Research On Key Technologies Of Wound-excited Doubly Salient Machine For Areospace

Wound-excited Doubly Salient Machine(WEDSM)has attracted widely attention because of its simple structure,convenient manufacture,reliable operation and flexible adjustment ability of air-gap flux and has potential application values in the area of aerospace and new energy resources.WEDSM with diode rectifier can form a brushless dc generator system and WEDSM with bridge inverter can also form a motor drive system.With the development of power electronics,there are more electric control gears in the aviation system and the generating capacity is getting much larger.However,operating environments are poor and easily disturbed by electromagnetic interference,so it requires the high reliability machine system.It is important to explore the reasonable structure of WEDSM and sensorless technologies to promote the technology development and applications of WEDSM.In this dissertation,the key technologies of WEDSM are researched for aircraft application,such as the winding structure and fault-tolerant characteristics of the generator,the senserless control technologies of the motor.The development history of doubly salient machine and appearance significance of WEDSM are given.Then the research status of basic characteristics,fault-tolerance and sensorless technologies of WEDSM are analyzed and the sensorless control technologies of switched reluctance machine and brushless direct current motor are summarized.The actual application values of WEDSM are explained by introducing the development of wind power generation technology and aircraft electric power source system.The structures and operating principle of WEDSM are described.The mathematical models of wound-excited doubly salient generator(WEDSG)and WEDSM are introduced then.The iron loss and other loss models and the fundamental electromagnetic characteristics are analyzed.The relationship between the fault-tolerance and the numbers of stator and rotor pole of WEDSM is researched.In order to make the WEDSG have the fault-tolerant ability,the proportion of stator pole and rotor pole numbers of WEDSG is deduced.The fundamental electromagnetic characteristics of five-phase 20/8-pole and 20/16-pole WEDSG are analyzed.On this basis,the fault-tolerant characteristics of the five-phase 20/16-pole WEDSG under the conditions of single-phase open circuit,single-phase short circuit,two adjacent phase open circuit,two non-adjacent phase open circuit,and phase-to-phase short circuit are analyzed by the theoretical and simulation analysis.The experimental results are given to verify that the topology of 20/16-pole WEDSG possesses high fault-tolerant ability.The generator system consisted of dual armature-winding WEDSG(DAW-WEDSG)and hybrid half-bridge rectifier is proposed.The fundamental electromagnetic characteristics of DAW-WEDSG,such as the turn numbers of armature windings in the same stator pole,armature winding structure,electromagnetic characteristics with and without load,are investigated.The three-phase single armature-winding WEDSG(SAW-WEDSG)and DAW-WEDSG have the same dimension.The comparison of the output characteristics of SAW-WEDSG with the switched reluctance generator mode and doubly salient generator 2 mode and DAW-WEDSG with hybrid generator mode are researched.The five-phase SAW-WEDSG and three-phase DAW-WEDSG have the same dimension and the fault-tolerant characteristics of the two generators are compared under three faults.The three-phase DAW-WEDSG has the similar fault-tolerant ability with five-phase SAW-WEDSG.The fundamental electromagnetic characteristics and fault-tolerant characteristics of DAW-WEDSG are verified by the experiments of a prototype three-phase DAW-WEDSG.The fundamental electromagnetic characteristics of SAW-WEDSG are verified by the experiments of a prototype three-phase SAW-WEDSG.The position sensorless control methods of WEDSM under different speed ranges are investigated.The series self-inductance detection method and terminal voltage detection method in consideration of cogging torque produced by field current are researched to identify the initial position.The test excitation duration and frequency of injected pulses are also be analyzed.The current pulse injection technique in the commutation point is proposed to detect the commutation moment in the low speed.In the high speed,the sensorless control method based on terminal voltage coordinate transformation is researched in the high speed.The smooth switch technology from start-up to high-speed operations is analyzed.The feasibility of the proposed sensorless schemes covered different speed ranges is verified by experiments.