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
Perl module has the following declaration at its top: This module, and its functionality, would commonly be invoked as follows: A 'missing' subroutine "could" be added from the using program's namespace. and invoked as below: However, though technically feasible, that would be dubious programming practice. You might just as well define the sub in the calling namespace, and call it from that namespace. Perl module A Perl module is a discrete component of software for the Perl programming language. Technically, it is a particular set of conventions for using Perl's package mechanism that has become universally adopted. A module defines its source