SU780135A1 - Reversible electric drive with two-zone regulation of rotational speed - Google Patents

Description

(54) REVERSE REGULATIONS The invention relates to the field of a valve-driven electric drive (VEP) and is intended to regulate the frequency of rotation of a direct current electric motor. The structures of an OuvEon VEP with a reverse motor floor are known, containing an irreversible core preophazor with a core voltage control system, a reversible thyristor exciter with an excitation current control system, an electric motor, a rotational frequency sensor, a logic unit for separate control of exciter sets. Voltage regulation of the engine core is carried out according to the subordinate regulation system. At the input of the rotational speed controller, the reference and feedback signals for the rotational frequency are summed. To do the braking, as well as for the reverse, the sign of the output signal of the rotational speed regulator changes, which affects the excitation control system. THE ELECTRIC DRIVE WITH DRIVE EMERGENCY OF ROTATION and reverses the excitation current - NEXT As a result of the EMF, the motor changes the thyristors The core converter is converted to an inverter mode and regenerative engine braking is performed. This drive has a number of disadvantages: 1. Connecting the excitation control system to the output of the rotational speed controller (motor voltage control channel) impairs stability and reduces the speed of the electric drive, since the output of the rotational speed controller, which is a delay signal for the control channel excitation (field) of the engine depends on the control and disturbing influences of both control channels. At the same time, in double-pole electric drives with a reverse field, the corrective RC circuit of the amplifier of the speed regulator is chosen so that the output signal of the amplifier does not change the p-Hct field during overshoots in the starting modes or in the load shedding mode; otherwise, the iBfeixboHorb direct sign changes (frequency controller enhancers ;; increase, the motor field changes, the control time increases, the regulation time. As a result, the correction of the rotation speed regulator significantly increases compared to the single-zone electric drive (in which field regulation), which dramatically reduces the speed of a two-zone electric drive, especially when operating in the first zone with constant excitation, corresponding to the regulation of the engine rotational speed from zero to nominal 2.Connecting the input of the logic unit to the output of the speed controller reduces the speed of the drive. This is because the command to switch to the input of the logic unit comes not after changing the error signal K but only after switching the output of the speed regulator, as a rule, covered by a correction and of low speed. Using the true value of the excitation current as a sensor for the current current transformers exacerbates the described drawback and reduces the reliability of 3.Suschestvennym disadvantage of this is that no VEP circuit EMF motor control that does not allow to maintain the electromotive force of the engine at a predetermined level and to limit its maximum value. Therefore, in VEP in transient modes .. emergency modes are possible, in particular, breakthrough and overturning of the inverter. The closest to the invention of a technical entity is an electric drive consisting of an inversion sensing transducer with a control system for the core voltage and a reverse thyristor exciter with a control system for the excitation current. Introducing the EMF control circuit of the motor with feedback voltage, switched to the tachogenerator zero-body, eliminated the main drawback of the above-described VEP system. But this electric drive, as well as the above-mentioned device, has the lack of excitation control carried out with the function of the polarity of the output signal of the speed controller, which is accomplished by connecting the output of the frequency regulator through a zero-organ and potentiometer with the control system input pathogen. Even insignificant changes in the rotational frequency of the transient process lead to a change in the field of the output signal of the rotational speed regulator, reversing the zero-organ and, accordingly, changing the engine's excitation. This disadvantage leads to an increase in transients and, in a number of cases, to a loss of stability. The second disadvantage is the connection of the logic unit to the output of the EMF regulator, which is included in the control system of the exciter. This reduces the performance of the electrical system, since the reversing of the lanyard begins after the reduction to zero of the output voltage of the EMF regulator, as a rule: having corrective links and low speed; The aim of the invention is to increase the stability and speed of the electric drive by providing electric deceleration of the engine only at significant deviations of the rotational frequency from a predetermined value, and electric brake braking and reversal of the engine at any speed levels. The goal is achieved by the fact that a reversible electric drive with dual-zone rotational frequency control, which contains measles electric aviators, a non-reversible thyristor converter, in the control circuit of which the speed regulator is connected with its inputs set up with a speed sensor, the second one which, through a null-organ, is connected to the control input of the switching unit of the atomic communication by EMF, the input of which is connected to the output of the non-reversing converter, and the output - to the input of the reversing switch a converter that supplies the excitation winding of the electric motor, the excitation control unit with the logic block and the valve state sensor connected to it, and the second null organ, two non- are inserted. linear links with characteristics such as dead band and saturation, the inputs of which are connected to the speed sensor $ 1, and the outputs to two inputs

the second zero-organ, the third input of which is connected with the rotation speed detector, and the output - with the input of the logic block.

