The Significance of Modeling Power Supply in Wind Energy Generation - Report Example

Name: University: Instructor: Date: Research Question What is the significance of Modelling Power Supply in Wind Energy Generation? Literature review Increasing the penetration levels of wind power to scores of power systems of nations as well as regions has resulted in the amplification of certain technical requirements for big wind farms connection, normally as grid codes’ element distributed by the TSOs (transmission system operators). According to Tsili and Papathanassiou (328), requirements for grid code has been the key motivating factor for the recent Wind Turbine Technology development and has been reviewed by a number of studies. Until now, the compatibility of wind turbine to the different requirements of grid code is recognized only by means of simulations or specific tests, which are carried out by the independent laboratories or manufacturers when demanded by the system operators. As stated by Tsili and Papathanassiou (328), standardized-type tests are yet to be created, because of the requirements diversity emerging in grid codes as well as the moderately inadequate utilization time. As mentioned by Merino, Veganzones and Sanchez (2352), there is a growing anciety concerning environmental issues as well as the scarcity and increasing fossil fuels’ costs have stimulated an increasing attention in massive integration of power systems as well as utilization of renewable energy sources. Basically, islands-based electrical grids are exceedingly suitable for the installing renewable sources in large scale considering that the cost of transporting fossil fuels to these islands is exceedingly high and also shipping results in emissions of greenhouse gases; further creating environmental challenges (Merino, Veganzones and Sanchez 2352). So generating power through wind turbines is very important for all regions including islands. Wind turbines have increased power generation and as a result, they have turned out to be the main choice for MW-scale turbines nowadays. At first, the concept of a variable-speed wind turbine with induction generator that is doubly fed as well as rotor circuit’s partial-scale back-to-back converter was very popular. This according to Adzic, Ivanovic and Adzic (132) was attributed to the fact that the partial-scale power converter was basically just 30 per cent of the electrical grid’s power. Economically, this appears lucrative; bearing in mind that the power electronics equipment cost has recently reduced tremendously. This in consequences, places the configuration of the wind turbine with a full-scale back-to-back converter as well as squirrel-cage induction generator foremost in the plan. This configuration is beneficial according to Adzic, Ivanovic and Adzic (132) because it promotes the utilistaion of robust as well as standard induction generator. Essentially, wind turbines are functional in the areas with lowest atmospheric boundary layer (ABL). In consequence, wakes behind the wind-turbine are impacted by the similar factors affecting the turbulent boundary layer, such as thermal stratification (Zhang, Markfort and Porté-Agel 162). Despite the crucial developments achieved in the wind turbines’ aerodynamic design, Zhang, Markfort and Porté-Agel (162) posit that the turbines multifaceted interaction with the ABL’s highly turbulent flow is yet to be comprehended. Comprehensive details concerning the properties of wind-turbine wake, which includes turbulence structures as well as mean flow characteristics, is crucially important for maximizing wind farms’ energy production, wind-turbine siting optimisation, as well as making certain wind turbines’ structural integrity during the wind-farm projects’ planning of (Zhang, Markfort and Porté-Agel 162). Presently, SEIGs (Self-Excited induction generators) are widely utilised in rural small power plants due to their various beneficial features as compared to synchronous generators. According to Haque (265), SEIG is different from the grid-connected induction generator since its frequency as well as the voltage is not constant. This in consequence makes SEIG analysis much more complex as compared to the analysis of the grid-connected generator. Since the urgency of both ecological pollution as well as energy crisis is growing, Huang, Mao and Lu (7731) posit that there is a growing need in search for alternative sources of fuel that are eco-friendly, clean, as well as reproducible. Echoing Tsili and Papathanassiou sentiments, Huang, Mao and Lu (7731) claim that wind power provides the most favourable economic as well as technical prospects as an alternative fuel source, and is currently growing fast as compared to other sources of renewable energy such solar and geothermal. The benefit of utilising DFIG in wind turbines according to Suganya and Rengarajan (2861) are rooted in the four-quadrant control of reactive as well as real power flow, low c cost of conversion, adjustable speed operation, as well as low power loss compared in contrast to other techniques. In their study, Huang, Mao and Lu (7731) highlight two types of wind power generators that are utilised in wind farms, DFIGs (doubly fed induction generators) as well as D-PMSGs (directly steered wind turbines integrated with permanent magnet synchronous generators). In this case, D-PMSG has drawn more attention in generating wind energy because of its benefits like higher energy yield, reliability and efficiency, inferior mechanical consumption, well as easier maintenance in contract to DFIGs (Huang, Mao and Lu 7731). Presently, as mentioned by Leon, Farias and Battaiotto (1609) new wind farms appear to utilise DFIG, or PMSG (permanent magnet synchronous generators) integrated