The weak energy storage performance of sensors leads to long delay and unsatisfactory energy-saving effect of sensor energy-saving controller network in photovoltaic power generation.
Therefore, a new sensor energy-saving controller for photovoltaic power generation is designed, which focuses on the design of power supply circuit, wireless communication chip and solar sensor chip. NRF905 wireless communication chip monitors data communication among devices, circuits and components in the controller to ensure energy-saving effect and shorten network delay. The power supply circuit supplies electric energy for the energy-saving work of the controller and optimizes the energy conversion of sunlight intensity. The optimized solar energy will be extracted and analyzed by the solar parameters of TSL2678 chip in the solar sensor to output the best collection direction of solar energy and the sunlight intensity in that direction, so as to realize the optimal energy saving of photovoltaic power generation. The software design of the controller gives the energy-saving control flow of the controller. The experimental results show that the designed controller has the characteristics of short network delay and good energy-saving effect. Solar energy is a renewable and clean energy. In recent years, with the continuous development of science and technology, photovoltaic power generation has become a very important way of power generation. Its purpose is to use the enormous energy radiated by the sun to the earth, so as to save the earth’s non-renewable resources and prevent the environment from deteriorating further [1?3]. Sensor is a kind of equipment to realize the effective interaction between human and nature.
It plays an important role in optimizing human production and life style. Therefore, a sensor energy-saving controller in photovoltaic power generation is designed to meet the increasing demand of human life [4?6]. Because of the weak energy storage performance of sensors, the sensor energy-saving controller network in photovoltaic power generation designed previously has long delay and unsatisfactory energy-saving effect. For example, the energy-saving controller of double-layer energy storage sensor in photovoltaic power generation is designed in reference [7]. By analyzing the weakness of sensor energy storage in photovoltaic power generation, the energy storage of sensor nodes is designed in double-layer, which effectively reduces the loss of solar energy and has good energy-saving effect, but the network delay of the controller is very long. In reference [8], the sensor nodes of sensor energy-saving controller in photovoltaic power generation are reasonably controlled, and shorter network delay is obtained. Designers will also connect solar collector panels directly to lithium batteries, hoping to save design costs, but lead to excessive damage to lithium batteries. Literature [9] Design a sensor energy-saving controller based on capacitance and single chip microprocessor for photovoltaic power generation, which sets capacitance as the power supply of the controller, and then uses single chip microprocessor to control the charging and discharging process of capacitance. The controller has good comprehensive performance, but the energy-saving effect still needs to be improved. Reference [10] Considering the sensor energy-saving controller in photovoltaic power generation, the energy-consuming devices are deleted, and the energy consumption of sensor nodes is further optimized. The energy-saving effect of the controller is good, but the network delay is long. Based on the analysis of the advantages and disadvantages of sensor energy-saving controller in photovoltaic power generation, the energy-saving realization scheme of photovoltaic power generation is discussed in depth, thermostatic element and a sensor energy-saving controller in photovoltaic power generation with short network delay and good energy-saving effect is designed. The sensor energy-saving controller in photovoltaic power generation is designed to adjust the position of solar energy acquisition in photovoltaic power generation as an energy-saving scheme to enhance the energy conversion rate between solar energy and electric energy in photovoltaic power generation, thereby realizing energy-saving control. A power supply circuit with the advantage of high level energy conversion is presented, which improves the energy storage performance of the sensor and provides a reasonable power supply for the controller. In addition, the optimal energy-saving of photovoltaic power generation can be achieved by choosing reasonable wireless communication chips and solar sensor chips for the controller. In the sensor energy-saving controller designed for photovoltaic power generation, wireless communication chip is the intermediate link connecting the data communication among devices, circuits and components. Because the wireless communication chip can monitor all the communication data in the controller, the high performance of the wireless communication chip will bring a very good energy-saving effect to the controller, and can effectively shorten the network delay, so the selected wireless communication chip should have good reliability and communication efficiency. The nRF905 wireless communication chip designed by Norwegian NORDIC company is selected as the wireless communication chip of the controller. NRF905 wireless communication chip has strong reliability and abundant on-chip resources. It can decode on-chip. It is very convenient to use and has high communication efficiency. Fig. 1 is the circuit diagram of nRF905 wireless communication chip. Figure 1 shows that when nRF905 wireless communication chip transmits communication data, the sensor energy-saving controller in photovoltaic power generation places input terminals 1 and 2 in high pin and low pin respectively, and then saves and counts the data through the communication bus to regenerate the communication file. After document management approves the communication file, the nRF905 wireless communication chip sends out the communication data.
In the process of receiving data, the digital control reads the data that meets the receiving standard of nRF905 wireless communication chip, and the interface 5 automatically enters the high pin. An important reason for choosing nRF905 wireless communication chip is that nRF905 wireless communication chip can provide energy-saving mode for communication work on the basis of realizing effective communication within the controller, which is of great significance for realizing the original design purpose. The energy-saving mode can reduce the current and data transmission duration while maintaining the normal communication of the controller. Usually, the nRF905 wireless communication chip with energy-saving mode can meet the communication needs of photovoltaic power generation, so it can be opened for a long time by default and closed in special cases. Because the energy storage performance of the sensor is weak, the reasonable design of the power supply circuit is of great significance to the sensor energy-saving controller in photovoltaic power generation. The designed power supply circuit can not only supply the working electric energy for the controller, but also optimize the energy conversion of sunlight intensity. In photovoltaic power generation, the strength of solar energy will affect the power distribution of power supply circuit to a certain extent. Therefore, sensor energy-saving controller in photovoltaic power generation has designed two kinds of power supply circuit. When the ambient solar energy is strong, the output current of the solar collector plate does not fluctuate greatly.
