Brake device of frequency converter, system and continuous casting machine variable frequency brake system
Through the coordinated control of the processor, relays, and contactors, the braking resistor is quickly engaged to consume the DC power of the frequency converter, solving the problem of frequency converter damage due to overvoltage and achieving safe operation of the frequency converter.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- PANGANG GRP PANZHIHUA STEEL & VANADIUM
- Filing Date
- 2025-05-30
- Publication Date
- 2026-06-26
Smart Images
Figure CN224418440U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of frequency conversion braking, and in particular to a braking device and system for a frequency converter and a frequency conversion braking system for a continuous casting machine. Background Technology
[0002] Currently, the billet conveyor rollers are controlled by PLCs (Programmable Logic Controllers) and driven by frequency converters. When the conveyor rollers switch between high and low speeds or stop, the mechanical energy of the conveyor rollers is converted into electrical energy by the motor and fed back to the DC side of the frequency converter. This causes the voltage on the DC side of the frequency converter to exceed the normal value. Power devices such as IGBTs (Insulated-Gate Bipolar Transistors) inside the frequency converter may break down due to overvoltage, resulting in damage to the frequency converter and affecting production. Utility Model Content
[0003] The purpose of this utility model is to provide a braking device and system for a frequency converter and a frequency conversion braking system for a continuous casting machine. Through the coordinated control of a processor, relays and contactors, the braking resistor can be quickly engaged when the conveyor rollers decelerate or stop, effectively consuming the feedback electrical energy on the DC side of the frequency converter and preventing overvoltage damage to the frequency converter.
[0004] To solve the above-mentioned technical problems, this utility model provides a braking device for a frequency converter, including a processor, a relay, a contactor, and a braking resistor;
[0005] The first end of the processor is connected to the first end of the auxiliary contact of the contactor, and the second end of the processor is connected to the first end of the coil of the relay, for outputting a high level when the conveyor roller decelerates or stops;
[0006] The second end of the auxiliary contact of the contactor is connected to the first power supply voltage;
[0007] The second end of the relay coil is connected to the negative terminal of the DC power supply, and is used to be energized when the processor outputs a high level;
[0008] The first end of the auxiliary contact of the relay is connected to a second power supply voltage, and the second end of the auxiliary contact of the relay is connected to the first end of the coil of the contactor, for closing after the coil of the relay is energized;
[0009] The second end of the contactor's coil is connected to the neutral wire, which is used to energize the relay after the auxiliary contact is closed;
[0010] The first end of the main contact of the contactor is connected to the positive terminal of the DC side of the frequency converter, and the second end of the main contact of the contactor is connected to the first end of the braking resistor, which is used to close the contactor after the coil is energized.
[0011] The second end of the braking resistor is connected to the negative terminal of the DC side of the frequency converter, and is used to consume the feedback electrical energy of the DC side of the frequency converter after the main contacts of the contactor are closed.
[0012] Optionally, it also includes a first voltage conversion module, a first end of which is connected to the power grid, and a second end of which is connected to the second end of the auxiliary contact of the contactor.
[0013] Optionally, a fuse may also be included, which is connected in series with the processor.
[0014] Optionally, the processor is a PLC.
[0015] Optionally, an alarm module may also be included, which is connected in series with the main contacts of the contactor.
[0016] Optionally, the alarm module is an indicator light, which is connected in series with the main contacts of the contactor.
[0017] To solve the above-mentioned technical problems, this utility model also provides a braking system for a frequency converter, including a braking unit and a braking device for the frequency converter as described above. The first end of the braking unit is connected to the positive terminal of the DC side of the frequency converter, the second end of the braking unit is connected to the second end of the main contact of the contactor and the first end of the braking resistor, the third end of the braking unit is connected to the second end of the braking resistor, and the fourth end of the braking unit is connected to the negative terminal of the DC side of the frequency converter.
[0018] To solve the above-mentioned technical problems, this utility model also provides a frequency conversion braking system for a continuous casting machine, including a continuous casting machine, a frequency converter, and a braking device of the frequency converter as described above. The frequency converter is connected to the motor of the continuous casting machine and the braking device of the frequency converter respectively.
