Shah Arifur Rahman

New Control of PV Solar Farm as STATCOM (PV-STATCOM) for Increasing Grid Power Transmission Limits During Night and Day

This paper presents a novel concept of utilizing PV solar farm inverter as STATCOM, termed PV-STATCOM, for improving stable power transfer limits of the interconnected transmission system. The entire inverter rating of PV solar farm which remains dormant in the nighttime is utilized with voltage and damping controls to enhance stable power transmission limits. During daytime, the inverter capacity left after real power production is used to accomplish the above objective. Transient stability studies are conducted on a realistic single machine infinite bus power system having a midpoint located PV-STATCOM using EMTDC/PSCAD simulation software. The PV-STATCOM improves the stable transmission limits substantially in the night and also in the day even while generating large amounts of real power. Power transfer increases are also demonstrated in the same power system for i) two solar farms operating as PV-STATCOMs, and ii) a solar farm as PV-STATCOM and an inverter based wind farm with similar STATCOM controls. This novel utilization of PV solar farm asset can thus improve power transmission limits which would have otherwise required expensive additional equipment such as, series/shunt capacitors, or separate Flexible AC Transmission System (FACTS) Controllers.

Novel control of a PV solar system as STATCOM (PV-STATCOM) for preventing instability of induction motor load

This paper presents a new control of PV solar system as a STATCOM, termed PV-STATCOM, for faster post-fault voltage recovery, thereby avoiding the voltage instability of a neighboring critical induction motor load. Distributed Generators (DGs), such as PV solar systems, are typically required to disconnect upon detection of fault according to the current grid code of DG interconnection. Although, the preferred industry trend is to allow them to remain connected with Low Voltage Ride Through (LVRT) capabilities. In this paper, a case study is presented where an induction motor close to a PV solar system becomes unstable due to slow post fault voltage recovery. A fast fault detection control strategy is utilized in the PV solar system to disconnect the PV solar panels and convert the PV solar system inverter into a STATCOM, thereby providing rapid reactive power support to stabilize the voltage. This novel control strategy of utilizing the PV solar farm temporarily as a STATCOM after the fault prevents a critical induction motor from becoming unstable.

PSCAD/EMTDC model of a 3-phase grid connected photovoltaic solar system

Photovoltaic (PV) solar farms are being increasingly utilized for producing energy, worldwide. To integrate such solar farms with the grid, a thorough technical study is required in terms of their impact on system voltage, power quality, response to faults and short circuit contributions, etc. These studies require a complete modeling of the PV solar system in an electromagnetic transient software environment like PSCAD/EMTDC. This paper presents a PSCAD/EMTDC model of PV solar panels, the grid connected three phase voltage sourced inverter (VSI) and its controller system. The VSI control is implemented with current control loops. A maximum power point tracking (MPPT) algorithm is implemented to get the maximum output power for any given solar irradiation and temperature. This is integrated with the inverter control in such a way that the requirement of DC-DC converter is eliminated to harvest the maximum power. The inverter model also maintains near unity power factor regardless of the level of power output and maintains an acceptable level of current harmonics. Finally, the developed model is validated with the output of a commercially used PV module.

Novel nighttime application of PV solar farms as STATCOM (PV-STATCOM)

Photovoltaic solar farms generate power only during daytime and remain completely idle during the nights. This paper presents a novel technology of utilizing Photovoltaic (PV) Solar Farms in the nighttime. New controls are developed for the solar farm inverters to operate as STATCOM - a Flexible AC Transmission System (FACTS) Controller, using the entire inverter capacity in the night for accomplishing various power system objectives, such as voltage regulation, improvement of power transfer capacity, load compensation, etc. During the daytime, the same objectives can be achieved to a substantial degree with the inverter capacity remaining after real power generation. This technology is termed PV-STATCOM. Two novel applications of solar farms operating as PV-STATCOM in realistic transmission and distribution systems are presented in this paper. These are : i) Improving power transfer capacity of transmission lines.; and ii) Increasing the connectivity of neighbouring wind farms.

