Fault Diagnosis and Prevention of Low Voltage Reactor in EHV Substation

Low voltage reactors are one of the important electrical equipment in ultra high voltage substations, and can generally be divided into series reactors and parallel reactors. Low-voltage reactors and capacitor banks form a series branch circuit, which can suppress switching inrush currents and limit higher harmonics, protect the capacitor, and effectively prevent harmonic damage to the capacitor; Shunt reactors can generally be used to compensate reactive power, regulate and stabilize grid voltage, and improve voltage waveform to ensure reliable operation of the system, reduce system losses, and improve grid power supply efficiency. With the continuous increase in electrical load, the rapid expansion of ultra high voltage power grids, and the development of automatic control technologies such as AVC, the number of low-voltage reactors has increased sharply. Low voltage dry type reactors are widely used in power systems due to their excellent performance, low cost, and ease of operation and maintenance. However, a large amount of data and low-voltage reactor failure cases show that low-voltage dry reactor failures occur frequently due to factors such as frequent switching overvoltage, replacement of old equipment, degradation of insulation performance, and insulation damage, seriously affecting the reliable operation of the power system. Especially in recent years, several dry type air core reactor fire accidents have occurred in Shandong Electric Power UHV power grid alone, causing significant economic losses. Based on consulting relevant literature and relying on the operation and maintenance practices of low-voltage reactors in Shandong Electric Power UHV Grid, this paper systematically analyzes the causes and characteristics of low-voltage reactor faults, summarizes the methods for diagnosing low-voltage reactor faults, and proposes effective preventive measures for common faults of low-voltage reactors in UHV substations. The main research work of this paper is as follows: (1) Common fault types and causes of low-voltage reactors in ultra high voltage substations are analyzed. Firstly, the common fault types of dry-type low-voltage reactors in EHV substations are listed, and the low-voltage reactor fault cases occurred in power grids in recent years are cited to illustrate them; Then, combined with a case study, the causes of common failures of low-voltage reactors in EHV substations are summarized and refined. (2) A comprehensive diagnosis method for low-voltage reactor faults in ultra high voltage power networks is studied. Firstly, aiming at the common fault types and causes of low-voltage reactors in ultra-high voltage substations, this paper lists common fault diagnosis methods for low-voltage reactors, and analyzes in detail the principles, functions, and advantages and disadvantages of various diagnostic methods in practical applications. In addition, a set of effective comprehensive diagnostic methods for power grid operation and maintenance practices is developed; Then, taking the ultra high voltage substation of Shandong Power Grid as an example, the application of this comprehensive diagnosis method is analyzed. (3) Effective preventive measures for common faults of low-voltage reactors in ultra-high voltage substations have been proposed, aiming to eliminate potential safety hazards in the early stages and prevent accidents from occurring. Firstly, analyze the principles of various preventive measures, including strengthening equipment access control, strengthening operation and maintenance, reducing switching inrush current, and switching overvoltage, and describe the implementation effects of each measure. Then, focus on further in-depth research on new technologies such as phase selection and closing of low voltage reactors, aiming to reduce overvoltage and closing inrush current during closing operation of low voltage reactor circuits by using such technologies as phase selection and closing, and address the root cause of inter turn insulation faults of low voltage reactors.

The above content is organized by Superb heater Company, super heater. Mainly professional production: industrial heating elements, temperature measuring elements, production equipment, accessories, and raw materials such as tubular heaters, tubular heaters, belt heaters, ceramic heaters, silicone rubber heaters, thermocouples, etc.

Welcome global industry partners to discuss cooperation!