Power Conversion Controller With Feedforward Voltage Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power conversion circuit controllers face challenges in maintaining the detection value of the second voltage at its target value when the first voltage varies, due to delays in feedback control, leading to potential overvoltage protection and increased device size.
Innovation Solution
A controller for power conversion circuits that includes a second voltage detection unit, a first voltage detection unit, a control value calculation unit for feedback control, a control value correction unit for feedforward correction based on the first voltage, and a switching control unit to manage the switching device, thereby maintaining the second voltage at its target value without relying on feedback control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If feedback control is used to maintain the second voltage at its target value when the first voltage varies, then the second voltage can be corrected, but a delay occurs due to feedback control causing the second voltage to deviate from the target value
Solution Approach 1:
The control value correction unit performs feedforward correction by calculating a corrected control value based on the detected first voltage before the feedback control loop can respond. This preliminary action anticipates the voltage variation and adjusts the duty ratio in advance, eliminating the delay inherent in feedback control and preventing the second voltage from deviating from its target value.
2Reliability
If the target value of the second voltage is reduced to prevent overvoltage protection activation, then voltage stability is improved, but the output voltage drops
Solution Approach 1:
By implementing feedforward correction that calculates the duty ratio based on the detected first voltage before voltage deviations occur, the system maintains the second voltage at its original target value without triggering overvoltage protection, thereby preserving full output voltage level while ensuring reliability.
Solution Approach 2:
The control value correction unit uses the detected first voltage as feedback to dynamically adjust the control value, creating a closed-loop feedforward control system that actively compensates for voltage variations and maintains stable second voltage output without requiring reduction of the target value.
3Reliability
If the capacity of the second terminal side smoothing capacitor is increased to reduce voltage rise, then voltage stability is improved, but the device size increases
Solution Approach 1:
The feedforward correction mechanism proactively adjusts the duty ratio based on the detected first voltage before significant voltage deviations occur at the second terminal. This preliminary control action reduces voltage rise without requiring increased capacitor capacity, thereby maintaining voltage stability while avoiding increased device size and weight.
Data Source
AI summary
To provide a controller for power conversion circuit which can maintain the detection value of second voltage at the target value of second voltage without depending on feedback control, when the first voltage is varied. A controller for power conversion circuit changes a control value by feedback control so that the detection value of second voltage approaches a target value of second voltage; calculates a control value for control, by correcting the control value based on the detection value of first voltage so as to correct, in feedforward manner, a change of the control value due to a change of the first voltage if correction of the control value is not performed; and controls on/off the switching device based on the control value for control.