Research On Key Technologies Of Vibration Energy Collection System For Rocker Arm Of Shearer

The rocker arm of shearer can produce certain vibration energy in the process of coal mining.The energy collection technology can be used to convert the vibration energy generated by electromechanical conversion,which can solve the energy supply problem in the wireless status monitoring system of the rocker arm of shearer.But the traditional vibration energy collection structure has high natural frequency,low power generation efficiency and low utilization rate of energy conversion circuit,so it is of great significance to study the vibration energy collection technology of the rocker arm of shearer.In this paper,an efficient vibration energy collection system of shearer rocker arm is designed based on the vibration energy generated by the shearer rocker arm,which can provide sufficient electric energy for the wireless sensor node.The research work mainly includes the following aspects:(1)In order to improve the efficiency of vibration energy collection of the rocker arm of the shearer,a novel multi-layer arranged piezoelectric structure with multiple resonant points and high output is designed.Firstly,the distribution characteristics of vibration signals in the working process of shearer rocker arm are analyzed,which provides a basis for the design of vibration energy collection system of shearer rocker arm.Secondly,based on the modeling analysis of the piezoelectric structure of a typical cantilever beam,a multi-layer piezoelectric structure is designed.Compared with the typical structure under the same conditions,the number of resonant points is increased,and the output voltage and power are improved.Finally,the structure is further optimized,and a novel multi-layer piezoelectric structure is proposed.The practical verification results show that the designed piezoelectric structure has the characteristics of low natural frequency,more resonant points and high output power,which is more in line with the vibration condition of the rocker arm of shearer.(2)In view of the typical vibration energy collection interface circuit affected by load and switching devices,a dual parallel synchronous switching inductive charge extraction circuit(DPSSI-SECE)is designed.Firstly,the equivalent circuit model of piezoelectric structure is analyzed,and the factors affecting the electromechanical conversion efficiency are studied.Secondly,the principle analysis,theoretical calculation and software simulation of DPSSI-SECE circuit are carried out.The results show that under the same conditions,the output of DPSSI-SECE circuit is about 8.6 times that of standard energy collection circuit,and about 2.8 times that of synchronous charge extraction circuit,and the output power basically remains unchanged when the load changes.(3)Due to the complexity of the vibration frequency of the rocker arm of shearer,the DPSSI-SECE circuit is difficult to generate accurate control signals.A voltage signal maximum detection control circuit based on STC15W4K32S4 is proposed.The results show that the output generated by the control method combined with software and hardware has less error than the direct calculation method.Secondly,the working principle of the circuit at different periods is studied,the calculation method of the circuit power consumption and output power is obtained,and the high efficiency energy collection voltage regulator circuit based on LTC3388-3 is proposed.At the same time,in order to ensure the continuity of load power supply,5.5V,0.1F supercapacitor is used in the circuit for energy storage.Finally,the experimental results show that the vibration energy collection system of shaker arm based on STC15W4K32S4 can produce higher output power and is not affected by load in a certain range.Through the study and analysis of piezoelectric structure and interface circuit,a multi-resonant and high-output vibration energy collection system of shearer rocker arm is designed,which realizes the rational recovery and utilization of energy,and promotes the development of the wireless status monitoring system of shearer rocker arm to the direction of intelligence and automation.