Temperature sampling circuit and temperature detection method

Abstract

The invention provides a temperature sampling circuit and a temperature detection method, and the temperature sampling circuit is used in an energy storage converter. The adjustable reference resistance module is connected with the thermistor, the adjustable reference resistance module has a plurality of reference resistance values of different gears, and the reference resistance values of different gears have different sampling voltage preset intervals; the sampling circuit is connected to the thermistor so as to obtain a sampling voltage value; the control circuit is connected with the output end of the sampling circuit to receive the sampling voltage value, is also connected with the adjustable reference resistance module and is used for determining the resistance value of the thermistor when the sampling voltage value meets the sampling voltage preset interval of the reference resistance value of the current gear; and when the sampling voltage value does not meet the sampling voltage preset interval of the reference resistance value of the current gear, the reference resistance value of another gear is replaced, so that the re-obtained sampling voltage value meets the sampling voltage preset interval of the reference resistance value of a new gear, and the temperature sampling precision in the full temperature range is improved.

Description

Technical Field

[0001] The present application relates to the field of energy storage, and in particular to a temperature sampling circuit and a temperature detection method. Background Art

[0002] The power conversion system (PCS) generates a lot of heat during operation, and temperature detection is required to ensure its safety. Temperature detection can not only help monitor the health of the equipment, but also detect potential faults in time and prevent damage caused by overheating. At present, the temperature detection method of the power storage converter usually uses thermistors for temperature detection, and the ambient temperature is obtained by looking up the table based on the resistance value of the thermistor.

[0003] The resistance value of a thermistor is generally detected by resistor voltage division. However, in the resistor voltage division method, the errors of the reference source, the reference resistor and the thermistor itself will affect the sampling accuracy, resulting in inaccurate temperature detection results. Summary of the invention

[0004] In view of this, the present application provides a temperature sampling circuit and a temperature detection method to help solve the problem of insufficient accuracy of temperature detection results in the prior art.

[0005] In a first aspect, an embodiment of the present application provides a temperature sampling circuit for use in an energy storage converter, wherein the temperature sampling circuit comprises: A thermistor having a first end and a second end, wherein the first end is used to connect to a power supply voltage and the second end is used to be grounded; an adjustable reference resistance module, wherein at least one of the first end and the second end is connected to the adjustable reference resistance module, wherein the adjustable reference resistance module has a plurality of reference resistance values ​​of different gears, and the reference resistance values ​​of different gears have different preset sampling voltage intervals; a sampling circuit having a sampling end and a sampling circuit output end, wherein the sampling end is connected to at least one of the first end and the second end to obtain a sampling voltage value; a control circuit having a control circuit input end and a control circuit output end, wherein the The input end of the control circuit is connected to the output end of the sampling circuit to receive the sampled voltage value, and the output end of the control circuit is connected to the adjustable reference resistance module; the control circuit is used to determine the resistance value of the thermistor according to the sampled voltage value when the sampled voltage value meets the sampled voltage preset interval of the reference resistance value of the current gear; and is also used to replace the reference resistance value of another gear when the sampled voltage value does not meet the sampled voltage preset interval of the reference resistance value of the current gear, so that the re-obtained sampled voltage value meets the sampled voltage preset interval of the reference resistance value of the changed gear.

[0006] In one possible implementation, the adjustable reference resistor module includes a gear controller and a plurality of reference resistors with different resistance values, the gear controller being connected to at least one of the first end and the second end; the gear controller is also connected to the output end of the control circuit, and the output end of the control circuit is used to send a control signal to the gear controller to control the reference resistor with the corresponding resistance value to be connected in series with the thermistor.

[0007] In a possible implementation, the sampling circuit includes an ADC module, the ADC module has an ADC module input end and an ADC module output end, the sampling end is the ADC module input end, and the sampling circuit output end is the ADC module output end.

[0008] In a possible implementation, the temperature sampling circuit includes an adjustable reference resistor module; when the adjustable reference resistor module is connected to the first end, the sampling end is connected to the first end; or, when the adjustable reference resistor module is connected to the second end, the sampling end is connected to the second end.

[0009] In a possible implementation, the temperature sampling circuit includes two adjustable reference resistance modules, one of which is connected to the first end, and the other is connected to the second end; the sampling end is connected to at least one of the first end and the second end.

[0010] In a possible implementation, the adjustable reference resistance module includes a first adjustable reference resistance module and a second adjustable reference resistance module, one of the first adjustable reference resistance module and the second adjustable reference resistance module is connected to the first end, and the other is connected to the second end; the first adjustable reference resistance module and the second adjustable reference resistance module are respectively connected to the output end of the control circuit, so that the output end of the control circuit can send control signals to the first adjustable reference resistance module and the second adjustable reference resistance module respectively; the first adjustable reference resistance module includes N first sub-reference resistors with different resistance values, N≥2, and N is an integer; the second adjustable reference resistance module includes M second sub-reference resistors with different resistance values, M≥2, and M is an integer.

[0011] In a second aspect, an embodiment of the present application provides a temperature detection method, which uses a temperature sampling circuit to detect the temperature in an energy storage converter, wherein the temperature sampling circuit includes a thermistor, an adjustable reference resistance module, a sampling circuit, and a control circuit, wherein the adjustable reference resistance module has a plurality of reference resistance values ​​of different gears, and the reference resistance values ​​of different gears have different sampling voltage preset intervals; the temperature detection method includes: selecting a gear of a reference resistance value; obtaining a sampling voltage value of a sampling point at a current gear through the sampling circuit; transmitting the sampling voltage value to the control circuit; the control circuit judges the sampling voltage value: if the sampling voltage value satisfies the sampling voltage preset interval of the reference resistance value of the current gear, then determining the resistance value of the thermistor according to the sampling voltage value, and obtaining the current temperature value of the environment according to the resistance value of the thermistor; if the sampling voltage value does not satisfy the sampling voltage preset interval of the reference resistance value of the current gear, then replacing the reference resistance value of another gear, obtaining the sampling voltage value of the sampling point after the gear is changed, and continuing to judge the re-acquired sampling voltage value.

