Anti-interference electricity module of frequency converter

Abstract

The utility model relates to the technical field of anti-interference electricity devices, in particular to an anti-interference electricity module of a frequency converter, which comprises a voltage monitoring unit, a signal acquisition unit, a control processing unit and an output execution unit. In the utility model, the voltage monitoring unit monitors the voltage of a control loop in real time, the signal acquisition unit collects the operation state and fault signals of the frequency converter, the data are analyzed by the control processing unit to determine whether the frequency converter needs to be restarted or reset, and the output execution unit sends out control signals according to the data. When it is detected that the frequency converter is shut down due to voltage drop and then the voltage recovers within the preset time, the device automatically sends a restarting signal, and if the frequency converter has a fault signal, a reset signal is firstly output to clear the fault state after the voltage recovers, so that restarting failure is avoided. The module not only can realize'interference electricity protection and interference electricity restart 'for a conventional direct circuit, but also can realize'ERROR reset and frequency conversion restart' for a frequency conversion circuit, and has high flexibility and practicability.

Description

Technical Field

[0001] The utility model relates to the technical field of anti-electrical shaking devices, in particular to an anti-electrical shaking module for a frequency converter. Background Art

[0002] With the continuous advancement of industrial automation, inverters (VFDs), as important drive control devices, are widely used in various applications. VFDs not only enable motor speed control but also improve system efficiency and reliability. However, in practical applications, grid voltage fluctuations are a common problem. In particular, lightning strikes or the start-up of high-power motors can cause transient voltage drops. This phenomenon is known as "sloshing."

[0003] Existing VFDs are typically equipped with built-in protection features to protect themselves against grid voltage drops or momentary power outages. These protection features typically include voltage drop protection and power outage protection. Specifically, when the grid voltage drops, the VFD's inverter will continue to operate for a short period of time. If the voltage drop or power outage duration is less than a set threshold, the VFD will continue to operate. If the voltage drop or power outage duration exceeds this threshold, the VFD will activate self-protection and cease operation.

[0004] While this protection measure can protect the VFD from damage to a certain extent, it has some significant drawbacks. First, to prevent damage to the VFD, existing protection thresholds are often set relatively high. This means that even slight fluctuations in grid voltage can trigger the protection mechanism and cause the VFD to shut down. Second, most VFDs take immediate action when they detect a voltage drop, lacking sufficient delay mechanisms to determine whether the voltage will recover quickly. Finally, because the low-voltage protection threshold is set high, the VFD may frequently shut down due to small fluctuations in grid voltage, which not only reduces production efficiency but can also cause unplanned downtime of the entire production line. Utility Model Content

[0005] The purpose of the present invention is to provide an inverter anti-electrical shaking module to solve the problem raised in the above background technology that the existing inverter frequently shuts down due to small fluctuations in grid voltage, thereby increasing the risk of equipment tripping.

[0006] To achieve the above-mentioned objectives, the present invention provides an inverter anti-electrical shaking module, including a voltage monitoring unit, a signal acquisition unit, a control processing unit and an output execution unit. The voltage monitoring unit is provided with three ports PH1, PH2, and PH3, which are respectively connected to the three-phase busbars L1, L2, and L3 in the main line. The signal acquisition unit is provided with port DI1, port DI2 and port DI3. The signal acquisition unit port DI1 is connected to the normally open contact of the intermediate relay KA1, and the normally open contact of the intermediate relay KA1 is connected to the inverter port SD. The signal acquisition unit port DI2 is connected to the inverter port ERR, and the signal acquisition unit port DI3 is connected to the inverter port RUN. The output execution unit is provided with port DO1 and port DO2. The output execution unit port DO1 is connected to the inverter port RESET, and the output execution unit port DO2 is connected to the inverter port START.

[0007] As a further improvement of this technical solution, the inverter power input ports R, S, and T are connected to the three-phase busbars L1, L2, and L3 respectively, and the inverter power input ports U, V, and W are connected to the motor M, and the motor M is connected to the main line neutral line N.

[0008] As a further improvement of the present technical solution, the three-phase busbar L1 is connected to the power input port L of the inverter anti-electrical shaking module, and the main line neutral line N is connected to the power input port N of the inverter anti-electrical shaking module.

