Speed Regulation Method Using Genetic Algorithm for Dual Three-phase Permanent Magnet Synchronous Motors

Dual three-phase Permanent Magnet Synchronous Motor(DTP-PMSM)is a nonlinear,strongly coupled,high-order multivariable system.In today’s application scenarios,it is difficult for traditional PI controllers to meet the requirements of fast response,high accuracy and good robustness.In order to improve the performance of DTP-PMSM speed regulation system,a control strategy of PI controller based on genetic algorithm is proposed.Firstly,the basic mathematical model of DTP-PMSM is established,and the PI parameters of DTP-PMSM speed regulation system are optimized by genetic algorithm,and the modeling and simulation experiments of DTP-PMSM control system are carried out by MATLAB/SIMULINK.The simulation results show that,compared with the traditional PI control,the proposed algorithm significantly improves the performance of the control system,and the speed output overshoot of the GA-PI speed control system is smaller.The anti-interference ability is stronger,and the torque and double three-phase current output fluctuations are smaller.

Switching of Capacitors in an Asymmetric Induction Motor with Single-Phase Power,Triggering Several Applied Loads

xThis study has as its objective to collaborate with the expansion in the market of electric energy in rural areas,offering as such an innovative prospect to the solution of associated problems through use of the asymmetric three-phase induction motor,supplied by a single-phase source.In this system,capacitor switching is applied during operation,while theoretical and practical results are presented for the application of this switching in a three-phase asymmetric induction motor of 20 hp.

Performance Analysis of Optimization Based FOC and DTC Methods for Three Phase Induction Motor

Three-phase induction motors are becoming increasingly utilized in industrialfield due to their better efficiency and simple manufacture.The speed control of an induction motor is essential in a variety of applications,but it is dif-ficult to control.This research analyses the three-phase induction motor’s perfor-mance usingfield-oriented control(FOC)and direct torque control(DTC)techniques.The major aim of this work is to provide a critical evaluation of devel-oping a simple speed controller for induction motors with improving the perfor-mance of Induction Motor(IM).For controlling a motor,different optimization approaches are accessible;in this research,a Fuzzy Logic Controller(FLC)with Fractional Order Darwinian Particle Swarm Optimization(FODPSO)algorithm is presented to control the induction motor.The FOC and DTC are controlled using FODPSO,and their performance is compared to the traditional FOC and DTC technique.Each scheme had its own simulation model,and the results were com-pared using hardware experimental and MATLAB-Simulink.In terms of time domain specifications and torque improvement,the proposed technique surpasses the existing method.

基于长周期暂态信号分析的电机驱动变换器直流母线电容在线状态监测

直流母线电容作为电机驱动变换器中最薄弱的元件之一,其老化会导致系统故障的概率增大,因此对电容老化进行在线监测至关重要。针对现有监测方法存在经济性差、采样频率高、影响系统正常运行等问题,提出一种基于长周期暂态信号分析的电容在线监测方法,用于估计电机驱动变换器直流母线等值串联电容(equivalent series capacitance,ESC)。首先,根据系统负载切换过程建立共节点感-容等值暂态模型,分析长周期暂态信号特点。其次,推导基于长周期暂态信号的在线监测模型,确定监测程序启动判定条件。然后,提出一种基于多项式重构的电容电流基线校准方法,消除传感器零漂影响,提高监测精度。最后,仿真和实验表明所提出方法的监测精度满足电容监测的要求。

计及总损耗功率的电动汽车母线电容主动快速放电方法

针对电动汽车遇到碰撞等紧急情况时,高压驱动系统母线电容电压需迅速降到安全电压(60 V),而传统基于PI控制的母线电容主动放电方法存在鲁棒性差、放电时间长和安全性低的问题,提出一种计及总损耗功率的电动汽车母线电容快速放电方法。首先,建立以永磁同步电机绕组作为泄放电阻的母线电容能量流动模型,将逆变器损耗、电机绕组铜耗、电机电感储能等损耗作为总损耗,利用扩展滑模观测器(ESMO)对总损耗功率进行估算,并通过Lyapunov稳定性理论对ESMO的稳定性进行了证明。然后,将观测的总损耗功进行前馈补偿,从而使母线电压快速降低并稳定在安全电压。仿真和实验结果表明,与现有主动放电方法相比,所提放电方法不仅显著减小了放电时间,而且提高了快速放电的鲁棒性和安全性。

Fault-tolerant stator flux oriented decoupling control for dual three-phase permanent magnet motor without diagnosis and reconfiguration

