Optimum Operation of Virtual Power Plant

Akshay Jamdade^*
*Correspondence: Akshay Jamdade, Department of Electrical Engineering, Delhi University, Delhi, India, Email:

Keywords

Renewable energy • Resource • Power plant • Solar energy

Introduction

The tricky thing about the power grid is that supply and demand have to match in real-time or else frequency and voltage can deviate and this can damage devices and lead to blackouts [1]. The grid itself has no ability to store power, so the incoming power supply and outgoing power consumption need to be controlled in a way that it maintains the balance. To point blank this concern, renewable energy sources like solar, hydro, wind energy posses an alternative to fossil fuel with clean and green energy generation. These sources comes with another concern of variable output nature, with integration with grid, there are few controlling points. Integration of such REs with energy storage system and maximum control proves to be liable solution [2]. Virtual power plant can be defined in many ways, one of which is that it is a cloud-based distributed power plant that aggregates the capacities of heterogeneous Distributed Energy Resources (DER) for the purposes of enhancing power generation, as well as trading or selling power on the electricity market. DG technologies (including RES) have undergone many enhancement, to facilitate these enhancements and outweigh the injected challenges, VPP stands as a solution [3]. It makes use of information collected from its entities and uses that information to form a stable, technically feasible, economically viable, environment friendly power grid. As the name suggests, VPP is digital and not a physical entity like the actual grid but works in tandem with the existing electric grid. VPP maximizes the energy harvesting process from the renewable resource.

New technologies were created and research was done in order to increase the overall effectiveness of RES. The majority of DG units are deployed in distribution networks today at low and medium voltage levels [4]. New issues are emerging, such as a shift in the power flow, as a result of the stochastic nature of RES and the large number of installed DG. Assistants at the Otto-Von Guericke university in Magdeburg, Germany, are Pio Lombardi, Michal Powalko and Krzysztof Rudion. These tasks include power system balancing, frequency control and overvoltages prevention. The introduction of innovative solutions, including as Energy Storage Systems (ESS), Network Security Management systems (NSM), and virtual power plants, was made in an effort to balance the production and consumption of energy [5].

In this project, VPP is constructed using solar, wind, fossil fuel and battery integrated to agrid operating in multiple modes based on the l oad profile.

Literature Review

The idea of VPPs was initiated in 2003 by K. Dielmann and Alwin van der Velden in 2003 and through about 16 years from 2003 to 2019, a lot of ideas discussed the perspective of VPPs as a future energy generation source. K. Dielmann et al. started their VPP idea from the point of view of the electric international market, energy must be provided so that it is as low priced and reliable as possible [6]. The most important factor to the success of a VPP is its use in the open energy market; adaptation must be made for the electric coupling of the VPP and above all the voltage and frequency performance, as well as the reliability aspects must be examined further. Integrated distributed energy resources include all renewable energy systems, intermittent renewables, photovoltaic systems, wind systems, power small and micro-units, hydro and small hydro power plants, some of thermal systems and Combined Heat and Power plants (CHP). Also, Energy Storage Systems (ESSs) and special loads can be integrated with DERs to form VPPs. ESSs include: Embedded energy storage, pumped storage power plant, and battery switch stations [7].

The special loads like: Electric vehicles, aggregated thermostatically controlled loads etc. VPPs comprise of four basic components: Generation technology (dispatchable power plants, and stochastic generating units), energy storage technologies, dispatchable and flexible loads and information communication technology. Modelling of VPPs and its components take different approaches and scenario.

