In the context of “dual carbon” goal, integrated photovoltaic storage and charging station (IPSCS) can effectively solve the problem of independent operation of multiple types of flexible resources. To enhance the collaborative consumption capacity of source load and reduce carbon emissions, this paper proposes a multi-timescale day-ahead operation strategy for IPSCS that considers carbon emission stratification and source load interaction. Firstly, hybrid prediction model and Monte Carlo method are applied to historical data to derive typical photovoltaic output and electric vehicle load scenarios, respectively. Secondly, the objective function of the mathematical model of the operation strategy of the integrated station is minimum comprehensive planning cost, minimum carbon emission, and maximum utilization of new energy. The model is solved using an improved whale optimization algorithm (IWOA) incorporating an opposition-based learning strategy and diversity variation processing. Finally, the rationality and effectiveness of the proposed strategy are verified through case analysis.

Ultra-high voltage AC power system usually uses standard lightning current parameters to calculate external overvoltage, and lightning observation data show that more than 80% of the lightning process is multiple lightning strikes, which is significantly different from the standard recommended waveform. Under the background of frequent multiple lightning accidents in ultra-high voltage AC system, it is urgent to put forward a rigorous and scientific evaluation method of multiple lightning parameters. Therefore, this paper takes a 500kV AC ultra-high voltage transmission system as the object, and proposes a multiple lightning current waveform parameter evaluation method considering the transient characteristics of the line from the extreme lightning conditions and the actual fault recording. The analysis shows that the fault recording inversion method can characterize the real multiple lightning strikes. Extreme multiple lightning strikes method analyzes the lightning current parameters under harsh conditions from the lightning resistance level of the cable. The waveform parameter evaluation method proposed in this paper provides a technical scheme for overvoltage analysis of ultr-high voltage transmission system in lightning-prone areas.

To fully exert the advantages of the convolutional neural network (CNN) in image recognition and classification, a fault diagnosis method for four-quadrant pulse rectifiers based on CNN and Gramian angular difference field (GADF) is proposed. GADF is utilized to transform the one-dimensional time series of rectifier current into a two-dimensional feature map, preserving the temporal dependency of the data and identifying the temporal correlations of the signal over different time intervals. The CNN then extracts and classifies the features of open circuit faults in the rectifier from the generated feature maps. This method is compared with other common fault diagnosis methods. Simulation analysis results indicate that this proposed method achieves higher diagnostic accuracy compared to other fault diagnosis methods.

Compared to other primary equipments such as busbars, lines, and circuit breakers, transformers have a more complex structure and are the only equipment in the power system that connect different voltage levels. In addition, the influence of the Y/D transform makes the fault characteristics complex and variable, making it difficult to locate the fault point. The fault localization depends on the experience of the engineer. There is an urgent need for a complete automated fault location system. This article first classifies the possible situations that may cause transformer protection starting or tripping, and then sets fault localization criterion step by step. The criterion greatly enhances the automation level of transformer fault localization and has good engineering implementation value. The feasibility and accuracy of this method are proved through multiple sets of simulation waveforms.

In order to solve the problem of high redundancy and low positioning accuracy of traditional cable fault location spectrum data, this paper proposes a high precision cable fault location method based on chirp-Z transform (CZT). Firstly, according to the transmission line theory, the distribution parameters and reflection coefficient characteristics of the fault cable are analyzed. Then, CZT is performed on the real part of the reflection coefficient. Finally, iterative filtering is used to denoise and obtain the cable fault location spectrum. The results show that the fault point recognition error of the proposed method is 0.025%~0.275%. Compared with fast Fourier transform (FFT), the proposed method has the advantages of refined location spectrum, high resolution, low redundancy and high fault location accuracy.

This paper compares the advantages and disadvantages of closed water cooling systems and open water cooling systems in terms of heat transfer efficiency, footprint, water consumption, and cost. The heat transfer capacity, site environmental conditions, inlet temperature of the phase modulator heat exchanger, and other requirements are taken into account for installing a phase modulator at a certain converter station, as well as the economic investment and operational factors. It is ultimately determined that the external water cooling system for the phase modulator at the converter station adopts an open water cooling scheme. The design scheme of external cooling system for the phase modulator is given in this paper, hoping to provide reference for the selection and design of the external cooling system for phase modulator in subsequent projects.

