Relay-based control method and apparatus for coil current, and device and medium

Abstract

The present application belongs to the technical field of electric vehicles. Provided are a relay-based control method and apparatus for a coil current, and a device and a medium. The method comprises: controlling a high-side driver module and a low-side driver module to close, so as to drive a relay module; after a preset duration, acquiring a voltage inputted by the high-side driver module, so as to obtain a first high-side voltage, and acquiring the temperature of the relay module, so as to obtain a first temperature; on the basis of the first high-side voltage and the first temperature, querying a pre-acquired first mapping relationship table, so as to obtain a target duty cycle; and outputting a pulse width modulation signal on the basis of the target duty cycle, and controlling a coil current of the relay module on the basis of the pulse width modulation signal. Fine control over a coil current of a relay module can be achieved, thereby avoiding the damage to the relay module.

Description

Relay-based coil current control method and device, equipment and medium

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202411380121.3, filed on September 29, 2024, and entitled "Relay-based coil current control method and device, equipment and medium", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of electric vehicles, in particular to a relay-based coil current control method and device, equipment and medium. BACKGROUND

[0004] Relay has been applied to high-voltage power control devices of various intelligent electric vehicles and energy storage systems to improve the reliability and safety of the system. In the related art, the power of the relay directly driven by the conventional voltage is 7W to 12W, and the power of the relay controlled by the pulse width modulation signal (PWM) is 1.5W to 3W. Since the energy consumption of the PWM control method is 25% of the direct voltage driving method, in order to reduce the driving energy consumption, the PWM controlled relay is usually used. However, the PWM driven relay has strict requirements on the coil current, and the actual coil current lower than the required coil current of the relay will cause the relay to be disconnected, and the actual coil current higher than the required coil current of the relay will cause the relay to be damaged. Therefore, how to make the actual coil current meet the required coil current of the relay based on the PWM driven relay has become a problem to be solved. SUMMARY

[0005] The main purpose of the embodiments of the present application is to propose a relay-based coil current control method and device, equipment and medium, which aims to accurately control the coil current of the relay and avoid damage to the relay.

[0006] To achieve the above-mentioned purpose, the first aspect of the embodiments of the present application proposes a relay-based coil current control method applied to a relay-based coil current control device, the relay-based coil current control device comprising a high-side drive module, a low-side drive module and a relay module, the coil current control method comprising the following steps:

[0007] controlling the high-side drive module and the low-side drive module to be closed to drive the relay module;

[0008] After a preset time length, a voltage output by the high-side drive module is acquired to obtain a first high-side voltage, and a temperature of the relay module is acquired to obtain a first temperature;

[0009] A first mapping relationship table is queried according to the first high-side voltage and the first temperature to obtain a target duty cycle; the first mapping relationship table is used to represent a mapping relationship among the voltage of the high-side drive module, the temperature of the relay module and the duty cycle;

[0010] A pulse width modulation signal is output according to the target duty cycle, and a coil current of the relay module is controlled according to the pulse width modulation signal.

[0011] In some embodiments, the coil current control method further comprises:

[0012] A current output by the high-side drive module is acquired to obtain a high-side current, and a current output by the low-side drive module is acquired to obtain a low-side current;

[0013] A current comparison result is obtained by comparing the high-side current and the low-side current; the current comparison result is used to represent a current size relationship between the high-side current and the low-side current;

[0014] If the current comparison result represents that the high-side current and the low-side current are equal, a current temperature of the relay module is acquired to obtain a second temperature;

[0015] A switching efficiency of the low-side drive module is obtained by querying a second mapping relationship table according to the second temperature; the second mapping relationship table is used to represent a mapping relationship between the temperature of the relay module and the switching efficiency of the low-side drive module;

[0016] Any one of the high-side current and the low-side current is taken as a reference current;

[0017] A current output by the relay module is calculated according to the reference current and the switching efficiency to obtain a candidate current.

[0018] In some embodiments, the coil current control method further comprises:

[0019] A standard current specification of the relay module is acquired;

[0020] If the candidate current meets the standard current specification, a voltage currently output by the high-side drive module is acquired to obtain a second high-side voltage, and a temperature currently output by the relay module is acquired to obtain a third temperature; the target duty cycle is adjusted according to the first high-side voltage, the second high-side voltage, the second temperature and the third temperature;

[0021] If the candidate current does not satisfy the standard current specification, the high-side current currently output by the high-side drive module is re-acquired, and the low-side current currently output by the low-side drive module is re-acquired; and the target duty cycle is adjusted according to the high-side current and the low-side current.

[0022] In some embodiments, the adjusting the target duty cycle according to the first high-side voltage, the second high-side voltage, the second temperature, and the third temperature comprises:

[0023] comparing the first high-side voltage, the second high-side voltage, the second temperature, and the third temperature;

[0024] If the first high-side voltage and the second high-side voltage are not equal, and / or the second temperature and the third temperature are not equal, the first mapping relationship table is queried according to the second high-side voltage and the third temperature to obtain a new duty cycle; and the new duty cycle is taken as the target duty cycle.

[0025] If the first high-side voltage and the second high-side voltage are equal, and the second temperature and the third temperature are equal, the high-side current currently output by the high-side drive module is re-acquired, and the low-side current currently output by the low-side drive module is re-acquired; and the target duty cycle is adjusted according to the high-side current and the low-side current.

[0026] In some embodiments, the coil current control method further comprises:

[0027] If the current comparison result indicates that the high-side current and the low-side current are not equal, the cumulative number of times that the high-side current and the low-side current are not equal is acquired;

[0028] If the cumulative number of times is less than a preset number threshold, the high-side current currently output by the high-side drive module is re-acquired, and the low-side current currently output by the low-side drive module is re-acquired; and the target duty cycle is adjusted according to the high-side current and the low-side current.

