A detection circuit method suitable for various power utilization information collection terminals

Abstract

The present application relates to the technical field of detection circuit suitable for various electric energy information collection terminals, and discloses a detection circuit method suitable for various electric energy information collection terminals. The method sets the ambient temperature, calibrates the shunt resistor and the thermistor, constructs a three-order resistance-temperature mapping relationship, and calculates the thermal resistance and the thermal response characteristics to realize accurate modeling. The thermistor is attached to the shunt resistor and forms a thermal coupling structure by adding heat-conducting silicone grease. The constant current source and the differential amplifier are used to collect voltage, convert resistance value to temperature in real time, calculate the instantaneous current based on the heat balance equation, and then complete energy integration and grade judgment to output various electric parameters. The method integrates modeling, collection, conversion and inversion processes, constructs a complete thermal-electric detection link, does not need traditional current sensors, has the advantages of compact structure, low cost, flexible deployment and the like, and is suitable for low-power distributed terminals.

Description

Technical Field

[0001] This invention relates to the field of detection circuit technology applicable to various electricity consumption information collection terminals, specifically to a detection circuit method applicable to various electricity consumption information collection terminals. Background Technology

[0002] With the rapid development of smart grid and Internet of Things technologies, various electricity information collection terminals (such as smart meters, home appliance monitoring modules, electric vehicle charging piles, etc.) have put forward higher requirements for high-precision and low-cost detection of real-time current and energy consumption.

[0003] Current measurement is achieved by placing a Hall element around the conductor under test and detecting changes in its magnetic field. This method offers advantages such as good signal isolation and high linearity, but Hall elements are expensive and require complex bias and temperature compensation circuits. In multi-terminal scenarios, multiple independent sensors are needed, significantly increasing cost and size, and ensuring calibration consistency across different terminals is difficult. Another method involves connecting a micro-ohm shunt resistor in series in the circuit under test, measuring the voltage drop across it, and calculating the current using Ohm's law. This method offers low device cost and simple structure, but the surface heating of the shunt resistor and changes in ambient temperature significantly affect measurement accuracy, often requiring external temperature sensing and compensation circuitry. Traditional temperature compensation typically uses linear or quadratic fitting, which struggles to cover a wider temperature range, and in multi-terminal deployments, it is highly dependent on different ambient temperatures, making it difficult to standardize the compensation model. A third method involves attaching a thermistor to the surface of the shunt resistor, indirectly estimating the conductor temperature rise by measuring resistance changes, and then calculating the current based on a thermal balance model. Existing solutions often employ empirical formulas or simple first-order system models, lacking a systematic procedure for calibrating thermal time and thermal resistance. Calibration is typically performed at a single temperature point or within a small temperature range, resulting in slow response times, large model errors, and a lack of energy accumulation and grading capabilities. This fails to meet the requirements for continuous multi-state monitoring and energy consumption classification across different terminals. While spectral analysis can extract fundamental and harmonic components, then weighted summaries of power and current are used, multi-harmonic detection relies on high-performance analog-to-digital converters and digital signal processors, leading to high hardware costs and power consumption, making it unsuitable for resource-constrained multi-terminal applications. Furthermore, the significant differences in load characteristics across different terminals necessitate complex calibration of weighting coefficients, hindering universal deployment.

[0004] Therefore, this case aims to propose a detection circuit method applicable to various electricity information collection terminals. Through multi-level technical means such as thermal coupling temperature measurement, thermal resistance modeling, current inverse calculation, and energy classification, it achieves accurate monitoring and dynamic classification of current and energy consumption. The overall technical approach integrates thermoelectric response mechanisms, high-precision analog circuit design, polynomial mathematical modeling, and real-time data acquisition and mapping, breaking through the traditional method of electrical parameter measurement relying solely on Hall elements or current transformers. This method establishes an efficient thermal coupling relationship between the shunt resistor and the thermistor, and combines thermistor characteristics for thermo-electric inverse modeling, thus deriving instantaneous current and its cumulative energy consumption without directly acquiring large current signals. Simultaneously, the system possesses an energy level assessment mechanism, providing technical support for fault alarms, energy management, and differentiated control at the terminal level. This solves the current lack of low-cost, high-precision current detection methods, improving the intelligence level and scenario adaptability of electricity information collection terminals. Summary of the Invention

[0005] This invention provides a detection circuit method applicable to various electricity information collection terminals, thereby helping to solve the problems mentioned in the background art.

[0006] This invention provides the following technical solution: a detection circuit method applicable to various electricity consumption information collection terminals, comprising:

[0007] Set the ambient temperature, apply a known calibrated current to the shunt resistor, measure the voltage drop across it to calculate the resistance value, and measure the resistance value of the thermistor at multiple temperature points to establish a third-order mapping relationship between resistance and temperature, and calculate the thermal resistance and thermal response characteristics.

