Power distribution area electric energy quality controllable degradation system based on true model test and test method of power distribution area electric energy quality controllable degradation system

Abstract

The invention discloses a power distribution area electric energy quality controllable degradation system based on a real-model test and a test method thereof. The controllable degradation system for the power quality of the power distribution area based on the real-model test comprises a power distribution transformer, an alternating-current simulation power grid power supply, a line, an adjustable alternating-current load of the power distribution area, an adjustable direct-current load and a reserved test station, the alternating-current simulation power grid power supply is connected in series between the low-voltage side of the power distribution transformer and the reserved test station, and the line is connected in series between the adjustable direct-current load and the reserved test station. Wherein the reserved test station is an installation access point of the tested equipment; the line is used for transmitting the electric energy to an adjustable alternating current load and an adjustable direct current load of a transformer area; the transformer area adjustable alternating current load is connected to the tail end of the line; the adjustable DC load T is connected to a first preset position of the line.

Description

Technical Field

[0001] This invention relates to the field of power distribution network testing technology, and more specifically, to a controllable degradation system for power quality in power distribution substations based on full-scale testing and its testing method. Background Technology

[0002] The distribution network is the main battleground for the construction of new power systems. The large-scale integration of distributed photovoltaic (PV) systems on the user side has led to increasingly pronounced high voltage, high reactive power, and high load characteristics, severely impacting power quality in distribution substations and user experience. This can even cause overload and overheating of distribution transformers, posing a risk of damage. To alleviate a series of problems caused by full-load and over-generation of distributed PV systems, such as overvoltage, overcurrent, harmonics, and backfeeding, as well as long-standing issues in distribution substations caused by load mismatch or unauthorized wiring leading to overload, heavy load, low power factor, three-phase voltage imbalance, and three-phase current imbalance, many voltage regulating devices or reactive power compensation devices for power quality restoration in distribution substations have emerged in the market. However, the functionality and performance evaluation of these devices often lack standardized criteria, making it difficult to assess their actual voltage, reactive power, or power quality improvement effects. Some laboratories have configured line impedance and load characteristic simulation devices based on power electronic devices, which can basically simulate distribution substation systems, but no experimental methods have been found regarding how power quality deteriorates, how to set up reasonable systems, or how monitoring and protection systems should operate. Currently, laboratories capable of constructing distribution substation experiments generally use various equivalent simulation devices to simulate lines and loads. They have only built semi-simulation or full simulation test scenarios and configured some simulation devices with functions to degrade power quality. However, there is a lack of research on what power indicators to simulate, to what extent to simulate these indicators, and how to achieve this to conform to actual operating conditions. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a controllable power quality degradation system for distribution substations based on full-scale testing and its testing method.

[0004] According to one aspect of the present invention, a controllable degradation system for power quality in a distribution substation based on full-scale testing is provided, comprising: a distribution transformer, an AC simulated grid power supply, lines, adjustable AC loads in the substation, adjustable DC loads, and reserved test positions, wherein...

[0005] An AC simulated power grid power supply is connected in series between the low-voltage side of the distribution transformer and the reserved test station, where the reserved test station is the installation and access point for the equipment under test.

[0006] The lines are used to transmit electrical energy to adjustable AC and adjustable DC loads in the distribution area;

[0007] The adjustable AC load of the transformer area is connected to the end of the line;

[0008] The adjustable DC load T is connected to the first preset position of the line.

[0009] Optionally, the power quality controllable degradation system for the distribution substation also includes: multiple switching switches and capacitor banks for current support, wherein

[0010] The capacitor bank for current support is connected to the second preset position of the line via a switching switch;

[0011] Multiple switching switches are installed at multiple preset points in the power quality controllable degradation system of the distribution area to control whether to connect the corresponding power supply, capacitor or load.

[0012] Optionally, the power quality controllable degradation system for the distribution substation also includes: a new energy power generation system, T-connected at the third preset position of the line, serving as the second type of power source for the power quality controllable degradation system for the distribution substation.

[0013] Optionally, the power quality controllable degradation system for the distribution area also includes a new energy simulator, which is T-connected at the fourth preset position of the line as a supplement when the configuration of the new energy power generation system is insufficient.

