The Future of Manufacturing - Additive Manufacturing by 3D Printing

During the Internet Of Things (IOT) World Congress celebrated in Barcelona from the 16th to 18th of September. It was shown multiple of companies, projects, industries and presentations regarding the great possibilities that IOT will bring soon to the humanity. 

Figure 1_General view of the visitors emplacement in the IOT World Congress_source: J. Sánchez Ríos.


Regarding the presentations, one of those presentations were about the Future of Manufacturing.

Mr. Bejoy, from HCL Technologies, exposed the main challenges which are going to face the Manufacturing in the next years. 

In the 19th century, era marked by livelihood, food and water, the manufacturing was focused on the Mechanization of Power Generation; Engines, Generators and the Power Looms.
During the first half of 20th century, era marked by wars, famine, diseases, colonialism and human rights, the focus of manufacturing was established around the Mechanization for Labor and Material productivity, starting with the concept of Mass Production, with the development and performance of the Drives, Motors, Controllers and the Instrumentation.

During the second half of 20th century, era marked by quality of life and productivity improvement. The focus of manufacturing was established the beginning of automation, increasing the speed, the precision and the quality in the manufacturing processes.
In the 21st century, in a hyper connected world, the focus of manufacturing is based in the cyber-physical systems; Information and Communication Technology (ICT) and Operation Technologies (OT), just to establish an increase of productivity and sustainability by sensors, smart devices/gateways, mobility, analytics, cloud and nano-electronics.

Figure 2_Picture of Mr. Bejoy George (HCL Technologies) at the begining of the presentation about the Future of Manufacturing_ source: J. Sánchez Ríos.

Mr. Bejoy thinks that the most significant technologies that will change the complete manufacturing processes will be in relation to some specific topics;

1. In first case, by the Sensors in Factory, the development of sensors will be able to give information about states which it was impossible before.
2. In second term, the Industrial Robots Market, with the inclusion of robotics in the digital factory and the "virtual engineering." This implementation will increase the quality of the simulation and test for the automation process of the virtual factories and then, increasing the value of the machine learning.
3. Furthermore, with the Connected Devices,  which will bring great changes in the manufacturing processes, getting in deep in what is called the digital factories. With the implementation of a Condition Monitoring System (CMS) in all the processes and products of the factories, it will be feasible to have information in real-time about everything what is involved the manufacturing process in all the manufacturing plants; from the raw material availability and cost, to the facility status, meteorological conditions, forecasting, customer behavior, etc. This implementation will optimize the processes which support the manufacturing; Inventory, packaging, maintenance, operations, Health, Safety & Environment.
4. Finally, one of the most relevant technological irruptions, and the propose of this blog, is 3D Printing technology and what is called "Additive Manufacturing."

Figure 3_View of a chemical industry plant where the automation of the complete processes is a reality for the properly production and security _source: J. Sánchez Ríos.

3D Printing Market and the additive manufacturing will create a new concept of manufacturing. The main reason is simply, for changing the production itself and making a democratization of the production and products. 3D Printing will create a mass customization and agile manufacturing, and the concept of "Bring Your own Device" (BYoD), creating the possibility to make the device on your home or small workshop.
This kind of new production concept, will bring a new consumption. In which, the customer will be the owner to create ideas, proposal and of course, the final products. 
In this context, the customers will create "the crowdsourcing of ideas", where the customer will drive the demand. With this new concept, he ideas and development of the products, not only will be given by the marketing or business development department of the companies, also or be only by the customer.

Following with the concept exposed, it is not difficult to think about the consequences in manufacturing. This will bring an important modification in the sales and customer behaviour. Nowadays, the power of the consumer decision is declining the Brand Loyalty and in consequence, declining the sales forecast accuracy, knowing that this have great consequences in the economic results of the companies. 
In future, the solutions will be in collaboration, the crowdsourced of ideas, will create alternative ways of sustainable manufacturing (e.g.: bio-manufacturing, nano-manufacturing)

Chronologically, 3D printing technology has been used by surgical planning:

• Firstly, in maxillofacial and craniofacial surgery, for the reconstruction of the skull, having more information of the situation and taking a previous study before the surgical operation.
• After this first application, Healthcare industry was made the first steps regarding soft tissues, after the patient was undergoing to a MRI (Magnetic Resonance Image) and X-ray CT (X-ray Computed Tomography).
• In case of tumors, the process is getting first a 3D printing of the zone of the tumor, getting this 3D printing with and without the tumor. With this situation, the doctor knows how is the situation, just to differentiate where there is the tumor, and where are veins and arteries, just for not damaging the patient in the process of separate the tumor of the body. The process starts with an tomographic study with a contrast agent, being possible to differentiate the organs and the vascular system. In the printing process, a head injects 3 different liquids, being one of it, such as support material for building overhangs, being easy to eliminate for the soluble of the material.