[0008] Connect the calibrated shunt resistor in series to the circuit under test, attach the thermistor to the surface of the shunt resistor, and apply high thermal conductivity silicone grease to the contact surface. At the same time, connect the thermistor to the constant current source and the differential amplifier.

[0009] The voltage signal across the thermistor is obtained through a constant current source and a differential amplifier, sampled at a set frequency, and the instantaneous resistance at the sampling time is calculated.

[0010] The collected resistance data is substituted into the polynomial mapping model and converted into the corresponding instantaneous temperature value.

[0011] Calculate the thermal response factor based on temperature changes;

[0012] The instantaneous current at each moment is obtained by back-calculating the current value using the heat balance equation;

[0013] Calculate the cumulative electrical energy at any given time, classify energy levels according to the preset maximum energy, and determine the current energy level;

[0014] Output the detected peak current, average current, total cumulative energy, and current sequence and energy level sequence.

[0015] Optionally, the process of setting an ambient temperature, applying a known rated current to a shunt resistor, measuring the voltage drop across it to calculate the resistance value, and measuring the resistance of the thermistor at multiple temperature points to establish a third-order mapping relationship between resistance and temperature, and calculating the thermal resistance and thermal response characteristics, specifically includes:

[0016] Measure and set the ambient temperature to T. env ;

[0017] Apply a known rated current I cal For the shunt resistor, measure the voltage drop V across the shunt resistor. cal Calculate the shunt resistance

[0018] At ambient temperature T env Measuring the resistance R of the thermistor ref ;

[0019] At three sets of temperature points (T) i ,R i The resistance value is measured at point ), let ΔR i =R i -R ref ΔT i =T i -T env Where i = {1, 2, 3} is the temperature point index; T i R is the temperature of the i-th calibration point; i Let ΔR be the resistance value corresponding to the i-th calibration point temperature; i For resistance deviation; ΔT i Temperature deviation;

[0020] Establish a third-order mapping relationship: Where c1 is the coefficient of the linear term; c2 is the coefficient of the quadratic term; and c3 is the coefficient of the cubic term.

[0021] Set the impedance matrix as follows:

[0022]

[0023] Set the temperature difference vector as: ΔT=(ΔT1,ΔT2,ΔT3) T ;

[0024] The coefficient vector is solved as follows:

[0025]

[0026] Apply constant current I th Power is generated by the thermistor.

[0027] Record the temperature versus time curve T(t);

[0028] Calculate steady-state temperature rise

[0029] Calculate thermal resistance

[0030] Select the one that satisfies Time t1, antipyretic duration:

[0031]

[0032] Optionally, the step of connecting the calibrated shunt resistor in series with the circuit under test, attaching the thermistor to the surface of the shunt resistor, coating the contact surface with high thermal conductivity silicone grease, and connecting the thermistor to the constant current source and the differential amplifier specifically includes:

[0033] The calibrated shunt resistor R sh Insert it into the circuit under test and place the thermistor tightly against its casing;

[0034] Apply high thermal conductivity silicone grease to the contact surface between the two surfaces to reduce the contact thermal resistance R. c <0.1Θ;

[0035] Connect the two ends of the thermistor to a constant current source I. th A differential amplifier, with its amplification factor denoted as G.

[0036] Optionally, the step of obtaining the voltage signal across the thermistor through a constant current source and a differential amplifier, sampling it at a set frequency, and calculating the instantaneous resistance at the sampling moment specifically includes:

[0037] Constant current source maintains I th ;

[0038] Differential amplifier output V t (t), using sampling frequency f s Sampling interval Recorded to the sampling sequence {V t (t k )};where, t k =(k-1)Δt, k={1,2,...,K}; V t (t k ) represents the voltage sampled at the kth time; K represents the total number of sampling points;

[0039] Calculate time t k instantaneous resistance of thermistor

[0040] Optionally, the step of substituting the collected resistance data into a polynomial mapping model to convert it into the corresponding instantaneous temperature value specifically includes:

[0041] Calculate the resistance deviation ΔR(t) k ) = R t (t k )-R ref ;

[0042] Set up a polynomial mapping to calculate the instantaneous temperature:

[0043] T t (t k ) = T env +c1ΔR(t k )+c2[ΔR(t k )] 2 +c3[ΔR(t k )] 3 Among them, T t (t k (t) represents time t k Convert the temperature.

