Frequency conversion and power frequency switching device of high-voltage frequency converter and use method

Abstract

The invention relates to the technical field of high-voltage frequency converters, in particular to a variable-frequency and power-frequency switching device of a high-voltage frequency converter and a using method of the variable-frequency and power-frequency switching device of the high-voltage frequency converter. And the power frequency starting module serves as a standby device of the high-voltage frequency converter, and when the high-voltage frequency converter breaks down, the high-voltage frequency converter can be switched to a power frequency mode to continue running. The high-voltage frequency converter fault detection system has the advantages that automatic detection and quick response are achieved when the high-voltage frequency converter breaks down through the PLC and the fault switching control system, and the high-voltage frequency converter fault detection system is more efficient and safer than a traditional system needing manual intervention. When the high-voltage frequency converter breaks down, the high-voltage frequency converter is rapidly switched to a power frequency power supply mode, continuous operation of load equipment such as a draught fan is guaranteed, and downtime is shortened to the maximum extent. The safety locking mechanism prevents accidental reclosing until manual resetting, thereby avoiding potential operational accidents.

Description

Technical Field

[0001] The invention relates to the technical field of high-voltage frequency converters, in particular to a high-voltage frequency converter frequency conversion and power frequency cutting device and a use method thereof. Background Art

[0002] In the field of modern industrial automation, especially in the power, metallurgy, chemical and other industries, high-voltage inverters, as key electrical equipment, are widely used in various fan drive systems to achieve precise control of motor speed and torque. Important auxiliary equipment in these industries, such as primary fans and blowers, are crucial to the stable operation of the system.

[0003] Traditional high-voltage inverter designs usually include multiple power units. When any of the power units fails, it should ideally have the function of automatically bypassing the failed unit to ensure that the entire system can continue to operate without being affected by the failure of a single component.

[0004] However, in actual applications, not all high-voltage inverters have achieved the above functions. This means that once these high-voltage inverters fail and cannot automatically switch to the power frequency operation mode, the fan may stop working, thus affecting the continuity of the entire production process. Moreover, without the appropriate DCS (distributed control system) logic to prevent parameter disturbances and make automatic adjustments, manual switching to power frequency operation may bring additional operational risks and uncertainties. Summary of the invention

[0005] Some simplifications or omissions may be made in this section and the abstract and title of the present application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0006] The purpose of the present invention is to provide a high-voltage frequency converter frequency conversion and power frequency cutting device.

[0007] Therefore, its purpose is to solve the problem that a high-voltage inverter fails and cannot automatically switch to the industrial frequency operation mode, which may cause the fan to stop working and thus affect the continuity of the entire production process.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: a high-voltage inverter frequency conversion and industrial frequency switching device, which includes a high-voltage inverter for speed control of a connected fan; an industrial frequency starting module, which serves as a backup device for the high-voltage inverter and can switch to the industrial frequency mode to continue operating when the high-voltage inverter fails.

[0009] As a preferred solution of the high-voltage inverter frequency conversion and power frequency cutting device of the present invention, the high-voltage inverter includes: an input end adapted to receive a high voltage input from a power supply; an output end adapted to provide an output voltage with adjustable frequency to the fan.

[0010] As a preferred solution of the high-voltage inverter frequency conversion and industrial frequency cutting device of the present invention, the industrial frequency starting module includes: a frequency conversion circuit, including a frequency converter incoming line vacuum contactor "K1", a frequency converter outgoing line vacuum contactor "K2", which are used to control the transmission of current to the load; an industrial frequency circuit, connected in parallel with the frequency conversion circuit, including a frequency converter bypass vacuum contactor "K3", which is used to provide a backup power path when the frequency conversion circuit fails; a high-voltage switch cabinet, located at the upper level of the frequency conversion circuit, is used to perform high-voltage control on the entire power supply system; a fault detection module is used to monitor the working status of the high-voltage inverter and issue a disconnection command when a serious fault of the high-voltage inverter is detected.