to the grid that has a back-to-back converter. Still, more than 50% of the modern wind farms are anchored on squirrel-cage induction generators (SCIG, which are connected directly to the grid. For this reason, STATCOMs (Static Compensators) based solutions are largely utilised so as to enable the wind farms to adhere to the latest challenging standards. Consequently, it regulates its reactive power consumption, enhances the stability of wind farm, as well as controls the PCC’s (point of common coupling) voltage amplitude. Furthermore, the incremental reliability advantage offered by power system’s wind generation lessens as the wind generation penetration increases, and this is because of the poor or negative relationship between the wind generation pattern as well as the related peak energy demand (Maisonneuve and Gross 2286). Besides that, as mentioned by Abdullah, Muttaqi and Agalgaonkar (1467) the inadequate wind resources in a geographical area that the electricity network covers is the main obstacle to wind generation growth in power systems. In United States, a number of states have chosen certain projects from the possible wind supply sources as well as other sources of renewable energy and placed them into Independent System Operators, Regional Transmission Organizations, as well as utilities’ generation interconnection queues. The abovementioned projects according to Osborn, Henderson and Nickell (62) is a response to the bids by utilities unaided or by ISO or RTO members in obtaining wind energy so as to achieve their targets. So as to achieve maximum wind power, Wu and Wang (690) assert that the Maximum power point tracking (MPPT) technique is useful for the grid-connected wind power generation system’s conversion interface. Wu and Wang (690) further claim that the majority of the MPPT technologies like maximum power extraction algorithm, fuzzy logic algorithm , mountain climb technique, perturbation and observation method (IP&O), as well as neural networks method have widely been proposed and utilised. But of the five, IP&O is the most widely utilised, however, it needs no less than two signals of detected currents or voltages so as to calculate the power generated. As mentioned by Joshi, Sandhu and Bansal (245) in their study, induction generators for wind generation integrated with cage rotor are appropriate for converting wind energy because of their benefits like rugged as well as simple design, economical and does not need synchronization with current grid. Such generators according to Joshi, Sandhu and Bansal (245) can function either in the self-excited or the grid-connected mode, as evidenced in the Haque study. Numerous induction generators for wind generation are used in parallel in regions with abundant natural resources so as to allow for full utilisation. Literature on wind power generation is immense, and this has made a number of scholars review the various generation techniques that can be used to achieve wind power. In Kamn paper, he presents the validation as well as applications of the Type-3 wind generation unit ‘steady-state sequence-frame model, the three-phase power-flow algorithm computational efficiency, large distribution networks power-flow solver feasibility, three-phase transformers having varying connections. According to Kamh (47) success can be achieved if the type-3 created model considers every feature of the control as well as its power-electronic converters' operating limits under either unbalanced or balanced grid conditions. This is always evidenced in Ríos and Guevara who established that the electronic compensation systems connection considerably enhanced the fixed-speed wind farms’ transient response in addition to its capability to maintain supply continuity counter to the three-phase voltage sags. In this case, the obtained DVR connection results indicate that although the fixed-speed wind farm’s transient response is improved, not all rigorous as well as current criteria is met in order to maintain supply continuity. For this reason, Ríos and Guevara (345) suggest that it is imperative to analyse other topologies of the DVR together with its control strategy in order to understand their impact on wind farms transient response counter to three-phase voltage sags. According to Abo-Khalil (134) electrical energy produced from wind power may be exceedingly inconstant at numerous differing timescales: seasonally, daily, or hourly. Still, the supply of wind is continuous, and so, it is a reliable energy source since it is constant available. There exists yearly variation, but the impact is not considerable, and akin to other sources of electricity, wind energy has to be scheduled. In this case, according to Abo-Khalil (134) forecasting techniques for wind power are utilised, but wind plant output predictability is always low for temporary operation. Since immediate power generation as well as consumption have to be balanced so as to maintain stability of the grid, the wind variability can in consequence lead to major challenges while integrating wind power (in large amounts) to the grid system. As stated by Amuthan, Mary and Subburaj (230), due to the green technologies revolution, wind power is developing hastily. Based on the current scenario about the wind, Amuthan, Mary and Subburaj (230) argue that power quality should be controlled, given that both the wind farm and load output vary in the daytime and the utilisation of power storage can reduce reactive as well as real power imbalance within the power system network. For this reason, during a network unbalance the general DFIG system operation may be enhanced by co-ordinately controlling the parallel grid-side converter as well as rotor-side converter. According to Yao, Li