[0014] Optionally, the power quality controllable degradation system for the distribution substation also includes: a control master station, used for remotely monitoring the entire power quality controllable degradation system for the distribution substation, and for remotely signaling, measuring, adjusting, and controlling all switching switches and AC / DC power supplies and AC / DC loads installed within the entire power quality controllable degradation system for the distribution substation.

[0015] Optionally, the power quality controllable degradation system for the distribution substation also includes: multiple monitoring devices configured on both sides of the distribution transformer and the AC analog power grid, at line sections and on each branch line, and at the load input end, for monitoring voltage, current, power factor and harmonic electrical parameters, and reading and displaying them through the control master station.

[0016] Optionally, the primary side of the distribution transformer is connected to the actual high-voltage power grid, and the rated voltage of the secondary side is 400V.

[0017] Optionally, the AC analog grid power supply is equipped with a bypass switch, which has the functions of emitting voltage harmonics and interharmonics of different frequencies, setting the three-phase voltage imbalance, setting different frequencies, realizing voltage flicker, and high / low voltage ride-through.

[0018] According to another aspect of the present invention, a method for controlling the degradation of power quality in a distribution substation is provided, comprising:

[0019] The controllable degradation system for power quality in the distribution substation is designed to be configured in seven dimensions: voltage amplitude, three-phase voltage imbalance, three-phase current imbalance, power factor, load factor, harmonics, and frequency. The controllable degradation test of power quality in the distribution substation is then conducted.

[0020] Optionally, settings can be made separately for seven dimensions: voltage amplitude, three-phase voltage imbalance, three-phase current imbalance, power factor, load factor, harmonics, and frequency.

[0021] The voltage amplitude can be set by remotely or locally controlling the AC simulated grid power supply, or the AC simulated grid power supply can be superimposed with a new energy power generation system and a new energy simulator to adjust the voltage amplitude of the AC line.

[0022] The three-phase voltage imbalance can be set by remotely or locally controlling the AC simulated grid power supply, or by jointly adjusting the load of each phase to different magnitudes to indirectly set the three-phase voltage imbalance by the AC simulated grid power supply, the adjustable AC load of the distribution area, the new energy power generation system, the new energy simulator and the adjustable DC load.

[0023] The AC analog grid power supply can be remotely or locally controlled to set the harmonic content and frequency.

[0024] The system can independently or locally control one or more of the following: adjustable AC loads, new energy power generation systems, new energy simulators, and adjustable DC loads to set the three-phase current imbalance.

[0025] The power factor can be set by adjusting the resistance, inductance, and capacitance of the AC load in a separate remote or local control area.

[0026] The load rate of the distribution transformer can be set by one or more of the following: an adjustable AC load, a new energy power generation system, a new energy simulator, and an adjustable DC load, either remotely or locally, in the control area.

[0027] Therefore, the distribution substation based on the full-scale test of this invention consists of a distribution transformer 1, an AC simulated grid power supply 2, a line 3, a capacitor bank for current support 4, an adjustable AC load for the substation 5, a switching switch 6, a new energy power generation system 7, a new energy simulator 8, an adjustable DC load 9, a monitoring device 10, a control master station 11, and a reserved test station 12. By remotely controlling the switch at the control master station 11 or manually controlling it on-site at the distribution substation, different types of power supplies and loads can be switched on and off, thereby building a customized distribution substation. In accordance with the standard test method, the output characteristics of AC and DC power supplies and AC and DC loads are set remotely at the control master station 11 or manually on-site at the distribution substation in the built distribution substation, thereby creating a controllable degradation test environment for power quality in the distribution substation that can be reproduced multiple times. Attached Figure Description

[0028] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0029] Figure 1 This is a schematic diagram of the structure of a controllable degradation system for power quality in a distribution substation based on a real-world test, provided by an exemplary embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram illustrating the implementation process of a controllable degradation test method for power quality in a distribution substation, provided by an exemplary embodiment of the present invention. Detailed Implementation

[0031] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0032] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0033] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of the present invention are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0034] It should also be understood that in the embodiments of the present invention, "multiple" can refer to two or more, and "at least one" can refer to one, two or more.

[0035] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more unless explicitly defined or given contrary instructions in the context.

[0036] Furthermore, the term "and / or" in this invention is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this invention generally indicates that the preceding and following related objects have an "or" relationship.