[0011] As a preferred solution of the high-voltage inverter frequency conversion and industrial frequency cutting device of the present invention, the industrial frequency starting module also includes: a control unit, which is electrically connected to the fault detection module, and performs the following actions after receiving the disconnection instruction: automatically disconnecting the inverter incoming line vacuum contactor "K1" and the inverter outgoing line vacuum contactor "K2" in the frequency conversion circuit; instructing to trip the high-voltage switch cabinet and cut off the upper power supply of the frequency conversion circuit; providing an indication signal to the operator to prompt manual switching to the industrial frequency circuit.

[0012] As a preferred solution of the high-voltage inverter frequency conversion and power frequency cutting device of the present invention, the control unit also includes: a logic judgment module, which is used to evaluate the severity of the high-voltage inverter fault and start the protection mechanism only when it is confirmed to be a serious fault; a safety locking mechanism, which remains locked after the frequency conversion circuit is disconnected to prevent accidental reclosing until manual reset.

[0013] As a preferred solution of the high-voltage inverter frequency conversion and power frequency cutting device of the present invention, the control unit is provided with a manual operation interface, allowing the operator to receive the indication signal from the control unit, manually close the inverter bypass vacuum contactor "K3" in the power frequency circuit, and reclose the switch in the high-voltage switch cabinet, so that the equipment can continue to operate under power frequency conditions.

[0014] As a preferred solution of the high-voltage inverter frequency conversion and industrial frequency cutting device of the present invention, the industrial frequency starting module further includes: a PLC, which is communicated with the high-voltage inverter and configured to monitor the status of the high-voltage inverter; and a fault switching control system, which is controlled by the PLC. When a serious fault is detected in the high-voltage inverter, the fault switching control system performs the following steps: sending instructions to the inverter incoming line vacuum contactor "K1" and the inverter outgoing line vacuum contactor "K2" to disconnect the frequency conversion circuit; after a predetermined time delay, sending instructions to the inverter bypass vacuum contactor "K3" to close the industrial frequency circuit.

[0015] As a preferred solution of the high-voltage inverter frequency conversion and power frequency cutting device of the present invention, the PLC includes a fault signal detection unit, which is integrated in the high-voltage inverter or independently set and connected to the PLC, and is used to monitor the operating status of the high-voltage inverter in real time and provide fault information to the PLC.

[0016] As a preferred solution of the high-voltage inverter frequency conversion and power frequency switching device of the present invention, the PLC also includes a time delay module, which is controlled by the PLC and is used to define the time interval from the disconnection of the frequency conversion circuit to the closure of the power frequency circuit to ensure safe and reliable switching operations.

[0017] In order to solve the above technical problems, the present invention also provides the following technical solutions: a method for using a high-voltage inverter frequency conversion and power frequency switching device, comprising a high-voltage inverter frequency conversion and power frequency switching device, and,

[0018] Check and verify the working status of all relevant switches (inverter incoming line vacuum contactor "K1", inverter outgoing line vacuum contactor "K2", inverter bypass vacuum contactor "K3") to ensure that they function normally and can accurately perform opening or closing actions when receiving control instructions; start the power equipment to enter the variable frequency operation mode, and wait until the output frequency reaches a stable state; simulate the situation of a serious fault in the high-voltage inverter, such as triggering the fault response mechanism by simulating a fan fault; the monitoring system's response to the above faults is as follows: whether the inverter incoming line vacuum contactor "K1" and the inverter outgoing line vacuum contactor "K2" can be opened in time to disconnect the inverter; whether the inverter bypass vacuum contactor "K3" correctly performs the closing action after the preset time delay, thereby connecting the system to the industrial frequency power supply; verify whether the power equipment can smoothly switch from the variable frequency mode to the industrial frequency mode to continue operating.

[0019] The beneficial effects of the present invention are: through the PLC and fault switching control system, automatic detection and rapid response to high-voltage inverter faults are achieved, which is more efficient and safer than traditional systems that require manual intervention.

[0020] When a high-voltage inverter fails, it quickly switches to industrial frequency power supply mode to ensure the continuous operation of load equipment such as fans, minimizing downtime.

[0021] The safety lockout mechanism prevents accidental reclosing until manually reset, thus avoiding potential operating accidents.

[0022] The time delay module ensures that the time interval from the opening of the variable frequency circuit to the closing of the power frequency circuit is long enough to fully achieve electrical isolation and avoid short circuits or other electrical hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0025] Figure 2 It is a circuit diagram of the present invention.

