What is the difference between electrical storage and hydraulic ERS?

Schematic of the ERS using hydraulic storage. The energy regeneration efficiency of hydraulic ERS is proportional to the volume of the hydraulic accumulator. The larger size can recover more energy and vice versa. Hence, the limited energy storage density of hydraulic accumulators is a major flaw when compared to ERSs using electrical storage.

How does a hydraulic ER work?

When the boom cylinder moves down, the flow rate in the bore chamber will go through the control valve and can be directly recovered in the accumulator. Therefore, hydraulic ERSs can reduce losses during the energy recovery process which often occurs in electrical ERS because of transferring from hydraulic energy to electric energy.

Can a double-chamber system reduce energy consumption in hydraulic cylinders?

The experimental results showed that 50.1% energy consumption of the boom and 64.9% peak power of the power source can be reduced in the proposed system compared with the double-chamber system. This design can be widely used in all kinds of devices using hydraulic cylinders.

How does a hydraulic energy storage system work?

Aimed at reducing energy losses in hydraulics, the new system architecture was being tested in the field. The machine’s work functions are connected to a hydraulic energy storage via a common pressure rail, comprised of two or more pressure lines.

How is potential energy converted to mechanical energy in a boom cylinder?

During the moving down process, the potential energy in boom cylinder was converted to mechanical energy by using a variable hydraulic transformer (motor mode) to drive the fixed hydraulic transformer (pump mode) and then, stored the energy in accumulator.

How to overcome energy recovery challenges in hydraulic ERS?

To overcome the above challenges in ERSs, new energy recovery elements combining with optimal management – control strategies are of significant importance. For instance, development of 3-port pump or 3-chamber cylinders could help to simplify and then reduce size of hydraulic ERSs whilst improving the overall performance.