SU692044A1 - D-c electric drive - Google Patents

Description

(54) DC ELECTRIC DRIVE

  W.  I.  The invention relates to high-speed direct-current electric drives and can be used to control electric motors of rolling mills, digging mechanisms of the Balkan type of a flat shovel and other devices in which it is necessary to realize an electric motor speed for an electric motor.  The overwhelming majority of the known control circuits for these electric motors are made with a constant rate of change of the amplitude of the current kf selected for the worst switching conditions, which leads to under utilization of the electric motors in the lungs for switching dynamic modes and an increase in dynamic loads on the mechanism at. shock stop.  E is particularly pronounced (the use of the electric motor's capabilities at the permissible speed of non-current of the current core during two-zone control.  A device for regulating a CKOpocf and a direct current electric motor is known, comprising an intensity setter, a propulsion controller of a scooter and an assembly for determining the stiffness value of adjusting characteristics, which contains a model of a control system under the control to one of the inputs of the comparison circuit, the input of which is connected to the speed sensor, and the output through the compensating link - with the input of the speed controller, and the model input is connected to the output of the intensity setter l.  .  Introduction to the circuit of the analog model of the load and the device for the formation of an additional forcing signal as a function of the velocity error or the integral of the error on scfs provides in the well-known device the force of the mode at. Won and dynamic speed errors.  However, in this device, with sufficient thyristorbogen generator exciter is possible, 6 the rate of change of the amplitude of the current is 20-30, which is dangerously large ZU - ai, which is dangerous for electric machines of conventional designs at voltages close to nominal magnetic flux , and especially when the speed of the motor is higher than the nominal one.  At the same time, the rate of change of the current amplitude of the core is perfectly safe when the motor speed is low and the nominal or forced magnetic flux a leads to under-utilization dynamically. In this mode, it is also known a device for controlling the rate of change of the current of the core, which contains a device that converts the sparking under the brushes of an electric motor into an electric signal, and devices for further processing of this signal for the purpose of controlling, for example, a comparator, a threshold switch and switching amplifier 2.   A disadvantage of this device is that the regulation of the rate of current measurement of the core current begins only after the occurrence of high arcing under the brushes t.  e.  with a lag that has a negative effect on the speed of the electric drive.  In addition, when using this device, it is possible (1Y and unreasonable reduction of operating parameters when sparking from the Whole brushes for mechanical reasons, when there are no conditions for arising yet. circular fire,; The closest to the invention of the known technical solutions is a device for two-speed speed control in a controlled transducer-motor system.  The device contains a setting device, a voltage regulator connected in series with an output signal limiter in its feedback circuit and a current controller, a field controller and sensors of a naff chevy and core current and field current, a nonlinearity unit.  The output limiter is connected via an adder and nonlinearity blocks to a voltage sensor and through the same adder to a unit not linear with the excitation current sensor of the current sensor core through an additionally introduced nonlinear block connected to the input of the excitation current regulator, but parallel to the current regulator input When the limiter is on, a sensor is connected to the input, a voltage is connected.  In the known device, the magnitude of the maximum permissible current of the electric core of the electric device is limited in accordance with the laws of commutation as a function of the excitation current and the voltage on the core.  This device is designed to optimize the control mechanisms with rel.  relatively large electromechanical time intervals, in which the high rate of current rise has almost no effect on the cycle time.  Therefore, in this device is not provided. the use of a high current rise rate possible in light-switching modes, which causes a slower response time when this device is used at small electromechanical time constants. .  