Modular multi-transmission frequency converter structure

Abstract

The utility model provides a modularized multi-transmission frequency converter structure, which can realize distributed arrangement, ensure independent functions of each module, ensure independent and reliable arrangement of each module and ensure stable operation of a multi-transmission system. The output end of the rectifier module is a common direct current bus; a system control module; the alternating current output end of each inversion module is connected with the motor at the corresponding position; the common direct current bus covers the corresponding positions of all the motors, each motor is correspondingly connected with an inversion module, and the common direct current bus is connected with direct current input interfaces of the inversion modules through first connecting cables at the adjacent positions corresponding to the inversion modules; the alternating current output end of each inversion module is connected with the adjacent motor through a second connecting cable; and the system control module is respectively connected with each group of inversion modules through control signal lines so as to control each group of inversion modules.

Description

Technical Field

[0001] This utility model relates to the technical field of multi-transmission frequency converters, specifically a modular multi-transmission frequency converter structure. Background Technology

[0002] In industrial production, multi-drive systems are widely used in many fields such as papermaking, steel rolling, and wind power to drive multiple motors to work together. Traditional low-power frequency converters (generally referring to those below 37kW) mostly adopt a "one-to-one" method, that is, one frequency converter drives one motor. When there are many motors on site, this mode will result in too many control cabinets, occupying a lot of space, and increasing wiring and maintenance costs.

[0003] To address the aforementioned issues, a "centralized multi-drive frequency converter" has emerged, where rectifiers and multiple inverters are integrated within a high-power cabinet. While this type of frequency converter reduces the number of cabinets to some extent, the centralized structure still has shortcomings for applications requiring distributed equipment layout, such as motor groups in different areas of a large industrial plant. During distributed installation, cable costs and signal transmission reliability are difficult to guarantee due to distance and interference, and there are also challenges in later maintenance and expansion. Therefore, there is an urgent need for a multi-drive frequency converter structure that can achieve both distributed layout and ensure high reliability of each module's operation. Utility Model Content

[0004] To address the aforementioned issues, this utility model provides a modular multi-transmission frequency converter structure that enables distributed arrangement while ensuring the independent function of each module and the independent and reliable configuration of each module, thereby ensuring the stable operation of the multi-transmission system.

[0005] A modular multi-transmission frequency converter structure, characterized in that it comprises:

[0006] The rectifier module has a common DC bus at its output.

[0007] System control module;

[0008] And several inverter modules, each inverter module’s AC output terminal is connected to the motor at the corresponding position;

[0009] The common DC bus covers the corresponding positions of all motors, and each motor is connected to an inverter module. The common DC bus is connected to the DC input interface of the inverter module through a first connecting cable at the adjacent positions corresponding to each inverter module. The AC output terminal of each inverter module is connected to the adjacent motor through a second connecting cable.

[0010] The system control module is connected to each inverter module via control signal lines to control each inverter module.

[0011] Its further features are:

[0012] It also includes a power distribution protection module, which includes grounding protection, alarm, zero-position protection, overcurrent and overspeed protection, overvoltage and undervoltage protection, and lifting overload protection modules, which ensure protection of the same common DC bus connection mechanism;

[0013] The front end of the rectifier module is sequentially connected to an optional reactor, a main contactor, an air switch, and a three-phase AC power supply. The output end of the rectifier module outputs DC power through a common DC bus. The interfaces of the common DC bus corresponding to the non-inverter modules are all covered with protective sleeves to ensure that no accidental electric shock will occur.

[0014] The system control module is also equipped with a data storage module. The data storage module receives data such as status data, alarm information, and fault information uploaded by each inverter module through the communication interface via the signal line in the control signal line, so that the system control module can reliably grasp the working status and motor status of the motor corresponding to each inverter module.

[0015] The power distribution protection module is connected to the rectifier module and the system control module. The system control module reads and analyzes the motor's operating status parameters in a timely manner. When the acquired parameters cause the motor to be in an abnormal operating state, the system control module works with the power distribution protection module to complete the power-off protection for the corresponding motor. When the parameters acquired by the system control module are still abnormal under the power-off protection state of a single inverter module, the power distribution protection module works to put the rectifier module in a power-off state. After the entire equipment has been checked and eliminated for safety hazards, it can be put into operation again.

