Research on the Suppression of Input Power Disturbance for Single-Phase Photovoltaic Grid-Connected Inverter

2011 ◽  
Vol 128-129 ◽  
pp. 243-246
Author(s):  
Kai Chen ◽  
Shu Lin Tian ◽  
Yu Hua Cheng
Keyword(s):  
Control Algorithm ◽  
Single Phase ◽  
Power Transmission ◽  
Input Power ◽  
Voltage Fluctuations ◽  
Theoretical Derivation ◽  
Pv Inverter ◽  
Maximum Power Tracking ◽  
Grid Connected Inverter ◽  
The Impact

The output power of single-phase PV inverter is AC and the input power is DC，so there exists fluctuations in the power transmission. Generally, the fluctuations can be removed by using coupling capacitors. However, the voltage fluctuations of coupling capacitors will result in corresponding input power fluctuations, and will affect the maximum power tracking of the system. In this paper, the power transfer process is analysised, and a theoretical derivation to voltage fluctuations of the generatrix capacitor and the impact on the input currents is designed.The corresponding correction control algorithm of subdivision control is developed according to its characteristics. The feasibility of the solution is verified by the 3KW experimental prototype.

Theoretical and Numerical Investigation of Supersonic Multiphase Gas Injection

2021 ◽  
Author(s):  
Da Zhu ◽  
Mohan Sivagnanam ◽  
Ian Gates
Keyword(s):  
Shock Wave ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Single Phase ◽  
Gas Injection ◽  
Continuous Phase ◽  
Solid Particles ◽  
Gas Flows ◽  
Theoretical Derivation ◽  
The Impact

Abstract Supersonic gas injection can help deliver gas uniformly to a reservoir, regardless of reservoir conditions. This technology has played a key role in enhanced oil recovery (EOR) and in particular, thermal enhanced oil recovery operations. Most previous studies have focused on single phase gas injection whereas in most field applications, multiphase and multicomponent situations occur. In the research documented in this paper, we report on results of evaluations of compressible multiphase supersonic gas flows in which gas is the continuous phase is seeded with dispersed liquid droplets or solid particles. Theoretical derivation and numerical simulations with and without relative motions between continuous and disperse phases are examined first. The results illustrate that the shock wave structures and flow properties associated with the multiphase gas flows are different than that of single-phase isentropic flows. The existence and importance of relaxation zones after the normal shock wave in multiphase flow is described. Numerical computational fluid dynamics (CFD) simulations are conducted to show how the multiphase multicomponent flow affects gas phase injection under different conditions. The impact of solid/liquid mass loading on flow performance is discussed. Finally, the practical application of the findings is discussed.

Extended Unbalanced Operation of Induction Motor Driven System Based on a Single-Phase Electronic Power Transformer

2015 ◽  
Vol 24 (04) ◽  
pp. 1550045 ◽  
Author(s):  
L. B. Wang ◽  
C. X. Mao ◽  
D. Wang ◽  
J. M. Lu ◽  
J. F. Zhang ◽  
...  
Keyword(s):  
Induction Motor ◽  
Control Strategy ◽  
Control Algorithm ◽  
Single Phase ◽  
Power Transformer ◽  
Integrated Control ◽  
Input Power ◽  
Voltage Source ◽  
Driven System ◽  
Electronic Power Transformer

A new control strategy to extend the unbalanced operation of the induction motor driven system based on a single-phase electronic power transformer (EPT) is proposed in this paper. This new motor driven system avoids the traditional input power transformer and only single-phase power network is needed. It has a modular structure and consists of series H-bridges rectifier, output-parallel dual active bridge converters and a three-phase voltage source inverter. In the input stage, a new control strategy is proposed to balance the dc voltages among the series H-bridges and regulate the current. This new control algorithm determines the minimal reactive current to stabilize the converter when the loads are seriously unbalanced. In order to verify the new driven system, a 3 kV/462 V/180 kW EPT driving an induction motor is constructed in MATLAB/SIMULINK. The simulations results illustrate the effectiveness of the proposed unbalanced control algorithm and good dynamic behavior of the integrated control system for this new driven system.

scholarly journals A Stationary Reference Frame Current Control Algorithm for Improvement of Transient Dynamics of a Single Phase Grid Connected Inverter

Electronics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 722 ◽  
Author(s):  
Horyeong Jeong ◽  
Jae Suk Lee
Keyword(s):  
Reference Frame ◽  
Disturbance Rejection ◽  
Control Algorithm ◽  
Single Phase ◽  
Current Control ◽  
Phase Lag ◽  
Phase Current ◽  
Disturbance Rejection Control ◽  
Stationary Reference Frame ◽  
Grid Connected Inverter

This paper proposes a stationary reference frame current control algorithm for a single-phase grid-connected inverter (GCI) for improvement of transient dynamic performance. Disturbance, i.e., grid voltage in a target system, is estimated using a stator current observer, and the estimated disturbance is applied to a current controller for implementation of disturbance rejection control (DRC). In the proposed current control algorithm, the disturbance rejection control algorithm is applied to reduce the overcurrent occurring in the single-phase grid-connected inverter when grid faults happen. In this paper, the AC phase current of a single-phase inverter is controlled, instead of the current vector, which is a DC signal. To compensate for the drawbacks of controlling the AC phase current, such as phase lag and steady-state error, command feedforward control is also applied in the proposed control system. The proposed control algorithm is mathematically derived and represented in transfer functions and implemented via simulation and experiment.