[0019] This application provides a braking device and system for a frequency converter, and a frequency conversion braking system for a continuous casting machine, including a processor, a relay, a contactor, and a braking resistor; a first terminal of the processor is connected to a first terminal of an auxiliary contact of the contactor, and a second terminal of the processor is connected to a first terminal of the coil of the relay; a second terminal of the auxiliary contact of the contactor is connected to a first power supply voltage; a second terminal of the coil of the relay is connected to the negative terminal of the first DC power supply, and is energized when the processor outputs a high level; a first terminal of the auxiliary contact of the relay is connected to a second power supply voltage, and the second terminal of the auxiliary contact of the relay is connected to the first terminal of the coil of the contactor, and is closed after the coil of the relay is energized; a second terminal of the coil of the contactor is connected to a neutral wire, and is energized after the auxiliary contact of the relay is closed; a first terminal of the main contact of the contactor is connected to the positive terminal of the DC side of the frequency converter, and a second terminal of the main contact of the contactor is connected to the first terminal of the braking resistor, and is closed after the coil of the contactor is energized; a first terminal of the braking resistor is connected to the negative terminal of the DC side of the frequency converter, and is used to consume the feedback electrical energy of the DC side of the frequency converter after the main contact of the contactor is closed. As can be seen, this application, through the coordinated control of the processor, relay and contactor, can quickly engage the braking resistor when the conveyor roller decelerates or stops, effectively consuming the feedback power on the DC side of the inverter and preventing overvoltage damage to the inverter. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the structure of a braking device for a frequency converter disclosed in this utility model;
[0022] Figure 2 This is a schematic diagram of a braking unit that independently performs frequency conversion braking, as disclosed in this utility model.
[0023] The attached diagram is labeled as follows: 1 is the processor, 2 is the frequency converter, and 3 is the braking unit. Detailed Implementation
[0024] The core of this utility model is to provide a braking device and system for a frequency converter and a frequency conversion braking system for a continuous casting machine. Through the coordinated control of a processor, relays and contactors, the braking resistor can be quickly engaged when the conveyor rollers decelerate or stop, effectively consuming the feedback electrical energy on the DC side of the frequency converter and preventing overvoltage damage to the frequency converter.
[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0026] For details, please see Figure 1 As shown, Figure 1 This is a schematic diagram of the braking device of a frequency converter disclosed in this utility model.
[0027] The braking device of the frequency converter includes a processor 1, a relay, a contactor, and a braking resistor R. The relay includes a coil KB and an auxiliary contact KB1. The contactor includes an auxiliary contact KM1, a coil KM, and a main contact KM2. The first terminal of the processor 1 is connected to the first terminal of the auxiliary contact KM1, and the second terminal of the processor 1 is connected to the first terminal of the coil KB of the relay. The second terminal of the auxiliary contact KM1 is connected to a first power supply voltage VCC1. The second terminal of the coil KB of the relay is connected to the negative terminal M of the DC power supply. The first terminal of the auxiliary contact KB1 of the relay is connected to a second power supply voltage VCC2, and the second terminal of the auxiliary contact KB1 is connected to the first terminal of the coil KM of the contactor. The second terminal of the coil KM of the contactor is connected to the neutral wire N. The first terminal of the main contact KM2 of the contactor is connected to the positive terminal P+ of the DC side of the frequency converter 2, and the second terminal of the main contact KM2 is connected to the first terminal of the braking resistor R. The second terminal of the braking resistor R is connected to the negative terminal N- of the DC side of the frequency converter 2.
[0028] In this embodiment, when the processor 1 detects that the conveyor roller needs to be braked, that is, when the conveyor roller changes from high speed to low speed or from high / low speed to stop, the processor 1 outputs Q1.0=1, sets it to a high level, the relay coil KB is energized, the relay auxiliary contact KB1 is closed, at this time the contactor coil KM is energized, the contactor main contact KM2 connects the DC side P+ / N- of the frequency converter 2, and the braking resistor R begins to consume the electrical energy of the DC side of the frequency converter 2. Simultaneously, the auxiliary contact KM1 of the contactor closes, and the processor 1 inputs I1.0=1, setting it to a high level. Based on I1.0=1, i.e., the inverter's braking device is activated, the processor 1 immediately controls the conveyor roller to switch from high speed to low speed or from high (low) speed to stop. When the low speed is running smoothly or when it stops, the processor 1 outputs Q1.0=0, setting it to a low level. The relay coil KB is de-energized, and the relay's auxiliary contact KB1 is opened. At this time, the contactor coil KM is de-energized, the contactor's main contact KM2 is opened, and the connection between the DC side P+ / N- of the inverter 2 and the braking resistor R is disconnected, ending the braking operation of the inverter 2.
