Power Transformer
YAwei is a professional manufacturer of transformers. It can produce Single phase transformer. Three-phase transformer, Pad mounted transformers, Dry transformer, Distribution transformer and High voltage transformer of 69KV and above. It can meet IEEE/ANSI/DOE/CSA and IEC standards. Moreover, we have over 30 years of export transformer manufacturing experience. YAWEI transformers have at least two-year warranty. OEM and ODM accepted.
Yawei Group has more than 180 engineers and technical personnel. More than 1000 employees, covering an area of 240,000 square meters. we have 6 branch Branch factories. Cover complete production line of transformer from winding wire silicon sheet slitting and rolling, transformer oil tank producing and power transformer manufacturing. Better control of quality and cost for complete production line.
Why choose us?
High quality
Our group company is distinguished by its comprehensive product line, great quality control that permeates every stage of our operations-from the selection of raw materials to the meticulous production process and the reliable delivery of our products.
Professional team
With a dedicated team of over 150 engineers and technical professionals supported by a workforce of more than 1800 employees, we cover every aspect from design to production to delivery. Our diverse teams are committed to offering you impeccable customization tailored to your unique needs.
Accept ODM/OEM Service
Our state-of-the-art domestic automotive stacking equipment, lightning shock apparatus, and epoxy vacuum pouring machines are designed to handle large-scale orders with unwavering commitment to quality and precision.
Custom service
Our seasoned after-sales team, backed by a sophisticated support process, stands ready to address your urgent needs around the clock, ensuring that you receive prompt and professional assistance whenever it's required.
A power transformer is a device operating with high voltages in power system, primarily to adjust voltage levels between generators and distribution circuits. It consists of two or more windings linked magnetically via a core. Current variations in one winding induce changes in magnetic flux in the core, thereby generating voltage in other windings. The voltage ratio between primary and secondary windings depends on their turn ratios.
Isolation and productivity
Transformers are incredibly useful devices that have a wide range of applications. They are especially useful in providing electrical isolation between two circuits. There is no electrical connection between the transformer's primary and secondary windings. Transformers work by transferring energy entirely through magnetic coupling, which makes them highly efficient and reliable. Additionally, transformers are relatively simple in construction, making them easy to produce and maintain electricity.
Power transmission and distribution
AC transformers play a critical role in the power system, which includes power generation, transmission, and distribution. Transformers make it possible to distribute electric power over large distances at a reasonable cost.
Stepping voltage and current up and down
Transformers are vital in power distribution and electronic systems. Reducing the high voltage in transmission at substations makes it possible for end-users to get the increased amount of current they need.
Efficiency in terms of costs
A transformer is a great alternative to a more expensive option for voltage level change and isolation. The traditional transformer provides a cheap and very efficient voltage level transformation and isolation method. The total cost of a transformer is not expensive.
Wide range of applications
All transformers work on the same concept but have different applications. They are also different in terms of power, distribution, potential, and isolation efficiency.
Simple working principle and construction
A transformer is a static device consisting of a winding, or two or more coupled windings, with different numbers of turns on a magnetic core, for inducing mutual coupling between circuits. The alternating magnetic field created in one winding induces a current in the other, which is proportional to the number of turns.
Various types and wide usage areas
Transformers have various types: distribution, power, current, potential, and isolation transformers. Each of them works on the same principle but has different usage areas. For example, current transformers step down currents for measurement instruments.
No moving parts, and starting time
A transformer has no internal moving parts and transfers energy from one circuit to another by electromagnetic induction. It ensures, under normal conditions, a long and trouble-free life. Besides, it does not require any starting time.
Reverse connected
Most transformers can be "reverse connected," which means the same transformer can be wired to be a "step-up" or "step-down, depending on how it's installed. This reversing capability must be allowed and specified by the manufacturer.
Multiple taps
Some transformers may be equipped with multiple taps on the primary to accommodate various input voltages. These taps are sized for standard voltages (220, 230, 240….etc.), or they can be slight variations to adjust for consistent over or under voltage at a particular location. These taps are most commonly provided as a percentage of the primary voltage, such as 2-1/2% and 5% (up or down from nominal).
Types of Power Transformer
Berry-type transformers have a core designed like the spokes of a wheel. They utilize distributed magnetic circuits and contain multiple independent magnetic circuits, typically more than two.
In core-type transformers, the primary and secondary windings encircle the core. The core is made by joining two L-shaped steel strips, which are then stacked to create the core layers. To minimize reluctance at the joints, the strips are arranged to avoid continuous joints. The flux is carried by the limbs and yoke of the core.
In shell-type transformers, the core encircles both the primary and secondary windings. The core is constructed from E-shaped and I-shaped steel strips, which are stacked to form layers. In this design, the central limb of the core carries the entire magnetic flux, while the side limbs each carry half of the flux.
