Multi-layer electromagnetic stirring control system and multi-layer electromagnetic stirring device

Abstract

The application discloses an electromagnetic stirring control system, which comprises a primary power module, a secondary power module, a controller and a feedback module, the controller is connected with the primary power module, the secondary power module and the feedback module respectively, and the primary power module is electrically connected with the secondary power module; the primary power module is used for generating direct current, and the secondary power module is used for inverting to generate multiple paths of alternating current with different phases; the controller can be used for controlling the on-off of the primary power module and the output of the secondary power module; the frequency and the phase of the multiple paths of alternating current output by the secondary power module can be controlled through the controller; and the feedback module feeds back a sensor signal to the controller. The application further discloses an electromagnetic stirring device. Compared with the prior art, the electromagnetic stirring control system has the beneficial effects that the device can generate a complex composite magnetic field and a locally strengthened magnetic field, the device has a feedback adjusting function, and the multi-layer stirring effect can be realized.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic stirring technology, specifically to a multi-layer electromagnetic stirring control system and a multi-layer electromagnetic stirring device. Background Technology

[0002] Electromagnetic stirring devices are widely used in traditional metallurgy due to their non-contact operation. However, existing electromagnetic stirring devices often use a single magnetic field. The advantages of this single magnetic field type are: 1. Electromagnetic stirring is a non-contact stirring method, as the electromagnetic stirring device does not need to directly contact the molten metal. This avoids physical wear and contamination between the stirrer and the melt, extends the service life of the equipment, and ensures the purity of the metal.

[0003] 2. Electromagnetic stirring devices with a single magnetic field configuration are relatively simple to design and have lower manufacturing and maintenance costs. Because the magnetic field configuration is fixed, the control system and operating procedures are also relatively simple, making them easy to operate and maintain. 3. Because the magnetic field remains constant, the electromagnetic stirring device operates with high stability, providing a consistent stirring effect. This is highly advantageous for certain processes requiring high consistency.

[0004] However, in recent years, with the development of new composite materials, higher requirements have been placed on metallurgical processes. Electromagnetic stirring devices with a single magnetic field configuration are insufficient to meet the metallurgical needs of high-performance composite materials. The main drawback of electromagnetic stirring devices with a single magnetic field configuration is: 1. The application scope of electromagnetic stirring devices with a single magnetic field configuration is limited. Electromagnetic stirring devices with a single magnetic field configuration can typically only be optimized for castings with specific shapes or material properties. This limitation makes it difficult for a single magnetic field configuration to meet diverse metallurgical needs; 2. Electromagnetic stirring devices with a single magnetic field configuration have a limited stirring effect. Because the magnetic field configuration is fixed, the direction and distribution pattern of the electromagnetic force generated during electromagnetic stirring are also relatively fixed. This may result in a single flow pattern in the melt, making it difficult to fully mix or uniformly distribute alloying elements, thus affecting the final quality of the cast billet. 3. Electromagnetic stirring devices with a single magnetic field configuration are insufficient to meet the requirements of high-performance materials. With the development of metallurgical technology, an increasing number of new composite materials are being applied in industrial production. These materials place higher demands on metallurgical processes, and electromagnetic stirring devices with a single magnetic field configuration may not provide sufficient process flexibility to meet the complex requirements of these high-performance materials.

[0005] 4. Electromagnetic stirring devices with a single magnetic field configuration lack process control flexibility. During the smelting process, different stages or locations may require different stirring intensities or modes. Devices with a single magnetic field configuration typically cannot flexibly adjust the magnetic field configuration, limiting the fine-grained control of the metallurgical process. 5. Electromagnetic stirring devices with a single magnetic field may lead to increased energy consumption: In some cases, a single magnetic field may require a higher current intensity or a longer stirring time to achieve the desired stirring effect, resulting in increased energy consumption.

[0006] 6. Electromagnetic stirring devices with a single magnetic field cannot achieve the technical effect of multi-layer stirring.

[0007] Therefore, there is an urgent need to research an electromagnetic stirring device with a non-single magnetic field mode that can adjust the magnetic field according to the actual situation of the object being stirred. There is also a need to research an electromagnetic stirring control system that can capture feedback electromagnetic signals and then control the magnetic field generated by the electromagnetic stirring device through these feedback signals. Additionally, there is a need to research a multi-layer electromagnetic stirring device capable of achieving layered stirring. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies and, in order to achieve multi-layer electromagnetic stirring functionality, provide a multi-layer electromagnetic stirring control system. This system includes a primary power module, a secondary power module, a controller, and a feedback module. The controller is connected to the primary power module, the secondary power module, and the feedback module, respectively. The primary power module is electrically connected to the secondary power module. The primary power module generates direct current (DC), and the secondary power module inverts and generates multiple alternating current (AC) currents of different phases. The controller can control both the on / off state of the primary power module and the output of the secondary power module. The controller enables control of the frequency and phase of the multiple AC outputs from the secondary power module. The feedback module feeds back sensor signals to the controller.

[0009] Preferably, the primary power supply module includes an AC input module, a first transformer module, a rectifier module, a first isolation module, a first filter module, a first voltage regulator module, and a DC output module connected in sequence. The AC input module is used to connect to two-phase or three-phase AC power from the main power supply. The first transformer module is an adjustable transformer and is connected to the AC input module, the rectifier module, and the controller. The rectifier module is used to convert AC power to DC power. The first isolation module is used to isolate and output DC power. The first voltage regulator module is used to maintain the stability of the output DC voltage and is connected to the secondary power supply module through the DC output module.