Figure 4_Example of 3D printing during the Sabadell Smart City Congress, where is reperesented kidneys, which left one has a tumor and is make by different material, used by Doctors to make a properly study and to train before the intervention_source: J. Sánchez Ríos.

Nowadays, the current trend are more related to reinforce systems and to create functionality. For that is important to think about the evolution of advanced materials, product customization and new business models.
Related to advance materials, the professionals are implementing new possibilities, and not only regarding the use of materials with different colours. The changes and possibilities are more in relation to material properties, like conductivity; thermal or electric. Just to optimize small volume production, with application in industries like aerospace and manufacturing support. 

The materials used for additive manufacturing industry are basically; 

1. ABS (Acrylonitrile butadiene styrene), 
2. Polylactic acid (PLA), 
3. Polyvynil alcohol (PVA): a water-soluble synthetic polymer, 
4. Plaster: manufactured as a dry powder, 
5. Metals; steel, stainless steel, titanium, gold, silver and others like glass, ceramics, etc.

The main challenges or needs required by the customer regarding the materials applied to 3D Printing technology are related to the property of the materials. 

The most relevant property of the materials applied to 3D Printing technology are in relation to Mechanical Strength, thermal stability, weak bonds, printing speed, viscosity, settling, electric conductivity or fire retardancy. 
Regarding the functions required to improve the properties mentioned are related to the reinforcement of the material, the rheology, the color, the electric and thermal conductivity, the delivery and the reactant.

Regarding the attributes employed in the materials used, the main attribute controls are related to surface chemistry, composition, size, structure, porosity, high purity and crystallinity.

Some properties which are in investigation in additive manufacturing, are related to conductivity of the materials, achieved via percolation (the property of the materials to move particles through the polymer materials).
Furthermore, it is necessary to mention the combination of properties, just mixing materials. 
Similarly, other possibility is by the surface treatment, providing better dispersibility versus color. Depending the surface, when the particle size is smaller, is more difficult to disperse properly the pigments. 

Figure 4_Picture of a 3D printing of the company PRUSA i3 in the Eurocon Congress_source: J. Sánchez Ríos.

In 3D printing there are different technologies, but the most accessible, in economical terms, is the technique FFF (Fused Deposition Modeling), because is a technique which is now an open source technology called reprap - replicating rapid prototyper, based in the University of Bath.

REFERENCES

i. GE advanced-manufacturing
ii. Webinar R&D Magazine - 3D Printing Tech
iii. Webinar IEEE - City of Tomorrow (IOT)




J. Sánchez Ríos
javier.sanchezrios.1978@ieee.org

Mixing Renewable Energy Technologies for mitigating grid perturbance or grid loss operation in Wind Power

Once the Wind Farm (WF) is in operation. The target is the get the Return on Investment (ROI) forecasted in the business plan.

If it is considered the onshore Wind Turbine Generator (WTG) class I, II and III. The machine has been designed for a minimum of 20 years, following the standard IEC 61400-1. In case of offshore WTG, the standard defined the S class. In that situation, the standard is not defining any specific time, but at least is considering the protection for offshore tropical storms such as hurricanes, cyclones and typhoons.

For getting the mentioned ROI, it is necessary to mention the relevance of the Operation and Maintenance (O&M). This O&M must be optimal for decreasing the operational cost.

Technically speaking, Wind Power has one important consideration. It is called utilization or use factor. It is regarding the high level of intermittency in the electricity production. It means, the difficult to control the energy yield, just by the nature of the wind.

For that reason, Wind Power has relevant implications for the management of the electric system by Transmission System Operator (TSO). Even more, when the generation of Wind Power, are increasing in the total of the mix generation year by year.

In consequence, it has been implemented what is called “Grid Code Compliance (GCC).” The GCC is a framework to establish the conditions to connect WF to the grid. See what is established in the Standard IEC 61400¹ and the proposal for ENTSO-E (for EU countries).

