Voltage regulating device

Abstract

The present invention discloses a voltage regulating device. Among them, the device is connected between a three-phase AC voltage source and a DC-side device, and includes: a high-frequency signal injection module, a rectification module, a first input filtering module, a second input filtering module, and an output filtering module. The first input filtering module is connected to the three-phase AC voltage source, the first input filtering module is connected to the second input filtering module, the second input filtering module is connected to the rectification module, the first input filtering module is connected to the high-frequency signal injection module, the rectification module is connected to the DC-side device, the rectification module is connected to the high-frequency signal injection module, the rectification module is connected to the output filtering module, and the output filtering module is connected to the DC-side device. The present invention solves the technical problems that in the related art, when achieving the neutral point voltage balance of the output filtering module, the implementation time is relatively long and the voltage balance cannot be maintained.

Description

Technical Field

[0001] The present invention relates to the field of rectifiers, and more particularly, to a voltage regulating device. Background Art

[0002] The Vienna rectifier has the advantages of low voltage stress of power devices, low harmonic content of output voltage, low switching loss of power devices, high withstand voltage level, no shoot-through phenomenon of bridge arms, and no need to set dead zones. It is a conversion topology with high efficiency, high power density, and high reliability. Therefore, it is widely used in medium and high voltage and high power applications where power bi-directional flow is not required, such as motor drives, photovoltaic systems, wind power generation, high voltage direct current transmission, electric vehicle charging, communication power supplies, aviation power supplies, etc. As a three-level converter, due to some characteristics of its own topology, the Vienna rectifier will have a voltage imbalance between the upper and lower voltage-dividing capacitors during operation, that is, the midpoint potential is unbalanced. The voltage imbalance between the upper and lower voltage-dividing capacitors will cause the output voltage distortion of the converter and an increase in low-frequency harmonic content, especially the increase in even harmonics, which affects the system performance and poses a great challenge to the power supply safety of the grid side. However, in the related art, when achieving the voltage balance of the rectifier, there are technical problems of long implementation time and inability to maintain voltage balance.

[0003] In view of the above problems, no effective solution has been proposed yet. Summary of the Invention

[0004] Embodiments of the present invention provide a voltage regulating device to at least solve the technical problems of long implementation time and inability to maintain voltage balance when achieving the midpoint voltage balance of the output filtering module in the related art.

[0005] According to one aspect of an embodiment of the present invention, a voltage regulating device is provided, which is connected between a three-phase AC voltage source and a DC-side device, and includes: a high-frequency signal injection module, a rectification module, a first input filtering module, a second input filtering module, and an output filtering module. Wherein, the first input terminal, the second input terminal, and the third input terminal of the first input filtering module are respectively connected to the first phase, the second phase, and the third phase of the three-phase AC voltage source. The first output terminal, the second output terminal, and the third output terminal of the first input filtering module are respectively connected to the first input terminal, the second input terminal, and the third input terminal of the second input filtering module. The first output terminal, the second output terminal, and the third output terminal of the second input filtering module are respectively connected to the first input terminal, the second input terminal, and the third input terminal of the rectification module. One output terminal of the first input filtering module is connected to one input terminal of the high-frequency signal injection module through an inductor, and the other two output terminals of the first input filtering module are respectively connected to the other two input terminals of the high-frequency signal injection module. The first output terminal and the second output terminal of the rectification module are respectively connected to the first input terminal and the second input terminal of the DC-side device. The third output terminal of the rectification module is connected to the output terminal of the high-frequency signal injection module. The third output terminal of the rectification module is connected to the input terminal of the output filtering module. The first output terminal and the second output terminal of the output filtering module are respectively connected to the first input terminal and the second input terminal of the DC-side device.

[0006] Optionally, the first input filtering module includes: a first inductor, a second inductor, and a third inductor. Wherein, the first end of the first inductor, the first end of the second inductor, and the first end of the third inductor are respectively the first input terminal, the second input terminal, and the third input terminal of the first input filtering module. The second end of the first inductor, the second end of the second inductor, and the second end of the third inductor are respectively the first output terminal, the second output terminal, and the third output terminal of the first input filtering module.

[0007] Optionally, the second input filtering module includes: a fourth inductor, a fifth inductor, and a sixth inductor. Wherein, the first end of the fourth inductor, the first end of the fifth inductor, and the first end of the sixth inductor are respectively the first input terminal, the second input terminal, and the third input terminal of the second input filtering module. The second end of the fourth inductor, the second end of the fifth inductor, and the second end of the sixth inductor are respectively the first output terminal, the second output terminal, and the third output terminal of the second input filtering module.

[0008] Optionally, the output filtering module includes: a first capacitor and a second capacitor, wherein a first end of the first capacitor and a first end of the second capacitor are respectively a first output end and a second output end of the output filtering module, and a second end of the first capacitor is connected to a second end of the second capacitor to obtain point O, where point O is an input end of the output filtering module.

[0009] Optionally, the high-frequency signal injection module includes: a third capacitor, a fourth capacitor and a fifth capacitor, wherein a first end of the third capacitor, a first end of the fourth capacitor and a first end of the fifth capacitor are respectively a first input end, a second input end and a third input end of the high-frequency signal injection module, and a second end of the third capacitor, a second end of the fourth capacitor and a second end of the fifth capacitor are connected to obtain an output end of the high-frequency signal injection module.

