Topological structure of series transformer voltage regulation electric furnace transformer

Abstract

The topological structure comprises a main transformer structure, a series transformer structure and a magnetic flux guiding component, and the main transformer structure and the series transformer structure share the magnetic flux guiding component; the main transformer structure comprises a voltage regulation excitation structure and a main winding which are arranged on the magnetic flux guide component, and the voltage regulation excitation structure comprises a plurality of coarse regulation excitation units and fine regulation excitation units which are respectively connected with the multi-gear voltage regulation switch; the voltage regulation excitation structure is electrically isolated from the main winding, and the output voltage is regulated in a magnetic flux mode; the series variable structure comprises an excitation input winding and an output winding, and the excitation input winding is electrically connected with the voltage regulation excitation structure; the output winding of the series transformer structure and the output winding of the main transformer structure form a series-connected output path to provide electric energy after voltage regulation; the structure has a multi-stage voltage regulation capability, and is suitable for output voltage regulation in a wide range.

Description

Technical Field

[0001] The present invention is a series variable-tuning piezoelectric furnace transformer topology structure. Background Art

[0002] As an important device in China's modern industrial system, electric furnaces are widely used in multiple industries such as metallurgy, chemical engineering, and machinery. For example, in the metallurgical industry, they are mainly used for the smelting of high-quality alloy steels and ferroalloys; in the chemical industry, they are used for the production of products such as yellow phosphorus, calcium carbide, and synthetic resins; in the machinery industry, they are mostly used in the melting processes of steel casting and iron casting. In order to meet the power supply requirements of electric furnaces for high power, low voltage, and large current, electric furnace transformers, as their core power supply devices, play a crucial role.

[0003] An electric furnace transformer is a typical special transformer, which has characteristics such as low voltage, large current, and multi-stage voltage regulation. Usually, the secondary voltage of this type of transformer is only several hundred volts, while the secondary current is as high as tens of thousands of amperes. In terms of structure, the common ones are single-core and double-core structure forms, and the single-core structure can be further divided into concentric type and interleaved type. Due to the drastic load changes during the operation of electric furnaces, electric furnace transformers must have a relatively high overload capacity, and the industry usually requires its overload capacity to reach about 130%. At the same time, it also needs to have extremely strong anti-short-circuit ability.

[0004] However, in the current industry, electric furnace transformers frequently experience the phenomenon of equipment damage due to external short-circuit impacts, which not only affects the reliability of equipment operation but also causes relatively large economic losses. In the existing technical solutions, multi-stage level difference output usually adopts a variable-flux structure of "auto-coupling modulation + main transformer". Although this auto-coupling modulation scheme realizes the voltage regulation function, its inherent impedance is small and it is difficult to withstand the frequent short-circuit impacts under the working conditions of electric furnaces, thus limiting its adaptability in high-intensity smelting application scenarios. In addition, to achieve a wide-range low-voltage output range of 100V - 532V, this type of transformer has extremely high costs in terms of material input and equipment volume, and the overall cost performance is poor.

[0005] In summary, the existing electric furnace transformer structures have obvious deficiencies in aspects such as voltage regulation range, short-circuit bearing capacity, and economy. There is an urgent need for a new type of electric furnace transformer topology solution with a more reasonable structure, stronger voltage regulation ability, and better anti-short-circuit performance to meet the complex electrical requirements of electric furnaces at different operation stages. Summary of the Invention

[0006] The purpose of the present invention is to solve the above deficiencies of the prior art and provide a series variable-tuning piezoelectric furnace transformer topology structure.