[0010] Preferably, the rectifier module includes thyristors Q1, Q2, Q3, Q4, Q5, and Q6; the first isolation module includes bidirectional thyristors Q7 and Q8; one end of the secondary side of the coil T1 of the first transformer module is connected to the anode of thyristor Q1 and the cathode of thyristor Q4; one end of the secondary side of the coil T2 of the first transformer module is connected to the anode of thyristor Q3 and the cathode of thyristor Q6; and one end of the secondary side of the coil T3 of the first transformer module is connected to the anode of thyristor Q5 and the cathode of thyristor Q2. The gates of thyristors Q1, Q2, Q3, Q4, Q5, and Q6 are connected to the corresponding trigger circuits. The gates of bidirectional thyristors Q7 and Q8 are connected to the corresponding trigger circuits. The cathodes of thyristors Q1, Q3, and Q5 are all connected to one end of bidirectional thyristor Q7. The other end of bidirectional thyristor Q7 is connected to one end of bidirectional thyristor Q8. The first filtering module includes capacitors C1 and C2. One end of the bidirectional thyristor Q8 is connected to one end of capacitor C1 and one end of capacitor C2, respectively. The anodes of thyristors Q2, Q4, and Q6, the other end of capacitors C1 and C2 are connected.

[0011] Preferably, the first voltage regulator module includes transistors VT1, VT2, VT3, VT4, and VT5; Zener diodes D1, D2, D3, and D4; variable resistors RP1 and RP2; capacitors C3 and C4; and resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10. The base of transistor VT1 is connected to one end of capacitor C3, one end of resistor R2, and the collector of transistor VT3. The collector of transistor VT1 is connected to one end of resistor R1. The emitter of transistor VT1 is connected to the base of transistor VT2. The other end of capacitor C3 is connected to the other end of capacitor C2. The other ends of resistor R2, the other ends of resistor R1, and the cathode of Zener diode D2 are connected to each other. The collector of transistor VT2 is connected to one end of capacitor C1 and one end of capacitor C2. The emitter of transistor VT3 is connected to the emitter of transistor VT2, the anode of Zener diode D1, one end of resistor R4, and one end of variable resistor RP1. The other end of resistor R4 is connected to the other end of capacitor C3. The other end of variable resistor RP1 and its adjustment terminal are both connected to one end of resistor R5. The base of transistor VT3 is connected to one end of resistor R3. The other end of resistor R3, the collector of transistor VT4, and one end of resistor R9 are connected together. The other end of resistor R9, the cathode of Zener diode D1, the anode of Zener diode D2, one end of capacitor C4, one end of resistor R8, one end of resistor R10, and the cathode of Zener diode D3 are connected together. The other end of resistor R10 is connected to one end of variable resistor RP2. The other end of variable resistor RP2 is connected to the other end of resistor R5. The adjustment terminal of RP2 is connected to the base of transistor VT4, the other end of resistor R8 is connected to the collector of transistor VT5, the base of transistor VT5, the anode of Zener diode D4 and one end of resistor R7 are connected to each other, the anode of Zener diode D3 is connected to the cathode of Zener diode D4, the emitter of transistor VT4, the emitter of transistor VT5 and one end of resistor R6 are connected to each other, and the other ends of resistor R6, resistor R7, capacitor C3 and capacitor C4 are connected to each other.

[0012] Preferably, the secondary power module includes a DC input module, a switch array, and output branches. The input terminal of the DC input module is connected to the DC output module of the primary power module. The switch array includes a pulse modulation circuit, a number of pairs of transistors VS, and a number of pairs of diodes VD. The base of the transistors VS is connected to the pulse modulation circuit. The number of output branches is variable.

[0013] Preferably, the DC input module includes capacitors C5 and C6. One end of capacitor C5 is connected to the first DC input terminal, and one end of capacitor C6 is connected to the second DC input terminal. The other end of capacitor C5 is connected to the other end of capacitor C6. The collector of transistor VS1, the cathode of diode VD1, and one end of capacitor C5 are connected to each other. The base of transistor VS1 is connected to the eighth pin of the pulse width modulation control chip. The emitter of transistor VS1, the anode of diode VD1, one end of the first output branch, the collector of transistor VS2, and the cathode of diode VD2 are connected to each other. The base of transistor VS1 is connected to the eleventh pin of the pulse width modulation control chip. The emitter of transistor VS2 and the anode of diode VD2 are both connected to the second DC input terminal. The pulse modulation circuit includes a pulse width modulation control chip. The seventh, ninth, and tenth pins of the pulse width modulation control chip are all grounded. Its twelfth pin is connected to the Vcc power supply. A resistor R22 is connected between its twelfth and eleventh pins. A resistor R23 is connected between its eighth and twelfth pins. Its fifth pin is grounded through a resistor R20. Its sixth pin is grounded through a capacitor C7. Its third and fourth pins serve as input terminals. Its fourth pin is connected to the second DC input terminal. Its first and sixteenth pins are both grounded. Its second pin is connected to its fifteenth pin. Its fifteenth pin is also connected to its fourteenth pin through a resistor R21. Its thirteenth pin is connected to the output control terminal. A single pulse modulation circuit controls the conduction of a pair of transistors VS.

[0014] Preferably, the controller is connected to the first transformer module, the thyristor trigger circuit, the pulse modulation circuit, the command input module, and the feedback module, respectively.

[0015] Preferably, the feedback module includes a coil current sensor, a coil voltage sensor, a magnetic field vector sensor, a container level sensor, a lidar, and a temperature sensor. The feedback module transmits the signals fed back by the coil current sensor, coil voltage sensor, magnetic field vector sensor, container level sensor, and temperature sensor to the controller, which is used to adjust the output parameters of each output branch.

[0016] The present invention also provides a multi-layer electromagnetic stirring control device, which includes the above-mentioned multi-layer electromagnetic stirring control system and stirring coil assembly. The stirring coil assembly is connected to the secondary power supply module. The stirring coil assembly includes multiple sets of stirring coils, and each stirring coil is connected to each output branch.

