A passive temperature sensor system and temperature calculation method

Abstract

The present invention discloses a passive temperature sensor system and a temperature calculation method. The passive temperature sensor comprises: an annular magnetic induction collector, a power supply circuit, a temperature sensor and a processor. The temperature calculation method obtains effective temperature data by first performing basic screening on the collected temperature data, and designs different calculation processes for the temperature rising or temperature falling stages respectively, so as to ensure the accuracy of temperature value calculation. The present invention solves the problems that a temperature sensor powered by mains electricity is not convenient to move, a temperature sensor powered by a battery needs to frequently replace the battery, and the temperature value of the existing temperature sensor is easily affected by the environment, and the temperature value calculation is not accurate enough.

Description

Technical Field

[0001] The present invention relates to the field of temperature sensors, and in particular to a passive temperature sensor system and a temperature calculation method. Background Art

[0002] At present, the power supply of existing temperature sensors is to convert the AC power supply to DC power supply of the temperature sensor, or to use a self-contained battery to power the temperature sensor after stabilizing the battery output voltage.

[0003] The temperature sensor using the first power supply method is not easy to move and cannot be applied to more special environments.

[0004] The power source of the temperature sensor using the second power supply mode is a battery, and the power of the battery is limited. Therefore, the temperature sensor using this power supply mode needs to replace the battery frequently.

[0005] At the same time, the temperature value of the existing temperature sensor is easily affected by the environment. For example, when measuring the temperature of a motor, it is easily affected by the vibration of the motor, resulting in an inaccurate temperature value. Summary of the invention

[0006] The technical problem to be solved by the present invention is: the present invention provides a passive temperature sensor system and a temperature calculation method to solve the following problems:

[0007] 1. Temperature sensors powered by AC power are not easy to move;

[0008] 2. Battery-powered temperature sensors require frequent battery replacement;

[0009] 3. The temperature value of the existing temperature sensor is easily affected by the environment, and the temperature value calculation is not accurate enough.

[0010] The technical solution adopted by the present invention is:

[0011] A passive temperature sensor system comprises: a ring-shaped magnetic induction collector, a power supply circuit, a temperature sensor and a processor;

[0012] The annular magnetic induction collector is composed of a ferrite ring and a coil wound around the ferrite ring, and is used to be mounted on a transmission line. The ferrite ring has a higher magnetic permeability than the surrounding air environment, and transmits the AC magnetic field of the transmission line to obtain the induced current of the coil wound around the ferrite ring, so as to generate an AC electromotive force and output electric energy.

[0013] The input end of the power supply circuit is connected to the annular magnetic induction collector, and the output end thereof is respectively connected to the power supply end of the temperature sensor and the processor, so as to power the temperature sensor and the processor; the temperature sensor is used to collect temperature data of the device to be tested; the processor is used to filter the temperature data collected by the temperature sensor to obtain a temperature value.

[0014] The present invention obtains alternating current on the transmission line through an annular magnetic induction collector, and transmits the obtained alternating current to the power circuit for processing. After being processed by the power circuit, it is used to power the temperature sensor and the processor. The passive temperature sensor designed by the present invention can adapt to more application scenarios and is easy to move.

[0015] Further, the power supply circuit includes: a battery charging unit, a battery and a voltage stabilizing unit;

[0016] The input end of the battery charging unit serves as the input end of the power supply circuit, and the output end thereof is respectively connected to the input end of the battery and the voltage stabilizing unit; the output end of the voltage stabilizing unit serves as the output end of the power supply circuit.

[0017] The beneficial effects of the above further scheme are: the power supply circuit is divided into three parts, a battery charging unit, a battery and a voltage stabilizing unit. When there is power on the transmission line, the battery charging unit can be used to charge the battery and supply power to the voltage stabilizing unit; when there is no power on the transmission line, the power stored in the battery can be used to supply power to the voltage stabilizing unit, thereby ensuring the normal operation of the temperature sensor without replacing the battery.

