An ac bus voltage stabilizer

Abstract

The application discloses an alternating current bus voltage stabilizer, which comprises a harmonic current output device, a voltage and current measurement module, a harmonic impedance calculation module, an impedance Bode diagram drawing module, a deep reinforcement learning decision module and a variable impedance module; the harmonic current output device is connected with a power grid; the voltage and current measurement module is connected with the power grid; the harmonic impedance calculation module is connected with the voltage and current measurement module; the impedance Bode diagram drawing module is connected with the harmonic impedance calculation module; the deep reinforcement learning decision module is connected with the impedance Bode diagram drawing module; and the variable impedance module is connected with the deep reinforcement learning decision module and the power grid respectively. The alternating current bus voltage stabilizer provided by the embodiment of the application can flexibly regulate and control the impedance characteristics of a system and realize stable operation of the system.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to an AC bus voltage stabilizer. Background Technology

[0002] With the increasing variety of sources and loads connected to the power supply system, the stability control of the power supply system is receiving more and more attention. When a mismatch occurs between the equivalent impedance of the power source, the equivalent impedance of the load, and the equivalent impedance of the transmission line in the power supply system, instability may occur, seriously affecting the operating characteristics of the system.

[0003] AC bus voltage stabilizers based on power electronic converters can flexibly adjust the impedance characteristics of the power grid system. However, the power grid's requirements for the output port characteristics of power electronic converters often need to be obtained based on experience, which is highly arbitrary and usually can only improve a single indicator of the power grid. Summary of the Invention

[0004] This invention provides an AC bus voltage stabilizer to address the shortcomings of existing technologies.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An AC bus voltage stabilizer includes a harmonic current output device, a voltage and current measurement module, a harmonic impedance calculation module, an impedance Bode plot plotting module, a deep reinforcement learning decision module, and a variable impedance module.

[0007] The harmonic current output device is connected to the power grid and is used to output harmonic current to the power grid in the form of frequency sweep.

[0008] The voltage and current measurement module is connected to the power grid and is used to measure the harmonic current generated by the harmonic current output device, as well as the harmonic voltage at the power grid side port and the harmonic voltage at the load side port caused by the harmonic current.

[0009] The harmonic impedance calculation module is connected to the voltage and current measurement module and is used to calculate the grid-side port impedance and the load-side port impedance based on the harmonic currents of different frequencies measured by the voltage and current measurement module and the harmonic voltages of the grid-side port and the load-side port under the action of the harmonic currents.

[0010] The impedance Bode plot drawing module is connected to the harmonic impedance calculation module and is used to draw the grid-side port impedance Bode plot and the load-side port impedance Bode plot respectively using the calculated grid-side port impedance and load-side port impedance at each frequency.

[0011] The deep reinforcement learning decision module is connected to the impedance Bode plot drawing module and is used to output a matching target impedance shape to the variable impedance module based on the power grid side port impedance Bode plot and the load side port impedance Bode plot.

[0012] The variable impedance module is connected to the deep reinforcement learning decision module and the power grid respectively, and is used to adjust the variable impedance to the target impedance form after receiving the target impedance form.

[0013] Furthermore, in the AC bus voltage stabilizer, the variable impedance module includes an H-bridge inverter. The DC side of the H-bridge inverter is connected to the deep reinforcement learning decision module via a capacitor, and the AC side of the H-bridge inverter is connected to the power grid via an inductor and a switch.

[0014] Furthermore, in the AC bus voltage stabilizer, the frequency of the harmonic current output by the harmonic current output device is 10Hz to 1kHz.

[0015] Furthermore, in the AC bus voltage stabilizer, the harmonic current output device is equipped with a timer for triggering the harmonic current injection device to periodically output harmonic current.

[0016] Furthermore, in the AC bus voltage stabilizer, the deep reinforcement learning decision module adopts a deep deterministic policy gradient framework.

[0017] The AC bus voltage stabilizer provided in this embodiment of the invention can flexibly adjust the impedance characteristics of the system to achieve stable system operation. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of an AC bus voltage stabilizer provided in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of harmonic current injection into the power grid in an embodiment of the present invention.