Bibliography of FACTS applications for grid integration of wind and PV solar power systems: 1995–2010 IEEE working group report

This paper presents the Bibliography of Flexible AC Transmission System (FACTS) applications for grid integration of wind power systems and PV solar power systems during the period 1995 to 2010. It provides a listing of various journal and conference papers in this area.

Harmonic Impact of a 20-MW PV Solar Farm on a Utility Distribution Network

This paper presents one of the first studies of the harmonic impact of a significantly large photovoltaic (PV) solar farm of 20 MW in a utility distribution system. This solar farm is a constituent of the 80-MW PV solar farm in Sarnia, Ontario, which is so far the largest solar farm in Canada. The utility network is modeled in detail using the commercial grade PSCAD/EMTDC software, which is validated through load flow studies conducted by CYME software and correlated with SCADA measurements. The validated network model is used for network resonance study and harmonics impact analysis of the solar farms under different network conditions. The harmonics data instrumented for several months were provided by the transmission utility at the two solar farm units and at the main feeder substation. These data were utilized for extensive harmonic impact studies with widely different short-circuit levels and network resonance conditions. This paper presents the detailed procedure adopted for performing such harmonic impact studies. It is concluded that this large solar farm may not cause any substantial voltage distortion on the distribution network during steady-state operating conditions. However, recommendations are made for utilities to perform such studies to ensure the safe operation of critical loads.

Technique for Fast Detection of Short Circuit Current in PV Distributed Generator

This paper proposes a new fast technique, in which the slope of a photovoltaic (PV) inverter current is utilized to predict if the current is expected to exceed its rated value due to any grid faults. Two applications of this technique are demonstrated. In jurisdictions where grid codes require distributed generators (DGs) to disconnect after a fault occurrence, such as in Ontario, Canada, this technique is utilized to rapidly disconnect the PV solar system even before the inverter short circuit current actually exceeds the rated current of the inverter, thereby obviating the problem of any adverse short circuit current contribution into the grid. However, in regions where grid codes require DGs to stay connected and provide grid support, such as low-voltage ride through, this technique can be used to rapidly and autonomously transform the PV solar farm into a dynamic reactive power compensator STATCOM (termed PV-STATCOM) for providing voltage support function. In this paper, the PV-STATCOM is used to stabilize a critical induction motor load in the vicinity of the solar farm, which would have otherwise become unstable due to the grid fault. PSCAD-based simulation studies are performed on a realistic distribution network to demonstrate the effectiveness of this technique.

Bibliography of FACTS 2013–2014: IEEE working group report

This paper presents the Bibliography of FACTS technology for 2013-2014. This Bibliography includes papers published in the latter part of 2013 which were not available at the time of submission of the previous years Bibliography paper, and those published until the submission of this Bibliography paper in November 2014. This Bibliography has been prepared by searching through various resources such as IEEE Xplore CIGRE, Engineering Village, Scopus and others. About 60% of papers are obtained from IEEE Xplore and the remaining are from other resources. Due to page limitation, a small selection of journal papers only are included in this Bibliography paper. All the remaining journal papers and conference papers of the comprehensive Bibliography are being made available through the website of the Working Group 15.05.17.

Bibliography of FACTS 2012–2013: IEEE working group report

This paper presents the Bibliography of FACTS technology for 2012. It provides a listing of various journal and conference papers in this area. This Bibliography includes papers published until November 2012.This paper presents the Bibliography of FACTS technology for 2012-2013. It provides a listing of various journal and conference papers in this area. This Bibliography includes papers published until November 2013.

Bibliography of FACTS 2011: Part II IEEE Working Group report

This paper presents the second part of the Bibliography of FACTS technology for 2011. It provides a listing of various journal and conference papers in this area. This Bibliography includes papers published until November 2011. If this paper is granted revise and resubmit status, the Working Group will update this bibliography to include all papers published till the end of year 2011 and make it more complete.