SU1501221A2 - Thyratron motor - Google Patents

Abstract

The invention relates to electrical engineering. The aim of the invention is to increase reliability by eliminating zones in the position of a rotor with zero electromagnetic moment, arising when one of the phases of the core winding breaks. In a valve motor, phase 1.2 of the crust winding is made with outlets 25, 26 from half of their turns and an additional winding 22 of the throttle 18 is inserted, which is connected to the leads of the 25.26 phase of the winding opposite the main winding of 19.20 throttle 18. 2 Il.

Description

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The invention relates to electrical engineering, in particular to valve motors.

The purpose of the invention is to increase reliability while maintaining high energy performance by eliminating zones in the rotor position with zero electromagnetic moment, arising in the event of a breakdown in the electrical connection between one of the two core windings and the power supply.

Figure 1 shows the functional diagram of the valve motor; FIG. 2 shows time diagrams explaining his work.

The valve motor (Fig. 1) contains a synchronous machine with phases 1, 2 of the crust winding, bridge switches 3, 4, transistor effective, 5-8 and 9-12, respectively, the position sensor 13 of the synchronous machine rotor, the driver 14 of the switching zone less than 180 electric grades, the driver 15 of the commutation zone is greater than 180 electric grades, disconnecting relays 16 and 17, throttle 18 with two main power windings 19 and 20 connected in series with each other, measuring winding 21 and additional winding 22, threshold unit 23 inverting circuit 24. F PS anchor coil formed with taps 25, 26 of half coils kx. Additional winding 22 Drossel 18 is connected to the taps 25, 26 opposite in relation to the windings 19, 20.

Phase 1 of the winding of the synchronous machine core is included in the first diagonal of bridge switch 3, and phase 2 in the first diagonal of bridge switch 4. One output of the second diagonal of each switch 3, 4 is connected to one terminal of the power source. The output of the rotor position sensor 13 is connected to the inputs of the switching area drivers 14 and 15, the outputs of which through the disconnecting relays 16 and 17 are connected to the control inputs of the power switches of the bridge switches (inverters) 3 and 4, respectively. The second output of the second diagonal of the inverter 3 is connected to the free output of the power winding 1 and the second output - the second diagonal of the inverter 4 - to the free output of the power winding 20 droplets 18. The connection point of the beginning of the power winding

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19 and the ends of the power winding 20 are connected to a different terminal of the power source. The measuring winding 21 of the throttles 18 is connected to the input of the threshold unit 23, the output of which is connected to the control input of the tripping relay 17 and through the inverting circuit 15 to the control input of the tripping relay 16.

The valve motor operates as follows.

In the initial state, the tripping relays 16 and 17 are open. When the supply voltage is applied to the motor, the signals of the rotor position 13 together with the control circuit will periodically switch the power transistors of the bridge switches 3 and 4 in a sequence that ensures the variation of the MDS F and Fg in accordance with the diagrams of Fig. 2 a, b.

Let the transistors 7.8 and 12 be saturated at the moment of pO.

Since the end 27 of phase 1 remained connected to the power source through two series-connected power transistors 7, 8 of the bridge switch 3, the starting current of the motor will flow through the following circuits: the first part of the current - from the bus + power source through the winding 19, transistor 7, half of phase 1 in direction from end 2 to midpoint, additional winding 22, half of phase 2 in direction from midpoint to end 28, transistor 10 to bus - power supply; at the same time, the second part of the inrush current will flow from the bus + power supply through the winding 20 through the transistor 9, phase 2 in the direction from the end 28 to the end 29, transistor 12 to the bus - power source. When the rotor rotates at an angle (ji) from position u) in bridge switch 4, transistors 9 and 12 are closed and transistors 10 and 11 open. In this case, the starting current will flow through the circuits: the first part of the current is from the bus + power source through winding 19, transistor 7, half of phase 1 from midpoint 25 to end 27, additional winding 22, half of phase 2 from midpoint 26 to end 28, transistor 10 to bus - power supply; the second part of the current is from the pin + power supply, i- ".

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through the winding 20, the transistor 11, phase 2 from the end 29 to the end 28, the transistor 16 to the bus - power source.

