10kV flexible voltage compensator and compensation method based on high-power silicon controlled rectifier

Abstract

The invention relates to the field of electric power, in particular to a 10kV flexible voltage compensator based on a high-power silicon controlled rectifier and a compensation method. The shunt transformer (T1) can transform 10kV voltage into 400V voltage and provide compensation voltage for the compensation transformer; the compensation transformer I (T2) and the compensation transformer II (T3) control the opening and closing of the high-power silicon controlled rectifier, provide a required compensation voltage for the 10kV line, and couple the compensation voltage into the 10kV line to realize the function of voltage adjustment; the silicon controlled rectifier switch selects a bidirectional conduction high-power silicon controlled rectifier, optocoupler control and zero-crossing switching, and the silicon controlled rectifier is used as a contactless switch to control the voltage of the parallel transformer to be input into the secondary side of the compensation transformer so as to realize a voltage compensation function; the current limiting reactor (L) is used for limiting the short-circuit current of the parallel transformer in the voltage adjusting and changing process or when the silicon controlled rectifier breaks down.

Description

Technical Field

[0001] The invention relates to the field of electric power, and in particular to a 10kV flexible voltage compensator based on a high-power thyristor and a compensation method. Background Art

[0002] As the country's requirements for power supply quality become increasingly higher and the number of distributed photovoltaic grid-connected devices increases, the uncontrollable voltage of distribution network lines is very prominent. It is necessary to add flexible voltage compensation equipment to the lines to ensure the safe operation of the lines.

[0003] The demand for power saving by power users is increasing. Voltage control is the main method of power saving. The demand for flexible voltage compensation equipment is also increasing. The capacity of voltage compensation equipment is increasing.

[0004] At present, flexible compensation equipment is mainly based on IGBT AC-DC-AC voltage adjustment equipment. This type of equipment is expensive, has insufficient network security, is large in size, has a short life, and cannot have a large capacity. It is very difficult to exceed 3000kVA. Most compensation capacities require 8000-20000kVA, which is beyond the capability of IGBT-based flexible voltage adjustment equipment.

[0005] On November 20, 2024, a search was conducted in the China Patent Publication Database with "high power and controllable and silicon and flexible and voltage and compensation and transformer" as the abstract keywords, and the option of allowing synonym expansion was checked, but no relevant literature was found.

[0006] On November 20, 2024, an abstract search for "high-power and controllable and silicon and flexible and voltage and compensation and transformer" was conducted on CNKI, and four documents were found: "Research on New Structure of Ultra-High Voltage Silicon Carbide IGBT Devices" published by Lou Qian; "Research on Compact Design and Control Technology of MMC Solid-State Transformers" published by Li Jiayi; "Research on Flexible Traction Substation Based on Vv Traction Transformer" published by Wang Hao; "Wide-area Damping Control of Inter-area Low-frequency Oscillation of AC / DC Hybrid Interconnected Power System Considering Time Delay" published by Song Enhao; "Research on Hybrid Asymmetric Multilevel Inverter Topology and Control Strategy" published by Sun Xingtao. The technology displayed is irrelevant to this patent.

[0007] On November 20, 2024, a search was conducted on the website of the United States Patent and Trademark Office for “High power with controllable with silicon with flexible with voltage with compensation with transformer”, and no relevant literature was found; the search URL was https: / / ppubs.uspto.gov / pubwebapp / .

[0008] On November 20, 2024, a search was conducted on the Korean Patent Office with "High power and controllable and silicon and flexible and voltage and compensation and transformer" and four documents were found, which are not related to this patent: Application number (date): 1020230014564 (2023.02.03) Distributed static series compensation module, system and method; Application number (date): 1020170039802 (2017.03.29 Operation test control and compensation device; Application number (date): 1020147027309 (2013.02.26) Laser splitting method and system; Application number (date): 1020147011240 (2012.09.26) Video display based on sensor input; Search URL http: / / eng.kipris.or.kr / enghome / main.jsp.

[0009] On November 20, 2024, a search was conducted on WIPO's https: / / patentscope2.wipo.int / for "High power and controllable and silicon and flexible and voltage and compensation and transformer" and the following was found: 200610104894.4 Adjustment method for AC stepless controllable parallel reactor; it is completely different from this patent.

[0010] On November 20, 2024, a search was conducted on the Japan Patent Office website https: / / www.j-platpat.inpit.go.jp / for "High power and controllable and silicon and flexible and voltage and compensation and transformer", but no relevant literature was found.