[0044] Optionally, the calculation of the thermal response factor based on temperature change specifically includes:

[0045] Set the normalized response factor to

[0046] Optionally, the step of calculating the instantaneous current at each moment by back-calculating the current value through the heat balance equation specifically includes:

[0047] Calculate the temperature rise ΔT(t) k ) = T t (t k )-T env ;

[0048] From the heat balance equation ΔT=I 2 R sh ΘF, solution time t k Instantaneous current:

[0049]

[0050] Optionally, the calculation of accumulated electrical energy, classifying energy levels according to a preset maximum energy level, and determining the current energy level specifically includes:

[0051] Calculate up to time t k Accumulated electrical energy is

[0052] Based on the maximum design current I max And the longest detection time T max Calculate the preset maximum energy:

[0053]

[0054] [0, E max Divided into N levels, with inter-level thresholds as follows: Where h = {0, 1, ..., N}; where N is the total number of energy levels; E h The threshold for level h; h is the level index;

[0055] Energy level determination: L(t) k ) = m, if E m-1 ≤E(t k ) <E m Where m = {1, 2, ... N}; where L(t) k (t) represents time t k Energy level; m is the energy level number.

[0056] Optionally, the peak current, average current, total accumulated energy, and current sequence and energy level sequence detected in the output specifically include:

[0057] Calculate peak current

[0058] Calculate the average current

[0059] Calculate the total cumulative energy E total =E(t) K );

[0060] Output current sequence {I m (t k )}、Energy level sequence {L(t) k Peak current I peak Average current I avg Total accumulated energy E total .

[0061] The present invention has the following beneficial effects:

[0062] 1. The parameter calibration section not only performs basic shunt resistance measurement but also introduces refined modeling steps such as three-point temperature calibration, third-order polynomial fitting, thermal resistance calculation, and thermal response time measurement. This calibration method, by establishing a third-order mapping relationship between resistance and temperature, not only adapts to resistance fluctuations of nonlinear thermistors under different environments but also significantly improves the accuracy of temperature estimation. In existing technologies, most systems rely on single-point or linear calibration, resulting in insufficient accuracy and sensitivity to environmental changes. In contrast, this invention introduces precise modeling methods such as "temperature difference matrix," "resistance difference matrix," and "coefficient vector solution" during the calibration stage, significantly enhancing the robustness and accuracy of subsequent thermo-electric inversion algorithms. Furthermore, applying a constant current and recording temperature change curves to calculate thermal resistance and thermal time avoids the risk of inaccurate empirical values, a crucial foundational step for achieving highly reliable thermal modeling.

[0063] 2. The proposed method of attaching a thermistor closely to a shunt resistor and coating it with high thermal conductivity silicone grease enhances thermal coupling at the structural and material levels, forming the physical basis for successful current inversion. Traditional thermoelectric measurement methods are often limited by long heat transfer paths, loose contact, and slow response, leading to significant deviations between temperature rise and actual current. This scheme optimizes the heat conduction path, enabling rapid reflection of thermistor resistance changes even under minute current fluctuations, providing a high-speed response foundation for current inversion. Simultaneously, constant current source driving and differential amplifier precise sampling of the voltage across the terminals enable the system to achieve high signal-to-noise ratio and low drift analog acquisition performance. This structural design avoids the use of expensive Hall effect or magnetic sensing devices, offering low cost, high integration, and strong adaptability, making it particularly suitable for end-user information acquisition devices with requirements regarding size, power supply, and cost.

[0064] 3. The real-time resistance acquisition stage employs a constant current source combined with a high-gain differential amplifier, along with a continuous sampling strategy using a set frequency and interval, to achieve high-precision tracking of minute voltage changes in the thermistor. Compared to traditional single-point or timed sampling methods, this scheme's time-series sampling significantly improves the ability to capture instantaneous temperature dynamics. Furthermore, the acquired resistance data is substituted into the polynomial mapping model obtained during the parameter calibration stage to achieve real-time conversion from resistance to temperature. This strategy not only improves the sensitivity and nonlinear response capability of temperature conversion but also breaks through the limitations of traditional methods relying on lookup tables or linear approximations, avoiding back-calculation deviations caused by interpolation errors. By mapping instantaneous temperature changes to current changes, the accuracy of the current back-calculation model is further solidified, providing a solid basis for subsequent energy consumption calculations.

[0065] 4. The introduction of the thermal response factor is a key technological breakthrough in dynamic response modeling. The thermal response factor reflects the response speed and characteristics of the thermistor from initial temperature rise to steady state. The system obtains a standardized response model through normalization of the power injection curve, enabling the current inverse calculation model to no longer be limited to steady-state conditions but dynamically adapt to unsteady power fluctuation scenarios. Compared to the static or empirical formula inverse methods commonly used in existing technologies, this scheme incorporates thermal dynamic behavior into the inverse equation for the first time, significantly enhancing its adaptability to complex situations such as rapid load changes and sudden current surges. The instantaneous current obtained from the thermal balance equation is the core calculation result of the entire system, ensuring accurate acquisition of highly dynamic load characteristics without directly sampling large currents. This represents an important application exploration of intelligent, non-contact current detection technology.