[0007] A series-variable voltage regulation piezoelectric furnace transformer topology includes a main transformer structure, a series-variable structure, and a magnetic flux guiding member. The main transformer structure and the series-variable structure share the magnetic flux guiding member;

[0008] The main transformer structure includes a voltage regulation excitation structure and a main winding arranged on the magnetic flux guiding member. The voltage regulation excitation structure includes a plurality of coarse adjustment excitation units and fine adjustment excitation units, which are respectively connected to a multi-step voltage regulation switch;

[0009] The voltage regulation excitation structure is electrically isolated from the main winding and is used to adjust the output voltage by means of magnetic flux;

[0010] The series-variable structure includes an excitation input winding and an output winding. The excitation input winding is electrically connected to the voltage regulation excitation structure;

[0011] The output winding of the series-variable structure and the output winding in the main transformer structure form a series-connected output path for providing the electrically energy after voltage regulation;

[0012] The series-variable voltage regulation piezoelectric furnace transformer topology has multi-step voltage regulation capabilities and is suitable for realizing output voltage regulation within a wide range.

[0013] Further, the fine adjustment excitation unit includes 21 levels of positive and negative adjustment excitation coils and is electrically connected to a ±11-level positive and negative voltage regulation switch.

[0014] Further, the coarse adjustment excitation unit includes two layers of three groups of linear coarse adjustment excitation coils and is electrically connected to a linear voltage regulation switch with three steps.

[0015] Further, the fine adjustment excitation unit and the coarse adjustment excitation unit together constitute an output voltage regulation structure with a 63-level step difference for realizing an output voltage range of 100 volts to 532 volts.

[0016] Further, the voltage regulation excitation structure is an excitation-type winding, which is electrically isolated from the main winding and realizes the voltage regulation function only through magnetic flux coupling.

[0017] Further, the output winding and the output winding in the main transformer structure are connected through an "8"-shaped series winding structure for realizing continuous low-voltage side voltage output.

[0018] Further, the magnetic flux guiding member is a three-phase three-column iron core, and the main transformer structure and the series-variable structure are co-wound on this iron core.

[0019] Beneficial effects: Compared with the prior art, the series-variable voltage regulation piezoelectric furnace transformer structure disclosed by the present invention has significant technical advantages.

[0020] First, through the combined voltage regulation method of "3 - stage linear coarse adjustment + 21 - stage fine adjustment", this structure realizes a wide - range output ability between 100 volts and 532 volts, and has a voltage regulation level with up to 63 levels of step difference, which can meet the usage requirements of industrial electric furnaces for high - precision and wide - range voltage regulation. The coarse - adjustment and fine - adjustment units work together, enabling the voltage output to have an extremely high adjustment resolution on the basis of being adjustable in a large range, effectively adapting to the changing requirements of the supply voltage in different smelting stages.

[0021] Secondly, the voltage - regulating excitation structure is completely electrically isolated from the main winding, and realizes voltage - regulating control only through magnetic - flux coupling, avoiding potential safety hazards such as electrical short - circuit and insulation aging, and improving the operation safety and long - term stability of the entire system. This structure is especially suitable for harsh working conditions such as frequent short - circuits and high - impact currents during the operation of electric furnaces, enhancing the reliability of the transformer and the fault - tolerance ability of the system.

[0022] In addition, the main - transformer structure and the series - transformer structure share a three - phase three - limb iron core, effectively compressing the structure volume and optimizing the magnetic - circuit design. This not only improves the magnetic - flux utilization efficiency, but also reduces the overall weight and floor area of the equipment. This compact and integrated design improves the modularity of the system, facilitating installation, maintenance, and industrial integrated application.

[0023] Furthermore, the output winding in the series - transformer structure and the low - voltage output winding in the main - transformer structure adopt an "8" - shaped series structure, which can achieve continuous and stable output on the low - voltage side, helping to ensure the power - supply consistency and control accuracy of the electric furnace during variable - voltage operation. This design optimizes the phase and magnetic - field distribution between windings, further reducing leakage inductance and losses.

