The power system is composed of various power equipment and lines, and forced oscillation may occur due to the mismatch of frequency characteristics of equipment or lines. Its inducing factors include the mismatch of equipment parameters, the instability of equipment, or errors in the control strategy. Forced oscillation will lead to the instability and even collapse of the power system, causing changes in voltage and frequency, damaging equipment, and affecting other equipment in the system. To solve this problem, common control strategies include phase angle compensation, which stabilizes the system by controlling the phase angle difference between the generator and the load and adjusting the generator excitation; dynamic damping, which increases the system damping ratio by controlling the generator excitation and the voltage regulator and uses a computer system to monitor and adjust in real time; frequency regulation control, which adjusts the frequency according to the system frequency and the generator output; and multi-machine coordination control, which maintains the system stability by coordinating the excitation and load distribution of multiple generators. Adopting these control strategies can reduce forced oscillation and improve the stability and reliability of the power system.

Equipment inspection and maintenance is crucial for ensuring the safe and stable operation of power equipment, and it has now moved towards intelligence. Intelligent power operation and maintenance relies on advanced technologies such as computer Internet and big data processing. It integrates power equipment condition detection technology and various online detection data, and constructs an intelligent operation and maintenance system for power equipment conditions based on a big data platform and with the Internet of Things as the link. Its management system can collect substation data in real time, and when there are abnormalities, it will promptly feedback and notify engineers to judge faults and guide operations. This business is widely applied in scenarios such as equipment, personnel, inspection, maintenance, fault, dynamic environment, security, and power control. It has significant advantages, including improving the utilization rate of production resources, realizing unmanned or minimally manned operation in distribution rooms based on energy efficiency big data; having a fault alarm function, predicting potential faults in advance through big data analysis; and using big data and Internet of Things technology to remotely, centrally, and real-timely monitor distribution rooms, saving labor costs and reducing the work pressure of operation and maintenance personnel.

يعد التفريغ الجزئي (PD) أحد العوامل الرئيسية المسببة لشيخوخة العزل أثناء التشغيل الطويل الأمد للمحولات. تقدم هذه المقالة بشكل أساسي تعريف التفريغ الجزئي ومخاطره وطرق الكشف عنه، وتستكشف التطبيقات المهمة للكشف عن التفريغ الجزئي في صيانة المحولات وتشخيص الأعطال.

تسلط هذه المقالة الضوء على مشكلة تشبع المحول المغناطيسي. ويشير أولاً إلى أن التشبع المغناطيسي يعد مشكلة شائعة أثناء تشغيل المحول. ثم يشرح مبدأه، أي أن المحول يعتمد على الحث الكهرومغناطيسي، وكثافة التدفق المغناطيسي للنواة المغناطيسية تتغير مع مصدر الطاقة بالتيار المتناوب. بمجرد الوصول إلى قيمة معينة، يدخل النواة المغناطيسية في حالة التشبع المغناطيسي. ويوضح بعد ذلك أن التشبع المغناطيسي سيؤدي إلى مشاكل مثل التيارات التوافقية العالية التي تسبب مشاكل في جودة الطاقة، وارتفاع درجة حرارة المعدات مما يؤدي إلى تقصير عمرها الافتراضي، وسوء تشغيل أجهزة الحماية مما يؤدي إلى عدم الاستقرار الديناميكي. وردًا على هذه المشاكل، تغطي الحلول المقترحة جوانب مثل اختيار المواد الأساسية المغناطيسية المناسبة، وضمان نسبة دورات مناسبة، وإدارة الحمل المعقولة، وتركيب مثبطات التشبع المغناطيسي، وتعزيز المراقبة والحماية، وإجراء الصيانة الدورية والإصلاحات، وتحسين التصميم، وذلك لضمان التشغيل الآمن والمستقر للمحول.

This article makes a comparative analysis of oil-immersed transformers and dry-type transformers. It expounds on the working principles of the two. The oil-immersed transformer relies on insulating oil for cooling and insulation, while the dry-type transformer uses natural air cooling or forced air cooling for heat dissipation. The advantages of the oil-immersed transformer are high heat capacity, high electrical strength, and low cost, while the disadvantages are easy leakage, regular maintenance required, and flammability. The dry-type transformer has the advantages of environmental friendliness, safety, and easy maintenance, but its disadvantages are weak heat dissipation, high cost, and high noise. The oil-immersed transformer is suitable for high-voltage and large-capacity scenarios, and the dry-type transformer is suitable for densely populated areas and places with high environmental protection requirements. In terms of performance, there are differences in heat dissipation, cost, safety, and environmental friendliness between the two. In terms of technological development, the oil-immersed transformer is researching and developing biodegradable insulating oil and optimizing the design, and the dry-type transformer is studying new heat dissipation materials and noise reduction technologies. In short, the two have different characteristics, and when making a choice, multiple factors need to be comprehensively considered, and attention should be paid to new technologies.

This power knowledge popularization focuses on the inspection of substation equipment, emphasizing its significance for equipment operation management. In addition to regular inspections, it details various situations where special inspections of transformers are required, such as within 72 hours after new equipment or renovated transformers are put into operation, in case of serious defects, overload, during high - temperature and peak - load periods, in the thunderstorm season (especially after thunderstorms), on windy days, on thunderstorm and foggy days, during holidays and special power - supply guarantee periods, etc. It also introduces the EDS MK3 General Transformer Performance On - line Monitoring, elaborating on its diagnostic functions including line current, temperature of the iron core and windings, moisture in the insulating oil, transformer life cycle, on - load tap changer, and cooling system diagnosis, which helps to better inspect the transformer.