[0017] Preferably, the stirring coil assembly includes a longitudinally arranged coil group and a circumferentially arranged coil group. The longitudinally arranged coil group is sleeved on the outside of the container, and multiple stirring coils are sequentially arranged in the longitudinally arranged coil group along the length of the container. The longitudinally arranged coil group includes a first coil group and a second coil group, and the coils of the first coil group and the coils of the second coil group are arranged alternately. The circumferentially arranged coil group includes a third coil group and a fourth coil group. The third coil group includes multiple coils, some of which are distributed around the circumference of the container. The fourth coil group is also distributed around the circumference of the container, and the coils of the fourth coil group are located inside the coils of the third coil group.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The multi-layer electromagnetic stirring device provided by this invention can also generate complex composite magnetic fields and locally reinforced magnetic fields. This device can select different magnetic field configurations for electromagnetic stirring during metal smelting based on different material properties, billet shapes, and working conditions to achieve optimal metallurgical results. The device also has a feedback adjustment function to further optimize the stirring effect.

[0019] Furthermore, the multi-layer electromagnetic stirring device provided by this invention allows for free control of the coil's conduction and movement, thereby achieving a multi-layer stirring effect. Different magnetic fields of varying shapes are generated within different regions of the container, and by partitioning the magnetic field, different stirring effects can be achieved in each region. The advantages of this multi-layer stirring are: 1. Multi-layer electromagnetic stirring can produce stirring effects at different depths, thereby making the temperature and composition of the melt more uniform.

[0020] 2. Multi-layer stirring allows for the application of varying intensities of stirring to different parts of the melt, enabling more precise control of the stirring process. This is particularly beneficial for processing complex alloys and in high-precision processes.

[0021] 3. Multi-layer electromagnetic stirring can achieve better stirring results without increasing energy consumption.

[0022] 4. Due to more uniform mixing, the formation rate of defects such as porosity and shrinkage cavities in the casting will be reduced, and the mechanical properties and surface quality of the final product will be significantly improved. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the electromagnetic stirring control system in Embodiment 1 of the present invention; Figure 2 This is a circuit diagram of a primary power supply module in Embodiment 1 of the present invention; Figure 3 This is a circuit diagram of a secondary power supply module in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the stirring coil assembly in Embodiment 1 of the present invention.

[0024] Figure label: The system includes: a primary power supply module 1, a secondary power supply module 2, a controller 3, a feedback module 4, a stirring coil assembly 5, a command input module 6, a container 7, an AC input module 10, a first transformer module 11, a rectifier module 12, a first isolation module 13, a first filter module 14, a first voltage regulator module 15, a DC output module 16, a DC input module 20, a switch array 21, a pulse modulation circuit 23, and an output branch 24. Detailed Implementation

[0025] The above-mentioned and other technical features and advantages of the present invention will be described in more detail below with reference to the accompanying drawings.

[0026] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, unless otherwise explicitly specified.

[0027] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] In the description of this specification, references to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example that is included in at least one embodiment or example of the present invention.

[0029] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0030] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0031] To illustrate the technical solution described in this invention, specific embodiments are described below. Example 1

[0032] like Figure 1 As shown, the electromagnetic stirring control system provided by the present invention includes: a primary power module 1, a secondary power module 2, a controller 3, and a feedback module 4. The controller 3 is connected to the primary power module 1, the secondary power module 2, and the feedback module 4. The primary power module 1 is electrically connected to the secondary power module 2.

[0033] Controller 3 can control both the on / off state of the primary power module 1 and the output of the secondary power module 2. By directly controlling the secondary power module 2, controller 3 can indirectly control the magnetic field generated by the stirring coil. Primary power module 1 can convert three-phase or two-phase AC power into DC power. Secondary power module 2 can convert DC power into AC power with multiple outputs. Controller 3 can control the frequency and phase of the multiple AC outputs. Secondary power module 2 is also connected to stirring coil assembly 5, which receives the alternating current output from secondary power module 2 and generates a corresponding alternating magnetic field.

[0034] Feedback module 4 can monitor the output current, voltage and magnetic field strength in real time and feed the data back to controller 3.

[0035] The primary power module 1 includes an AC input module 10, a first transformer module 11, a rectifier module 12, a first isolation module 13, a first filter module 14, a first voltage regulator module 15, and a DC output module 16 connected in sequence. The AC input module 10 is used to connect to two-phase or three-phase AC power from the main power supply. The connected AC voltage can be 380V or a higher industrial voltage. The AC input module 10 preferably connects to 380V three-phase AC power, with the corresponding terminals including L1, L2, L3, N, and PE. L1, L2, and L3 are connected to the three-phase live wires, N is connected to the neutral wire, and PE is connected to the grounding protection wire. The first transformer module 11 is an adjustable transformer, connected to the AC input module 10, the rectifier module 12, and the controller 3. The controller 3 can adjust the transformation ratio of the first transformer module 11. The rectifier module 12 is used to convert AC power to DC power, and can be a three-phase bridge rectifier circuit.

[0036] The first filter module 14 smooths the pulsating DC power generated after rectification, reducing voltage fluctuations. The first isolation module 13 isolates the DC power output. The first voltage regulator module 15 maintains a stable output DC voltage, preventing voltage fluctuations from affecting the operation of the secondary power supply module 2. The first voltage regulator module 15 is preferably a linear regulator or a switching power supply module to ensure a constant DC voltage. The DC output module 16 is connected to both the first voltage regulator module 15 and the DC input module 20 of the secondary power supply module 2. The DC output module 16 provides a stable DC power supply to the DC input module 20.

[0037] Preferably, the circuit structure of the primary power module 1 is as follows: Figure 2 As shown, the AC input module 10 has input terminals including L1, L2, L3, and N. The first transformer module 11 includes coils T1, T2, and T3. The primary side of coil T1 is connected to input terminals L1 and N. The primary side of coil T2 is connected to input terminals L2 and N. The primary side of coil T3 is connected to input terminals L3 and N. The other ends of the secondary sides of coils T1, T2, and T3 are interconnected.

