IET Power Electronics最新文献

The paper presents a novel step-up converter featuring ultralow output ripple and elimination of right-half-plane (RHP) zeros, making it suitable for high-precision and high-reliability boost applications. The equivalent circuit of the proposed topology is established using the T-equivalent model of the transformer. Based on this model, a systematic analysis reveals that the proposed topology is functionally equivalent to cascaded Buck converters superimposed with the input DC voltage, where the number of stages is determined by the transformer turns ratio. As a result, the proposed converter offers a linear boost characteristic while inheriting the advantages of Buck converters. Compared to existing methods for eliminating RHP zeros, this topology exhibits superior overall performance, including reduced voltage stress of semiconductors, a lower component count, and a simplified circuit structure. In addition, unlike conventional interleaved boost converters that mitigate output ripple through structural redundancy, the proposed approach suppresses output voltage ripple naturally. The theoretical steady-state performance is experimentally verified by means of a semi-physical platform and a prototype under various operating conditions.

10 kV and above silicon carbide (SiC) power modules, with advantages such as high blocking voltage, high frequency, high junction temperature, and low switching loss, have become the core components for the development of power electronics in new power systems. This paper first summarised the development of existing 10 kV and above SiC power modules, including SiC MOSFET, SiC IGBT, SiC GTO and SiC ETO, and analysed the packaging technology and characteristics adopted by each power module. Secondly, facing the challenges of SiC power module packaging in high-voltage insulation, parasitic parameter control and heat dissipation, this paper summarised a variety of advanced packaging technologies, such as the internal electric field regulation method, the parasitic parameter reduction method and the new structure design method with high heat dissipation performance. Finally, according to the development tendency of power electronics, a summary and prospect of the packaging technology of 10 kV and above SiC power modules were proposed.

Different from the traditional unit-based topology derivation method, this paper aims to infer all the topologies under the model from the most basic inductance model, combined with mathematical principles. First, this method establishes the potential relationship through the inductance model, then proposes the topology restriction rules based on circuit principles, and finally enumerates all the topologies by mathematical methods. Based on this method, it is deduced that the single-inductor converter has only three topologies, and the double-inductor single-capacitor converter has nine topologies, and the physical characteristics of each topology are obtained according to the inductance model. What's more, in order to prove the feasibility of the derived topologies, one of the dual-inductor converters is selected for theoretical analysis and experimental verification, and the results have proved the reliability and feasibility of the proposed derivation method.

The purpose of the inductive power transfer (IPT) system is to deliver sufficient power from the power supply to the load via a magnetic coupler. To optimise the efficiency, transmission power, and stability of IPT systems, it is essential to sustain the resonant conditions of the system while stabilising the output voltage in the presence of parameter variations. Therefore, in a fully realised IPT system, the primary objectives are precisely tuning the operating frequency and regulating the output voltage. This paper proposes a novel hybrid control strategy that integrates a phase-locked loop utilising the second-order generalised integrator (SOGI) with phase shift control. The proposed method effectively maintains the stability of the output voltage and the resonant state of the system by concurrently adjusting the operating frequency and the phase shift angle, employing the variable frequency phase shift (VFPS) algorithm. The control strategy demonstrates high precision, provides a smooth transient response during start-up across a range of operational conditions, and ensures that ZVS operation can be achieved. Furthermore, it significantly enhances the system's robustness in the presence of parameter fluctuations. The superiority of this approach is validated through a comprehensive analysis of MATLAB simulation results and empirical testing on a dedicated experimental setup.

This paper presents the design, simulation, and fabrication of a load-independent Class E inverter utilizing an artificial neural network (ANN) facilitator. The load-independent inverter is intended for wireless power transfer systems, such as wireless charging for small electronic devices, medical applications, robotics and electric vehicles. Class E inverters are favoured due to their high efficiency, low-cost design and compatibility with resonant power transfer circuits; however, they face challenges such as sensitivity to load changes and complexity in theoretical calculations. Also, the design process addresses the presence of parasitic nonlinear elements and harmonic distortions, making it time-consuming and potentially less accurate. To overcome these challenges, a two-layer ANN is employed to determine the structural parameters of the circuit, resolving issues in the design process and ensuring sufficient accuracy despite parasitic components and maintaining a constant output voltage regardless of load resistance variations. The ANN accelerates the design process by calculating inverter parameters based on the desired operating frequency. Experimental results show strong agreement with theoretical and simulation outcomes, validating the proposed inverter design. The proposed load-independent Class E inverter has an output power of 2 W at a load resistance of 15 Ω and a DC input voltage of 5 V at a frequency of 1 MHz.