[0029] In some embodiments, the coil current control method further comprises:

[0030] determining whether a condition for closing the relay is met;

[0031] If the determination result is no, a fault type is stored, and a pre-warning information is generated according to the fault type;

[0032] If the determination result is yes, the step of controlling the high-side drive module and the low-side drive module to be closed is executed.

[0033] In some embodiments, the obtaining the temperature of the relay module to obtain a first temperature comprises:

[0034] obtaining the voltage across the coil when the relay module is closed;

[0035] querying the voltage-temperature relationship according to the voltage across the coil to obtain the current temperature of the relay module to obtain a first temperature.

[0036] In some embodiments, the coil current control method further comprises:

[0037] obtaining the relationship between the duty cycle, the voltage output by the high-side drive module, and the temperature according to the voltage-temperature relationship and the duty cycle calculation formula;

[0038] taking the relationship between the duty cycle, the voltage output by the high-side drive module, and the temperature as a first mapping relationship table.

[0039] In some embodiments, the obtaining the current temperature of the relay module to obtain a second temperature comprises:

[0040] collecting the current voltage across the coil of the relay module;

[0041] querying the voltage-temperature relationship according to the current voltage to obtain the current temperature of the relay module to obtain a second temperature.

[0042] To achieve the above-mentioned purpose, a second aspect of the embodiments of the present application proposes a coil current control device based on a relay, which is suitable for the coil current control method based on a relay of the first aspect, and the coil current control device comprises:

[0043] a relay module, a control module, a high-side drive module, a low-side drive module, and a temperature module, wherein the control module is connected with the relay module through the high-side drive module, the low-side drive module, and the temperature module.

[0044] In some embodiments, the high-side drive module comprises a high-side driver, a high-side voltage detection unit, and a high-side current detection unit, wherein the high-side driver is connected with the high-side voltage detection unit, the high-side current detection unit, and the first end of the relay module respectively, and the control module is connected with the high-side driver.

[0045] In some embodiments, the first end of the relay module is the high-potential side of the relay module.

[0046] In some embodiments, the low-side driving module comprises a low-side driver, a low-side voltage detection unit and a low-side current detection unit, the low-side driver is connected with the low-side voltage detection unit, the low-side current detection unit and the second end of the relay module respectively; and the control module is connected with the low-side driver.

[0047] In some embodiments, the second end of the relay module is a low potential side of the relay module.

[0048] In some embodiments, the coil current control device further comprises a diode, a positive electrode of the diode is connected with the second end of the relay module, and a negative electrode of the diode is connected with the first end of the relay module.

[0049] To achieve the above object, a third aspect of the embodiments of the present application provides an electronic device, which comprises a memory and a processor, the memory stores a computer program, and the processor implements the relay-based coil current control method of the first aspect when executing the computer program.

[0050] To achieve the above object, a fourth aspect of the embodiments of the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the relay-based coil current control method of the first aspect.

[0051] The relay-based coil current control method, the relay-based coil current control device, the electronic device and the computer readable storage medium provided by the present application can drive the relay module by controlling the high-side driving module and the low-side driving module to close, so as to finely control the coil current of the relay module based on the high-side driving module and the low-side driving module, and ensure the accuracy and reliability of the coil current control. The temperature of the relay module and the voltage output by the high-side driving module to the relay module are very important to ensure the normal operation of the relay module, and the coil current is controlled by considering the voltage output by the high-side driving module and the temperature of the relay module. After a preset time period, the voltage output by the high-side driving module is obtained to obtain a first high-side voltage, and the temperature of the relay module is obtained to obtain a first temperature. In order to improve the efficiency and accuracy of the coil current control, the first mapping relationship table obtained in advance is queried according to the first high-side voltage and the first temperature, so as to determine a suitable duty cycle to obtain a target duty cycle. The pulse width modulation signal is output according to the target duty cycle, and the coil current of the relay module is controlled according to the pulse width modulation signal, so that the coil current meets the current specification requirement, and the relay module can operate normally, avoiding damage of the relay due to too large coil current or failure of the relay to operate normally due to too small coil current. BRIEF DESCRIPTION OF DRAWINGS

[0052] FIG. 1 is a flow chart of a relay-based coil current control method according to an embodiment of the present application;

[0053] FIG. 2 is another flow chart of a relay-based coil current control method according to an embodiment of the present application;

[0054] FIG. 3 is another flow chart of a relay-based coil current control method according to an embodiment of the present application;

[0055] FIG. 4 is a flow chart of step S320 in FIG. 3;

[0056] FIG. 5 is another flow chart of a relay-based coil current control method according to an embodiment of the present application;

[0057] FIG. 6 is another flow chart of a relay-based coil current control method according to an embodiment of the present application;

[0058] FIG. 7 is a structural schematic diagram of a relay-based coil current control device according to an embodiment of the present application;

[0059] FIG. 8 is a hardware structural schematic diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not intended to limit the present application.

[0061] It should be noted that although the functional modules are divided in the device schematic diagram, and the logical order is shown in the flow chart, in some cases, the steps shown or described can be executed in a manner different from the module division in the device or the order in the flow chart. The terms "first", "second", etc. in the specification and claims and the above-described drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the specification herein is for describing the embodiments of the present application only and is not intended to limit the present application.

[0063] With the development of new energy industry and energy storage industry, relays are widely used in high-voltage power control devices of various intelligent electric vehicles such as electric vehicles, hybrid electric vehicles and energy storage systems. The power of a conventional voltage directly driven relay is 7W to 12W, and the power of a relay controlled by a pulse width modulation (PWM) signal is 1.5W to 3W. Since the energy consumption of the PWM control method is 25% of the direct voltage driving method, in order to reduce the driving energy consumption, a PWM controlled relay is usually used. However, the PWM driven relay has strict requirements on the coil current, and the actual coil current lower than the required coil current of the relay will cause the relay to be disconnected, and the actual coil current higher than the required coil current of the relay will cause the relay to be damaged.

