The concentrating photovoltaic (CPV) technology has greater potential to generate high PV electricity in high insolation area. Assessment of CPV's performance is vital for disseminating this technology. Most current modeling softwares in PV sector are targeted for non-concentrating PV, such as TRNSYS, PVsyst, HOMER, etc. We have modified the PV array component in TRNSYS with parameters adjusted for CPV array. In these modified parameters, temperature coefficients of short-circuit current and open-circuit voltage, and transmittance-absorptance product are either taken from available measurements or algebraic calculation. The CPV system used for field test consists of high accurate two-axis solar tracker with two CPV modules installed. In sunny days, prediction of power output of CPV module agreed well with measured CPV power in Jhong-Li, Taiwan. Our study has extended the applicability of TRNSYS for dynamic modeling of PV system.