Magnetic latching relay thermal control method, device, system, and computer device

Abstract

The application relates to a magnetic latching relay heat control method, device, system and computer equipment. The method comprises the following steps: acquiring a relay contact temperature based on an end voltage and a load current of a magnetic latching relay when the magnetic latching relay is in a closed state, and acquiring a control pump speed duty cycle according to the relay contact temperature and a direct current bus voltage change rate; when the working state of a phase change heat dissipation piece is not a failure state, controlling the working state of a convection heat exchange piece according to the control pump speed duty cycle; and when the working state of the phase change heat dissipation piece is the failure state and the relay contact temperature exceeds a contact temperature threshold value, controlling a thermoelectric refrigeration piece to start. The method can improve heat dissipation efficiency.

Description

Technical Field

[0001] This application relates to the field of electromagnetic device reliability and thermal management technology, and in particular to a thermal control method, device, system and computer equipment for a magnetic latching relay. Background Technology

[0002] Magnetic latching relays use permanent magnets to provide holding force, allowing the contacts to maintain a stable state even without continuous coil power supply. They offer advantages such as low energy consumption and compact structure. However, during the switching process, especially under load or high current conditions, electric arcs can easily form between the contacts. These arcs release a large amount of energy in a very short time, causing transient high temperatures on the contact surface and in the adjacent magnetic circuit structure. This high temperature is transferred to the permanent magnet through the heat conduction path, potentially causing the permanent magnet's local or overall temperature to exceed its tolerance range. This can lead to irreversible or partially irreversible demagnetization, ultimately resulting in a decrease in the relay's holding force, contact chattering, or even failure.

[0003] Traditional technologies primarily reduce heat generation by selecting contact materials that are resistant to high temperatures and arc wear. However, this approach typically cannot flexibly adjust the heat dissipation intensity according to different heat load conditions, resulting in low heat dissipation efficiency. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, device, system, and computer equipment for thermal control of magnetic latching relays that can improve heat dissipation efficiency in response to the above-mentioned technical problems.

[0005] In a first aspect, this application provides a thermal control method for a magnetic latching relay, comprising:

[0006] When the magnetic latching relay is in the closed state, the relay contact temperature is obtained based on the terminal voltage and load current of the magnetic latching relay, and the duty cycle for controlling the pump speed is obtained based on the relay contact temperature and the DC bus voltage change rate.

[0007] When the phase change heat sink is not in a failed state, the working state of the convection heat exchanger is controlled according to the control pump speed duty cycle.

[0008] When the phase change heat sink is in a failed state and the relay contact temperature exceeds the contact temperature threshold, the thermoelectric cooling component is activated.

[0009] In one embodiment, the step of obtaining the relay contact temperature based on the terminal voltage and load current of the magnetic latching relay includes:

[0010] The contact resistance value is obtained based on the terminal voltage and load current of the magnetic latching relay;

[0011] The relay contact temperature is obtained based on the contact resistance value, the preset reference resistance value, the resistance temperature coefficient, and the preset reference temperature.

[0012] In one embodiment, the step of obtaining the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate includes:

[0013] A saturation function is constructed based on a preset temperature feedback coefficient and a preset feedforward control coefficient.

[0014] The saturation function is solved based on the relay contact temperature, the DC bus voltage change rate, and the target safe temperature to obtain the duty cycle for controlling the pump speed.

[0015] In one embodiment, the process of acquiring the operating state of the phase change heat sink includes:

[0016] The rate of temperature change is obtained based on the temperature of the relay contacts.

[0017] If the rate of temperature change meets the preset growth condition, the working state of the phase change heat sink is determined to be the failure state.

[0018] In one embodiment, the method further includes:

[0019] Obtain the DC bus voltage and battery pack voltage, and obtain the voltage difference between the DC bus voltage and the battery pack voltage;

[0020] The closing voltage difference of the magnetic latching relay is determined based on the voltage difference.

[0021] Secondly, this application also provides a magnetic latching relay thermal control device, comprising:

[0022] The temperature acquisition module is used to acquire the relay contact temperature based on the terminal voltage and load current of the magnetic latching relay when the magnetic latching relay is in the closed state, and to acquire the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate.

[0023] The first thermal control module is used to control the working state of the convective heat exchanger according to the control pump speed duty cycle when the working state of the phase change heat sink is not in a failed state.

[0024] The second thermal control module is used to control the thermoelectric cooling component to start when the phase change heat sink is in a failed state and the relay contact temperature exceeds the contact temperature threshold.

[0025] Thirdly, this application also provides a magnetic latching relay thermal control system, comprising:

[0026] At least one magnetic latching relay, the magnetic latching relay includes a relay module and a heat dissipation module, one end of the magnetic latching relay is connected to the DC bus and the other end is connected to the battery pack; the heat dissipation module includes a phase change heat sink, a convection heat exchanger and a thermoelectric cooling element;

[0027] The data acquisition and control unit is connected to the magnetic latching relay and the DC bus respectively. It is used to acquire the relay voltage of the magnetic latching relay and the DC bus voltage, and to obtain the relay contact temperature and the DC bus voltage change rate based on the relay voltage and the DC bus voltage.

