Electric power resonance elimination device

Abstract

The utility model discloses an electric power resonance elimination device, which belongs to the technical field of electric power system protection, and is characterized in that a control module is arranged in the device, the control module is connected with a voltage detection module and a switch unit, and the voltage detection module is connected with a primary resonance elimination module and a secondary microcomputer resonance elimination module; the primary resonance elimination module is formed by connecting a plurality of resonance elimination action mechanisms in series; the switch unit respectively controls electromagnetic switches in all resonance elimination action mechanisms in the primary resonance elimination module, the secondary microcomputer resonance elimination module mainly consists of a rectifier, an inverter and a resonance elimination resistor which are connected in series, the rectifier is used for carrying out full-wave rectification on network voltage to form direct-current voltage, the inverter is used for inverting the direct-current voltage to alternating-current voltage, and the resonance elimination resistor is used for carrying out resonance elimination on the alternating-current voltage. An inductor connected in series or in parallel with the resonance elimination resistor is driven to work; and the control module determines the on-state of the switch unit by judging the type and amplitude of the output signal of the voltage detection module.

Description

Technical Field

[0001] This utility model relates to the field of power system protection technology, specifically to a power harmonic suppression device. Background Technology

[0002] In power systems, a large number of iron-core inductive components, such as transformers and voltage transformers, exist. These components, together with the system's capacitance, form complex oscillating circuits. Under certain conditions, these circuits may induce ferroresonant overvoltages that last for a long period of time, seriously threatening the insulation of power equipment and the safe and stable operation of the system.

[0003] Existing harmonic suppression devices still have some shortcomings in terms of harmonic suppression effect, response speed, reliability, and adaptability to different fault types. For example, traditional harmonic suppression devices mainly use passive filtering technology, forming a series resonant absorption circuit with inductors and capacitors to absorb harmonic currents and reduce the amount of harmonics in the power grid. However, these devices have some limitations in practical applications, such as limited filtering effect and inability to monitor and respond to system status in real time. Therefore, a higher-performance power harmonic suppression device is needed. Utility Model Content

[0004] This invention provides a power harmonic elimination device to solve the problems mentioned in the background art.

[0005] This utility model provides a power harmonic elimination device. The device includes a control module connected to a voltage detection module and a switching unit. The voltage detection module is connected to a primary harmonic elimination module and a secondary microcomputer harmonic elimination module. The primary harmonic elimination module consists of several harmonic elimination mechanisms connected in series. The switching unit controls the electromagnetic switches in all harmonic elimination mechanisms of the primary harmonic elimination module. The secondary microcomputer harmonic elimination module mainly consists of a rectifier, an inverter, and a harmonic elimination resistor connected in series. The rectifier is used to rectify the grid voltage into DC voltage, and the inverter converts the DC voltage into AC voltage to drive the inductor connected in series or parallel with the harmonic elimination resistor. The control module determines the opening state of the switching unit by judging the type and amplitude of the output signal of the voltage detection module.

[0006] Optionally, the device combines the primary harmonic elimination module and the secondary microcomputer harmonic elimination module in a single power harmonic eliminater, with the control module controlling the switching unit to trigger the discharge of the primary harmonic elimination module.

[0007] Optionally, each of the harmonic suppression mechanisms consists of an electromagnetic switch connected in series with a harmonic suppression resistor and then connected in parallel with another electromagnetic switch.

[0008] Optionally, if a harmonic suppression resistor in the harmonic suppression mechanism fails, another parallel electromagnetic switch will be turned on through the switching unit to isolate the faulty harmonic suppression mechanism, allowing the remaining harmonic suppression mechanisms to operate normally.

[0009] Optionally, the primary harmonic elimination module is connected in series between the neutral point of the PT winding and ground, and the secondary microcomputer harmonic elimination module is installed at the open delta of the PT winding.

[0010] Optionally, the voltage detection module monitors the voltage of the circuit where the primary harmonic elimination module is located in real time. When the detected voltage exceeds the set threshold, the voltage detection module sends a signal to the control module. The control module determines whether the primary harmonic elimination module needs to be activated for harmonic elimination based on the signal.

