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Thursday, 21 September 2023

Buchholz relay

 

In electric power distribution and transmission, a Buchholz relay is a safety device mounted on some oil-filled power transformers and reactors, equipped with an external overhead oil reservoir called a "conservator".

The Buchholz relay is used as a protective device sensitive to the effects of dielectric failure inside the equipment. A generic designation for this type of device is "gas detector relay". 

 Buchholz relays have been applied on oil-filled power and distribution transformers at least since the 1940s. The relay is connected to the oil piping between the overhead conservator tank and the main oil tank of a transformer. The piping between the main tank and conservator is arranged so that any gas evolved in the main tank tends to flow upward toward the conservator and gas detector relay.

 

Operation

Depending on the model, the relay has multiple methods to detect a failing transformer. On a slow accumulation of gas, due perhaps to slight overload, gas produced by decomposition of insulating oil accumulates in the top of the relay and forces the oil level down. A float switch in the relay is used to initiate an alarm signal. Depending on design, a second float may also serve to detect slow oil leaks.

If an electrical arc forms, gas accumulation is rapid, and oil flows rapidly into the conservator. This flow of oil operates a switch attached to a vane located in the path of the moving oil. This switch normally will operate a circuit breaker to isolate the apparatus before the fault causes additional damage. Buchholz relays have a test port to allow the accumulated gas to be withdrawn for testing. Flammable gas found in the relay indicates some internal fault such as overheating or arcing, whereas air found in the relay may only indicate low oil level or a leak. 

Through a connected gas sampling device the control can also be made from the ground. Depending on the requirements, the Buchholz relay has a flange or threaded connection. The classic Buchholz relay has to comply with the requirements of the DIN EN 50216-2 standard. Depending on the requirements, it is equipped with up to four (2 per float) switches or change-over switches, which can either send a light signal or switch off the transformer.

The relay was first developed by Max Buchholz (1875–1956) in 1921. details

Transformer oil

 

Transformer oil  :

Transformer oil or insulating oil is an oil that is stable at high temperatures and has excellent electrical insulating properties. It is used in oil-filled wet transformers, some types of high-voltage capacitors, fluorescent lamp ballasts, and some types of high-voltage switches and circuit breakers. Its functions are to insulate, suppress corona discharge and arcing, and to serve as a coolant.

Transformer oil is most often based on mineral oil, but alternative formulations with different engineering or environmental properties are growing in popularity. 

 

Transformer oil's primary functions are to insulate and cool a transformer. It must therefore have high dielectric strength, thermal conductivity, and chemical stability, and must keep these properties when held at high temperatures for extended periods. Typically, they have a flash point greater than 140 °C (284 °F), pour point less than −40 °C (−40 °F), and a dielectric breakdown at greater than 28 kVRMS. To improve cooling of large power transformers, the oil-filled tank may have external radiators through which the oil circulates by natural convection. Power transformers with capacities of thousands of kilovolt-ampere may also have cooling fans, oil pumps, and even oil-to-water heat exchangers.

Power transformers undergo prolonged drying processes, using electrical self-heating, the application of a vacuum, or both to ensure that the transformer is completely free of water vapor before the insulating oil is introduced. This helps prevent corona formation and subsequent electrical breakdown under load.

Oil filled transformers with a conservator oil reservoir may have a gas detector relay like a Buchholz relay. These safety devices detect the buildup of gas inside the transformer due to corona discharge, overheating, or an internal electric arc. On a slow accumulation of gas, or rapid pressure rise, these devices can trip a protective circuit breaker to remove power from the transformer. Transformers without conservators are usually equipped with sudden pressure relays, which perform a similar function as the Buchholz relay. details

 

Thursday, 14 September 2023

Solar Drone @ Possible Services

 

 A drone, is an aircraft without any human pilot, crew, or passengers on board. Drones were originally developed through the twentieth century for military missions too for humans, and by the twenty-first, they had become essential assets to most militaries. As control technologies improved and costs fell, their use expanded to many non-military applications.These include aerial photography, precision agriculture, forest fire monitoring, river monitoring, environmental monitoring, policing and surveillance, infrastructure inspections, smuggling, product deliveries, entertainment, and drone racing.Solar drones are those  which are powered by solar energy.Solar cells or solar  panels are used for development. It can be very small or huge in size depending on it's works.It can be 24 hour on duty drones as it power itself.No fuel costs  but one time  PV installation.



Polycrystalline vs monocrystalline silicon

 















In single-crystal silicon, also known as monocrystalline silicon, the crystalline framework is homogeneous, which can be recognized by an even external colouring. The entire sample is one single, continuous and unbroken crystal as its structure contains no grain boundaries. Large single crystals are rare in nature and can also be difficult to produce in the laboratory (see also recrystallisation). In contrast, in an amorphous structure the order in atomic positions is limited to short range.

