Research And Design Of Elevator Braking Energy Recycling And Storage System Based On Super Capacitor

With the implementation of national energy conservation and emission reduction policy, to promote the elevator energy conservation in our country and improve the level of elevator energy efficiency, has become an important problem needed to resolve for the government and the elevator enterprises. Due to the super capacitor has many advantages such as fast charge and discharge rate, large power density, and so on, it is significance to use the super capacitor as the energy storage device in the elevator energy-saving system. In this context, this paper designs an elevator braking energy recycling and storage system based on super capacitor, and dose many research on design and control of the bidirectional DC/DC converter which is the key part of the system.This paper has carried on the overall design of the elevator braking energy recycling and storage system based on the super capacitor and analyzed the important role of parts of the system. The advantages and disadvantages of the isolated bi-directional DC/DC converter and the non isolated bidirectional DC/DC converter are studied. And the selection of the bidirectional DC/DC converter is completed.In the aspect of system parameters matching, the typical operating conditions of the lift are analyzed in this paper. According to the operation characteristics of the lift, the capacity management of the super capacitor is achieved, the matching method of the super capacitance parameters is summarized, and according to designed matching method, the parameters of the super capacitor are designed. Cost analysis is completed in this paper, too. Then the buck working mode and boost working mode of the bidirectional DC/DC converter are analyzed and researched in theory. On the basis of theoretical research, the parameters of the buck working mode and the boost working mode of the bidirectional DC/DC converter are calculated.In the aspect of control scheme, data-driven control theory and method and the control limits of the design based on the traditional control scheme for the bidirectional DC/DC converter are described. On this basis, the PID controller parameter setting method was studied and the Simulink simulation is carried on. Double closed loop cascade control is designed, and the controller parameters of the bidirectional DC/DC converter working in the buck and the boost mode are optimized respectively, and the optimization results are analyzed. Then, based on the designed controller parameters, the specific conditions of the whole system simulation by Simulink are carried on, the simulation waveform of the super capacitor charge and discharge is given.Finally, the detailed design of hardware circuit of the system is carried on in this paper. The selection of the main control chip, IGBT module as well as a variety of important components are analyzed and calculated. After the software design of the system control part completed, the super capacitor charge-discharge experiment and the elevator system running experiment are implemented through the experiment platform.The experimental results show that the controller optimized has a faster response performance. And the controller does not depend on the mathematical model of the plant. The model mismatch, unmodelled dynamics and other issues are effectively overcomed. The current and voltage have a good follow performance when the super capacitor working in the process of charging and discharging. The elevator braking energy recycling and storage system based on the super capacitor energy storage device running smoothly.