Tidal Wave Energy Research Articles

Observations of waves and currents on the fore-reef and reef flat of a coral reef atoll in the South China Sea

Understanding the wave and current conditions of coral reef ecosystems is essential for maintaining their health, as many reef processes are controlled by these hydrodynamic conditions. In this study, high-frequency measurements of tides, waves, and currents were made using acoustic, electromagnetic, and pressure instruments over a 28-d period on the fore-reef and reef flat of a coral reef atoll in the South China Sea. The research revealed wave transformation, tidal and wave modulation of flow, and wave setup conditions for the first time at this typical atoll. Three large wave processes dominated by gravity waves (GWs) are observed in the fore-reef. The GWs are significantly attenuated on the reef flat, whereas infragravity (IG) waves strengthened. The tidal modulation of GWs and IG waves on the reef flat is significant when the incident wave height exceeded 1 m. In the fore-reef, the modulation of progressive tidal waves and large waves leads to relatively stronger upper-layer currents, and weak near-bottom currents are primarily attributed to the dissipation of tidal wave energy by the rough coral terrain. In calm conditions, flow variations on the reef flat are modulated by tides, thereby allowing seawater flow to pass through the reef flat during spring tides. Conversely, during periods with large waves, tidal modulation of flow on the reef flat is less significant, and the cross-reef flow velocity increases with increasing incident wave height. The occurrence of wave setup on the reef flat enhances cross-reef flow towards the lagoon. The wave setup is positively linearly correlated with the incident wave height. The magnitude of wave setup is associated with the distance between the measurement sites on the fore-reef and reef flat.

Assessing geomorphological changes in coastal lagoon inlet using geospatial tools: A case study Moulay Bousselham lagoon, Morocco

Coastal monitoring is crucial for coastal management and both sustainable progress and environmental protection. This study aims to assess the morphodynamic changes undergone by an inlet, sandpits, and adjacent beaches of Moulay Bousselham lagoon (Morocco Atlantic coast), considered a RAMSAR site of significant biodiversity. Firstly, a Digital Shoreline Analysis System (DSAS) is applied to monitor shoreline evolution between 1949 and 2021, based on the End Point Rate (EPR) and Linear Regression Rate (LRR) methods, with the study area divided into south and north sides. Secondly, we mapped sandpit areas in the lagoon using recent satellite images and historical aerial photos covering a period of 75 years (1949–2024) within a GIS (Geographic Information System) environment. As a result, the average annual accretion rates on the north side, comprising 735 transects (1.45 km length), are +3.23 m/year (EPR) and +3.26 m/year (LRR). Additionally, the accretion phenomenon is observed in 117 transects, while erosion is recorded in 618 transects with −0.73 m/year and −0.81 m/year for EPR and LRR methods, respectively. The south side, comprising 1085 transects (2.46 km length), shows average annual erosion rates of −0.99 m/year (EPR) and −0.76 m/year (LRR) concerning the south part of the entrance inlet, with 278 transects showing accretion and 807 transects indicating erosion. Moreover, flood-dominated deltas (sandpit) mapping shows significant changes in the sandpit areas at the entrance inlet and inside the lagoon, with the area of accumulation increasing from around 155662,57 m2 in 1949 to 306020,22 m2 in March 2024. Inlet width measurements reveal fluctuations over time, from 53 m in 1949 to 177 m by 1988, reflecting dynamic coastal processes. However, by March 2024, the width decreased to 30 m, indicating sediment blockage and intense siltation. This analysis revealed that these sedimentation trends are mainly controlled by southward-directed littoral transport and the change in inlet position induced by several factors, including tidal currents, wave energy and river flow, particularly during winter seasons and extreme events (marine submersions and flooding). This article will help us to understand the relationship between the evolution of the coastline and its immediate influence on sediment supply to the lagoon.

