Patent ID: 7843076
Filing Date: 2010-11-30
Classification: F15B

Abstract:
1. An energy storage system comprising: a fluid circuit comprising: an electrical unit configured to operate as a motor in a first phase of operation and to operate as a generator in a second phase of operation, wherein in the first phase of operation electricity is supplied to the first hydraulic/motor unit Whereby the first hydraulic/motor unit transmits the first working fluid from the tank into the first fluid container, and wherein in the second phase of operation pressurized first working fluid in the first fluid container is transmitted from the first fluid container through the first hydraulic/motor unit to the tank thereby causing the electrical unit to generate electricity; wherein the second hydraulic motor/pump unit is operatively connected to the electrical unit and fluidically connected between the second fluid container and the third hydraulic motor/pump unit, wherein the third hydraulic motor/pump unit is fluidically connected between the second hydraulic motor/pump unit and the first fluid container; and wherein the second hydraulic motor/pump unit and the third hydraulic motor/pump unit are configured during the first phase of operation to operate as pumps to transmit fluid from the second fluid container to the first fluid container, and during the second phase of operation to operate as motors as fluid from the first fluid container is transmitted to the second fluid container; wherein the electrical unit is configured during the first phase of operation to operate as the motor for the second hydraulic motor/pump unit and during the second phase of operation to operate as a generator driven by the second hydraulic motor/pump unit.