As the solar photovoltaic power generation capacity continues to climb, attention to the protection of the photovoltaic array constant. It is understood that IEC62548Ed. 1.0 the photovoltaic (PV) power generation unit device and safety requirements "(" the Installation and safety requirement sforphotovoltaic PV) generators") of the CDV (members voted to Draft) has voted in September 16, 2011, its CCDV (Draft Circulatedas Committee Draftwith Vote) also plans in July the IEC central office, that is to say, the key technical contents have been identified, a formal standard is estimated in the second half of 2012 or 2012 will be released. In addition, the photovoltaic fuse standards IEC60269-6 Ed. 1 again modification is in progress. The birth of the new standard and standard changes, reflect the latest technical requirements, reflects the advanced nature, it's worth it engineers study seriously, ensure selection design more reasonable and reliable.
 
IEC62548 covers more than 50 w power, open-circuit voltage 30 v above all of the photovoltaic power generation units. Part of the overcurrent protection the IEC62548 standards involved in the summarized as follows:
 
1, over current protection: the necessity of photovoltaic array in photovoltaic panels, pv connection box, or part of photovoltaic panels wiring short circuit, and the ground fault occurred in the pv array wiring, could produce a current. Fault current in the photovoltaic system can't disconnect the overcurrent protection device of photovoltaic array, is likely to produce electric arc; For photovoltaic panels and the requirement of equipment manufacturers provide overcurrent protection, according to its requirements; There are no rules for manufacturers of overcurrent protection is according to the standard requirement set IEC62548 overcurrent protection.
 
Photovoltaic fuse standards IEC60269-6, is also put forward in the photovoltaic inverter return current, causing trouble in photovoltaic (pv) rating of the fuse breaking capacity, within the scope of photovoltaic fuse can provide protection to avoid the damage to the array of cables and photovoltaic panels.
 
2, overcurrent protection, fuse and fuse support a choice: due to the lower the temperature the greater the open circuit voltage of photovoltaic panels, considering the characteristic of photovoltaic array, photovoltaic pv arrays, string, and the maximum voltage of photovoltaic panels, shall be installed according to the site according to the lowest temperature expected to fix, photovoltaic panels manufacturer's instructions for photovoltaic panels manufacturer did not provide correction method, should be determined according to standard requires correction of pv array maximum voltage. IEC62548 standards specified in the correction coefficient in the following table.
 
Monocrystalline silicon and polycrystalline silicon photovoltaic panels maximum voltage correction coefficient
 
Application of light volt array protection fuse body should meet the following requirements:
 
A, greater than or equal to the rated voltage according to the installation site according to the lowest temperature expected photovoltaic panels manufacturer's instructions or above to fix it is concluded that the maximum voltage;
 
B, the dc fuse body;