[0018] Further, the battery charging unit includes: a diode D1, a diode D2, a diode D3, a diode D4, a diode D5, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a switch tube Q1, a switch tube Q2 and a mutual inductance coil T1;

[0019] The positive electrode of the diode D1 and one end of the resistor R1 serve as the input end of the battery charging unit; the negative electrode of the diode D1 is respectively connected to the positive electrode of the capacitor C1, one end of the resistor R2, one end of the resistor R3, one end of the capacitor C2 and one end of the primary side of the mutual inductance coil T1; the collector of the switch tube Q2 is respectively connected to the base of the switch tube Q1, one end of the resistor R2, the negative electrode of the diode D3 and one end of the resistor R5, and its emitter is respectively connected to the negative electrode of the capacitor C1, the other end of the resistor R1, one end of the resistor R4, the positive electrode of the capacitor C3 and one end of the first secondary side of the mutual inductance coil T1, and its base is connected to the negative electrode of the diode D3;

[0020] The collector of the switch tube Q1 is respectively connected to the positive electrode of the diode D2 and the other end of the primary side of the mutual inductance coil T1, and the emitter thereof is respectively connected to the positive electrode of the diode D3 and the other end of the resistor R4; the negative electrode of the diode D2 is respectively connected to the other end of the capacitor C2 and the other end of the resistor R3; the positive electrode of the diode D3 is respectively connected to the negative electrode of the capacitor C3 and the positive electrode of the diode D4; the other end of the resistor R5 is connected to one end of the capacitor C4; the other end of the capacitor C4 is respectively connected to the negative electrode of the diode D4 and the other end of the first secondary side of the mutual inductance coil T1; one end of the second secondary side of the mutual inductance coil T1 is connected to the positive electrode of the diode D5, and the other end thereof is connected to the negative electrode of the capacitor C5; the negative electrode of the diode D5 is connected to the positive electrode of the capacitor C5; the two ends of the capacitor C5 serve as the output ends of the battery charging unit.

[0021] The beneficial effects of the above further scheme are as follows: after the AC power is input into the battery charging unit, one end is half-wave rectified by the diode D1, and the other end is passed through the resistor R1. The capacitor C1 is used for filtering, and the resistor R1 is used to protect the circuit. When a fault occurs in the subsequent circuit and causes overcurrent, the resistor R1 will be burned out, thereby avoiding causing a larger fault. The capacitor C2, the diode D2 and the resistor R3 constitute a high-voltage absorption circuit. When the switch tube Q1 is turned off, it is used to absorb the induced voltage on the mutual inductance coil T1, thereby preventing the high voltage from being added to the switch tube Q1, causing the problem of the switch tube Q1 breaking down. By controlling the on-off of the switch tube Q1, the on-off between the primary side of the mutual inductance coil T1 and the input end of the battery charging unit is controlled. When the primary side of the mutual inductance coil T1 is continuously on and off, a changing magnetic field will be formed in the mutual inductance coil T1, thereby generating an induced voltage in the secondary side.

[0022] Resistor R2 is used to provide current to the base of switch tube Q1. Resistor R4 is a current sampling resistor, which provides base voltage for switch Q2. When the base voltage is greater than 1.4V, switch tube Q2 is turned on, and the voltage of the base of switch tube Q1 is lowered, which limits the current of the collector of switch tube Q1 and prevents switch tube Q1 from being burned due to excessive current.

[0023] Furthermore, the voltage stabilizing unit is a linear voltage stabilizer.

