Control method of frequency-assisted electric drive |
|
IPC classes for russian patent Control method of frequency-assisted electric drive (RU 2496219):
 Controller for load start-up system / 2496218
Controller for load start-up system, which includes converter for changing output voltage of direct current power supply source, inverter for conversion of direct current voltage supplied from converter to three-phase alternating current voltage that is supplied to load, and smoothing capacitor connected parallel between converter and inverter, includes controller of inverter for pulse-width modulation (PWM) control of inverter with two-phase modulation and controller of converter for PWM control of converter. Frequencies of carrier signal of inverter, which is used in controller of inverter, and carrier signal of converter, which is used in controller of converter, are the same. And when the point of time, to which input electric current to inverter is generated, which corresponds to carrier signal of inverter, is diverted for the specified period of time, phase difference between carrier signal of inverter and carrier signal of converter is offset by the value equal to the specified period.
 Electric machine and vehicle power system / 2494524
Electric machine comprises a vessel, where stator windings are installed in close proximity to the rotor. There is also a circuit comprising transistors and diodes and connected to the specified windings. A switching circuit is included into a current inverter, which also comprises a pair of inductors installed on power supply buses, and switching capacitors. The current inverter as well as the windings is inside the vessel. A vehicle power system comprises a source of continuous power connected to electric machines by means of integrated electric drives. Each of electric drives comprises at least three windings installed in close proximity to rotors of engines associated with these electric drives. The switching circuit of the accumulating circuit electrically connected to each winding is in closed condition for rotation of the rotors or in opened condition for supply of energy into a local power accumulator.
 Linear asynchronous electric drive / 2494522
Linear asynchronous electric drive comprises an inductor 1, comprising a core, on teeth 2 of which there are winding coils 3, and an electroconductive anchor 4. In each upper part of teeth there are two screening turns 5, outputs of which are connected to contacts of sealed-contact relays 6, coils of which are connected with a switching device. The switching device provides for the possibility of simultaneous closure of at least four screening turns, placed on four adjacent teeth of the inductor, which form the initial row. In first two teeth the turns that screen their right parts are closed, and in the third and fourth teeth the turns are closed, which screen their left parts. To start a pitch of the electroconductive anchor, the switching device opens a turn that screens the left part of the fourth tooth, and to complete the pitch - it opens a turn that screens the right part of the first tooth, closes turns that screen the right parts of the second and third teeth, and a turn screening the left part of the fifth tooth. To fix the electroconductive anchor, after the pitch the switching device opens turns that screen the third and the fourth teeth, and disconnects winding coils arranged on these teeth from the source of voltage.
 Electric drive of reciprocating action for impulse vibration source / 2491709
Electric drive is made as a non-linear electromagnetic motor with body made of sections mounted at diamagnetic pin guide; out of these two joining sections that contain power windings one section is connected to the support while the other one is connected to intermediate sections equipped with pin position proximity sensors; at that the diamagnetic pin guide is fixed in an intermediate section of the body connected to the section of a holding electromagnet made as a sucking coil with poles.
 Device for power supply of long stator winding with several sections / 2491695
Device for power supply of a long stator winding (1) with several sections (2) contains a power supply source, a power line (6) connected to the power supply source, switches (3) of sections related to the power line (6) and having an output for connection with respective winding section used for compensation of reactive power notwithstanding power control and device for reactive power compensation in which impedance of the device can be set.
 Control unit for ac rotating machine / 2491692
In control unit for alternating-current rotating machine with function of current limitation in order to protect AC rotating machine and excitation module, for example, of the inverter from current overload the frequency correction arithmetic device has an element for amplification coefficient computation based on electric permanent values related to AC rotating machine and an amplifier to calculate arithmetic value of frequency correction based on amplification coefficient computed by the element for amplification coefficient computation and current of AC rotating machine, at that an arithmetic value of frequency correction is output as frequency correction value within the preset mode of rotation for AC rotating machine.
 Converter of frequency with explicit dc link / 2490778
Frequency converter with explicit DC ling contains a three-phase voltage inverter, a smoothing capacitor, LC-filter, active front end with fully-controllable single-phase semiconductor bridge based on IGBT-modules with integrated free-wheeling diodes, a reactor. Four auxiliary diodes are introduced into the active front end and the reactor consists of two identical reactors. Two additional windings are installed at the magnetic core of each reactor. Auxiliary diodes and windings of the reactors are connected as specified in the application materials.
