| 摘要 |
An electric drive system 200 for driving an output comprises: a first electric motor 250 arranged to drive a first input shaft 230 at a first angular velocity, ω1, and a second electric motor 260 arranged to drive a second input shaft 240 at a second angular velocity, ω2. A gear mechanism 210 transmits angular rotation of the first and second input shafts to drive the output 220 at an output angular velocity, ωout, such that ωout is proportional to aω1bω2, where a and b are constants. When the output is to be driven from ωout=0, controller 270 controls the first and second motors to drive the first and second input shafts in a first phase to primary first and second angular velocities, ω1,p and ω2,p, such that aω1,p≈bω2,p . The input shafts are subsequently driven in a second phase in which the first angular velocity, ω1, or the second angular velocity, ω2, or both are varied such that aω1≠bω2 and the output is driven from ωout=0. The invention is suitable for motors powering an electric vehicle, particularly when pulling off in situations of high output load such as off-road or otherwise difficult terrain, or moving at low velocity. |
