This article establishes a multi-VSG parallel admittance model based on the control foundation of virtual synchronous generator (VSG). First, a detailed study is conducted on the influence of line parameters on the stability and oscillation mechanism of parallel systems, based on existing references. Second, a power-angle compensation control is designed using the equal-area method to enhance transient stability and is supported by power-angle equations that reveal dynamic interactions. Finally, for multi-VSG systems with parameter discrepancies, a phase-angle decoupling coordination strategy is proposed to eliminate cross-coupling in phase angle control loops. This improves regulation accuracy of phase deviations and suppresses transient/steady-state oscillations while optimizing power sharing. This strategy demonstrates superior stability margins over conventional methods after parameter-design via return-difference matrix singular value analysis and stability-verification through generalized Nyquist criterion. Simulations and experiments confirm enhanced dynamic and steady-state performance, addressing the fundamental synchronization issue in parallel systems.

Bidirectional DC–DC converters that offer high efficiency, galvanic isolation, and dependable operation across a broad voltage range are necessary for residential photovoltaic–battery energy storage systems. Conventional methods, such as dual-active-bridge (DAB) converters and non-isolated buck-boost converters, have drawbacks in terms of reduced efficiency under partial-load conditions, circulating current losses, and safety requirements. A three-phase interleaved bidirectional LLC resonant converter for home PV-battery applications is proposed in this paper. In order to guarantee consistent resonant behavior and soft-switching operation in both charging and discharging modes, the suggested architecture makes use of a symmetrical LLC structure. Interleaving is used to improve thermal performance, lower current ripple, and increase power scalability. A passive current balancing technique based on flying capacitors is presented to address current imbalance across phases, allowing automated current sharing without the need for extra sensors or intricate control schemes. The basic harmonic approximation is used to assess the converter's working principle, and a frequencybased control plan is put into place to manage bidirectional power flow. MATLAB/Simulink simulations and laboratory prototype testing are used to validate the suggested system. The suggested converter's appropriateness for home energy storage applications is confirmed by the findings, which show steady operation, efficient current sharing among phases, and high conversion efficiency.

With the evolving demands of renewable energy power systems and the progressive establishment of industry standards, grid-connected inverters are required to possess enhanced functionalities. In microgrid systems, inverters must support grid stabilization through flexible charging/discharging during grid-connected operation, while maintaining autonomous islanded operation with load-bearing capability under specific conditions. These requirements present significant challenges in control strategy design. To address this, this study proposes an innovative mode-switching control strategy based on state machine theory. By introducing transition modes and optimizing state machine switching logic, the proposed strategy effectively suppresses voltage/current fluctuations, significantly improving system stability, dynamic response characteristics, and power quality. Experimental results validate the feasibility of the strategy, demonstrating active grid-to-island transition in 100 ms (50 % faster than the national standard requirement of 200 ms), active island-to-grid transition in 150 ms (25 % improvement over the 200 ms national standard), and passive grid-to-island transition within 120 ms (achieving a 94 % reduction compared to the 2 s national standard). The developed methodology ensures compliance with contemporary grid code specifications while exhibiting superior transient performance.

As a new ultra-low frequency electromagnetic communication mode, mechanical antenna has high application value in the field of underwater communication and submerged command. Aiming at the problem of low signal-to-noise ratio of rotating permanent magnet mechanical antenna signal radiation magnetic field weakness and the problem of low band utilization of FSK modulation, this paper proposes MSK modulation scheme of mechanical antenna system and its high-performance servo control strategy, establishes the mapping relationship between MSK signal modulation and rotary servo control, and puts forward MSK modulation strategy based on improved fuzzy PI controller by designing fuzzy rules to improve the motor's performance in underwater communication and submergence command. Aiming at the working condition of mechanical antenna system with large transient current and frequent switching of rotational speed, the MSK modulation strategy based on improved fuzzy PI controller is proposed to improve the symmetry of motor acceleration and deceleration by designing the fuzzy rules to eliminate the cumulative error of phase. By controlling the relative position of the motor rotor, it is guaranteed that the rotor phase is always changed in one code element time ±π/2. Finally, the experimental platform of rotating permanent magnet mechanical antenna system is built, and the control performance verification experiment of the servo control algorithm, the modulation signal loading experiment, the penetration ability test under the underground and seawater, and the communication experiment are completed, which verified the feasibility of MSK modulation scheme and servo control strategy.

