Fluid Heater Leakage Signal Normalization for Temperature Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heating devices for fluids face challenges in accurately distinguishing between temperature changes caused by variations in supply voltage and actual temperature changes, particularly in environments with frequent switching of electrical loads, leading to potential overheating and damage.
Innovation Solution
Incorporating a voltage divider network to measure supply voltage and normalize the leakage current signal, allowing the control unit to differentiate between voltage fluctuations and temperature changes, thereby enabling precise temperature monitoring and fluid management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If leakage current is used to detect temperature changes, then temperature monitoring capability is improved, but the ability to distinguish between voltage-induced current changes and temperature-induced current changes deteriorates
Solution Approach 1:
The patent implements feedback by continuously measuring the supply voltage and using this information to compensate for voltage-induced leakage current variations. The control unit monitors both the leakage current and supply voltage, then uses the voltage data to distinguish between current changes caused by voltage fluctuations versus those caused by temperature changes, thereby maintaining accurate temperature detection despite voltage variations
Solution Approach 2:
The patent introduces the supply voltage measurement as an intermediary parameter that mediates between the leakage current signal and the temperature detection. By measuring the supply voltage separately and using it as a reference, the system can isolate the temperature-related component of the leakage current from the voltage-related component, thus recovering accurate temperature information
2Adaptability or versatility
If heating device operates in environments with frequent electrical load switching, then adaptability to real-world conditions is improved, but reliability of temperature detection deteriorates due to voltage fluctuations
Solution Approach 1:
The system continuously feeds back supply voltage measurements to the control unit, which uses this feedback to dynamically adjust the temperature detection algorithm. This allows the system to maintain reliable temperature detection even when operating in environments with frequent electrical load switching and voltage fluctuations
Solution Approach 2:
The patent changes the detection parameters by introducing supply voltage as an additional measured parameter. By monitoring both leakage current and supply voltage simultaneously, the system adapts its detection approach to account for voltage variations, thereby maintaining reliability across different electrical environments
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 solution allows for more accurate temperature detection and fluid management, reducing the risk of overheating and damage by effectively accounting for supply voltage variations, ensuring safe and efficient operation of the heating device.
Implementation Method 1
The insulation layer has a temperature-dependent electrical resistance, so that a so-called leakage current or ground current or fault current can thereby be detected and can be used as a measure of a temperature at the heating device
Implementation Method 2
Incorporating a voltage divider network to measure supply voltage
Implementation Method 3
The heating element may be used to heat fluid, for example water, in the fluid chamber
Data Source
AI summary
In a method for operating a heating device, fluid is initially introduced into a fluid chamber, then the heating elements of the heating device are switched on and a leakage current is detected as a temperature-dependent current flow through a dielectric insulation layer. A supply voltage of the heating devices is measured and is taken into account in an evaluation of the temperature at the fluid chamber as a function of the leakage current. The leakage current is converted into a leakage voltage by means of a resistor, which is then divided by the measured supply voltage. Subsequently, the quotient obtained may be multiplied by a compensation value in order to obtain a normalized leakage signal, which is normalized to a base value of the supply voltage. The normalized leakage signal is used, if a particular absolute value of the leakage signal is exceeded or if a particular slope of the profile of the leakage signal is exceeded, in order to top up the fluid chamber with more fluid and/or to reduce the heating power of at least one heating element.