Grid-connected photovoltaic power system Solar energy gathered by photovoltaic solar panels, intended for delivery to a power grid, must be conditioned, or processed for use, by a grid-connected inverter. Fundamentally, an inverter changes the DC input voltage from the PV to AC voltage for the grid. This inverter sits between the solar array and the grid, draws energy from each, and may be a large stand-alone unit or may be a collection of small inverters, each physically attached to individual solar panels. See AC Module. The inverter must monitor grid voltage, waveform, and frequency. One reason for monitoring is if the grid is dead
Generating set of a module ideal "m" and residue field "k" and "M" finitely generated module. Then Nakayama's lemma says that "M" has a minimal generating set whose cardinality is formula_3. If "M" is flat, then this minimal generating set is linearly independent (so "M" is free). See also: minimal resolution. A more refined information is obtained if one considers the relations between the generators; cf. free presentation of a module. Generating set of a module In algebra, a generating set "G" of a module "M" over a ring "R" is a subset of "M" such that the smallest submodule of "M" containing "G" is