Performance analysis of a high-speed on/off valve based on an intelligent pulse-width modulation control

Abstract

Dynamic performance is an important index of high-speed on/off valve in the digital hydraulic field. Optimizing the control algorithm is an effective method to improve the dynamic performance of existing high-speed on/off valves. Usually, a high-voltage excitation method is used to realize fast switching of the high-speed on/off valve, but this also leads to a high temperature rise, large energy consumption, and long delay times when switching off. In this article, an intelligent pulse-width modulation control algorithm is proposed to improve dynamic performance while minimizing temperature rise and energy consumption of high-speed on/off valves. A high-frequency voltage source with full positive, low positive, full negative, and zero duty ratios is applied to drive the high-speed on/off valve in opening, maintaining opened, closing and maintaining closed states, respectively. The adaptive switching of these four duty ratios is realized by real-time current feedback which can estimate the operational state of the high-speed on/off valve, so that the current in the loop is always in the optimal state. A mathematical model of the high-speed on/off valve is built, and based on it, the theoretical formulas for the delay time, temperature rise, and energy consumption of the high-speed on/off valve are deduced. Simulation results indicate that the intelligent pulse-width modulation control algorithm has a better performance in dynamic characteristics than normal high-voltage excitation methods. Moreover, experimental results from a test system indicate that the intelligent pulse-width modulation control has the potential to shorten the opening time by 23.6% and closing time by 17.0%, which confirms the simulation results. Results also showed the ability to extend the controllable working duty ratio by 83.3%, to reduce temperature rise by 69.9%, and reduce energy consumption by 88.8% when compared to the matched controller of the tested high-speed on/off valve. This article presents an effective and practical method to improve the performance of high-speed on/off valves.