Movable steel rail double-frequency normalizing equipment control device

Abstract

The utility model relates to the technical field of welded joint heat treatment, in particular to a mobile steel rail double-frequency normalizing equipment control device integrating mechanic, electric, hydraulic and gas, which comprises a medium-frequency induction heating power supply, a capacitor, a transformer, a normalizing coil, a PLC (programmable logic controller) and an industrial control computer, and the medium-frequency induction heating power supply, the capacitor, the transformer and the normalizing coil are sequentially connected in series. The PLC is connected with the medium-frequency induction heating power supply, and the industrial control computer is connected with the PLC. The frequency during normalizing can be controlled only by controlling the connection mode of the capacitors and the capacitance value of the capacitors, and the control effect is better than the effect of controlling the turn ratio of the transformer.

Description

Technical Field

[0001] This utility model relates to the field of heat treatment technology for welded joints, and in particular to a mobile dual-frequency normalizing equipment control device for steel rails that integrates mechanical, electrical, hydraulic and pneumatic systems. Background Technology

[0002] Currently, the main heat treatment methods for welded rails in China are oxy-acetylene flame heating and medium-frequency induction heating (electric normalizing). Flame heating has many drawbacks and the quality is unstable; while electric normalizing reduces the influence of human factors and the external environment and is gradually replacing flame heating.

[0003] In existing electric normalizing technologies, utility model patents, such as CN201120365185.8, achieve dual-frequency normalizing by changing the capacitor value and adjusting the transformer turns ratio. This utility model achieves dual-frequency normalizing by changing the capacitor value to alter the frequency. Furthermore, it employs phase and frequency correction to adjust the power, resulting in higher heating efficiency at both low and high frequencies. Summary of the Invention

[0004] To address the aforementioned shortcomings in the existing technology, this application provides a mobile dual-frequency normalizing equipment control device for steel rails, which can effectively adjust the output power of the medium-frequency normalizing power supply during the low-frequency and high-frequency stages to achieve higher heating efficiency.

[0005] To achieve the above-mentioned technical effects, the technical solution of this application is as follows:

[0006] A mobile rail dual-frequency normalizing equipment control device includes a medium-frequency induction heating power supply, a capacitor C2, a transformer, a normalizing coil, a PLC, and an industrial control computer. The medium-frequency induction heating power supply, capacitor, transformer, and normalizing coil are connected in series. The PLC is connected to the medium-frequency induction heating power supply, and the industrial control computer is connected to the PLC.

[0007] Furthermore, the medium-frequency induction heating power supply includes a main circuit and a load circuit. The main circuit includes a rectifier, a DC filter capacitor C1, and an inverter. The rectifier is connected to the DC filter capacitor C1, and the DC filter capacitor C1 is connected to the inverter. The load circuit includes a capacitor C2 for the normalizing equipment, a transformer, and a normalizing coil. The capacitor C2 is connected to the transformer, and the transformer is connected to the normalizing coil.

[0008] Furthermore, the output terminal of the rectifier is connected to the DC filter capacitor C1, the input terminal of the DC filter capacitor C1 is connected to the output terminal of the rectifier, the output terminal of the rectifier is connected to the input terminal of the inverter, and the input terminal of the inverter is connected to the output terminal of the DC filter capacitor.

[0009] Furthermore, the output terminal of the inverter is connected to the input terminal of capacitor C2 in the normalizing equipment, the input terminal of capacitor C2 is connected to the output terminal of the medium-frequency induction heating power supply, the output terminal is connected to the primary side of the transformer, the primary side of the transformer is connected to the output terminal of capacitor C2, and the output terminal is connected to the normalizing coil.

[0010] Furthermore, the rectifier includes diodes D1, D3, and D5, thyristors D2, D4, and D6. Diodes D1 and D2 are connected to form a semi-controlled rectifier module, diodes D3 and D4 are connected to form a semi-controlled rectifier module, and diodes D5 and D6 are connected to form a semi-controlled rectifier module. The three semi-controlled rectifier modules constitute a three-phase bridge semi-controlled rectifier.

[0011] Furthermore, the negative terminals of diodes D1, D3, and D5 are connected together, the positive terminal of diode D1 is connected to the cathode of thyristor D2, the positive terminal of diode D3 is connected to the cathode of thyristor D4, the positive terminal of diode D5 is connected to the cathode of thyristor D6, and the anodes of thyristors D2, D4, and D6 are connected together.

