A Novel Digital Control Technique for Brushless DC Motor Drives

Brushless DC (BLDC) motor drives are continually gaining popularity in motion control applications. Therefore, it is necessary to have a low cost, but effective BLDC motor speed/torque regulator. This paper introduces a novel concept for digital control of trapezoidal BLDC motors. The digital controller was implemented via two different methods, namely conduction-angle control and current-mode control. Motor operation is allowed only at two operating points or states. Alternating between the two operating points results in an average operating point that produces an average operating speed. The controller design equations are derived from Newton's second law. The novel controller is verified via computer simulations and an experimental demonstration is carried out with the rapid prototyping and real-time interface system dSPACE.     

Implementation of Hybrid Control for Motor Drives

This paper presents the implementation of a hybrid-control strategy applied to a permanent-magnet synchronous-motor (PMSM) drive. Hybrid control is a general approach for control of a switching-based hybrid system (HS). This class of HS includes a continuous process controlled by a discrete controller with a finite number of states. In the case of ac motor drives, in contrast to conventional vector control like proportional-integral control or predictive control, where the inverter is not taken into account by the controller, hybrid control integrates the inverter model and considers the state of the inverter as a control variable. It allows to obtain faster torque dynamics than vector-control algorithms. The hybrid control algorithm requires both computing velocity for real-time implementation and code flexibility for management of low-performance functions and analog-digital interfaces. Codesign appears as a promising methodology for partitioning hybrid-control algorithm between software (flexible) and hardware (velocity) while taking care of overall time constrains. In this paper, the implementation of hybrid-control algorithm for a PMSM drive is performed through a codesign approach on an Excalibur board, embedding a CPU-core (Nios-2 by Altera) inside an APEX20KE200EFC484-2X field-programmable gate array. The partitioning of software and hardware parts is explained. Experimental results show the effectiveness of the implementation. Performances, advantages, and limitations are discussed.     

Implementation of Artificial Neural Network-Based Tracking Controller for High-Performance Stepper Motor Drives

Two distinct multilayer perception neural networks (NNs) are implemented via laboratory experiment to simultaneously identify and adaptively control the trajectory tracking of a hybrid step motor assumed to operate in a high-performance drives environment. That is, a neural network identifier (NNI) which captures the nonlinear dynamics of the stepper motor drive system (SMDS) over any arbitrary time interval in its range of operation, and a neural network controller (NNC) to provide the necessary control actions as to achieve trajectory tracking of the rotor speed. The exact form of the control law is unknown, and must be estimated by the NNC. Consequently, the NNC is constructed as a nonlinear unknown function depending on the current state of the drive system supplies by the NNI and the reference trajectory we wish the outputs to follow. The two NNs are online trained using dynamic back-propagation algorithm. The composite structure is used as a speed controller for the SMDS. Performance of the composite controller is evaluated through a laboratory experiment. Experimental results show the effectiveness of this approach, and demonstrate the usefulness of the proposed controller in high-performance drives     

一种用于马达驱动芯片的新型过温保护电路

为简化电路结构,提高精度和降低功耗,提出了一种新型过温保护电路。该电路无需基准电压和比较器,利用PTAT电流源的正温度系数特性,对温度进行检测,同时设计迟滞回路,避免了热震荡的发生。基于HHNEC的0.35μm BCD工艺实现,在电源电压为3V~5.5V下进行测试结果表明,该电路热关断温度为165℃,温度迟滞量为15℃,误差为1℃,与仿真结果一致,可以广泛应用于功率集成芯片中。     

A New Model-Based Technique for the Diagnosis of Rotor Faults in RFOC Induction Motor Drives

