CONTROL FUNCTIONS (CONT’D) Engine Control - General (Cont’d) Torque curve and engine regulation Standard engine torque curves are outlined in [Figure 10-40-15] and [Figure 10-40-16]. The figure is an image. Details of the curves vary depending on the engine models. When the engine load or speed is changed instantaneously, there is some delay until the engine speed is set to the specified regulations. For the Eco-governor, engine regulations are available in the following variations: •
Isochroous The engine speed is constant, regardless of the load (regulation 0%).
•
Virtual droop (torque curve of base engine) Approx. 7% regulation regardless of the engine speed. The engine speed is kept until a torque equivalent to a load factor of approx. 30% is reached, in order that the idling (non load) speed does not fluctuate even if installation of the engine on a machine causes some power loss. Even when virtual droop is active, it is possible that the engine speed does not decrease to lower than the low-idling speed (optional)
Figure 10-40-15
②Virtual Droop（Const. regulation:7%） ①Iso-chronous 120% 110% Mech. Governor Droop
Torque
100%
30%
Virtual Droop H/I
1000min-1
65〜70%
100%
Iso-chronous H/I(Rating+30min-1)
Engine Speed
10-40-13 61 of 182
E55W, E60, E80 Electronic Control System Manual