[0064] In the related art, two methods are usually used to drive the PWM relay. The first method is to use a special chip to drive the PWM relay, but the cost of the special chip is high, and the design and development workload is large. The second method is to connect a small resistance (current sampling resistance) in series in the driving circuit, use the voltage drop generated by the current on the small resistance, and calculate the coil current by amplifying the voltage drop across the current sampling resistance by an operational amplifier. However, the second method has high requirements on the current sampling resistance and the operational amplifier (such as rail-to-rail, low zero drift, high voltage resistance). If the resistance value of the current sampling resistance is too large, the actual coil current of the relay will decrease. The operational amplifier amplifies the voltage drop across the current sampling resistance, and the error of the resistance accuracy is also amplified, so the resistance value accuracy of the current sampling resistance will also affect the actual coil current of the relay. With the increase of the use time, the resistance value will drift, and the performance of the operational amplifier will also degrade, resulting in a decrease in current control accuracy.

[0065] Therefore, based on the above problems, the embodiment of the present application provides a relay-based coil current control method, a relay-based coil current control device, an electronic device and a computer readable storage medium, which aims to accurately control the coil current based on the pulse width modulation signal.

[0066] The relay-based coil current control method, the relay-based coil current control device, the electronic device and the computer readable storage medium provided by the embodiment of the present application are specifically described by the following embodiments. First, the relay-based coil current control method in the embodiment of the present application is described.

[0067] The relay-based coil current control method provided in the embodiments of the present application relates to the technical field of electric vehicles. The relay-based coil current control method provided in the embodiments of the present application can be applied to a terminal and can also be applied to a server end, and specifically can be software running in the terminal or the server end. In some embodiments, the terminal can be a smart phone, a tablet computer, a notebook computer, a desktop computer or the like; the server end can be configured as a stand-alone physical server, can also be configured as a server cluster or a distributed system formed by multiple physical servers, and can also be configured as a cloud server providing basic cloud computing services such as cloud service, cloud database, cloud computing, cloud function, cloud storage, network service, cloud communication, middleware service, domain name service, security service, CDN and big data and artificial intelligence platform; and the software can be an application program implementing the relay-based coil current control method, but is not limited to the above forms.

[0068] The present application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld devices or portable devices, tablet devices, multi-processor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, and the like. The present application can be described in the general context of computer-executable instructions executed by a computer, such as a program module. Generally, program modules include routines, programs, objects, components, data structures, and the like that perform specific tasks or implement specific abstract data types. The present application can also be practiced in a distributed computing environment in which tasks are performed by remote processing devices connected by a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media, including storage devices.

[0069] FIG. 1 is an optional flowchart of a relay-based coil current control method according to an embodiment of the present application. The method in FIG. 1 is applied to a relay-based coil current control device including a high-side drive module, a low-side drive module and a relay module. The coil current control method can include, but is not limited to, steps S110 to S140.

[0070] In step S110, the high-side drive module and the low-side drive module are controlled to be closed to drive the relay module.

[0071] In step S120, after a preset time period, the voltage output by the high-side drive module is obtained to obtain a first high-side voltage, and the temperature of the relay module is obtained to obtain a first temperature.

[0072] In step S130, the first mapping relationship table is queried according to the first high-side voltage and the first temperature, and a target duty cycle is obtained; the first mapping relationship table is used to represent the mapping relationship among the voltage of the high-side drive module, the temperature of the relay module, and the duty cycle.

[0073] In step S140, a pulse width modulation signal is output according to the target duty cycle, and the coil current of the relay module is controlled according to the pulse width modulation signal.

[0074] In step S110 of some embodiments, the control module in the coil current control device is connected to the power supply and receives power supply from the power supply to power on the control module. After being powered on, the control module performs initialization operation to detect faults of the preset system, which can be an electric vehicle, an energy storage system, etc. If the preset system has no fault, it means that the relay closing condition is met and the relay module needs to be closed, and the control module sends a closing instruction to the high-side drive module and the low-side drive module respectively, and controls the high-side drive module and the low-side drive module to close according to the closing instruction. If the preset system has a fault, the control module stores the fault type and generates a warning information according to the fault type.

[0075] In step S120 of some embodiments, the relay module needs to be closed for 100% duty cycle for 100ms to 500ms. In order to close the relay module, the control module keeps the high-side drive module in the closed state, and obtains the time length of the low-side drive module in the closed state to obtain a preset time length (activation signal duration). If the activation signal duration is within the preset time length range, the voltage currently output by the high-side drive module is obtained to obtain a first high-side voltage. The voltage across the coil when the relay module is closed, i.e. the voltage across the temperature sensor, is obtained, the voltage-temperature relationship is queried according to the voltage, the current temperature of the relay module is obtained, and a first temperature is obtained. The preset time length range is determined according to the relay specification requirement, which can be [100ms, 500ms], and ms represents millisecond. The voltage-temperature relationship is used to represent the mapping relationship between the voltage across the coil and the temperature of the relay module.

[0076] The voltage-temperature relationship can be obtained according to the following steps: according to the relay specification requirement or the relay coil resistance test, the resistance-temperature change relationship table or the resistance-temperature change relationship curve of the temperature sensor is obtained. According to the relay specification requirement, the minimum current and the maximum current allowed when the relay module is closed are obtained, the current interval (including the minimum current and the maximum current) formed by the minimum current and the maximum current is sampled according to a preset step, and a plurality of currents are obtained. Each current is multiplied by a plurality of resistances in the resistance-temperature change relationship table (resistance-temperature change relationship curve) in turn to obtain the change relationship of the voltage with the temperature. The voltage can be spaced at intervals of 0.5V, and the temperature can be spaced at intervals of 5℃.

