Abstract: In the context of the rapid development of modern industry, China’s extreme energy consumption and excessive consumption, resulting in a shortage of non-renewable energy. As a new renewable energy, solar photovoltaic power generation can effectively alleviate the current problem of energy shortage, and the reasonable application of electrical automation technology can greatly improve the effect of solar photovoltaic power generation. Therefore, the article first analyzes the current situation of solar photovoltaic power generation, summarizes solar photovoltaic power generation from the principle and advantages of solar photovoltaic power generation, and makes an in-depth study on the specific application of electrical automation in solar photovoltaic power generation.
Keyword: electrical automation; solar energy; photovoltaic power generation; application;
Introduction: Solar energy is a kind of renewable energy, which has the advantages of convenience, large reserves, cleanness and pollution-free. It has a very broad application space and development potential in various fields. Photovoltaic system can convert solar energy into electric energy without energy loss, air pollution and other problems. How to improve the utilization effect of solar photovoltaic power generation has become an urgent research topic. Based on this, this paper studies the application of electrical automation in the power industry, grid connected system, photovoltaic building, water pump system, DC frequency conversion control, reactive power compensation control and other aspects of solar photovoltaic power generation, and constantly improves the utilization effect of solar photovoltaic power generation, which provides an important energy basis for the sustainable development of China’s economy.
1. Analysis of the current situation of solar photovoltaic power generation
In recent years, with the concept of sustainable development becoming more and more popular, green and low-carbon has become a way of production and life that people pursue. As a clean and pollution-free renewable energy, solar photovoltaic power generation has been taken as the mainstream direction of using power resources in China’s production and life. The scale of development and utilization has expanded rapidly, promoting the rapid development of solar photovoltaic power generation. Compared with western developed countries, China’s solar photovoltaic power generation technology started relatively late. However, due to the country’s attention and policy support to solar photovoltaic power generation, the scale of China’s photovoltaic power generation has developed very rapidly. In particular, in 2017, China’s installed capacity reached a historical high. Affected by the new policy of photovoltaic 531, China’s installed capacity decreased in 2018 and 2019, but since 2013, Photovoltaic power generation in China has grown rapidly, with a year-on-year growth of 26.3% in 2019. According to the statistics of relevant departments, the change of photovoltaic power generation in China from 2013 to 2019 is shown in Figure 1. It has become the largest application market in the world and a strategic emerging industry with international competitive advantages in China.
2. Overview of solar photovoltaic power generation
2.1 Basic principle of power generation
According to the principle of photovoltaic effect, solar photovoltaic power generation uses solar cells to convert scattered radiation, reflected radiation, direct radiation and other different forms of solar radiation energy into electrical energy to meet the needs of electricity. It is mainly composed of solar cell arrays, battery packs, controllers, inverters, DC loads, AC loads and other equipment. The principle structure diagram is shown in Figure 2.
2.2 Power generation advantages
Compared with other forms of power generation, solar power generation has great advantages. The details are as follows:
(1) Solar energy is an inexhaustible energy, with huge radiant energy. It is not affected by changes in the current energy market, and is the most resource rich power generation technology.
(2) Because each region receives light and can use solar energy resources anytime and anywhere, solar power generation is not affected or restricted by the region, and can effectively solve the power problem in remote and special areas.
(3) Solar photovoltaic power generation is safe, pollution-free, flexible and can operate safely and stably.
(4) Solar photovoltaic power generation is in a static state, and various equipment components will not move, reducing the probability of equipment failure and extending the service life of equipment.
3. Application of electrical automation in solar photovoltaic power generation
According to the actual development of solar photovoltaic power generation in China, electrical automation technology is one of the most attractive technologies, which can effectively improve the utilization rate of solar energy. The application of electrical automation in solar photovoltaic power generation is discussed below.
3.1 Application in power industry
In the power industry, electrical automation technology plays an important role in promoting the continuous development of China’s industrial field. In electric power engineering, the scientific and reasonable application of electrical automation technology can reduce the work intensity of relevant personnel to a certain extent, reduce the loss caused by human factors, and effectively improve the working efficiency of the power system. In addition, the reasonable application of electrical automation technology in the power system has changed the resource utilization structure of electrical engineering, guaranteed the security and stability of the power system itself, and ensured the economic benefits of electrical engineering.
