Supply of an electric drive for PEMA 250-80 electric pump units, supplied to the world's largest universal nuclear-powered icebreakers of LK-60YA type (project 22220)

Icebreakers of LK-60YA type (project 22220) are a new type of Russian nuclear icebreakers. The name stands for «icebreaker», with the capacity of 60 MW, with nuclear power plant.

Central design bureau «Iceberg», which is a part of JSC «USC» designing ships of civil purpose and nuclear power facilities, was engaged in development of the project.

The nuclear ship of the project 22220 will be the largest and most powerful in the world, and, due to the expense of increased width, (34 m instead of 30 on the nuclear-powered submarines of «Arktika» type) universal nuclear icebreaker will be able to undertake on its own tankers in the Arctic with a displacement of up to 100 thousand tons. Icebreaker of this project will be able to conquer the ice up to three meters. According to its technical characteristics, the nuclear icebreaker will be able to equally work effectively in the estuaries of Siberian Rivers and on the Northern sea route.

«EnergoFront» company was given the task of finding a technical solution for the supply of an electric drive for the electric pump unit PEMA 250-80 produced by JSC «HMS Livgidromash», designed for feeding of steam generators of marine nuclear power plant of the icebreaker of JSC «Zavod «Kirov-Energomash» (subsidiary of JSC «Kirovskiy zavod»).

The equipment had strict requirements for weight and dimensions, and the task was complicated by the need of certification by the Russian Maritime Register of Shipping (RMRS).

The electric drive includes a step-down transformer, frequency converter and electric motor. The electric drive must be designed for normal operation at voltage deviations +6/-10 % and frequency ±5%.

In the course of deep study of the technical side of the issue, the specialists of «EnergoFront» company have decided to supply the induction electric motor with short-circuited rotor of Polish manufacturer «Emit S.A» and frequency converter with a transformer of LLC «Triol-Elektrik».

Electric motor of mShw400H2Es type stands for the electric motor with squirrel-cage rotor, marine version, with water cooling and designed to operate from a frequency converter.

Nominal parameters of the motor:

• capacity - 800 kW;

• voltage - 690 V;

• frequency - 50 Hz;

• rotation speed - 2987 rmp;

• current – 775 A;

• capacity factor – 0,89;

• efficiency – 97%;

• control depth 20-100%.

Due to unique engine cooling scheme IC77A1W7 with closed-circuit ventilation system, the engineers of Emit plant managed to solve a difficult task to comply with strict requirements for weight, size and range of regulation (20-100%). At the request of RMRS, operational tests were carried out in Gdansk, confirming the efficiency of the motor under the following conditions:

• at the change of the atmospheric pressure in the range of 600-800 mm Hg;

• at the change of the ambient temperature changes from 0 to 45˚С

• at relative humidity up to 95±3%;

• at vibration in the range from 2 to 80 Hz;

• at simultaneous static inclinations: rolls up to 15˚, trims up to 5˚;

• electric motors must withstand without infringement short-term dynamic overload, acting on fastening units, with 5g acceleration amplitude in vertical and horizontal directions.

The most difficult requirement of the customer was to conduct tests on load sketches and drops. The electric motor had to cycle change the load from maximum to minimum in the shortest possible time. Electric motor of mShw400H2Es type fulfilled this requirement and corresponds to the operating mode S9.

All factory and operational tests were carried out with the participation of the acceptance committee, which included representatives of customers, specialists of the group of technical supervision over the construction of NPI of FSUE «Atomflot».

The transformer, which is a part of the electric drive, is designed to reduce the supply voltage from 10.5 kV to 690 V for power supply of the frequency converter with 12-pulse rectification scheme.

Technical characteristics:

The production and testing of the step-down transformer were carried out under the technical supervision of RMRS representatives and technical customer specialists.

The frequency converter (FC), which is a part of the electric drive, is designed to change the rotation speed, as well as for smooth start of the electric motor of the electric pump unit.

The frequency converter control has to be carried out in three ways:

• local control - from the operator panel on the front panel of the cabinet;

• remote control - with a local control panel, attached directly to the frame of the electric pump unit PEMA 250-80;

• automatic control - from the top-level system developed by the concern Avrora Scientific and Production Association JSC.

Technical parameters:

Acceptance of the electric drive took place at the sites of manufacturers in Poland and Moscow region, was carried out by the acceptance commission, composed of the representatives of LLC «EnergoFront», JSC «HMS Livgidromash», JSC «Zavod «Kirov-Energomash» and specialists of the group of technical supervision of construction of NPI of FSUE «Atomflot».

Now the equipment is shipped to JSC «Baltiyskiy zavod» and successfully tested as a part of PEMA 250-80 electric pump units on a new test stand of JSC «HMS Livgidromash».

«EnergoFront» company once again proved its professionalism and willingness to implement complex engineering tasks in shipbuilding industry.

Project achievements