Voltage detection device for primary side of transformer and transformer system
By adding auxiliary windings to the transformer core column for voltage sampling, the problem of large volume and heavy weight of the high-voltage voltage transformer is solved, and a lightweight voltage detection device suitable for compact inverter systems is provided.
Patent Information
- Application Number
- CN202422038183.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-21
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-08-21
AI Technical Summary
In the prior art, high voltage voltage transformers are difficult to be installed in compact inverter systems due to their large size and heavy weight, and are costly.
Add auxiliary windings to the iron core column of the transformer, adopt a star connection method, spaced from the primary and secondary windings, and use the auxiliary windings for voltage sampling to avoid the use of additional inductor products.
It realizes voltage detection with a simple structure, small size and light weight, and is suitable for compact inverter systems, reducing costs and installation difficulties.
Smart Images
Figure CN223244687U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to detection of a primary-side voltage of a transformer, and more particularly, to a voltage detection device for detecting the primary-side voltage of a transformer and a transformer system including the voltage detection device. Background Art
[0002] In current inverter systems, the input voltage level of the primary side of the transformer often ranges from several thousand volts to more than ten kilovolts, and even reaches 35 kilovolts. In inverter systems with such high input voltages, primary side voltage signal acquisition is usually achieved through high-voltage voltage transformers. Figure 1 As shown, transformer 200 includes a primary side (i.e., high-voltage side, denoted by HV) winding 210 and a secondary side (i.e., low-voltage side, denoted by LV) winding 220. A high-voltage voltage transformer 100' collects the voltage of the primary side winding 210 at the three-phase input terminals A, B, and C, and outputs a low-voltage signal proportional to the collected voltage of the primary side winding 210 from the three-phase output terminals a, b, and c of the transformer 100'. Therefore, for high-voltage voltage transformers, the primary consideration is to ensure sufficient safety distance and insulation strength to guarantee the performance and safety of the electrical system. To this end, transformer manufacturers typically provide sufficient electrical safety distances and use sufficient insulating materials when designing their products to meet product performance requirements. However, this also brings about a problem: high-voltage voltage transformer products are typically large in size, making them difficult to install in the already very compact inverter system. Especially when the primary high-voltage input voltage level of the transformer reaches more than 10 kilovolts or even 35 kilovolts, the volume of the high-voltage voltage transformer can reach up to one cubic meter. Furthermore, since the system is three-phase, three transformers of this size need to be installed simultaneously, posing a significant structural design challenge. Such large transformers require a larger cabinet to accommodate them. Furthermore, the transformers' large size also results in heavy weight. For example, a single 35kV high-voltage transformer weighs nearly 100 kilograms, and three weigh nearly 300 kilograms combined, making installation and handling extremely inconvenient. Furthermore, the higher the voltage rating of the high-voltage transformer, the more expensive the unit price, and the higher the product cost. If problems arise, the after-sales and maintenance costs will also increase.
[0003] In view of this, it is desired to provide a voltage detection device suitable for detecting the primary side voltage of a transformer, which has a simple structure, a small size, and a light weight. Utility Model Content
[0004] The present application is proposed in view of the above-mentioned problems. The main purpose of the present application is to provide a voltage detection device with a simple structure, small size and light weight suitable for detecting the primary side voltage of a transformer, so as to at least solve the technical problem in the prior art that a voltage transformer with high cost, large weight and large space is used to detect the primary side voltage of the transformer, which is not suitable for a compact inverter system.
[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a voltage detection device for the primary side of a transformer is provided, wherein the transformer is a three-phase transformer and includes an iron core column, a primary winding and a secondary winding on each phase, the number of turns of the primary winding is greater than the number of turns of the secondary winding, and the primary winding adopts a star connection method, and the voltage detection device includes: an auxiliary winding, located on the iron core column of each phase of the transformer, the auxiliary winding has a preset turns ratio with the primary winding, and the auxiliary winding adopts a star connection method, wherein the arrangement position of the auxiliary winding on the iron core column of each phase is separated from the arrangement positions of the primary winding and the secondary winding on the iron core column.
