A method and device for online evaluation and detection of power supply dynamic efficiency

Abstract

The present application relates to power supply dynamic efficiency detection technical field, and disclose a kind of power supply dynamic efficiency online evaluation detection method, comprising the following steps, shunt resistance and binding post key position in resistance load instrument are deployed acquisition module, temperature is collected in real time, resistance change caused by temperature is converted into electric signal, in the present application, the scheme is deployed thin film platinum resistance acquisition module in resistance load instrument shunt resistance and binding post key position, four-wire connection method is used to eliminate lead resistance influence, establish the relationship model of shunt resistance and binding post temperature and resistance, the resistance change amount is calculated in combination with Kalman filter and adaptive weighted average algorithm, the measurement signal is corrected in real time by compensation module consisting of programmable gain amplifier and digital potentiometer, the measurement error caused by shunt resistance and binding post temperature change can be reduced by more than 90%, the measurement accuracy of electronic load instrument is improved to ±0.1% or less, ensure that power supply dynamic efficiency evaluation detection result is accurate and reliable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power supply dynamic efficiency detection, in particular to a power supply dynamic efficiency online evaluation and detection method and device. BACKGROUND

[0002] The power supply dynamic efficiency refers to the ratio of output effective power to input power of the power supply in the process of load dynamic change, which reflects the adaptability of the power supply to dynamic load and energy conversion efficiency. When the load current or power changes suddenly, the output voltage and current of the power supply will have transient response, and the energy conversion efficiency of the power supply will be different from that in the steady state. The power supply with good dynamic efficiency can maintain high energy conversion efficiency when the load changes rapidly, reduce energy loss, ensure the stability of output voltage, and reduce ripple and noise, which is very important for electronic devices with high requirements on power supply performance, such as servers and communication devices.

[0003] Electronic load instrument is often used to evaluate and detect the dynamic efficiency of power supply. The electronic load instrument can simulate the dynamic change of actual load by setting parameters such as load rising or falling slope, change amplitude, period, etc., so that the power supply works under different dynamic load conditions. During the detection process, the electronic load instrument monitors the input voltage, current and output voltage, current, etc. of the power supply in real time, and calculates the corresponding dynamic efficiency. At the same time, the transient response characteristics of the power supply under dynamic load change can be observed, such as voltage overshoot and recovery time, so as to comprehensively evaluate the dynamic performance of the power supply.

[0004] In the prior art, when the electronic load instrument is used for evaluation and detection, the shunt resistance and terminal post inside the electronic load instrument will generate heat due to the current passing through, and the temperature change will affect the resistance value of the shunt resistance. According to the temperature characteristics of the resistance, when the temperature rises, the resistance value of the shunt resistance may change, which will cause deviation in current measurement. At the same time, the temperature change of the terminal post may also cause the change of contact resistance, which will affect the actual working state of the circuit. There is no detection and compensation mechanism for the temperature change of the shunt resistance and terminal post, so the measurement error introduced by these temperature factors cannot be corrected, which finally affects the stability of power supply dynamic efficiency evaluation and detection, and reduces the accuracy and reliability of the detection results.

[0005] Therefore, we propose a power supply dynamic efficiency online evaluation and detection method and device. SUMMARY

[0006] (1) The technical problem to be solved

[0007] In view of the deficiencies of the prior art, the present application provides a power dynamic efficiency online evaluation detection method and device, which solves the problem that the internal shunt resistor and the terminal post will generate heat due to current passing, affecting the actual working state of the circuit, lacking a temperature change detection compensation mechanism, and affecting the detection accuracy.

