust temperature in the dual-supply air conditioner respectively; and two groups of pressure sensors for detecting the high-pressure side pressure of the refrigeration system and the low-pressure side pressure of the refrigeration system in the dual-supply air conditioner respectively; the three groups of temperature sensors and the two groups of pressure sensors are electrically connected to the signal sampling port of the controller respectively;

[0012] Further, the protection device further comprises a temperature relay, and the moving breaking contact points of the temperature relay are electrically connected to the overheat protection signal of the controller respectively;

[0013] Further, the protection device further comprises a plurality of groups of high-voltage DC fuses, and each group of the high-voltage DC fuses is connected to the compressor pre-charging element, the PTC electric heater and the DC 600V power supply bus positive line.

[0014] The utility model discloses the beneficial effect:

[0015] 1, the utility model discloses the preflush element of compressor and control the start -stop timing of high -voltage DC relay in it, before high -voltage DC electric scroll compressor operation, through the preflush electricity of capacitor and establish direct -current bus voltage, prevent the short circuit of high -voltage DC circuit in the power -on moment of compressor, and the damage that impact current causes to power supply main circuit power device, guarantee the safety of weapon system and air conditioning equipment.

[0016] 2, the utility model carries out data communication with compressor, realizes air conditioning equipment soft start through the control compressor speed and adjusts the refrigerating capacity of air conditioning equipment, guarantees temperature to maintain in the vicinity of set value, and the technology is advanced, mature and reliable, energy -conserving.

[0017] 3. The utility model discloses a group control, time-sharing start-stop high voltage direct current PTC electric heater, and through PWM speed control signal control circulating fan's rotating speed, rely on PTC material's physical property change, rapidly adjust PTC heating power, guarantee temperature to maintain at the vicinity of set value, simple and reliable and saved cost.

[0018] 4. The utility model discloses set up compressor overcurrent, PTC overheat and overcurrent, circulating fan overload, condensing fan overload, evaporator anti-freezing, refrigeration system pressure and compressor exhaust temperature protection, improve the security of air conditioning equipment, reliability and service life. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is the utility model embodiment circuit principle block diagram. DETAILED DESCRIPTION

[0020] The utility model is further explained below in connection with the drawings and examples.

[0021] As Figure 1 The utility model discloses a control system of DC28V and DC600V dual power air conditioner, evaporative fan MD1, condensing fan MD2, compressor MC, PTC electric heater PTC1~PTC4 in dual power air conditioner are powered by DC600V power supply, namely: the positive electrode power supply end of evaporative fan MD1 is connected DC600V power supply bus positive line, and the negative electrode power supply end of evaporative fan MD1 is connected DC600V power supply bus negative line;The positive electrode power supply end of condensing fan MD2 is connected DC600V power supply bus positive line, and the negative electrode power supply end of condensing fan MD2 is connected DC600V power supply bus negative line;The positive electrode power supply end of compressor MC is connected DC600V power supply bus positive line, and the negative electrode power supply end of compressor MC is connected DC600V power supply bus negative line;The positive electrode power supply end of PTC electric heater PTC1~PTC4 is connected DC600V power supply bus positive line, and the negative electrode power supply end of PTC electric heater PTC1~PTC4 is connected DC600V power supply bus negative line.DC28V power supply is powered for the controller AP in dual power air conditioner, and DC28V power voltage is isolated and stabilized through DC-DC power supply in the controller AP, and DC24V voltage power supply is provided for the coil of high voltage pressure sensor YCQ1, low voltage pressure sensor YCQ2, compressor MC's CAN communication circuit and high voltage direct current relay KA1~KA8.

[0022] The embodiment includes controller AP, signal detection element, compressor pre-charging element, control device and protection device, wherein:

[0023] The controller AP is electrically connected with the evaporative fan MD1, the condensing fan MD2 and the compressor MC in the dual power supply air conditioner. Specifically, the evaporative fan MD1 and the condensing fan MD2 are PWM speed-controlled high-voltage direct-current fans, the controller AP controls the speed of the evaporative fan MD1 and the condensing fan MD2 by controlling the duty cycle of the PWM speed control signal of the evaporative fan MD1 and the condensing fan MD2, and then controls the air volume. The compressor MC is a high-voltage direct-current electric scroll compressor with a control module, the controller AP communicates with the control module of the compressor MC through CAN, controls the speed of the compressor MC through software logic, and thus controls the soft start of the air conditioning equipment and adjusts the refrigerating capacity of the air conditioning equipment.