[0012] Furthermore, the inverter includes an insulated-gate bipolar transistor (IGBT) T1, an IGBT T2, an IGBT T3, and an IGBT T4, wherein the emitter of IGBT T1 is connected to the collector of IGBT T2, the collector of IGBT T1 is connected to the collector of IGBT T3, the emitter of IGBT T2 is connected to the emitter of IGBT T4, and the collector of IGBT T4 is connected to the emitter of IGBT T3.

[0013] Furthermore, the capacitor C2 is a capacitor bank formed by connecting multiple fixed-rate capacitors in parallel or series. The connection method of the capacitors is changed by controlling the coil of the contactor. The output point of the PLC is connected to the coil of the contactor, and the two ends of the contactor contacts are connected to the two ends of the two capacitors respectively. When the PLC outputs a frequency switching signal, the coil of the contactor is energized, the contacts of the contactor close, and the two capacitors are connected in parallel, thereby changing the capacitance value and thus changing the frequency of the normalizing equipment to achieve dual-frequency normalizing.

[0014] Furthermore, the transformer is a step-down transformer with a fixed number of turns. The output terminal of the inverter in the medium-frequency induction heating power supply is connected to the primary side of the transformer, and the secondary side of the transformer is connected to the normalizing coil.

[0015] Furthermore, the normalizing coil is equipped with an infrared temperature sensor.

[0016] This application has the following technical effects:

[0017] 1. This application can control the frequency during normalizing simply by controlling the connection method and capacitance value of the capacitor, and the control effect is better than controlling the turns ratio of the transformer.

[0018] 2. While controlling the normalizing equipment, a frequency tracking method is adopted to control the power of the medium-frequency induction heating power supply in real time during the normalizing process. Through frequency correction and phase angle correction, the output power of the medium-frequency induction heating power supply is controlled in real time, resulting in higher heating efficiency. Attached Figure Description

[0019] Figure 1 The diagram shown is a basic structural block diagram of the medium-frequency induction heating power supply provided in this embodiment of the present invention.

[0020] Figure 2 The diagram shown is a flowchart of the power control strategy of the medium-frequency induction heating power supply provided in this embodiment of the present invention.

[0021] In the attached diagram: 1-rectifier, 2-inverter, 3-transformer, 4-normalizing coil. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0024] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0025] In the description of this application, it should be noted that the terms "upper," "vertical," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0027] Example 1

[0028] like Figure 1 As shown, a mobile rail dual-frequency normalizing equipment control device includes a medium-frequency induction heating power supply, a capacitor C2, a transformer 3, a normalizing coil 4, a PLC, and an industrial control computer. The medium-frequency induction heating power supply, capacitor C2, transformer 3, and normalizing coil 4 are connected in series. The PLC is connected to the medium-frequency induction heating power supply, and the industrial control computer is connected to the PLC.

[0029] The medium-frequency induction heating power supply includes a main circuit and a load circuit. The main circuit includes a rectifier 1, a DC filter capacitor C1, and an inverter 2. The rectifier 1 is connected to the DC filter capacitor C1, and the DC filter capacitor C1 is connected to the inverter 2. The load circuit includes a capacitor C2 for the normalizing equipment, a transformer 3, and a normalizing coil 4. The capacitor C2 is connected to the transformer 3, and the transformer 3 is connected to the normalizing coil 4.

[0030] Capacitor C2 is a capacitor bank formed by connecting multiple fixed-value capacitors in parallel or series. The capacitance value can be provided in a range: two 16uf capacitors. The connection method of the capacitors is changed by controlling the coil of the contactor. The output point of the PLC is connected to the coil of the contactor, and the two ends of the contactor contacts are connected to the two ends of the two capacitors respectively. When the PLC outputs a frequency switching signal, the coil of the contactor is energized, the contacts of the contactor close, and the two capacitors are connected in parallel. The capacitance value changes from 16uf to 32uf, thereby changing the capacitance value and thus changing the frequency of the normalizing equipment to achieve dual-frequency normalizing.

[0031] Example 2

[0032] like Figure 1 As shown, a mobile rail dual-frequency normalizing equipment control device includes a medium-frequency induction heating power supply, a capacitor C2, a transformer 3, a normalizing coil 4, a PLC, and an industrial control computer. The medium-frequency induction heating power supply, capacitor C2, transformer 3, and normalizing coil 4 are connected in series. The PLC is connected to the medium-frequency induction heating power supply, and the industrial control computer is connected to the PLC.