[0028] The energy-saving management unit is connected to the data acquisition and control unit at one end and to the battery pack at the other end. It is used to control the working status of the heat dissipation module based on the relay contact temperature and the DC bus voltage change rate.

[0029] In one embodiment, the data acquisition and control unit is further configured to obtain the temperature change rate based on the relay contact temperature; the energy-saving management unit is further configured to control the start-up and shutdown status of the thermoelectric cooling element based on the temperature change rate.

[0030] In one embodiment, the convection heat exchanger includes a cooling channel and a cooling medium;

[0031] The data acquisition and control unit is also used to obtain the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate; the energy-saving management unit is also used to control the flow rate of the cooling medium in the cooling channel based on the control pump speed duty cycle.

[0032] Fourthly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method steps of any one of the second aspects.

[0033] Fifthly, this application also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the method steps of any one of the second aspects.

[0034] In a sixth aspect, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the method steps of any one of the second aspects.

[0035] The aforementioned thermal control method, device, system, and computer equipment for magnetic latching relays, by obtaining the relay contact temperature based on the relay's terminal voltage and load current when the magnetic latching relay is in the closed state, and obtaining the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate, and controlling the thermoelectric cooling component to start when the phase change heat sink is in a failed state and the relay contact temperature exceeds the contact temperature threshold, can specifically address the heat dissipation requirements under all operating conditions after the magnetic latching relay is closed, achieve dynamic and precise matching between heat load and heat dissipation capacity, improve heat dissipation efficiency, quickly suppress contact temperature rise, and thus extend the service life of the magnetic latching relay. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the connection relationship of a magnetic latching relay thermal control system in one embodiment;

[0038] Figure 2 This is a flowchart illustrating a thermal control method for a magnetic latching relay in one embodiment;

[0039] Figure 3 This is a flowchart illustrating the thermal control method for a magnetic latching relay in another embodiment;

[0040] Figure 4 This is a structural block diagram of a magnetic latching relay thermal control device in one embodiment;

[0041] Figure 5 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0043] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0044] In one exemplary embodiment, such as Figure 1 As shown, a magnetic latching relay thermal control system is provided, including: at least one magnetic latching relay 100, a data acquisition and control unit 200, and an energy-saving management unit 300. The magnetic latching relay 100 includes a relay module 110 and a heat dissipation module 120. One end of the magnetic latching relay 100 is connected to a DC bus 400, and the other end is connected to a battery pack 500. The data acquisition and control unit 200 is connected to both the magnetic latching relay 100 and the DC bus 400, and is used to acquire the relay voltage of the magnetic latching relay 100 and the DC bus voltage, and to obtain the relay contact temperature and the DC bus voltage change rate based on the relay voltage and the DC bus voltage. The energy-saving management unit 300 is connected to the data acquisition and control unit 200 at one end and to the battery pack 500 at the other end, and is used to control the operating state of the heat dissipation module 120 based on the relay contact temperature and the DC bus voltage change rate.

[0045] The magnetic latching relay 100 serves as the core power switching device, with one end connected in series with the DC bus 400 and the other end connected in series with the battery pack 500. Its internal relay module 110 is the core for power switching, and the heat dissipation module 120 is physically integrated with the relay module 110, directly acting on the heat-generating core component. The data acquisition and control unit 200 is the core for data acquisition, establishing electrical connections with both the magnetic latching relay 100 and the DC bus 400 to capture the two voltage signals in real time. Simultaneously, it establishes a data transmission connection with the energy-saving management unit 300 to transmit the calculated core parameters. The energy-saving management unit 300 interfaces with the data acquisition and control unit 200, receiving temperature control decision data and controlling the heat dissipation module 120 of the magnetic latching relay 100 through the data acquisition and control unit 200, issuing heat dissipation execution commands. It also establishes an auxiliary connection with the battery pack 500 to achieve energy-saving power supply / control linkage.

[0046] The heat dissipation module 120 includes a phase change heat sink, a convection heat exchanger, and a thermoelectric cooling component. The phase change material undergoes a solid-liquid phase change and absorbs latent heat within a preset temperature range. When the surge current during relay switching generates transient heat, the phase change material undergoes a phase change after reaching its phase change point, buffering the relay's internal temperature by absorbing the latent heat of the phase change, thereby suppressing a rapid rise in relay temperature. Because the phase change process occurs within a nearly constant temperature range, it effectively reduces temperature peaks. The phase change material is primarily used to absorb transient thermal shocks, acting as a passive thermal buffer unit to reduce the probability of the relay entering the demagnetization-sensitive temperature range.

[0047] The convection heat exchanger consists of several cooling channels ranging from micrometers to sub-millimeters in size. The cooling medium flows within these channels and undergoes forced convection heat transfer with the channel walls, thereby achieving rapid heat transfer from the inside of the relay. Due to the large heat transfer area per unit volume and the short heat transfer path of the convection heat exchanger, the convective heat transfer coefficient between the cooling medium and the heat-generating components is significantly higher than that of traditional air cooling or macroscopic liquid cooling structures. The heat generated by the relay during switching on and off or during high-load operation can be rapidly transferred to the cooling medium through the channel walls and carried away from the motor body, effectively suppressing the rapid rise in the temperature of the permanent magnet.