[0024] Furthermore, each group of PTC electric heaters PTC1-PTC4 is separately wired, the controller AP controls the gear switching of the PTC electric heaters PTC1-PTC4 through group control, controls the speed of the evaporative fan MD1 through a PWM speed control signal to adjust the air volume, and adjusts the heating power of the PTC electric heaters depending on the physical property change of the PTC material itself.

[0025] In the embodiment, the signal detection element includes a temperature sensor RT1 for detecting the return air temperature in the dual power supply air conditioner, a temperature sensor RT2 for detecting the coil temperature in the dual power supply air conditioner, a temperature sensor RT3 for detecting the exhaust air temperature in the dual power supply air conditioner, a pressure sensor YCQ1 for detecting the high-pressure side pressure in the dual power supply air conditioner, and a pressure sensor YCQ2 for detecting the low-pressure side pressure in the dual power supply air conditioner. The temperature sensor RT1, the temperature sensor RT2, the temperature sensor RT3, the pressure sensor YCQ1 and the pressure sensor YCQ2 are electrically connected with the signal sampling port of the controller AP.

[0026] The controller AP automatically controls the air conditioning equipment to perform ventilation, refrigeration, heating and dehumidification according to the difference between the return air temperature detected by the temperature sensor RT1 in the signal detection element and the target temperature set by the controller.

[0027] In this embodiment, the compressor pre-charging element includes a pre-charging circuit and a high-voltage connector XP1. The pre-charging circuit is connected to the DC 600V power supply bus and the controller AP. The pre-charging circuit includes a high-voltage DC fuse FU1, high-voltage DC relays KA3, KA4, freewheeling diodes D3, D4, resistors R1-R2, and a capacitor C1. The input end of the high-voltage DC fuse FU1 is connected to the positive line of the DC 600V power supply circuit, the output end of the high-voltage DC fuse FU1 is connected to the contact input end of the high-voltage DC relays KA3, KA4, the contact output end of the high-voltage DC relay KA3 is connected in series with the contact output end of the high-voltage DC relay KA4, and the two are connected in parallel to one terminal of the capacitor C1. The other terminal of the capacitor C1 is connected to the negative line of the DC 600V power supply circuit. The two terminals of the capacitor C1 are connected to the high-voltage connector XS1 of the high-voltage DC input end of the control module of the high-voltage DC scroll compressor through the high-voltage connector XP1.

[0028] The signal output end of the controller AP is connected to the coil of the high-voltage DC relays KA3, KA4, and the coils of the high-voltage DC relays KA3, KA4 are connected in reverse parallel with the freewheeling diodes D3, D4. The controller AP controls the start-stop sequence of the high-voltage DC relays KA3, KA4 in the compressor pre-charging element. Before the high-voltage DC scroll compressor operates, the DC bus voltage is pre-charged and established by the capacitor C1 to prevent short circuit of the high-voltage DC circuit at the moment of power-on of the compressor, to prevent damage to the main circuit power devices caused by the impact current, and to ensure the safety of the weapon system and air conditioning equipment.

[0029] In this embodiment, the control device includes high-voltage DC relays KA1-KA8. The make contact of the high-voltage DC relay KA1 is connected to the positive power supply end of the evaporative fan MD1 and the positive line of the DC 600V power supply bus. The make contact of the high-voltage DC relay KA2 is connected to the positive power supply end of the condensing fan MD2 and the positive line of the DC 600V power supply bus. The make contact of the high-voltage DC relay KA5 is connected to the positive power supply end of the electric heater PTC1 and the positive line of the DC 600V power supply bus. The make contact of the high-voltage DC relay KA6 is connected to the positive power supply end of the electric heater PTC2 and the positive line of the DC 600V power supply bus. The make contact of the high-voltage DC relay KA7 is connected to the positive power supply end of the electric heater PTC3 and the positive line of the DC 600V power supply bus. The make contact of the high-voltage DC relay KA8 is connected to the positive power supply end of the electric heater PTC4 and the positive line of the DC 600V power supply bus. The coils of the high-voltage DC relays KA1, KA2, KA5, KA6, KA7, and KA8 are connected to the controller AP.

[0030] In the embodiment, the protection device comprises two groups of high-voltage DC circuit breakers QF1 and QF2, four groups of temperature relays ST1-ST4, and five groups of high-voltage DC fuses FU1-FU5.

