With the large-scale integration of renewable energy sources and the growing demand for grid flexibility， lithium batteries have become increasingly prominent in energy storage applications due to their high energy density， long cycle life， and rapid response capabilities. However， safety concerns remain one of the most critical challenges limiting their broader deployment. Electrochemical impedance spectroscopy （EIS）， as a non-destructive diagnostic technique， offers unique advantages in the investigation of battery safety. By tracking impedance variations during charge-discharge cycles， EIS enables the early detection of latent internal faults， thereby contributing to the reliable and secure operation of energy storage systems. This review provided a comprehensive overview of recent developments in the application of EIS for battery design， equivalent circuit model construction， and characteristic parameter identification. Furthermore， the current state of research on the utilization of EIS in the multi-physics coupling analysis under complex operating conditions was examined. Finally， the review discussed the potential of EIS for battery state monitoring and fault diagnosis， and presented future perspectives on the integration of multidimensional physical monitoring information through EIS-based approaches.

Under the background of "dual-carbon" goal and intensified market competition， the electrolytic aluminum industry is facing severe energy consumption challenges. As a key energy-consuming unit， the compressed air system has many efficiency problems. Based on detailed data from Qinghai Baihe Aluminum Industry， an energy-saving optimization model of the compressed air system suitable for the electrolytic aluminum industry is constructed. The model integrates a full-link collaborative strategy， covering gas supply， transmission and distribution， gas consumption， and management and control links. Verified by the case of Baihe Aluminum Industry， the model can accurately calculate energy savings. After correction， it achieves an annual net electricity saving of 8×10⁶ kW·h with a comprehensive energy-saving rate of 17.9%， providing a quantifiable and reproducible systematic energy-saving methodology for the industry. Results show that the energy-saving of the compressed air system in electrolytic aluminum urgently requires support from a global perspective and systematic engineering thinking. In the future， higher-level system optimization will be realized by integrating artificial intelligence （AI）， digital twin technology and energy management platform.

The “three-renovation-linkage” of coal-fired power units is an important measure for the clean， low-carbon， efficient and flexible transformation of coal power， effectively promoting the high-quality development of the coal power industry. This article summarized the typical technical routes and implementation effectiveness of the “three-renovation-linkage” for coal-fired power units in Jiangsu Province since the launch of the 14th Five-year Plan， and analyzed its achievements in reducing net coal consumption rate， enhancing unit flexibility， and meeting the heat demand for local economic development. Meanwhile， based on the upgrade special action plan for new generation of coal-fired power， this article proposed to promote the transformation and upgrading of coal-fired power units around cleanliness， carbon reduction， safety， reliability， efficient regulation， and intelligent operation， while ensuring the safe and stable operation of the units and combining the requirements of the new power system construction for the new generation of coal-fired power.

To address the issue of low waste heat utilization efficiency of aero-derivative gas turbines， a waste heat recovery system based on the supercritical carbon dioxide （S-CO₂） Brayton cycle was proposed. Through the establishment of a thermodynamic-dynamic coupling model， the thermodynamic performance of simple， recuperative， and recompression cycles was compared and analyzed， and the influence mechanisms of key parameters on the system efficiency were explored. The findings reveal that the recompression S-CO₂ Brayton cycle demonstrates optimal comprehensive performance. At a working fluid mass flow rate of 3 000 t/h， the system achieves a cycle efficiency of 46.855%， representing 198.4% and 13.0% improvements over simple and recuperative cycles， respectively. Moreover， the cooler heat absorption decreases to 101.178 MW， achieving an 81.6% reduction compared to the simple cycle. The turbine inlet pressure and temperature exhibit synergistic effects on efficiency， with the peak efficiency reaching 47.179% at 20 MPa and 650 ℃. Optimal efficiency is attained at a split ratio of 0.65. The results demonstrate that the recompression cycle significantly reduces waste heat boiler heating requirements and thermal losses through multistage heat recovery and working fluid splitting strategies， thereby providing theoretical support and technical pathways for efficient waste heat utilization in aero-derivative gas turbines.