[0033] The medium-frequency induction heating power supply includes a main circuit and a load circuit. The main circuit includes a rectifier 1, a DC filter capacitor C1, and an inverter 2. The rectifier 1 is connected to the DC filter capacitor C1, and the DC filter capacitor C1 is connected to the inverter 2. The load circuit includes a capacitor C2 for the normalizing equipment, a transformer 3, and a normalizing coil 4. The capacitor C2 is connected to the transformer 3, and the transformer 3 is connected to the normalizing coil 4.

[0034] The output terminal of rectifier 1 is connected to the DC filter capacitor C1, the input terminal of the DC filter capacitor C1 is connected to the output terminal of rectifier 1, the output terminal of rectifier 1 is connected to the input terminal of inverter 2, and the input terminal of inverter 2 is connected to the output terminal of the DC filter capacitor.

[0035] The output terminal of the medium-frequency induction heating power supply (i.e., the output terminal of the inverter 2) is connected to the load circuit, i.e., the input terminal of the capacitor C2 in the normalizing equipment is connected to the input terminal of the medium-frequency induction heating power supply, the output terminal is connected to the primary side of the transformer 3, the primary side of the transformer 3 is connected to the output terminal of the capacitor C2, and the output terminal is connected to the normalizing coil 4.

[0036] Rectifier 1 includes diodes D1, D3, and D5, thyristors D2, D4, and D6. Diodes D1 and D2 are connected to form a semi-controlled rectifier module, diodes D3 and D4 are connected to form a semi-controlled rectifier module, and diodes D5 and D6 are connected to form a semi-controlled rectifier module. The three semi-controlled rectifier modules constitute a three-phase bridge semi-controlled rectifier 1.

[0037] The negative terminals of diodes D1, D3, and D5 are connected together. The positive terminal of diode D1 is connected to the cathode of thyristor D2. The positive terminal of diode D3 is connected to the cathode of thyristor D4. The positive terminal of diode D5 is connected to the cathode of thyristor D6. The anodes of thyristors D2, D4, and D6 are connected together.

[0038] Inverter 2 includes an insulated-gate bipolar transistor (IGBT) T1, an IGBT T2, an IGBT T3, and an IGBT T4. The emitter of IGBT T1 is connected to the collector of IGBT T2, the collector of IGBT T1 is connected to the collector of IGBT T3, the emitter of IGBT T2 is connected to the emitter of IGBT T4, and the collector of IGBT T4 is connected to the emitter of IGBT T3. This configuration is used to regulate the output power of the medium-frequency induction heating power supply.

[0039] The control, drive, and protection circuit of the medium-frequency induction heating power supply is connected to the control terminals T1, T2, T3, and T4 of the inverter 2. The PLC is connected to the control circuit, and the contacts of the contactor are connected to the capacitor C2 (capacitor bank). The medium-frequency induction heating power supply also includes a control circuit, which includes a sampling and processing circuit for load current and voltage signals, an amplification circuit for four control pulse signals with adjustable frequency and phase shift angle, and a communication interface circuit. The input terminal of the load current signal sampling circuit (i.e., the precision rectifier and filter circuit) is connected to the output terminal of the Hall sensor. The input terminal of the Hall sensor is connected to the resonant circuit for detecting the load current. The output terminal of the load current signal sampling and processing circuit is connected to the ADC port of the DSP chip for sampling processing. The load current signal processing circuit (i.e., the current zero-crossing detection circuit) detects the phase of the load.

[0040] Capacitor C2 is a capacitor bank formed by connecting multiple fixed-value capacitors in parallel or series. The capacitance value can be provided in a range: two 16uf capacitors. The connection method of the capacitors is changed by controlling the coil of the contactor. The output point of the PLC is connected to the coil of the contactor, and the two ends of the contactor contacts are connected to the two ends of the two capacitors respectively. When the PLC outputs a frequency switching signal, the coil of the contactor is energized, the contacts of the contactor close, and the two capacitors are connected in parallel. The capacitance value changes from 16uf to 32uf, thereby changing the capacitance value and thus changing the frequency of the normalizing equipment to achieve dual-frequency normalizing.

[0041] Transformer 3 is a step-down transformer with a fixed number of turns. The output terminal of inverter 2 in the medium-frequency induction heating power supply is connected to the primary side of transformer 3, and the secondary side of transformer 3 is connected to the positive coil 4.