Figure 1_ Wind Power Generation in real-time in Spain in two different days. In the top, for September 30th 2015, and in the bottom for 1st October 2015. In the pictures is possible to see the difference in the power generation between two days _source: Spanish TSO - Red Electrica de España (Ree)

Normally, in the past, the technical requirements for a WF to be coupled into the grid was established an accordance by two parts; by one side, by the WF operator, and by the other side, by the purchaser, an Utility, in the most of cases.

With this model, the issues came, when the TSO claims in case of black-outs, and the high associated cost.

For that reason, TSO establish GCC. Just to mitigate issues in relation to the power system operation management and its expensive consequence in case of issues.

GCC is basically related with the quality of wave delivered by the WTG, or in general by WF to the grid in the Point of Common Coupling (PCC). Similarly, GCC are considering also the conditions for WTG to inject electricity into the grid in case of fault of the grid.

It is mandatory mentioning, when there is a dip voltage, one WTG can be disconnected to the grid. This issue also can affect the complete WF indeed. This phenomenon is called “the cascade effect.” When there is a dip voltage in the grid, the WTG can recover the connection depending the time of the dip voltage. If this time is longer than the capacity of WTG to stay in connection, the WTG gets unplugged from the grid until the grid is recovered. 

This effect also can affect others WTG of the WF, because this WTG out of connection increases the dip voltage in the grid. In first term, for non supplying power, and also for the consumption of power in the state of recovering the normal performance. In this scenario, there is the possibility to affect the complete WF. 

In the worst possible case, the cascade effect of the all complete WF can make great consequences for the management of the electric balance by the TSO. Just for being necessary to inject or increase the generation available to replace the missing electric yield of the mentioned WF.

Figure 2_ View inside the Nacelle of Enercon WTG during Hannover Messe in 2004. In the picture is possible to see the high number of pols in the generator, the cabinets in the top right side, and on the bottom right side, three motors of the yaw system. As a consideration, all those systems must be supplied with the main electricity connection for the properly performance of the complete WTG_source; J. Sánchez Ríos

Getting in more detail in the technical frameworks, one of the most important consideration is Fault Ride Through (FRT). FRT is relevant in case of stability of the grid voltage during faults or unbalanced in the grid. Those unbalanced mostly are caused by starting and shutting down heavy loads such as large motors, but also by Wind or Photovoltaic farms.
FRT can be separated in low and high voltage faults. Having Low Voltage Ride Through (LVRT) or High Voltage Ride Through (HVRT).

In case of voltage dip, the conditions which must comply every WTG must be the following;

• in first term, the WTG must stay connected to the grid,
• secondly, the WTG mus avoid any consumption of active or reactive power and,
• finally, and depending of the level of wind. The WTG and WF in general, must produce active and reactive power to help recovering the grid at levels of normal functionality, following the International Grid Codes*.

After the voltage has been recovered, and due to the unbalance generated in the grid by the dip voltage. The WTG must deliver Active Power, proportionally to the voltage values in the present situation of the grid.

It is necessary to remark that, a part of the well known meteorological effects in the mechanical structure of the WTG, the electric transients by the dip voltage creates as well, serious problems for the torque stress to the gear and the drive shaft, just for the inertia in the magnetic winding in the generator during the fault or dip voltage.

Figure 3_ Two WTG with a Meteorological Mast between them in southern Tarragona (Catalonia - Spain) _source; J. Sánchez Ríos

To solve LVRT issues, one possibility is to mix other Renewable Energies in the same WTG, to supply the ancillary systems and the generator in the WTG or in the WF.

In second term, it also can supply power to the grid, helping the TSO to control the possible unbalance in the electric system.

The WTG has incorporated an Uninterruptible Power Supply (UPS). With this UPS, some essential systems of the WTG are being supplied in case of power loss, mainly the pitch control, yaw system, communication systems and other ancillary systems in relation, basically to safety or essential operational systems.

The proposal is to add other Renewable Energy Technologies with its respective storage system, in its different technologies, to help in case of grid loss to the WTG or WF.  Just to recover the grid loss as soon as possible, injecting reactive or active power, depending of the electric system needs and to help in the recovering process when there is a fault in the grid.