[0024] A temperature calculation method for a passive temperature sensor comprises the following steps:

[0025] S1. Pre-collect a set of temperature data and calculate the effective value of the initial temperature data;

[0026] S2, collect new temperature data to obtain effective temperature data;

[0027] S3, judging whether the newly acquired valid temperature data is greater than the valid value, if so, the first counting unit increments by 1 and jumps to step S4, if not, jumps to step S6;

[0028] S4, calculating the temperature value of the object to be measured during the heating stage;

[0029] S5, determine whether the count of the first counting unit is greater than the counting threshold. If so, use the currently calculated temperature value of the object to be measured to update the effective value, reset the count of the first counting unit, and jump to step S2. If not, directly jump to step S2;

[0030] S6, judging whether the newly acquired valid temperature data is equal to the valid value, if so, the current valid value is used as the temperature value of the object to be measured, if not, the second counting unit is incremented by 1, and the process jumps to step S7;

[0031] S7, calculating the temperature value of the object to be measured during the cooling stage;

[0032] S8, determine whether the count of the second counting unit is greater than the counting threshold, if so, use the currently calculated temperature value of the object to be measured to update the effective value, and clear the count of the second counting unit, and jump to step S2, if not, directly jump to step S2;

[0033] S9. Obtain the temperature value of the object to be measured at the corresponding moment according to the temperature values ​​of step S4, step S6 and step S7.

[0034] The beneficial effects of the present invention are as follows: the present invention first collects some temperature data, and screens the temperature data to obtain a group of valid temperature data, and calculates the effective value of the initial temperature data for the group of valid temperature data. In fact, the effective value of the initial temperature data is the temperature value corresponding to the group of valid temperature data, and the newly obtained effective temperature data is compared with the current effective value. If it is greater than, the first counting unit will add 1, and the temperature measured by the temperature sensor is in the rising process. When the first counting unit counts continuously rising, it means that the temperature is continuously increasing, then the current effective value cannot represent the current temperature, so the effective value must be updated so that the effective value of the effective temperature data comparison also increases. After the update, the first counting unit starts counting again for the next update of the effective value.

[0035] At the same time, in the temperature drop stage, when the count of the second counting unit continues to rise, it means that the temperature is continuing to drop. Then the current effective value cannot represent the current temperature which has dropped a lot. Therefore, the effective value needs to be updated in real time to ensure the accuracy of the judgment of the heating or cooling stage.

[0036] The present invention first performs basic screening on the collected temperature data to obtain effective temperature data, and designs different calculation processes for the temperature rising or temperature falling stages to ensure the accuracy of temperature value calculation.

[0037] Furthermore, the step S1 includes the following sub-steps:

[0038] S11, collecting temperature data;

[0039] S12, calculating the difference between the currently collected temperature data and the temperature data collected at the previous moment, if the difference is greater than the error value, removing the currently collected temperature data and jumping to step S11 until a set of valid temperature data is obtained;

[0040] S13. Calculate the effective value of the initial temperature data according to the set of effective temperature data.

[0041] The beneficial effect of the above further scheme is: after collecting temperature data, the difference between the temperature data collected twice before and after is determined. If the difference is too large and exceeds the normal range, the abnormal data is discarded to ensure that the temperature data used are valid.

[0042] Furthermore, the calculation formula for calculating the effective value of the initial temperature data in step S13 is:

[0043]

[0044] Among them, y is the effective value of the initial temperature data, x1 is the first effective temperature data, x2 is the second effective temperature data, and x n is the nth valid temperature data, and n is the number of valid temperature data.

[0045] The beneficial effect of the above further scheme is: according to the different proportions of each valid temperature data in the group, different weights are assigned to each valid temperature data, and the effective value of the temperature data is calculated to represent the temperature value of the valid temperature data of the group.

[0046] Furthermore, the formula for calculating the temperature value of the object to be measured during the heating stage in step S4 is:

[0047]

[0048] in, is the temperature value at time t, x t-j is the effective temperature data at time tj, x t-j+1 is the effective temperature data at time t-j+, ω t-j is the effective temperature data weight at time tj, ω t-j+1 is the effective temperature data weight at time t-j+1, x t-1 is the effective temperature data at time t-1, ω t-1 is the effective temperature data weight at time t-1, j is the number used for counting, x t is the effective temperature data at time t, ω tis the effective temperature data weight at time t, m is the count in the first counting unit, M is the count threshold of the first counting unit, and a is the first adjustment parameter.