[0038] The rectifier module 12 includes thyristors Q1, Q2, Q3, Q4, Q5, and Q6. The first isolation module 13 includes bidirectional thyristors Q7 and Q8. One end of the secondary side of coil T1 is connected to the anode of thyristor Q1 and the cathode of thyristor Q4, respectively. One end of the secondary side of coil T2 is connected to the anode of thyristor Q3 and the cathode of thyristor Q6, respectively. One end of the secondary side of coil T3 is connected to the anode of thyristor Q5 and the cathode of thyristor Q2, respectively.

[0039] The gates of thyristors Q1, Q2, Q3, Q4, Q5, and Q6 are connected to their respective trigger circuits. The gates of bidirectional thyristors Q7 and Q8 are also connected to their respective trigger circuits. The cathodes of thyristors Q1, Q3, and Q5 are all connected to one end of bidirectional thyristor Q7. The other end of bidirectional thyristor Q7 is connected to one end of bidirectional thyristor Q8.

[0040] The first filter module 14 includes capacitors C1 and C2. One end of the bidirectional thyristor Q8 is connected to one end of capacitor C1 and one end of capacitor C2, respectively.

[0041] The anodes of thyristor Q2, thyristor Q4, and thyristor Q6 are connected to the other end of capacitor C1 and capacitor C2.

[0042] The first voltage regulator module 15 includes transistors VT1, VT2, VT3, VT4, and VT5; Zener diodes D1, D2, D3, and D4; variable resistors RP1 and RP2; capacitors C3 and C4; and resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10.

[0043] The base of transistor VT1 is connected to one end of capacitor C3, one end of resistor R2, and the collector of transistor VT3. The collector of transistor VT1 is connected to one end of resistor R1. The emitter of transistor VT1 is connected to the base of transistor VT2. The other end of capacitor C3 is connected to the other end of capacitor C2. The other ends of resistor R2, resistor R1, and the cathode of Zener diode D2 are interconnected.

[0044] The collector of transistor VT2 is connected to one end of capacitor C1 and one end of capacitor C2. The emitter of transistor VT3 is connected to the emitter of transistor VT2, the anode of Zener diode D1, one end of resistor R4, and one end of variable resistor RP1. The other end of resistor R4 is connected to the other end of capacitor C3. The other end and adjustment terminal of variable resistor RP1 are both connected to one end of resistor R5.

[0045] The base of transistor VT3 is connected to one end of resistor R3. The other end of resistor R3, the collector of transistor VT4, and one end of resistor R9 are connected together. The other end of resistor R9, the cathode of Zener diode D1, the anode of Zener diode D2, one end of capacitor C4, one end of resistor R8, one end of resistor R10, and the cathode of Zener diode D3 are connected together. The other end of resistor R10 is connected to one end of variable resistor RP2. The other end of variable resistor RP2 is connected to the other end of resistor R5. The adjustment terminal of variable resistor RP2 is connected to the base of transistor VT4. The other end of resistor R8 is connected to the collector of transistor VT5. The base of transistor VT5, the anode of Zener diode D4, and one end of resistor R7 are connected together. The anode of Zener diode D3 is connected to the cathode of Zener diode D4. The emitter of transistor VT4, the emitter of transistor VT5, and one end of resistor R6 are connected together. The other ends of resistor R6, resistor R7, capacitor C3, and capacitor C4 are connected to each other.

[0046] Preferably, the resistance of resistor R1 is 22 kΩ. The resistance of resistor R2 is 5.6 kΩ. The resistance of resistor R3 is 120 kΩ. The resistance of resistor R4 is 49 kΩ. The resistance of resistor R5 is 60 kΩ. The resistance of resistor R6 is 60 kΩ. The resistance of resistor R7 is 80 kΩ. The resistance of resistor R8 is 5.6 kΩ. The resistance of resistor R9 is 5.6 kΩ. The resistance of resistor R10 is 5.6 kΩ. The maximum resistance of variable resistor RP1 is 120 kΩ. The maximum resistance of variable resistor RP2 is 5 kΩ. The capacitance of capacitor C1 is 220 μF. The capacitance of capacitor C2 is 0.1 μF. The capacitance of capacitor C3 is 0.01 μF. The capacitance of capacitor C4 is 5 μF. Transistors VT1 and VT2 are high-power transistors, and their combination forms a composite regulating transistor. Capacitor C3 is preferably a ceramic capacitor, which has anti-vibration function. The dynamic range of the output can be optimized by adjusting the variable resistors RP1 and RP2 in combination.

[0047] The first voltage regulator module 15 outputs a voltage of U1 to the DC output module 16.

[0048] Electromagnetic stirring is commonly used in the metallurgical field, so using three-phase alternating current (AC) as the main power supply is quite common. The rectifier module 12 converts the three-phase AC power into adjustable DC power. In addition, an adjustable transformer is also included. Together, they allow for precise control and modification of the desired DC output voltage. Of the thyristors Q1 to Q6 in the rectifier module 12, at least two thyristors must be conducting in the operating state. One of these thyristors must be in a common cathode group, and the other in a common anode group; only when both are conducting simultaneously can a conductive circuit be formed.

[0049] The requirement for trigger pulses in a common-cathode group is to ensure that thyristors Q1, Q3, and Q5 conduct sequentially; therefore, the phase difference between their trigger pulses should be 120°. The requirement for trigger pulses in a common-anode group is to ensure that thyristors Q2, Q4, and Q6 conduct sequentially; therefore, the phase difference between their trigger pulses is also 120°. Since the thyristors in a common-cathode group are triggered during the positive half-cycle, and those in a common-anode group are triggered during the negative half-cycle, the phase difference between the trigger pulses of two thyristors connected in the same phase should be 180°. A thyristor needs to commutate every 60°, from the previous thyristor to the next, with the trigger pulse sequence being: Q1→Q2→Q3→Q4→Q5→Q6→Q1, and so on. The phase difference between adjacent pulses is 60°. Because a thyristor can be turned on again after a current interruption, trigger pulses must be applied simultaneously to the pair of thyristors that should be conducting in both groups. To achieve this goal, wide-pulse triggering and dual-pulse triggering can be used.