[0026] In the figure:

[0027] 100. High voltage inverter;

[0028] 200, industrial frequency starting module; 201, inverter incoming line vacuum contactor "K1"; 202, inverter outgoing line vacuum contactor "K2"; 203, inverter bypass vacuum contactor "K3". DETAILED DESCRIPTION

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0032] Example 1

[0033] Reference Figure 1-2 , which is the first embodiment of the present invention, provides a high-voltage inverter frequency conversion and industrial frequency switching device, including a high-voltage inverter 100, which is used to control the speed of the connected fan; an industrial frequency starting module 200, which serves as a backup device for the high-voltage inverter 100 and can switch to the industrial frequency mode to continue operating when the high-voltage inverter 100 fails.

[0034] In this embodiment, the high-voltage frequency converter 100 is a device for changing the power supply frequency of the AC fan, and it controls the speed of the fan by adjusting the power supply frequency. Compared with the traditional mechanical speed regulation or slip speed regulation, this speed regulation method has higher efficiency and better dynamic response characteristics. In addition, since it can achieve smooth start-up, it reduces the impact on the power grid when the fan starts, and can reduce the wear of the fan and extend its service life.

[0035] When the high-voltage inverter 100 fails or cannot work normally during maintenance, in order to ensure the continuity and reliability of the system, the power frequency starting module 200 is introduced as a backup device. The so-called "power frequency" refers to the standard power frequency, that is, the original power supply frequency that has not been adjusted by the high-voltage inverter 100. The main function of the power frequency starting module 200 is to automatically or manually switch to the mode of direct power supply from the power grid when the high-voltage inverter 100 fails, so that the wind turbine can operate at a fixed frequency to avoid economic losses caused by downtime.

[0036] The high-voltage inverter 100 comprises: an input end adapted to receive a high voltage input from a power source; and an output end adapted to provide an output voltage with an adjustable frequency to the wind turbine.

[0037] In this embodiment, the input port is connected to the power grid and is responsible for receiving high voltage input from the power supply. After the output end converts the DC power into three-phase or multi-phase AC power through the inverter, the output end provides a power supply with adjustable frequency and voltage to the fan. This allows the fan to run at different speeds to adapt to different load requirements.

[0038] The industrial frequency starting module 200 further includes: a PLC, which is communicatively connected to the high-voltage frequency converter 100 and configured to monitor the status of the high-voltage frequency converter 100; and a fault switching control system, which is controlled by the PLC. When a serious fault is detected in the high-voltage frequency converter 100, the fault switching control system performs the following steps: sending instructions to the frequency converter incoming line vacuum contactor "K1" 201 and the frequency converter outgoing line vacuum contactor "K2" 202 to disconnect the frequency conversion circuit; after a predetermined time delay, sending instructions to the frequency converter bypass vacuum contactor "K3" 203 to close the industrial frequency circuit; wherein the PLC is also configured to set the "frequency conversion to industrial frequency enable" to "automatic position" so that the entire switching process can be completed without manual intervention.

[0039] In this embodiment, once a conventional high-voltage inverter 100 fails, manual intervention is usually required to repair it or switch to a backup power source, which is not only time-consuming but also increases operational risks.

[0040] The PLC in this solution is the control unit of the power frequency starting module 200. It establishes a connection with the high-voltage inverter 100 through a communication interface and monitors the state parameters of the high-voltage inverter 100 in real time, such as voltage, current, temperature, etc. A variety of fault judgment logics are preset inside the PLC, which can identify whether a serious fault state occurs in the high-voltage inverter 100. When an abnormality is detected, the PLC will immediately trigger the fault switching control system and execute a series of predetermined operation steps to ensure the safe switching of the system.

[0041] The inverter inlet vacuum contactor "K1" 201 and the inverter outlet vacuum contactor "K2" 202 are used to disconnect the input and output circuits of the high-voltage inverter 100 to prevent the expansion of the fault and prepare for switching to the industrial frequency power supply.

[0042] The inverter bypass vacuum contactor "K3" 203 is responsible for closing the industrial frequency circuit, so that the fan can directly obtain electrical energy from the power grid and continue to work normally.

