A 24-pulse autotransformer modulation and phase-inverted parallel connection rectifier transformer topology

Abstract

The utility model relates to a kind of 24-pulse self-coupling modulation and in-phase inverse parallel rectifier transformer topology, comprising: two rectifier transformers, including two bodies respectively, each body includes a set of high-voltage winding and a set of low-voltage winding, high-voltage winding adopts star connection, low-voltage winding adopts delta connection, and low-voltage winding is connected to rectifier output loop in in-phase inverse parallel mode;A self-coupling voltage regulating device, the primary side is connected to AC power grid, the secondary side outputs multiple voltage, and supplies the high-voltage side input of rectifier transformer respectively;Rectifier transformer high-voltage winding is provided with different phase shift angle respectively, to form the phase difference combination of preset angle, realize equivalent twenty-four pulse wave output;Self-coupling voltage regulating device is constant magnetic flux junction;Rectifier transformer adopts variable magnetic flux mode voltage regulation;Two rectifier transformers have independent circuit and magnetic circuit structure respectively.

Description

Technical Field

[0001] This utility model is a 24-pulse autotransformer and in-phase reverse parallel rectifier transformer topology. Background Technology

[0002] Converter systems include rectification, inversion, and frequency conversion. Among these, rectification technology is most widely used in the industrial field, often for supplying high-current DC power in industries such as metallurgy and electrolysis. Existing rectifier equipment typically consists of an AC power grid via a rectifier transformer and a rectifier unit, and is widely used in applications such as electrolysis of metals, electrolysis of salt, and electrolysis of water, generally employing a 6-pulse or 12-pulse structure.

[0003] However, traditional rectifier systems have significant drawbacks. On the one hand, they cause severe harmonic pollution to the power grid, affecting power quality; on the other hand, they have low power factors and high energy consumption, which do not meet the requirements for the development of green power grids. In addition, the low-voltage, high-current structure design is complex, with large copper and iron losses, limiting operating efficiency.

[0004] To address the aforementioned issues, this invention employs a 24-pulse rectifier transformer and introduces a d-connection in-phase reverse parallel configuration on the low-voltage side. This effectively reduces harmonics, improves the power factor, enhances rectification performance, and is more suitable for green and efficient power systems. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a 24-pulse autotransformer and in-phase reverse parallel rectifier transformer topology.

[0006] A 24-pulse autotransformer and in-phase antiparallel rectifier transformer topology includes:

[0007] Two rectifier transformers, each comprising two transformer bodies, each comprising a set of high-voltage windings and a set of low-voltage windings, wherein the high-voltage windings are connected in a star configuration and the low-voltage windings are connected in a delta configuration, and the low-voltage windings are connected to the rectifier output circuit in a parallel configuration with the same phase but opposite direction.

[0008] An autotransformer voltage regulator has its primary side connected to the AC power grid and its secondary side outputting multiple voltage levels, which are respectively supplied to the high-voltage side input of the rectifier transformer.

[0009] The high-voltage windings of the two rectifier transformers are respectively set with different phase shift angles to form a phase difference combination with a preset angle, thereby achieving an equivalent twenty-four-pulse output.

[0010] The autotransformer voltage regulator is a constant flux junction;

[0011] The rectifier transformer uses a variable flux method to regulate voltage, and the output voltage on the valve side is automatically adjusted according to the change of the secondary voltage level of the autotransformer voltage regulator.

[0012] The two rectifier transformers each have independent circuit and magnetic circuit structures, which are used to improve the electrical isolation capability and anti-interference performance of the system.

[0013] Furthermore, the two rectifier transformers are the first rectifier transformer and the second rectifier transformer, respectively. The high-voltage winding of the first rectifier transformer is set with a phase shift angle of +7.5° and -22.5°, and the high-voltage winding of the second rectifier transformer is set with a phase shift angle of +22.5° and -7.5°, with a preset angle of 15°.

[0014] Furthermore, the low-voltage winding of the rectifier transformer includes two sets of windings connected in phase, connected in a voltage superposition manner, and connected to the rectifier output terminal in a reverse parallel manner.

