eChapters

Aim: To verify the relationship between the input and output voltage for 3-phase transformer connection in various ways:

A 3-phase transformer can be considered as a set of 3 single-phase transformer bank or as single unit of 3 phase windings. Since three winding are available in both primary and secondary side then there can be different types of connections and so far, different characteristics.

Aim: Perform the parallel operation of single-phase transformer and observe the load sharing of each transformer.

A power transformer is one of the most vital and an equally expensive component in a power system. It may so happen that, over time, due to load growth in its service area, an existing transformer may not be able to withstand the demand during peak-hours without exceeding its long-term MVA rating. Operating a transformer in such a fashion would cause overheating and degrade its expected life. In most cases, instead of commissioning an entirely new higher capacity unit, a more viable alternative exists in adding a smaller unit in parallel to complement the existing one. In other words, a new smaller capacity transformer can now be connected in parallel to the existing one such that the two shares a large peak load in a specific proportion and the one operating near limits is relieved of the burden.

Aim: To perform Sumpner’s test (back-to-back test) on a pair of similar transformer and thus calculating efficiency of operation.

Sumpner’s test givens an effective way, to actually see the performance of transformers of large rating without loading them, at full load. This back to back test allows heat run test so that temperature rise and its rate can be analysed.

The two identical transformers are connected back to back as shown in figure such that their polarities are in opposition. To do this, two terminals of the secondary winding are connected as shown and the voltages between the other two are measured by exciting primaries.

Aim: Determination of percentage regulation and efficiency of a single phase transformer by direct loading method.

Percentage regulation

When the load on the transformer is increased, the voltage drop in its primary and secondary windings also increases causing variations in secondary terminal voltage. The term voltage regulation of transformer means the change in secondary terminal voltage when full load is thrown off keeping supply voltage and frequency constant. It is generally expressed as percentage of no load terminal voltage for a desired power factor.

Aim: To perform open and short circuit test on a single-phase transformer, to obtain equivalent circuit parameters.

Open circuit test

The core loss or iron loss i.e. the no-load loss in a transformer is determined by performing the no-load test at normal sine wave impressed voltage. Through the iron loss in a transformer is not governed by the supply being connected to primary or secondary side but when measuring this no-load loss.

It is usually more convenient and safer to supply the voltage to the low voltage side. This makes the test apparatus cheaper and becomes safer for the low testing personal. To determine the shunt branch parameter of the equivalent circuit, the primary side (L.V.) is connected to a normal supply voltage and rated frequency and secondary side (H.V.) is left open with care so that there is no possibility of coming in contact with any part of (H.V.) terminals. The wattmeter connected in the primary (L.V.), will then read the total hysteresis.

On the morning of 13 Oct 2023 morning (9:30 am - 12:00 pm), ITAF participants visited snake-skin gourami local farms in Samut scorn province. Snake-skin gourami is one of the best delicacies in Thailand which has large demand in local and international markets. Snake-skin gourami can breed after reaching 100-200 gms ( 2 months). The culture period of snake- skin gourami is 9-10 months. In snake- skin gourami males have a large body and long dorsal fin than females.

Farm 1

Snake-skin gourami culture is done in 30 rai ( 1 rai= 1600 m2) area of the farm. The depth of the pond is 1.5m. A single crop is taken in one year. 50,000 no. of fry are stocked in 30 rai area. Feeding areas are constructed by the net embankment where feed is given to fish harvesting is done after 8-9 months. The cost of production for one crop is 2 million/year in that they produce 30-40 tonnes /30 rai, which is almost 3 million / year.

Introduction

We, the participants of ITAF 2023 along with Dr. B. R. Chavan and Dr. Prashant Bodake visited Farm Song Nam under the guidance of Asst. Prof. Dr. Naphat Panthukumbol and Dr. Sorawit Powtongsookon 18/10/23 at 01:00 pm. This research station is under NSTDA (National Science and Technology Development Agency). The purpose of the visit was to learn about the latest developments in aquaculture technologies.

Dr. Sorawit explains that this system is able to monitor water quality, floc sedimentation, the current age of shrimp, quantity in the pond, total weight, density, size, total amount of water used, pond volume, and volume of water in the pond at a time. This system is equipped with cloud backup that can store all recorded pieces of information. After monitoring, the available information is automatically uploaded to the cloud and accessible through mobile by simply visiting the website. The key feature of Aqua-IoT is the integration of key data– physical, chemical, and biological water qualities and weather – into one single dashboard that enables users to understand the relationship between the data, analyze the data, and make informed decisions.