[0008] (II) Technical scheme

[0009] To achieve the above object, the present application is implemented by the following technical scheme: a power dynamic efficiency online evaluation detection method, comprising the following steps:

[0010] Step one: deploy a collection module at the key position of the shunt resistor and the terminal post in the resistance load instrument to collect temperature in real time, convert the resistance change caused by temperature into an electrical signal, and provide real-time and accurate temperature data basis for the system;

[0011] Step two: establish a shunt resistor temperature and resistance relationship model and a terminal post temperature and resistance relationship model;

[0012] Step three: after receiving the temperature data in real time, calculate the resistance change amount of the shunt resistor and the terminal post according to the relationship model and the dynamic compensation algorithm, and generate accurate compensation parameters;

[0013] Step four: adjust the gain and resistance value of the measurement signal through the compensation module, and correct the signal in real time through the hardware circuit to offset the influence of temperature change on the resistance value of the shunt resistor and the terminal post, thereby improving the accuracy of the electronic load instrument in evaluating and detecting the power dynamic efficiency and ensuring the reliability of the output measurement signal.

[0014] Preferably, the collection module is a thin-film platinum resistor, wherein at least not less than two thin-film platinum resistors are arranged on the shunt resistor and the terminal post, a four-wire connection method is adopted, and the influence of lead resistance is eliminated through independent excitation lines and measurement lines.

[0015] Preferably, the relationship model between the shunt resistor temperature and the resistance is that the resistance value change of the shunt resistor has a linear relationship with the temperature, and the mathematical model can be expressed as:

[0016]

[0017] wherein R T is the resistance value under temperature T, is the resistance value under reference temperature T0, and a is the temperature coefficient of the resistance.

[0018] Preferably, the relationship model between the terminal post temperature and the resistance has a mathematical model as follows:

[0019]

[0020] wherein R is the resistance of the terminal at temperature T, R0 is the resistance of the terminal at reference temperature T0, contact β is the temperature coefficient of the terminal material.

[0021] Preferably, the dynamic compensation algorithm: by receiving data in real time, by calculating the actual resistance of the shunt resistance and the terminal at the current temperature through the above relationship model, introducing the dynamic correction mechanism based on Kalman filtering algorithm, denoising the temperature data, and combining the historical data to predict the temperature change trend, at the same time, in order to eliminate the influence of environmental temperature mutation on measurement, using adaptive weighted average algorithm, dynamically adjusting the compensation parameter weight according to the temperature change rate, ensuring the timeliness and accuracy of compensation;

[0022] The shunt resistance resistance change ΔR shunt The calculation formula is:

[0023]

[0024] The terminal resistance change calculation formula is:

[0025]

[0026] The overall resistance change ΔR total The rate calculation formula is:

[0027] ΔR total = ΔR J + ΔR shunt

[0028] wherein T fusion is the temperature value after Kalman filtering and adaptive weighted fusion, and ΔR contact is the terminal contact resistance change.

[0029] The core formula of Kalman filtering algorithm

[0030] I. State space model

[0031] State vector x k : wherein T k is the temperature at the kth moment, is the temperature change rate, i.e. the temperature change per unit time;

[0032] Prediction equation:

[0033] Measurement equation: z k = [1, 0] x k + v k , wherein w kv k For process noise and measurement noise, Δt is the sampling period, and x is the measurement noise. k-1 Let z be the state vector at time k-1. k Let be the measurement value at time k.

[0034] II. Iterative Update Formula

[0035] predict: P k|k-1 =AP k-1|k-1 A T +Q, where To predict the state vector, based on the state at time k-1, predict the state at time k. Let A be the state transition matrix, describing the state transition from time k-1 to time k. Let P be the state vector. k|k-1 Predicted covariance matrix, Q-process noise covariance, P k-1|k-1 The covariance matrix is ​​corrected at time k-1. This is the state vector after correction at time k-1.

