scholarly journals Control Strategy of Intergrated Photovoltaic-UPQC System for DC-Bus Voltage Stability and Voltage Sags Compensation

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 4009
Author(s):  
Dongsheng Yang ◽  
Zhanchao Ma ◽  
Xiaoting Gao ◽  
Zhuang Ma ◽  
Enchang Cui
Keyword(s):  
Power Quality ◽  
Control Strategy ◽  
Control Method ◽  
Integrated System ◽  
Normal Operation ◽  
Photovoltaic Array ◽  
Point Tracking ◽  
Dc Bus ◽  
Bus Voltage ◽  
Power Point

Power quality problem, because of its various forms and occurrence frequency, has become one of the most critical challenges confronted by a power system. Meanwhile, the development of renewable energy has led to more demands for an integrated system that combines both merits of sustainable energy generation and power quality improvement. In this context, this paper discusses an integrated photovoltaic-unified power quality conditioner (PV-UPQC) and its control strategy. The system is composed of a series compensator, shunt compensator, dc-bus, and photovoltaic array, which conducts an integration of photovoltaic generation and power quality mitigation. The fuzzy adaptive PI controller and the improved Maximum Power Point Tracking (MPPT) technique are proposed to enhance the stability of dc-bus voltage, which is aimed at the power balance and steady operation of the whole system. Additionally, the coordinate control strategy is studied in order to ensure the normal operation and compensation performance of the system under severe voltage sag condition. In comparison to the existing PV-UPQC system, the proposed control method could improve the performance of dc-bus stability and the compensation ability. The dynamic behavior of the integrated system were verified by simulation in MATLAB and PLECS. Selected results are reported to show that the dc-bus voltage was stable and increased under severe situations, which validates the effectiveness of the proposed integrated PV-UPQC system and its control strategy.

scholarly journals Dual-Mode Photovoltaic Bidirectional Inverter Operation for Seamless Power Transfer to DC and AC Loads with the Grid Interface

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
M. Srikanth ◽  
B. Pakkiraiah ◽  
Poonam Upadhyay ◽  
S. Tara Kalyani
Keyword(s):  
Distribution System ◽  
Output Voltage ◽  
Power Flow ◽  
Boost Converter ◽  
Power Transfer ◽  
Dual Mode ◽  
Point Tracking ◽  
Dc Bus ◽  
Bus Voltage ◽  
Power Point

This paper develops the photovoltaic bidirectional inverter (BI) operated in dual mode for the seamless power transfer to DC and AC loads. Normal photovoltaic (PV) output voltage is fed to boost converter, but in space application, boost converter is not so preferable. To overcome this, buck and boost converters are proposed in this paper. Duty cycle to this converter is provided with the help of the outcome of the maximum power point tracking (MPPT) controller. This can be implemented by using perturbation and observation method. The MPPT will operate the switch between buck and boost modes. When the output voltage of a PV array is close to the dc bus voltage, then the bidirectional inverter can fulfill both rectification and grid connected mode. To control the power flow between dc bus and ac grid, a dc distribution system is used to regulate the dc bus voltage to a convinced level. Moreover, the bidirectional inverter must fulfill grid connection (sell power) and rectification (buy power) with power factor correction (PFC) to control the power flow between dc bus and ac grid. The simulations and hardware experimental results of a 2.5 kVA circuit are presented to validate the performance of the proposed dual-mode seamless power transfer.

Modeling and Simulation of Three Phase Photovoltaic Grid-Connected Generation System

2011 ◽  
Vol 347-353 ◽  
pp. 1144-1148
Author(s):  
Jin Yong Lei ◽  
Xu Zhu Dong ◽  
Hong Bin Wu
Keyword(s):  
Control Strategy ◽  
Characteristic Curve ◽  
Mathematic Model ◽  
Photovoltaic Array ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Three Phase ◽  
Loop Feedback ◽  
Power Point ◽  
Feedback Control Strategy

According to the principle of photovoltaic(PV) grid-connected generation, the maximum power point tracking (MPPT) and grid-connected control strategy were presented in this paper. Based on the V-I characteristic curve of photovoltaic array, it built the mathematic model of photovoltaic array and the MPPT algorithm. Through adopting the double-loop feedback control strategy, it achieved the unit power factor control. Lastly, with the example system, it implemented the simulations analysis including the sunlight changing and the temperature changing. The simulation results show that the proposed models and the control strategy are correct.