At this time, the power supply circuit should provide positive bias for the controller, as shown in Figure 2. When the ambient solar energy is weak, it is necessary to enhance the sensitivity of the power supply circuit to the output current of the solar collector plate, as shown in Figure 3. Figures 2 and 3 show that R in the power supply circuit represents the total load of the external functional circuit. Because the load value is uncertain, it is described by dotted lines. D is a PN junction photodiode. The response time of this kind of diode is very short, and the process of solar energy absorption and sensor radio frequency transmission can be realized. It also has very strong photoelectric conversion performance, which can optimize the solar energy conversion reasonably; U is the output end of the power supply circuit; R0 and R1 are used to enhance the sensitivity of the power supply circuit to the output current of the solar collector board, and the resistance of the two loads is a large or a small value, and the two loads are connected in series and one of them is connected with PN photodiode. Parallel connection of tubes has little effect on the output value of power supply circuit, which can be neglected. Sunlight sensor is a special sensor which can accurately sense the trajectory and radiation intensity of the sun without restriction of latitude and longitude. TSL2678 is the solar sensor chip chosen by the sensor energy-saving controller in photovoltaic power generation. The chip has low energy consumption, high sensing efficiency and wide range. It can automatically correct the solar fluctuation below 60 Hz, and is more suitable for photovoltaic power generation. Figure 4 depicts the structure of TSL2678 chip. As shown in Figure 4, the sunlight intensity with fluctuation amplitude less than 60 Hz can be input into the TSL2678 chip of the solar sensor as a locking event for parameter extraction. Solar light intensity above 60 Hz fluctuation amplitude will be transformed through power supply circuit, optimized to lock event, and then input into TSL2678 chip. The integrated analog-to-digital converter first converts the solar parameters into digital signal form, and then realizes the best acquisition position and precise output of the solar light intensity in the position of the solar sensor. The energy-saving control flow of the proposed sensor energy-saving controller in photovoltaic power generation is shown in Fig. 5. Fig. 5 shows that in order to enhance the energy conversion between solar energy and electric energy in photovoltaic power generation, and then realize the energy-saving control of sensor energy-saving controller in photovoltaic power generation, this paper uses nRF905 wireless communication chip to monitor the whole energy-saving control process. After the initialization of the power supply circuit, nRF905 wireless communication chip helps to search for the sunlight intensity needed for energy conversion in the communication data, and realizes energy optimization through the power supply circuit. Thereafter, the nRF905 wireless communication chip wakes up the solar sensor and calculates the optimum collection position and the intensity of the solar light using TSL2678 chip. Managers will refer to the output results to adjust and maintain the sensor energy-saving controller in photovoltaic power generation. The simulation experiment of a provincial photovoltaic power plant is carried out to analyze whether the controller designed in this paper has shorter network delay and better energy-saving effect. Contrasted with the controller in this paper, there are two controllers: energy-saving controller of double-layer energy storage sensor and energy-saving controller of sensor based on capacitance and single chip computer. The parameters of the experimental photovoltaic power station from April to June 2016 are simulated. The actual power generation of the experimental photovoltaic power station in 2014 and 2015 are shown in Table 1. In the experimental photovoltaic grid, the standard of network delay limitation is different in different months. The experimental results of network delay of the controller, the energy-saving controller of double-layer energy storage sensor and the energy-saving controller of sensor based on capacitor and single chip computer are shown in figs. 6-8. From figs. 6 to 8, it can be seen that the network delay limit criteria given by photovoltaic grid in April-June are straight lines, and the lower area of the line represents the standard range of network delay. The network delay curves of two-layer energy storage sensor energy-saving controller and sensor energy-saving controller based on capacitor and microcontroller both exceed the standard range, while the network delay curves of the controller in this paper are always below the standard line of network delay limit, which proves that the network delay of the controller in this paper is relatively short. Table 2 describes the power generation of experimental photovoltaic power plants in April-June under the energy-saving control of three controllers. Comparing with Table 1 and Table 2, it can be seen that the power generated by the controller in this paper is the highest. It can save the coal power generated by the experimental photovoltaic power station about 740.50 kW.h per month on average. It can effectively reduce the emission of harmful gases such as carbon dioxide and sulfur dioxide produced by burning coal, which proves that the controller in this paper has better energy-saving effect. In this paper, a new sensor energy-saving controller for photovoltaic power generation is designed. The energy-saving scheme is to adjust the position of solar energy acquisition in photovoltaic power generation, enhance the energy conversion rate between solar energy and electric energy in photovoltaic power generation, and realize energy-saving control. The designed controller has a high level of energy conversion power supply circuit, which can improve the energy storage performance of the sensor and provide a reasonable power supply for the controller. By choosing reasonable wireless communication chips and solar sensor chips, the original design intention can be realized. In this paper, a provincial photovoltaic power plant is simulated to verify that the controller has a shorter network delay and better energy-saving effect.