In recent years, the AC characteristics of metal oxide varistors have attracted growing research interest. This study presents an insulated-gate bipolar transistor-based device designed to address the limitations of existing power supply systems, which are unable to simultaneously maintain waveform stability and provide sufficient power when varistors operate in the non-linear region. The proposed device generates a sinusoidal decaying oscillatory voltage waveform with adjustable amplitude and frequency, meeting the experimental requirements for varistors across a range of voltage levels and effectively extending the upper limit of the output current. Using this device, it is possible to capture the full dynamic response of leakage current, from capacitive to resistive behaviour, and to investigate the voltage-sharing characteristics of varistor discs in surge arresters under AC excitation. Looking ahead, the device is expected to be applied to multiple tasks such as energy absorption evaluation of arresters/varistors, insulation tests of high-voltage equipments and damped AC partial discharge detection of cables.

With the rapid development of renewable energy, the power system is characterized by both a high percentage of renewable energy sources and a high percentage of power electronic equipment, which has caused problems such as wideband oscillations, inertia deficiency, weakened grid strength and so on. In order to solve these problems, a dual winding induction machine (DWIM) based grid-tied inverting system is proposed in this paper. The DWIM is used instead of the conventional inverter, interfacing renewable energy sources or energy storage units to the grid. In this system, one set of the stator windings of the DWIM is connected to the grid directly, while the other is controlled with an inverter. Energy transfer is accomplished through electromagnetic induction effects. Although there is no extra mechanical load on the shaft, the mechanical inertia is available to actively damp the grid oscillations and frequency deviations. A control strategy, achieving independent control of the active and reactive power exchanged with the grid, is also proposed. The effectiveness of the inverting system is verified through simulations and experiments. Comparing with the synchronous condenser (SC) shows that this new system possesses all of the merits of the SC in addition to the inverting function. Therefore, it inherits the advantages of both SC and grid-tied inverters.

This work presents an overview and comparative analysis of surface-mounted devices (SMDs) and pin-through-hole (PTH) low-voltage MOSFETs (LV, tens of volts) for power electronics in industrial equipment. A commercial 1 kW full-bridge inverter, powered by a 24 V battery is evaluated. Efficiency and cost are analysed using the Pareto front in a database of 200 MOSFETs, including packages of PTH (TO220) and SMD (DPAK, $��D^2�\mathrm{PAK}�$, TOLL, SuperSO8). The results indicate that SMD technologies, especially $��D^2�\mathrm{PAK}�$, SuperSO8, and TOLL, significantly improve efficiency over TO220 MOSFETs. This efficiency increase allows to halve the number of MOSFETs used in the commercial product by eliminating parallelism. A heat transfer evaluation is conducted to verify the feasibility of using a single MOSFET per position for both PTH and SMD designs. For TO220 MOSFETs, the original PCB equipment is considered. For SMD designs, the influence of thermal vias configuration is analysed in four different PCB layouts, under natural convection and forced airflow (parallel and perpendicular to the PCB). The thermal resistances of all designs are experimentally evaluated. The results for TO220 show that only one part number was feasible, which allowed a cost reduction of 25.8%. The results for the SMD designs show that the natural convection had the highest thermal resistances, which made all designs infeasible. Under forced airflow, changing airflow from parallel to perpendicular to the PCB reduces thermal resistance and achieves cost reductions. The greatest cost reductions were found with perpendicular forced airflow, achieving 73.7% for $��D^2�\mathrm{PAK}�$ and 81.6% for SuperSO8.

This paper focuses on maintaining the optimal common mode voltage of the existing zero common mode voltage (ZCMV) method while reducing its large zero-sequence circulating current. The analysis presented reveals that the large zero-sequence circulating current of the existing method results from the large zero-sequence circulating current change rates included in its timing sequences, and by exchanging the original switching states between the parallel legs, the large zero-sequence circulating current change rates can be eliminated without affecting the original common mode voltage and output voltages. To achieve the necessary switching state exchange, we have modified the original modulation signals of the existing method and introduced a new switching logic. The proposed method, incorporating these modifications and the new switching logic, has been developed and validated through both analytical and experimental investigations. The results confirm that the proposed method maintains the optimal common mode voltage while significantly reducing the zero-sequence circulating current associated with the existing ZCMV method.

Power quality is of importance for modern and future aircraft microgrids, while the aviation industry demands a notable increase in the efficiency and power density of onboard power converters. In this article, an innovative and optimal design of a power conditioning system is presented. The proposed design has a two-fold improvement. It enhances the system performance by employing an effective control loop based on the peak current control method, along with the detailed converter average model. Furthermore, the proposed design improves the converter's gravimetric power density by introducing an innovative inductor design. By the aid of an exhaustive sensitivity analysis on system parameters, the significance of the inductor resistance on the performance of the control loop is indicated. Thus, a multi-objective optimisation for a wide E-shaped ferrite core dataset is performed, aiming to minimise its value while keeping an acceptable power density level. The generated Pareto front reveals the trade-offs and limitations between the two aforementioned critical factors. Finally, extensive simulations validate the sensitivity analysis, whereas the suitability, functionality, and performance of the proposed controller are experimentally evaluated on a scaled-down hardware prototype.