[0077] It should be noted that, since the temperature range of the automobile product is [-40℃, 125℃], the relay coil internal resistance test can be performed at the temperature range to obtain a relationship table or a curve of the relay coil internal resistance with the temperature change, and the relay coil internal resistance is the resistance value of the temperature sensor.

[0078] In step S130 of some embodiments, the first mapping relationship table is used to represent the mapping relationship between the voltage of the high-side drive module, the temperature of the relay module, and the duty cycle. When the relay module is closed, the first mapping relationship table is queried according to the first high-side voltage and the first temperature to obtain the target duty cycle, so as to select a suitable duty cycle and further improve the efficiency of the coil current control. The duty cycle is the ratio of the high-level duration of the pulse width modulation signal to the signal period.

[0079] The calculation formula of the duty cycle is defined as D = V hold / Vh, D is the duty cycle, V hold is the voltage across the coil when the relay module is closed, and Vh represents the voltage output by the high-side drive module. According to the voltage-temperature relationship (V hold -temperature) and the duty cycle calculation formula, the relationship between the duty cycle, the voltage Vh output by the high-side drive module, the voltage V hold across the coil when the relay module is closed, and the temperature is obtained, and the relationship between the duty cycle, the voltage output by the high-side drive module, and the temperature is taken as the first mapping relationship table.

[0080] In step S140 of some embodiments, the switching frequency of the low-side drive module is determined according to the relay specification requirements, the signal period is determined according to the switching frequency, the pulse width modulation signal is output according to the signal period and the target duty cycle, the control module sends the pulse width modulation signal to the enable pin of the low-side drive module, and the low-side driver controls the coil current of the relay according to the pulse width modulation signal to realize the PWM driving of the relay module. The reciprocal of the signal period is the switching frequency, and the signal period is the sum of the high-level duration and the low-level duration. The high-level duration is the duration of the low-side driver in the closed state, and the low-level duration is the duration of the low-side driver in the open state. It should be noted that when the pulse width modulation signal is high, the relay coil charges the stored energy. When the pulse width modulation signal is low, the stored energy in the coil continues to provide energy to the coil through the diode.

[0081] Referring to FIG. 2, in some embodiments, the coil current control method of the relay can further include but is not limited to steps S210 to S260:

[0082] In step S210, the current output by the high-side drive module is obtained to obtain a high-side current, and the current output by the low-side drive module is obtained to obtain a low-side current.

[0083] Step S220, comparing the high-side current and the low-side current to obtain a current comparison result, the current comparison result being used to represent a current magnitude relationship between the high-side current and the low-side current.

[0084] Step S230, if the current comparison result represents that the high-side current and the low-side current are equal, obtaining a current temperature of the relay module to obtain a second temperature.

[0085] Step S240, querying the second mapping relationship table according to the second temperature to obtain a switching efficiency of the low-side driving module; the second mapping relationship table being used to represent a mapping relationship between a temperature of the relay module and the switching efficiency of the low-side driving module.

[0086] Step S250, taking any one of the high-side current and the low-side current as a reference current.

[0087] Step S260, calculating a current output by the relay module according to the reference current and the switching efficiency to obtain a candidate current.

[0088] In step S210 of some embodiments, the method two does not diagnose the confidence difference of the current sampling resistor, in order to ensure that the target duty cycle determined based on the first mapping relationship table can make the coil current be in the range required by the relay module, the current output by the high-side driving module is obtained to obtain a high-side current, and the current output by the low-side driving module is obtained to obtain a low-side current. The current detection is performed on the high-side current and the low-side current to improve the accuracy and reliability of the coil current control.

[0089] In step S220 of some embodiments, the high-side current is a current on the high potential side of the relay module, and the low-side current is a current on the low potential side of the relay module, so the high-side current and the low-side current are usually equal. In order to determine whether the relay module is faulty, the high-side current and the low-side current are compared to obtain a current comparison result, the current comparison result being used to represent a current magnitude relationship between the high-side current and the low-side current, the current magnitude relationship including that the high-side current and the low-side current are equal or not equal.

[0090] In step S230 of some embodiments, if the current comparison result represents that the high-side current and the low-side current are equal, it is determined that the relay module is in a normal state, in the normal state, a current voltage across the coil of the relay module is collected by a temperature sensor, and the current voltage is used to query a voltage-temperature relationship to obtain a current temperature of the relay module to obtain a second temperature.

[0091] In step S240 of some embodiments, the pre-acquired second mapping relationship table is queried according to the second temperature, to obtain the switching efficiency of the low-side drive module, and the second mapping relationship table is used to represent the mapping relationship between the temperature of the relay module and the switching efficiency of the low-side drive module. The switching efficiency of the low-side drive module can be tested under high and low temperature conditions of [-40℃, 125℃], to form a relationship table of temperature and switching efficiency, and obtain the second mapping relationship table. The switching efficiency is the energy conversion efficiency, and the switching efficiency is the ratio of the output power of the low-side drive module to the input power when the low-side drive module switches between the closed state and the open state. The input power is the power input to the low-side drive module by the relay module when the low-side drive module is closed, and is represented as the product of the voltage output by the low-side drive module and the low-side current. The output power is the power output by the low-side drive module.

[0092] In step S250 of some embodiments, since the high-side current and the low-side current are equal, any one of the high-side current and the low-side current is taken as the reference current.

[0093] In step S260 of some embodiments, the reference current is multiplied by the switching efficiency, and the result obtained by the multiplication is divided by the current duty cycle (target duty cycle) to obtain the candidate current output by the relay module. The candidate current is the average current of the relay coil estimated according to the reference current and the switching efficiency.

[0094] The steps S210 to S260 described above can reduce the error of current detection by the high and low side dual current, to improve the accuracy of coil current estimation, so that the relay module can work normally.