In this paper,the fault-tolerant capability of the existing stator-flux-oriented decoupling control(SFOC)for the DTP-PM motor is investigated,and a simple fault-tolerant SFOC is further designed to enhance fault tolerance.Firstly,the mathematical model of the DTP-PM motor in the stator-flux-oriented rotating coordinate system is analyzed.An SFOC is proposed to guarantee healthy operation performance,considering torque,flux linkage,and harmonic currents.Secondly,the coupling relationship under open-phase conditions is assessed.The assessed result shows that the coupling relationship between the harmonic and fundamental components results in conflicts and poor post-fault operation.Thirdly,the proposed SFOC includes an automatic deactivation module to detect conflicts with a variable threshold.The conflicted harmonic current controllers can be excluded automatically.Hence,fault-tolerant control can be remedied without diagnosing the specific fault scenario,and excellent faulttolerant capability can be achieved.Finally,experiments on a DTP-PM motor are carried out to verify the feasibility and effectiveness of the proposed strategy.

异步电动机自动内补偿技术的研究

异步电动机的三V形接法,是分别将主绕组Wa1、Wb1、Wc1的首端连接为A1、B1、C1,并将副绕组Wc2、Wa2、Wb2的末端对应联接,构成夹角为60度的V形接线,引出九个接线端;用接于三对或三个接线端的主电容器C01、C02、C03进行主导的电流内补偿,并用接于三对接线端的副电容器C04、C05、C06配合调节器进行PWM控制动态调节,达到功率因数接近1.0的内补偿效果;可将三相绕线式转子绕组短时与副绕组三端联接,并用三相调节器进行重载的电机起动。

New Approach to the Power Selection for Asynchronous Motor

The heating calculation of three-phase squirrel- cage asynchronous motor on the condition of starting for a prescribed rotary angle is firstly studied with time dissection method and its corresponding algorithm is provided. Then based upon the algorithm, a new method for motor power selection is established. Motor initial power determined by load power ischecked and modified in terms of time crit erion, heating criterion,and starting torque criterion.An appropriate motor power which meets three criterions is obtained at last, in the meantime, working displacement matrix andfrequency matrix used for control are acquired. Lifting motor of MDJ1800 low-level high- speed palletizer is taken as a reaI case in the paper.

Towards Economic Single-Phase Motor

Studying of operation balance in single-phase induction motors is an issue of interest due to the need for reducing the power consumption and increasing the motors’ life. The paper focuses on improving the motor performance by balancing the stator phase operation for the most common-used connection diagrams of single-phase capacitor-run induction motors (SPCRIMs) and three-phase induction motors (TPIMs) operating from single-phase supply (SPS). Therefore, a mathematical model is used to balance the motor operation by varying the frequency supply voltage. Characteristics of balancing parameters are investigated, various methods of motor balancing are presented and comparisons were done among these balancing methods.

无电解电容永磁电机高功率因数控制策略

无电解电容驱动系统常采用体积小,寿命长的薄膜电容贮存网侧输入能量,但该拓扑结构易引起网侧输入功率和逆变器侧输出功率耦合的问题。针对无电解电容驱动电路中由于功率耦合导致的网侧谐波含量多和功率因数降低的问题,提出了一种基于二阶广义积分锁相环和比例积分谐振控制器的带相位补偿的逆变器输出功率控制策略以改善网侧电流品质。首先,通过分析无电解电容驱动系统的电路拓扑结构,明确无电解电容驱动系统高功率因数条件;其次,利用二阶广义积分锁相环获取网侧电压的相位与幅值信息,并利用基尔霍夫电流定律计算逆变器输出功率相位补偿角;然后,建立了基于比例积分谐振控制器的逆变器输出功率控制回路,将逆变器输出功率调节接近理想值。最后,对比实验结果验证了所提方案的有效性。

电动汽车电机控制器母线电容纹波电流研究

在电动汽车电机控制器中,由于电机负载电流的变化和功率器件高频开关的影响,在直流母线上会产生纹波电流,纹波电流通过直流母线电容,会导致母线电容发热,纹波电流过大会引起电容发热严重,直接影响电容使用寿命。本文通过对电机控制器建立Matlab/Simulink仿真模型,分析了母线电容上纹波电流波形特征,同时分析了纹波电流影响因素,最后介绍了母线电容关键电气参数,结合纹波电流影响因素,对母线电容选型匹配提供参考。

无电解电容五相永磁同步电机驱动系统主动阻尼控制策略

无电解电容电机驱动系统具有体积小、寿命长、可靠性高的优点。然而采用薄膜电容的电机驱动系统可能会出现直流母线电压不稳定的问题,主要表现为薄膜电容与网侧电感容易产生LC谐振导致直流母线电压出现过电压现象,且现有的谐振抑制策略广泛应用于三相电机,而对于五相永磁同步电机的无电解电容谐振抑制策略应用较少。为此,针对五相永磁同步电机提出一种主动阻尼的谐振抑制策略。首先基于简化驱动电路的传递函数分析了系统的不稳定性和LC谐振并构建五相永磁同步电机数学模型;其次介绍了主动阻尼电流具体的实现方式;最后将阻尼电流转化为电压指令构建反馈回路实现母线电压谐振抑制,并在仿真中验证了该方法的有效性。

