Dual temperature control system and method for electric control room

Abstract

The invention provides a dual temperature control system and method for an electric control room. The dual temperature control system comprises a fan, a liquid heat exchanger, an upper computer, a power circuit and a control circuit, wherein the fan and the liquid heat exchanger are installed in the electric control room. The fan, the liquid heat exchanger and the upper computer are connected in parallel to be connected with the power circuit to achieve power supply, the control circuit monitors temperature information of the electric control chamber and flow information of the liquid heat exchanger and uploads the information to the upper computer, and the control circuit cooperates with the upper computer to control operation of the fan and the liquid heat exchanger to achieve temperature control over the electric control chamber. According to the invention, temperature control of the electric control room and automatic switching of multiple heat dissipation modes under dynamic thermal load are realized at low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric control room monitoring, and in particular relates to a dual temperature control system and method for an electric control room. Background Art

[0002] Temperature control in an electric control room is a core link to ensure the stable operation of power electronic devices. Traditional solutions mainly rely on forced air cooling by fans or air conditioning for refrigeration, including three categories: forced air cooling, compression refrigeration, and heat exchangers. Fans rely on ambient air flow for cooling, but are easily blocked by dust and their efficiency drops sharply in high-temperature environments. Although cabinet air conditioners can maintain a low temperature, they have high energy consumption and a risk of condensate leakage. Although heat exchangers isolate external pollution, their heat capacity hysteresis causes response delays and they cannot cope with sudden load changes. These temperature control methods generally have three major limitations: First, a single heat dissipation mode is difficult to balance energy efficiency and dynamic response in high power density scenarios (such as rapid acceleration and deceleration of frequency converters); second, there is a lack of real-time coordination with the heat source state, often resulting in local overheating or excessive cooling; third, there is a lack of emergency temperature control ability in case of mechanical failures (such as the temperature rise rate reaching 3°C / s after the fan stops rotating). Existing heat exchangers are dust-proof but rely on the ambient temperature difference, and their heat dissipation ability is insufficient in extreme working conditions. How to transform the existing electric control room at low cost to achieve efficient temperature control is a current problem in electric control room temperature control. Summary of the Invention

[0003] In view of this, the present invention aims to propose a dual temperature control system and method for an electric control room to achieve temperature control in the electric control room at low cost and automatic switching of multiple heat dissipation modes under dynamic thermal loads.

[0004] To achieve the above object, the technical solution of the present invention is realized as follows:

[0005] A dual temperature control system for an electric control room.

[0006] Furthermore, it includes a fan and a liquid heat exchanger installed in the electric control room, a host computer, a power circuit, and a control circuit. The fan, the liquid heat exchanger, and the host computer are connected in parallel to the power circuit for power supply. The control circuit monitors the temperature information of the electric control room and the flow information of the liquid heat exchanger and uploads them to the host computer. The control circuit cooperates with the host computer to control the operation of the fan and the liquid heat exchanger to achieve temperature control of the electric control room.

[0007] Furthermore, the power circuit includes a transformer T1, a switching power supply T1, a UPS, and a collection module, which supplies power to the fan and the liquid heat exchanger with three-phase electricity. The three-phase electricity supplies power to the host computer through the transformer T1. The transformer T1 outputs 24V direct current as the power supply for the control circuit through the switching power supply PS1;

[0008] The host computer is configured with a UPS to achieve uninterrupted power supply. The collection module of the host computer reads the temperature, flow information, and controls the fan speed and the liquid heat exchanger flow rate.