[0029] In practical applications, processor 1 can be a PLC, the first power supply voltage VCC1 is +24V, and the second power supply voltage VCC2 can be 220V.
[0030] It should be noted that for a schematic diagram of the independent frequency conversion braking of braking unit 3, please refer to [link / reference needed]. Figure 2 As shown in the diagram. The braking unit 3 is used to monitor the voltage of the DC side P+ and N- of inverter 1 in real time. When the voltage exceeds the normal value, the braking unit 3 opens, and the DC side P+ / N- of inverter 2 is connected to the braking resistor R through the braking unit 3. The feedback energy is consumed in the braking resistor R, preventing overvoltage damage to inverter 2's DC side P+ / N- and ensuring the normal operation of inverter 2.
[0031] When the required deceleration or stopping accuracy of the conveyor rollers is not high, or when the inverter's braking unit 3 is damaged and has no spare, the inverter's braking device can be used as an emergency replacement for braking unit 3 to achieve economical operation. Specifically, the requirement for low deceleration and stopping accuracy mainly refers to the speed of deceleration, such as deceleration from 30 m / min to 10 m / min, with a deceleration time of 3 to 10 seconds; the requirement for low stopping accuracy mainly refers to exceeding the required stopping position by 100 to 500 mm.
[0032] As can be seen, this application, through the coordinated control of processor 1, relays and contactors, can quickly engage the braking resistor R when the conveyor roller decelerates or stops, effectively consuming the DC side power of inverter 2 and preventing overvoltage damage to inverter 2.
[0033] Based on the above embodiments:
[0034] As an optional embodiment, it also includes a first voltage conversion module, a first terminal of which is connected to the power grid, and a second terminal of which is connected to the second terminal of the auxiliary contact KM1 of the contactor.
[0035] Specifically, because processor 1 requires a stable first power supply voltage VCC1 to ensure its normal operation, and processor 1 typically uses 24V DC power, while the power grid is generally 220V AC power. Therefore, a first voltage conversion module is needed to step down and rectify the 220V AC power to convert it into the 24V DC power required by processor 1 to ensure that processor 1 works normally.
[0036] As can be seen, this utility model utilizes the first voltage conversion module to step down and rectify the AC power, converting the AC power from the power grid into the required DC power to provide uninterrupted power to the processor 1, thereby ensuring the normal operation of the processor 1.
[0037] As an optional embodiment, a fuse is also included, which is connected in series with the processor 1.
[0038] In this embodiment, the fuse can quickly cut off the current when a short circuit occurs in the circuit, thereby preventing damage to the processor 1. Specifically, when a short circuit occurs inside or outside the processor 1, the fuse connected in series with the processor 1 will melt due to the short circuit, quickly cutting off the circuit and isolating the short circuit point from the processor 1 to avoid further damage.
[0039] It is evident that the main function of a fuse in a circuit is to provide short-circuit protection, ensuring that the circuit is quickly cut off when a short circuit occurs inside or outside the processor 1, thereby protecting the entire inverter's braking device from damage.
[0040] As an optional embodiment, an alarm module is also included, which is connected in series with the main contact KM2 of the contactor.
[0041] In this embodiment, the alarm module is used to detect the current, temperature or connection status of the braking resistor R. When an abnormality occurs, the alarm module triggers protection or alarm to ensure the safe operation of the inverter's braking device.
[0042] Specifically, the alarm module can be an indicator light. This indicator light can detect the current and connection status of the braking resistor R. When processor 1 detects that the conveyor rollers need braking, under normal circumstances, the braking resistor R is connected to the DC side P+ / N- of the inverter 2, and current flows through it, causing the indicator light to illuminate until the conveyor rollers run smoothly at low speed or stop. However, if the main contact KM2 of the contactor is stuck (cannot disconnect) or cannot engage, the indicator light will provide a fault signal. The alarm module can also be a temperature switch. This temperature switch can detect the temperature of the braking resistor R. If the braking resistor R overheats due to prolonged operation or overload, the temperature switch will automatically disconnect to prevent it from burning out. If the braking resistor R is open-circuited (e.g., burned out), the alarm module will detect zero current, indicating a fault.
[0043] As can be seen, the alarm module monitors the working status of the braking circuit in real time and triggers protection or alarm in abnormal situations to ensure the safe operation of the inverter's braking device.