[0011] Completely different from the concept of this patent. Summary of the invention

[0012] Purpose of the invention: To provide a 10kV flexible voltage compensator and compensation method based on high-power thyristors with better effects. The specific purpose can be seen in the multiple substantial technical effects in the specific implementation part.

[0013] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0014] A 10kV flexible voltage compensator based on high-power thyristor, characterized in that:

[0015] The 10kV flexible voltage compensator includes a parallel transformer T1, which is connected to a compensation transformer 1 T2 and a compensation transformer 2 T3;

[0016] The parallel transformer T1 is connected to the current limiting reactor L and then connected to the thyristor switch 1 K1, thyristor switch 2 K2, thyristor switch 3 K3, and thyristor switch 4 K4;

[0017] The thyristor switch K1 and the thyristor switch K2 correspond to the compensation transformer T2;

[0018] Thyristor switch three K3 and thyristor switch four K4 correspond to compensation transformer two T3;

[0019] The shunt transformer T1 is a voltage source type transformer, which provides a voltage source for the device;

[0020] The compensating transformer 1 T2 and the compensating transformer 2 T3 are current source type transformers.

[0021] A 10kV flexible voltage compensation method based on high-power thyristor, characterized in that a 10kV flexible voltage compensator based on high-power thyristor is used.

[0022] The parallel transformer T1 function can transform the 10kV voltage into 400V and provide compensation voltage to the compensation transformer;

[0023] Compensation transformer 1 T2 and compensation transformer 2 T3 control the opening and closing of high-power thyristors to provide a required compensation voltage to the 10kV line, and couple the compensation voltage to the 10kV line to achieve the voltage regulation function;

[0024] Thyristor switch 1 K1, thyristor switch 2 K2, thyristor switch 3 K3 and thyristor switch 4 K4 use bidirectional high-power thyristors, optocoupler control, zero-crossing switching. The thyristors are used as contactless switches to control the voltage input of the parallel transformer to compensate the secondary side of the transformer and realize the voltage compensation function.

[0025] The current limiting reactor L is used to limit the short-circuit current of the parallel transformer during the voltage adjustment process or when the thyristor fails.

[0026] A further technical solution of the present invention is that the control logic of the method is:

[0027] The compensation voltage cannot exceed 10±7% kV of the qualified range of line voltage, and the compensation range of each voltage level is 5%;

[0028] When the line voltage is greater than 10kV, the compensator voltage compensation is 0;

[0029] When the line voltage is in the range of 9.5-10kV, the compensator voltage is compensated by 5%, and the voltage after compensation is 10-10.5kV;

[0030] When the line voltage is in the range of 9-9.5kV, the compensator voltage is compensated by 10%, and the line voltage after compensation is 10-10.5kV;

[0031] In this application scenario, the parallel transformer voltage ratio is 10 / 0.4kV, and the compensation transformer phase voltage ratio is 231 / 289V.

[0032] A further technical solution of the present invention is that when the 10kV line voltage is greater than 10kV, by detecting the low voltage of the parallel transformer, when the voltage is greater than 400V, the controller sends a signal to close the thyristor switch K1 and the thyristor switch K3; disconnect the thyristor switch K2 and the thyristor switch K4; the secondary side voltage of the compensation transformer is 0, and the primary side compensation voltage is 0, so that the line voltage remains unchanged at the rear end of the compensator.

[0033] A further technical solution of the present invention is that when the line voltage is between 9.5-10kV, when the low voltage of the parallel transformer is detected to be 380-400V, the controller sends a signal to first close and open the thyristor switch 2 K2, and after 20ms, the thyristor switch 1 K1 is opened, the thyristor switch 3 K3 is closed, and the thyristor switch 4 K4 is opened.

[0034] A further technical solution of the present invention is that when the line voltage is lower than 9.5kV, when the low voltage of the parallel transformer is detected to be less than 380V, the controller sends a signal to first close the thyristor switch four K4, and then disconnect the thyristor switch three K3 after 20ms, so that the thyristor switch one K1 is closed and the thyristor switch two K2 is disconnected.

[0035] A further technical solution of the present invention is that it also includes a controller, which adopts DSP or PLC. The control source uses the low voltage of the parallel transformer as the detection value, and uses 400V and 380V as the threshold. It sends K1-K4 thyristor breaking signals in three control states: greater than 400V, 380-400V, and below 380V. The signals are sent in sequence to control the thyristor breaking and realize the voltage adjustment function of 0%, 5%, and 10%.

