Passive Tuning Circuit for Compact Capacitive Voltage Sensors
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Solution Overview
Problem
Existing capacitive voltage sensors in energy distribution networks suffer from phase and amplitude errors due to signal deviations caused by the connection to measurement devices, necessitating complex and time-consuming individual calibration, and large primary capacitors are cumbersome to manufacture and handle.
Innovation Solution
A capacitive voltage sensor arrangement incorporating a tuning circuit with passive components to correct signal errors, allowing for accurate voltage measurement within defined tolerances without active components, reducing the size and complexity of the sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the primary capacitance of the primary capacitor is chosen very high to meet accuracy requirements, then the measurement precision is improved, but the size of the primary capacitor becomes very large
Solution Approach 1:
A tuning circuit is introduced as an intermediary component between the capacitive voltage divider and the measurement device. This tuning circuit compensates for the influence of the measurement device on the measured value, allowing accurate measurements to be achieved without requiring an excessively large primary capacitor. The tuning circuit acts as a mediator that corrects the measurement errors caused by the interaction between the sensor and measurement device.
2Measurement precision
If a high primary capacitance is used to reduce measurement errors, then the measurement precision is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The tuning circuit serves as an intermediary that simplifies the overall sensor design by eliminating the need for an oversized primary capacitor. Instead of making the primary capacitor very large to achieve accuracy, the tuning circuit is introduced to correct measurement errors, thereby reducing the physical size and manufacturing complexity of the sensor while maintaining high measurement precision.
3Measurement precision
If correction circuits with active components are used to correct amplitude and phase errors, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The patent employs passive components (resistors, capacitors, inductors) in the tuning circuit instead of expensive and complex active components. These passive components are simpler, more reliable, and easier to manufacture. The tuning circuit uses a combination of passive elements to achieve the necessary amplitude and phase correction without requiring complex active circuitry, thereby improving measurement precision while keeping device complexity low.
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
The solution effectively meets international accuracy standards by compensating phase and amplitude errors, reducing the size of the primary capacitor, and simplifying installation and manufacturing processes.
Implementation Method 1
a capacitive voltage divider including a primary capacitor arranged between the first input terminal and a first node, and a secondary capacitor arranged between the first node and the second input terminal
Implementation Method 2
The tuning circuit has only one or more passive components
Data Source
AI summary
A capacitive voltage sensor arrangement includes a first input terminal, a second input terminal, a first sensor output terminal, and a second sensor output terminal. The sensor arrangement includes a capacitive voltage divider including a primary capacitor arranged between the first input terminal and a first node, and a secondary capacitor arranged between the first node and the second input terminal and electrically connected in series to the primary capacitor. The sensor arrangement further includes a tuning circuit arranged between the first node, a second node, a third node, and a fourth node. The second node is connected with the first sensor output terminal, the third node is connected with the second input terminal, and the fourth node is connected with the second sensor output terminal. The tuning circuit has only one or more passive components.