[0009] Furthermore, the control circuit includes a temperature sensor U1, a flow sensor U2, a signal isolator U3, a fan start / stop button SB1, a liquid heat exchanger start button SB2, a manual / automatic changeover knob SA1, a fault control button SB3, a relay KA1, a relay KA2, a contactor KM1, a contactor KM2, a flow rate adjustment knob, and a wind speed adjustment knob;

[0010] The temperature sensor U1 and the flow sensor U2 are connected in parallel, and the temperature and flow signals are transmitted to the input end of the host computer acquisition module through the signal isolator U3;

[0011] The fan start / stop button SB1, the liquid heat exchanger start button SB2, and the manual / automatic changeover knob SA1 are connected in parallel to the input end of the host computer acquisition module;

[0012] The fan control circuit and the proportional valve of the liquid heat exchanger are electrically connected to the output end of the host computer acquisition module respectively;

[0013] The coils of the contactor KM1 and the contactor KM2 are connected in parallel and electrically connected to the output end of the host computer acquisition module. The normally open contacts of the contactor KM1 are connected in series on the power supply line of the liquid heat exchanger, and the normally open contacts of the contactor KM2 are connected in series on the power supply line of the fan;

[0014] The manual / automatic changeover button SB3 controls the coils of the relay KA1 and the relay KA2 to be energized / de-energized synchronously. The two normally closed contacts of the relay KA1 are respectively connected in series at the output ends of the fan start / stop button SB1 and the liquid heat exchanger start button SB2. The input ends of the two normally closed contacts of the relay KA1 are respectively electrically connected to the output ends of the fan start / stop button SB1 and the liquid heat exchanger start button SB2, and the output ends of the two normally closed contacts are respectively electrically connected to the contactor KM1 and the contactor KM2;

[0015] The two normally closed contacts of the relay KA2 are respectively connected in series between the fan control circuit and the proportional valve of the liquid heat exchanger and the host computer acquisition module. The input ends of the two normally open contacts of the relay KA2 are respectively electrically connected to the flow rate adjustment knob and the wind speed adjustment knob, and the output ends of the two normally open contacts are respectively electrically connected to the input end of the fan control circuit and the input end of the proportional valve of the liquid heat exchanger;

[0016] The host computer is used to control the fan speed, start / stop, and the opening degree and start / stop of the proportional valve of the liquid heat exchanger through the hard-wired switching of the automatic changeover button SB3, or the flow rate adjustment knob and the wind speed adjustment knob are used to control the fan speed, start / stop, and the opening degree and start / stop of the proportional valve of the liquid heat exchanger respectively.

[0017] Further, a dual-temperature control method for an electrical control room, based on a dual-temperature control system, sets several temperature sensors to collect temperature data of each area in the electrical control room, and coordinates and controls the fan and liquid heat exchanger in real time according to the temperature and liquid cooling flow rate to control the overall temperature of the electrical control room within the normal range. The dual-temperature control method includes establishing a state machine to achieve a multi-layer temperature control mode:

[0018] Natural heat dissipation: The upper computer receives the random temperature sensor data of each area in the electrical control room. When the temperature of one area exceeds the limit, it switches to air-cooled heat dissipation;

[0019] Air-cooled heat dissipation: The upper computer receives the random temperature sensor data of each area in the electrical control room, controls the temperature of the fan according to the temperature data. When the temperature of more than one area exceeds the limit, it switches to collaborative heat dissipation;

[0020] Collaborative heat dissipation: The upper computer continuously receives all the temperature sensor data of the temperature-exceeding areas in the electrical control room, and controls the coordinated operation of the fan and liquid heat exchanger according to the temperature data for temperature control. When the temperatures of all areas are within the normal temperature range, it switches to natural heat dissipation.

[0021] Further, the upper computer communicates with the acquisition module based on the serial port. The upper computer sends data blocks to the acquisition module using a queue. The data frame sent by the acquisition module to the upper computer includes the sensor ID, temperature data, liquid heat exchanger flow rate, and fan speed. The data frame sent by the upper computer to the acquisition module includes the sensor ID, opening of the liquid heat exchanger proportional valve, and fan speed.