When the rotor is rotated through the angle u) t 5Г from the position, the transistor will be locked and the transistor 8 of the bridge switch will saturate. The starting current of the motor will flow through the circuits: the first part of the current is from the bus + power supply through the winding 20, transistor 11, half of phase 2 from end 29 to midpoint 26, additional winding 26, half of phase 1 from midpoint 25 to end 27, transistor 8 to bus - power supply; the second part of the current is from the bus + power source through the winding 20, the transistor 11, phase 2 from the end 29 to the end 28, the transistor 10 to the bus - the power source.

Subsequently, the processes in the engine proceed analogously, periodically repeating, depending on the angle of rotation of the rotor,

At the time of starting the engine, when the angular rotational speed of the rotor is still very small (u) tO), the starting currents flowing through phases 1 and 2 create magnetomotive forces (MDS) with amplitudes F, respectively

(and is the motor supply voltage; Rj is the phase resistance; Wj is the number of phase turns; KO is the winding factor), whose diagrams for the full period of switching processes are shown in Fig. 2 a, b (continuous lines). VAT F and F, interconnected separately with the magnetic flux of the inductor (rotor), provides the starting torque of the electromagnetic moments in the engine, respectively, m l expressions:

4 and t ,, opdedeP1, F. cp / sin (57-u) t) / F f / siniut /; ; . T / sLn (-u) t) /

m

F5 f / cosiOt /,

where f is the magnetic flux of the inductor. The operation of taking the module of the trigonometric functions sinu) t and cosiJ t

sixteen

in the valve motor, bridge switches 3, 4 are operated, controlled by the signals of the rotor position sensor. The physical meaning of this operation is to provide these devices with a unidirectional electromagnetic moment due to a periodic change in the direction of the currents in phases 1, 2 at times when the angle between the corresponding MDS vector and the vector φ reaches the value of electr. The instantaneous value of the total starting electromagnetic moment of the Shvd valve engine is equal to the sum of the moments t and

 f (/ sini) t / +

 / COS4f) t /)

where F F T with u) 0 at the time of starting the engine; The moment diagrams, mj and are shown in Fig. 2, c, d, d in solid lines. The average value of the starting electromagnetic moment (fig. 2d) is determined by integrating the expression for th in the range from to (J t -J7 / 2:

 yi

- | - f Fj (/ sincJt /

J o

five

0

+ / Cos tOt /) - duDt

ZG / 4

Jt /

five

0

five

2 X.

 G), p (cos u) t / + sinu3t /)

  oh oh

.

Under the action of the moment m "A", the rotational speed of the rotor of the engine increases and, on the power windings 19 and 20 throttles 18, arises due to their power supply by the difference of cosine bridge voltage and sinusoidal voltage emf, rectified by bridge switches, the frequency of which is twice the voltage the frequency of the emf-phase s, and the amplitude is proportional to the frequency of rotation of the rotor. The constant supply voltage of the motor is summed with the triangular alternating voltage on the windings 19, 20. The resulting voltage is supplied in a phase with alternating voltage to the bridge inverter 3 and in antiphase to the bridge inverter 4, which ensures that

switching inverter transistors according to the signals of the rotor position sensor. a, the formation in the phases of the main winding of almost rectangular currents of different currents in any engine operating conditions. A voltage is also generated on the vertical winding 21 of the drogings 18, the amplitude of which is proportional to the frequency of rotation of the motor shaft. This voltage is compared with a voltage proportional to a given rotational frequency, at which threshold block 23 triggers and generates a signal to close the contacts of the relay 17 and through the inverting circuit 15 to open the contacts of the relay 16. In this case, the power switches of the inverters 3 and 4 begin to switch current in phases 1 and 2 of the core winding with a switching zone exceeding 180 el.grad. The latter virtually eliminates high-frequency ripple currents in the phases of the core winding and eliminates the occurrence of overvoltages on power transistors at the moments of their switching off, which provides a significant increase in energy performance of the valve electric motor, a decrease in the pulsation of the instantaneous frequency of rotation of its shaft and, as a result, fold) increase the service life of bearings and the entire machine. Since the additional winding 22 of the drossel 10, in which alternating voltage is also generated, is connected to the terminals from the half phases of the main winding in antiphase with successively according to the included windings 19, 20 and has two times less turns than the total number of turns of these windings , then the sum of voltages and emf acting in a closed circuit formed by the indicated windings, half phases of the core winding and saturated transistors of bridge switches 3, 4 will be zero at any time. Therefore, when the valve motor is in good condition, the surge current in the winding 22 does not flow, and the combination of the terminals 25 26 of phases 1, 2 through this winding does not adversely affect the energy performance of the machine.

