Tehonhäviöitä

Tehonhäviöitä, or power losses, refer to the reduction in electrical power that occurs during the transmission, distribution, and utilization of electricity. These losses are an inherent part of any electrical system and arise from various physical phenomena.

The primary source of power loss in electrical conductors is Joule heating, also known as resistive loss. As electric current flows through a conductor, it encounters resistance, which converts some of the electrical energy into heat. This loss is proportional to the square of the current and the resistance of the conductor (P = I²R).

In AC (alternating current) systems, additional losses occur due to factors like eddy currents and hysteresis in magnetic materials of transformers and motors. Eddy currents are induced circulating currents within conductive materials that dissipate energy as heat. Hysteresis loss is associated with the repeated magnetization and demagnetization of ferromagnetic materials.

Power transformers, essential for stepping voltage up or down, also experience losses. Core losses, comprising eddy current and hysteresis losses, occur in the iron core, while copper losses (Joule heating) happen in the windings.

In distribution systems, the length and resistance of power lines contribute significantly to overall power loss. Higher transmission voltages are used to reduce current for a given power level, thereby minimizing resistive losses over long distances. However, the conversion of voltage at substations introduces further transformer losses.

While complete elimination of power losses is impossible, engineers continuously work to minimize them through the use of materials with lower resistivity, optimized conductor sizing, improved transformer designs, and efficient motor technologies. Reducing tehonhäviöitä is crucial for improving energy efficiency and reducing the cost of electricity.