Integrated intelligent variable frequency high-voltage motor inspection device

Abstract

The utility model discloses an integrated intelligent frequency conversion high -voltage motor inspection device, include: power interface unit is used for receiving external low -voltage ac power supply, micro low -voltage frequency converter unit, electric connection power interface unit is used for output low -frequency low -voltage power supply, micro -voltage unit, connect micro low -voltage frequency converter unit output, for low -frequency low -voltage is raised to the preset inspection voltage, switching and interlock unit, connect micro -voltage unit output and high -voltage motor, contain inspection contactor and the interlocking mechanism of high -voltage motor main power supply loop, intelligent control and communication unit, electric connection and control preceding unit, carry out inspection logic and monitor process, the utility model discloses an integrated design has reduced cost and volume significantly, has simplified the system, has improved reliability and intelligent level, and has strengthened the operation security, is applicable to the regular low -speed inspection maintenance of the long -term standby high -voltage motor such as fire water pump, prevents the corrosion and stagnation.

Description

Technical Field

[0001] This utility model relates to the field of motor control technology, specifically to an integrated intelligent variable frequency high voltage motor inspection device. Background Technology

[0002] High-voltage motors, such as those at 6kV or 10kV, are widely used in many industrial sectors. In certain specific situations, such as fire protection systems, emergency backup systems, or "one-use-multiple-standby" operating modes, these high-voltage motors and their driven loads (such as water pumps) may be in a standby state for extended periods. However, prolonged idleness, especially in high-humidity environments, can easily cause metal components such as the pump shaft and impeller to corrode, potentially leading to mechanical seizure and a phenomenon known as "rust seizure." If this occurs, in emergencies such as fires, the motor may fail to start or have difficulty starting due to rust seizure, directly delaying rescue efforts, potentially causing significant property damage, and even threatening lives.

[0003] To effectively avoid the aforementioned problems and ensure the reliable operation of backup high-voltage motors and their drive equipment during critical moments, the industry commonly adopts a maintenance approach of periodically conducting "trial runs" or "inspections" of the motors and loads. In existing high-voltage motor inspection solutions, a common practice is to utilize a low-voltage power supply system, driving the motor at a low speed for short periods via a low-voltage frequency converter. In practice, this typically requires configuring an independent low-voltage frequency converter and using a dedicated step-up transformer to increase its output voltage to a level sufficient to drive the high-voltage motor at low speed. This inspection power supply is then connected to the high-voltage motor via a contactor switching device.

[0004] However, such existing technical solutions have several shortcomings: (1) They are costly. Adding an extra low-voltage frequency converter and a step-up transformer of a specific voltage level will significantly increase the overall hardware procurement cost of the system; (2) They occupy a lot of space and the system is complex. The low-voltage frequency converter and the step-up transformer, especially the latter, usually have a large physical volume even if the power requirement is not large. They need to occupy additional installation space in the control cabinet, making the system layout not compact enough. At the same time, the number of introduced components increases and the external wiring becomes more complex, which not only increases the difficulty of installation and debugging, but also increases the potential failure points of the system and reduces the overall reliability; (3) The integration and intelligence level are not high. The components are usually purchased and integrated separately. There is a lack of unified optimization and targeted inspection function design. It often needs to rely on external PLC (programmable logic controller) or more complex control system to realize the inspection logic and safe switching of high and low voltage circuits, which further increases the complexity and cost of the system; (4) Safety risks. The switching between the high voltage main operating circuit and the low voltage inspection circuit depends entirely on the reliability of the contactor and its control logic. Once the interlocking mechanism is poorly designed or fails, there is a risk that the high voltage power supply and the inspection power supply may be mistakenly superimposed on the motor, which may lead to serious equipment damage and safety accidents.

[0005] Therefore, there is an urgent need for a low-speed inspection solution for high-voltage motors that is more compact, lower in cost, more integrated, more intelligent in control, and safer. Summary of the Invention

[0006] Purpose of the invention: The purpose of this utility model is to address the shortcomings of the existing technology by providing an integrated intelligent variable frequency high-voltage motor inspection device. This module highly integrates the core functional components required for low-speed inspection of high-voltage motors, has a compact structure, low cost, intelligent control, and a reliable safety interlock mechanism.

[0007] Technical solution: The integrated intelligent high-voltage motor inspection module of this utility model includes a power interface unit, a micro low-voltage frequency converter unit, a micro boost unit, a switching and interlocking unit, and an intelligent control and communication unit.

[0008] The power interface unit is used to receive external low-voltage AC power and supply power to the module.

[0009] The miniature low-voltage frequency converter unit is electrically connected to the power interface unit and is used to convert the low-voltage AC power supply into a low-frequency, low-voltage output with adjustable frequency and voltage.

