Aircraft Power Stabilizing System Using DC Bus Energy Storage
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Solution Overview
Problem
Existing electric systems in aircraft, primarily driven by AC power, face challenges in stabilizing voltage fluctuations due to increased power loads and regenerative power, leading to weight increments and design complexities, as existing solutions are not effectively applicable to AC-driven systems.
Innovation Solution
An electric system stabilizing system that includes a DC power supply and an AC power supply, with a power converter section to convert AC power to DC and a power stabilizing device that controls voltage using a power stabilizing control section to absorb regenerative power and stabilize both AC and DC power buses, avoiding weight increases and design changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the power generation capacity is increased to meet increased power loads, then the power supply stability is improved, but the weight of the aircraft increases due to larger generators and more wires
Solution Approach 1:
The power system is segmented into multiple independent power sources (AC generators, DC generators, and energy storage devices) rather than relying on a single large generator. This allows the system to meet increased power demands without proportionally increasing the weight of individual generators.
Solution Approach 2:
The system changes the operational parameters by introducing energy storage devices that can rapidly discharge to supplement power during high-demand periods, allowing smaller generators to be used while maintaining power supply stability.
2Loss of energy
If regenerative power occurs in loads such as control surface actuators, then energy recovery is achieved, but voltage significantly increases temporarily causing system instability
Solution Approach 1:
Energy storage devices serve as an intermediary between regenerative loads and the power system. They absorb the regenerative power temporarily, preventing voltage spikes, and then release it when needed, thus stabilizing the voltage while recovering energy.
Solution Approach 2:
The energy storage devices are pre-charged and positioned to cushion against voltage fluctuations before they occur. When regenerative power is detected, the storage devices immediately absorb the excess energy, preventing voltage instability.
3Adaptability or versatility
If the number of power loads increases temporarily, then system functionality is enhanced, but significant voltage decrease occurs causing power supply instability
Solution Approach 1:
The energy storage devices continuously monitor and compensate for voltage changes. When power loads increase temporarily, the storage devices discharge to maintain voltage levels, ensuring continuous and stable power supply without interruption.
Solution Approach 2:
The system employs feedback control where the state of charge of energy storage devices and voltage levels are continuously monitored. Based on this feedback, the control system adjusts the charging/discharging of storage devices to maintain stable power supply under varying load conditions.
4Reliability
If existing solutions for voltage stabilization are applied, then voltage fluctuation is reduced, but device complexity and design changes increase
Solution Approach 1:
The energy storage devices are designed to perform multiple functions: absorbing regenerative power, supplementing power during high-demand periods, and stabilizing voltage fluctuations. This multi-functionality reduces the need for separate dedicated components for each function, thereby limiting complexity increase.
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
The system effectively stabilizes the electric power output in aircraft, preventing voltage fluctuations and weight increments, while maintaining simplicity and efficiency in design, by using a DC power supply to absorb regenerative power and control voltage in AC and DC power buses.
Implementation Method 1
a power converter section for converting AC power from at least the AC power supply into DC power to supply the DC power to the DC power supply bus
Implementation Method 2
the DC power supply is configured to absorb regenerative power from the electrified device and transiently supply the electric power to the electrified device
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A power stabilizing device in a system includes as a portion of a power converter section, a second PWM converter provided between a second primary AC bus and a second DC bus in an electric system and configured to perform mutual conversion between DC power and AC power. A power stabilizing control section in the power stabilizing device controls charging and discharging of a secondary battery based on a voltage and a frequency in the second primary AC bus, thereby stabilizing the electric system.