A novel voltage-control scheme for low-voltage DC-DC converters with fast transient recovery

2002 ◽  
Author(s):  
Hoi Lee ◽  
P.K.T. Mok ◽  
Wing-Hung Ki
Keyword(s):  
Low Voltage ◽  
Voltage Control ◽  
Control Scheme ◽  
Fast Transient

scholarly journals DC-Link Voltage Control of a Grid-Connected Solar Photovoltaic System for Fault Ride-Through Capability Enhancement

2019 ◽  
Vol 9 (5) ◽  
pp. 952 ◽  
Author(s):  
S. Mohamed ◽  
P. Jeyanthy ◽  
D. Devaraj ◽  
M. Shwehdi ◽  
Adel Aldalbahi
Keyword(s):  
Power Converters ◽  
Reactive Power ◽  
Low Voltage ◽  
Voltage Control ◽  
Maximum Power ◽  
Solar Photovoltaic ◽  
Maximum Power Point ◽  
Control Scheme ◽  
Mppt Controller ◽  
Power Point

The high penetration level of solar photovoltaic (SPV) generation systems imposes a major challenge to the secure operation of power systems. SPV generation systems are connected to the power grid via power converters. During a fault on the grid side; overvoltage can occur at the direct current link (DCL) due to the power imbalance between the SPV and the grid sides. Subsequently; the SPV inverter is disconnected; which reduces the grid reliability. DC-link voltage control is an important task during low voltage ride-through (LVRT) for SPV generation systems. By properly controlling the power converters; we can enhance the LVRT capability of a grid-connected SPV system according to the grid code (GC) requirements. This study proposes a novel DCL voltage control scheme for a DC–DC converter to enhance the LVRT capability of the two-stage grid-connected SPV system. The control scheme includes a “control without maximum power point tracking (MPPT)” controller; which is activated when the DCL voltage exceeds its nominal value; otherwise, the MPPT control is activated. Compared to the existing LVRT schemes the proposed method is economical as it is achieved by connecting the proposed controller to the existing MPPT controller without additional hardware or changes in the software. In this approach, although the SPV system will not operate at the maximum power point and the inverter will not face any over current challenge it can still provide reactive power support in response to a grid fault. A comprehensive simulation was carried out to verify the effectiveness of the proposed control scheme for enhancing the LVRT capability and stability margin of an interconnected SPV generation system under symmetrical and asymmetrical grid faults.

scholarly journals A Novel Voltage Control Scheme for Low-Voltage DC Distribution Systems Using Multi-Agent Systems

Energies ◽  
2017 ◽  
Vol 10 (1) ◽  
pp. 41 ◽  
Author(s):  
Trinh Hai ◽  
Hector Cho ◽  
Il-Yop Chung ◽  
Hyun-Koo Kang ◽  
Jintae Cho ◽  
...  
Keyword(s):  
Distribution Systems ◽  
Low Voltage ◽  
Voltage Control ◽  
Multi Agent Systems ◽  
Agent Systems ◽  
Dc Distribution ◽  
Control Scheme ◽  
Multi Agent

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.

The reactive power voltage control strategy of PV systems in low-voltage string lines

2017 ◽  
Author(s):  
Feng Zhang ◽  
Xiaolong Guo ◽  
Xiqiang Chang ◽  
Guowei Fan ◽  
Lianger Chen ◽  
...  
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Low Voltage ◽  
Voltage Control ◽  
Voltage Control Strategy ◽  
Pv Systems
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