Model of a chopper-driven magnetic actuator in an electrohydraulic system

An electrohydraulic system is modeled using a version of the electric circuit analysis program SPICE. The input is a typical DC voltage source and the output is a hydraulic pressure and flow. Analogies between hydraulic circuits and electrical circuits are used, along with nonlinear tables obtained by electromagnetic finite element analysis of a magnetic actuator that operates a proportional hydraulic valve. The control circuit is a chopper that produces variable pulse widths. Computed results show waveforms of chopper currents, magnetic actuator force, diode current, and hydraulic pressure.