[0015] Furthermore, the secondary output voltage of the autotransformer voltage regulator is a 27-level differential voltage, used to meet the output regulation requirements under different operating conditions.

[0016] Furthermore, the system also includes a temperature rise monitoring device, a voltage stabilizing module, and a short-circuit protection circuit to ensure the safety and reliability of system operation.

[0017] Beneficial Effects: Compared with existing technologies, this utility model innovatively uses two 12-pulse rectifier transformers combined to form a 24-pulse rectifier system, and combines a constant flux autotransformer voltage regulator and a low-voltage connection in reverse parallel with the same phase. This effectively overcomes the problems of heavy harmonic pollution, low power factor, large equipment size, and low energy efficiency existing in existing 6-pulse or 12-pulse rectifier systems, and has the following significant technical advantages:

[0018] First, this invention achieves 24-pulse rectified output by setting phase shift angle combinations of +7.5°, -22.5°, +22.5°, and -7.5° on the high-voltage side of two rectifier transformers, thus forming an equivalent 15-degree phase difference. This multi-pulse design significantly reduces the harmonic content of the output voltage, effectively improves the interference of the rectifier system on the power grid, meets national power quality standards, and enhances the overall operational stability of the system.

[0019] Secondly, the low-voltage side of the rectifier system adopts a delta connection and is designed as a parallel-in-phase structure, ensuring that the output voltages of each winding are in phase and their energy is superimposed, thereby improving the rectifier output capacity and current carrying capacity. Compared with traditional series or simple parallel methods, this structure can significantly reduce winding losses, improve output efficiency, and effectively integrate the output waveform, making it suitable for high-power electrolytic load scenarios.

[0020] Furthermore, the autotransformer voltage regulator used in this invention possesses constant flux characteristics, and its secondary output has 27 levels of differential voltage. Combined with the variable flux voltage regulation method of the rectifier transformer, it can automatically adjust the rectifier's input voltage according to different operating conditions, achieving continuous and precise control of the load-side output voltage. This voltage regulation method offers fast response speed and high control accuracy, which is beneficial for energy-saving operation and refined process control.

[0021] Furthermore, this invention features a compact structure and a small footprint. The two transformers in the rectifier system each have independent circuits and magnetic circuits, effectively avoiding magnetic flux coupling and control interference, enhancing the system's anti-interference capability and electrical isolation characteristics, and improving operational safety and maintenance convenience. It is particularly suitable for high current density processes such as electrolytic zinc, electrolytic copper, and electrolytic aluminum.

[0022] Finally, the system is equipped with auxiliary functions such as temperature rise monitoring, overvoltage protection, short circuit protection, and voltage regulation, which further enhances the intelligence and reliability of the rectifier system and meets the high requirements for stability and safety in continuous industrial operation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the phase-shifting topology of the first rectifier transformer, which combines 12 pulses to form a 24-pulse rectifier transformer.

[0024] Figure 2 This is a schematic diagram of the phase-shifting topology of the second rectifier transformer, which combines 12 pulses to form a 24-pulse rectifier transformer.

[0025] Figure 3 This is a schematic diagram of the phase difference combination and wiring principle of the first 12-pulse rectifier transformer;

[0026] Figure 4 This is the first rectifier transformer's -22.5° high-voltage winding phase shift vector diagram;

[0027] Figure 5 This is the vector diagram of the low-voltage winding corresponding to the -22.5° high-voltage winding of the first rectifier transformer;

[0028] Figure 6 This is the first rectifier transformer with a +7.5° high-voltage winding phase shift vector diagram;

[0029] Figure 7 This is the vector diagram of the low-voltage winding corresponding to the +7.5° high-voltage winding of the first rectifier transformer;

[0030] Figure 8 It is the first 12-pulse rectifier transformer with low-voltage winding phase difference combination and vector diagram;

[0031] Figure 9 This is a schematic diagram of the phase difference combination and wiring principle of the 12 pulses of the second rectifier transformer;

[0032] Figure 10 This is the phase shift vector diagram of the -7.5° high-voltage winding of the second rectifier transformer;

[0033] Figure 11 This is the vector diagram of the low-voltage winding corresponding to the -7.5° high-voltage winding of the second rectifier transformer;

[0034] Figure 12 This is the phase shift vector diagram of the +22.5° high-voltage winding of the second rectifier transformer;

[0035] Figure 13 This is the vector diagram of the low-voltage winding corresponding to the +22.5° high-voltage winding of the second rectifier transformer;

[0036] Figure 14 This is the phase difference combination and vector diagram of the low-voltage winding of the 12-pulse second rectifier transformer.

