Abstract: A powertrain, a control method, and a hybrid electric vehicle. The powertrain includes a motor controller unit and a motor. The motor controller unit includes N bridge arms, and the motor includes N motor windings corresponding to the N bridge arms. Each of the N bridge arms includes a first end and a second end, the first end of each bridge arm is connected to a positive bus, the second end of each bridge arm is connected to a negative bus, a midpoint of each bridge arm is connected to one end of one motor winding, the other end of each of the N motor windings is connected to one end of a power battery, and the other end of the power battery is connected to the positive bus or the negative bus.

Abstract: A secondary battery contains cyclic siloxane and/or ring-opening polymerization derivative thereof, where a cyclic structure of the cyclic siloxane has at least one structure, one and only one of R1 and R2 contains a group with stronger electron withdrawing property than phenyl, and the group is directly linked to Si.