[0095] Referring to FIG. 3, in some embodiments, the coil current control method can further include but is not limited to steps S310 to S330:

[0096] In step S310, the standard current specification of the relay module is obtained;

[0097] In step S320, if the candidate current meets the standard current specification, the voltage currently output by the high-side drive module is obtained to obtain a second high-side voltage, and the temperature currently output by the relay module is obtained to obtain a third temperature; the target duty cycle is adjusted according to the first high-side voltage, the second high-side voltage, the second temperature and the third temperature;

[0098] In step S330, if the candidate current does not meet the standard current specification, the high-side current currently output by the high-side drive module is re-acquired, and the low-side current currently output by the low-side drive module is re-acquired; the target duty cycle is adjusted according to the high-side current and the low-side current.

[0099] In step S310 of some embodiments, the duty cycle is corrected according to the candidate current, so that the coil current of the relay is within the required current range. Specifically, the standard current specification of the relay module is obtained, which is the required current range of the relay module.

[0100] In step S320 of some embodiments, if the candidate current meets the standard current specification, it means that the current duty cycle for controlling the coil current is correct, and the relay module can operate normally. The high-side voltage and the relay temperature are real-time changes. In order to ensure the correctness of the duty cycle in the entire relay closing stage, it is necessary to adjust the duty cycle in real time according to the high-side voltage and the temperature, so as to continue to obtain the current high-side voltage of the high-side drive module to obtain the second high-side voltage, and continue to obtain the current temperature of the relay module to obtain the third temperature. The target duty cycle is corrected in real time according to the first high-side voltage, the second high-side voltage, the second temperature and the third temperature. The PWM duty cycle is corrected by continuously detecting the high-side voltage and the relay temperature, so as to ensure the correctness of the duty cycle in the entire relay closing stage, and make the relay module operate normally in the entire closing stage. The third temperature is obtained in the same way as the first temperature and the second temperature, which will not be repeated here.

[0101] In step S330 of some embodiments, if the candidate current does not meet the standard current specification, the control module corrects the target duty cycle, and after the target duty cycle is corrected, the current output of the high-side current of the high-side drive module is re-obtained, and the current output of the low-side current of the low-side drive module is re-obtained. Refer to steps S210 to S260 and steps S310 to S330, adjust the target duty cycle according to the high-side current and the low-side current.

[0102] It should be noted that if the candidate current is greater than the allowable maximum current, the control module reduces the target duty cycle to reduce the candidate current. If the candidate current is less than the allowable minimum current, the control module increases the target duty cycle to increase the candidate current.

[0103] In steps S310 to S330 described above, after the relay module is closed, the candidate current of the relay module is estimated according to the high-side current of the high-side drive module, the low-side current of the low-side drive, and the switching efficiency of the low-side drive, so as to correct the PWM duty cycle according to the candidate current, and ensure that the coil current is within the required range of the relay.

[0104] Please refer to FIG. 4, in some embodiments, step S320 can include but is not limited to steps S410 to S430:

[0105] Step S410, compare the first high-side voltage, the second high-side voltage, the second temperature and the third temperature;

[0106] Step S420, if the first high-side voltage and the second high-side voltage are not equal, and / or the second temperature and the third temperature are not equal, the first mapping relationship table is queried according to the second high-side voltage and the third temperature, and a new duty cycle is obtained; the new duty cycle is taken as the target duty cycle.

[0107] Step S430, if the first high-side voltage and the second high-side voltage are equal, and the second temperature and the third temperature are equal, the high-side current currently output by the high-side drive module is re-acquired, and the low-side current currently output by the low-side drive module is re-acquired; the target duty cycle is adjusted according to the high-side current and the low-side current.

[0108] In step S410 of some embodiments, in order to determine whether the high-side voltage changes, the first high-side voltage and the second high-side voltage are compared. In order to determine whether the relay temperature changes, the second temperature and the third temperature are compared.

[0109] In step S420 of some embodiments, if the first high-side voltage and the second high-side voltage are not equal, and / or the second temperature and the third temperature are not equal, it indicates that the high-side voltage changes and / or the relay temperature changes, and the duty cycle needs to be re-determined, then the first mapping relationship table is queried according to the second high-side voltage and the third temperature, a new duty cycle is obtained, and the new duty cycle is taken as the target duty cycle.

[0110] In step S430 of some embodiments, if the first high-side voltage and the second high-side voltage are equal, and the second temperature and the third temperature are equal, the high-side current currently output by the high-side drive module is re-acquired, and the low-side current currently output by the low-side drive module is re-acquired, the high-side current and the low-side current are compared, and according to steps S210 to S260 and steps S310 to S330, the target duty cycle is adjusted according to the high-side current and the low-side current, so that the coil current meets the relay current requirement, and the normal operation of the relay is ensured.

[0111] The above steps S410 to S430 adjust the duty cycle according to the voltage change and the temperature change, so that the duty cycle changes with the voltage change and the temperature change, and real-time automatic control of the relay is realized.

[0112] Please refer to FIG. 5, in some embodiments, the coil current control method of the relay can further include but is not limited to including steps S510 to S520:

[0113] Step S510, if the current comparison result indicates that the high-side current and the low-side current are not equal, the cumulative number of times that the high-side current and the low-side current are not equal is acquired;

[0114] In step S520, if the accumulated number of times is less than the preset number of times threshold, the high-side current currently output by the high-side drive module is re-acquired, and the low-side current currently output by the low-side driver is re-acquired; and the target duty cycle is adjusted according to the high-side current and the low-side current.

[0115] In step S510 of some embodiments, if the high-side current and the low-side current are not equal, it indicates that the relay module may have a fault, the number of times that the high-side current and the low-side current acquired continuously are not equal is counted to obtain an accumulated number of times, so as to further determine whether the relay module is faulty according to the accumulated number of times.

[0116] In step S520 of some embodiments, if the accumulated number of times is less than the preset number of times threshold, the high-side current currently output by the high-side drive module is re-acquired, and the low-side current currently output by the low-side driver is re-acquired; and the target duty cycle is adjusted according to the high-side current and the low-side current, as described in steps S210 to S260 and steps S310 to S330, steps S510 to S520.

