SU1598097A1 - Reversible thyratron electric drive - Google Patents

Abstract

The invention relates to electrical engineering and can be used in a drive with two-phase synchronous motors. The aim of the invention is to increase reliability. To achieve this goal, the reversible valve electric drive additionally contains two pulse-width converters 16, 17, four formers 18-21 pulses, two logical elements OR 22, 23. Semiconductor switches are made in the form of thyristor reversing bridges 4,5, connected via power switches 32 , 33 with a positive output of the power source, and a diode bridge, in the motor of which, according to its conductivity, the power terminals of the transistor switches 42, 43 are included. Phases 2,3 windings of the electric motor are included in the total gonal diode and thyristor bridges. As the motor rotates, the pulse width modulators 16, 17 modulate the positional control signal. The formers 18-21 control the turning on of thyristors 24-31. In the signal pause, one of the keys 32.33 is turned off. The current of the corresponding phase continues to close under the action of self-induced emf and rotational emf. When the drive is de-energized, the phases are shunted with the keys 42, 43, providing dynamic engine braking, which ensures its reliability. 1 il.

Description

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The main terminals of the transistor switches 42, 43. The phases 2, 3 of the motor windings are included in the total diagonal of the diode and thyristor bridges. As the motor rotates, the pulse width modulators 16, 17 modulate the positional control signal. The formers 18-21 control the turning on of thyristors 24-31. AT

When the signal is paused, one of the keys 32, 33 is turned off. The current of the corresponding phase continues to close under the action of self-induced EMF and rotational EMF. When the drive is de-energized, the phases are shunted with the keys 42,43, providing dynamic engine braking, which ensures its reliability. 1 il.

The invention relates to electrical engineering, in particular to an electric drive, and can be used in controlled drives with two-phase synchronous machines.

The aim of the invention is to increase the reliability of the reversible valve actuator.

The drawing shows a diagram of the reverse valve actuator.

The reversible valve motor contains a two-phase synchronous electric motor with permanent magnets on the rotor 1 and phases 2 and 3 of the winding on the crust (stator), two semiconductor switches 4 and 5, two intermediate amplifiers b and 7, a sensor 8 of the rotor position with input 9 and two output 10 and 11 windings, a rotational speed setting device 12, connected via a modulator 13 to the input winding 9 of the sensor 8. The windings 10 and 11 of the sensor 8 are connected to the inputs of two demodulators 14 and 15, respectively. In addition, the electric drive contains two pulse-width converters 16 and 17 with two outputs each, four formers of 18-21 pulses with two outputs each, two logical elements OR 22 and 23.

The semiconductor switch 4 is made in the form of a thyristor reversing bridge on thyristors 24-27, and the semiconductor switch 5 in the form of a thyristor bridge on thyristors 28-31. The switches are connected to the positive output of the power source of the synchronous motor through power transistor switches 32 and 33. The bridges on diodes 34-37 and 38-41 are included in the switch, in the diagonals of which, according to its conductivity, the power leads of transistor switches 42 and 43 are inserted. my conductivity.

The bases of transistor switches 42 and 43 are connected to thyristor anodes 24, 26 and 28, 30, respectively, connected to a power transistor switch 32 and 33 through a resistor 44 and 45 and two additional diodes 46 and 47 and 48 and 49 to the terminals 2 and 3

synchronous electric motor included in the total diagonal of diode and thyristor bridges. The control inputs of the thyristors 24, 27 and 25, 26 of the switch 4 and the thyristors 28, 31 and 29, 30 of the switch 5 are connected to the inputs of the corresponding drivers 18, 19 and 20; 21 pulses. The inputs of the formers 18, 19 and 20, 21 pulses are connected to the outputs of the first 16 and second 17 pulse-width converters (SHIP), which are connected by outputs to the inputs of the first 22 and second 23 logical elements OR, respectively. The outputs of the elements OR 22 and 23 are connected via intermediate amplifiers 6 and 7, respectively, to the control inputs of the power transistor switches 32 and 33, and the inputs of the pulse-width converters 16 and 17 are connected to the outputs of the corresponding demodulators 14 and 15.

The drive works as follows.

The control voltage Uy generated by the setting device 12 of the rotational speed is fed to the input of the modulator 13. The output voltage of the modulator is an amplitude-modulated alternating electric signal of a constant frequency, is fed to the input winding 9 of the rotor position 8 sensor (DPR) -sinus-cosine rotating transformer, consistent with the number of poles with a synchronous motor. At the same time, modulated voltages are formed at the output windings 10 and 11 of DPR 8, the amplitudes of which are proportional to the sine and cosine of the rotation angle of the rotor 1 of the motor relative to the stator (core) and simultaneously depend on the nature and amplitude of the output voltage of the setpoint generator 12, the rotational speed, i.e. . The following mathematical dependencies are realized:

.- sln,

 -K.-cosyjp,

where Us is the output voltage of the sinus output winding 10 DPR 8:

Uc is the output voltage of the cosine output winding 11 of the DPR 8;

Uy-control voltage from the setpoint 12 output;

K - transformation ratio DPR 8;

p-rotation of the rotor 1;

p is the number of poles of the DPR 8.