[0043] By setting the time delay between the disconnection of the inverter inlet vacuum contactor "K1" 201 and the inverter outlet vacuum contactor "K2" 202 and the closing of the inverter bypass vacuum contactor "K3" 203, it is ensured that electrical isolation is fully completed to avoid short circuits or other electrical hazards.

[0044] Automation settings: "Frequency conversion and power frequency switching enable" (In electronic technology, "enable" is a common term, corresponding to the English "Enable", which means allowing a pin (pin), chip or module of an electronic device to enable a preset function and enter a preset state)

[0045] In order to fully automate the entire switching process, the PLC is configured to set the "Frequency Conversion to Power Frequency Enable" to "Automatic Position". This means that in any case, as long as the pre-set conditions are met, the PLC will automatically execute the switching process without human intervention. This not only improves the system's response speed, but also reduces the risk of human error.

[0046] Switching process:

[0047] The PLC continuously monitors various operating parameters of the high-voltage inverter 100, and once abnormal data exceeding the safety range is found, it is immediately determined as a serious fault.

[0048] After confirming the fault, the PLC quickly sends a disconnect command to the inverter input vacuum contactor "K1" 201 and the inverter output vacuum contactor "K2" 202 to cut off the connection between the high-voltage inverter 100 and the fan.

[0049] After a preset time delay (e.g., several seconds) to ensure that all charges have been fully discharged, the PLC then commands the inverter bypass vacuum contactor "K3" 203 to close, establishing a new industrial frequency power supply path.

[0050] At this point, the fan has been converted to be powered directly by the industrial frequency power supply and can resume normal operation.

[0051] Finally, the PLC will record the relevant information of the switching event and report it to the remote monitoring center through the communication network for subsequent analysis and maintenance.

[0052] In summary, by integrating PLC technology and fault switching control system, the industrial frequency starting module 200 can not only effectively ensure the rapid response when the high-voltage inverter 100 fails, but also ensure the safety and reliability of the switching process, thereby minimizing the impact on production activities.

[0053] The PLC includes a fault signal detection unit, which is integrated into the high-voltage inverter 100 or independently provided and connected to the PLC, and is used to monitor the operating status of the high-voltage inverter 100 in real time and provide fault information to the PLC. The PLC also includes a time delay module, which is controlled by the PLC and is used to define the time interval from the disconnection of the frequency conversion circuit to the closure of the power frequency circuit, so as to ensure safe and reliable switching operation.

[0054] In this embodiment, the integrated fault signal detection unit can be built into the high-voltage inverter 100 or connected to the PLC as an independent module. In either form, it can continuously collect data from the high-voltage inverter 100, including but not limited to parameters such as current, voltage, and temperature, and analyze the data to identify potential problems.

[0055] Time delay module, which is controlled by PLC, allows users to customize the time interval between the disconnection of the frequency conversion circuit and the closure of the power frequency circuit. This feature ensures that in the event of a fault, the system can smoothly transition to the backup operation mode without damaging any components.

[0056] This improved PLC control system is suitable for a variety of industrial environments, especially those with high requirements for continuity and safety, such as petrochemical, steel metallurgy, papermaking and printing industries. It can effectively reduce the losses caused by unexpected power outages or equipment failures, ensure the smooth operation of the production line, and also reduce maintenance costs and the workload of technicians.

[0057] Example 2

[0058] Reference Figure 1-2 , which is the second embodiment of the present invention, and provides a high-voltage inverter frequency conversion and power frequency cutting device. The power frequency starting module 200 includes: a frequency conversion circuit, including two inverter incoming line vacuum contactors "K1" 201, and an inverter outgoing line vacuum contactor "K2" 202, which are used to control the transmission of current to the load; a power frequency circuit, which is connected in parallel with the frequency conversion circuit, including a inverter bypass vacuum contactor "K3" 203, which is used to provide a backup power path when the frequency conversion circuit fails; a high-voltage switch cabinet, located at the upper level of the frequency conversion circuit, is used to perform high-voltage control on the entire power supply system; a fault detection module, which is used to monitor the working status of the high-voltage inverter 100 and issue a disconnection command when a serious fault of the high-voltage inverter 100 is detected.