Affected by the working environment and flight state of electric VTOL aircraft, the starting torque of the aircraft motor is unknown, and the load torque varies widely. The traditional V/f control is difficult to start reliably and run stably under this condition. To solve this problem, a closed-loop V/f control based on instantaneous power detection is proposed in this paper. By the disturbance of instantaneous active power, the angular velocity of the given voltage vector is compensated, the damping torque component of the system is increased, and the speed convergence is accelerated. By detecting the instantaneous reactive power, the magnitude of voltage vector is adjusted to make the motor work in the state of Maximum Torque Per Ampere and adapt to the sudden change of load torque. At the same time, the closed-loop transfer functions of traditional and improved V/f are obtained by simplifying the model, and the damping ratios of the two are compared. Finally, the simulation verifies that the improved closed-loop V/f control can reduce the speed fluctuation and speed convergence time, improve the current utilization rate, adapt to the unknown and sudden load torque, adjust the given voltage amplitude in time, and achieve reliable starting.

This study delves into the realm of control systems engineering, aiming to establish a thorough understanding of sensorless control strategies through the creation and validation of a comprehensive simulation model. The simulation model, intricately designed to replicate real-world conditions, serves as a dependable platform for the evaluation of sensorless control strategy performance. Employing rigorous analysis and experimentation, our study validates and optimizes the proposed sensorless control strategy within this simulated environment.Incorporating a background in control systems engineering, this research contributes valuable insights to the field. It provides a sturdy foundation for the application of sensorless control strategies in practical scenarios, particularly in systems where obtaining sensor data proves challenging or limited. By bridging the gap between theoretical advancements and practical implementation, our work propels the state-of-the-art in sensorless control methodologies, offering a forward stride in the integration of these strategies into real-world applications.

A vibration suppression strategy for the dual three-phase permanent magnet synchronous motor (PMSM) in five degree of freedom (DOF) magnetic levitation system is proposed in this paper. Firstly, magnetic bearings (MBs) are designed to support the high-speed operation of the dual three-phase PMSM. Secondly, in order to suppress the vibration caused by the motor, the radial electromagnetic forces generated by the air gap magnetic field interaction are analyzed. After that, to suppress the vibration of the whole rotating shaft, fifth and seventh harmonics are injected in the windings of the dual three-phase PMSM by synchronous frame PI regulators. Amplitude and phase of harmonic currents are adjusted to counteract the radial electromagnetic forces, and then the vibration can be suppressed accordingly. Simulation results verify the effectiveness of the proposed strategy.

For 6/4 linear-rotary switched reluctance motors (LRSRMs), the magnetic-flux paths of the two windings are coupled in the radial direction, thus it is difficult to design the two-winding current algorithm for the linear and rotary control simultaneously. To solve this problem and achieve linear motion and rotation at the same time, speed and axial position control method is proposed by employing the equal magnetomotive force of two windings to calculate the given currents. This control method has the advantages of simple principle, easy implementation and can realize the coordinated control of rotation and linear motion. In addition, the mathematical model of LRSRM is established to facilitate the design of current algorithm. Simulation and various experiments are completed to verify the demonstrated performance of the proposed control method.

This article takes household photovoltaic energy storage systems as the research object. In order to improve the economy of household photovoltaic energy storage systems, the photovoltaic modules always work in MPPT mode with constant output power. Therefore, the task of maintaining system power balance is mainly completed by the energy storage system. In order to suppress the imbalance of DC microgrid bus voltage during power fluctuations, virtual inertial control is usually used in energy storage systems. This method increases the damping and inertia of the system, and achieves the effect of suppressing bus voltage fluctuations by slowing down the response time. This article establishes the transfer function of the energy storage system, compares the stability of PI control and virtual inertial control, and designs specific parameters for the virtual inertial control of the energy storage system through root locus and Bode diagrams. This parameter design method can obtain the optimal parameters of virtual inertial control, thereby enabling the energy storage system to have good stability while also having fast dynamic response characteristics. Finally, the correctness of the parameter design was verified through experiments.

