Transformers
Glossary of Power Transformer Terms
There are many terms associated with power and distributive transformers used in electrical networks. These are just some of the most important. Feel free to add any of missing terms in the comment below ;) An Ansi (American National Standard… Read more
Jun 05, 2013 | By Edvard Csanyi
Energy and Power
Transformer temperature, oil level and pressure gauges
Temperature controls are required in order to turn on and off the cooling equipment. These controls are usually combined with a visible dial-type gauge that measures ‘winding temperature’. This is really a misnomer because the gauge does not actually contact… Read more
Jun 03, 2013 | By Edvard Csanyi
Testing and Commissioning
Condition Monitoring of Transformers
It is possible to provide transformers with measuring devices to detect early signs of degradation in various components and provide warning to the operator in order to avoid a lengthy and expensive outage due to failure. The technique, which can… Read more
May 24, 2013 | By Edvard Csanyi
Testing and Commissioning
Transformer Routine Dielectric (Insulation) Test
The following insulation tests are performed in order to meet the transformer insulation strength expectations. Unless otherwise requested by the customer, the following test are performed in the following order (IEC 60076-3) : To confirm the insulation of the transformer terminals… Read more
May 23, 2013 | By Edvard Csanyi
Testing and Commissioning
Erection Procedure for Power Transformer
This technical article deals with transformers and their installation so we restrict ourselves here to the procedures associated with their commissioning. Transformers should be inspected for internal or external damage, particularly if they have been dropped or tipped over. This should include such… Read more
May 20, 2013 | By Edvard Csanyi
Energy and Power
Ferroresonance Occurrence In Power Transformer
Ferroresonance occurs when line capacitance resonates with the magnetizing reactance of a core while it goes in and out of saturation. Ferroresonance is usually associated with potential transformers, which are instrument transformers that are used to develop voltages used by… Read more
May 10, 2013 | By Edvard Csanyi
Testing and Commissioning
When a transformer has stomach pain and wants to…
During normal operation, transformer internal structures and windings are subjected to mechanical forces due to the magnetic forces. These forces are illustrated in Figure 1. By designing the internal structure very strong to withstand these forces over a long period of… Read more
May 08, 2013 | By Edvard Csanyi
Electric Motor
Starting Motor With Auto-transformer
An auto-transformer starter makes it possible to start squirrel-cage induction motors with reduced starting current, as the voltage across the motor is reduced during starting. In contrast to the star-delta connection, only three motor leads and terminals are required. On… Read more
Mar 18, 2013 | By Edvard Csanyi
Energy and Power
An Overview Of Short Circuit Current (part 3)
Fault calculations are carried out to find the magnitude of fault current at various voltage levels of electrical system. One of the key components in the calculation process is to determine the total impedance of the circuit from the utility /… Read more
Mar 08, 2013 | By Asif Eqbal
Testing and Commissioning
Transformer Routine Test – Measurement of Voltage Ratio and Check of Phase Displacement
The no-load voltage ratio between two windings of a transformer is called turn ratio. The aim of measurement is: Confirming the no-load voltage ratio given in the customer order specifications, determining the conditions of both the windings and the connections… Read more
Mar 02, 2013 | By Edvard Csanyi
Testing and Commissioning
Transformer Routine Test – Measurement Of No-Load Loss And Current
The no-load losses are very much related to the operational performance of a transformer. As long as the transformer is operated, these losses occur. For this reason, no load losses are very important for operational economy. No-load losses are also… Read more
Feb 18, 2013 | By Edvard Csanyi
Transformers
What is transformer rating based on?
In the U.S., transformers are rated based on the power output they are capable of delivering continuously at a specified rated voltage and frequency under “usual” operating conditions without exceeding prescribed internal temperature limitations. Insulation is known to deteriorate with… Read more
Jan 30, 2013 | By Edvard Csanyi
Transformers
D.M.C.R. Protection Relay for Oil Transformer
Introduction to D.M.C.R. Faults detected on live transformer unit: Dielectric fluid level is detected as low Overheating is detected Excess pressure is detected Standards Possibilities of D.M.C.R.: Oil level control and gas detection Pressure control Temperature control The DMCR is… Read more
Jan 16, 2013 | By Edvard Csanyi
Testing and Commissioning
Transformer routine test – The measurement of winding resistance
Measurement is made to check transformer windings and terminal connections and also both to use as reference for future measurements and to calculate the load loss values at reference (e.g. 75ºC) temperature. Measuring the winding resistance is done by using… Read more
Jan 05, 2013 | By Edvard Csanyi
Transformers
Importance of Transformer Inrush Current
When a transformer is taken off-line, there will be a certain amount of residual flux that can remain in the core due to the properties of the magnetic core material. The residual flux can be as much as 50 to… Read more
Dec 28, 2012 | By Edvard Csanyi