[0010] The micro boost unit has its input terminal electrically connected to the output terminal of the micro low-voltage frequency converter unit, and is used to boost the low-frequency low-voltage output to a preset inspection voltage.

[0011] The switching and interlocking unit has its input terminal electrically connected to the output terminal of the micro boost unit, and its output terminal is used to connect to the high-voltage motor. The switching and interlocking unit includes a monitoring contactor for controlling the switching of the monitoring voltage and the high-voltage motor, and includes an interlocking mechanism with the main power supply circuit of the high-voltage motor.

[0012] The intelligent control and communication unit is electrically connected to and controls the miniature low-voltage frequency converter unit and the switching and interlocking unit, and is used to execute preset inspection logic and monitor the inspection process.

[0013] To further improve the above technical solution, the power interface unit, the miniature low-voltage frequency converter unit, the miniature boost unit, the switching and interlocking unit, and the intelligent control and communication unit are all housed in a single module housing, forming an independently installed module unit.

[0014] Furthermore, the miniature boost unit has a boost assembly for short-term operation, the rated power of which is less than 10% of the rated power of the high-voltage motor, and its physical dimensions are adapted for integrated installation within the single module housing.

[0015] Furthermore, the intelligent control and communication unit is provided with a safety confirmation input port, which is used to receive status signals from the main power supply circuit of the high-voltage motor. The intelligent control and communication unit is configured to output a control signal to close the inspection contactor only when it receives a signal indicating that the main power supply circuit is disconnected through the safety confirmation input port.

[0016] Furthermore, the intelligent control and communication unit is also provided with a current monitoring path, which is used to receive current signals reflecting the high-voltage motor during inspection, and the intelligent control and communication unit is configured to output a control signal to disconnect the inspection contactor when the current signal received through the current monitoring path exceeds a preset range.

[0017] Furthermore, the interlocking mechanism of the switching and interlocking unit includes: the control signal input terminal of the inspection contactor, and the normally closed auxiliary contact output terminal of the high-voltage motor main power supply circuit contactor connected in series.

[0018] Furthermore, the intelligent control and communication unit also has a communication port, which is used for bidirectional data transmission with external devices to receive control commands or send module status information.

[0019] Beneficial effects: Compared with the prior art, the advantages of this utility model are: (1) Compact structure, reduced cost and space occupation: By highly integrating the functional units required for inspection into a single module housing and adopting miniaturized and targeted core components (such as micro boost units), the overall volume and weight of the device are significantly reduced, reducing hardware costs and installation space requirements.

[0020] (2) System simplification and improved reliability: The integrated design greatly reduces the number of external wiring and discrete components, simplifies the system structure, thereby reducing potential failure points and improving the overall operational reliability and anti-interference capability of the system.

[0021] (3) Intelligent control improves operation and maintenance efficiency: The built-in intelligent control unit can realize the automated execution of inspection tasks, flexible configuration of inspection parameters, real-time monitoring of operating status and self-diagnosis and alarm of faults. It supports remote communication, which is convenient to be included in centralized monitoring and management, thus improving the level of intelligence and efficiency of equipment maintenance.

[0022] (4) Enhanced safety and protection of equipment and personnel: The electrical and logical interlocking mechanism integrated within the module and coordinated by the intelligent control unit ensures that the high-voltage main circuit and the inspection circuit cannot act on the motor simultaneously under any circumstances, effectively preventing accidents caused by misoperation. The current monitoring and protection functions during the inspection process further enhance operational safety.

[0023] (5) Easy installation and maintenance: The modular product form makes the installation and replacement process simple and quick, just like installing a standard electrical component. When a fault occurs, it can be quickly located at the module level, which facilitates maintenance and replacement and shortens system downtime. Attached Figure Description

[0024] Figure 1 A schematic diagram of the overall structure of the integrated intelligent high-voltage motor inspection module applied to a high-voltage motor system;

[0025] Figure 2 This is a functional block diagram of the integrated intelligent high-voltage motor inspection module.

[0026] Figure 3 This is a flowchart of the integrated intelligent high-voltage motor inspection process. Detailed Implementation

[0027] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings, but the protection scope of this utility model is not limited to the described embodiments.

[0028] Example 1: Refer to Figure 1 and Figure 2The present invention provides an integrated intelligent variable frequency high voltage motor inspection device 100, which is mainly used to perform regular low-speed inspections on high voltage motors M (such as 6kV or 10kV fire pump motors) to prevent them and the mechanical loads they drive from rusting and jamming due to long-term idleness.

[0029] The integrated intelligent high-voltage motor inspection module integrates all core functional units into a single module housing, forming an independently installable module unit. These core units include:

[0030] Power Interface Unit 10: This unit is used to receive external low-voltage AC power, such as three-phase AC 380V. It can integrate necessary input protection components, such as miniature circuit breakers or fuses, and EMI filters, to provide a stable and clean power supply to other units within the module.