The voltages Us and Uc from the output windings of the DPR are fed to demodulators 14 and 15, while at the outputs of the demodulators sinusoidal voltages are formed, shifted in phase by 90 °, the amplitude of which is proportional to the voltage Uy.

The output voltages of the demodulators are converted by pulse width converters (SHIP) 16 and 17 into a series of square pulses, the duty ratio of which varies in proportion to the voltage of the demodulators 14 and 15.

Suppose that when a positive control voltage Uy appears at the output of the setting device 12, the voltage phase at the output of the modulator 13 is such that at the outputs of the demodulators 14 and 15, positive half-waves of sinusoidal voltage begin to form.

In this case, at the same output of the SHIP 16 (17), for example, the first, pb, are duration-modulated rectangular pulses that, through the logic element OR 22 (23) and intermediate amplifier 6 (7), control the operation of the power transistor switch (STK) 32 (33), as well as through the shaper 19 (20) pulses are fed to the inclusion of diagonal thyristors 24 and 27 (28 and 31) of the reverse thyristor bridge 4 (5).

During the pulse SHIP, the power transistor switch 32 (33) is open and the current from the power supply source flows through the circuit: STK 32 (33), thyristor 24 (28), winding 2 (3), thyristor 27 (31), minus the power supply. While STK 32 (33) is open and current flows through the thyristor 24 (28), the base of the transistor switch 42 (43) is connected to the positive power supply bus, and the voltage drop on the thyristor 24 (28) is for its input the locking circuits (plus at the base, minus at the anode of the diode 34 (38)), therefore, the transistor switch 42 (43) is closed during the operation of the control pulse. Upon termination of the control pulse, when CTK 32 (33) enters the cut-off mode (fully closed), windings 2 (3) are disconnected from both power supply buses,

Under the action of induced in phase 2 (3) emf self-induction along the circuit; diode 36 (40),

the emitter-base junction of the transistor switch 42 (43), a series-connected resistor 44 (45) and a diode 46 (48) the current flows, and the transistor switch opens

42 (43). As a result, the current in the motor phase due to the magnetic energy stored in the inductance continues to flow in the same direction, closing in the circuit; phase 2 (3), diode 36 (40), transition emitter-collector of the transistor switch (42) 43, diode 35 (39), phase 2 (3). Subsequently, during the operation of the control pulses, the switched on STK 32 (33) and diagonal thyristors 24 and 27 (28 and 31) are provided

5 current flowing through the motor phases from the power supply. In the pauses between pulses, transistor switch 42 (43) is turned on in the same way and creates a circuit for current flow in the same direction as the scientific research institute from self-induced EMF.

The magnetic fluxes generated by the currents of the crustal (static) windings 2 (3) cause the occurrence of the resulting magnetic field of the stator, which,

5 interacts with the field of the permanent magnets of the rotor 1, creates a rotating electromagnetic moment, as a result of which the rotor of the engine begins to turn in the same direction, for example, forward

0 and stator field. When the rotor rotates the motor, the DPR 8 rotor also rotates, mechanically connected to the motor shaft, which leads to a change in the amplitude and phase of the voltages on its output windings.

5 10 and 11 and, respectively, the voltages at the outputs of demodulators 14 and 15 are sinusoidally shifted by 90 °.

In the DPR 8 positions, when the output voltages of demodulators pass through

0 is zero and the polarity is changed, the supply of control pulses from the first output of the SHIP 16 (17) to the logical element IL AND 22 (23) and the driver 19 (21) of the pulses stops and their supply starts from the second output

5 SHIP 16 (17) to another input of the element OR 22 (23) and shaper 18 (20) pulses. Diagonal thyristors 24 and 27 (28, 31) are closed, and when turned on STK 32 (33), diagonal thyristors 25 and

0 26 (29 and 30). There is a reversal of the current in the winding 2 (3) synchronous motor,

with the direction of the electromagnetic

rotating moment remains the same.

When STK 32 (33) is on and leaking

5, the current through the thyristor 26 (30), the transistor switch 42 (43) also remains closed, since in this case the voltage drop on the thyristor 26 (30) is already blocking for its input circuit. In the pause between control pulses STK 32 (33) thyristors

25 and 26 (29 and 30) turn off and disconnect the winding 2 (3) of the motor from the power supply buses, and the transistor switch 42 (43) under the action of self-induction EMF opens along the circuit: phase 2 (3), diode 34 (38), emitter -base transition key, resistor 44 (45), diode 47 (49), phase 2 (3) and together with diodes 34, 37 (38, 41) forms a closed loop, along which the winding current continues to flow in the previous direction under the action of stored in its inductance of magnetic energy.