[0012] In a possible implementation, when the reference resistance value is changed to another gear, the temperature detection method specifically includes: if the sampling voltage value is greater than the upper limit of the sampling voltage preset interval of the reference resistance value of the current gear, then changing to a gear with a larger reference resistance value; if the sampling voltage value is less than the lower limit of the sampling voltage preset interval of the reference resistance value of the current gear, then changing to a gear with a smaller reference resistance value.

[0013] In a possible implementation, when the resistance of the thermistor is determined according to the sampled voltage value, and the current temperature value of the environment is obtained according to the resistance of the thermistor, the temperature detection method specifically includes: the control circuit calculates the resistance of the thermistor according to the sampled voltage value; the control circuit calls the corresponding thermistor resistance-temperature comparison table, and obtains the current temperature value of the environment by looking up the table according to the resistance of the thermistor.

[0014] In a possible implementation, before selecting the gear of the reference resistance value, the temperature detection method further includes: determining the number of gears of the adjustable reference resistance module and the reference resistance value corresponding to each gear according to the range of the ambient temperature to be measured; formulating a thermistor resistance-temperature comparison table corresponding to different gears according to the temperature characteristics of the thermistor; selecting sampling points, and setting the preset sampling voltage interval corresponding to the reference resistance value of each gear according to the actual circuit parameters of the sampling points.

[0015] The temperature sampling circuit provided in the embodiment of the present application can realize the dynamic adjustment of the reference resistance value in the temperature sampling circuit by setting an adjustable reference resistance module with multiple gear reference resistance values, and using a control circuit to realize the gear adjustment of the adjustable reference resistance module, so as to dynamically adjust the reference resistance value in the temperature sampling circuit according to the resistance range of the thermistor, so that the thermistor can have a reference resistance value adapted thereto when it is at different ambient temperatures. That is, the temperature sampling circuit provided in the present application can realize the accurate matching of the reference resistance value and the thermistor within the full temperature range, so as to reduce the influence of the reference power supply, the reference resistance value and the thermistor's own errors on the sampling accuracy, thereby improving the sampling accuracy within the full temperature range and ensuring the accuracy of the ambient temperature result finally obtained. Moreover, the temperature sampling circuit provided in the embodiment of the present application does not need to use an additional high-precision reference source or precision resistor, which effectively controls the hardware cost of the temperature sampling circuit.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 is a circuit structure diagram of a temperature sampling circuit in the related art; Figure 2 for Figure 1 The resistance value-temperature comparison table corresponding to NTC in; Figure 3 A circuit structure diagram of the temperature sampling circuit provided by the present application in a first embodiment; Figure 4 A circuit structure diagram of the temperature sampling circuit provided in the present application in a second embodiment; Figure 5 A circuit structure diagram of the temperature sampling circuit provided by the present application in a third embodiment; Figure 6 This is a flow chart of the temperature detection method provided in this application.

[0019] Reference numerals: 10-NTC; 20- a first reference resistor; 30- a second reference resistor; 40-voltage-dividing sampling circuit; 1- Thermistor; 11- first end; 12- second end; 2-Adjustable reference resistance module; 2a-first adjustable reference resistance module; 21a- first gear controller; 22a-first sub-reference resistor; 22a1-first sub-reference resistor of first gear; 22a2 - first sub-reference resistor of the second gear; 22aN-the first sub-reference resistor of the Nth gear; 2b-second adjustable reference resistance module; 21b- second gear controller; 22b- a second sub-reference resistor; 22b1-second sub-reference resistor of the first gear; 22b2-second sub-reference resistor for the second gear; 22b3-second sub-reference resistor of the third gear; 22bM-the second sub-reference resistor of the Mth gear; 21- gear controller; 22-reference resistor; 221- first gear reference resistance; 222-second gear reference resistance; 223-third gear reference resistance; 224- fourth gear reference resistor; 3- Sampling circuit; 4- Control circuit. DETAILED DESCRIPTION

[0020] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0021] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0022] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0023] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0024] The energy storage converter is a bidirectional current controllable conversion device that connects the energy storage battery system and the power grid. It can accurately and quickly adjust the voltage, frequency, and power between the power grid and the energy storage system to achieve constant power and constant current charging and discharging as well as smooth fluctuating power output. The electronic components in the energy storage converter are very sensitive to temperature. Excessive temperature will cause the performance of these components to degrade or even be permanently damaged. Therefore, it is necessary to set up a temperature sampling circuit to monitor the ambient temperature in the energy storage converter in real time so that timely measures (such as increasing cooling, reducing load, etc.) can be taken to avoid overheating, thereby extending the service life of the electronic components and the entire energy storage system.

[0025] Figure 1 is a circuit structure diagram of a temperature sampling circuit in the related art, such as Figure 1 As shown, the temperature sampling circuit includes NTC (negative temperature coefficient thermistor), a first reference resistor 20, a second reference resistor 30 and a voltage-dividing sampling circuit. The first reference resistor 20 and the second reference resistor 30 are respectively connected in series at both ends of the NTC. The first reference resistor 20 and the second reference resistor 30 are both fixed resistance resistors. The resistance of the first reference resistor 20 and the second reference resistor 30 matches the resistance of the NTC at room temperature. The voltage-dividing sampling circuit can take a point collection circuit voltage at the upper end or the lower end of the NTC. The collected voltage division is calculated by the voltage division ratio to obtain the real-time resistance value of the thermistor, and then the ambient temperature at this time can be obtained by looking up the resistance-temperature comparison table (RT table) of the NTC.

