In this article, a novel single-switch, high step-up dc–dc converter based on three-winding coupled inductor and voltage multiplier circuit (VMC) is proposed. And on this basis, pump capacitor unit (PCU) is integrated to achieve a very high voltage gain. The converter makes full use of the advantages of three-winding coupled inductor, skillfully combines it with the VMC, and integrates the PCU that can be used in superposition to further improve the voltage gain. The voltage stress of the switch is reduced by using a passive clamping circuit to recycle the leakage energy of the coupled inductor. The operating principle and steady-state analysis of the presented converter in continuous conduction mode are introduced in detail. Moreover, the comparative analysis shows that under the same conditions, the proposed converter has higher voltage gain and lower voltage stress than others. Several advantages include high voltage gain, low voltage stress, low turns ratio of coupled inductor, and high conversion efficiency, make the proposed converter very suitable for new energy generation applications, such as photovoltaic systems. Finally, the feasibility of the proposed converter and the correctness of theoretical analysis are verified by a 500-W prototype at 50 kHz switching frequency.

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.

To realize the online observation of the flux linkage of interior permanent magnet (PM) synchronous machine for electric vehicles after uniform demagnetization under multiple operating conditions, an improved model reference adaptive system (MRAS) flux linkage observer is proposed based on a novel double closed-loop control approach in this article. First, a double closed-loop control strategy of interior permanent magnet synchronous motor (IPMSM) is established employing maximum torque per ampere (MTPA) and sliding mode controller (SMC). The MTPA significantly improves the current utilization and system efficiency, and the SMC is applied to replace the traditional PI velocity loop controller to increase the anti-interference capability of the whole system. Then, the MRAS and single neuron adaptive proportional integral (SNPI) algorithm are adopted to develop an SNPI-MRAS flux linkage observer, which can modify the adaptive law of the MRAS online and overcome the shortage of low observation accuracy of traditional PI-MRAS flux observer when the machine parameters change. Next, a feedback gain matrix term is inserted in the SNPI-MRAS, which can guarantee that the linear forward channel of the SNPI-MRAS is a strictly positive real matrix. Finally, the effectiveness of the proposed method is verified. The outcomes demonstrate that the proposed method can effectively improve the dynamic response of the observer and increase its accuracy and convergence speed.

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.

This article presents an improved transient temperature evaluation method for permanent magnet synchronous machine (PMSM) based on the lumped parameter thermal network (LPTN) and the segmented iron loss calculation model with compensation terms. The modeling methodology for the proposed iron loss calculation model (PILCM) is given in detail, including the process of model establishment and parameter determination. By introducing the compensation term of eddy current loss and hysteresis loss in different frequencies and magnetic density ranges, the loss characteristics of the proposed model demonstrate higher computational accuracy than conventional iron loss calculation model (CILCM), which can be confirmed by magnetic characteristic testing experiments of lamination steel. In addition, an experimental platform of the temperature rise is built for evaluating the temperature of end winding, the absolute error of the LPTN + PILCM and the LPTN + CILCM under rated condition are $1~^{\circ }$ C and $2.3~^{\circ } $ C, respectively. The error of overload running time predicted by LPTN + PILCM under two overload conditions are 3.6% and 5.3%, respectively, which has higher accuracy than the results of 11.7% and 13.1% predicted by LPTN + CILCM.

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.