[0050] The input three-phase AC voltage is rectified by rectifier module 12 and then filtered by first filter module 14, providing a maximum DC voltage of 330V between the collector and ground of the composite voltage regulator. The voltage regulator circuit can output a stable voltage. The preferred output is DC 100V to 280V.

[0051] Zener diode D2 and resistor R1 form the primary voltage regulator circuit, ensuring the forward bias of the emitter of the composite structure composed of transistors VT1 and VT2. Zener diode D2 provides a stable voltage value to the collector of transistor VT3. Its beneficial effects are to improve the voltage regulation rate of the first voltage regulator module 15 and reduce the output impedance of the first voltage regulator module 15 caused by power supply output voltage fluctuations. Zener diode D1 limits the voltage at the emitter of transistor VT3 above a certain voltage, restricting the voltage between the collector and emitter of transistor VT3, thus improving the voltage withstand characteristics of transistor VT3. Zener diodes D3 and D2 are Zener diodes with positive and negative temperature coefficients, which can significantly reduce the impact of temperature changes on the output. Together, they constitute the back-end voltage regulator circuit of the first voltage regulator module 15.

[0052] To reduce the impact of temperature changes on the power supply and obtain sufficient output dynamic range, the first voltage regulator module 15 uses a differential circuit as a sampling and comparison circuit. Its advantages include good voltage regulation performance, unaffected by temperature changes. During the voltage regulation process, if the output voltage changes, a differential input voltage is formed across the differential amplifier, generating a larger voltage to control the change in the CE terminal voltage. This pulls back the output voltage for transistors VT1 and VT2, resulting in voltage stabilization.

[0053] The primary power module 1 converts three-phase AC power into high-voltage DC power and outputs it stably and reliably to the secondary power module 2, providing a stable guarantee for the subsequent inverter process of the secondary power module 2. The parameters of the DC power output from the primary power module 1 are also adjustable and can be adaptively adjusted according to actual operating conditions.

[0054] like Figure 1 As shown, the secondary power supply module 2 includes a DC input module 20 and a switch array 21. The input terminal of the DC input module 20 is connected to the DC output module 16. The DC input module 20 also includes capacitors C5 and C6. The switch array 21 includes a pulse modulation circuit 23, several pairs of transistors VS, and several pairs of diodes VD. The base of the transistors VS is connected to the pulse modulation circuit. The number of output branches 24 of the secondary power supply module 2 is variable, preferably more than three output branches. The number of output branches is the same as the number of transistor VS pairs, that is, the number of output branches is twice that of transistors VS.

[0055] Preferably, the circuit structure of the secondary power module 2 is as follows: Figure 3As shown, there are 4 output branches. There are also 4 transistor VS pairs. There are eight transistors with the VS pair. There are eight diodes with the VD pair. One end of capacitor C5 is connected to the first DC input terminal, and one end of capacitor C6 is connected to the second DC input terminal. The other end of capacitor C5 is connected to the other end of capacitor C6. The collector of transistor VS1, the cathode of diode VD1, and one end of capacitor C5 are interconnected. The base of transistor VS1 is connected to pin 8 of the pulse width modulation control chip. The emitter of transistor VS1, the anode of diode VD1, one end of the first output branch, the collector of transistor VS2, and the cathode of diode VD2 are interconnected. The base of transistor VS1 is connected to pin 11 of the pulse width modulation control chip. The emitter of transistor VS2 and the anode of diode VD2 are both connected to the second DC input terminal.

[0056] The pulse modulation circuit includes a pulse width modulation (PWM) control chip. The PWM control chip is preferably a TL494 chip. Its pins 7, 9, and 10 are all grounded. Pin 12 is connected to the Vcc power supply. Resistor R22 is connected between pins 12 and 11. Resistor R23 is connected between pins 8 and 12. Pin 5 is grounded through resistor R20. Pin 6 is grounded through capacitor C7. Pins 3 and 4 serve as input terminals. Pin 4 is connected to the second DC input terminal. Pins 1 and 16 are both grounded. Pin 2 is connected to pin 15. Pin 15 is also connected to pin 14 through resistor R21. Pin 13 is connected to the output control terminal. One pulse modulation circuit controls the conduction of paired transistors VS1 and VS2. Similarly, transistors VS3 and VS4 are controlled by another pulse modulation circuit (not shown in the circuit diagram). Each pair of transistors VS has its own dedicated pulse modulation circuit. Figure 4 Only the pulse modulation circuits connected to transistors VS1 and VS2 are shown. The remaining pulse modulation circuits are omitted. Of course, a corresponding number of pulse modulation circuits should be added when expanding the size of the switch array.

[0057] Preferably, the capacitance of capacitor C7 is 0.01 microfarads. The resistance of resistor R20 is 12 kΩ. The resistances of resistors R23 and R22 are 150 Ω. The resistance of resistor R21 is 50 kΩ.

[0058] The emitter of transistor VS3, the anode of diode VD3, one end of the second output branch, the collector of transistor VS4, and the cathode of diode VD4 are connected together. The emitter of transistor VS5, the anode of diode VD5, one end of the third output branch, the collector of transistor VS6, and the cathode of diode VD6 are connected together. The emitter of transistor VS7, the anode of diode VD7, one end of the fourth output branch, the collector of transistor VS8, and the cathode of diode VD8 are connected together.

[0059] The other ends of the first output branch, the second output branch, the third output branch, and the fourth output branch are connected. The output branches include resistors and inductors connected in series.

[0060] Controller 3 controls the output signal of the pulse modulation circuit by connecting to pin 13 of the pulse width modulation control chip. When one output branch is required to operate, controller 3 activates the pulse modulation circuit connected to transistors VS1 and VS2, while disabling other pulse modulation circuits. When two output branches are required to operate, the pulse modulation circuit connected to transistors VS1 and VS2 is switched to the operating state, while other unnecessary pulse modulation circuits remain disabled. When three, four, or more output branches are required to operate, the corresponding pulse modulation circuit is selected and activated according to the same principle.

