Development and manufacturing of adjustable speed drives (ASD) and power-supply systems are of high importance within JSC “VNII “Signal” scope of activity.
Generators, motors, and static power converters (SPC) are the main components to provide energy conversion in ASD and PSS.
Synchronous motor control is provided by:
- frequency-current control, that makes it possible to set the required rotation velocity and torque output by applying proper current to the stator;
- vector control, that makes it possible to keep maximum torque output;
- subordinate control, i.e. outer circuit controls every inner circuit. Easy calculations and adjustment are provided by this type of architecture.
SDM motors have built-in measurement instrumentation to gauge electromagnetic parameters that results in improvement of adjustment parameters, accuracy and operation speed of adjusted drives. SDM excitation caused by high-coercivity magnet provides SDM motor efficiency factor of 94-97% and power density 2-4 times greater as compared to a hydraulic drive and a CD motor. Lack of commutator-and-brush assembly makes it possible to enlarge operational life that is limited in this case only by bearing degradation, by 3-5 times as compared to a hydraulic drive and by 8-10 times as compared to low-mass CD motor of EDM type.
SPC design includes microintegrated system (MIS). Its combination with built-in sensors of SDM motor provides usage of the most efficient algorithms to control, check and adjust SPC and the drive as a whole.
Modular blocks comprising SDM motor, electromagnetic brake, angle sensors, speed sensors and intermediate gear placed between SDM motor and adjusted object have been designed for several artillery systems and azimuth rotary systems. This kind of design eliminates backlashes, kinematic errors, and elastic strain between component parts and results in actuator weight reduction.
Combination of IGBT–based power converters used to control synchronous motors and SDM motor results in raise of efficiency factor of the drive as a whole up to 88-90% (50-60% as far as a hydraulic drive is concerned) and improved reliability.
Built-in controlled rectifiers and inverters make another large group of SPC developed by “VNII “Signal” experts.
Power converter for railcar air conditioner (“PNVK”) of 10 kW rated power is the most popular SPC of “VNII “Signal” design.
The converter was developed according to statement of work of OAO “Teploobmennik” (N. Novgorod) to provide power supply for air cooling compressor of passenger railcars (“MAB-II” railcar air conditioners for railcars of 47k and RIC-160 type).
The main “PNVK” advantages are better performances, particularly wider operating temperature range (up to + 60° C as compared to + 45° C of other products of Russian design).
“PNVK” Performance Specification:
| Parameter | Value |
|---|---|
| Frequency regulation range | 40 … 60 Hz |
| Voltage control range | 190 … 270 V |
| Rated current | 21 А |
| Efficiency factor | 0,94 |
| Rated power | 10 kW |
| Weight | 55 kg |
| MTBF | 15000 h |
| Overall dimensions | 664 х 514 х 200 mm |
JSC “VNII “Signal” has developed several hybrid power-supply systems (HPSS), that produce energy to power consumers from three sources: primary power supply (gas turbine, windwheel, traction motor shaft of mobile carrier), standby power supply (diesel engine, gas turbine engine, etc.), electric energy storage (accumulator battery, EDLC (super capacitor), etc.). A HPSS consists of generator, required electric power converters, and digital control system to provide controlled optimal power distribution between power consumers.
One of the most important HPSS components is an electric generator (EG) providing optimal matching of input shaft velocity and primary motor shaft, and output signals and primary SPCs.
HPSS EG Performance Specification:
| Parameter / HPSS Name | “Zhavoronok” | PSS – 0.3 | PSS - 12 |
|---|---|---|---|
| Rotor nominal speed, revolutions per minute | 300 | 20000 | 12000 |
| Maximum rotor operating speed, revolutions per minute | 360 | 25000 | 15000 |
| Minimum rotor operating speed, revolutions per minute | 120 | 7500 | 5000 |
| Power output at nominal speed, kW | 30 | 0,3 | 8,5 |
| Output voltage | 3 phases, 380 V, 50 Hz | 3 phases, V, 2 kHz | 3 phases, 400 V, 2 kHz |
| Efficiency factor under nominal conditions | 0,95 | 0,9 | 0,9 |
| Weight, kg | 500 |
While designing HPSS and its components the main attention is paid to optimal matching of all the components to primary power supplies and energy consumers, high efficiency factor and reliability.
Different HPSS designs provide creation of efficient methods of autonomous and ensured electric power supply.
For example, turbogenerator HPSS makes it possible to get electric power at gas distribution stations (GDS), gas dispensers (GD), boiler plants, heat-electric generating plants at no extra consumption of natural resources due to conversion of energy, releasing during natural gas decompression. Thus design and endorsement of plans of GDS and GD connections to electricity network and building of long power lines are in no need. Non-electrified GDS/GD can be automated; the number of duty officers and the costs for GDS/GD inspecting rides can be reduced.
HPSSs taking primary power off traction motor shaft are in need for almost every mobile working and defense systems that imply control over a great number of members using only energy of primary traction motor.
HPSSs taking primary power off windwheel are in demand nowadays, but the fact is that design of efficient system of this type has not been accomplished yet.
HPSS of “VNII “Signal” design is used in “Zhavoronok” wind-diesel system.
High requirements to advanced systems such as available power rise, flexibility and reliability improvement, weight and size minimization, fuel consumption reduction specify the task of development of highly integrated, jam-resistant, high-efficiency power-supply systems and their components.
As an expert in SPC and PSS design, “VNII “Signal” is ready to cooperate in this field with Russian and foreign customers.
