SU1651350A1 - Dc electric drive with potential load torque - Google Patents

Abstract

The invention relates to electrical engineering and CANZT to be used in safety crane drives. The electric drive contains an electric motor, the windings 1 and 3 of the core and the independent excitation of which are connected to the thyristor converter 2 and to the thyristor exciter 4. The controller 28 is connected with the regulator 6 of the voltage of the converter 2. The sensor 12 of the current of the winding 1 is connected to control key 22 the input of the regulator 6. When the load is lifted, the key 22 is closed and the electric drive increases the speed by decreasing the load by increasing the voltage of the winding 1. To eliminate the emergency increase in speed, the current and voltage of 1. Coils 1 yl

Description

The invention relates to electrical engineering and can be used in crane electric drives.

The purpose of the invention is to increase safety.

The drawing shows a diagram of the drive.

A DC electric drive with a potential load moment contains an electric motor, the winding 1 of the core of which is connected to the reversing thyristor converter 2, and the winding 3 of independent excitation to the thyristor exciter 4. The converter control system contains a voltage intensity regulator 6 sequentially connected, a regulator current torus 7 and pulsed-phase control unit 8 connected to the input of the formers 9 and 10. The regulator input 6 is connected to the rectified voltage converter 11 OWATER 2. Controller input 7 connect /

chen to the output of the sensor 12 winding current 1 box. The drive control system includes a voltage sensor 13 in series, a winding 1 core, an OR 14 block, a delay element 15, a scaling block 16, a threshold element 17, an OR block 18, an AND block 19, the output of which is connected to the control input of the driver 4 the control input of the scaling unit 20, the input of the unit 21 And the control key 22. The inverse output of the block And 19 is connected to the control input of the scaling block 16. The inverse output of the threshold element 23 is connected to the input of the block OR 14, the inverse output of the element 15 is connected to the input of the block And 19. The sensor 12 through the diode 24 is connected to the input of the block 16, the output of the element 17 is connected to the control input of the scaling unit 25. Threshold element 26 is connected through block 25 to the winding voltage of 1 core, the output of element 26 is included in the white circuit

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the coil of the zero contactor through which the electric drive control system and the winding of the mechanical brake of the drive are powered. The output 27 of the setting device 28 operating mode is connected via block 20 to the input of the setting device 5. The output 29 of the setting device 28 is connected to the input of the unit 21. The output 30 is connected to the input of the element 23 and to the input of the block AND 19. The output 31 is connected to the input of the block OR 18. Sensor 12 current through the key 22 and the low-pass filter 32 is connected to the input of the regulator 6. Element 15 is connected via diode 33 to block 16.

The electric drive can be implemented on the basis of a TPE series crane and thyristor converter, an electric motor of the D series and a microprocessor, microelectronic, or relay-contactor control system, for example, a P-3263 control panel.

The drive works as follows.

The signal amplitude at the output 27 of the setting device 28 corresponds to the specified rectifying voltage of the converter 2, and the sign, to the corresponding polarity of the voltage. In the mode of lifting the load with the highest speed signal at the outputs 29-31 corresponds to a logical unit. In the mode of lowering a load with the highest speed, the signal at outputs 29 and 31 corresponds to a logical zero, and at output 30 - to a logical one. In the mode of lowering the load with intermediate speed, the signals at the outputs 29 and 31 are equal to logical zero.

When the load is lifted at the highest speed, the signal at the output of the block 20 corresponds to the nominal voltage of the electric motor and the latter accelerates at the rate of the intensity setter 5 under the control of the current regulator 7. When the voltage on the winding 1 is 0.8-0.95 nominal, the threshold element of the sensor 13 is turned on, and with the time delay of the element 15, the block 19 closes the key 22 and changes the transfer coefficient of the block 20, and the winding current sensor 12 of the core is connected to the control input torus 6 voltage, and the signal at the output of block 20 corresponds to an increased voltage on the winding of the core. In the statistical mode, the signal at the output of the voltage regulator 6 is equal to

U UM3KC-KJ, (1)

where 1) max is the highest voltage on the core winding that can reach double the nominal voltage of winding 1;

K - coefficient of proportionality;

J - winding current

The steady-state voltage on the winding 1 core depends on the load of the electric drive (at high currents the voltage is equal to nominal, and for small currents it rises to double nominal). When descending, the load with the highest speed in the IV quadrangle

Those tilted electromechanical characteristics are unstable; therefore, the voltage across the winding 1 of the core depends stepwise on its current. Signal to increase the voltage in the winding current function

supplies the threshold element 17 after acceleration of the drive to the nominal speed. The signal of the logical unit at the output of the AND 19 block not only gives the command to increase the voltage of the winding of the core, but also allows to reduce the current in the winding 3 of the excitation as a function of the current of the grounding 1 of the core. .

In this way, an increase in the speed of the electric drive in the function

its load is up to four times the nominal value.

To eliminate the accident of the drive when the key 22 connecting the feedback is not functioning correctly

The flow to the input of the voltage regulator is provided by means of stopping the electric drive in case of an increase in the voltage on the winding of 1 core for sufficiently large currents of the core. Setting threshold

element 17 corresponds to 0.1–0.25 of the rated current of the core, and the setting of element 26 corresponds to 2.1–2.3 of the rated voltage of the electric drive core winding. When the signal is given by the block 1/1 19 to increase

voltages on winding 1 in excess of rated blocks 16 and 25 change the settings of the elements 17 and 26 to 0, 4-0.7 of the rated current of the winding 1 and 1.3-1 J of the rated voltage of the winding 1, respectively.

In the event of an increase in the voltage on the winding 1 above the nominal value at a sufficiently high current, the core turns on element 26 and the electric drive stops. If the voltage increase on the winding

1 occurred at a comparatively small core current, the threshold element 17 will be turned off, and unit 25 will change the setting of the element 26 to 2.1-1.3 of the nominal value, element 26 will not turn on and the electric drive

will continue to work.

Thus, the drive has a high operating safety.

Claims (1)

Claims of the invention. Electric direct current with potential load moment according to auth.St. Mz 1545316, from l and h and y and with the fact that, in order to increase security, it introduced the second and third scaling units and the second threshold element, the output which is connected to the control input of the contactor in the power supply circuit of the equation system by the electric drive and winding of the mechanical brake, and the input is connected to the output of the third scaling unit, the information input of which is connected parallel to the winding of the electric motor core, and the control input is connected to the output of the first threshold element, the input of which includes the second scaling unit, the information input of which is connected to the output of the current sensor, and the control input is connected to the inverse output of the unit I. I G