Consider the processes in the engine in the case when at the time of its launch

five

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five

0

five

0

five

0

five

or, up to this point, there will be a breakdown in the electrical connection between one of the two phases of the core winding and the power source due to a break in one end of the phase or due to a burnout of two series-connected power transistors of the bridge switch.

Suppose for definiteness that the end 30 of phase 1 is disconnected from the power source shown in Fig. 1. When the power source voltage is applied to the motor, the signals of the rotor position 13 together with the control circuit will periodically switch the power transistors of bridge switches 3 and 4 in sequence, providing a change in VAT F and F in accordance with the diagrams of figure 2 a, b. Since the end 27 of phase 1 remained connected to the power source through two series-connected power thyristors 7, 8 of the bridge switch 3, the starting current of the motor will flow into one half-cycle through the circuits: the first part of the current will flow from the positive power supply bus through the winding 19 , the power transistor 7 of the bridge switch 3, through half the turns of phase 1 from the end 27 to the midpoint 25 on the additional winding 22, through the power transistor 12 of the bridge switch 4 and to the negative bus of the power supply, the second part of the starting one It will flow from the positive source power supply to the winding 20, through the transistor 11 of the bridge switch 4, through the second phase 2, through the transistor 10 of the bridge switch 4, and to the negative power supply bus. When the motor rotates at a yaw) from the initial position, when w), the transistors 11, 10 are closed in the bridge switch 4, and the transistors 9, 12 open. In this case, the direction of the current in phase 2 is reversed and the full starting current flows on the left half of phase 2 turns.

When the rotor of the motor is rotated at an angle lO t 5 from the initial position, the upper right transistor of the bridge switch 3 will be locked and its lower left transistor will be saturated. The direction of the current in half the turns of phase 1 will change to

the opposite. In the future, the processes in the engine will be repeated. As a result of the considered malfunction half of the starting

t and

In current of engine protea, /) to 5

half the turns of phase 1, then its MDS will now be determined by the expression

tg - and l lkk °

which is three times less than in the case of a good engine (diagram F in figure 2a, shown as a broken line).

In the second phase, the magnitude of the MDS F does not change, since half of the starting current of the motor will flow through one block of | Wines of its turns, and the full starting current will flow through the other (, motor

W

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1.5 R,

 -i-; W..K ,.

From the above it follows that the electromagnetic moment created by phase 1 will be reduced by 3 times (Fig. 2 in the discontinuous line), and the moment created by phase 2 will not change. Therefore, the diagram of the electromagnetic torque of the valve engine will have the form shown in fig.2 dashed line. It can be seen from the diagram that the minimum starting torque t in the event of a malfunction is 1/3 of the minimum starting torque of a working engine. Since usually the nominal value of a DC motor torque is 1/5 - 1/8, from the starting torque, the proposed valve motor will keep

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operability after occurrence of the considered malfunction.

From the graphs shown in Fig. 2, c, d it follows that the average value of the electromagnetic moment of the proposed engine decreases only 1.5 times with the appearance of the considered malfunction in it.

It should be noted that the average value of the electromagnetic moment of the valve engine with duplicated phases and bridge switches with the break of one of the phases would be

with more than the supply of only 12.5%. However, such an increase in the average moment would be achieved at the cost of an increase in the number of power transistors and the phases of the core winding in 2

Q times compared to the proposed valve motor.

Thus, the implementation of the phases of the core winding and the valve engine with taps from half of their windings, supply throttle additional winding having a number of turns equal to the number of turns of one of its two main series consistently according to the connected power windings,

Q And the connection of the additional winding to the phase outlets in antiphase with the main winding significantly increases the reliability of the valve motor.

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Claims (1)

Invention Formula Valve motor auth.St. No. 1387124, characterized in that, in order to make it more reliable by excluding zones in the position of a rotor with zero electromagnetic moment, arising from the breakdown of electrical connections, the choke is equipped with an additional winding with the number of turns of one of its main windings, and Each phase of the root winding is made with a tap, the conclusions of the additional winding of the throttles are connected to the outlets of the phases of the main windings opposite to the Main windings of the throttles. W, UG .fj at Z wt EH 9 1 0.5. ABOUT - - -v -x ::. If F 2 Editor M.Tovtin corner 23G FIG. g Compiled by A.Golovchenko Tehred M. Khodanich ./ Proof-reader S Shekmar tvt