AC and DC Transmission Systems
AC and DC transmission systems have distinct characteristics, advantages, and disadvantages. AC transmission is often preferred for short-distance transmission due to its simplicity and cost-effectiveness, while DC transmission is suitable for long-distance transmission with better voltage regulation and fewer losses. The choice between AC and DC depends on the specific requirements and constraints of the transmission scenario.
Difference between AC and DC Transmission Systems
| Parameter | AC Transmission System | DC Transmission System |
|---|---|---|
| Definition | An electric power transmission system that uses alternating current. | An electric power transmission system that transmits power in the form of DC supply. |
| Construction of Transmission Line | More complicated. | Less complicated. |
| Generation | Electric power can be generated easily at high voltages. | Electric power cannot be easily generated at high voltage due to commutation problems. |
| Number of Conductors | Three conductors are required (for red phase, yellow phase, and blue phase). | Only two conductors (positive and negative) are required. |
| Need of Transformer | Transformer is used for stepping up or down the voltage. | Transformer cannot be used as it does not work with DC supply. |
| Insulation Material | Requires more insulation material due to more conductors. | Requires less insulation material due to fewer conductors. |
| Stability and Surges | Effects of stability and surges are found. | Free from the effects of stability and surges. |
| Factor Present | Capacitance, inductance, and phase displacement are present. | Capacitance, inductance, and phase displacement do not exist. |
| Effect of Capacitance | Presence of capacitance causes continuous power loss. | No capacitance, no power loss. |
| Effect of Inductance | Inductance causes more voltage drop, poor voltage regulation. | No inductance, less voltage drop, good voltage regulation. |
| Change in Voltage Level | Transformer is used for changing voltage level. | Chopper and booster are used for changing voltage level. |
| Skin Effect | Skin effect occurs. | No skin effect. |
| Corona Effect | Corona exists. | Corona rarely exists. |
| Required Components | Transformer, conductors, and insulators. | Rectifier, conductors, insulators, and inverter. |
| Cost | Construction and maintenance are cheap. | Construction and maintenance are expensive. |
| Repair and Maintenance | Repair and maintenance are simple and easy. | Repair and maintenance are difficult. |
| Length of Conductors | Used for short-distance transmission. | Used for long-distance transmission. |
| Interference | Interferes with nearby communication lines. | Does not interfere with communication lines. |
| Dielectric Loss | Has dielectric losses. | Does not have dielectric losses. |