The aim of the invention is to increase the speed of the electric drive and reduce the likelihood of a circular fire; collector. The goal is achieved by the fact that, in a known DC electric drive containing an electric motor with adjustable transducers in the core circuit and in the field of the excitation winding, successively included an end device, a wap regulator on the core with a signal limiter in a VHP & connection and current regulator of the core, excitation current control with a limiter connected in parallel, voltage sensor on the core, field current current connected to the cooler input of the external regulators, in which the voltage sensor on the core is connected to the input a limiter at the input of the excitation current regulator, and the current sensor core through the nonlinearity unit is connected to another input regulated and the excitation current is introduced by a voltage limiter on the collector; its output is connected to the feedback circuit of the current regulator The numerator is the maximum emf of seconds of the core, the output of which is connected to one side of the inputs of the limited end. , A scientific research institute on a collector, summing U) a supporting amplifier, one input of which is connected to a 7 voltage sensor on the junction multiplication unit, a magnetic sensor. flow to the analog frequency sensor is driven by an electric motor, while BTqpc vhol the collector voltage limiter is connected to the output of the totalized 5th proportional amplifier, the inputs of the calculator of the maximum ZDS of the core section are connected to the output of the current sensor to p, to the output of the magnetic flux sensor, to the input of the totalizer the shop of proportional amplifier and with the output of the multiplication unit, the inputs of which are connected to the output of the magnetic flux sensor and to the analog sensor of the rotational speed of the electric motor core.  In addition, the voltage limiter on the collector contains a nonlinear network with an irreversible output, a diode bridge, whose DCs are connected non-linearly and counter-output by the resistor, opposite the output of the diode, while the inputs of the diode bridge are non-linear. These inputs are the limiter voltage on the collector, the calculator maximum emf section of the core contains the first nonlinear unit, the input of which is connected to.  the output of the second nonlinearity unit, and the output to the first input of the multiplication unit, when, the inputs of both the nonlinearity units and the second input of the multiplication unit are inputs, and the output of the multiplication unit 1 OUTPUT of the calculator 1 "(the maximum emf of the corr.  With such an implementation of the device at the input of the limiter voltage on the collection; T (voltage is applied, proportional to the maximum interlamer voltage, which can be expressed in I -}) - r and.  g ti. Jjil Allch1ss g7 l 12Bs 2s.  di J (1 is the average value of the EMF in the motor winding section} 2d is the number of collector lamellae.  Chr - the number of pairs of poles; - coefficient taking into account the uneven distribution of the internal emf of an electric motor and which is a complex function of the mag- netic flow and current cor: 1 (2 {, -.  - inductance of one section - active resistance of one section; 044 2a - the number of parallel branches.  In the formula (1) the following replacement can be made: cHc G, f - 1 2p h3,. .  one .   2 - 1 51-EP17 1 (3) Then in the final: as.  and -2r. .  .  ar) MA Llax 7; With the help of a voltage limiter on the collector, the voltage on the crust is limited as a function of the maximum interlame voltage calculated by analogue preoaeting, which allows using high speeds of rise and fall of the current in the lungs during switching; performance while reducing the likelihood of circular fire on the collector.  The formation of a signal proportional to the maximum of the interlaminary voltage is provided by new connections between the known and additionally introduced elements of the proposed direct current drive.  Connecting the output of the magnetic flux sensor to one of the inputs of the multiplication unit connected by its other input to the output of the analog speed sensor core, and the output to the input of the summing proportional amplifier / connected also to the output of the voltage sensor on the core, produces a signal proportional to the Lamb, the difference and the EMF on the cortex and therefore equal to the fall of the pressure of one section. .  The connection of the first input of the calculator with the maximum emf — a cort session with the output of the current sensor corr provides at the output of the second non-linearity a signal proportional to the function f (3 j)), which takes into account the effect of the reaction to field distortion under the main ones. ; The connection of one of the inputs of the first nonlinearity block with the output of the second nonlinearity block and its other input with the output of the magnetic flux sensor provides at the output of the first nonlinearity block signal conversion, one of the cottages is proportional to the motor magnetic flux, and the other function i 3jj) into a signal proportional to the coefficient uneven internal ZDS sections of the winding of the electric motor core.  