[0006] In this way, by adding an auxiliary winding to the transformer's core leg, and by using a star connection for both the auxiliary winding and the primary winding to be tested, the auxiliary winding can be used to sample the input voltage of the primary winding without the need for an additional inductor product to collect the primary voltage signal. Furthermore, by spacing the auxiliary winding on the core leg from the primary and secondary windings of the transformer, a sufficient electrical safety distance can be provided for the voltage detection device. This greatly simplifies the structure of the voltage detection device while ensuring the safety of subsequent components of the auxiliary winding (such as voltage measurement equipment).
[0007] Further, according to one embodiment of the present application, the primary side winding on each phase includes a primary side starting end, which is located at one of the top and bottom of the iron core column on the phase, and the auxiliary winding on each phase is located at the other of the top and bottom of the iron core column on the phase.
[0008] In this way, the auxiliary winding can be spaced apart from the primary side starting end with high voltage, further ensuring that there is a sufficient electrical safety distance between the voltage detection device and the input high voltage of the transformer.
[0009] Further, according to an embodiment of the present application, the auxiliary winding on each phase includes an auxiliary end and an auxiliary start, the auxiliary start on each phase is connected to a voltage measuring device, and the auxiliary ends on the three phases are commonly connected to a neutral point.
[0010] In this way, using a voltage measuring device connected to the auxiliary winding, the voltage on the auxiliary winding on each phase can be measured, and thus the primary side voltage of the transformer can be measured.
[0011] Further, according to one embodiment of the present application, the primary side starting ends of the primary side windings on the three phases and the auxiliary side starting ends of the auxiliary windings on the three phases are located on opposite sides of the core column, and the primary side starting ends of the primary side windings on the three phases and the neutral points of the auxiliary windings are located on the same side of the core column.
[0012] In this way, the electrical safety distance between the rear-stage components of the auxiliary winding and the primary-side starting end of the transformer can be further increased, while the space occupied by the auxiliary winding on the core leg can be reduced.
[0013] Further, according to one embodiment of the present application, the tops of the three core columns on the three phases are connected by an upper yoke, and the bottoms of the three core columns are connected by a lower yoke, the upper yoke is attached with a first bracket and a second bracket, and the lower yoke is attached with a third bracket and a fourth bracket, the first bracket and the third bracket are located on the first side of the three core columns, and the second bracket and the fourth bracket are located on the second side of the three core columns opposite to the first side, wherein the primary side starting end on the three phases is located on the first bracket, and the auxiliary starting end on the three phases is located on the fourth bracket.
[0014] In this way, it can be achieved that the primary start and the auxiliary start are located on opposite sides of the core leg, while the primary start and the neutral point are located on the same side of the core leg.
[0015] Furthermore, according to an embodiment of the present application, the voltage detection apparatus further includes: the voltage measuring device includes a fixed resistor and a digital control rack connected in series.
[0016] In this way, the primary voltage on each phase of the transformer can be automatically measured using a digital control chassis.
[0017] According to another aspect of the present application, a transformer system is provided, comprising: the above-mentioned voltage detection device for the primary side of the transformer, and a transformer, wherein the transformer is a three-phase transformer and includes an iron core column, a primary winding and a secondary winding on each phase, the number of turns of the primary winding is greater than the number of turns of the secondary winding, and the primary winding adopts a star connection.
[0018] In this way, in a transformer system, the voltage signal on the primary side of the transformer can be sampled by adding an auxiliary winding to the core leg, eliminating the need for a bulky and costly inductor. Furthermore, compared to the original transformer, the transformer system including this voltage detection device has minimal increase in size and cost, making it suitable for compact inverter systems.
[0019] Further, according to one embodiment of the present application, the primary side winding on each phase includes a primary side starting end, the primary side starting end of the primary side winding on each phase is located at the top of the iron core column on the phase, and the auxiliary winding on each phase of the voltage detection device is located at the bottom of the iron core column on the phase.
[0020] In this way, the auxiliary winding can be spaced apart from the primary side start end with high voltage, further ensuring that there is a sufficient electrical safety distance between the voltage detection device and the high voltage of the transformer.
[0021] Furthermore, according to an embodiment of the present application, the primary winding is connected to an input power source, and the secondary winding is connected to a power module of the inverter system.
