Constant Voltage Transmission in Long Transmission Line
Synchronous motors are specially designed for constant voltage transmission, called synchronous phase modifiers. It is installed at the receiving end, which maintains the voltage drop on the line constant. As the load changes, the power factor of the synchronous motor also changes, and thus the voltage drops in the direction of the line constant.
The constant voltage supply is an important issue in transmission lines. Voltage variation in the transmission line has an effect at the consumer end, which is undesirable. Measures taken in transmission lines to prevent excessive voltage variation at the consumer end are as follows-
1. Using tap changing transformer in transmission line,
2. Use of auto transformer in transmission line,
3. Use of booster transformer in transmission line.
Advantages and disadvantages of constant voltage transmission system are given below-
What is the advantage of constant voltage transmission?
1. Enhanced power transmission is possible.
2. Power factor is improved in medium to heavy load applications.
3. If it is possible to use high terminal reactance in the line, better protection is possible.
4. Steady voltage is always available across the line terminals of all loads.
What is the disadvantages of constant voltage transmission?
1. Short circuit current in the system increases.
2. A fault in any of the synchronous motors causes the synchronous phase modifier to deviate from synchronism and any accident may occur.
3. If any trouble occurs in the line, lower reserve is created in the line.