- 【Capacity selection】

- 【The best harmonic solution】
Recently, power electronic devices are widely applied in electric power equipment, such as uninterruptible power supply, motor driver, arc furnace, trolley car, battery charger, and lighting appliance. The electric power equipment may generate a large amount of harmonic currents due to the nonlinear input characteristic of such loads. The harmonic current will pollute the power distribution system and result in transformer over-heat, rotary machine vibration, degrading voltage quality, and destruction of electric power components and equipment. It is extremely urgent to bring the harmonic pollution under control.
Active Power Filter (APF) is the most efficient equipment to dispose the power harmonic pollution, enhance the power quality, ensure the safety of the power and equipment, and bring about the green power finally.
- 【Harmonic and sources】
When a non-linear load, such as a rectifier, is connected to the system, it draws a current that is not necessarily sinusoidal. Through Fourier series analysis, it is possible to decompose it into a series of simple sinusoids, which start at the fundamental power system frequency and occur at integer multiples of the fundamental frequency. The wave whose frequency is an integer multiple of the fundamental frequency is called harmonic.
With the increased presence of electronics on power distribution systems, disruptive anomalies are created, and harmonics can become a problem. Typical sources are:
● Rectifier devices(electrolysis, electroplate)
● AC/DC Variable Speed Drive
● DC Power Systems/Chargers
● Arc Welding furnace, Induction Heating Equipment
● Welding Machines
● Electric Training, Marine electric drive
● Air condition
● Fluorescent Lamps
● Uninterruptible Power Supplies (UPS)
● Computers and Peripherals
- 【Harmonic harm】
● Harmonic pollution may disturb electrical equipment and systems’ normal operation badly, and causes the following problems:
● Over voltage/current in the distribution network
● Overheat power cables, transformers, & generators
● Overheating in all types of electronics systems causing component failures
● Nuisance tripping in circuit breakers and protection relays
● Malfunction of automatic control system
● Damage to capacitors due to resonance
● Inaccuracy of instrument measurement
● Interference to telecommunication systems● Interference to telecommunication systems
● Voltage distortion and lagging in power factor