Introduction

We, the participants of ITAF2023 with Dr. B. R. Chavan and Dr. Prashant Bodake, visited Boonsawang Co. under the guidance of Asst. Prof. Dr. Naphat Panthukumbol and Mr. Suthi Mahalao on 18/10/2023 at 09:00 am. Boonsawang Co. in Chonburi, owned by Suthi Mahalao, also exports fry to Vietnam, Malaysia, Singapore, Taiwan, Australia, and Israel. In addition, Suthi runs his sea bass farm and is a feed distributor to farms in the province. The purpose of the visit was to learn about the seabass culture system and get familiar with technical aspects. The farm occupies an area of 10 hectares and is covered in 11 ponds. The farm is aimed to grow from fry to marketable size seabass. The single crop duration is divided into 4 periods.

We, the participants of ITAF2023 visited The ocean farm under the guidance of Asst.Prof.Dr.Naphat Panthukumbol and Dr.Somrat Taweedet on 17/10/23 at 3:00 pm. The farm is certified by fisheries department and is located in Chonburi Province. The purpose of visit was to learn about the nursery rearing of shrimp and use of frozen artemia.

1) Nursery rearing details

The cultured species was Litopenaeus vannamei. Rearing was done from nauplii to PL15 stage. The farm is producing 2 variants named- ‘The ocean hero’ which is disease resistant and ‘The ocean speedy’ having high growth rate. They are procuring nauplii from Phuket. Then double certification from DOF and Burapha university lab is done to ensure SPF stock. The purchasing price of nauplii is 12,000 baht/ million nauplii and transportation done by plane. The culture period of shrimp is around 21 days.

On 17 October we visited the Institute of Marine Science, Burapha University (BIMS), THAILAND at 9 a.m. The institute is situated in Bangsean. BIMS is a marine research institute of Burapha University. They have 6 organizations: Marine Research Department, Marine Aquarium Department, Marine Museum Department, Academic Service Department, Office of the Director and Research Station.

They have shown us their Life Support System of Public Aquarium and coral propagation and conservation.

1) Public aquarium

We have seen the Life Support System of Public Aquarium i.e. Filtration System, which involves the complex systems and technologies used to maintain the health and well-being of marine life in public aquariums. This is crucial for keeping the animals and ecosystems on display healthy and sustainable. The display tank has having 10,00,000-liter capacity.

We, the participants of ITAF2023 visited Sriracha fisheries research station under the guidance of Asst. Prof. Dr. Naphat Panthukumbol and Dr. Somrat Taweedet on 16/10/23 at 08:00am. The research station is under faculty of fisheries, Kasetsart university in Chonburi Province. The purpose of visit was to learn about the mussel aquaculture and Integrated Multi- Trophic Aquaculture (IMTA).

1) Mussel aquaculture

Cultured species was Perna viridis( Green mussel ). Almost all rafts were owned by fishermen and 10 rafts were under the management of sriracha fisheries research station. The cost of production was 100 baht /acre. Simple method of culture is practiced by installing rafts before breeding season and allowing the natural spawn to attach. The harvesting size of mussel is 8 cm. Observed growth rate is 1cm/ month. Other maintenance includes repairing of ropes ,buoys etc. during off-season. Farmers face many constraints like plankton bloom, waste water discharge, predation by sting ray,parasitism during summer months.

Frog farming in Thailand started 20 years ago. The frogs commonly found and farmed in Thailand are the local species, Rana tigerina and Rana rugulosa. The first imported bullfrog, Rana catesbeiana was introduced in 1980 and is popular in the northern part of the country. Rana tigerina is olive brown in colour which is about 15cm long when fully grown. The adult weighs about 300g. Rana rugulosa is another local species that is olive-brown in colour with a dark head. It is about 13cm long when fully grown and weighs about 270g. The imported species, Rana catesbeiana is olive-brown to green in colour. It is 17 cm long when fully grown and weighs around 459g.

We visited the CPF (Thailand Public Company limited) in Samutsakorn on 12/ 10/23 at 1:30 pm. The purpose of the visit was to know about the feed ingredients and production process.