This paper proposes a new model-based diagnostic technique, which is the so-called virtual current technique (VCT), for the diagnosis of rotor faults in direct rotor field oriented controlled (DRFOC) induction motor drives. By measuring the oscillations at twice the slip frequency found in the rotor flux of the machine, and by conjugating this information with the knowledge of some motor parameters, as well as the parameters of the flux and current controllers, it is possible to generate a virtual magnetizing current which, after normalization, allows the detection and quantification of the extension of the fault. The proposed method allows one to overcome the major difficulties usually found in the diagnosis of rotor faults in closed-loop drives by providing information about the condition of the machine in a way that is independent of the working conditions of the drive such as the load level, reference speed, and bandwidth of the control loops. Although the VCT was primarily developed for traction drives used in railway applications, it can be incorporated in any DRFOC drive at almost no additional cost. Several simulation results, obtained with different types of DRFOC drives, as well as experimental results obtained in the laboratory, demonstrate the effectiveness of this new diagnostic approach.      

变频器中电机过载保护实现方法

分析现有的电机过载保护方法.提出了一种新的程序实现方法,该方法基于电机的一阶热模型方程,适用于电机负荷频繁变化、断续过载、重复短时过载等复杂工况。同时.用户能更直观地了解电机过载能力。     

A Novel Polygon Based 18-Pulse AC–DC Converter for Vector Controlled Induction Motor Drives

This paper presents a novel configuration of an autotransformer based 18-pulse ac-dc converter for improving the power quality at the point of common coupling (PCC) in variable frequency induction motor drives (VFIMDs). The polygon based connection of autotransformer for achieving 18-pulse rectification is utilized to result in reduction in rating of the magnetics. The design of the autotransformer is carried out for an 18-pulse ac-dc converter feeding a vector controlled induction motor drive (VCIMD). Moreover, the autotransformer design is modified for making it suitable for retrofit applications, where presently a 6-pulse diode bridge rectifier is used. The effect of load variation on VCIMD is also studied and the performance of the proposed 18-pulse ac-dc converter is compared in terms of different power quality indices on both ac as well as dc side with other ac-dc converters. A laboratory prototype of the proposed autotransformer based 18-pulse ac-dc converter feeding a 10-hp induction motor drive is developed to verify the design and simulated results     

An Adaptive Sliding Stator Flux Observer for a Direct-Torque-Controlled IPM Synchronous Motor Drive

This paper focuses on performance improvements of the stator flux estimation for a direct-torque-controlled interior permanent magnet synchronous motor drive. In this paper, an adaptive sliding observer is presented to estimate the stator flux linkage based on the motor current model. The experimental results show that the proposed observer has been able to deliver more accurate estimation than an open-loop estimator both in the steady state and during transients. The observer has better dynamic behavior, disturbance resistance, and high-accuracy estimation ability. With the integrated flux observer, the drive system can operate at very low speed down to 10 r/min (0.33 Hz) with half full load.     

一种新颖的代码保护系统的设计与FPGA实现

针对嵌入式系统软件代码容易被盗用的问题,提出了一种基于高速TDES的加密系统,由PC机上运行的预加密软件和安全芯片两部分组成,能够防范当前各种针对嵌入式计算机的软件程序的恶意窃取以及修改,有效保护Flash存储器中的嵌入式软件代码。     

电控机械式自动变速器在线故障诊断系统的开发

根据电控机械式自动变速器系统的特点,采用基于模型的设计方法,在MATLAB／SIMUuNK软件环境下,运用Stateflow逻辑系统建模工具建立了AMT系统的在线故障诊断模型,从而有效地对AMT系统中的传感器、执行机构和TCU硬件的主要故障进行在线诊断。大量试验表明,该设计方法是行之有效的且非常实用。     

Improved PWM Control Strategy for Inverters and Induction Motor Drives

This paper develops a novel pulse-width modulation (PWM) strategy for application in uninterruptible power supply (UPS) and ac motor drive systems. The voltage/current harmonic spectra and other properties of this PWM scheme are thoroughly investigated. This modulation strategy is compared with other modulation techniques, especially with the commonly used sinusoidal modulation scheme, from the standpoints of simplicity, inverter switching losses, motor losses, and other output performance features. This novel modulation scheme produces an acceptable motor curent waveform while keeping the number of inverter commutations low. Implementation of this scheme is quite simple in hardware-based as well as microprocessor-based systems.     

