Propelling electrical machine with multilevel frequency converter

FIELD: transport.

SUBSTANCE: invention relates to electrically driven propulsion systems for transport facilities. Electrically driven propulsion plant comprises electric power source, main switchboard with generator, feeder and section circuit breakers, multiwinding transformers of frequency converter with primaries, input rectifier modules, isolator, DC link capacitors, inverters, and motor with two windings. One primary of said multiwinding transformers is connected in star circuit and another one is connected in delta circuit. Frequency converters for supply of every motor winding are integrated in common circuit by series connection of rectifier modules. Isolator is connected between extreme internal assemblies of rectifiers and capacitors of frequency converters feeding different motor windings.

EFFECT: higher reliability.

1 dwg

 

The invention relates to electric traction systems of vehicles and drive enhanced survivability and reliability of multilevel inverters and winding AC motors and is intended for use on vessels (ships) with elektrodvizheniem, other vehicles with elektrodvizheniem, in the actuator with a multi-level inverters.

Known multilevel inverters [Ndonko, A.Ivanov, VMotion, Yosaku "offline Multilevel inverters for electric drive and electric power". Power electronics, 2008, No. 1].

Known static multi-level frequency Converter for power asynchronous and synchronous motors [patent # EN (11) 2303851 (13) C1].

Known electronic device for converting electrical energy [RF patent 2182741].

The drawback of such multilevel inverters is low reliability and survivability associated with the presence of only one of the input transformer.

The prototype was taken propeller electrical installation with double propeller motor, frequency Converter and the input of multiwinding transformers, which together with a rectifier modules form megapulse system straightening [L.Berh, Ulrika Hellden "Electrical systems in pod propulsion", Goteborg, Sweden, Department of Energy and Environment, 2007].

The disadvantages of such facilities is the increased influence of the power Converter on the power quality of the entire system, high ripple voltage in the DC link, which reduces the quality of the electric power consumed by the propeller motor.

The invention solves the problem of improving sinusoidally current consumed by the system transformer-frequency Converter-propeller motor, which leads to improvement of sinusoidality bus bar voltage main switchboard system, as well as to reduce the ripple voltage in the DC link converters, increasing the reliability and survivability of the drive.

The invention consists in using two-winding transformer with primary windings connected to one transformer on a "star", the second "triangle", and a series connection of a rectifier modules, frequency converters, supply various windings of the propeller motor.

The technical result obtained by carrying out the invention, is that as a result of this connection is formed straightening system with double pulsesto that leads to improved waveform of the total current consumption is about the Converter, as well as the use of two transformers and switch improves reliability and survivability of the drive.

The invention is illustrated by scheme, in which figure 1 shows a functional electric diagram of the inventive propeller electrical installation.

The installation consists of the power plant 1, which includes the required number of power sources 2, the main switchboard 3 generator 4, the feeder 5 and section 6 switches, multiwinding transformers 7, a rectifier 8 modules, capacitors DC link 10, the inverter 11, the switch 9. Through feeder switches are powered by the primary winding winding transformer 7 frequency Converter connected to one of the star schema, the other is "triangle". The quantity and patterns of connections of the secondary winding of the transformer is determined by the number of level converters. The mapping consists of rectifier modules 8, switch 9, the capacitors of the DC link 10, inverters 11. From the output of the inverter is powered motor with two windings 12. The number of rectifiers 8 and capacitor 10 is determined by the number of levels of the output inverter, which is depicted in figure 1 by dashed lines.

Rowing electrical installation works as the way. In the basic modes of use of the electricity system sectionalizing switch 6 is on, thus the total current energy sources 2 is equal to the sum of the currents consumed by the transformer 7. Various schemes of connection of the primary windings of the transformers 7 provide the shear stresses their secondary windings 30 electrical degrees, which results in doubling the rippling of rectifying circuit consisting of series connected rectifier units 8, compared with pulsesto separate converters for each of the motor windings. The switch 9 is designed to provide separate functioning converters depending on the modes of installation or fault of one of the transducers or one of the motor windings.

Between the extreme inner nodes of rectifiers and capacitors frequency converters feeding the various windings of the propeller motor, a switch 9. The switch 9 is designed to provide separate functioning converters depending on the modes of installation or fault of one of the transducers or one of the motor windings.

Thus, PulseNet system straightening doubles that improves the form of distorting the total current consumed by the Converter, increases the reliability and survivability of the drive.

