Power Converter Control Circuit for Fast Bus Voltage Event Detection
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Solution Overview
Problem
Existing power converters struggle to quickly detect and respond to high dV/dt events, leading to potential over-current protection and disabling of the converter.
Innovation Solution
A control circuit and method that includes a pulse width modulator, current feedback loop, bus voltage feedforward path, and logic circuit to rapidly detect voltage variations and adjust the PWM control signal to regulate the load current, enabling fast-response protection and restart.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional feedback control is used to detect voltage variations, then the control system remains simple, but the detection speed is too slow to prevent over-current protection engagement
Solution Approach 1:
The patent implements a bus voltage feedforward path that proactively monitors bus voltage and predicts upcoming voltage variations before they affect the power converter output. This preliminary detection mechanism allows the system to prepare compensatory control actions in advance, achieving fast response without requiring complex feedback loops to catch up after the disturbance occurs.
Solution Approach 2:
The patent introduces a dedicated voltage variation detection circuit that acts as an intermediary between the bus voltage and the main control system. This separate detection path processes voltage signals independently and triggers fast-response protection mechanisms, allowing the main feedback control to remain relatively simple while gaining enhanced detection capabilities through the intermediary detection circuit.
2Reliability
If the power converter continues operating during voltage variation events, then productivity is maintained, but over-current damage may occur
Solution Approach 1:
The patent implements dynamic control that adapts the power converter's operating state based on real-time bus voltage conditions. During normal operation, the converter runs at full capacity for maximum productivity. When voltage variation events are detected through the feedforward path, the system dynamically adjusts by engaging fast protection mechanisms that temporarily modify operation to prevent damage, then automatically restarts when conditions normalize, optimizing both reliability and productivity.
Solution Approach 2:
The patent prepares protective measures in advance by continuously monitoring bus voltage through the feedforward path. When voltage variations are anticipated, the system pre-engages protection mechanisms and adjusts operating parameters before over-current conditions develop, cushioning against potential damage. This allows the converter to maintain high availability by quickly recovering after protected events rather than requiring manual intervention.
Data Source
AI summary
A control circuit for a power converter is provided. The control circuit includes a pulse width modulator, a current feedback loop, a bus voltage feedforward path, and a logic circuit. The pulse width modulator generates a control signal for the power converter to regulate a load current. The current feedback loop controls the pulse width modulator to converge the load current to a demanded current. The bus voltage feedforward path measures a bus voltage supplied to the power converter at an input bus and, in combination with the current feedback loop, control the pulse width modulator to regulate the load current based on the bus voltage. The logic circuit collects load current measurements and determines, based at least partially thereon, a voltage variation event has occurred on the input bus, and disables the control signal for the power converter in response to determining the voltage variation event has occurred.