The current tendency for high-voltage circuit breaker diagnostic is a reasonable combination of online and offline control methods
In power systems, high-voltage (HV) circuit breaker is the type of electrical equipment that requires high responsibility the most. At the same time, HV circuit breaker functioning quality determines the degree of reliability and energy security of the entire system of electricity transmission and distribution in both normal and emergency modes. Therefore, technical control and diagnostic are very important, because they allow to detect defects or malfunctions, and eliminate them at an early stage.
For more than 30 years SKB EP, LLC has been developing and manufacturing portable diagnostic instruments for monitoring HV circuit breakers and other electrical equipment technical condition. All the SKB EP devices are being implemented on the basis of modern control requirements and user needs. Therefore, at the stage of changing the methods of fault prevention and detection of electrical equipment, including HV circuit breakers, a lot of work has been done to develop new instruments that meet new market trends.
Since the middle of the past century, the most common method of fault prevention and detection has been the use of planned preventive maintenance system. It always has been a well-developed and organized system, but currently it requires adaptation, because it does not meet some of the modern trends. And moreover, insufficient economic case of recommended standards of the system reduces the effectiveness of its application.
At the moment, not at the legislative level, but as recommendations and resolutions, new standards are being implemented that allow to change the approach to the diagnostic of substation equipment. Thus, according to the "Rules for the organization of maintenance and repair of equipment, buildings and structures of electric power stations and networks" developed by the Ministry of Energy of the Russian Federation, it is necessary to provide not only planned preventive maintenance system, but also technical condition repairs, which allow companies to choose their own maintenance and repair strategy. At the same time, maintenance and repair strategy by the actual technical condition assumes an assessment of the equipment condition according to the limit and real values.
It is the control of the real equipment parameters values that allows you to get information about the real technical condition. But the engineers should remember that diagnostic should be carried out with modern diagnostic methods. Control of the real equipment parameters allows to monitor the fault development tendency, assess the equipment operational life, predict when and what maintenance or repair will be necessary, while repairing only defective equipment (or its components).
Instruments of PKV group manufactured by SKB EP (PKV/M6N, PKV/M7, PKV/U3.1, PKV/U3.0) are implemented in order to monitor current values of the parameters of HV circuit breakers and evaluate their actual technical condition. The instruments are designed to record the processes of Closing and Opening of the equipment contacts, as well as movements of movable contacts, speeds and currents in the Opening and Closing coils. All these measurements make it easy and reliable to assess the HV circuit breaker mechanical part condition. Oscillography of Opening / Closing dynamic processes makes it possible to prevent or monitor the process of faults development. In addition, due to the use of advanced technologies, the instruments can be used on circuit breakers of all types and voltage classes.
New requirements need new solutions, therefore, as the new year 2022 approaches, SKB EP is launching a new instrument for this diagnostic segment: PKV/M15 circuit breaker analyzer. The instrument includes the best characteristics of its predecessors, considering the modern component base in a compact and portable case.
PKV/M15 was designed on the base of well-established PKV/M6N circuit breaker analyzer, which is one of the most affordable, simple and understandable devices corresponding to good balance of price and quality. In PKV/M15, the above-mentioned characteristics are preserved, and also it has a light weight and small dimensions. The instrument is equipped with modern methods of data transmission via Bluetooth. In addition, for circuit breaker testing in complex cycles, PKV/M15 implements the possibility of switching control signal with a test current up to 20 A.
One of the significant differences between PKV/M15 and the previous instruments of PKV group is the implementation of additional triggering types for HV circuit breaker monitoring that take into account different circumstances during diagnostic:
- Triggering by closing the main contacts is a universal triggering type that facilitates users’ work and does not require additional settings (measurement time, signal duration, cycle type, triggering front).
- Triggering by «dry contact» (AUX) is one of highly-demanded modes among the service personnel of TAVRIDA ELECTRIC circuit breakers, where Closing and Opening time is normalized by dry contact closing.
At the moment, PKV/M15 is being tested for registration in the Russian Federation State Register. More detailed information about this instrument, its complete set and operating modes you may find on the website www.skbep.com in the section "Devices" - "High-voltage circuit breaker control".
With the modern automated systems development, there is also the need of devices for continuous real time monitoring of HV circuit breaker technical condition without taking the equipment out of operation. Thus, according to the report of ROSSETI, PJSC Chief Engineer on implementation of concept of technical diagnostic system development, it is assumed that nowadays diagnostic should be based on monitoring systems (if it is possible).
SKB EP suggested the solution for this task: new special instrument UMVV-1.1. It performs online-monitoring of the commutation resource of high-voltage circuit breakers of various voltage classes, based on the wear rate of their contacts.
After the device is installed at the object, it can be set up remotely or locally. The set up mode is available in the special software.
The data recorded with UMVV-1.1 provide information about the consumption tendency of the commutation resource of the circuit breaker (a recommendation for its decommissioning when it is necessary) and additional information about the need of mechanical elements maintenance or arc-extinguishing contact / chamber of HV circuit breaker replacement, which reduces the risk of unnecessary repair works. It allows you to use a more cost-effective approach and carry out maintenance "as necessary".
Trial operation: With an integrated approach to the installation of UMVV-1.1 device, we recommend conducting a diagnostic of a specific high-voltage circuit breaker technical condition offline with SKB EP devices (PKV, PUV and MIKO). This approach will significantly reduce enterprise expenses by obtaining the missing parameters for assessing the technical condition and commutation resource as fully as possible, using data in offline format, with a minimum amount of data in online format. This will allow to use more cost-effective approach and carry out maintenance "as necessary".
The format of continuous monitoring solves a lot of problems and takes monitoring and diagnostic to a new level, but only a comprehensive assessment of the circuit breaker technical condition by online and offline diagnostic together allows to identify the "weak link" in the chain of technological transit of electricity, to direct the appropriate material and technical resources for conducting maintenance and repair, while maintaining the level of power supply reliability at a high level and with low costs.
Equipment technical condition can be described with a set of diagnostic parameters, and their number differs for different equipment. For example, the number of measured parameters for power transformers can reach 38, for oil circuit breakers — 29, for SF6 circuit breakers – 25, for excess-voltage suppressors and arresters – 10, for disconnectors (with a drive) — 14, for oil-filled measuring transformers – 9. With such a variety of parameters, it is always very important to choose the most effective methods and compromises when creating control systems. It is advisable to make final decision on installation and selection of type and composition of complex for monitoring equipment based on the results of an economic efficiency assessment.
If your company is facing the challenge of transition from planned repairs to repairs depending on equipment technical condition, and you do not want to aimlessly use expensive transducers, but are going to install understandable and effective data analysis systems, then feel free to contact SKB EP specialists. Professionals in the field of diagnostic will analyze your objects and recommend the most effective solution for your specific tasks.
You may always contact us via e-mail firstname.lastname@example.org or via phone +7 (812) 500-25-48.