10
2
.4 Circuit structure design
The basic schematic diagram of CPS SCA23/28KTL-DO/US-480 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.
PE
Three level
inverter
N
L1
L2
L3
PV1+
PV1+
PV1+
PV1+
PV1-
PV1-
PV1-
PV1-
DC
Switch
MPPT1
MPPT2
PV1+
PV1-
PV2+
PV2-
AC
Output
PV
Input
PV2+
PV2+
PV2+
PV2+
PV2-
PV2-
PV2-
PV2-
AFD
AC
Switch
Fuses
Figure 2-2 Schematic diagram of CPS SCA23/28KTL-DO series inverter