scholarly journals Comparison of Si and SiC based Power Converter Module of 150 kVA for Power System Applications

2020 ◽  
Vol 7 (1) ◽  
pp. 10-13
Author(s):  
Jan Štěpánek ◽  
Luboš Streit ◽  
Tomáš Komrska
Keyword(s):  
Power Systems ◽  
Single Phase ◽  
Power Converters ◽  
Reactive Power ◽  
Mechanical Design ◽  
Power Converter ◽  
Voltage Source ◽  
Phase Voltage ◽  
Power Semiconductors ◽  
Power Semiconductor

The paper deals with the comparison of power semiconductors based on Si and SiC in application of power converters for power systems. These are single-phase voltage-source bridge inverters with nominal power of 150 kVA. Power converters are designed to operate under both active power and reactive power. Mechanical design of the converters is ready for interchange the power semiconductor modules and assess the operation with both, Si and SiC technology.

scholarly journals Control of the Transformer Phase Powers Using a Single-Phase Voltage Source

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1038
Author(s):  
Tomasz Drabek ◽  
Paweł Dybowski
Keyword(s):  
Control System ◽  
Phase Angle ◽  
Single Phase ◽  
Reactive Power ◽  
Phase Distribution ◽  
Active Power ◽  
Voltage Source ◽  
Current Phase ◽  
Phase Voltage ◽  
Distribution Transformer

Power flow in three-phase distribution grids containing single-phase prosumer voltage sources strongly depends on the RMS value of the voltage of these sources and their phase shifts in relation to the grid voltage. The ideal way to control single-phase prosumer sources should guarantee no return active power to the MV grid through a distribution transformer and no additional reactive power flows in the LV grid. This means that the active power of the one-phase voltage source is consumed by other single-phase customers (in the same phase or in other phases) and the reactive power of this source is equal to zero. The paper presents the results of the investigations of the dynamic control system of a single-phase voltage source that allows meeting these conditions. On the basis of steady-state calculations, the static characteristics of the above-mentioned control, needed to determine of the proper working point of a prosumer source were also obtained. The control process involves the control of the RMS value and phase angle of the voltage source against the phase voltage of the LV grid, to which the source is connected, with simultaneous control of the current phase angle issued by the power source against voltage. The result of the research is the confirmation of the necessity of using a zig–zag connection of the secondary side of distribution transformers. The developed control system of the prosumer voltage source does not fully control the active power of individual phases of the distribution transformer. The paper shows that the power losses in a distribution transformer strongly depend not only on the active power of the prosumer source, but also on its effective voltage and phase in relation to the transformer voltage.

A Structural-Algorithmic and Parametric Synthesis of Single-Phase Voltage Source Inverters for Increased Power Capacity

2021 ◽  
Vol 2 (2) ◽  
pp. 44-53
Author(s):  
GENNADY S. MYTSYK ◽  
◽  
ZAW HTET HEIN ◽  
Keyword(s):  
Energy Flow ◽  
Output Voltage ◽  
Power Plants ◽  
Single Phase ◽  
Voltage Source ◽  
Phase Voltage ◽  
Power Capacity ◽  
Voltage Source Inverters ◽  
Solar Power Plants ◽  
Output Filter

The recent interest of developers of new technology in studying a structural and algorithmic synthesis (SAS) of voltage source inverters (VSI) for solar power plants (SPP) is stemming from a growing need to solve problems in connection with the revealed new possibilities of converting energy flow (from DC to AC) with better energy efficiency by reducing the depth of its pulse modulation. This problem is solved by using more rational structural and algorithmic solutions. It is shown that for SPPs for a capacity of about 1 MW and more, it is more expedient to construct inverters based on the energy flow multichannel conversion principle. Given a limited power capacity of the transistor components, the application of this principle allows the problem to be solved in fact without using an output filter. The output voltage waveform is shaped using the energy flow pulse-amplitude modulation (PAM), and its M parts are summed in the output circuit by out using M winding transfilters (M-TF). The proposed method for carrying out combined SAS of single-phase voltage source inverters with multichannel conversion is considered, which consists in using an N-level single-phase VSI (N-SPVSI) in each of the M channels with the voltage levels optimized in terms of the minimum total harmonic distortion (THD). The resulting voltage of this class of single-phase inverters, designated as MxN-SPVSI, is formed by the corresponding phase shift of the channel voltages followed by summing the channel currents by M-TF. It is shown that the resulting output voltage levels are also close to their values optimized with respect to the minimum of the THD indicator. The results from a comparative analysis of two options — a single-channel 8-level inverter and a four-channel 8-level inverter are given. For the second option, only one intermediate voltage tap in the solar battery is required (instead of seven taps in the first option) along with modern transistor components that are available for practical implementation. In both options, the THD value less than 5% is obtained with almost no need of using an output filter. The presented results provide a certain information and methodological support for system designing of single-phase voltage source inverters as applied to the specific features of solar power plants. Three-phase inverters can be built on the basis of three single-phase inverters with galvanic isolation of the power sources for each phase.

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