[0037] It should also be understood that the description of the various embodiments in this invention emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0038] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0039] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0040] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0041] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0042] Figure 1 This is a schematic diagram of a controllable degradation system for power quality in a distribution substation based on a full-scale test, provided by an exemplary embodiment of the present invention. Figure 1 As shown, the controllable degradation system for power quality in a distribution substation based on a full-scale test includes: a distribution transformer 1, an AC simulated grid power supply 2, a line 3, an adjustable AC load 5, an adjustable DC load 9, and 12 reserved test positions.

[0043] AC simulated grid power supply 2 is connected in series between the low-voltage side of distribution transformer 1 and reserved test station 12, where reserved test station 12 is the installation access point of the equipment under test;

[0044] Line 3 is used to transmit electrical energy to the adjustable AC load 5 and adjustable DC load 9 in the transformer area;

[0045] The adjustable AC load 5 in the transformer area is connected to the end of line 3;

[0046] An adjustable DC load of 9T is connected to the first preset position of line 3.

[0047] Specifically, this invention establishes a fully realistic distribution substation area, thereby maximally reproducing the actual operating conditions of the distribution substation area. By constructing a real distribution substation power supply, distributed power supply, substation lines and user loads, and configuring necessary monitoring facilities, under the premise of ensuring test safety, it uses technical means that closely resemble natural generation to create different power indicators such as degraded voltage, current, power factor, and harmonics, thereby creating a reproducible distribution substation operating environment with degraded power quality characteristics.

[0048] Furthermore, distribution transformer 1 is a conventional step-down transformer for distribution network areas. Its primary side is connected to the actual high-voltage power grid, and its secondary side has a rated voltage of 400V. Its capacity can meet the power supply capacity requirements of the entire test system, including the load. If there are no high-voltage connection conditions on site, a three-phase voltage regulator can also be used as an alternative AC power source. Its input voltage is the system voltage at the test site, and its output line voltage range should cover 0 to 500V.

[0049] Furthermore, the AC simulated grid power supply 2 should have a bypass switch and functions such as emitting voltage harmonics and interharmonics of different frequencies from 2 to 50, setting three-phase voltage imbalance, setting different frequencies, realizing voltage flicker, and high / low voltage ride-through. The AC simulated grid power supply 2 is connected in series between the low-voltage side of the distribution transformer 1 and the reserved test station 12. When AC power supply test conditions that do not meet national power quality standards are required, its bypass switch is disconnected to activate the device; when the device is not needed, the bypass switch can be closed to disconnect it. The AC simulated grid power supply 2 can be locally controlled or remotely controlled, remotely signaled, remotely measured, and remotely adjusted via the control master station 11.

[0050] Furthermore, line 3 can be an overhead line, a cable line, or a hybrid line. The length and number of lines depend on the test requirements. Line 3 is used to transmit electrical energy from the AC / DC power supply side to the AC / DC load.

[0051] Furthermore, the adjustable AC load 5 of the distribution area is connected to the end of line 3. The device type can be centralized or distributed, and the device can be a traditional resistor, inductor, or capacitor, or a power electronic power supply type load. The capacity and power factor of the adjustable AC load 5 of the distribution area can be controlled locally or remotely controlled, remotely signaled, remotely measured, and remotely adjusted through the control master station 11. Figure 1 In the middle, the adjustable AC load 5 in the substation area is distributed, indicating that line 3 has branches.

[0052] Furthermore, the adjustable DC load 9 should itself be equipped with an AC / DC converter, which is T-connected to a certain point on line 3 as needed for testing. The device type can be centralized or distributed. The capacity of the adjustable DC load 9 can be locally controlled or remotely controlled, remotely signaled, remotely measured, and remotely adjusted through the control master station 11. Figure 1 In the middle, the adjustable DC load 9 is a charging pile, connected to the end of line 3, simulating a centralized DC load.

[0053] Furthermore, the reserved test station 12 is the installation access point for the equipment under test. It can be located at any location in the distribution area, either a reserved station on line 3 or an empty space left after the equipment that has been connected to the distribution area is removed. Figure 1 The reserved test station 12 is located between the AC simulated power grid power supply 2 and the adjustable AC load 5 of the transformer area.

