Abstract:
In linear load conditions, power factor
definition is unique. However increased use of power
electronic devices, adjustable speed drives, and other
nonlinear loads, causes the voltage and current waveforms
to become non sinusoidal and highly distorted. In such a
situation, different power factors are proposed. In this
paper a new fuzzy based harmonics power factor (FHPF)
meter is introduced to represent these power factors as a
single index. The proposed harmonics power factor
amalgamates the recommended PQIs, such as displacement
power factor, transmission efficiency power factor and
oscillation power factor. The FHPF was applied to non
linear load with different distortion cases under, sinusoidal
and non sinusoidal conditions. Considering the advantages
of the fuzzy systems such as simplicity, ease of application,
flexibility, speed and ability to deal with imprecision and
uncertainties, this factor can be useful for power quality
evaluation, cost-effective analysis of PQ mitigation
techniques and billing purposes. It is shown that the new
FHPF is expressive and accurately represents the existing
power quality indices in all cases and in all situations.
MATLAB simulations are performed. A hardware prototype
of FHPF meter is developed using PIC. The current and
voltage signals are sampled and the different power factors
are calculated. Fuzzy logic coding is done and using a
LCD, the index is displayed. The results are promising for
implementation.