以单相无刷直流电机(SPBLDC)控制系统为研究对象,针对小型风机位置传感器安装受限等问题,提出基于单相无刷直流电机的高效全速域无位置控制策略,该策略通过单相 I/f电流幅值与功率因数补偿相结合的控制方法实现.通过构建SPBLDC的小信号模型,根据小信号根轨迹分析法,分别对单相I/f电流幅值控制以及单相I/f电流幅值与功率因数补偿相结合控制方法下系统全速域稳态及动态调速过程进行稳定性分析,选取了合适的升速斜率,理论分析了该控制策略能够提高电机运行效率,同时保证系统全速域均具备良好的稳定性能.在Matlab/Simulink环境中仿真验证该控制策略下系统全速域均高效运行于最大转矩/电流比状态,电机转速、电流收敛性能及稳定性均有提升.最后,实验验证了该控制策略的有效性及工程应用的可行性.

For linear-rotary switched reluctance motors (LRSRMs) with two radial windings, the coupling between torque and axial force increases the complexity of control. Due to the calculation of current in existing control method for LRSRMs, the complicated derivation of current expression was necessary, and some constraints were also introduced which meant the difficulties on designing the current control algorithm were greatly increased. In order to solve these problems, a direct torque and direct axial force control method is proposed in this article. By the way of selecting appropriate space voltage vectors, the proposed method can directly regulate torque and axial force at the same time to achieve rotation and linear motion and significantly reduce the ripple of the torque. Moreover, the mechanism of two-DOF motion and the principle of the proposed method are demonstrated in detail based on a 6/4 LRSRM with two radial windings. Based on MATLAB/Simulink and the experimental prototype, the feasibility of the proposed control method has been verified according to the simulation and experimental results.

研究了一种基于不确定干扰估计器(UDE)的永磁同步电机控制策略.根据UDE控制理论,设计UDE控制器代替双闭环矢量控制中的传统PI控制器,增强了电机系统对外部干扰和内部参数变化的抗扰能力,并通过仿真与实验对控制策略进行验证.结果表明,针对突变干扰以及参数不确定性等影响因素,UDE控制器相较于PI控制器具有更好的鲁棒性.

针对永磁同步电机电流环PI控制器参数自整定依赖电机参数和系统模型精确度的问题,提出一种基于模型与规则相结合的PI控制参数自整定及优化方法.首先,采用直流激励法对电机的电阻和电感进行离线辨识;其次,利用零极点对消法设计出一组合适的PI控制器参数;最后,以这一组PI控制参数为初值,将响应的上升时间、超调量和调整时间纳入综合评价指标中,通过二自由度变量轮换法在PI控制参数初值邻域内优化后得到一组性能最优的PI控制参数.实验结果表明,该方法可以快速整定得到一组合适的PI参数,同时优化后的PI参数控制性能相较于优化前明显提升,响应调整时间减少50%,具有良好的动态性能.

Due to the lack of inertia support in traditional grid based power systems, virtual synchronous generator (VSG) technology has emerged to simulate the inertia damping characteristics of synchronous generators. This paper derives an active power transfer function model considering the power coupling pathway based on the principle of VSG, and adjusts its parameters. The interaction between power and phase angle in parallel system was derived based on the power angle equation. Based on phase angle decoupling control to address the power oscillation problem caused by inconsistent circuit parameters among modules in multi-VSG parallel system, this paper proposes a multi-VSG collaborative control strategy. The strategy eliminates the cross coupling at the output terminals of different phase angle control loops by introducing decoupling control, which improves the control performance of difference and mean of phase angle, effectively suppresses transient disturbances and steady-state power oscillations, and improves the ability of uniform power distribution and the dynamic and steady-state performance of the power. In this paper, the method of return-difference matrix singular value is used to design the theoretical parameters of dynamic steady state performance of multiple-input multiple-output (MIMO) system. Finally, this paper compares the results of different control strategies through simulation and experiments, and verifies the superiority of the proposed control strategy.

