Asynchronous motor with excluded idling
SUBSTANCE: to device consisting of three-phase cage asynchronous motor, thyristor regulator for the purpose of reduced power consumption at idling by means of automatic transfer of the device to pulse mode in circuit of each stator phase downstream thyristors there are three in-series inductance coils and additional three capacitors coupled in parallel to stator windings of the caged asynchronous motor.
EFFECT: reduced power consumption at idling.
The unit refers to the electromechanics.
It is known Device for welding" RF patent No. 2032506, IPC B23K 9/00 from 10.04.95,, - , consisting of a welding transformer, thyristor regulator circuit of the primary winding and capacitor, connected in parallel to the secondary winding. The device provides low power consumption in idle mode by placing the device in burst mode, but to use this schematic for asynchronous motor with squirrel-cage winding is not possible due to the fact that the induction motor secondary winding (rotor winding) is always closed, even in idle mode.
Closest to the proposed is "Thyristor voltage Converter for speed control of induction motor" in patent RF №2115213, IPC NM 5/00 from 10.07.1998, - , consisting of three-phase asynchronous motor with squirrel-cage rotor and the thyristor regulator in the circuit of the stator winding. The disadvantage of this device is a significant power consumption in idle mode.
The proposed device (see Fig.1) consists of three-phase asynchronous motor with squirrel-cage rotor, the thyristor regulator in the circuit of the stator winding, three additional inductances in series in the circuit to the each phase of the stator after the thyristor regulator and three capacitors, connected in parallel to the windings of the stator of an induction motor.
The essence of the proposed technical solution is that the induction motor is excluded from the idling mode, consisting of three-phase asynchronous motor with squirrel-cage rotor, the thyristor regulator in the circuit of the stator winding, is additionally connected in series in the circuit of each phase of the stator after the thyristor regulator three inductors and three capacitors connected in parallel stator windings of an induction motor, thanks also includes the inductances and capacitors in idle mode automatically switches to burst mode, which ensures lower energy consumption.
The claimed invention solves the problem of reducing power consumption in the idle mode by the automatic transfer device in a pulsed mode at idle.
When the device is in the mode of start-up and operation under load (load creates a working mechanism) additional inductance and capacitance has no impact. The device will work as normal thyristor regulation.
When switching to idle mode (working mechanism ceased to create a braking torque on the motor shaft) reduced current consumption and affecting effects the additional inductances and capacitances on the operation of the thyristors. The control circuit of thyristor delivers a short pulse to the control electrodes of all of the SCRs at the same time. Open the thyristors to which is applied a positive voltage. The voltage applied to the motor windings. This starts a charge capacitors through additional inductance L. As is well known from theory of transients (the inclusion of the L-C circuit under voltage), the capacitor during the transition process is charged to a dual instantaneous value of the mains voltage. With the end of the charge current flowing through the thyristor, will cease, and it will close. The current drawn by the motor will be small, because the engine runs without load and insufficient to hold the thyristor in an open state. After the charge of the capacitor should discharge to the motor winding. Moreover, the capacitor voltage is directed oppositely to the network voltage exceeds the voltage in 2 times (due to the transition process). Therefore, for a considerable period of time until the voltage on the capacitor is compared with the network voltage, the thyristor will be applied reverse voltage necessary for reliable locking of the thyristor.
Thus, in the idle mode, the thyristors will be opened only for a very short period of time and then Bud is t closed by the reverse discharge voltage. As a result, the windings of the motor are only short voltage pulses with duration of ~300 µs, sufficient to maintain the engine speed at idle. The motor continues to rotate and the power consumption is significantly reduced compared to the normal idling mode.
When load or slowing down the rotation of the motor increases, the current drawn by the motor. Decreases the resistance of the motor winding, shunt capacitors. The result is reduced and the charging voltage of the capacitor. The capacitor voltage can not reach the level of the network. The thyristors will not be closed. The device will work as normal thyristor regulation.
The inventive device for welding meets the requirement of "novelty", as it has new features:
1) three additional inductance, connected in series in the circuit of each phase of the stator after thyristors;
2) three capacitor, connected in parallel to the windings of the stator of an induction motor.