At the next change of the voltage sign at the output of the demodulator 14 (15), the formation of control pulses at the second output of the SHIP 16 (1.7) stops and they are again formed at the first output. In this case, the thyristors 25 and 26 (29 and 30) are turned off and the current is reversed through the included thyristors 24 and 27 (28 and 31). Further, the processes in the electric drive proceed in a similar way, i.e. during the operation of the control pulses, the CTC 32 (33) and the thyristors 24 and 27 (28 and 31) provide a path for the current to flow in phase 2 (3) from the power source, and in the pauses between the control pulses, the transistor switch 42 (43) and together with diodes 36 and 35 (40 and 39) forms a circuit for current flow in the previous direction from self-induction EMF. Increasing the control voltage from the setting device 12 increases the duty cycle of the pulse control pulse and, therefore, increases the amplitude of the first harmonic of the modulated voltage on the motor windings and, accordingly, the speed of rotation of the rotor 1. When the rotor rotates in the windings of the core, an emf of rotation is induced directed opposite and sinusoidal change. In transient conditions, for example, when the load is shed or the control voltage is reduced in a speed feedback system, the duty cycle of the control pulses decreases and may become zero, i.e. The emf of rotation can be greater than the medium-voltage applied to the motor windings.

In this case, the CCS 32 (33) and open thyristors, for example 24 and 27 (28 and 31), are closed and under the action of the EMF of the rotation, the transistor switch 42 (43) opens along the circuit: phase 2 (3), diode 34 (38) , transition emitter-base key, resistor 44 (45), diode 47 (49), motor winding.

The current in phase 2 (3) changes its direction and flows in a circuit formed by an open transistor switch 42 (43) and

diodes 34 and 37 (38 and 41). When the emf of rotation changes at the terminals of the winding 2 (3), the transistor switch 42 (43), together with diodes 36 and 35 (40 and 39), forms a circuit for current flow from the emf of rotation in the other direction. Consequently, in transient modes in the electric drive, the engine automatically switches to the braking mode, i.e. There is a partial discharge of electromagnetic energy stored in the engine and its braking.

When the engine is stopped, when control pulses are removed, as well as in emergency modes, for example, when the power supply to the engine disappears, elements of semiconductor switches become uncontrollable in known electric drives and the motor brakes

0 coasting. In such situations in the proposed electric drive, the motor windings are disconnected by power transistor switches and thyristors of the reversible thyristor bridge from the power supply and

5, under the action of the induced emf of rotation, they open automatically the transistor keys of direct conductivity, which, together with the diodes of reverse diode bridges, form the circuits of dynamic braking. The currents in the windings change their direction and create a braking torque opposite to that of rotation, as a result of which the motor quickly stops. To limit the inrush current, a resistor may be included in the collector circuit of transistor switch 42 (43).

When the polarity of the control voltage at the output of the setting device 12 is changed, the phase of the output voltage of the modulator 13 and the phase of the voltage on the windings of the DPR and the outputs of the demodulators change by 180 °. In this case, control pulses appear first at the second outputs.

5 SPIRES 16 and 17 and from the formers 18 (20) of the pulses are included first diagonal thyristors 25 and 26 (29 and 30), i.e. there is a change in the phase of the generated current in the motor windings and, accordingly, a change in the direction of the electromagnetic torque. The rotor of the engine moves and rotates back, and the switching processes in the electric drive circuit are the same as

5 while turning the engine forward.

Thus, in the electric drive, due to the introduction of new elements, the voltage is pulsed on the windings of the synchronous motor and, consequently, its speed is only two

power transistor switches, and a change in the direction of the current in the windings is carried out according to separate law with thyristor reversors, which reduces the likelihood of the occurrence of through currents in semiconductor switches. In addition, in the electric drive with pulse voltage regulation, the current in the motor windings is continuous in all operating modes, and the motor is automatically switched to the dynamic braking mode in emergency situations, and no additional control devices and power sources are required. All this increases the reliability of his work.

Claims (1)

Invention Formula A reversible valve motor containing a two-phase synchronous electric motor, each phase of which is connected to a semiconductor switch, two intermediate amplifiers, a rotor position sensor with an input and two output windings, a rotation frequency adjuster connected through the modulator to the input winding of the rotor position sensor, two output windings of which connected respectively to the inputs of two demodulators, characterized in that, in order to increase reliability, two pulse-width converters are introduced into it Atel with two outputs each, four pulse makers with two outputs each, two logical elements OR, and each semiconductor switch made in the form of a thyristor reversing bridge with a power transistor for connection to the positive pole of the power source and the diode bridge, the diagonal of which is included in accordance with its conductivity is the power terminals of the transistor switch of direct conductivity, the base of which is connected to the anodes of the thyristors connected to the power transistor switch, and through a resistor and two Additional diodes are connected to the conclusions of the corresponding phase of the synchronous motor included in the common diagonal of the diode and thyristor bridges, the control inputs of the diagonally located thyristors of each switch are connected to the outputs of the corresponding pulse drivers, the inputs of the pulse driver of the first and second switches are connected respectively to the outputs of the first and second pulse-width converters and the inputs of the corresponding logic elements OR, the outputs of which are connected to control inputs of the transistor power switches, and the input of each pulse-width converter is connected to the output of the corresponding demodulator.