Strategies to Increase the Transient Active Power of Photovoltaic Units during Low Voltage Ride Through

Due to a limitation in the magnitude of the three-phase output inverter currents, the output active power of the photovoltaic (PV) unit has been de-rated during low voltage ride through, which brings great instability risk to the power system. With the increase in the penetration rate of new energy, the impact of the power shortage on the system transient stability increases. It is of great significance to analyze the impact of this transient power shortage on system stability. This article explores methods to improve the active power output capability of photovoltaic units during low-breakthrough periods. A transient simulation model of a grid-connected PV generator with low-voltage ride-through (LVRT) capability is presented, under the condition of meeting the overcurrent capacity of the PV inverter and the requirement of dynamic reactive power support supplied by the PV generator specified in the China grid codes (GB/T 19964-2012) during grid fault. An example system with high PV penetration is built. The change principle and influencing factors of PV transient active power output are analyzed. The simulation model is designed in PowerFactory/DIgSILENT, and several types of three-phase voltage sags are performed in simulation to assess the impact of the active current reference calculation method and the maximum inverter output current (Imax) limit value on the PV active power output. According to the three indexes, namely the maximum active power of PV unit during the fault, the power improvement gradient and the power surge after the fault is cleared. Simulation results showed that using the orthogonal decomposition method to calculate the active current reference can make full use of the current capacity of the converter. Setting Imax to 1.1 rated current of photovoltaic inverter (IN) can reduce the cost-effectiveness ratio of the transient active power output of the PV unit. Therefore, we aim to improve the unit’s transient active power output capacity and realize the optimal effect of improving the transient active power shortage of the system.

[1]  Liqun Shang,et al.  Maximum power point tracking of PV system under partial shading conditions through flower pollination algorithm , 2018 .

[2]  Michael Negnevitsky,et al.  Risk Assessment for Power System Operation Planning With High Wind Power Penetration , 2015, IEEE Transactions on Power Systems.

[3]  Staffan Norrga,et al.  Grid integration aspects of large solar PV installations: LVRT capability and reactive power/voltage support requirements , 2011, 2011 IEEE Trondheim PowerTech.

[4]  Shichao Fan,et al.  Modelling and simulation of the photovoltaic power station considering the LVRT and HVRT , 2009 .

[5]  N. F. Guerrero-Rodríguez,et al.  Enhanced controller for grid-connected modular multilevel converters in distorted utility grids , 2018, Electric Power Systems Research.

[6]  Ab Halim Abu Bakar,et al.  Strategy to enhance the low-voltage ride-through in photovoltaic system during multi-mode transition , 2017 .

[7]  Vassilios G. Agelidis,et al.  Single- and Two-Stage Inverter-Based Grid-Connected Photovoltaic Power Plants With Ride-Through Capability Under Grid Faults , 2015, IEEE Transactions on Sustainable Energy.

[8]  Johannes Stockl,et al.  Modeling and Design of the Vector Control for a Three-Phase Single-Stage Grid-Connected PV System with LVRT Capability according to the Spanish Grid Code , 2019, Energies.

[9]  Tayeb Allaoui,et al.  Power Quality Improvement and Low Voltage Ride Through Capability in Hybrid Wind-PV Farms Grid-Connected Using Dynamic Voltage Restorer , 2018, IEEE Access.

[10]  Kamaruzzaman Sopian,et al.  Prospects of life cycle assessment of renewable energy from solar photovoltaic technologies: A review , 2018, Renewable and Sustainable Energy Reviews.

[11]  Nadarajah Mithulananthan,et al.  Harmonic impact of high penetration photovoltaic system on unbalanced distribution networks - learning from an urban photovoltaic network , 2016 .

[12]  Seyed Hamid Fathi,et al.  A New Approach for Photovoltaic Arrays Modeling and Maximum Power Point Estimation in Real Operating Conditions , 2017, IEEE Transactions on Industrial Electronics.

[13]  R. Yinger,et al.  Solar PV inverter testing for model validation , 2011, 2011 IEEE Power and Energy Society General Meeting.

[14]  Bin Zhao,et al.  Modeling and Parameter Optimization of Grid-Connected Photovoltaic Systems Considering the Low Voltage Ride-through Control , 2020 .

[15]  Mesut E. Baran,et al.  Fault Analysis on Distribution Feeders With High Penetration of PV Systems , 2013, IEEE Transactions on Power Systems.

[16]  Dianguo Xu,et al.  A Unified Modeling Method of Photovoltaic Generation Systems Under Balanced and Unbalanced Voltage Dips , 2019, IEEE Transactions on Sustainable Energy.

[17]  Hazlee Azil Illias,et al.  Establishment of fault current characteristics for solar photovoltaic generator considering low voltage ride through and reactive current injection requirement , 2018, Renewable and Sustainable Energy Reviews.

[18]  Ali I. Maswood,et al.  Low-voltage ride-thorough capability of photovoltaic grid-connected neutral-point-clamped inverters with active/reactive power injection , 2017 .

[19]  Ioannis-Thomas Theologitis.  Comparison of existing PV models and possible integration under EU grid specifications , 2011 .

[20]  Frede Blaabjerg,et al.  Analysis and Modeling of Interharmonics From Grid-Connected Photovoltaic Systems , 2018, IEEE Transactions on Power Electronics.

[21]  Huiqing Wen,et al.  Simulation and Analysis of Perturbation and Observation-Based Self-Adaptable Step Size Maximum Power Point Tracking Strategy with Low Power Loss for Photovoltaics , 2018, Energies.