A Novel TOPSIS-Based Test Vector Compaction Technique for Analog Fault Detection

Technique for Order preference by Similarity to Ideal Solution (TOPSIS) is a Multi Attribute Decision Making (MADM) technique employed in diverse disciplines for the prioritization of alternative options/solutions to a problem. Test vector compaction for analog fault detection is a field which is witnessing continuous growth and experimentation. This study suggests a novel TOPSIS-based approach for the compaction of analog test vector to be constituted from test signals achieved by an exhaustive search method. The compacted test vector can help to reduce the test costs while at the same time enabling the test designer to base the compaction methodology on objectively obtained deterministic data.     

A Novel Design Technique for Brushless DC Motor in Wireless Medical Applications

Wireless Personal Communications - The wireless technology plays a vital role in various fields such as aerospace, home appliances and global positioning system etc. This is important, especially...     

开关磁阻电机无位置传感器的CGSM驱动策略

本文详细地介绍了使用电压PWM控制方式实现开关磁阻电机间接位置检测方案。该方案应用电机相电流导数的变化来检测电机定转子相开始重叠的位置，确定出定转子的相对位置。该方法只需知道电机定转子报数，不需要电机的相关参数，这种方法可适用于宽广的转速和功率的磁阻电机，可适用于闭环动态操作。为了启动电机，采用前馈步进法，该算法确保电机在没有位置传感器的条件下甚至在有负载条件下能够由静止状态启动到给定速度。实验证实了该方法的可靠性。     

用于电器和轻工业先进电动机驱动器的集成封装工艺

为家用电器设计的电动机是全球电能产品的最大用户之一，并代表电子工业直接产生积极影响的应用领域。这些电动机的效率在不断提高，即使增幅很小，都会对世界能量消耗产生巨大影响，并使环境、政府和用户受益。基于逆变器的电动机控制是提高效率的关键，但只有减少常规逆变器设计的开发时间、材料成本和总尺寸，才能在市场上获得成功。     

Digital Simulation of PWM Induction Motor Drives for Transient and Steady-State Performance

In this paper, the influence of nonsinusoidal voltage excitation applied to a squirrel cage induction motor is investigated using direct three-phase machine simulation method. Computer packages are developed to generate various types of inverter modulation techniques, namely the sine, step, and current impressed schemes. These packages together with a three-dimensional plotting subroutine are used to investigate the characteristics of an inverter-fed induction motor system. The effects of switching frequency ratio, overmodulation, and start-on machine waveform characteristics are investigated. Harmonic distortion comparisons between sine and step modulation schemes are presented. A vector controller-driven current-impressed scheme are simulated. The effect of varying hysteresis band in a current-impressed scheme is discussed.     

异步电动机故障实时在线监测系统的研制

针对异步电动机故障诊断的特点,研制了一种异步电动机故障实时在线监测系统。该系统对所采集异步电动机的各种电压、电流、绕组温度等进行数据预处理后,通过TCP/IP数据采集通信模块传输给上位机,再结合信息融合技术和神经网络技术,判断系统状态,实现对异步电动机实时、可靠的在线故障诊断。通过以太网,基于LabVIEW界面对该系统进行了实验,结果表明其故障诊断快速、有效。     

交流电动机传动用电压源逆变器损耗的分析

整流器与逆变器是工业变频器中重要的两种变换器,其功率损耗的大小决定于变换器的调制算法、传动系统的负载特性与运行方式等因素,而变换器的功率器件功耗大小又决定了整个变频器的效率、散热处理、安全运行等方面。本文理论推导了普通SPWM、谐波注入PWM、损耗最小PWM、常规SVPWM、以及共模电压抑制时电压源逆变器中功率器件功耗的计算公式,所得结果均得到了仿真分析验证。以22kW工业变频器100A IGBT和SPWM算法为例,进行了初步模拟计算。所推导的功耗计算公式对实际逆变器散热设计具有一定的参考价值。