[0044] This utility model also provides a braking system for a frequency converter, including a braking unit 3 and a braking device for the frequency converter as described above. The first end of the braking unit 3 is connected to the positive terminal P+ of the DC side of the frequency converter 2. The second end of the braking unit 3 is connected to the second end of the main contact KM2 of the contactor and the first end of the braking resistor R. The third end of the braking unit 3 is connected to the second end of the braking resistor R. The fourth end of the braking unit 3 is connected to the negative terminal N- of the DC side of the frequency converter 2.
[0045] It should be noted that when the requirements for deceleration and stopping of the conveyor rollers are not high, it is uneconomical to use braking unit 3, or when braking unit 3 is damaged and there is no spare braking unit 3 to replace it, the above-mentioned frequency converter braking device can be used.
[0046] Furthermore, for an introduction to the braking system of the frequency converter provided by this utility model, please refer to the above-described embodiment of the braking device of the frequency converter; this utility model will not be described again here.
[0047] As can be seen, by coordinating the braking unit 3 and the braking device of the inverter, this application can use the braking device of the inverter when the conveyor roller decelerates or stops, thereby improving the economy of frequency conversion braking while consuming the DC side power of the inverter 2.
[0048] This utility model also provides a frequency conversion braking system for a continuous casting machine, including a continuous casting machine, a frequency converter 2, and a braking device for the frequency converter as described above. The frequency converter 2 is connected to the motor of the continuous casting machine and the braking device of the frequency converter.
[0049] For an introduction to the variable frequency braking system for a continuous casting machine provided by this utility model, please refer to the embodiment of the braking device of the variable frequency drive mentioned above. This utility model will not be described again here.
[0050] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.
[0051] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0052] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A braking device for a frequency converter, characterized in that, Includes processors, relays, contactors, and braking resistors; The first end of the processor is connected to the first end of the auxiliary contact of the contactor, and the second end of the processor is connected to the first end of the coil of the relay, for outputting a high level when the conveyor roller decelerates or stops; The second end of the auxiliary contact of the contactor is connected to the first power supply voltage; The second end of the relay coil is connected to the negative terminal of the DC power supply, and is used to be energized when the processor outputs a high level; The first end of the auxiliary contact of the relay is connected to a second power supply voltage, and the second end of the auxiliary contact of the relay is connected to the first end of the coil of the contactor, for closing after the coil of the relay is energized; The second end of the contactor's coil is connected to the neutral wire, which is used to energize the relay after the auxiliary contact is closed; The first end of the main contact of the contactor is connected to the positive terminal of the DC side of the frequency converter, and the second end of the main contact of the contactor is connected to the first end of the braking resistor, which is used to close the contactor after the coil is energized. The second end of the braking resistor is connected to the negative terminal of the DC side of the frequency converter, and is used to consume the feedback electrical energy of the DC side of the frequency converter after the main contacts of the contactor are closed.
2. The braking device of the frequency converter as described in claim 1, characterized in that, It also includes a first voltage conversion module, the first end of which is connected to the power grid, and the second end of which is connected to the second end of the auxiliary contact of the contactor.
3. The braking device of the frequency converter as described in claim 1, characterized in that, It also includes a fuse, which is connected in series with the processor.
4. The braking device of the frequency converter as described in claim 1, characterized in that, The processor is a PLC.
5. The braking device of the frequency converter as described in any one of claims 1 to 4, characterized in that, It also includes an alarm module, which is connected in series with the main contacts of the contactor.
6. The braking device of the frequency converter as described in claim 5, characterized in that, The alarm module is an indicator light, which is connected in series with the main contacts of the contactor.
7. A braking system for a frequency converter, characterized in that, The device includes a braking unit and a braking device for the frequency converter as described in any one of claims 1 to 6, wherein a first end of the braking unit is connected to the positive terminal of the DC side of the frequency converter, a second end of the braking unit is connected to the second end of the main contact of the contactor and the first end of the braking resistor, a third end of the braking unit is connected to the second end of the braking resistor, and a fourth end of the braking unit is connected to the negative terminal of the DC side of the frequency converter.
8. A variable frequency braking system for a continuous casting machine, characterized in that, It includes a continuous casting machine, a frequency converter, and a braking device for the frequency converter as described in any one of claims 1 to 6, wherein the frequency converter is connected to the motor of the continuous casting machine and the braking device of the frequency converter respectively.