and Chen (2543) by co-ordinately controlling the series grid-side converter, the parallel grid-side converter and the rotor-side converter, the DFIG system integrated with series grid-side can handle the low voltage ride through (LVRT) operation under severely unsymmetrical as well as symmetrical network unbalance or grid faults in steady-state operation. The existing literature in the SEIG area has mainly concentrated on three notable areas. Firstly, as indicated by Farrag and Putrus (279), are the isolated self-excited operation characteristics of the induction generators for wind power generation. Another area is the capacitance selection needed for self-excitation as well as machine terminal voltage build-up. This according to Farrag and Putrus is discussed for two distinct topologies; a fixed capacitor whose connecting with the machine stator winding is in series or a reactive power compensator that is connected to the machine terminals. In this case, according to Farrag and Putrus (279), the reactive power is regulated in order to support the terminal voltage of the machine counter to the variations of the load. The last widely studied are is controlling the ballast load wherein the needed reactive power is achieved through fixed capacitors connection across the stator terminals of the SEIG. To sum up, the contemporary power system structure as indicated by Hossain, Pota and Mahmud (74) is turning out to be more and more complex with the intention of making energy economically accessible with less greenhouse gas emission through renewable energy sources such as wind. Recently, the demand for power has substantially increased despite the fact that the power transmission lines expansion has sternly been inadequate because of the environmental limitations as well as insufficient resources. Therefore, a number of transmission lines are loaded heavily and the stability of the system has turned out to be a limiting factor for power transfer. For this reason, wind generators are crucially important for generating power to meet the ever increasing demand. Work Cited Abdullah, Md. Abu, et al. "New approach for sharing wind generation spatial diversification in multi-area power systems using trade-off analysis." IET Generation, Transmission & Distribution 8.8 (2014): 1466–1478. Abo-Khalil, Ahmed G. "Impacts of Wind Farms on Power System Stability." Muyeen, S. M., Ahmed Al-Durra and Hany M. Hasanien. Modeling and Control Aspects of Wind Power Systems. Rijeka, Croatia: InTechOpen, 2013. 134-151. Adzic, Evgenije, et al. "Maximum Power Search in Wind Turbine Based on Fuzzy Logic Control." Acta Polytechnica Hungarica 6.1 (2009): 131-149. Amuthan, N., et al. "Ride-through and direct model reference adaptive internal model controller with rule-based adjustment mechanism for DFIG wind farms." International Journal of Sustainable Energy 31.4 (2012): 229–250. Farrag, Mohamed E. A. and Ghanim A. Putrus. "Analysis of the Dynamic Performance of Self-Excited Induction Generators Employed in Renewable Energy Generation." Energies 7 (2014): 278-294. Haque, M. H. "Analysis of a Self-Excited Induction Generator With P–Q Load Model." IEEE TRANSACTIONS ON ENERGY CONVERSION 25.1 (2010): 265-267. Hossain, M. J., et al. "Investigation of the Impacts of Large-Scale Wind Power Penetration on the Angle and Voltage Stability of Power Systems." IEEE Systems Journal 6.1 (2012): 76 - 84 . Huang, Hui, et al. "Electronic Power Transformer Control Strategy in Wind Energy Conversion Systems for Low Voltage Ride-through Capability Enhancement of Directly Driven Wind Turbines with Permanent Magnet Synchronous Generators (D-PMSGs)." Energies 7 (2014): 7730-7347. Joshi, Dheeraj, K.S. Sandhu and R.C. Bansal. "Steady-state analysis of self-excited induction generators using genetic algorithm approach under different operating modes." International Journal of Sustainable Energy 32.4 (2013): 244–258. Kamh, Mohamed Zakaria. "Three-Phase Steady-State Model of Type-3 Wind Generation Unit—Part II: Model Validation and Applications." IEEE TRANSACTIONS ON SUSTAINABLE ENERGY 3.1 (2012): 41-48. Leon, Andres E., et al. "Control Strategy of a DVR to Improve Stability in Wind Farms Using Squirrel-Cage Induction Generators." IEEE TRANSACTIONS ON POWER SYSTEMS 26.3 (2011): 1609- 1617. Maisonneuve, N. and G. Gross. "A production simulation tool for systems with integrated wind energy resources’,." IEEE Transactions on Power Systems 26.4 (2011): 2285–2292. Merino, Julia, et al. "Power System Stability of a Small Sized Isolated Network Supplied by a Combined Wind-Pumped Storage Generation System: A Case Study in the Canary Islands." Energies 5 (2012): 2351-2369. Osborn, Dale, et al. "Driving Forces Behind Wind." IEEE power & energy magazine 9.6 (2011): 60-74. Ríos, Alberto and David Guevara. "Influence of the DVR on the Transient Response of Wind Farms Against Voltage Sags." WIND ENGINEERING 39.3 (2015): 335–348. Suganya, P. and N. Rengarajan. "Enhanced control of variable speed DFIG wind turbine using fuzzy logic controller." Journal of Intelligent & Fuzzy Systems 26 (2014): 2861–2872. Tsili, M. and S. Papathanassiou. "A review of grid code technical requirements for wind farms." IET Renewable Power Generation 3.3 (2009): 308–332. Wu, Jinn-Chang and Yao-Hui Wang. "Power conversion interface for small-capacity wind power generation system." IET Generation, Transmission & Distribution 8.4 (2015): 689–696. Yao, Jun, et al. "Coordinated Control of a DFIG-Based Wind-Power Generation System with SGSC under Distorted Grid Voltage Conditions." Energies 6 (2013): 2541-2561. Zhang, Wei, Corey D. Markfort and Fernando Porté-Agel. "Wind-Turbine Wakes in a Convective Boundary Layer: A Wind-Tunnel Study." Boundary-Layer Meteorol 146 (2013): 161–179. Read More

