| With the development of modern science and technology, robot technology has been promoted and has a long-term development, but the power system has always been a key issue which limits the development of robot technology. Fuel cell is a new power supply solution for its energy efficiency and environmental protection. However, the fuel cell itself can't meet the robot system dynamic requirement. To solve this problem, a robot with fuel cell hybrid power system has been discussed in this thesis. Main research results are as below:On the basis of analysis the characteristics of fuel cell, this thesis proposed a fuel cell with auxiliary power which including battery and ultra capacitor module (UCM). And with the robot work patterns and system load requirement discussed the power and the capacity that battery and UCM contain. By comparing the mutual DC-bus topology, proposed a new cascade bi-directional configuration. And analysis the configuration's work patterns.Base on the topology and the system's performance requirements, this dissertation give the selection of MOSFET, transformers and capacitors for bi-directional DC/DC converter, and determine the overall control system block diagram. On this basis, this thesis designed the hardware with TMS320F2812 as a core controller, which is including the drive unit, signal measurement and processing unit, sampling unit, isolation unit and the protection unit.By the analysis of robot work patterns and the characteristics for power system, with four constraints. Proposed a power flow switch strategy with sliding mode control and PI control, when the deviation is large, using sliding mode controller reduced the deviation to the threshold quickly, and when the deviation is less than the threshold vale, using PI controller reduced static error.This thesis simulates the proposed fuel cell hybrid power flow control strategy, simulation results show that when robat load changed, the system can achieve good power flow control. |
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