Modular multi-transmission frequency converter structure

Abstract

The invention provides a modularized multi-transmission frequency converter structure, which can realize distributed arrangement, can ensure the independent function of each module, ensures that each module is independently and reliably arranged, and ensures the 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] The present invention relates to the technical field of multi-drive frequency converters, and specifically to a modular multi-drive frequency converter structure. Background Art

[0002] In industrial production, multi-drive systems are widely used in many fields such as papermaking, steel rolling, and wind power generation to drive multiple motors to work together. Most traditional low-power frequency converters (generally referring to those below 37 kW) adopt the "one-to-one" method, that is, one frequency converter drives one motor. When there are a large number of motors on-site, this mode will lead to an excessive number of control cabinets, occupying a large amount of space, and at the same time increasing the wiring and maintenance costs.

[0003] To solve the above problems, a "centralized multi-drive frequency converter" in which rectification and multiple inversions are centrally arranged in a high-power cabinet body has emerged. Although this type of frequency converter reduces the number of cabinet bodies to a certain extent, for some occasions where equipment needs to be distributed, such as motor groups in different areas of a large industrial plant, the centralized structure still has deficiencies; during the distributed installation process, due to reasons such as distance and interference, it is difficult to ensure the cable cost and the reliability of signal transmission, and there are also certain difficulties in later maintenance and expansion. Therefore, there is an urgent need for a multi-drive frequency converter structure that can both achieve distributed layout and ensure the highly reliable operation of each module. Summary of the Invention

[0004] In view of the above problems, the present invention provides a modular multi-drive frequency converter structure, which can achieve distributed layout, ensure the independent functions of each module, and ensure the independent and reliable setting of each module, thus ensuring the stable operation of the multi-drive system.

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

[0006] A rectification module, whose output end is a common DC bus;

[0007] A system control module;

[0008] And a plurality of inversion modules, the AC output end of each inversion module is connected to the motor at the corresponding position;

[0009] The common DC bus covers the corresponding positions of all motors, each motor is correspondingly connected to an inversion module, the common DC bus is respectively connected to the DC input interface of the inversion module through a first connection cable at adjacent positions corresponding to each inversion module, and the AC output end of each inversion module is connected to the adjacent motor through a second connection cable;

[0010] The system control module is respectively connected to each group of inversion modules through control signal lines to complete the control of each group of inversion modules.

[0011] It is further characterized in that:

[0012] It further includes a power distribution protection module, and the power distribution protection module includes a ground protection, an alarm, a zero position protection, an overcurrent and overspeed protection, an overvoltage and undervoltage protection, and a hoisting overload module, which ensures the protection of the same common DC bus connection mechanism;

[0013] The front end of the rectification 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 rectification module outputs DC power through a common DC bus. The interfaces corresponding to the non-inverter modules of the common DC bus are all covered with protective sleeves to ensure that no accidental electric shock accidents occur;

[0014] The system control module is further provided 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 signal lines in the control signal lines, so that the system control module can reliably master the working status and motor status of the motors corresponding to each inverter module;

[0015] The power distribution protection module is connected to the rectification module and the system control module. The system control module timely reads and analyzes the working state parameters of the motor. When the obtained parameters make the motor in an abnormal operating state, the system control module cooperates with the power distribution protection module to complete the power-off protection for the corresponding motor. When the parameters obtained by the system control module are still abnormal under the power-off protection state of a single inverter module, the power distribution protection module operates to make the rectification module in a power-off state, and then after the entire equipment eliminates potential safety hazards, it runs again;

[0016] The system control module is further provided with an upload communication interface. The data in the data storage module in the system control module is transmitted to the enterprise's big data box through the upload communication interface, and the big data box then transmits the data to the remote big data center through 5G communication or WIFI communication, which is convenient for reliable maintenance and monitoring of the equipment.

[0017] The beneficial effects of adopting the present invention are as follows:

[0018] Space saving. By adopting the design of a common DC bus and freely combinable inverter modules, combined with the method of distributing the inverter modules, the number of control cabinets and the floor area are effectively reduced, which is especially suitable for industrial environments with limited space;

[0019] Cost reduction. By shortening the cable length between the inverter module and the motor, the procurement and installation costs of the cables are reduced. At the same time, the modular design makes maintenance more convenient and reduces the maintenance cost;

[0020] Improve reliability. The distributed layout reduces the signal transmission distance, reduces signal interference, improves the reliability of signal transmission and the accuracy of motor control, thereby enhancing the stability of the operation of the entire multi-drive system;

[0021] Enhance flexibility. Users can freely select and combine inverter modules according to actual needs to adapt to different industrial application scenarios, improving the versatility and adaptability of the structure of the multi-drive frequency converter. Brief Description of the Drawings

[0022] Figure 1 It is a structural schematic block diagram of a specific embodiment of the present invention;

[0023] Figure 2 It is a data transmission structural schematic block diagram of the system control module and the corresponding inverter module of a specific embodiment of the present invention;

[0024] Figure 3 It is a connection schematic block diagram of the rectifier module and the three-phase AC power supply of a specific implementation of the present invention;

[0025] Figure 4 It is a schematic block diagram of the power distribution protection module of a specific embodiment of the present invention. Detailed Description of the Invention

[0026] A multi-drive frequency converter structure with modular settings, as shown in Figures 1-4 , which includes a rectifier module, a system control module, and several inverter modules;

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

[0028] The common DC bus covers the corresponding position areas of all motors. Each motor is correspondingly connected to an inverter module. The common DC bus is respectively connected to the DC input interface of the inverter module through the first connection cable at adjacent positions corresponding to each inverter module. The AC output end of each inverter module is connected to the adjacent arranged motor through the second connection cable;

[0029] The system control module is respectively connected to each group of inverter modules through control signal lines to complete the control of each group of inverter modules.