The connection of the third input of the maximum EMF calculating section, which is one of the inputs of the multiplication unit included in it, with the output of the multiplication unit, the inputs of which are connected to the output of the analog sensor, as well as the rotational speed of the motor magnet. This second stream, which is included in the calculator of the maximum emf of the core of the nonlinearity block, also includes the second nonlinearity block in its composition, which ensures the formation at the output of the last signal proportional to the maximum emf of the section.  The output connection of the calculator maximizes the emf of a section with one of the inputs of a voltage boundary across the collector, to the second input of which is a summable proportional amplifier providing a non-linearity output on the output of the collector. The voltage that is proportional to the maximum MILE voltage of the collector.  Shunting of the output of the nonlinearity block, which is part of the limiter on the collector, is performed by the resistor; switching it on to the DC outputs of the diode bridge and connecting the DC inputs to the current output and to the current controller input, the co r controls the speed of the electric motors from the maximum interlayer collector on the collector, which makes it possible to increase the speed of the electric drive while reducing the possibility of circular fire on the cellar and more fully use the engine.   The implementation of a magnetic flux sensor in the form of a nonlinearity unit, to the input of which is an input of an excitation current sensor, is necessary in the case of dual-zone motor speed control.  In the same case, the Hall sensor can be used as the mentioned one, but in especially important locations.  With single-zone regulation, a source of stable voltage should be used as a magnetic flux sensor.  The invention is illustrated in drawing, which shows a DC drive circuit.  6 48 The device contains the bark 1 of an electric motor with an adjustable converter 2 in the crustal circuit and a converter 3 in the excitation winding 4, the driver 5, the regulator 6 voltage on the core with the limiter 7 of the signal in the feedback circuit, which includes bridge circuit 8, summing amplifier 9 and non-linearity blocks 10 to 11.  The device elements also include a core current regulator 12, a field current regulator 13 with a limiter 14 connected in parallel, including a nonlinearity unit 15 and a bridge diode circuit 16, a core voltage sensor 17 connected to the input of the limiter 14, and a sensor ; 18 a core current connected to one of the inputs of the current regulator 12 core and through a nonlinearity unit 19 connected to the input of the excitation current controller 13.  A 2O voltage collector on the collector, a calculator 21 of the maximum emf of the core section, summing proportional to the amplification 22, multiplication unit 23, magnetic flux sensor 24 and analog sensor 25 are entered into the circuit.  The limiter 20 is connected by its output between the output and the input of the current regulator 12, one of the inputs is connected to the output of the amplifier 22 and the other of the inputs is connected to the output of the calculator 21.  One of the inputs of the calculator 21 is connected to the sensor 18 of the current core, its second input is connected to the output of the sensor 24 mag-i ntnnogo flow and its third input is connected to the input of the amplifier 22 and the output of the multiplication unit 23, one of the inputs of which is connected to the output of the magnetic sensor 24 flow, and the second input to the output of the sensor 25 of the frequency of rotation of the core.  Voltage collector 2O at the collector contains a nonlinearity block 26 with an irreversible output and a diode bridge circuit 27, the DC outputs which are connected oppositely with the output of block 26 and are bridged by a resistor 28, and the AC inputs of circuit 27 are output of the limiter 2O and the inputs of the block 26 are the inputs of the limiter 2O.  The calculator 21 of the maximum emf of the core section contains a multiplication unit 29 connected by one of the inputs to the output of the nonlinearity unit 30, one of the inputs of which is connected to the output of the nonlinearity unit 31.  The first input of the calculator 21 is the input of a flea 31 nonline 1cx: the second one is from the other input of the nonlinearity block 30, the third input is the second input of the multiplication unit 29, the output of which is the output of the calculator 21.  The magnetic flux sensor 24 is composed of a ks nonlinearity unit 32, to the input of which the output of the sensor 33 is connected.  