[0061] Because the coils of multi-layer electromagnetic stirring devices require a low-frequency power supply, existing electromagnetic stirring devices often use three-phase AC power directly after frequency reduction. This results in a very limited mode of AC power supply to the coils, making timely adjustment according to operating conditions impossible. However, the secondary power module 2 of this invention enables the output of multiple low-frequency AC voltages. The output frequency is adjustable, and the types of output voltages are varied and controllable. Multiple variable output voltages can provide energy to various electromagnetic stirring device coils. The output voltages of each output branch of the secondary power module 2 can also achieve different phases. For example, when three-phase output is required, all three output branches can operate with a 120° phase difference. When four-phase output is required, all four output branches can operate with a 90° phase difference. Similarly, five-phase or six-phase output can be achieved. The secondary power module 2's ability to output AC with different phases and frequencies offers the advantage of allowing for a more varied magnetic field distribution generated by the electromagnetic stirring device coils, expanding the application range of the electromagnetic stirring device, and optimizing the stirring effect. These different AC outputs can also be applied to different types of electromagnetic stirring coils to suit the electromagnetic stirring of composite materials. A second transformer module can also be installed between the output branch and the stirring coil assembly 5. The second transformer module adjusts the amplitude of the output voltage and current to meet the needs of the stirring coil.

[0062] The controller 3 is connected to the first transformer module 11, the thyristor trigger circuit, the pulse modulation circuit, the instruction input module 6, and the feedback module 4. The controller 3 controls the DC output of the first-stage power supply module 1 through the first transformer module 11. The controller 3 controls the triggering of the thyristor components through the thyristor trigger circuit. The controller 3 controls the conduction of the corresponding switch array through the pulse modulation circuit. The instruction input module provides input instructions to the controller 3. The controller 3 adjusts each circuit according to the input instructions and the feedback signal from the feedback module 4. The controller 3 is used for overall control logic and parameter adjustment.

[0063] Feedback module 4 includes a coil current sensor, a coil voltage sensor, a magnetic field vector sensor, a container level sensor, a lidar, and a temperature sensor. Feedback module 4 transmits various signals from the coil current sensor, coil voltage sensor, magnetic field vector sensor, container level sensor, and temperature sensor to controller 3. Controller 3 adjusts the number of output branches based on the feedback signals, determines the on / off state of each output branch, and adjusts the output parameters of each output branch. Traditional electromagnetic stirring devices do not achieve feedback control because, even if they cannot achieve multi-phase output adjustment, the adjustment range is very limited even with feedback signals. In this invention, the lidar can measure the shape of the corresponding container 7, thus allowing for the rational selection of the required conductive output branches and corresponding stirring coils. Furthermore, if the container 7 shifts during stirring, the output can be adjusted promptly to optimize the stirring effect.

[0064] Based on the object being stirred and the desired stirring effect, a dynamic theoretical magnetic field vector field can be determined. The magnetic field vector sensor can also monitor the magnetic field vector generated by the stirring coil assembly in real time and adjust the output mode of each output branch in a timely manner so that the actual output magnetic field vector field is closer to the theoretical value.

[0065] The container level sensor can determine the position of the liquid or semi-solid metal inside container 7, and the controller 3 uses this position to control the activation of the stirring coil at the appropriate location. This allows for precise control of stirring and reduces energy waste.

[0066] The temperature sensor can monitor the temperature distribution at different locations, thereby determining whether there are areas where mixing is insufficient. Based on this temperature distribution, the controller 3 can promptly change the on / off state of the output branch to strengthen the magnetic field intensity in the areas of insufficient mixing. Ultimately, this achieves the goal of optimizing the mixing effect.

[0067] The real-time status of each stirring coil is monitored by coil current sensor and coil voltage sensor, so that the controller 3 can achieve better control function and also avoid the coil working time being too long.

[0068] The present invention also provides a multi-layer electromagnetic stirring device, which includes a multi-layer electromagnetic stirring control system and a stirring coil assembly 5, wherein the stirring coil assembly 5 is connected to a secondary power supply module 2. The stirring coil assembly 5 includes multiple sets of stirring coils, and each stirring coil is connected to a respective output branch.

[0069] The stirring coil assembly 5 includes a longitudinally arranged coil group and a circumferentially arranged coil group. The longitudinally arranged coil group is fitted onto the outside of the container 7. Multiple stirring coils are sequentially arranged in the longitudinally arranged coil group along the length of the container 7. The longitudinally arranged coil group includes a first coil group 51 and a second coil group 52. The coils of the first coil group 51 are circular ring coils, and the coils of the second coil group 52 are square ring coils. Alternatively, other shapes of ring coils can also be used in the longitudinal coil group. The coils of the first coil group 51 and the second coil group 52 are arranged alternately.

[0070] The circumferentially arranged coil groups include a third coil group 53 and a fourth coil group 54. The third coil group 53 includes multiple coils, which are distributed around the circumference of the container 7. The fourth coil group 54 is also distributed around the circumference of the container 7. The coils of the fourth coil group 54 are located inside the coils of the third coil group 53.

[0071] A longitudinally arranged coil group of the same type can generate a rotating magnetic field when operating alone. A circumferentially arranged coil group of the same type can generate a traveling wave magnetic field when operating alone. When both longitudinally and circumferentially arranged coil groups are simultaneously supplied with excitation current, their magnetic fields interact to generate a helical magnetic field. The helical angle generated by the helical magnetic field is determined by the magnitude and direction of the current in the rotating magnetic field coil and the traveling wave magnetic field coil. Furthermore, the combined action of multiple types of coils and coils in different positions can create various locally enhanced magnetic fields.

