With the arrival of the Fourth Industrial Revolution, the transportation industry such as automobiles, ships, and trains, which are one of the pillar industries of the national economy, has developed rapidly. Due to its rapid development, countries have seen a sharp increase in demand for fossil fuels such as coal and oil, which provide power for transportation vehicles such as cars, ships, and trains. At present, the energy issue has evolved into a top priority for various countries: firstly, as people endlessly exploit limited fossil fuels, it leads to energy depletion; Secondly, the extensive use of fossil fuels such as coal and oil can generate many toxic gases that are harmful to human health, such as carbon dioxide, carbon monoxide, carbon particles, etc., causing extremely serious health problems for people; Finally, the combustion of a large amount of chemical energy will also cause harm to the environment, such as acid rain, greenhouse effect, and environmental problems such as ozone depletion. These issues have brought enormous challenges to people’s daily life, physical health, and socio-economic development, and have attracted high attention from people.
In this context, China’s demand for clean and renewable energy development has risen to a new height. Transportation vehicles are also facing a transformation from fossil fuel power systems dominated by internal combustion engines to new energy power systems dominated by electricity. For example, in the automotive industry, China has mentioned the development goals of new energy vehicles in multiple planning documents. The “Energy Conservation and New Energy Vehicle Development Plan (2012-2020)” released in 2012 identified pure electric drive as the strategic direction for China’s new energy vehicle development, and the “New Energy Vehicle Industry Development Plan (2021-2035)” (draft for soliciting opinions) released at the end of 2019 further updated the development goals of new energy vehicles, By 2025, the proportion of new car sales will reach around 25%. Therefore, designing a green, environmentally friendly, and efficient new energy storage power supply system is of great significance.
Compared with traditional fuel powered vehicle power systems, new energy storage power systems have advantages such as high efficiency and green environmental protection. Although the principle and structure of a single fuel cell as a new energy storage power system are simple and the design difficulty of the control system is low, there are also many drawbacks, such as inability to achieve low-temperature start-up, poor dynamic response, and inability to recover energy. To make up for the above, it is necessary to add auxiliary new energy power storage power sources to achieve rapid system response, normal use in cold weather, and energy-saving and emission reduction functions.
At present, the main energy combination methods include fuel cells, lithium battery power systems, fuel cells, supercapacitor power systems, fuel cells, lithium batteries, and supercapacitor power systems. Compared to a single fuel cell, the first two power systems can solve problems such as low-temperature starting, rapid response, and energy recovery during braking, but there are also many other problems, such as performance degradation in cold weather, overcharging, and rapid discharge of lithium batteries; Supercapacitors may not be able to continuously output energy due to their low energy density, resulting in an increased dependence on fuel cells and a lack of significant improvement in the overall economic performance of the system.
The fuel cell, lithium battery, and supercapacitor power system cleverly combine the advantages of fuel cell, lithium battery, and supercapacitor. This system has the advantages of high energy density and power density, which not only increases system efficiency but also protects energy sources and recovers energy, improving the power and economy of the system. But the system also has drawbacks: the system topology is more complex, the difficulty coefficient of energy coupling between different power sources will be higher, and the control difficulty will be greater. Therefore, based on the above situation, it is urgent to design a hybrid power system consisting of fuel cells, lithium batteries, and supercapacitors in order to achieve the advantages of green, environmentally friendly, and high efficiency of the system.
With the rapid development of China’s economy in recent years, it has led to a series of problems such as environmental pollution and energy crisis. Therefore, designing a green, environmentally friendly, renewable raw material, and efficient hybrid power system is of great significance. At present, the energy topology structure composed of fuel cells, lithium batteries, and supercapacitors has been applied in new energy vehicles. However, most of them adopt methods of comprehensive energy management and independent control of energy equipment, which are difficult to cope with core challenges such as “multi energy complementarity, multi time scale, and multi agent collaboration” under this topology structure, and cannot meet the needs of efficient complementary collaboration in the new generation of hybrid power systems.
Therefore, starting from the characteristics of fuel cells, lithium batteries, and supercapacitors, a multi time scale modeling and state estimation will be carried out for the hybrid power system. Under the double-layer structure MPC framework, multi energy and multi time scale collaborative complementarity and closed-loop optimization will be achieved, and a new hybrid power system with high integration of energy flow and information flow will be constructed. A comprehensive energy management and optimization control theoretical method will be constructed for the system, Providing theoretical support for ensuring the safe and economic operation of hybrid power systems and improving energy utilization efficiency is of great significance for solving environmental pollution and energy crises in China.