Electric drive

АВЗ-7100-6 А05 for the Main circulating pumping unit-1391 (MCP) with water lubricated bearings

At the end of 2008  JSC “NPO VEI Elektroizolyatsiya” (CJSC “NPO VEI Elektroizolyatsiya”) together with OJSC “TSKBM” started developing a prototype of a vertical asynchronous engine for MCP -1391, which, unlike the production sample of the type ДВДАЗ 173/109 -6-8-2 at 6 kV produced by UETM instead of oil bearings should be made with water lubricated bearings developed by OJSC “TSKBM”. It was assumed that the design of the active part of the electric engine will not undergo any changes and will be performed with a two-speed winding to provide starting regimes with an increased (more than 1.5 times) starting torque compared to oiled bearings.

In the process of development of a prototype of a two-speed electric engine for MCP drive with water lubricated bearings, a one-speed version of this engine for 10 kV  was developed in response to the wishes of the NPP designers, expressed during the coordination of the technical assignment for a two-speed engine.

The experts of JSC “NPO VEI Elektroizolyatsiya” have managed to find an appropriate solution to the problem of maintenance of the active parts of the prototype engine. A single-speed 10 kV engine fully meet the requirements of the technical specification for a two-speed engine with water lubricated bearings, and has obvious advantages in terms of performance.

Tests of MCP-1391 complete with a single-speed engine, conducted in 2011-2012 at the stand of OJSC “TSKBM” have confirmed the calculated parameters of the engine developed, and this fact has allowed recommending it for usage at newly designed nuclear power plants.

The prototype of the АВЗ-7100 on the test bench of OJSC "TSKBM -2" in Sosnovy Bor.
The prototype of the АВЗ-7100 on the test bench of OJSC “TSKBM -2” in Sosnovy Bor.
The technical specifications

Rated power, kW 7100
Rated voltage, V 10000
Rated stator current, A 470
Rated current frequency, Hz 50
Rated synchronous speed, rpm 1000
Rated torque, kN ∙ m 68,3
Rated sliding,% 0,646
Power coefficient , cos φ 0,92
Coefficient of efficiency with the installed flywheel,% 94,8
Ratio of the maximum torque to the nominal, r.u. 3,65
Ratio of initial starting current to rated current, r.u. 8,38
Ratio of initial starting torque to rated torque, r.u. 1,29
Ratio of the minimum torque to the nominal, r.u. 1,29
Moment of inertia of the flywheel engine rotor, kg.m², not less than 7800

Features of the electric engine АВЗ 7100-6 АО5

  • water cooling and lubrication of bearings, full refusal of application of oil in MCP;
  • one-speed engine with a nominal synchronous speed of 1000 rpm with the ability to perform a direct start in the conditions of a given permissible level of voltage drop in the grid;
  • 10 kV voltage while retaining the main dimensions of its active parts and dimensions adopted for the two-speed engine ДВДАЗ 173 / 109-6-8 AM05 for 6 kV;
  • three spin speed sensors of the third safety class are installed on the shaft of the engine to monitor the engine speed and its protection against a failed start.


Application area

NPP-2006:  In the project of the NPP-2006 reactor facility MCP-1391 with a two-speed electric engine of type ДВДАЗ 173 / 109-6-8АМ05 with oil lubricated bearings is used.

ВВЭР-ТОИ: In the project of the reactor with ВВЭР-ТОИ, a single-speed АВЗ 7100-6 A05 electric engine with water lubricated bearings is planned to be used as the basic electric engine of MCP.

The developed engine is also used in the new design of a single-speed MCP 1753 with a common shaft and three supports, which was tested at the stand of OJSC “TSKBM” in 2015-2016.


Main conclusions and results

Application of electric engine АВЗ 7100-6 А05 with water lubricated bearings will allow:

  • exclude oil in the MCP box;
  • increase the fire safety of nuclear power plants;
  • simplify the NPP fire fighting system;
  • simplify the layout in the MCP box;
  • simplify the start-up procedure for MCP.