As an important power equipment， gas turbines are widely used in aero engines， combined cycle power stations， ship propulsion and other industrial fields. With the continuous improvement of performance requirements for gas turbines， increasing the inlet temperature of the turbine is an important means to enhance the thermal efficiency of gas turbines. However， limited by high-temperature base materials， the application of advanced cooling technologies has become the main approach to raise the turbine inlet temperature. Air film cooling technology is widely used in the cooling of gas turbine blades， but the mixing of the cooling air with the mainstream after its discharge will increase the energy loss of the turbine stage and reduce its performance， and also have a certain impact on the flow capacity of the blade cascade. In this paper， the first stage turbine of a heavy-duty gas turbine was taken as the object， and the influence of cooling air mixing on the stage performance was studied through simulation tests. The results indicate that， under the condition of a relatively constant expansion ratio， the stage efficiency decreases with the increase of cooling air flow rate. The magnitude of this decrease becomes larger as the cooling air flow rate increases. There exists a limit for the cooling air mixing ratio， beyond which the turbine performance parameters undergo significant changes.

The steam-water separator is one of the key components of the supercritical thermal power units. The operation stability of this equipment affects the safety of the downstream superheater heating surface， and even affects the main system of steam turbine. A dynamic model of the conventional steam-water separator based on the lumped parameter method was established， and the operating characteristics of the separator under step disturbances with different amplitudes and periodic disturbances under wet operating conditions were analyzed. Results show that the mass flow velocity disturbance of the inlet gas-liquid two-phase flow will be transferred to the outlet vapor within a response time on the order of seconds. For both step and periodic disturbances， the amplitude of the outlet steam pressure and temperature variations increases with the disturbance ratio. The research findings provide guidance for studying the operational characteristics of the boiler steam-water system in thermal power units.

A comprehensive analysis was conducted to investigate the causes of perforation in the oil cooler plates of a steam turbine. The investigation involved macroscopic morphology examination， chemical composition analysis， metallographic structure observation， hardness testing， microscopic morphology analysis， corrosion product examination， and water quality testing of the cooling water on the water side. The analysis results show that the perforations are corrosive perforations， mainly distributed at the wavy protrusions of the plates and the protruding shoulders， and are caused by the combined effects of pitting corrosion， fretting wear and crevice corrosion. The concentration ratio of cooling water and the indicators of calcium hardness and total alkali are not up to standard， resulting in the formation of hard scale on the water side of the plates. The concentration of chloride ions under the scale is the main cause of pitting and perforation of the plates. Meanwhile， during the standby period of the oil cooler， the concentration of cooling water and the local accumulation of corrosive ions serve as auxiliary promoting factors.

The oil film pressure of the bearing at the excitation end of a 330 MW turbine generator gradually decreased during operation. During the slow-speed stage of the shutdown process， the metal temperature of the bearing rose suddenly and slightly. The tungsten alloy of the bearing was damaged， and there were "wave-like" defects of uneven wear on the journal. Various factors that cause journal wear and bearing tungsten alloy surface damage during the equipment design， manufacturing， installation， operation and maintenance processes were analyzed. Corresponding countermeasures were proposed， including improvements to oil system cleanliness， repair of the bearing and journal， and optimization of jacking oil control. Measurement guidelines following extensive bearing scraping were also provided， offering practical guidance for similar unit repairs.

To address the insufficient research on leakage phenomena at the gap between the steam soot blower outer tube and furnace wall， the leakage characteristics of cold air and flue gas at the gap under different operating conditions were studied， and the unit leakage rate for each operating condition was quantitatively calculated based on an improved flat plate leakage model. The results show that under standard conditions， the physical properties of the infiltrated cold air in the superheater zone change relatively little along the leakage path， while the density and pressure of the infiltrated cold air in the reheater zone and economizer zone show a linearly decreasing trend. Under slightly positive pressure conditions， only the pressure of the leaked flue gas in the gap shows a small decrease. A comparative analysis of unit leakage rates reveals that the economizer zone exhibits the largest cold air infiltration under negative pressure， while the superheater zone produces the highest flue gas leakage under positive pressure. These findings provide a theoretical basis and practical reference for leakage control in rotating components during engineering applications.

In order to ensure the safety of primary frequency regulation of thermal power generating units under deep peak regulation conditions， a primary frequency regulation model integrating the safety constraints of units was established， and primary frequency regulation margin was taken as the core evaluation index. Based on the actual data of a 1 000 MW unit with 30%-50% load， the valve step limit and frequency response limit that meet the safety constraints were solved by simulation， and the safe frequency regulation margin under various working conditions was accurately calculated. The results show that the upper and lower limits of the margin and speed difference exhibit a significant load dependent variation， which provides a quantitative basis for the safe primary frequency regulation of deep peak regulation units.

