Boost Converter Protection Circuitry for Fault Isolation
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Solution Overview
Problem
Existing power supply systems, particularly DC/DC boost converters, face challenges in protecting against short-circuits and faults, as conventional methods like fuses and PTC resistors suffer from inefficiencies and thermal dissipation issues, and active methods can draw excessive current during sustained faults.
Innovation Solution
A protection circuitry that monitors voltage and current at the output node, using a diode-based unidirectional current source and MOSFETs to control the boost converter's operation, enabling it only when conditions are within a safe range, and disabling it during faults to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fuse element or PTC resistor is placed in series with the input supply to protect the boost converter, then the converter is protected from short-circuit damage, but the fuse may drain the supply during sustained ground fault events and the PTC presents voltage drop and efficiency loss
Solution Approach 1:
The patent introduces an intermediary protection circuit that includes a monitoring circuit and a pass device. The monitoring circuit detects output node voltage conditions and controls the pass device to either regulate or interrupt input current, thereby protecting the boost converter without the energy losses associated with fuses or PTC resistors.
Solution Approach 2:
The protection circuit employs feedback by continuously monitoring the output node voltage and using this information to control the pass device. When the monitored voltage indicates a fault condition (voltage proximate to or lower than input voltage), the circuit responds by regulating or interrupting the input current, creating a closed-loop protection mechanism that eliminates the need for passive protective elements.
2Reliability
If an active protection method using a pass device is used to control input current, then the boost converter is protected from output faults, but the pass element dissipates large thermal energy during sustained output faults and draws large currents from the supply
Solution Approach 1:
The patent implements dynamic protection by using a monitoring circuit that actively adjusts the pass device state based on real-time output node voltage conditions. Instead of a static protective element that continuously dissipates energy, the dynamic circuit only activates protection when fault conditions are detected, minimizing thermal dissipation during normal operation and providing intelligent response to actual fault conditions.
3Power
If the boost converter is enabled to drive the load, then the load receives sufficient power, but the converter becomes vulnerable to damage from short-circuits and faults
Solution Approach 1:
The patent applies preliminary action by implementing a protection circuit that is pre-configured and continuously monitoring before any fault occurs. The monitoring circuit is already in place to detect output node voltage conditions, and the pass device is ready to be controlled, allowing the system to respond immediately to faults without compromising the power delivery capability during normal operation.
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 effectively prevents damage to the boost converter during short-circuits and faults while minimizing current draw from the input supply, ensuring efficient and reliable operation.
Implementation Method 1
The first circuit may comprise a unidirectional current source for generating the voltage at the output node. The unidirectional current source may comprise a diode.
Data Source
AI summary
Protection circuitry protects a boost converter coupled between input and output nodes for driving a load coupled to the output node. The protection circuitry may comprise a first circuit configured for monitoring a voltage at the output node, the voltage being caused by a signal having a voltage proximate to, or lower than, an input voltage of the boost converter. The protection circuitry may also include a second circuit configured for coupling together the input node with respect to the output node and enabling the boost converter only if the monitored voltage exceeds a reference voltage.