Surge Protection Method for Solar PCS (Power Conditioning System)

The surge protection method of solar PCS (Power Conditioning System) can be summarized as follows.

1. Surge Protection

• SPDs suitable for the respective voltage and characteristics must be installed on both the DC (panel to inverter) and AC (inverter to grid) lines of the solar power system.

• SPDs should be installed as close as possible to critical components, such as inverters, combiner boxes, and panels , and additional SPDs should be installed if the cable length exceeds 10 m.

• DC SPD and AC SPD must use products designed according to their respective current characteristics (direct current/alternating current), and DC SPD must use products certified for solar use.

2. Grounding

Proper grounding is essential for effective operation of the SPD . The ground terminal of the SPD must be connected to a reliable grounding system and the grounding resistance must be kept low.

3. SPD SPEC. & Selection Considerations

• SPD must be selected by considering the Uc selection and capacity that matches the system voltage specifications and the power system, and the maximum no-load voltage of the solar power system, installation environment, and lightning risk, etc.

• Install IoT surge monitoring devices to monitor surge inflow information, leakage current status, and SPD health.

• Use high-quality products with proven performance and confirmed after-sales service, and install them according to the manufacturer's instructions.

4. Maintenance

• SPDs should be regularly checked to ensure they operate normally even after lightning or other surges occur, and replaced if necessary.

5. Standards and specifications

Lightning rods/lightning protection systems can be installed in parallel, and the protection effect is enhanced when used with integrated grounding of the entire system, fuses, circuit breakers, etc.

6. Other considerations

The key to surge protection of solar PCS is the selection of appropriate SPD, proper installation in the right location, surge monitoring, reliable grounding, and regular maintenance . Using SPDs suitable for DC and AC respectively, and installing and operating them according to standards can secure the reliability and safety of the PCS and the entire system.

SPDs that comply with international/domestic standards as described in lightning protection system IEC 62305 must be used. This standard regulates the performance, safety, and test methods of SPDs installed on the DC side of solar power generation facilities and the DC side of inverters.