Figure 4_ Example of  Off-Grid Street Lighting system composed by a Solar Photovoltaic tracker systems, Small Wind Energy system in the top of the lighting systems and the respective storage system with an autonomy of 58 hours (by the company Eolgreen) in a Beach of Barcelona City _source; J. Sánchez Ríos

It is well known the foundations systems in Wind Offshore; monopile, substructure and gravity-base. 

Furthermore, and regarding the floating foundations, it is feasible to talk about barge floater, tension leg platforms and spar floater. 

As information, these new implementations in the foundations represent a great cost in the total investment of the Wind Farm Project.

For mitigating the FRT in Wind Offshore, the proposal is to use storage systems, in concrete by ultracapacitors (ultracaps) for short voltage dips and batteries systems for longer dips.

For that, it is possible to insert tidal, marine or wave energy in the foundations systems, instead of being monopile or triple structure in fixed or floating foundations.

Installing those power systems in the foundations, it is feasible to get electricity and storage it. With this power, it can be supplied electricity in situations of FRT or even grid loss state.

With that implementation of tidal, marine or wave energy, the new system is reducing the impact of waves in normal functionality, grid loss or low wind (idling). In consequence, reducing the fatigue in the substructure, the tower and in the complete WTG.

On the other hand, it is important to remark some issues caused by the meteorological conditions. In concrete, the consequences of aerodynamic damping in WTG. The WTG are design to resist the impact of wind in the complete WTG in the normal functionality.

Figure 5_ Example of consequences in Aerodynamic Damping. In the left side of the figure is shown the scenario when there is no enough wind or the WTG is under grid loss state. In the right side, the normal functionality of the WTG versus idling or grid loss state_source: J. Sánchez Ríos

However, in the case of having low levels of wind or the WTG is in a grid loss state. It is feasible to have the impact of other forces. For that, it is mandatory thinking about the misaligned between three forces that can impact to the whole WTG structure; the wind, the waves and the current. Those three forces can get a vector in different direction and module, depending of high (wind) or depth (currents).

To introduce the behavior of the wind, waves and current. The wind and waves can be aligned (co-directional) and acting from a single force. In the worst case, there is only one direction (uni-directional).

Regarding waves, waves are irregular in shape, varying in height, length and speed of propagation. Furthermore, it is necessary to consider the water depth and the seabed topology. Just to mention the model of the waves; which are defined such as normal sea state (NSS), normal wave height (NWH), extreme sea state (ESS) and extreme wave height (EWH).

Regarding currents, must be considered as a horizontally uniform flow field of constant velocity, varying only as a foundation of depth. At the same time, it is necessary to contemplate the sub surfaces currents generated by tide storm surge, atmospheric pressure variations, wind generated surfaces currents, and braking wave induced surf currents. In the case of currents classification, it is feasible to mention; normal current models (NCM) and extreme current models (ECM).

Consequently, the considerations for the correct site assessment for the offshore WTG, such as indicated in IEC 61400-1, are; 

• the Metocean data, 
• the assessment of waves, 
• currents, 
• water levels, including tides and storm surges, 
• sea ice, 
• scour and seabed movement, 
• weather windows and weather downtime, and 
• eabed soil conditions.

In cases of normal functionality in the WTG, the misaligned is mostly, the result from the vector subtraction of the wind direction and the wave direction. In some cases, it is needed to add the water current direction.

Nevertheless, in some cases, the wind is low for power production, and then; the aerodynamic damping is almost null. However, it is feasible in this case, to pay attention in the wave level, which is not negligible in terms of the exposition of the complete WTG to the fatigue.

Similarly, it is mandatory considering, the reduction of the possible fatigue in the WTG structure, and to take advantage of the energy produced by the waves or stream.

All this implementation can be a study to insert in the offshore substations, to maintain the complete WF in operation, even in dip voltage or grid loss and for the ancillary systems in case of grid loss.

Figure 6_ Example of Substation in a Wind Onshore Farm to connect to the electric yield from the Wind Farm to the Point of  Common Coupling (PCC)_source: J. Sánchez Ríos

As a conclusion, mixing Renewable Energies with its respective storage system can be a great solution to mitigate the yield with high intermittency.

The example exposes can be extended to other technologies, depending the emplacement or the technology applied (see other examples by Geothermal and Biogass).

It is well known, the efficiency of the Renewable Energy technologies and the storage system is increasing its performance and cost day by day. However, similarly, other kinds of Renewable Energies are being introduced into the field.

