The dual permanent magnet linear synchronous motors (PMLSMs) under synchronized feed servo control are susceptible to disturbances such as parameter variations, external interference and friction, so they are not synchronous in positions. Aimed at this problem, an improved cross-coupled synchronization control algorithm for dual linear motors is proposed, which is based on linear active disturbance rejection control (LADRC). On the basis of the structure of this algorithm, LADRC controllers based on position average and position difference are designed, respectively, ensuring the high-precision control of each linear motor position and effectively reducing the synchronization errors between the two linear motors. Simulation and experimental results demonstrate that the proposed control method can achieve high-precision synchronization control of the two linear motors.

Discharge-pumped excimer laser has some unique applications in the biomedical field. However, there still exist some practical problems to be solved in the process of engineering, such as machine heating and electromagnetic compatibility. The discharge-pumped circuit structure of excimer laser was introduced, the electromagnetic radiation and heat generation of the laser head and high-voltage charging power supply were analyzed, and the working states of an LC series resonant high-voltage capacitor charging power supply in different modes were compared. In addition, the heating and electromagnetic radiation of each part in the high-voltage capacitor charging power supply in different working modes were compared through experiments. Experimental results show that when the circuit switch tube worked in the mode of f_s=f_r/2, the IGBT junction temperature decreased by 16.8 ℃ compared with that in the mode of f_s≥f_r, and the IGBT loss was also reduced by 83.7 W (i.e., 82.8% in proportion) in the meantime, thus effectively reducing the temperature of the high-voltage charging power supply and improving the machine’s electro-optical conversion efficiency. Moreover, the peak value of magnetic field intensity was reduced by 16.53 dB, and the peak value of electric field intensity was reduced by 20.05 dB, effectively suppressing the electromagnetic radiation interference.

The electromagnetic propulsion unit requires precise control of the armature end-of-rail velocity. A closed-loop control strategy for the armature end-of-rail velocity is proposed based on an inertial energy storage pulsed power supply system. Under this strategy, the actual armature end-of-rail velocity is controlled by detecting the armature velocity at the key position of the guiderail and adjusting the number of triggered pulsed alternators in the pulsed alternator array. Simulation results show that when the desired armature end-of-rail velocity is 850 m/s and if the field current of the pulsed alternator and the armature mass of load simultaneously change in the perturbation of 2%, the relative error of the armature end-of-rail velocity will be 0.376% without closed-loop regulation. However, the armature end-of-rail velocity error can be reduced to 0.020% after using the closed-loop control strategy.

Due to its advantages such as low cost and high space utilization, the electric-drive-reconstructed vehicle-to-grid (V2G) system has become a research hotspot recently. The open-phase fault is inevitable during the operation of the electric-drive-reconstructed V2G system, under which the grid-side current will fail to keep balance and the motor torque may even increase sharply. Therefore, there are many potential safety problems. Aimed at these problems, an electric-drive-reconstructed V2G system based on an asymmetric six-phase permanent magnet synchronous motor is constructed, and its fault tolerant control scheme under open-phase fault is proposed. First, the circuit topology of the six-phase electric-drive-reconstructed V2G system is analyzed. Second, the relationship between the grid-side current and the motor’s x-y space current is deduced, so that the working mechanism of the system during its normal operation is obtained. Third, a fault tolerant operation scheme for the six-phase electric-drive-reconstructed V2G system under open-phase fault is put forward by injecting current to the o₁-o₂ space of the motor, so as to produce zero torque and balanced grid-side current and ensure the system’s normal operation under open-phase fault. Finally, a 270 W experimental prototype was built, and experimental results verified the feasibility of the system and its fault tolerant operation scheme.

Bi-directional DC-DC convertersare usually used in vehicle charging pile application circuits, which have problems such as slow system dynamic response and poor output voltage stability due to load perturbations. On the basis, acapacitor-inductor-inductor-capacitor (CLLC) resonant DC-DC converter is taken as a research object, and a control method for the CLLC resonant converter based on sliding mode active disturbance rejectionis proposed. A model-assisted linear state observer is used to improve the estimation accuracy of perturbation, so as to control the stable operation of the system. Sliding mode control is used to design a linear state error feedback control law to improve the dynamic performance and rapidity of the system. Simulations and experimental verification show that the proposed control strategy can effectively improve the dynamic response of the bi-directional DC-DC converter and enhance the output voltage stability.