[0049] The beneficial effect of the above further solution is that after assigning different weights to each valid temperature data, the weights are also used for correction, so that the calculated temperature value is more accurate. The above formula also introduces the count m and the count threshold M. When the count m continues to grow, that is, when the temperature rises, x will gradually increase. t The weight before makes the temperature value The growth rate of gradually increases and approaches the true value.

[0050] Furthermore, the formula for calculating the temperature value of the object to be measured in the cooling stage in step S7 is:

[0051]

[0052] in, is the temperature value at time t, x t-j is the effective temperature data at time tj, x t-j+1 is the effective temperature data at time t-j+, ω t-j is the effective temperature data weight at time tj, ω t-j+1 is the effective temperature data weight at time t-j+1, x t-1 is the effective temperature data at time t-1, ω t-1 is the effective temperature data weight at time t-1, j is the number used for counting, x t is the effective temperature data at time t, ω t is the effective temperature data weight at time t, k is the count in the second counting unit, K is the count threshold of the second counting unit, and b is the second adjustment parameter.

[0053] The beneficial effect of the above further solution is that after assigning different weights to each valid temperature data, the weights are also used for correction, so that the calculated temperature value is more accurate. The above formula also introduces the count k and the count threshold K. When the count k continues to grow, that is, when the temperature rises, x will gradually increase. t The weight before makes the temperature value y t The decreasing speed of increases gradually and approaches the true value. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a system block diagram of a passive temperature sensor;

[0055] Figure 2 A circuit diagram of a battery charging unit;

[0056] Figure 3The present invention is a flow chart of a temperature calculation method of a passive temperature sensor. DETAILED DESCRIPTION

[0057] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0058] like Figure 1 As shown, a passive temperature sensor system includes: a ring-shaped magnetic induction collector, a power supply circuit, a temperature sensor and a processor;

[0059] The annular magnetic induction device is composed of a ferrite ring and a coil wound around the ferrite ring, and is used to draw electricity from the transmission line. When in use, the annular magnetic induction device is mounted on the transmission line, and the ferrite ring, with its higher magnetic permeability than the surrounding air environment, effectively conducts the AC magnetic field of the transmission line, so that the coil wound around the ferrite ring generates an induced current, thereby generating an AC electromotive force, and outputting electrical energy to the subsequent circuit.

[0060] The input end of the power supply circuit is connected to the coil of the annular magnetic induction collector, and the output end is connected to the power supply end of the temperature sensor and the processor respectively, so as to power the temperature sensor and the processor; the temperature sensor is used to collect temperature data of the device to be tested; the processor is used to filter the temperature data collected by the temperature sensor to obtain a temperature value.

[0061] The present invention obtains alternating current on the transmission line through an annular magnetic induction collector, and transmits the obtained alternating current to the power circuit for processing. After being processed by the power circuit, it is used to power the temperature sensor and the processor. The passive temperature sensor designed by the present invention can adapt to more application scenarios and is easy to move.

[0062] The power supply circuit includes: a battery charging unit, a battery and a voltage stabilizing unit;

[0063] The input end of the battery charging unit serves as the input end of the power supply circuit, and the output end thereof is respectively connected to the input end of the battery and the voltage stabilizing unit; the output end of the voltage stabilizing unit serves as the output end of the power supply circuit.

[0064] The power supply circuit is divided into three parts: a battery charging unit, a battery, and a voltage stabilizing unit. When there is power on the transmission line, the battery charging unit can be used to charge the battery and supply power to the voltage stabilizing unit. When there is no power on the transmission line, the power stored in the battery can be used to supply power to the voltage stabilizing unit, ensuring the normal operation of the temperature sensor without replacing the battery. The voltage stabilizing unit is a linear voltage regulator.

