scholarly journals A Cost-Effective Decentralized Control for AC-Stacked Photovoltaic Inverters

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2262 ◽  
Author(s):  
Hua Han ◽  
Chao Luo ◽  
Xiaochao Hou ◽  
Mei Su ◽  
Wenbin Yuan ◽  
...  
Keyword(s):  
Decentralized Control ◽  
Cost Effective ◽  
Current Control ◽  
Control Mode ◽  
Communication Link ◽  
Grid Voltage ◽  
Point Tracking ◽  
Pv Inverter ◽  
Communication Links ◽  
Voltage Phase

For an AC-stacked photovoltaic (PV) inverter system with N cascaded inverters, existing control methods require at least N communication links to acquire the grid synchronization signal. In this paper, a novel decentralized control is proposed. For N inverters, only one inverter nearest the point of common coupling (PCC) needs a communication link to acquire the grid voltage phase and all other N − 1 inverters use only local measured information to achieved fully decentralized local control. Specifically, one inverter with a communication link utilizes the grid voltage phase and adopts current control mode to achieve a required power factor (PF). All other inverters need only local information without communication links and adopt voltage control mode to achieve maximum power point tracking (MPPT) and self-synchronization with grid voltage. Compared with existing methods, the communication link and complexity is greatly reduced, thus improved reliability and reduced communication costs are achieved. The effectiveness of the proposed control is verified by simulation tests.

scholarly journals Decentralized Control of PV Inverter to Mitigate Voltage Rise in Resistive Feeder

2018 ◽  
Vol 69 ◽  
pp. 01009
Author(s):  
Tzung-Lin Lee ◽  
Shang-Hung Hu ◽  
Shih-Sian Yang
Keyword(s):  
Decentralized Control ◽  
Reactive Power ◽  
Low Voltage ◽  
Voltage Measurement ◽  
Maximum Power Point ◽  
Voltage Rise ◽  
Point Tracking ◽  
Pv Inverter ◽  
Power Point Tracking ◽  
Power Point

Increasing installation of photovoltaic (PV) in the distribution power system has resulted in serious voltage rise, limiting grid-connectable power. This scenario becomes significant in the low-voltage resistive feeder. This paper proposes a decentralized control for distributed PV inverters to mitigate voltage rise. Instead of MPPT (maximum power point tracking) mode, the proposed PV inverter is able to curtail its real power and compensate the reactive power according to the impedance at the installation location. The drooped characteristics between the output power and the impedance are developed so that the PV inverters are able to cooperatively suppress voltage rise based on their local voltage measurement only. Therefore, PV inverters are allowed to supply more power to the utility within voltage limitation. Simulations are conducted to guarantee the proposed control on improvement of voltage rise considering different parameter of feeder. A lab-scaled prototype circuit is established to verify effectiveness in a resistive feeder.

scholarly journals An Enhanced Control Strategy for the Stable Operation of Distributed Generation during Grid-Connected and Islanded Mode

2018 ◽  
Vol 7 (2) ◽  
pp. 147
Author(s):  
Suman Khichar ◽  
Yatindra Gopal ◽  
Mahendra Lalwani
Keyword(s):  
Power Flow ◽  
Current Control ◽  
Detection Technique ◽  
Control Mode ◽  
Constant Current ◽  
Stable Operation ◽  
Point Tracking ◽  
Loop Detection ◽  
Nondetection Zone ◽  
Voltage Control Mode

The incident of islanding occurs while the distributed generator fed constant power into the grid after power flow on the source of essential utility has been intermittent. If islanding is not rapidly detected, it can reason serious security and harmful condition.  This paper presents coordinated manage of solar photovoltaic unit through maximum power point tracking technique to make available voltage and frequency support for an islanding condition. In normal condition, structure works as constant current control mode subsequent to islanding the structure switched to voltage control mode. The projected technique is capable to discriminate involving an islanding and a non-islanding occurrence. In this paper phase locked loop detection technique designed for detecting islanding situation is conceded out. The authentication of proposed system is established efficiently using MATLAB/ Simulink environment. The simulated results exhibit that the islanding detection technique has zero nondetection zone property and be able to detect islanding within few seconds

scholarly journals A novel current controller design for grid-integrated PV inverter system

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Ayaz Ahmad ◽  
L. Rajaji ◽  
A. Iqbal
Keyword(s):  
Controller Design ◽  
Vital Role ◽  
Current Feedback ◽  
Lcl Filter ◽  
Design Algorithm ◽  
Grid Voltage ◽  
Pv Inverter ◽  
Current Controller ◽  
Experimental Implementation ◽  
Grid Connected Inverter

