Voltage Sensing Circuit for LC-Filtered Multi-Source Power Output
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power systems face challenges in providing adaptable output power with different ranges of AC voltage and accurate voltage measurement, especially when LC filters introduce phase shifts and make direct voltage measurement difficult, limiting the usability of electrical devices across different regions with varying mains electrical power standards.
Innovation Solution
A power system with a series-connected inductor and differential amplifiers for measuring voltages across multiple sets of voltage sources, using fixed reference voltages and filtering operations to calculate output voltage without direct measurement, and a switch for parallel or series connection of energy storage modules to adjust voltage ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an LC filter is included at the output to convert DC voltage to AC voltage, then the power conversion function is improved, but the filter introduces phase shift and makes direct voltage measurement difficult
Solution Approach 1:
The patent introduces an intermediary voltage sensing circuit that measures voltage before the LC filter rather than directly at the output. This intermediary measurement point avoids the phase shift problem while still providing accurate voltage information for control purposes. The circuit uses differential amplifiers to sense the voltage across the DC link capacitors, which are positioned before the filter inductor.
Solution Approach 2:
The patent segments the voltage measurement function from the power output path by using separate sensing circuits for different voltage points. Multiple differential amplifiers measure voltages at different locations (across first and second sets of voltage sources), and these measurements are combined to calculate the total output voltage without requiring direct measurement at the filtered output.
2Difficulty of detecting and measuring
If the inductor and capacitor of an LC filter are not directly connected to enable voltage measurement, then voltage sensing becomes possible, but the circuit complexity increases
Solution Approach 1:
The patent makes the voltage sensing circuit universal by designing it to work with multiple configurations of voltage sources. The same differential amplifier circuitry can measure voltages across different sets of sources (first set, second set, or both in combination), making the sensing system adaptable to various operating modes without requiring separate measurement circuits for each configuration.
Solution Approach 2:
The patent merges multiple voltage measurements into a single control signal by combining the outputs of differential amplifiers that measure voltages across different source sets. This combined signal represents the total output voltage and can be used for unified control of the power conversion circuit, reducing the need for separate measurement and control paths.
3Device complexity
If a power system is designed for one specific mains voltage standard, then the control circuitry is simplified, but the usability across different regions is limited
Solution Approach 1:
The patent implements dynamic adaptability by enabling the power system to operate in multiple modes (single-phase, three-phase, different voltage levels) using the same hardware platform. The control circuitry dynamically adjusts its operation based on the detected configuration of voltage sources and the required output, allowing the system to adapt to different regional standards without requiring separate dedicated circuits for each standard.
Solution Approach 2:
The patent creates a universal power conversion system that can serve multiple functions and standards. The same inverter circuitry can output different voltage levels and phases by utilizing different combinations of the available voltage sources. This multi-functional design allows a single device to replace multiple region-specific devices, achieving global usability without proportionally increasing control circuitry complexity.
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
Enables adaptable output voltage control and accurate voltage sensing across different regions, ensuring compatibility and reliability of electrical devices with varying mains power standards, while reducing impedance and loop currents, and preventing component damage from voltage mismatches.
Implementation Method 1
measuring, via a first differential amplifier, a first voltage across the first set of voltage sources to generate a first signal
Implementation Method 2
The first set of voltage sources and the second set of voltage sources may be connected via an inductor
Data Source
Figure 1A
Figure 1B~1C
Figure 2A
AI summary
An example power circuit may include a first set of voltage sources and a second set of voltage sources. The first set of voltage sources and the second set of voltage sources may be connected via an inductor. In a mode of operation, the inductor may be disposed in a series connection between the first set of voltage sources and the second set of voltage sources. An example method for monitoring an output voltage of the power circuit may include measuring, via a first differential amplifier, a first voltage across the first set of voltage sources to generate a first signal and measuring, via a second differential amplifier, a second voltage across the second set of voltage sources to generate a second signal. A total voltage signal may be evaluated based on the first signal and the second signal. The output voltage may be calculated from the total voltage signal.