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
Module (mathematics) to zero by "f". The isomorphism theorems familiar from groups and vector spaces are also valid for "R"-modules. The left "R"-modules, together with their module homomorphisms, form a category, written as "R"-Mod (see category of modules for more.) This is an abelian category. Finitely generated. An "R"-module "M" is finitely generated if there exist finitely many elements "x", ..., "x" in "M" such that every element of "M" is a linear combination of those elements with coefficients from the ring "R". Cyclic. A module is called a cyclic module if it is generated by one element. Free. A free "R"-module