| Abstract |
In this paper, a strategy for compensating
reactive and harmonic currents produced by non-linear
loads, when being connected to the low- voltage side of the
power system, is investigated. The loads in the low-voltage
network can be classified, from the harmonics point of view,
into a harmonic current producing type, a harmonic voltage
producing type and a harmonic sensitive type. In spite of its
associated problems, the compensation in the low- voltage
network seems more reliable, economical, effective and
straightforward. In general, these problems arise due to the
interaction between the load and the power network
parameters. The idea here stems from the fact that when
applying a pollution treatment for a river, it is not the
optimum solution (for all cases) to establish a treatment
station across the river. The reliable alternative is to purify
those outlets discharging into the river in an individual
manner. The proposed strategy will be presented and
demonstrated through analysis, design and practical
simulation. The flexibility of the technique makes it suitable
even to be applied to a small scale loads e.g. a productionline
in a factory. It is amazing to deal with the instantaneous
reactive power (q) as a time-signal to extract the reference
reactive current, without introducing low-pass or high-pass
filters into the forward control path. On the other hand, the
characterization of loads according to the classification
mentioned above is strongly recommended. It will be seen
that this task can be done using a shunt active power filter. |