System Improvements of Photovoltaic Inverters with SiC-Transistors

2010 ◽  
Vol 645-648 ◽  
pp. 1171-1176 ◽  
Author(s):  
Dirk Kranzer ◽  
Florian Reiners ◽  
Christian Wilhelm ◽  
Bruno Burger
Keyword(s):  
Power Density ◽  
Single Phase ◽  
State Of The Art ◽  
Production Costs ◽  
World Record ◽  
Pv Inverter ◽  
Three Phase ◽  
Single Phase Inverter ◽  
Basic Characteristics ◽  
The Impact

In this paper the system improvements of PV-inverters with SiC-transistors are demonstrated. The basic characteristics of engineering prototypes of normally-off SiC-JFETs and SiC-MOSFETs were measured and their differences in the application are considered. To demonstrate the improvement in PV-inverter performance, a 5 kW single-phase and a three-phase full bridge inverter with normally-off SiC-JFETs were developed at Fraunhofer ISE. Different switching frequencies up to 144 kHz were applied and the impact on production costs and inverter performance was rated under the aspects of an industrial product development. This means, the influences on the efficiency and power density. In this work, a world record in PV-inverter efficiency of 99 % was achieved in a single-phase inverter and for the three-pase inverter, the power density was tripled with respect to commercially available state of the art PV-inverters.

DC to Single-Phase AC Grid Connected Inverter with Boost Type Active Buffer Circuit Operated in Discontinuous Current Mode

2018 ◽  
Vol 138 (5) ◽  
pp. 453-462
Author(s):  
Jun-ichi Itoh ◽  
Tomokazu Sakuraba ◽  
Hoai Nam Le ◽  
Hiroki Watanabe ◽  
Keisuke Kusaka
Keyword(s):  
Single Phase ◽  
Current Mode ◽  
Grid Connected Inverter

scholarly journals Impact of the Wind Turbine on the Parameters of the Electricity Supply to an Agricultural Farm

2021 ◽  
Vol 13 (13) ◽  
pp. 7279
Author(s):  
Zbigniew Skibko ◽  
Magdalena Tymińska ◽  
Wacław Romaniuk ◽  
Andrzej Borusiewicz
Keyword(s):  
Power Plant ◽  
Wind Turbine ◽  
Wind Power ◽  
Rural Areas ◽  
Power Plants ◽  
Reactive Power ◽  
Supply Voltage ◽  
Common Source ◽  
Voltage Fluctuations ◽  
The Impact

Wind power plants are an increasingly common source of electricity located in rural areas. As a result of the high variability of wind power, and thus the generated power, these sources should be classified as unstable sources. In this paper, the authors attempted to determine the impact of wind turbine operation on the parameters of electricity supplied to farms located near the source. As a result of the conducted field tests, variability courses of the basic parameters describing the supply voltage were obtained. The influence of power plant variability on the values of voltage, frequency, and voltage distortion factor was determined. To estimate the capacity of the transmission lines, the reactive power produced in the power plant and its effect on the value of the power factor were determined. The conducted research and analysis showed that the wind power plant significantly influences voltage fluctuations in its immediate vicinity (the maximum value registered was close to 2%, while the value required by law was 2.5%). Although all the recorded values are within limits specified by the current regulations (e.g., the THD value is four times lower than the required value), wind turbines may cause incorrect operation of loads connected nearby. This applies mainly to cases where consumers sensitive to voltage fluctuations are installed in the direct vicinity of the power plant.

scholarly journals A Model for the Thermal Behaviour of an Offshore Cable Installed in a J-Tube

Proceedings ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 31
Author(s):  
Jeremy Arancio ◽  
Ahmed Ould El Moctar ◽  
Minh Nguyen Tuan ◽  
Faradj Tayat ◽  
Jean-Philippe Roques
Keyword(s):  
Sensitivity Analysis ◽  
Numerical Model ◽  
Thermal Behaviour ◽  
Energy Production ◽  
Power Transmission ◽  
Temperature Fields ◽  
Sobol Indices ◽  
Lumped Element ◽  
Thermal Phenomena ◽  
The Impact

In the race for energy production, supplier companies are concerned by the thermal rating of offshore cables installed in a J-tube, not covered by IEC 60287 standards, and are now looking for solutions to optimize this type of system. This paper presents a numerical model capable of calculating temperature fields of a power transmission cable installed in a J-tube, based on the lumped element method. This model is validated against the existing literature. A sensitivity analysis performed using Sobol indices is then presented in order to understand the impact of the different parameters involved in the heating of the cable. This analysis provides an understanding of the thermal phenomena in the J-tube and paves the way for potential technical and economic solutions to increase the ampacity of offshore cables installed in a J-tube.

scholarly journals Simulation of 2-Coil and 4-Coil Magnetic Resonance Wearable WPT Systems

Proceedings ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 13
Author(s):  
Yixuan Sun ◽  
Stephen Beeby
Keyword(s):  
Power Efficiency ◽  
Power Transmission ◽  
Rotation Angle ◽  
Wireless Power ◽  
Peak Efficiency ◽  
Frequency Splitting ◽  
At Resonance ◽  
Higher Power ◽  
The Impact ◽  
Proper Frequency

This paper presents the COMSOL simulations of magnetically coupled resonant wireless power transfer (WPT), using simplified coil models for embroidered planar two-coil and four-coil systems. The power transmission of both systems is studied and compared by varying the separation, rotation angle and misalignment distance at resonance (5 MHz). The frequency splitting occurs at short separations from both the two-coil and four-coil systems, resulting in lower power transmission. Therefore, the systems are driven from 4 MHz to 6 MHz to analyze the impact of frequency splitting at close separations. The results show that both systems had a peak efficiency over 90% after tuning to the proper frequency to overcome the frequency splitting phenomenon at close separations below 10 cm. The four-coil design achieved higher power efficiency at separations over 10 cm. The power efficiency of both systems decreased linearly when the axial misalignment was over 4 cm or the misalignment angle between receiver and transmitter was over 45 degrees.

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