Virtual Power Plant (VPP) is a term used for aggregation of Distributed Energy Resources (DERs) in order to make them appear as a single, larger power plant. When the VPP also includes storage and demand response capabilities, it allows variable renewable energy sources, such as wind and solar Photovoltaic (PV) power, to act as a large dispatchable power plant. Amongst other REs Wind power stands as an immeasurable power in the world intensely attracts the attention of planners of power distribution networks [8]. WT technologies are extremely promoting to better and better technologies so that they are able to alter the wind power to electricity power with higher efficiency. ESSs are utilized to preserve the excess energy and to release it in order to supply the energy demands of customers in the moments when the demand is high. Studies in solar energy have upscaled REs contribution to the system one of which is presented by S.A. Keshuov et al. in 2018 where he studied voltage stability while integration of solar power plant while integrating it with distribution network [9]. The added value of solar energy and wind energy is been discussed by Despina Koraki et al. in 2018. Energy storage technologies like Pumped Hydro Storage (PHS), Compressed Air Energy Storage (CAES), Battery Energy Storage System (BESS), Flow Battery Energy Storage System (FBES) enhances the integration of REs with grid. These systems are flexible and can be designed for various applications like EMS for high altitude and pumping stations as described.

The rapid growth of large-scale renewables and Distributed Energy Resources (DER) leads to increased uncertainty and reduced controllability of energy generation. Thus, control of demand is becomes more necessary to maintain network energy balancing. Individually these devices are often too small to operate in the electrical markets and operated individually can have negative impact on the local network [10]. The fast growing penetration of Distributed Energy Resources (DER) and the continuing trend towards a more liberalized electricity market requires more efficient energy management strategies to handle both emerging technical and economic issues [11]. Thus for energy management, VPP is designed by using stochastic programming and stochastic robust models followed by other mathematical models for control, hydraulics etc by Yu.V. Monakov et al. in 2018. From economical point of view various market trends, characteristics and demands from the Medium Term Market (MTM) to the Real Time Market (RTM) with different target of VPP in the Energy Market (EM) and Ancillary Service Market (ASM) are discussed by Xue Jin et al. in 2018. In 2010, K. El Bakari et al. highlighted the advantages of the VPP taking major technical, economical and regulatory aspects in an adaptive power system which stands true even after a decade [12].

Discussion

Problem identification

From the above literature review, two main challenges can be revealed. These are discussed in the following. From a carbon offset point of view, more and more renewables need to be merge into the grid, which are intermittent and variable in nature Integration of REs is inevitable for transition to clean affordable sustainable energy. As more renewable generation comes onto the grid, a few things happen [13]. Reduced control: Generation can't be as easily turned up to follow demand and its ill advised to turn down the energy generated or else this clean energy generated will be lost framing a setback for the transition towards clean energy. Uncertainty: Generation can't be forecast precisely, and it can change quickly. This rapid change is hard to predict and it takes a heavy toll on the grid contributing Intermittency: Due to its intermittency, renewables can’t be considered as a dispatchable power source and never can be a base load as well, unless there is a massive energy storage option. As a result, the practice adopted by the grid operator is to give priority to renewable sources whenever it is available and regulate the production of dispatchable sources.

As more and more renewables, especially solar PV systems, are getting installed, the grid operators find it difficult for its integration [14]. To a greater extent the energy storage systems will overcome the challenges mentioned above. But the grid integration for the energy storage systems particularly for the decentralized systems (for business units and households) have got its own practical difficulties to implement. Due to the same, there is a good chance that the system can waste the generated power during low demand (Table 1) [15].

Table 1. Sustainable solutions for these challenges thus became crucial.

Conclusion

Energy Storage technologies like Pumped Hydro Storage (PHS), Compressed air energy storage (CAES), Battery Energy Storage System (BESS), Flow Battery Energy Storage system (FBES) enhances the integration of REs with grid. These systems are flexible and can be designed for various applications like EMS for high altitude and pumping stations as described. As more and more renewables, especially Solar PV systems, are getting installed, the grid operators find it difficult for its integration. To a greater extent the energy storage systems will overcome the challenges mentioned above. But the grid integration for the energy storage systems particularly for the decentralized systems (for business units and households) have got its own practical difficulties to implement.

References

1. Zhu, Z Q and Jiabing Hu. "Electrical Machines and Power�Electronic Systems for High�Power Wind Energy Generation Applications: Part II-Power Electronics and Control Systems." Int J Comput Math Electr Electron Eng 1 (2013): 34-71.