Rowing electrical installation consisting of a plant, which includes energy sources, the main switchboard generator, feeder and section switches, multi-winding transformers of the frequency Converter with the primary windings, rectifier modules, connected in series, the switch, the capacitors of the DC link, the inverter and the electric motor with two windings, wherein the primary winding winding transformer connected to one of the star schema, the other a triangle, frequency converters to power each of the windings of the motor are combined in a common circuit through serial connection of their rectifier modules, between the extreme inner nodes rectifiers and capacitors frequency converters feeding the various windings of the propeller motor, a disconnector.



 

Same patents:

FIELD: electricity.

SUBSTANCE: converter with a higher frequency link comprises a single-phase inverter bridge with back-to-back diodes, a transformer, a rectifier, two control systems, one of which controls operation of inverter transistors. The rectifier is arranged as diode with a zero point and is loaded to the resonant circuit. In parallel to the resonant circuit, a thyristor is connected, which is joined to the second control system. When controlling the converter, an interval t1 of transistor control pulses, where a positive half-wave of current is generated in a load, is alternated with an interval t2 of a zero pause, in process of which with the help of the first control system all transistors of the inverter are closed, with the help of the second control system the thyristor connected in parallel to the resonant circuit, is unlocked, providing for the mode of double conductivity of inductor current and generation of the negative half-wave of load current. The interval of inverter control pulses supply is always lower than the interval of zero pause, in which the thyristor is closed (t1<t).

EFFECT: reduced number of thyristors and lower voltages at thyristors and diodes to double output voltage of a transformer due to provision of inductor current continuity.

4 cl, 2 dwg

FIELD: electricity.

SUBSTANCE: converter with a higher frequency link comprises a single-phase inverter bridge with back-to-back diodes, a transformer, a rectifier, two control systems, one of which controls operation of inverter transistors. The rectifier is arranged as diode with a zero point and is loaded to the resonant circuit. In parallel to the resonant circuit, a thyristor is connected, which is joined to the second control system. When controlling the converter, an interval t1 of transistor control pulses, where a positive half-wave of current is generated in a load, is alternated with an interval t2 of a zero pause, in process of which with the help of the first control system all transistors of the inverter are closed, with the help of the second control system the thyristor connected in parallel to the resonant circuit, is unlocked, providing for the mode of double conductivity of inductor current and generation of the negative half-wave of load current. The interval of inverter control pulses supply is always lower than the interval of zero pause, in which the thyristor is closed (t1<t).

EFFECT: reduced number of thyristors and lower voltages at thyristors and diodes to double output voltage of a transformer due to provision of inductor current continuity.

4 cl, 2 dwg

FIELD: electricity.

SUBSTANCE: method is proposed to control multiple power converters, which may be used for coupling with a supplying electric grid, an AC bus, etc. Each power converter comprises a network bridge, operating in compliance with width-pulse modulation (WPM), having one and the same switching period, which generates at least one unwanted harmonic in voltage of the supplying electric grid. The method includes an operation for creation of a WPM switching period of each network bridge with a different time shift relative to the point of time count.

EFFECT: unwanted harmonic in voltage of supplying electric grid will be partially suppressed.

49 cl, 14 dwg

FIELD: electricity.

SUBSTANCE: device to convert DC voltage into AC voltage and back includes a control system to control voltage conversion and at least one phase circuit (1), in which the first (Uvp1) source of voltage is connected in series between the first DC terminal (4) and the first AC terminal (6), and in which the second (Uvn1) source of voltage is connected in series between the first AC terminal (6) and the second DC terminal (5). Each of voltage sources comprises at least the first and second submodules (15), connected in series, besides, each submodule (15) comprises at least two electronic power switches (16), connected in parallel with at least one capacitor (17). The control system comprises a central control unit (19) and at least two subunits (20), besides, the central control unit (19) sends to each subunit (20) the reference AC voltage (ua_ref) and the bearing signal (s_sw) of switching, and each subunit (20) controls switching of electronic power switches (16) of one of submodules (15) according to a WPM template so that each time, whenever the bearing signal (s_sw) of switching crosses the reference AC voltage (ua_ref), to output terminals (26, 27) of the appropriate submodule (15) either voltage on the capacitor (17) arrives, or zero voltage.

EFFECT: minimised volume of data sent by a central control unit.

14 cl, 8 dwg

FIELD: electricity.

