This paper presents a hybrid AC/DC dual-stator winding induction generator (DWIG) and a multi-objective optimization design method for more-electric aircraft application. The DWIG has two sets of stator windings. One is DC winding which handles with part of reactive power for excitation and output 25kW/270 V DC power through power converter. The other is AC winding which directly outputs 25kVA/115 V AC power. To achieve the hybrid AC/DC generation with good performances, a separate-slot winding pattern is presented for two sets of stator windings and the winding factor is designed to obtain the optimal induced voltage ratio as well as electromotive force. A metamodel-of-optimal-prognosis (MOP)-based optimization method is proposed to handle with the conflicts between the optimization targets and constraints. By the parameter sensitivity analysis based on the response surface method, the important optimization variables and a MOP model with high parameter sensitivity and high quality is built. A multi-objective evolutionary algorithm is used with the MOP model to obtain the Pareto set. A design point is selected from the Pareto set as the final optimal design. The performances of the optimal DWIG are compared with the initial design. A prototype DWIG is manufactured and the test results validate its performance.

High-frequency switching operations of power switching tubes generate high-frequency voltage and current pulse signals, resulting in substantial electromagnetic interference. As servo drive systems continue to evolve toward higher power density, integration and miniaturization, their internal electromagnetic environment grows increasingly complex, further intensifying interference levels and imposing higher demands on system electromagnetic compatibility (EMC) design. To address this challenge, this paper proposes a modelling method based on multi-software co-simulation to precisely model radiated interference in permanent magnet servo drive systems. Through an in-depth analysis of interference sources and their main propagation paths within the servo drive system, high-frequency impedance models were established for key components including cables, bus capacitance, MOSFETs and permanent magnet motors. Combined with a field-circuit-control co-simulation strategy, this approach enables prediction of radiated interference. To validate the reliability of the model, a measurement scheme under typical operating conditions was designed. Radiated interference data from the actual system was obtained and compared with simulation results. The findings demonstrate that the established model is highly accurate and provides a reliable pre-evaluation tool for subsequent system-level EMC design and optimization.

With the electromagnetic environment becoming more complex, how to reduce the electromagnetic interference that equipment causes to external devices has become a major problem for many electronic devices. Conducting electromagnetic compatibility rectification in the later stage of equipment design is often quite complex, so metal enclosures are often used as shielding covers to reduce the external electromagnetic radiation from equipment in the later stage of equipment design. Finite element simulation calculations were carried out by ANSYS HFSS in this paper, which aimed to predict the radiation suppression effect of the enclosures at a low cost, discover the regularity of trepanning, and obtain a systematic enclosure design scheme. Through precise simulation, the influence of the area, position, shape, and length-to-width ratio of the apertures on the shielding effectiveness of the enclosure was investigated. And a systematic enclosure design scheme was obtained. The optimal trepanning position was first determined through simulation, and then the shape and length-width ratios of the apertures were optimized. Through a variable iterative process, finally, the optimal enclosure trepanning design scheme was determined.

ABSTRACT The aviation actuation servo system is typically required to drive loads in periodic motion. During operation, servo systems are frequently subjected to nonlinear time‐varying load disturbances. Extended state observers (ESO) estimate the total disturbance of the system, effectively suppressing time‐varying load disturbances and high frequency harmonics. However, high‐order disturbance observers are susceptible to system noise and have numerous adjustable parameters, making it challenging to balance good disturbance suppression and noise rejection performance. This paper analyses the contradiction between the disturbance suppression capability and noise rejection capability of high‐order disturbance observers and proposes a multiple‐degree‐of‐freedom gain optimisation strategy to decouple the disturbance rejection performance from the noise suppression performance. Additionally, the system delay is modelled using a second‐order Pade approximation, and a compensation link is added to eliminate observer instability caused by system delay, ultimately achieving high robustness and stable control of permanent magnet motor servo systems. Simulation and experimental results demonstrate that this method effectively suppresses the issue of time‐varying load disturbances.

In motor drive systems, electromagnetic interference (EMI) filters suppress conducted emissions; however, non-ideal coupling among internal components may introduce additional differential-mode (DM) noise and degrade filtering performance. To address this issue, this paper investigates the formation mechanism of DM coupling in EMI filters for motor drives. An equivalent model incorporating high-frequency distributed parameters is established to reveal the influence of component layout and magnetic-field coupling on the DM noise spectrum. Based on the analytical results, an optimization method for suppressing DM coupling is proposed by adjusting the relative positions and orientations of filter components without modifying the filter topology. Experimental results demonstrate that the proposed method effectively reduces DM noise in critical frequency bands and improves the overall suppression performance of the EMI filter.