[0117] If the accumulated number of times is greater than or equal to the preset number of times threshold, it is determined that the relay module is in a fault state, and a disconnection instruction is sent to the enable pin of the high-side drive module and the enable pin of the low-side drive module according to the fault state, so that the high-side drive module and the low-side driver are in a disconnected state according to the disconnection instruction. The preset number of times threshold can be set according to actual conditions, for example, 10 times.

[0118] The above steps S510 to S520 can determine whether the relay is faulty through the accumulated number of times that the high-side current and the low-side current are not equal, which can avoid fault misjudgment caused by one-time current detection error, ensure the accuracy of fault detection, and further avoid damage to the relay.

[0119] Referring to FIG. 6, the embodiment of the application further provides a coil current control method based on a relay, and the coil current control method comprises:

[0120] In step S6010, the control module performs an initialization operation.

[0121] In step S6020, the control module determines whether a condition for closing the relay is met; if the determination result is no, step S6030 is performed; if the determination result is yes, step S6040 is performed.

[0122] In step S6030, the control module stores a fault type.

[0123] In step S6040, the control module sends an instruction to close the high-side driver.

[0124] In step S6050, the control module sends an instruction to close the low-side driver for a period of time.

[0125] Step S6060, the control module detects the high-side voltage output by the high-side driver and the relay temperature;

[0126] Step S6070, the control module selects the duty cycle according to the voltage-temperature variation and duty cycle relationship table based on the high-side voltage and the relay temperature, and outputs the PWM signal;

[0127] Step S6080, the control module starts the high-side current detection and the low-side current detection, and obtains the high-side current and the low-side current;

[0128] Step S6090, the control module determines whether the high-side current and the low-side current are consistent; if the determination result is yes, step S6100 is performed; if the determination result is no, step S6160 is performed;

[0129] Step S6100, the control module reads the current relay temperature;

[0130] Step S6110, the control module selects the switching efficiency of the low-side driver according to the relationship table of the temperature and the efficiency;

[0131] Step S6120, the coil current is calculated according to any one of the switching efficiency, the high-side current and the low-side current, and the duty cycle;

[0132] Step S6130, the control module determines whether the coil current meets the relay requirement; if the determination result is yes, step S6140 is performed; if the determination result is no, step S6150 is performed;

[0133] Step S6140, the control module detects whether the high-side voltage output by the high-side driver and the relay temperature change; if the determination result is yes, step S6070 is performed; if the determination result is no, step S6080 is performed;

[0134] Step S6150, the control module corrects the duty cycle;

[0135] Step S6160, the control module determines whether the consecutive high-side current and the low-side current are inconsistent for more than 10 times; if the determination result is yes, step S6170 is performed; if the determination result is no, step S6080 is performed;

[0136] Step S6170, the control module stores the fault type, and sends a command to disconnect the high-side driver and the low-side driver.

[0137] Fig. 7 is a coil current control device based on a relay according to an embodiment of the present application, which is suitable for the coil current control method based on a relay, and the coil current control device includes a relay module 710, a control module 720, a high-side driving module 730, a low-side driving module 740, and a temperature module 750, and the control module 720 is connected to the relay module 710 through the high-side driving module 730, the low-side driving module 740, and the temperature module 750 respectively.

[0138] The high-side driving module 730 includes a high-side driver, a high-side voltage detection unit, and a high-side current detection unit, the high-side driver is connected to the high-side voltage detection unit, the high-side current detection unit, and the first end of the relay module 710 respectively, and the first end is the high potential side of the relay module 710. The high-side voltage detection unit is used for detecting the high-side voltage output by the high-side driver, and the high-side current detection unit is used for detecting the high-side current output by the high-side driver. The control module 720 is connected to the high-side driver, the high-side driver has an enable pin, and the control module 720 is used for sending an enable signal to the enable pin to control the high-side driver to be in an open state or a closed state according to the enable signal. When the enable signal is at a high level, the high-side driver is in the closed state; when the enable signal is at a low level, the high-side driver is in the open state. The high-side driver can be a MOSFET, the source of the MOSFET is connected to the high potential side of the relay module 710, the drain of the MOSFET is connected to the positive pole of a preset power supply, and the gate of the MOSFET is connected to the control module 720, and the high-side driver is used for controlling the current to flow from the preset power supply to the relay module 710.

[0139] The low-side driving module 740 includes a low-side driver, a low-side voltage detection unit and a low-side current detection unit. The low-side driver is connected with the low-side voltage detection unit, the low-side current detection unit and the second end of the relay module 710 respectively. The second end is the low potential side of the relay module 710. The control module 720 is connected with the low-side driver. The low-side driver also has an enable pin. The control module 720 is used to send an enable signal to the enable pin to control the low-side driver to be in an open state or a closed state according to the enable signal. When the enable signal is high, the low-side driver is in the closed state. When the enable signal is low, the low-side driver is in the open state. When the low-side driver is in the closed state, the low-side driver receives the low-side voltage and the low-side current input by the relay module 710. The low-side voltage and the low-side current are the voltage and the current input by the relay module to the low-side driver, i.e. the voltage and the current output by the low-side driver. The low-side voltage detection unit is used to detect the low-side voltage. The low-side current detection unit is used to detect the low-side current. The low-side driver can be a MOSFET. The gate of the MOSFET is connected with the control module 720. The drain of the MOSFET is connected with the low potential side of the relay module 710. The source of the MOSFET is grounded. The low-side driver is used to control the current to flow from the relay module to the ground. The temperature module 750 adopts a temperature sensor to obtain the temperature of the relay module 710. The temperature sensor can be integrated in the relay itself or set independently from the relay. The temperature sensor can be set close to the coil of the relay.