[0022] In this way, the transformer system according to the present application can be used in a frequency converter system.
[0023] In an embodiment of the present application, a voltage detection device for the primary side of a transformer is provided, wherein the transformer is a three-phase transformer and includes an iron core column, a primary winding and a secondary winding on each phase, the number of turns of the primary winding is greater than the number of turns of the secondary winding, and the primary winding adopts a star connection mode, and the voltage detection device includes: an auxiliary winding, located on the iron core column of each phase of the transformer, the auxiliary winding has a preset turns ratio to the primary winding, and the auxiliary winding adopts a star connection mode, wherein the arrangement position of the auxiliary winding on the iron core column of each phase is spaced apart from the arrangement positions of the primary winding and the secondary winding on the iron core column, thereby achieving the technical effect of providing a voltage detection device with a simple structure, small size and light weight suitable for detecting the primary side voltage in the transformer. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The drawings that constitute part of this application are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation on this application. In the drawings:
[0025] Figure 1 A circuit diagram of a voltage transformer used to detect the primary side input voltage of a transformer in the prior art is shown;
[0026] Figure 2 A circuit diagram of a voltage detection device and a voltage detection system for the primary side of a transformer according to an embodiment of the present application is shown;
[0027] Figure 3 A schematic diagram showing the arrangement of a voltage detection device for the primary side of a transformer on a transformer core leg according to an embodiment of the present application is shown;
[0028] Figure 4 A schematic cross-sectional view of a voltage detection device for the primary side of a transformer on a transformer core column according to an embodiment of the present application is shown.
[0029] The above drawings include the following reference numerals:
[0030] 100': High voltage voltage transformer
[0031] 100: Voltage detection device
[0032] 110: Auxiliary winding
[0033] 110a, 110b, 110c: Auxiliary start
[0034] 110N: Neutral point
[0035] 120: Voltage measuring equipment
[0036] 200: Transformer
[0037] 210: Primary winding
[0038] 210A, 210B, 210C: Primary side start
[0039] 220: Secondary winding
[0040] 220a, 220b, 220c: Secondary side output terminals
[0041] 230: Iron core column
[0042] 231: Yoke
[0043] 232: Lower Yoke
[0044] 241: First bracket
[0045] 242: Second bracket
[0046] 243: Third bracket
[0047] 244: Fourth bracket
[0048] 300: Transformer system DETAILED DESCRIPTION
[0049] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0050] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by ordinary technicians in the technical field to which this application belongs.
[0051] In this application, unless otherwise specified, directional words such as "up, down, top, bottom" are usually used with reference to the directions shown in the drawings, or with reference to the components themselves in the vertical, perpendicular or gravity direction; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit this application.
[0052] The purpose of the present application is to provide a voltage detection device suitable for detecting the primary side voltage of a transformer with a simple structure, small size and light weight, and a transformer system including the same.
[0053] Figure 2 A circuit diagram of a voltage detection device and a voltage detection system for the primary side of a transformer according to an embodiment of the present application is shown. Figure 3 A schematic diagram of the arrangement of a voltage detection device for the primary side of a transformer on a transformer core column according to an embodiment of the present application is shown. Figure 4 The cross-sectional view of the voltage detection device for the primary side of the transformer according to the embodiment of the present application on the transformer core column is shown. Figures 2 to 4 A voltage detection device for the primary side of a transformer and a transformer system including the same according to an embodiment of the present application are described in detail.
[0054] In this application, transformer 200 is a three-phase transformer and includes an iron core 230, a primary winding 210, and a secondary winding 220 for each phase (Phase A, Phase B, and Phase C). The primary winding 210 has more turns than the secondary winding 220, and the primary winding 210 is connected in a star configuration. Accordingly, the primary end of the star-connected primary winding 210 serves as the high-voltage power supply input.
[0055] refer to Figures 2 to 4 As shown, the voltage detection device 100 according to the present application includes: an auxiliary winding 110, which is located on the core column 230 of each phase of the transformer, the auxiliary winding 110 and the primary winding 210 have a preset turns ratio, and the auxiliary winding 110 adopts a star connection method, wherein the arrangement position of the auxiliary winding 110 on the core column 230 of each phase is separated from the arrangement positions of the primary winding 210 and the secondary winding 220 on the core column 230.