The current level of technology and technical literature known asynchronous motors, with the inductance in the circuit of the stator and capacitors, connected in parallel to the windings of the stator of an induction motor. But the use of this combination of features allows you to get a new quality is the equip - low power consumption at idle by moving in a pulsed mode. This allows to conclude that the criterion of "inventive step".
The technical result of the proposed solutions - automatically reduce power consumption when switching to the idle mode by the automatic transfer device mode in pulse mode. The technical result is achieved that the device adds three additional inductance, connected in series in the circuit of each phase of the stator after thyristors and three capacitor, connected in parallel to the windings of the stator of an induction motor. Additional inductance and capacitance affect transients when switching the thyristors so that at low load (low current consumption of the engine is in the idling mode) release reverse voltage when turning on the thyristor leads to its locking and result in operation of the device in a pulse mode that conserves energy. With increasing motor load current increases, reduced the amplitude and duration of the reverse discharge voltage and the thyristor controller automatically switches to the mode of thyristor control.
The tests were conducted in a laboratory setting with three-phase asynchronous motor A B4 BONDS with nominal is through the power of 1.5 kW, rated speed 1400 rpm, rated voltage 380 Century Antiparallel thyristors had mark T 142-80. To control the thyristors used a well-known scheme (Equipment for arc welding: a reference Handbook / edited by centuries Smirnova. HP: Energoatomizdat.Leningrad branch, 1986. -656 with: ill.) - , pp. 393-397. A requirement for the control circuit is the short duration pulses, triggering thyristors, which is achieved by use of a pulse transformer, for generating control signals. If this condition is not met, the implementation of the pulse mode will not be possible. Additional inductance represented air coil, wound with insulated wire. The inductance of each coil was 0.1 MT. Additional capacitors type MGC-1 had a capacity of 4 µf, rated voltage 500 C. In a pulsed mode, the pulse amplitude was reached 400 V, and the duration is 2 MS.
A decrease in the inductance L or the capacitance C can cause the parameters of the pulses will not be enough to sustain rotation at idle, it will cause slowing of the rotation of the engine, the increase in the current consumption and, as a result, the transition from pulse mode to the normal thyristor regulation.
Idling losses in pulsed mode with the left 15...25 W, instead of 60...80 watts in normal idle mode.
The tests allow us to conclude on the compliance of the claimed invention, the criterion of "industrial applicability".
Sources of information
1. RF patent №2032506, IPC B23K 9/00, "Device for welding", authors: Gukov Century, Gukov, S. C., bull. No. 10 from 10.04.95,
2. RF patent №2115213, IPC NM 5/00 "Thyristor voltage Converter for speed control of induction motor", authors: Gladyshev, S. P., A. Bakin, A., Gladyshev P.F., published 10.07.1998,
3. Equipment for arc welding: a reference Handbook / edited by centuries Smirnova. - L.: Energoatomizdat. Leningrad branch, 1986. - 656 S.: ill.
Induction motor with excluded idling mode, consisting of three-phase asynchronous motor with squirrel-cage rotor, the thyristor regulator in the circuit of the stator winding, characterized in that in the circuit of each phase of the stator sequentially after the thyristor regulator included three inductance and parallel to the windings of the stator of an induction motor is connected with the three capacitor, with the added inductance and capacitors in idle mode automatically put the device in a pulsed mode.
SUBSTANCE: invention relates to electric engineering and may be used in ac converter-fed electric drive of stand-alone objects. The electric drive of stand-alone object with AC current-fed motor includes the rotor position transmitter, stand-alone voltage inverter, speed regulator, trigonometric converters. Current regulator outputs as projected to axis q and current regulator as projected to axis d are connected to the calculator, and calculator output is connected to the control input of the stand-alone voltage inverter that is connected with windings of the AC current-fed device via current feedback, speed feedback and flow feedback as projected to axis d.
EFFECT: power efficiency increasing due to optimisation under start-up mode and use of regenerative braking mode.