Standard modeling methodologies and classic PI control strategies are poorly suited for doubly salient permanent-magnet (DSPM) motors because of their nonlinear magnetic characteristics and commutation-dependent operating behavior. This study establishes a control-oriented nonlinear model for a 12/8-pole DSPM with an internal radial permanent-magnet arrangement. Current- and position-dependent finite-element flux-linkage Jacobians, rotor-position derivatives, and total electromagnetic torque are organized as three-dimensional lookup tables in the stationary αβ frame, thereby retaining the effects of saturation, armature reaction, interphase coupling, and simultaneous nonzero phase currents. Fuzzy-PI control, implemented as a low-complexity nonlinear gain-scheduling approach, provides a practical alternative to computationally intensive advanced algorithms. To optimize the operational performance, a closed-loop control system is introduced, which utilizes an outer fuzzy-PI loop and an inner current hysteresis loop. This fuzzy-PI speed controller is then compared with a conventionally tuned PI controller under the same conditions. The results demonstrate the usefulness of the FEA-derived model for control evaluation and the favorable transient performance of the fuzzy-PI controller.

This paper proposes a hybrid electric vehicle (HEV) transmission system using a doubly-fed induction generator (DFIG) that directly drives an induction motor (IM). The purpose is to reduce the capacity and voltage level of the inverter in the system, thereby reducing costs. The DFIG's rotor is managed by a small inverter, and the IM is directly driven by the DFIG's stator. A speed matching algorithm is developed to optimize the internal combustion engine's (ICE) efficiency and minimize the inverter's power and voltage by adjusting the vehicle's speed in some intervals, that keeps the ICE either idling or in a high-efficiency state. Additionally, the paper introduces a vector control algorithm for the DFIG direct-drive IM integrated system, ensuring high-performance speed control similar to the traditional vector control for single motor. Experiment results prove that this system meets the vehicle's speed control requirements and reduces the inverter's power and voltage to less than 2/3 of the original system.

This article focuses on the energy extraction system of an aviation double-compound turbo jet under a high-voltage DC multi-generator electrical power system, and conducts research on the parallel operation control strategy of a dual winding induction generator high-voltage DC power generation system. This article proposes a control method for a dual winding induction generator based on droop control. Under the above architecture, the control method and system design are elaborated in detail. Based on the analysis of the generator and power system impedance characteristics, a parameter tuning method for parallel systems is proposed. The effects of generator voltage loop parameters and power distribution ratios on system performance are discussed, providing a basis for the design of parallel systems based on dual-winding induction generators. This article aims to integrate the advantages of parallel power generation systems and double winding induction generators, and conduct preliminary verification through experiments.

Bipolar DC systems have attracted much attention for their ability to provide multiple voltage levels and high power supply reliability. The three-phase voltage source converter (VSC) topology with a coupled ground inductor can suppress midpoint potential fluctuation caused by load imbalance without adding an additional voltage balancer. However, conventional dual-loop proportional-integral (PI) control exhibits slow dynamic response and entails complex parameter tuning, making it difficult to realize both fast AC current tracking and precise DC voltage balancing simultaneously. To address this, this paper proposes a three-loop cooperative control architecture: the voltage outer loop adopts PI control to ensure the stability of the total DC bus voltage; the current inner loop adopts the continuous control set model predictive current control (CCS-MPCC) to realize the fast and accurate tracking of the AC side current; and a zero-sequence control loop balances the positive and negative bus voltages by regulating the ground inductor current. Simulation results demonstrate that the proposed strategy significantly enhances the dynamic response of the bipolar DC converter under load transients and improves midpoint potential balancing performance.

This paper proposes an emergency power supply system based on a dual-stator winding induction generator (DWIG) operating in parallel with an energy storage system (ESS), enabling a flexible multi-voltage power supply while improving dynamic response and light-load efficiency. A flux-orientated decoupled control strategy combined with a multi-mode operation mechanism is developed to achieve independent regulation of output voltage and power under different operating conditions. A comprehensive cost model considering diesel fuel consumption, power conversion losses, and battery ageing is established, and a real-time energy management strategy based on Pontryagin's Minimum Principle (PMP) is proposed to optimise power allocation between the diesel generator and the ESS. Simulation studies under different load ranges and initial state of charge (SOC) conditions show that the proposed PMP-based strategy achieves a net fuel saving of approximately 0.1-0.4 L compared with the conventional rule-based method. Experimental results further verify the feasibility and effectiveness of the proposed control and energy management strategy.