[0054] Optionally, the power quality controllable degradation system for the distribution substation also includes: multiple switching switches 6 and capacitor banks 4 for current-supporting applications, wherein

[0055] The current-capacitance support capacitor bank 4 is connected to the second preset position of line 3 via the switching switch 6;

[0056] Multiple switching switches 6 are installed at multiple preset points in the power quality controllable degradation system of the power distribution area to control whether to switch on the corresponding power supply, capacitor or load.

[0057] Specifically, the capacitor bank 4 for current-capacitance support is connected to a certain point on line 3 via a switching switch 6. The specific location depends on the test requirements. It is used to represent a certain length of overhead line or cable line and is usually composed of multiple sets of traditional power capacitors connected in series and parallel. The capacitance of the capacitor bank 4 for current-capacitance support should be adjustable locally or remotely controlled and signaled via the control master station 11. Figure 1 In the diagram, the capacitor bank 4 for current support is connected to the front end of the adjustable AC load 5 in the distribution area, indicating that the distance between the load in the distribution area and the power distribution transformer 1 of the distribution area is farther than that provided by the actual line 3.

[0058] Furthermore, there are multiple switching switches 6, used to control whether to connect the corresponding power supply, capacitor, or load. Depending on the maximum breaking current, they can be circuit breakers, air switches, contactors, or low-voltage intelligent switches. Switches 6 should be installed on at least one side of the equipment, and ideally on both sides. Switches 6 can be locally controlled or remotely controlled and signaled via the control master station 11.

[0059] Optionally, the power quality controllable degradation system for the distribution substation also includes: a new energy power generation system 7, which is T-connected to the third preset position of line 3, serving as the second type of power source for the power quality controllable degradation system for the distribution substation.

[0060] Specifically, the new energy power generation system 7 is a real photovoltaic power generation system or wind power generation system, T-connected to a certain point on the line, serving as the second type of power source for the entire distribution substation area, and its commissioning can be determined according to test requirements. The new energy power generation system 7 can be locally controlled or remotely controlled, remotely signaled, remotely measured, and remotely adjusted through the control master station 11. Figure 1 In the middle, the new energy power generation system 7 is a photovoltaic power generation system, which, along with the adjustable AC load 5 of the distribution area, is connected to the end of line 3, simulating a household distributed power generation system.

[0061] Optionally, the power quality controllable degradation system for the distribution area also includes: a new energy simulator 8, which is T-connected to the fourth preset position of line 3, as a supplement when the configuration of the new energy power generation system 7 is insufficient.

[0062] Specifically, the new energy simulator 8 is a device that simulates photovoltaic or wind power generation. It is connected to a certain point on the line and serves as a supplement when the configuration of the new energy power generation system 7 is insufficient. The new energy simulator 8 can be controlled locally or remotely controlled, remotely signaled, remotely measured, and remotely adjusted through the control master station 11. Figure 1 In the middle, the new energy simulator 8 is connected to the end of line 3.

[0063] Optionally, the power quality controllable degradation system for the distribution substation also includes: a control master station 11, used for remotely viewing the entire power quality controllable degradation system for the distribution substation, and for remotely signaling, measuring, adjusting, and controlling all switching switches 6 and AC / DC power supplies and AC / DC loads installed within the entire power quality controllable degradation system for the distribution substation.

[0064] Specifically, the control master station 11 can remotely view the entire distribution transformer area, and remotely signal, measure, adjust, and control all the switching switches 6 and AC / DC power supplies and loads installed within the entire distribution transformer area. Figure 1 In this system, the control master station 11 is independent of the distribution station area and transmits signals bidirectionally only through optical fiber.

[0065] Optionally, the power quality controllable degradation system for the distribution substation also includes: multiple monitoring devices 10, configured on both sides of the distribution transformer 1 and the AC analog power grid 2, at the section of the line 3 and on each branch line, and at the load input end, for monitoring voltage, current, power factor and harmonic electrical parameters, and reading and displaying them through the control master station 11.

[0066] Specifically, the monitoring device 10 is configured on both sides of the power supply, at the 3rd section of the line, on each branch line, and at the load input end. It is used to monitor electrical parameters such as voltage, current, power factor, and harmonics, and can be read and displayed through the control master station 11. Through the monitoring device 10, the energized operation status of the entire distribution substation can be understood, including whether each normally energized device is operating normally, whether the degree of power quality degradation reaches the expected level when setting the AC simulated grid power supply 2, the adjustable AC load 5 of the substation, the new energy simulator 8, and the adjustable DC load 9, and whether the operation of the test item meets the requirements after it is put into operation.

