Control Scheme for a Bidirectional Converter in a Self-Sustaining Low-Voltage DC Nanogrid

2015 ◽  
Vol 62 (10) ◽  
pp. 6317-6326 ◽  
Author(s):  
Saravana Ilango Ganesan ◽  
Dinesh Pattabiraman ◽  
Ramesh Krishna Govindarajan ◽  
Manoj Rajan ◽  
Chilakapati Nagamani
Keyword(s):  
Low Voltage ◽  
Bidirectional Converter ◽  
Control Scheme

scholarly journals The LVRT Control Scheme for PMSG-Based Wind Turbine Generator Based on the Coordinated Control of Rotor Overspeed and Supercapacitor Energy Storage

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 518
Author(s):  
Xiangwu Yan ◽  
Linlin Yang ◽  
Tiecheng Li
Keyword(s):  
Energy Storage ◽  
Wind Turbine ◽  
Low Voltage ◽  
Specific Capacity ◽  
Coordinated Control ◽  
Input Power ◽  
Voltage Sags ◽  
Rotor Speed ◽  
Control Scheme ◽  
Supercapacitor Energy Storage

With the increasing penetration level of wind turbine generators (WTGs) integrated into the power system, the WTGs are enforced to aid network and fulfill the low voltage ride through (LVRT) requirements during faults. To enhance LVRT capability of permanent magnet synchronous generator (PMSG)-based WTG connected to the grid, this paper presents a novel coordinated control scheme named overspeed-while-storing control for PMSG-based WTG. The proposed control scheme purely regulates the rotor speed to reduce the input power of the machine-side converter (MSC) during slight voltage sags. Contrarily, when the severe voltage sag occurs, the coordinated control scheme sets the rotor speed at the upper-limit to decrease the input power of the MSC at the greatest extent, while the surplus power is absorbed by the supercapacitor energy storage (SCES) so as to reduce its maximum capacity. Moreover, the specific capacity configuration scheme of SCES is detailed in this paper. The effectiveness of the overspeed-while-storing control in enhancing the LVRT capability is validated under different levels of voltage sags and different fault types in MATLAB/Simulink.

scholarly journals Implementation of Snubber Circuits in a PV-Based Off-Grid Electric Vehicle Charging Station—Comparative Case Studies

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5853
Author(s):  
Divya Krishnan Nair ◽  
Krishnamachar Prasad ◽  
Tek Tjing Lie
Keyword(s):  
Low Voltage ◽  
Solar Array ◽  
Paradigm Shifts ◽  
Storage Unit ◽  
Charging Infrastructure ◽  
Energy Storage Unit ◽  
Leakage Inductance ◽  
Zero Voltage Switching ◽  
Charging Station ◽  
Bidirectional Converter

With the penetration of electric vehicles (EVs), there have been paradigm shifts in the transportation sector. EVs are ideally considered to be clean and eco-friendly, but they can overload the existing grid infrastructure and significantly contribute towards carbon emissions depending on the source of charging. The ideal solution is to develop a charging infrastructure for EVs that is integrated with solar energy technology. This paper presents the design of a zero-voltage switching snubber-based bidirectional converter for an off-grid charging station for EVs. The proposed system includes a solar array with a boost converter, a bidirectional converter with snubber circuits and an energy storage unit. A comprehensive comparison between various types of snubbers, such as the resistive capacitive diode snubber, active clamp snubber and flyback snubber, is presented. This type of system configuration clamps the rail voltage, due to the difference in current between leakage inductance and low voltage side-fed inductor currents, resulting in reduced current spikes at the converter’s switches. Such a converter, therefore, leads to higher efficiency of the charging station for EVs. The design of a snubber-based off-grid charging station for EVs is formulated and validated in the MATLAB/Simulink environment.

