Power Factor Correction IC for AC Voltage Interruption Handling
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Solution Overview
Problem
Power supply circuits face challenges in maintaining stable operation during AC voltage interruptions and sudden load changes, which affect the power factor correction circuit's performance.
Innovation Solution
An integrated circuit that controls the inductor current by comparing it to predetermined and target values, adjusting these values based on feedback voltage and AC voltage input conditions, and using a drive circuit to switch an NMOS transistor to maintain optimal power factor correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the power factor correction circuit operates with a fixed target value for inductor current, then the circuit structure remains simple, but the circuit cannot adapt to AC voltage interruptions or sudden load changes
Solution Approach 1:
The patent implements dynamic adjustment of the target value based on operating conditions. The control circuit monitors AC voltage input status and load conditions, then dynamically modifies the target value parameter to match current operating requirements. This allows the power factor correction circuit to adapt to interruptions and load changes without requiring complete circuit redesign.
Solution Approach 2:
The patent employs feedback mechanisms where the control circuit continuously monitors the actual inductor current and compares it with the dynamically adjusted target value. Based on this feedback and detection of operating conditions (AC voltage presence, load status), the circuit automatically adjusts the target value to maintain optimal power factor correction performance under varying conditions.
2Stability of the object's composition
If the target value is increased to maintain output voltage during sudden load changes, then the output voltage stability improves, but surge voltages may occur during AC voltage restoration
Solution Approach 1:
The patent detects AC voltage interruption conditions in advance and performs preliminary adjustment of the target value before restoration occurs. When AC voltage restoration is detected, the control circuit proactively reduces the target value to a safe level, preventing surge voltage generation while the output voltage stabilization process is still ongoing. This preliminary action approach addresses the harmful effect before it can manifest.
Solution Approach 2:
The patent applies preliminary anti-action by detecting the impending AC voltage restoration and preemptively reducing the target value to counteract the potential surge voltage effect. This opposite adjustment (reducing target value instead of maintaining high values for stability) prevents the harmful surge while the system transitions to the restored AC voltage condition.
Data Source
AI summary
A power supply circuit that generates an output voltage from an AC voltage. The power supply circuit includes a rectifier circuit that rectifies the AC voltage, an inductor receives a rectified voltage from the rectifier circuit, a transistor that controls an inductor current flowing through the inductor, and an integrated circuit that performs switching of the transistor. The integrated circuit includes an error output circuit that outputs an error between a feedback voltage and a reference voltage, a target value generating circuit that generates a target value of the inductor current based on the error, an adjustment circuit that adjusts the target value, first and second comparison circuits that compare the inductor current with a predetermined value and with the target value, respectively, and a drive circuit that turns on the transistor when the inductor current reaches the predetermined value, and turns off the transistor when the inductor current reaches the target value.