[0036] Correction:

[0037] K k =P k|k-1 H T HP k|k-1 H T +R) -1

[0038]

[0039] Where K k Kalman gain, The corrected state vector, where H is the observation matrix and R is the measurement noise covariance matrix;

[0040] Adaptive weighted average algorithm formula

[0041] I. Dynamic Weight Calculation

[0042]

[0043] Where w i Let λ be the dynamic weight corresponding to the temperature-related data at time i, and let λ be the weight adjustment coefficient. k

[0044] The estimated rate of temperature change over time. This is the estimated rate of temperature change at time i. For the first j

[0045] The estimated rate of temperature change at any given time, where n is the total number of historical time points (or data sets) involved in the weighting calculation and temperature fusion;

[0046] II. Temperature fusion value

[0047]

[0048] Wherein is the temperature estimation value at the previous i moment;

[0049] Preferably, the compensation module comprises a programmable gain amplifier PGA and a digital potentiometer.

[0050] Preferably, the compensation circuit of the programmable gain amplifier PGA and the digital potentiometer works together, according to the calculated resistance change amount, outputs a control signal to adjust the resistance value of the digital potentiometer, changes the gain multiple of the PGA, and the gain adjustment formula of the compensation circuit is:

[0051]

[0052] Wherein, A is the gain of the compensation circuit, R comp is the compensation resistance value of the digital potentiometer, R ref is the reference resistance value.

[0053] An online evaluation and detection device of power supply dynamic efficiency comprises a plurality of thin film platinum resistors, a signal adjustment chip, a micro control unit MCU, a programmable gain amplifier PGA and a digital potentiometer; the plurality of thin film platinum resistors are respectively mounted on the binding posts and shunt resistors, and each thin film platinum resistor is connected with each signal adjustment chip by adopting four-wire system; the signal adjustment chip communicates with the MCU by adopting SPI interface, transmits the digital temperature data to the micro control unit MCU for processing; the micro control unit MCU is connected with the master control unit of the electronic load instrument by adopting CAN bus, and transmits the temperature data and the calculated compensation parameters.

[0054] Preferably, the micro control unit MCU needs to be configured with at least 2MHz SPI clock frequency, so as to ensure that the temperature data acquisition period is less than 10ms.

[0055] Preferably, the programmable gain amplifier PGA is connected with the micro control unit MCU by adopting SPI / I 2 C bus, and the digital potentiometer is connected with the micro control unit MCU by adopting I 2 C bus.

[0056] In summary, the technical effects and advantages of the present application are:

[0057] 1. In the present application, the scheme is to deploy thin film platinum resistance acquisition modules at the key positions of the shunt resistance and the terminal post of the resistance load instrument, to eliminate the influence of lead resistance by adopting four-wire connection method, to establish the relationship model of the temperature and resistance of the shunt resistance and the terminal post, to calculate the resistance change amount by combining Kalman filtering and adaptive weighted average algorithm, and to reduce the measurement error caused by the temperature change of the shunt resistance and the terminal post by more than 90% through the compensation module composed of the programmable gain amplifier and the digital potentiometer, so as to improve the measurement accuracy of the electronic load instrument to within ±0.1%, and to ensure the accuracy and reliability of the power dynamic efficiency evaluation and detection results. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 A flow chart of the online evaluation and detection method of the power dynamic efficiency. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0060] An online evaluation and detection device of power dynamic efficiency, comprising a plurality of thin film platinum resistors, a signal adjustment chip, a micro control unit MCU, a programmable gain amplifier PGA and a digital potentiometer.

[0061] Among them, a plurality of thin film platinum resistors are respectively installed on the terminal post and the shunt resistance, and each thin film platinum resistor is connected with each signal adjustment chip by four-wire connection, the signal adjustment chip communicates with the MCU by SPI interface, transmits the digitized temperature data to the micro control unit MCU for processing, the micro control unit MCU is connected with the main control unit of the electronic load instrument by CAN bus, transmits the temperature data and the calculated compensation parameters, the micro control unit MCU needs to be configured with at least 2MHz SPI clock frequency to ensure that the temperature data acquisition period is less than 10ms, the programmable gain amplifier PGA is connected with the micro control unit MCU by SPI / I 2 C bus, and the digital potentiometer is connected with the micro control unit MCU by I 2 C bus.