[0065] like Figure 2 As shown, the battery charging unit includes: a diode D1, a diode D2, a diode D3, a diode D4, a diode D5, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a switch tube Q1, a switch tube Q2 and a mutual inductance coil T1;

[0066] The positive electrode of the diode D1 and one end of the resistor R1 serve as the input end of the battery charging unit; the negative electrode of the diode D1 is respectively connected to the positive electrode of the capacitor C1, one end of the resistor R2, one end of the resistor R3, one end of the capacitor C2 and one end of the primary side of the mutual inductance coil T1; the collector of the switch tube Q2 is respectively connected to the base of the switch tube Q1, one end of the resistor R2, the negative electrode of the diode D3 and one end of the resistor R5, and its emitter is respectively connected to the negative electrode of the capacitor C1, the other end of the resistor R1, one end of the resistor R4, the positive electrode of the capacitor C3 and one end of the first secondary side of the mutual inductance coil T1, and its base is connected to the negative electrode of the diode D3;

[0067] The collector of the switch tube Q1 is respectively connected to the positive electrode of the diode D2 and the other end of the primary side of the mutual inductance coil T1, and the emitter thereof is respectively connected to the positive electrode of the diode D3 and the other end of the resistor R4; the negative electrode of the diode D2 is respectively connected to the other end of the capacitor C2 and the other end of the resistor R3; the positive electrode of the diode D3 is respectively connected to the negative electrode of the capacitor C3 and the positive electrode of the diode D4; the other end of the resistor R5 is connected to one end of the capacitor C4; the other end of the capacitor C4 is respectively connected to the negative electrode of the diode D4 and the other end of the first secondary side of the mutual inductance coil T1; one end of the second secondary side of the mutual inductance coil T1 is connected to the positive electrode of the diode D5, and the other end thereof is connected to the negative electrode of the capacitor C5; the negative electrode of the diode D5 is connected to the positive electrode of the capacitor C5; the two ends of the capacitor C5 serve as the output ends of the battery charging unit.

[0068] After the AC power is input into the battery charging unit, one end is half-wave rectified by diode D1, and the other end is passed through resistor R1. Capacitor C1 is used for filtering, and resistor R1 is used to protect the circuit. When a fault occurs in the subsequent circuit and causes overcurrent, resistor R1 will be burned out to avoid causing a larger fault. Capacitor C2, diode D2 and resistor R3 form a high-voltage absorption circuit. When the switch tube Q1 is turned off, it is used to absorb the induced voltage on the mutual inductance coil T1, thereby preventing the high voltage from being added to the switch tube Q1, causing the switch tube Q1 to break down. By controlling the on and off of the switch tube Q1, the on and off between the primary side of the mutual inductance coil T1 and the input end of the battery charging unit is controlled. When the primary side of the mutual inductance coil T1 is continuously on and off, a changing magnetic field will be formed in the mutual inductance coil T1, thereby generating an induced voltage in the secondary side.

[0069] Resistor R2 is used to provide current to the base of switch tube Q1. Resistor R4 is a current sampling resistor, which provides base voltage for switch Q2. When the base voltage is greater than 1.4V, switch tube Q2 is turned on, and the voltage of the base of switch tube Q1 is lowered, which limits the current of the collector of switch tube Q1 and prevents switch tube Q1 from being burned due to excessive current.

[0070] like Figure 3 As shown, a temperature calculation method for a passive temperature sensor system includes the following steps:

[0071] S1. Pre-collect a set of temperature data and calculate the effective value of the initial temperature data;

[0072] The step S1 comprises the following sub-steps:

[0073] S11, collecting temperature data;

[0074] S12, calculating the difference between the currently collected temperature data and the temperature data collected at the previous moment, if the difference is greater than the error value, removing the currently collected temperature data and jumping to step S11 until a set of valid temperature data is obtained;

[0075] S13. Calculate the effective value of the initial temperature data according to the set of effective temperature data.

