Application of the Series power supply 1500V High-Voltage Output in EL Testing

The Series power supply is a programmable power supply unit developed specifically to address the reverse-bias energization characteristics of photovoltaic (PV) strings. It converts AC power into DC power to energize PV panels and induce electroluminescence (EL), enabling the detection of internal defects. It offers a voltage output range of 0 to 1500V and a current output range of 0 to 3A.

The Series power supply is a specialized power supply designed for the reverse-bias energization of PV strings; it facilitates internal defect testing via EL imaging by converting AC power to DC to excite the panels. Primarily used in PV module EL inspection, the device applies a forward bias to trigger light emission resulting from minority carrier recombination within the solar cells. When paired with a high-sensitivity camera to capture these emissions, it can pinpoint internal defects such as micro-cracks, broken busbars, and "black cores." The Series power supply provides the necessary high-voltage output, which is critical for inducing the electroluminescent response in the cells.

The FT-150030 model Series power supply is a programmable power supply for R&D applications, featuring software-based control of electrical performance and safety mechanisms. Its "Pro" version utilizes high-quality software configurations, imported electronic components, and an open-architecture programming host to ensure superior stability and safety during string testing. Key technical specifications include a voltage output range of 0–1500V (with 1V resolution and 12V compensation voltage) and a current output range of 0–3A (with 0.1A resolution). Electrical precision is rated at ±0.1A and ±1V. The device delivers 0–4.5kW of power with ±0.1% stability and ±0.1% output accuracy; it boasts an efficiency exceeding 80%, with both line and load regulation rates of ±0.5%. Input specifications include 220VAC voltage, 50/60Hz frequency, and a power factor greater than 0.75; power-up is manually controlled. The unit measures 430 × 88 × 450 mm and weighs 13 kg. The Series power supply incorporates multiple safety measures for protection. It features protection against PV string reverse-connection and short-circuits, preventing diode breakdown within PV modules. A reverse-current protection function allows for the setting of impedance thresholds to prevent back-feeding of string current. Programmable soft-start protection manages the connection and disconnection of PV strings to prevent high-inrush currents from damaging the panels. High-voltage isolation ensures operator safety in high-voltage environments. The device can simultaneously connect and power up to 32 PV panels (rated up to 1500V), supporting various connection points such as combiner boxes, inverters, string terminals, and module terminals. It features programmable remote interfaces supporting RS-485 and analog signals (0–10V), and the control panel allows for the programming of parameters such as power switching, scheduled activation, and protection thresholds.