Econometric Analysis of the Influence of Factors on the Share of Energy From Renewable Sources in the EU

The use of renewable energy is at the core of EU energy policy, reducing dependence on fossil fuels imported from non-EU countries, reducing greenhouse gas emissions and decoupling energy costs from oil prices. Currently, 22.5% of energy consumed in the EU comes from renewable sources. This increase over 2021 is due to strong growth in solar energy. This share is also increasing due to the consumption of non-renewable energy sources in 2022. According to expert forecasts, the share of renewable energy sources in Europe will continue to grow. Achieving the 42.5% target by 2030 will require a deep transformation of the European energy system. The very strong climate and energy policies pursued in the EU for about a dozen years and aimed at limiting emissions of harmful substances into the environment have led to a gradual abandonment of traditional energy sources. Increasing demand for energy while reducing its supply from traditional sources means that in order not to make the economy too dependent on energy imports, the dynamic development of renewable energy is necessary. The EU is therefore taking very extensive operational and strategic actions to use other sources for production, such as wind, solar energy, mechanical water energy, biomass and geothermal energy, as well as tidal waves, ocean heat, wave energy and sea currents. In this study, we assess the impact of energy, economic and environmental factors on the share of renewable energy in the EU. The aim of these studies was to identify the energy, economic and environmental indicators that have the greatest impact on the share of energy from renewable sources in the European Union. The study was conducted using the Statgraphics Centurion software package. The source data for the study was data from the official Eurostat website for the period from 2012 to 2022. The results of this study show that changes in gross domestic product in market prices per capita have a positive impact, as do changes in greenhouse gas emissions per capita negatively affect the share of energy from renewable sources in the EU in the period 2012-2022. This may most likely be due to the fact that EU countries are more likely to invest in renewable energy as they can afford to invest in the development of expensive renewable energy technologies and support subsidies for the promotion and regulation of renewable energy. The negative impact of per capita greenhouse gas emissions on renewable energy development is due to the high share of coal in the EU energy mix, meaning that coal not only has negative environmental impacts, but also negative environmental impacts. development of renewable energy.

Modeling and control of planar dielectric elastomer energy harvester

Dielectric Elastomer Generators (DEGs) have been used as mechanical-electrical transducers in energy harvesting systems. However, material safety assurance control, which prevents dielectric elastomer (DE) failures, is not fully investigated. Since various DEG configurations share common failure modes, incorporating these modes into the system is crucial for extending DEG lifetime and improving output power capacity of DE energy harvesters. This paper develops a physics-based model for a planar DE energy harvester and material failure modes identified through analytical analysis of the model. A real-time algorithm for internal safety control is developed to allow operation within a broader feasible region while preventing electrical breakdown (EB), electromechanical instability (EMI), loss of tension (LT), or rupture by stretch (RS). The algorithm prioritizes safety control when the feasible space is violated and allows primary control when operating within the safe space. As a step towards prototyping of an energy harvester using a DE, a prototype concept model is outlined. By using the safety control algorithm, energy harvesting output power is maximized without violating material safety rules, making it applicable to various energy source conversions like human motion, tidal wave, and wind energy.

Powering the Blue Economy: Marine Energy at Kelp Farm Sites

Abstract Marine energy (ME) has the potential to power businesses in the blue economy. Kelp farms are an emerging maritime market of the blue economy and are predicted to grow, but they are not currently using ME for their power needs. As the number and size of kelp farms increase, more offshore power will be needed onsite for operations, monitoring, and harvesting. ME devices such as tidal current energy converters and wave energy converters (WECs) may be used to supply power for these needs. This article assesses the status of kelp farming in the continental United States, investigates the electricity needs of kelp farms, and examinesthe feasibility of generating the required electricity from wave and tidal current energy. The United States currently has 165 kelp farms that have either active or pending permits. The farms use electricity for boat operations, kelp drying, environmental monitoring, offshore lighting, and the raising and lowering of lines. Most kelp farms are in protected, nearshore waters that do not have significant wave energy resources. The limited available wave energy could be used to power small devices, but WECs have not yet been developed for that application. Some kelp farms are in locations that feature significant tidal energy resources, but small tidal current energy converters that are compatible with existing farm operations are not yet commercially available. As low-power WECs and tidal current energy converters are developed, kelp farms could be research partners and early adopters of the new technologies, which would encourage their broader use by other blue economy businesses.