Vienna整流器因其高功率密度、高可靠性等优点,适用于多电飞机的交流供电系统.航空电网对可靠性有很高的要求,需要考虑电网不平衡甚至缺相故障的情况.当电网出现三相不平衡情况时,需要采取合适的控制方法消除电网负序分量对整流器输入输出性能的影响.而当电网出现缺相故障时,常规的三相控制方法失效,整流器通常需要停机保护,但降低了供电系统的可靠性.为了使整流器在电网缺相故障下维持输出功能,该文通过分析缺相状态下Vienna整流器的工作模态,提出一种单相空间矢量脉宽调制方法,并设计相应的控制环路,使得Vienna整流器在缺相状态下能够维持稳定的直流输出,并同时给出一种缺相判断方法.通过仿真和实验验证了所提Vienna整流器缺相控制方法的有效性.

The cooling fan of the electric reactor is based on the brushless DC motor with delta winding and the commutation point of sensorless drive is 60° after the back electromotive force (EMF) passes through zero point. In this paper, the mechanism of back EMF zero-crossing detection method for delta winding is deduced and the starting problem at low speed and the commutation error caused by diode freewheeling at high speed and large current are analyzed. On this basis, combining I/f constant current up-frequency starting and the back EMF zero-crossing detection method and performing the commutation angle compensation, a full-speed range sensorless control strategy is proposed. Based on this strategy, an electric reactor cooling fan with rated speed of 4750(r/min) and rated power of 800W under low voltage and large current conditions is verified by simulations and experiments. The results show that the sensorless control strategy proposed can ensure the stable operation of the cooling fan of the electric reactor in the full-speed range, which has good feasibility and robustness.

In order to reduce vibration from the source of the vibration of the helicopter and improve the efficiency of the damping of vibration, a propeller hub top mounted vibration damping actuator system and its position loop decoupling control strategy are proposed in this paper. By decoupling the position difference and average value of permanent magnet synchronous motors (PMSMs), high-precision servo control of the amplitude and phase of output force is achieved. The parameters of position loop are designed by small-signal modeling and root-locus stability analysis, and the effect of the vibration damping of the system is verified by simulation.

虚拟同步整流器技术可实现负荷侧变换器与电网的友好交互.为使并联系统中虚拟同步整流器能按额定容量输出功率,详细分析了直流电压采样偏差对功率均分的影响,提出一种基于有功电流反馈的功率均分策略.在此基础上,针对直流负载、有功-频率下垂、无功-电压下垂模式下的功率分配,给出了参数设计方法.其次,建立了双机并联系统的小信号模型,结合特征根轨迹分析了主要控制参数对系统稳定性的影响.最后,仿真和实验结果证明了所提方法的有效性.

消振电力作动器采用四台电机各自独立驱动四个偏心质量块的形式实现减振,传统的并行控制策略会因为在系统输出端存在强耦合而导致控制效果不佳.针对以上问题,首先建立了作动器输出力的数学模型,提出了消振电力作动器用位置环解耦控制策略,并将广义频率法和主导极点法相结合应用于控制系统的参数设计上.然后,分析了系统的动态性能,并通过回差矩阵奇异值法等稳定裕度量测方法计算出了解耦控制系统的稳定裕度,结果表明本文所设计的系统具有良好的动态特性和鲁棒性.最后,研制出了原理样机,实验验证了控制策略的有效性和参数设计的合理性.

Mechanical antenna(MA) is a new type of low frequency electromagnetic signal transmission technology, which has the characteristics of miniaturization and low power consumption. In order to reduce the control difficulty of the large inertia rotating magnet based mechanical antenna (RMBMA) and expand the form of signal modulation, RMBMA array system and its ASK modulation method are proposed in this paper. By controlling the speed and position difference of permanent magnet synchronous motors (PMSMs), the motion control of the rotating magnetic sources and the loading of the ASK modulation signal are realized. The feasibility of the proposed modulation method is verified by the electromagnetic simulation of magnetic sources, the control simulation of PMSMs and the near-field experiment.