Sequential Solar Array Power Control for Satellite Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional satellite power systems using linear-shunt regulators experience significant thermal stress and inefficient power utilization due to unnecessary shunting of solar array currents, leading to reduced reliability and suboptimal power utilization over the lifespan of the spacecraft.
Innovation Solution
A highly efficient power and control architecture employing distributed dc-dc converters that sequentially regulate power flows from independent solar-array sources, allowing all but one activated channel to operate in maximum power tracking mode, thereby reducing thermal stress and maximizing power utilization while enabling efficient power expansion through parallel connection of Commercial-off-the-Shelf converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If linear-shunt regulators are used to regulate bus voltage, then voltage regulation is achieved, but thermal stress on shunt devices increases and power utilization efficiency decreases
Solution Approach 1:
The patent extracts the voltage regulation function from the shunt devices and relocates it to a dedicated bus voltage regulator. This separates the shunting function (current diversion) from the regulation function (voltage control), allowing shunt devices to operate without thermal stress while a specialized regulator handles voltage stabilization.
Solution Approach 2:
The patent introduces a bus voltage regulator as an intermediary component between the solar array channels and the load. This mediator component absorbs the thermal stress of voltage regulation, protecting the shunt devices from harmful thermal effects while maintaining system reliability.
2Reliability
If regulated bus voltage is set significantly below BOL peak-power voltage to ensure sufficient voltage near EOL, then voltage sufficiency is maintained, but power utilization efficiency decreases
Solution Approach 1:
The patent implements dynamic voltage regulation where the bus voltage can adapt to different operating conditions. The system actively manages voltage levels to maximize power extraction from solar arrays while ensuring sufficient voltage is maintained near end-of-life, rather than using a fixed conservative voltage setting.
Solution Approach 2:
The patent changes the operating voltage parameter dynamically based on system needs. By using a dedicated bus voltage regulator, the system can optimize voltage levels for maximum power transfer from solar arrays while maintaining sufficient voltage margins for end-of-life operation, rather than being constrained by a fixed voltage setting.
3Reliability
If multiple shunt devices are used for voltage regulation, then voltage control capability is improved, but device complexity and thermal stress increase
Solution Approach 1:
The patent extracts the voltage regulation function from multiple shunt devices and consolidates it into a single dedicated bus voltage regulator. This reduces the number of active components required for regulation while improving reliability through functional specialization.
Solution Approach 2:
The dedicated bus voltage regulator serves multiple functions: voltage regulation, thermal stress management, and system protection. This multi-functional component replaces multiple specialized shunt devices, reducing overall system complexity while maintaining or improving regulation capability.
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 solution achieves 25% more power throughput over the spacecraft's life with 33% array degradation at end-of-life, reduces thermal stress, and minimizes array cable mass and overall system weight by maintaining solar arrays in maximum power tracking mode, thus prolonging system reliability and efficiency.
Implementation Method 1
The sequentially-controlled solar array power system offers a certain sequence of maximum utilization of the distributed solar array sources. Every solar array source will be assigned its own turn (or priority) to participate in the output voltage regulation while the previously activated array sources have already operated in their maximum power tracking modes.
Data Source
AI summary
A power and control architecture employing circuitry that sequentially regulate power flows from independent solar-array sources or a mixture of power sources providing power to a common load. The device may be used on a satellite with solar-array sources; however it may also be used on ground based systems. Stiff bus voltage regulation is obtained by tightly controlling the most recently activated power-processing channel while keeping the previously activated power-processing channels in the Maximum Power Tracking mode to supply maximum power to a common load. The remaining power-processing channels are turned off or operated in stand-by mode. In an alternative system, with primary design goal of uniform power sharing among solar-array sources, all solar array sources are activated with uniform power sharing at light load and, as load demand increases, sequentially controlled to operate in the Maximum Power Tracking mode one solar array source at a time as necessary.