[0024] Finally, compared with the traditional voltage - regulation method using the combination of autotransformer regulation and main transformer, the present invention adopts an excitation - coil variable - magnetic - flux structure, effectively avoiding the short - circuit problem caused by the low - impedance structure, significantly reducing the material cost and manufacturing - process complexity, and enhancing the cost - performance of the system. This new structure is not only technologically advanced, but also has obvious economic benefits and industrialization prospects in practical applications, especially suitable for the rapid development needs of heavy - load industrial fields such as metallurgical smelting. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of the topological structure of a series - transformer voltage - regulating electric - furnace transformer;

[0026] In the figure, 1. Linear voltage - regulating switch, 2. Voltage - regulating excitation structure, 3. High - voltage winding in the main - transformer structure, 4. Excitation input winding in the series - transformer structure, 5. Output winding in the main - transformer structure, 6. Output winding of the series - transformer structure. DETAILED DESCRIPTION OF THE INVENTION

[0027] To deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0028] A series variable-tuning piezoelectric furnace transformer topology structure includes a main transformer structure, a series variable structure, and a magnetic flux guiding member. The main transformer structure and the series variable structure share the magnetic flux guiding member. The main transformer structure includes a voltage regulating excitation structure 2 and a main winding disposed on the magnetic flux guiding member. The voltage regulating excitation structure 2 includes a plurality of coarse-tuning excitation units and fine-tuning excitation units, which are respectively connected to a multi-step voltage regulating switch. The voltage regulating excitation structure 2 is electrically isolated from the main winding and is used to adjust the output voltage by means of magnetic flux. The series variable structure includes an excitation input winding and an output winding. The excitation input winding is electrically connected to the voltage regulating excitation structure 2. The output winding and the output winding 5 in the main transformer structure form a series-connected output path for providing the electrical energy after voltage regulation. The series variable-tuning piezoelectric furnace transformer topology structure has a multi-step voltage regulation ability and is suitable for realizing the output voltage regulation within a wide range.

[0029] This topology structure realizes the wide-range fine voltage regulation of the electrical energy required by the electric furnace through the coordinated operation of the main transformer structure and the series variable structure. The voltage regulating excitation structure 2 in the main transformer structure cooperates with the main winding by means of magnetic flux coupling to realize the voltage regulation function without direct connection. Specifically, the voltage regulating excitation structure 2 is composed of a plurality of coarse-tuning and fine-tuning excitation units. By adjusting the excitation magnetic flux generated by these units, the induced voltage output in the main winding is controlled. The series variable structure further cooperates with the voltage regulation function. Its excitation input winding receives the magnetic energy from the voltage regulating excitation structure 2, outputs electrical energy through the output winding, and the output winding is then connected in series with the output winding 5 in the main transformer structure to form an overall output path to obtain a continuous and stable voltage regulation effect.

[0030] Since the main transformer structure and the series variable structure share the same magnetic flux guiding member (such as an iron core), the integrated magnetic circuit design significantly improves the energy efficiency utilization rate and the system response rate, and at the same time helps to reduce the equipment volume and manufacturing cost.

[0031] The series variable-tuning piezoelectric furnace transformer topology structure of this invention has the following remarkable advantages: First, the contactless voltage regulation is realized through the magnetic flux coupling method of the voltage regulating excitation structure 2 and the main winding, improving the system reliability and regulation accuracy; Second, the combination of the coarse-tuning and fine-tuning structures improves the voltage regulation resolution and adaptability, and can meet the multi-step adjustment requirements from lower to higher output voltages; Third, the series variable structure provides an additional adjustment channel, significantly broadening the output voltage range and meeting the complex voltage requirements of industrial electric furnaces at different working stages; In addition, the sharing of the magnetic flux guiding member optimizes the structural space and simplifies the magnetic circuit design, improving the electromagnetic performance and manufacturing consistency.

[0032] In a possible implementation, the fine-tuning excitation unit includes 21 levels of positive and negative adjustable excitation coils and is electrically connected to the ±11-level positive and negative voltage regulating switches.

