Diode Reverse Recovery Time Research Articles

Characterization of a 3.3-kV Si-SiC Hybrid Power Module in Half-Bridge Topology for Traction Inverter Application

A state-of-the-art 3.3-kV/450-A hybrid power module for the next generation traction inverter of rolling stock is reported in this paper, combining the silicon (Si) insulated-gate bipolar transistor (IGBT) and silicon carbide Schottky barrier diodes (SBDs) chips. Compared with the existing hybrid technology at the same voltage level, this module is characterized by a half-bridge topology, in which 6 IGBT and 12 SBD chips are integrated in each switch. The outnumbering of the diodes represents a promising mitigation to the low availability of SBDs at this voltage level. Both static and dynamic test of this module and an equivalent Si-based module are carried out comparatively. Apart from describing the features of compactness, low-inductance, and good current distribution among chips, this module is characterized by low turn-ON current overshooting and turn-ON loss of IGBTs, negligible diode reverse recovery time and loss, as well as flexible allowance of IGBT turnON current rising rate dI/dt. A parameterized study is carried out to benchmark the advantage of this new topology. Based on the experimental results, the performance of the hybrid module in a three-phase traction inverter circuit is also evaluated by means of electro-thermal simulation. The hybrid module distinguishes itself by describing much lower power loss and junction temperature than its Si-based counterpart.

Non‐linear bifurcation method to determine the boost converter switching frequency

Prior to the design of the feedback system for a boost converter, a suitable switching frequency for the transistor has to be determined. A non-linear method for determining this frequency via an experimental open-loop converter model is studied. Utilising the open-loop model as an investigative tool, two non-linear distinct resonant frequencies have been found to be a source of chaos. This condition for chaos holds when the boost diode's reverse-recovery time, its non-linear capacitance, as well as the inductance are the combined parameters within these frequencies. When the switching frequency is synchronised with these frequencies, ultra-harmonics, period-doublings and sudden transitions to chaos occur for various switching frequency ranges. The dependence equations of our theoretical model that incorporate these resonant frequencies predict the unstable frequency regions. The authors’ numerical method utilises a bifurcation peak-to-peak analysis that detects the waveform periodicity of certain voltage variables. Highly unstable behaviour of the converter is reported both in simulation and in the laboratory. The periodic and non-periodic regions are confirmed by the corresponding computations of the Lyapunov exponent, Poincare sections, frequency spectra and bifurcation diagrams.

DC-Link Current and Voltage Ripple Analysis Considering Antiparallel Diode Reverse Recovery in Voltage Source Inverters

In this paper, a method is proposed to investigate the dc-link current and voltage ripple calculations in voltage source inverters by considering the reverse recovery of the antiparallel diodes. The impact of the diode reverse recovery transient on the dc-link current and voltage within the switching period is first analyzed. The analysis indicates that the current ripple rms value is affected by the value of inverter switching frequency, diode reverse recovery time, and current. However, the diode reverse recovery shows negligible impact on the dc-link voltage ripple calculation, since the difference between the voltage ripples calculated by the proposed and existing method is less than 1%. To evaluate the estimation accuracy of the dc-link current ripple rms value by the proposed method, the experiments are implemented and the comprehensive analysis is done under different operating conditions, including various power factors, modulation indexes, inverter output currents, and inverter switching frequencies. Experimental results show that the accuracy of dc-link rms current ripple calculation by the proposed method is in the range of $\pm$ 5% and increased by up to 7% compared with the existing method neglecting the antiparallel diode reverse recovery.

Automatic Measurement and Modeling Implementation of Diode Reverse Recovery

Diode reverse recovery current dissipation is the most important source of power dissipation for diodes used in fast switching converters or other power devices applications. As the reverse recovery current can peak at very high currents, this may cause the failures of other devices in the circuit. Therefore the Diode Reverse Recovery phenomena should no longer be ignored in device model and circuit simulations employing diodes. Automatic measurement of Diode Reverse Recovery time is becoming essential for mass production industrial process monitoring and device modeling. In this paper, a novel Sagittarius automatic Diode Reverse Recovery Time Measurement System was developed. This system has enabled the automation measurement and improved the measurement speed for about 5-7 times. A new Verilog A Diode Reverse Recovery model which can reflect the actual device characteristics was developed base on the data measured using this new system.

Research on Battery Charging-Discharging in New Energy Systems

As an energy storage component, the battery plays increasingly important role in new energy industry. Charging and discharging system is the vital part of the application of the battery, but the charge and discharge are always designed separately and carried by different part in the traditional application. Additionally, most battery discharge mode and method are always simplified which cannot ensure to meet the demand of power utilization. In the actual energy storage system, the design of the energy converter, which make the power storage and supply as a whole and the design of the charge and discharge method, will play an important role in efficient utilization of the battery system. As a part of the new energy system, the study makes battery and the charging and discharging system as a whole to store energy, which can store and release electric energy high efficiently according to the system state and control the bidirectional flow of energy precisely. Using TMS320F2812 as the control core, the system which integrates charging and discharging with battery monitoring can achieve the bidirectional Buck/Boost power control. It can achieve three-stage charging and selective discharging of the battery. Due to the influence of the diode reverse recovery time, current oscillation will appear. In order to eliminate the oscillation, we can set the circuit to work in critical conduction mode. The experimental result shows that the system can achieve the charging and discharging control of lead-acid battery and increase the battery life time further.

Precision Full-Wave Rectifiers with Current Active Elements and Current Biasing

This article discusses universal precision rectifiers using current active elements and current sources for the diode excitation. The paper introduces circuit solution of the universal precision full-wave rectifier with intention to reduce negative effect of diode reverse recovery time. Furthermore, experimental results are given and a comparison of new circuit of precision full-wave rectifier and its known variant is presented.

On-resistance, thermal resistance and reverse recovery time of power MOSFETs at 77 K

Measurements of the on-resistance, the approximate thermal resistance and the drain-source diode reverse recovery time of new commercially available power MOS field-effect transistors at room and at liquid nitrogen temperature (77 K) are presented and compared. It is demonstrated that all three parameters drastically improve in cooled devices, especially in those with high breakdown voltage.