Traditional harmonic reduction technique | BengalStudents

1.4.1 Traditional harmonic reduction technique

The traditional method of current harmonic reduction involves passive filters LC, parallel-connected to the grid. Filters are usually constructed as series-connected legs of capacitors and chokes [the number of legs depends on number of filtered harmonics (5th, 7th, 11th, 13th) ]. The advantages of passive filters are simplicity and low cost.

The disadvantages are:

each installation is designed for a particular application (size and placement of the filter elements, risk of resonance problems),

high fundamental current resulting in extra power losses,
filters are heavy and bulky.

In case of diode rectifier, the simpler way to harmonic reduction of line current are additional series coils used in the input or output of rectifier (typical 1-5%).

7 views

Tags

Power Electronics

Related Items

Rectifiers, their advantages, and disadvantages

Power electronics in broader aspect actually controls the flow of power to make it suitable to be used by diverse type of instruments and appliances. The ability to control the flow of power is derived from using solid state switches along with their controllers.

PWM Rectifier

The most interesting reduction technique of current harmonic is a PWM (active) rectifier (Fig. 1.3). Two types of PWM converters, with a voltage source output (Fig. 1.4) and a current source output (Fig. 1.5) can be used.

Active PWM filter

An alternative to the passive filter is use of the active PWM filter (AF), which displays better dynamics and controls the harmonic and fundamental currents. Active filters are mainly divided into two different types..

Multi-pulse rectifier

1.4.3 Multi-pulse rectifier.

Mixing single and three phase diode rectifier

1.4.2 Mixing single and three phase diode rectifier