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This paper presents a comprehensive testing, validation and installation plan for a new technology which utilizes PV solar farm as a STATCOM both during nighttime and daytime. This technology is termed PV-STATCOM. It will be utilized in the night for power factor correction and voltage control at the terminals of an induction motor operating at poor power factor. During daytime, the same objectives will be accomplished together with production of real power from solar insolation, by utilizing the inverter capacity remaining after real power generation. The local distribution company London Hydro is implementing this new technology, for the first time in Canada, on a 10 kW solar system to be installed on the rooftop of their headquarters building in Spring 2012. The proposed new control on PV solar system will help increase the utilization of the PV solar system, improve overall electrical system performance and provide a potential of additional revenue earning for solar system for providing the above services, both during night and day. [ABSTRACT FROM PUBLISHER]

This paper presents a study for determining the maximum amount of PV solar generation that can be connected in a 27.6 kV feeder of a distribution utility - London Hydro. Various factors such as steady state voltage rise, Temporary Over Voltage (TOV), short circuit current and harmonic contributions, that could potentially constrain DG connectivity are investigated. Load flow studies with PSS/E and electromagnetic transient simulation studies with EMTDC/PSCAD software are utilized for performing the above investigations. It is shown that harmonic amplification due to network resonance could potentially be the limiting factor for PV solar connectivity in this distribution feeder. This paper also makes a case that the conventional Connection Impact Assessment (CIA) studies for DG connections need to be made broader to include such harmonic aspects. [ABSTRACT FROM PUBLISHER]

In this paper, the impact of large-scale penetration of distributed generation (DG) system in the presence of non-linear loads is addressed. The effect of different DG penetration levels on the grid side current harmonics is examined. It is found that current harmonics generated by downstream non-linear loads with a TDD (total demand distortion) that is compliant with IEEE Standards can lead to significantly high THD (total harmonic distortion) values at the grid side under certain loading scenarios. These low magnitude highly distorted currents may cause protection circuitry and grid-synchronizing circuitry malfunctioning, and may even cause a resonance condition with power factor correction capacitor on the network. This paper further presents a control application of Photovoltaic (PV) solar plant based DG inverter o mitigate the above harmonics problem. The increased harmonic level issue and the application of PV solar plant to mitigate such problem have been demonstrated both by MATLAB/ SIMULINK simulation studies and laboratory experimental results. [ABSTRACT FROM PUBLISHER]

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. [ABSTRACT FROM PUBLISHER]

The connection of Distributed Generation (DG) to the distribution system can be limited by factors such as steady state voltage rise, temporary over voltage (TOV) during single line to ground (SLG) faults and other limits defined by the utility. The installation of a Static Var Compensator (SVC) on a distribution feeder can increase the allowable DG penetration by addressing the above mentioned limiting factors. This paper examines the benefits of using a SVC with a novel controller modification to improve TOV reduction while substantially increasing the amount of wind based generation connected to a distribution feeder. Studies are performed in EMTDC/PSCAD on a real distribution feeder located in Ontario, Canada with a desired target of connecting 20MW of wind based generation. [ABSTRACT FROM PUBLISHER]

Series compensation is being increasingly considered for increasing transmission capacity for integration of large wind farms. This paper presents the potential of subsynchronous resonance (SSR) in large squirrel cage induction generator based wind farms connected to the series compensated transmission line. In order to suppress the unstable SSR oscillations, a STATCOM with suitable controller is proposed at the terminal of the wind farm. A detailed linear state space model is developed for the wind farm, transmission system which is a modified IEEE First SSR Benchmark system and the STATCOM. Eigenvalues are calculated for a wide range of wind farm power outputs and series compensation levels. The potential of SSR involving both induction generator effect and torsional interaction is investigated in-depth. The eigenvalues obtained from the linear state space model are validated through the electromagnetic transient simulation carried out with PSCAD/ EMTDC software. It is shown that SSR may potentially occur for large wind farms at higher level of series compensation which can be mitigated by the STATCOM with an appropriate controller. [ABSTRACT FROM PUBLISHER]

This paper presents a Bibliography of High Voltage Direct Current (HVDC) transmission technology for 2009–2010. 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. [ABSTRACT FROM PUBLISHER]

This paper presents the third 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. [ABSTRACT FROM PUBLISHER]

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. [ABSTRACT FROM PUBLISHER]

This paper presents a 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 accepted with revisions, the Working Group will update this bibliography to include all papers published till the end of year 2011 and make it more complete. [ABSTRACT FROM PUBLISHER]

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. [ABSTRACT FROM PUBLISHER]