[0140] In the normal driving process of the relay module 710, the high-side driver is in the closed state and the low-side driver is in the PWM switching state. The PWM switching state means that the low-side driver is in the closed and open state according to the period. The control module 720 is used to output a pulse width modulation signal to the low-side driver according to the high-side voltage, the high-side current, the low-side voltage, the low-side current and the temperature. The low-side driver is used to control the coil current of the relay according to the pulse width modulation signal to close or open the relay module based on the coil current to realize the high-voltage power transmission or cut off the power transmission path of the electric vehicle. The coil current is the actual current of the coil of the relay. The control module 720 is provided with an analog-to-digital conversion module to perform analog-to-digital conversion on the high-side voltage, the high-side current, the low-side voltage, the low-side current and the temperature. Multiple analog-to-digital conversion modules can be set in parallel to improve the efficiency of analog-to-digital conversion on multiple signals.

[0141] The high-side drive module and the low-side driver are adopted to control the coil current in two paths, and the current sampling resistor and the operational amplifier are not adopted, so that the resistance value drift of the current sampling resistor caused by long-term current impact is avoided, and the control precision reduction caused by the aging of the operational amplifier is also avoided, and the accuracy and reliability of the coil current control are improved. In addition, the problems of high material cost, long development cycle and large development workload caused by the special chip are solved.

[0142] The coil current control device further comprises a diode, a positive electrode of the diode is connected with the second end of the relay module 710, and a negative electrode of the diode is connected with the first end of the relay module 710. When the pulse width modulation signal is at a low level, the low-side driver is in an open state, and the target current is provided for the relay module 710 through the high-side driver 731 in a closed state and the diode, so that the relay maintains the closed state according to the target current. The target current is the freewheeling current generated when the diode is in a forward bias state.

[0143] Please refer to FIG. 8, which shows the hardware structure of the electronic device of another embodiment, and the electronic device comprises:

[0144] The processor 810 can be implemented in a manner of a general-purpose CPU (Central Processing Unit), a microprocessor, an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits, and is used to execute related programs to implement the technical solutions provided by the embodiments of the present application;

[0145] The memory 820 can be implemented in a form of a ROM (ReadOnly Memory), a static storage device, a dynamic storage device, or a RAM (Random Access Memory). The memory 820 can store an operating system and other application programs. When the technical solutions provided by the embodiments of the present application are implemented by software or firmware, the related program codes are stored in the memory 820 and are called and executed by the processor 810 to implement the coil current control method based on a relay provided by the embodiments of the present application;

[0146] The input / output interface 830 is used to realize information input and output;

[0147] The communication interface 840 is used to realize the communication interaction between the device and other devices, and the communication can be realized in a wired manner (for example, a USB, a network cable, etc.) or in a wireless manner (for example, a mobile network, WIFI, Bluetooth, etc.);

[0148] A bus 850 is used to transmit information between the various components (e.g., the processor 810, the memory 820, the input / output interface 830, and the communication interface 840) in the device.

[0149] The processor 810, the memory 820, the input / output interface 830, and the communication interface 840 are communicatively connected to each other through the bus 850.

[0150] The computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the coil current control method based on a relay.

[0151] The memory is a non-transitory computer readable storage medium, and can be used to store a non-transitory software program and a non-transitory computer executable program. In addition, the memory can include a high-speed random access memory, and can also include a non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state memory device. In some embodiments, the memory can optionally include a memory remotely arranged relative to the processor, and the remote memory can be connected to the processor through a network. Examples of the network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0152] The embodiments described in the embodiments of the present application are used to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that, with the evolution of technology and the appearance of new application scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0153] Those skilled in the art can understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and can include more or fewer steps than those shown in the figures, or combine certain steps, or different steps.

[0154] The device embodiments described above are only schematic, and the units described as separate components can or can not be physically separate, that is, can be located in one place, or can be distributed on multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0155] Those skilled in the art can understand that all or some of the steps in the above disclosed method, the functional modules / units in the system and the device can be implemented as software, firmware, hardware, and appropriate combinations thereof.

[0156] The terms "first", "second", "third", "fourth", and the like in the description of this application and in the claims hereof, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the use of the terms so termed herein is solely for the convenience of the reader and does not limit the scope of the application. It is also to be understood that the description and examples in this application are intended to cover all possible combinations where any of the several elements can represent one or more elements.

[0157] It should be understood that, in the application, "at least one" refers to one or more, and "multiple" refers to two or more. "And / or" is used to describe the relationship between associated objects, which means that there can be three relationships, for example, "A and / or B" can represent three cases: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0158] In several embodiments provided in the application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative, for example, the division of the above-mentioned units is only a logical function division, and actual implementation can have another division manner, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. The coupling or direct coupling or communication connection between the displayed or discussed each other can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0159] The units described above as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on multiple network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment of the application.

[0160] In addition, each function unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software function unit.

[0161] If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in part, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes multiple instructions used to cause a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods in the embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various other media that can store programs.

[0162] The preferred embodiments of the embodiments of the present application are described above with reference to the accompanying drawings, and are not limited to the scope of the embodiments of the present application. Any modifications, equivalent replacements and improvements made by those skilled in the art without departing from the scope and essence of the embodiments of the present application shall be within the scope of the embodiments of the present application.

Claims

1. A method of controlling the current in the coil of a relay, wherein, The coil current control method is applied to a relay-based coil current control device, and the relay-based coil current control device comprises a high-side drive module, a low-side drive module and a relay module. The high-side drive module and the low-side drive module are controlled to be closed to drive the relay module; After a preset time period, a voltage output by the high-side drive module is obtained to obtain a first high-side voltage, and a temperature of the relay module is obtained to obtain a first temperature; A first mapping relationship table is queried according to the first high-side voltage and the first temperature to obtain a target duty cycle, and the first mapping relationship table is used to represent a mapping relationship among the voltage of the high-side drive module, the temperature of the relay module and the duty cycle; A pulse width modulation signal is output according to the target duty cycle, and the coil current of the relay module is controlled according to the pulse width modulation signal.