[0059] In this embodiment, under normal circumstances, the frequency conversion circuit controls the transmission of current to the load through the frequency converter incoming line vacuum contactor "K1" 201 and the frequency converter outgoing line vacuum contactor "K2" 202. The high-voltage frequency converter 100 adjusts the output frequency according to the set parameters to meet the load requirements. At the same time, the power frequency circuit is in standby mode as a backup path. Once the fault detection module detects a serious fault in the high-voltage frequency converter 100, it will immediately issue a command to disconnect the frequency converter incoming line vacuum contactor "K1" 201 and the frequency converter outgoing line vacuum contactor "K2" 202.

[0060] Inverter inlet vacuum contactor "K1" 201, inverter outlet vacuum contactor "K2" 202: These two components are located in the frequency conversion circuit and are responsible for controlling whether the current flows to the load. They respond to the signal from the fault detection module to quickly cut off or connect the power supply.

[0061] Inverter bypass vacuum contactor "K3" 203 This component is part of the power frequency circuit. When the frequency conversion circuit fails due to a fault, the inverter bypass vacuum contactor "K3" 203 will be manually closed under the operation of the operator to establish a new power supply path to ensure that the load can continue to obtain the required electrical energy.

[0062] The high-voltage switchgear is installed at the upper level of the frequency conversion circuit and is responsible for managing and distributing the input high voltage. It not only provides the necessary protection mechanisms, such as overload protection, short circuit protection, etc., but also can execute remote monitoring and operation commands, enhancing the intelligence level of the system.

[0063] The fault detection module has built-in advanced sensors and algorithms, which can accurately identify various abnormal conditions of the high-voltage inverter 100, including but not limited to problems such as over-temperature, over-current, and voltage fluctuation. Once a major safety hazard is found, the fault detection module will immediately start the emergency procedure and send a disconnection command to prevent the potential risk from expanding.

[0064] The industrial frequency starting module 200 also includes: a control unit, which is electrically connected to the fault detection module and performs the following actions after receiving the disconnection command: automatically disconnecting the inverter incoming line vacuum contactor "K1" 201 and the inverter outgoing line vacuum contactor "K2" 202 in the frequency conversion circuit; instructing the high-voltage switch cabinet to trip and cut off the upper power supply of the frequency conversion circuit; providing an indication signal to the operator to prompt manual switching to the industrial frequency circuit.

[0065] In this embodiment, the control unit can monitor the information from the fault detection module in real time and respond according to preset conditions. Specifically:

[0066] Once the disconnection command issued by the fault detection module is received, the control unit will immediately trigger a series of predetermined action sequences. First, it will automatically disconnect the inverter inlet vacuum contactor "K1" 201 and the inverter outlet vacuum contactor "K2" 202 in the frequency conversion circuit, which are responsible for cutting off the current path between the high-voltage inverter 100 and the fan to ensure that the fault will not expand further.

[0067] Next, the control unit sends a signal to the high-voltage switchgear, instructing it to perform a tripping operation. This step is to completely cut off the upstream power supply of the frequency conversion circuit to prevent possible reverse current or other dangerous situations.

[0068] Finally, in order to assist the operator in completing the subsequent manual switching steps, the control unit will also generate corresponding indication signals. These signals can be conveyed to the operator through visual (such as LED lights), auditory (such as buzzers) or digital display interfaces, guiding them to switch the system to the power frequency circuit in the correct way.

[0069] Example 3

[0070] Reference Figure 1-2 , which is the third embodiment of the present invention, and provides a high-voltage inverter frequency conversion and power frequency cutting device, and the control unit also includes: a logic judgment module, which is used to evaluate the severity of the high-voltage inverter 100 fault and start the protection mechanism only when it is confirmed to be a serious fault; a safety locking mechanism, which remains locked after the frequency conversion circuit is disconnected to prevent accidental reclosing until manual reset. The control unit is provided with a manual operation interface, allowing the operator to receive the indication signal from the control unit, manually close the inverter bypass vacuum contactor "K3" 203 in the power frequency circuit, and reclose the switch in the high-voltage switch cabinet, so that the equipment can continue to operate under power frequency conditions.

