ENABLING ELECTRIFIED DIESEL ENGINE-POWERED AND VEHICLE-SUPPORTED MICROGRIDS

A sudden increase in microgrid electrical power consumption requires the fast supply of energy from different generating sources to guarantee microgrid voltage stability. This paper presents the results of simulations investigating the integration of an electric supercharger into a Heavy Duty Diesel (HDD) genset connected to a microgrid for reducing engine speed droop in response to an abrupt power demand requested from the grid. First, a mean value model for the 13 L HDD engine is used to study the response of the baseline turbocharged engine during a fast load increase at low engine speed. The limited air mass in the cylinder during the transient results in engine lugging and ultimately engine stall. Then, an electrical supercharger is integrated before the turbocharger compressor to increase the engine air charge. During steady state operation, the simulation results indicate that the supercharger is able to increase the air-charge by approximately 50% over the lower half of the engine map, which is the key area of interest for load acceptance as it restricts the HDD response during fast power requests. Then, the supercharged engine is tested with abrupt power disturbances applied at engine idle. The results show the ability of the supercharger to mitigate engine speed droop, reducing it from 180 RPM to less than 30 RPM. Strategies are also shown where the supercharger can increase the engine’s load acceptance ability without increasing fuel consumption compared to strategies such as increased engine idle speed.