[0076] After the present invention collects temperature data, it is necessary to determine the difference between the temperature data collected twice before and after. If the difference is too large and exceeds the normal range, the abnormal data is discarded to ensure that the temperature data used are all valid.

[0077] The calculation formula for calculating the effective value of the initial temperature data in step S13 is:

[0078]

[0079] Among them, y is the effective value of the initial temperature data, x1 is the first effective temperature data, x2 is the second effective temperature data, and x n is the nth valid temperature data, and n is the number of valid temperature data.

[0080] The present invention assigns different weights to each valid temperature data according to the different proportions of each valid temperature data in the group, and calculates the effective value of the temperature data to represent the temperature value of the valid temperature data of the group.

[0081] S2, collect new temperature data to obtain effective temperature data;

[0082] The new temperature data collected in step S2 is similarly treated by the method of step S12 to remove abnormal values ​​and obtain valid temperature data.

[0083] S3, judging whether the newly acquired valid temperature data is greater than the valid value, if so, the first counting unit increments by 1 and jumps to step S4, if not, jumps to step S6;

[0084] S4, calculating the temperature value of the object to be measured during the heating stage;

[0085] S5, determine whether the count of the first counting unit is greater than the counting threshold. If so, use the currently calculated temperature value of the object to be measured to update the effective value, reset the count of the first counting unit, and jump to step S2. If not, directly jump to step S2;

[0086] S6, judging whether the newly acquired valid temperature data is equal to the valid value, if so, the current valid value is used as the temperature value of the object to be measured, if not, the second counting unit is incremented by 1, and the process jumps to step S7;

[0087] S7, calculating the temperature value of the object to be measured during the cooling stage;

[0088] S8, determine whether the count of the second counting unit is greater than the counting threshold, if so, use the currently calculated temperature value of the object to be measured to update the effective value, and clear the count of the second counting unit, and jump to step S2, if not, directly jump to step S2;

[0089] S9. Obtain the temperature value of the object to be measured at the corresponding moment according to the temperature values ​​of step S4, step S6 and step S7.

[0090] The present invention first collects some temperature data and screens the temperature data to obtain a group of valid temperature data, and calculates the effective value of the initial temperature data for the group of valid temperature data. In fact, the effective value of the initial temperature data is the temperature value corresponding to the group of valid temperature data. The newly obtained effective temperature data is compared with the current effective value. If it is greater than, the first counting unit will add 1, and the temperature measured by the temperature sensor is in the rising process. When the first counting unit counts continuously rising, it means that the temperature is continuously increasing, then the current effective value cannot represent the current temperature, so the effective value must be updated so that the effective value of the effective temperature data comparison is also increased. After the update, the first counting unit starts counting again for the next update of the effective value.

[0091] At the same time, in the temperature drop stage, when the count of the second counting unit continues to rise, it means that the temperature is continuing to drop. Then the current effective value cannot represent the current temperature which has dropped a lot. Therefore, the effective value needs to be updated in real time to ensure the accuracy of the judgment of the heating or cooling stage.

[0092] The present invention first performs basic screening on the collected temperature data to obtain effective temperature data, and designs different calculation processes for the temperature rising or temperature falling stages to ensure the accuracy of temperature value calculation.

[0093] The formula for calculating the temperature value of the object to be measured during the heating stage in step S4 is:

[0094]

[0095] in, is the temperature value at time t, x t-j is the effective temperature data at time tj, x t-j+1 is the effective temperature data at time t-j+, ω t-j is the effective temperature data weight at time tj, ω t-j+1 is the effective temperature data weight at time t-j+1, x t-1 is the effective temperature data at time t-1, ω t-1 is the effective temperature data weight at time t-1, j is the number used for counting, x t is the effective temperature data at time t, ω t is the effective temperature data weight at time t, m is the count in the first counting unit, M is the count threshold of the first counting unit, and a is the first adjustment parameter.

