【Symbol】

   F

【Unit】

   Hz

【Definition】/【Calculation Formula】

   The frequency of alternating current (AC) refers to the number of periodic changes in the AC within a unit of time. It is inversely proportional to the period: F=1/T

【Standard】

   According to Article 53 of the "Regulations on Power Supply Business," the permissible deviation of power supply frequency under normal conditions of the power system is as follows:

   For power grids with an installed capacity of 3 million kilowatts (3,000,000 kW) or more, the deviation is ±0.2 Hz.

   For power grids with an installed capacity of less than 3 million kilowatts (3,000,000 kW), the deviation is ±0.5 Hz.

   Under abnormal conditions of the power system, the permissible deviation of power supply frequency should not exceed ±1.0 Hz.

   UL Standard in the Americas (e.g., USA, Canada): 120V/60Hz

   EU GS Standard in Europe: 240V/50Hz

   Japan Standard: 110V/60Hz

   China Standard: 220V/50Hz

【Hazards】

   The excessive variation of system frequency can have adverse effects on both users and power plants:

   1. Motor Speed Variation: A decrease in system frequency will reduce the speed and power of electric motors, leading to lower output from mechanical drives and reduced production efficiency.

   2. Reduced Reactive Power from Capacitors: When system frequency drops, the reactive power output of capacitors decreases proportionally. This weakens the capacitors' ability to support voltage levels, making voltage regulation more difficult.

  3. Impact on Electronic Devices: Measurement and control equipment used in industrial and scientific applications may be affected by frequency fluctuations, leading to reduced accuracy and performance. In extreme cases, low frequency can cause these devices to malfunction.

  4. Increased Error in Energy Meters: Large frequency deviations can increase the measurement error of induction-type energy meters, resulting in underestimation of electricity consumption.

  5. System Stability and Safety: A decrease in system frequency can affect the safe operation of power plants and the entire system. It can lead to a drop in generator voltage, a significant reduction in system voltage levels, and potentially cause voltage collapse, leading to widespread power outages.

【Product】

   Most of our company's instruments, including the entire MA series, DZS series, and the majority of the MS series, can measure frequency.

【Related Terms】

   Frequency deviation