[0048] Thermoelectric cooling components operate based on the Peltier effect. When current is applied across the thermoelectric cooling unit, heat is absorbed on one side and released on the other, thus achieving active cooling. When the relay is under continuous high heat load or the phase change material has completed its phase change, power is supplied to the thermoelectric cooling unit to actively cool the cooling medium. This increases the temperature difference between the cooling medium and the motor in the convection heat exchanger structure, improving overall heat exchange efficiency. The operating power of the thermoelectric cooling component can be adjusted according to the relay temperature or demagnetization risk indicators to meet demagnetization prevention requirements while avoiding unnecessary energy consumption increases.

[0049] Specifically, the data acquisition and control unit 200 continuously acquires the relay voltage of the magnetic latching relay 100 (reflecting the contact voltage drop) and the bus voltage of the DC bus 400 (reflecting the system load status). Based on the relay voltage mapping, the relay contact temperature is calculated. Since contact heating causes changes in contact resistance, the voltage drop is strongly correlated with temperature, directly characterizing the degree of heating. Then, the voltage change rate is calculated based on the DC bus voltage. The voltage change rate reflects bus load fluctuations and current changes, indirectly predicting the intensity of relay current-carrying heating. The energy-saving management unit 300 performs logical judgments based on the contact temperature and voltage change rate, combined with preset thresholds. For example, if the contact temperature exceeds the limit or the voltage change rate is drastic (sudden load change, increased current, and intensified heating), the relay is determined to be in a high-heat-risk state; if the contact temperature is normal and the voltage change rate is stable, the relay is determined to be in a low-temperature safe state. Based on the decision results, the energy management unit 300 controls the working status of the heat dissipation module 120 as needed. For example, when there is a high risk of heat, the heat dissipation module 120 is started to operate efficiently to dissipate heat from the relay module 110 and quickly reduce the core temperature. When the temperature is low and safe, the heat dissipation module 120 is turned off or operates at low power to avoid unnecessary energy consumption and achieve energy-saving management.

[0050] In this embodiment, the relay contact voltage drop is directly acquired by the acquisition and control unit. The signal is attenuated and interference-free, reflecting the contact heating status in real time. The heat dissipation module is physically integrated with the relay module and fits tightly, acting directly on the heat source. This constructs the shortest heat conduction path, ensuring that the heat dissipation energy acts directly on the core heating area of ​​the contact, avoiding heat accumulation, improving heat dissipation efficiency, and quickly controlling the relay temperature within a safe threshold. This prevents the relay from demagnetizing due to overheating, thereby improving the service life of the magnetic latching relay.

[0051] In one exemplary embodiment, the data acquisition control unit 200 is further configured to acquire the temperature change rate based on the relay contact temperature; the energy-saving management unit 300 is further configured to control the start-up and shutdown status of the thermoelectric cooling element based on the temperature change rate.

[0052] Specifically, during the instant the relay is switched on and off and during operation, when the relay temperature rise is low or the heat load is within an acceptable range, thermal buffering is performed by phase change material and low-speed convection heat exchanger; when the temperature rise increases, the flow rate of the convection heat exchanger is increased to improve the cooling effect; when the contact temperature continues to rise, that is, the heat load continues to exist, the thermoelectric cooling device is further activated, thus forming a graded thermal management mechanism that is activated on demand and enhanced step by step.

[0053] In this embodiment, three heat dissipation materials—phase change heat sink, convection heat exchanger, and thermoelectric cooling element—are added to the magnetic latching relay to achieve efficient heat dissipation and improve the heat dissipation capacity. At the same time, the different properties of the three materials are utilized to address the relay's heat generation problem in different ways, thereby significantly enhancing the heat dissipation capacity while maintaining low power consumption.

[0054] In an exemplary embodiment, the convection heat exchanger includes a cooling channel and a cooling medium; wherein, the acquisition and control unit 200 is further configured to acquire the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate; and the energy-saving management unit 300 is further configured to control the flow rate of the cooling medium in the cooling channel based on the control pump speed duty cycle.

[0055] The data acquisition and control unit 200 uses the relay contact temperature and DC bus voltage change rate to couple and calculate the control pump speed duty cycle. The duty cycle is a quantized value of the control command and is positively correlated with the cooling pump speed. The energy-saving management unit 300 precisely controls the flow rate of the medium in the cooling channel based on the duty cycle. When the temperature is high and the load fluctuates drastically, it outputs a high duty cycle, increases the flow rate, and improves the forced convection heat transfer coefficient between the cooling medium and the heat source, quickly removing a large amount of heat. When the temperature is low and the load is stable, it outputs a low duty cycle, decreases the flow rate, and adapts the heat transfer efficiency to the low heat load, reducing ineffective work. This stabilizes the contact temperature within a narrow safe range, avoiding overheating aging or low-temperature redundant heat dissipation, and improving the relay's service life and switching reliability.