[0036] A 10kV flexible voltage compensator based on high-power thyristor, characterized in that:

[0037] The compensator voltage adjustment range is ±10%;

[0038] The 10kV flexible voltage compensator includes a parallel transformer T1, which is connected to a compensation transformer 1 T2 and a compensation transformer 2 T3;

[0039] The parallel transformer T1 is connected to the current limiting reactor L and then connected to four sets of thyristor switches;

[0040] Each group of thyristor switches contains two thyristor switches;

[0041] Two of the four groups are connected in parallel to each other and connected to the thyristor switch 14 K14 corresponding to the compensation transformer 1 T2, and the other two groups are connected in parallel to the thyristor switch 8 K8 corresponding to the compensation transformer 2 T3.

[0042] The present invention adopting the above technical solution has the following beneficial effects compared with the prior art: by adopting a flexible voltage compensation device based on high-power thyristors and utilizing electrical technology, the capacity can be increased to 25000kVA, with a small size, low cost, high operating reliability and a service life of up to 30 years. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to further illustrate the present invention, the following is further described in conjunction with the accompanying drawings:

[0044] Figure 1 is the schematic diagram of the device;

[0045] Figure 2 This is the working diagram when the line voltage is greater than 10kV;

[0046] Figure 3 This is the working diagram when the line voltage is between 9.5-10kV;

[0047] Figure 4 This is the working diagram when the line voltage is lower than 9.5kV;

[0048] Figure 5 Internal wiring diagram for voltage adjustment of -10%;

[0049] Figure 6 Internal wiring diagram for voltage adjustment of ±10%;

[0050] Among them: T1: parallel transformer; T2: compensation transformer one; T3: compensation transformer two; L: current limiting reactor; K1: thyristor switch one; K2: thyristor switch two; K3: thyristor switch three; K4: thyristor switch four; K5 thyristor switch five; K6 thyristor switch six; K7 thyristor switch seven; K8 thyristor switch eight; K9 thyristor switch nine; K10 thyristor switch ten; K11 thyristor switch eleven; K12 thyristor switch twelve; K13 thyristor switch thirteen; K14 thyristor switch fourteen. DETAILED DESCRIPTION

[0051] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "top", "bottom", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

[0052] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0053] This patent provides a variety of parallel solutions. The different expressions are improved solutions or parallel solutions based on the basic solution. Each solution has its own unique characteristics. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. The fixing method not described in the text can be any fixing method such as thread fixing, bolt fixing or glue bonding.

[0054] A 10kV flexible voltage compensator based on high-power thyristor, characterized in that:

[0055] The 10kV flexible voltage compensator includes a parallel transformer T1, which is connected to a compensation transformer 1 T2 and a compensation transformer 2 T3;

[0056] The parallel transformer T1 is connected to the current limiting reactor L and then connected to the thyristor switch 1 K1, thyristor switch 2 K2, thyristor switch 3 K3, and thyristor switch 4 K4;

[0057] The thyristor switch K1 and the thyristor switch K2 correspond to the compensation transformer T2;

[0058] Thyristor switch three K3 and thyristor switch four K4 correspond to compensation transformer two T3;

[0059] The shunt transformer T1 is a voltage source type transformer, which provides a voltage source for the device;

[0060] The compensating transformer 1 T2 and the compensating transformer 2 T3 are current source type transformers.

[0061] The substantial technical effect and implementation process of the technical solution herein, i.e., the basic function, are as follows: a 10kV flexible voltage compensation method based on high-power thyristors, characterized in that a 10kV flexible voltage compensator based on high-power thyristors is used.

[0062] The parallel transformer T1 function can transform the 10kV voltage into 400V and provide compensation voltage to the compensation transformer;

[0063] Compensation transformer 1 T2 and compensation transformer 2 T3 control the opening and closing of high-power thyristors to provide a required compensation voltage to the 10kV line, and couple the compensation voltage to the 10kV line to achieve the voltage regulation function;

[0064] Thyristor switch 1 K1, thyristor switch 2 K2, thyristor switch 3 K3 and thyristor switch 4 K4 use bidirectional high-power thyristors, optocoupler control, zero-crossing switching. The thyristors are used as contactless switches to control the voltage input of the parallel transformer to compensate the secondary side of the transformer and realize the voltage compensation function.

