Crane multi-mechanism integrated frequency conversion speed regulation control system

Abstract

According to the crane multi-mechanism integrated frequency conversion speed regulation control system, the whole control system is simple in structure, and the protection function and the control function of the system are ensured. The system comprises a rectification unit which provides a power supply for the system and protection of overload, short circuit, overcurrent, overvoltage and undervoltage of a line; a control unit; the first inverter unit is used for controlling a main lifting main transmission motor and a main lifting brake; the second inverter unit is used for controlling an auxiliary lifting main transmission motor and an auxiliary lifting brake; the third inverter unit is used for controlling a cart main transmission motor and a cart brake; the fourth inverter unit is used for controlling a trolley main transmission motor and a trolley brake; the input end of the rectification unit is connected with a three-phase alternating current, the output end of the rectification unit outputs the three-phase alternating current and a direct current power supply, the rectification unit is also externally connected with a brake resistor, and the output end of the rectification unit is respectively connected with all the inversion units which are arranged in parallel through lines.

Description

Technical Field

[0001] The present invention relates to the technical field of crane control, and particularly to a multi-mechanism integrated variable frequency speed control system for a crane. Background Art

[0002] At present, most of the variable frequency control systems for cranes use one frequency converter installed in one variable frequency control box to control one mechanism of the crane respectively. Since the mechanisms of the crane include four mechanisms: main hoist, auxiliary hoist, trolley mechanism, and crab mechanism, four control boxes are required to install four frequency converters, which results in a large number of control boxes, and thus requires a large occupied volume and high cost. For this reason, the prior art stacks the variable frequency control boxes of the four mechanisms in a large variable frequency control box body, and its control and protection functions are not comprehensive. Since the four variable frequency control boxes are stacked in a large variable frequency control box body, it requires the user to configure relevant protection and control functions according to the on-site situation, which in turn leads to the need to arrange complex cable lines and a large amount of construction work. Summary of the Invention

[0003] In view of the above problems, the present invention provides a multi-mechanism integrated variable frequency speed control system for a crane, which integrates four independent variable frequency control mechanisms into four inverter units arranged in parallel, and controls the operations of the four inverter units through a rectifier unit and a control unit, making the entire control system simple in structure and ensuring the protection function and control function of the system.

[0004] A multi-mechanism integrated variable frequency speed control system for a crane, characterized in that it includes:

[0005] A rectifier unit, which provides power for the system and protects against overload, short circuit, overcurrent, overvoltage, and undervoltage of the circuit;

[0006] A control unit;

[0007] A first inverter unit, which is used to control the main hoist main drive motor and the main hoist brake;

[0008] A second inverter unit, which is used to control the auxiliary hoist main drive motor and the auxiliary hoist brake;

[0009] A third inverter unit, which is used to control the trolley main drive motor and the trolley brake;

[0010] And a fourth inverter unit, which is used to control the crab main drive motor and the crab brake;

[0011] The input end of the rectification unit is connected to three-phase alternating current. The output end of the rectification unit outputs three-phase alternating current and a DC power supply. The rectification unit is also externally connected to a braking resistor. The output end of the rectification unit is respectively connected to a first inverter unit, a second inverter unit, a third inverter unit, and a fourth inverter unit arranged in parallel through lines.

[0012] Its further features are as follows:

[0013] The rectification unit includes a first circuit breaker, a second circuit breaker, a rectification module, and a braking module. The R / S / T terminals of the first circuit breaker and the second circuit breaker are respectively connected to the AC380V 50HZ power supply. The output end of the first circuit breaker is connected to the rectification module and then connected to the first inverter unit through the + / - terminals to provide a DC power supply for it. The second circuit breaker is connected to the first inverter unit through the L1 / L2 / L3 terminals to provide an AC power supply for it;

[0014] The braking module is set as a braking resistor. The first circuit breaker and the second circuit breaker are connected to the braking resistor through the B1 / B2 terminals;

[0015] The control unit is connected to the first inverter unit through a first connection line. The first inverter unit is connected to the second inverter unit through a second connection line. The second inverter unit is connected to the third inverter unit through a third connection line. The third inverter unit is connected to the fourth inverter unit through a fourth connection line. The control unit controls and connects all the inverter units through the first connection line, the second connection line, the third connection line, and the fourth connection line;

[0016] Each group of inverter units includes an IGBT module, a circuit breaker, and a contactor;

[0017] The input end of the IGBT module of each group of inverter units is connected to the DC power supply. The IGBT module converts the DC power supply into alternating current and is connected to the respective drive motors through the output end, thereby providing an alternating current power supply with adjustable frequency for the drive motors;

[0018] The AC power supply output by the rectification unit is connected to the corresponding brake through a circuit breaker and a contactor;

[0019] The control unit drives the IGBT module to provide an alternating current power supply with adjustable frequency for the corresponding drive motors, and drives the corresponding brakes to work or not by controlling the on - off of the circuit breaker.

