Analysis and Suppression of Unwanted Turn-On and Parasitic Oscillation in SiC JFET-Based Bi-Directional Switches

Abstract

Silicon Carbide (SiC)-based Bi-Directional Switches (BDS) have great potential in the construction of several power electronic circuits including multi-level converters, solid-state breakers, matrix converters, HERIC (high efficient and reliable inverter concept) photovoltaic grid-connected inverters and so on. In this paper, two issues with the application of SiC-based BDSs, namely, unwanted turn-on and parasitic oscillation, are deeply investigated. To eliminate unwanted turn-on, it is proposed to add a capacitor (C X ) paralleled at the signal input port of the driver IC (integrated circuit) and the capacitance range of C X is also analytically derived to guide the selection of C X . To mitigate parasitic oscillation, a combinational method, which combines a snubber capacitor (C J ) paralleled with the JFET (Junction Field Effect Transistor) and a ferrite ring connected in series with the power line, is proposed. It is verified that the use of C J mainly improves the turn-off transient and the use of a ferrite ring damps the current oscillation during the turn-on transient significantly. The effects of the proposed methods have been demonstrated by theoretical analysis and verified by experimental results.

Onto a higher power handling for very high frequency direct antenna modulation

“…This results in the degradation of the transmission efficiency and prevention of the desired signal's transmission. One of the possible effects of this phenomenon is that during the OFF‐state of the circuit, the transistor, due to the presence of a high V RF level, may turn ON [40, 41], preventing the efficient transmission of the signal at f off . Therefore, the isolation between the RF and switching signals is integral to a successful high‐power BFSK DAM transmitter.…”

“…One of the effects under high‐power handling that can reduce the efficiency of the operation is the self‐turn ON effect during the OFF‐state [40, 41]. This occurs when a high‐power RF signal is impinged on the drain port of the transistor as seen in Figure 2 and the drain voltage falls below that of the source voltage.…”

“…This symmetry prevents the RF signal from coupling into the switching signal due to the cancellation of two out of phase paths which create a virtual RF ground for the antenna. It is shown that such coupling could affect the absolute voltage of the switching signal which could lead to self‐turning on effects when the transistors are biased OFF [40, 41]; hence, the complementary pair topology is necessary for ensuring the DAM system is operating normally under high‐power RF applications. This isolation is essential for synchronisation over the time‐varying operation of the antenna to effectively maximise efficiency as shown in [32, 33].…”

Modelling of Dynamic Properties of Silicon Carbide Junction Field-Effect Transistors (JFETs)

“…Nowadays, the dynamic development of high-power electronic systems requires modern electronic components and devices that are characterized by improved electrical and thermal properties [1][2][3][4]. A new generation of junction field-effect transistors made of silicon carbide (SiC-JFETs) has appeared on the market as a result of technological progress in the construction of semiconductor devices [1,3,5].…”

Estimation of Parasitic Capacitance of Common Mode Noise in Vehicular Applications: An Unscented Kalman Filter-Based Approach

“…There are different parasitic capacitances in the power electronics circuits such as the parasitic capacitances between the gate-source, gate-drain, and drain-source of MOSFETs. These parasitic capacitances, however, mostly influence the switching behavior of the semiconductor switches [20]- [21]. On the other hand, the CM noise is mostly affected by the parasitic capacitances between the drain of the MOSFET to the…”