[0021] Figure label:

[0022] Harmonic current output device 1, voltage and current measurement module 2, harmonic impedance calculation module 3, impedance Bode plot drawing module 4, deep reinforcement learning decision module 5, variable impedance module 6. Detailed Implementation

[0023] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0024] In the description of this invention, it should be understood that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component present simultaneously. When a component is considered to be "set" on another component, it can be directly set on the other component or there may be an intermediate component present simultaneously.

[0025] Furthermore, terms such as “long,” “short,” “inner,” and “outer” indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings. They are used only for the purpose of describing the present invention and are not intended to indicate or imply that the device or component referred to must have this specific orientation or operate in a specific orientational configuration. Therefore, they should not be construed as limitations of the present invention.

[0026] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0027] Example 1

[0028] Please refer to Figure 1 This invention provides an AC bus voltage stabilizer, including a harmonic current output device 1, a voltage and current measurement module 2, a harmonic impedance calculation module 3, an impedance Bode plot drawing module 4, a deep reinforcement learning decision module 5, and a variable impedance module 6.

[0029] The harmonic current output device 1 is connected to the power grid and is used to output harmonic current to the power grid in the form of frequency sweep.

[0030] The voltage and current measurement module 2 is connected to the power grid and is used to measure the harmonic current generated by the harmonic current output device 1, as well as the harmonic voltage at the power grid side port and the harmonic voltage at the load side port caused by the harmonic current.

[0031] The harmonic impedance calculation module is connected to the voltage and current measurement module 2 and is used to calculate the grid-side port impedance and the load-side port impedance based on the harmonic currents of different frequencies measured by the voltage and current measurement module 2 and the harmonic voltages of the grid-side port and the load-side port under the action of the harmonic currents.

[0032] The impedance Bode plot drawing module 4 is connected to the harmonic impedance calculation module and is used to draw the grid-side port impedance Bode plot and the load-side port impedance Bode plot respectively using the calculated grid-side port impedance and load-side port impedance at each frequency.

[0033] The deep reinforcement learning decision module 5 is connected to the impedance Bode plot drawing module 4 and is used to output the matching target impedance shape to the variable impedance module 6 according to the impedance Bode plot of the grid side port and the impedance Bode plot of the load side port; wherein, the evaluation index of the deep reinforcement learning decision module 5 is the current bus power quality index, including power factor and total harmonic distortion rate.

[0034] The variable impedance module 6 is connected to the deep reinforcement learning decision module 5 and the power grid, respectively, and is used to adjust the variable impedance to the target impedance form after receiving the target impedance form.

[0035] Preferably, in the AC bus voltage stabilizer, the variable impedance module 6 includes an H-bridge inverter. The DC side of the H-bridge inverter is connected to the deep reinforcement learning decision module 5 via a capacitor, and the AC side of the H-bridge inverter is connected to the power grid via an inductor and a switch.

[0036] Preferably, in the AC bus voltage stabilizer, the frequency of the harmonic current output by the harmonic current output device 1 is 10Hz to 1kHz.

[0037] Preferably, in the AC bus voltage stabilizer, the harmonic current output device 1 is provided with a timer for triggering the harmonic current injection device to periodically output harmonic current.

[0038] Preferably, in the AC bus voltage stabilizer, the deep reinforcement learning decision module 5 adopts a deep deterministic policy gradient framework.

[0039] The AC bus voltage stabilizer provided in this embodiment of the invention can flexibly adjust the impedance characteristics of the system to achieve stable system operation.

[0040] Thus far, the description of the above embodiments has been provided for illustrative and descriptive purposes. This is not intended to be exhaustive or limiting of the present disclosure. Individual elements or features of particular embodiments are generally not limited to those particular embodiments, but may be interchanged and used in selected embodiments where applicable, even if not specifically shown or described. In many respects, the same elements or features may also be varied. Such variations are not considered a departure from this disclosure, and all such modifications are intended to be included within the scope of this disclosure.

[0041] Example embodiments are provided so that this disclosure will become thorough and will fully convey the scope to those skilled in the art. Numerous details, such as examples of specific parts, apparatus, and methods, are set forth to provide a thorough understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that the specific details are not required, and the example embodiments may be implemented in many different forms, neither of which should be construed as limiting the scope of this disclosure. In some example embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.