[0022] Further, the upper computer receives the random temperature sensor data of each area in the electrical control room, including:

[0023] S1. Establish a sequential structure, where all areas in the electrical control room correspond one by one to the sub-structures of the sequential structure according to the spatial order;

[0024] S2. Each sub-structure includes a random number generator. The random number range generated by each random number emitter corresponds to the temperature sensor ID range of this area in the electrical control room, so that the random numbers generated by the sub-structure can only cover all the temperature sensor IDs of this area in the electrical control room;

[0025] S3. The sequential structure continuously returns the random sensor IDs generated by all sub-structures, and generates a data block of random sensor ID addresses to be collected and sends it to the acquisition module to randomly collect the temperature information of each area in the electrical control room;

[0026] The upper computer traverses and cyclically generates all temperature sensor IDs to receive all the temperature sensor data of each area in the electrical control room.

[0027] Further, the data of the upper computer acquisition module is called and analyzed by the interrupt mechanism thread in the form of local variables to output the control signals of the fan and the liquid heat exchanger proportional valve and the switching enumeration variable of the state machine, and the temperature control mode of the state machine operation is switched through the switching enumeration variable.

[0028] Furthermore, when in air-cooled heat dissipation, the fan speed is controlled by PID according to the feedback temperature data to control the temperature.

[0029] When in collaborative heat dissipation, the opening of the proportional valve of the liquid heat exchanger is adjusted by PID according to the feedback temperature data and the liquid cooling flow rate, and the fan compensation is adjusted to control the temperature.

[0030] Furthermore, when in collaborative heat dissipation, the control of the opening of the proportional valve of the liquid heat exchanger includes:

[0031] ;

[0032] ;

[0033] ;

[0034] In the formula, is the opening of the proportional valve, is the flow error, is the required flow rate, is the actual flow rate, , , are PID parameters, is the system thermal conductivity, is the temperature of the electrical control room, is the target temperature, is the specific heat capacity of the coolant, is the outlet temperature of the liquid heat exchanger, is the inlet temperature of the liquid heat exchanger.

[0035] Furthermore, when in collaborative heat dissipation, the control of the fan speed includes:

[0036] ;

[0037] In the formula, is the fan speed, is the temperature error, , , are PID parameters, is the weight of the temperature rise rate, is the temperature rise rate of the hot area of the electrical control cabinet, is the weight of the heat load, is the deviation of the heat exchange quantity, is the maximum power of the fan, are the lower limit and the upper limit of the fan speed respectively.

[0038] Compared with the prior art, the dual temperature control system and method for the electrical control room described in the present invention have the following beneficial effects:

[0039] Through the multi-sensor dynamic fusion temperature measurement, hierarchical state decision-making mechanism and double-closed-loop collaborative algorithm, high-precision dynamic regulation of the temperature in the electrical control room is achieved. The intelligent linkage of the liquid cooling system and the air cooling system has the advantage of eliminating local overheating; the liquid cooling starts and stops as needed and cooperates with the fan to cool down, reducing energy consumption. Different temperature sensor reading methods are adopted under different temperature control modes. For example, under natural heat dissipation and air cooling heat dissipation, the host computer receives random temperature sensor data from each area of the electrical control room, improving the efficiency of monitoring the temperature in the electrical control room and reducing the hardware load. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0041] Figure 1 Schematic diagram of the power circuit according to the embodiment of the present invention;

[0042] Figure 2 Schematic diagram of the control circuit according to the embodiment of the present invention;

[0043] Figure 3 Schematic diagram of the communication between the host computer and the acquisition module according to the embodiment of the present invention;

[0044] Figure 4 Schematic diagram of the communication between the host computer and the acquisition module according to the embodiment of the present invention;

[0045] Figure 5 Schematic diagram of selecting temperature sensor to collect data according to the embodiment of the present invention;

