SU1641969A1 - Electric drive of drilling rig - Google Patents

Abstract

This invention relates to an automated electric drive, and may be. used in the automation of technological processes. The purpose of the invention is to increase productivity by forming the maximum allowable mechanical x-k in intermittent modes. The device contains a current transformer 1, controlled rectifiers 2,3, 4, a motor 5 with a switch of 6 operating modes and a setpoint generator 7 of rotational speed, a setter 8 of acceleration and deceleration intensity, adders 9, 13, 24, a voltage regulator 10, keys 11, 12, 16, control unit 14, sensor

Description

The electric drive relates to an automated electric drive and can be used in the automation of technological processes, for example, in building control systems for electric drives of geological exploration drilling tanks.

The aim of the invention is to increase productivity by forming the maximum allowable mechanical speed in a re-short-term mode.

Figure 1 - shows the functional diagram of the electric drilling machine; figure 2 - electromechanical characteristics of the electric drilling rig; in Fig.3.4 - output static characteristics of pvgchouyury blocks of the electric drive; figure 5 is an example of the technical implementation of the nonlinear element and its output static characteristics.

The drive actuator includes a current transformer 1, controlled rectifiers 2,3,4, a motor 5, an operating mode switch 6, a rotational speed setting device 7, an intensity setting device 8, a first adder 9, a voltage regulator 10 with direct voltage inverse outputs, keys 11, 12, second adder 13, control unit 14 for controllable rectifiers 2.3, keys 15.16, current sensor 17, voltage sensor 18 and core current sensor 19, current cut-off unit 20, block 21 switching with four control outputs, as well as a non-linear element 22 with dead band and saturation, elineyny member 23 is dead band, and saturation of a variable gain coefficient, a third adder 24, winding 25, excitation controller 26 drive voltage and Olik. 27, driver control, threshold voltage source 28, nominal field current setting source 29.

The nonlinear element 23 consists of an amplifier 30, diodes 31, 32, resistors 33-39, and contacts 40, 41 of the operating mode switch.

Unit 8 intensity acceleration and

deceleration is an integrator with adjustable intensities of rise and fall of the signal. The steady state output signal of the setting device 8 is always equal on the level, on the input level. A smoothing filter can be used as an intensity adjuster 8. 4, b shows the static characteristic of the intensity setting device 8.

Voltage regulators 10 and 26 are of proportional type. The voltage regulator 10 has direct and inverse outputs, and can be implemented on two operational amplifiers.

Current sensor 17 is designed to rectify the output signal of current transformer 1. The current sensor 17 includes a contact 6-1 of the manual switch 6 of the operating mode, which is intended to change the transmission coefficient of the current sensor 17. .4, and shows the static characteristics of the sensor 17 current. In the long-time mode of operation of the electric drive (100%), the contact of the manual mode switch 6 is open, i.e. Ue-1 0, and the sensor 17 current has a large transmission coefficient. In the intermittent operation mode of the electric power (), the contact of the operating mode switch 6 is closed, i.e.

Ue-1 1. and the current sensor 17 has a lower transmission coefficient,

The overcurrent block 18 is a threshold element. When the input signal of the sensor 17 current value

a threshold 18, which can be set, for example, by means of a zener diode, a signal appears at the output of block 18, which

arrives at the second adder 13. And since the 18-cutoff block has a large gain factor, as the signal from the current sensor 17 increases further, the output signal of the block 18 quickly increases, which leads to compensation of the output signal of the voltage regulator 10. FIG. 4,6 shows static characteristic of the block 18 current cutoff.

Switching unit 21 is designed to control the keys 11, 12, 15, 16.

The switching unit 21 is implemented as a function of the polarity of the output signal of the first adder 9 if there is no current in the engine circuit 5 (the zero-current switch signal is 20). If the polarity of the output signal 9 is positive, on the second and third outputs of the logical switching unit, the output signals appear and the keys 11 and 15 are closed. On the first and fourth outputs there are no signals and the keys 12 and 16 are open. When the polarity of the output signal of the adder 9 changes from positive to negative, block 21 should switch, but it will not switch until the current in the crustal circuit of the executive motor 4 becomes zero. At this point in time, the inhibit signal from the output of current sensor 20 of the core becomes zero and block 21 is switched. The signals at the second and third outputs become zero and the keys 11 and 15 are opened. On the other hand, signals appear on the first and fourth outputs of block 21, and keys 12 and 16 are closed.

The nonlinear element 22 with the dead zone and saturation is intended for the PID of the output signal of the setpoint of the rotational speed of the unipolar positive reference signal to the change of the excitation current. Fig. 3a shows its static characteristic. It can be implemented on two operational amplifiers.

