An automatic control system for electromagnetic iron remover

Abstract

The present invention discloses an automatic control system for an electromagnetic iron remover, which relates to a voltage and current stabilization control, including a power supply, the power supply supplies power to an electromagnetic coil EC1, and the excitation coil power supply circuit is: a motor switch Q1, a transformer T1, a motor switch Q4, a contactor KM4, a three-phase intelligent voltage regulating module RB1, a rectifier bridge RB2, and a leakage current detection transmitter TR4 are connected in series in sequence, and a DC voltage is output to the electromagnetic coil EC1; between the leakage current detection transmitter TR4 and the electromagnetic coil EC1, a DC current transmitter TR1 is connected in series with the electromagnetic coil EC1, a DC voltage transmitter TR2 is connected in parallel with the electromagnetic coil EC1 and the DC current transmitter TR1, and a series circuit of a resistor R1 and a freewheeling diode D1 is connected in parallel with the freewheeling diode D1, and a DC voltage transmitter TR3 is connected in parallel with the freewheeling diode D1. The system can realize constant voltage or constant current control within a certain range, so that the output voltage or current is not affected by power grid fluctuations and coil temperature, and the stable magnetic field strength of the coil is ensured, so that it is applicable to a wider range of iron removal fields.

Description

Technical Field

[0001] The invention relates to an electromagnetic iron remover control system, in particular to a voltage and current stabilization control of an electromagnetic iron remover. Background Art

[0002] Electromagnetic iron remover is a device that can generate a strong magnetic field attraction, which can remove ferromagnetic materials mixed in fluid materials or bulk materials. Since the electromagnetic iron remover is magnetic when it is powered on and loses its magnetism when it is powered off, it is very convenient to clean itself without the need for additional structures, and the magnetic field strength is adjustable, which has a wide range of applications, making it widely used in the removal of iron from ceramics, glass, chemicals, plastics, food, etc. However, the temperature of the excitation coil of the electromagnetic iron remover will increase during use, and the increase in temperature will cause changes in the magnetic field strength, and the external voltage will also directly affect the magnetic field strength of the electromagnetic iron remover, which causes a major defect of the electromagnetic iron remover: the magnetic field strength is unstable during use. This instability makes it difficult to use electromagnetic iron removers in precision machining to remove iron. In the field of precision machining, expensive permanent magnets are often used for iron removal. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides an automatic control system for an electromagnetic iron remover. The system can achieve constant voltage or constant current control within a certain range, so that the output voltage or current is not affected by power grid fluctuations and coil temperature, thereby ensuring a stable magnetic field strength of the coil, making it suitable for a wider range of iron removal fields.

[0004] In order to solve the above technical problems, the present invention is solved by the following technical solutions: an electromagnetic iron remover automatic control system, including a power supply, the power supply supplies power to the excitation coil EC1, the excitation coil power supply circuit is: motor switch Q1, transformer T1, motor switch Q4, contactor KM4, three-phase intelligent voltage regulation module RB1, rectifier bridge RB2, leakage current detection transmitter TR4 are connected in series in sequence, and a DC voltage is output to the excitation coil EC1; between the leakage current detection transmitter TR4 and the excitation coil EC1, the DC current transmitter TR1 is connected in series with the excitation coil EC1, and the DC current transmitter TR1 is used to monitor the excitation current of the excitation coil EC1 in real time; between the leakage current detection transmitter TR4 and the excitation coil EC1, the DC voltage transmitter TR2 is connected in parallel with the excitation coil EC1 and the DC current transmitter TR1, and the DC voltage transmitter TR2 is connected in parallel with the excitation coil EC1 and the DC current transmitter TR1. Used to monitor the excitation voltage of the excitation coil EC1 in real time; between the leakage current detection transmitter TR4 and the excitation coil EC1, a series circuit of a resistor R1 and a freewheeling diode D1 is connected in parallel, and the freewheeling diode D1 is connected in parallel with a DC voltage transmitter TR3. The DC voltage transmitter TR3 is used to monitor the voltage value of the freewheeling diode in real time, and has an alarm function for the breakdown of the diode and a comparison function with the DC voltage transmitter TR2.

