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
Topological module Topological module In mathematics, a topological module is a module over a topological ring such that scalar multiplication and addition are continuous. A topological vector space is a topological module over a topological field. An abelian topological group can be considered as a topological module over Z, where Z is the ring of integers with the discrete topology. A topological ring is a topological module over each of its subrings. A more complicated example is the "I"-adic topology on a ring and its modules. Let "I" be an ideal of a ring "R". The sets of the form , for