SUBSTANCE: inverter installation includes basically an inverter (3), a component (12, 26, 27) for rotation rate detection and a control component (9). The inverter (3) comprises plurality of pairs of switching elements (Q1-Q6). The control component (9) controls on-off state of the switching elements (Q1-Q6) to convert direct current from the direct-current power source (1) to alternating current performing the first and second controls in sequence when rotation rate of the engine (4) coupled to the switching elements is more than the specified rotation rate. The first control switches on the switching elements (Q1, Q3, Q5), which are connected directly to the positive electrode of the power supply source and switches off the switching elements (Q2, Q4, Q6), which are connected directly to the negative electrode of the power supply source. The second control switches on the switching elements (Q2, Q4, Q6), which are connected directly to the negative electrode and switches off the switching elements (Q1, Q3, Q5), which are connected directly to the positive electrode.
EFFECT: increased service life of the switching elements.
11 cl, 7 dwg
FIELD: engines and pumps.
SUBSTANCE: group of inventions relates to the method and device of digital processing of signals from a pulse sensor of rotor movement in an electric motor-encoder, which may be used in an electric drive, in particular, a thrust electric drive of vehicles of different type and purpose. To process information about angular position of the rotor, an observer is used to observe mechanical variables of electric drive condition and a predictor, for functioning of which they previously before start of electric drive operation they set initial values of angular position of the electric motor rotor equal to zero, as well as values of angular speed of rotor rotation and load moment on the electric motor shaft, and an initial correcting signal of the predictor. During each cycle of calculations they produce a measured value of the angular position of the rotor, calculate the preliminary value of the correcting signal of the predictor. Further they produce the value of the correcting signal of the predictor and determine the value of the angular position of the rotor predicted for the start of the next cycle of calculations.
EFFECT: increased accuracy of assessment of angular position and angular speed of electric motor rotor rotation, which makes it possible to considerably improve characteristics of a drive control system.
3 cl, 2 dwg
SUBSTANCE: invention is attributed to the field of electric engineering and may be used for electric motor start-up. Start-up method for the electric motor (100) with a rotor includes the following stages: rotor rotation in the first direction by means of the first torque, at that maximum value of the first torque does not exceed maximum value of torque counteracting the rotor rotation so that the rotor is braked in the first idle position; rotation of the rotor in the first idle position in the second direction opposite the first one until the rotor is braked in the present second idle position and start-up of rotation for the rotor in the second idle position in the first direction of rotation.
EFFECT: improving reliability of the electric motor when mo data are available about the initial rotor position.
17 cl, 5 dwg
SUBSTANCE: invention is related to the area of electric engineering and may be used for electromagnetic torque control of alternating-current two-phase squirrel-cage induction motor. Excitation winding of the squirrel-cage motor is coupled to the alternating-current power supply in series connected through a compensating load unit, which, in its turn is connected in parallel with a switching unit. Input of the switching unit is coupled to output of the amplification coefficient control device, which is coupled to the first input of the amplifier with controlled amplification coefficient. Input of the amplification coefficient control device and the second input of the amplifier with controlled amplification coefficient are coupled to the voltage control source and output of the amplifier with controlled amplification coefficient is coupled to input of the power amplifier, which is connected in parallel to the control winding.
EFFECT: improved efficiency factor, reduced heat generation in the motor windings due to introduction of the operation mode with reduced electromagnetic torque.
SUBSTANCE: invention relates to electrical engineering and can be used in electric drive for mine winders. The device comprises a wound rotor induction motor, the main contactor with normally opened contacts and normally closed block contact, a dynamic braking contactor with normally opened contacts, an accelerating resistor, a semi-controlled three-phase rectifier and thyristors with current-limiting resistors, a resistor in excitation circuit, shunt, a thyristor switch, stabilitron and optron.
EFFECT: reduction of path to be passed by a vehicle in case of emergency shutdown of the mine winder, increase of the period between repairs for brake shoes and resultant improvement of the mine winder efficiency.