Polycrystalline and paracrystalline phases are composed of a number of smaller crystals or crystallites. Polycrystalline silicon (or semi-crystalline silicon, polysilicon, poly-Si, or simply "poly") is a material consisting of multiple small silicon crystals. Polycrystalline cells can be recognized by a visible grain, a "metal flake effect". Semiconductor grade (also solar grade) polycrystalline silicon is converted to single-crystal silicon – meaning that the randomly associated crystallites of silicon in polycrystalline silicon are converted to a large single crystal. Single-crystal silicon is used to manufacture most Si-based microelectronic devices. Polycrystalline silicon can be as much as 99.9999% pure. Ultra-pure poly is used in the semiconductor industry, starting from poly rods that are two to three meters in length. In microelectronic industry (semiconductor industry), poly is used both at the macroscale and microscale (component) level. Single crystals are grown using the Czochralski method, zone melting and Bridgman techniques.

Wednesday, 13 September 2023

Light-emitting diode


 

A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor.White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device.

Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared (IR) light. Infrared LEDs are used in remote-control circuits, such as those used with a wide variety of consumer electronics. The first visible-light LEDs were of low intensity and limited to red.

Early LEDs were often used as indicator lamps, replacing small incandescent bulbs, and in seven-segment displays. Later developments produced LEDs available in visible, ultraviolet (UV), and infrared wavelengths, with high, low, or intermediate light output, for instance white LEDs suitable for room and outdoor area lighting. LEDs have also given rise to new types of displays and sensors, while their high switching rates are useful in advanced communications technology with applications as diverse as aviation lighting, fairy lights, automotive headlamps, advertising, general lighting, traffic signals, camera flashes, lighted wallpaper, horticultural grow lights, and medical devices.

LEDs have many advantages over incandescent light sources, including lower power consumption, longer lifetime, improved physical robustness, smaller size, and faster switching. In exchange for these generally favorable attributes, disadvantages of LEDs include electrical limitations to low voltage and generally to DC (not AC) power, inability to provide steady illumination from a pulsing DC or an AC electrical supply source, and lesser maximum operating temperature and storage temperature.

In contrast to LEDs, incandescent lamps can be made to intrinsically run at virtually any supply voltage, can utilize either AC or DC current interchangeably, and will provide steady illumination when powered by AC or pulsing DC even at a frequency as low as 50 Hz. LEDs usually need electronic support components to function, while an incandescent bulb can and usually does operate directly from an unregulated DC or AC power source.

As a transducer of electricity into light, LEDs operate in reverse of photodiodes.

Solar cell


 



A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical phenomenon. It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as current, voltage, or resistance, vary when exposed to light. Individual solar cell devices are often the electrical building blocks of photovoltaic modules, known colloquially as solar panels. The common single-junction silicon solar cell can produce a maximum open-circuit voltage of approximately 0.5 to 0.6 volts.

Solar cells are described as photovoltaic, regardless of whether the source is sunlight or artificial light. In addition to producing energy, they can be used as a photodetector (for example infrared detectors), detecting light or other electromagnetic radiation near the visible range, or measuring light intensity.

The operation of a photovoltaic (PV) cell requires three basic attributes: The absorption of light, generating excitons (bound electron-hole pairs), unbound electron-hole pairs (via excitons), or plasmons.
The separation of charge carriers of opposite types.
The separate extraction of those carriers to an external circuit.

In contrast, a solar thermal collector supplies heat by absorbing sunlight, for the purpose of either direct heating or indirect electrical power generation from heat. A "photoelectrolytic cell" (photoelectrochemical cell), on the other hand, refers either to a type of photovoltaic cell (like that developed by Edmond Becquerel and modern dye-sensitized solar cells), or to a device that splits water directly into hydrogen and oxygen using only solar illumination.

Photovoltaic cells and solar collectors are the two means of producing solar power. 

 


 

 

 

Image: Solar cell symbol

Tuesday, 12 September 2023

Renogy Flexible Solar Panel 50 Watt 12 Volt Monocrystalline

 


  • Extremely Flexible] This flexible panel is capable of meeting a wide range of applications where standard panels can be inconvenient to mount, such as on the curved roof of an airstream
  • [Ultra Lightweigh] Thanks to advanced polymer materials, this product weighs 70% less than conventional solar panels, making transportation and installation a breeze
  • [Super Thin Lamination] Hardly noticeable, the Renogy 50W Lightweight Panel laid flat is only a tenth of an inch tall. Approximately 95% thinner than its rigid counterpart, this panel is ideal for a stealthy solar setup
  • [Highly Durable] Rigorously tested, the 50W panel Was designed to withstand extreme wind of up to 2400 PA and snow loads of up to 5400 Pa
  • [Potential Uses] The Renogy 50 Watt Flexible Monocrystalline Panel can be primarily used on off-grid applications that include marine, rooftop, RV, boats and any curvy surfaces 

 


 Traditional solar panels are rigid and often enclosed in tempered glass. The Renogy 50W Flexible Solar Panel is anything but traditional. Perfect for marine use or placement on top of a van or vehicle, the Renogy 50W Lightweight Solar Panel is thin and capable of flexing up to 248 degrees. At 2.87 pounds, this flexible solar panel weighs only a quarter of its traditional 50W counterpart. Highly flexible, this lightweight panel can easily be installed on curved surfaces. This panel can also be used for other various applications, including providing power on a boat or teardrop trailer. 

