  We present the discovery of two very-high-energy gamma-ray sources in an
ongoing systematic search for emission above 100 GeV from pulsar wind nebulae
in survey data from the H.E.S.S. telescope array. Imaging Atmospheric Cherenkov
Telescopes are ideal tools for searching for extended emission from pulsar wind
nebulae in the very-high-energy regime. H.E.S.S., with its large field of view
of 5 degrees and high sensitivity, gives new prospects for the search for these
objects. An ongoing systematic search for very-high-energy emission from
energetic pulsars over the region of the Galactic plane between -60 degrees < l
< 30 degrees, -2 degrees < b < 2 degrees is performed. For the resulting
candidates, the standard H.E.S.S. analysis was applied and a search for
multi-wavelength counterparts was performed. We present the discovery of two
new candidate gamma-ray pulsar wind nebulae, HESS J1718-385 and HESS J1809-193.
H.E.S.S. has proven to be a suitable instrument for pulsar wind nebula
searches.
