Oil Filled Potential Current Transformer

Oil Filled Current Transformer

Outdoor Oil Filled Current Transformer is a type of electrical current transformer in which the core of the transformer along with its secondary windings is placed in the tank. Live Tank Current Transformers are different from Dead Tank Current Transformers in their design and tank fabrication. At a macro level, the basic functionality of both remain the same, which is to step down high voltage current to low voltage current for measurement by energy meters or other such instruments.

In an outdoor oil filled live tank current transformer, the core and secondary windings are insulated from high voltage with insulating material and placed in the top tank. In Live Tank CTs, the primary conductor is shorter in length which makes it stronger to withstand high short circuit currents. Also, the primary winding in Live Tank Current transformers is homogeneously distributed around the core to create a current transformer which has low reactance and excellent transient performance.

Live Tank Current transformers are smaller and compact in size compared to Dead Tank Current Transformers. They are also more economical to be produced and are hence cheaper than Dead Tank CTs.

Macroplast manufactures oil filled live tank Current transformer supto 132 KV system voltage. The Live tanks CTs manufactured by us have cores, primary and secondary windings arranged in the top tank of the transformer body. The primary windings are then connected to the primary terminals which are also arranged in the top tank. The secondary windings are taken through the HT insulator to the bottom mounting base. The mounting base has arrangement for secondary terminals inside the secondary terminal box.

Outdoor Oil Filled Dead Tank Current Transformer is a type of current transformer in which both the core and secondary windings of the transformer are placed in the bottom tank. This bottom tank is then earthed to make it dead, and hence the name dead tank transformer. In Dead Tank CTs, the primary winding is made to pass through an insulator constructed of porcelain material. It is then connected to the bottom tank and insulated from the tank and the cores of the transformer. The internal design Dead Tank Current Transformers ensure the primary conductor produces maximum mechanical force during short time dynamic current to prevent damage to internal insulation.

The biggest advantage of Oil Filled Dead Tank Current Transformers in comparison to Live Tank Current transformer is its high seismic strength. Since the core and secondary windings are place in the lower tank, the stability of Dead tank CTS is much stronger. Also, it is easier to transport them from the place of manufacturing to the place of installation with lesser chances of breakage or damage. Dead Tank Oil Filled Current transformers are however expensive and heavy compared to Live tank current transformers.

Macroplast manufactures outdoor oil filled dead tank current transformer of various system voltages. In our Dead tank CT design, the cores, primary and secondary windings are arranged in the lower tank. The primary windings are taken to the top tank through HT insulators and connected to the primary terminals. The secondary windings are connected to the secondary terminals arranged inside the secondary terminal box placed on the bottom tank.

The Dead Tank design is preferred where the No. of CT Cores are more because more cores means more weight and lesser stability. In such cases, Live Tank CTs are not preferred from Technical Point of view.

Outdoor oil minimum current transformer is a unique current transformer design developed in-house by Macroplast. These type of CT design has only one tank which reduces the requirement of oil in manufacturing the transformer. This in turn reduces the cost of producing the transformer. Oil minimum CTs are cheaper than both Live tank CTs and Dead Tank CTs

In this design, the cores and primary windings are taken through porcelain insulators and connected to primary terminals. Unlike other Current transformers, this design has two porcelain insulators for incoming and outgoing conductors. The LT terminal box is also attached on the body of the tank. Oil minimum current transformers are usually used in lower system voltages power systems upto 33 Kilovolts (KV).

Macroplast manufactures Outdoor oil minimum current transformer upto 33kv system voltage. Our outdoor oil minimum current transformers are widely used by several state electrical utilities in India.

Oil Minimum Current Transformers are preferred where the primary currents are not more than 400 A and the CT Cores are also less maximum to 2. Primary currents more than 400 A will lead to manufacturing problems and is not feasible from Technical point of view.

Keywords :

  • - Outdoor, Oil Filled Current Transformers
  • - Outdoor, Oil Immersed Current Transformers