A nonlinear element 23 with a dead zone, saturation, and a variable gain is designed to correct the reference signal for a change in the excitation current as a function of this signal and the output signal of the current sensor 17. Three signals are input to the input of the element 23: a threshold Unop, an output signal of the block 22 and a signal from the current sensor 17. In addition, the composition of the nonlinear element 23 introduced two contacts of the manual switch 6 modes. In the long-time operation of the electric drive (PV 100%), the contacts of the switch 6 operating modes are open and the nonlinear element 23 has

large gain factor. Therefore, when the signal from the sensor 17 of the current threshold signal Unop at the output of the element 23 appears, the output signal 5 which is supplied to the third adder 24 appears. In the long-term operation mode, the output signal of the block 22 does not affect the operation of the nonlinear element 23, since - due to the open contact of the switch 6 operation modes, the signal of the block 22 is not received at the input of the element 23.

The drive works as follows.

When moving the control knob

5, the engine speed setting device 7 generates a reference signal at its output, which simultaneously arrives at the input of the intensity setting device 8 and the element 22 with the dead zone.

0 At the output of element 22, the signal is

zero as long as the signal from the output of the engine speed control unit 7 does not exceed the dead zone of the element 22.

5 The voltage at the output of the intensity setting device 8 changes from zero to a certain steady-state value. The dead band of element 22 is chosen equal to the amplitude of the output signal.

0 setting unit 7 of the engine speed, at which the nominal voltage is on the engine bark 5.

With further movement of the handle 7 control unit 8 amplitude

5 of the output signal from the output of the intensity adjuster 8 remains unchanged, and the output signal of the element 22 begins to increase from zero to a certain value, the value of which is determined by the angle

0 rotation control knob knob 7 engine speed

Until the executive engine 4 accelerates to the nominal number

5 turns, the output of element 22 is zero. Therefore, the input signal of the rectifier 4 is determined by the setting signal of the nominal excitation current Tsvn, fed to the adder 24 along with the signals

0 elements 22 and 23, which are equal to zero. In this case, the rated current flows through the excitation winding 25.

The intensity setting unit 7 generates a linearly varying voltage, the intensity of which change determines the acceleration (deceleration) rate of the engine 5. The voltage regulator 10 together with the voltage sensor 18 and the adder 9 form the voltage stabilization circuit on the engine bark 5 at the level determined by the output signal setpoint 8 intensity. Under the influence of the output signal of the intensity setting device 8 and the voltage sensor 18 at the output of the adder 9, a signal proportional to their difference is affected. As a result, the signals are also formed at the direct and inverse outputs of the voltage regulator 10.

Keys 11 and 12 cannot be simultaneously closed, i.e. when one of them is closed, the other is necessarily open. Keys 15,16 work in the same way.

Since at the first moment of time the voltage on the engine bark 5 is zero, smina with voltage sensor 18 also Oven zero O, then the entire signal from the output of the setpoint device 8 g / shge gi: 1yusty is fed to the input of the iO nonvoltage regulator. There is no power current in the core unit, therefore, the prohibition signal and the switching of the block 21, there is no switching from the 20-current sensor. Under the action of the pa, the output signal from the output of the era era 9 block 21 will include either keys 11 and 15, or keys 12 and 16.

In spite of which key is closed, both the input or control unit 14 receives the signal of the direct or inverse output of voltage regulator 10 after adder 13, since at the second input of adder 13 the signal from the output of current-cutoff unit 20 is zero. The control unit 14 provides the formation of control pulses of rectifier 2 or 3 and their phase shift is proportional to the input signal from the output of voltage regulator 10.

The keys 15 or 16 control the imyjLCL are fed to rectifiers 2 or 3 and the voltage of the main winding of the motor 5 is formed at the output of one of them.

At the output of the voltage sensor 19, a voltage is produced according to the VITS, which is fed to the sum TOD 9. However, since an increasing signal is generated at the output of the intensity setting device 8, its amplitude will be greater than the amplitude of the signal from the voltage sensor 19. Therefore, the polarity of the difference signal at the output of the adder 9 does not change. Therefore, the block 21 will retain its state and the keys 11, 12, 15, 16 will remain in the same state, i.e. engine 5 will continue to accelerate in the same direction

In the steady-state mode, there is always a difference in the setpoint and feedback signals, under the influence of which the predetermined position of the knob of the knob 7 of the rotational speed of the engine 5 will be maintained,

In the event that the acceleration rate of the executive motor is determined by the setting device 8 sufficiently high, then the current of the engine core 5 will reach such

the magnitudes that the output voltage of the current sensor 17 can reach the insensitivity threshold of the current-cutoff unit 20. At the output of unit 20, Vits voltage that will be subtracted from the voltage of the controller 10 of the voltage in the adder 13. The control voltage of the unit 14 due to this decreases and will be maintained at such a level that the current of the motor 5 does not exceed the specified value depending on the mode of operation of the drive. The intensity of acceleration of the engine 5 in this case will become lower than the intensity specified by unit 8 and will be determined only by the load on the shaft of the engine 5.