[0056] In one exemplary embodiment, such as Figure 2 As shown, a thermal control method for a magnetic latching relay is provided, which can be applied to... Figure 1 The following explanation uses a magnetic latching relay thermal control system as an example, including steps 202 to 206. Wherein:

[0057] S202: When the magnetic latching relay is in the closed state, the relay contact temperature is obtained based on the terminal voltage and load current of the magnetic latching relay, and the duty cycle of the control pump speed is obtained based on the relay contact temperature and the DC bus voltage change rate.

[0058] Optionally, after the magnetic latching relay closes, the data acquisition and control unit collects the relay terminal voltage and the load current flowing through it in real time. It calculates the real-time contact resistance of the contacts based on Ohm's law, and then uses the temperature characteristics of the metal resistivity to calculate the real-time temperature of the relay contacts. By directly mapping temperature to electrical parameters, compared to traditional temperature sensing elements, there is no physical contact lag, allowing for a true reflection of the temperature in the core heating area of ​​the contacts. The pump speed duty cycle is obtained using the real-time contact temperature as a feedback parameter and the DC bus voltage change rate as a feedforward parameter, generating the pump speed duty cycle through a coupling algorithm. The DC bus voltage change rate reflects the system load fluctuation trend, predicts changes in contact heating intensity, and compensates for the lag of simple temperature feedback; the temperature feedback accurately matches the current actual heat load, achieving precise speed control with dual parameters of trend prediction and current adaptation.

[0059] S204: When the phase change heat sink is not in a failed state, the working state of the convection heat exchanger is controlled according to the control pump speed duty cycle.

[0060] Optionally, the effectiveness of the phase change heat sink is determined by the temperature change rate operator. If the relay contact temperature does not exceed or is close to the phase change temperature, but the temperature change rate operator is close to 0, it indicates that the phase change material is undergoing a solid-liquid phase change and absorbing a large amount of latent heat, effectively buffering the contact temperature rise, and is in a non-failure state. If the relay contact temperature does not exceed the phase change temperature and the temperature change rate operator increases, it indicates that the phase change material has completely liquefied and can no longer absorb heat, and is in a failure state. When the phase change heat sink is not in failure, the energy-saving management unit adjusts the speed of the cooling pump in the convective heat exchanger according to the calculated control pump speed duty cycle, thereby controlling the flow rate of the cooling medium in the cooling channel: the higher the duty cycle, the faster the pump speed, the greater the medium flow rate, the higher the convective heat transfer coefficient, and the stronger the heat dissipation capacity; the lower the duty cycle, the slower the pump speed and the lower the energy consumption. At this time, the phase change heat sink acts as a passive thermal buffer to absorb most of the heat, while the convection heat exchanger acts as an active heat transfer device to quickly remove the heat absorbed by the phase change. The two work together to achieve efficient thermal management under low power consumption, which is suitable for low-load and steady-state heating conditions after the relay is closed.

[0061] S206: When the phase change heat sink is in a failed state and the relay contact temperature exceeds the contact temperature threshold, control the thermoelectric cooling component to start.

[0062] Optionally, when the phase change material can no longer absorb heat, the contact temperature rise loses its buffer, and convective heat transfer alone is insufficient to meet the heat dissipation requirements, and the contact temperature reaches the demagnetization sensitive zone, the thermoelectric cooling device is activated to prevent the permanent magnet from demagnetizing due to high temperature at the source. The thermoelectric cooling device operates based on the Peltier effect; after being energized, it absorbs heat on one side and releases heat on the other. It is placed in the cooling medium return pipe of the convective heat exchanger to actively cool the heated cooling medium, reducing its temperature. After cooling, the cooling medium re-enters the cooling channel, significantly increasing the temperature difference with the contact heating zone, thereby significantly improving the efficiency of convective heat transfer and achieving a synergistic effect of thermoelectric cooling enhancing convective heat dissipation. Simultaneously, after the thermoelectric cooling device is activated, it continues to work in conjunction with the convective heat exchanger with the original pump speed duty cycle, forming a three-stage heat dissipation full-power synergy, quickly reducing the contact temperature to a safe threshold and solving the problem of temperature rise runaway under extreme high heat loads.

[0063] In the aforementioned thermal control method for magnetic latching relays, the relay contact temperature is obtained based on the relay's terminal voltage and load current when the relay is in the closed state. The control pump speed duty cycle is obtained based on the relay contact temperature and the DC bus voltage change rate. When the phase change heat sink is in a failed state and the relay contact temperature exceeds the contact temperature threshold, the thermoelectric cooling component is activated. This method can specifically address the heat dissipation requirements under all operating conditions after the magnetic latching relay is closed, achieving dynamic and precise matching between heat load and heat dissipation capacity, improving heat dissipation efficiency, and quickly suppressing contact temperature rise, thereby extending the service life of the magnetic latching relay.