In Japan, the offshore solar farms are a reality. This technology with its storage system can help to supply the ancillary systems in the WTG or in the Substations in the Offshore Wind Farms.

If the example is regarding Wind Onshore. Some projects in Canary Islands are mixing pumped-storage systems for the Wind Onshore in an Off-grid System. Otherwise, and following with Onshore Wind, the geothermal energy can help to mitigate the issues in extreme conditions, being necessary to supply heat to get the properly temperature for some electronic equipments. In the study of the foundation systems, it would be possible to introduce the geothermal energy to adecuate the temperature inside the tower and the nacelle.

Figure 7_ Example of Wind Onshore Farm in La Muela (Zaragoza - Spain), an emplacement with high temperture in summer and very cold in winter. Emplacement where will be possible to insert geothermal energy for getting the properly work temperature in WTG for the electronica, mechanical systems (even lubrication) and the ancillary systems in case of extreme temperature_source: J. Sánchez Ríos

The mixing of Renewable Energies for new applications are open for discussion, depends on the evolution and the willingness to invest in these technologies. 

Nowadays are being developed by an isolated way. The technological development, the maturity of some Renewable Energy technologies, the reduction of the cost (LCOE and the necessity of the TSO to find solutions to mitigate the use factor, can help to develop the mixing of Renewable Energy technologies with storage systems, even with the possibility to mix also different storage technologies.

REFERENCES

2. Sistemas Eólicos de Producción de Energía Eléctrica – Editorial Rueda S.L. - J. L Rodriguez Amenedo, J.C. Burgos Díaz, S. Arnalte Gómez.
3. Smart Grids – Technology and Applications – Wiley – Janaka Ekanayake, Kithsiri Liyanage, Jianzhoung Wu, Akihiko Yokohama, Nick Jenkins.
4. Aerodynamic Damping in the design of support Structures for Offshore Wind Turbines – Delft University of Technology – David Cerda Salzmann, Jan Van der Tempel.
5. Description of the relation of Wind, Wave and Current Characteristics ot the Offshore Wind Farms Egmond aam Zee (OWEZ) location in 2006 – S.Bath, P. J. Eecen
6. Grid Code Compliance beyond simple LVRT – Tobias Gelhaarg
7. Comparison of Fault Ride-Through Strategies for Wind Turbines with DFIM Generators – Andreas Dittrich, Alexander Stoev
8. Standard IEC 61400 – 3 (Wind Offshore)
9. ENTSO-E Network Code for Requirements for Grid connection applicable to all Generators

_________________________________________________________________________

¹ Normal Electrical Power Network conditions apply when the following parametrs fall within the ranges stated bellow:

1. Voltage-nomial value (according to IEC 60038) ± 10 %
2. Frequency-nominal value ± 2 %
3. Voltage imbalance, the ratio of the negative-sequence component of voltage which must not exceed the value of 2 %
4. Auto-reclosing cycles and auto-reclosing cycle periods of 0,1 to 5 seconds for the first reclose shall be considered
5. Outages – electrical network outages shall be assumed to occur 20 times per year. An outage of up to 6 hours shall be considered a normal condition. An extreme condition is one week.

* Example of International Grid Codes in voltage and frequency for Portugal:

1. Maximum Voltage 1 and 2:

• > 110% of nominal voltage for more than 1 second,
• > 115% of nominal voltage for more than 0,1 seconds
1. Frequency before disconnecting:
• above 53 Hz for more than 0,3 seconds
• bellow 47 Hz for more than 0,3 seconds

_________________________________________________________________________

Related Blogs: Wind Power Over production, Supergrid - Future of the Electric Systems, 100% Renewable Energy by global wireless Power Transmission System, Renewable Energy Investment - CSP, Electric System Challenges

Index Terms:

Generation, Wind Power, Transmission System Operator (TSO), Wind Turbine Generator (WTG), Wind Farms (WF), used factor, Point of Common Coupling (PCC), voltage, active power, reactive power, frequency, Fault Ride-Through (FRT), High Voltage Ride-Through (HVRT), Low Voltage Ride-Through (LVRT), balance of power, tidal energy, marine energy, wave energy, floating systems, substructure, intermittence, Metheorological Mast (Metmast).

J. Sánchez Ríos

javier.sanchezrios.1978@ieee.org