[0056] In this way, by adding an auxiliary winding 110 to each core leg 230 of the transformer 200, and by using a star connection for both the auxiliary winding 110 and the primary winding 210 to be tested, the auxiliary winding 110 can be used to sample the voltage of the primary winding 210, without the need for an additional inductor product to collect the primary voltage signal. Furthermore, by spacing the auxiliary winding 110 on the core leg 230 from the primary winding 210 and the secondary winding 220 of the transformer 200, a sufficient electrical safety distance can be provided for the voltage detection device 100. This greatly simplifies the structure of the voltage detection device 100 while ensuring the safety of subsequent components of the auxiliary winding (e.g., voltage measurement equipment).
[0057] Furthermore, the predetermined turns ratio between the auxiliary winding 110 and the primary winding 210 may be determined by the voltage across the primary winding 210 and the voltage to be output from the auxiliary winding 110. For example, the voltage across the primary winding 210 may be as high as several thousand volts to more than ten kilovolts, or even thirty-five kilovolts, while the voltage output from the auxiliary winding 110 is typically between one hundred volts and several hundred volts, such as 120V.
[0058] Figure 3 and Figure 4 As an example, the primary winding 210 and the secondary winding 220 of the transformer 200 are arranged at the upper and middle parts of the core leg 230. Specifically, the primary winding 210 is arranged on the inner side of the secondary winding 220. Secondary output terminals 220a, 220b and 220c for connecting the load are arranged on the outer surfaces of the secondary windings 220 on the three phases. On the core leg 230 of each phase, the auxiliary winding 110 is arranged at the bottom of the core leg 230 to be separated from the primary winding 210 and the secondary winding 220. However, the present application is not limited to this. For example, the primary winding 210 and the secondary winding 220 can also be arranged in the upper part of the core leg 230, while the auxiliary winding 110 can be arranged in the lower part of the core leg 230.
[0059] Further, in an embodiment of the present application, the primary side winding 210 on each phase includes a primary side starting end (200A or 200B or 200C), which is located at one of the top and bottom of the core column 230 on the phase, and the auxiliary winding 110 on each phase is located at the other of the top and bottom of the core column 230 on the phase. Figure 3 and Figure 4As an example, the primary side starting ends 210A, 210B, and 210C of the primary side windings 210 on the three phases A, B, and C are all located at the top of the core leg 230, while the auxiliary windings 110 on the three phases are all located at the bottom of the core leg 230. However, the present application is not limited to this arrangement, and an arrangement may also be adopted in which the primary side starting ends 210A, 210B, and 210C are all located at the bottom of the core leg 230, while the auxiliary windings 110 on the three phases are all located at the top of the core leg 230.
[0060] Through the above arrangement, the auxiliary winding 110 can be spaced apart from the primary side starting end of the primary side winding 210 with high voltage, further ensuring that the voltage detection device 100 has a sufficient electrical safety distance from the primary side high voltage of the transformer 200.
[0061] In addition, in the present application, the primary winding 210 in a star connection manner further includes a primary end, and the primary ends on the three phases are commonly connected to a primary neutral point (not shown).
[0062] In addition, if Figures 2 to 4 As shown, in the voltage detection device 100, the auxiliary winding 110 on each phase includes an auxiliary end and an auxiliary start. The three phases of the auxiliary winding 110 can be represented by phase a, phase b and phase c. Figures 2 to 4 In FIG, the auxiliary start terminals of the three phases are indicated by 110a, 110b, and 110c, respectively. Auxiliary start terminals 110a, 110b, and 110c are each connected to a voltage measuring device 120, while the auxiliary end terminals of the three phases are commonly connected to a neutral point 110N. Thus, the voltage of the auxiliary winding 110 on each phase can be measured using the voltage measuring device 120, thereby measuring the input voltage of the primary winding 210 of the transformer 200.