[0020] The present invention simplifies four frequency conversion control mechanisms for independently controlling corresponding drive motors and brakes into corresponding inverter units, and then connects the four inverter units in parallel to a rectifier unit, enabling the rectifier unit to independently output three-phase alternating current and DC power supply for each inverter unit. Meanwhile, the control unit independently controls each inverter unit. It integrates four independent frequency conversion control mechanisms into four inverter units arranged in parallel, and controls the operation of the four inverter units through the rectifier unit and the control unit, making the entire control system simple in structure and ensuring the protection function and control function of the system. Brief Description of the Drawings

[0021] Figure 1 It is a structural schematic block diagram of the present invention. Detailed Embodiment

[0022] A multi-mechanism integrated variable frequency speed control system for a crane, as shown in Figure 1 , which includes a rectifier unit 1, a control unit 2, a first inverter unit 3, a second inverter unit 4, a third inverter unit 5, and a fourth inverter unit 6;

[0023] The rectifier unit 1 provides power for the system and protects against overload, short circuit, overcurrent, overvoltage, and undervoltage of the circuit. The input end of the rectifier unit 1 is connected to three-phase alternating current, and the output end of the rectifier unit 1 outputs three-phase alternating current and DC power supply. The output end of the rectifier unit 1 is respectively connected to the first inverter unit 3, the second inverter unit 4, the third inverter unit 5, and the fourth inverter unit 6 arranged in parallel through lines.

[0024] The first inverter unit 3 is used to control the main hoist main drive motor 301 and the main hoist brake 302. The main hoist main drive motor 301 needs to be connected to alternating current with adjustable frequency, and the main hoist brake 302 needs to be connected to three-phase alternating current;

[0025] The second inverter unit 4 is used to control the auxiliary hoist main drive motor 401 and the auxiliary hoist brake 402. The auxiliary hoist main drive motor 401 needs to be connected to alternating current with adjustable frequency, and the auxiliary hoist brake 402 needs to be connected to three-phase alternating current;

[0026] The third inverter unit 5 is used to control the trolley main drive motor 501 and the trolley brake 502. The trolley main drive motor 501 needs to be connected to alternating current with adjustable frequency, and the trolley brake 502 needs to be connected to three-phase alternating current;

[0027] The fourth inverter unit 6 is used to control the crab main drive motor 601 and the crab brake 602. The crab main drive motor 601 needs to be connected to alternating current with adjustable frequency, and the crab brake 602 needs to be connected to three-phase alternating current.

[0028] During specific implementation, the rectification unit 1 includes a first circuit breaker Q1, a second circuit breaker Q2, a rectification module, and a braking module. The R / S / T terminals of the first circuit breaker Q1 and the second circuit breaker Q2 are respectively connected to the AC380V 50HZ power supply. The output terminal of the first circuit breaker Q1 is connected to the rectification module and then connected to the DC input port of the first inverter unit 3 through the + / - terminals to provide DC power for it. The second circuit breaker Q2 is connected to the three-phase AC input port of the first inverter unit 3 through the L1 / L2 / L3 terminals to provide AC power for it.

[0029] The DC input port of the first inverter unit 3 is connected to the DC input port of the second inverter unit 4 through the first DC conduction line 11. The DC input port of the second inverter unit 4 is connected to the DC input port of the third inverter unit 5 through the second DC conduction line 12. The DC input port of the third inverter unit 5 is connected to the DC input port of the fourth inverter unit 6 through the third DC conduction line 13. The three-phase AC input port of the first inverter unit 3 is connected to the three-phase AC input port of the second inverter unit 4 through the first AC conduction wire group 14. The three-phase AC input port of the second inverter unit 4 is connected to the three-phase AC input port of the third inverter unit 5 through the second AC conduction wire group 15. The three-phase AC input port of the third inverter unit 5 is connected to the three-phase AC input port of the fourth inverter unit 6 through the third AC conduction wire group 16. This enables the three-phase alternating current and the DC power supply of the rectification unit 1 to be respectively connected in parallel to the corresponding three-phase AC input ports and DC input ports of all inverter units.

[0030] During specific implementation, the braking module is set as a braking resistor 101. The first circuit breaker Q1 and the second circuit breaker Q2 are connected to the on-site braking resistor 101 through the B1 / B2 terminals.

