Máy phân tích bộ điều áp dưới tải OLTC của máy biến áp SKB PKR-2M

OLTC in-place check enables to conduct express diagnostics of the OLTC technical condition without opening the tank or OLTC removing. This check enables to obtain the contactor switchover diagrams for a wide range of switching devices (except reactor type ones) and conduct the OLTC condition evaluation based on the obtained diagrams, that gives the reasons to denote a defect nature and grounds for decisions related to repair of these on-load tap changers.

For example, for type RS, RNOA, etc., on-load tap changers the correctness of operation of the main and arcing contactor contacts, their condition (burned or not burned contact), current-limiting resistor integrity may be determined. For type RNTA – 35/320 on-load tap changers and in the analogous on-load tap changers, in which the contactor and selector are changed for a fine control circuit breaker, the main and arcing contacts, current-limiting resistor condition, as well as condition of surface of all fixed contacts of the circuit breaker, through which the moving contacts move, may be checked.

The application of in-place check mode based on the DRM method does not require:

• Opening of the tank or hatch of the fault-free/faulty OLTC and oil drain;
• Additional money and labor costs for the OLTC diagnostics;
• Connection of additional elements or knowledge of resistances of current-limiting resistors of the checked on-load tap changer, since all fine adjustments to a certain OLTC are conducted automatically in the instrument.

The instrument is completed with a special transducer for the radial diagram measurement. Its interface with shafts of different drives is provided with a set of axes and bushings, which are installed without any tools by simply putting on the shaft extension.

All characteristics are measured simultaneously based on three phases for OLTCs located in the neutral conductor of "star-connected" windings, and single phase for OLTCs located in the line of "star-" or "delta-connected windings".

The switchover oscillography enables to detect the actuation delay, non-simultaneity of in phase actuation and bouncing during switchover.

All characteristics are measured simultaneously based on three phases for the OLTCs located in the neutral conductor of "star-connected" windings, and single phase for the OLTCs located in the line of "star-" or "delta-connected windings".

Check conducted during the drive shaft slow rotation using a handle with simultaneous display of contact closures/openings in degrees and voltage and current values.

No additional elements (for example, resistors) or knowledge of resistances of current-limiting resistors of the checked on-load tap changer are required to measure the OLTC parameters. All adjustments to a specific OLTC are performed automatically in the instrument.

The instrument is completed with special long calipers to be conveniently connected to some OLTCs (in this case, it is not necessary to drain oil from the contactor tank)..

The instrument may be connected to the on-load tap changer with measuring cables provided with alligator clips without contact calipers with oil being partially drained from the contactor tank or removal of the on-load tap changer from the transformer tank.

PKR-2М is equipped with inbuilt battery, which makes it more mobile and easy to use. The inbuilt battery enables to use the instrument during the entire workday without recharge on the vast territory of substation or workshop, which does not require the use of the power supply cable, mains socket extension cord and grounding.

The instrument is equipped with a large color high-brightness and high-contrast display facilitating the graph processing to present information in graphical or tabular form.

The measurement results are stored in the non-volatile memory of the instrument, on the external flesh memory, and they may be transferred to the computer.

Therefore, the instrument may be controlled by the PC. It enables to measure diagrams being ins

* In-place check mode enables to conduct the in-place diagnostics of OLTCs with current-limiting resistors with the contactor tank cover in place. This mode is based on the DRM method (see above) and consists in measurement of current intensity through the winding, in which the OLTC is switched on.