In this paper, a data-driven robust distributed control strategy is proposed for cooperative voltage regulation of the direct-current (DC) microgrids such that the output voltages of all distributed generation units (DGUs) track the specified reference signal. Unlike in decentralized control where all DGUs need to know the information of the reference signal, each DGU only needs to obtain the information of its neighbors in the proposed distributed control strategy. In the presence of the unknown parameters of DGUs, a data-driven robust control method is proposed to achieve cooperative voltage regulation under the available data affected by noise. It is shown that the cooperative voltage regulation problem can be transformed into a local stabilization problem based on the proposed distributed control protocol. To address the local stabilization problem, the noisy data from local DGU and the constructed auxiliary system is collected, and then we develop a data-driven control framework that guarantees robust closed-loop stability under bounded noise. We formulate a data-dependent linear matrix inequality (LMI) based on DQ-stabilization theory. This LMI enforces all eigenvalues of the closed-loop system to lie within a specified region inside the unit disk, thereby quantifying robustness through guaranteed stability margins when the collected data is corrupted by noise. The resulting gain matrices of the distributed control protocol are computed directly from noisy-data-dependent LMI without requiring any explicit model knowledge. Several simulation results are provided to show the effectiveness and robustness of the proposed methods.

This study proposes a method for wind-solar power generation forecasting based on Genetic Algorithm optimized BP neural networks. By integrating BP neural networks with Genetic Algorithms, the aim is to improve the accuracy of power generation forecasts. Initially, the BP neural network is trained using historical data comprising 60000 samples to create a preliminary prediction model. Subsequently, the Genetic Algorithm is used to optimize the weights and biases of the BP neural network, enhancing its predictive performance. Experimental results indicate that the optimized GA-BP neural network outperforms the traditional BP neural network in terms of prediction error, error rate, and prediction accuracy. This method offers an effective solution for wind-solar power forecasting and has the potential to significantly contribute to smart grid and renewable energy management.

To address the issue of insufficient torque ripple suppression, high computational complexity, and complex weight factor design in traditional direct torque control (DTC) for open-winding brushless dc motors (OW-BLDCMs), this article introduces a novel torque control method integrating model predictive control (MPC) called the finite control set model predict torque control (FCS-MPTC). The approach stands out by integrating DTC's dynamic responsiveness, and the single-phase voltage vector expands the voltage vector set, significantly improving voltage adaptability and enabling precise torque control. Furthermore, a torque flag based on fast optimization algorithm reduces the number of voltage vector traversals and computational complexity, cutting single-cycle computation time by 53.6%. Additionally, based on the analysis of the strong coupling mechanism between torque and flux linkage, simplifying their regulation to a single torque objective, a cost function excluding weight factors is constructed. The experimental results validate the method's superiority, demonstrating a maximum of torque ripple reductions of 4.1%-7.7% across all speed ranges and decreases in total harmonic distortion (THD) by 7.5%-9.5%, compared to traditional DTC. The proposed algorithm addresses real-time performance bottlenecks, paving the way for embedded applications in demanding fields such as electric vehicles and aerospace.

Brushless DC motors (BLDCM) are widely utilised due to their simple mechanical structure and high power density. To enhance energy efficiency, environmental sustainability and control flexibility, open-winding brushless DC motors (OW-BLDCM) have been introduced. Direct torque control (DTC) is an efficient control strategy for BLDCM; however, the nonsinusoidal back electromotive force and phase-off operation characteristics of OW-BLDCM present fundamental theoretical challenges for its implementation. This paper investigates these challenges from both mechanistic and physical perspectives. The commutation current paths under zero-voltage vector conditions are analysed, and an optimised zero-voltage vector selection strategy is proposed to prevent simultaneous three-phase conduction and phase current reversal, thereby mitigating commutation torque ripple. Additionally, a duty-cycle control algorithm is introduced to further reduce torque ripple within each sector. Experimental results demonstrate that the proposed zero-voltage vector strategy effectively reduces torque ripple by 27.8% by eliminating undesirable current behaviours. Further application of the duty-cycle control algorithm achieves an additional 26.9% reduction in torque ripple. These findings validate the theoretical analysis and confirm the effectiveness of the proposed method, providing a solid foundation for the future application of modern control strategies in OW-BLDCM.