[0066] 5. By integrating the current sequence, the cumulative energy value at each moment is obtained, and it is divided into several levels according to a preset energy upper limit, realizing continuous classification and risk level assessment of electricity consumption behavior. This mechanism can set level thresholds based on the terminal equipment design current and detection cycle to generate a dynamic energy level sequence, which not only facilitates the analysis of load operating status but also serves as a basic parameter for equipment overload early warning, fault identification, and energy-saving control. Compared with the coarse-grained judgment of existing technologies that only calculate total energy or maximum current, this invention constructs a complete multi-level data chain of "current-energy-level", improving the analysis dimensions and real-time response capabilities, and is particularly suitable for implementation in multiple scenarios such as industrial power distribution, smart grids, and new energy equipment monitoring.

[0067] 6. The final output module not only includes single data indicators but also comprehensively covers results from multiple dimensions, such as peak current, average value, cumulative energy, real-time current sequence, and energy level sequence. This output structure can directly interface with host computer systems, IoT gateways, or intelligent analysis platforms, supporting extended functions such as data visualization, intelligent alarms, and behavior pattern recognition. Its multi-dimensional output content has significant advantages over traditional single-channel, single-indicator measurement systems, especially in practical operation and maintenance scenarios, providing a more comprehensive reflection of the overall load operation. Through deployment with embedded chips or edge computing devices, the system can also achieve localized processing and data compression, providing an ideal solution for low-power, edge-intelligent power monitoring systems. Attached Figure Description

[0068] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0069] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0070] Example, refer to Figure 1 A detection circuit method applicable to various electricity consumption information collection terminals, comprising:

[0071] Set the ambient temperature, apply a known calibrated current to the shunt resistor, measure the voltage drop across it to calculate the resistance value, and measure the resistance value of the thermistor at multiple temperature points to establish a third-order mapping relationship between resistance and temperature, and calculate the thermal resistance and thermal response characteristics.

[0072] Connect the calibrated shunt resistor in series to the circuit under test, attach the thermistor to the surface of the shunt resistor, and apply high thermal conductivity silicone grease to the contact surface. At the same time, connect the thermistor to the constant current source and the differential amplifier.

[0073] The voltage signal across the thermistor is obtained through a constant current source and a differential amplifier, sampled at a set frequency, and the instantaneous resistance at the sampling time is calculated.

[0074] The collected resistance data is substituted into the polynomial mapping model and converted into the corresponding instantaneous temperature value.

[0075] Calculate the thermal response factor based on temperature changes;

[0076] The instantaneous current at each moment is obtained by back-calculating the current value using the heat balance equation;

[0077] Calculate the cumulative electrical energy at any given time, classify energy levels according to the preset maximum energy, and determine the current energy level;

[0078] Output the detected peak current, average current, total cumulative energy, and current sequence and energy level sequence.

[0079] This system integrates multiple steps, including environmental parameter calibration, circuit construction, resistance acquisition, temperature conversion, current inversion, energy integration, and risk assessment, forming a complete thermo-electric modeling and inverse calculation detection chain. By setting the ambient temperature and performing multi-point resistance measurements, a temperature-resistance mapping model for thermistors is established, ensuring the accuracy of temperature calculations from the source. A physical thermal coupling structure (thermistor and shunt resistor bonded together with thermal grease) enhances the thermal response speed, ensuring the thermistor's immediate response to current changes. Furthermore, a constant current source and differential amplifier enable real-time, high-precision sampling of minute voltage changes. After substituting the sampled resistance value into a polynomial model for real-time temperature conversion, the instantaneous current is inversely calculated using the thermal balance formula. This method avoids the cost and size issues associated with traditional current detection methods that require the use of Hall effect devices or high-power current sensors. Simultaneously, energy calculation is performed by combining current integration, and the results are further output according to risk levels, enabling electricity consumption behavior classification and risk warning. The entire method is not only compact and low-cost, but also achieves high-precision, widely compatible, and easily deployed embedded intelligent power detection capabilities, making it particularly suitable for low-power, distributed sensing terminals.

