Design Of Boost Converter For Photovoltaic Cell In Wireless Sensor Network Nodes

Since the new century,wireless sensor network technology has come into life from theory.For the small nodes in the wireless sensor network,we hope that they can work continuously and steadily,but the reality is that many wireless sensor network nodes(Wireless Sensor Network nodes,WSNs)work environment is very harsh,and the number of nodes is huge,covering a wide range,in terms of power supply,the use of ordinary batteries can not meet the requirements,so the current research direction is to collect and use energy in the environment,To achieve self-sufficiency of the power supply,the most common natural energy source is light energy,and the light energy collection element is a photovoltaic cell.This paper first investigates the research achievements of boost voltage converter chips with the Maximum Power Point Tracking(MPPT)function related to photovoltaic cells at home and abroad,and summarizes the existing boost conversion circuit structure.Based on the actual application scenario,this paper establishes a system-level mathematical model of the photovoltaic cell,simulates the system-level structure,and obtains the output characteristic curve of the photovoltaic cell.Based on the system-level simulation results,the circuit model of the photovoltaic cell is established in order to provide a simulation source for the design of the boost conversion circuit.This paper analyzes various MPPT algorithms,and finally selects a disturbance observation method suitable for hardware implementation with high accuracy,and establishes a system-level model of the disturbance observation method,and the simulation results of the MPPT algorithm are verified.The MPPT algorithm is adapted to the output characteristics of the photovoltaic cell,and based on this theory,the algorithm in the system is modified.This paper designs a boost conversion chip for photovoltaic cells.The entire system includes a new four-phase high-efficiency charge pump module,MPPT control circuit module,feedback control module,nano-ampere current reference,etc.Designing each module and simulation,with higher power conversion efficiency and larger output voltage is the goal,combined with simulation results for optimization.The circuit design of the boost voltage converter chip with MPPT is carried out using SMIC's deep-well technology of 0.18?m.The final circuit simulation results show that when the light intensity is 400W/m~2,when the input voltage of the photovoltaic cell is 0.618 V,if there is no resistive load after the boost conversion chip,the output voltage is 1.84 V,and the voltage conversion efficiency is 98.7%;if the output terminal cascade resistance,the maximum output power is 358.4?W,the power conversion efficiency can reach 71.3%.Finally,the layout is drawn,and the area of the overall layout is 1.45 mm×0.98 mm.After the layout is verified,the post-imitation is performed.When there is no load,the maximum voltage output voltage is 1.80 V,the output ripple is less than 15 m V,and the chip meets the design function requirements.