[0062] Step one: deploy the acquisition module at the key positions of the shunt resistance and the terminal post in the resistance load instrument, and collect the temperature in real time, and convert the resistance change caused by the temperature into an electrical signal to provide real-time and accurate temperature data basis for the system;

[0063] Step two: establish the relationship model of shunt resistance temperature and resistance, and establish the relationship model of terminal temperature and resistance;

[0064] Step three: after receiving real-time temperature data, calculate the resistance change of shunt resistance and terminal according to the relationship model and dynamic compensation algorithm, and generate accurate compensation parameters;

[0065] Step four: adjust the gain and resistance value of the measurement signal through the compensation module, and correct the signal in real time through the hardware circuit, offset the influence of temperature change on the resistance value of shunt resistance and terminal, so as to improve the accuracy of electronic load instrument in evaluating and detecting the dynamic efficiency of power supply, and ensure the reliability of output measurement signal.

[0066] Among them, the collection module is a thin film platinum resistance, in which at least two thin film platinum resistances are arranged on the shunt resistance and the terminal, and four-wire connection method is adopted to eliminate the influence of lead resistance through independent excitation line and measurement line.

[0067] Among them, the relationship model of shunt resistance temperature and resistance: the resistance change of shunt resistance has a linear relationship with temperature, and its mathematical model can be expressed as:

[0068]

[0069] Among them, R T is the resistance value at temperature T, is the resistance value at reference temperature T0, and α is the temperature coefficient of resistance.

[0070] Among them, the relationship model of terminal temperature and resistance is:

[0071]

[0072] Among them is the resistance of terminal at temperature T, is the resistance of terminal at reference temperature T0, ΔR contact is the additional resistance caused by the change of contact state, and β is the temperature coefficient of terminal material.

[0073] Among them, the dynamic compensation algorithm: by receiving data in real time, calculating the actual resistance of shunt resistance and terminal at current temperature through the above relationship model, introducing dynamic correction mechanism based on Kalman filtering algorithm, carrying out noise reduction processing on temperature data, combining historical data to predict temperature change trend, at the same time, in order to eliminate the influence of environmental temperature mutation on measurement, adopting adaptive weighted average algorithm, dynamically adjusting the weight of compensation parameters according to temperature change rate, ensuring the timeliness and accuracy of compensation;

[0074] The resistance change of shunt resistance ΔR shunt The calculation formula is:

[0075]

[0076] The terminal resistance change amount calculation formula is:

[0077]

[0078] The overall resistance change ΔR total The rate calculation formula is:

[0079] ΔR total = ΔR J + ΔR shunt

[0080] Where T fusion is the temperature value after Kalman filtering and adaptive weighted fusion, and ΔR contact is the terminal contact resistance change amount.

[0081] The core formula of Kalman filtering algorithm

[0082] I. State space model

[0083] State vector x k : Where T k is the temperature at the kth time, is the temperature change rate, i.e. the temperature change amount per unit time;

[0084] Prediction equation:

[0085] Measurement equation: z k = [1, 0] x k + v k , where w k , v k are process noise and measurement noise, Δt is the sampling period, x k-1 is the state vector at the k-1th time, z k is the measurement value at the kth time.

[0086] II. Iterative update formula

[0087] Prediction: P k|k-1 = AP k-1|k-1 A T + Q, where is the predicted state vector, the state at the kth time based on the state at the k-1th time, A is the state transition matrix, describing the transition relationship of the state from the k-1th time to the kth time, P k|k-1 is the predicted covariance matrix, Q is the process noise covariance, P k-1|k-1 is the covariance matrix after correction at the k-1th time, the corrected state vector at time k-1.

[0088] correction:

[0089] K k = P k|k-1 H T (HP k|k-1 H T + R) -1

[0090]

[0091] where K k is the Kalman gain, the corrected state vector, H is the observation matrix, and R is the measurement noise covariance matrix.