 Direct current electric drive for controlling object with elastic coupling / 2489797
Device has a power converter, a current sensor connected to a dc motor, a first speed sensor, kinematic viscoelastic transmission, an actuating mechanism, a second speed sensor, a nonlinear element, a speed controller and a current controller. The electric drive includes an integrator, comparison elements from the third to the twelfth and inertialess units from the first to the eleventh.
 Method of distributing power in multilevel frequency converter for powering synchronous and asynchronous motors / 2489791
In the method of distributing power in a multilevel converter, output voltage is obtained using output inverter-recuperation units, each having two single-phase bridges and a buffer capacitor, connected so as to form three groups that are connected into a star, the leads of which are connected to an output filter. Power is distributed between all inverter-recuperation units of the multilevel frequency converter at high frequency through a single high-voltage power unit made as described in the claim, which is controlled by a single frequency-setting signal and through which, by mutual power exchange, there is automatic levelling of voltage on the buffer capacitors of the input and output inverter-recuperation units similar to linked vessels with a liquid.
 Controlled electric drive with advanced reliability performance / 2488216
In controlled electric drive there are six semiconductor switches (transistors) connected to the supply DC mains and stator windings of a non-standard three-phase six-wound asynchronous motor having three identical pairs of stator windings. Collectors of transistors are connected to stator windings of the non-standard three-phase six-wound asynchronous motor, at that collectors of odd transistors are connected to inputs of stator windings of the non-standard three-phase six-wound asynchronous motor while collectors of even transistors are connected to outputs. Emitters of the transistors are united in a common point and connected to negative side of the supply DC mains. Outputs of odd transistors and inputs of even transistors of the non-standard three-phase six-wound asynchronous motor are connected to positive side of the supply DC mains. Transistors are controlled so that half-wave sine voltage is delivered to respective stator windings.
 Thyristor device for smooth start of hv synchronous electric motor by underfrequency relay (versions) / 2455747
According to the first version, the thyristor device for smooth start of a HV synchronous electric motor by the underfrequency relay contains a dependent frequency converter consisting of a thyristor rectifier, a thyristor inverter, a smoothing choke, a transistor inverter, a transistor inverter with a control unit and a filter capacitor at the outputs, a voltage stabiliser paralleled to the filter capacitor, commutation apparatus connecting the corresponding input and output clamps of the thyristor and the transistor inverter by means of power contacts. According to the second version, the device contains all the elements as per the first version and, additionally, a unit setting the intensity of connection with the transistor inverter control unit and the voltage controller.
 Method of ac motor soft start / 2422977
In method of AC motor soft start, the motor is connected to a frequency converter, frequency start of the electric motor is carried out until the previously specified value of the frequency converter output voltage, which is less than the rated value of the electric motor supply frequency, afterwards the electric motor is disconnected from the specified frequency converter and is connected directly to the power supply network.
 Frequency-adjusted electric drive / 2282299
In frequency-adjusted electric drive, containing force transformer with at least four three-phased secondary windings, group of rectifier-inverter frequency transformers and driving electric engine with 2P number of poles, connected serially, in accordance to invention, winding of driving electric engine is made of 2P identical coil groups, each one of which is connected to separate three-phased rectifier-inverter frequency transformer, each one of which in its turn is connected to appropriate secondary windings of force transformer with transformation coefficient, equal to 2P.
 Method and device for quasi-frequency stepless start of synchronous motor / 2277289
Proposed method and device that can be used, for instance, in gas industry for starting electric drives of gas-transfer units involve connection of excitation unit to field winding, determination of pre-start rotor position relative to stator windings, measurement of voltage across stator windings, current through stator windings, supply voltage and field winding current, evaluation of motor speed by electromotive force induced in stator windings and estimated by voltage across stator windings and current through stator windings, current pulse supply to stator windings with aid of thyristor voltage regulator by sending control signals to control outputs of mentioned voltage-regulator thyristors, regulation of parameter of current pulses supplied to stator windings and field current so that mean torque of machine were higher than motor moment of resistance.