[0026] Figure 2 is a resistance-temperature comparison table of NTC in a specific embodiment, the horizontal axis is the ambient temperature, the vertical axis is the resistance of NTC, Figure 2 It can be seen that the resistance of NTC at 25°C is 5kΩ. Taking the resistance of the first reference resistor 20 and the second reference resistor 30 as 5kΩ and the reference source (VREF) as 12V as an example: Formula (1) When the ambient temperature is low, such as -30°C or -35°C, the resistance of the NTC is 60.94 kΩ and 80.39 kΩ respectively. Without considering the error, according to the above formula (1), the sampling circuit voltage division is approximately 11.15 V and 11.34 V respectively, that is, the theoretical sampling circuit voltage division difference corresponding to a 5°C temperature difference is approximately 0.19 V.

[0027] When the ambient temperature is high, such as 80°C and 85°C, the resistance of the NTC is 832Ω and 725Ω respectively. Without considering the error, according to the above formula (1), the sampling circuit voltage division is approximately 6.461V and 6.406V respectively, that is, the theoretical sampling circuit voltage division difference corresponding to a 5°C temperature difference is approximately 0.055V.

[0028] Therefore, it can be known that when the ambient temperature is low, the resistance value of NTC is much larger than that of the reference resistor. At this time, the error of NTC itself will have a great impact on the sampling accuracy, resulting in inaccurate temperature detection results; when the ambient temperature is high, the resistance value of NTC is much smaller than that of the reference resistor, and the difference in the voltage division of the theoretical sampling circuit at different temperatures is very small. At this time, the error of the reference source and the reference resistor will have a great impact on the sampling accuracy, resulting in inaccurate temperature detection results. Moreover, the larger the resistance value of the reference resistor, the more obvious the impact on the sampling accuracy at high temperatures. In other words, the reference resistor cannot guarantee the sampling accuracy within the full temperature range of the thermistor, but can only guarantee the sampling accuracy within a specific temperature range.

[0029] In order to solve the above problems, the embodiment of the present application provides a temperature sampling circuit, which can be used to detect the ambient temperature in the energy storage converter, such as Figure 3 As shown, the temperature sampling circuit includes a thermistor 1, an adjustable reference resistance module 2, a sampling circuit 3 and a control circuit 4. The thermistor 1 is a negative temperature coefficient thermistor, and its resistance value decreases as the temperature increases. The thermistor 1 has a first end 11 and a second end 12, the first end 11 is used to connect the power supply voltage, and the second end 12 is used to ground, and at least one of the first end 11 and the second end 12 is connected to the adjustable reference resistance module 2. The adjustable reference resistance module 2 has a plurality of reference resistance values ​​of different gears, and the reference resistance values ​​of different gears have different preset sampling voltage intervals. The sampling circuit 3 has a sampling end and a sampling circuit output end, and the sampling end is connected to at least one of the first end 11 and the second end 12 to obtain a sampling voltage value, and the sampling voltage value is the divided voltage of the sampling point. The control circuit 4 has a control circuit input end and a control circuit output end, and the control circuit input end is connected to the sampling circuit output end to receive the sampling voltage value, and the control circuit output end is connected to the adjustable reference resistance module 2, and is used to send a control signal to the adjustable reference resistance module 2. The control circuit 4 is used to determine the resistance value of the thermistor 1 according to the sampled voltage value when the sampled voltage value meets the sampled voltage preset interval of the reference resistance value of the current gear; and is also used to replace the reference resistance value of another gear when the sampled voltage value does not meet the sampled voltage preset interval of the reference resistance value of the current gear, so that the re-obtained sampled voltage value meets the sampled voltage preset interval of the reference resistance value of the changed gear.

[0030] In this embodiment, the reference resistance value of each gear has a corresponding temperature range, and the reference resistance value of the gear has the smallest effect on the accuracy of the sampled voltage value within the corresponding temperature range. When the power supply voltage (reference source, VREF) is determined, the corresponding range of the sampled voltage values ​​can be obtained according to the reference resistance value of the gear and the resistance range of thermistor 1 within the temperature range. The obtained range of the sampled voltage values ​​is the preset interval of the sampled voltage corresponding to the reference resistance value of the gear.

[0031] The specific working process of the temperature sampling circuit is as follows: first set the adjustable reference resistance module 2 to a certain gear, that is, first select the reference resistance value, then obtain the sampling voltage value under the current gear through the sampling end of the sampling circuit 3, and transmit the data of the sampling voltage value to the input end of the control circuit through the output end of the sampling circuit. After receiving the sampling voltage value, the control circuit 4 can judge the sampling voltage value. If the sampling voltage value meets the sampling voltage preset interval of the reference resistance value of the current gear, it means that the reference resistance value of the current gear is adapted to the current temperature range of the thermistor 1. The control circuit 4 can obtain the current resistance value of the thermistor 1 according to the sampling voltage value, and query the resistance-temperature comparison table of the thermistor 1 according to the obtained resistance value of the thermistor 1, so as to obtain the current ambient temperature.