3.2 Application in grid connected solar photovoltaic power generation system
With the intelligent development of solar photovoltaic power generation system, there are some differences in power generation modes according to different actual needs, mainly including independent photovoltaic power generation, grid connected photovoltaic power generation and distributed photovoltaic power generation. Because grid connected photovoltaic power generation system has the advantages of high security, low installation cost, low resource consumption and short construction period, it is widely used. Grid connected photovoltaic power generation system is that the direct current generated by solar modules is converted into alternating current meeting the requirements of the municipal power grid through grid connected inverter, and the sinusoidal alternating current generated is directly connected to the public grid. The application of electrical automation technology in grid connected power generation system can effectively avoid the severe impact of photovoltaic power generation system on the grid in the process of grid connection, so as to reduce the load and loss on the grid in the actual power generation process. In addition, the electrical automation technology can also effectively monitor the electrical quantities on both sides of the synchronization point, capture data and judge information efficiently and accurately, to make up for the time difference in the data transmission process, and improve the scientific and accuracy of data information.
3.3 Application in photovoltaic buildings and water pump systems
With the continuous progress of science and technology, there are more and more solar photovoltaic systems, which increases the difficulty of management. It is difficult to find faults of the solar photovoltaic system in time, which seriously affects the normal operation of the solar photovoltaic power generation system. In recent years, the number and types of automation products are increasing, and the application of electrical automation technology and automation products in photovoltaic buildings and photovoltaic pump systems is more and more extensive, among which the automation monitoring system is the one with the highest application frequency. Through the automatic monitoring system, real-time monitoring can be carried out on the voltage and current of the photovoltaic building and photovoltaic pump system’s battery panels, as well as the operating conditions, and the working conditions of the inverter. The system’s operating parameters are recorded in detail, and the system’s faults are alarmed. Relevant workers can analyze and judge the specific location of the fault through the data recorded by the automatic monitoring system, and carry out emergency maintenance, To ensure the normal operation of solar photovoltaic power generation.
3.4 Application in DC frequency conversion control process of photovoltaic power generation system
At present, China’s photovoltaic power generation system is mainly DC power. DC power system has the advantages of simple structure and low cost, but it is difficult to achieve standardization due to the impact of load voltage. With the continuous development of solar photovoltaic power generation and the emergence of grid connected operation, a higher requirement is put forward for photovoltaic power generation system, that is, to convert into alternating current. Reasonable use of electrical automation technology to effectively control the components of photovoltaic power generation system with AC power output, mainly including battery array, battery pack, controller, inverter, etc. By monitoring the operation status of the primary and secondary distribution networks, we can understand the operation status of each equipment, and monitor the distribution of photovoltaic modules and inverters of each component, so as to timely understand the DC voltage, current, power, AC voltage, current, grid frequency, power factor, etc., so as to smoothly convert the DC power output by photovoltaic power generation into AC power.
3.5 Application in reactive power compensation control
Most of the components used in the photovoltaic power generation system are electronic components. During the use of electronic components, they will produce reactive power loss and harmonics, which will lead to instability of the power system, and even lead to unqualified voltage quality (insufficient supply voltage or voltage overload), affecting the stability of solar photovoltaic power supply. However, by reasonably using dynamic reactive power compensation devices and filtering devices, accurately adjusting the reactive power voltage of photovoltaic power generation, and timely controlling the reactive power loss, it can ensure that power loss and harmonics will not affect the voltage quality.
3.6 Application in life cycle control of photovoltaic system equipment
As China started relatively late in the field of solar photovoltaic power generation, there are many deficiencies in management. Generally, the maintenance of relevant equipment is completed only when problems occur in photovoltaic power generation, which reduces the power generation efficiency and quality, affects the reliability of power generation, and shortens the full life cycle of photovoltaic power system equipment. Through the reasonable application of electrical automation technology in the life cycle control of photovoltaic power system equipment, the operation status of equipment such as vibration deviation and allowable temperature rise can be monitored to determine whether the equipment is operating “with problems”, develop a reasonable equipment maintenance plan, and constantly improve the equipment life cycle and quality.