Current Measurement Gain Compensation for Power Component Temperature Drift
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Solution Overview
Problem
Current current measuring devices in electrical circuits face inaccuracies due to temperature-dependent internal resistance of power components, leading to measurement errors, especially at higher currents where thermal coupling between the power component and temperature sensor results in temperature differences, causing underestimation of internal resistance and overestimation of current.
Innovation Solution
A temperature compensation method that adjusts the gain of the amplifier stage using a digital variable resistor, where the calculator corrects temperature measurements based on output voltage and calculates internal resistance to maintain a constant ratio, accounting for temperature variations caused by current values, thereby compensating for thermal differences and improving measurement precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If thermal coupling is improved by placing temperature sensor closer to power component, then temperature measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The patent introduces an intermediary computational model that mathematically relates temperature to internal resistance characteristics. Instead of physically coupling the sensor, the model acts as a mediator that infers the power component's temperature through its electrical characteristics, eliminating the need for direct thermal coupling while maintaining measurement accuracy.
Solution Approach 2:
The patent replaces the mechanical/physical thermal coupling system with an electrical measurement and computational system. By measuring electrical parameters (voltage, current) and using a computational model to derive temperature, the system substitutes physical thermal contact with electrical field-based measurement and digital processing.
2Adaptability or versatility
If digital variable resistor is used for gain adjustment, then adaptability to temperature variations is improved, but device complexity increases
Solution Approach 1:
The patent implements dynamic adaptation by using a digital variable resistor that can be programmatically adjusted based on detected temperature conditions. The system continuously monitors temperature and dynamically reconfigures the gain of the measurement circuitry, allowing the device to adapt its characteristics in real-time to maintain measurement accuracy across varying temperature conditions.
Solution Approach 2:
The patent changes the electrical parameters of the measurement system (specifically the gain parameter through digital variable resistor adjustment) in response to temperature variations. By programmatically modifying circuit parameters based on environmental conditions, the system maintains optimal measurement characteristics across different operating temperatures.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method minimizes current measurement errors to less than 1%, effectively eliminating disturbances from temperature variations and ensuring accurate current measurement across the operating temperature range.
Implementation Method 1
thermal coupling between the chip(s) of the power component and the temperature sensor
Implementation Method 2
an amplifier stage whose input is connected to one of the terminals of the power component
Data Source
Figure 1~2
AI summary
The present invention relates to a temperature compensation method in a current measurement device (1) comprising: a power component (2) having an internal resistance Ron in the on state; an amplifier stage (20) whose input is connected to one of the terminals of the power component (2); and a computer (5) coupled to a temperature sensor (6) configured to measure the temperature of the power component (2) and to a digital variable resistance Rv of a gain adjustment circuit of the amplifier stage (20), the computer (5) being configured to correct the measured temperature value as a function of the output voltage Vs of the amplifier stage (20), according to a first law or table incorporated in the computer (5).