 Method of overexcitation of synchronous hysteresis motor by anchor reaction / 2465713
Invention may be used to overexcite a rotor of a synchronous hysteresis motor (HM). In the method of overexcitation of the synchronous hysteresis motor, overexcitation is carried out due to effect of "anchor reaction" by short-term changeover of the HM into the generator mode with connection of a capacitance load as a whole to its outlets. Current thus flowing along the HM stator windings develops a magnetic field directed in accordance with the rotor field, and additionally magnetises it. Afterwards the HM again connects to the source of power supply, having completed synchronisation of voltages, if required. At the same time, due to availability of additional magnetisation of the rotor, power consumption is reduced. Supply voltage may be reduced below the rated value with preservation of a motor torque.
 Frequency converter control method / 2462808
In frequency converter control method, when supply voltage fails, motor (7) rotates at the runout. When the network (1) is being restored, shaper (11) supplies signals to two (or three) channels (transistors) in various groups of inverter (6); current that exceeds the set point (approximately 200-300% of nominal motor current (7)) rises in two phases of motor. Under action of stator current pulse in rotor of motor there created is decaying current pulse and magnetic field that corresponds to it, which induces e.m.f. in stator windings, the frequency of which is equal to rotation frequency. Frequency of that signal is measured with unit (9) and transmitted to inverter (6) control unit (13). Repeated acceleration of electric motor (7) starts exactly from that frequency.
 Asynchronous electric motor start and stop control device / 2454784
Change of rotation speed of asynchronous motor armature consists in change of frequency and voltage supplied to stator windings; at that, voltage on stator is controlled proportionally to frequency. Device includes two pulse generators, alternating voltage rectifier, voltage comparator, voltage integrator, pulse-width modulator and in-series connected binary pulse counter, permanent storage unit, pulse shaper and voltage switching unit intended to connect working voltage to electric motor circuit.
Method of ac motor soft start / 2422977
In method of AC motor soft start, the motor is connected to a frequency converter, frequency start of the electric motor is carried out until the previously specified value of the frequency converter output voltage, which is less than the rated value of the electric motor supply frequency, afterwards the electric motor is disconnected from the specified frequency converter and is connected directly to the power supply network.
 High voltage electric drive of alternating current (versions) / 2334349
Composition of the electric drive of an alternating current includes the frequency converter, the invention can be used for the launching and control of the work of asynchronous or synchronous electric drives with the working voltage 6...10 kV and power of up to tens of mW. The high-voltage electric drive of the alternating current with the three-phase electric motor contains a source of an adjustable direct current, three-phase bridge thyristor chopper, switching devices connected to the outputs of alternating current of the inverter consistently with the phases of the three-phase winding of the electric motor, sensors of current and voltage and the control devices of the inverter and switching devices. Each switching device contains a capacitor with two outputs and the bidirectional symmetric operated semi-conductor key connected in parallel to it completely. Starting of the switching device in the electric drive is carried out in the manner as it specified in the materials of application for each of the three variants. In the electric drive for each of the variants protection of semi-conductor keys is provided at extraordinary and emergency situations.
 Phase-shifting device / 2320071
Device contains control signal source (input of phase-shifting device), adder, amplitude modulator, integrator, 2 relay elements, logical element "XOR", three logical elements "2AND", subtracting "n"-bit binary counter, input for connecting a supply of supporting voltage, generator of stable frequency impulses, adding "n"-bit binary counter, digital comparator, logical element "kAND", where n>k, mono-stable multi-vibrator, logical element "2OR", input for connecting the source of control impulses for power thyristors. Device belongs to the class of integrating systems with two digital scanning functions. One scan is independent and is generated due to generator of stable frequency impulses. The second scan is dependent, which is generated from control signal, and transformed due to impulse signal from output of voltage transformer to impulse frequency. Command for managing power thyristors is generated at the time moments when numeric values of independent and dependent scanning functions are equal or exceeded.
