Master’s Day in PJSC Lenenergo

2 june 2017

On May 29-31, 2017 on the territory of the training polygon of PJSC Lenenergo in Tervolovo settlement a three-day tutorial was held by SKB EP Company that was based on the Mater’s Day program. The tutorial was attended by foremen, engineers, electricians, repairmen and technical specialists from different network and energy companies dealing with the equipment repair and diagnostics.

The polygon is equipped with modern high-voltage equipment, which allows demonstration of new capabilities of devices and control techniques. Moreover, it includes a training center for theoretical courses, which allows rather comprehensive training of specialists.

On the first day of the tutorial the SKB EP specialists delivered a lecture on the main peculiarities of measuring the contact-type connections of high-voltage circuit breakers, on techniques for measuring the electric resistance of power transformer, CT and voltage transformer windings using devices of the MIKO group. The tutorial was attended by specialist who had experience in using the MIKO microohmmeters and milliohmmeters; they asked a lot of questions and revealed new functions of the devices that they had not used before.

The next subject of the lecture course was devoted to diagnosis of OLTC devices of  RS-3/RS-4, RNOA, and RNT-13 types. The matter is that the OLTC device is a rather important node in the power transformer, and the major share of failures falls on this very mechanism. The main problem is that the device is placed in a closed tank and repairmen have no possibility to visually control it, therefore, special equipment for non-destructive control of OLTC would considerably reduce labor intensity and costs.  For solving this problem the SKB EP Company has designed a special-purpose PKR-2M analyzer and MIKO-8 and MIKO-9 milliohmmeters.  

PKR-2M is a special-purpose analyzer for control of the OLTC devices both in the destructive and non-destructive modes (DRM-test).  The analyzer allows recording the oscillograms of the closing switch operation and circular diagrams for three phases simultaneously; MIKO-8 and MIKO-9 are milliohmmeters. DRM-test mode for the OLTC devices is an additional function; the DRM-test is less developed from the standpoint of mathematical calculations (oscillogramms are recorded by phases, no circular diagrams).  But this very device is designed specifically for express-diagnosis and approximate estimation of the OLTC state without opening the tank.

Lectures were supported by demonstration of DRM-test on the OLTC devices of MR type of the TDTN-40000/110/35/10 transformer. 

Functions of PKR-2M and operation of MIKO-8 milliohmmeter designed for measuring the electric resistance and for express-diagnosis of the OLTC devices were demonstrated to the tutorial attendants.

Each specialist could try to measure dynamic resistance of the OLTC device, to get the oscillogram of switch-over, to interpret the graphs obtained, and to ask all the questions.

The second day, according to the training schedule, was devoted to studying the peculiarities of high-voltage circuit breakers (oil, SF6, vacuum, air, electromagnetic) oscillography using the PKV devices.

Training was performed on a high-voltage VGT-110 circuit-breaker with a spring-type PPrK drive. Operation of PKV/M7 and PKV/M6N devices was demonstrated.  Diagnostics was performed both in simple cycles (Close, Open, Close-Open, Open-Close) and in complex Close-Open-Close operations by setting different Close, Open and Pause pulses.

It should be noted that PKV/M7 analyzer has an in-built switch for setting both the simple operations and complex cycles of circuit-breakers for current of up to 14A for AC and DC drives. PKV/M6N automatically recognizes the type of a simple operation or a complex cycle but for their setting a special control unit out of PUV-type devices is needed. Control panel of dispatcher’s station can also be used. For the purpose of training the PKV/M6N device was completed with a PUV-controller for controlling the drives of HV circuit breakers and for checking the minimum voltage of circuit breaker coils operation according to RD 34.45-51.300-97.

Specialists highly appraised operation of PKV/M6N and stressed its positive characteristics: simple operation, low weight, small size, availability of a special “Measurement Rod - Angle Indicator” mode, which allows circuit breaker adjustment without using special equipment, ability to quickly obtain the results owing to an in-built thermal printer. According to the opinion of attendees, the main merit of PUV-regulator is an Umin function for automatic determination of operation, which allows us to obtain the required data faster than measurements with the resistor adjustment.

The third day was devoted to teaching the software for PC and PKV devices. Specialists of SKB EP delivered information on the principles and rules of using the software, on data base development and control, on the options of devices operation using software, on peculiarities of the graphic results analysis, and on checking the obtained values against their passport analogues.

To prove their new knowledge the attendees were to be certified. The specialists successfully passed the tests, which confirmed their high professional level. Upon termination of the tutorial Alexander G. Gushchinsky, Deputy Head of the Training Center, handed the Advanced Training Certificates to the participants of the Mater’s Day program. 

We congratulate all the participants and thank them for participation!