[0005] Preferably in the above technical solution, the power supply is a three-phase power supply.

[0006] Preferably, in the above technical solution, the leakage current detection transmitter TR4 is used to detect the DC leakage current output by the rectifier module combination, and is used to detect the insulation of the coil and personal safety protection.

[0007] Preferably in the above technical solution, an on-off switch F1 is provided on the main circuit of the power supply.

[0008] Preferably in the above technical solution, the power supply supplies power to the vibration motor, and the vibration power supply circuit is: the motor switch Q2, the contactor KM2, and the vibration motor are connected in series.

[0009] Preferably in the above technical solution, the power supply supplies power to the cooling pump, and the cooling pump circuit is: a motor switch Q3, a contactor KM3, and a cooling pump are connected in series.

[0010] Preferably in the above technical solution, the power supply supplies power to the control power supply, and the control power supply circuit is: an on-off switch F1 and a transformer T2 are connected in series.

[0011] Preferably, in the above technical solution, the system is controlled by PLC, and the PLC has a PID module. The PID module maintains the stability of the voltage and current of the excitation coil EC1 by adjusting the voltage and current.

[0012] The core of this system is to dynamically adjust the coil voltage and current to be constant. Its core control method is to use PID control with constant excitation coil voltage and constant excitation coil current. PID control: According to the given value and the actual output value, the control deviation is formed, and the deviation is linearly combined by proportion, integration and differentiation to form the control quantity to control the controlled object.

[0013] Voltage PID control: The PID control of the PLC collects the voltage feedback value of the output of the rectifier module combination and compares it with the voltage value set by the user, and then performs PID automatic adjustment to keep the output value equal to the set value. External interference such as grid voltage fluctuations, set value changes, switching between voltage PID control and current PID control, etc. will not affect the stability of the output. Voltage PID control can make the output voltage constant. At this time, the excitation current increases with the increase of coil temperature and the internal resistance increases. According to U=IR, the current will decrease accordingly. Because the coil excitation magnetic field is theoretically proportional to the excitation current, the coil excitation magnetic field will decrease with the increase of coil temperature until the coil reaches thermal equilibrium. However, according to the formula P=U² / R, the coil excitation power will decrease with the increase of temperature.

[0014] Current PID control: The PID control of the PLC collects the output current feedback value of the rectifier module combination and compares it with the current value set by the user, and then performs PID automatic adjustment to keep the output value equal to the set value. Current PID control can ensure that the output excitation current is constant, thereby ensuring the stability of the coil excitation magnetic field. At this time, the excitation voltage will increase as the coil temperature increases and the internal resistance increases. The excitation power will increase according to the formula P=I²R.

[0015] Compared with the prior art, the system of the present invention can realize constant voltage or constant current control within a certain range, so that the output voltage or current is not affected by power grid fluctuations and coil temperature, ensuring the stable magnetic field strength of the coil, making it applicable to a wider range of iron removal fields. It also has a leakage detection function, which can monitor the insulation of the excitation coil; coil temperature and rectifier module temperature monitoring function to increase system reliability; through logical judgment, it can realize the judgment of transmitter failure, disconnection failure, output voltage or current instability failure, etc., and output fault information alarm; based on RS485 and RJ45 two communication interfaces, it can realize a variety of standard communication protocols, which is convenient for the upper system to do online control. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the operation flow chart of the electromagnetic iron remover of the present invention.

[0017] Figure 2 This is the PID control logic diagram of the present invention.

[0018] Figure 3 This is the main power supply circuit diagram of the present invention.

[0019] Figure 4 This is the coil voltage transformation circuit diagram of the present invention.

[0020] Figure 5 This is the coil detection circuit diagram of the present invention.