[0037] Figure 15 This is a schematic diagram of the phase difference of a system with two rectifier transformers, each with a 12-pulse combination, equivalent to a 24-pulse rectifier. Detailed Implementation

[0038] To enhance understanding of this utility model, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. These embodiments are only used to explain the present utility model and do not constitute a limitation on the scope of protection of the present utility model.

[0039] The 24-pulse autotransformer and in-phase anti-parallel rectifier transformer topology includes: two rectifier transformers, each comprising two transformer bodies, each body including a high-voltage winding and a low-voltage winding. The high-voltage winding adopts a star connection, and the low-voltage winding adopts a delta connection. The low-voltage windings are connected in-phase anti-parallel in the rectifier output circuit; an autotransformer voltage regulator, whose primary side is connected to the AC power grid, and whose secondary side outputs multiple voltage levels, respectively supplying the high-voltage side input of the rectifier transformer; the high-voltage windings of the two rectifier transformers are respectively set with different phase shift angles to form a phase difference combination of preset angles, realizing an equivalent 24-pulse output; the autotransformer voltage regulator has a constant flux junction structure; the rectifier transformer uses a variable flux method for voltage regulation, and the valve-side output voltage is automatically adjusted according to the change of the secondary voltage level of the autotransformer voltage regulator; the two rectifier transformers each have independent circuit and magnetic circuit structures to improve the electrical isolation capability and anti-interference performance of the system.

[0040] This embodiment constructs a 24-pulse rectifier system based on a dual-rectifier transformer configuration. The two rectifier transformers each consist of two transformer bodies, each equipped with a high-voltage winding and a low-voltage winding. The high-voltage windings are connected in a star configuration (Y-connection) to ensure symmetry and connection stability among the three-phase voltages; the low-voltage windings are connected in a delta configuration (d-connection) and are connected to the rectifier output circuit via a reverse parallel connection in the same phase to achieve voltage synthesis and harmonic suppression.

[0041] By introducing differentiated phase shift angle settings on the high-voltage side, the two rectifier transformers operate in a specific phase shift mode, thereby forming multiple time-staggered rectified waveforms at the output end, which are then synthesized into a 24-pulse output, effectively reducing the harmonic components in the output current.

[0042] The input power supply is connected to the system through an autotransformer, which is constructed with a constant flux junction to ensure constant flux during voltage regulation and improve operational stability. Its secondary side outputs multiple voltage levels (e.g., 27 levels) to supply power to the high-voltage windings of two rectifier transformers, thereby achieving multi-level input control.

[0043] The rectifier transformer regulates voltage by varying magnetic flux. When the secondary voltage of the autotransformer changes, the rectifier transformer can adaptively adjust its valve-side output voltage to achieve dynamic voltage stabilization. Simultaneously, to ensure no electrical interference exists between different transformers, each rectifier transformer has its own independent circuitry and magnetic circuitry, avoiding magnetic flux coupling interference and enhancing the overall system's electrical isolation and anti-interference performance.

[0044] This structure achieves efficient voltage regulation and rectification by introducing a constant flux junction autotransformer and a variable flux controlled rectifier transformer, improving the system's voltage control accuracy and response speed. The 24-pulse rectification technology significantly reduces the harmonic content in the output waveform, helping to minimize interference to the power grid and load. The independent circuit and magnetic circuit design of the rectifier transformer improves the system's electrical isolation, enhances its anti-interference capability and reliability, and facilitates stable operation in high-precision DC power supply scenarios.

[0045] In one possible implementation, the two rectifier transformers are a first rectifier transformer and a second rectifier transformer, wherein the high-voltage winding of the first rectifier transformer is set with a phase shift angle of +7.5° and -22.5°, and the high-voltage winding of the second rectifier transformer is set with a phase shift angle of +22.5° and -7.5°, with a preset angle of 15°.