[0033] By configuring 21 levels of positive and negative adjustable excitation coils, the fine-tuning excitation unit cooperates with the ±11-level voltage regulating switch to achieve multi-level and fine magnetic flux regulation functions. Through the positive and negative excitation methods, the magnetic flux intensity is positively and negatively regulated, so that the output voltage smoothly changes within a continuous range. The ±11-level switch structure means that it can be divided into 11 levels each from the center 0 point to the positive and negative ends, realizing a total of 21 adjustment gears, which helps the symmetrical adjustment and higher resolution control of the output voltage.

[0034] The combination of 21 levels of positive and negative adjustable excitation coils and the ±11-level switch makes the voltage regulation ability more detailed and the regulation response more sensitive, especially suitable for industrial electric furnace systems that require high-precision voltage control. This structure not only ensures the breadth of voltage regulation but also the smoothness and continuity of the adjustment process.

[0035] In a possible implementation, the coarse-tuning excitation unit includes two layers of three groups of linear coarse-tuning excitation coils and is electrically connected to the linear voltage regulating switch 1 with three gears.

[0036] The coarse-tuning excitation unit adopts a two-layer three-group structure, and each group of coils provides a linear excitation path. By switching different coil combinations or positions through the three-gear linear voltage regulating switch 1, the intensity of the excitation magnetic flux is changed to achieve rough voltage adjustment. This structure is mainly used to cover a wide range of voltage changes, providing an initial voltage framework during the voltage regulation process and providing a regulation basis for the fine-tuning part.

[0037] This structure provides the preliminary adjustment ability for large-amplitude voltage changes and is suitable for application scenarios with large requirements for voltage range changes. The two-layer three-group structure optimizes the coil distribution, improves the heat dissipation ability and magnetic field uniformity of the system, and enhances the overall stability and reliability of the system.

[0038] In a possible implementation, the fine-tuning excitation unit and the coarse-tuning excitation unit together constitute an output voltage regulation structure with a 63-level step difference, which is used to achieve an output voltage range of 100V to 532V.

[0039] The coarse-tuning and fine-tuning excitation units jointly achieve up to 63 voltage regulation levels through coordinated adjustment. Each level is arranged in a stepped manner with a certain voltage step, covering the output range of 100V to 532V. The coarse-tuning provides large voltage steps, and the fine-tuning makes fine adjustments between each coarse-tuning gear to ensure the smooth transition of the output voltage within the entire adjustment range.

[0040] This structure realizes the unity of a wide voltage regulation range and high regulation accuracy, and is adapted to industrial electric furnace systems with different specifications and requirements. Through hierarchical design, the complexity requirements for single-stage excitation components are effectively reduced, while ensuring the voltage stability and continuity of the output.

[0041] In a possible implementation, the voltage regulating excitation structure 2 is an excitation type winding, which is electrically isolated from the main winding and realizes the voltage regulating function only through magnetic flux coupling.

[0042] The voltage regulating excitation structure 2 exists in the form of an excitation type winding, is completely electrically isolated from the main winding, and conducts magnetic flux coupling through a common magnetic flux guiding component. This magnetic flux transfer method avoids the energy loss and interference that may be introduced in traditional electrical connections. When regulating the voltage, the induced voltage of the main winding is indirectly affected by adjusting the magnetic flux intensity of the excitation winding, thereby realizing voltage regulating control.

[0043] The adoption of the excitation type winding makes the voltage regulating control safer and more reliable, avoiding risks such as electrical short circuits and insulation breakdowns. This structure improves the voltage withstand capacity and anti-interference ability of the system, and is suitable for industrial environments that require long-term stable operation.

[0044] In a possible implementation, the output winding is connected to the output winding 5 in the main transformer structure through an "8"-shaped series winding structure to realize continuous low-voltage side voltage output.

[0045] The "8"-shaped series winding structure enables the output windings 6 of the main transformer structure and the series transformer structure to be interconnected in a specific magnetic coupling manner, so that the output voltages of the two parts are accurately superimposed in terms of phase, direction, and voltage level, and then continuous and stable voltage output is realized on the low-voltage side. This structure optimizes the magnetic field coupling path of the winding, reduces magnetic leakage, and improves efficiency.

