功率要点

在物理学中，功率是能量传递或转换的速率。它是单位时间内消耗的能量量。理解功率对电气工程、机械学和日常能源消耗至关重要。

介绍

Power measurement is crucial for understanding energy consumption, system performance, and efficiency. From light bulbs to industrial motors, power ratings help determine energy costs and system capabilities.

历史

James Watt developed the concept of horsepower in the 18th century to market his steam engines. The watt, named in his honor, became the SI unit of power. Power measurement became increasingly important with the development of electrical systems.

关键单位

Watt (W)

The SI unit of power, equal to one joule per second.

Kilowatt (kW)

Equal to 1,000 watts, commonly used for electrical appliances and motors.

Horsepower (hp)

Equal to 745.7 watts, traditionally used for engine and motor power ratings.

Megawatt (MW)

Equal to 1,000,000 watts, used for large power plants and industrial facilities.

Gigawatt (GW)

Equal to 1,000,000,000 watts, used for national power generation capacity.

应用

  • Electrical appliance specifications and energy labeling
  • Motor and engine performance ratings
  • Power plant capacity and electricity generation
  • Solar panel and wind turbine output ratings
  • Electronic device power consumption analysis
  • HVAC system sizing and efficiency calculations

Power Calculations

P = W/t = V×I = I²R

Power equals work over time, voltage times current, or current squared times resistance.