POWER CONTROL DEVICE AND HYBRID CONSTRUCTION MACHINE PROVIDED WITH SAME

摘要

To assist an engine by using an electric power of an electric storage device in a high load state and prevent excessive reduction of the charged rate of an electric storage device when the high load state continues for a long time. When the necessary power (P L ) is greater than an upper limit value (P gu ) and either the integral power value (E A ) or the duration time (T A ) of an assist provided by the electric storage device (18) during the continuous assist by the electric storage device (18) exceeds a predetermined first threshold value (T Th1 ), the controller (30) performs a first control of reducing the assist power by the electric storage device (18) to a value smaller than the assist power for the regular control and greater than zero. Further, when the necessary power (P L ) is greater than the upper limit value (P gu ) and either the integral power value (E A ) or the duration time (T A ) exceeds a predetermined second threshold value (T Th2 ) greater than the first threshold value (T Th1 ), the controller (30) performs a second control of setting the assist power to zero.