[0065] The current limiting reactor L is used to limit the short-circuit current of the parallel transformer during the voltage adjustment process or when the thyristor fails.

[0066] The control logic of this method is:

[0067] The compensation voltage cannot exceed 10±7% kV of the qualified range of line voltage, and the compensation range of each voltage level is 5%;

[0068] When the line voltage is greater than 10kV, the compensator voltage compensation is 0;

[0069] When the line voltage is in the range of 9.5-10kV, the compensator voltage is compensated by 5%, and the voltage after compensation is 10-10.5kV;

[0070] When the line voltage is in the range of 9-9.5kV, the compensator voltage is compensated by 10%, and the line voltage after compensation is 10-10.5kV;

[0071] In this application scenario, the parallel transformer voltage ratio is 10 / 0.4kV, and the compensation transformer phase voltage ratio is 231 / 289V.

[0072] When the 10kV line voltage is greater than 10kV, by detecting the low voltage of the parallel transformer, when the voltage is greater than 400V, the controller sends a signal to close the thyristor switch K1 and the thyristor switch K3; disconnect the thyristor switch K2 and the thyristor switch K4; the secondary side voltage of the compensation transformer is 0, and the primary side compensation voltage is 0, so that the line voltage remains unchanged at the back end of the compensator. The schematic diagram is as follows Figure 2 :

[0073] When the line voltage is between 9.5-10kV and the low voltage of the parallel transformer is detected to be 380-400V, the controller sends a signal to first close and open the thyristor switch 2 K2, and then open the thyristor switch 1 K1 after 20ms, close the thyristor switch 3 K3, and open the thyristor switch 4 K4.

[0074] Schematic diagram Figure 3 : At this time, the voltage on the secondary side of the compensation transformer T2 is 231V, which changes to 289V on the primary side. Since the direction of this voltage is consistent with the line voltage, the line voltage after compensation is equal to the phase voltage before line compensation plus 289V. When the line voltage is 9500V, the phase voltage is 5485V. After adding 289V, the voltage is 5774V and the line voltage is 10kV, that is, when the line voltage is 9.5kV, the voltage after compensation is 10kV.

[0075] When the line voltage is lower than 9.5kV and the low voltage of the parallel transformer is detected to be less than 380V, the controller sends a signal to close the thyristor switch four K4 first, and then disconnect the thyristor switch three K3 after 20ms. The thyristor switch one K1 is closed and the thyristor switch two K2 is disconnected.

[0076] Schematic diagram Figure 4 : At this time, the secondary sides of compensation transformer T2 and compensation transformer T3 are both added with a voltage of 231V, and the primary sides are both induced with a voltage of 289V, which is consistent with the direction of the original line phase voltage. Add 2 289V. If the line voltage is 9.4kV and the phase voltage is 5427V, add 2 289V. After compensation, the phase voltage is 6005V and the line voltage is 10.4kV. The line voltage is qualified.

[0077] It also includes a controller, which adopts DSP or PLC. The control source uses the low voltage of the parallel transformer as the detection value, and uses 400V and 380V as the threshold. There are three control states: greater than 400V, 380-400V, and less than 380V. It sends K1-K4 thyristor breaking signals, sends signals in sequence, controls the thyristor breaking, and realizes the voltage adjustment function of 0%, 5%, and 10%.

[0078] At the same time, protection judgment is made on the compensator and signals are given to protect the safe operation of the equipment.

[0079] Combination Figure 5 , the compensator voltage adjustment range is -10%;

[0080] With this structure, the direction of the line compensation voltage through the compensation transformers - T1 and T2 is opposite to the original line voltage direction, and the phase angle is consistent. After the voltage is superimposed, the line voltage is reduced, thereby realizing the function of reducing the line voltage when the line voltage is high.

[0081] Detect the outlet voltage of the parallel transformer T1. If the outlet voltage is less than 400V, the controller sends a signal to close the thyristor switch K1 and the thyristor switch K3, and disconnect the thyristor switch K2 and the thyristor switch K4. The primary coil voltage of the compensation transformer T2 and the compensation transformer T3 is 0, and there is no need to adjust the line voltage. If the outlet voltage is between 400-420V, the controller sends a signal to disconnect the thyristor switch K2 and the thyristor switch K3, and close the thyristor switch K1 and the thyristor switch K4. The thyristor switch T2 has a compensation voltage of 0, and the thyristor switch T3 generates a compensation voltage of -289V, realizing the -5% function. When the outlet voltage is greater than 420V, the controller sends a signal to disconnect thyristor switch 2 K2 and thyristor switch 4 K4, and close thyristor switch 1 K1 and thyristor switch 3 K3. Compensation transformer 1 T2 and compensation transformer 2 T3 both generate a voltage of -289V, a total of -578V, and achieve the -10% function.