Static and Fatigue Characterization of Large Composite T-Bolt Connections in Marine Hygrothermal Environments

Fiber-reinforced polymer composites have been highlighted as ideal candidates for structural applications in marine renewable energy devices, such as tidal turbines and wave energy converters. It is well understood that harsh marine environments can cause strength degradation of composite laminates, which has been extensively researched at the coupon scale; however, no research has investigated how this translates into larger-scale composite structures. This paper presents a subcomponent-scale study which investigates the effects of hygrothermal aging and subsequent static and fatigue characterization of thick composite T-bolt connections as part of a large, multilaboratory materials research effort. Of the glass-reinforced epoxy and vinylester-epoxy matrix composites tested, both showed measurable static strength degradation (4–36%) after being hygrothermally aged, even though the composite specimens were only partially saturated with water. Under tension–tension fatigue loading, the epoxy specimens performed very well in their dry states but exhibited significant degradation after hygrothermal aging. In comparison, the vinylester-epoxy specimens had much shorter fatigue lives in their dry states but exhibited no degradation after hygrothermal aging. Overall, this research demonstrates that hygrothermal aging can have significant effects on the ultimate strengths and fatigue lives of even partially saturated thick composite T-bolt connections, indicating that degradation of the outer plies on thick composite laminates can have pronounced effects on the whole structure. It discusses the challenges of building an understanding of the effects of harsh marine environments in large-scale composite structures.

Research on field testing and assessment technology of ocean energy converters

The field testing and assessment technology for evaluating the power performance and power quality performance of an ocean energy converter plays a crucial role in enhancing the power generation capabilities of the tested converter. Moreover, it facilitates the advancement and growth of the ocean energy converter industry. On the basis of analyzing the current research and development status and test requirements of tidal energy converters and wave energy converters around the world, a field testing and assessment method for power performance and power quality performance of ocean energy converters was explored, measurement requirements for tidal parameters, wave parameters and electric parameters were proposed, and field testing systems for power performance and power quality performance of ocean energy converters were investigated and constructed. The field testing systems and assessment methods investigated in the present study were used to conduct field testing work on a tidal energy converter and a wave energy converter, and the test data was processed and analyzed to obtain the power characteristics performance and power quality characteristics performance of the tested ocean energy converters. The present study not only provides a field testing and assessment technology for ocean energy converters, but also a reference for future field testing and assessment work of ocean energy converters.

Marine energy converters: Potential acoustic effects on fishes and aquatic invertebrates.

The potential effects of underwater anthropogenic sound and substrate vibration from offshore renewable energy development on the behavior, fitness, and health of aquatic animals is a continuing concern with increased deployments and installation of these devices. Initial focus of related studies concerned offshore wind. However, over the past decade, marine energy devices, such as a tidal turbines and wave energy converters, have begun to emerge as additional, scalable renewable energy sources. Because marine energy converters (MECs) are not as well-known as other anthropogenic sources of potential disturbance, their general function and what is known about the sounds and substrate vibrations that they produce are introduced. While most previous studies focused on MECs and marine mammals, this paper considers the potential of MECs to cause acoustic disturbances affecting nearshore and tidal fishes and invertebrates. In particular, the focus is on particle motion and substrate vibration from MECs because these effects are the most likely to be detected by these animals. Finally, an analysis of major data gaps in understanding the acoustics of MECs and their potential impacts on fishes and aquatic invertebrates and recommendations for research needed over the next several years to improve understanding of these potential impacts are provided.

Green energy: current state and prospects

The article is devoted to the study of the current state of green energy, characteristics of its various types and prospects for development. Green energy is a part of the energy production system that uses renewable energy sources. The most common types of green energy are photovoltaic conversion of solar energy and the use of wind energy. Less well known are technologies for using marine tidal energy and wave energy from the sea surf. There are such exotic green energy projects as reverse osmosis, one-way diffusion − using the interaction of fresh and salt water to generate electricity by raising wind turbines into the upper stratosphere in the form of airships (such projects are currently being developed in Alaska). It is obvious that renewable energy sources do not pollute the environment, help reduce greenhouse gas emissions and mitigate the effects of climate change. They are virtually inexhaustible, while fossil fuels will eventually run out. Today, the reality of green energy is as follows. Globally, about 1 % of electricity is generated by solar installations and just over 2 % by wind turbines. If we consider not only electricity, but all the energy produced, the share of green energy, despite its rapid development over the past decade, is now about 5 %. Globally, the growth of installed solar and wind power capacity is doubling every four years. The main purpose of the article is to conduct a critical comparative analysis of published data on energy consumption in Europe and the world, based on the need to significantly reduce the gap in energy consumption per capita in developed countries. A review of the effectiveness of the use of various energy sources in machine building, shipbuilding and ship repair in the world as a whole was also carried out in the direction of developing practical recommendations for creating an effective process of performing logistical tasks in transport using alternative energy sources. It is known that traditional sources such as oil, gas and other minerals are gradually becoming more expensive. That is why solar panels, wind farms, and hydroelectric power plants are becoming so popular today as new sources of alternative or green energy. Let us emphasize the role of hydrogen energy. Hydrogen can be used in the large power industry, while it can replace natural gas and oil products, in transport; in the sector of buildings (for heat and power supply, including autonomous, with the replacement of natural gas or oil products); in industry − as a raw material and a substitute for traditional hydrocarbons.

