Bo Zhao

Synchronous reluctance motors in quadruped robot joint drives are prone to active-current peaks, abrupt rate variations, and switching-neighborhood error concentration under foot–ground impacts and obstacle-induced load steps, leading to prediction lag and peak underestimation. To address these issues, this paper proposes a dynamic-response-enhanced multi-condition active-current prediction method based on TPE-VMD-BiLSTM-TRC. First, the original sequence is segmented according to operating-condition boundaries, and prediction samples are constructed within each segment to reduce cross-condition information leakage and distribution inconsistency. Second, variational mode decomposition is performed on each segmented sequence to separate multi-scale fluctuation components, and BiLSTM is used for mode-wise one-step prediction. Third, TPE jointly optimizes the VMD decomposition parameters and BiLSTM hyperparameters to improve parameter matching under different operating conditions. Furthermore, a switching-aware composite loss and a switch-gated residual correction branch are introduced to enhance dynamic tracking and compensate for structural bias in switching neighborhoods. Experiments on variable-frequency drive data show that, compared with TPE-VMD-BiLSTM, the proposed method reduces the overall RMSE, switching-neighborhood RMSE, and MAPE by approximately 29.8%, 38.8%, and 7.4%, respectively. On the additional held-out operating-condition segment, the overall RMSE is reduced by 28.8%, indicating stable prediction performance across different segments.

To address the degraded prediction accuracy, increased torque ripple, and weakened dynamic response of conventional finite-control-set model predictive control (FCS-MPC) under magnetic saturation, parameter mismatch, and load disturbances in permanent magnet synchronous motors (PMSMs), this paper proposes a hierarchical FCS-MPC framework based on PINN-RLS and virtual-voltage-vector extension, termed HRPV-MPC. Built upon a unified nonlinear motor model, the proposed method integrates PINN-RLS-based online parameter correction, virtual-voltage-vector extension, disturbance-observer-based feedforward compensation, maximum-torque-per-ampere (MTPA) and quadratic-programming (QP) reference reconstruction, and deep-neural-network (DNN)-based torque-ripple compensation into the same closed-loop control framework. Unlike existing studies that usually optimize parameter identification, disturbance compensation, or ripple suppression separately, the proposed method emphasizes their coordinated interaction within the predictive control chain so as to simultaneously improve steady-state precision, disturbance rejection, and dynamic recovery performance. Simulation results show that the proposed HRPV-MPC achieves coordinated improvements in steady-state precision, dynamic response, and disturbance rejection under various operating conditions; compared with baseline FCS-MPC, it exhibits clear advantages in torque-ripple suppression, torque-error reduction, load-disturbance recovery, and speed-tracking performance, thereby validating the effectiveness and superiority of the constructed hierarchical collaborative framework.

By applying the inverse current commutation with semiconductor devices (ICCOS) technique to the meat grinder circuit, various circuit topologies have been derived. However, these circuit topologies require pre-charging of the pulse capacitor in the ICCOS circuit module, which adds a charging device or operational steps. To simplify the pre-charging process of pulse capacitors, this article improves the currently popular meatgrinder with an SECT circuit. The improved circuit uses the primary power supply to charge both the pulse capacitor and the energy storage inductor simultaneously. In this circuit, an auxiliary inductor is added to the charging branch of the pulse capacitor to alleviate the charging current surge and ensure that the charged pulse capacitor voltage is higher than the primary power supply voltage. In this article, the influence of circuit parameters on the pre-charging of pulse capacitors was analyzed, and the feasibility of the improved circuit was verified through simulation and experiments.

Inductive pulsed power supplies (IPPSs) are considered an attractive alternative to capacitive supplies for electromagnetic launch (EML) in all-electric mobile systems. The main obstacle to the early development of IPPS is the switching technology of large current, which can now be solved by a technique called inverse current commutation with semiconductor devices (ICCOS). In this article, a novel repetitive IPPS circuit with an improved ICCOS module is proposed. A bridge-type circuit composed of a capacitor, a diode, a small inductor, and three thyristors is used as the ICCOS module. With the ICCOS module, the proposed circuit can turn off the main switch thyristor, recover the residual energy of the system, self-recover the capacitor voltage of the ICCOS module, and generate continuous current pulses. To verify the feasibility of the proposed circuit, simulations and experiments are carried out based on a small high-temperature superconducting (HTS) pulse transformer. The results confirm the theoretical analysis and show the validity of the circuit scheme.

