Accurate power sharing and harmonic mitigation scheme for parallel operation of single-phase voltage source inverters

2020 ◽  
Vol 21 (1) ◽  
pp. 164-172
Author(s):  
Minh-Duc Pham ◽  
Hong-Hee Lee
Keyword(s):  
Single Phase ◽  
Power Sharing ◽  
Voltage Source ◽  
Parallel Operation ◽  
Phase Voltage ◽  
Voltage Source Inverters ◽  
Harmonic Mitigation

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.

scholarly journals Feedforward Harmonic Mitigation Strategy for Single-Phase Voltage Source Converter

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Qing Zhong ◽  
Junjie Feng ◽  
Gang Wang ◽  
Haifeng Li
Keyword(s):  
Single Phase ◽  
Control Strategies ◽  
Mitigation Strategy ◽  
Voltage Source ◽  
Effective Control ◽  
Voltage Source Converter ◽  
Phase Voltage ◽  
Analysis Model ◽  
Harmonic Pollution ◽  
Harmonic Mitigation

With the development of distributed generations (DGs), single-phase voltage source converter (SPVSC) has been widely used, but it brings about the problem of harmonic pollution to power grid. Hence, it is significant to explore the mechanism of harmonic injection from SPVSC and propose effective control strategies to mitigate the harmonic pollution. In this paper, a harmonic analysis model of SPVSC based on dynamic phasor (DP) has been established. With the model, the harmonics interaction between the ac side and the dc side can be analyzed with the consideration of the control strategies, which reveals the generation mechanism of the harmonics in SPVSC. Based on the mechanism, a feedforward harmonic mitigation strategy has been presented. The principle of the strategy is to add low-order harmonic signal to the PWM modulation signals to reduce the harmonic current on the ac side. The harmonic mitigation strategy not only has clear physical meaning and fast calculation, but also is robust for the uncertainty of parameters. Finally, the simulation and experiment results demonstrate the correctness of the model and the effectiveness of the harmonic mitigation strategy.

Sign in / Sign up

Export Citation Format

Share Document