[0009] As a further improvement of the present technical solution, the voltage monitoring unit and the signal acquisition unit are connected to the control processing unit, and the control processing unit is connected to the output execution unit.

[0010] As a further improvement of this technical solution, the other end of the normally open contact of the intermediate relay KA1 is connected to the positive pole of the 24V DC power supply, the negative pole of the 24V DC power supply is connected to the inverter port COM, the intermediate relay KA1 coil is connected to the PLC port DO, and the other end of the intermediate relay KA1 coil is connected to the PLC port COM.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1. In the inverter's anti-sway module, when the voltage monitoring unit detects a voltage drop that causes the inverter to shut down, if the voltage can be restored within a preset time, the output execution unit will automatically send a restart signal to restart the inverter, ensuring production continuity; if the inverter has a fault signal when the voltage recovers, the output execution unit will first output a reset signal to clear the fault state, ensuring that the inverter can be successfully restarted, thereby improving equipment stability and production efficiency.

[0013] 2. In the inverter's anti-sway module, the control circuit voltage is monitored in real time through the voltage monitoring unit, and the inverter's operating status and fault signals are collected through the signal acquisition unit. This can promptly determine the grid voltage drop and decide whether to restart or reset the inverter based on the actual situation. This effectively avoids frequent shutdowns caused by small fluctuations in the grid voltage and reduces the risk of equipment tripping. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the overall structural connection method of the utility model. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0016] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0017] See also Figure 1As shown, this embodiment provides an inverter anti-electrical shaking module, including a voltage monitoring unit, a signal acquisition unit, a control processing unit, and an output execution unit. The voltage monitoring unit is provided with three ports PH1, PH2, and PH3 respectively connected to the three-phase busbars L1, L2, and L3 in the main line. The signal acquisition unit is provided with ports DI1, DI2, and DI3. The signal acquisition unit port DI1 is connected to the normally open contact of the intermediate relay KA1, and the normally open contact of the intermediate relay KA1 is connected to the inverter port SD. The signal acquisition unit port DI2 is connected to the inverter port ERR, and the signal acquisition unit port DI3 is connected to the inverter port RUN. The output execution unit is provided with ports DO1 and DO2. The output execution unit port DO1 is connected to the inverter port RESET, and the output execution unit port DO2 is connected to the inverter port START. The voltage monitoring unit ports are respectively connected to the three-phase busbars to monitor the grid voltage in real time and determine whether electric shaking occurs. The signal acquisition unit connects to the normally open contacts of intermediate relay KA1 via ports DI1, DI2, and DI3, and then to the inverter's SD (start detection), ERR (fault signal), and RUN (run signal) ports. This unit collects the inverter start relay signal, the inverter ERROR signal, and the run signal, respectively. The control processing unit receives and analyzes data from the voltage monitoring unit and the signal acquisition unit to determine whether to restart or reset the inverter. Finally, the output execution unit, based on instructions from the control processing unit, sends a reset or start signal to the inverter via the RESET (reset signal) and START (start) ports.

[0018] The inverter's power input ports R, S, and T are connected to the three-phase busbars L1, L2, and L3, respectively. The inverter's power input ports U, V, and W are connected to the motor M, which in turn is connected to the main line neutral line N. This provides the inverter with three-phase AC power, which controls the motor's speed and torque by adjusting the frequency and voltage of this input power. The power supply, inverter, and motor form a complete main power transmission circuit.

[0019] Connect the three-phase busbar L1 to the inverter's anti-sway module power input port L, and the main line neutral line N to the inverter's anti-sway module power input port N. Connect one phase of the three-phase busbar and then the neutral line to provide 220V input voltage to the inverter's anti-sway module.

[0020] The voltage monitoring unit and signal acquisition unit are connected to the control processing unit, which is in turn connected to the output execution unit. The control processing unit determines whether to initiate a restart or reset based on the data provided by the voltage monitoring and signal acquisition units. If the voltage recovers within a preset time, the control processing unit sends a corresponding control signal to the output execution unit.