The reluctance coil launchers have attracted the attention of researchers due to its advantages of no mechanical contact and easy implementation. One of the inherent obstacles of traditional reluctance coil launchers is that the electromagnetic force on the projectile is reversed during the launch process due to the influence of residual current in the driving coils. This affects the improvement of launch speed and efficiency. The method of suppressing this reverse electromagnetic force is to eliminate residual current in the driving coil. A bridge capacitor circuit was proposed in our previous studies. This circuit uses two insulated-gate bipolar transistors (IGBTs) to control the discharge of the capacitor to the driving coil and switch the residual current path to suppress the reverse electromagnetic force. For higher power reluctance coil launch systems, the cost of IGBT switches with high voltage and high current is expensive. In this article, a capacitive pulsed power supply circuit for reluctance coil launchers is presented. Unlike the above bridge circuit, thyristors are used as the main switch and the technique of inverse current commutation with semiconductor devices (ICCOSs) proposed by the Institute of Saint Louis (ISL) is used to turn off the residual current in the driving coil. The principle of the proposed circuit is described in detail, and its feasibility is verified by simulation comparison and experiment. The results show that the proposed circuit has promising application prospects in reluctance coil launchers.

Launch efficiency is an important indicator to judge the performance of electromagnetic launchers. The goal of the conventional parameter optimization method for multistage launch is to maximize projectile kinetic energy in each stage acceleration. For reluctance coil launchers with residual recovery and utilization mode, the effect of the launcher parameters on the recovery energy should be considered in addition to the kinetic energy of the projectile. In this article, the feasibility of the model and the correctness of the original model are first verified by a four-stage launching experiment. Then, the influence of the drive coil parameters on the projectile acceleration and energy recovery is analyzed through theoretical analysis. In addition, a drive coil parameter optimization method for multistage reluctance coil launchers with residual energy recovery and utilization mode is proposed. By this method, the coil parameters of the original simulation model are optimized, and the simulation and experimental results before and after optimization are compared. The comparison results show that the optimization method proposed in this article integrates the relationship between projectile velocity and recovery energy, which can significantly improve the overall launch efficiency of the multistage system.

The reluctance electromagnetic launchers mainly use the driving coils to generate high magnetic field to accelerate the ferromagnetic projectiles. Its advantages in accelerating large-mass projectiles have attracted considerable attention. However, during the projectile acceleration of conventional reluctance electromagnetic launchers, residual currents in the drive coils may produce opposing forces that reduce launch speed and efficiency. For this issue, an improved pulsed power supply circuit for reluctance electromagnetic launchers is proposed in this article based on a bridge-type capacitor circuit. The circuit can quickly reduce the residual current of the driving coil and recover the residual current energy. Since the circuit uses the same capacitor to power the drive coil and recover the remaining energy, the remaining energy recovered by the capacitor can be used as the initial energy storage for a new cycle. This can shorten the charging time for new cycles. In this article, the basic principle of the improved pulsed power supply circuit is introduced and analyzed in detail, and a comparative analysis is carried out with the traditional circuit through simulation. The results show that the new circuit has better characteristics in terms of residual energy recovery.

Launch efficiency has always been the focus of reluctance coil launchers research. In a traditional launch mode, the residual current in the drive coil creates a reverse force on the projectile. This is undesirable since the reverse force is in the opposite direction of movement, reducing the launch efficiency of the system. To address this problem, a multistage discharge circuit with the residual energy recovery and utilization mode is proposed in this article. As the projectile approaches the center of each stage of the drive coil, the current in the drive coil decays rapidly to zero by using the last stage capacitor to absorb the residual energy. The residual energy from the previous stages is eventually recovered by the last stage capacitor. This capacitor with residual energy is used to power the last stage drive coil of the reluctance coil launcher. This mode effectively suppresses the reverse force on the projectile and realizes the reuse of residual energy. Taking a four-stage reluctance coil launcher as an example, this article introduces the working principle of this mode in detail. The feasibility of the model is verified by finite-element simulation and experiments. Both simulation and experimental results show that this mode performs well in the recovery and reuse of residual energy and can effectively improve the launch efficiency of system.

This paper proposes a novel deadbeat predictive torque control (DPTC) scheme to minimize the torque ripple of switched reluctance motor (SRM) drives. The proposed DPTC consists of torque inverse model and flux‐linkage controller. The torque inverse model is used to realize the nonlinear mapping from the desired torque to the flux‐linkage. On this basis, the flux‐linkage controller predicts the required voltage for a given reference torque at each digital time step. Besides, an improved pulse width modulation (PWM) control is developed to offset the losses caused by power converter and winding resistance. And the digital delay in the actual implementation of the proposed DPTC algorithm is compensated through the estimation + prediction technology. Both simulation and experimental testing are carried out to verify the effectiveness of the proposed control scheme. The results show that the proposed DPTC method has better torque ripple suppression performance than the conventional direct torque control (DTC) scheme. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.