[0063] Accordingly, the voltage detection device 100 according to the embodiment of the present application may further include the voltage measuring device 120. In the embodiment of the present application, the voltage measuring device 120 may include, but is not limited to, a multimeter, a voltmeter, a power analyzer, or other devices capable of measuring voltage. In an exemplary embodiment of the present application, the voltage measuring device 120 may include a fixed resistor and a digital control rack (DCR) connected in series. Specifically, the auxiliary starting end (110a, 110b, or 110c) of the auxiliary winding 110 on each phase may be connected to a fixed resistor, and the other end of the fixed resistor is connected to the digital control rack. The fixed resistor is used to convert the low voltage at the auxiliary starting end on the corresponding phase into a milliampere current signal, and the converted milliampere current signal can be directly input into the digital control rack. Thus, the digital control rack can calculate the input voltage of the primary winding 210 corresponding to the current signal according to its internal preset algorithm.
[0064] Further, if Figure 3 and Figure 4 As shown, the primary start ends 210A, 210B, and 210C of the primary windings 210 on the three phases and the auxiliary start ends 110a, 110b, and 110c of the auxiliary windings 110 on the three phases are located on opposite sides of the core leg 230. This further increases the electrical safety distance between the downstream components of the auxiliary windings 110 and the primary start end of the transformer 200 that carries high voltage.
[0065] Furthermore, the primary start ends 210A, 210B, and 210C of the primary windings 210 on the three phases and the neutral point 110N of the auxiliary winding 110 are located on the same side of the core leg 230. Thus, the auxiliary start ends 110a, 110b, and 110c and the neutral point 110N are located on opposite sides of the core leg 230, thereby reducing the space occupied by the auxiliary winding 110 on each phase on the core leg 230, thereby reducing the size of the transformer system 300 including the auxiliary winding 110 and the transformer 200.
[0066] Further, if Figure 3 As shown, the tops of the three core legs 230 of the three phases are connected by an upper yoke 231, and the bottoms of the three core legs 230 are connected by a lower yoke 232. A first bracket 241 and a second bracket 242 are attached to the upper yoke 231, and a third bracket 243 and a fourth bracket 244 are attached to the lower yoke. The first bracket 241 and the third bracket 243 are located on a first side of the three core legs 230 (shown as the back side of the core legs 230 in the figure), and the second bracket and the fourth bracket are located on a second side of the three core legs opposite the first side (shown as the front side of the core legs 230 in the figure). The three primary start terminals 210A, 210B, and 210C of the three phases are all located on the first bracket 241, and the three auxiliary start terminals 110a, 110b, and 110c of the three phases are all located on the fourth bracket 244. Furthermore, the neutral point 110N of the auxiliary winding 110 is located on the third bracket 243.
[0067] Thus, the primary side start end and the auxiliary start end are located on opposite sides of the core leg 230 , while the primary side start end and the neutral point of the auxiliary winding 110 are located on the same side of the core leg 230 .
[0068] The present application also provides a transformer system 300, which includes the voltage detection device 100 for the primary side of the transformer and the transformer 200. Figure 2 and Figure 3 shown.
[0069] In an exemplary embodiment of the present application, the primary side starting ends 210A, 210B, 210C of the primary side winding 210 on each phase of the transformer 200 are located at the top of the core leg 230 on the phase, and the auxiliary winding 110 on each phase is located at the bottom of the core leg 230 on the phase, as shown in FIG. Figure 3 shown.
[0070] In an exemplary embodiment of the present application, the primary-side starting ends of the three-phase primary windings 210 can be connected to an input power source (e.g., a power grid output), while the secondary-side output terminals 220a, 220b, and 220c of the three-phase secondary windings 220 can be connected to a power module (e.g., a rectifier) of an inverter system. Thus, the transformer system 300 according to an embodiment of the present application can be used in an inverter system.
[0071] In particular, because the transformer system according to the embodiments of the present application can sample the voltage of the transformer's primary winding simply by adding an auxiliary winding to the core leg, without requiring the use of an additional bulky and costly inductor, the transformer system 300 including the voltage detection device 100 has minimal increase in size and cost compared to the transformer 200, making it suitable for use in compact inverter systems.
[0072] The transformer system 300 according to the embodiment of the present application includes reference Figures 2 to 4 The functions and effects of the voltage detection device 100 are described above, so they will not be repeated here.