In the quality of the second nonlinear link, a rotational speed regulator diode limiter can be used.

FIG. 1 is a diagram of the electric drive; “FIG. 2 - diagrams, according to his work ..

In this device, the inputs of speed controller 1, containing amplifier 2, resistors 3-5, capacitor 6, diode limiter with diodes 7 and 8 are connected to the setpoint generator 9 of the rotational speed and the sensor 1O of the rotational speed and the output to the control system of the core converter 11. A motor 12 is connected to the output of the converter 11. The motor excitation winding 13 is connected to the output of the converter 14. The inputs of the control system of the converter 14 are connected, respectively, via a potentiometer 15, which is an emf setting device, s with a zero-body output 16, s The output of the feedback switch 17 is the motor EMF, whose inputs are connected to the output of the core converter II, and the contacts are switched connected to the rotational speed sensor 10 by the zero-body 18. The zero-body inputs 16 are connected directly to the output of the rotational speed generator 9 through nonlinear links 19 and 20 to the sensor 10. The logic block 21 is connected to the output of the setpoint device EMF of the engine 15 and, if there is an output resolution from the sensor 22. The state of the valves selects the required value according to the polarity of the signal of the setting device 15 BP board of Eni, the impact on the root of the control system of the converter 11 and inverter 14.

Consider the operation of the drive in the following modes:

a) Start at rated speed {work in the 1st zone).

When a driver voltage is applied to the setpoint 9, signals appear at the output of the regulator 1 and the zero-body 16. The half-width of the output signal of the zero-body 16 determines the operation of the three-position logic block 21 from the zero position to one of the positions, for example, to the engine rotation to the left. (Block 21 of logic has the following position: O (zero); rotation of the engines to the right or left). In the function of the signals of the block 21, the following keys are triggered. in the control systems of the core generator II and converter 14, which provide a signal passing from the setting unit 15 emf to the input of the converter 14 and the output signal of the regulator 1 to the input of the core converter II. As a result, the excitation current and voltage on the engine core rise to the nominal Vedichin . During the start-up process, the core current is limited by a current-limiting device, the input to the pre-Phase II component, and the motor accelerates to the nominal rotational speed. In so doing, the signals at the input of the null organ 16 are set to the values indicated in FIG. 3a (here, Ux, 40 ° DULI of voltages, respectively, at the output

unit 9 and nonlinear links 19 and 20, the characteristics of which, as a function of frequency, of engine 12 are shown in FIG. 3 b).

Nonlinear link 19 has the characteristic of the dead zone type. The zone level is chosen to be proportional to the permissible magnitude of the absolute value of the dynamic error in frequency vrr1). according to the permissible overshoot during start, reverse, reset, and so on. Within the limits of this dynamic error, the inertial control channel of the motor excitation should not have a regulating effect, otherwise the total time control of the rotation frequency of the engine is increased. The nonlinear link 2O has a saturation type characteristic. The voltage level of the saturation is not chosen from the condition of engine braking down to low speeds. In the event of overshooting of the engine speed (speed) at start-up, the following occurs:

- if the speed override module

1iHlHti (t) -n, J,

where is the mouth - the steady-state value of the rotation frequency corresponding to the reference voltage U ® exceeds the deadband | di) defined by the signals | 4U lUq | -lU) hUid (l)

then there is no electric braking on the engine; if the frequency is overshoot and the

Kp17 | li1. (2)

This is done by an electric control unit. In this case, the output

The nu-bargan 16 changes polarity and the converter 14 is switched by the logic block 21 to the opposite direction of operation — the excitation current in the winding 13 reverses, the EMF

engine 12 changes the sign and carries an electric then | It is possible to convert the inverter 11 into the inverter mode and recover the engine energy to the network. Inhibition occurs as long as condition (2) disappears. With DSP {the switching of the logic block 21 to the previous position takes place, and the excitation current returns its own (predetermined) polarity} 15

b) Deceleration at rated speed. When braking 0 O signals, Urtft determines the 5th output of the zero voltage of the output organ 16, and the block 21 recurs the excitation current and the emf of the 20 gatel. As a result, braking with reyperyyyyyyyrgyy in a network, similarly to the woman. A characteristic feature of this electric drive is that, despite the presence of 25 dead zones, defined by link 19, electrical braking from ftpofeKae up to very low speeds. This effect over the avenue