[0021] Figure 6 Schematic diagram of communication of the system of the present invention. DETAILED DESCRIPTION

[0022] Example 1: Figures 1 to 6As shown, an automatic control system for an electromagnetic iron remover includes a three-phase power supply, and an on-off switch F1 is provided on the main circuit of the power supply. The excitation coil power supply circuit is: a motor switch Q1, a transformer T1, a motor switch Q4, a contactor KM4, a three-phase intelligent voltage regulating module RB1, a rectifier bridge RB2, and a leakage current detection transmitter TR4 are connected in series in sequence, and a DC voltage is output to the excitation coil EC1; between the leakage current detection transmitter TR4 and the excitation coil EC1, a DC current transmitter TR1 is connected in series with the excitation coil EC1, a DC voltage transmitter TR2 is connected in parallel with the excitation coil EC1 and the DC current transmitter TR1, and a series circuit of a resistor R1 and a freewheeling diode D1 is connected in parallel with the freewheeling diode D1, and a DC voltage transmitter TR3 is connected in parallel with the freewheeling diode D1.

[0023] The power supply supplies power to the vibration motor, and the vibration power supply circuit is: motor switch Q2, contactor KM2, and vibration motor are connected in series. The power supply supplies power to the cooling pump, and the cooling pump circuit is: motor switch Q3, contactor KM3, and cooling pump are connected in series. The power supply supplies power to the control power supply, and the control power supply circuit is: on-off switch F2 and transformer T2 are connected in series.

[0024] The system is controlled by PLC, which has a PID module. The PID module keeps the voltage and current of the excitation coil EC1 stable by adjusting the voltage and current. The PLC is integrated with two communication interfaces: RS485 and RJ45.

[0025] The main circuit power supply is controlled by F1 for on-off control and short-circuit protection. The controlled equipment mainly includes cooling pump, vibration motor and coil. The cooling pump and vibration motor are protected by two motor switches Q2 and Q3 for overload and phase loss, and contactors KM2 and KM3 for start-stop control. The coil adopts DC excitation, and the control is mainly composed of transformer + controlled rectifier combination. Motor switch Q1 is used to protect the primary side of the three-phase isolation transformer. The function of transformer T1 is to prevent the output voltage from being too high and to provide isolation protection. Motor switch Q4 and contactor KM4 are used to start and stop and protect the rectifier module combination. The three-phase intelligent voltage regulation module RB1, rectifier bridge RB2, and cooler form a rectifier module combination, which adjusts the secondary voltage of transformer T1 to DC voltage and outputs it to the DC coil. DC current transmitter TR1 is used to monitor the excitation current of the excitation coil EC1 in real time. DC voltage transmitter TR2 is used to monitor the excitation voltage of the excitation coil EC1 in real time. The DC voltage transmitter TR3 is used to monitor the voltage value of the freewheeling diode in real time, and has the function of alarming the breakdown of the diode and comparing with the DC voltage transmitter TR2. The leakage current detection transmitter TR4 is used to detect the DC leakage current output by the rectifier module combination, and is used to detect the insulation of the coil and personal safety protection.

[0026] The control and feedback of each component are all automatically controlled by PLC, which is connected to the touch screen HMI through communication, so that it can be used for local operation and monitoring of equipment through the touch screen. The system reserves two communication interfaces based on RS485 and RJ45, which is convenient for customers to choose remote communication protocols. It makes it easier to realize system linkage.

[0027] The system includes two control location functions: local control and remote control. Local control is controlled by the operator through the touch screen. Remote control is the upper system using communication or hard wiring to control the electromagnetic control system. Local control and remote control have an interlocking function, that is, remote control is invalid during local control, and local control is invalid during remote control. Whether it is local or remote control, the monitoring function is valid. After the system is powered off and restarted, it will default to the state before the power outage. Local control has two modes: manual control and automatic control. When the system is powered off and restarted or there is a fault alarm, it will default to manual control mode. If the remote control cabinet is connected through communication, it can realize remote manual and automatic control modes. The system defaults to hard wiring for remote control. In manual control mode, the system will not automatically clean up. At this time, the device operation can be controlled by the buttons on the manual operation interface.

