SiC Power Devices in Impedance Source Converters

2017 ◽  
Vol 897 ◽  
pp. 701-704
Author(s):  
Jacek Rabkowski
Keyword(s):  
Unique Feature ◽  
Power Converters ◽  
Current Source ◽  
Voltage Source ◽  
Switching Frequency ◽  
Power Devices ◽  
Frequency Increase ◽  
Fast Switching ◽  
New Family ◽  
Specific Impedance

This paper discusses issues related to application of SiC power devices to new family of power converters. Impedance source converters show unique feature, buck boost characteristics due to specific impedance network. Passive elements of this network may be seriously reduced with the switching frequency increase, possible with fast-switching SiC transistors. On the other hand, switching conditions of the power devices are more severe than in traditional voltage-source or current-source converters. These issues are discussed on the base of the 6kVA/100kHz quasi-Z-source inverter example.

THE CONNECTION OF CONVERTERS INSTEAD OF SEMICONDUCTOR POWER DEVICES — A HIGH PERFORMANCE SOLUTION FOR THE MVA RANGE OF POWER COMVERTERS

1995 ◽  
Vol 05 (03) ◽  
pp. 503-521 ◽  
Author(s):  
LOURENCO MATAKAS ◽  
CATALIN BURLACU ◽  
EISUKE MASADA
Keyword(s):  
High Power ◽  
High Performance ◽  
Power Converters ◽  
State Of The Art ◽  
High Reliability ◽  
Motor Drives ◽  
Switching Frequency ◽  
Power Devices ◽  
Parallel Connection ◽  
Severe Limitation

Recently, there is an increased demand for high power, high performance converters for power system applications, motor drives, etc. The low switching frequency of the existing semiconductor power devices poses a severe limitation that can be overcome by the use of interconnected smaller power converters (multiconverter) with appropriate control. This paper gives an overview of the state of the art of multiconverters, followed by a comparison based on analytically calculated values of the spectra, RMS and peak values of their ripple currents, and the peak values of the transformer's flux. Special attention has been given to show that the transformerless parallel connection of converters is feasible and offers features such as simplicity, gracefully degrading operating, high reliability, easy expandability and easy maintenance.

scholarly journals Contribution of Voltage Support Function to Virtual Inertia Control Performance of Inverter-Based Resource in Frequency Stability

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4220
Author(s):  
Dai Orihara ◽  
Hiroshi Kikusato ◽  
Jun Hashimoto ◽  
Kenji Otani ◽  
Takahiro Takamatsu ◽  
...  
Keyword(s):  
Reactive Power ◽  
Control Function ◽  
Current Source ◽  
Voltage Control ◽  
Frequency Stability ◽  
Voltage Regulation ◽  
System Stability ◽  
Voltage Source ◽  
Apparent Difference ◽  
Virtual Inertia

Inertia reduction due to inverter-based resource (IBR) penetration deteriorates power system stability, which can be addressed using virtual inertia (VI) control. There are two types of implementation methods for VI control: grid-following (GFL) and grid-forming (GFM). There is an apparent difference among them for the voltage regulation capability, because the GFM controls IBR to act as a voltage source and GFL controls it to act as a current source. The difference affects the performance of the VI control function, because stable voltage conditions help the inertial response to contribute to system stability. However, GFL can provide the voltage control function with reactive power controllability, and it can be activated simultaneously with the VI control function. This study analyzes the performance of GFL-type VI control with a voltage control function for frequency stability improvement. The results show that the voltage control function decreases the voltage variation caused by the fault, improving the responsivity of the VI function. In addition, it is found that the voltage control is effective in suppressing the power swing among synchronous generators. The clarification of the contribution of the voltage control function to the performance of the VI control is novelty of this paper.

Switching frequency modulation for GaN-based power converters

2015 ◽  
Author(s):  
B. Weiss ◽  
R. Reiner ◽  
R. Quay ◽  
P. Waltereit ◽  
F. Benkhelifa ◽  
...  
Keyword(s):  
Frequency Modulation ◽  
Power Converters ◽  
Switching Frequency

scholarly journals Bandwidth and Common Mode Optimization for Current and Voltage Sources in Bioimpedance Spectroscopy

2021 ◽  
Vol 12 (1) ◽  
pp. 135-146
Author(s):  
Tobias Menden ◽  
Jascha Matuszczyk ◽  
Steffen Leonhardt ◽  
Marian Walter
Keyword(s):  
Patient Safety ◽  
Current Source ◽  
The Body ◽  
Voltage Source ◽  
Bioimpedance Spectroscopy ◽  
Laboratory Measurements ◽  
Output Impedance ◽  
Frequency Range ◽  
Common Mode ◽  
High Bandwidth

Abstract Bioimpedance measurements use current or voltage sources to inject an excitation signal into the body. These sources require a high bandwidth, typically from 1 kHz to 1 MHz. Besides a low common mode, current limitation is necessary for patient safety. In this paper, we compare a symmetric enhanced Howland current source (EHCS) and a symmetric voltage source (VS) based on a non-inverting amplifier between 1 kHz and 1 MHz. A common mode reduction circuit has been implemented in both sources. The bandwidth of each source was optimized in simulations and achieved a stable output impedance over the whole frequency range. In laboratory measurements, the output impedance of the EHCS had its -3 dB point at 400 kHz. In contrast, the VS reached the +3 dB point at 600 kHz. On average over the observed frequency range, the active common mode compensation achieved a common mode rejection of -57.7 dB and -71.8 dB for the EHCS and VS, respectively. Our modifications to classical EHCS and VS circuits achieved a low common mode signal between 1 kHz and 1 MHz without the addition of complex circuitry, like general impedance converters. As a conclusion we found VSs to be superior to EHCSs for bioimpedance spectroscopy due to the higher bandwidth performance. However, this only applies if the injected current of the VS can be measured.

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