[0032] If the sampled voltage value does not meet the preset sampling voltage interval of the reference resistance value of the current gear, it means that the reference resistance value of the current gear is not suitable for the temperature range where the thermistor 1 is currently located. The control circuit output end of the control circuit 4 can send a signal to the adjustable reference resistance module 2 to control the adjustable reference resistance module 2 to change to the reference resistance value of another gear. The sampling end of the sampling circuit 3 obtains a new sampled voltage value under the new gear, and transmits the data of the new sampled voltage value to the control circuit input end through the sampling circuit output end. After receiving the new sampled voltage value, the control circuit 4 judges the new sampled voltage value. If the new sampled voltage value meets the preset sampling voltage interval of the reference resistance value of the new gear, it means that the reference resistance value of the new gear is suitable for the temperature range where the thermistor 1 is currently located. The control circuit 4 can obtain the current resistance value of the thermistor 1 according to the new sampled voltage value, and query the resistance-temperature comparison table of the thermistor 1 according to the obtained resistance value of the thermistor 1, so as to obtain the current ambient temperature. If the new sampled voltage value still does not meet the preset sampling voltage interval of the reference resistance value of the new gear, repeat the above steps: control the adjustable reference resistance module 2 to continue to replace the reference resistance value of another gear, obtain the sampled voltage value again by the sampling circuit 3, and judge the new sampled voltage value by the control circuit 4 until the new sampled voltage value meets the preset sampling voltage interval of the reference resistance value of the new gear.

[0033] The temperature sampling circuit provided in the present application can realize dynamic adjustment of the reference resistance value in the temperature sampling circuit by setting an adjustable reference resistance module 2 with multiple gear reference resistance values, and using the control circuit 4 to realize the gear adjustment of the adjustable reference resistance module 2, so as to dynamically adjust the reference resistance value in the temperature sampling circuit according to the resistance range of the thermistor 1, so that the thermistor 1 can have a reference resistance value adapted to it when it is in different ambient temperatures. That is, the temperature sampling circuit provided in the present application can realize accurate matching of the reference resistance value with the thermistor 1 in the full temperature range, so as to reduce the influence of the reference power supply, the reference resistance value and the thermistor 1's own errors on the sampling accuracy, thereby improving the sampling accuracy in the full temperature range and ensuring the accuracy of the ambient temperature result finally obtained. Moreover, the temperature sampling circuit provided in the present application does not need to use an additional high-precision reference source or precision resistor, which effectively controls the hardware cost of the temperature sampling circuit.

[0034] Among them, the matching standard of the reference resistance value and the temperature range should meet the following requirements: a smaller reference resistance value corresponds to a higher temperature range, so as to reduce the influence of the error of the reference source and the reference resistance value on the sampling accuracy when the ambient temperature is high; a larger reference resistance value corresponds to a lower temperature range, so as to reduce the influence of the error of thermistor 1 itself on the sampling accuracy when the ambient temperature is low, thereby ensuring the accuracy of the temperature detection results of the temperature sampling circuit within the full temperature range.

[0035] In a specific implementation, the sampling circuit 3 includes an ADC (Analog-to-Digital Converter) module, the ADC module has an ADC module input end and an ADC module output end, the ADC module input end is the sampling end, and the ADC module output end is the sampling circuit output end. The ADC module can convert the continuously changing analog signal (sampling voltage value) collected by the ADC input end into a discrete digital signal, and output the digital signal to the control current input end through the ADC output end. The sampling circuit 3 may also include an operational amplifier or other processing module for signal processing of the sampling voltage value, which is not limited in this embodiment. The control circuit 4 may use a DSP (Digital Signal Processor) chip to implement functions such as data analysis, data storage and circuit control, or may use other chips with data analysis and circuit control functions, which is not limited in this embodiment.

[0036] In a specific embodiment, Figure 3As shown, the adjustable reference resistor module 2 includes a gear controller 21 and a plurality of reference resistors 22 with different resistance values, each reference resistor 22 corresponds to a gear, and the gear controller 21 is connected to at least one of the first end 11 and the second end 12. The gear controller 21 is also connected to the output end of the control circuit, and the output end of the control circuit is used to send a control signal to the gear controller 21 to control the reference resistor 22 of the corresponding resistance value to be connected in series with the thermistor 1. Therefore, when it is necessary to change the reference resistor value of another gear, it is only necessary to control the reference resistor 22 of another resistance value to be connected in series with the thermistor 1 through the control circuit 4.

[0037] Among them, the gear controller 21 can be specifically a single-pole multi-throw switch, the fixed end of the single-pole multi-throw switch is connected to the thermistor 1, and the multiple mobile ends are respectively used to connect to multiple reference resistors 22. In addition, the single-pole multi-throw switch can also be connected to the output end of the control circuit to receive the control signal sent by the output end of the control circuit, and realize the conduction between the fixed end and the corresponding mobile end according to the control signal, so as to realize the series connection of the corresponding reference resistor 22 and the thermistor 1. At this time, the remaining mobile ends are disconnected from the fixed ends. When it is necessary to change the reference resistance value of another gear, it is only necessary to control the mobile end corresponding to the reference resistor 22 of the current gear to be disconnected from the fixed end through the control circuit 4, and control the mobile end corresponding to the reference resistor 22 of the required gear to be connected to the fixed end.

[0038] Alternatively, the gear controller 21 may be composed of a plurality of MOS tubes, the drains of the plurality of MOS tubes are respectively connected to the thermistor 1, the sources of the plurality of MOS tubes are respectively corresponding to a plurality of reference resistors 22 with different resistance values, and the gates of the plurality of MOS tubes are respectively connected to the output end of the control circuit. The output end of the control circuit is used to send control signals to the plurality of MOS tubes respectively, control the MOS tube corresponding to the reference resistor 22 of the required gear to be turned on with the reference resistor 22 of the required gear, and control the MOS tube corresponding to the reference resistor 22 of the remaining gears to be disconnected from the reference resistor 22 of the remaining gears, thereby realizing the series connection of the corresponding reference resistor 22 with the thermistor 1. When the reference resistor value of another gear needs to be changed, it is only necessary to control the MOS tube corresponding to the reference resistor 22 of the current gear to be disconnected with the reference resistor 22 of the current gear through the control circuit 4, and control the MOS tube corresponding to the reference resistor 22 of the required gear to be turned on with the reference resistor 22 of the required gear.

