What does electrical maintenance mainly do?

Electrical maintenance refers to the professional maintenance of electrical equipment by technical engineers using professional instruments, including generators, transformers, power lines, circuit breakers and other equipment.

Scope of electrical maintenance

Voltage, current and frequency

Main analysis parameters: effective value and frequency of voltage and current.

Application: By analyzing the voltage and current waveforms, we can judge whether there are harmonics. By testing the effective values of voltage and current, it can be preliminarily judged whether there is voltage deviation or current imbalance.

harmonic wave

Main analysis parameters: total harmonic distortion rate, harmonic number and harmonic generation reason.

Harmonic generation source:

(a) Electronic switch types: mainly various AC /DC conversion devices (rectifiers, inverters).

(b) Arc type: The high nonlinearity caused by the ignition and drastic changes of various steelmaking electric arc furnaces makes the current fluctuate irregularly.

Electricity and electricity

Main analysis parameters: active power, reactive power, apparent power, power factor and wattage.

Voltage surges, dips and transients

Main analysis parameters:

Impulsive overvoltage

Voltage sag

transient

Three-phase imbalance

Main analysis parameters: voltage and current three-phase unbalance and three-phase unbalance phase angle.

The reason of three-phase imbalance: three-phase load asymmetry

Single-phase large-capacity load

The distribution of capacity and electrical location in the system is unreasonable.

Harm of three-phase imbalance:

Lead to misoperation of relay protection, additional vibration torque and motor heating.

Intransitive verb surge voltage and current generator

sparkling

1 Definition: People's subjective feeling of brightness change is caused by the change of effective value of voltage source.

Cause: Voltage fluctuation caused by electric arc furnace and rolling mill.

Hazards of flicker: The flicker of lighting may stimulate people's visual nerve.