IEC 62109-2 pdf download

IEC 62109-2 pdf download.Safety of power converters for use in photovoltaic power systems – Part 2: Particular requirements for inverters
1 Scope and object
This clause of Part 1 is applicable with the following exception: 1 .1 Scope Addition: This Part 2 of IEC 621 09 covers the particular safety requirements relevant to d.c. to a.c. inverter products as well as products that have or perform inverter functions in addition to other functions, where the inverter is intended for use in photovoltaic power systems. Inverters covered by this standard may be grid-interactive, stand-alone, or multiple mode inverters, may be supplied by single or multiple photovoltaic modules grouped in various array configurations, and may be intended for use in conjunction with batteries or other forms of energy storage. Inverters with multiple functions or modes shall be judged against all applicable requirements for each of those functions and modes. NOTE Throughout this standard where terms such as “grid-interactive inverter” are used, the meaning is either a grid-interactive inverter or a grid-interactive operating mode of a multi-mode inverter This standard does not address grid interconnection requirements for grid-interactive inverters. NOTE The authors of this Part 2 did not think it would be appropriate or successful to attempt to put grid interconnection requirements into this standard, for the following reasons: a) Grid interconnection standards typically contain both protection and power quality requirements, dealing with aspects such as disconnection under abnormal voltage or frequency conditions on the grid, protection against islanding, limitation of harmonic currents and d.c. injection, power factor, etc. Many of these aspects are power quality requirements that are beyond the scope of a product safety standard such as this. b) At the time of writing there is inadequate consensus amongst regulators of grid-interactive inverters to lead to acceptance of harmonized interconnect requirements. For example, IEC 61 727 gives grid interconnection requirements, but has not gained significant acceptance.
3 Terms and definitions
This clause of Part 1 is applicable, with the following exceptions: Additional definitions 3.1 00 functionally grounded array a PV array that has one conductor intentionally connected to earth for purposes other than safety, by means not complying with the requirements for protective bonding NOTE 1 Such a system is not considered to be a grounded array – see 3.1 02. NOTE 2 Examples of functional array grounding include grounding one conductor through an impedance, or only temporarily grounding the array for functional or performance reasons NOTE 3 In an inverter intended for an un-grounded array, that uses a resistive measurement network to measure the array impedance to ground, that measurement network is not considered a form of functional grounding. 3.1 01 grid-interactive inverter an inverter or inverter function intended to export power to the grid NOTE Also commonly referred to as “grid-connected”, “grid-tied”, “utility-interactive”. Power exported may or may not be in excess of the local load. 3.1 02 grounded array a PV array that has one conductor intentionally connected to earth by means complying with the requirements for protective bonding NOTE 1 The connection to earth of the mains circuit in a non-isolated inverter with an otherwise ungrounded array, does not create a grounded array. In this standard such a system is an ungrounded array because the inverter electronics are in the fault current path from the array to the mains grounding point, and are not considered to provide reliable grounding of the array NOTE 2 This is not to be confused with protective earthing (equipment grounding) of the array frame NOTE 3 In some local installation codes, grounded arrays are allowed or required to open the array connection to earth under ground-fault conditions on the array, to interrupt the fault current, temporarily ungrounding the array under fault conditions. This arrangement is still considered a grounded array in this standard.