[0011] Optionally, the voltage detection module monitors the zero-sequence voltage at the open delta of the PT winding in real time. When the zero-sequence voltage exceeds the set threshold, the voltage detection module sends a signal to the control module. The control module determines whether the secondary microcomputer harmonic elimination module needs to be activated for harmonic elimination based on the signal.

[0012] Compared with the prior art, this utility model has the following advantages:

[0013] The power harmonic elimination device in this scheme combines a primary harmonic elimination module and a secondary microcomputer harmonic elimination module. Through the control of the control module, it can quickly and effectively eliminate resonant overvoltages in the power system and has a high-efficiency harmonic elimination capability. The parallel electromagnetic switch design of the harmonic elimination action mechanism can automatically isolate the faulty mechanism when the harmonic elimination resistor fails, ensuring the normal operation of the remaining mechanisms and improving the overall operational stability of the device. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a module diagram of a power harmonic suppression device according to the present invention;

[0016] Figure 2 This is a schematic diagram of the harmonic elimination mechanism of a power harmonic elimination device according to the present invention. Detailed Implementation

[0017] The technical solution of this utility model will be clearly and completely described below with reference to its embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0018] Example 1

[0019] See Figures 1-2 As shown, a power harmonic elimination device includes a control module, a voltage detection module, a switching unit, a primary harmonic elimination module, a secondary microprocessor-based harmonic elimination module, and a PT winding. The control module is connected to the voltage detection module and the switching unit, and the voltage detection module is connected to the primary harmonic elimination module and the secondary microprocessor-based harmonic elimination module. The primary harmonic elimination module consists of several harmonic elimination mechanisms connected in series. The switching unit controls the electromagnetic switches in all harmonic elimination mechanisms in the primary harmonic elimination module. The secondary microprocessor-based harmonic elimination module mainly consists of a rectifier, an inverter, and a harmonic elimination resistor connected in series. The control module determines the opening state of the switching unit by judging the type and amplitude of the output signal from the voltage detection module.

[0020] The control module consists of a microprocessor, a signal acquisition unit, and a control logic unit. The microprocessor is responsible for processing, analyzing, and judging the acquired voltage signals, generating control commands according to a preset control strategy, and coordinating the work of each module. For example, when a voltage anomaly is detected, the microprocessor determines which harmonic suppression module needs to be activated and sends a command to the corresponding switching unit. The signal acquisition unit is used to acquire voltage signals in the power system, such as the voltage of the circuit where the primary harmonic suppression module is located and the zero-sequence voltage at the open delta of the PT winding, and converts these analog signals into digital signals for the microprocessor to process and analyze. Based on the microprocessor's judgment results, the control logic unit generates specific control signals according to the set logical relationships and control strategies to control the opening and closing of the switching units, as well as the working status of the primary harmonic suppression module and the secondary microprocessor harmonic suppression module.

[0021] When the power harmonic elimination device is powered on, the control module begins self-testing, initializes the connection with the voltage detection module, switching unit, primary harmonic elimination module and secondary microcomputer harmonic elimination module, ensuring that each module is in standby mode. The voltage detection module begins to monitor the voltage of the circuit where the primary harmonic elimination module is located and the zero-sequence voltage at the open delta of the PT winding in real time, and transmits the monitored voltage signal to the control module.