[0092] adaptive weighted average algorithm formula

[0093] I. Dynamic weight calculation

[0094]

[0095] where w i is the dynamic weight corresponding to the temperature-related data at the i-th time, and λ is the weight adjustment coefficient, the estimated value of the temperature change rate at the k

[0096] -th time, is the estimated value of the temperature change rate at the i-th time, is the estimated value of the temperature change rate at the j

[0097] -th time, and n is the total number of historical times (or data sets) participating in weight calculation and temperature fusion.

[0098] II. Temperature fusion value

[0099]

[0100] where is the estimated value of the temperature at the i-th time.

[0101] The compensation module includes a programmable gain amplifier (PGA) and a digital potentiometer.

[0102] The programmable gain amplifier (PGA) and the digital potentiometer work together in the compensation circuit, which outputs a control signal to adjust the resistance value of the digital potentiometer according to the calculated resistance change, changes the gain multiple of the PGA, and the gain adjustment formula of the compensation circuit is:

[0103]

[0104] Wherein, A is the compensation circuit gain, R comp is the compensation resistance of the digital potentiometer, R ref is the reference resistance value.

[0105] Embodiment one

[0106] This embodiment provides an online evaluation and detection method for the dynamic efficiency of a power supply, which is used to collect the temperature of the shunt resistor and the terminal post of an electronic load instrument. The specific implementation content includes:

[0107] The implementation purpose is to accurately collect the real-time temperature of the shunt resistor and the terminal post of the electronic load instrument, to provide real-time and reliable basic data for the subsequent temperature compensation algorithm, and to ensure the measurement accuracy of the electronic load instrument under different working conditions.

[0108] Hardware:

[0109] A plurality of thin film platinum resistors (Pt1000 Heraeus PT160) are respectively installed on the terminal post and the shunt resistor, and each thin film platinum resistor is connected to each signal adjustment chip MAX31865 (supporting PT100 / PT1000, SPI output) using four-wire connection. The signal adjustment chip communicates with the micro control unit MCU STM32F103 (supporting high-speed SPI and CAN bus, main frequency ≥ 72MHz) using the SPI interface, transmits the digitized temperature data to the micro control unit MCU (STM32 series) for processing, and the micro control unit MCU is connected to the main control unit of the electronic load instrument using the CAN bus (ISO 11898 standard) to transmit the temperature data and the calculated compensation parameters.

[0110] Real-time effect: by using the high-precision and good stability of the thin film platinum resistor (the precision can reach ±0.1℃), and combining the four-wire connection method to eliminate the lead resistance error, high-precision temperature data collection (collection error ≤±0.1℃) can be realized, which provides reliable raw temperature data for the system and lays a foundation for the accuracy of the subsequent compensation algorithm.

[0111] Embodiment two

[0112] This embodiment provides an online evaluation and detection method for the dynamic efficiency of a power supply, which is used to establish the relationship model between the shunt resistor temperature and the resistance, and the relationship model between the terminal post temperature and the resistance. The specific implementation content includes:

[0113] The implementation purpose is to respectively establish the relationship model between the shunt resistor temperature and the resistance, and the relationship model between the terminal post temperature and the resistance, to describe the influence law of temperature change on the resistance values of the two through mathematical models, to provide a theoretical basis for calculating the resistance change amount according to the real-time temperature data, and to make the calculation of resistance change have a clear mathematical expression.

[0114] Relationship model:

[0115]

[0116] Implementation effect: The shunt resistance and the resistance value of the terminal post at different temperatures can be accurately calculated based on the model, and accurate calculation basis (model error ≤±0.5%) is provided for the generation of compensation parameters.