Excitation current.  The DC electric drive operates as follows. With a stationary core 1, the electric motor drives the excitation current ijj across the excitation winding 4, which causes the output of the sensor33 to have some signal proportional to the excitation current i, using the nonlinearity block 32, the output signal the sensor 33 is converted at the output of the sensor 24 of the magnetic flux of an electric motor into a flux fd. The voltage at the output of the rotational speed sensor 25 with a fixed crust is zero, therefore at the output of the multiplication unit 23 a voltage proportional to the emf of the electric motor E is zero.  The voltage at the output of converter 2, and consequently, at the output of sensor 17, the voltage on the cortex is zero, which causes the absence of voltage jia at the output of block 10 of nonlinearity of limiter 7 and at the output of voltage regulator 6 to iucope.  In this case, due to the absence of current, the signal at the output of the sensor, ka 18, the current of the core is zero, the current in the excitation winding 4 is minimal and the signal at the input of the nonlinearity unit 11 is minimal.  Due to the absence of voltage at the output of multiplier 23, the signals at the output of amplifier 22 and calculator 21 are zero and limiter 20 is set at its maximum.  After the signal from the back of the device 5 arrives at the input and output of the voltage regulator 6, a small signal is generated, because the voltage at the output of the limiter 7 is low, and therefore a small voltage appears at the input of the current regulator 12, which causes a small voltage current value, cor.  In this case, the voltage at the output of the regulator 12 and the valve converter 2, and, consequently, the speed, the increase of the current in the core circuit will be due to the voltage at the output of the lim. Nichitel 7.  Under the action of this current, the measles 1 of the electric motor begins to reel and chooses play in the gears.  At the same time, the voltage at the input of the block 19: is very low, as a result of which the voltage at its output does not change and the value of the excitation current is kept to a minimum.  The EMF of the electric motor and the voltage on the bark until the end of the selection of the gaps remains small and there are practically no changes in the voltage at the output of the calculator 21 and the limiter 20.  After the choice of gaps is completed, an inevitable surge of current occurs in the electric motor circuit.  In this case, an abrupt increase in voltage occurs at the output of the sensor 18 of the core, the nonlinearity unit 19, the exciter current regulator 13, the cortical converter 3. Under the influence of the increased voltage at the output of the converter 3, the current in the excitation winding 4 begins to increase.  As a result, the voltage at the output of the sensor 33 of the excitation current increases, under the action of which the voltage at the input of the nonlinearity unit 11 increases, as a result of which the supporting voltage at the output of this block increases, the voltage at the output of the amplifier 9, at the inputs of the direct current diode - bridge circuit 8 and the output voltage of the regulator 6.  Under the action of the growing voltage at the output of the regulator 6, the current B in the winding of the core 1, at the output of the regulator 13 of the excitation current, the current transformer 3 in the winding 4 increases.  This process continues until the voltage at the output of the blocks 11 or 19 reaches the limiting level.  At the same time, the rotation frequency of the motor increases, and the voltage on the core 1 and on the output of the rotation speed sensor 25 increases.  This process is accompanied by an increase in the voltage at the output of the non-linearity unit 32 and the voltage at the output of the multiplier unit 23.  Under the influence of an increase in the excitation current and voltage at the output of block 32, the voltage at the input of the non-linearity block is reduced.  At the same time, it increases the voltage at the output of the nonlinearity unit 31 at both inputs of the multiplication unit 29, which causes a change in the voltage at the output of the nonlinearity unit 26 supporting the voltage at the DC outputs of the bridge circuit 27, shunted by a resistor 8, and a change in compliance with the laws of the commutation of the permissible level and “-Teconstruction at the output of the regulator 12 of the current cor.  .  By . As the motor accelerates, the voltage is applied to the core 1, the output of the voltage sensor 17 and the output of the rotational speed sensor 25.  With the growth of voltage at the output of sensor 17, the voltage at the output of block 14 increases, the voltage at 1 output of voltage amplifier 9 decreases at the output of regulator 6 and the current in the core circuit.  