Aimed at the hard-switching issues associated with the traditional zero current switching (ZCS) switched capacitor converters (SCCs), a zero voltage and zero current switching (ZVZCS) DC-DC SCC based on an LC auxiliary network is proposed, which can achieve zero voltage switching (ZVS) for all switches throughout the entire operating range. Under certain conditions, it can also simultaneously achieve both the ZVS and ZCS, significantly reducing the switching losses. On this basis, an in-depth investigation into the impact of dead time on converters is conducted, revealing a quantitative relationship between dead time selection under different load conditions and converter loss distribution. Subsequently, a design methodology for key parameters of auxiliary networks based on dead time is put forward. Finally, based on the proposed ZVZCS SCC, a 24 V DC-12 V DC experimental prototype with 100 W was constructed with a peak efficiency of 99.07%, thus validating the correctness of the theoretical analysis.

A hybrid compensation scheme based on variable output capacitance is proposed to improve the start-up speed and anti-load impact capability of a non-ideal peak current mode (PCM) Buck converter, under which the loop stability and dynamic response performance are ensured while realizing the synchronous switching of output capacitance and loop compensation parameters. A complete small-signal model of the non-ideal PCM Buck converter is established, the open-loop transfer function of the system is analyzed to obtain the influence of different output capacitance parameters on the compensation network, and the design of reasonable loop compensation is carried out. Simulation results show that the compensated system can maintain the crossing frequency around 10 kHz (1/20 fsw) and the phase margin around 70° under a variety of conditions. Moreover, a synchronous switching circuit of output capacitance and compensation parameters is designed. Finally, a 15 W experimental prototype was built, and experimental results further verified the feasibility of the proposed scheme.

With the vigorous development of electric vehicles and energy storage industries, the power electronics technology has been applied on an increasing scale. In these applications, power electronic converters not only require wide voltage gain to adapt to different scenarios, but also require a high conversion efficiency to reduce volume. Therefore, bidirectional isolated DC-DC converters with soft switching have been widely studied. On the basis, the principle of isolated DC-DC converters was analyzed, and the conversion efficiency under wide voltage gain was improved by reducing the reactive power current and implementing soft switching. First, a mathematical model was established through fundamental wave analysis to obtain the conditions for controlling the phase shift angle on the primary side, secondary side, and both the primary and secondary sides to achieve reactive power current elimination. Then, the conditions for achieving soft switching of switching devices on the primary and secondary sides were analyzed, and the dead time was designed to adjust the phase shift angle between the primary and secondary sides, so that a modulation strategy for achieving ZVS with minimal reactive power current was obtained. Finally, a 9.6 kW experimental prototype was designed to verify the feasibility of the proposed modulation strategy.

A current-source inverter (CSI) possesses several advantageous features, including stable output current, a wide load range and immunity to current surges during load open-circuit conditions. In applications where reliability is critical, CSIs outperform voltage-source inverters (VSIs). However, traditional CSIs suffer from significant current droop during continuous discharge and the risk of overvoltage at the inductor terminals when the load is open-circuited, limiting their practical utility. To address these limitations, the relative positions of the inductor, switches and diodes within conventional CSIs are modified, so as to enable energy replenishment during continuous discharge. Meanwhile, a continuous current path through the inductor is ensured to effectively prevent overvoltage across the inductor terminals. A detailed theoretical analysis of the proposed circuit is conducted, and it is verified by simulations. Finally, an experimental prototype was designed to further validate the feasibility of this circuit.

For a system with deterministic models of control objects such as power electronic converters and electric motors, a system model-based composite control strategy is proposed by combing a full state feedback (FSF) controller and ageneralized integrator (GI). First, compared with the proportional-integral-derivative (PID) and proportional-resonant (PR) controllers, this strategy canfully take advantage of the knowledge and information about the system model, so as to simplify the controller design and improve the system’s control performance. Then, based on the system-based model including the control object, the combination of a reference/disturbance model and an FSF closed-loop system model provides a simple and universal design approach for the composite control without the need for time-consuming trial and error. Finally, the proposed composite control strategy was applied to a 3 kVA three-phase PWM inverter, and results verified the feasibility of this strategy.