SUBSTANCE: twenty-four-pulse converter comprises two three-phase transformers, coils of secondary windings of all phases in which have taps from the half of turns and are connected into one circuit in the form of a "dodecadron", voltage, between tops of which a twelve-phase system of voltages is created, and valves are connected into two groups - anode and cathode. In the anode group of valves the anodes are connected into one unit representing a single pole at the DC side, and in the cathode group of valves the cathodes are connected into a different unit, representing another pole on the DC side. Each valve of the anode group by its cathode is connected to one top of the "dodecadron" of secondary windings, and each valve of the cathode group by its anode is connected to the middle point of one of coils in the secondary windings of the transformer.

EFFECT: higher efficiency of a converter, reduced dimensions, weight and cost.

2 dwg

FIELD: electricity.

SUBSTANCE: rectangular voltage pulses are generated, middles of generated rectangular pulses are synchronised with phase voltages of a supply network by moments of voltages transition via zero, the actual value of the first harmonic of the phase current is measured, the value of the angle δ is calculated according to the expression where: ω - circular frequency of supply grid phase voltage; L - phase inductance of a rectifier; I1 - actual value of the first harmonic of the input phase current; U1 - actual value of phase voltage of the supply grid; U*d - relative mean value of rectifier rectified voltage, generated rectangular pulses are shifted along the phase to the lagging side by the angle δ, and then sent to control inputs of bidirectional keys of a three-phase three-level rectifier.

EFFECT: possibility to generate a permanent mean value of rectified voltage of a three-phase three-level semiconductor rectifier with a capacitance voltage divider in case of phase current value change.

3 dwg

FIELD: electricity.

SUBSTANCE: in the method to control stabilised sources of AC voltage operating in parallel for a common load in addition to operations specified in the invention formula, one of parallel operating sources is selected as master, and others - as slaves, besides, the first and second differential signals of the master source are generated by subtraction of appropriate signals proportional to d - and q - components of total voltage from reference signals for d - and q - components of total voltage, for other slave sources the first and second differential signals are generated by subtraction of signals proportional to d - and q -components of current of the slave source from a signal proportional to d - and q - components of master source current.

EFFECT: increased accuracy of specified distribution of load current between parallel operating sources proportionally to rated capacity of each source in static mode.

1 dwg

FIELD: electricity.

SUBSTANCE: in the method to control stabilised sources of AC voltage operating in parallel for a common load in addition to operations specified in the invention formula, one of parallel operating sources is selected as master, and others - as slaves, besides, the first and second differential signals of the master source are generated by subtraction of appropriate signals proportional to d - and q - components of total voltage from reference signals for d - and q - components of total voltage, for other slave sources the first and second differential signals are generated by subtraction of signals proportional to d - and q -components of current of the slave source from a signal proportional to d - and q - components of master source current.

EFFECT: increased accuracy of specified distribution of load current between parallel operating sources proportionally to rated capacity of each source in static mode.

1 dwg

FIELD: electricity.

SUBSTANCE: in the method to control stabilised sources of AC voltage operating in parallel for a common load in addition to operations specified in the invention formula, one of parallel operating sources is selected as master, and others - as slaves, besides, the first and second differential signals of the master source are generated by subtraction of appropriate signals proportional to d - and q - components of total voltage from reference signals for d - and q - components of total voltage, for other slave sources the first and second differential signals are generated by subtraction of signals proportional to d - and q -components of current of the slave source from a signal proportional to d - and q - components of master source current.

EFFECT: increased accuracy of specified distribution of load current between parallel operating sources proportionally to rated capacity of each source in static mode.

1 dwg

FIELD: electricity.

SUBSTANCE: invention relates to electric engineering, namely, to single-phase semi-bridge transistor inverters, is designed for use in electrotechnical industry and may be applied in various secondary sources of supply, for instance, in electric welding devices, charging devices, sources of current with high stabilisation of output rectified current, etc. The proposed device for this comprises an input rectifier, an output rectifier, a smoothening capacitor, a throttle, a current sensor, a high-frequency transformer and a control system, arranged on the basis of transistor keys. Terminals of connection to the load and a current sensor via a unit of galvanic isolation are connected with a unit of anticipatory correction and with a control system.

EFFECT: reduced sensitivity of an inverter to load oscillations and higher stability of an output rectified current as a result.

2 dwg

FIELD: transport.

SUBSTANCE: invention relates to water transport and aims at perfecting underwater apparatus driving self-contained means and may be used as their propulsor in surface and underwater positions. Proposed drive (dwg. 1) comprises tight housing 1 accommodating power supply 2 and motor 3. The latter has two stators 5, 6 and two rotors 7, 8 fitted on aligned shafts 9, 10. Output extensions of said shafts carry counter rotation propellers 12, 13. Housing 1 accommodates also inverter 14 with solid-state modules 15 arranged on housing inner surface. Said modules 15 are arranged so that their heat conducting elastic elements 17 seat on contact sites 18 of housing 1. Terminals 19 of motor windings are connected to modules 15. Multiphase winding 21 is fitted in grooves 20 of stator 5. Permanent magnets 23 are fitted inside rotor 7, in chambers 22. Vent vanes 25, 26 are arranged on ends of rotors 7, 8. Radial holes are made in motor housing 3.