[0080] The ambient temperature is set, a known calibration current is applied to the shunt resistor, the voltage drop across it is measured to calculate the resistance value, and the resistance value of the thermistor is measured at multiple temperature points to establish a third-order mapping relationship between resistance and temperature. The thermal resistance and thermal response characteristics are then calculated, specifically including:

[0081] Measure and set the ambient temperature to T. env ; Obtain the baseline temperature of the testing environment to provide a reference line for all subsequent temperature rise calculations;

[0082] Apply a known rated current I cal For the shunt resistor, measure the voltage drop V across the shunt resistor. cal Calculate the shunt resistance Accurately measure the shunt resistance R sh This provides accurate resistance values ​​for subsequent current conversion;

[0083] At ambient temperature T env Measuring the resistance R of the thermistor ref ; Obtain the resistance value of the thermistor at the reference temperature for subsequent resistance deviation calculation;

[0084] At three sets of temperature points (T) i ,R i The resistance value is measured at point ), let ΔR i =R i -R ref ΔT i =T i -T env Where i = {1, 2, 3} is the temperature point index; T iR is the temperature of the i-th calibration point; i Let ΔR be the resistance value corresponding to the i-th calibration point temperature; i For resistance deviation; ΔT i Temperature deviation;

[0085] Establish a third-order mapping relationship: Where c1 is the coefficient of the linear term; c2 is the coefficient of the quadratic term; and c3 is the coefficient of the cubic term.

[0086] Set the impedance matrix as follows:

[0087]

[0088] Set the temperature difference vector as: ΔT=(ΔT1,ΔT2,ΔT3) T ;

[0089] The coefficient vector is solved as follows:

[0090]

[0091] A polynomial mapping model of thermistor resistance deviation ΔR and temperature deviation ΔT is constructed to provide an accurate mathematical relationship for substituting the collected resistance data into the polynomial mapping model in real time and converting it into the corresponding instantaneous temperature value.

[0092] Apply constant current I th Power is generated by the thermistor.

[0093] Record the temperature versus time curve T(t);

[0094] Calculate steady-state temperature rise

[0095] Calculate thermal resistance

[0096] Select the one that satisfies Time t1, antipyretic duration:

[0097]

[0098] The dynamic characteristics of the thermistor—thermal resistance Θ and thermal time constant τ—are determined for thermal equilibrium and response modeling.

[0099] The parameter calibration process was detailed, particularly focusing on temperature setting, resistance measurement, and thermal modeling, proposing a complete modeling and calculation workflow. First, a baseline measurement environment was established by setting the ambient temperature, ensuring controlled temperature rise changes in resistance values. Second, a constant calibration current was applied to the shunt resistor, and the voltage drop was measured. Ohm's law was used to accurately deduce the resistance value, providing a reliable physical basis for current inversion. Furthermore, the system collected thermistor resistance values ​​at multiple temperature points, constructing a thermal resistance-temperature correspondence sample set, and establishing a mapping relationship using a third-order polynomial fitting method. This modeling method offers higher approximation accuracy and interpretability than traditional first-order or lookup table methods, better reflecting the nonlinear characteristics of thermistors. Next, steady-state temperature rise and thermal resistance values ​​were obtained through constant current excitation and temperature curve recording, further determining the thermal duration. This process ensures that the thermal response characteristics can be dynamically quantified under different current excitation conditions. The overall calibration strategy, based on data integrity, model accuracy, and physical repeatability, lays a solid foundation for the accuracy of subsequent inversion calculations.

[0100] The process of connecting the calibrated shunt resistor in series with the circuit under test, attaching a thermistor to the surface of the shunt resistor, applying high thermal conductivity silicone grease to the contact surface, and connecting the thermistor to a constant current source and a differential amplifier specifically includes:

[0101] The calibrated shunt resistor R sh Insert it into the circuit under test and place the thermistor in close contact with its casing; ensure that the heat generated by the shunt resistor can be efficiently transferred to the thermistor;

[0102] Apply high thermal conductivity silicone grease to the contact surface between the two surfaces to reduce the contact thermal resistance R. c <0.1Θ; Reduces the heat transfer barrier, improving measurement rate and sensitivity;

[0103] Connect the two ends of the thermistor to a constant current source I. th A differential amplifier, with an amplification factor denoted as G, provides a stable drive current and amplifies weak voltage signals to prepare for high-precision sampling.

[0104] From a hardware construction perspective, the physical connection method between the shunt resistor and the thermistor is clearly defined, and the thermal coupling enhancement method is emphasized. Specifically, the shunt resistor is connected in series with the circuit under test as a heating element, while the thermistor is attached to its surface to form a thermal contact coupling structure. To optimize the heat conduction path, high thermal conductivity silicone grease is applied between the two to reduce thermal resistance and improve heat transfer efficiency. This structural design ensures that the thermistor can quickly sense the heat rise caused by current changes, enhancing response speed and measurement accuracy. In the supporting circuit, a constant current source and a differential amplifier are connected to the two ends of the thermistor. The constant current source provides stable excitation, while the differential amplifier amplifies the weak thermistor voltage drop signal for subsequent sampling and processing. This structured and integrated circuit construction method effectively solves practical problems such as thermal response hysteresis, weak signal-to-noise ratio, and high structural complexity. It achieves a deep integration of hardware structure optimization and thermoelectric characteristic adaptation, providing a reliable current sensing solution for low-power, highly integrated terminal devices.