AbstractDistributed generators are playing a vital role in supporting the grid in ever-increasing energy demands. Grid code regulation must be followed when integrating the photovoltaic inverter system to the grid. The paper investigates and analyzes a controller model for grid-connected PV inverters to inject sinusoidal current to the grid with minimum distortion. To achieve better tracking and disturbance rejection, a DSP-based current controller is designed with LCL filter. The controller gets the current feedback from the grid, compares it with reference current, and calculates duty cycle to generate PWM pulses to trigger H-bridge converters. The grid voltage is loaded to the initial value in proposed PR controller to ensure the initial inverter voltage to match the grid voltage. The paper presents a novel current controller algorithm for grid-connected inverter system, and simulation is done. A detailed analysis has been carried out to validate the proposed design algorithm. Experimental implementation of the current controller in the DC/AC converter circuits with an LCL filter is done for 5.4 kW to validate and match the simulation model.

Study on Reactive Power Compensation Control of STATCOM Based on MMC

2014 ◽  
Vol 530-531 ◽  
pp. 1022-1025
Author(s):  
Yan Xie ◽  
Ya Ne Liao ◽  
Hong Xie
Keyword(s):  
Reactive Power ◽  
Power Level ◽  
Response Speed ◽  
Reactive Power Compensation ◽  
Current Control ◽  
Control Mode ◽  
Compensation Control ◽  
Control Response ◽  
In Series ◽  
Level Converter

This paper introduced a new modular multi-level converter (MMC), which could enhance the voltage and power level by sub-converter modules in series and was easy to extend to any level of output. Its structure and working mechanism were described. By analyzing the performance of STATCOM based on MMC working conditions in the reactive power compensation, this paper studied compensation control theory in reactive changing conditions. To obtain compensation control response speed faster and better compensation effect, a compensation control strategy was proposed based on direct current control mode. The simulation results show the strategy has a better tracking precision and response speed for the reactive power compensation.

H∞ Control to the BUCK-Type Switching Power Supply with Small Perturbation

2013 ◽  
Vol 347-350 ◽  
pp. 1358-1362
Author(s):  
Zi Сheng Li ◽  
Li Xu ◽  
Bao Shan Yuan
Keyword(s):  
Power Supply ◽  
Current Control ◽  
Control Mode ◽  
State Variables ◽  
Switching Power Supply ◽  
Small Perturbations ◽  
Switching Power ◽  
Current Sampling ◽  
Output Filter ◽  
Filter Capacitor

The purpose in this paper is the design of the control to switching power supply for small perturbations. By the theoretical analysis and calculation, with the output filter inductor current and filter capacitor voltage switching power supply as two state variables, the conclusion is that control of the output filter inductor current sampling do well in the anti-jamming. The simulation is made for verification. And comparing the results, the current control mode shows a very strong anti-interference ability.

Line–Line Fault Analysis and Protection Challenges in Solar Photovoltaic Arrays

2013 ◽  
Vol 60 (9) ◽  
pp. 3784-3795 ◽  
Author(s):  
Ye Zhao ◽  
Jean-Francois De Palma ◽  
Jerry Mosesian ◽  
Robert Lyons ◽  
Brad Lehman
Keyword(s):  
Fault Location ◽  
Short Circuit ◽  
Fault Analysis ◽  
Small Scale ◽  
Solar Photovoltaic ◽  
Pv System ◽  
Safety Hazards ◽  
Point Tracking ◽  
Pv Inverter ◽  
Power Point

Fault analysis in solar photovoltaic (PV) arrays is a fundamental task to protect PV modules from damage and to eliminate risks of safety hazards. This paper focuses on line-line faults in PV arrays that may be caused by short-circuit faults or double ground faults. The effect on fault current from a maximum-power-point tracking of a PV inverter is discussed and shown to, at times, prevent overcurrent protection devices (OCPDs) to operate properly. Furthermore, fault behavior of PV arrays is highly related to the fault location, fault impedance, irradiance level, and use of blocking diodes. Particularly, this paper examines the challenges to OCPD in a PV array brought by unique faults: One is a fault that occurs under low-irradiance conditions, and the other is a fault that occurs at night and evolves during “night-to-day” transition. In both circumstances, the faults might remain hidden in the PV system, no matter how irradiance changes afterward. These unique faults may subsequently lead to unexpected safety hazards, reduced system efficiency, and reduced reliability. A small-scale experimental PV system has been developed to further validate the conclusions.

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