[0117] Example three

[0118] The embodiment provides an online evaluation and detection method for dynamic efficiency of a power supply, which is used for calculating resistance variation of a shunt resistance and a terminal post, and generating accurate compensation parameters. The specific implementation content includes:

[0119] Implementation purpose: After real-time receiving of temperature data, resistance variation of the shunt resistance and the terminal post is calculated according to an established relationship model and a dynamic compensation algorithm (combined with Kalman filtering and adaptive weighted average algorithm), and accurate compensation parameters are generated, noise of the temperature data is processed (Kalman filtering), temperature change trend is predicted, and the weight of the compensation parameters is dynamically adjusted according to the temperature change rate (adaptive weighted average), so that the compensation parameters can accurately reflect the influence of the current temperature change on the resistance.

[0120] Hardware:

[0121] A micro control unit MCUSTM32F103 (supporting high-speed SPI and CAN bus, and main frequency ≥72MHz) and a storage chip.

[0122] Software:

[0123] The Kalman filtering algorithm realizes a state space model and an iterative update formula, denoises the temperature data, and predicts the temperature trend; the adaptive weighted average algorithm dynamically calculates the weight according to the temperature change rate, and fuses the temperature data to generate; and the resistance variation calculation is based on the model and the fused temperature.

[0124] Implementation effect: The temperature noise error can be reduced by more than 80% through Kalman filtering for denoising the temperature data, and the weight can be dynamically adjusted according to the temperature mutation condition in combination with the adaptive weighted average algorithm, so that the generation of the compensation parameters is more timely and accurate (resistance variation calculation error ≤±0.3%), and the generated compensation parameters can accurately reflect the shunt resistance variation, the terminal post variation and the overall change rate, thereby providing accurate basis for hardware compensation.

[0125] Example four

[0126] The embodiment provides an online evaluation and detection method for dynamic efficiency of a power supply, which is used for calculating resistance variation of a shunt resistance and a terminal post, and generating accurate compensation parameters. The specific implementation content includes:

[0127] The purpose of implementation: using compensation module (programmable gain amplifier PGA and digital potentiometer) to adjust the gain and resistance value of the measurement signal, and correcting the signal in real time through hardware circuit to offset the influence of temperature change on the shunt resistance and the resistance value of the terminal post, improve the accuracy of the power supply dynamic efficiency evaluation and detection of the electronic load instrument, ensure the reliability of the output measurement signal, and eliminate the measurement error introduced by temperature factors.

[0128] Hardware:

[0129] Programmable gain amplifier PGA (TIPGA204 gain range 1-1000, SPI control), digital potentiometer AD5290 (10kΩ resistance, I 2 C interface, 100-step adjustment), micro control unit MCU STM32F103 (supports high-speed SPI and CAN bus, frequency ≥ 72MHz).

[0130] The implementation effect: through the cooperative work of PGA and digital potentiometer, the resistance value of the digital potentiometer is adjusted according to the compensation parameters, the PGA gain is changed, the measurement signal can be corrected in real time, after compensation, the measurement error caused by temperature change can be reduced by more than 90%, the measurement accuracy of the electronic load instrument can be improved to within ±0.1%, and the accuracy and reliability of the power supply dynamic efficiency evaluation and detection result are ensured.

[0131] Comparative example one

[0132] Example one: adopting thin film platinum resistance (such as Pt1000) + four-wire connection method + signal adjustment chip (MAX31865), deploying ≥2 thin film platinum resistances for each shunt resistance / terminal post, eliminating lead resistance error through independent excitation line and measurement line, transmitting data to STM32 MCU through SPI interface, and reflecting the resistance fluctuation of the shunt resistance and the terminal post caused by temperature change in real time.

[0133] Comparative example: the existing electronic load instrument does not set acquisition sensor or only deploys temperature sensor at the shunt resistance, does not collect the temperature of the terminal post at all, the terminal post resistance is a fixed value, and the temperature correlation is not considered.

