High-speed electric machines

Research and Production Company “ERGA” by individual purchase orders designs, produces prototype samples, executes stand tests and manages a small batch production of direct-acting power sets-built-in electrical permanent-magnet generators or briefly DPSGs.

Nowadays, high-speed electrical machines are applied as electromechanical alternative energy converters (non-traditional energy, for driving turboblowers, compressors, pumps and centrifuges, in energy accumulators with the help of flywheel weights). Micro turbine generators can be used in decentralized power systems as autonomous power supplies, standby sources in case of natural calamities and accidents, as well as equipment automatic control systems during the oil and gas recovery, for the environment diagnosis and monitoring.

Permanent-magnet generators do not have a rotor excitation winding, and their exciting flux is created by permanent magnets, located at the rotor. Stator of these standard machines has two- or three-phase winding.

Under the effect of a rotating moment of the drive motor, the generator rotor is rotated with the preset speed. In this case, the EDF appears in the stator winding according to the electromagnetic induction appearance. Because the stator winding is loaded, current appears in this winding circuit. During the rotor rotation, the permanent-magnet magnetic field also rotates with the preset speed that is why each of stator winding conductors alternately appears either in the north magnetic pole or in the south one. Thereby, every pole change is accompanied with a change of EDF direction in the stator winding. So, an alternate EDF appears in the stator winding of synchronous generator, and therefore the current in this winding and load is also alternate.

The power supply of autonomous loads, supposing a high reliability, simple design and maintenance, stipulates the application of permanent magnets as the generator excitation source. Moreover, permanent-magnet generators have a higher efficiency, reliable excitation (no brush rig), and enhanced output characteristics, differ with a quick transient attenuation; they have simpler cooling system (no excitation losses). Permanent-magnet generators have higher weight and outline parameters.

Technical characteristics of high-speed generators to be integrated into gas turbine units:

  • rated power - from 5kW to 300 kW;
  • rated speed - from 20000 rpm to 100000 rpm with the efficiency of no less than 0.9;
  • operation in motor mode is possible;
  • decrease of rotor breaking force to the friction value in rotor bearings due to the magnetic system configuration;
  • application as rotor bearings:
    - active magnetic levitation (AML), ensuring the full absence of a mechanical contact and lubrication demand;
    - permanent-magnet bearings;
    - gas bearings.

Permanent-magnet DPSGs are widely applied in gas turbine units, cold air refrigerating plants and special-purpose equipment. The usage of high-speed electrical machines improves the equipment reliability and reduces the weight and outline characteristics due to the increase of generator (motor) speed. Research and Production Company “ERGA” produces, executes stand tests and manages by individual purchase orders both high-speed generators (motors) and bearing assemblies ensuring the rotor speed to 100 000 rpm, the design and the production of a starting and control system of these plants is also possible.

The key feature of research and production association “ERGA” is the fact that all the researches at the enterprise are done by highly-qualified engineers together with material and process engineers, i.e. the design goes from initial materials (raw materials) to the creation of unique magnets, carbon fibers (bandage) to original designs, with preliminary mathematic calculations. The mechanical base and prototype production with test stands allow bringing the researches to prototype samples with a high quality.

The design complexity of this device consists in the solution need of both traditional electromagnetic challenges and in the calculation of a complex challenge of the dynamics of the ‘generator – drive’ rotor system. In process of the solution of this challenge, it is necessary to determine dynamic system characteristics taking into account of real supports stiffness, and aerodynamic rotor losses and extra electromagnetic losses.

Research and Production Company “ERGA” is capable to design and produce a high-speed electrical permanent-magnet generator of high reliability and efficiency. On a customer’s request, we produce devices with the preset voltage value in the rated power mode with a moment of rotor breaking force, reduced to a minimum. The efficiency of our devices is not less than 0.9.

Ask a question
Leave your contact details and we will contact you
Additional information:
Branch application equipment:
Separation / detection product:
Нажимая на кнопку "Отправить", вы принимаете условия Cоглашения об использовании сайта