[0082] Combination Figure 6 , a 10kV flexible voltage compensator based on high-power thyristor, characterized in that,

[0083] The compensator voltage adjustment range is ±10%;

[0084] The 10kV flexible voltage compensator includes a parallel transformer T1, which is connected to a compensation transformer 1 T2 and a compensation transformer 2 T3;

[0085] The parallel transformer T1 is connected to the current limiting reactor L and then connected to four sets of thyristor switches;

[0086] Each group of thyristor switches contains two thyristor switches;

[0087] Two of the four groups are connected in parallel to each other and connected to the thyristor switch 14 K14 corresponding to the compensation transformer 1 T2, and the other two groups are connected in parallel to the thyristor switch 8 K8 corresponding to the compensation transformer 2 T3.

[0088] The control logic is as follows:

[0089] (refer to Figure 6 )

[0090] -10%: thyristor switch twelve K12, thyristor switch thirteen K13, thyristor switch seven K7, and thyristor switch nine K9 are turned on; thyristor switch eleven K11, thyristor switch five K5, thyristor switch six K6, thyristor switch ten K10, thyristor switch fourteen K14, and thyristor switch eight K8 are turned off.

[0091] -5%: thyristor switch twelve K12, thyristor switch thirteen K13, thyristor switch eight K8 are turned on; thyristor switch eleven K11, thyristor switch five K5, thyristor switch six K6, thyristor switch seven K7, thyristor switch nine K9, thyristor switch ten K10, thyristor switch fourteen K14 are turned off.

[0092] 0%: thyristor switch fourteen K14 and thyristor switch eight K8 are turned on; thyristor switch eleven K11, thyristor switch twelve K12, thyristor switch thirteen K13, thyristor switch five K5, thyristor switch six K6, thyristor switch seven K7, thyristor switch nine K9 and thyristor switch ten K10 are turned off.

[0093] +5%: thyristor switch eleven K11, thyristor switch five K5, thyristor switch eight K8 are turned on; thyristor switch twelve K12, thyristor switch thirteen K13, thyristor switch fourteen K14, thyristor switch six K6, thyristor switch seven K7, thyristor switch nine K9, thyristor switch ten K10 are turned off.

[0094] +10%: thyristor switch eleven K11, thyristor switch five K5, thyristor switch six K6, thyristor switch ten K10 are turned on; thyristor switch twelve K12, thyristor switch thirteen K13, thyristor switch seven K7, thyristor switch nine K9, thyristor switch fourteen K14, thyristor switch eight K8 are turned off.

[0095] Advantages of the present invention:

[0096] 1. The voltage regulation speed is 20ms, which can realize the function of fast and stable line voltage.

[0097] 2. It can achieve voltage regulation to any voltage value within 20ms, which is different from the disadvantage of traditional voltage regulators that regulate voltage one level at a time.

[0098] 3. The voltage regulation uses a high-power thyristor switch, which has no mechanical contacts. The thyristor can operate more than 2 million times, solving the problem that the mechanical switch can only operate 20,000 times.

[0099] 4. It can realize flexible voltage regulation and can solve the problem of high-power equipment. It has the characteristics of large capacity, low cost and high reliability compared with the flexible voltage regulation equipment using IGBT devices, which is conducive to promotion.

[0100] The basic principle, main features and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the protection required.

Claims

1. A 10kV flexible voltage compensator based on high-power thyristor, characterized in that: The 10kV flexible voltage compensator includes a shunt transformer (T1), which is connected to a compensation transformer 1 (T2) and a compensation transformer 2 (T3); The parallel transformer (T1) is connected to the current limiting reactor (L), and then connected to the thyristor switch 1 (K1), the thyristor switch 2 (K2), the thyristor switch 3 (K3), and the thyristor switch 4 (K4); Thyristor switch 1 (K1) and thyristor switch 2 (K2) correspond to compensation transformer 1 (T2); Thyristor switch three (K3) and thyristor switch four (K4) correspond to compensation transformer two (T3); The shunt transformer (T1) is a voltage source type transformer, which provides voltage source for the device; The compensating transformer 1 (T2) and the compensating transformer 2 (T3) are current source type transformers.