Marine Power Generation Methods and Future Developments

With the continuous advancement of science and technology, ocean energy continues to develop because of its renewable, clean and stable advantages. This paper mainly studies the issue of ocean energy power generation, focusing on tidal energy power generation, wave energy power generation and ocean current power generation. The practical application of tidal energy power generation, and the negative and positive impacts of clean energy such as tidal energy on the marine environment after application, various methods and advantages and disadvantages of ocean current/ocean current power generation are described, and the explanation of many instruments in these power generation methods. For instance, the equipment used in tidal energy, wave energy and ocean current power generation are oscillating water column wave energy converter, mechanical wave energy generation, the diffuser-augmented floating hydro turbine, Darrieus deep-sea vertical axis turbine and so on. At last, from the actual cases of China's use of clean energy such as tidal energy and wave energy to generate electricity, we analyzed the future development trend of ocean energy and concluded that ocean energy will be vigorously developed in the future to replace some fossil energy.

Numerical Assessments of Tidal Stream and Wave Energy in Coastal Shelf Seas

Tidal stream and wave energy resources may have the potential to complement the exploitation of wind power currently promoted, in industrial countries, as one of the alternatives to fossil fuel energies [...]

A Study on Geo-morphological Analysis and Risk Assessment Method Using Geospatial Information

Rock platforms and TTP (breakwater) are dangerous environments commonly subject to tidal and high wave energy on the open coast. This paper is a study on risk assessment to provide risk information, which is a representative method for preventing coastal safety accidents. Risk assessment based on geo-morphological information was conducted for the Halmi-Halabi rock platform in Anmyeon-eup, Taean-gun, Chungcheongnam-do. As a result of the risk assessment in 16 directions, the risk was evaluated high in the NE, ENE, S, SSW, and W directions, where there are many sections with slopes exceeding ±20o, and the NW direction was the lowest. Geo-morphology on rock platform is central to understanding what makes one stretch of complex coastline more hazardous than another, and it can be used to create site-specific morphological risk item. In particular, it will be assisting coastal managers in an effort to reduce the number of injuries and drowning incidents by providing hazard information to assess the relative risk.

Design Optimization of a Direct-Drive Electrically Excited Synchronous Generator for Tidal Wave Energy

In the field of marine renewable energies, the extraction of marine currents by the use of tidal current turbines has led to many studies. In contrast to offshore wind turbines, the mass minimization is not necessarily the most important criterion. In that case, Direct-Drive Electrically Excited Synchronous Generators (EESG) can be an interesting solution in a context where the permanent magnet market is more and more stressed. In the particular case of a tidal turbine, the electric generator operates at variable torque and speed all the time. Its sizing must therefore take into account the control strategy and check that all the constraints are respected during the working cycle, particularly the thermal one because its permanent regime is never reached. There is no solution today that can completely solve such a sizing problem. The paper presents a specific solution. In particular, we will see that the method presented allows an avoidance of an oversizing of the generator compared to conventional methods while finding the optimal control strategy. Thus, the design optimization of an EESG is conducted considering the variable torque and speed profiles related to marine currents. The analytical model used in the paper is presented at first. In a second step, the innovative and original method that allows solving at the same time the design optimization and the control strategy (dq stator currents and rotor current) are presented. It shows how it is possible to minimize both the lost energy during the working cycle and the mass while fulfilling all the constraints (especially the thermal constraint with its transient temperature response) and keeping a reduced computation time. The case of a 2 MW tidal wave turbine is chosen to illustrate this study. Finally, the optimal design selected is validated by a 2D magnetic Finite Element Analysis (FEA).

