RU-2861401-C1 - DEVICE FOR AUTOMATED DETERMINATION OF PARAMETERS AND CONDITION MONITORING OF POWER TRANSFORMER UNDER LOAD

RU2861401C1RU 2861401 C1RU2861401 C1RU 2861401C1RU-2861401-C1

Abstract

FIELD: electric power industry. SUBSTANCE: invention relates to automated control systems for power transformers. The technical result is achieved by the fact that the device for automated determination of parameters and condition monitoring of power transformers under load can be used for transformers of any type, and synchronised vector measurement units (SVMU) are used as current and voltage measuring units. The device also comprises a time synchronisation unit and a computing unit. The computing unit is configured to receive said synchronised voltage and current vectors from all SVMUs and perform direct real-time calculation of transformer parameters. The device additionally comprises a transformer tank temperature measurement unit and a power supply unit, and the control device is made as a combined control and indication device. EFFECT: increasing the reliability and safety of operation of power transformers by providing continuous and comprehensive information about the current state of the transformer, including electrical and non-electrical parameters, which makes it possible to prevent equipment failures. 2 cl, 1 dwg

Inventors

KOSORLUKOV IGOR ANDREEVICH
TIMCHENKO MAKSIM SERGEEVICH
SOLOVEV ALEKSANDR VLADIMIROVICH
Avdonkin Sergej Aleksandrovich
Strochkov Aleksej Vladimirovich

Dates

Publication Date: 20260505
Application Date: 20251114

Claims (2)

1. A device for automated determination of parameters and monitoring of the state of power transformers under load, containing units for measuring voltage, current, ambient temperature, units for measuring temperature, humidity of transformer oil, a unit for measuring air humidity inside the oil tank, which are connected to a computing unit, as well as an output signal generation unit and a control device, characterized in that it is equipped with a time synchronization unit and additionally contains a memory unit for storing time series of calculated parameters and analyzing their changes over time by comparing with base values and values of past measurements and a power supply unit that ensures the continuous operability of the device, wherein the current and voltage measuring units are made in the form of synchronized vector measurement units connected to the current and voltage measuring transformers of the high-voltage side and the low-voltage side, the control device is made in the form of a combined control and indication device containing information input/output means, the output signal generation unit contains a built-in Ethernet port; The time synchronization unit is connected to a precise time source and is connected for transmitting signals to the high-voltage side synchronized vector measurement units and the low-voltage side synchronized vector measurement units, as well as to a computing unit; the computing unit is configured to receive synchronized voltage and current vectors and to directly calculate in real time the actual transformation ratio, the total resistance of the windings with division into active and reactive components, and the losses of total, active and reactive power based on a single synchronous measurement in one current operating mode of the transformer.
2. The device according to paragraph 1, characterized in that, in order to control the temperature of dry-type transformers, it is supplemented with a unit for measuring the temperature of the transformer tank.

Description

Field of technology to which the invention relates The invention pertains to the field of electric power engineering and control and measurement technology, specifically to systems for continuous automated monitoring and control of the technical condition of high-voltage power transformers and autotransformers directly during their operation under electrical load. It is intended for use in electrical substations, power plants, and industrial distribution networks to improve the operational reliability of critical equipment and prevent unexpected failures. State of the art It is well known that the reliable operation of power transformers is a key factor in the stable operation of electric power systems. Monitoring their technical condition enables the early detection of developing defects. Control systems based on insulation monitoring, for example, by recording partial discharges (PD) or chromatographic analysis of dissolved gases in oil (CADG), are known. The disadvantage of these approaches is that they monitor the consequences of degradation processes rather than the root cause, without providing information on the fundamental electrical parameters of the transformer itself, such as winding resistance and inductance. A technical solution is known (RU Patent No. 71445 U1, G01R 31/02, application No. 2007132320/22 dated 08/27/2007, published 03/10/2008), which is a device for operational monitoring and protection of transformer windings. The device comprises primary and secondary voltage measuring transducers connected to the primary and secondary windings of a transformer, wherein each of the measuring transducers is connected to a series-connected switch and an analog-to-digital converter, to which a reduction unit and a difference calculating unit are connected, which is connected to a resistance calculating unit and to an inductive voltage component unit, which is connected to an inductance calculating unit, which is connected to a series-connected averaging unit and a control programmer connected to a push-button keyboard, wherein the reduction unit is connected to the difference calculating unit, the resistance calculating unit, the inductive voltage component unit and to the differentiation unit, which is connected to the inductance calculating unit, and the resistance calculating unit is connected to the inductive voltage component unit and to the control programmer. The operating principle of the device is based on calculating the deviations of the active resistance and inductance of the windings and comparing them with empirically determined settings. The disadvantages of this technical solution include the use of empirically determined settings, which must be determined using a known-good similar transformer, as well as the inability to track gradual changes in parameters, which may indicate developing damage (decrease in insulation resistance, short-circuits, etc.). A technical solution is known (RU Patent No. 162784 U1, H02H 7/04, application No. 2015123248/07 dated 16.06.2015), which is a device for monitoring power transformers. The device comprises a current measurement unit connected to a current conversion unit on the low-voltage side and a device for processing the received data, a voltage measurement unit and a transformer oil cooling system control unit connected to a device for processing the received data, a current conversion unit on the high-voltage side, and a current comparison unit containing a filter from higher harmonic currents, connected to current conversion units on the high and low voltage sides and a device for processing the received data. The device ensures monitoring of currents and voltages on the high and low voltage sides of the transformer, as well as the oil temperature and level; if a gas relay is present, its operation can be recorded. If the parameters deviate from normal values (for example, an increase in current on the high-voltage side while the current on the low-voltage side remains constant, or an increase in oil temperature above 95°C), the device generates a fault signal. The disadvantages of this technical solution include the implementation of the current comparison unit as a simple differential element, which limits its sensitivity to internal faults in the transformer, as it requires adjusting its tripping setting based on the operating current imbalances caused by errors in the measuring transducers and directly proportional to the load current. A technical solution is known (RU Patent No. 105536 U1, H02H 7/04, application No. 2011108790/07 dated 03/09/2011, published on 06/10/2011), which is a mobile device for monitoring, controlling and protecting power transformers without disconnecting them from the load. The device contains outputs of measuring elements (current, voltage, frequency) included in the circuit of each phase of the primary and secondary windings, which are connected to the output of the element setting the time for data acquisi