SUBSTANCE: invention is related to the area of electric engineering and may be used to convert alternating voltage or current to alternating voltage or current without intermediate conversion to direct voltage or current. Technical result lies in provision of arbitrary and continuous control of current passage from input phase leads to output phase leads of the direct converter. The direct converter (1) is equipped with n input phase leads (U1, V1, W1) and p output phase leads (U2, V2, W2), where n≥2 and p≥2, n·p double-pole switching elements (2) for connecting of at least one positive and at least one negative voltage between poles. Each output phase lead (U2, V2, W2) is connected in series with each input phase lead (U1, V1, W1) through one switching element (2).
EFFECT: in order to provide arbitrary and continuous control of current passage from input phase leads to output phase leads of the direct converter and exchange electrical energy between double-pole switching elements at least one inductance coil (3) is included to each serial connection.
20 cl, 16 dwg
SUBSTANCE: invention relates to electrical engineering and can be used in AC drives. The system and method for AC motor drive control comprises a control system with programmed energy saving algorithm in which the operation of the electric motor drive is optimised. The control system provides the drive with an initial command "voltage-frequency" on the basis of the initial characteristic voltage/frequency (V/Hz), in real time it receives the drive's output data generated in accordance with the initial command "voltage-frequency" and sends back a variety of changed commands "voltage-frequency". Each command out of the variety of changed commands "voltage-frequency" contains a deviation from the initial characteristic "V/Hz". In real time the control system also defines the value of electric motor parameter corresponding to each command of the said variety of changed commands "voltage-frequency" and sends a changed command "voltage-frequency" back to the AC electric motor drive so that the indicated value of the electric motor parameter defined on a real time basis falls within the range of permissible values for the electric motor parameter.
EFFECT: minimisation of input power of an electric motor and provision for additional energy saving at keeping the stable operation of the electric motor.
11 cl, 10 dwg
SUBSTANCE: invention is related to electric engineering, in particular, to variable alternating current electric drives. An AC electric drive comprising an induction motor with a phase rotor and an inverter with PWM current controller, two stator current sensors, a speed sensor set on the motor's shaft, a calculating unit for the setup of the motor torque, a calculating unit for the setup of stator current, a setup unit for stator phase currents, a setup unit for stator field rotation speed, is equipped by a correction unit for the motor torque setup including additional rotor current sensors and a unit for calculation operations which generates a correction signal for the motor torque setup in the function of the parameter defined in simpler way - tangent of angle between the vectors of stator currents and of magnetising current calculated on the basis of the measured phase currents of the motor stator and rotor. Inverter generates stator phase currents with amplitude and frequency required to generate the specified torque value provided that stator current consumption from the network is minimised. The electric drive is fitted by the correction system with actual measured variables thus simplifying the algorithm for correction signal calculation and bating requirements to the process controller.
EFFECT: reduction of stator current that ensures the specified motor torque, simplification and improved operability of the device.
FIELD: motor vehicle industry.
SUBSTANCE: electric vehicle having an electric motor (1) as its power source comprises a module (91) of F/F-calculation or operation, a module (92) of F/B-calculation or operation, an adder (97), modules (93, 95) of the model definition and modules (94, 96) of switching the values of the target torque. The module (91) of F/F-calculating calculates the value (Tm*1) of the first target torque by F/F-operation. The module (92) F/B-calculating calculates the value (Tm*2) of the second target torque by F/B-operation using the model (GP(s)). The adder (97) adds the value (Tm*1) of the first target torque and the value (Tm*2) of the second target torque to obtain a value (Tm) of the torque command of the motor. The modules (93, 95) of the model definition evaluate whether the interruption in the transmission of torque to the drive shafts (4) occurs or not. The modules (94, 96) of switching the values of the target torque stop F/F- and F/B-operations, when the interruption of transmission of the torque is confirmed.
EFFECT: suppression or damping of unexpected vibrations or impact shocks during the interruption in the transmission of torque.
10 cl, 9 dwg
SUBSTANCE: in a proposed design of an electric machine comprising a stator and a rotor arranged outside the stator, bearing supports perceiving vertical and horizontal loads, and an electromagnet reducing the load at bearing supports. At the same time, according to this invention, the specified electromagnet is placed inside the stator.
EFFECT: improved power characteristics of an electric machine, its improved weight and dimension characteristics, higher reliability and seismic resistance, significant savings of structural materials.