2. The relay-based coil current control method of claim 1, wherein, The coil current control method further comprises: A current output by the high-side drive module is obtained to obtain a high-side current, and a current output by the low-side drive module is obtained to obtain a low-side current; The high-side current and the low-side current are compared to obtain a current comparison result, and the current comparison result is used to represent a current size relationship between the high-side current and the low-side current; If the current comparison result represents that the high-side current and the low-side current are equal, a current temperature of the relay module is obtained to obtain a second temperature; A second mapping relationship table is queried according to the second temperature to obtain a switching efficiency of the low-side drive module, and the second mapping relationship table is used to represent a mapping relationship between the temperature of the relay module and the switching efficiency of the low-side drive module; Any one of the high-side current and the low-side current is taken as a reference current; The current output by the relay module is calculated according to the reference current and the switching efficiency to obtain a candidate current.

3. The relay-based coil current control method of claim 2, wherein, The coil current control method further comprises: A standard current specification of the relay module is obtained; If the candidate current meets the standard current specification, a current voltage output by the high-side drive module is obtained to obtain a second high-side voltage, and a current temperature output by the relay module is obtained to obtain a third temperature; the target duty cycle is adjusted according to the first high-side voltage, the second high-side voltage, the second temperature and the third temperature; If the candidate current does not meet the standard current specification, the high-side current output by the high-side drive module is re-obtained, and the low-side current output by the low-side drive module is re-obtained; the target duty cycle is adjusted according to the high-side current and the low-side current.

4. The relay-based coil current control method of claim 3, wherein, The target duty cycle is adjusted according to the first high-side voltage, the second high-side voltage, the second temperature and the third temperature, which comprises: The first high-side voltage, the second high-side voltage, the second temperature and the third temperature are compared. If the first high-side voltage and the second high-side voltage are not equal, and / or the second temperature and the third temperature are not equal, the first mapping relationship table is queried according to the second high-side voltage and the third temperature, and a new duty cycle is obtained; the new duty cycle is taken as the target duty cycle; If the first high-side voltage and the second high-side voltage are equal, and the second temperature and the third temperature are equal, the high-side current currently output by the high-side drive module is re-acquired, and the low-side current currently output by the low-side drive module is re-acquired; the target duty cycle is adjusted according to the high-side current and the low-side current.

5. The relay-based coil current control method of claim 2, wherein, The coil current control method further comprises: If the current ratio result represents that the high-side current and the low-side current are not equal, the cumulative number of times that the high-side current and the low-side current are not equal is acquired; If the cumulative number of times is less than a preset number threshold, the high-side current currently output by the high-side drive module is re-acquired, and the low-side current currently output by the low-side drive module is re-acquired; the target duty cycle is adjusted according to the high-side current and the low-side current.

6. The relay-based coil current control method of claim 1, wherein, The coil current control method further comprises: determining whether a condition for closing the relay is met; If the determination result is no, a fault type is stored, and a pre-warning information is generated according to the fault type; If the determination result is yes, the step of controlling the high-side drive module and the low-side drive module to be closed is performed.

7. The relay-based coil current control method of claim 1, wherein, The acquiring of the temperature of the relay module to obtain a first temperature comprises: acquiring the voltage across the coil when the relay module is closed; querying the voltage-temperature relationship according to the voltage across the coil to acquire the current temperature of the relay module, and obtaining the first temperature.

8. The relay-based coil current control method of claim 7, wherein, The coil current control method further comprises: obtaining the relationship between the duty cycle, the voltage output by the high-side drive module, and the temperature across the coil when the relay module is closed according to the voltage-temperature relationship and a duty cycle calculation formula; taking the relationship between the duty cycle, the voltage output by the high-side drive module, and the temperature as a first mapping relationship table.

9. The relay-based coil current control method of claim 2, wherein, The acquiring of the current temperature of the relay module to obtain a second temperature comprises: acquiring the current voltage across the coil of the relay module; querying the voltage-temperature relationship according to the current voltage to acquire the current temperature of the relay module, and obtaining the second temperature.

10. A relay-based coil current control apparatus adapted to the relay-based coil current control method of any one of claims 1 to 5, wherein The coil current control device comprises: a relay module, a control module, a high-side drive module, a low-side drive module, and a temperature module, wherein the control module is connected with the relay module through the high-side drive module, the low-side drive module, and the temperature module.

11. The relay-based coil current control apparatus of claim 10, wherein, The high-side drive module comprises a high-side driver, a high-side voltage detection unit, and a high-side current detection unit, wherein the high-side driver is connected with the high-side voltage detection unit, the high-side current detection unit, and a first end of the relay module; the control module is connected with the high-side driver.

12. The relay-based coil current control apparatus of claim 11, wherein, The first end of the relay module is the high-potential side of the relay module.

13. The relay-based coil current control apparatus of claim 10, wherein, The low-side driving module comprises a low-side driver, a low-side voltage detection unit and a low-side current detection unit, the low-side driver is connected with the low-side voltage detection unit, the low-side current detection unit and the second end of the relay module respectively; the control module is connected with the low-side driver.

14. The relay-based coil current control apparatus of claim 13, wherein, The second end of the relay module is a low potential side of the relay module.

15. The relay-based coil current control apparatus of claim 10, wherein, The coil current control device further comprises a diode, the positive electrode of the diode is connected with the second end of the relay module, and the negative electrode of the diode is connected with the first end of the relay module.

16. An electronic device, comprising: The electronic device comprises a memory and a processor, the memory stores a computer program, and the processor implements the relay-based coil current control method in any one of claims 1 to 9 when executing the computer program.

17. A computer-readable storage medium storing a computer program, wherein, The computer program is executed by the processor to implement the relay-based coil current control method in any one of claims 1 to 9.

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