[0039] Therefore, the structure and control method of the adjustable reference resistance module 2 provided in the embodiment of the present application are relatively simple, which is conducive to further reducing the hardware cost of the temperature sampling circuit.

[0040] In a specific implementation, the temperature sampling circuit may include only one adjustable reference resistor module 2, and the adjustable reference resistor module 2 includes at least two reference resistors 22 with different resistance values. When the adjustable reference resistor module 2 is connected to the first end 11, the sampling end should be connected to the first end 11. When the adjustable reference resistor module 2 is connected to the second end 12, the sampling end should be connected to the second end 12.

[0041] like Figure 4 As shown, the following takes the adjustable reference resistor module 2 connected to the second end 12, and the adjustable reference resistor module 2 includes 4 reference resistors 22 with different resistance values ​​as an example, and the specific working process of the temperature sampling circuit is described in detail. Specifically, the 4 reference resistors 22 with different resistance values ​​are respectively a first-level reference resistor 221, a second-level reference resistor 222, a third-level reference resistor 223 and a fourth-level reference resistor 224. The first-level reference resistor 221 has a corresponding first sampling voltage preset interval {VT1}, the second-level reference resistor 222 has a corresponding second sampling voltage preset interval {VT2}, the third-level reference resistor 223 has a corresponding third sampling voltage preset interval {VT3}, and the fourth-level reference resistor 224 has a corresponding fourth sampling voltage preset interval {VT4}. The sampling voltage value satisfies the following formula: Formula (2) Wherein, VREF is the power supply voltage value; R is the resistance value of the reference resistor 22; and NTC is the resistance value of the thermistor 1.

[0042] During sampling, the adjustable reference resistor module 2 is first set to a certain gear, for example, to the first gear. At this time, the resistance R of the reference resistor 22 is the resistance of the first gear reference resistor 221. Then, the sampling voltage value under the first gear is obtained by the sampling end, and the control circuit 4 judges the sampling voltage value. If the sampling voltage value falls within the first sampling voltage preset interval {VT1}, the control circuit 4 can substitute the sampling voltage value and the resistance value of the first gear reference resistor 221 into the above formula (2) to obtain the current resistance value of the thermistor 1, and query the resistance value-temperature comparison table of the thermistor 1 according to the obtained resistance value of the thermistor 1, so as to obtain the current ambient temperature.

[0043] If the sampled voltage value does not fall within the first sampled voltage preset interval {VT1}, the control circuit 4 controls the gear controller 21 to replace the reference resistor 22 of another gear, for example, to replace it with the second gear reference resistor 222. At this time, the resistance R of the reference resistor 22 is the resistance value of the second gear reference resistor 222. Then, the sampling end obtains the sampled voltage value under the second gear, and the control circuit 4 judges the sampled voltage value. If the sampled voltage value falls within the second sampled voltage preset interval {VT2}, the control circuit 4 can substitute the sampled voltage value and the resistance value of the second gear reference resistor 222 into the above formula (2) to obtain the current resistance value of the thermistor 1, and query the resistance value-temperature comparison table of the thermistor 1 according to the obtained resistance value of the thermistor 1, so as to obtain the current ambient temperature.

[0044] If the sampled voltage value does not fall within the second sampled voltage preset interval {VT2}, the control circuit 4 controls the gear controller 21 to replace the reference resistor 22 of another gear, for example, replace it to the third gear reference resistor 223, and repeat the above sampling and analysis steps, which will not be repeated here.

[0045] It should be noted that the resistance values ​​of the first-level reference resistor 221 , the second-level reference resistor 222 , the third-level reference resistor 223 and the fourth-level reference resistor 224 may be successively increasing or decreasing, and this embodiment does not impose any limitation on this.

[0046] In another specific embodiment, Figure 3 As shown, the temperature sampling circuit may include two adjustable reference resistor modules 2, one of the two adjustable reference resistor modules 2 is connected to the first end 11, the other is connected to the second end 12, and the sampling end is connected to at least one of the first end 11 and the second end 12. When the sampling end is only connected to the first end 11, the sampling voltage value is the voltage division value of the thermistor 1 and the second adjustable reference resistor module 2; when the sampling end is only connected to the second end 12, the sampling voltage value is the voltage division value of the second adjustable reference resistor module 2; when the sampling end is connected to the first end 11 and the second end 12 at the same time, the voltage division value of the thermistor 1 can be obtained by differential sampling. This embodiment does not limit the specific connection position of the sampling end, and the above three connection methods are all applicable. However, among the three methods, only the differential sampling method can be applied to the case where the reference ground of the adjustable reference resistor module 2 is different from the reference ground of the sampling circuit 3.

[0047] Specifically, Figure 5As shown, the two adjustable reference resistance modules 2 are respectively a first adjustable reference resistance module 2a and a second adjustable reference resistance module 2b. The first adjustable reference resistance module 2a includes a first gear controller 21a and N first sub-reference resistors 22a with different resistance values, N≥2, and N is an integer. The second adjustable reference resistance module 2b includes a second gear controller 21b and M second sub-reference resistors 22b with different resistance values, M≥2, and M is an integer. N and M may be equal or unequal.