In addition, there is a process of reducing the excitation current in the winding 4, the voltage at the output of the magnetic flux sensor 24, the increase in voltage at the output of the transmitter 21, and the decrease in the supporting voltage of the limiter 20.  In the event of a shock load being applied to the motor shaft and an abrupt change in the motor, the EMF and voltage on the core 1 change, as well as a very rapid change in the voltage value at the output of voltage regulator 6.  At the same time, the current feedback signal is changed at the input of the current regulator 12 of the box.  Since the voltage at the output of the regulator 12 is limited due to the action of the limiter 20, the rate of change of the current in the crustal circuit of the electrode will not exceed the allowable one and conditions will not be created that contribute to the occurrence of circular fire on the collector. .  In the same way, when an abrupt change in the sigil of the setting by device 5, the voltage change at the output of the regulator 12 will be limited in level due to the action of the limiter 20, as a result, the current change in the core 1 will occur with the maximum speed allowed by the conditions of clocking, t.  Do not exceed your speed.  When accelerating to a steady-state speed, the current kqp 1 decreases, and the voltage is set in accordance with the level determined by the voltage and output of the device 5.  At the same time, the excitation current is minimal, and the DDS of the electric motor is very close to the saturation of the motor (re 1, Therefore, at the maximum frequency of the electric motor, the output voltage of the calculator 21 is maximum, and the motor circuit has a voltage of the limiter 2O mini.  At the transition to the braking mode, it decreases or decreases to zero voltage at the output of the driver 5.  Therefore, at the output of the regulator 6, the voltage also changes sign.  The amplitude of the voltage at the output of the regulator 6 is determined at the beginning of this process by the voltage of the subtime in the limiter 7, t.  e.  excitation current and the voltage that existed before braking.  Under the action of a changed voltage sign at the input, the voltage sign at the output of current regulator 12 changes.  The voltage amplitude at the output of the regulator 12 is determined (in accordance with the laws of the commutation) by the voltage of the sub-limiter 20.  Therefore, the current cor 1 will start to change from the maximum speed.  and will change its sign} under the action of the braking torque, the frequency of rotation of the core of the electric motor will begin to decrease.   At the same time, when current decreases in the core circuit, the voltage at the output of the corr current sensor 18, unit 19, winding current sensor 33 decreases.  As a consequence, it decreases for example. output output limiter 7 and level; The current limit is 1.  The magnitudes of the current of the core and magnetic flux; the electric motor in this mode is small, since after the passage of the current of the core through zero and before the end of the selection of gaps in the gears these values are determined by the small output of the nonlinearity unit 19, the input-output characteristic consists of three matrices with each other.  plots: dead zone, lignal plot and saturation plot; moreover, the insensitive zone width is larger than the input voltage, which corresponds to the motor travel of the motor, but less than the voltage corresponding to the motor current after the end of the choice of gaps.  Therefore, when after the end of the selection of gaps in the transmission, an increase in the root current occurs,. If the circuit is connected to the current of an electric motor connected to the mechanism, then on 1 output of the nonlinearity block 19 the voltage increases.  Under the action of this voltage, the voltage at the output of the regulator 13 of the exciter 3 starts to increase, the current in the winding 4 in the electromotive force of the electric motor.  An increase in the electromotive force of an electric motor leads to an increase in the amorphous current of core 1, the voltage at the output of terminal 18, block 19, regulator 13 of preophazel 3, winding current 4,, 7, in the circuit described above in the braking mode b can drive current to the maximum values at which this link breaks with - when. . the voltage at the input of the block 19 corresponds to the saturation region of the characteristics of the input-output. : If at the same time the frequency of rotation of the i core was no more than 0.7-0.8 of the nominal, then the emf zhor 1 was obviously less than the voltage supplying preo phase generator 2, the voltage taken from the output of the non-linearity block 15 is greater than the voltage on the outputs direct current dyod: no-bridge circuit 16 and the limiter 14 does not bypass the input of the regulator 13.  