[0046] Through the "8"-shaped series structure, the continuity of voltage regulation and the stability of low-voltage output can be realized, especially suitable for load scenarios sensitive to voltage fluctuations. Its reasonable layout also helps to reduce the volume of the equipment and improve the heat dissipation performance.

[0047] In a possible implementation, the magnetic flux guiding component is a three-phase three-column iron core, and the main transformer structure and the series transformer structure are co-wound on this iron core.

[0048] Using a three-phase three-column iron core as the magnetic flux guiding component, the three columns respectively correspond to the three-phase main magnetic flux paths. The main transformer structure and the series transformer structure are co-wound on it and work together in the same magnetic circuit system. This iron core structure ensures the symmetry of the magnetic flux distribution and the consistency of the magnetic circuit, making the magnetic flux coupling between the main transformer and the series transformer more efficient and balanced.

[0049] By unifying the iron core structure, not only the structural design is simplified, but also the magnetic energy utilization rate and the system power density are improved. At the same time, since each structure works on the same iron core, it is beneficial to reduce magnetic leakage and magnetic circuit losses, and improve the operation efficiency and stability of the overall transformer.

[0050] Working principle: This structure is based on the principle of variable magnetic flux voltage regulation. Continuous and controllable voltage regulation is achieved through the coupling of the voltage regulation excitation structure 2 and the output winding. The voltage regulation excitation structure 2 is composed of two layers of three groups of linear coarse adjustment excitation coils and 21 - stage forward and reverse fine adjustment excitation coils, which are used to provide excitation magnetic flux for the series - transformer structure.

[0051] The two - layer three - group linear coarse adjustment excitation coils and the 21 - stage forward and reverse adjustment excitation coils are arranged on the magnetic flux guiding member, and are co - wound with the high - voltage winding 3 and the low - voltage winding in the main transformer structure on the same three - phase three - limb iron core. The three - phase three - limb iron core serves as a unified magnetic flux guiding path to ensure the efficient coupling and symmetric operation of the magnetic circuit of the entire system. The voltage regulation excitation structure 2 is only used for excitation, and its excitation coils are completely electrically isolated from the high - voltage winding and the low - voltage winding of the main transformer structure, and only energy coupling is carried out through the magnetic flux method, thus greatly improving the electrical safety of the system and the flexibility of magnetic flux control.

[0052] In terms of structural configuration, the voltage regulation excitation structure 2 supplies power to the excitation input winding 4 in the series - transformer structure, and the latter then forms an output path through its output winding. The output winding is connected in series with the low - voltage output winding in the main transformer structure in an "8" - shaped structure to form a stable and continuous low - voltage side voltage output path. This structure not only realizes continuous and controllable wide - range voltage output, but also can meet the operation requirements of the electric furnace system under special working conditions such as frequent short - circuits and high impacts.

[0053] Compared with the "autotransformer regulation + main transformer magnetic flux regulation" mode used in traditional special transformers, due to the problems of low impedance and insensitivity to short - circuits in the autotransformer regulation structure, its reliability under frequent impact loads is insufficient, and in order to achieve wide - range voltage regulation, usually a large amount of materials need to be invested, resulting in a large volume and high cost, and it is difficult to meet the comprehensive requirements of industrial scenarios for high cost - effectiveness, compact structure and high reliability.

[0054] The structural design of the present invention introduces a main transformer + series - transformer combined structure through the magnetic flux coupling voltage regulation mechanism, which not only retains the flexibility and accuracy of voltage regulation, but also greatly reduces the material consumption and the overall manufacturing cost. At the same time, due to the high integration degree and compact layout of the winding structure, the volume and weight of the system are effectively reduced, further improving the adaptability and industrial promotion ability of the equipment, and it is especially suitable for scenarios with strict requirements for equipment performance such as metallurgical smelting.

