A probabilistic framework for evaluating voltage unbalance mitigation by photovoltaic inverters

In three-phase Low Voltage (LV) networks, distributed photovoltaic (PV) units can contribute to voltage unbalance mitigation in case they are connected with the use of three-phase inverters integrating unbalance mitigation control schemes. This paper presents a probabilistic framework that simulates the time-varying action of voltage magnitude and unbalance mitigation schemes, locally implemented by PV inverters in LV feeders. The scope includes evaluating the effect of such strategies, in the context of a long-term techno-economic planning of the LV network, and characterizing LV network operation for increasing the observability of state estimation techniques applied in the Medium Voltage level. The presented framework evaluates the action of four distributed control schemes in an extensive range of possible network states assembled with the use of feeder-specific smart metering (SM) data. The simulation of a real LV feeder with distributed PV generation and historic SM measurements is presented. A control strategy that acts resistively towards the negative- and zero-sequence voltage components, without modifying the total nodal injected power (three-phase damping control strategy), results to be more effective compared with traditionally applied voltage control schemes.

[1]  H. A. Toliyat,et al.  Performance Analysis of a Three-Phase Induction Motor under Mixed Eccentricity Condition , 2002, IEEE Power Engineering Review.

[2]  B. N. Gafford,et al.  Heating of Induction Motors on Unbalanced Voltages , 1959, Transactions of the American Institute of Electrical Engineers. Part III: Power Apparatus and Systems.

[3]  B. Banerjee,et al.  Assessment of Voltage Unbalance , 2001, IEEE Power Engineering Review.

[4]  L. Pierrat,et al.  A Method Integrating Deterministic and Stochastic Approaches for the Simulation of Voltage Unbalance in Electric Power Distribution Systems , 2001 .

[5]  V. Katic,et al.  Power Quality Problems Compensation With Universal Power Quality Conditioning System , 2007, IEEE Transactions on Power Delivery.

[6]  Peter Schegner,et al.  Impact of electrical car charging on unbalance in public low voltage grids , 2011, 11th International Conference on Electrical Power Quality and Utilisation.

[7]  Francois Vallee,et al.  Development of a probabilistic tool using Monte Carlo simulation and smart meters measurements for the long term analysis of low voltage distribution grids with photovoltaic generation , 2013 .

[8]  H. E. Shaalan,et al.  Time varying load analysis to reduce distribution losses through reconfiguration , 1993 .

[9]  Francisco Jurado,et al.  Voltage unbalance assessment in secondary radial distribution networks with single-phase photovoltaic systems , 2015 .

[10]  Jovica V. Milanovic,et al.  Estimating the voltage unbalance factor using distribution system state estimation , 2010, 2010 IEEE PES Innovative Smart Grid Technologies Conference Europe (ISGT Europe).

[11]  Bin-Kwie Chen,et al.  Effects of various unbalanced voltages on the operation performance of an induction motor under the same voltage unbalance factor condition , 1998 .

[12]  Francois Vallee,et al.  On the Correlation between Prosumers in Probabilistic Analysis of Low Voltage Distribution Systems , 2016 .

[13]  Ahmad Abdel-Majeed,et al.  Low voltage system state estimation using smart meters , 2012, 2012 47th International Universities Power Engineering Conference (UPEC).

[14]  Charis S. Demoulias,et al.  A control strategy for enhancing the Fault Ride-Through capability of a microgrid during balanced and unbalanced grid voltage sags , 2015 .

[15]  Mario Paolone,et al.  Real-time state estimation of the EPFL-campus medium-voltage grid by using PMUs , 2015, 2015 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference (ISGT).

[16]  L. Pierrat,et al.  Probabilistic modeling of voltage asymmetry , 1995 .

[17]  Lieven Vandevelde,et al.  Three-phase inverter-connected DG-units and voltage unbalance , 2011 .

[18]  Lieven Vandevelde,et al.  Converter-connected distributed generation units with integrated harmonic voltage damping and harmonic current compensation function , 2009 .

[19]  Antonio Gómez Expósito,et al.  State estimation in two time scales for smart distribution systems , 2015, 2015 IEEE Power & Energy Society General Meeting.

[20]  J. V. Milanovic,et al.  Probabilistic Estimation of Voltage Unbalance in MV Distribution Networks With Unbalanced Load , 2015, IEEE Transactions on Power Delivery.

[21]  Francois Vallee,et al.  Probabilistic simulation framework for balanced and unbalanced low voltage networks , 2016 .

[22]  Math Bollen IEEE Richard Harold Kaufmann Award Call for Nominations , 2002 .

[23]  Albert Moser,et al.  Impact of distributed reactive power control of renewable energy sources in smart grids on voltage stability of the power system , 2014, 2014 Electric Power Quality and Supply Reliability Conference (PQ).

[24]  Jorge E. Mendoza,et al.  Low voltage distribution planning considering micro distributed generation , 2013 .

[25]  Lieven Vandevelde,et al.  Voltage dip mitigation capabilities of three-phase damping control strategy , 2015 .

[26]  Francois Vallee,et al.  Estimating the Photovoltaic Hosting Capacity of a Low Voltage Feeder Using Smart Meters’ Measurements , 2016 .

[27]  Lieven Vandevelde,et al.  Neutral-point shifting and voltage unbalance due to single-phase DG units in low voltage distribution networks , 2009, 2009 IEEE Bucharest PowerTech.

[28]  Mehdi Savaghebi,et al.  Autonomous Voltage Unbalance Compensation in an Islanded Droop-Controlled Microgrid , 2013, IEEE Transactions on Industrial Electronics.