Comparative Analysis of Modulation Techniques for Advanced Controller of Integrated Starter Generator

In recent years, there has been a significant increase in the demand for hybrid vehicles. A crucial technology used in modern hybrid vehicles is the Integrated Starter Generator (ISG), which plays a vital role in enhancing the electrical generation capacity and contributing to the fuel efficiency and emission advantages of hybrid electric propulsion. The design of an ISG presents several challenges due to the conflicting requirements of high starting torque and field-weakening capability across a broad range of speeds. Currently, there are two types of ISGs in use: belt-driven ISGs and direct-crankshaft ISGs. Both types offer advantages over traditional separate starter and generator systems. The belt-driven ISG configuration involves connecting the ISG via a belt between the engine and the gearbox. On the other hand, the direct-crankshaft ISG is mounted behind the engine, with separate components such as the clutch or torque converter. This design eliminates the cost and complexity associated with belt-driven constructions. Field-Oriented Control (FOC) based on the Permanent Magnet Synchronous Machine (PMSM) is a commonly employed method for ISGs. FOC enables precise control over the torque and flux of the PMSM, ensuring efficient operation. In this study, two modulation techniques, Sinusoidal Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM) are compared for speed control and settling characteristics.