[0022] Furthermore, the control module continuously receives voltage signals from the voltage detection module, determines their type and amplitude, and thus identifies whether the detected voltage is a primary-side overvoltage or a zero-sequence voltage. When the voltage in the circuit containing the primary harmonic suppression module exceeds a set threshold, the voltage detection module sends a corresponding signal to the control module. The control module then determines whether to activate the primary harmonic suppression module for harmonic suppression. If the control module determines that activation is necessary, it sends an activation command to the switching unit. The switching unit controls the electromagnetic switches of each harmonic suppression mechanism in the primary harmonic suppression module to conduct, connecting the primary harmonic suppression module in series between the neutral point of the PT winding and ground, forming a discharge circuit to dissipate resonant energy and achieve harmonic suppression. During the harmonic suppression process, the voltage detection module continuously monitors voltage changes and feeds them back to the control module, allowing the control module to adjust the switching unit state based on voltage recovery. When the zero-sequence voltage at the open delta of the PT winding exceeds a set threshold, the voltage detection module sends a signal to the control module. The control module determines whether the secondary microprocessor-based harmonic suppression module needs to be activated for harmonic suppression. If the control module determines that the secondary microprocessor-based harmonic suppression module needs to be activated, the rectifier in the secondary microprocessor-based harmonic suppression module rectifies the grid voltage into DC voltage, and the inverter inverts the DC voltage into AC voltage, driving the inductor connected in series or parallel with the harmonic suppression resistor to work, generating a damping signal to interfere with the resonant circuit and eliminate resonance. The voltage detection module monitors the zero-sequence voltage change in real time and feeds it back to the control module. The control module controls the working state of the secondary microprocessor-based harmonic suppression module according to the voltage recovery status.

[0023] Specifically, if the harmonic suppression resistor in the harmonic suppression mechanism fails, causing an abnormal voltage signal, the voltage detection module sends the signal to the control module. After the control module determines that the harmonic suppression resistor is faulty, it sends a command to the switching unit to control another electromagnetic switch connected in parallel with the harmonic suppression mechanism where the faulty harmonic suppression resistor is located to turn on, isolating the faulty harmonic suppression mechanism and allowing the remaining harmonic suppression mechanisms to operate normally.

[0024] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A power harmonic suppression device, characterized in that, The device includes a control module connected to a voltage detection module and a switching unit. The voltage detection module is connected to a primary harmonic elimination module and a secondary microprocessor-based harmonic elimination module. The primary harmonic elimination module consists of several harmonic elimination mechanisms connected in series. The switching unit controls the electromagnetic switches in all harmonic elimination mechanisms of the primary harmonic elimination module. The secondary microprocessor-based harmonic elimination module mainly consists of a rectifier, an inverter, and a harmonic elimination resistor connected in series. The rectifier is used to rectify the grid voltage into DC voltage, and the inverter converts the DC voltage into AC voltage to drive the inductor connected in series or parallel with the harmonic elimination resistor. The control module determines the opening state of the switching unit by judging the type and amplitude of the output signal from the voltage detection module.

2. The power harmonic suppression device according to claim 1, characterized in that, The device combines a primary harmonic elimination module and a secondary microcomputer harmonic elimination module into a single power harmonic eliminater. The control module controls the switching unit to trigger the discharge of the primary harmonic elimination module.

3. The power harmonic suppression device according to claim 1, characterized in that, Each of the aforementioned harmonic suppression mechanisms consists of an electromagnetic switch connected in series with a harmonic suppression resistor and then connected in parallel with another electromagnetic switch.

4. The power harmonic suppression device according to claim 3, characterized in that, If a harmonic suppression resistor in the harmonic suppression mechanism fails, another parallel electromagnetic switch will be turned on through the switching unit, thereby isolating the faulty harmonic suppression mechanism and allowing the remaining harmonic suppression mechanisms to operate normally.

5. The power harmonic suppression device according to claim 1, characterized in that, The primary harmonic elimination module is connected in series between the neutral point of the PT winding and ground, and the secondary microcomputer harmonic elimination module is installed at the open delta of the PT winding.

6. The power harmonic suppression device according to claim 5, characterized in that, The voltage detection module monitors the voltage of the circuit where the primary harmonic elimination module is located in real time. When the detected voltage exceeds the set threshold, the voltage detection module sends a signal to the control module. The control module determines whether the primary harmonic elimination module needs to be activated for harmonic elimination based on the signal.

7. The power harmonic suppression device according to claim 5, characterized in that, The voltage detection module monitors the zero-sequence voltage at the open delta of the PT winding in real time. When the zero-sequence voltage exceeds the set threshold, the voltage detection module sends a signal to the control module. The control module determines whether the secondary microcomputer harmonic elimination module needs to be activated for harmonic elimination based on the signal.

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