[0031] In the two groups of high-voltage DC circuit breakers QF1 and QF2, the main contact of the first group of high-voltage DC circuit breakers QF1 is connected to the line connecting the positive power supply end of the evaporating fan MD1 to the positive line of the power supply bus, and the auxiliary contact of the first group of high-voltage DC circuit breakers QF1 is electrically connected to the overload protection signal of the controller AP. The main contact of the second group of high-voltage DC circuit breakers QF2 is connected to the line connecting the positive power supply end of the condensing fan MD2 to the positive line of the power supply bus, and the auxiliary contact of the second group of high-voltage DC circuit breakers QF2 is electrically connected to the overload protection signal of the controller AP. When the fan is short-circuited or overloaded, the high-voltage DC circuit breaker trips and disconnects the main contact and the auxiliary contact, cutting off the main circuit power supply, and at the same time, the auxiliary contact disconnects the signal feedback to the controller AP, stopping the compressor MC and the PTC electric heater in time, ensuring electrical safety.

[0032] The four groups of temperature relays ST1-ST4 are electrically connected to the overheat protection signal of the controller AP.

[0033] In the five groups of high-voltage DC fuses FU1-FU5, the first group of high-voltage DC fuses FU1 is connected to the line connecting the pre-charging circuit positive power supply end of the compressor pre-charging element to the positive line of the power supply bus, the second group of high-voltage DC fuses FU2 is connected to the line connecting the positive power supply end of the electric heater PTC1 to the positive line of the power supply bus, the third group of high-voltage DC fuses FU3 is connected to the line connecting the positive power supply end of the electric heater PTC2 to the positive line of the power supply bus, the fourth group of high-voltage DC fuses FU4 is connected to the line connecting the positive power supply end of the electric heater PTC3 to the positive line of the power supply bus, and the fifth group of high-voltage DC fuses FU5 is connected to the line connecting the positive power supply end of the electric heater PTC4 to the positive line of the power supply bus.

[0034] In the embodiment, the controller AP is connected to an alarm circuit, and in addition to the above-mentioned overload and overheat protection, it also has protection circuits for refrigeration system pressure abnormalities, compressor pre-charging abnormalities, and CAN communication abnormalities.

[0035] In the utility model, the controller AP automatically controls the air conditioning equipment to perform ventilation, refrigeration, heating, and dehumidification work according to the difference between the return air temperature detected by the temperature sensor RT1 and the set target temperature.

[0036] When the return air temperature detected by the temperature sensor RT1 is 2℃ higher than the set target temperature, the air conditioning equipment cools. Compared with conventional air conditioning control systems, the most important thing is that the high-voltage DC electric scroll compressor is pre-charged before operation to establish a DC bus voltage, preventing the impact current from damaging the main circuit power device during the power-on moment of the compressor MC.

[0037] When refrigerating, the high-voltage direct-current relay KA1 is closed, the circulating fan MD1 is started, and after 10s, it is determined whether there is a mode switching instruction. If there is, it is switched to other modes. If not, it is determined whether the refrigeration condition is met and the refrigeration system low-pressure pressure YCQ2 and the CAN communication of the compressor MC are normal. If normal, the high-voltage direct-current relay KA2 is closed, the condenser fan MD2 is started, and after 3s, the high-voltage direct-current relay KA3 is closed. After 30s, it is determined whether the voltage of the compressor pre-charging is higher than 380VDC. If less than 380VDC, the pre-charging fault alarm is reported. If greater than 380VDC, the high-voltage direct-current relay KA4 is closed, the main power supply loop of the compressor MC is started, and after 1s, the high-voltage direct-current relay KA3 is opened, the pre-charging is closed, and after 1s, the controller AP sends the start instruction to the compressor MC through the CAN communication, the speed is 2500rpm, the small current is started, and the refrigeration is entered.

[0038] During the refrigeration process, it is monitored whether the circulating fan MD1, the condenser fan MD2, and the compressor MC have overload, overcurrent, and other faults, and it is detected whether the refrigeration system high-pressure pressure YCQ1 is higher than the specified value. If there is a fault, it is switched to the protection process. If there is no fault, it continues to refrigerate. It is determined whether there is a relevant machine instruction. If there is, the refrigeration stops. If not, it continues to refrigerate. It is determined whether there is a mode switching instruction. If there is, it is switched to other modes. If not, it continues to refrigerate. If it is close to the set temperature, the controller AP controls the speed of the circulating fan MD1 and the condenser fan MD2 through the PWM speed signal, adjusts the air volume of the circulating fan MD1 and the condenser fan MD2 through the speed, controls the compressor speed through the CAN communication, and adjusts the refrigeration capacity of the air conditioning equipment through the speed. It is detected whether the refrigeration system low-pressure pressure YCQ2 is lower than the specified value. If there is a fault and lasts for 3s, it is switched to the protection process. If there is no fault, it continues to refrigerate.

