Novel optimal control strategy for power fluctuation and current harmonic suppression of a three-phase photovoltaic inverter under unbalanced grid faults

Summary This paper presents photovoltaic (PV) systems modeling and fault analysis with solar energy fluctuation to discuss maximum fault current profiles. The modeled PV farm is arranged with series and parallel PV modules to offer 6.5 kV power. Two‐level 3‐phase voltage source inverter (VSI) and dc‐dc boost converter are used for all PV systems with LCL filter. A current control strategy using synchronous rotating frame method is implemented with park transformation approach. Average and aggregate models give inaccuracy, which this paper overcomes with accurate isolated single PV system, and PV‐dominated feeder. Pulse width modulation and sinusoidal pulse width modulation techniques are applied. Incremental conductance maximum power point tracking technique is used to extract PV maximum power. Phase locked loop technique for grid synchronization and proportional integral voltage control technique are also applied. Here, the maximum fault current corresponds to the maximum phase current at specified time. This simple and effective method is applied on PSCAD software simulations to collect the data. Discussions on obtained results showed short‐time irradiation fluctuation impacts on fault current profiles and argue on related aspects. The data comments and explanations to address analyzed protection challenges with PV penetration in distribution system are very promising.

Section: Introductionmentioning

confidence: 99%

Modeling and fault analysis of solar photovoltaic grid-connected systems under solar radiation fluctuation consideration

Tekpeti

Kang

Kheshti

et al. 2018

“…Performance and convergence rate constraints are imposed on the design to enhance transient responses and dynamic behavior. Parameter selection guidelines are also given. During asymmetrical voltage sags, real power delivered to the grid is kept constant, and the injected currents are kept sinusoidal without requiring a PLL or the PN sequence components of unbalanced voltages or currents that are generally employed under unbalanced conditions and to keep real power injection constant during grid support . This leads to a significant reduction in computational complexity and design requirements of the control strategy.…”

Section: Introductionmentioning

confidence: 99%

A novel low-voltage ride-through capable energy management scheme for a grid-connected hybrid photovoltaic-fuel cell power source

Sabir

2018

Summary A novel low‐voltage ride‐through capable energy management control system is proposed for a grid‐connected hybrid photovoltaic‐fuel cell power source. The scheme is designed to enable the hybrid power source to follow a power demand from the grid operator. Additionally, the system is able to ride through both symmetrical and asymmetrical voltage sags while providing active and reactive power support to the grid. The injected active power is kept constant during asymmetrical voltage sags without requiring a phase locked loop or positive‐negative sequence extraction, thus lowering the computational complexity and design requirements of the control system. Several test cases are simulated using the SimPowerSystems toolbox of MATLAB/Simulink computing environment to demonstrate effectiveness of the proposed strategy both under normal and voltage sag conditions. Results of the control algorithm's digital implementation on a low‐cost microcontroller are also presented.

“…In recent years, power quality issues of active distribution systems with PVGs are gaining much interest . The interface inverter of the PVG has been used with different control options to supply active and reactive powers to the utility.…”

Section: Introductionmentioning

confidence: 99%

“…The complete system, which composes, of 4 wires has been implemented using power simulator program (PSIM). The coordination of rooftop PV is introduced to improve voltage profile in three‐phase residential feeders . The coordination study has been performed using steady‐state unbalanced power‐flow analysis.…”

Section: Introductionmentioning

confidence: 99%

“…In recent years, power quality issues of active distribution systems with PVGs are gaining much interest. [7][8][9][10][11][12] The interface inverter of the PVG has been used with different control options to supply active and reactive powers to the utility. A variety of methodologies is adopted either to simulate the control actions or to promote new control methods.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Voltage control of unbalanced three-phase networks using reactive power capability of distributed single-phase PV generators

Eid

Abdel‐Akher

2017

Summary In this paper, a developed voltage control method for distributed single‐phase photovoltaic (PV) generators in unbalanced distribution networks is proposed. The reactive power capability of the PV inverters has been used to regulate bus voltages during irradiance or load variations. The amount of the reactive power required to optimize phase voltages is calculated using fuzzy logic control function, and hence, the power factor is precisely determined. The proposed control for the PV inverters is based on the dq‐current control to regulate the DC bus voltage and the amount of the reactive power. A hysteresis current control is used as a pulse width modulation gate generator. The proposed control precisely determines the amount of the required reactive power to regulate the system bus voltages to lie within standard limits. The efficiency of the proposed control is evaluated with a 10‐node, 5 kV/phase unbalanced three phase distribution system. The analysis includes different test cases under transient and steady state operations to ensure accurate representation of the actual system. The obtained results assess the quality of the network voltages of the studied system regarding voltage levels and the degree of the unbalance. Moreover, the proposed control is capable of operation under different power factors of the PV inverter.