[0064] In an exemplary embodiment, the step of obtaining the relay contact temperature based on the terminal voltage and load current of the magnetic latching relay includes: obtaining a contact resistance value based on the terminal voltage and load current of the magnetic latching relay; and obtaining the relay contact temperature based on the contact resistance value, a preset reference resistance value, a resistance temperature coefficient, and a preset reference temperature.

[0065] Optionally, in the problem of relay thermal demagnetization, the high heat generated by the inrush current at the moment of switching on and off is the main cause. This can be addressed by acquiring the DC bus voltage through the data acquisition and control unit. Calculate the rate of change of DC bus voltage. :

[0066]

[0067] The calculated DC bus voltage change rate To determine whether the relay is ready to close, once the magnetic latching relay is closed, its contacts become the core path for current conduction. The data acquisition and control unit synchronously acquires the relay terminal voltage in real time. Load current flowing through the relay Based on Ohm's Law The real-time contact resistance value R of the relay contact is obtained.

[0068] Furthermore, since the resistivity of metallic materials has a significant positive temperature coefficient, meaning that the resistance of a metal increases linearly (or approximately linearly) with increasing temperature, this characteristic provides a physical basis for the mapping between resistance and temperature. Combining preset calibration parameters, the contact temperature is derived using a resistance-temperature conversion formula. :

[0069]

[0070] in, R is the contact temperature, and R is the contact resistance. β is the reference contact resistance, and β is the temperature coefficient of resistance. This is the reference temperature.

[0071] In this embodiment, the contact resistance value is obtained based on the terminal voltage and load current of the magnetic latching relay. The relay contact temperature is then obtained based on the contact resistance value, the preset reference resistance value, the temperature coefficient of resistance, and the preset reference temperature. This method can accurately reflect the true temperature of the core heating area and improve the accuracy of the contact temperature.

[0072] In an exemplary embodiment, the step of obtaining the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate includes: constructing a saturation function based on a preset temperature feedback coefficient and a preset feedforward control coefficient; and solving the saturation function based on the relay contact temperature, the DC bus voltage change rate, and the target safe temperature to obtain the control pump speed duty cycle.

[0073] Optionally, the pump speed of the microchannel is controlled by the calculated temperature to increase the flow rate of the cooling medium when the temperature is high and decrease the flow rate when the temperature is low. To efficiently dissipate the high heat generated at the moment the relay closes, feedforward control is incorporated, using the DC bus voltage change rate α as the control factor for the microchannel flow rate. Cooling is activated just before the relay closes to prevent the high heat generated at the moment of switching on and off from failing to dissipate effectively, thus accelerating the control speed. Therefore, the duty cycle for controlling the pump speed is... :

[0074]

[0075] in, For preset temperature feedback coefficient, For contact temperature, For the set target safe temperature, α is the preset feedforward control coefficient, α is the DC bus voltage change rate, and Sat[ ] is the saturation function (limiting the duty cycle range to 0-100%).

[0076] Among them, the preset feedforward control coefficient is the weighting coefficient of the DC bus voltage change rate α, which is calibrated by engineering experiments. Its value determines the degree of influence of load fluctuation trend on pump speed and adapts the heat generation prediction sensitivity under different operating conditions. The preset temperature feedback coefficient is the weighting coefficient of contact temperature deviation, which is calibrated by relay thermal characteristics and heat dissipation requirements. Its value determines the adjustment range of pump speed when the actual temperature deviates from the safe temperature, ensuring the accuracy of temperature control.

[0077] Optionally, the above formula can be used to control the flow rate of the microchannel cooling medium based on two variables: relay temperature and DC bus voltage, enabling faster temperature control. Before and at the moment of relay closure, the contact resistance cannot be detected to calculate the contact temperature, making it impossible to effectively dissipate the high heat generated at the moment of closure. However, before relay closure, the rate of change of DC bus voltage increases, with α reaching its maximum. At this point, feedforward control becomes dominant, increasing the flow rate of the microchannel cooling medium to rapidly dissipate heat before closure, addressing the high heat generated at the moment of relay closure. After the relay closes, the contact resistance can be used to calculate the contact temperature. If the temperature is still high, temperature feedback becomes dominant, again increasing the flow rate of the microchannel cooling medium to enhance heat dissipation and protect the relay from demagnetization.

[0078] In an exemplary embodiment, the process of obtaining the operating state of the phase change heat sink includes: obtaining the temperature change rate based on the relay contact temperature; and determining that the operating state of the phase change heat sink is a failure state when the temperature change rate meets a preset growth condition.

[0079] Optionally, phase change materials (PCMs) provide passive heat dissipation. Therefore, regardless of the state of the microchannels, PCMs will effectively dissipate heat. However, PCMs cannot absorb heat indefinitely for heat dissipation; it is necessary to identify the state of the PCM to determine whether it is in an effective heat-absorbing state. Based on this, the temperature change rate can be calculated. :

[0080]

[0081] Among them, by establishing the rate of temperature change It can determine the state of the PCM at this time. If the temperature does not exceed the phase transition temperature or is close to the phase transition temperature after the relay is closed, but... A value close to 0 indicates that the PCM is absorbing heat, and the system is safe; after the relay is closed, if the phase change temperature is exceeded and An increase in temperature indicates that the PCM has completely liquefied and can no longer absorb heat. At this point, the temperature will rise, and the system will enter a dangerous state.