EFFECT: higher reliability, reduced noise, increased range.

3 cl, 5 dwg

FIELD: transport.

SUBSTANCE: invention relates to ship building, particularly, to modification power generators with frequency converters and propulsion motors. Proposed power plant is available in two versions. In compliance with first version, power plant comprises propulsion diesel or turbine and main sync generators with stator windings connected to feeder switchboard, frequency converters including rectifiers and inverters with their inputs connected to main switchboard feed line and their outputs connected to propulsion motors, standby diesel generator with stator winding connected to standby switchboard feed line. Stator of every main sync generator is furnished with two or more isolated identical three-phase windings with linear voltages at proper angle. Main switchboard has three-phase feed lines, each being connected to main generator stator three-phase windings with liner voltages at proper angle. Outputs of rectifiers are connected to multilevel inverter inputs. In compliance with second version, stator of every main sync generator is furnished with two or more isolated identical three-phase windings with phase-shifted like voltages.

EFFECT: higher efficiency and reliability.

2 cl, 2 dwg

FIELD: transport.

SUBSTANCE: invention relates to ship building, particularly, to modification power generators with frequency and propulsion motors. Proposed unit comprises primary diesels or turbines and main synchronous generators with their stators connected via automatic circuit breakers to supply line of the main distribution panel, frequency converters, each made up of 12-pulse rectifier, and independent inverter. Propulsion motor is connected to output of each inverter as well as emergent diesel-generator with its stator winding being connected via automatic circuit breaker to supply line of the main distribution panel. Two identical three-phase windings with linear voltages shifted through 30 electrical degrees are arranged on stator of each main generator. Main distribution panel has two three-phase supply lines whereto connected are via automatic circuit breakers the main generator stator three-phase windings with linear voltages across them feature phase coincidence. Inputs of propulsion motor frequency inverter 12-pulse rectifiers are connected via automatic circuit breakers to two three-phase supply lines of the main distribution panel. First line transformer winding is star-connected while secondary of second supply line transformer is delta-connected.

EFFECT: higher efficiency, lower costs, weight and overall dimensions.

1 dwg

FIELD: power engineering.

SUBSTANCE: self-propelled marine vessel comprises body, propeller, electric motor. Along vessel sides, in its submersible part, there is a plateau arranged with electrodes isolated from each other and from vessel body. Electrodes are connected to each other serially and in parallel and form galvanic elements under action of sea water, which are joined with electric motor, providing for vessel motion. In process of vessel motion electrodes are depolarised.

EFFECT: invention provides for motion of vessel due to transformation of sea energy into energy of vessel motion.

5 dwg

FIELD: transport.

SUBSTANCE: proposed boat has flow passage passing through the boar hull. The latter accommodates motor and storage battery, motor control units and propeller screw arranged at least partially, in aforesaid flow passage. Note here that the storage battery are arranged in waterproof casing to be in heat conducting contact with the casing in certain sections. Aforesaid motor represents an inner-rotor motor. Stator is in heat conducting contact, via heat conducting assembly, with the motor receiving housing. Note here that aforesaid receiving housing, partially coupled with heat conducting assembly, consists of heat conducting material and is partially located in aforesaid flow passage.

EFFECT: higher efficiency.

19 cl, 2 dwg

FIELD: transport.

SUBSTANCE: ferry designed for forward-drive vehicle represents catamaran with its floats interconnected by beams and furnished with guiding cargo paths with gangway boards. Every device of kinematic linkage between driving wheel drive and water propeller comprises flange mounted at the vehicle drive wheel seat to transmit rotation via flexible linkage to propeller shaft. The said shaft is linked up with angle drive to drive the aforesaid water propeller. There is bearing support moving crosswise on bearing beams with their ends attached to the floats. Support assemblies are fitted to move crosswise on bearings beams with their ends attached to the floats to move lengthwise.

EFFECT: pontoon-catamaran with simple and reliable fastening of vehicle, higher efficiency of transmitting rotation from driving wheels to water propeller, reduced total weight.

6 cl, 8 dwg

FIELD: transport.