[0046] This implementation sets the high-voltage windings of the two rectifier transformers to complementary phase angles (+7.5° / -22.5° and +22.5° / -7.5°), achieving a 15° phase difference between the two windings, thereby forming a 24-pulse rectification characteristic at the output of the rectifier system. Different phase angle combinations ensure the uniformity of voltage waveform coverage on the time axis of the input AC signal, significantly reducing harmonic content, optimizing the rectified output waveform quality, and improving the system power factor.

[0047] By designing the phase shift angle of the high-voltage winding to a specific combination of ±7.5° and ±22.5°, 24-pulse rectified output can be effectively achieved. This not only improves the system rectification efficiency but also significantly reduces the total harmonic distortion rate, thereby improving power quality and meeting the high standards required by high-performance industrial power supplies for rectification stability and output stability.

[0048] In one possible implementation, the low-voltage winding of the rectifier transformer includes two sets of windings connected in phase, connected in a voltage superposition manner, and connected to the rectifier output terminal in an anti-parallel manner.

[0049] This implementation uses two sets of in-phase windings on the low-voltage side to multiply the output voltage through voltage superposition. These are then connected to the rectifier output in reverse parallel, allowing the voltages of the two in-phase windings to compensate for current loss when their directions are opposite, thereby reducing the AC component in the output current. This configuration improves the smoothness of the rectified output and effectively reduces DC output ripple voltage and harmonic interference.

[0050] By connecting two sets of in-phase windings in parallel with voltage superposition, the rectifier output terminal maintains constant voltage output while significantly reducing voltage ripple, improving system stability and power supply quality. It is especially suitable for DC load applications with high requirements for output voltage quality.

[0051] In one possible implementation, the secondary output voltage of the autotransformer is a differential voltage with twenty-seven levels, used to meet the output regulation requirements under different operating conditions.

[0052] This implementation uses 27 voltage taps on the secondary side of the autotransformer to achieve voltage level outputs with equal or unequal spacing, thus providing multiple input voltage levels to the high-voltage winding of the rectifier transformer. The rectified output voltage can automatically adjust the input voltage level according to different operating conditions, forming a continuous or stepped voltage regulation capability, achieving wide-range, high-precision voltage control, which is especially suitable for variable load environments.

[0053] The autotransformer with 27-stage secondary voltage output can achieve multi-stage voltage regulation without affecting magnetic flux stability, improving the system's adaptability to complex operating conditions and effectively meeting the needs of precision electronic equipment, electrolytic power supply systems, and other applications for stable and adjustable DC power supply.

[0054] In one possible implementation, the system also includes a temperature rise monitoring device, a voltage regulation module, and a short-circuit protection circuit to ensure the safety and reliability of system operation.

[0055] This implementation introduces a temperature rise monitoring device to detect the operating temperature of the rectifier transformer and autotransformer in real time. If the temperature is abnormal, an early warning will be issued or a protection program will be activated. The voltage stabilization module automatically adjusts the control signal by detecting changes in the output voltage to achieve dynamic stability of the output voltage. When a fault occurs at the output terminal or the current rises abnormally, the short-circuit protection circuit quickly cuts off the power supply or shunts and limits the current to prevent system damage.

[0056] This system significantly improves overall operational safety and reliability by constructing a complete safety control chain. The triple mechanism of temperature rise monitoring, overvoltage protection and stabilization, and short-circuit protection effectively prevents electrical overload, thermal breakdown, or circuit failure, improving the continuity of equipment operation and maintenance efficiency.

[0057] Working Principle: Based on the coordinated operation of multiple power conversion and control technologies, including phase-shifting rectification, autotransformer voltage regulation, variable flux control, and electrical isolation. The entire system consists of two rectifier transformers and one autotransformer. Each rectifier transformer employs a two-body structure, with each body containing a high-voltage winding and a low-voltage winding. The high-voltage winding uses a star connection to ensure symmetrical electromotive force for the three-phase input voltage; the low-voltage winding uses a delta connection, and after voltage superposition, it is connected to the rectifier output circuit in a reverse parallel configuration, effectively achieving voltage synthesis and harmonic cancellation.

