It is known that this type of transformer has one primary coil and two secondary coils. The LW8-40 outdoor High-voltage circuit breaker to the primary is diverted through the magnetic shunt and further increases in primary voltage produces little change in the secondary emf.
Effectively the aim is to keep the Iron core of the secondary saturated, which keeps the voltage on the output winding constant. The very best power protection comes from a special type of transformer known as a Constant Voltage Transformer ( CVT ). Providing unparalleled reliability and conditioning performance, spikes and electrical noise are neutralised with attenuation as high as 75dB. Voltage and potential transformers include under-current sensing and over-current sensing devices, as well as Noncontact current transformers.
Split-core voltage and potential transformers feature a hinge and locking snap mechanism that allows attachment without interrupting the current-carrying wire. In parallel, blue instrument transformers are extremely powerful and space saving: They operate reliably at temperatures below minus 50 degree Celsius, without additional heating, and have the same space requirements as SF6-filled voltage transformers, in the same voltage range. Ferroresonant Transformers are inherently self-protected against short circuits, and are able to supply large surge currents if required because of the large amount of energy stored in the secondary circuit.
Because of the capacitor and magnetic shunt, the secondary magnetic circuit is operating above the knee” in the flat portion of the magnetization curve, and the output flux change is reduced. The magnetic shunt provides a path for the imbalanced flux of the primary and secondary by allowing a portion of the primary flux to return to the primary winding without coupling the secondary. The voltage induced in the capacitor winding by the primary flux causes a capacitive current to flow.
Secondary Windings: Enamelled electrolytic copper wire is used for secondary windings of voltage transformer. Primary Windings: Enamelled electrolytic copper wire is used for primary windings of voltage transformer. One of the latest developments, started in 2006, the Power Voltage Transformer type VPT is based on the Inductive Voltage Transformer type VPU which brings more than 45 years of both design and sevice experience.
Power Voltage Transformers – Type VPT. Current transformers with primary winding for alternating current from 1 to 600A. They adapt the values of the primary current to the characteristics of the measuring or protection equipment, providing a secondary current proportionally reduced to the standard values 5A or 1A. The IME current transformers comply with the standards EN / IEC 61869-1, EN / IEC 61869-2 and, depending on the intended use, can be divided into:
There are three primary types of potential transformers (PT): electromagnetic, capacitor, and optical. Some transformer winding primary (usually high-voltage) connecting wires are of many types. This causes metering PTs to saturate at lower secondary voltage outputs saving sensitive connected metering devices from damaging large voltage spikes found in grid disturbances.
Voltage transformers (VT), also called potential transformers (PT), are a parallel connected type of instrument transformer. One type provides an IR voltage output that is proportional to the measured current; another, called a Rogowski coil , requires an external integrator in order to provide a proportional output.