Comprehensive details concerning the properties of wind-turbine wake, which includes turbulence structures as well as mean flow characteristics, is crucially important for maximizing wind farms’ energy production, wind-turbine siting optimisation, as well as making certain wind turbines’ structural integrity during the wind-farm projects’ planning of (Zhang, Markfort and Porté-Agel 162). Presently, SEIGs (Self-Excited induction generators) are widely utilised in rural small power plants due to their various beneficial features as compared to synchronous generators.

According to Haque (265), SEIG is different from the grid-connected induction generator since its frequency as well as the voltage is not constant. This in consequence makes SEIG analysis much more complex as compared to the analysis of the grid-connected generator. Since the urgency of both ecological pollution as well as energy crisis is growing, Huang, Mao and Lu (7731) posit that there is a growing need in search for alternative sources of fuel that are eco-friendly, clean, as well as reproducible.

Echoing Tsili and Papathanassiou sentiments, Huang, Mao and Lu (7731) claim that wind power provides the most favourable economic as well as technical prospects as an alternative fuel source, and is currently growing fast as compared to other sources of renewable energy such solar and geothermal. The benefit of utilising DFIG in wind turbines according to Suganya and Rengarajan (2861) are rooted in the four-quadrant control of reactive as well as real power flow, low c cost of conversion, adjustable speed operation, as well as low power loss compared in contrast to other techniques.

In their study, Huang, Mao and Lu (7731) highlight two types of wind power generators that are utilised in wind farms, DFIGs (doubly fed induction generators) as well as D-PMSGs (directly steered wind turbines integrated with permanent magnet synchronous generators). In this case, D-PMSG has drawn more attention in generating wind energy because of its benefits like higher energy yield, reliability and efficiency, inferior mechanical consumption, well as easier maintenance in contract to DFIGs (Huang, Mao and Lu 7731).

Presently, as mentioned by Leon, Farias and Battaiotto (1609) new wind farms appear to utilise DFIG, or PMSG (permanent magnet synchronous generators) integrated to the grid that has a back-to-back converter. Still, more than 50% of the modern wind farms are anchored on squirrel-cage induction generators (SCIG, which are connected directly to the grid. For this reason, STATCOMs (Static Compensators) based solutions are largely utilised so as to enable the wind farms to adhere to the latest challenging standards.

Consequently, it regulates its reactive power consumption, enhances the stability of wind farm, as well as controls the PCC’s (point of common coupling) voltage amplitude. Furthermore, the incremental reliability advantage offered by power system’s wind generation lessens as the wind generation penetration increases, and this is because of the poor or negative relationship between the wind generation pattern as well as the related peak energy demand (Maisonneuve and Gross 2286). Besides that, as mentioned by Abdullah, Muttaqi and Agalgaonkar (1467) the inadequate wind resources in a geographical area that the electricity network covers is the main obstacle to wind generation growth in power systems.

In United States, a number of states have chosen certain projects from the possible wind supply sources as well as other sources of renewable energy and placed them into Independent System Operators, Regional Transmission Organizations, as well as utilities’ generation interconnection queues. The abovementioned projects according to Osborn, Henderson and Nickell (62) is a response to the bids by utilities unaided or by ISO or RTO members in obtaining wind energy so as to achieve their targets.

So as to achieve maximum wind power, Wu and Wang (690) assert that the Maximum power point tracking (MPPT) technique is useful for the grid-connected wind power generation system’s conversion interface.

Read More