In order to help achieve the goal of “carbon peaking, carbon neutralization” and build a new power system, China Southern Power Grid Corporation clearly proposed to basically build a new power system in the southern region by 2030 and fully build a new power system by 2060. In this process, we will vigorously develop pumped storage. It is planned to increase the installed capacity of 6 million kilowatts, 15 million kilowatts and 15 million kilowatts respectively during the “Fourteenth, Fifteenth and Sixteenth Five Year Plan” periods. We will strive to reach about 44 million kilowatts of pumped storage capacity in the southern region by 2035, making it a new type of power system disturbance balancer, load balancer and power grid stabilizer.
Source: WeChat official account “China Energy Media Intelligent Manufacturing”
Author: Peng Yumin, Energy Storage Research Institute of China Southern Power Grid Peak shaving and Frequency Modulation Power Generation Co., Ltd
Main features of new power system
The new power system is dominated by clean energy, and the proportion of new energy in energy consumption will continue to increase, gradually forming a form of energy utilization with new energy, hydropower, nuclear power as the main form of power generation. The proportion of fossil energy consumption will gradually be reduced to meet the carbon neutral target, and the remaining installed capacity of fossil energy will be used as the backup power supply of the new power system. In the new power system, new energy will be connected to the power grid in a centralized and distributed manner. In terms of centralized access, the southern region strives to achieve onshore wind power of more than 24 million kilowatts, offshore wind power of more than 20 million kilowatts, and photovoltaic access of more than 56 million kilowatts by 2025. In terms of distributed access, distributed power sources with small capacity, low voltage level of access grid and can be consumed nearby will be built in various regions according to local conditions.
In the new power system with new energy as the main body, the actual output of new energy power generation equipment is greatly affected by the meteorological environment, which has obvious characteristics of randomness, volatility and intermittency. The wide application of electric energy substitution, household energy storage equipment and smart home makes the user side load develop in a diversified and interactive direction, and the user terminal enters a new mode that is both a consumer and a producer. The new power system with new energy as the main body presents the “double high” characteristics of high proportion of new energy and high proportion of power electronic equipment. In order to cope with the large-scale fluctuations of new energy and various extreme situations, it is necessary to match the installed capacity of pumped storage with the corresponding scale according to the installed capacity and output scale of new energy. When the output of new energy is abnormal, pumped storage should maintain the state of the new power system of the grid as much as possible, and prevent the transformation of the new power system to the traditional power system. Therefore, the development and construction of pumped storage power stations will be faster and more large-scale.
Problems and countermeasures of rapid and large-scale development of pumped storage
The rapid and large-scale development and construction has brought about problems of safety, quality and personnel shortage. In order to meet the construction needs of the new power system, a number of pumped storage power stations have been approved for construction every year. The required construction period has also been greatly shortened from 8-10 years to 4-6 years. The rapid development and construction of the project will inevitably bring about problems of safety, quality and personnel shortage.
In order to solve a series of problems brought about by rapid development and construction of projects, construction and project management units need to first carry out technical research and practice on mechanization and intelligence of civil engineering of pumped storage power plants. TBM (Tunnel Boring Machine) technology is introduced for the excavation of a large number of underground caverns, and TBM equipment is developed in combination with the characteristics of pumped storage power station, and a construction technical scheme is formulated. In view of various operation scenarios such as excavation, shipment, support and inverted arch during civil construction, a supporting application scheme for the whole process of mechanized and intelligent construction has been developed, and research has been carried out on topics such as intelligent operation of single process equipment, automation of the whole process construction system, digitalization of equipment construction information, unmanned construction of remote control mechanical equipment, intelligent perception analysis of construction quality, etc, Develop various mechanized and intelligent construction equipment and systems.
In terms of mechanization and intelligence of mechanical and electrical engineering, we can analyze the application demand and possibility of mechanization and intelligence from the aspects of reducing operators, improving work efficiency, reducing work risks, etc., and develop various mechanical and electrical engineering mechanization and intelligence construction equipment and systems for various operation scenarios of mechanical and electrical equipment installation.
In addition, 3D engineering design and simulation technology can also be used to prefabricate and simulate some facilities and equipment in advance, which can not only complete part of the work in advance, shorten the construction period on site, but also carry out functional acceptance and quality control in advance, effectively improving the quality and safety management level.
