GB/T 18802.31-2016

This section specifies the performance requirements and test methods for SPDs installed on the DC side of photovoltaic systems. These SPDs are used to reduce the impact of lightning induction or direct lightning strikes on the DC side of photovoltaic power generation equipment. These devices will be connected to the DC power supply circuits of photovoltaic power generation equipment with a rated voltage not exceeding 1,500 V. This section takes into account the following characteristics of photovoltaic power generation equipment: -- characteristics similar to current sources; -- nominal current depending on the intensity of sunlight; -- short-circuit current almost equal to the nominal current; -- output of various sizes of voltage, current, and power in series and/or parallel combinations, ranging from hundreds of watts (for civilian facilities) to several megawatts (for photovoltaic power plants). The very special electrical parameters of the DC side of photovoltaic equipment pose special testing requirements for SPDs. SPDs with special series impedances between separate input and output terminals (so-called two-port SPDs in EN 6164311) are not fully covered by the performance requirements of this standard and require additional consideration. Note: For SPDs applied to photovoltaic systems, due to considerations of power supply efficiency, there are usually no special series impedances between the input and output terminals. SPDs that comply with this standard are only designed for installation on the DC side of photovoltaic generators, and do not consider photovoltaic equipment containing battery packs and other DC devices. Additional requirements and tests are needed for SPDs used in such equipment. For SPDs whose manufacturers declare overload characteristics in short-circuit mode, special measures must be required to prevent DC arcs that may occur during maintenance and replacement of such SPDs from harming operators.