2. A 10kV flexible voltage compensation method based on high-power thyristor, characterized in that: Using a 10kV flexible voltage compensator based on high-power thyristor, The parallel transformer (T1) function can transform the 10kV voltage into 400V and provide compensation voltage to the compensation transformer; Compensation transformer 1 (T2) and compensation transformer 2 (T3) control the opening and closing of high-power thyristors to provide a required compensation voltage to the 10kV line, and couple the compensation voltage to the 10kV line to achieve the voltage regulation function; Thyristor switch 1 (K1), thyristor switch 2 (K2), thyristor switch 3 (K3), and thyristor switch 4 (K4) use bidirectional high-power thyristors, optocoupler control, zero-crossing switching, and thyristors are used as contactless switches to control the voltage input of the parallel transformer to compensate the secondary side of the transformer and realize the voltage compensation function; The current limiting reactor (L) is used to limit the short-circuit current of the parallel transformer during the voltage adjustment process or when the thyristor fails.

3. A 10kV flexible voltage compensation method based on high-power thyristor as claimed in claim 2, characterized in that: The control logic of this method is: The compensation voltage cannot exceed 10±7% kV of the qualified range of line voltage, and the compensation range of each voltage level is 5%; When the line voltage is greater than 10kV, the compensator voltage compensation is 0; When the line voltage is in the range of 9.5-10kV, the compensator voltage is compensated by 5%, and the voltage after compensation is 10-10.5kV; When the line voltage is in the range of 9-9.5kV, the compensator voltage is compensated by 10%, and the line voltage after compensation is 10-10.5kV; In this application scenario, the parallel transformer voltage ratio is 10 / 0.4kV, and the compensation transformer phase voltage ratio is 231 / 289V.

4. A 10kV flexible voltage compensation method based on high-power thyristor as claimed in claim 3, characterized in that: When the 10kV line voltage is greater than 10kV, by detecting the low voltage of the parallel transformer, when the voltage is greater than 400V, the controller sends a signal to close the thyristor switch 1 (K1) and thyristor switch 3 (K3); and disconnect the thyristor switch 2 (K2) and thyristor switch 4 (K4); The secondary side voltage of the compensation transformer is 0, and the primary side compensation voltage is 0, so that the line voltage remains unchanged at the rear end of the compensator.

5. A 10kV flexible voltage compensation method based on high-power thyristor as claimed in claim 3, characterized in that: When the line voltage is between 9.5-10kV and the low voltage of the parallel transformer is detected to be 380-400V, the controller sends a signal to first close and open thyristor switch 2 (K2). After 20ms, thyristor switch 1 (K1) is opened, thyristor switch 3 (K3) is closed, and thyristor switch 4 (K4) is opened.

6. A 10kV flexible voltage compensation method based on high-power thyristor as claimed in claim 3, characterized in that: When the line voltage is lower than 9.5kV and the low voltage of the parallel transformer is detected to be less than 380V, the controller sends a signal to close thyristor switch four (K4) first, and then disconnect thyristor switch three (K3) after 20ms. Thyristor switch one (K1) is closed and thyristor switch two (K2) is disconnected.

7. A 10kV flexible voltage compensation method based on high-power thyristor as claimed in claim 2, characterized in that: It also includes a controller, which adopts DSP or PLC. The control source uses the low voltage of the parallel transformer as the detection value, and uses 400V and 380V as the threshold. There are three control states: greater than 400V, 380-400V, and less than 380V. It sends K1-K4 thyristor breaking signals, sends signals in sequence, controls the thyristor breaking, and realizes the voltage adjustment function of 0%, 5%, and 10%.

8. A 10kV flexible voltage compensator based on high-power thyristor, characterized in that: The compensator voltage adjustment range is ±10%; The 10kV flexible voltage compensator includes a shunt transformer (T1), which is connected to a compensation transformer 1 (T2) and a compensation transformer 2 (T3); The parallel transformer (T1) is connected to the current limiting reactor (L) and then to four sets of thyristor switches; Each group of thyristor switches contains two thyristor switches; Two of the four groups are connected in parallel to thyristor switch 14 (K14) corresponding to compensation transformer 1 (T2), and the other two groups are connected in parallel to thyristor switch 8 (K8) corresponding to compensation transformer 2 (T3).

Images