Implementation of Single-Phase Two-Switch Midpoint Unidirectional Multilevel Converter System

2018 ◽  
Vol 19 (4) ◽  
Author(s):  
Peethala Rajiv Roy ◽  
P. Parthiban ◽  
B. Chitti Babu
Keyword(s):  
Single Phase ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Open Loop ◽  
Current Control ◽  
Control Technique ◽  
Control Scheme

Abstract This paper deals with implementation of a single-phase three level converter system under low voltage condition. The frequency of the switches is made constant and involves change in ${t_{on}}$ and ${t_{off}}$ duration. For this condition the pulse width modulation control scheme for a single phase three level rectifier is developed to improve the power quality. The hysteresis current control technique is adopted to bring forth three-level PWM on the dc side of the bridge rectifier and to achieve high power factor and low harmonic distortion. Based on the proposed control scheme, the line current is driven to follow the sinusoidal current command which is in phase with the supply voltage. By using three-level voltage pattern the blocking voltage of each power device is clamped to half of the dc link voltage. The simulation and experimental results of 20W converter under low input voltage condition are shown to verify the circuit performance. Open loop simulation and hardware tests are implemented by applying a low voltage of 15 V(rms) on the input side.

Enhancement of low-voltage ride-through capability of permanent magnet synchronous generator wind turbine by applying state-estimation technique

2020 ◽  
Vol 39 (2) ◽  
pp. 363-377
Author(s):  
Sayyed Ali Akbar Shahriari ◽  
Mohammad Mohammadi ◽  
Mahdi Raoofat
Keyword(s):  
Wind Turbine ◽  
State Estimation ◽  
Low Voltage ◽  
Synchronous Generator ◽  
Estimation Algorithm ◽  
Voltage Measurement ◽  
Content Type ◽  
Low Voltage Ride Through ◽  
Speed Sensor ◽  
Control Scheme

Purpose The purpose of this study is to propose a control scheme based on state estimation algorithm to improve zero or low-voltage ride-through capability of permanent magnet synchronous generator (PMSG) wind turbine. Design/methodology/approach Based on the updated grid codes, during and after faults, it is necessary to ensure wind energy generation in the network. PMSG is a type of wind energy technology that is growing rapidly in the network. The control scheme based on extended Kalman filter (EKF) is proposed to improve the low voltage ride-through (LVRT) capability of the PMSG. In the control scheme, because the state estimation algorithm is applied, the requirement of DC link voltage measurement device and generator speed sensor is removed. Furthermore, by applying this technique, the extent of possible noise on measurement tools is reduced. Findings In the proposed control scheme, zero or low-voltage ride-through capability of PMSG is enhanced. Furthermore, the requirement of DC link voltage measurement device and generator speed sensor is removed and the amount of possible noise on the measurement tools is minimized. To evaluate the ability of the proposed method, four different cases, including short and long duration short circuit fault close to PMSG in the presence and absence of measurement noise are studied. The results confirm the superiority of the proposed method. Originality/value This study introduces EKF to enhance LVRT capability of a PMSG wind turbine.

scholarly journals A Unified Multimode Control of a DC–DC Interlinking Converter Integrated into a Hybrid Microgrid

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1314 ◽  
Author(s):  
Oswaldo López-Santos ◽  
Yeison Alejandro Aldana-Rodríguez ◽  
Germain Garcia ◽  
Luis Martínez-Salamero
Keyword(s):  
Energy Exchange ◽  
Low Voltage ◽  
Voltage Regulation ◽  
The Other ◽  
Theoretical Development ◽  
System Response ◽  
Control Approach ◽  
Uniform System ◽  
Hybrid Microgrid ◽  
Control Scheme

DC–DC interlinking converters (ILCs) allow bidirectional energy exchange between DC buses of different voltage levels in microgrids. This paper introduces a multimode control approach of a half-bridge DC–DC converter interlinking an extra-low-voltage DC (ELVDC) bus of 48 VDC and a low-voltage DC (LVDC) bus of 240 VDC within a hybrid microgrid. By using the proposed control, the converter can transfer power between the buses when the other converters regulate them, or it can ensure the voltage regulation of one of the buses, this originating from its three operation modes. The proposed control scheme is very simple and provides a uniform system response despite the dependence of the converter dynamic on the operating point and the selected mode. Simulation and experimental results validated the theoretical development and demonstrated the usefulness of the proposed scheme.

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