[0067] Specifically, the distribution substation based on the real-world test of this invention consists of a distribution transformer 1, an AC simulated grid power supply 2, a line 3, a capacitor bank for current-capacitance support 4, an adjustable AC load for the substation 5, a switching switch 6, a new energy power generation system 7, a new energy simulator 8, an adjustable DC load 9, a monitoring device 10, a control master station 11, and a reserved test station 12. By remotely controlling the switch at the control master station 11 or manually controlling it on-site at the distribution substation, different types of power supplies and loads can be switched on and off, thereby building a customized distribution substation. In accordance with the standard test method, the output characteristics of AC and DC power supplies and AC and DC loads are set remotely at the control master station 11 or manually on-site at the distribution substation in the built distribution substation, thereby creating a controllable degradation test environment for power quality in the distribution substation that can be reproduced multiple times.

[0068] According to another aspect of the present invention, a method for controlling the degradation of power quality in a distribution substation is provided, comprising:

[0069] The controllable degradation system for power quality in the distribution substation is designed to be configured in seven dimensions: voltage amplitude, three-phase voltage imbalance, three-phase current imbalance, power factor, load factor, harmonics, and frequency. The controllable degradation test of power quality in the distribution substation is then conducted.

[0070] Specifically, refer to Figure 2 As shown, the settings for power quality degradation are implemented from seven dimensions: voltage amplitude, three-phase voltage imbalance, three-phase current imbalance, power factor, load factor, harmonics, and frequency. The range of each parameter setting expands the scope of power quality degradation beyond the existing national or industry standards for relevant power quality indicators, with the extreme range encompassing the upper and lower limits of existing power quality monitoring or management devices. For voltage amplitude settings, the AC simulated grid power supply 2 can be directly controlled remotely or locally, or the AC simulated grid power supply 2 can be combined with the new energy power generation system 7 and the new energy simulator 8 to adjust the AC line voltage amplitude. For three-phase voltage imbalance settings, the AC simulated grid power supply 2 can be directly controlled remotely or locally, or the AC simulated grid power supply 2, the adjustable AC load 5 in the distribution area, the new energy power generation system 7, the new energy simulator 8, and the adjustable DC load 9 can be used to indirectly adjust the load of each phase to different values. For harmonic content and frequency settings, the AC simulated grid power supply 2 can be remotely or locally controlled. The current simulation grid power supply 2 can be directly implemented; in setting the three-phase current imbalance, one or more of the four devices—regional adjustable AC load 5, new energy power generation system 7, new energy simulator 8, and adjustable DC load 9—can be controlled remotely or locally; in setting the power factor, the inductance and capacitance of regional adjustable AC load 5 can be set remotely or locally; in setting the load rate of distribution transformer 1, one or more of the four devices—regional adjustable AC load 5, new energy power generation system 7, new energy simulator 8, and adjustable DC load 9—can be controlled remotely or locally.

[0071] Therefore, the present invention provides a controllable power quality degradation system and testing method for distribution substations based on real-world testing. Its advantage lies in constructing a typical power quality degradation test scenario for a distribution substation that can be repeatedly performed, is stable and controllable, and is flexibly adjustable within a real-world distribution substation. This scenario can be widely matched to typical power quality problems encountered in urban and rural distribution substations and new industrial parks after the integration of new energy sources. By creating such test scenarios and providing test methods, this invention provides a basis-based, step-by-step, operable, and evaluable testing method for assessing the actual compensation effects of various power quality management devices widely available on the market, thereby meeting the needs for evaluating and testing power quality management devices.

[0072] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A controllable power quality degradation system for distribution substations based on full-scale testing, characterized in that, include: The distribution transformer (1), AC simulated grid power supply (2), line (3), adjustable AC load of the distribution area (5), adjustable DC load (9), and reserved test station (12) are included. The AC simulated grid power supply (2) is connected in series between the low-voltage side of the distribution transformer (1) and the reserved test station (12), wherein the reserved test station (12) is the installation access point of the device under test; The line (3) is used to transmit electrical energy to the adjustable AC load (5) and the adjustable DC load (9) of the transformer area; The adjustable AC load (5) of the transformer area is connected to the end of the line (3); The adjustable DC load (9)T is connected to the first preset position of the line (3).

