What is the Komatsu Hybrid electrical system?
The main difference between the Komatsu Hybrid excavator and its conventional equivalent is the hybrid electrical system.
The Komatsu Hybrid electrical system consists of three main components:
- An electric generator motor
- An electric swing motor generator
- A Komatsu-designed Ultra Capacitor with inverter.
The generator motor is positioned between the engine and hydraulic pumps, the electric swing motor generator is used in place of the hydraulic swing motor and the inverter/capacitor is used to rapidly convert and store electrical charge.
The electric swing motor generator uses electrical power from the inverter/capacitor or the generator motor to drive the upperstructure during the swing function.
During the deceleration or swing-braking phase, the electric swing motor generator converts kinetic energy back into electrical power and returns it to the capacitor via the inverter.
The generator motor generates electric power with engine torque to drive the swing motor or to charge the capacitor when necessary.
The inverter rapidly converts electricity from either the electric swing motor generator or the generator motor from AC to DC for storage in the ultra capacitor and from DC to AC to supply the swing motor or generator motor for engine assist as required.
The engine assist function of the generator motor gives the Komatsu Hybrid excavator the unique ability to provide power on demand utilising only the engine RPM required for the operation. It also enables a very low idle speed of 700 rpm and downsizing of the engine from a six cylinder to a four cylinder with no loss of performance, power or productivity.
Apart from the hybrid system and the smaller engine, Komatsu Hybrid excavators are basically the same as a conventional Komatsu excavator, offering equivalent performance in breakout force and operating speed, and are operated in precisely the same manner.
In addition, capacitor cells deteriorate far less quickly when compared with batteries, and are completely maintenance-free without the need for refilling of electrolyte.