At present， the problems existing in condition monitoring system （CMS） of wind turbine drive chains are as follows. First， as the operating power of wind turbine generator system varies frequently， the monitoring indicators defined by the VDI3834 standard increase as the power rises， leading to false alarms when the fixed threshold is exceeded. Second， the forms of drive chains are diverse， and the types of faults are variable. Specific frequency band indicators tend to overlook fault characteristics， while full-band indicators have low sensitivity to energy changes in specific frequency bands， resulting in delayed early fault warnings. Third， most existing systems adopt the method of triggering early warnings upon a single over-limit， which is prone to a high false alarm rate due to the occasional over-limit of indicators. To address the above issues， fused monitoring indicators based on anomaly detection with generative adversarial network （AnoGAN） and an intelligent early warning method for drive chain faults under variable operation conditions were proposed. The effectiveness of the proposed method was verified by using the data collected from the actual wind field. Results show that the proposed fused monitoring indicators can effectively represent the degradation trend of drive chain components. In addition， the proposed alarm trigger logic is able to reduce the false alarm rate. Simultaneously， the proposed method can also issue alarms approximately one month before the actual maintenance time， thus providing a reasonable maintenance preparation window phase for the wind farm.

To explore the influence mechanisms of turbulence intensity and wind speed on the load characteristics of wind turbine generator systems， a fully coupled dynamic model of a 2.5 MW horizontal-axis wind turbine was established in this study. A series of parameterized numerical simulations were conducted to systematically investigate the effects of varying wind speeds （7.3 m/s， 8.3 m/s， 9.3 m/s， and 11.3 m/s） and turbulence intensities （0.05， 0.10， 0.14， 0.16， and 0.20） on the output power and critical dynamic loads of the turbine. Simulation results show that the output power， nacelle acceleration， blade root flapping bending moment， and tower base bending moment all exhibit a regular increasing trend as the turbulence intensity and wind speed increase. Quantitative analysis shows that a 0.02 increase in turbulence intensity results in an approximate 9.5% increase in the mean blade root flapping bending moment， while a 1 m/s increase in wind speed leads to an average 6.68% rise in the standard deviation of the fore-aft tower base bending moment. This study offers significant engineering guidance for strategic micro-siting of wind farms and operational adaptability of wind turbine generator systems.

To improve the optical efficiency and economy of the solar thermal power generation system， a Campo layout optimization method based on genetic algorithm was proposed to solve the problem of limited energy utilization caused by ignoring the dynamic characteristics and shadowing effects of the sun in the traditional uniform annular heliostat field layout. By constructing the solar position dynamic model and the multi-physical field optical efficiency model， the parameters such as the size and installation height of the heliostat were optimized to maximize the annual average thermal output power per heliostat unit. The penalty function was used to handle the constraint conditions， and the genetic operator was used to realize the variable collaborative optimization. The simulation results show that the Campo layout based on genetic algorithm can significantly improve the optical efficiency and energy output capability， which provides a practical optimization strategy for heliostat field design.

During the operation of energy storage stations， heat generated by lithium batteries and auxiliary equipment inside the battery compartments constitutes a major source of energy loss and the main source of heat for the battery compartment. The battery compartments of energy storage stations in the northwest region also receive a significant amount of solar radiation heat in summer. In order to control the temperature rise of the battery compartment within a safe range， cooling systems such as air cooling and liquid cooling consume energy storage capacity. Research shows that the combined heat loss and cooling energy consumption account for 8.4% of the total charged electricity， which has a significant impact on the charging and discharging efficiency of energy storage stations. Two schemes for installing reflective panels and photovoltaic panels on the top of the battery compartment were proposed. The effects of reducing solar radiation heating and lowering or offsetting cooling energy consumption were compared and analyzed. Results show that installing reflective panels saves 3 560 kW·h of cooling electricity per battery compartment each year， with a payback period of approximately 4.9 years； installing photovoltaic panels saves 3 000 kW·h of cooling electricity and generates 8 064 kW·h of photovoltaic power on the compartment roof each year， with a payback period of about 5.5 years. Both schemes can improve the charging and discharging efficiency of the energy storage power stations， reduce the operating time of the air conditioning systems， and effectively support the quality improvement and efficiency enhancement of the energy storage power stations.