Wave Trap Working Function & Purpose of Line Trap:
Wave trap is used to create high impedance to the carrier wave high frequency communication entering in to unwanted destinations typically substation. Carrier wave communication uses up to 150kHz to 800kHz frequency to send the all the communication. These high frequency damages the power system components which are designed to operate 50 or 60 Hz. Wave traps are also called as line traps. It consists of an inductor coil which is connected in series with the high voltage power system. Please refer the figure.
Construction of Wave trap circuits:
Wave trap circuit consists of three major components such as..
- Main Coil
- Tuning Device
- Protective Device
Main Coil is nothing but an outer part of the wave trap circuits and which is made from standed aluminum cable. If the application of more than one layer is necessary, separation between layers is required to provide a cooling duct between them to avoid overheating. The cooling duct is created with spacer bars made out of epoxy resin and fiberglass. The coil carries rated continuous power frequency currents, therefore this is the power inductor in this system. It provides a low impedance path for the electricity flow. The total current carrying capacity of the transmission system will be calculated, and the trap coil are designed according to that. That’s why the coil become bigger size as you can see in High voltage transmission.
When the frequency increases, the inductive reactance will get increases. That’s why it creates high impedance for high frequency signal and low impedance for low frequency signal. This unit prevents the high frequency carrier signal from entering the power circuits.
A coupling capacitor is used to receive high frequency communication signal. As the capacitor principle of capacitor creates low impedance for high frequency signal.
As the frequency increases, the impedance value decreases and the frequency decreases the impedance increases.
Tuning Device of Wave Trap:
The next major component is the tuning device. This device is securely installed inside the main coil. It adjusts blocking frequency or bandwidth, and consists of coils, capacitors, and resistors. Tuning device is connected in parallel with main and protective device. It provides blocking impedance over a specified frequency range. It can be sing band tuned or multiple bands. The tuning circuit is enclosed in weather proof enclosures filled with resin/foam to protecting from weather conditions.
The last main component is the protective device, which is parallel with the main coil and the tuning device. Protective device ensures protection of tuning device and main coil against surge voltages. Also It protects the main coil and the tuning device by lowering the over-voltage levels. The bandwidth of a line trap is the frequency range over which the line trap can provide a certain specified minimum blocking impedance or resistance.
Line traps are connected in series with power line and thus their coils are rated to carry the full line current. The impedance of a line trap is very low at the power frequency and will not cause any significant voltage drop.
Inside of Wave trap :
Ref : https://en.wikipedia.org/wiki/High_frequency_line_trap
- Why 60 Watts incandescent Bulb Glow in Yellow color
- Why Aluminium and Copper Vessels & Pot not Used in Induction Stove
- Why Are Alternators Rating in KVA or MVA
- Why Battery Cannot Store AC voltage
- Why Capacitor and Inductor are used in Filtering Circuit
- Why Capacitors Use As High Voltage Protection
- Why Carbon brushes are selected, How to Select Good carbon brushes
- Why CT secondary should not Open condition- Live Test Demo
- Why DC Voltage is preferred for Control circuit?
- Why Does Bird Not Get Shock on Transmission lines?
- Why Earth Pin is Plastic Thicker and Longer
- Why Earthing Transformer are used
- Why in India 11kV, 22kV, 33kV, 66kV, 132kV…
- Why India has 50 Hz Power System and US has 60 Hz 110 Volts Power System
- Why induction motor Takes high starting current
- Why Inductors Use In Filtering Circuit and VFDs
- Why is Battery United AmpsHour AH
- Why Lighting Transformer Used for Lighting Loads
- Why line chokes are used in VFD
- Why Permanent magnet generator (PMG) poles are high
- Why PT and CT Terminals are Star Connected
- Why Slip ring Induction motor is preferred for High starting Torque application
- Why Star delta starters are preferred for higher HP motor
- Why Tertiary Winding is used in transformer?
- Why transformer Rating in KVA exact answer
- Why VFD duty motor Frame size come in higher size
- Why we should not give dc supply to Transformer
- Why Zig-Zag Winding Transformer Used