0 Acceleration of the engine 5 will be carried out according to the limiting electromechanical characteristic, having the form of an excavator (figure 2, a).

In case the control knob for sensor 5 of the rotation frequency 7 specifies the opposite polarity of the reference signal, the algorithm of the drive operation is similar to the one given above with the difference that the polarity of the difference signal at the output

0 adder 9 will be opposite, switching unit 21 will turn on other switches, control unit 14 will be connected to another output of speed controller 10, and pulses from unit 14 will be sent to

5 another rectifier 2 or 3, the voltage on the main winding of the motor 3 will have a different polarity.

If after the end of acceleration of the engine 5 to the nominal rotational frequency, the moment of resistance on the motor shaft is absent, and the control knob of the setting device 7 is set in such a position that the output signal of the nonlinear element 22 also generates a reference signal, thus, the reference signal at the output of the reference 8, the intensity does not change, the voltage on the engine bark 5 is also constant.

The target signal from the output of the element 22 0 is fed to the adder 24. At the output of the adder 24, a signal is formed and fed to the input of the controller 26 of the excitation voltage. Under the action of this signal, the regulator 26 changes (decreases) its output signal 5, the control unit 27 changes the phase of the control pulses fed to the rectifier 4. As a result, the output voltage of the rectifier 4 changes (decreases), and consequently, the excitation current.

The engine 5 begins to accelerate to a speed determined by the excitation flow, and therefore by the setting signal 7, i.e. The speed of the engine 5 in the second control zone is determined by the position of the control knob of the speed setting device 7.

If the moment of resistance on the motor shaft increases, then under its influence the current in the engine winding 5 begins to increase, and consequently, the signal from the current transformer 1 increases.

A nonlinear element 23 with a dead zone, saturation, and a variable gain is intended to change the current setpoint of the electric drive in the second control zone when the power constant mode is implemented at a PV of 100%.

Functionally, to form the section AB of the characteristic 2 of the drive when the vertical section of the HELL of the characteristic 1 at 100% P (figure 2), element 23 modifies the control signal of the regulator 26, so that the excitation current increases in proportion to the current exceeding the nominal value core .

The slope of the above sections of the drive characteristics is determined by the transfer coefficient of the nonlinear element 23 at the input U17, and the response threshold is determined by the voltage of source 28 as well as 1) 22 at which goes to the other two inputs of element 23. The change in the characteristics implemented by the electric drive A manual mode switch that commits both element 23 and sensor 17.

In the 100% duty cycle mode, when the current of the actuator motor reaches its nominal (characteristic 1, figure 2) value at the output of element 23, voltage U23 appears, which due to the high transmission coefficient of element 23 becomes large with the slightest increase in the current of the core. In this case, the resulting signal at the output of the adder 24 changes in such a way that the excitation current will increase, the rotational speed of the engine 5 will decrease, and the torque developed by the drive will increase due to an increase in the flow of the engine 5. As a result, the drive will develop an increased torque on the shaft due to an increase engine flow 5 while reducing the rotational speed with little or no increase in the current of the core.

As a result, the element 23 provides for stabilization of the current of the core at the nominal level due to the enhancement of the excitation flow as a function of the current exceeding the current of the core 5 of the nominal value. This ensures that the engine 5 is operating at rated power.

In the mode, the element 23 has a significantly lower transmission coefficient at the input Ui7, therefore the section AB of characteristic 2 (FIG. 2) is flatter. In this mode of drive operation, the input element 23, in addition to the voltage source 28, also receives the signal U22, which is necessary to change the resulting threshold of the element 23.

In this case, the resultant trigger threshold of element 23 is a function of the output signal of element 22, which in the second control zone is proportional to the rotational speed of engine 25, whereby the mechanical characteristic contains a section AB of characteristic 2 (figure 2), which is 5 extremely valid for the actuator at.

With a PV of 100% control signals of a manual switch, the 6 operating modes are zero, i.e. its contacts, stuck in the 0 part of the element 23 (in figure 5, and marked 40 and 41), are open. Then the input of the amplifier 30 receives signals:

through the resistor 37 enters the threshold

signal source 28 negative sign;

5 through the resistor 38 receives a signal from

current sensor 17 proportional to current

cor, positive sign.

The command signal U22 to attenuate the excitation current to the amplifier 30 does not flow, 0, since contact 40 is open.

The magnitude of the threshold signal of source 28 is chosen equal to the magnitude of the signal from sensor 17 at a current of the core flowing through the engine core winding equal to the nominal value of 5 min.