A thorough analysis of the harmonic characteristics of a feeder in the London Hydro distribution system is presented in this paper. This feeder interconnects several solar photovoltaic (PV) arrays as well as two shunt capacitor banks. Harmonic measurements were acquired over one week at critical locations in the feeder. The analysis highlights higher than expected harmonic distortion levels, though still within limits established in IEEE 519-1992. Harmonics injected by the solar systems are partially additive, contributing approximately 0.1% to the total harmonic distortion (THD) at the feeder terminal. Significant 3rd, 5th, 7th, 9th, 11th, and 13th harmonic levels are discovered. Although the system is not subject to an immediate risk, future addition of inverter-based distributed generation (DG) coupled with possible resonant conditions presents the prospect of a rise in harmonic distortion levels beyond acceptable limits. [ABSTRACT FROM PUBLISHER]

This paper presents the design of a load management device for the load management of a distribution network in presence of Electric Vehicles (EV). With a projected EV penetration of up to 50% by 2050, the life expectancy of already overloaded utility transformers and other network assets needs to be investigated to accommodate large penetration of EV loads. This research work has been done in collaboration with the local utility London Hydro, to create a device that is capable of handling heavy residential loads, and providing network control of loads, such as, EVs to increase better network asset management. Two Atmel microcontroller based hardware boards are used. One hardware board is used to get load information from the utility transformer whereas the other is used to control the EV loads and household appliances. Based on the load information from the transformer, one microcontroller sends control signal to the other controller running on customer premises to switch ON/OFF the EV load or any other appliances thus controlling the load on the network. The main purpose of this device is to automatically reallocate loads in an attempt to prevent damage to overhead residential transformers due to overloading and also offers the capability of reducing consumer energy use. This device when installed in a utility network will reduce cost to the home owner, and will increase network sustainability. [ABSTRACT FROM PUBLISHER]

This papers presents a comprehensive analysis of the potential of sub-synchronous resonance (SSR) in Type-1 wind farms connected to Line Commutated Converter (LCC) based HVDC transmission line. Since series compensated lines are also known to cause induction generator effect SSR in Type 1 wind turbine generators, this paper also considers a series compensated line in parallel with the HVDC line for the investigation of potential SSR. CIGRE Benchmark HVDC system and IEEE First Benchmark system are considered as the study system components. A dynamic model of the study system is developed and linearized at several operating points for eigenvalue analysis of the potential of SSR. A sensitivity study of the SSR modes with respective to variation in different model parameter such as rectifier firing angle, DC line power flow, series compensation level is also reported. It is found that HVDC rectifier station current regulator does not interact with any sub-synchronous modes of the wind turbine generator. Hence, the operation of a Type-1 wind farm connected to series compensated line and HVDC line is may not be subject to SSR issues. However, when the wind farm operates radially with the series compensated line, it may experience SSR oscillation due to induction generator effect. [ABSTRACT FROM PUBLISHER]

This paper presents a real-time digital simulation study of a PV solar system as a STATCOM (PV-STATCOM) on RTDS (Real Time Digital Simulator) in a unique state-of-the-art research laboratory in a utility premise. This PV-STATCOM technology is utilized in the night for power factor correction and voltage regulation at the terminals of an induction motor operating at poor power factor. During daytime, the same objectives will be accomplished together with production of real power from solar insolation, by utilizing the inverter capacity remaining after real power generation. The local distribution company London Hydro is implementing this new technology, for the first time in Canada, on a 10 kW solar system to be installed on the rooftop of their headquarters building in Fall 2012. The proposed new control on PV solar system will help increase the utilization of the PV solar system, improve overall electrical system performance and provide a potential of additional revenue earning for solar farms for providing the above services, both during night and day. [ABSTRACT FROM PUBLISHER]

This paper presents a study of subsynchronous mode instability in Induction Generator (IG) based wind farm connected to a series compensated transmission line. The IEEE First SSR benchmark system is modified by replacing the synchronous generator with an aggregated wind farm. A small signal stability analysis is carried out to detect the instability analytically and then results are validated through a detailed electromagnetic transient simulation using PSCAD/EMTDC. Two types of studies are performed for the small signal analysis. First, a linearized state space model is developed for the eigenvalue calculation. Then, a simple equivalent circuit model is developed for the resonant speed analysis. From the equivalent circuit model, two resonant speeds - upper resonant speed (URS) and lower resonant speed (LRS), are obtained. If the post fault speed of the aggregated generator comes close or enters in the band within these two resonant speeds, the induction generator may become unstable. The performance of the aggregated wind farm model is validated with a distributed wind farm model. It is shown that the wind generator may experience SSR if the fault occurs at the terminals of the wind farm even at a realistic level of series compensation. [ABSTRACT FROM PUBLISHER]