Magnetic encoders have the advantages of small size, resistance to harsh environments, and strong anti-interference ability, and are widely used in the industrial field. In order to improve the resolution and accuracy of the magnetic encoder, this paper starts from the working principle of the magnetic encoder and the working principle of the magnetic sensor. Through detailed theoretical analysis and simulation verification of the output error of the magnetic encoder, after determining the source of the error, a combined sensor and a differential operational amplifier circuit are used on the hardware instead of the integrated high-speed magnetic angle encoder chip. The software uses the quadrature phase-locked loop method to solve the angle of the output signal after amplitude normalization and Kalman filtering algorithm compensation. The test results show that the output signal after error compensation is close to the ideal waveform. Compared with the uncorrected magnetic encoder, the maximum angle error is 0.211°, and the maximum angle error after angle solution is 0.142°, with an absolute accuracy of 12bit.

This paper proposes new beveling consequent pole hybrid magnet dual stator machines (BCP-HMDSMs). The proposed BCPHMDSMs employ two layers of consequent-pole modulation rings, in which the PMs all are dual-beveling topologies. The hybrid NdFeBFerrite magnets are employed to achieve low cost and avoid demagnetization, which NdFeB magnets on inner stator and Ferrite magnets on rotor. The rotor teeth act the role of modulation pole to modulate the magnetic field excited by NdFeB magnets. The configuration and design consideration of the proposed BCP-HMDSMs are described, respectively. In addition, the electromagnetic performances of the proposed BCP-HMDSM are evaluated using finite element analysis (FEA) and compared with the conventional dual stator machine (DSM). The FEA-predicted results show that the proposed BCP-HMDSM has the merits of high steady torque, low torque ripple, low cogging torque and high power factor.

The key to the realization of direct torque control method for brushless DC motor with open winding is the selection of voltage vector, in which the analysis of different voltage vector characteristics and the establishment of the optimal voltage vector selection table have a crucial influence on the motor performance. In this paper, the characteristics of different voltage vectors under the direct torque control method of brushless DC motor with open winding are analyzed in detail, and the motor state under the action of different vectors is analyzed and different voltage vector selection tables are established. The results show that when the large vector is selected as the positive voltage vector and the large vector, medium vector, small vector and zero vector are respectively used as the zero-voltage vector, the two-phase conduction mode in the three-phase six state of OW-BLDCM can be satisfied. The simulation results verify the correctness of the theoretical analysis. The motor torque ripple is approximate and large when the large and middle vector act as the zero voltage vector, and approximate and small when the small and zero vector act as the zero-voltage vector. The motor performance is better when the small vector acts as the zero-voltage vector.

In traditional Direct Torque Control of Open-Winding brushless DC motors, large vectors are used as negative vectors, leading to significant torque fluctuations. This article proposes a novel zero vector and combines it with a duty cycle control algorithm to reduce motor torque ripple and improve system performance. Numerical simulations are conducted using MATLAB/Simulink, and experimental comparisons are made under different control conditions, including rated speed, low speed, and high speed operation, to observe torque ripple. The experimental results show a threefold suppression of torque ripple, indicating a significant improvement.

分析了永磁同步电机电磁振动噪声原理,计算了一台4极/6槽内置式永磁同步电机多转速下的电磁振动噪声,并通过二维傅里叶分解分析其径向电磁力谐波分量.提出一种新型定转子结构,建立以噪声和转矩脉动为目标的多目标优化数学模型,并采用响应面算法确定最优的设计参数.对优化前后电机的电磁振动噪声进行了仿真对比.结果显示,电机结构优化后,转速3500 r/min运行时电磁振动噪声减小较为明显,从62.02 dB削弱至53.53 dB;平均转矩基本无变化,转矩脉动有所减小;多转速运行时,电机振动噪声整体性能亦得到改善,验证了该结构优化对电机电磁振动噪声有较为明显的抑制作用.