[0134] Core difference: when the current passes through the terminal post, the temperature can rise by 10-20℃ (such as 10A current), and the contact resistance can increase by 5-10mΩ (1-2% of the total measurement resistance). The comparative example does not compensate for this part of error, and a single temperature point cannot reflect the comprehensive change of the actual resistance network. Under dynamic load (such as pulse current), the terminal post temperature fluctuation amplitude can reach 1.5 times of the shunt resistance (because the contact thermal resistance is large), the comparative example cannot respond to the sudden change of the terminal post resistance in real time, resulting in significant transient error during dynamic efficiency evaluation (such as the error can reach 3% at the moment of load switching).

[0135] Example two: Establish the relationship model between shunt resistance temperature and resistance, and establish the relationship model between terminal temperature and resistance. Considering the change of terminal contact resistance and shunt resistance, the model error is ≤±0.5%.

[0136] Comparative example: Only use the linear model of shunt resistance, ignore the change of terminal resistance.

[0137] Core difference: When the terminal temperature changes (such as the temperature rises 10℃ caused by current fluctuation), the contact resistance may change 5-10mΩ (accounting for 1-2% of the total resistance), and the comparative example does not compensate for this part of the error.

[0138] Example three: By receiving real-time data, calculating the actual resistance of shunt resistance and terminal at current temperature through the above relationship model, introducing dynamic correction mechanism based on Kalman filter algorithm, denoising temperature data, and combining historical data to predict temperature change trend, at the same time, in order to eliminate the influence of environmental temperature mutation on measurement, using adaptive weighted average algorithm, dynamically adjusting compensation parameter weight according to temperature change rate, to ensure the timeliness and accuracy of compensation.

[0139] Comparative example: Using simple moving average filter, 5-point moving average filter.

[0140] Core difference:

[0141] Dynamic response: Moving average filter lags 3-5 sampling periods (30-50ms lag under 10ms period) when temperature suddenly changes (such as 5℃ / s temperature rise), while Kalman filter compensates in advance through state prediction; Anti-noise ability: sudden noise (such as sensor peak interference) will be retained by moving average algorithm, while Kalman filter dynamically suppresses abnormal values through covariance matrix; Fixed weight: The comparative example cannot distinguish between "stable temperature period" and "mutation period", such as when the environmental temperature is stable, it still processes historical data with equal weight, while adaptive weighting can automatically reduce the weight of historical data.

[0142] Example four: Adjust the gain and resistance value of the measurement signal through the compensation module, and correct the signal in real time through hardware circuit, to offset the influence of temperature change on shunt resistance and terminal resistance, so as to improve the accuracy of electronic load instrument in evaluating and detecting the dynamic efficiency of power supply, and ensure the reliability of output measurement signal.

[0143] Comparative example: Only use fixed resistance voltage divider network, preset compensation value.

[0144] Core difference:

[0145] Adaptive difference: Fixed compensation is only for a single temperature point (such as 25℃), and compensation fails when the temperature deviates (such as compensation error up to ±1.5% at 50℃);

[0146] Dynamic adjustment: real-time calculation of resistance change, and adjustment of gain, while the proportion needs manual resistance replacement and cannot respond to real-time temperature changes;

[0147] Precision limit: digital potentiometer resolution is 0.1% (100 steps), and fixed resistance division precision is only ±5% (ordinary chip resistor).

[0148] Through comparison, it can be seen that the above embodiment scheme solves the problems of the traditional scheme in precision, dynamic response and environmental adaptability through four-layer design of "high-precision acquisition + dynamic modeling + intelligent algorithm + programmable hardware", and improves the precision of the electronic load instrument in online evaluation and detection of power supply dynamic efficiency.

[0149] The electrical components appearing in the text are all connected with the main controller and 220V mains, and the main controller can be a conventional known device such as a computer.