[0046] Figure 6 Schematic diagram of the temperature control switching control code according to the embodiment of the present invention DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0048] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0049] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0050] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0051] A dual-temperature control system for an electrical control room, as Figure 1 - Figure 2 shown, includes a fan and a liquid heat exchanger installed in the electrical control room, a host computer, a power circuit, and a control circuit; the fan, the liquid heat exchanger, and the host computer are connected in parallel to the power circuit to realize power supply. The control circuit monitors the temperature information of the electrical control room and the flow information of the liquid heat exchanger and uploads them to the host computer. The control circuit cooperates with the host computer to control the operation of the fan and the liquid heat exchanger to realize the temperature control of the electrical control room. The power circuit includes a transformer T1, a switching power supply T1, a UPS, and an acquisition module, which supplies power to the fan and the liquid heat exchanger with three-phase electricity. The three-phase electricity supplies power to the host computer through the transformer T1. The transformer T1 outputs 24V DC power through the switching power supply PS1 as the power supply for the control circuit; the host computer is configured with a UPS to realize uninterrupted power supply. The acquisition module of the host computer reads the temperature, flow information and controls the fan speed and the liquid heat exchanger flow rate. The power supply preferably adopts a three-phase five-wire system, and the live wire and the neutral wire are taken as the supply side of the transformer T1.

[0052] Specifically, as Figure 2As shown in the figure, the control circuit includes a temperature sensor U1, a flow sensor U2, a signal isolator U3, a fan start / stop button SB1, a liquid heat exchanger start button SB2, a manual / automatic switch knob SA1, a fault control button SB3, a relay KA1, a relay KA2, a contactor KM1, a contactor KM2, a flow rate adjustment knob, and a wind speed adjustment knob; the temperature sensor U1 and the flow sensor U2 are connected in parallel, and the temperature and flow signals are transmitted to the input end of the upper computer acquisition module through the signal isolator U3; the fan start / stop button SB1, the liquid heat exchanger start button SB2, and the manual / automatic switch knob SA1 are connected in parallel to the input end of the upper computer acquisition module; the fan control circuit and the liquid heat exchanger proportional valve are respectively electrically connected to the output end of the upper computer acquisition module; the coils of the contactor KM1 and the contactor KM2 are connected in parallel to the output end of the upper computer acquisition module, and the normally open contacts of the contactor KM1 are connected in series on the power supply line of the liquid heat exchanger, and the normally open contacts of the contactor KM2 are connected in series on the power supply line of the fan; the manual / automatic switch button SB3 controls the coils of the relay KA1 and the relay KA2 to be energized / de-energized synchronously. Two normally closed contacts of the relay KA1 are respectively connected in series at the output ends of the fan start / stop button SB1 and the liquid heat exchanger start button SB2. The input ends of the two normally closed contacts of the relay KA1 are respectively electrically connected to the output ends of the fan start / stop button SB1 and the liquid heat exchanger start button SB2, and the output ends of the two normally closed contacts are respectively electrically connected to the contactor KM1 and the contactor KM2; two normally closed contacts of the relay KA2 are respectively connected in series between the fan control circuit and the liquid heat exchanger proportional valve and the upper computer acquisition module. The input ends of the two normally open contacts of the relay KA2 are respectively electrically connected to the flow rate adjustment knob and the wind speed adjustment knob, and the output ends of the two normally open contacts are respectively electrically connected to the input end of the fan control circuit and the input end of the liquid heat exchanger proportional valve. The control principle is: the upper computer controls the fan speed, start / stop, and the opening and start / stop of the liquid heat exchanger proportional valve through the hard wire switching of the automatic switch button SB3, or the flow rate adjustment knob and the wind speed adjustment knob respectively control the fan speed, start / stop, and the opening and start / stop of the liquid heat exchanger proportional valve.