[0073] further, Figures 2 to 4 The transformer 200 of the present application is shown to include one primary winding 210 and multiple secondary windings 220. However, the present application is not limited thereto, and the transformer 200 may also include only one primary winding 210 and one secondary winding 220. In addition, Figure 2 It is shown that the connection mode of the secondary side winding 220 is a triangle extension connection. Similarly, the present application is not limited to this. The secondary side winding 220 can also adopt other connection modes such as a triangle connection and a star connection.
[0074] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, tasks, devices, components and / or combinations thereof.
[0075] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. Nouns and pronouns referring to persons in this patent application are not limited to a specific gender.
[0076] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.
Claims
1. A voltage detection device for a primary side of a transformer, wherein the transformer (200) is a three-phase transformer and comprises an iron core (230), a primary winding (210), and a secondary winding (220) on each phase, wherein the number of turns of the primary winding (210) is greater than the number of turns of the secondary winding (220), and the primary winding (210) adopts a star connection mode, characterized in that: The voltage detection device (100) comprises: An auxiliary winding (110) is located on the iron core leg (230) of each phase of the transformer (200), the auxiliary winding (110) and the primary winding (210) have a preset turns ratio, and the auxiliary winding (110) adopts a star connection mode. The auxiliary winding (110) on the core column (230) of each phase is arranged at a position spaced apart from the primary winding (210) and the secondary winding (220) on the core column (230).
2. The voltage detection device for the primary side of a transformer according to claim 1, characterized in that: The primary winding (210) on each phase includes a primary start located at one of the top and bottom of the core leg (230) on the phase, and the auxiliary winding (110) on each phase is located at the other of the top and bottom of the core leg (230) on the phase.
3. The voltage detection device for the primary side of a transformer according to claim 2, characterized in that: The auxiliary winding (110) on each phase includes an auxiliary end and an auxiliary start. The auxiliary start on each phase is connected to a voltage measuring device (120), and the auxiliary ends on three phases are commonly connected to a neutral point (110N).
4. The voltage detection device for the primary side of a transformer according to claim 3, characterized in that: The primary side starting ends of the primary side windings (210) on the three phases and the auxiliary starting ends of the auxiliary windings (110) on the three phases are located on opposite sides of the core column (230), and the primary side starting ends of the primary side windings (210) on the three phases and the neutral point (110N) of the auxiliary windings (110) are located on the same side of the core column (230).
5. The voltage detection device for the primary side of a transformer according to claim 4, characterized in that: The tops of the three core legs (230) on the three phases are connected by an upper yoke (231), and the bottoms of the three core legs (230) are connected by a lower yoke (232), the upper yoke (231) is attached with a first bracket (241) and a second bracket (242), the lower yoke (232) is attached with a third bracket (243) and a fourth bracket (244), the first bracket (241) and the third bracket (243) are located on a first side of the three core legs (230), and the second bracket (242) and the fourth bracket (244) are located on a second side of the three core legs (230) opposite to the first side, The primary side starting ends of the three phases are located on the first bracket (241), and the auxiliary starting ends of the three phases are located on the fourth bracket (244).
6. The voltage detection device for the primary side of a transformer according to claim 3, characterized in that: The voltage detection device (100) further includes: The voltage measuring device (120) comprises a fixed resistor and a digital control rack connected in series.
7. Transformer system, characterized in that, include: A voltage detection device for the primary side of a transformer according to any one of claims 1 to 6; as well as A transformer (200) is provided, the transformer being a three-phase transformer and comprising an iron core leg (230), a primary winding (210) and a secondary winding (220) on each phase, the number of turns of the primary winding (210) being greater than the number of turns of the secondary winding (220), and the primary winding (210) being connected in a star configuration.
8. The transformer system according to claim 7, characterized in that: The primary side winding (210) on each phase includes a primary side start end, the primary side start end of the primary side winding (210) on each phase is located at the top of the iron core leg (230) on the phase, and the auxiliary winding (110) on each phase of the voltage detection device (100) is located at the bottom of the iron core leg (230) on the phase.
9. The transformer system according to claim 7, characterized in that The primary winding (210) is connected to an input power source, and the secondary winding (220) is connected to a power module of a frequency converter system.