This study proposes a series of high step‐up DC/DC converters based on the coupled inductor and switched capacitors. The priority of the switched capacitor connection methods of the converters is presented by their contributions to the voltage gain so that the converters can be selected optimally according to the gain demand. For this converter, the voltage gain can be adjusted by both of the turns ratios of the coupled inductor and the number of switched‐capacitor units. It makes it possible to further improve the voltage gain when the turns ratio of the coupled inductor is rather high. Moreover, the introduction of switched capacitors can reduce the voltage stress of power components. In this study, the operating principle and performance characteristics of the converters are analysed. Also, a 300 W prototype is set up for verification. The experimental results demonstrate the effect of the theoretical analysis and superiority of the converter.

In this article, an asynchronous machine with ferrofluid in the gap (AM-WFIG) is analyzed. The principle of this machine was derived theoretically. The magnetic-flux density distribution inside the machine is analyzed and calculated by the numerical finite-element analysis methods. The electromagnetic force performances, loss, power factor, and efficiency are also investigated for the asynchronous machine (AM) by using a 2-D finite-element analysis of Ansoft Maxwell. The computational friction model of the AM-WFIG is built to analyze the influence of the viscosity of the ferrofluid. Finally, a prototype of the AM-WFIG is created and tested, and the performance curve of power factor versus speed is acquired to confirm the proposed design.

In this paper, a novel limited swing angle torque permanent magnet motor (LSATPMM) is proposed, and the operating principle of the circuit breaker of the proposed LSATPMM and a mathematical model are analyzed. The characteristics of the high voltage circuit breaker (HVCB) of the proposed machine are analyzed and calculated by numerical finite element analysis methods. The co-simulation of the Maxwell Circuit Editor and Ansoft Maxwell is used to analyze the dynamic characteristics of HVCB. The advantages of the presented operating mechanism for LSATPMM, such as the ability to adjust the opening and closing torque characteristic, high reliability, robust drive system and fault tolerance, are discussed. Finally, a prototype of LSATPMM is created and tested; and the characteristic curve of position versus torque is acquired in order to confirm the proposed design.

In this study, an unsymmetrical bistable multi‐magnetic circuit permanent magnetic actuator is proposed. The operating principle and mathematical model of the high‐voltage circuit breaker with the proposed machine are analysed. Additionally, the static and dynamic characteristics of the high‐voltage circuit breaker with the presented machine are investigated and evaluated using numerical finite element analysis methods. Furthermore, the influence of the length of the middle gap and the additional coil in the proposed machine are studied. The advantages of the presented machine, such as less magnet volume, low cost, high force density, and short starting time, are discussed. Finally, a prototype is created and tested, followed by the retrieval of the characteristic curves of the holding force to confirm the proposed design.

In this article, a sensorless control method based on signal injection and a high-pass filter (HPF) circuit is presented to control the unsymmetrical bistable multimagnetic circuit permanent magnetic actuator. In this method, a high-frequency sinusoidal signal was indirectly injected into the idle phase via a HPF circuit, and the peak of the high-frequency capacitance current was measured, which was used to calculate the idle phase inductance. Thereafter, the mover position was calculated by the one-to-one relationship between the idle phase inductance and the mover position. Combined with the HPF circuit and the proposed average current peak algorithm, the influences of back-EMF and coil resistance were eliminated. The magnetic saturation effects can also be ignored in the proposed strategy. The estimated noise, caused by measurement noise and signal distortion, was filtered using a simple mathematical filter. The flexibility and accuracy of the presented strategy were verified by simulation and experimental investigation.

In this paper, a novel asymmetrical bistable short mover permanent magnet actuator is presented. The comparisons between the presented machine and the asymmetrical structure bistable permanent magnet actuator are introduced. The static and dynamic characteristics of the high-voltage circuit breaker with the presented machine are calculated and discussed. The influences of the length of the mover and the initial mover position in the presented machine are studied and researched. The merits of the presented machine, such as less permanent magnet volume, low cost, small mover mass, and high starting speed, are researched and discussed. The Genetic Algorithm is used to optimize the presented machine. Finally, a conventional permanent magnet actuator prototype is created and tested on account of the limited experimental conditions. The characteristic curves of position versus retaining force are acquired to confirm the proposed design.