SUBSTANCE: invention refers to the sphere of transport, namely to diesel-electric ships. This method of acceleration and braking of diesel-electric ship during its unearthing - approach to the pier with power supply from coastal network consists in the following: before ship gathers its way during its unearthing from the pier, electricity is transmitted into ship network from coastal network provided with extensive section of contact current distributor, by means of pressing against it a moveable current collector of the ship. Propelling motor of the ship, connected with its propeller screw, should be turned on, working from ship network, connected at the moment with coastal network, at the forward running. Then its speed should be enhanced for acceleration of the ship. When ship is approaching to the pier, the propelling motor is stopped or the frequency of its rotation is reduced. After that, backward running is switched on and that leads to ship braking. Current collector of the ship is used in the form of moveable gear located above the ship, which contacts with coastal current distributor. It is placed above the water surface and given the limited extent above the water. Contacting is short-term - when ship is situated near the pier. During ship unearthing, power is transmitted into ship network by upward moving and pressing the current collector against the coastal current distributor for unearthing and acceleration of the ship. Thereafter, when the length of the limited coastal current distributor comes to an end, ship network should be disconnected from coastal network with the simultaneous switching to the ship source of electrical power. Then the moveable current collector is descended. After the propelling motor is stopped or the frequency of its rotation is reduced during the ship approaching to the pier, moveable current collector is lifted and when the gear is located under the terminal section of the coastal network current distributor, it is pressed against the area of the current distributor. Ship network is simultaneously switched to coastal network. Propelling motor is switched then to "backward running" for ship braking.

EFFECT: cheap of use; enhancement of reliability; expansion of the area of diesel-electric ships' usage.

3 cl, 2 dwg

FIELD: electrical engineering; propeller drives of surface ships in module including the propulsion plant which may be turned relative to ship's hull.

SUBSTANCE: stopping the electric motor included in propulsion plant is based on shorting the electric motor with permanent magnets. As a result, electric motor speed is reduced and/or limited without separate mechanical stopping unit.

EFFECT: enhanced reliability and economical efficiency of stopping system.

22 cl, 9 dwg

FIELD: water transport; shipbuilding; construction of multi-functional transportation and transfer complexes; development of smaller rivers; delivery of cargoes to hard-to-get-at regions.

SUBSTANCE: proposed complex includes ship equipped with propulsive and steering complex operated by hydraulic drive, ramp, mooring gear and ground tackle and ground self-propelled machine provided with attached equipment and hydraulic system. Hydraulic system is used for transmission of energy to propulsive and steering complex, to ramp hydraulic cylinders, to mooring gear and ground tackle. This machine operates ashore. It is provided with unit for securing it for sea on board ship. In this case it is used as power generating set, ship's control station and shipboard cargo handling facility.

EFFECT: enhanced efficiency of complex; possibility of performing many functions.

5 dwg

FIELD: shipbuilding; construction of propulsive and/or steering complexes at least partially surrounded by water.

SUBSTANCE: proposed complex is provided with electric motor located in hermetic chamber formed by joints of complex and propeller shaft connected with electric motor. Propeller is mounted outside hermetic chamber. Complex is provided with units for building-up increased pressure in hermetic chamber by means of air or another filling medium whose conductivity increases with increase of pressure in chamber. This pressure may exceed pressure of water in compartment located under pressure. Method of control of fluid flows consists in sealing-up the chamber relative to pressure of surrounding medium and relative to other compartments of ship; pressure in chamber and composition of medium discharged from chamber under action of pressure built-up inside it are subjected to tracking. Heat conductivity of gaseous medium in chamber is increased by building-up increased pressure and removal of heat generated by electric motor which is in direct contact with chamber walls; then, heat is transferred directly to surrounding medium through chamber walls.

EFFECT: improved operational characteristics of propulsive complex.

21 cl, 1 dwg

FIELD: transport.

SUBSTANCE: invention relates to railway transport, particularly, to means of adjusting excitation current in electric transmission of diesel locomotive with self-contained heat engine, AC traction generator operated in diesel locomotive electric braking mode. Proposed method consists in setting heat engine rpm, exciting traction generator to be connected to circuit composed of braking motor excitation windings connected in series and to be loaded by three-phase bridge-type uncontrolled rectifier to excite braking traction motors. Motors rpm is measure, motor armature current is measured to be compared with setting to feed the comparison result to input of controlled supply rectifier so that excitation current may be adjusted. Results of said comparison are used to vary the structure of control system of traction generator excitation winding supply controlled bridge-type rectifier built around the thyristor.

EFFECT: higher reliability and stability of operation.

3 dwg

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