[0071] In this embodiment, the logic judgment module monitors the health status of the high-voltage inverter 100 in real time and judges the nature of the fault according to preset rules. Specifically, the logic judgment module can perform the following functions:

[0072] Various operating parameters of the high-voltage inverter 100, such as current, voltage, temperature, etc., are continuously collected through built-in sensors and communication interfaces.

[0073] Based on historical data and machine learning algorithms, currently collected data is analyzed to identify potential problems.

[0074] For each detected fault, the logic judgment module will classify it according to its possible consequences, into mild faults, moderate faults and severe faults.

[0075] The protection mechanism is triggered only when a serious fault is confirmed, avoiding unnecessary downtime while ensuring system reliability.

[0076] Once the logic judgment module determines that the high-voltage inverter 100 has a serious fault, the switch will immediately operate to cut off the connection between the high-voltage inverter 100 and the load. At this time, the safety locking mechanism starts to work to ensure that the disconnected state will not be changed due to external interference.

[0077] Specifically, the safety locking mechanism has the following features:

[0078] Physical methods are used to ensure that the transfer switch is in the off position, which will not cause erroneous operation even if external conditions change.

[0079] Only after inspection and confirmation by professionals can the lock be manually released and normal frequency conversion operation be restored.

[0080] The method of using the high-voltage inverter frequency conversion and power frequency cutting device is that the PLC continuously monitors the status parameters (such as current, voltage, temperature, etc.) of the high-voltage inverter 100, and uses the fault signal detection unit to monitor the working status of the high-voltage inverter 100 in real time. The built-in logic judgment module evaluates the severity of any detected fault and triggers the protection mechanism only when it is confirmed to be a serious fault. If the logic judgment module confirms that a serious fault has occurred, it will immediately send a disconnection command to the inverter inlet vacuum contactor "K1" 201 and the inverter outlet vacuum contactor "K2" 202 to cut off the connection between the high-voltage inverter 100 and the fan to prevent the fault from expanding. At the same time, the control unit instructs the high-voltage switch cabinet to jump off and cut off the upper power supply of the frequency conversion circuit to ensure that there is no reverse current or other dangerous conditions.

[0081] Switch to industrial frequency mode: After a preset time delay after the inverter inlet vacuum contactor "K1" 201 and the inverter outlet vacuum contactor "K2" 202 are disconnected to ensure that electrical isolation is fully completed, the PLC commands the inverter bypass vacuum contactor "K3" 203 to close, establishing a new industrial frequency power supply path, so that the fan can directly obtain electricity from the power grid and continue to work normally.

[0082] Manual intervention: The control unit provides an indication signal to guide the operator to perform necessary manual operations, such as closing the inverter bypass vacuum contactor "K3" 203 in the power frequency circuit or reclosing the switch in the high-voltage switch cabinet so that the equipment can continue to operate under power frequency conditions. The operator can perform these steps through the manual operation interface to ensure that the system can safely transition to power frequency mode.

[0083] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and ratio of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of the execution function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to several modifications still falling within the scope of the appended claims.

[0084] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment may not be described (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention).

[0085] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0086] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. High-voltage frequency converter frequency conversion and power frequency cutting device, characterized by: include, A high-voltage frequency converter (100) for controlling the speed of a connected fan; The industrial frequency starting module (200) serves as a backup device for the high-voltage frequency converter (100), and when the high-voltage frequency converter (100) fails, it can switch to the industrial frequency mode to continue running.

2. The high-voltage frequency converter frequency conversion and power frequency cutting device according to claim 1, characterized in that: The high-voltage frequency converter (100) comprises: an input terminal adapted to receive a high voltage input from a power source; The output terminal is adapted to provide an output voltage with adjustable frequency to the fan.

