Local Sense Control Dominant Over Remote Sense in Power Systems
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Solution Overview
Problem
Existing power systems with remote-sense dominant control loops fail to account for failure modes like electrical open or shorted remote sense lines, leading to uncontrolled voltage output and potential system shutdown or component failure.
Innovation Solution
Configuring a power system with a local sense control loop as dominant, using circuitry to pass the local sense signal with a higher voltage level, combining signals to compensate for voltage drops, and applying voltage limits to prevent over-voltage conditions through a comparator and limiter, ensuring stable voltage regulation even under failure modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the remote-sense loop is used as the dominant control loop, then automatic switching to local regulation is enabled when remote-sense lines are accidentally disconnected, but the system becomes vulnerable to uncontrolled voltage output when electrical opens or shorts occur in power lines or remote sense leads
Solution Approach 1:
The patent inverts the traditional control loop hierarchy by making the local-sense loop dominant over the remote-sense loop. This is achieved through a control circuit that receives both sense signals and selectively enables the local-sense signal as the primary feedback, reversing the conventional approach where remote-sense dominates. This inversion ensures that the power converter always has a reliable local reference for voltage regulation, preventing uncontrolled voltage output during remote-sense failures.
Solution Approach 2:
The patent implements beforehand cushioning by providing a default local-sense control mechanism that is always active and ready to prevent uncontrolled voltage output. The control circuit is designed to automatically detect remote-sense failure modes (opens or shorts) and switch to local-sense dominance in advance, cushioning the system against the harmful effects of these failure modes before they can cause damage.
2Reliability
If the local-sense loop is made dominant with circuitry to pass the local sense signal, then over-voltage conditions are prevented under failure modes, but the device complexity increases due to additional control circuitry
Solution Approach 1:
The patent merges the remote-sense and local-sense control loops into a unified control architecture where both sense signals are received by a single control circuit. The control circuit integrates functionality to selectively enable the local-sense signal while maintaining remote-sense capability, combining multiple functions (voltage sensing, failure detection, selective enabling) into one cohesive unit, thereby reducing overall system complexity despite the added protective functionality.
Data Source
AI summary
A power system is configured to provide a regulated voltage to an electrical load connected to a power source through at least one power line. The power system includes a first voltage control loop based on a remote sense signal indicative of voltage level at the load. The power system further includes a second voltage control loop based on a local sense signal indicative of a level of output voltage at the power source. The voltage level of the local sense signal is generally at a higher voltage level relative to the voltage level of the remote sense signal. Circuitry is configured to pass just the signal with the higher voltage level to ensure that the local sense control loop is a dominant control loop with respect to the remote sense control loop. This avoids effects on the power source from one or more failure modes that can occur in interconnections of the system.