[0082] Furthermore, a thermoelectric cooler (TEC) can serve as the final stage of heat dissipation. It can be used in conjunction with microchannels, placing the TEC in the microchannel's return line to cool the coolant. The TEC requires power and, to reduce power consumption, is only activated under specific conditions. It activates when the temperature exceeds the maximum rated value or when the temperature change rate suddenly increases. At this point, due to the high temperature, the PCM has liquefied and failed, and the microchannel coolant is also hot. Therefore, activating the TEC cools the coolant flowing out of the microchannel, increasing the microchannel's heat dissipation capacity and achieving triple cooling for the relay. After the relay stops operating under high load, the PCM remains liquid due to insufficient cooling and cannot respond promptly to the next heat dissipation. Again, activating the TEC and adjusting the microchannel pump speed rapidly cools the PCM, restoring it to its initial state, ensuring efficient heat dissipation when the relay closes again.

[0083] In an exemplary embodiment, the method further includes: acquiring the DC bus voltage and the battery pack voltage, and acquiring the voltage difference between the DC bus voltage and the battery pack voltage; and determining the closing voltage difference of the magnetic latching relay based on the voltage difference.

[0084] Optionally, the relay closing logic is to close the relay when the voltage difference across its terminals is within a set range. Before closing, the motor will be in a generating or motoring state, meaning the DC bus voltage will increase or decrease, exhibiting a high rate of change. The DC bus voltage is acquired by the acquisition and control unit. With battery voltage Calculate the DC bus voltage change rate α and the voltage difference between the bus and the battery. :

[0085]

[0086] By setting an appropriate closing voltage difference, the inrush current can be minimized, thereby improving the service life of the relay.

[0087] In one exemplary embodiment, such as Figure 3 As shown, a thermal control method for a magnetic latching relay is provided, the method comprising the following steps:

[0088] S302: When the magnetic latching relay is in the closed state, obtain the contact resistance value based on the terminal voltage and load current of the magnetic latching relay; obtain the relay contact temperature based on the contact resistance value, the preset reference resistance value, the resistance temperature coefficient, and the preset reference temperature.

[0089] S304: Based on the preset temperature feedback coefficient and the preset feedforward control coefficient, a saturation function is constructed; the saturation function is solved according to the relay contact temperature, the DC bus voltage change rate, and the target safe temperature to obtain the control pump speed duty cycle.

[0090] S306: Obtain the temperature change rate based on the relay contact temperature; if the temperature change rate meets the preset growth condition, determine that the working state of the phase change heat sink is the failure state.

[0091] S308: When the phase change heat sink is not in a failed state, the working state of the convection heat exchanger is controlled according to the control pump speed duty cycle.

[0092] S310: When the phase change heat sink is in a failed state and the relay contact temperature exceeds the contact temperature threshold, control the thermoelectric cooling component to start.

[0093] S312: Obtain the DC bus voltage and battery pack voltage, and obtain the voltage difference between the DC bus voltage and the battery pack voltage; determine the closing voltage difference of the magnetic latching relay based on the voltage difference.

[0094] In this embodiment, when the magnetic latching relay is in the closed state, the relay contact temperature is obtained based on the relay's terminal voltage and load current. The control pump speed duty cycle is obtained based on the relay contact temperature and the DC bus voltage change rate. When the phase change heat sink is in a failed state and the relay contact temperature exceeds the contact temperature threshold, the thermoelectric cooling component is started. This can specifically address the heat dissipation requirements under all operating conditions after the magnetic latching relay is closed, achieve dynamic and precise matching between heat load and heat dissipation capacity, improve heat dissipation efficiency, quickly suppress contact temperature rise, and thus extend the service life of the magnetic latching relay.

[0095] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0096] Based on the same inventive concept, this application also provides a magnetic latching relay thermal control device for implementing the above-described magnetic latching relay thermal control method. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations of one or more magnetic latching relay thermal control device embodiments provided below can be found in the limitations of the magnetic latching relay thermal control method described above, and will not be repeated here.

[0097] In one exemplary embodiment, such as Figure 4 As shown, a magnetic latching relay thermal control device is provided, including: a temperature acquisition module 402, a first thermal control module 404, and a second thermal control module 406, wherein:

[0098] The temperature acquisition module 402 is used to acquire the relay contact temperature based on the terminal voltage and load current of the magnetic latching relay when the magnetic latching relay is in the closed state, and to acquire the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate.

[0099] The first thermal control module 404 is used to control the working state of the convective heat exchanger according to the control pump speed duty cycle when the working state of the phase change heat sink is not in a failed state.

[0100] The second thermal control module 406 is used to control the thermoelectric cooling component to start when the phase change heat sink is in a failed state and the relay contact temperature exceeds the contact temperature threshold.

[0101] In an exemplary embodiment, the temperature acquisition module 402 is further configured to acquire the contact resistance value based on the terminal voltage and load current of the magnetic latching relay; and acquire the relay contact temperature based on the contact resistance value, a preset reference resistance value, a resistance temperature coefficient, and a preset reference temperature.