[0096] After assigning different weights to each valid temperature data, the present invention also uses the weights to make corrections, so that the calculated temperature value is more accurate. The above formula also introduces the count m and the count threshold M. In the process of continuous growth of the count m, that is, the temperature rises, the x value will gradually increase. t The weight before makes the temperature value y t The growth rate of gradually increases and approaches the true value.

[0097] The formula for calculating the temperature value of the object to be measured during the cooling stage in step S7 is:

[0098]

[0099] in, is the temperature value at time t, x t-j is the effective temperature data at time tj, x t-j+ 1 is the effective temperature data at time t-j+, ω t-j is the effective temperature data weight at time tj, ω t-j+1 is the effective temperature data weight at time t-j+1, x t-1 is the effective temperature data at time t-1, ω t-1 is the effective temperature data weight at time t-1, j is the number used for counting, x tis the effective temperature data at time t, ω t is the effective temperature data weight at time t, k is the count in the second counting unit, K is the count threshold of the second counting unit, and b is the second adjustment parameter.

[0100] After assigning different weights to each valid temperature data, the present invention also uses the weights to make corrections, so that the calculated temperature value is more accurate. The above formula also introduces the count k and the count threshold K. In the process of continuous growth of the count k, that is, the temperature rises, the x value will gradually increase. t The weight before makes the temperature value y t The decreasing speed of increases gradually and approaches the true value.

Claims

1. A passive temperature sensor system, characterized in that: It includes: a ring-shaped magnetic induction collector, a power supply circuit, a temperature sensor and a processor; The annular magnetic induction collector is used to draw electricity from the transmission line; the input end of the power supply circuit is connected to the annular magnetic induction collector, and the output end thereof is respectively connected to the power supply end of the temperature sensor and the processor, and is used to power the temperature sensor and the processor; the temperature sensor is used to collect temperature data of the device to be tested; the processor is used to filter the temperature data collected by the temperature sensor to obtain a temperature value; the power supply circuit includes: a battery charging unit, a battery and a voltage stabilizing unit; The input end of the battery charging unit serves as the input end of the power supply circuit, and the output end thereof is connected to the input end of the battery and the voltage stabilizing unit respectively; the output end of the voltage stabilizing unit serves as the output end of the power supply circuit; The battery charging unit includes: a diode D1, a diode D2, a diode D3, a diode D4, a diode D5, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a switch tube Q1, a switch tube Q2 and a mutual inductance coil T1; The positive electrode of the diode D1 and one end of the resistor R1 serve as the input end of the battery charging unit; the negative electrode of the diode D1 is respectively connected to the positive electrode of the capacitor C1, one end of the resistor R2, one end of the resistor R3, one end of the capacitor C2 and one end of the primary side of the mutual inductance coil T1; the collector of the switch tube Q2 is respectively connected to the base of the switch tube Q1, one end of the resistor R2, the negative electrode of the first diode D3 and one end of the resistor R5, and its emitter is respectively connected to the negative electrode of the capacitor C1, the other end of the resistor R1, one end of the resistor R4, the positive electrode of the capacitor C3 and one end of the first secondary side of the mutual inductance coil T1, and its base is connected to the negative electrode of the second diode D3; The collector of the switch tube Q1 is respectively connected to the positive electrode of the diode D2 and the other end of the primary side of the mutual inductance coil T1, and the emitter thereof is respectively connected to the positive electrode of the second diode D3 and the other end of the resistor R4; the negative electrode of the diode D2 is respectively connected to the other end of the capacitor C2 and the other end of the resistor R3; the positive electrode of the first diode D3 is respectively connected to the negative electrode of the capacitor C3 and the positive electrode of the diode D4; the other end of the resistor R5 is connected to one end of the capacitor C4; the other end of the capacitor C4 is respectively connected to the negative electrode of the diode D4 and the other end of the first secondary side of the mutual inductance coil T1; one end of the second secondary side of the mutual inductance coil T1 is connected to the positive electrode of the diode D5, and the other end thereof is connected to the negative electrode of the capacitor C5; the negative electrode of the diode D5 is connected to the positive electrode of the capacitor C5; the two ends of the capacitor C5 serve as the output ends of the battery charging unit.