Utilization of tidal current and wave energy help the implement of the carbon emissions peak and carbon neutrality strategy in China

The resources of ocean energy including the wave energy, the tidal range energy, the tidal current energy, the Ocean Thermal Energy, the salinity gradient energy and the offshore wind energy are abundant in China. The paper introduces the tidal current and wave energy for their relative high technology readiness level. The technical potential just in the coastal area is more than 70 GW with additional potential in remote sea areas. The utilization of marine renewable energy resources provides a potential and essential road to reach the reduction of the carbon emission. According to the national strategy, such as the Renewable Energy Law implemented from 2006 and revised in 2010, the special fund program for ocean energy was established from 2010 and has advanced the progress of ocean energy technology research, development and demonstration since then. The ocean energy technologies achieved rapid development under the support of the Ministry of Science and Technology, the Ministry of Natural Resources, the Ministry of Finance and so on. The accumulated installed capacity of ocean energy is leading internationally, but the industry is still in a low level. The carbon emissions peak and carbon neutrality strategy put forward in China requires the transition to green electricity, which also provides crucial opportunity for the development of marine renewable energy resources. The paper introduces the status of tidal current and wave energy technology and industry in China. Then, the problems and opportunities are analysed. The potential of utilization of tidal current and wave energy is estimated to support carbon emission reduction. Finally, the vision and main tasks are given.

Exploiting the Capabilities of Surfcam for Coastal Morphodynamic Analysis

Valentini, N.; Balouin, Y., and Bouvier, C., 2020. Exploiting the capabilities of Surfcam for coastal morphodynamic analysis. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1333–1338. Seville (Spain), ISSN 0749-0208.A free webcam network is used in this study, operated by ©Viewsurf, a European company with more than 1200 stations in France, among beaches, urban and mountain areas in order to assess the capabilities of surfcam for coastal morphodynamics analysis. Four representative coastal sites, with different tidal range and wave energy are monitored in order to extract optical signatures for morphodynamic analysis: three in the Atlantic and a gravel beach in the Mediterranean area. A representative site is here documented, Hendaye beach, which is characterized by a meso-tidal environment, with highly energetic waves often present, which makes the image processing challenging. Shoreline detections for beach width and intertidal area calculation are accomplished by using a new image segmentation algorithm, based on a framework, derived by opportunely coupling a superpixels algorithm and a Deep-Conditional-Neural-Network DCNN model. Aiming to exploit the capabilities of cBathy algorithm (Holman, Plant, and Holland, 2013), a version of the open-source methodology (https://coastal-imaging-research-network.github.io), is employed for bathymetry reconstruction. A coupled bathymetry by merging cBathy depth estimate and intertidal reconstructed depth from automatically extracted shorelines is accomplished, which is compared with survey and lead to an RMS error of 0.43 m. Discussions are given with respect to this new potential open-source resource and its limitations.

Development and management of ocean energy in China

Renewable energy is one important countermeasure for global climate change problems. Chinese government has paid more attentions to renewable energy in the context of increasing energy demand. The national strategy, such as the Renewable Energy Lawand special fund program for ocean energy, have advanced the big progress of the technology research, development and demonstration for ocean energy in recent years, especially for tidal current energy technologies and wave energy technologies in China. Nevertheless, there are some problems in the development of ocean energy, such as technology readiness levels, incentive policies, test sites, industrialization and so on. Some suggestions are given to improve the applications in remote islands and foster the ocean energy industries in China.

Experiences in Developing Tidal Current and Wave Energy Devices for Mediterranean Sea

In the last years, the interest for renewable energies has shown a continuously increasing trend, in search of a convenient and sustainable source alternative to carbon and fossil fuels, also due to government incentive systems, as can be seen for example in the objectives proposed by the EU 2020 target. In such context, marine energy sources are particularly attractive, both for the high conceptual available resource and for some specific technical characteristics, such as a more predictable behavior with respect to other sources like wind energy. The work here presented resumes the experience gained over more than twenty years of activities conducted at Department of Industrial Engineering of the University of Naples “Federico II”, in collaboration with research consortium Seapower scrl, in the field of ocean renewable energies. The work refers to several case reports related to different projects in which the research group has been involved. Two main energy sources have been investigated, namely tidal currents and wave energy, through the development, among others, of two different projects reported in this paper: • GEMSTAR: a submerged floating tidal current hydrokinetic turbine system (an evolution of GEM turbine) • PIVOT: a wave energy converter based on a pivoting buoy GEMSTAR is a project which is at Technology Readiness Level (TRL) 7 being the first prototype tested in real field while PIVOT is at TRL 5 since the full-scale prototype has been tested only in controlled environment. In any case both projects are still in development, evolving to more mature technology levels. The article reports the two case studies related to the above-mentioned systems at the present development stage along with the resource assessment of both energy sources in Mediterranean area.