This document elaborates in detail on the installation standards and operation procedures of distribution transformers. First, the formalities for work approval and acceptance of construction tasks need to be completed, with written approval from the competent department. Then, on-site investigation is carried out by the on-site construction leader and technicians. They record relevant information, determine hazard points and control measures, and formulate a construction plan. Before construction, a pre-shift meeting should be held. The work leader needs to conduct a technical disclosure, explaining the construction plan, process quality requirements, and precautions. Meanwhile, a safety disclosure is carried out, clarifying hazard points such as prevention of falling from heights, electric pole collapse and injury, falling objects from heights causing injury, and the transformer falling or collapsing and causing injury, as well as corresponding control measures. Finally, work tasks are assigned and personnel are divided.

توفر هذه المقالة مقدمة مفصلة عن محول الاختبار من النوع الجاف GTB. ويغطي جوانب مثل خصائصه في تخطيط هيكل العزل، وحلول مشاكل تسرب الزيت، والتعامل مع نهاية الإخراج ذات الجهد العالي، وتصميم خزان الزيت، وهيكل القلب الحديدي والملفات. يتناول هذا الكتاب الغرض من هذا المحول في إخراج جهد عالي من التيار المتردد والتيار المستمر للكشف في الموقع عن أداء العزل لمختلف المعدات الكهربائية، ويسرد العديد من الأسماء البديلة، ويقدم طرق الاستخدام التفصيلية، بما في ذلك الاستعدادات قبل الاستخدام، وتوصيل الطاقة، وتكوين المجموعة الكاملة من المعدات، والعمليات لاختبارات التيار المستمر، والاحتياطات اللازمة للتوصيل المتتالي. وتؤكد أيضًا أنها تتبع بدقة المعايير ذات الصلة لضمان السلامة.

This article focuses on 15 fundamental issues of power transformers, covering key areas such as the grounding of the transformer core, gas protection, and the handling of cooler failures. It elaborates in detail on aspects like the conditions for parallel operation of transformers, the causes of abnormal noises, and the adjustment limitations of the tap changers of on-load tap changer devices. It also involves knowledge points such as methods to improve the efficiency of transformers and the influencing factors of transformer capacity. By answering these questions, it systematically sorts out the basic knowledge of the operation and maintenance of power transformers for readers.

تتميز تقنية المسح الضوئي بالليزر ثلاثي الأبعاد بطريقة قياس عالية السرعة بدون تلامس، مما يتيح الحصول بكفاءة على بيانات ذات صلة بالتضاريس والأشياء المعقدة. بعد المعالجة، يمكنها إنشاء نماذج ثلاثية الأبعاد وتُعرف أيضًا بتقنية تكرار المشهد الحقيقي.

يتكون حل المسح الضوئي ثلاثي الأبعاد لمحطات الطاقة الفرعية من الخطوات التالية. ويتضمن تحليل متطلبات القياس، وتوضيح منطقة المسح، والدقة، والطريقة وفقًا للوضع الفعلي للمحطة الفرعية. أثناء إجراء القياس في الموقع، ينبغي الاهتمام باختيار وتخطيط وتصحيح أخطاء معدات المسح. تتضمن معالجة البيانات عمليات مثل التنظيف والتسجيل لإنشاء نماذج ثلاثية الأبعاد. يضمن التحقق من النموذج دقة البيانات وسلامتها. وأخيرا، يتم تطبيق النموذج على جوانب مختلفة من إدارة التشغيل والصيانة للمحطة الفرعية.

تجدر الإشارة إلى أن هذا الحل يحتاج إلى تصميم وتعديل مع مراعاة عوامل مثل ظروف الموقع ومتطلبات السلامة ودقة القياس، كما يتطلب الأمر التكنولوجيا والمعدات المهنية لضمان جودة البيانات.

Transformers are of great importance in the distribution network, and their operating conditions have a far-reaching impact. This article focuses on the daily maintenance of transformers, covering two major aspects.

The first is to strengthen daily inspections, maintenance, and regular testing. This includes checking the appearance for oil leakage, listening to the sound to identify faults, cleaning oil stains and dust, observing the oil color and temperature, measuring the insulation resistance, measuring and balancing the load, and regularly checking and replacing fuses.

The second is to prevent external damage, involving reasonable site selection, avoiding the installation of low-voltage metering boxes, prohibiting the unauthorized adjustment of tap changers, installing insulation covers, and regularly inspecting the lines and cutting branches along the line channels. All these measures aim to ensure the safe and stable operation of transformers.

Transformers play a crucial role in the power system, and their operating status is directly related to the stability of power supply. This content focuses on the maintenance and fault repair methods of transformers. Firstly, it introduces the basic principles, components, functions, and common classifications of transformers.

Then, it elaborates on the key points of maintenance: In terms of capacity, the normal operating load should preferably be 75 - 90% of the rated capacity. The temperature needs to be recorded regularly, and the three-phase load of distribution transformers should be paid attention to during the period of maximum load. For insulation monitoring, the insulation resistance of the coils should be measured after installation, maintenance, and long-term outages. In terms of the current range, the maximum unbalanced current on the low-voltage side should not exceed 25% of the rated value, and the change in the power supply voltage should be within ±5% of the rated value. If it exceeds this range, a tap changer should be used for adjustment. In the case of overload, it is allowed for a short time under special circumstances, but there are different limits for winter and summer.

Finally, it explains the fault repair. Common faults include short circuits, open circuits, and leakage, which are caused by design errors, poor manufacturing quality, and exceeding the designed operating conditions. The repair steps are to disassemble the iron core, heat it to melt the poured materials, and carefully remove the silicon steel sheets. Then, disassemble the coils, inspect the appearance and the faulty coil, record key data, deal with the fault, rewind it according to the original method, and conduct a comprehensive test. It can be put back into use only after passing the test.