[0021] The other end of the normally open contact of intermediate relay KA1 is connected to the positive terminal of the 24V DC power supply, and the negative terminal of the 24V DC power supply is connected to the inverter's COM port. The coil of intermediate relay KA1 is connected to the PLC's DO port, and the other end of the coil of intermediate relay KA1 is connected to the PLC's COM port. When the PLC issues a start signal, the PLC's DO port outputs a voltage, energizing the coil of KA1. This energized coil generates a magnetic field, closing the normally open contact of KA1 and providing a conductive path for starting the inverter. Once conductive, the 24V DC voltage outputs a signal to the inverter's SD port, with the COM port serving as the common terminal, completing the circuit. The COM port of both the inverter and the PLC completes the circuit from the power supply to the relay coil and then to the COM port, ensuring proper relay operation.

[0022] Working principle:

[0023] The inverter's anti-sway module uses a voltage monitoring unit to continuously monitor the grid voltage level. Once the grid voltage drops below a pre-set voltage threshold, the subsequent control process is triggered.

[0024] The signal acquisition unit is responsible for collecting the status information of the inverter. It obtains this information through different digital input ports (DI): DI1 port is used to receive the inverter's start signal, DI2 port is used to receive the fault signal, and DI3 port is used to obtain the inverter's running signal.

[0025] Next, the control processing unit makes a logical decision based on the grid voltage information provided by the voltage monitoring unit and the inverter status signal from the signal acquisition unit. Specifically, if the grid voltage returns to normal within a preset time, the control processing unit considers whether to send a restart signal to the inverter. Furthermore, if the inverter generates a fault signal, the control processing unit also determines whether to first send a reset signal to clear the fault condition.

[0026] The output execution unit ultimately executes the command. If no fault signal is detected, the unit sends a restart signal via digital output port DO2 after the preset restart delay. However, if a fault signal is present, the output execution unit first sends a reset signal via port DO1 to clear the fault. Then, after the preset restart delay, it also sends a restart signal via port DO2. This allows the entire module to effectively manage the inverter's operating status under abnormal grid voltage conditions and ensure its normal operation to the greatest extent possible.

[0027] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. The inverter anti-sway module is characterized by: It includes a voltage monitoring unit, a signal acquisition unit, a control processing unit and an output execution unit. The voltage monitoring unit is provided with three ports PH1, PH2, and PH3, which are respectively connected to the three-phase busbars L1, L2, and L3 in the main line. The signal acquisition unit is provided with ports DI1, DI2, and DI3. The signal acquisition unit port DI1 is connected to the normally open contact of the intermediate relay KA1, and the normally open contact of the intermediate relay KA1 is connected to the inverter port SD. The signal acquisition unit port DI2 is connected to the inverter port ERR, and the signal acquisition unit port DI3 is connected to the inverter port RUN. The output execution unit is provided with ports DO1 and DO2. The output execution unit port DO1 is connected to the inverter port RESET, and the output execution unit port DO2 is connected to the inverter port START.

2. The inverter anti-electrical shaking module according to claim 1, characterized in that: The inverter power input ports R, S, and T are connected to the three-phase busbars L1, L2, and L3 respectively, and the inverter power input ports U, V, and W are connected to the motor M, and the motor M is connected to the main line neutral line N.

3. The inverter anti-electrical shaking module according to claim 2, characterized in that: The three-phase bus L1 is connected to the power input port L of the inverter anti-electrical shaking module, and the main line neutral line N is connected to the power input port N of the inverter anti-electrical shaking module.

4. The inverter anti-electrical shaking module according to claim 1, characterized in that: The voltage monitoring unit and the signal acquisition unit are connected to the control processing unit, and the control processing unit is connected to the output execution unit.

5. The inverter anti-electrical shaking module according to claim 1, characterized in that: The other end of the normally open contact of the intermediate relay KA1 is connected to the positive pole of the 24V DC power supply, the negative pole of the 24V DC power supply is connected to the inverter port COM, the coil of the intermediate relay KA1 is connected to the PLC port DO, and the other end of the coil of the intermediate relay KA1 is connected to the PLC port COM.

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