In our previous guide, we discussed the different types of Hybrid Electric Vehicles (HEVs) where we discussed Plug-in Hybrid Electric Vehicles as one of the hybrid configuration of Hybrid Electric Vehicles (HEVs) alongside Micro HEVs, Mild HEVs, and Full or Power-Assist HEVs.
In this guide, we will delve deeper into Plug-in hybrid electric vehicle, their advantages, disadvantages, and the different types of plug-in energy management modes.
Table of Contents
Plug-in Hybrid Electric Vehicle
Plug-in hybrid electric vehicles are closer to all-electric vehicles compared to other hybrid vehicle configurations, they feature a larger electric vehicle battery pack that can be charged by an EV charger, either a Level 1 charger for slow charging or a Level 2 charger for fast charging, some of the notable Plug-in hybrid electric vehicle is the Toyota Prius which is the best selling plug-in hybrid electric vehicle.
The success of the Plug-in hybrid electric vehicles can be attributed to the high energy efficiency of mixing the use of an electric motor and an internal combustion engine, the electric motor can be used as the primary energy source to power the engine reducing gasoline consumption and emission during all-electric mode.
One setback that holds consumers from purchasing a plug-in hybrid electric vehicle is the high costs of the vehicle associated with the high manufacturing costs and material expenses of the larger batteries, and due to range and charging anxiety.
Plug-in Hybrid Electric Vehicle Energy Management Modes
Plug-in hybrid electric vehicles (PHEVs) operate using four energy management modes: charge-depleting, charge-sustaining, electric vehicle, and engine-only modes.
Before diving into these modes, it’s important to note that PHEV battery capacity is typically drawn to 10% of its nominal level (around 50% state of charge or SOC). This reserve ensures there’s enough room for both charging and discharging without depleting the battery below 25% or overcharging it above 75% SOC.
Given the critical importance of managing a PHEV’s battery and maintaining optimal charge levels, having the right diagnostic tool is essential. The Autel MaxiSys Ultra EV excels in this area by providing detailed insights into battery health, including SOC, voltage, current, and temperature readings.
Autel MaxiSys Ultra EV Review
Electric Vehicle battery diagnostics helps ensure the battery operates safely and efficiently. By offering accurate diagnostics, the Autel MaxiSys Ultra EV supports battery longevity and performance, making it an ideal tool for both vehicle owners and professionals. For more detailed information on its capabilities, check out our Autel MaxiSys Ultra EV Review.
Charge Depleting Mode (CD-Mode)
After charging a Plug-in hybrid electric vehicle, the vehicle operates in a charge-depleting mode where the battery state of charge (SOC) is controlled in a reducing state when the vehicle is in use. The battery depletes until it reaches a target state of charge usually around 35% SOC, In charge-depleting mode the vehicle may be in use or parked, if in motion the energy is provided by the vehicle energy storage system (ESS).
Charge Sustaining Mode (CS-Mode)
Charge-sustaining mode is a situation where the Plug-in hybrid electric vehicle battery is controlled to remain within a narrow operating band.
After the vehicle is charge depleted mode and reaches the target state of charge (SOC), it shifts to charge-sustaining mode where the engine maintains the battery state of charge (SOC).
Engine Only Mode
After charge sustaining mode, if the Plug-in hybrid electric vehicle is still in motion, it enters engine-only mode where the electric traction system of the Plug-in hybrid electric vehicle doesn’t provide tractive power to the vehicle.
Electric Vehicle Mode (EV Mode)
Electric vehicle mode prohibits the operation of the internal combustion engine, and the Plug-in hybrid electric vehicle battery becomes the only source of energy used to propel the vehicle.
Range-extended Plug-in hybrid electric vehicles act as all-electric vehicles when in electric vehicle mode and only use the electric motor, for blended Plug-in hybrid electric vehicles the electric motor is used as a primary source of energy with occasional help of the internal combustion engine to provide additional power when needed.
About the Author: James Ndungu
James Ndungu, founder and editor-in-chief of Electric Vehicle Geek, brings over five years of hands-on experience in Electric Vehicle Supply Equipment (EVSE) selection, permitting, and installation. He specializes in assisting businesses and homeowners in the United States with a seamless transition to electric vehicles.
As a certified EV charger installer and holder of advanced certifications, including the EVITP (Electric Vehicle Infrastructure Training Program), Diploma in Electric Vehicle Technology, and Diploma in Engineering Fundamentals of Electric Vehicles, I provide expert guidance and in-depth reviews on the latest EV charging equipment.