[0105] The process of acquiring the voltage signal across the thermistor via a constant current source and a differential amplifier, sampling it at a set frequency, and calculating the instantaneous resistance at the sampling moment specifically includes:

[0106] Constant current source maintains I th Maintain a stable current in the thermistor so that its temperature rise is determined only by current fluctuations;

[0107] Differential amplifier output V t (t), using sampling frequency f s Sampling interval Recorded to the sampling sequence {V t (t k )};where, t k =(k-1)Δt, k={1,2,...,K}; V t (t k () represents the voltage at the kth sampling point; K represents the total number of sampling points; the microvolt-level signal across the resistor is amplified and acquired according to a fixed timing sequence;

[0108] Calculate time t k instantaneous resistance of thermistor Based on Ohm's law, the voltage sample value is converted into the instantaneous resistance value of the thermistor.

[0109] This design focuses on solving the problem of high-frequency, high-precision data acquisition. It achieves continuous sampling of the thermistor voltage signal through a combination of a constant current source and a differential amplifier. The sampling process uses a fixed frequency and time interval, recording the data as a sequence to provide fundamental data support for subsequent calculations. The constant current source provides a constant current, stabilizing the thermistor's operating state and ensuring that the thermistor's heating process is only affected by current changes, eliminating interference from drive fluctuations. The differential amplifier amplifies small voltage differences with high gain, improving the signal-to-noise ratio and adapting to the small output range and rapid changes of the thermistor. Ohm's law is used to calculate the instantaneous resistance of the thermistor, accurately reflecting its thermal changes. In traditional detection methods, sampling delay and resolution are often bottlenecks in the accuracy of electrical parameter measurements. This invention, through a combination of hardware gain and sampling strategies, not only improves the system's dynamic response capability but also significantly reduces cost and complexity, providing data support for subsequent temperature and current inversion.

[0110] The step of substituting the collected resistance data into a polynomial mapping model to convert it into the corresponding instantaneous temperature value specifically includes:

[0111] Calculate the resistance deviation ΔR(t) k ) = R t (t k )-R ref Extracting resistance fluctuations involves substituting the collected resistance data into a polynomial mapping model to convert it into the corresponding instantaneous temperature value input.

[0112] Set up a polynomial mapping to calculate the instantaneous temperature:

[0113] T t (t k ) = T env +c1ΔR(t k )+c2[ΔR(t k )] 2 +c3[ΔR(t k )] 3 Among them, T t (t k (t) represents time t k Temperature conversion; mapping resistance deviation to real-time temperature to reflect the thermistor characteristics.

[0114] By establishing a mapping relationship between thermistor resistance and temperature, real-time conversion from resistance to temperature is achieved. First, the deviation data between the current thermistor resistance and the reference resistance is extracted. Then, this deviation is used as a variable input into a pre-modeled polynomial mapping equation. Compared to traditional lookup table methods or linear mapping, this method uses third-order polynomial modeling, which can more accurately fit the nonlinear thermal response characteristics of the thermistor and avoid temperature calculation errors caused by linear simplification. This mapping method is particularly effective in scenarios with large ambient temperature variations and frequent load fluctuations, demonstrating greater system robustness. Furthermore, real-time temperature conversion based on resistance provides a physical basis for subsequent thermal response factor calculation and current inversion. This scheme transforms complex thermophysical changes into rapidly solvable algebraic problems through mathematical modeling, improving system response speed while enhancing its versatility and deployment flexibility.

[0115] The calculation of the thermal response factor based on temperature change specifically includes:

[0116] Set the normalized response factor to It depicts the dynamic evolution of the thermistor from the initial state to the steady state, and is used to compensate for transient temperature rise.

[0117] This invention introduces the concept of a "thermal response factor" to establish a quantitative model of the response process of a thermistor from a cold state to a thermal steady state. Through normalization, the actual temperature rise curve is standardized into a unit response function, which reflects the thermal dynamic evolution characteristics of the thermistor. In practical applications, load current changes are often instantaneous, while the thermistor's response exhibits hysteresis. Failure to correct for this hysteresis can lead to inaccurate or delayed current calculations. This invention compensates for the error caused by thermal hysteresis through a thermal response factor calculation step, enabling relatively accurate instantaneous current estimation results even under non-steady-state conditions. This design significantly improves the system's adaptability to dynamic scenarios such as rapid load changes and power surges, enhancing the model's practicality.