[0042] Technical terms are used herein for the purpose of describing specific exemplary embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a” and “the” as used herein may also refer to the plural forms. The terms “comprising” and “having” are inclusive and therefore specify the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or additional having of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof. Unless expressly indicated in order of execution, the method steps, processes, and operations described herein are not to be construed as necessarily requiring performance in the specific order discussed and shown. It should also be understood that additional or optional steps may be employed.

[0043] When an element or layer is described as "on," "joined with," "connected to," or "linked to" another element or layer, it may be directly on, joined to, connected to, or linked to another element or layer, or there may be an element or layer in between. Conversely, when an element or layer is described as "directly on," "directly joined with," "directly connected to," or "directly linked to" another element or layer, there may not be an element or layer in between. Other terms used to describe element relationships should be interpreted in a similar manner (e.g., "between" and "directly between," "adjacent" and "directly adjacent," etc.). The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts are not limited by these terms. These terms may be used only to distinguish one element, component, region, or part from another element, component, region, or part. Unless the context clearly indicates otherwise, the use of terms such as “first,” “second,” and other numerical terms herein does not imply sequence or order. Therefore, the terms “first element,” “component,” “region,” “layer,” or “part” discussed below may be used in the context of “second element,” “component,” “region,” “layer,” or “part” without departing from the teachings of this exemplary embodiment.

[0044] Spatial relative terms, such as “inside,” “outside,” “below,” “under,” “lower,” “above,” “upper,” etc., may be used herein for descriptive purposes to describe the relationship between one element or feature and one or more other elements or features as shown in the figure. Spatial relative terms may refer to different orientations of the device other than those depicted in the figure. For example, if the device in the figure is rotated, an element described as “below other elements or features” or “below the element or feature” will be oriented “above other elements or features.” Therefore, the example term “below” can encompass both upward and downward orientations. The device may be oriented in other ways (rotated 90 degrees or other orientations) and interpreted using the spatial relative descriptions herein.

Claims

1. An AC bus voltage stabilizer characterized by comprising: The harmonic current output device, the voltage and current measurement module, the harmonic impedance calculation module, the impedance Bode diagram drawing module, the deep reinforcement learning decision module and the variable impedance module are included. The harmonic current output device is connected with the power grid and is used for outputting harmonic currents to the power grid in the form of frequency sweeping. The voltage and current measurement module is connected with the power grid and is used for measuring the harmonic currents generated by the harmonic current output device and the grid-side port harmonic voltage and load-side port harmonic voltage caused by the harmonic currents. The harmonic impedance calculation module is connected with the voltage and current measurement module and is used for calculating the grid-side port impedance and the load-side port impedance according to the harmonic currents at different frequencies and the grid-side port harmonic voltage and load-side port harmonic voltage under the harmonic currents measured by the voltage and current measurement module. The impedance Bode diagram drawing module is connected with the harmonic impedance calculation module and is used for drawing the grid-side port impedance Bode diagram and the load-side port impedance Bode diagram respectively by using the calculated grid-side port impedance and load-side port impedance at each frequency. The deep reinforcement learning decision module is connected with the impedance Bode diagram drawing module and is used for outputting the matched target impedance form to the variable impedance module according to the grid-side port impedance Bode diagram and the load-side port impedance Bode diagram. The variable impedance module is connected with the deep reinforcement learning decision module and the power grid respectively and is used for adjusting the variable impedance to the target impedance form after receiving the target impedance form.

2. The AC bus voltage stabilizer according to claim 1, characterized by The variable impedance module includes an H-bridge inverter, the DC side of the H-bridge inverter is connected with the deep reinforcement learning decision module through a capacitor, and the AC side of the H-bridge inverter is connected with the power grid through an inductor and a switch.

3. The AC bus voltage stabilizer according to claim 1, characterized by The frequency of the harmonic currents output by the harmonic current output device is 10 Hz to 1 kHz.

4. The AC bus voltage stabilizer of claim 1, wherein The harmonic current output device is provided with a timer for triggering the harmonic current output device to output harmonic currents periodically.

5. The AC bus voltage stabilizer of claim 1, wherein The deep reinforcement learning decision module adopts a deep deterministic policy gradient framework.

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