7 cl, 10 dwg
FIELD: electrical engineering.
SUBSTANCE: in proposed asynchronous controlled machine, apart from the main magnetic conductors of rotor and stator, the first additional magnetic conductor of stator and rotor are installed from separate ring packets with AC windings, and also the second additional magnetic conductor of rotor with induction winding. Opposite cylindrical sides of packets are closed with magnetic conductor. Toroidal AC windings are placed between adjacent ring packets of magnetic conductors. Rotor windings of the main and first additional magnetic conductors are connected to each other, and winding of the main magnetic conductor stator is equipped with unit of frequency converter and is connected to stator winding of the second additional magnetic conductor. Besides input terminals are installed on toroidal windings of the first additional magnetic conductor stator.
EFFECT: substantial improvement of energy properties of proposed asynchronous controlled machine.
SUBSTANCE: present invention relates to electrical engineering and electric machine building, particularly to controlled alternating current electric machines. On the stator and rotor of the asynchronous electric machine there are extra magnetic conductors, made from separate circular packets with alternating current toroid windings between adjacent packets, matching up on the stator bore of the magnetic conductor through a circular air gap. Input terminals are fitted on the toroid windings of the stator. Opposite cylindrical sides of the packets of magnetic conductors are provided with extra closing magnetic conductors. The stator winding of the main magnetic conductor is provided with a block of controlled resistors and controlled direct current source. Between the units of the stator and rotor of the extra magnetic conductor, there is no torque and rotational emf. The frequency of rotation of the rotor has no effect on the electromagnetic field in the circular air gap. Therefore, exchange of electrical energy between windings of the stator and rotor of the extra magnetic conductor takes place through transformer coupling. The torque of the electric machine in the given range of frequency of rotation is controlled by varying resistance of the stator circuit. The machine switches into synchronous mode of operation by supplying direct current to the stator winding of the main magnetic conductor when subsynchronous frequency of rotation is attained.
EFFECT: wider range of regulating frequency of rotation, improved starting characteristics and increased power coefficient of the asynchronous electric machine in nominal conditions.
FIELD: electrical engineering; submersible electric motors.
SUBSTANCE: proposed submersible electric motor has barrel-shaped stator incorporating press-fitted magnetic core, extended three-phase winding, head, rotor disposed inside stator barrel, shaft passed through head, thrust bearing assembly, and current lead-in assembly connected to stator winding. Head is provided with duct to receive case of telemetering unit incorporating pressure, temperature, and vibration transducers, processor, power amplifier, dc voltage supply, and interface. Pressure transducer has series-connected strain sensor, pressure-transducer voltage amplifier, and pressure-transducer analog-to-digital converter. Temperature transducer has series-connected temperature-transducer sensing element, temperature-transducer voltage amplifier, and temperature-transducer analog-to-digital converter. Interface output is connected to input of dc voltage supply whose first output is connected to power amplifier, second one, to pressure strain sensor, and third output, to voltage amplifiers and analog-to-digital converters of pressure and temperature transducers, temperature-transducer sensing element, vibration transducer, and processor that affords analysis of information arriving from above-mentioned transducers, computation, coding, and data transfer to control station. Power amplifier output is connected to control device input. Analog-to-digital converter of pressure transducer is built in processor. Analog-to-digital converter of temperature transducer is connected to processor. Two outputs of vibration transducer are connected to two inputs of processor whose output is connected through power amplifier to interface input; interface output is connected to current lead-in assembly.
EFFECT: improved design.
1 cl, 2 dwg
FIELD: engines and pumps.
SUBSTANCE: invention relates to a squirrel-cage rotor for an induction machine and to a method of its fabrication. The squirrel-cage rotor comprises a rotor core 1 of sheets, short-circuited rods 2 arranged inside the said core 1 and short-circuited rings 3 abutting on the said core 1 to electrically interconnect the said rods 2 at the rotor core end sides. For better heat removal, heat pipes 4 are fitted axially in the said rotor core 1 to extend therefore at end sides and to fit in the short-circuited rings 3.
EFFECT: better heat removal from the squirrel-cage rotor of the induction motor.
14 cl, 8 dwg