[0039] When the refrigeration stops, the speed of the compressor MC is gradually reduced by 100rpm every 5s, it is determined whether the speed of the compressor MC is lower than 10rpm. If not, the speed of the compressor MC is continuously reduced. If yes, it is delayed for 5s, the stop working instruction is sent to the compressor MC through the CAN communication, it is delayed for 3s, the high-voltage direct-current relay KA2 is closed, the main power supply loop of the compressor MC is disconnected, and then it is delayed for 3s, the condenser fan stops running, and the air conditioner enters the ventilation state. The compressor is automatically delayed for 3min to start to protect the compressor from being damaged.

[0040] The utility model discloses a temperature sensor RT1 detects the return air temperature is 2 DEG C lower than the target temperature of setting, and air conditioning equipment heats. Compared with the conventional air conditioning control system, the most important thing is that the group control, the time -sharing start -stop high voltage direct current PTC electric heater is adopted, and the rotating speed of circulating fan MD1 is controlled through the PWM speed signal, thereby the air volume of circulating fan MD1 is adjusted, and the PTC heating power is adjusted depending on the physical property change of PTC material.

[0041] When heating, circulating fan MD1 works first, when the return air temperature is 2 DEG C lower than the set temperature, the electric heater PTC1 is started to work, whether circulating fan MD1 is overloaded or overcurrent is detected, if there is a fault, it is switched to heating shutdown, if there is no fault, it continues to heat, whether the electric heater PTC1 is overheated or overcurrent is detected, if there is a fault, it is switched to protection processing, if there is no fault, it continues to heat, whether there is a mode switching instruction, if there is, it is switched to other mode, if there is no, it continues to heat, the return air temperature is 2 DEG C lower than the set temperature, a group of PTC electric heaters PTC2, PTC3, PTC4 are started to work, and gear switching determination is executed once per second, whether it is close to the set temperature, if it is close to the set temperature, the rotating speed of circulating fan MD1 is controlled through the PWM speed signal, thereby the air volume of circulating fan MD1 is adjusted, and the PTC heating power is adjusted depending on the physical property change of PTC material.

[0042] When heating stops, PTC1, PTC2, PTC3, PTC4 electric heaters are closed in turn, and the air conditioner enters the ventilation state, when the heating state is shut down, circulating fan works for 1.5 minutes and then stops working.

[0043] In the embodiment, there is a perfect protection processing design, and the protection devices include high voltage direct current fuses FU1-FU5, high voltage direct current circuit breakers QF1-QF2 and temperature relays ST1-ST4, and the signal detection elements also include evaporator coil temperature RT2, exhaust high temperature protection RT3, high pressure sensor YCQ1 and low pressure sensor YCQ2.

[0044] The high voltage direct current fuses FU1-FU5 in the protection devices are arranged in the high voltage direct current main circuit of the compressor MC and the electric heater PTC, and are fused when short circuit or overcurrent occurs, so that the electrical safety is ensured, the high voltage direct current circuit breakers QF1-QF2 are arranged in the high voltage direct current main circuit of the circulating fan MD1 and the condenser fan MD2, and are tripped when short circuit or overload occurs, so that the main circuit power supply is cut off, and the auxiliary contact is opened to feed the signal to the protection interface of the controller AP, and the work of the compressor MC and the PTC electric heater is stopped in time through the software control logic, so that the electrical safety is ensured.

[0045] The temperature relays ST1-ST4 in the protection device are arranged on the PTC support, and the temperature relays ST1-ST4 can sense the surface temperature of the evaporator in real time. When the surface temperature of the evaporator is higher than the action value of the temperature relay, the temperature relay contact is tripped, the switch signal is input to the protection interface of the controller AP, and the control loop of the PTC electric heater is disconnected in time through the software control logic, so that the surface temperature of the evaporator is prevented from being too high to cause the temperature of the surrounding components to rise and deform or the heat to accumulate to cause a fire.

[0046] The temperature sensor RT2 in the signal detection element is arranged on the coil of the evaporator, and the temperature sensor RT2 can sense the temperature of the coil of the evaporator in real time. The sampling value is converted and input to the corresponding A / D channel of the controller AP, and when the temperature of the coil of the evaporator RT2 is lower than -5℃, the controller AP displays a fault alarm and immediately stops refrigeration to prevent the evaporator from icing; when the temperature of the coil is higher than 3℃, the alarm is cancelled. If the compressor stops working for more than 3 minutes, the refrigeration process is allowed to start again.