2. The controllable degradation system for power quality in a distribution substation according to claim 1, characterized in that, Also includes: Multiple switching switches (6) and capacitor banks (4) for current-capacitive support, wherein The current-capacitance support capacitor bank (4) is connected to the second preset position of the line (3) via a switching switch (6); Multiple switching switches (6) are installed at multiple preset points in the power quality controllable degradation system of the power distribution area to control whether to switch on the corresponding power supply, capacitor or load.

3. The controllable degradation system for power quality in a distribution substation according to claim 1, characterized in that, Also includes: The new energy power generation system (7) is connected to the third preset position of the line (3) as the second type of power source of the power quality controllable degradation system of the distribution area.

4. The controllable degradation system for power quality in a distribution substation according to claim 3, characterized in that, Also includes: The new energy simulator (8) is connected to the fourth preset position of the line (3) as a supplement when the configuration of the new energy power generation system (7) is insufficient.

5. The controllable degradation system for power quality in a distribution substation according to claim 2, characterized in that, Also includes: The control master station (11) is used to remotely monitor the entire power quality controllable degradation system of the entire power distribution area, and remotely signal, measure, adjust and control all switching switches (6) and AC / DC power supplies and AC / DC loads installed in the entire power quality controllable degradation system of the entire power distribution area.

6. The controllable degradation system for power quality in a distribution substation according to claim 5, characterized in that, Also includes: Multiple monitoring devices (10) are configured on both sides of the distribution transformer (1) and the AC analog power grid (2), at the section of the line (3) and on each branch line, and at the load input end, to monitor voltage, current, power factor and harmonic electrical parameters, and to read and display them through the control master station (11).

7. The controllable degradation system for power quality in a distribution substation according to claim 1, characterized in that, The primary side of the distribution transformer (1) is connected to the actual high-voltage power grid, and the rated voltage of the secondary side is 400V.

8. The controllable degradation system for power quality in a distribution substation according to claim 1, characterized in that, The AC analog power grid power supply (2) is equipped with a bypass switch, which has the functions of emitting voltage harmonics and interharmonics of different frequencies, setting the three-phase voltage imbalance, setting different frequencies, realizing voltage flicker and high / low voltage ride-through.

9. A test method for controllable degradation of power quality in a distribution substation, implemented by a controllable degradation system for power quality in a distribution substation according to any one of claims 1-8, characterized in that, include: The controllable degradation system for power quality in the distribution substation is designed to be configured in seven dimensions: voltage amplitude, three-phase voltage imbalance, three-phase current imbalance, power factor, load factor, harmonics, and frequency. The controllable degradation test of power quality in the distribution substation is then conducted.

10. The method according to claim 9, characterized in that, The settings are configured separately for seven dimensions: voltage amplitude, three-phase voltage imbalance, three-phase current imbalance, power factor, load factor, harmonics, and frequency. The voltage amplitude can be set by remotely or locally controlling the AC simulated grid power supply (2), or the AC simulated grid power supply (2) can be superimposed with the new energy power generation system (7) and the new energy simulator (8) to jointly adjust the voltage amplitude of the AC line; The three-phase voltage imbalance can be set by the AC simulated grid power supply (2) alone, remotely or locally, or by the AC simulated grid power supply (2), the adjustable AC load (5) of the distribution area, the new energy power generation system (7), the new energy simulator (8) and the adjustable DC load (9) jointly adjusting the load of each phase to different sizes to indirectly set the three-phase voltage imbalance. (2) Set the harmonic content and frequency by controlling the AC analog power grid power supply remotely or locally; The three-phase current imbalance can be set by one or more of the following: a remote or local control area adjustable AC load (5), a new energy power generation system (7), a new energy simulator (8), and an adjustable DC load (9); The power factor is set by adjusting the resistance, inductance, and capacitance of the adjustable AC load (5) in the control area, either remotely or locally. The load rate of the distribution transformer (1) can be set by one or more of the following: an adjustable AC load (5), a new energy power generation system (7), a new energy simulator (8), and an adjustable DC load (9) in a single remote or local control area.

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