216
6 Power Technology of Lunar Lander
same. The advantage of such design method was that a more reasonable installation and configuration method could be achieved for each group of printed circuit
boards or circuit functional modules, which facilitated the design of a single module
in reliable internal cable, lightweight and convenient maintenance. In addition, the
internal structure of each functional module in the modular structure was independent, which facilitated further optimization in its thermal design and electromagnetic
compatibility design. Moreover, the same external shape and flexible combination
of modular structures created favorable advantages for development of new power
transmission methods.
Due to the special lunar surface environment and lunar night of 14 days, the battery
pack could not meet the power load requirement during lunar night. Before it was
entering lunar night, the power load must be disconnected and the discharge switch
of the battery pack should be disconnected to make the system go into hibernation.
When the lunar daytime was coming, the discharge switch of the battery pack should
be closed and the OBDH computer of the lunar lander was awakened. The hibernation
and awakening control circuits should be designed for the power controller.
Due to strict mass constraint, the lunar lander and the lunar rover were designed
with energy reuse circuits to save mass. In design of the power controller, it was
necessary to consider the method of sharing the energy of the two probes. The detail
of common design method of energy share is given in Sect. 6.5.5.
In order to reduce the mass, the aluminum alloy structure was usually used in the
power controller. For further reduction of the mass, the magnesium alloy mechanism
was used in the power controller. Each structural module was formed by a whole
piece of magnesium plate and the chassis was composed of left and right wall plates
with titanium alloy connecting rods.
6.5.2 Design of Battery Pack
The energy storage device used in the power system of the Chang’E-3 lunar lander
was lithium-ion battery packs. It was composed of several and even dozens of
rectangular battery cells connected in series and parallel.
Because of the strict mass constraint, the equalization control of lithium-ion
battery packs was not used for the Chang’E-3 lunar lander. To ensure that the single
cell’s performance of the battery packs was not dispersed during the one-year life on
orbit, single cells were screened to ensure consistency. After the monomer formation
efficiency, charge and discharge efficiency, internal resistance, self-discharge efficiency and monomer capacity were compared, the monomers consistent with each
specification were selected to form the battery packs.
The drawbar type structure was adopted for the battery packs to achieve a tight
assembly between the individual battery cells for preventing the battery cells from
being deformed due to internal pressure and facilitating heat dissipation at the same
time. The space between the single storage battery and the structural member was an
insulating polyimide tape to ensure good insulation performance between the single
6 Power Technology of Lunar Lander
same. The advantage of such design method was that a more reasonable installation and configuration method could be achieved for each group of printed circuit
boards or circuit functional modules, which facilitated the design of a single module
in reliable internal cable, lightweight and convenient maintenance. In addition, the
internal structure of each functional module in the modular structure was independent, which facilitated further optimization in its thermal design and electromagnetic
compatibility design. Moreover, the same external shape and flexible combination
of modular structures created favorable advantages for development of new power
transmission methods.
Due to the special lunar surface environment and lunar night of 14 days, the battery
pack could not meet the power load requirement during lunar night. Before it was
entering lunar night, the power load must be disconnected and the discharge switch
of the battery pack should be disconnected to make the system go into hibernation.
When the lunar daytime was coming, the discharge switch of the battery pack should
be closed and the OBDH computer of the lunar lander was awakened. The hibernation
and awakening control circuits should be designed for the power controller.
Due to strict mass constraint, the lunar lander and the lunar rover were designed
with energy reuse circuits to save mass. In design of the power controller, it was
necessary to consider the method of sharing the energy of the two probes. The detail
of common design method of energy share is given in Sect. 6.5.5.
In order to reduce the mass, the aluminum alloy structure was usually used in the
power controller. For further reduction of the mass, the magnesium alloy mechanism
was used in the power controller. Each structural module was formed by a whole
piece of magnesium plate and the chassis was composed of left and right wall plates
with titanium alloy connecting rods.
6.5.2 Design of Battery Pack
The energy storage device used in the power system of the Chang’E-3 lunar lander
was lithium-ion battery packs. It was composed of several and even dozens of
rectangular battery cells connected in series and parallel.
Because of the strict mass constraint, the equalization control of lithium-ion
battery packs was not used for the Chang’E-3 lunar lander. To ensure that the single
cell’s performance of the battery packs was not dispersed during the one-year life on
orbit, single cells were screened to ensure consistency. After the monomer formation
efficiency, charge and discharge efficiency, internal resistance, self-discharge efficiency and monomer capacity were compared, the monomers consistent with each
specification were selected to form the battery packs.
The drawbar type structure was adopted for the battery packs to achieve a tight
assembly between the individual battery cells for preventing the battery cells from
being deformed due to internal pressure and facilitating heat dissipation at the same
time. The space between the single storage battery and the structural member was an
insulating polyimide tape to ensure good insulation performance between the single