Distributed filtering of high harmonics in microgrids

Currently great attention is paid to more efficient use of electric energy and considerable significance is attached to increase in power quality, in particular, by decreasing high harmonics in supply voltage. It seems reasonable to apply Smart Grid technologies, which imply continuous control and measurement of network parameters by the sensors of current, voltage, frequency, etc., and control of network operation on the basis of the data obtained. We suggest using smart meters of high harmonic energy and distributed filtering that provide minimum network resistance for the fundamental harmonic. The reactive components are used to tune the network. These are capacitances of network, inductances of transformers, capacitances of synchronous compensators and specially applied regulated inductances and capacitances. Information on network tuning to resonant conditions with fundamental harmonic comes from phase meters and high harmonic energy meters. The paper shows the necessity of measuring separately fundamental and high harmonic energy. Measurement of high harmonic energy and settlement of legal issues related to payment for this energy should encourage power supply companies and consumers to take technical and organizational measures to decrease high harmonic level in the network. These measures should lead to the improvement of the supply network voltage waveform which will enhance the efficiency of electric energy use by consumers.