摘要
在高速(基速以上)区域,由于逆变器提供的电压有限,异步电机需要工作在弱磁状态。提出一种应用在直接转矩控制(DTC)中的简单过调制策略。该方法作用在电机加速以及高速区域,既扩大了恒转矩范围,提高了转矩能力,又可在弱磁阶段利用六步模型自发削弱磁链值。随着转速的升高,定子磁链轨迹从近似圆形平滑切换到近似六边形。方法的实现是通过修改定子磁链滞环控制器的输出状态。提出的控制策略的主要优点是保持传统DTC的简单结构,不需要电压空间矢量调制。仿真结果证明了该调制策略方法的有效性。
At high-speed （ above the base speed） region, the induction motor is operated in the field weake- ning range due to the voltage limit of the inverter. In this paper, a simple overmodulation strategy for direct torque control （DTC） was proposed. This method acted on the motor acceleration and the high speed region, and extended a constant torque region and hence produce high torque capability, utilizing six-mode in the field weakening range to weaken the flux reference. With the angular velocity increasing, controlling the stator flux locus from circular to the hexagonal shape. This method of DTC with the proposed overmodulation strategy was implemented by modifying the error state of the stator flux controller. The main benefit of the proposed method is to maintain the traditional DTC simple structure and does not require a space-vector mod- ulation. Simulation results verify the effectiveness and feasibility of the proposed DTC method.
出处
《微电机》
2017年第12期51-56,共6页
Micromotors
基金
国家自然科学基金委员会与宝钢集团有限公司联合资助项目(U1260203)
河北省高等学校创新团队领军人才培养计划项目(LJRC013)
关键词
异步电机
直接转矩控制
高转矩能力
过调制
弱磁
induction motor
direct torque control
high torque capability
overmodulation
field-weakening