Increasing industrial development puts forward high requirements for the performances of stator permanent magnet (PM) machines, such as torque density and efficiency. The paper proposes a new dual stator PM machine based on field modulation theory (DSPMM), which employs the intermediate rotor participating in the electromechanical energy conversion of the internal and external machine. The proposed machine has the advantages of high torque density and high efficiency and solves the problem of insufficient space utilization of a single stator machine. The evolution process and working principle of the proposed DSPMM are studied. The flux-switching-type PM (FSPM) and the flux-reversal-type PM (FRPM) are employed in the proposed DSPMM, which forms four representative machines. For a fair comparison, the proposed machines employ identical key parameters, i.e., PM volume, the outer radius of the outer stator, and active airgap length. Based on finite element analysis (FEA), the electromagnetic performances of the four representative DSPMM under no-load and rated load, and different copper consumption conditions are analyzed and compared. The calculated results show that the proposed DSPMM with inner FSPM stator and outer FRPM stator can provide high output torque, low torque ripple, high power factor, and high efficiency.

This article proposes a new separated type permanent magnet (ST-PM) excitation machine (STPMM) based on bidirectional field modulation effect, which has the merits of high quality output torque and high power density. ST-PM can be designed by separating rotor surface-mounted PM into one piece radially excited outer PM and two pieces circumferentially excited inner PMs. This design takes advantage of high airgap flux density, which can be achieved by extending the length and adjusting the rotating angle of inner PMs. The operating principle and design method of the proposed STPMM are provided including the key design parameters. The analytical modeling considering rotating angle of inner PMs in STPMM and bidirectional field modulation effect is presented. The electromagnetic performances of the proposed STPMM are evaluated using finite-element analysis (FEA) and compared with the conventional designs. The FEA-predicted results show that the proposed STPMM exhibits high quality electromagnetic performances. The prototype of the proposed STPMM is manufactured and tested, then, the experimental result confirms the advantages of the new machine topology.

磁编码器是新型非接触式位置传感器,具有体积小、成本低等优点,应用于伺服、机器人等高精度控制领域.阐述了磁编码器的工作原理,介绍了磁阻式和霍尔式两类磁编码器的研究现状及应用.总结了单极型和多极型磁编码器的位置解算方法,包括正反切法、锁相环法、游标卡尺法等.剖析了谐波失真、幅值相位偏差、随机噪声等磁编码器位置检测的主要误差来源及其误差补偿算法.深入探讨了目前市场上常见的磁编码器产品性能、应用领域,并展望磁编码器的未来发展方向.

In this paper, the influence of additional air gaps between stator tooth and back-iron on the acoustic performance of spoke-type permanent magnet synchronous motor (STPMSM) is studied. It is found that the existence of these gaps can reduce the electromagnetic vibration noise, and its sound pressure level decreases by 2.3dB. By comparing radial electromagnetic forces acting on the stator, it is found that the additional air gap will weaken the 2-order radial electromagnetic force in space, which leads to the reduction of electromagnetic vibration noise. In order to further consider the influence of non-uniform additional air gap, the electromagnetic force is decomposed by two-dimensional fast Fourier transform (2D-FFT). The results of space-time spectrum show that the non-uniform air gap will introduce new space-time components of electromagnetic force, but it will not have a great impact on the acoustic performance of STPMSM. In addition, several commonly used stator tooth segments and back-iron segments are compared, which have different shapes of additional air gaps. The results show that the structure with triangular separated stator tooth and back-iron has better acoustic performance.

数字时代互联网、人工智能等信息技术的快速发展,为大多数人带来了技术便利,但对于部分老年人来讲却事与愿违."蓝马甲行动"正是"银发乐网"网络素养暖心工程的一个缩影.文章基于"蓝马甲行动"的志愿服务实践,介绍"蓝马甲行动"的帮扶模式,并分析了"蓝马甲行动"志愿服务过程中存在的困境,进而从实现组织差异化、进行区域性应用定位、对组织运行进行考核、推动实现志愿服务常态化等方面提出建议和措施.