The large-scale operation of the power station brings about the problem of reliable operation, intelligent and intensive demand. Large scale operation of pumped storage power stations will bring about problems such as high operation and maintenance costs, shortage of personnel, etc. To reduce the cost of operation and maintenance, the key is to improve the operation reliability of pumped storage units; To solve the problem of personnel shortage, it is necessary to realize intelligent and intensive operation management of the power plant.
To improve the operation reliability of the unit, in terms of equipment type selection and design, technicians need to deeply summarize the practical experience in design and operation of pumped storage power plants, carry out optimization design, type selection and standardization research on relevant equipment subsystems of pumped storage power plants, and update them iteratively according to equipment commissioning, fault handling and maintenance experience. In terms of equipment manufacturing, traditional pumped storage units still have some key equipment manufacturing technologies in the hands of foreign manufacturers. It is necessary to carry out localization research on these “choke” equipment, and integrate years of operation and maintenance experience and strategies into them, so as to effectively improve the product quality and operation reliability of these key core equipment. In terms of equipment operation monitoring, technicians need to systematically formulate equipment status monitoring element configuration standards from the perspective of equipment status observability and measurability, deeply carry out research on equipment control strategies, status monitoring strategies and health evaluation methods based on intrinsic safety requirements, build an intelligent analysis and early warning platform for equipment status monitoring, find hidden dangers in equipment in advance and conduct early warning in a timely manner.
In order to realize intelligent and intensive operation management of the power plant, technicians need to carry out research on equipment automatic control or one key operation technology in terms of equipment control and operation, so as to realize fully automatic startup and shutdown and load regulation of the unit without personnel intervention, and realize operation sequencing and multi-dimensional intelligent confirmation as far as possible; In terms of equipment inspection, technicians can carry out technical research on machine vision perception, machine auditory perception, robot inspection and other aspects, and carry out technical practice on replacement of inspection machines; In terms of intensive operation of the power station, it is necessary to carry out research and practice on centralized monitoring technology of one person and multiple plants to effectively solve the problem of shortage of human resources on duty brought about by the development of pumped storage power stations.
The miniaturization of pumped storage and the integrated operation of multi energy complementation brought about by the consumption of a large number of distributed new energy sources. A remarkable feature of the new power system is that there are a large number of small-scale new energy scattered in various areas of the grid, operating in the low-voltage grid. To absorb and utilize these distributed new energy sources as much as possible and effectively alleviate the power congestion of the large power grid, it is necessary to build distributed pumped storage units near the distributed new energy sources to realize the local storage, consumption and utilization of new energy through low-voltage power grids. Therefore, it is necessary to solve the problems of miniaturization of pumped storage and integrated operation of multi energy complementation.
It is necessary for engineers and technicians to vigorously carry out research on site selection, design and manufacture, control strategy and integrated application of multiple types of distributed pumped storage power stations, including small reversible pumped storage units, coaxial independent operation of pumps and turbines, joint operation of small hydropower stations and pump stations, etc; At the same time, research and project demonstration on the integrated operation technology of pumped storage and wind, light and hydropower are carried out to propose technical solutions for the exploration of energy efficiency and economic interaction in the new power system.
The problem of technical “choke” of variable-speed pumped storage units adapted to high elastic power grid. Variable speed pumped storage units have the characteristics of rapid response to primary frequency regulation, adjustable input force under pump working conditions, and the unit operating at the optimal curve, as well as sensitive response and high moment of inertia. In order to effectively curb the randomness and volatility of the power grid, more accurately adjust and absorb the excess power generated by the new energy at the generation side and the user side, and better control the load balance of the highly elastic and interactive power grid, it is necessary to increase the proportion of variable speed units in the power grid. However, at present, most of the key technologies of variable speed water pumping and storage units are still in the hands of foreign manufacturers, and the problem of technical “choke” needs to be solved.
In order to realize the independent control of key core technologies, it is necessary to concentrate domestic scientific research and technical forces to deeply carry out the design and development of variable-speed generator motors and pump turbines, the development of control strategies and devices for AC excitation converters, the development of coordinated control strategies and devices for variable-speed units, the research of governor control strategies for variable-speed units, the research of working condition conversion process and integrated control strategies for variable-speed units, Realize the full localization design and manufacturing and engineering demonstration application of large variable speed units.
Post time: Dec-09-2022
