US 7,512,466 B2Granted

High-torque, low power reaction wheel array and method

AssigneeHoneywell International Inc.

InventorsRobert J. Hart, Mason A. Peck

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Abstract

Methods and apparatus are provided for reaction wheel (RW) assemblies for spacecraft. The apparatus comprises a M/G coupled to an inertia wheel and a controller coupled to the M/G that, in response to commands it receives, couples power to or from an M/G of another RW assembly over a shared transfer connection (VXFR), so that one M/G acts as a generator powering another M/G acting as a motor. The controller compares generator voltage VGEN to the BEMF of the motor on VXFR and reconfigures a multi-winding M/G or steps-up the generated voltage to maintain VGEN>VXFR to maximize direct energy transfer from one RW to the other as long as possible. When VGEN declines sufficiently, the controller can couple the motor to the spacecraft power bus and/or the generator to a power dump so as to continue to provide the commanded torque if needed. Operation is automatic.

Claims20

Dependent claims

A spacecraft attitude control apparatus, comprising:

first and second reaction wheel assemblies (RWA) comprising:
first and second reaction wheels;
first and second motor-generators (M/Gs) rotationally coupled to the first and second reaction wheels, respectively, for adding energy to or removing energy from the first and second reaction wheels, respectively;
and
first and second power flow controllers electrically coupled to the first and second M/Gs respectively, and adapted to control operation of the first and second M/Gs as motors or generators;
and
a power bus coupling to the first and second power flow controllers of the first and second RWAs for transferring energy between the first and second M/Gs, whereas when a torque command is received requiring that the first RWA decelerate and the second RWA accelerate, the first power flow controller configures the first M/G as a decelerating generator and the second power flow controller configures the second M/G as an accelerating motor and power flows from the decelerating first M/G to the accelerating second M/G via the power bus while an output voltage derived from the first decelerating M/G exceeds a back EMF of the second accelerating M/G.

4 more elements

Dependencies are inferred from the claim text.