基于混合逆变器的开绕组永磁同步电机驱动系统简化模型预测控制

为了解决混合逆变器开绕组永磁同步电机(OW-PMSM)系统传统控制策略将电源与电容电压之比控制为某一固定比值的问题,提出一种简化模型预测控制(MPC)策略。根据电机运行需求动态调节两侧逆变器直流母线的电压比值,从而提升电机在不同运行工况下的性能,并拓展OW-PMSM的使用场景。但在电容侧直流母线电压不固定的情况下,传统MPC算法造成的计算负担较大,因而提出简化MPC策略。对两组逆变器精简后的7种待选矢量进行轮流遍历计算,选取最优电压矢量输出,能够在减小计算量、降低开关频率的同时,最大限度地提升d-q轴电流及电容电压控制精度。最后,实验验证了所提出控制策略在电流控制、电容电压控制以及开关频率降低方面均具备有效性。

考虑功率分配的混合供电型开绕组永磁同步电机过调制算法

针对混合供电型开绕组永磁同步电机系统因功率分配约束难以执行过调制的问题,提出一种考虑功率分配的新型过调制方法。首先分析了传统过调制方法对系统功率平衡的影响,定义了有功电压调制度,使过调制区在考虑功率分配的情况下得到更清晰的界定。为了平衡过调制区的功率分配以及保障不同调制区的平滑切换,基于重新界定的过调制区分别提出定子电压矢量和有功电压的过调制方法。实验结果验证了所提新型过调制方法的有效性和优越性。

MMC中压电机驱动系统全转速范围电容轻量化研究

模块化多电平换流器(modular multilevel converter,MMC)应用于中压电机驱动系统时存在子模块电容尺寸过大的问题,在电机低速运行时尤其明显。文中提出一种基于横向子模块互联的低容值MMC(low capacitance MMC,LC-MMC)电机驱动系统,利用拓扑特点实现了系统在电机全转速范围内的电容轻量化。LC-MMC基于横向子模块输入波动电流的三相对称性,在互联通道中实现了他们的相互抵消,从而大幅减小了子模块电容尺寸,并且不受电机运行频率的影响。文中从传统MMC电机驱动系统出发,分析其对子模块电容的具体需求;对所提LC-MMC实现全转速范围内的电容轻量化方案进行详细介绍;然后,对两种MMC电机驱动系统进行对比评估,并分析LC-MMC的共模电压自然抑制特性;最后,对所提LC-MMC方案进行仿真与实验验证。

Small Signal Stability of Three-phase and Six-phase Synchronous Motors:A Comparative Analysis

Small signal stability analysis is conducted for an asymmetrical six-phase synchronous motor in comparison with its equivalent three-phase counterpart.For this purpose,a linearized model of the six-phase synchronous motor is developed using the dq0 approach,which is used in eigenvalue criteria to determine absolute stability in comparison with its equivalent three-phase counterpart.The analysis includes a comparison of the variation in evaluated eigenvalues associated with the stator and rotor sides according to changes in both the three and six-phase machine parameters and working conditions.Key analytical results are experimentally investigated and validated on a test rig.

低压开关柜配套元件的选型

介绍了低压开关柜配套元件刀开关、低压断路器、交流接触器、电动机保护器、变频器和电容器的选型注意事项。

Analysis on Circulating Current and Split Capacitor Voltage Balance for Modular Multilevel Converter Based Three-phase Four-wire Split Capacitor DSTATCOM

We propose a modular multilevel converter(MMC)based three-phase four-wire(3P4W)split capacitor distribution static synchronous compensator(DSTATCOM),aiming at compensating unbalanced and reactive load currents.Due to the zero-sequence current compensation,the circulating current char-acteristics of 3P4W MMC-DSTATCOM are different from conventional MMCs.Moreover,the distinct working principle of IMMC would affect the features of split capacitor voltage.The decoupled positive-,negative-and zero-sequence second-order and DC components of the circulating current are deduced explicitly.Two proportional-integral controllers with dual dq transformation are employed to suppress the positive-and negative-sequence components of second-order circulating current,while quasi proportional-resonance controller is designed to eliminate the zero-sequence component.Besides,the phenomenon of the unbalanced split capacitor voltages is revealed,and fast-tracking balancing method by controlling zero-sequence current flowing through the split capacitors is provided.Digital simulation results verify the accuracy of the analysis and the feasibility of the suppression methods.