[0016] The system control module is also equipped with an upload communication interface. Data in the data storage module within the system control module is transmitted to the enterprise's big data box through the upload communication interface. The big data box then transmits the data to a remote big data center via 5G or WIFI communication, facilitating reliable maintenance and monitoring of the equipment.

[0017] The beneficial effects of using this utility model are as follows:

[0018] Space-saving design with a common DC bus and freely combinable inverter modules, combined with a distributed inverter module layout, effectively reduces the number of control cabinets and floor space, making it particularly suitable for industrial environments with limited space.

[0019] Cost reduction is achieved by shortening the cable length between the inverter module and the motor, thereby reducing cable procurement and installation costs. At the same time, the modular design makes maintenance more convenient and reduces maintenance costs.

[0020] To improve reliability, the distributed layout reduces signal transmission distance, reduces signal interference, improves the reliability of signal transmission and the accuracy of motor control, thereby enhancing the stability of the entire multi-transmission system.

[0021] Enhanced flexibility allows users to freely select and combine inverter modules according to actual needs, adapting to different industrial application scenarios and improving the versatility and adaptability of the multi-transmission inverter structure. Attached Figure Description

[0022] Figure 1 This is a schematic block diagram illustrating the structure of a specific embodiment of the present utility model;

[0023] Figure 2 This is a schematic block diagram of the data transmission structure of the system control module and the corresponding inverter module in a specific embodiment of this utility model;

[0024] Figure 3 This is a schematic block diagram showing the connection between the rectifier module and the three-phase AC power supply in a specific embodiment of this utility model.

[0025] Figure 4 This is a schematic block diagram of a power distribution protection module according to a specific embodiment of the present utility model. Detailed Implementation

[0026] A modular multi-pass inverter structure, see Figures 1-4 It includes a rectifier module, a system control module, and several inverter modules;

[0027] The output of the rectifier module is a common DC bus; the AC output of each inverter module is connected to the motor at the corresponding position.

[0028] The common DC bus covers the corresponding area of ​​all motors. Each motor is connected to an inverter module. The common DC bus is connected to the DC input interface of the inverter module through a first connecting cable at the adjacent position corresponding to each inverter module. The AC output terminal of each inverter module is connected to the adjacent motor through a second connecting cable.

[0029] The system control module connects to each inverter module via control signal lines to control each inverter module.

[0030] In practical implementation, the multi-transmission frequency converter structure also includes a power distribution protection module, which includes grounding protection, alarm, zero-position protection, overcurrent and overspeed protection, overvoltage and undervoltage protection, and lifting overload protection modules, ensuring protection of the same common DC bus connection mechanism.

[0031] A specific embodiment provides a multi-channel inverter structure for the crane; there are five inverter modules, namely the main hoisting inverter module, the auxiliary hoisting inverter module, the trolley inverter module, the trolley inverter module, and the spreader inverter module. The main hoisting inverter module controls the main hoisting main drive motor, the auxiliary hoisting inverter module controls the auxiliary hoisting main drive motor, the trolley inverter module controls the trolley main drive motor, the trolley inverter module controls the trolley main drive motor, and the spreader inverter module controls the spreader drive motor.

[0032] The front end of the rectifier module is sequentially connected to an optional reactor, a main contactor, an air switch, and a three-phase AC power supply. The output end of the rectifier module outputs DC power through a common DC bus. The interfaces of the common DC bus corresponding to the non-inverter modules are all covered with protective sleeves to ensure that no accidental electric shock will occur.

[0033] The system control module is also equipped with a data storage module. The data storage module receives data such as status data, alarm information, and fault information uploaded by each inverter module through the communication interface via the signal lines in the control signal line, so that the system control module can reliably grasp the working status and motor status of the motor corresponding to each inverter module.

[0034] In a specific embodiment, the power distribution protection module includes, in addition to grounding protection, alarm, zero-position protection, overcurrent and overspeed protection, overvoltage and undervoltage protection, and lifting overload protection modules, door limit, lifting limit, trolley limit, trolley limit, and lifting device limit modules, which are used to ensure the safe operation of the corresponding motors.