[0028] In automatic control mode, the system will automatically turn on the cooling pump, vibration motor and transformer power supply, and then automatically start the rectifier module. When the excitation voltage or current reaches the set magnetic force, the three-way valve turns to the discharge port. At this time, the electromagnetic iron remover will automatically clean according to the set running time or automatically clean through the "forced cleaning" button on the touch screen. Cleaning process: stop unloading first, and after the set emptying time is reached, the three-way valve turns to the slag discharge port, the excitation is turned off, and the slag cleaning begins. After the set cleaning time, the coil excitation is started again, and the entire cleaning process ends. At this time, the system will restart the timing to start the next cycle.

Claims

1. An automatic control system for an electromagnetic iron remover, comprising a power supply and a cooler, wherein the power supply supplies power to an excitation coil EC1. Its characteristics are: The power supply circuit of the excitation coil EC1 is: the motor switch Q1, the transformer T1, the motor switch Q4, the contactor KM4, the three-phase intelligent voltage regulating module RB1, the rectifier bridge RB2, and the leakage current detection transmitter TR4 are connected in series in sequence to output a DC voltage to the excitation coil EC1; The three-phase intelligent voltage regulating module RB1, the rectifier bridge RB2 and the cooler form a rectifier module combination; Between the leakage current detection transmitter TR4 and the excitation coil EC1, the DC current transmitter TR1 is connected in series with the excitation coil EC1, and the DC current transmitter TR1 is used to monitor the excitation current of the excitation coil EC1 in real time; Between the leakage current detection transmitter TR4 and the excitation coil EC1, the DC voltage transmitter TR2 is connected in parallel with the excitation coil EC1 and the DC current transmitter TR1, and the DC voltage transmitter TR2 is used to monitor the excitation voltage of the excitation coil EC1 in real time; Between the leakage current detection transmitter TR4 and the excitation coil EC1, a series circuit of a resistor R1 and a freewheeling diode D1 is connected in parallel, and the freewheeling diode D1 is connected in parallel with a DC voltage transmitter TR3. The DC voltage transmitter TR3 is used to monitor the voltage value of the freewheeling diode D1 in real time, to provide an alarm for the breakdown of the diode, and to compare the voltage value of the freewheeling diode D1 with the voltage value output by the DC voltage transmitter TR2; The system is controlled by PLC, which has a PID module. The PID module control component collects the voltage feedback value of the output of the rectifier module combination and compares it with the voltage value set by the user, and then performs PID automatic adjustment to keep the output value equal to the set value; the PID module control component collects the current feedback value of the output of the rectifier module combination and compares it with the current value set by the user, and then performs PID automatic adjustment to keep the output value equal to the set value; the PID module maintains the stability of the voltage and current of the excitation coil EC1 by adjusting the voltage and current.

2. According to claim 1, an automatic control system for an electromagnetic iron remover, Its characteristics are: The power supply is a three-phase power supply.

3. An automatic control system for an electromagnetic iron remover according to claim 1, Its characteristics are: The leakage current detection transmitter TR4 is used to detect the DC leakage current output by the rectifier module combination, and is used to detect the insulation of the coil and personal safety protection.

4. An automatic control system for an electromagnetic iron remover according to claim 1, Its characteristics are: An on-off switch F1 is provided on the main circuit of the power supply.

5. The automatic control system for an electromagnetic iron remover according to claim 1, characterized in that the controlled equipment of the automatic control system for an electromagnetic iron remover includes a vibration motor, a cooling pump and a control power supply, The power supply supplies power to the vibration motor, and the vibration motor power supply circuit is: the motor switch Q2, the contactor KM2, and the vibration motor are connected in series; The power supply supplies power to the cooling pump, and the cooling pump circuit is: the motor switch Q3, the contactor KM3, and the cooling pump are connected in series; The power supply supplies power to the control power supply, and the control power supply circuit is: an on-off switch F2 and a transformer T2 are connected in series.

6. An automatic control system for an electromagnetic iron remover according to claim 1, Its characteristics are: The PLC is integrated with two communication interfaces: RS485 and RJ45.

Images