[0058] To achieve 24-pulse output, the high-voltage windings of the two rectifier transformers are set with different phase shift angles, such as ±7.5° and ±22.5°. Utilizing the symmetry and angle differences of the three-phase system, 24 voltage pulse components can be generated at the output, effectively reducing the total harmonic distortion (THD). This technology, based on the phase-shifting rectification principle, improves the smoothness and quality of the DC output through the superposition of time-domain misaligned rectified waveforms, and is a key component of high-performance rectifier systems.

[0059] The autotransformer in the system features a constant flux junction structure. Its primary side is connected to a three-phase AC power grid, while its secondary side outputs multiple voltage levels, typically providing 27 voltage taps. By controlling the tap positions, precise adjustment of the rectified input voltage is achieved. The constant flux junction structure ensures the stability of the core flux during voltage regulation, avoiding magnetic saturation or over-excitation, and improving the reliability of the system's voltage regulation.

[0060] In conjunction with the multi-stage output of the autotransformer, the rectifier transformer employs a variable flux method for output voltage regulation. That is, as the input voltage level changes, the excitation state of the rectifier transformer adjusts accordingly, allowing the valve-side output voltage to automatically adapt to load changes, thereby achieving continuous or stepped output control capabilities. This control mechanism ensures that the rectifier system possesses excellent load responsiveness and output stability.

[0061] Furthermore, this invention features a specially designed independent circuit and magnetic circuit structure for the rectifier transformers, ensuring complete electromagnetic isolation between the two rectifier transformers. This avoids magnetic flux coupling and noise crosstalk, improving the system's anti-interference performance and electrical isolation level. This structure enhances the overall system's operational stability and safety in complex electromagnetic environments.

[0062] In summary, this invention achieves a rectifier system with high-quality DC output voltage, precise control, fast response, and safe and reliable operation by rationally configuring winding connection, phase shift angle, autotransformer multi-stage voltage regulation, variable flux control, and structural isolation. It is particularly suitable for high-power and high-precision DC power supply applications.

[0063] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A 24-pulse autotransformer and in-phase anti-parallel rectifier transformer topology, characterized in that, include: Two rectifier transformers, each comprising two transformer bodies, each comprising a set of high-voltage windings and a set of low-voltage windings, wherein the high-voltage windings are connected in a star configuration and the low-voltage windings are connected in a delta configuration, and the low-voltage windings are connected to the rectifier output circuit in a parallel configuration with the same phase but opposite direction. An autotransformer voltage regulator has its primary side connected to the AC power grid and its secondary side outputting multiple voltage levels, which are respectively supplied to the high-voltage side input of the rectifier transformer. The high-voltage windings of the two rectifier transformers are respectively set with different phase shift angles to form a phase difference combination with a preset angle, thereby achieving an equivalent twenty-four-pulse output. The autotransformer voltage regulator is a constant flux junction; The rectifier transformer uses a variable flux method to regulate voltage, and the output voltage on the valve side is automatically adjusted according to the change of the secondary voltage level of the autotransformer voltage regulator. The two rectifier transformers each have independent circuit and magnetic circuit structures, which are used to improve the electrical isolation capability and anti-interference performance of the system.

2. The structure according to claim 1, characterized in that, The two rectifier transformers are the first rectifier transformer and the second rectifier transformer. The high-voltage winding of the first rectifier transformer is set with a phase shift angle of +7.5° and -22.5°, and the high-voltage winding of the second rectifier transformer is set with a phase shift angle of +22.5° and -7.5°. The preset angle is 15°.

3. The structure according to claim 1, characterized in that, The low-voltage winding of the rectifier transformer includes two sets of windings connected in phase, connected by voltage superposition, and connected to the rectifier output terminal by anti-parallel connection.

4. The structure according to claim 1, characterized in that, The secondary output voltage of the autotransformer voltage regulator is a 27-level differential voltage, which is used to meet the output regulation requirements under different operating conditions.

5. The structure according to claim 1, characterized in that, The system also includes a temperature rise monitoring device, a voltage stabilizing module, and a short-circuit protection circuit to ensure the safety and reliability of system operation.

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