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Climate change and environmental degradation are critical global challenges, and the G-20 nations play a pivotal role in addressing these issues due to their substantial contributions to global GDP and carbon emissions. Transitioning toward renewable energy sources is imperative for mitigating CO2 emissions and achieving sustainable development. This study investigates the impact of technological innovation, gross domestic product (GDP), renewable energy consumption, economic freedom, and financial advancement on renewable energy use and environmental pollution levels in G-20 countries from 1995 to 2022. Utilizing the PMG-ARDL dynamic panel method, the research analyzes both long-term and short-term relationships among the variables. The findings reveal that technological innovation significantly boosts renewable energy adoption, with a 1% increase in technological innovation leading to a 0.33% rise in renewable energy use in the long run and a 0.17% increase in the short run. Additionally, increased renewable energy consumption is strongly associated with reductions in CO2 emissions, highlighting its critical role in promoting environmental sustainability. The study emphasizes the importance of policies designed to enhance technological innovation to foster renewable energy usage and reduce environmental pollution. It recommends expanding and reforming the technological sector to align international and local resources with renewable energy initiatives, providing a workable framework for supporting the green growth of institutions and achieving a more sustainable future for G-20 nations. This research contributes to understanding the intricate dynamics of renewable energy transitions, offering actionable insights for policymakers and stakeholders in addressing global environmental challenges.

This paper studies the target tracking control strategy of a snake robot and proposes an adaptive sliding mode control method. The strategy ensures the robot follows the target path by controlling the joint angle through feedback, pushing the robot to reach the target position through gait function. In order to achieve target tracking, a kinematic model of a snake robot was first established in this paper. Then, we used double-sine serpentine gait to solve the problem of low steering efficiency caused by regular serpentine gait, and we explored the relationship between control parameters and robot steering. On the basis of gait, in order to further improve the efficiency of target tracking for the snake robot, an adaptive sliding mode control method, based on a new sliding mode reaching law, was proposed. Finally, the effectiveness and practicability of the proposed strategy was demonstrated by comparative analysis and simulation experiments.

An optimal load-tracking operation strategy for a grid-connected tubular solid oxide fuel cell (SOFC) is studied based on the steady-state analysis of the system thermodynamics and electrochemistry. Control of the SOFC is achieved by a two-level hierarchical control system. In the upper level, optimal setpoints of output voltage and the current corresponding to unit load demand is obtained through a nonlinear optimization by minimizing the SOFC’s internal power waste. In the lower level, a combined L1-MPC control strategy is designed to achieve fast set point tracking under system nonlinearities, while maintaining a constant fuel utilization factor. To prevent fuel starvation during the transient state resulting from the output power surging, a fuel flow constraint is imposed on the MPC with direct electron balance calculation. The proposed control schemes are testified on the grid-connected SOFC model.

This study fully considers the incomparable factors in city's energy efficiency assessment, and proposes a framework for city's energy efficiency assessment based on classification. In the process of classifying cities, the SVM method is used to establish a quantitative relationship model between relevant factors and city's energy consumption. Based on the model, the objective energy demand of the city is calculated, and the city is classified according to the level of objective energy demand. By comparing the actual energy consumption of the city with the objective energy demand, we can eliminate the interference of the incomparable factors on the city's energy efficiency assessment.

Decarbonization of industrial process heating plays a crucial role in China’s carbon neutrality strategy. Traditionally, industrial users make decision on heat supply system design based solely on economy, with little regard for carbon emission. This study proposes an auxiliary design system to help the designers choosing proper industrial heating supply scheme considering carbon reduction benefit. Through traversal the existing scheme database, all feasible solutions are screen out and then evaluated by calculating an proposed comprehensive economy evaluation index. The comprehensive economy evaluation index takes carbon reduction as revenue since industry users will be able to trade their carbon emission rights at the carbon markets though CCER programs in the future. Future carbon price given by the carbon price prediction module is used to calculate the revenue user can get from carbon reduction. Grid emission factor prediction module makes prediction for changing grid emission factor, which is also involved in the evaluation to consider the benefit from continuously increasing green power in the future. A case study is given with heating demand data of a food factory to shown that the proposed method can reflect the value of carbon reduction, which helps to promote low-carbon technologies in the future.

High voltage direct current transmission has the advantages of high transmission capacity, low loss, no simultaneous operation of the AC system on both sides, and small loss on the power grid in case of failure. The stability of synchronous operation does not limit its transmission capacity and distance, while avoiding the effects caused by low frequency oscillations. And, in the event of a blackout, it won’t cause massive power outages either, reducing losses. The DC transmission system may withstand both normal working DC high voltage and polarity reversal voltage, so it is extremely necessary to conduct theoretical analysis of the DC cable terminal under polarity reversal voltage. This article simulates the distribution of the electric field at the reverse polarity voltage of a DC cable terminal and analyzes its law of variation. The results show that when the conductivity of the main insulation to the reinforced insulation is equal to its dielectric permittivity ratio, the build-up of space charges can be effectively inhibited and guide relevant studies.

We propose a method of climbing pipe with different diameter, which enables snake robot to divide itself into 3 parts to complete transition on the pipe according to the joints’ state for now. To avoid controlling the robot from building dynamic model, a gait-based open-loop control framework is adopted. An extended kalman filter (EKF) is applied here to estimate the adaptive parameter of gait-based function for different 3 parts and corresponding joints. The adaptive parameter will help snake robot perceive the environment better and climb the pipe more steadily.

Photovoltaics, energy storage, direct current and flexibility (PEDF) are important pillars of achievement on the path to manufacturing nearly zero energy buildings (NZEBs). HVAC systems, which are an important part of public buildings, play a key role in adapting to PDEF systems. This research studied the basic principles and operational control strategies of a DC inverter heat pump using a DC distribution network with the aim of contributing to the development and application of small DC distribution systems. Along with the characteristics of a DC distribution network and different operating conditions, a DC inverter heat pump has the ability to adapt to changes in the DC bus voltage and adds flexibility to the system. Theoretical models of the DC inverter heat pump integrated with an ice storage unit were developed. The control strategies of the DC inverter heat pump system considered the influence of both room temperature and varied bus voltage. A simulation study was conducted using MATLAB & Simulink software with simulation results validated by experimental data. The results showed that: (1) The bus fluctuation under the rated working voltage had little effect on the operation of the unit; (2) When the bus voltage was fluctuating from 80%–90% or 105%–107%, the heat pump could still operate normally by reducing the frequency; (3) When the bus voltage was less than 80% or more than 107%, the unit needed to be shut down for the sake of equipment safety, so that the energy storage device could adjust to the sharp decrease or rise of voltage.

The paper introduces the principle of on-line monitoring of the dielectric loss factor of capacitive equipment and the composition of the monitoring system. It explains the software-based mathematical analysis method and harmonic analysis method, and uses DSP for digital filtering. At the same time, the paper establishes an intelligent auxiliary monitoring terminal in the substation, uses the equipment ADP+ equipment protocol library to dynamically connect to various auxiliary monitoring equipment, uses signal frequency conversion sampling, alarm recording and other acquisition strategies to extract key equipment operation information, and hierarchically redundant storage data. Improve the real-time monitoring level of operating equipment and reduce the cost of operation and maintenance.

This paper introduces the items and principles of transmission line parameter test, finds out the interference factors through the detailed analysis of the field test results, and puts forward the relevant precautions.