Product Protection Functions; Circuit Structure Design - Chint Power CPS SCA20KTL-DO Installation And Operation Manual

 Long service life: Uses thin-film capacitors to extend inverter's service life
 2 MPPTs: Support independent and parallel modes of PV connection
 High protection degree: IP65 protection degree meets the needs of both
indoor and outdoor use; Embedded DC switch makes field maintenance
more flexible and safer

2.3 Product protection functions


Polarity reverse protection of DC input

Short circuit protection

DC input insulation against ground monitoring

AC output voltage and frequency monitoring

Leakage current against ground monitoring

Monitoring of DC injection from AC output

Anti-islanding protection

Input and output over-voltage protection

Input over-current protection

Environmental temperature monitoring

Module temperature monitoring

2.4 Circuit structure design

The basic schematic diagram of CPS SCA20/25KTL-DO series inverter is
shown in Figure 2-2.
The input of PV modules passes through surge protection circuitry, DC
EMI wave filter, and the front-end boost circuitry to achieve maximum power
tracking and boost up voltages. The output of the inverter converts the DC
voltage to 3-phase AC voltage. The high frequency AC components are
removed with a wave filter. Then the 3-phase AC voltage is passed through
two-stage relays and EMI wave filter to produce high quality AC power.
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