[0053] Dual temperature control method for the electrical control room. Based on the above dual temperature control system, several temperature sensors are set to collect the temperature data of each area in the electrical control room. According to the temperature and liquid cooling flow rate, the fan and liquid heat exchanger are coordinated and controlled in real time to keep the overall temperature of the electrical control room within the normal range. The dual temperature control method includes establishing a state machine to achieve multi-layer temperature control modes: Natural heat dissipation: The upper computer receives the random temperature sensor data of each area in the electrical control room. When the temperature of one area exceeds the limit, it switches to air-cooled heat dissipation; Air-cooled heat dissipation: The upper computer receives the random temperature sensor data of each area in the electrical control room and controls the temperature of the fan according to the temperature data. When the temperature of more than one area exceeds the limit, it switches to collaborative heat dissipation; Collaborative heat dissipation: The upper computer continuously receives all the temperature sensor data of the temperature-exceeding areas in the electrical control room and controls the coordinated operation of the fan and liquid heat exchanger according to the temperature data. When the temperatures of all areas are within the normal temperature range, it switches to natural heat dissipation. In this embodiment, LabVIEW is used as the upper computer development platform.

[0054] Specifically, as Figure 3 - Figure 4 and Figure 6 shown, the upper computer communicates with the acquisition module based on the serial port. The upper computer sends data blocks to the acquisition module using a queue. The data frame sent by the acquisition module to the upper computer includes the sensor ID, temperature data, liquid heat exchanger flow rate, and fan speed. The data frame sent by the upper computer to the acquisition module includes the sensor ID, liquid heat exchanger proportional valve opening, and fan speed. In this embodiment, the serial port data communicates in byte stream.

[0055] Specifically, as Figure 5 shown in the sensor data reading code segments in different modes, the upper computer receives the random temperature sensor data of each area in the electrical control room, including:

[0056] S1. Establish a sequential structure, and all areas in the electrical control room correspond one by one with the sub-structures of the sequential structure according to the spatial order;

[0057] S2. Each sub-structure includes a random number generator. The random number range generated by each random number emitter corresponds to the temperature sensor ID range of this area in the electrical control room, so that the random numbers generated by the sub-structure can only cover all the temperature sensor IDs of this area in the electrical control room;

[0058] S3. The sequential structure continuously returns the random sensor IDs generated by all sub-structures and generates a data block of random sensor ID addresses to be collected and sends it to the acquisition module to randomly collect the temperature information of each area in the electrical control room;

[0059] Under global sampling, the upper computer traverses and loops to generate all temperature sensor IDs to receive all the temperature sensor data of each area in the electrical control room;

[0060] In the case of temperature control, the upper computer continuously receives all the temperature sensor data of the temperature-exceeding areas in the electrical control room.

[0061] Specifically, asFigure 6 As shown, the data of the host computer acquisition module is called and analyzed by the interrupt mechanism thread in the form of local variables to output the control signals of the fan and the proportional valve of the liquid heat exchanger and the switching enumeration variable of the state machine, and the temperature control mode of the state machine operation is switched through the switching enumeration variable. When in air-cooled heat dissipation, the fan speed is controlled by PID according to the feedback temperature data; when in collaborative heat dissipation, the opening of the proportional valve of the liquid heat exchanger is adjusted by PID according to the feedback temperature data and the liquid cooling flow rate, and the fan compensation is adjusted for temperature control.

[0062] Specifically, when in collaborative heat dissipation, the control of the opening of the proportional valve of the liquid heat exchanger includes:

[0063] ;

[0064] ;

[0065] ;

[0066] In the formula, is the opening of the proportional valve, is the flow error, is the required flow rate, is the actual flow rate, , [[ID=З0]] , are PID parameters, is the system thermal conductivity, <ИD= is the temperature of the electrical control room, is the target temperature, is the specific heat capacity of the coolant, is the outlet temperature of the liquid heat exchanger, is the inlet temperature of the liquid heat exchanger.

[0067] Specifically, when in collaborative heat dissipation, the control of the fan speed includes:

[0068] ;

[0069] ;

[0070] ;

[0071] ;

[0072] ;

[0073] In the formula, is the fan speed, is the temperature error, , , are PID parameters, is the weight of the temperature rise rate, is the temperature rise rate of the hot zone of the electrical control cabinet, is the weight of the heat load, is the deviation of the heat exchange quantity, is the maximum power of the fan, are respectively the lower limit and the upper limit of the fan speed, is the required heat exchange quantity, is the actual heat exchange quantity.

