基于间接二次谐波注入的三级式同步电机低速阶段无位置传感器起动控制

针对航空三级式同步电机实现起动功能存在的转子位置检测问题,该文提出一种从主励磁机间接向主发电机注入高频信号的方法,利用旋转整流器产生的二次谐波作为向主发电机励磁绕组注入的高频信号,分析起动过程高频响应信号的频率特性,提出一种通过主励磁机的励磁电流生成同步解耦信号的方法,设计基于带通滤波器级联陷波器的转子位置误差信息提取方法,降低提取的高频信号的相移,增强谐波抑制能力,提高位置估计精度。最后,通过仿真和实验证明所提无位置传感器起动控制方法具有良好的位置估计精度,能够实现三级式同步电机在低速阶段的可靠起动控制。

Sensorless Control of IPMSM for Last 10 Years and Next 5 Years

This paper presents the developments of sensorless control of interior permanent magnet synchronous machine(IPMSM)for last 10 years,which could be divided into the past and the present for each 5 years.Several popular methods developed for last 10 years would be described and evaluated,and the limitations with the methods are discussed.In the past a concept extended EMF(EEMF)was introduced and it can model IPMSM as a non-salient motor,meaning that the representation of IPMSM in the estimated rotor reference frame would be much simpler and accurate.However,because it still relied on back EMF,standstill operation was impossible.And,the position control of IPMSM could not be achieved with EEMF concept.For sensorless drive,the high-frequency signal injection method exploiting inherent saliency of IPMSM has been continuously developed for last 10 years and applied to various industry fields,where torque control at standstill is essential.Its performance has been improved but there are still many problems to be solved.In the present,the square-wave signal injection at estimated d-axis has improved the control performance conspicuously.However,there are strong demands to improve the control performance of sensorless drive,yet.Based on the problems in the present,in this paper the possible developments of sensorless drive of IPMSM in next 5 years are enlightened as the future of sensorless control.

模拟局部放电信号注入法在电缆带电测试中的应用

为了解运行电缆及其附件的绝缘状况,及时发现潜在缺陷隐患,以保障电力电缆线路的安全可靠运行,提出采用模拟局部放电(partial discharge,PD)信号的脉冲发生器(pulse generator,PG)在运行电缆的中间接头或终端注入模拟PD信号的方法对110 kV及以上电压等级电缆进行带电PD检测。介绍模拟PD信号的PG在电缆带电PD测试中的应用原理及操作方法。以一些现场实际电缆线路测试为案例,采用直接注入和间接注入模拟PD信号进行电缆中间接头、终端、PD定位测试,分析注入模拟PD信号与实测PD信号的异同,证明了模拟PD信号注入法对PD信号的判断、定位以及定量评价均可行、有效。

An MRAS method for sensorless control of induction motor over a wide speed range

This paper addresses the problem of wide speed range sensorless control of induction motor.The proposed method is based on model reference adaptive system (MRAS),in which the current model serves as the adjustable model,and a novel hybrid model integrating the modified voltage model (MVM) and high-frequency signal injection method (HFSIM) are established to serve as the reference model.The HFSIM works together with MVM to improve the performance of the rotor speed and rotor flux position estimation at low speed,whereas at high speed,the MVM acts alone.In addition,a rotor resistance online estimation scheme is proposed to update the rotor resistance contained in the adjustable model and to ensure the estimation accuracy further.Experimental results show that the proposed MRAS method is very effective from low to high speed range,including zero speed.

Sensorless Control of Permanent Magnet Synchronous Motor in Full Speed Range

Aiming at resolving the limitation of the speed regulation range of sensorless control technology,a new composite sensorless control strategy is proposed to realize a control method for a permanent magnet synchronous motor(PMSM)in full speed range.In the medium-and high-speed range,the improved new sliding mode observer method is used to estimate the motor speed and rotor position information.In the zero and low speed range,in order to avoid the defects of the sliding mode method,the rotating high-frequency voltage signal injection method is used.When switching between low,medium,and high speed,the fuzzy control algorithm is adopted to achieve smooth transitions.The simulation experiment results show that the hybrid mode combining the sliding mode observer and rotating high-frequency voltage injection methods,can effectively reduce the jitter in the algorithm switching process,and realize the smooth control of a PMSM in full speed range.

Saliency-Based Position Sensorless Control Methods for PMSM Drives-a Review

Permanent magnet synchronous motor(PMSM)drives are finding expanded use for industrial and domestic drive applications.With the distinguished characteristics such as reduced cost and increased reliability and robustness,position sensorless(self-sensing)control techniques have been good candidates for reliable and costless PMSM drives.The saliency-tracking based techniques further bring the expansion of applications with the extended controllable sensorless operating speed range.This paper presents a review on state of the art techniques for position sensorless drives using the saliency-tracking based methods.The signal injection methods and the future scope of research including the dynamic bandwidth improvement and the acoustic noise reduction are discussed.