[0102] In an exemplary embodiment, the temperature acquisition module 402 is further configured to construct a saturation function based on a preset temperature feedback coefficient and a preset feedforward control coefficient; and to solve the saturation function according to the relay contact temperature, the DC bus voltage change rate, and the target safe temperature to obtain the control pump speed duty cycle.

[0103] In an exemplary embodiment, the first thermal control module 404 is further configured to obtain the temperature change rate based on the relay contact temperature; and determine the working state of the phase change heat sink as a failure state if the temperature change rate meets a preset growth condition.

[0104] In an exemplary embodiment, the temperature acquisition module 402 is further configured to acquire the DC bus voltage and the battery pack voltage, and acquire the voltage difference between the DC bus voltage and the battery pack voltage; and determine the closing voltage difference of the magnetic latching relay based on the voltage difference.

[0105] Each module in the aforementioned magnetic latching relay thermal control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0106] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 5As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When executed by the processor, the computer program implements a magnetic latching relay thermal control method. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0107] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0108] In one exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to perform the following steps: when the magnetic latching relay is in a closed state, obtaining the relay contact temperature based on the terminal voltage and load current of the magnetic latching relay, and obtaining the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate; when the phase change heat sink is not in a failed state, controlling the operation state of the convection heat exchanger based on the control pump speed duty cycle; when the phase change heat sink is in a failed state and the relay contact temperature exceeds the contact temperature threshold, controlling the thermoelectric cooling element to start.

[0109] In one embodiment, the process of obtaining the relay contact temperature based on the terminal voltage and load current of the magnetic latching relay when the processor executes a computer program includes: obtaining a contact resistance value based on the terminal voltage and load current of the magnetic latching relay; and obtaining the relay contact temperature based on the contact resistance value, a preset reference resistance value, a temperature coefficient of resistance, and a preset reference temperature.

[0110] In one embodiment, the process of obtaining the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate when the processor executes the computer program includes: constructing a saturation function based on a preset temperature feedback coefficient and a preset feedforward control coefficient; and solving the saturation function based on the relay contact temperature, the DC bus voltage change rate, and the target safe temperature to obtain the control pump speed duty cycle.

[0111] In one embodiment, the process of obtaining the operating state of the phase change heat sink involved when the processor executes a computer program includes: obtaining the temperature change rate based on the relay contact temperature; and determining that the operating state of the phase change heat sink is a failure state when the temperature change rate meets a preset growth condition.

[0112] In one embodiment, when the processor executes the computer program, it further performs the following steps: acquiring the DC bus voltage and the battery pack voltage, and acquiring the voltage difference between the DC bus voltage and the battery pack voltage; and determining the closing voltage difference of the magnetic latching relay based on the voltage difference.

[0113] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon. When the computer program is executed by a processor, it performs the following steps: when the magnetic latching relay is in a closed state, obtaining the relay contact temperature based on the terminal voltage and load current of the magnetic latching relay, and obtaining the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate; when the phase change heat sink is not in a failed state, controlling the operating state of the convection heat exchanger based on the control pump speed duty cycle; when the phase change heat sink is in a failed state and the relay contact temperature exceeds the contact temperature threshold, controlling the thermoelectric cooling element to start.

[0114] In one embodiment, the computer program, when executed by a processor, involves obtaining the relay contact temperature based on the terminal voltage and load current of the magnetic latching relay, including: obtaining a contact resistance value based on the terminal voltage and load current of the magnetic latching relay; and obtaining the relay contact temperature based on the contact resistance value, a preset reference resistance value, a temperature coefficient of resistance, and a preset reference temperature.

[0115] In one embodiment, the computer program, when executed by a processor, involves obtaining the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate, including: constructing a saturation function based on a preset temperature feedback coefficient and a preset feedforward control coefficient; and solving the saturation function based on the relay contact temperature, the DC bus voltage change rate, and the target safe temperature to obtain the control pump speed duty cycle.

[0116] In one embodiment, the process of obtaining the operating state of the phase change heat sink involved when the computer program is executed by the processor includes: obtaining the temperature change rate based on the relay contact temperature; and determining that the operating state of the phase change heat sink is a failure state when the temperature change rate meets a preset growth condition.

[0117] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: acquiring the DC bus voltage and the battery pack voltage, and acquiring the voltage difference between the DC bus voltage and the battery pack voltage; determining the closing voltage difference of the magnetic latching relay based on the voltage difference.

[0118] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps: when the magnetic latching relay is in a closed state, obtaining the relay contact temperature based on the terminal voltage and load current of the magnetic latching relay, and obtaining the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate; when the phase change heat sink is not in a failed state, controlling the operating state of the convection heat exchanger based on the control pump speed duty cycle; and when the phase change heat sink is in a failed state and the relay contact temperature exceeds the contact temperature threshold, controlling the thermoelectric cooling element to start.