[0042] The normalizing coil 4 is equipped with an infrared temperature sensor to detect the temperature of the top and bottom of the rail during normalizing.

[0043] The PLC is used to control the switching on and off of the medium-frequency induction heating power supply, outputting a 4-20mA current signal to control the power required during normalizing. The PLC also controls the contactor coils, controlling the frequency switching of the normalizing equipment. The PLC can be a Keyence programmable logic controller.

[0044] An industrial control computer is connected to the PLC to input various parameters required for normalizing into the PLC, and to collect and record information such as normalizing time and temperature to form a normalizing curve.

[0045] Example 3

[0046] like Figure 1 As shown, in one embodiment, the main circuit of the medium-frequency induction heating power supply consists of a rectifier 1, a DC filter capacitor C1, and an inverter 2. The load circuit consists of a capacitor C2, a transformer 3, and a normalizing coil 4 of the normalizing equipment. Specifically, the output terminal of the rectifier 1 is connected to the DC filter capacitor C1, the input terminal of the DC filter capacitor C1 is connected to the output terminal of the rectifier 1, and its output terminal is connected to the input terminal of the inverter 2. The input terminal of the inverter 2 is connected to the output terminal of the DC filter capacitor. The output terminal of the medium-frequency induction heating power supply (i.e., the output terminal of the inverter 2) is connected to the load circuit, i.e., connected to the input terminal of the capacitor C2 in the normalizing equipment. The input terminal of the capacitor C2 is connected to the output terminal of the medium-frequency induction heating power supply, and its output terminal is connected to the primary winding of the transformer 3. The primary winding of the transformer 3 is connected to the output terminal of the capacitor C2, and its output terminal is connected to the normalizing coil 4. More specifically, the control, drive, and protection circuit of the medium-frequency induction heating power supply is connected to the control terminals T1, T2, T3, and T4 of the inverter 2, the PLC is connected to the control circuit, and the contacts of the contactor are connected to the capacitor C2 (capacitor bank).

[0047] It should be noted that when the normalizing operation is started, the PLC sends a signal to control the activation of the intermediate frequency induction heating power supply for induction heating normalizing. In the low-frequency stage, the PLC converts the set initial power, secondary power, and tertiary power values ​​into 4-20mA current signals and transmits them to the control circuit of the intermediate frequency induction heating power supply, which then adjusts the power. The power adjustment method is the same in the high-frequency stage.

[0048] It should be noted that when the temperature of the rail top and bottom measured by the infrared temperature sensor reaches the set value for frequency switching, the PLC sends a signal to control the on / off state of the contactor, changing the connection method of capacitor C2 and changing the capacitance value of capacitor C2, thereby realizing the switching from low frequency to high frequency.

[0049] It should be noted that when the temperature of the rail top and rail bottom measured by the infrared temperature sensor reaches the set value of the final normalizing temperature, the PLC sends a signal to control the shutdown of the intermediate frequency induction power supply and stop the normalizing operation.

[0050] like Figure 2 As shown, in this embodiment, the control circuit of the medium-frequency induction heating power supply needs to adjust its output power in the low-frequency and high-frequency stages. ① When the medium-frequency induction heating power supply is not started, there is no current in the load circuit. With the phase shift angle at zero, the voltage frequency output by the medium-frequency induction heating power supply changes from high to low, and frequency sweeping starts. When the control circuit detects a decrease in load current, the control frequency control loop corrects the frequency until the power switching device on the left upper bridge arm... Figure 1 The driving pulse signal of T1 in the circuit is in phase with the load current. ② Once the phases are aligned, the power is checked. If the power does not meet the requirements, the phase shift angle is adjusted, and the frequency control loop corrects the frequency until the driving pulse signal of the power switch device on the left upper bridge arm is in phase with the load current. If the power meets the requirements, no adjustment is made to the phase shift angle or frequency. ③ Then, the phase alignment is checked again. If the phases are not aligned, frequency correction is performed; if the phases are aligned, step ② is repeated. Even after the correction process, the power output reaches the target requirements. Changes in rail temperature can cause changes in the load resonant frequency, leading to a misalignment between the driving pulse signal of the power switch device T1 on the left upper bridge arm and the load current. In this case, step ③ will be executed, and dynamic adjustment is maintained throughout the induction heating process.

