An Isolation Transformer is a device which is use to decouple two circuit, the load to the Isolation Transformer and to the Input supply, Isolation Transformer suppress electrical noise which occurs in transmission line. An Isolation Transformer blocks transmission of DC signal from one circuit to other and allow ac signal to transmit. It also prevent interference cost by ground looping. Isolation Transformers are constructed with two isolated Faraday shields between the primary and secondary windings. Theuse of two shields in the construction of the isolation transformer diverts high frequency noise, which would they occur. The two shields provide more effective isolation of the primary and secondary circuits and also isolation to their grounds.
Common – Mode Noise
This noise appears between both sides of power line and ground. These High Frequencies noise occurs between ground and conductor.
Transverse – Mode
Transverse – Mode noise is much more difficult to eliminate than common-mode noise. These High magnitudes noise occurs between two conductors due to switching action of equipments
Switching of electrical utilities like Capacitors, MCCBs
Welding systems pollutes earthing systems, adds notches and high frequency noises in the wave form,generatingpower quality anomalies.Lightening, precipitation of static charges and electrical discharges in the atmosphere are the natural cause of generation of various electrical noises.Ultra Isolation Transformers are used where high attenuation level is required like Communication Systems, Wireless Station, Sensitive Medical
Equipments etc., These special type transformers are manufactured by splitting primary and secondary coils results reduction in coupling Capacities in transformer Circuit Common – Mode, Transverse M ode and Electromagnetic. Range: From 40 VA to 40 KVA single
phase and 50 VA to 2000 KVA3 phase
Advantages of Magnetic Clean line Isolation Transformers Very high noise attenuation capacity Reduced coupling capacitance. Lesser leakage current Suitable for higher harmonic loads. Core will not saturate
Electrical Noises are generated due to
| Switching of electrical utilities like Capacitors, MCCBs, ACB’s…etc. Larger the inductance of the system and larger the current change during switching, larger the magnitude of electrical noises.
The inductive loads like big Motors, Compressors, Overhead Cranes, Elevators, Presses etc. also generates substantial switching noises Switching equipments like Invertors, Converters, SMPS etc generate electrical noises due to switching of Thyristors, Transistors, Relays etc. |
Electrical noises are observed to occur over a wide band of frequency ranging from 1 KHz to 100 MHz and above. In magnitude observed to be as high as 4000 to 6000 Volts on 3 phase supply system. The high frequency noise can interfere with digital electronic equipments causing untraceable data errors, change of programme, loss of memory, erratic behaviour, etc. The high voltage spikes can cause the failure of Thyristors or Transistor, Micro Processors and other |