In the context of the global traditional energy crisis and the urgent need to explore green, environmentally friendly, and sustainable new energy, in order to break through the limitations of the understanding of photovoltaic application environment, scope, and carrying capacity, a telescopic and high-efficiency solar roof collector device is developed to address energy challenges and promote energy conservation and emission reduction. This scheme adopts a comparative research and data analysis method to deeply analyze the compatibility between solar energy and automotive characteristics. Through self created design, it integrates efficient photoelectric conversion technology and flexible telescopic structure to ensure maximum collection of solar energy for photoelectric conversion. The experimental results show that the device has high photoelectric conversion efficiency, and numerical examples verify the effectiveness of the proposed scheme and the feasibility of fully utilizing solar energy and extending the service life of automobiles.

This article analyzes the characteristics of single phase grounding faults and cross line grounding faults in the same tower double circuit line, as well as the impact of zero sequence mutual inductance on grounding distance protection, in response to the misoperation fault of under range longitudinal distance protection during a cross line grounding fault on the same tower double circuit line. It is concluded that the additional impedance caused by zero sequence mutual inductance is the fundamental reason for the reduction of grounding distance protection range and the refusal of protection. In order to solve the problem, an adaptive zero sequence mutual inductance compensation method is proposed. The new method based on the adjacent zero sequence current injection and local auxiliary judgement can enable the compensation adaptively. The performance of the proposed method is evaluated based on the real time digital simulation system, and results show that this method is valid.

In order to solve the ground fault in ungrounded systems, this paper applies the differential protection method based on the “external signal generating device and feeder terminal unit” to the external signal ground fault selection technology, proposes differential protection method of ground fault detection criteria and action principles, and achieves segment selection on the basis of ground fault phase selection. Finally, the effectiveness of the method is verified through a case study, and the results show that the proposed fault discrimination method has high accuracy and can minimize the range of ground fault power outages, which can also improve fault handling efficiency and power supply reliability.

The grounding wire is an important equipment for ensuring the personal safety of power operators. Traditional grounding wire lacks informationization and intelligent management methods. There is no closed-loop management method for the extraction and return of grounding wire, which can easily lead to misconnection, no connection, and without returning, bringing huge risks to the safe and stable operation of the power grid. This article focuses on the Internet of Things (IoT) and intelligent transformation of grounding wire, grounding wire cabinet, and grounding pile. The design covers the full-process control system architecture covering the “cloud-network-edge-end”, and the full-process control system of grounding wire and intelligent monitoring device are developed. Through the method of edge IoT proxy cross regional collaboration, the consistency of the real-time status of grounding wire, grounding wire cabinet and grounding pile and business data between the security Ⅳ region and the Internet region is achieved. Based on cross regional collaboration of data, cross regional data collection and panoramic monitoring of grounding wire are achieved to ensure accurate grounding connection, improving the safety and work efficiency of on-site operators, and providing guarantees for the safe and stable operation of the power grid.

The assignment of work orders is an essential part of the power operation and maintenance management system. Timely and accurate assignment methods can effectively improve the efficiency of work order circulation. Based on in-depth analysis of the characteristics of work order management in the field of power operation and maintenance, this article proposes an automatic assignment model for power operation and maintenance work orders based on fit degree. The model adopts criteria importance though intercrieria correlation (CRITIC) weighting method and fuzzy comprehensive evaluation to calculate the compatibility between operation and maintenance personnel and work orders, determine the optimal candidate for work order assignment, and then achieve automatic assignment of work orders. The practical application results show that compared to manual assignment, this automatic assignment model can effectively improve the efficiency and accuracy of work order assignment.

To meet the production demand for offline automatic stacking of large transformer cores, this paper researches on the feasibility of the double hole positioning system of the truss type transformer core laminating machine, introduces visual positioning technology and conducts data verification. In the paper, by means of building an actual architecture and combining corresponding control theories and algorithms, the performance, precision, stability and reliability of the system are analyzed and evaluated. The experimental data and analysis results based on practical application scenarios indicate that the system is feasible.