Exciter Control Using Line-to-Line Voltage for Load-Off Stability
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Solution Overview
Problem
Aircraft DC power supplies require two voltage regulation loops, one on the DC side and one on the AC side, to manage load-off transients, which complicates the control system and increases complexity.
Innovation Solution
A direct current power supply with a controller that calculates the maximum line-to-line voltage from phase voltages and uses this calculation to operate an exciter winding driver with an oscillating signal, reducing the need for multiple sensing loops by maintaining the quadratic mean of the direct current link capacitor voltage during load-off conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two voltage regulation loops are used (one on DC side and one on AC side), then voltage stability during load-off transients is improved, but device complexity increases
Solution Approach 1:
The patent combines the DC-side and AC-side voltage regulation loops into a single unified control loop. The controller monitors the DC link capacitor voltage and adjusts the exciter winding duty cycle accordingly, eliminating the need for separate regulation loops while maintaining voltage stability during load-off transients.
Solution Approach 2:
The single control loop performs multiple functions: it regulates DC link voltage, manages load-off transients, and controls exciter winding duty cycle. This multi-functional approach replaces the traditional two-loop system, reducing complexity while maintaining comprehensive voltage regulation capability.
2Measurement precision
If two control loops are used to manage load-off transients, then voltage regulation performance is improved, but sensing requirements and system complexity increase
Solution Approach 1:
The patent merges multiple sensing requirements into a single sensing approach. The controller only needs to sense the DC link capacitor voltage to regulate the output, eliminating the need for separate AC-side and DC-side sensing loops. This single sensing requirement simplifies the measurement system while maintaining precise voltage regulation.
3Speed
If traditional two-loop control is used, then transient response during load-off is improved, but ease of operation deteriorates due to complex control
Solution Approach 1:
The patent combines the control functions into a single loop that directly responds to DC link voltage changes. When a load-off transient occurs, the controller detects the voltage change and immediately adjusts the exciter winding duty cycle, providing fast transient response without the complexity of coordinating multiple control loops.
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 approach simplifies the control system by allowing single-loop control during load-off transients, preventing under-excitation and maintaining voltage stability with reduced sensing requirements.
Implementation Method 1
An oscillating signal is generated according to the maximum line-to-line voltage to operate an exciter winding driver with the oscillating signal. The exciter winding driver is operable to energize an excitation winding to induce an alternating current.
Implementation Method 2
The generator is operable to generate the multiphase output defining the phase voltages based on the excitation voltage.
Data Source
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AI summary
A system and a method for exciting a generator of a direct current power supply with a controller is disclosed. The method includes receiving a phase voltages associated with multiphase output of the generator. The method includes determining a maximum line-to-line voltage based on the phase voltages. The method includes operating an exciter winding driver with an oscillating signal generated according to the maximum line-to-line voltage.