[0048] Among them, the first gear controller 21a and the second gear controller 21b are respectively used to connect with the output end of the control circuit, so that the output end of the control circuit can send control signals to the first adjustable reference resistance module 2a and the second adjustable reference resistance module 2b respectively, so as to realize the independent control of the first adjustable reference resistance module 2a and the second adjustable reference resistance module 2b. In this case, when the first adjustable reference resistance module 2a includes N first sub-reference resistors 22a with different resistance values ​​and the second adjustable reference resistance module 2b includes M second sub-reference resistors 22b with different resistance values, different first sub-reference resistors 22a and different second sub-reference resistors 22b can be connected in series with the thermistor 1 at the same time, so that the reference resistance value in the temperature sampling circuit has a variety of combinations, that is, the number of gears in the temperature sampling circuit can be increased, and each gear can correspond to a more accurate temperature range, which is conducive to improving the accuracy of the temperature detection result.

[0049] like Figure 5 As shown, the N first sub-reference resistors 22a with different resistance values ​​are respectively the first-gear first sub-reference resistor 22a1, the second-gear first sub-reference resistor 22a2... and the N-th-gear first sub-reference resistor 22aN, and the M second sub-reference resistors 22b with different resistance values ​​are respectively the first-gear second sub-reference resistor 22b1, the second-gear second sub-reference resistor 22b2, the third-gear second sub-reference resistor 22b3... and the M-th-gear second sub-reference resistor 22bM. Accordingly, the reference resistance values ​​in the temperature sampling circuit can have M·N combinations.

[0050] In a specific implementation, the first adjustable reference resistor module 2a can be set as a coarse adjustment module, that is, the resistance difference between N different first sub-reference resistors 22a is set to be larger, and the second adjustable reference resistor module 2b can be set as a fine adjustment module, that is, the resistance difference between M different second sub-reference resistors 22b is set to be smaller. In this embodiment, the resistance of any first sub-reference resistor 22a can be set to be greater than the resistance of any second sub-reference resistor 22b, so that when sampling, if the difference between the sampled voltage value and the preset interval of the sampled voltage of the current gear is too large, the first adjustable reference resistor module 2a is adjusted, and the first sub-reference resistor 22a of the different gear is replaced; if the difference between the sampled voltage value and the preset interval of the sampled voltage of the current gear is small, the second adjustable reference resistor module 2b is adjusted, and the second sub-reference resistor 22b of the different gear is replaced, thereby realizing flexible adjustment of the reference resistance value.

[0051] The embodiment of the present application also provides a temperature detection method, which uses the temperature sampling circuit described in any of the above embodiments to detect the temperature in the energy storage converter. The temperature sampling circuit may include an adjustable reference resistor module, or may include two adjustable reference resistor modules 2. When the temperature sampling circuit includes two adjustable reference resistor modules 2, the sampling end may be connected to the first end 11 of the thermistor 1, or to the second end 12 of the thermistor 1, or may be connected to the first end 11 and the second end 12 at the same time.

[0052] like Figure 6 As shown, the temperature detection method specifically includes: Step S1: Select a reference resistance value.

[0053] In this step, a reference resistance value of any gear can be selected as the default gear according to the predicted temperature, that is, any reference resistor 22 can be selected to be connected in series with the thermistor 1.

[0054] Step S2: obtaining a sampled voltage value of the sampling point at the current gear position through the sampling circuit 3.

[0055] Step S3: transmitting the sampled voltage value to the control circuit 4 .

[0056] In the above steps S2 and S3, the sampling end of the sampling circuit 3 obtains the sampled voltage value under the default gear, and transmits the data of the sampled voltage value to the control circuit input end of the control circuit 4 through the sampling circuit output end, so that the control circuit 4 performs data processing on the sampled voltage value.

[0057] Step S4: the control circuit 4 determines the sampled voltage value: determines whether the sampled voltage value satisfies the preset sampling voltage interval of the reference resistance value of the current gear.

[0058] In this step, the control circuit 4 is used to analyze the received sampled voltage value to determine whether the current sampled voltage value falls within the preset sampled voltage interval corresponding to the reference resistor 22 of the current gear.

[0059] If the sampled voltage value satisfies the preset sampling voltage interval of the reference resistance value of the current gear, proceed to step S5: determine the resistance value of thermistor 1 according to the sampled voltage value, and obtain the current temperature value of the environment according to the resistance value of thermistor 1.

[0060] If the sampled voltage value does not meet the preset sampling voltage interval of the reference resistance value of the current gear, step S6 is performed: the reference resistance value of another gear is changed. Then steps S2 to S4 are repeated: the sampling circuit 3 obtains the sampled voltage value of the sampling point after the gear is changed, and the control circuit 4 continues to judge the re-acquired sampled voltage value.

[0061] Among them, for step S5, the temperature detection method specifically includes: the control circuit 4 calculates the resistance of the thermistor 1 according to the sampled voltage value, and the control circuit 4 calls the corresponding resistance-temperature comparison table of the thermistor 1, and obtains the current temperature value of the environment according to the resistance of the thermistor 1.

[0062] In this step, the control circuit 4 is used to store the data of the preset sampling voltage interval corresponding to the reference resistance value of each gear and the resistance value-temperature comparison table of thermistor 1 corresponding to each preset sampling voltage interval. The control circuit 4 can not only perform data analysis on the sampling voltage value, determine whether the current sampling voltage value falls within the preset sampling voltage interval corresponding to the reference resistor 22 of the current gear, but also calculate the current resistance value of thermistor 1 through the current sampling voltage value, and call the corresponding resistance value-temperature comparison table of thermistor 1 according to the resistance value, so as to output the current temperature value of the environment. That is, the control circuit 4 has the functions of data processing and analysis, data storage and data calculation, and can realize automatic temperature detection.

[0063] For step S6, the control circuit 4 may send a signal to the gear controller 21 to control the gear controller 21 to connect the reference resistors 22 with different resistance values ​​in series with the thermistor 1, which will not be described in detail here.