[0074] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dual temperature control system for an electrical control room, characterized in that: It includes a fan, a liquid heat exchanger, a host computer, a power circuit, and a control circuit installed in the electric control room; the fan, the liquid heat exchanger, and the host computer are connected in parallel to the power circuit to achieve power supply. The control circuit monitors the temperature information of the electric control room and the flow information of the liquid heat exchanger and uploads them to the host computer. The control circuit cooperates with the host computer to control the operation of the fan and the liquid heat exchanger to achieve temperature control of the electric control room.

2. The dual temperature control system for the electrical control room according to claim 1, characterized in that: The power circuit includes a transformer T1, a switching power supply T1, a UPS, and an acquisition module, and supplies power to the fan and the liquid heat exchanger with three-phase electricity. The three-phase electricity supplies power to the host computer through the transformer T1. The transformer T1 outputs 24V DC power through the switching power supply PS1 as the power supply for the control circuit. The host computer is configured with a UPS to achieve uninterrupted power supply. The acquisition module of the host computer reads the temperature, flow information, and controls the fan speed and the liquid heat exchanger flow rate.

3. The dual temperature control system for an electrical control room according to claim 2, characterized in that: The control circuit includes a temperature sensor U1, a flow sensor U2, a signal isolator U3, a fan start / stop button SB1, a liquid heat exchanger start button SB2, a manual / automatic switching knob SA1, a fault control button SB3, a relay KA1, a relay KA2, a contactor KM1, a contactor KM2, a flow rate adjustment knob, and a wind speed adjustment knob. The temperature sensor U1 and the flow sensor U2 are connected in parallel and transmit the temperature and flow signals to the input end of the acquisition module of the host computer through the signal isolator U3. The fan start / stop button SB1, the liquid heat exchanger start button SB2, and the manual / automatic switching knob SA1 are connected in parallel to the input end of the acquisition module of the host computer. The fan control circuit and the liquid heat exchanger proportional valve are respectively electrically connected to the output end of the acquisition module of the host computer. The coils of the contactor KM1 and the contactor KM2 are connected in parallel and electrically connected to the output end of the acquisition module of the host computer. The normally open contacts of the contactor KM1 are connected in series in the power supply line of the liquid heat exchanger, and the normally open contacts of the contactor KM2 are connected in series in the power supply line of the fan. The manual / automatic switching button SB3 controls the coils of the relay KA1 and the relay KA2 to be energized / de-energized synchronously. The two normally closed contacts of the relay KA1 are respectively connected in series at the output ends of the fan start / stop button SB1 and the liquid heat exchanger start button SB2. The input ends of the two normally closed contacts of the relay KA1 are respectively electrically connected to the output ends of the fan start / stop button SB1 and the liquid heat exchanger start button SB2, and the output ends of the two normally closed contacts are respectively electrically connected to the contactor KM1 and the contactor KM2. The two normally closed contacts of the relay KA2 are respectively connected in series between the fan control circuit and the liquid heat exchanger proportional valve and the acquisition module of the host computer. The input ends of the two normally open contacts of the relay KA2 are respectively electrically connected to the flow rate adjustment knob and the wind speed adjustment knob, and the output ends of the two normally open contacts are respectively electrically connected to the input end of the fan control circuit and the input end of the liquid heat exchanger proportional valve. The host computer controls the fan speed, start / stop, and the opening degree and start / stop of the liquid heat exchanger proportional valve through the hard wire switching of the manual / automatic switching button SB3, or the flow rate adjustment knob and the wind speed adjustment knob respectively control the fan speed, start / stop, and the opening degree and start / stop of the liquid heat exchanger proportional valve.

