Hybrid Electric Vehicle Series Design
A hybrid electric vehicle (HEV) with a series configuration uses the heat engine or fuel cell with a generator to produce electricity for the battery pack and electric motor. Series HEVs have no mechanical connection between the hybrid power unit and the wheels; this means that all motive power is transferred from chemical energy to mechanical energy to electrical energy, and back to mechanical energy to drive the wheels. Here are some benefits of a series configuration:
- The engine never idles, which reduces vehicle emissions.
- The engine can continuously operate in its most efficient region.
- The engine drives a generator to run at optimum performance.
- The design allows for a variety of options when mounting the engine and vehicle components.
- Some series hybrids do not need a transmission.
The downside is that series HEVs require larger, and therefore, heavier battery packs than parallel vehicles. In addition, the engine works hard to maintain battery charge because the system is not operating in parallel. There is also the inefficiency of converting the chemical energy to mechanical to electrical energy and back to mechanical energy.
