Development of the Intelligent Power Unit for 2006 Civic Hybrid 2006-01-1504
To make the Intelligent Power Unit (IPU) of the Integrated Motor Assist (IMA) system more compact with higher output than that of the previous model was the goal for this project. In the IMA inverter, a C-Cu board has been used to achieve high output and compactness. IGBT trench-gate construction and flat-film capacitors have been adopted and motor control functions and current sensors have been built-in to achieve compactness. Digital control and variable switching frequency have been adopted in the 12V DC-DC converter for high output and compactness. In the IMA battery, by modifying the current collector and by using electrolytic solution with high electrical conductivity, the internal resistance has been reduced to obtain higher output. The number of modules in the battery box was increased to attain higher output. The pitch between modules has also been reduced and a staggered arrangement of modules adopted to realize compactness. The cooling system has been made more compact by integrating the cooling fan within the IPU. Compactness and weight savings have also been achieved by passing the three-phase high-voltage cables through an aluminum pipe.
With the technical developments mentioned above, the output of the IPU has been enhanced by 17% and the IPU simultaneously made 13% more compact compared to the previous model, thus making a valuable contribution to the high driving performance and increased cabin space of compact-size, four-door sedans.