6.5 Typical Technology
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storage battery and the structural member. Lithium-ion battery cells were electrically
connected with the guide bars. The battery and the wires were connected through
the terminals. All the current wires and voltage wires were integrated into different
electrical connectors according to different functions, so the signal transmission was
isolated from the power transmission.
With increasing number of charge and discharge of lithium-ion battery packs, the
difference in the charging capacity and self-discharge rate of each cell in battery packs
gradually accumulated, so the voltage gap between battery cells within battery packs
became larger and larger with a divergent trend. In order to ensure safety of lithiumion battery packs, each single cell in battery packs must be charged with voltagebalanced charge control. In charge design of the power controller, the battery pack
voltage and the cell voltage were limited to ensure the charging safety of lithium-ion
battery packs.
6.5.3 Design of Solar Cell Circuits
The solar array circuit was composed of many solar cells in series and parallel. The
design of the solar array circuit was design of series, parallel and combination of
solar cells. The method for calculating the number of solar cell series and parallel
plates was basically the same as the calculation method for Earth orbit spacecraft.
For the lunar lander, when the solar cell array was designed, it was also necessary to
be designed for the ultra-wide operation temperature range and occlusion prevention
of solar array.
During LTO and operation on lunar surface, operation temperature of the solar
array working temperature might be as higher as +120 °C. The output voltage of
solar array at the highest temperature was low. In order to ensure satisfaction of
the minimum main bus voltage requirement, the worst case temperature should be
considered during design of series number of solar cells. The design of solar cell array
configuration was based on the theoretical calculation results of solar cells series and
parallel design, along with the substrate area of carbon-fiber aluminum honeycomb,
direction and coefficient of distribution. For the Chang’E-3 lunar lander, there was
energy reuse for the lunar lander and the lunar rover. After the lunar lander was
landed on lunar surface, there were two sub-arrays in solar panels of the lunar lander
to charge the battery packs of the lunar rover. Therefore, in configuration design of
the solar array, the two sub-arrays were designed to prevent occlusion as much as
possible.
In design of the solar arrays, some measures should be taken to ensure the reliability, safety, maintainability and interchangeability of solar cell array as well as
reliability of diode welding and circuit output.
There are two methods in installation of spacecraft solar array including bodymounted and deployable solar array. The solar arrays of the Chang’E-3 lunar lander
were composed of four panels including two deployable solar arrays and two bodymounted solar arrays of carbon-fiber aluminum honeycomb.
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storage battery and the structural member. Lithium-ion battery cells were electrically
connected with the guide bars. The battery and the wires were connected through
the terminals. All the current wires and voltage wires were integrated into different
electrical connectors according to different functions, so the signal transmission was
isolated from the power transmission.
With increasing number of charge and discharge of lithium-ion battery packs, the
difference in the charging capacity and self-discharge rate of each cell in battery packs
gradually accumulated, so the voltage gap between battery cells within battery packs
became larger and larger with a divergent trend. In order to ensure safety of lithiumion battery packs, each single cell in battery packs must be charged with voltagebalanced charge control. In charge design of the power controller, the battery pack
voltage and the cell voltage were limited to ensure the charging safety of lithium-ion
battery packs.
6.5.3 Design of Solar Cell Circuits
The solar array circuit was composed of many solar cells in series and parallel. The
design of the solar array circuit was design of series, parallel and combination of
solar cells. The method for calculating the number of solar cell series and parallel
plates was basically the same as the calculation method for Earth orbit spacecraft.
For the lunar lander, when the solar cell array was designed, it was also necessary to
be designed for the ultra-wide operation temperature range and occlusion prevention
of solar array.
During LTO and operation on lunar surface, operation temperature of the solar
array working temperature might be as higher as +120 °C. The output voltage of
solar array at the highest temperature was low. In order to ensure satisfaction of
the minimum main bus voltage requirement, the worst case temperature should be
considered during design of series number of solar cells. The design of solar cell array
configuration was based on the theoretical calculation results of solar cells series and
parallel design, along with the substrate area of carbon-fiber aluminum honeycomb,
direction and coefficient of distribution. For the Chang’E-3 lunar lander, there was
energy reuse for the lunar lander and the lunar rover. After the lunar lander was
landed on lunar surface, there were two sub-arrays in solar panels of the lunar lander
to charge the battery packs of the lunar rover. Therefore, in configuration design of
the solar array, the two sub-arrays were designed to prevent occlusion as much as
possible.
In design of the solar arrays, some measures should be taken to ensure the reliability, safety, maintainability and interchangeability of solar cell array as well as
reliability of diode welding and circuit output.
There are two methods in installation of spacecraft solar array including bodymounted and deployable solar array. The solar arrays of the Chang’E-3 lunar lander
were composed of four panels including two deployable solar arrays and two bodymounted solar arrays of carbon-fiber aluminum honeycomb.