Link to Buy : Amazon 




Friday, 8 September 2023

An Electrical Ballast

 

An electrical ballast is a device placed in series with a load to limit the amount of current in an electrical circuit.

A familiar and widely used example is the inductive ballast used in fluorescent lamps to limit the current through the tube, which would otherwise rise to a destructive level due to the negative differential resistance of the tube's voltage-current characteristic.

Ballasts vary greatly in complexity. They may be as simple as a resistor, inductor, or capacitor (or a combination of these) wired in series with the lamp; or as complex as the electronic ballasts used in compact fluorescent lamps (CFLs). 

 

 Current Limiting : 

An electrical ballast is a device that limits the current through an electrical load. These are most often used when a load (such as an arc discharge) has its terminal voltage decline when current through the load increases. If such a device were connected to a constant-voltage power supply, it would draw an increasing amount of current until it is destroyed or causes the power supply to fail. To prevent this, a ballast provides a positive resistance or reactance that limits the current. The ballast provides for the proper operation of the negative-resistance device by limiting current.

Ballasts can also be used simply to limit the current in an ordinary, positive-resistance circuit. Prior to the advent of solid-state ignition, automobile ignition systems commonly included a ballast resistor to regulate the voltage applied to the ignition system.

ECO-WORTHY 4 String PV Combiner Box

 


ECO-WORTHY 4 String PV Combiner Box 10A Circuit Breaker with Plastic ABS Cover Electrical Box - Waterproof Safe Protection Photovaltaic Generator for Solar Power System Solar Panel Kit Home 

 


Seller : Amazon Uk 

 

 

 

 

 

 

 

 

 

LED Bulbs E27 Screw 220V-240V 12W

 


Specification:

Base type:E27 LED Lamp Light Bulb

Voltage:AC 220V (200V-240V)

Color temperature:6000-6500K(cold white)

High-Grade Series: 12W Brightness: 100LM/W

Packing

1pcs/lot

 


Average Life : 15000 hours 

Beam  Angle : 270

EU Energy Efficiency Label : A+++

 

Wednesday, 6 September 2023

120W Portable Solar Panels with A+ Monocrystalline PV Cell

 


  • Easy to Carry: Crafted from advanced 3rd-generation polymer materials and featuring a foldable structure, it boasts a weight that is 30% lighter than comparable products, making it an excellent choice for portable use. Whether for RV solar panels, camping adventures, or outdoor excursions, this solar panel is the ideal companion.
  • Remarkable Efficiency: Equipped with high-quality monocrystalline silicon PV cells, ACACIA's 100W solar panel boasts an industry-leading 23% conversion rate, ensuring a faster and more efficient charging experience for your solar generator. It easily connects to 300Wh power stations via solar connectors, allowing you to recharge in just 2.5 hours.
  • Longer-lasting Quality: Featuring A+ PV cells, this product guarantees a service life of over 25 years. It incorporates third-generation polymer materials, providing a semi-flexible design that enhances durability and reduces the risk of panel breakage.
  • All-Weather Resilience: ACACIA's flexible solar panel is equipped with an IP67 waterproof enclosure, providing protection against water for up to 30 minutes at a depth of 1 meter. Rigorous testing, including over 300 hours of exposure to extreme conditions at 185°F with 85% humidity, ensures its durability.
  • Versability: For off-grid camping and to tackle unexpected power outages, this solar panel is a great match for any 300/500/1000/1500W power stations (sold separately).
  • Simplified Setup: The ACACIA solar panel features three effortlessly adjustable kickstands, enabling the panel to optimize light capture. Additionally, a built-in sundial aids in panel angle adjustment and serves as a reliable timekeeping tool in emergency situations.
  • Adaptability: The ACACIA solar panel folds down to a compact 18.3 * 21.7-inch size, featuring embedded holders for easy and comfortable transport. Plus, its durable magnetic locks allow for quick packing in just 60 seconds, even in stressful situations.
  • What's in the box: 1*120W solar panel,1* MC4 output controller, 1* User Manual, 1*Warrenty Card. 

 

Buy it from  link : Link

 




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