[0055] As Figure 1 shown, the upper square is the main transformer body, and the structure of the main transformer body from the inside to the outside includes in turn:

[0056] Fine-tuning excitation unit: Set in the innermost layer, composed of 21 levels of positive and negative adjustable excitation coils, and electrically connected to the ±11-level positive and negative voltage regulating switches to achieve high-precision voltage fine-tuning function;

[0057] Coarse-tuning excitation unit: Located outside the fine-tuning excitation unit, adopting a two-layer and three-group linear coarse-tuning excitation coil structure, and switched through a three-stage linear voltage regulating switch to achieve wide-range initial voltage adjustment;

[0058] High-voltage winding in the main transformer structure: Arranged outside the voltage regulating and exciting structure, used to receive the energy after flux modulation;

[0059] Low-voltage output winding in the main transformer structure: As the outer winding of the main transformer part, it participates in constructing the final output path.

[0060] The lower square is the series transformer body, and its structure from the inside to the outside is as follows:

[0061] Excitation input winding (i.e., high-voltage winding), used to receive the flux input from the voltage regulating and exciting structure;

[0062] Output winding (i.e., low-voltage winding), interconnected with the low-voltage winding in the main transformer structure through an "8"-shaped series winding structure to form a continuous and stable low-voltage side voltage output path.

[0063] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A series transformer topology structure for regulating voltage in electric furnace, comprising a main transformer structure, a series transformer structure and a magnetic flux guide component, characterized in that: The main transformer structure and the series transformer structure share the magnetic flux guide component; The main transformer structure includes a voltage regulating excitation structure and a main winding arranged on a magnetic flux guide member, wherein the voltage regulating excitation structure includes a plurality of coarse adjustment excitation units and a fine adjustment excitation unit, which are respectively connected to a multi-speed voltage regulating switch; The voltage regulating excitation structure is electrically isolated from the main winding and is used to adjust the output voltage by means of magnetic flux; The series transformer structure comprises an excitation input winding and an output winding, and the excitation input winding is electrically connected to the voltage regulating excitation structure; The output winding of the series transformer structure and the output winding of the main transformer structure form an output path connected in series, which is used to provide voltage-regulated electric energy; The series-transformer voltage-regulating electric furnace transformer topology structure has a multi-stage voltage regulation capability and is suitable for achieving output voltage regulation within a wide range.

2. The topological structure of the series-transformer voltage-regulating electric furnace transformer according to claim 1 is characterized in that: The fine-tuning excitation unit includes 21 levels of positive and negative adjustment excitation coils and is electrically connected to ±11 levels of positive and negative voltage regulation switches.

3. The topological structure of the series-transformer voltage-regulating electric furnace transformer according to claim 2 is characterized in that: The coarse adjustment excitation unit comprises two layers and three groups of linear coarse adjustment excitation coils, and is electrically connected to a linear voltage regulating switch with three gears.

4. The topological structure of the series-transformer voltage-regulating electric furnace transformer according to claim 3 is characterized in that: The fine adjustment excitation unit and the coarse adjustment excitation unit together form an output voltage adjustment structure with 63 levels of difference, which is used to achieve an output voltage range of 100 volts to 532 volts.

5. The topological structure of the series-transformer voltage-regulating electric furnace transformer according to claim 4 is characterized in that: The voltage regulating excitation structure is an excitation type winding, which is electrically isolated from the main winding and realizes the voltage regulating function only through magnetic flux coupling.

6. The topological structure of the series-transformer voltage-regulating electric furnace transformer according to claim 5 is characterized in that: The output winding is connected to the output winding in the main transformer structure through an "8"-shaped series winding structure to achieve continuous low-voltage side voltage output.

7. The topological structure of the series-transformer voltage-regulating electric furnace transformer according to claim 6 is characterized in that: The magnetic flux guiding component is a three-phase three-column iron core, and the main transformer structure and the series transformer structure are wound together on the iron core.

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