[0118] The process of calculating the instantaneous current at each moment by back-calculating the current value through the heat balance equation specifically includes:

[0119] Calculate the temperature rise ΔT(t) k ) = T t (t k )-T env ; Calculate the actual temperature increment to prepare for current estimation;

[0120] From the heat balance equation ΔT=I 2 R sh ΘF, solution time t k Instantaneous current:

[0121] The instantaneous current being measured can be deduced by using a thermal balance model.

[0122] One of the core innovations of this method is the reverse current estimation achieved through the thermal balance equation. Based on the temperature rise and thermal response characteristics of the thermistor, the system inversely derives the current value at the corresponding moment. This approach avoids the problems of large size, high power consumption, and integration difficulties associated with directly sampling current signals using Hall sensors or current transformers. Provided the thermal modeling is accurate, the thermal balance formula is used to link parameters such as temperature rise, electrical power, and thermal resistance, constructing a reverse current estimation path. This method not only possesses strong computability and physical basis but also, due to its reverse modeling logic, has a greater advantage in detecting small current fluctuations in high-voltage systems, showing broad engineering application prospects.

[0123] The calculation of accumulated electrical energy at each time point, based on a preset maximum energy level classification, determines the current energy level, specifically including:

[0124] Calculate up to time t k Accumulated electrical energy is Discrete integral, quantized to the current time step of energy consumption;

[0125] Based on the maximum design current I max And the longest detection time T max Calculate the preset maximum energy:

[0126] The upper limit of the cumulative grading is defined based on the maximum design current and the longest measurement duration.

[0127] [0, E max Divided into N levels, with inter-level thresholds as follows: Where h = {0, 1, ..., N}; where N is the total number of energy levels; E h The threshold for level h is defined by h, where h is the level index. Isostatic energy level boundaries are generated for subsequent level determination.

[0128] Energy level determination: L(t) k ) = m, if E m-1 ≤E(t k ) <E m Where m = {1, 2, ... N}; where L(t) k (t) represents time t k Energy level; m is the energy level number; mapping the current accumulated energy to the corresponding energy level facilitates segmented statistics and alarms.

[0129] This invention converts current integration into energy values ​​and classifies energy levels to endow the system with intelligent monitoring capabilities. During integration, current values ​​at discrete time points are accumulated to obtain the cumulative electrical energy at any given moment. An energy upper limit is set based on the system's maximum designed current and time window, and the energy is evenly divided into multiple levels to generate a threshold sequence. This grading mechanism facilitates risk classification and anomaly identification of electricity consumption behavior. For example, if the energy level rises too rapidly in a short period, it can indicate overload or equipment malfunction. Traditional energy statistics methods only output total electricity data, making it difficult to reflect real-time trend changes. This invention, however, can dynamically output energy level change curves, improving the practicality and forward-looking nature of the electricity monitoring system.

[0130] The output includes the detected peak current, average current, total cumulative energy, and current sequence and energy level sequence, specifically:

[0131] Calculate peak current Obtain the maximum current value throughout the entire detection cycle to assess load spikes;

[0132] Calculate the average current Calculate the average current during the monitoring period to reflect the overall electricity consumption level;

[0133] Calculate the total cumulative energy E total =E(t) K Provides the total energy consumption during the testing period for energy consumption analysis.

[0134] Output current sequence {I m (t k )}、Energy level sequence {L(t) k Peak current I peak Average current I avg Total accumulated energy E total It presents complete detection results to users or monitoring platforms, supporting statistics, visualization, and alerts.

[0135] It integrates all system detection results, including peak current, average current, cumulative energy, current sequence, and energy level sequence. These results can be used for user behavior analysis, equipment operation diagnosis, fault early warning, and energy consumption optimization. The output data is rich in variety and fine in granularity, far exceeding traditional single power or current value output methods. It has high visualization and statistical analysis capabilities, making it suitable for embedded deployment and edge intelligent processing. This output mechanism not only supports historical behavior tracking but also provides a training data foundation for intelligent algorithm modeling, serving as an important support for achieving adaptive energy-saving control and predictive maintenance.

[0136] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0137] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A detection circuit method applicable to various electricity consumption information collection terminals, characterized in that, include: Set the ambient temperature, apply a known calibrated current to the shunt resistor, measure the voltage drop across it to calculate the resistance value, and measure the resistance value of the thermistor at multiple temperature points to establish a third-order mapping relationship between resistance and temperature, and calculate the thermal resistance and thermal response characteristics. Connect the calibrated shunt resistor in series to the circuit under test, attach the thermistor to the surface of the shunt resistor, and apply high thermal conductivity silicone grease to the contact surface. At the same time, connect the thermistor to the constant current source and the differential amplifier. The voltage signal across the thermistor is obtained through a constant current source and a differential amplifier, sampled at a set frequency, and the instantaneous resistance at the sampling time is calculated. The collected resistance data is substituted into the polynomial mapping model and converted into the corresponding instantaneous temperature value. Calculate the thermal response factor based on temperature changes; The instantaneous current at each moment is obtained by back-calculating the current value using the heat balance equation; Calculate the cumulative electrical energy at any given time, classify energy levels according to the preset maximum energy, and determine the current energy level; Output the detected peak current, average current, total cumulative energy, and current sequence and energy level sequence.