[0150] Finally, it should be noted that: the above only describes the preferred embodiments of the present application and is not intended to limit the present application, although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacement for some technical features, and any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for online evaluation and detection of power supply dynamic efficiency, characterized in that, The method comprises the following steps: S1: Deploy a collection module at key positions of the shunt resistor and the terminal in the resistance load instrument to collect temperature in real time, convert the resistance change caused by temperature into an electrical signal, and provide real-time and accurate temperature data basis for the system; S2: Establish a relationship model between the temperature of the shunt resistor and the resistance, and a relationship model between the temperature of the terminal and the resistance; S3: After receiving the temperature data in real time, calculate the resistance change of the shunt resistor and the terminal according to the relationship model and the dynamic compensation algorithm, and generate accurate compensation parameters; S4: Adjust the gain and resistance value of the measurement signal through the compensation module, and correct the signal in real time through the hardware circuit to offset the influence of temperature change on the resistance value of the shunt resistor and the terminal, thereby improving the accuracy of the electronic load instrument in evaluating and detecting the dynamic efficiency of the power supply and ensuring the reliability of the output measurement signal.

2. The method of claim 1, wherein: The collection module is a thin-film platinum resistor, wherein at least two thin-film platinum resistors are arranged on the shunt resistor and the terminal, and a four-wire connection method is adopted to eliminate the influence of lead resistance through independent excitation lines and measurement lines.

3. The method of claim 1, wherein: The relationship model between shunt resistance temperature and resistance: the resistance value change of shunt resistance has linear relationship with temperature, and the mathematical model can be expressed as: Wherein is the resistance value at temperature T, is the resistance value at reference temperature , and is the temperature coefficient of resistance.

4. The method of claim 1, wherein: The relationship model between the terminal post temperature and the resistance is as follows: Wherein, is the terminal post resistance at temperature , is the terminal post resistance at reference temperature , is the additional resistance caused by the change of the contact state, and is the temperature coefficient of the terminal post material.

5. The method of claim 1, wherein: The dynamic compensation algorithm: through real-time data reception, the actual resistance values of the shunt resistor and the terminal at the current temperature are calculated through the above relationship model, a dynamic correction mechanism based on Kalman filtering algorithm is introduced to perform noise reduction processing on the temperature data, and the temperature change trend is predicted in combination with historical data, and at the same time, in order to eliminate the influence of environmental temperature mutation on measurement, an adaptive weighted average algorithm is adopted to dynamically adjust the compensation parameter weight according to the temperature change rate, ensuring the timeliness and accuracy of compensation.

6. The method of claim 1, wherein: The compensation module comprises a programmable gain amplifier PGA and a digital potentiometer.

7. The method of claim 6, wherein: The compensation circuit of the programmable gain amplifier PGA and the digital potentiometer cooperates to output a control signal to adjust the resistance value of the digital potentiometer according to the calculated resistance change, and change the gain multiple of the PGA.

8. An apparatus for on-line evaluation and detection of power supply dynamic efficiency, which refers to the method for on-line evaluation and detection of power supply dynamic efficiency according to claim 1, characterized in that: It comprises a plurality of thin-film platinum resistors, a signal adjustment chip, a micro control unit MCU, a programmable gain amplifier PGA, and a digital potentiometer. The plurality of thin-film platinum resistors are respectively mounted on the terminal and the shunt resistor, and each thin-film platinum resistor is connected to each signal adjustment chip in a four-wire system, the signal adjustment chip communicates with the MCU through an SPI interface, transmits digital temperature data to the micro control unit MCU for processing, the micro control unit MCU is connected to the main control unit of the electronic load instrument through a CAN bus, and transmits temperature data and calculated compensation parameters.

9. The apparatus for online evaluation of power supply dynamic efficiency according to claim 8, characterized in that: The micro control unit MCU needs to be configured with an SPI clock frequency of at least 2MHz to ensure that the temperature data collection period is less than 10ms.

10. The apparatus for online evaluation of power supply dynamic efficiency according to claim 8, characterized in that: The programmable gain amplifier PGA is connected to the micro control unit MCU through an SPI / I2C bus, and the digital potentiometer is connected to the micro control unit MCU through an I2C bus.

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