[0064] In a specific implementation, for step S6, the temperature detection method specifically includes: if the sampled voltage value is greater than the upper limit of the sampled voltage preset interval of the reference resistance value of the current gear, then switch to a gear with a larger reference resistance value. If the sampled voltage value is less than the lower limit of the sampled voltage preset interval of the reference resistance value of the current gear, then switch to a gear with a smaller reference resistance value.

[0065] Specifically, this embodiment uses Figure 4Taking the temperature sampling circuit in as an example, the adjustable reference resistor module 2 includes four reference resistors 22 with different resistance values, namely, a first-level reference resistor 221, a second-level reference resistor 222, a third-level reference resistor 223 and a fourth-level reference resistor 224, and the resistance values ​​of the first-level reference resistor 221, the second-level reference resistor 222, the third-level reference resistor 223 and the fourth-level reference resistor 224 increase in sequence. The first-level reference resistor 221 has a corresponding first sampling voltage preset interval {VT1}, the second-level reference resistor 222 has a corresponding second sampling voltage preset interval {VT2}, the third-level reference resistor 223 has a corresponding third sampling voltage preset interval {VT3}, and the fourth-level reference resistor 224 has a corresponding fourth sampling voltage preset interval {VT4}.

[0066] During sampling, the adjustable reference resistance module 2 can be first set to the second gear, and the control circuit 4 judges the sampling voltage value under the second gear. If the sampling voltage value does not fall within the second sampling voltage preset interval {VT2}, and the sampling voltage value is greater than the second sampling voltage preset interval {VT2}, it indicates that the voltage division of the adjustable reference resistance module 2 is too small at this time, and the reference resistance value needs to be increased. Therefore, the gear of the adjustable reference resistance module 2 can be changed to the third gear with a larger reference resistance value.

[0067] If the sampling voltage value does not fall within the second sampling voltage preset interval {VT2}, and the sampling voltage value is less than the second sampling voltage preset interval {VT2}, it indicates that the voltage division of the adjustable reference resistance module 2 is too large at this time, and the reference resistance value needs to be reduced. Therefore, the gear position of the adjustable reference resistance module 2 can be changed to the first gear position with a smaller reference resistance value.

[0068] When step S6 implements the gear adjustment in accordance with the above-mentioned manner, the efficiency of the gear adjustment can be improved, thereby improving the efficiency of the temperature detection.

[0069] In a specific implementation, before step S1, the temperature detection method further includes: Step A1: Determine the number of gears of the adjustable reference resistance module 2 and the reference resistance value corresponding to each gear according to the range of the ambient temperature to be measured.

[0070] In this step, first, the number of gears of the adjustable reference resistance module 2 and the reference resistance value of each gear are determined according to the measured temperature range and the measurement accuracy requirements. The reference resistance value of each gear corresponds to a temperature range, and it is necessary to ensure that the resistance value of each gear has the least effect on the sampling accuracy within its corresponding temperature range, thereby ensuring the accuracy of the temperature detection result.

[0071] Among them, this embodiment does not limit the specific number of gears and the specific resistance value of the reference resistance value of each gear, and can be designed according to the requirements of the temperature measurement range or temperature measurement accuracy.

[0072] Step A2: according to the temperature characteristics of the thermistor 1 , a resistance value-temperature comparison table of the thermistor 1 corresponding to different gears is formulated.

[0073] In this step, the resistance-temperature comparison table of the same thermistor 1 is fixed. The complete resistance-temperature comparison table can be truncated into multiple suitable resistance-temperature comparison tables according to the temperature range corresponding to the reference resistance value of each gear designed in step A1. The multiple truncated resistance-temperature comparison tables correspond one-to-one to the temperature ranges of the reference resistance values ​​of multiple gears, that is, the reference resistance value of each gear has its own resistance-temperature comparison table, which makes it easier for the control circuit 4 to retrieve and process data.

[0074] Step A3: Select sampling points, and set the preset sampling voltage interval corresponding to the reference resistance value of each gear according to the actual circuit parameters of the sampling points.

[0075] In this step, based on the power supply voltage, the reference resistance value of each gear, and the resistance range of thermistor 1 in the temperature range corresponding to each reference resistance value, the range of sampling voltage values ​​corresponding to the reference resistance value of each gear can be obtained, that is, the preset sampling voltage range corresponding to the reference resistance value of each gear can be obtained.

[0076] It should be noted that there should be an overlap between the preset sampling voltage intervals of the reference resistance values ​​of two adjacent gears to avoid the situation where the sampling voltage value does not conform to the preset sampling voltage interval of the reference resistance value of any gear.

[0077] The temperature detection method provided in the present application uses a control circuit to realize the gear adjustment of the adjustable reference resistance module, and can realize the dynamic adjustment of the reference resistance value in the temperature sampling circuit, so as to dynamically adjust the reference resistance value in the temperature sampling circuit according to the resistance range of the thermistor 1, so that the thermistor 1 can have a reference resistance value adapted to it when it is in different ambient temperatures. This effectively improves the sampling accuracy within the full temperature range and ensures the accuracy of the final ambient temperature result.