 Method for controlling three-phased asynchronous electric motor of down-pump and system for controlling electric motor of down-pump / 2308144
In the method for controlling the three-phased asynchronous electric motor of down- pump and in the system for controlling electric motor of down-pump in case of failure of frequency regulator or jamming of electric motor rotor, by means of mode switch, mode of direct launch from electric network is set. In that mode transfer of electric energy to electric motor occurs via chain: three-phased electric network - increasing voltage transformer - three-phased asynchronous electric motor. The control system contains a frequency control circuit and direct launch circuit, first key, connected to frequency controller and controlling feeding of power to it; input and output filters, second key, by means of which control modes are switched, third key, controlled by controller, and transformer which increased power voltage of electric motor.
|
FIELD: electricity. SUBSTANCE: according to control method of frequency-boosted electric drive in closed positions of commutators (1, 5) and disconnected commutator (7) as per signals of controller (9) there performed is engine acceleration to the frequency close to frequency of network 8. During acceleration, converter gradually increases output frequency starting from zero one. Upon completion of acceleration process of motor 6, converter 2, as a rule, is synchronised with network 6. After that, controller 9 supplies command for closure of network switch 7 and pickup of control pulses (locking) by inverter (4). When this command is being implemented, almost immediate locking of converter takes place and contacts (7) are closed just in a few milliseconds. On the motor side, converter with closed transistors represents a diode bridge, to the poles of which a capacitor is connected. Therefore, it serves as a damping chain at connection of contacts (7). Such a chain reduces possible overvoltages and vibrations occurring at connection due to non-homogeneity of closure of contacts, their rebound, disturbance of phase synchronism at synchronisation, etc. EFFECT: improving reliability. 1 dwg
The invention relates to the field of electrical engineering and is used in electric drives. The closest to the technical essence and the achieved results is /1/ a method of controlling a frequency-dispersed motorized containing induction motor associated with the network via a network switch and a frequency Converter via the starting switch, the control inputs of switches connected to the controller, the Converter is connected to the network through the input switch and provided with entrance locks pulses, consisting in dispersing the motor gradual increase in the frequency after acceleration to rated frequency translation engine power from the network. The disadvantage of this method is the relatively low reliability, because when passing from the Converter on the network device arise peaks currents and fluctuations in the mains voltage, which reduces the reliability. The aim of the invention is to improve the reliability. This goal is achieved due to the fact that after the acceleration of the motor to the rated frequency serves a command to lock the Converter and the inclusion of the network switch. The drawing shows a line diagram of the drive. To the input switch 1 is connected to the input of the rectifier 2, the pole of which is connected to the capacitor 3 and the inverter 4 tense is I, the output of which through the trigger switch 5 is connected with the motor 6, which via a network switch 7 is connected to the network 8. The rectifier 2,the condenser 3 and the inverter 4 are the frequency Converter. Converter control and switches 1, 5, 7 is provided from the microprocessor 9 (or manually). The method is implemented as follows. In the closed positions of the switches 1 and 5, and when the switch 7 on signals from the controller 9 is the acceleration of the engine to a frequency close to the frequency of the network 8. To this end, the Converter is in the process of acceleration gradually increase the output frequency starting from zero. At the end of the process of acceleration of the engine 6, the Converter 2, as a rule, is synchronized with the network 6. After that, the controller 9 sends the command to the circuit network switch 7 and the removal of impulse control (locking)of the inverter 4. During execution of this command is almost immediate locking of the Converter (for microseconds and a few milliseconds closed contacts 7. Entrance lock carries out the removal of the control pulses from the transistor and is available in all converters (for example, the circuit of the Stop button). Of the motor-side Converter with closed transistor is a diode bridge, to the poles of which are connected kondensatoren he plays the role of a damping circuit when connecting the contacts 7. This circuit reduces the potential surge and fluctuations that occur when the connection due to the non-simultaneity of contact closure, rebound, violations of correlation during synchronization, etc. After closure of the contacts 7 with a small delay contacts 5 can be opened by command of the controller 9. The source of information 1. Patent RU 2154891 C1, CL NR 1/54, 1991. The method of controlling a frequency-dispersed motorized containing induction motor associated with the network via a network switch and a frequency Converter via the starting switch, the control inputs of switches connected to the controller, the Converter is connected to the network through the input switch and provided with entrance locks pulses, and consisting in the acceleration of the motor is a gradual increase in frequency after acceleration to rated frequency translation engine powered by a network, characterized in that after the acceleration of the motor to the rated frequency serves a command to lock the Converter and the inclusion of the network switch.
|