[0031] The control unit 2 is connected to the first inverter unit 3 through the first connection line 21. The first inverter unit 3 is connected to the second inverter unit 4 through the second connection line 22. The second inverter unit 4 is connected to the third inverter unit 5 through the third connection line 23. The third inverter unit 5 is connected to the fourth inverter unit 6 through the fourth connection line 24. The control unit 2 controls and connects all inverter units through the first connection line 21, the second connection line 22, the third connection line 23, and the fourth connection line 24.

[0032] Each group of inverter units includes an IGBT module, a circuit breaker, and a contactor. The input end of the IGBT module of each group of inverter units is connected to the DC power supply. The IGBT module converts the DC power supply into alternating current and is connected to the respective drive motors through the output end, thereby providing an AC power supply with adjustable frequency for the drive motors. The AC power supply output by the rectification unit is connected to the corresponding brake through the circuit breaker and the contactor.

[0033] The control unit 2 drives the IGBT module to provide an AC power supply with adjustable frequency for the corresponding drive motor, and drives the corresponding brake to work or not by controlling the on / off of the circuit breaker.

[0034] It simplifies the four variable-frequency control mechanisms for independently controlling the corresponding drive motors and brakes into the corresponding inverter units, and then connects the four inverter units in parallel to the rectifier unit, so that the rectifier unit independently outputs three-phase alternating current and DC power supply for each inverter unit. At the same time, the control unit independently controls each inverter unit. It integrates the four independent variable-frequency control mechanisms into four inverter units arranged in parallel, and controls the operation of the four inverter units through the rectifier unit and the control unit, making the entire control system simple in structure and ensuring the protection function and control function of the system.

[0035] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0036] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A crane multi-mechanism integrated variable frequency speed control system, characterized in that: It includes: Rectifier unit, which provides power to the system and protects the line from overload, short circuit, overcurrent, overvoltage and undervoltage; Control unit; The first inverter unit is used to control the main hoisting main drive motor and the main hoisting brake; The second inverter unit is used to control the auxiliary lifting main drive motor and the auxiliary lifting brake; The third inverter unit is used to control the main drive motor and the brake of the trolley; and a fourth inverter unit, which is used to control the main drive motor of the trolley and the trolley brake; The input end of the rectifier unit is connected to three-phase alternating current, the output end of the rectifier unit outputs three-phase alternating current and direct current power supply, the rectifier unit is also externally connected to a braking resistor, and the output end of the rectifier unit is respectively connected to a first inverter unit, a second inverter unit, a third inverter unit, and a fourth inverter unit arranged in parallel through lines.

2. A crane multi-mechanism integrated variable frequency speed control system according to claim 1, characterized in that: The rectifier unit includes a first circuit breaker, a second circuit breaker, a rectifier module, and a brake module. The R / S / T terminals of the first circuit breaker and the second circuit breaker are respectively connected to the AC380V50HZ power supply. The output end of the first circuit breaker is connected to the rectifier module and then connected to the first inverter unit through the + / - terminal to provide a DC power supply for it. The second circuit breaker is connected to the first inverter unit through the L1 / L2 / L3 terminal to provide an AC power supply for it.

3. A crane multi-mechanism integrated variable frequency speed control system according to claim 2, characterized in that: The braking module is configured as a braking resistor, and the first circuit breaker and the second circuit breaker are connected to the braking resistor via the B1 / B2 terminals.

4. The crane multi-mechanism integrated variable frequency speed control system according to claim 1 is characterized in that: The control unit is connected to the first inverter unit through a first connection line, the first inverter unit is connected to the second inverter unit through a second connection line, the second inverter unit is connected to the third inverter unit through a third connection line, the third inverter unit is connected to the fourth inverter unit through a fourth connection line, and the control unit controls the connection of all the inverter units through the first connection line, the second connection line, the third connection line, and the fourth connection line.

5. The crane multi-mechanism integrated variable frequency speed control system according to claim 1 is characterized in that: Each inverter unit includes an IGBT module, a circuit breaker, and a contactor.

6. A crane multi-mechanism integrated variable frequency speed control system according to claim 5, characterized in that: The input end of the IGBT module of each inverter unit is connected to a DC power supply. The IGBT module converts the DC power supply into AC power and connects it to the respective transmission motors through the output end, thereby providing the transmission motors with frequency-adjustable AC power.

7. The crane multi-mechanism integrated variable frequency speed control system according to claim 5, characterized in that: The AC power output by the rectifier unit is connected to the corresponding brake through a circuit breaker and a contactor.

8. The crane multi-mechanism integrated variable frequency speed control system according to claim 5, characterized in that: The control unit drives the IGBT module to provide frequency-adjustable AC power to the corresponding drive motor, and drives the corresponding brake to work or not by controlling the on and off of the circuit breaker.

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