Increased integration between innovative ocean energy and the EU habitats, species and water protection rules through Maritime Spatial Planning

This article investigates whether Maritime Spatial Planning (MSP) –which promotes the integrated planning and management of seas and oceans– can play a role in creating increased integration between the EU's renewable energy policy and the potentially conflicting rules on the protection of habitats, species and water. The article focuses on innovative ocean energy (tidal stream, wave and salinity gradient energy). It can be said that there is a possible lack of integration between the Renewable Energy Directive and the EU rules on the protection of habitats, species and water: the Habitats Directive, the Birds Directive, the Water Framework Directive and the Marine Strategy Framework Directive. The role that MSP could play in solving this is assessed with regard to the following two legal issues that reflect the said lack of integration: 1) while there are derogation clauses, there is no obligation for Member States to apply these clauses and to undertake a balancing act between ocean energy, on the one hand, and the protection of habitats, species and water, on the other; 2) even if these clauses are applied, it remains unclear how much weight Member States should attach to ocean energy under a subsequent balancing act. The concept of Maritime Spatial Planning in theory is very suitable for guaranteeing that the interests of both renewable energy policy and environmental policy are duly taken into account in licensing procedures and management measures. The contribution that MSP can make towards increased integration is, however, strongly dependent on the way MSP is interpreted on the Member State level. This is illustrated by a discussion of the differences in the current MSP approaches in Scotland and the Netherlands. This article concludes that Maritime Spatial Planning may –if certain conditions are fulfilled– be a suitable way to create a necessity to balance the EU's habitats, species and water protection rules with (ocean) renewable energy projects, on different levels of governance. Nevertheless, it also concludes that MSP alone cannot guarantee a balancing act that represents the goals of the Renewable Energy Directive and those of the aforementioned environmental directives in an equal manner. This article proposes to link MSP to detailed renewable energy plans per Member State in order to solve this issue.

Seawater ageing effect on the mechanical properties of composites with different fiber and matrix types

The use of fiber-reinforced composites in marine applications such as components of tidal turbines and wave energy converters is becoming attractive because of their reduced weight and improved corrosion resistance. However, when these polymer matrix composite structures are exposed to seawater environment, degradation of material properties is produced affecting reliability. A deep understating of seawater ageing effect on composite structures is essential to ensure long-term performance and durability. A systematic investigation was conducted in this work to evaluate the effect of seawater ageing on mechanical properties of five different composites manufactured with two types of fiber fabrics (unidirectional glass and carbon) and three types of resin systems (epoxy, vinylester and polyester). The behavior of samples with and without accelerated seawater ageing and subjected to tensile, compressive, flexural and shear loading was evaluated. A significant strength reduction due to seawater ageing was observed on composites with epoxy and polyester matrices. Low strength and stiffness values of composites with vinylester matrix are in general observed; however, seawater ageing makes these properties increase slightly. Fracture surface examination by scanning electron microscopy revealed delamination, fiber debonding and resin crumbling due to seawater effect.

Stability and optimisation of direct drive permanent magnet synchronous generator based tidal turbine

Magnetic materials have become more and more user friendly in recent days particularly in an electronic based infrastructure. The study proposes a direct drive permanent magnet based Synchronous Generator as Tidal turbine in a hybrid tidal wave energy conversion system (TWECS) and discusses its performance for better stability. The objective of the study is to analyse the role of permanent magnet based generator in TWECS for overall improvement of stability through reactive power management. The isolated TWECS becomes unstable either by random load variations or by non uniform wind and tidal power inputs. Consequently the overall stability of the TWECS is brought to stable and normal stage by the control of reactive power with the inclusion of the custom power based devices. In addition to the effects of permanent magnet in case of DDPMSG for improving the overall system stability, optimisation tools like PSO, GSA and PSOGSA are added for further improvement in system performance.