[0031] Miniature Low-Voltage Frequency Converter Unit 20 (LVVFD): This unit is electrically connected to the output of the power interface unit 10. Its function is to convert the input low-voltage AC power at the industrial frequency into a low-frequency, low-voltage output with adjustable frequency and voltage. In inspection mode, the frequency range of this VFD unit's output is typically between 1Hz and 10Hz, such as 5Hz, and the corresponding output voltage is also relatively low. Selecting a small-power, compact VFD model, such as 0.75kW or 1.5kW, is sufficient to drive a high-voltage motor to rotate at low speed under no-load or very light-load conditions.

[0032] Miniature Boost Unit 30: The input of this unit is electrically connected to the output of the miniature low-voltage inverter unit 20. Its core is a boost component used to increase the low-frequency, low-voltage output of the VFD (e.g., AC 380V, 5Hz) to a preset check voltage (e.g., AC 0.6kV~1.5kV, 5Hz) sufficient to drive the high-voltage motor M to overcome static friction and rotate stably at extremely low speeds. This boost component is preferably optimized for short-time duty cycles (e.g., S2-10min, i.e., short-term operation for 10 minutes) and low-frequency input characteristics, making its rated power much smaller than the rated power of the high-voltage motor M (e.g., less than 10% of the motor's rated power), and its physical size and weight optimized for integrated installation within a single module housing. This can be achieved by using a miniaturized, customized power frequency transformer, or by employing high-frequency boost technology (e.g., DC-DC boost followed by inversion, or a high-frequency transformer combined with AC-AC conversion) to achieve a higher degree of miniaturization.

[0033] Switching and Interlocking Unit 40: The input of this unit is electrically connected to the output of the miniature boost unit 30, and its output is used to connect to the stator winding of the high-voltage motor M. This unit contains a critical inspection contactor KM_insp, used to control the connection and disconnection between the boosted inspection voltage and the high-voltage motor M. Crucially, this unit also includes an interlocking mechanism with the main power supply circuit of the high-voltage motor M (i.e., the circuit used for normal high-voltage operation, whose main control element is typically the high-voltage contactor KM1). This interlocking mechanism ensures that the high-voltage main power supply circuit and the low-voltage inspection circuit cannot simultaneously supply power to the motor M. A specific electrical interlocking structure involves connecting a normally closed auxiliary contact output of the high-voltage motor main power supply circuit contactor KM1 in series with a control signal input terminal of the inspection contactor KM_insp. Correspondingly, the control circuit of KM1 should also have a similar interlocking mechanism related to the state of KM_insp.

[0034] Intelligent Control and Communication Unit 50: This unit is electrically connected to and controls the inspection contactor KM_insp in the miniature low-voltage frequency converter unit 20 and the switching and interlocking unit 40. It is typically composed of a microcontroller (MCU) or a small PLC. Its main functions include: executing preset inspection logic: for example, automatically starting inspection according to a set cycle (such as once a week), or responding to inspection start commands sent from external sources (such as fire control systems); safety confirmation and control: this unit is equipped with a safety confirmation input port for receiving status signals from the main power supply circuit of the high-voltage motor (usually the status of the normally closed auxiliary contact of KM1).

[0035] The intelligent control unit is configured to output a control signal to close the inspection contactor KM_insp, thereby initiating the inspection, only when a signal indicating that the main power supply circuit has been confirmed to be disconnected is received through this port. VFD control: Sends commands to the miniature low-voltage frequency converter unit 20 to control its start, stop, output frequency (e.g., inspection frequency), voltage, and acceleration / deceleration time. Process monitoring and protection: This unit also has a current monitoring path to receive the current signal reflecting the high-voltage motor M during the inspection (this signal can come from feedback from the VFD unit or be obtained through an independent current sensor). The intelligent control unit monitors this current in real time. When the monitored current signal exceeds the preset safety range (e.g., over-high indication stall, or under-low indication disengagement), it immediately outputs a control signal to disconnect the inspection contactor KM_insp, stops the VFD output, executes protection actions, and issues an alarm.

[0036] Example 2: This example adds a communication function to Example 1: By integrating a communication port (e.g., RS485 interface, supporting Modbus RTU and other protocols), it is used to perform bidirectional data transmission with an external host computer, PLC or distributed control system (DCS) to enable remote parameter setting, status monitoring, fault diagnosis or remote start and stop control.

[0037] Example 3: This example adds human-computer interaction functionality to Example 1: indicator lights (such as power, running, and fault status), a small display screen (displaying running parameters or fault codes), and operation buttons can be set on the module panel.