Silicon carbide (SiC) devices offer significantly faster switching speeds than traditional silicon devices, thereby improving motor drive efficiency. However, these high switching speeds can exacerbate voltage reflection issues, especially when the motor is connected via long cables. Although driving parameters are often tuned to address this, existing techniques struggle to balance effective voltage suppression with acceptable switching losses. This paper proposes an approach to simultaneously mitigate voltage reflection and reduce switching losses through optimized driving circuit design. Specifically, it analyzes the effects of key parameters: gate resistance and external Miller capacitance on voltage behavior and energy loss. A detailed model is developed to characterize both the voltage reflection process and the switching dynamics of SiC MOSFETs in a single phase-leg configuration. Based on this model, the study quantifies how voltage transition time and switching loss evolve under various drive conditions. Furthermore, a Pareto front-based optimization method is introduced to balance the trade-off between voltage slew rate and switching efficiency. Experimental validation on a 1.2 kW SiC-based motor drive shows that voltage overshoot can be reduced from 83.3% to 63.3% by optimizing the gate resistor, while adding an external Miller capacitor further reduces it to 23.3%, a 40% improvement over resistor adjustment alone, with only a 0.06% efficiency penalty.

ABSTRACT Synchronous rectification (SR) technique can significantly enhance the efficiency of LLC resonant converters. However, at high frequencies, SR control strategies based on drain–source voltage suffer from substantial duty ratio loss due to the influence of parasitic inductance, thereby limiting further efficiency improvements. To mitigate duty cycle loss at high frequencies, this paper proposes a digital control strategy for switching timing adjustment by compensating the lost conduction time. To achieve this aim, the mechanism of duty ratio loss at high frequencies is analysed and a mathematical model is developed to quantify the lost conduction time across different loads and frequencies in real time. The synchronous rectifier's conduction time is then compensated and optimized by a digital signal processor. Additionally, the issue of premature turn‐on of the synchronous rectifier under light load conditions is addressed by adjusting the turn‐on timing in real time according to load variations, thereby preventing reverse current flow. The SR control strategy is well‐suited for high‐frequency and wide‐load applications, offering low cost and algorithmic simplicity. Experimental results from a 6kW full‐bridge LLC resonant converter prototype validate the feasibility of the proposed SR control strategy, showing a 0.21% increase in peak efficiency compared to traditional SR control strategy.

Emergency power supplies, such as diesel generator vehicles, are a core component of modern power security systems, playing an irreplaceable role in maintaining the operation of critical infrastructure and reducing losses from unexpected power outages. However, conventional mobile diesel generator vehicles are limited by their single voltage output, which does not support multi-voltage operational scenarios, and they suffer from low efficiency and high costs when operating at low power levels. In response to these challenges, this paper proposes a novel dieselstorage hybrid power supply architecture based on dual-stator winding induction generator (DWIG). By leveraging the multiwinding characteristics of DWIG to achieve multi-voltage outputs and efficiently integrating them with energy storage, and by developing multi-mode control strategies, the proposed system ensures high efficiency and reliability across all scenarios. Simulation results validate the feasibility of the proposed architecture and its control strategies.

The optimal control of energy storage systems is crucial for the operation of microgrids. This paper proposes an optimized control strategy for the parallel operation of energy storage systems in an AC microgrid, using the state of charge (SOC) of the storage systems as a criterion to modulate their power output. The control model was developed in MATLAB/Simulink, and the simulation results demonstrate that the control strategy enables rational energy distribution within the microgrid, thereby enhancing its flexibility and reliability while simultaneously extending the lifespan of the energy storage systems.

The speed signal plays a vital role in the starting/generation system of dual winding induction generator (DWIG). However, due to the poor working environment, the sampling of the speed signal is limited. Therefore, based on the velocity control strategy of the sliding mode observer and the mathematical model of the DWIG, the shortcomings of traditional sliding mode velocity control are analyzed in this article. Based on the principle that the two sets of windings of a double-winding motor are tightly coupled and the flux link is connected, the mechanical parameters of the traditional sliding mode observer are replaced by those on the power winding side that can be observed in real time, thus reducing the inaccurate observation caused by complex conditions and realizing the precise control of the sliding mode without velocity. The compatibility and efficiency of starting control and generation control of DWIG are improved, and the smooth transition and stable generation of the DWIG are ensured.

