  The radio emission mechanism in active galactic nuclei (AGN) with high
accretion rates is unclear. It has been suggested that low-power jets may
explain the observed radiation at sub-parsec scales. The mechanisms for jet
formation at super-Eddington rates, however, are not well understood. On the
same scale, clouds from the broad-line region (BLR) propagating with supersonic
velocities in the wind launched by the accretion disk may lead to the
production of nonthermal radiation. We aim to characterize the nonthermal
emission produced by the propagation of clouds through the wind of the
accretion disk in super-accreting AGNs and to estimate the relevance of such
contribution to the radio band of the electromagnetic spectrum. We determine
the conditions under which the BLR clouds are not destroyed by shocks or
hydrodynamic instabilities when immersed in the powerful wind of the accretion
disk. These clouds form bowshocks that are suitable sites for particle
acceleration. We develop a semianalytical model to calculate the distribution
of relativistic particles in these bowshocks and the associated spectral energy
distribution (SED) of the emitted radiation. For typical parameters of
super-accreting AGNs, we find that the cloud-wind interactions can produce
nonthermal emission from radio up to a few tens of TeV, with slight absorption
effects, if the processes occur outside the wind photosphere. Radio emission in
AGNs without jets can be explained if the accretion rate is super-Eddington and
there is a broad-line region at sub-parsec scales around the central black
hole. The accretion rate must not be extremely high so most of the clouds orbit
outside of the wind photosphere and the radiation can escape to the observer.