This article proposes a rotor design method suitable for double-layer interior permanent magnet synchronous motor (DIPMSM), which can reduce electromagnetic torque ripple and at the same time reduce the electromagnetic noise of the motor. In previous studies, the inverse cosine function (ICF) was used to modify the rotor shape for making the air-gap flux density distribution sinusoidal under no-load conditions, which can reduce the torque ripple. However, conventional ICF can only be used in a single-layer interior rotor structure. Consequently, this article proposes a piecewise inverse cosine function (PICF) based on ICF, which can be applied to DIPMSM. To verify the improvement of the proposed method in the electromagnetic and noise aspects of the motor, the electromagnetic model and a noise prediction model of the 36-slot/8-pole motor are established by the finite element method. The PICF model is compared with the prototype in the aspects of electromagnetic performance and noise. The torque ripple is reduced by 54.16%, from ±2.4 to ±1.1 N m, and the electromagnetic noise is reduced by about 4.9 dB. Finally, the accuracy of the noise prediction model is verified by the noise test of the prototype.

In hydrogen recirculation side channel pumps, the motor rotor is exposed to a high-pressure mixture of steam and hydrogen, which makes hydrogen embrittlement occur in permanent magnets (PMs). A protective coating is necessary for the PMs in high-pressure hydrogen. However, in the process of sleeve interference installation, the protective coating of the PMs is easily damaged. This paper proposes two surface-mounted insert permanent magnet (SIPM) synchronous motor topologies, SIPM1 and SIPM2, in which the retaining sleeves can be eliminated and the PM protective coating is safe in the assembling process. A dovetail PM and rotor core structure is used to protect the PM with higher rotor strength without retaining the sleeve. The electromagnetic performance of the motors with different rotors, including airgap flux density, output torque, torque ripple, and energy efficiency is compared and optimized. It is concluded that the output torque of the SIPM motor can be promoted by 22.4% and torque ripple can be reduced by 2.9%, while the PM volume remains the same as that of the conventional SPM motor. At the same time, the SIPM motor can have lower harmonic contents of back electromotive force (EMF) and rotor loss compared to the SPM motor with a retaining sleeve. Furthermore, the stress of the PM is analyzed under conditions of PM glue action and failure. The proposed SIPM2 has the ability to operate safely at high-speed and high-temperature operating conditions when the PM glue fails.

无差拍预测电流控制能为电流环提供良好的动态性能,但电机模型参数与电机实际参数失配时会产生电流静差,使电机无法输出准确额定转矩.设计了一种非线性积分滑模电流静差补偿算法,将参数失配导致的电流静差转化为电压补偿量添加到预测控制中,相比于常规积分滑模补偿算法,该控制算法既能有效补偿存在的电流静差,又能改善误差过大而导致的积分饱和、调节时间过长等问题,改善了系统的暂态性能;采用改进的幂次趋近律可保证滑模面的可到达性,又能抑制抖振.最后通过仿真验证了该算法能够有效、快速地消除电流静差.

剖析了双管零矢量与单管零矢量的各自的优劣,针对反向续流问题改进双管零矢量,使新型零矢量可对续流回路截流.为了适应新型单零矢量控制策略,替换原有零矢量,建立了单管零矢量选择表.电机在相同转速、不同负载以及相同负载、不同转速等不同给定条件下进行实验,通过数据分析,发现实验结果高度贴合实验理论.

BLDCMs are widely used in automotive, industrial and intelligent equipment fields due to their high power density, simple control, and good dynamic performance. However, its non-sinusoidal characteristics have brought problems such as turn-off phase freewheeling to the research and application of BLDCM DTC. This paper proposes the definition, particular characteristic analysis, selection scheme and realization method of the voltage vector, especially the novel zero-voltage vector. Based on the novel zero-voltage and twelve-sector vector selection switch table, an improved PWM modulation strategy in a single cycle is proposed to cooperate with them to achieve the reduction of torque ripple. Finally, the correctness and feasibility of the proposed voltage vector and control strategy theory are verified by a series of experiments.

针对传统星形连接无刷直流电动机直接转矩控制下存在较大关断相续流引起转矩脉动坠落的问题,提出在断开电机绕组下通过电压矢量来实现关断相电流的抑制方法.该方法基于开绕组多维度的电压矢量分析,结合共直流母线拓扑自身多电平的优势,利用新型零电压矢量和正电压矢量的联合控制来实现关断相电流抑制并最终达到转矩脉动的抑制效果.仿真结果表明,该方法在电机正常运行的基础上可以减小关断相续流,从而达到转矩脉动抑制效果.