Isolation transformers have a turns ratio equal to 1, which means the number of turns in the primary and secondary windings is equal. They are used to isolate the load from the power source while supplying alternating currents. They protect the electrical device, operation, and persons from electrical noise, shock, and damage. They are commonly used in computers, measurement devices, industrial machinery, laboratory and medical equipment, and other sensitive equipment.
Step-down transformers have a turns ratio of less than 1, which means that the primary winding has more turns. These transformers convert the high voltage and low current input from the primary winding to a low voltage and high current output on the secondary winding.
Step-up transformers have a turns ratio greater than 1, which means that the secondary winding has more turns. These transformers convert the low voltage and high current input from the primary winding to a high voltage and low current output on the secondary winding.
Single-phase transformers consist of a single pair of windings arranged around a core and produce a single alternating voltage, represented by a single sine wave. They feature four terminals, with each winding having two terminals. These transformers do not include star (wye) or delta connections.
Three-phase transformers are composed of three pairs of primary and secondary windings. They can be constructed by connecting three single-phase transformers to form a transformer bank or by assembling three pairs of windings into a single laminated core. Three-phase transformers generate three-phase alternating current flowing in separate conductors. Three sine waves represent this, and the waves are separated by 120 degrees from one another. The amplitude is reached more frequently which makes three-phase transformers supply power at an almost constant rate.
Power transformers work on the principle of electromagnetic induction, which was discovered by Michael Faraday. The principle states that a changing magnetic field within a coil of wire induces a voltage across the ends of the coil. A power transformer contains two main components: primary and secondary windings. These coils of wire are wound around a common iron core.
A changing magnetic field is generated in the iron core when an alternating current flows through the primary winding. This alternating magnetic field results in an alternating voltage in the secondary winding. This induced voltage depends on the turn ratio of the windings. If the turns are more in the secondary than the primary winding, the transformer increases the voltage. On the other hand, if the secondary winding has fewer turns than the primary winding, the transformer steps down the voltage. The role of the core in a transformer is to efficiently transfer the magnetic flux between the windings with minimal energy loss.
Application of Power Transformer
Substations
Transformers in substations play a key role in high-voltage transmission. Here, step-up transformers elevate distribution voltages for efficient long-distance power transmission through transmission lines. On the other hand, step-down transformers lower transmission voltages for distribution to towns and cities through distribution lines.
Copper mines
Because of the fire and explosion risks underground, copper mines require specially designed isolated transformers. These transformers have enclosures surrounding the coil assemblies to prevent arcing from causing ignitions in hazardous mine atmospheres.
Power plants
Within thermal and hydroelectric power plants, generators produce electricity at a voltage suitable for efficient generation, which may differ from transmission standards. Hence, station service transformers adjust the voltages to the required transmission levels before sending them out through transmission lines.
Residential distribution
Pole-mount transformers located on utility poles along streets help reduce distribution voltages even further for safe usage levels in homes. Pad-mount transformers installed above ground at housing complexes perform a similar voltage conversion function for supplying various residential loads.
Transformer tank
This holds the transformer windings and its insulating medium (oil-filled). Transformer tanks must be air-tightly sealed for it to isolate its content from any atmospheric contaminants.
High voltage bushing
This is the terminals where the primary windings of the transformer terminates and serves as an insulator from the transformer tank. Its creapage distance is dependent on the voltage rating of the transformer.
Low voltage bushing
Like the high voltage bushing, this is the terminals where the secondary windings of the transformer terminates and serves as an insulator from the transformer tank. Low voltage bushing can be easily distinguished from its high voltage counterpart since low voltage bushings are usually smaller in size compared to the high voltage bushing.
Cooling fins/radiator
In order for the transformer to dissipate the heat it generated in its oil-insulation, cooling fins and radiators are usually attached to the transformer tanks. The capacity of the transformer is dependent to its temperature that is why it is imperative for it to have a cooling mechanism for better performance and higher efficiency.
Cooling fans
Can be usually found attached to the cooling fins. Cooling fans can be either be a timer controlled or a winding/oil temperature controlled. Cooling fans helps raises the transformer capacity during times when the temperature of the transformer rises due to its loading. Cooling fans used on the transformer are actuated by the help of a relaying device which when senses a relatively high temperature enables the fan to automatically run.
Conservator tank
An oil preservation system in which the oil in the main tank is isolated from the atmosphere, over the temperature range specified, by means of an auxiliary tank partly filled with oil and connected to the completely filled main tank.
System ground terminal
System ground terminals in a power transformer are usually present whenever the connection type of the transformer windings has wye in it. This terminal can be found in-line with the main terminals of the transformer.
Drain valve
Can be usually found in the bottom part of the transformer tank. Drain valves are used whenever oil replacement is necessary. Through this valve, the replacement of oil in an oil-filled transformer can be easily done simply by opening this valve like that of a faucet.
