Ground-Referenced Current Regulator Stabilizes Parallel Branches
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Solution Overview
Problem
Conventional current regulating systems using simple linear series regulators are prone to oscillations due to impedances in the control path, especially when multiple series branches are connected in parallel, requiring separate auxiliary voltages and leading to unstable control circuits.
Innovation Solution
A current regulating system where the reference signal, current measurement signal, and manipulated variable signal are referenced to ground, with the manipulated variable signal being corrected by a subtractor to eliminate the difference between the supply voltage and output voltage, preventing oscillations by maintaining a stable voltage between the control and output terminals of the semiconductor control element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If each series regulator uses a separate auxiliary voltage referenced to its output voltage, then the regulator can generate sufficient manipulated variable signal, but the system becomes complex and unstable with oscillations
Solution Approach 1:
The patent merges multiple separate auxiliary voltage supplies into a single common auxiliary voltage supply. Instead of each series regulator having its own auxiliary voltage referenced to its output voltage, all series regulators share one common auxiliary voltage referenced to ground. This reduces the number of auxiliary supplies from multiple to one, simplifying the system while maintaining the ability to generate sufficient manipulated variable signals for controlling semiconductor control elements.
2Reliability
If separate auxiliary voltages are used for each series regulator, then each regulator operates independently, but the system becomes unstable due to positive feedback from line impedance
Solution Approach 1:
The patent introduces ground as a common reference potential that mediates between multiple series regulators. By referencing all auxiliary voltages and manipulated variable signals to ground rather than to individual output voltages, the system eliminates the positive feedback path through line impedance that causes oscillations. The ground reference acts as an intermediary that decouples the regulators while maintaining stability.
3Power
If auxiliary voltage is referenced to output voltage, then manipulated variable signal is sufficient, but oscillations occur above the cut-off frequency of the series regulator
Solution Approach 1:
The patent establishes ground as a common equipotential reference for all auxiliary voltages and signals. By referencing the auxiliary voltage to ground rather than to the output voltage, the system creates a stable reference potential that does not vary with output voltage changes. This eliminates the oscillation-prone feedback path while maintaining sufficient manipulated variable signal amplitude for effective control of the semiconductor control element.
Data Source
AI summary
A current control system comprising at least one series arm including a linear series regulator for generating a manipulated variable signal, wherein the linear series regulator is connected to a semiconductor control element which is connected to a supply voltage referenced to a ground potential, and the semiconductor control element includes an output voltage at its output side relative to the ground potential. A reference signal fed to the series regulator, a current measurement signal, and the manipulated variable signal are referenced to the ground potential, where the manipulated variable signal is fed to a subtractor which subtracts the difference of the feed voltage minus the output voltage from the manipulated variable signal, and the generated output signal of the subtractor is fed to the semiconductor control element as a corrected manipulated variable signal.