[0035] In a specific embodiment, the power distribution protection module is connected to the rectifier module and the system control module. The system control module reads and analyzes the operating status parameters of the motor in a timely manner. When the acquired parameters cause the motor to be in an abnormal operating state, the system control module works with the power distribution protection module to complete the power-off protection for the corresponding motor. When the parameters acquired by the system control module are still abnormal under the power-off protection state of a single inverter module, the power distribution protection module works to put the rectifier module in a power-off state. After the entire equipment has been checked and eliminated for safety hazards, it can be put into operation again.

[0036] In a specific embodiment, the system control module is also equipped with an upload communication interface. Data in the data storage module within the system control module is transmitted to the enterprise's big data box through the upload communication interface. The big data box then transmits the data to a remote big data center via 5G or WIFI communication, facilitating reliable maintenance and monitoring of the equipment.

[0037] A specific implementation example is the motor corresponding to a crane unit in a small workshop. When selecting a model, a large-capacity rectifier module is chosen, and a common DC bus design is adopted. Meanwhile, five inverter modules with appropriate power are selected, each driving one motor. These five inverter modules are installed near their respective motors using a distributed arrangement for fixing and connection. This minimizes the cable length between each inverter module and the motor, significantly reducing cable costs and signal interference. All inverter modules are connected to the rectifier module via a common DC bus, which provides a stable DC power supply to each inverter module. A communication module is used to enable communication between the system control module and each inverter module, for example, using the CAN bus protocol. The system control module can send control commands to each inverter module, and each inverter module can also feed back its operating status and fault information to the system control module. During system operation, the rectifier module stabilizes the DC voltage on the common DC bus according to production process requirements. Each inverter module independently controls the speed, torque, and other operating parameters of its corresponding motor based on the received control commands. When an inverter module malfunctions, maintenance personnel can quickly locate and replace the faulty module without affecting other normally operating modules, ensuring the normal operation of the entire multi-transmission system.

[0038] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0039] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider 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 modularly configured multi-transmission frequency converter structure, characterized in that, It includes: The rectifier module has a common DC bus at its output. System control module; And several inverter modules, each inverter module’s AC output terminal is connected to the motor at the corresponding position; The common DC bus covers the corresponding positions of all motors, and each motor is connected to an inverter module. The common DC bus is connected to the DC input interface of the inverter module through a first connecting cable at the adjacent positions corresponding to each inverter module. The AC output terminal of each inverter module is connected to the adjacent motor through a second connecting cable. The system control module is connected to each inverter module via control signal lines to control each inverter module.

2. The modular multi-transmission frequency converter structure according to claim 1, characterized in that: It also includes a power distribution protection module, which includes grounding protection, alarm, zero-position protection, overcurrent and overspeed protection, overvoltage and undervoltage protection, and lifting overload protection modules, ensuring protection of the same common DC bus connection mechanism.

3. The modular multi-transmission frequency converter structure according to claim 2, characterized in that: The front end of the rectifier module is sequentially connected to an optional reactor, a main contactor, an air switch, and a three-phase AC power supply. The output end of the rectifier module outputs DC power through a common DC bus.

4. The modular multi-transmission frequency converter structure according to claim 2, characterized in that: The system control module is also equipped with a data storage module, which receives status data, alarm information, fault information and other data uploaded by each inverter module through the communication interface via the signal lines in the control signal line.

5. The modular multi-transmission frequency converter structure according to claim 4, characterized in that: The power distribution protection module is connected to the rectifier module and the system control module. The system control module reads and analyzes the motor's operating status parameters in a timely manner. When the acquired parameters cause the motor to be in an abnormal operating state, the system control module works with the power distribution protection module to complete the power-off protection for the corresponding motor. When a single inverter module is under power-off protection and the parameters acquired by the system control module are still abnormal, the power distribution protection module works to put the rectifier module in a power-off state. After the entire equipment has been checked and eliminated for safety hazards, it can be put back into operation.

6. The modular multi-transmission frequency converter structure according to claim 4, characterized in that: The system control module is also equipped with an upload communication interface. Data in the data storage module within the system control module is transmitted to the enterprise's big data box through the upload communication interface. The big data box then transmits the data to a remote big data center via 5G or WIFI communication.

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