1) Overview

Product like shrimp feed and fish feed are prepared by the company. Company was spread in 61 Rai( 24 acre) area. 400 employees are working in the company.Working hours is 3 shift / day and working days – 6 days / week.Shrimp feed unit have the capacity of 13,000 T/M and actual production was 7000 T/M. 8 line pellet machine was used for this purpose. Fish and frog feed unit have capacity of 11,000 T/M and actual production 7000 T/M. 6 line extruder machine was used.

The ITAF participants visited the Anuban Tilapia Floating Cage Culture on the Canoy River situated in the central part of Thailand on 11/10/2023 at 1:30 p.m. The purpose of the visit was to learn about the floating cage culture on a large scale.

Construction Details

The farmer had a total 500 number of cages divided into 5 units i.e. 1 unit contains 100 cages. The dimensions of the floating cage are 7m in length, 5m in width and 2m in depth having an area of 70 m3. The fabrication of the cage was done by using the GI pipes attached to the barrels for buoyancy. The double HDPE netting was done from five sides and on the upper side bird net was fixed as a biosecurity measure. The construction cost of the cage was 140000 baht /cage.

Construction details

They had a total of 36 tanks, and most of them were made of tin. Each tank had a diameter of 6 meters, was 1.2 meters deep, and could hold up to 30 tons of water. Inside these tanks, there was a plastic lining. Additionally, there were 4 to 5 tanks made from bamboo. Bamboo tanks have a shorter lifespan, lasting 1 to 2 years, while tin tanks can last for 8 to 10 years.

Culture details

The species that was cultured over there was Red tilapia. Culture practice was intensive. The nursery-rearing period was 70 days. In the first step, fish were raised from 0.5 grams to 10 grams in a separate tank for 35 days. The second step involved the growth of fish from 10 grams to 30 grams for the next 35 days in another separate tank. The fishes were bought from outer sources and they were all male fishes.

We visited The Model Sea Farm Project under the Royal Initiative of Her Majesty Queen Sirikit on 10/10/2023 at 1 pm It is a government farm located at Phetchaburi Coastal Aquaculture Research and Development Center. The purpose of the visit was to learn more about seaweed production and zero waste aquaculture system.

1) Sea ranching

Species used for sea ranching was Banana shrimp (Fenneropenaeus merguiensis). 2 months old shrimps were collected from tank and used for ranching

Overview of Inland Fisheries Status

In Thailand, inland capture fisheries are carried out mainly in rivers, lakes, swamps and reservoirs. These fisheries are an important source of animal protein for the rural people. Since 2005, production from inland capture fisheries has increased by almost 13 percent. Gillnets, longlines, hook-and-line, scoop nets, cast nets, and lift nets are some of the fishing gears being used. Among these fishing gears, gillnets are the most popular and efficient, particularly in swamps and reservoirs. Thai silver barb, snakehead, walking catfish, local carps, and Nile tilapia are caught. Nile tilapia, hybrid catfish, silver barb, snakeskin gourami, giant river prawn, striped catfish and striped snake-head contributed 95 percent in quantity and 92 percent in value in fresh water aquaculture.

The Aquatic Resources Research Institute (ARRI) was established to conduct research & answer important impending questions associated with the nation’s aquatic resources, like conservation of marine organisms, marine science, oceanography, aquaculture, biotechnology etc. It also works for transferring or sharing the knowledge to public, for guiding towards sustainable development.

Sichang Marine Science Research & Training Station: (SMaRT) Chonburi Province

Thailand This is another unit of the ARRI. It was established in 1979, in Chonburi Province Thailand.

Introduction

Ammonia, nitrite and nitrate are considerable in the water quality management because they can be produced a toxic depending to their form and concentration. The solubilities of nitrogen contain in water at different temperatures and pressures. Nitrogen is a basic growth substance and an important element in aquatic ecosystems as well as in the pond water. It exists variously forms in water and manly classified in organic and inorganic.

Introduction

Ammonia is the major end product in the breakdown of proteins in fish. Fish digest the protein in their feed and excrete ammonia through their gills and in their faces. The amount of ammonia excreted by fish varies with the amount of feed put into the pond or culture system – increasing as feeding rates increase. Ammonia also enters the pond from bacterial decomposition of organic matter such as uneaten feed or dead algae and aquatic plants.