Closed-loop impedance modeling and analysis of three-phase active rectifier below 150 kHz frequency range

This paper derives the closed-loop impedance model for the typical three-phase active rectifier and investigates the dominant factors influencing the converter impedance below 150 kHz frequency range from the basic performance (e.g., steady-state and dynamic performance) and EMI perspectives. Therefore, the complete modeling process of the closed-loop impedance is described, including the control analysis and impedance modeling. The discussion of improving basic performances and EMI performance for the power converter is proposed. Moreover, an advanced impedance measurement technique is introduced. Finally, the validation of the derived closed loop impedance model and the dominant influence analysis for the three-phase rectifier are carried out in MATLAB and PLECS

Power Losses Analysis of Converter for Switched Reluctance Motor Drive with Fault-Tolerant Control

Power losses of power converters are critical information related to the overall system reliability. To quantitatively assess the impact of fault-tolerant control on the reliability of switched reluctance machine (SRM) system, this paper investigates the power loss distribution of the converter for an SRM system under different controls (i.e., with and without fault-tolerant control). Besides, different mission profiles are considered to make the assessment more practical. The drive system is firstly presented under normal and fault tolerant operations, and then followed by the corresponding power losses calculation and analysis. Simulations are carried out on an SRM drive system to support the power losses analysis

Hybrid Transformerless PV Converters with Low Leakage Currents:Analysis and Configuration

Abstract This paper proposes a hybrid transformerless photovoltaic (PV) converter with simultaneous AC and DC outputs. It is specifically suitable for residential PV systems due to its high efficiency, versatility and flexibility, while maintaining lower leakage currents. The proposed converter is configured by replacing the control switch of the boost converter with a transformerless voltage‐source inverter (VSI), enabling multiple outputs. In addition, a symmetrical boost inductor is adopted to clamp the common‐mode voltage as a constant, resulting in low leakage currents. To illustrate the configuration principle, a hybrid converter with a highly efficient and reliable inverter concept (HERIC) as the VSI is exemplified. Besides, the dedicated modulation scheme for the proposed converter is detailed to achieve low leakage currents, reactive power injection and high efficiency. Furthermore, as the shoot‐through state of inverter legs is allowable for the proposed converter, i.e. no need to add dead time, the reliability and power quality of the proposed converter can be improved. Simulations and experimental tests are performed on an example hybrid converter (with an HERIC as the VSI) to validate the analysis