Design and experiment of controlled bistable vortex induced vibration energy harvesting systems operating in chaotic regions

•Bistable spring widens the working range of vortex induced vibration energy generator.•Bistable spring might exhibit chaotic responses that limit the system performance.•OGY controller is designed and developed to stabilize the chaotic responses.•The controller regulates the electrical load damping as the manipulated variable.•The controller is positively validated by simulation and experiment at various cases.