Research on drive circuit of piezoelectric injector for common rail system

A driving circuit of piezoelectric injector based on the current and voltage activation was designed to achieve precise closed-loop control and energy recovery. Several control strategies based on the circuit were also proposed. The optimal control strategy was selected through experimental comparison. Experiment results show that the circuit can realize fast and accurate charge and discharge control of the piezoelectric injector, reaching 120μs of charge period and 100μs of discharge period when the capacitor of the piezoelectric injector is about 3.3μ F, it also can achieve five times injection in one cycle. The energy recovery circuit can save energy and reduce the heat load as well. The single injection energy consumption using the piezoelectric injector is about 0.048 J, less than that of using solenoid injector in the same condition.