An Electronically Controlled Pressure Regulator

This paper describes the analysis, design, implementation, and evaluation of an electronically controlled fluid back-pressure regulator system. The control scheme is unique in that it is purely electronic, and employs a nested pair of feedback loops. This approach overcomes several problems associated with purely mechanical regulation, such as friction in the control valve. Further, since the control is electronic, compensation functions are easily implemented via operational amplifier circuits. The pressure control system is derived with classical control techniques through linearization of the measured valve characteristics. The solutions to nonlinear problems encountered in the implementation are discussed. The design achieves good performance and stability over the entire pressure and flow operating regime.