   [Crossref] [Google Scholar]

2. Song, Yantao, and Bingsen Wang. "Survey on Reliability of Power Electronic Systems." IEEE Trans Power Electron 1 (2012): 591-604.

   [Crossref] [Google Scholar]

3. Zare, Firuz. "EMI issues in Modern Power Electronic Systems." The IEEE EMC Soc Newsletters 221 (2009): 53-58.

   [Google Scholar]

4. Carrasco, Juan Manuel, Leopoldo Garcia Franquelo, Jan T Bialasiewicz and Eduardo Galvan, et al. "Power-Electronic Systems for the Grid Integration of Renewable Energy Sources: A Survey." IEEE Trans Indus Electron 4 (2006): 1002-1016.

   [Crossref] [Google Scholar]

5. Emadi, Ali, Sheldon S Williamson and Alireza Khaligh. "Power Electronics Intensive Solutions for Advanced Electric, Hybrid Electric, and Fuel Cell Vehicular Power Systems." IEEE Trans Power Electron  3 (2006): 567-577.

   [Crossref] [Google Scholar]

6. Cottet, Didier, Uwe Drofenik and Jean-Marc Meyer. "A Systematic Design Approach to Thermal-Electrical Power Electronics Integration." Electron Syst Integr Technol Confer 219-224. IEEE (2008).

   [Crossref] [Google Scholar]

7. Rosero, J A, J A Ortega, E Aldabas and L A R L Romeral. "Moving Towards a More Electric Aircraft." IEEE Aerosp Electron Syst Mag  3 (2007): 3-9.

   [Crossref] [Google Scholar]

8. Wang, Cheng, Wei Wei, Jianhui Wang and Feng Liu, et al. "Robust Defense Strategy for Gas-Electric Systems against Malicious Attacks." IEEE Trans Power Syst  4 (2016): 2953-2965.

   [Crossref] [Google Scholar]

9. Abourida, Simon, Christian Dufour, Jean Bélanger and Guillaume Murere, et al. "Real-Time PC-Based Simulator of Electric Systems and Drives." Appl Power Electron Confer Exposit  1, 433-438. (2002).

   [Google Scholar]

10. Lauss, Georg, Felix Lehfu, Alexander Viehweider and Thomas Strasser. "Power Hardware in the Loop Simulation with Feedback Current Filtering for Electric Systems." Annu Confer Indus ElectronSoc 3725-3730. 2011.

    [Crossref] [Google Scholar]

11. Ni, Kai, Yongjiang Liu, Zhanbo Mei and Tianhao Wu, et al. "Electrical and Electronic Technologies in More-Electric Aircraft: A Review." IEEE Access 7 (2019): 76145-76166.

    [Crossref] [Google Scholar]

12. Sulligoi, Giorgio, Andrea Vicenzutti and Roberto Menis. "All-Electric ship Design: From Electrical Propulsion to Integrated Electrical and Electronic Power Systems." IEEE Trans Transp Electr 2 (2016): 507-521.

    [Google Scholar]

13. Mummadi, Veerachary and Bala Sudhakar Singamaneni. "Stability Analysis of Cascaded DC-DC Power Electronic System." IEEJ Trans Electr Electron Eng 6 (2009): 763-770.

    [Crossref] [Google Scholar]

14. Hischier, Roland, Patrick Wager and Johannes Gauglhofer. "Does WEEE Recycling Make Sense from an Environmental Perspective? The Environmental Impacts of the Swiss take-back and Recycling Systems for Waste Electrical and Electronic Equipment (WEEE)." Environ Impact Assess Rev  5 (2005): 525-539.

    [Crossref] [Google Scholar]

15. Moriya, Tohru and Tetsuya Takimoto. "Anomalous Properties Around Magnetic Instability in Heavy Electron Systems." J Phys Soc Japan  3 (1995): 960-969.

    [Crossref] [Google Scholar]