In this paper, the effectiveness of these three different control algorithms is thoroughly investigated via simulation and a proposed efficiency evaluation method of experimentation. Both the steady-state and transient characteristics of each control algorithms along with its measured efficiency are analyzed. Finally, a novel two-mode maximum power point tracking (MPPT) control algorithm combining the modified constant voltage control and IncCond method is proposed to improve the efficiency of the 3 kW PV power generation system at different insolation conditions. Finally, a novel two-mode MPPT control algorithm combining the modified constant voltage control and IncCond method is proposed to improve the efficiency of the 3 kW PV power generation system at different insolation conditions. Experimental results show that the proposed two-mode MPPT control provides excellent performance at less than 30% insolation intensity, covering the whole insolation area without additional hardware circuitry. (C) 2003 Elsevier Ltd. All rights reserved.