[0047] The temperature sensor RT3 in the signal detection element is arranged on the exhaust pipe of the compressor, and the temperature sensor RT3 can sense the exhaust temperature of the compressor in real time. The sampling value is converted and input to the corresponding A / D channel of the controller AP, and when the exhaust temperature exceeds 110℃, the compressor speed is reduced to 2000rpm and runs for 30s. There are three actions: if the exhaust temperature still exceeds 110℃, a fault alarm is given and the refrigeration stop process is executed. When the exhaust temperature returns to be lower than 70℃ after the fault alarm, the alarm is cancelled, and if the compressor stops working for more than 3 minutes, the refrigeration process is allowed to start again; if the temperature exceeds 90℃, the compressor continues to run at 2000rpm until the temperature is lower than 90℃ and the action is executed; if the exhaust temperature is lower than 90℃, the speed of the compressor is restored to the standard value.

[0048] The high-pressure pressure sensor YCQ1 and the low-pressure pressure sensor YCQ2 in the signal detection element are arranged on the exhaust pipe of the compressor and the return pipe respectively, and the sampling values are converted and input to the corresponding A / D channels of the controller AP. Through the software control logic, when the system pressure sampled by YCQ1 exceeds 3.2Mpa or the system pressure sampled by YCQ2 is lower than 0.05Mpa, the controller AP displays a fault alarm and immediately stops refrigeration.

[0049] The preferred embodiments of the present application are described in detail above with reference to the drawings. The embodiments described in the present application are merely a description of the preferred embodiments of the present application, and are not intended to limit the concept and scope of the present application. In the above specific embodiments, each specific technical feature described can be combined in any suitable manner without contradiction, and such combination should also be considered as disclosed by the present disclosure, as long as it does not deviate from the technical concept of the present application. In order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0050] The present application is not limited to the specific details described in the above embodiments, and various modifications and improvements to the technical solutions of the present application made by those skilled in the art within the technical concept of the present application and without departing from the design idea of the present application should fall within the protection scope of the present application. The technical content claimed by the present application has been fully recorded in the claims.

Claims

1. A control system of a DC 28V and DC 600V dual power air conditioner, wherein the evaporative fan, the condensing fan, the compressor and the PTC electric heater in the dual power air conditioner are powered by a DC 600V power supply, and the controller is powered by a DC 28V power supply, characterized in that, The signal detection element, the compressor pre-charging element, the control device, and the protection device are included. The controller is electrically connected with the evaporative fan, the condensing fan, and the compressor in the dual power supply air conditioner. The signal detection element includes temperature sensors and pressure sensors for detecting the temperature and pressure in the dual power supply air conditioner, and is electrically connected with the signal detection interface of the controller. The compressor pre-charging element includes a high-voltage connector and a pre-charging circuit, and the control module of the compressor is connected to the DC600V power supply line through the high-voltage connector and the pre-charging circuit, and the compressor pre-charging element is electrically connected with the control signal interface of the controller. The control device includes multiple groups of high-voltage DC relays, and the closing of the moving contact makes the power supply end of the evaporative fan, the condensing fan, the compressor, and the PTC electric heater connected to the DC600V power supply line, and the coil of each group of high-voltage DC relays is electrically connected with the control signal interface of the controller. The protection device includes two groups of high-voltage DC circuit breakers, one group of which is connected to the evaporative fan and the DC600V power supply bus positive line, and the other group of which is connected to the condensing fan and the DC600V power supply bus positive line, and the auxiliary contact of the two groups of high-voltage DC circuit breakers is respectively electrically connected with the overload signal detection port of the controller.

2. The control system of a dual supply air conditioner of DC 28V and DC 600V according to claim 1, characterized in that, The signal detection element includes three groups of temperature sensors for detecting the return air temperature, the coil temperature, and the exhaust temperature in the dual power supply air conditioner, respectively, and two groups of pressure sensors for detecting the high-pressure side pressure of the refrigeration system and the low-pressure side pressure of the refrigeration system in the dual power supply air conditioner, respectively, and the three groups of temperature sensors and the two groups of pressure sensors are respectively electrically connected with the signal sampling port of the controller.

3. The control system of a dual supply air conditioner of DC 28V and DC 600V according to claim 1, characterized in that, The protection device further includes a temperature relay, and the moving breaking contact of the temperature relay is respectively electrically connected with the overheat protection signal of the controller.

4. The control system of a dual supply air conditioner of DC 28V and DC 600V according to claim 1, characterized in that, The protection device further includes multiple groups of high-voltage DC fuses, and each group of high-voltage DC fuses is connected to the compressor pre-charging element, the PTC electric heater, and the DC600V power supply bus positive line.

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