Flexible Solar Generator Arc Protection via Segmented Strings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flexible solar generators on spacecraft and satellites are vulnerable to impacts from celestial objects due to the close proximity of solar cells and electrical power conductors, leading to electrical arcs and permanent short circuits, which result in power loss without adequate protection.
Innovation Solution
A flexible solar generator design with independent transverse strings of solar cells and dedicated blocking diodes located outside the solar cell array, along with a multilayer substrate and etched conductive tracks for electrical transfer conductors, ensures that electrical arcs are limited and shielding is maintained without increasing weight, by managing electrical currents and positioning blocking diodes to prevent self-sustaining arcs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If electrical power conductors are positioned close to solar cells on the flexible support, then the device complexity is reduced and manufacturing is simplified, but the solar generator becomes vulnerable to electrical arcs and short circuits from celestial object impacts
Solution Approach 1:
The solar generator is divided into independent transverse strings, each with its own blocking diode. This segmentation ensures that an impact causing an electrical arc in one string does not affect other strings, limiting the damage to a single string rather than the entire generator. The blocking diodes are positioned outside the solar cell array to provide individual protection for each string.
Solution Approach 2:
Blocking diodes are introduced as intermediary protective elements between the solar cells and the electrical power conductors. These diodes act as mediators that prevent harmful electrical arcs from propagating through the system by blocking current flow in the reverse direction, thus protecting the solar generator from short circuits caused by celestial object impacts.
2Reliability
If blocking diodes are positioned close to solar cells to protect against electrical arcs, then protection effectiveness is improved, but the distance for electrical connection increases and device complexity increases
Solution Approach 1:
The blocking diodes are positioned outside the solar cell array in a different spatial arrangement, connected to the positive polarity ends of the transverse strings. This dimensional repositioning allows the diodes to provide effective protection against electrical arcs while maintaining compact electrical connections through the flexible support's conductor network, avoiding the need for long connection distances.
3Reliability
If transverse strings are made electrically independent with individual blocking diodes, then protection against electrical arcs is improved, but the quantity of components and device complexity increases
Solution Approach 1:
The blocking diodes serve multiple functions: they protect against electrical arcs from celestial object impacts, prevent reverse current flow, and enable independent operation of each transverse string. This multi-functionality justifies the addition of components by providing comprehensive protection and operational independence across the solar generator system.
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 design effectively limits electrical current intensity and prevents permanent short circuits, maintaining power generation while ensuring the rear face is shielded, thus reducing power loss and enhancing the solar generator's durability against impacts.
Implementation Method 1
the solar cells, covering the surface of support panels being suitable for transforming the solar energy into electrical energy transmitted to the electrical equipment items of the satellite
Implementation Method 2
The impact creates a plasma bubble which, when the electrical voltage between the impacted solar cell and the electrical conductor is sufficient, for example greater than 50 Volts, can generate an electrical arc 14 between said impacted solar cell and the electrical conductor placed under that solar cell
Data Source
AI summary
A solar generator comprises a flexible support, an array of solar cells, electrical transfer conductors, blocking diodes, the solar cells being formed along different transverse strings, the solar cells situated in a same string being electrically connected in series, each string comprising two opposite ends, respectively of positive polarity and of negative polarity. The positive polarity end of each string of solar cells is individually connected to a respective blocking diode via an electrical transfer conductor dedicated to the string, the electrical transfer conductors dedicated to the different strings being independent of one another, the blocking diodes being located at the proximal end of the solar generator, outside of the array of solar cells.