LADRC Control for the Three-Phase Voltage-Type PWM Rectifier

2012 ◽  
Vol 591-593 ◽  
pp. 1531-1534 ◽  
Author(s):  
Jin Fang Zhang ◽  
En Li Yao ◽  
Jin Chao Xing
Keyword(s):  
Control Method ◽  
External Disturbance ◽  
Processing System ◽  
Normal Operation ◽  
Equivalent Resistance ◽  
Phase Voltage ◽  
Pwm Inverter ◽  
Three Phase ◽  
Dc Bus ◽  
Bus Voltage

In the three-phase voltage-type pulse width modulation (PWM) inverter system, the steady DC-bus voltage is significant for normal operation of PWM converter. With traditional control method, DC-bus voltage has poor anti-disturbance performance and large steady-state error generated by parametric uncertainties of inductive resistance and switching devices’ equivalent resistance. To cope with these problems, a linear active disturbance rejection control (LADRC) controller is designed based on the advantages of the LADRC in processing system internal perturbation and external disturbance. The simulation study shows that under the same disturbance the proposed method can realize not only faster dynamic response and better property of anti-disturbance performance, but also unity power factor control. For the uncertainties of AC equivalent resistance and inductance, the method shows strong adaptability and robustness.

scholarly journals Power Quality in Distribution Grids

2019 ◽  
Vol 9 (1) ◽  
pp. 2964-2967 ◽  
Keyword(s):  
Power Quality ◽  
Low Voltage ◽  
Control Procedure ◽  
Minimum Power ◽  
Point Tracking ◽  
Voltage Controller ◽  
Facts Controllers ◽  
Bus Voltage ◽  
Tracking Point ◽  
Power Point

Voltage constrained DSTATCOM-based voltage controller is executed for low voltage appropriation system. To meet grid code, unexpected investment postponing, voltage regulator is designed while a complete arrangement could be wanted to tackle guideline issues. 3 yield voltage closed paths with dynamic damping and 2 bus voltage closed paths are associated with control procedure. Also, two circles are incorporated to the control architecture proposed: the idea of Tracking the Minimum Power Point then recurrence closed path. Results demonstrate the guideline limit, the calculation of tracking point of minimum power direct recurrence steadiness. Record Terms— Power Quality, FACTS Controllers, power point tracking, compensation of frequency, DSTATCOM

scholarly journals Reduction of single DC bus capacitance in photovoltaic cascaded multilevel converter

2020 ◽  
Vol 11 (3) ◽  
pp. 1660
Author(s):  
Turki Kahawish Hassan
Keyword(s):  
Control System ◽  
Harmonic Distortion ◽  
Voltage Control ◽  
Partial Shading ◽  
Point Tracking ◽  
High Bandwidth ◽  
Dc Voltage Control ◽  
Dc Bus ◽  
Bus Voltage ◽  
Power Point

<span lang="EN-US">This paper presented single DC bus single phase seven level cascaded H-bridge (CHB) inverter for multi-panel photovoltaic grid-connected applications. A single DC bus supplying flyback converters to produce DC link voltages for CHB cells is suggested. A balanced operation of CHB inverter cells is obtained irrespective to power unbalance occurred by individual maximum power point tracking boost converter of photovoltaic (PV) panels due to the non-uniform irradiation and partial shading. A DC bus voltage control system with addition of estimated DC bus ripple voltage to the reference is proposed to eliminate the second order harmonic contained in the feedback voltage of DC bus enabling to design high bandwidth of DC voltage control loop. This produces fast dynamic response, low total harmonic distortion (THD) of grid current and smaller DC bus capacitance. Mathematical modeling of bus voltage control system is presented. PSIM simulation program is used and the simulation results are obtained to validate the proposed control system.</span>

A Novel Control Strategy of PWM Rectifier

2013 ◽  
Vol 380-384 ◽  
pp. 290-293
Author(s):  
Wei Wang ◽  
Xin Chun Shi
Keyword(s):  
Dynamic Response ◽  
Reference Frame ◽  
Control Strategy ◽  
Control Method ◽  
Voltage Source ◽  
Pwm Rectifier ◽  
Phase Voltage ◽  
Three Phase ◽  
Dc Bus ◽  
Bus Voltage

Based on the mathematical model analysis of the three-phase voltage source PWM rectifier under abc reference frame and dq reference frame in this paper, a kind of three-phase voltage source PWM rectifier feed-forward decoupling control strategy is proposed. Dynamic response of DC bus voltage for PWM rectifier is very important, because higher response means little DC bus capacitor. An adaptive PI controller for the DC bus voltage was designed in this paper in order to improve the dynamic response. The experimental results indicate that this control method has good steady-state performance and fast dynamic response. For the reason of its simple, this control method has certain practical value.

Enhanced Zeta Converter for DC Bus Voltage Regulation

2017 ◽  
Vol 8 (4) ◽  
pp. 1503
Author(s):  
P. Suresh ◽  
D. Kirubakaran
Keyword(s):  
Voltage Regulation ◽  
Maximum Power ◽  
Photovoltaic System ◽  
Maximum Power Point ◽  
Point Tracking ◽  
Power Point Tracking ◽  
High Voltage Gain ◽  
Dc Bus ◽  
Bus Voltage ◽  
Power Point

In this paper, an Enhanced Zeta Converter (EZC) along with a high voltage gain converter is presented for DC Bus voltage regulation. The enhanced zeta converter consists of capacitors connected in parallel with the conventional zeta structure. The proposed zeta converter is applied to the Photo Voltaic system (PV) The well known Maximum Power Point Tracking (MPPT)     P &amp; O algorithm is used to extract maximum power from the photovoltaic system. The increased voltage is obtained with reduced number of switches using the proposed structure. The results to the proposed structure are compared with the conventional topology. The proposed converter is simulated using MATLAB and the same is verified with the hardware.

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