I am trying to charge a capacitor using repeatable damped sinusoid current signals from a piezoelectric bender (Figure at left) - Result of the free vibration of the piezo beam (Current source plus piezoelectric capacitance in parallel - Figure at Right). The current from the piezo bender is rectified and used to charge a capacitor. I have simulated it Matlab/Simulink [See model in Figure 1] but it yields a weird behaviour when the input is a damped sinusoid current signals. The voltage across the capacitor never reaches the open circuit voltage but grows indefinitely.
[See Figure 2]- >This is the expected behaviour (From a sinusoidal no-damped current input): Graph1: Voltage Across Cp1(Piezo Bender) Graph2: Voltage Across Capacitor that is being charged.
[See Figure 3]->However, this is what I get (The voltage across the capacitor never reaches the open circuit voltage but grows indefinitely): Graph1: Voltage Across Cp1(Piezo Bender) Graph2: Voltage Across Capacitor that is being charged.
Would you have any suggestion or hint about what is happening here? Thank you very much for your help in advance.
Best wishes, Lucas