4. A dual temperature control method for an electrical control room, based on the dual temperature control system for an electrical control room according to claims 1-3, characterized in that: A number of temperature sensors are set to collect the temperature data of each area in the electric control room. According to the temperature and liquid cooling flow rate, the fan and liquid heat exchanger are coordinated and controlled in real time to control the overall temperature of the electric control room within the normal range. The dual temperature control method includes establishing a state machine to achieve a multi-layer temperature control mode: Natural heat dissipation: The upper computer receives the random temperature sensor data of each area in the electric control room. When the temperature of one area exceeds the limit, it switches to air-cooled heat dissipation; Air-cooled heat dissipation: The upper computer receives the random temperature sensor data of each area in the electric control room. According to the temperature data, the fan is controlled to regulate the temperature. When the temperature of more than one area exceeds the limit, it switches to coordinated heat dissipation; Coordinated heat dissipation: The upper computer continuously receives all the temperature sensor data of the temperature-exceeding areas in the electric control room. According to the temperature data, the fan and liquid heat exchanger are coordinated to operate to control the temperature. When the temperatures of all areas are within the normal temperature range, it switches to natural heat dissipation.

5. The dual temperature control method for the electrical control room according to claim 4, characterized in that: The upper computer communicates with the acquisition module based on the serial port. The upper computer sends data blocks to the acquisition module using a queue. The data frame sent by the acquisition module to the upper computer includes the sensor ID, temperature data, liquid heat exchanger flow rate, and fan speed. The data frame sent by the upper computer to the acquisition module includes the sensor ID, opening of the liquid heat exchanger proportional valve, and fan speed.

6. The dual temperature control method for an electrical control room according to claim 4, characterized in that: The upper computer receives the random temperature sensor data of each area in the electric control room, including: S1. Establish a sequential structure, and all areas in the electric control room correspond one by one with the sub-structures of the sequential structure according to the spatial order; S2. Each sub-structure includes a random number generator. The random number range generated by each random number generator corresponds to the temperature sensor ID range of this area in the electric control room, so that the random numbers generated by the sub-structure can only cover all the temperature sensor IDs of this area in the electric control room; S3. The sequential structure continuously returns the random sensor IDs generated by all sub-structures, and generates a data block of random sensor ID addresses to be collected and sends it to the acquisition module to randomly collect the temperature information of each area in the electric control room; The upper computer traverses and cyclically generates all temperature sensor IDs to receive all the temperature sensor data of each area in the electric control room.

7. The dual temperature control method for an electrical control room according to claim 4, characterized in that: The data of the upper computer acquisition module is called and analyzed by the interrupt mechanism thread in the form of local variables to output the control signals of the fan and liquid heat exchanger proportional valve and the switching enumeration variable of the state machine, and the temperature control mode of the state machine operation is switched through the switching enumeration variable.

8. The dual temperature control method for the electrical control room according to claim 7, characterized in that: When in air-cooled heat dissipation, the fan speed is controlled to regulate the temperature using PID according to the feedback temperature data; When in coordinated heat dissipation, the opening of the liquid heat exchanger proportional valve is regulated using PID according to the feedback temperature data and liquid cooling flow rate, and the fan compensation is adjusted to control the temperature.

9. The dual temperature control method for an electrical control room according to claim 8, characterized in that: When in coordinated heat dissipation, the control of the opening of the liquid heat exchanger proportional valve includes: ； ； ； In the formula, is the opening degree of the proportional valve, is the flow error, is the required flow rate, is the actual flow rate, , , are the PID parameters, is the system thermal conductivity, is the temperature of the electric control room, is the target temperature, is the specific heat capacity of the coolant, is the outlet temperature of the liquid heat exchanger, is the inlet temperature of the liquid heat exchanger.

10. The dual temperature control method for an electrical control room according to claim 8, characterized in that: When in coordinated heat dissipation, the control of the fan speed includes: ； Wherein, is the fan speed, is the temperature error, , , are the PID parameters, is the weight of the temperature rise rate, is the temperature rise rate of the hot zone of the electrical control cabinet, is the heat load weight, is the deviation of the heat exchange quantity, is the maximum power of the fan, are respectively the lower limit and the upper limit of the fan speed.

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