[0038] Example 4: Reference Figure 3 The workflow of the inspection module provided in this embodiment is as follows:

[0039] 301: Beginning;

[0040] 302: Module power-on, intelligent control unit 50 initializes, and loads inspection parameters;

[0041] 303: Inspection trigger signal received (internal timer or external command);

[0042] 304: The intelligent control unit 50 checks the status of the high-voltage main circuit contactor KM1 through the safety confirmation input port to confirm that it has been disconnected;

[0043] 305: If not disconnected, inspection is prohibited and an alarm will sound;

[0044] 306: After confirming safety, prepare the micro low-voltage frequency converter unit 20 and set the inspection frequency and voltage;

[0045] 307: Close the inspection contactor KM_insp to connect the inspection power supply to the high-voltage motor M;

[0046] 308: VFD unit 20 starts, driving motor M to rotate at low speed. Intelligent control unit 50 monitors motor current in real time;

[0047] 309: After the preset inspection time is reached,

[0048] 310: If the current is abnormal, perform a protective shutdown;

[0049] 311: Perform VFD unit 20 deceleration and shutdown;

[0050] 312: Disconnect the inspection contactor KM_insp;

[0051] 313: Record inspection results, provide status feedback, and the module returns to standby mode;

[0052] 314: The End.

[0053] This utility model's integrated intelligent high-voltage motor inspection module provides an innovative, efficient, economical, and safe solution to the maintenance challenges of high-voltage motors (especially critical equipment such as fire pumps) in long-term standby mode, and has significant value for widespread application.

[0054] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes in form and detail may be made to the present invention without departing from the spirit and scope of the appended claims.

Claims

1. An integrated intelligent variable frequency high-voltage motor inspection device, characterized in that, include: The power interface unit is used to receive external low-voltage AC power and output power. The miniature low-voltage frequency converter unit is electrically connected to the power interface unit and is used to convert the low-voltage AC power supply into a low-frequency, low-voltage output with adjustable frequency and voltage. A miniature boost unit, whose input terminal is electrically connected to the output terminal of the miniature low-voltage inverter unit, is used to boost the low-frequency low-voltage output to a preset inspection voltage. The switching and interlocking unit has its input terminal electrically connected to the output terminal of the micro boost unit, and its output terminal is used to connect to the high-voltage motor. The switching and interlocking unit includes a monitoring contactor for controlling the on / off state of the monitoring voltage and the high-voltage motor, and includes an interlocking mechanism with the main power supply circuit of the high-voltage motor. The intelligent control and communication unit, composed of a microcontroller or a programmable logic controller, is electrically connected to the control terminals of the inspection contactor in the micro low-voltage frequency converter unit and the switching and interlocking unit, respectively, and is used to execute preset inspection logic and monitor the inspection process. The intelligent control and communication unit is equipped with a safety confirmation input port and a current monitoring path. The safety confirmation input port is used to electrically connect to and receive status electrical signals from the main power supply circuit of the high-voltage motor. The current monitoring path is used to receive current signals reflecting the high-voltage motor during inspection. The intelligent control and communication unit receives electrical signals through the safety confirmation input port and the current monitoring path, and outputs corresponding control signals to the miniature low-voltage frequency converter unit and the inspection contactor.

2. The integrated intelligent variable frequency high-voltage motor inspection device according to claim 1, characterized in that, The power interface unit, the miniature low-voltage frequency converter unit, the miniature boost unit, the switching and interlocking unit, and the intelligent control and communication unit are all housed in a single module housing, forming an independently installed module unit.

3. The integrated intelligent variable frequency high-voltage motor inspection device according to claim 2, characterized in that, The miniature boost unit has a boost component for short-term operation, the rated power of which is less than 10% of the rated power of the high-voltage motor, and its physical dimensions are adapted for integrated installation within the single module housing.

4. The integrated intelligent variable frequency high-voltage motor inspection device according to claim 1, characterized in that, The intelligent control and communication unit is configured to output a control signal to close the inspection contactor only when a signal indicating that the main power supply circuit is disconnected is received through the safety confirmation input port.

5. The integrated intelligent variable frequency high-voltage motor inspection device according to claim 1 or 4, characterized in that, The intelligent control and communication unit is configured to output a control signal to disconnect the inspection contactor when the current signal received through the current monitoring path exceeds a preset range.

6. The integrated intelligent variable frequency high-voltage motor inspection device according to claim 1, characterized in that, The interlocking mechanism of the switching and interlocking unit includes: the control signal input terminal of the inspection contactor, and the normally closed auxiliary contact output terminal of the high-voltage motor main power supply circuit contactor connected in series.

7. The integrated intelligent variable frequency high-voltage motor inspection device according to claim 1, characterized in that, The intelligent control and communication unit also has a communication port, which is used for bidirectional data transmission with external devices to receive control commands or send module status information.

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