Research On River Monitoring And Composite Energy Self-supply System

In recent years,floods have occurred frequently in our country,causing huge economic losses to the society and posing a huge threat to the lives of the people.Flood disasters are closely related to water regime information.By collecting and analyzing water regime information,the occurrence of floods can be predicted.Although wireless sensor networks are suitable for data collection in river monitoring,their development is limited by issues such as battery power supply.The river environment includes abundant solar energy and water vibration energy,and the effective collection of these two kinds of energy can provide energy for the wireless river monitoring system.To this end,this paper has carried out research on the river monitoring system and its composite energy self-supply system.The main contents are as follows:Firstly,the principle of photovoltaic power generation and piezoelectric power generation is theoretically analyzed,and photovoltaic cells and piezoelectric ceramics are selected as photovoltaic cells and piezoelectric cells respectively.On this basis,a spherical composite energy harvesting device is designed and a matching energy management circuit is designed.The spherical composite energy harvesting device uses a transparent polymethyl methacrylate shell.A number of circular PZT-5 piezoelectric ceramic wafers with a diameter of 3 cm are uniformly installed in each ball cavity,and the piezoelectric sheets are separated by 90°,and photovoltaic cells are installed on the two tops of this energy ball.The composite energy management circuit adds a diode at the input end to eliminate the load effect.It uses the principle of stepwise amplification to manage and store the electrical energy output by the energy harvesting device into the supercapacitor energy storage element.Secondly,the hardware circuit design and software design of the river monitoring system based on STM32 are completed,which mainly includes two parts: sensor data acquisition and communication circuit.The sensor data acquisition module is mainly responsible for collecting water regime information.The water level sensor kps-49c2 is applied to collect river water level information,and the magnetic sensor YF-S201 is used to collect water speed information based on the Hall principle,and the temperature and humidity sensor DHT11 is used to collect humidity information.In order to achieve flood forecasting,the existing river water regime information is applied to construct training samples and prediction samples.On the one hand,the BP neural network prediction model is obtained by using the training samples.On the other hand,flood prediction is carried out separately based on the prediction samples and local water regime information.And flood classification early warning information is displayed through the developed host computer.Finally,an experimental test platform was built to test the composite energy harvesting device and the river monitoring system.The experimental results show that the highest output power of the photovoltaic power generation unit in March on a sunny day is 760?W,and the highest output power in a cloudy day is 258?W.There are obvious differences in the output power of the piezoelectric unit under different vibration frequencies.Different piezoelectric balls are configured.It is found that the output power is the highest when the diameter of the piezoelectric ball is 120 mm and 8 PTFE balls are embedded,reaching 57.7 ?W.The composite energy is higher than the simple superposition of the two energies,which is mainly due to the decrease in energy consumption of the energy management circuit during composite collection.The river monitoring system was tested,the water regime information of the local river was collected,the power consumption of wireless sensor nodes was analyzed,and the feasibility of self-supplying energy was demonstrated from the perspective of energy balance.