[0072] Therefore, the multi-layer electromagnetic stirring device of the present invention not only possesses the functions of an electromagnetic stirring device with a single magnetic field mode, but also enables the switching of multiple magnetic field modes. This switching of magnetic field modes can be triggered by input commands, such as inputting relevant commands after modifying the object being stirred. Of course, this magnetic field mode transformation can also be triggered by feedback signals, adjusting the magnetic field distribution based on various feedback signals to optimize the stirring effect. The electromagnetic stirring control system can provide the coil with an alternating current of 100A or more and a frequency of 1-10Hz. Furthermore, the magnetic fields generated by different phase currents can provide a richer variety of electromagnetic stirring modes.

[0073] In summary, compared to traditional electromagnetic stirring devices, the multi-layer electromagnetic stirring device of this invention can not only generate various single magnetic field modes, but also form more complex composite magnetic fields and locally enhanced magnetic fields. The multi-layer electromagnetic stirring device of this invention can select different magnetic field modes for electromagnetic stirring during the metal smelting process according to different material properties, billet shape, and working conditions to achieve the best metallurgical effect. The multi-layer electromagnetic stirring device of this invention can effectively improve the surface, subsurface, and internal quality of billets. Example 2

[0074] This embodiment differs from Embodiment 1 in that it provides a multi-layer electromagnetic stirring device that further includes a motion control module. The motion control module is connected to both the controller 3 and the stirring coil assembly 5. The controller 3 controls the spatial position of the stirring coil assembly 5 via the motion control module. For example, the controller 3 controls the spacing between the coils of the first coil group 51, or the spacing between the coils of the second coil group 52, or the spacing between adjacent coils of the first coil group 51 and the second coil group 52. Additionally, the controller 3 can control the positions of the third coil group 53 and the fourth coil group 54 via the motion control module. For example, it can increase or decrease the distance between a coil of the third coil group 53 and the central axis of the container 7, or increase or decrease the distance between a coil of the fourth coil group 54 and the central axis of the container 7, or adjust the position of the corresponding coil of the fourth coil group 54 within the third coil group 53.

[0075] Therefore, the controller 3 can adjust the position of the stirring coil assembly 5, control the on / off state of each coil in the stirring coil assembly 5, and control the frequency of the coil drive current. These three control functions enable multi-layer stirring effects of three or more layers, such as forming five different magnetic field regions. The magnetic field vectors of the five regions are different, and the electromagnetic force obtained by the molten metal in each region is also different. Specifically, from bottom to top, a spiral magnetic field region, a rotating magnetic field region, a traveling wave magnetic field region, a spiral magnetic field region, and a rotating magnetic field region are formed. Each magnetic field can be freely transformed.

[0076] The following beneficial effects can be achieved through multi-layer mixing: 1. Multi-layer electromagnetic stirring can produce stirring effects at different depths, thereby making the temperature and composition of the melt more uniform.

[0077] 2. Multi-layer stirring allows for the application of varying intensities of stirring to different parts of the melt, enabling more precise control of the stirring process. This is particularly beneficial for processing complex alloys and in high-precision processes.

[0078] 3. Multi-layer electromagnetic stirring can achieve better stirring results without increasing energy consumption.

[0079] 4. Due to more uniform mixing, the formation rate of defects such as porosity and shrinkage cavities in the casting will be reduced, and the mechanical properties and surface quality of the final product will be significantly improved.

[0080] In addition, feedback module 4 also includes a displacement sensor, which is used to identify the position of each coil and provide feedback signals for the control of controller 3. Controller 3 can also use signals from other sensors to control the motion control module.

[0081] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A multi-layer electromagnetic stirring control system, characterized in that, It includes a primary power module, a secondary power module, a controller, and a feedback module. The controller is connected to the primary power module, the secondary power module, and the feedback module, respectively. The primary power module is electrically connected to the secondary power module. The primary power module generates direct current (DC), and the secondary power module inverts and generates multiple alternating currents of different phases. The controller can control both the on / off state of the primary power module and the output of the secondary power module. The controller can control the frequency and phase of the multiple AC outputs from the secondary power module. The feedback module feeds back sensor signals to the controller.

2. The multi-layer electromagnetic stirring control system as described in claim 1, characterized in that, The primary power supply module includes an AC input module, a first transformer module, a rectifier module, a first isolation module, a first filter module, a first voltage regulator module, and a DC output module connected in sequence. The AC input module is used to connect to two-phase or three-phase AC power from the main power supply. The first transformer module is an adjustable transformer and is connected to the AC input module, the rectifier module, and the controller. The rectifier module is used to convert AC power to DC power. The first isolation module is used to isolate and output DC power. The first voltage regulator module is used to maintain the stability of the output DC voltage and is connected to the secondary power supply module through the DC output module.

3. The multi-layer electromagnetic stirring control system as described in claim 2, characterized in that, The rectifier module includes thyristors Q1, Q2, Q3, Q4, Q5, and Q6. The first isolation module includes bidirectional thyristors Q7 and Q8. One end of the secondary side of the coil T1 of the first transformer module is connected to the anode of thyristor Q1 and the cathode of thyristor Q4, respectively. One end of the secondary side of the coil T2 of the first transformer module is connected to the anode of thyristor Q3 and the cathode of thyristor Q6, respectively. One end of the secondary side of the coil T3 of the first transformer module is connected to the anode of thyristor Q5 and the cathode of thyristor Q2, respectively. The gates of thyristors Q1, Q2, Q3, Q4, Q5, and Q6 are connected to the corresponding trigger circuits. The gates of bidirectional thyristors Q7 and Q8 are connected to the corresponding trigger circuits. The cathodes of thyristors Q1, Q3, and Q5 are all connected to one end of bidirectional thyristor Q7. The other end of bidirectional thyristor Q7 is connected to one end of bidirectional thyristor Q8. The first filtering module includes capacitors C1 and C2. One end of the bidirectional thyristor Q8 is connected to one end of capacitor C1 and one end of capacitor C2, respectively. The anodes of thyristors Q2, Q4, and Q6, the other end of capacitors C1 and C2 are connected.