3. The high-voltage frequency converter frequency conversion and power frequency cutting device according to claim 1, characterized in that: The power frequency starting module (200) comprises: The frequency conversion circuit includes a frequency converter inlet vacuum contactor "K1" (201) and a frequency converter outlet vacuum contactor "K2" (202), which are used to control the transmission of current to the load; A power frequency circuit connected in parallel with the frequency conversion circuit, including a frequency conversion bypass vacuum contactor "K3" (203) for providing a backup power path in the event of a frequency conversion circuit failure; A high-voltage switch cabinet, located upstream of the frequency conversion circuit, is used to perform high-voltage control on the entire power supply system; The fault detection module is used to monitor the working state of the high-voltage frequency converter (100) and issue a disconnection instruction when a serious fault of the high-voltage frequency converter (100) is detected.

4. The high-voltage frequency converter frequency conversion and power frequency cutting device according to claim 3, characterized in that: The power frequency starting module (200) further comprises: The control unit is electrically connected to the fault detection module and performs the following actions after receiving the disconnection instruction: Automatically disconnect the inverter input line vacuum contactor "K1" (201) and the inverter output line vacuum contactor "K2" (202) in the frequency conversion circuit; The command trips the high-voltage switch cabinet and cuts off the upper power supply of the frequency conversion circuit; Provide an indication signal to the operator to prompt manual switching to the power frequency circuit.

5. The high-voltage frequency converter frequency conversion and power frequency cutting device according to claim 4, characterized in that: The control unit also includes: A logic judgment module, used to evaluate the severity of a fault of the high-voltage inverter (100) and activate a protection mechanism only when a serious fault is confirmed; The safety locking mechanism remains locked after the frequency conversion circuit is disconnected to prevent accidental reclosing until manual reset.

6. The high-voltage inverter frequency conversion and power frequency cutting device according to claim 5, characterized in that: The control unit is provided with a manual operation interface, which allows the operator to receive the indication signal from the control unit, manually close the inverter bypass vacuum contactor "K3" (203) in the power frequency circuit, and reclose the switch in the high-voltage switch cabinet, so that the equipment can continue to operate under power frequency conditions.

7. The high-voltage inverter frequency conversion and power frequency cutting device according to claim 6, characterized in that: The power frequency starting module (200) further comprises: A PLC is connected in communication with the high-voltage frequency converter (100) and is configured to monitor the status of the high-voltage frequency converter (100); and The fault switching control system is controlled by a PLC. When a serious fault is detected in the high-voltage frequency converter (100), the fault switching control system performs the following steps: Sending instructions to the inverter inlet vacuum contactor "K1" (201) and the inverter outlet vacuum contactor "K2" (202) to disconnect the inverter circuit; After a predetermined time delay, a command is sent to the inverter bypass vacuum contactor "K3" (203) to close the power frequency circuit.

8. The high-voltage inverter frequency conversion and power frequency cutting device according to claim 7, characterized in that: The PLC comprises a fault signal detection unit, which is integrated into the high-voltage frequency converter (100) or independently arranged and connected to the PLC, and is used to monitor the operating state of the high-voltage frequency converter (100) in real time and provide fault information to the PLC.

9. The high-voltage inverter frequency conversion and power frequency cutting device according to claim 8, characterized in that: The PLC also includes a time delay module, which is controlled by the PLC and is used to define the time interval from the disconnection of the frequency conversion circuit to the closing of the power frequency circuit, so as to ensure safe and reliable switching operation.

10. The method for using the high-voltage frequency converter frequency conversion and power frequency cutting device is characterized by: The invention comprises the high-voltage inverter frequency conversion and power frequency cutting device as claimed in any one of claims 1 to 9, and Check the working status of the inverter inlet vacuum contactor "K1", inverter outlet vacuum contactor "K2", and inverter bypass vacuum contactor "K3" to ensure that they function normally and can accurately perform opening or closing actions when receiving control commands; Start the power equipment to enter the variable frequency operation mode and wait until the output frequency reaches a stable state; Simulate a serious fault in a high-voltage inverter, such as triggering a fault response mechanism by simulating a fan fault; The monitoring system's response to the above faults is as follows: Whether the inverter inlet vacuum contactor "K1" and the inverter outlet vacuum contactor "K2" can be opened in time to disconnect the inverter; Whether the inverter bypass vacuum contactor "K3" correctly performs the closing action after the preset time delay, thereby connecting the system to the industrial frequency power supply; Verify whether the power equipment can smoothly switch from variable frequency mode to industrial frequency mode and continue to operate.

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