20 ((| IG, 3 6) high speed T; YAH30

The motor has a voltage of 10 at the rotational speed of the helicopter; as a result, the Jul-Organ 16 is affected by both signals Jl and U Po. At speed decreases up to the DO level, the signal Um O and 35 hold the Zero-organ 16 in the former manner, with a signal ttg whose magnitude is small (OD-O, 58), in Reverse, at a speed higher than the main one.

When reversing the master aap nse%, C

neither u signals

JO b {fezel yu

the polarity BtctdfiHoro of the null-organ 16, and the logic block 21 reverses the excitation current and engine VDS, Proc-5 electric braking of the engine 12 goes with the transition of the core converter 11 to the inverter mode and recovery of the engine energy into the network. When the polarity of the tachogenerator signal changes with the help of the switch 17, the feedback is switched through the motor EMF. First, there is an increase in the voltage on the core and the engine rotation frequency to the nominal values of the research institute, then to the specified rotation frequency when the field is weakened, and the emf of the ECOVt t is maintained in the second zone. The maintenance of the EMF fe-CO "st is carried out by the EMF controller 18 in the control system of the driver.

In general, the reverse process includes braking and starting processes. Above in nn. a), b) the operation of nonlinear links 19 and 20 in the start and stop modes was considered. Therefore, in the case of overshooting the engine rotational speed at starting, braking and reverse at speeds above the main one, the operation of nonlinear links 19 and 20 and the reverse is generally similar to the above.

It should be noted that this drive can be performed without the switch 17, but with preservation of the operation algorithm due to the introduction of other elements.

In a number of cases, link 20 can be excluded, and its functions are combined with diode limiter 7 and 8 of controller I, then when braking (|} l O especially in the zone of low engine speeds, when U.jrt O, to the input of the zero-organ 16 sensor 10 signal is received through resistors 3. And 4 | while its maximum value is limited by the voltage drop across diodes 7 and 8. Such a combination is possible with certain iB of types of resistors 3 and 4,

Claims (1)

This electric drive provides electric braking of the engine down to the zero value of the rotational speed, and underdropping is possible only with changes in the driving signal by the amount of the restraint zone. In this case, the braking is provided (when the driving voltage is turned off) at the expense of a nonlinear link with a saturation characteristic. As a result, despite the presence of a dead zone in the submode of the vanity mode, the braking of the Hbix modes is eliminated, and braking takes place at any levels. engine rotational stunts. In this case, in comparison with the known drives, this drive has a higher speed and larger areas of stability, since field control is not determined by the full input voltage of controller I, which can vary at small values in absolute value overshoot. no speed. This allows in this drive to have a light corrected RC-circuit (elements 5 and 6). In the prototype, the use of such a correction led to a reversal of the field; which at low levels of speed is ineffective because it leads to an increase in the regulation time. The switching of logic block 21 to the output of the null organ 16 made it possible to increase the speed of the drive during the roar of the sex. The use of the invention will improve the speed of electric drives with poly reversing. This leads to a decrease in time, engine reversal and, ultimately, increases the performance of the mechanism. / .. Claims of the invention A dual-zone variable speed rotation electric motor containing a measurable non-reversible thyristor converter that powers the electric motor of bodies, the control circuit of which includes a frequency regulator with 3510 and a frequency sensor connected to its inputs, the second of which is zero -organ is connected to the control by the input of the feedback switch via the EMF, the input of which is connected to the output of the non-reversing converter, and the output to the input of the reversing converter, a motor excitation winding, an excitation control unit with a logic unit and a valve state sensor connected to it, and a second zero-organ, characterized in that, in order to increase the stability and speed of the electric drive, two nonlinear units with characteristics of the type deadband and saturation, the inputs of which are connected to the rotational speed sensor, and the outputs - to two second zero-organs, the third input of which is connected to the unit of rotational speed, and the output - to the input of the logic unit. lUI jV n Ui SnoKC 0 L - n