Author(s): Li Quanwu, Dou Manfeng, Northwestern Polytechnical University
Pages: 19-26
Year: 2015 Issue:  22
Journal: Transactions of China Electrotechnical Society
Keyword:  Dual-redundancy; brushless DC motors; split ratio; thermal limitation;
Abstract: A novel split ratio optimization method used in aviation electromechanical actuator is proposed to increase the torque of dual redundancy brushless DC motor(DRBLDCM), where volume and reliability can be ensured. Global thermal limitation of motor is set by limiting copper loss density, and local thermal limitation of coil is set by limiting current density. Expression of optimal split ratio for warm spare and cold spare is presented by analyzing the relationship between spilt ratio and electromagnetic torque. The analytical optimal split ratio value is verified by finite element analysis(FEA), and the error is less than 2%. Testing value of electromagnetic torque is 9.3% less than the analytical value. FEA and testing results proved that the method can increase the torque of DRBLDCM with limited size and heat.