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The trend toward higher switching frequency and larger scale of power electronic systems poses challenges for real-time simulation. This article presents an event-driven hardware-in-the-loop (ED-HIL) simulation framework that does not rely on the small fixed simulation step-size related to the switching frequency. ED-HIL framework can improve the calculation efficiency by positioning switch events and using variable simulation step-size. Further, a parallel acceleration and circuit partitioning (PACP) solver is proposed based on this framework. The PACP solver partitions the circuit with energy storage elements and ensures that the partitioning does not introduce simulation distortion by using the higher order derivatives of the energy storage elements. Meanwhile, it achieves a process-level paralleling through a shared memory architecture in order to accelerate the simulation. As a result, the proposed PACP solver based on the ED-HIL framework can achieve about three times the simulation scale of a commercial FPGA-based real-time simulator at 1/16 the hardware cost under the same conditions. An accurate real-time HIL example of a power electronic transformer with 32 switches at a switching frequency of 20 kHz has been implemented on a personal computer. The simulation results are analyzed by comparing with experiment, offline software, and commercial real-time simulator. [ABSTRACT FROM AUTHOR]

The multiactive-bridge (MAB) structure has obvious efficiency and cost advantages in multiport power electric transformer, but it brings the characteristics of strong current coupling of each transformer. To improve the dynamic response speed of MAB and reduce the coupling characteristics, a high-frequency current predictive control (CPC) method for MAB is proposed in this letter. The controller uses the enhanced single-phase shift modulation method to adjust the phase shift angle and duty cycle of four ports at the same time so that the high-frequency current can be adjusted in several switching cycles. In the proposed CPC method, the influence of control delay is analyzed and compensated, and the dc offset, which may occur in the dynamic process is analyzed and gives corresponding solutions. More importantly, the proposed CPC method can be extended to the power predictive control method to realize power decoupling of multiple ports of MAB. The parameter robustness of current and power predictive control is analyzed briefly in this letter. The proposed control method is validated on a hardware-in-loop simulation platform based on RT-lab. Experiment results show the superior dynamic performance and good robustness of the proposed method. [ABSTRACT FROM AUTHOR]

The noninverting buck–boost (NIBB) converter is a step-up and step-down dc–dc converter suitable for applications with a wide input voltage range. However, this circuit will face the problem of operating mode switching when the input voltage is close to the output voltage. Considering this problem, the principles of the NIBB converter are analyzed in this article. The duty cycle combinations of an NIBB converter are analyzed, and an analysis method for the mode transition problem from a geometric perspective is proposed. Using the two-edge pulsewidth modulation method, a novel bumpless mode transition control method is proposed. A nonlinear feedforward controller with hysteresis is designed according to the state equation of the circuit. Moreover, the inductor current reference value is compensated when the mode is switched so that the mode transition problem of the NIBB circuit is effectively solved. In addition, a small-signal analysis of the proposed method is performed. The analysis shows that the proposed method has good stability and dynamic performance in various typical conditions. A 10-kW NIBB prototype is built in this article, and the corresponding experimental scenarios are designed. The experimental results show that compared with the results of unified PI control during the mode transition, the transient oscillation of the output voltage is smaller, and the duration of the transient process is shorter. [ABSTRACT FROM AUTHOR]

This letter proposes a deadbeat current controller for isolated bidirectional dual-active-bridge dc–dc converter. The controller uses an enhanced single phase shift modulation method by exploiting pulse width as an extra control variable besides phase shift ratio, the only control variable of the conventional single phase shift modulation. The current reference can be tracked within one switching cycle during the bidirectional power transmission and transition of the two directions. Deadtime effect is studied and the compensation method for the controller is proposed. Parameter robustness is analyzed by mathematical derivation and the online autotuning method for the inductance is presented. The proposed deadbeat current controller is simple and easy for implementation. Moreover, it shows superior dynamic performance, which is verified by experimental results during the transient processes of the converter. The effectiveness of the autotuning method is also validated by the prototype experiment. [ABSTRACT FROM AUTHOR]

The nonlinear junction capacitances of power devices are critical for the switching transient, which should be fully considered in the modeling and transient analysis, especially for high-frequency applications. The silicon carbide (SiC) MOSFET combined with SiC Schottky Barrier Diode (SBD) is recognized as the proposed choice for high-power and high-frequency converters. However, in the existing SiC MOSFET models only the nonlinearity of gate-drain capacitance is considered meticulously, but the drain–source capacitance, which affects the switching commutation process significantly, is generally regarded as constant. In addition, the nonlinearity of diode junction capacitance is neglected in some simplified analysis. Experiments show that without full consideration of nonlinear junction capacitances, some significant deviations between simulated and measured results will emerge in the switching waveforms. In this paper, the nonlinear characteristics of drain–source capacitance in SiC MOSFET are studied in detail, and the simplified modeling methods for engineering applications are presented. On this basis, the SiC MOSFET model is improved and the simulation results with improved model correspond with the measured results much better than before, which verify the analysis and modeling. [ABSTRACT FROM AUTHOR]

Although the maximum collector–emitter voltage of a high-voltage insulated-gate bipolar transistor (HV-IGBT) reaches 3300 V or higher, it still cannot satisfy the requirements of some high-voltage high-power converters. Applying power semiconductor devices in series connection can effectively improve the voltage rating and power rating of a power electronic converter. The key issue of device series connection is voltage balancing in static switching state and dynamic switching state. In this paper, a three-level converter based on series-connected HV-IGBTs is presented, its voltage-balancing subcircuits are analyzed, and the parameter design method for the converter is proposed. During the design process, key performance indexes of the series connection circuit, such as the voltage-balancing effect, loss of the voltage-balancing circuit, switching loss, and switching time, are comprehensively considered. Moreover, component parameters of the three-level converter are calculated considering the influence of the voltage-balancing circuit. The proposed parameter design method is applied in the development of a three-level HV-IGBT (4500 V/600 A) series connection test platform with 10 000-V rated dc-link voltage. Experimental results verify the validity of the proposed method. [ABSTRACT FROM AUTHOR]