Dehydrating breather
Dehydrating breathers are used to prevent the normal moisture in the air from coming in contact with the oil in electrical equipment as the load or temperature changes. This reduces the degeneration of the oil and helps maintain its insulation capability. When used with conservator system with a rubber air cell it reduces moisture accumulation in the cell. Some breathers are designed for sealed tank transformers and breathe only at pre-set pressure levels. ABB
Oil temperature/pressure gauges
These are used for monitoring the internal characteristics of the transformer especially its windings. These gauges help the operator in knowing the level of temperature and pressure inside the transformer (oil & winding). This will also serve as an alarm whenever a certain level is reached that could be harmful to the transformer windings.
Bushing current transformers
Modern transformer construction today now includes current transformers. These are usually found around the transformer terminals which will be later be used for metering and relaying purposes. Its terminals are found in the control panels attached to the transformer.
Control panel
This houses all of the transformer’s monitoring devices terminals and auxiliary devices including the terminals of the bushing current transformers and cooling fans. Control panels are very useful especially when a remote control house is needed to be constructed, this will serve as their connection point.
Surge arresters
This type of arresters are placed right directly before and after the transformer terminals in order to minimize the exposure of the transformer. Like any other surge arresters, its purpose is to clip sudden voltage surge that can be damaging to the winding of the transformer.
How to Maintain Power Transformer
It is vital to perform regular checks on the load capacity of your transformers. Electrical transformers that operate below the maximum load capacity have a longer lifespan.
It is advisable to maintain your transformers’ load capacity between 75 to 90 per cent of the stated max capacity. Doing so reduces the risk of the transformers malfunctioning and giving you problems.
Prepare a maintenance schedule beforehand and circulate it among the maintenance crew so everyone is informed. Your team must perform a daily check on the magnetic oil gauge (MOG) of both the main and conservator tank.
This assessment is to ensure the oil level is filled up to the desired level. If any leakage is detected, you have to seal it as soon as possible.
The oil level in the oil cap has to be checked monthly to ensure it does not drop below the recommended level. Any dip below this level could cause potential damage to your electrical transformers.
The oil condition of the tap changer also has to be checked annually. The oil has to be checked for its moisture content and dielectric strength. If the values are found to be irregular, then the oil has to be replaced.
The silica gel plays a critical role in the performance of electrical transformers. Always make sure the breathing holes are clean to allow for proper breathing action at all times. Ensure your maintenance crew pays close attention to the colour of the silica gel. If the colour changes to pink, you have to replace it immediately.
However, change in colour aside, if you notice any other issues you’re unsure of – requesting assistance from a professional may be necessary. Just like how you would engage one for generator overhauling to run a thorough check of your motor generator – you should also do the same for your transformer.
With an overhaul, your engineer will know what’s the exact next step to take for maintaining your equipment.
It is advisable to perform an open-circuit test on your transformers. An open circuit fault is one of the most common defects. The fault is usually caused by joint failures of cables and overhead lines, circuit breaker failures, or the fuse/conductor melting.
Carrying out frequent testing allows you to detect these issues and fix them promptly. If left unchecked, these issues can mount and cause significant problems down the line.
Suppose you do not have a regular maintenance crew – you may want to consider scheduling an external engineer to conduct routine inspection and maintenance of your transformers. With a professional engineer’s expertise and knowledge, you can trust in their ability to maintain your transformer’s condition or even increase its efficiency over time; depending on which service you’re going for.
It’s best to get in touch with an engineer who is well-versed in numerous services, from generator rewinding, switchgear maintenance, to retrofilling. That way, you can approach the engineer for any other services that you need help in.
Even though your electrical transformers are running smoothly, you should not neglect to conduct regular check-ups. Routine inspection and maintenance can help to reduce the risk of a breakdown.
Certifications
Our Factory
Yawei Group has more than 180 engineering and technical person , more than 1200 employees, covering an area of 240,000 square meters.
We have strong production capacity and built a highly efficient marketing team. The products include 110kvpage-3-5220kv and 500kv ultra-high voltage transformers, 35kv and below dry-type transformers, oil immersed transformers, amorphous metal transformer, wind and solar storage new energy transformers, prefabricated substation and special transformers such as reactors, electric furnace transformers, rectifier transformers,mining transformers, split transformers and phase shifting transformers of various specifications. In order to assure the implementation of the advanced design and manufactural technology,some key equipments, moulds and tools had been replaced and improved with the latest technologies to meet the requirements of product quality.
FAQ
Jiangsu Yawei Transformer Co.,Ltd. is one of the most professional power transformer manufacturers and suppliers in China, specialized in providing high quality customized service. We warmly welcome you to buy high-grade power transformer made in China here from our factory.
Power Transformers, 75 kVA Single Phase Pad Mounted Transformer, Furnance Transformer