Claims

1. A control device for a mobile dual-frequency normalizing equipment for steel rails, characterized in that: It includes a medium-frequency induction heating power supply, a capacitor C2, a transformer (3), a normalizing coil (4), a PLC and an industrial control computer. The medium-frequency induction heating power supply, the capacitor, the transformer (3) and the normalizing coil (4) are connected in series. The PLC is connected to the medium-frequency induction heating power supply and the industrial control computer is connected to the PLC. The medium-frequency induction heating power supply includes a main circuit and a load circuit. The main circuit includes a rectifier (1), a DC filter capacitor C1, and an inverter (2). The rectifier (1) is connected to the DC filter capacitor C1, and the DC filter capacitor C1 is connected to the inverter (2). The load circuit includes a capacitor C2, a transformer (3), and a normalizing coil (4) for the normalizing equipment. The capacitor C2 is connected to the transformer (3), and the transformer (3) is connected to the normalizing coil (4).

2. The mobile rail dual-frequency normalizing equipment control device according to claim 1, characterized in that: The output terminal of the rectifier (1) is connected to the DC filter capacitor C1, the input terminal of the DC filter capacitor C1 is connected to the output terminal of the rectifier (1), the output terminal is connected to the input terminal of the inverter (2), and the input terminal of the inverter (2) is connected to the output terminal of the DC filter capacitor.

3. The mobile rail dual-frequency normalizing equipment control device according to claim 1, characterized in that: The output terminal of the inverter (2) is connected to the input terminal of the capacitor C2 in the normalizing equipment. The input terminal of the capacitor C2 is connected to the output terminal of the medium frequency induction heating power supply. The output terminal is connected to the primary side of the transformer (3). The primary side of the transformer (3) is connected to the output terminal of the capacitor C2. The output terminal is connected to the normalizing coil (4).

4. The mobile rail dual-frequency normalizing equipment control device according to claim 1, characterized in that: The rectifier (1) includes diodes D1, D3 and D5, thyristors D2, D4 and D6. Diodes D1 and D2 are connected to form a semi-controlled rectifier module, diodes D3 and D4 are connected to form a semi-controlled rectifier module, and diodes D5 and D6 are connected to form a semi-controlled rectifier module. The three semi-controlled rectifier modules constitute a three-phase bridge semi-controlled rectifier (1).

5. The mobile rail dual-frequency normalizing equipment control device according to claim 4, characterized in that: The negative terminals of diodes D1, D3, and D5 are connected together. The positive terminal of diode D1 is connected to the cathode of thyristor D2. The positive terminal of diode D3 is connected to the cathode of thyristor D4. The positive terminal of diode D5 is connected to the cathode of thyristor D6. The anodes of thyristors D2, D4, and D6 are connected together.

6. The mobile rail dual-frequency normalizing equipment control device according to claim 1, characterized in that: The inverter (2) includes an insulated gate bipolar transistor (IGBT) T1, an IGBT T2, an IGBT T3, and an IGBT T4. The emitter of IGBT T1 is connected to the collector of IGBT T2, the collector of IGBT T1 is connected to the collector of IGBT T3, the emitter of IGBT T2 is connected to the emitter of IGBT T4, and the collector of IGBT T4 is connected to the emitter of IGBT T3.

7. The mobile rail dual-frequency normalizing equipment control device according to claim 1, characterized in that: The capacitor C2 is a capacitor bank formed by connecting multiple fixed-rate capacitors in parallel or series. The connection method of the capacitors is changed by controlling the coil of the contactor. The output point of the PLC is connected to the coil of the contactor, and the two ends of the contactor contacts are connected to the two ends of the two capacitors respectively. When the PLC outputs a frequency switching signal, the coil of the contactor is energized, the contacts of the contactor close, and the two capacitors are connected in parallel, thereby changing the capacitance value and thus changing the frequency of the normalizing equipment to achieve dual-frequency normalizing.

8. The mobile rail dual-frequency normalizing equipment control device according to claim 1, characterized in that: The transformer (3) is a step-down transformer with a fixed number of turns. The output terminal of the inverter (2) in the medium frequency induction heating power supply is connected to the primary side of the transformer (3), and the secondary side of the transformer (3) is connected to the normalizing coil (4).

9. The mobile rail dual-frequency normalizing equipment control device according to claim 1, characterized in that: The normalizing coil (4) is equipped with an infrared temperature sensor.

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