PLC - at the design of charging machine cont...

Figure 1 electronic detection circuit flux

3 Control System Design 
                                                  

Figure 2 shows the Magnetizer system diagram. Circuit is adjustable DC high voltage power supply, discharge switching circuit, plc controller, touch screen, magnetic heads and other testing and charging circuit. Control requirements:

① adjustment to adjust the angle of thyristor controlled magnetizing current;

② products automatically detect the magnetic flux intensity of magnetization;

③ man-machine dialogue, the set parameters and display the operating status;

④ plc reality system control and operation;

⑤ power over-current and over-voltage protection components;

⑥ with input short circuit protection, safe operation.

Magnetizing circuit are the main circuit and trigger circuit. Magnetizer circuit shown in Figure 3. AC voltage regulator circuit is mainly composed of the main boost, energy storage and discharge rectifier circuit. TRIAC vt1 by adjusting the phase angle and tv2 (or conduction angle) to adjust the input voltage step-up transformer t, and then ripple through the bridge rectifier circuit to DC voltage, the energy stored in the capacitor cl. When the SCR vt7 conduction, the instant charge and head to produce a strong pulse current discharge, fast charge and magnetic material. In the two-way synchronization phase control thyristor trigger circuit, the analog module fx0n-3a controls the output voltage vout conduction angle, to adjust the deposit to the upper capacitor voltage.

Figure 3 magnetizing circuit

3.2 System control circuit

Figure 4 for the system control circuit,analog fx0n-3a has two inputs and one output, where the input current signal and the magnetic flux detection signal output control triac conduction angle.

Figure 4, system control circuit

Figure 5 Block Diagram

3.3 Design Control Program

Control procedures are manual and automatic. Manual control program for the capacitor switching and capacitor charging check, magnetizing inspection debugging and maintenance.

Control program includes automatic sequence control procedures, grading capacitor charging routine, magnetic detection subroutine, hmi interface program, close the door and filling head connection, over voltage over current. As the work moves by water, so the use of sequential control routine series of these work together, so that the preparation procedure is simple, and easy to read instructions with stl. (www.hzbst.com)

Routine grading capacitor charge is taken into account in the zero state capacitor charging current may have a great impact, it will damage the bridge rectifier and bi-directional control GUI. Secondary energy storage capacitance charging, began to take maximum resistor r1, after the contact with the shorting km2, the total pressure charging.

After magnetizing the top of the workpiece is to detect the magnetic flux valve coil, should be on the Figure 1, short the integration capacitor discharge (test cleared), then insert the coil in the magnetic parts, you can check the product flux, which identification of the batch performance requirements, while the stable triac conduction angle, to ensure product quality.

Set the pole numbers, magnetizing current, flux and job status display. (www.hzbst.com)hmi touch screen interface program is to achieve the configuration between and plc.

4 Conclusion

Magnetizer storage capacitor discharge, the maximum instantaneous discharge current can reach more than 30ka, in the 10ms time to generate extremely high magnetic field strength will not affect the impact on the grid. Magnetic coil with the appropriate charge, in an instant 30000 oe (oersted) or more magnetic field, high coercive force for the NdFeB magnet, magnetizing better. Magnetization and magnetic flux detection for pipeline operations as a whole, an efficient, reliable, and interference characteristics, however, reduce the power electronic devices around the time of the on-off effects to be in further study.

 www.hzbst.com