Variable speed digital hydraulic transformer–based servo drive

2019 ◽  
Vol 234 (3) ◽  
pp. 287-298
Author(s):  
Matti Linjama
Keyword(s):  
Power Management ◽  
Management System ◽  
Peak Power ◽  
Average Power ◽  
Variable Speed ◽  
Servo Drive ◽  
Hydraulic Power ◽  
Hydraulic Servo ◽  
Power Management System ◽  
Hydraulic Accumulator

This article studies a digital hydraulic servo drive driven by a variable speed electric servomotor. Digital displacement control is implemented by using a two-port digital hydraulic power management system having six pistons and 18 on/off control valves. The first port of the digital hydraulic power management system controls the cylinder speed, while the second port is connected to a hydraulic accumulator. The peak power is taken from the accumulator, and the electric servomotor supplies only the average power into the system. An experimentally validated simulation model is used, and the results show a combination of adequate controllability and excellent energy efficiency. The estimated reduction in the size of the electric motor is 57%.

Comparison of Proportional Control and Displacement Control Using Digital Hydraulic Power Management System

2014 ◽  
Author(s):  
Mikko Heikkilä ◽  
Matti Karvonen ◽  
Matti Linjama ◽  
Seppo Tikkanen ◽  
Kalevi Huhtala
Keyword(s):  
Power Management ◽  
Management System ◽  
Low Flow ◽  
Energy Losses ◽  
Hydraulic Systems ◽  
Displacement Control ◽  
Hydraulic Power ◽  
Proportional Control ◽  
System Pressure ◽  
Power Management System

The Digital Hydraulic Power Management System (DHPMS) is a solution based on the digital pump-motor technology and has shown to be a promising approach to improve the energy efficiency of hydraulic systems. The DHPMS is controlled by active on/off valves, but unlike the digital pump-motors the DHPMS has multiple independent outlets; hence, the DHPMS can operate also as a transformer. In this experimental study, a proportional control of a mobile boom is compared with a displacement control when a six-piston DHPMS is used. In the proportional control, the system pressure is controlled by the DHPMS and a lift cylinder with a proportional valve. In the displacement control, the cylinder fluid volumes are controlled directly using the DHPMS. Firstly, the systems under study are presented along with the control methods. Then the control performance of the DHPMS is studied and finally, the energy losses in the systems are analysed. The results show the versatility of the DHPMS; it is capable of fast and accurate pressure control but also handles the direct flow control. According to the measurements, the losses are significantly smaller in the displacement controlled system thanks to the minimised throttling losses and the energy recovery. Nevertheless, the energy losses in the prototype DHPMS are rather high due to the leakage in the control valves and their low flow capacity, and therefore improvements in the design are needed.

Aspects of the Energy Consumption of a Digital Hydraulic Power Management System Supplying a Digital and Proportional Valve Controlled Multi Actuator System

2014 ◽  
Author(s):  
Matti Karvonen ◽  
Mikko Heikkilä ◽  
Seppo Tikkanen ◽  
Matti Linjama ◽  
Kalevi Huhtala
Keyword(s):  
Energy Consumption ◽  
Power Management ◽  
Management System ◽  
Control Method ◽  
Inverse Kinematic ◽  
Hydraulic Power ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Power Management System

Hydraulic motion control is traditionally done with servo or proportional valves. A digital hydraulic valve is based on arrays of simple on/off valves. Independent metering control is possible with digital valves since control notches are not linked together. With commonly used commercial proportional valves constant opening ratios are used. In this paper, a small mobile boom is studied. The lift and tilt cylinders can be controlled with proportional or digital valves. Closed loop control system is based on a robust control method of a multi actuator boom and also inverse kinematic equations are required in coordinate drive. The supply system consists of a Digital Hydraulic Power Management System (DHPMS) which is capable of supplying separate supply pressures for both actuator supply lines. Measurements are done, and one vs. two supply pressures and digital vs. proportional valves are compared. Two different test trajectories and two different load masses are used. Analysis focuses on the energy consumption of different test cases and sources of losses are inspected. Results show that energy consumption can be reduced up to 44%.

scholarly journals Intelligent Electric Power Management System for Economic Maximization in a Residential Prosumer Unit

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 48713-48731
Author(s):  
William Felipe Ceccon ◽  
Roberto Z. Freire ◽  
Anderson Luis Szejka ◽  
Osiris Canciglieri Junior
Keyword(s):  
Electric Power ◽  
Power Management ◽  
Management System ◽  
Power Management System
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