2. A passive temperature sensor system according to claim 1, characterized in that: The voltage stabilizing unit is a linear voltage stabilizer.

3. A temperature calculation method for a passive temperature sensor system according to any one of claims 1 to 2, characterized in that: The following steps are involved: S1. Pre-collect a set of temperature data and calculate the effective value of the initial temperature data; S2, collect new temperature data to obtain effective temperature data; S3, judging whether the newly acquired valid temperature data is greater than the valid value, if so, the first counting unit increments by 1 and jumps to step S4, if not, jumps to step S6; S4, calculating the temperature value of the object to be measured during the heating stage; S5, determine whether the count of the first counting unit is greater than the counting threshold. If so, use the currently calculated temperature value of the object to be measured to update the effective value, reset the count of the first counting unit, and jump to step S2. If not, directly jump to step S2; S6, judging whether the newly acquired valid temperature data is equal to the valid value, if so, the current valid value is used as the temperature value of the object to be measured, if not, the second counting unit is incremented by 1, and the process jumps to step S7; S7, calculating the temperature value of the object to be measured during the cooling stage; S8, determine whether the count of the second counting unit is greater than the counting threshold, if so, use the currently calculated temperature value of the object to be measured to update the effective value, and clear the count of the second counting unit, and jump to step S2, if not, directly jump to step S2; S9. Obtain the temperature value of the object to be measured at the corresponding moment according to the temperature values ​​of step S4, step S6 and step S7.

4. The temperature calculation method of a passive temperature sensor system according to claim 3, characterized in that: The step S1 comprises the following sub-steps: S11, collecting temperature data; S12, calculating the difference between the currently collected temperature data and the temperature data collected at the previous moment, if the difference is greater than the error value, removing the currently collected temperature data and jumping to step S11 until a set of valid temperature data is obtained; S13. Calculate the effective value of the initial temperature data according to the set of effective temperature data.

5. The temperature calculation method of a passive temperature sensor system according to claim 4, characterized in that: The calculation formula for calculating the effective value of the initial temperature data in step S13 is: Among them, y is the effective value of the initial temperature data, x1 is the first effective temperature data, x2 is the second effective temperature data, and x n is the nth valid temperature data, and n is the number of valid temperature data.

6. The temperature calculation method of a passive temperature sensor system according to claim 3, characterized in that: The formula for calculating the temperature value of the object to be measured in the heating stage in step S4 is: in, is the temperature value at time t, x t-j is the effective temperature data at time tj, x t-j+1 is the effective temperature data at time t-j+1, ω t-j is the effective temperature data weight at time tj, ω t-j+1 is the effective temperature data weight at time t-j+1, x t-1 is the effective temperature data at time t-1, ω t-1 is the effective temperature data weight at time t-1, j is the number used for counting, x t is the effective temperature data at time t, ω t is the effective temperature data weight at time t, m is the count in the first counting unit, M is the count threshold of the first counting unit, and a is the first adjustment parameter.

7. A passive temperature sensor system according to claim 3, characterized in that: The formula for calculating the temperature value of the object to be measured in the cooling stage in step S7 is: in, is the temperature value at time t, x t-j is the effective temperature data at time tj, x t-j+1 is the effective temperature data at time t-j+1, ω t-j is the effective temperature data weight at time tj, ω t-j+1 is the effective temperature data weight at time t-j+1, x t-1 is the effective temperature data at time t-1, ω t-1 is the effective temperature data weight at time t-1, j is the number used for counting, x t is the effective temperature data at time t, ω t t The effective temperature data weight at the moment, k is the count in the second counting unit, K is the count threshold of the second counting unit, and b is the second adjustment parameter.

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