4. The multi-layer electromagnetic stirring control system as described in claim 2, characterized in that, The first voltage regulator module includes transistors VT1, VT2, VT3, VT4, and VT5; Zener diodes D1, D2, D3, and D4; variable resistors RP1 and RP2; capacitors C3 and C4; and resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10. The base of transistor VT1 is connected to one end of capacitor C3, one end of resistor R2, and the collector of transistor VT3. The collector of transistor VT1 is connected to one end of resistor R1. The emitter of transistor VT1 is connected to the base of transistor VT2. The other end of capacitor C3 is connected to the other end of capacitor C2. The other ends of resistor R2, the other ends of resistor R1, and the cathode of Zener diode D2 are connected to each other. The collector of transistor VT2 is connected to one end of capacitor C1 and one end of capacitor C2. The emitter of transistor VT3 is connected to the emitter of transistor VT2, the anode of Zener diode D1, one end of resistor R4, and one end of variable resistor RP1. The other end of resistor R4 is connected to the other end of capacitor C3. The other end of variable resistor RP1 and its adjustment terminal are both connected to one end of resistor R5. The base of transistor VT3 is connected to one end of resistor R3. The other end of resistor R3, the collector of transistor VT4, and one end of resistor R9 are connected together. The other end of resistor R9, the cathode of Zener diode D1, the anode of Zener diode D2, one end of capacitor C4, one end of resistor R8, one end of resistor R10, and the cathode of Zener diode D3 are connected together. The other end of resistor R10 is connected to one end of variable resistor RP2. The other end of variable resistor RP2 is connected to the other end of resistor R5. The adjustment terminal of RP2 is connected to the base of transistor VT4, the other end of resistor R8 is connected to the collector of transistor VT5, the base of transistor VT5, the anode of Zener diode D4 and one end of resistor R7 are connected to each other, the anode of Zener diode D3 is connected to the cathode of Zener diode D4, the emitter of transistor VT4, the emitter of transistor VT5 and one end of resistor R6 are connected to each other, and the other ends of resistor R6, resistor R7, capacitor C3 and capacitor C4 are connected to each other.

5. The multi-layer electromagnetic stirring control system as described in claim 1, characterized in that, The secondary power module includes a DC input module, a switch array, and output branches. The input terminal of the DC input module is connected to the DC output module of the primary power module. The switch array includes a pulse modulation circuit, several pairs of transistors VS, and several pairs of diodes VD. The base of the transistors VS is connected to the pulse modulation circuit. The number of output branches is variable.

6. The multi-layer electromagnetic stirring control system as described in claim 5, characterized in that, The DC input module includes capacitors C5 and C6. One end of capacitor C5 is connected to the first DC input terminal, and one end of capacitor C6 is connected to the second DC input terminal. The other end of capacitor C5 is connected to the other end of capacitor C6. The collector of transistor VS1, the cathode of diode VD1, and one end of capacitor C5 are connected to each other. The base of transistor VS1 is connected to the eighth pin of the pulse width modulation control chip. The emitter of transistor VS1, the anode of diode VD1, one end of the first output branch, the collector of transistor VS2, and the cathode of diode VD2 are connected to each other. The base of transistor VS1 is connected to the eleventh pin of the pulse width modulation control chip. The emitter of transistor VS2 and the anode of diode VD2 are both connected to the second DC input terminal. The pulse modulation circuit includes a pulse width modulation control chip. The seventh, ninth, and tenth pins of the pulse width modulation control chip are all grounded. Its twelfth pin is connected to the Vcc power supply. A resistor R22 is connected between its twelfth and eleventh pins. A resistor R23 is connected between its eighth and twelfth pins. Its fifth pin is grounded through a resistor R20. Its sixth pin is grounded through a capacitor C7. Its third and fourth pins serve as input terminals. Its fourth pin is connected to the second DC input terminal. Its first and sixteenth pins are both grounded. Its second pin is connected to its fifteenth pin. Its fifteenth pin is also connected to its fourteenth pin through a resistor R21. Its thirteenth pin is connected to the output control terminal. A single pulse modulation circuit controls the conduction of a pair of transistors VS.

7. The multi-layer electromagnetic stirring control system as described in claim 6, characterized in that, The controller is connected to the first transformer module, the thyristor trigger circuit, the pulse modulation circuit, the command input module, and the feedback module, respectively.

8. The multi-layer electromagnetic stirring control system as described in claim 1, characterized in that, The feedback module includes a coil current sensor, a coil voltage sensor, a magnetic field vector sensor, a container liquid level sensor, a lidar, and a temperature sensor. The feedback module transmits the signals fed back by the coil current sensor, coil voltage sensor, magnetic field vector sensor, container liquid level sensor, and temperature sensor to the controller. The controller is used to adjust the output parameters of each output branch.

9. A multi-layer electromagnetic stirring control device, characterized in that, It includes the electromagnetic stirring control system as described in claim 1 and the stirring coil assembly, the stirring coil assembly being connected to the secondary power module, the stirring coil assembly including multiple sets of stirring coils, each stirring coil being connected to each output branch.

10. The multi-layer electromagnetic stirring device as described in claim 9, characterized in that, The stirring coil assembly includes a longitudinally arranged coil group and a circumferentially arranged coil group. The longitudinally arranged coil group is sleeved on the outside of the container, and multiple stirring coils are sequentially arranged in the longitudinally arranged coil group along the length of the container. The longitudinally arranged coil group includes a first coil group and a second coil group, and the coils of the first coil group and the second coil group are arranged alternately. The circumferentially arranged coil group includes a third coil group and a fourth coil group. The third coil group includes multiple coils, which are distributed around the circumference of the container. The fourth coil group is also distributed around the circumference of the container, and the coils of the fourth coil group are located inside the coils of the third coil group. The controller controls the spatial position of the stirring coil assembly through a motion control module.

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