The seamless transition between island mode and grid-connected mode is a significant challenge faced by current emergency power supply. This paper proposes an emergency power solution based on a dual-winding induction generator and an energy storage system. The scheme achieves seamless gridconnection by adjusting the voltage phase of the emergency power supply to align with the grid phase, thereby effectively reducing the impact during the grid connection process and ensuring stable power supply. The paper introduces the basic architecture of the system and provides a detailed explanation of the phase adjustment mechanism during the grid connection process. A simulation model is then established, and the simulation results validate the effectiveness of the proposed scheme in achieving a smooth transition during grid connection.

Marine shaft generator is an efficient power generation device directly mounted on the main propulsion shaft of a vessel. It rotates along with the shaft via a “shaft-clamping” structure, utilizing surplus power from the main engine to generate electricity. It offers advantages such as energy saving and consumption reduction, compact structure, and easy maintenance. Widely applied in commercial vessels, cruise ships, and green ships, it helps meet IMO environmental regulations and serves as a key component in integrated energy management systems for modern intelligent ships. This paper quantitatively analyzes the distribution characteristics of copper losses, iron losses, and mechanical losses based on an electromagnetic-thermal-fluid coupled model. Furthermore, it innovatively adopts a combined airflow-thermal circuit calculation method to optimize the design of cooling air ducts, providing critical technical support for thermal safety design of high-power-density marine electric machines.

The article analyses the vibration of a high-power dual three-phase generator with eccentricity fault. Firstly, analyses the radial electromagnetic force decomposition and time-space dimension decomposition of the dual three-phase generator under different eccentricity conditions. Combined with the analytical expression of the radial electromagnetic force wave, the spatial and temporal order effects on the radial electromagnetic force are analyzed under different forms of rotor eccentricity. Then import the inhomogeneous electromagnetic force into the harmonic response module, simulate the electromagnetic vibration under the rotor eccentricity and analyze the effects of different rotor eccentricity forms on the generator vibration. The results indicate that eccentricity can cause harmonics in the time or spatial dimensions of the radial electromagnetic forces. Both static and dynamic rotor eccentricity lead to an increase in electromagnetic vibration of the generator. As the eccentricity distance increases, the vibration displacement of the generator also increases. Compared to the normal non-eccentric condition, additional vibration frequency components are observed.

Silicon carbide metal-oxide-semiconductor fieldeffect transistors (SiC MOSFETs) are extensively utilized in highefficiency and high-frequency applications due to their exceptional performance. While the high switching speed of SiC MOSFETs significantly enhances operational efficiency, it also exacerbates electromagnetic interference (EMI) issues during the switching transient process. This study introduces a spectral analysis method for identifying interference sources, with a focus on highfrequency ringing in SiC MOSFETs. The method considers the impact of parasitic parameters during switching transients and uncovers the characteristics of high-frequency oscillations. By employing an asymmetric trapezoidal waveform, spectral and envelope models that account for high-frequency oscillations caused by parasitic parameters are derived, enabling the evaluation of main influencing factors to EMI noise. A spectral calculation approach for high-frequency ringing effects is proposed. Experimental validation demonstrates a maximum error reduction from approximately 18 dB mu V to 8 dB mu V when compared to traditional methods.

To enhance power supply reliability and reduce customer outage time, Mobile Emergency Power Supply Vehicles (MEPSVs), including Mobile Diesel Generator Vehicles (MDGVs) and Mobile Energy Storage Vehicles (MESVs), have become indispensable sources for grid maintenance and disaster response. However, in practice, relying solely on MESVs is constrained by battery capacity, making it difficult to meet long-duration power demands. Conversely, using only MDGVs often results in low efficiency and high fuel consumption under fluctuating load conditions, posing challenges to achieving economical and efficient power supply. To address these issues, this paper investigates the parallel power supply architecture of MDGV and MESV, and develops control models for diesel generator and energy storage converter. A fuel-minimization-oriented power distribution strategy is proposed for coordinated operation, aiming to minimize fuel consumption while maintaining the energy storage state of charge (SOC) within a reasonable range. Furthermore, a voltage–frequency control strategy is employed for the energy storage converter, while active power control is applied to the diesel generator. Through adaptive operation mode switching, the proposed strategy enables efficient and cost-effective parallel operation of MDGV and MESV, ensuring long-duration power supply across a wide load range. This approach overcomes the limitations of conventional single-source power supply methods and provides an effective control solution for the intelligent and efficient operation of emergency power supply systems. Finally, the feasibility of the proposed strategy is verified through simulation and further demonstrated by experiments on a hardware platform.