[0078] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A temperature sampling circuit, characterized in that: Used in an energy storage converter, the temperature sampling circuit comprises: A thermistor (1) having a first end (11) and a second end (12), wherein the first end (11) is used to connect to a power supply voltage, and the second end (12) is used to connect to ground; An adjustable reference resistance module (2), wherein at least one of the first end (11) and the second end (12) is connected to the adjustable reference resistance module (2), and the adjustable reference resistance module (2) has a plurality of reference resistance values ​​of different gears, and the reference resistance values ​​of different gears have different preset sampling voltage intervals; A sampling circuit (3) having a sampling end and a sampling circuit output end, wherein the sampling end is connected to at least one of the first end (11) and the second end (12) to obtain a sampled voltage value; A control circuit (4) having a control circuit input end and a control circuit output end, wherein the control circuit input end is connected to the sampling circuit output end to receive the sampled voltage value, and the control circuit output end is connected to the adjustable reference resistance module (2); The control circuit (4) is used to determine the resistance value of the thermistor (1) according to the sampled voltage value when the sampled voltage value satisfies the sampled voltage preset interval of the reference resistance value of the current gear; and is also used to replace the reference resistance value of another gear when the sampled voltage value does not satisfy the sampled voltage preset interval of the reference resistance value of the current gear, so that the re-obtained sampled voltage value satisfies the sampled voltage preset interval of the reference resistance value of the changed gear.

2. The temperature sampling circuit according to claim 1, characterized in that: The adjustable reference resistor module (2) comprises a gear position controller (21) and a plurality of reference resistors (22) with different resistance values, wherein the gear position controller (21) is connected to at least one of the first end (11) and the second end (12); The gear position controller (21) is also connected to the output end of the control circuit, and the output end of the control circuit is used to send a control signal to the gear position controller (21) to control the reference resistor (22) of the corresponding resistance value to be connected in series with the thermistor (1).

3. The temperature sampling circuit according to claim 1, characterized in that: The sampling circuit (3) comprises an ADC module, the ADC module having an ADC module input end and an ADC module output end, the sampling end being the ADC module input end, and the sampling circuit output end being the ADC module output end.

4. The temperature sampling circuit according to claim 1, characterized in that: The temperature sampling circuit comprises an adjustable reference resistor module (2); When the adjustable reference resistance module (2) is connected to the first end (11), the sampling end is connected to the first end (11); Alternatively, when the adjustable reference resistance module (2) is connected to the second end (12), the sampling end is connected to the second end (12).

5. The temperature sampling circuit according to claim 1, characterized in that: The temperature sampling circuit comprises two adjustable reference resistance modules (2), one of the two adjustable reference resistance modules (2) is connected to the first end (11), and the other is connected to the second end (12); The sampling end is connected to at least one of the first end (11) and the second end (12).

6. The temperature sampling circuit according to claim 2, characterized in that: The adjustable reference resistance module (2) comprises a first adjustable reference resistance module (2a) and a second adjustable reference resistance module (2b), wherein one of the first adjustable reference resistance module (2a) and the second adjustable reference resistance module (2b) is connected to the first end (11), and the other is connected to the second end (12); The first adjustable reference resistance module (2a) and the second adjustable reference resistance module (2b) are respectively connected to the output end of the control circuit, so that the output end of the control circuit can send control signals to the first adjustable reference resistance module (2a) and the second adjustable reference resistance module (2b) respectively; The first adjustable reference resistor module (2a) comprises N first sub-reference resistors (22a) with different resistance values, N≥2, and N is an integer; The second adjustable reference resistor module (2b) comprises M second sub-reference resistors (22b) with different resistance values, where M≥2, and M is an integer.

7. A temperature detection method, characterized in that: A temperature sampling circuit is used to detect the temperature in an energy storage converter, the temperature sampling circuit comprising a thermistor (1), an adjustable reference resistance module (2), a sampling circuit (3) and a control circuit (4), the adjustable reference resistance module (2) having a plurality of reference resistance values ​​of different gears, the reference resistance values ​​of different gears having different preset sampling voltage intervals; The temperature detection method comprises: Select the reference resistance value; Obtaining a sampled voltage value of the sampling point at the current gear position through the sampling circuit (3); Transmitting the sampled voltage value to the control circuit (4); The control circuit (4) judges the sampled voltage value: if the sampled voltage value satisfies the sampled voltage preset interval of the reference resistance value of the current gear, the resistance value of the thermistor (1) is determined according to the sampled voltage value, and the current temperature value of the environment is obtained according to the resistance value of the thermistor (1); If the sampled voltage value does not satisfy the preset sampling voltage interval of the reference resistance value of the current gear, the reference resistance value of another gear is changed, the sampled voltage value of the sampling point after the gear is changed is obtained, and the re-acquired sampled voltage value is continued to be judged.

8. The temperature detection method according to claim 7, characterized in that: When the reference resistance value of another gear is changed, the temperature detection method specifically includes: If the sampled voltage value is greater than the upper limit of the preset sampling voltage interval of the reference resistance value of the current gear, switching to a gear with a larger reference resistance value; If the sampled voltage value is less than the lower limit of the preset sampling voltage interval of the reference resistance value of the current gear, the gear is switched to a gear with a smaller reference resistance value.

9. The temperature detection method according to claim 7, characterized in that: When the resistance value of the thermistor (1) is determined according to the sampled voltage value, and the current temperature value of the environment is obtained according to the resistance value of the thermistor (1), the temperature detection method specifically comprises: The control circuit (4) calculates the resistance value of the thermistor (1) according to the sampled voltage value; The control circuit (4) retrieves a corresponding thermistor (1) resistance-temperature comparison table, and obtains the current temperature value of the environment by looking up the table according to the resistance value of the thermistor (1).

10. The temperature detection method according to claim 7, characterized in that: Before selecting the reference resistance value, the temperature detection method further includes: Determining the number of gears of the adjustable reference resistance module (2) and the reference resistance value corresponding to each gear according to the range of the ambient temperature to be measured; According to the temperature characteristics of the thermistor (1), a thermistor (1) resistance-temperature comparison table corresponding to different gears is formulated; A sampling point is selected, and a preset sampling voltage interval corresponding to the reference resistance value of each gear is set according to the actual circuit parameters of the sampling point.

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