[0030] During specific implementation, the multi-drive frequency converter structure further includes a power distribution protection module. The power distribution protection module includes a ground protection, an alarm, a zero position protection, an overcurrent and overspeed, an overvoltage and undervoltage, and a hoisting overload module, which ensures the protection of the connection mechanism of the same common DC bus.

[0031] The specific embodiment provides a multi-winding frequency converter structure for a crane; at this time, there are five inverter modules, namely the main hoist inverter module, the auxiliary hoist inverter module, the trolley inverter module, the gantry inverter module, and the spreader inverter module. Among them, the main hoist inverter module correspondingly controls the main drive motor of the main hoist, the auxiliary hoist inverter module correspondingly controls the main drive motor of the auxiliary hoist, the trolley inverter module correspondingly controls the main drive motor of the trolley, the gantry inverter module correspondingly controls the main drive motor of the gantry, and the spreader inverter module correspondingly 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 corresponding to the non-inverter modules of the common DC are all covered with protective sleeves to ensure that accidental electric shock accidents will not occur;

[0033] The system control module is also provided 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 signal lines in the control signal lines, so that the system control module can reliably master the working status and motor status of the motors corresponding to each inverter module.

[0034] In the specific embodiment, the power distribution protection module includes, in addition to ground protection, an alarm, zero position protection, overcurrent and overspeed, overvoltage and undervoltage, and hoisting overload modules, but also includes door limit, hoisting limit, trolley limit, gantry limit, and spreader limit modules, which are used to ensure the safe operation of the corresponding motors.

[0035] In the specific embodiment, the power distribution protection module is connected to the rectifier module and the system control module. The system control module timely reads and analyzes the working state parameters of the motor. When the obtained parameters make the motor in an abnormal operating state, the system control module cooperates with the power distribution protection module to complete the power-off protection for the corresponding motor. When the parameters obtained 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 make the rectifier module in a power-off state, and then after the entire device checks and eliminates potential safety hazards, it runs again.

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

[0037] In a specific embodiment, taking the motor corresponding to the crane unit in a small workshop as an example, a rectifier module with a large capacity is selected during the model selection, and a common DC bus design is adopted. At the same time, five inverter modules with appropriate power are selected, and each inverter module corresponds to driving one motor; these five inverter modules are respectively installed near their corresponding motors, and the distributed layout modules are used for fixing and connecting. In this way, the cable length between each inverter module and the motor is the shortest, greatly reducing the cable cost and signal interference; all inverter modules are connected to the rectifier module through the common DC bus, and the rectifier module provides a stable DC power supply for each inverter module. At the same time, the communication module is used to realize the communication between the system control module and each inverter module. For example, the CAN bus protocol is used for communication. The system control module can send control instructions to each inverter module, and each inverter module can also feedback its own working status and fault information to the system control module. During the operation of the system, the rectifier module stably controls the DC voltage on the common DC bus according to the production process requirements, and each inverter module independently controls the operating parameters such as the speed and torque of the corresponding motor. When a certain inverter module fails, the maintenance personnel can quickly locate the faulty module according to the fault information and replace it quickly without affecting other normally operating modules, ensuring the normal operation of the entire multi-drive system.

[0038] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. 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 claimed rights.

[0039] In addition, it should be understood that although this specification is described according to the 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 modular multi-transmission inverter structure, characterized in that: It includes: A rectifier module, whose output end is a common DC bus; System control module; and a plurality of inverter modules, wherein the AC output terminal of each inverter module is connected to a motor at a corresponding position; The common DC bus covers the corresponding positions 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 at the adjacent position corresponding to each inverter module through a first connecting cable, and the AC output end of each inverter module is connected to the adjacently arranged motors through a second connecting cable; The system control module is connected to each group of inverter modules through control signal lines to complete the control of each group of inverter modules.

2. A modular multi-transmission inverter 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, overvoltage and undervoltage, and lifting overload modules, which ensure the protection of the same common DC bus connection mechanism.

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

4. The modular multi-transmission inverter structure according to claim 2, characterized in that: The system control module is also provided with a data storage module, and the data storage module receives data such as status data, alarm information, fault information, etc. uploaded by each inverter module through the communication interface through the signal line in the control signal line.

5. The modular multi-transmission inverter 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 working 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 cooperates with the power distribution protection module to complete the power-off protection for the corresponding motor. When a single inverter module is in a power-off protection state 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, and then the entire equipment is operated again after the safety hazards are checked and eliminated.

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

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