Due to the diodes 31, 32, the amplifier 30 (FIG. 5, a) is connected in the ideal diode circuit, i.e. at its output may be present

0 only negative voltage. Therefore, until the signal from the output of sensor 17 becomes equal to the value of the threshold signal Unop (until the current of the core becomes equal to the nominal value), the output of the amplifiers 30 is a zero signal. With a further increase in the current of the core, since the signal from the positive sign sensor 17, at the output of the amplifier 30, the signal changes from zero to a maximum negative value.

Thus, the adder 24 of the nonlinear element 23 receives the maximum signal opposite to the sign of the task to attenuate the excitation current, which leads to a reduction to zero of the signal at the output of the adder 24, and therefore to an increase to the nominal excitation current.

The value of the core current at which the excitation juice reaches the nominal value is determined by the gain factor 30. The gain factor 30 by the signal from the sensor 17 is quite large, K-20-30, therefore, the characteristic of the electric drive in the continuous mode is almost vertical (Fig. 2, feature 1). In Fig. 5, b, the output characteristic of the unit 23 in the PV mode is 100% indicated by a dotted line, and the corresponding characteristic of the electric drive in Fig. 2 is denoted by numeral 1.

Now consider the operation of block 23 in the operation mode at.

In this case, the contact 40 connects the signal 1) 22 (a negative sign) to the input of the amplifier 30 via the elements 39 and 33, and the contact 41 is closed. Consequently, in addition to the signals from block 17 and the threshold signal, a reference to the attenuation of the excitation current U22 will be sent to the input of the amplifier 30.

Since the resistor 35 is shunted by pin 41, the gain in the amplifier is 30 K 4 - 5, therefore, the output characteristic of element 23 is not vertical, but canopy. The drive characteristic also has a flat area AB (Fig. 2), the slope of which is determined by the gain of the amplifier 30.

The reference signal for the attenuation of the excitation current is fed to the input of the amplifier 30 to change the resulting threshold of the element 23. The resulting threshold is added up from the threshold signal Unop and the reference signal to the attenuation of the excitation current U22.

Element 23 is designed in such a way that, at the maximum voltage of the setpoint for attenuating the excitation current, the magnitude of the resulting threshold corresponds to the rated current of the motor 5, and when the voltage of the setpoint for the attenuation of the excitation current decreases, the resulting threshold increases linearly and at IJ22 0 corresponds to the maximum permissible current of the corr 1 imax.

Thus, the element 23 carries out the formation of a section of the characteristic of the electric drive as if the voltage of the task for current attenuation changes

excitation and change of load on the motor shaft.

Claims (1)

Invention Formula The electric drive of the drilling machine, containing a current transformer, the output of which is connected to a current sensor, the output of which is connected to a current cut-off unit, the output of the rotational frequency control unit is connected to the input of the first nonlinear element and to the input of the intensity setting unit, the output of which is connected to the first input of the first adder, to the second input of which is connected to the voltage sensor, and the output of the first adder is connected to the input of the voltage regulator, the first output of which through the first key is connected to the first input of the second totalizer Pa, and the second output of the voltage regulator is connected via the second switch to the first input of the second adder, to the second input of which the output of the current cutoff unit is connected, and the output of the second adder through the first control unit is connected to the inputs of the third and fourth switches, the output of the third switch is connected to the control input of the first controllable rectifier, and the output of the fourth key is connected to the control input of the second controllable rectifier, the first and second controllable rectifiers being switched on and counter inputs Without the current transformer to the mains and the outputs through the current sensor kor to the motor core, the output of the first adder is connected to the first input of the switching unit, to the second input of which the output of the current sensor kor is connected, and the first and second outputs of the switching unit are connected respectively to the control the inputs of the first and second keys, the third and fourth outputs of the switching unit are connected to the control inputs of the third and fourth keys, respectively, and the field voltage regulator through the second connection control unit to the third controlled rectifier, the output of which is connected to the motor excitation winding, characterized in that, in order to improve performance by forming the maximum permissible mechanical characteristics in the re-intermittent mode, the actuator is equipped with a second non-linear element, mode switch, third adder, source of setpoint rated excitation current and the source of the threshold voltage, the output of which is connected to the first input of the second nonlinear element, to the second input to The output of the current sensor is expensively connected, and to the third input - the output of the first nonlinear element, and the output of the second nonlinear element is connected to the first input of the third adder, to the second input of which the output of the first nonlinear element is connected, and to the third - the output of the source of the nominal excitation current, the third output the adder is connected to the input of the excitation voltage regulator, and the first output of the operation mode switch is connected to the second input of the current sensor, the second and third outputs of the operation mode switch are connected to the fourth and fifth inputs of the second nonlinear element.  // Schi 2 and, t, t o Repeated - short term mode but Long mode 1 meg "81 tz y v Fig.Z On 4 Un