[0119] In one embodiment, the computer program, when executed by a processor, involves obtaining the relay contact temperature based on the terminal voltage and load current of the magnetic latching relay, including: obtaining a contact resistance value based on the terminal voltage and load current of the magnetic latching relay; and obtaining the relay contact temperature based on the contact resistance value, a preset reference resistance value, a temperature coefficient of resistance, and a preset reference temperature.

[0120] In one embodiment, the computer program, when executed by a processor, involves obtaining the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate, including: constructing a saturation function based on a preset temperature feedback coefficient and a preset feedforward control coefficient; and solving the saturation function based on the relay contact temperature, the DC bus voltage change rate, and the target safe temperature to obtain the control pump speed duty cycle.

[0121] In one embodiment, the process of obtaining the operating state of the phase change heat sink involved when the computer program is executed by the processor includes: obtaining the temperature change rate based on the relay contact temperature; and determining that the operating state of the phase change heat sink is a failure state when the temperature change rate meets a preset growth condition.

[0122] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: acquiring the DC bus voltage and the battery pack voltage, and acquiring the voltage difference between the DC bus voltage and the battery pack voltage; determining the closing voltage difference of the magnetic latching relay based on the voltage difference.

[0123] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0124] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0125] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A thermal control method for a magnetic latching relay, characterized in that, Applied to a thermal control system for magnetic latching relays; the method includes: When the magnetic latching relay is in the closed state, the relay contact temperature is obtained based on the terminal voltage and load current of the magnetic latching relay, and the duty cycle of the control pump speed is obtained based on the relay contact temperature and the DC bus voltage change rate. When the phase change heat sink is not in a failed state, the working state of the convection heat exchanger is controlled according to the control pump speed duty cycle. When the phase change heat sink is in the failed state and the relay contact temperature exceeds the contact temperature threshold, the thermoelectric cooling element is activated.

2. The method according to claim 1, characterized in that, The method of obtaining the relay contact temperature based on the terminal voltage and load current of the magnetic latching relay includes: The contact resistance value is obtained based on the terminal voltage and load current of the magnetic latching relay; The relay contact temperature is obtained based on the contact resistance value, the preset reference resistance value, the resistance temperature coefficient, and the preset reference temperature.

3. The method according to claim 1, characterized in that, The step of obtaining the pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate includes: A saturation function is constructed based on a preset temperature feedback coefficient and a preset feedforward control coefficient. The saturation function is solved based on the relay contact temperature, the DC bus voltage change rate, and the target safe temperature to obtain the control pump speed duty cycle.

4. The method according to claim 1, characterized in that, The process of obtaining the working state of the phase change heat sink includes: The temperature change rate is obtained based on the temperature of the relay contacts. If the temperature change rate meets the preset growth condition, the working state of the phase change heat sink is determined to be a failure state.

5. The method according to claim 1, characterized in that, The method further includes: Obtain the DC bus voltage and the battery pack voltage, and obtain the voltage difference between the DC bus voltage and the battery pack voltage; The closing voltage difference of the relay is determined based on the voltage difference.

6. A thermal control device for a magnetic latching relay, characterized in that, The device includes: The temperature acquisition module is used to acquire the relay contact temperature based on the terminal voltage and load current of the magnetic latching relay when the magnetic latching relay is in the closed state, and to acquire the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate. The first thermal control module is used to control the working state of the convective heat exchanger according to the duty cycle of the control pump speed when the working state of the phase change heat sink is not in a failed state. The second thermal control module is used to control the thermoelectric cooling component to start when the phase change heat sink is in the failure state and the relay contact temperature exceeds the contact temperature threshold.

7. A thermal control system for a magnetic latching relay, characterized in that, include: At least one magnetic latching relay, the magnetic latching relay including a relay module and a heat dissipation module, one end of the magnetic latching relay being connected to a DC bus and the other end being connected to a battery pack; the heat dissipation module including a phase change heat sink, a convection heat exchanger and a thermoelectric cooling element; The data acquisition and control unit is connected to the magnetic latching relay and the DC bus, respectively, and is used to acquire the relay voltage of the magnetic latching relay and the DC bus voltage, and to obtain the relay contact temperature and the DC bus voltage change rate based on the relay voltage and the DC bus voltage. The energy-saving management unit is connected to the acquisition and control unit at one end and to the battery pack at the other end. It is used to control the working state of the heat dissipation module based on the temperature of the relay contacts and the rate of change of the DC bus voltage.

8. The magnetic latching relay thermal control system according to claim 7, characterized in that, The data acquisition and control unit is also used to obtain the temperature change rate based on the temperature of the relay contacts; the energy-saving management unit is also used to control the start-up and shutdown status of the thermoelectric cooling component based on the temperature change rate.

9. The magnetic latching relay thermal control system according to claim 8, characterized in that, The convection heat exchanger includes a cooling channel and a cooling medium; The data acquisition and control unit is further configured to obtain the control pump speed duty cycle based on the relay contact temperature and the DC bus voltage change rate; the energy-saving management unit is further configured to control the flow rate of the cooling medium in the cooling channel based on the control pump speed duty cycle.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 5.

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