Therefore, the current of the core 1 is determined in accordance with the laws of the switching voltage of the backwater of the diode-bridge circuit 8 of the limiter 7, t.  e.  emits the maximum possible, and the current is not the maximum current.  Consequently, the braking comes with the maximum byproduct and therefore is as efficient as possible.  If the frequency of rotation of the core 1 pepper, the onset of deceleration was significantly higher than the nominal one, then put it under the action of the described above. In a positive feedback, the growth of the excitation current of the winding 4 and the emf of the core 1 will continue until the emf and, therefore, the voltage on: caf 1 does not exceed the allowable values.  In this case, the voltage at the outputs of the direct current of the ayodon-Moscow circuit 16 will become greater than the voltage at the output of the unit 15 and the signal at the input of the regulator 13 will decrease, which will cause k to limit the emf and, therefore, the current of the motor core.  As the braking and reduction of the rotation frequency of the core 1 decrease, the EMF and voltage of the electric motor decrease, and the additional negative signal at the input of the regulator 13 decreases.  After the voltage at the output of the bottom-bridge circuit 16 again becomes less than the supporting voltage at the output of the block 15, braking will occur as described above.  Thus, the invention makes it possible to more fully utilize the switching capabilities of the electric motor in all modes, which makes it possible to obtain high speed, the maximum possible rates of change in the current of the core.  In addition, by maintaining a limited level & max. Slamming voltage, the reliability of the motor is increased.  44 14 o {izoretsni zmula and 3 o b p e 1.  A DC electric drive containing an electric motor with adjustable converters in the main circuit and in the field of the excitation winding, a series-connected master device, a voltage regulator with a signal limiter in its reverse feedback circuit. The current regulator and the core current regulator, the excitation current regulator with an on-1 parallel to the input of the limiter, the voltage sensors on the cortex, the current core and the current of the excitation connected to the inputs of the corresponding regulators, when the atom voltage sensor on the core is also connected to the input of the exciter current, and the Current sensor cor, through the nonlinearity block, is connected to the input of the excitation regulator, T L ia and so that, in order to increase speed and reduce the likelihood of circular fire, on the coil, in It introduced a voltage limiter on the collector, with its output connected to the feedback circuit of the current regulator, the calculator of the maximum emf of the core section, the output of which is connected to one of the inputs of the voltage limiter on the collector, a summing proportional amplifier, one input of which is connected to the sensor Caffeine, multiplication unit, magnetic flux sensor and anal. The second motor rotational speed sensor, the second input of the voltage limiter i on the collector is connected to the output of a combined hand amplifier, the inputs of the calculator of the maximum EMF of the core section are connected to the flow sensor, the current sensor core, to the input of the summing proportional amplifier and the output of the multiplication unit the inputs of which are connected to the sensor of the magnetic flux and the sensor of rotational speed of the electric motor.  2 Electric drive according to claim.  1, about t l and-.  due to the fact that the voltage limiter on the collector contains a block.  nonlinearity with irreversible output and a diode bridge, the output of a constant current of which is connected to the output of the nonlinearity unit and shunted by a resistor, while the outputs of the alternating current of the diode bridge are the output and the inputs of the nonlinearity unit are the inputs of the voltage suppressor in the collector.  3 Electric drive according to claim.  1, characterized in that the calculator

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15

The maximum emf of its core is the first nonlinearity unit, whose input is connected to the output of the second linearity unit, and the output to the first input of the multiplication unit, the inputs of both the unit (the nonlinearity and the second input of the multiplication unit are inputs output of the calculator of the maximum EMF of the sections cor.,: -.; - .- |.

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Sources of information taken into account in the examination

1. Authors certificate of the USSR 439052, cl. H 02 R 5/06, 1974.

2. GDR patent N9 105593, H 02 P 5/00, 1973.

3. Authors certificate of the USSR 400965, cl. H O2 P 5/06, 1973.