2. The detection circuit method applicable to various electricity consumption information collection terminals according to claim 1, characterized in that, The ambient temperature is set, a known calibration current is applied to the shunt resistor, the voltage drop across it is measured to calculate the resistance value, and the resistance value of the thermistor is measured at multiple temperature points to establish a third-order mapping relationship between resistance and temperature. The thermal resistance and thermal response characteristics are then calculated, specifically including: Measure and set the ambient temperature to ; Apply a known rated current For the shunt resistor, measure the voltage drop across the shunt resistor. Calculate the shunt resistance ; At ambient temperature Measuring the resistance of a thermistor ; At three sets of temperature points The resistance value is measured at [location], let [condition] ,;in, For temperature point indexing; For the first Temperature at each calibration point; For the first The resistance value corresponding to each calibration point temperature; This refers to the resistance deviation. Temperature deviation; Establish a third-order mapping relationship: ;in, The coefficient of the linear term; The coefficient of the quadratic term; The coefficient of the cubic term; Set the impedance matrix as follows: ； Set the temperature difference vector as follows: ; The coefficient vector is solved as follows: ； Apply constant current Power is generated by the thermistor. ; Record temperature over time curve ; Calculate steady-state temperature rise ; Calculate thermal resistance ; Select the one that satisfies The moment Antipyretic frequency: 。 3. The detection circuit method applicable to various electricity consumption information collection terminals according to claim 2, characterized in that, The process of connecting the calibrated shunt resistor in series with the circuit under test, attaching a thermistor to the surface of the shunt resistor, applying high thermal conductivity silicone grease to the contact surface, and connecting the thermistor to a constant current source and a differential amplifier specifically includes: The calibrated shunt resistor Insert it into the circuit under test and place the thermistor tightly against its casing; Apply high thermal conductivity silicone grease to the contact surface between the two surfaces to reduce contact thermal resistance. ; Connect the two ends of the thermistor to a constant current source. Differential amplifiers, the amplification factor is denoted as... .

4. The detection circuit method applicable to various electricity consumption information collection terminals according to claim 3, characterized in that, The process of acquiring the voltage signal across the thermistor via a constant current source and a differential amplifier, sampling it at a set frequency, and calculating the instantaneous resistance at the sampling moment specifically includes: Constant current source maintenance ; Differential amplifier output Using sampling frequency Sampling interval Recorded to the sampling sequence ;in, For the first Second sampling voltage; This represents the total number of sampling points; Calculation time instantaneous resistance of thermistor .

5. The detection circuit method applicable to various electricity consumption information collection terminals according to claim 4, characterized in that, The step of substituting the collected resistance data into a polynomial mapping model to convert it into the corresponding instantaneous temperature value specifically includes: Calculate resistance deviation ; Set up a polynomial mapping to calculate the instantaneous temperature: ;in, For a moment Convert the temperature.

6. The detection circuit method applicable to various electricity consumption information collection terminals according to claim 5, characterized in that, The calculation of the thermal response factor based on temperature change specifically includes: Set the normalized response factor to .

7. The detection circuit method applicable to various electricity consumption information collection terminals according to claim 6, characterized in that, The process of calculating the instantaneous current at each moment by back-calculating the current value through the heat balance equation specifically includes: Calculate temperature rise ; From the heat balance equation Solution time Instantaneous current: 。 8. The detection circuit method applicable to various electricity consumption information collection terminals according to claim 7, characterized in that, The calculation of accumulated electrical energy at each time point, based on a preset maximum energy level classification, determines the current energy level, specifically including: Calculate up to time Accumulated electrical energy is ; Based on the maximum design current and longest detection time Calculate the preset maximum energy: ； Will Divided into equal parts Level, inter-level threshold is: ,in, ;in, The total number of energy levels; For the first Level threshold; For level index; Energy level determination: ,like ;in, ;in, For a moment Energy level; This is the energy level sequence number.

9. A detection circuit method applicable to various electricity consumption information collection terminals according to claim 8, characterized in that, The output includes the detected peak current, average current, total cumulative energy, and current sequence and energy level sequence, specifically: Calculate peak current ; Calculate total accumulated energy ; Output current sequence Energy level sequence Peak current Average current Total accumulated energy .

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