[0010] Optionally, the rectification module includes a first rectification unit, a second rectification unit and a third rectification unit. A first end of the first rectification unit is connected to a first input end of the rectification module, a second end of the first rectification unit is connected to a first output end of the rectification module, a third end of the first rectification unit is connected to a third output end of the rectification module, a fourth end of the first rectification unit is connected to a second output end of the rectification module. A first end of the second rectification unit is connected to a second input end of the rectification module, a second end of the second rectification unit is connected to a first output end of the rectification module, a third end of the second rectification unit is connected to a third output end of the rectification module, a fourth end of the second rectification unit is connected to a second output end of the rectification module. A first end of the third rectification unit is connected to a second input end of the rectification module, a second end of the third rectification unit is connected to a first output end of the rectification module, a third end of the third rectification unit is connected to a third output end of the rectification module, a fourth end of the third rectification unit is connected to a second output end of the rectification module.

[0011] Optionally, the first rectification unit, the second rectification unit and the third rectification unit each include a first diode, a second diode, a first switching tube and a second switching tube, wherein a positive electrode of the first diode is a first end of the corresponding rectification unit, a negative electrode of the first diode is a second end of the corresponding rectification unit, a negative electrode of the second diode is connected to the positive electrode of the first diode, a positive electrode of the second diode is a fourth end of the corresponding rectification unit, a drain of the first switching tube is connected to the positive electrode of the first diode, a source of the first switching tube is connected to a source of the second switching tube, and a drain of the second switching tube is a third end of the corresponding rectification unit.

[0012] Optionally, the first rectifying unit, the second rectifying unit, and the third rectifying unit each include a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode, and a switching transistor. Among them, the negative electrode of the first diode is the second terminal of the corresponding rectifying unit, the negative electrode of the second diode is connected to the negative electrode of the fourth diode, the positive electrode of the second diode is the first terminal of the corresponding rectifying unit, the negative electrode of the third diode is connected to the positive electrode of the second diode, the positive electrode of the third diode is connected to the positive electrode of the fifth diode, the negative electrode of the fifth diode is the third terminal of the corresponding rectifying unit, the positive electrode of the fourth diode is connected to the negative electrode of the fifth diode, the source electrode of the switching transistor is connected to the negative electrode of the sixth diode, the drain electrode of the switching transistor is connected to the positive electrode of the first diode, and the positive electrode of the sixth diode is the fourth terminal of the corresponding rectifying unit.

[0013] Optionally, the switching transistors included in the rectifying module each include at least one of the following: an insulated gate bipolar transistor with an anti-parallel diode, a metal oxide semiconductor field effect transistor.

[0014] Optionally, it includes: the rectifying module is a Vienna rectifier.

[0015] In an embodiment of the present invention, a voltage regulating device is connected between a three-phase AC voltage source and a DC-side device. The device includes: a high-frequency signal injection module, a rectification module, a first input filtering module, a second input filtering module, and an output filtering module. Among them, the first input terminal, the second input terminal, and the third input terminal of the first input filtering module are respectively connected to the first phase, the second phase, and the third phase of the three-phase AC voltage source. The first output terminal, the second output terminal, and the third output terminal of the first input filtering module are respectively connected to the first input terminal, the second input terminal, and the third input terminal of the second input filtering module. The first output terminal, the second output terminal, and the third output terminal of the second input filtering module are respectively connected to the first input terminal, the second input terminal, and the third input terminal of the rectification module. One output terminal of the first input filtering module is connected to one input terminal of the high-frequency signal injection module through an inductor, and the other two output terminals of the first input filtering module are respectively connected to the other two input terminals of the high-frequency signal injection module. The first output terminal and the second output terminal of the rectification module are respectively connected to the first input terminal and the second input terminal of the DC-side device. The third output terminal of the rectification module is connected to the output terminal of the high-frequency signal injection module, and the third output terminal of the rectification module is connected to the input terminal of the output filtering module. The first output terminal and the second output terminal of the output filtering module are respectively connected to the first input terminal and the second input terminal of the DC-side device. Through the first input filtering module, the AC voltage input from the three-phase AC voltage source can be filtered and boosted; through the second input filtering module, the AC voltage input from the first input filtering module can be filtered and further boosted; through the rectification module, the AC voltage input from the second input filtering module is converted into a DC voltage; through the output filtering module, the voltages injected by the rectification module and the high-frequency signal injection module can be filtered to improve the quality of the voltage output to the DC-side device; through the voltage division effect of the high-frequency signal injection module and the inductor, the voltage between the first capacitor and the second capacitor in the output filtering module can be balanced, thereby achieving the technical effect of quickly achieving the midpoint voltage balance of the output filtering module and maintaining the voltage balance, and further solving the technical problem that the implementation time is long and the voltage balance cannot be maintained when realizing the midpoint voltage balance of the output filtering module in the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0017] Figure 1 is a schematic diagram of a voltage regulating device according to an embodiment of the present invention;

[0018] Figure 2 is a first schematic diagram of a voltage regulating device provided by an alternative embodiment of the present invention;

[0019] Figure 3 It is the second schematic diagram of the voltage regulation device provided by an alternative embodiment of the present invention;

[0020] Figure 4 It is the third schematic diagram of the voltage regulation device provided by an alternative embodiment of the present invention;

[0021] Figure 5 It is the fourth schematic diagram of the voltage regulation device provided by an alternative embodiment of the present invention;

[0022] Figure 6 It is the fifth schematic diagram of the voltage regulation device provided by an alternative embodiment of the present invention;

[0023] Figure 7 It is a schematic diagram of the relationship curve between voltage and time during the process of achieving voltage balance at the neutral point between the first capacitor and the second capacitor in the output filter module in the prior art;

[0024] Figure 8 It is a schematic diagram of the relationship curve between voltage and time during the process of achieving voltage balance at the neutral point between the first capacitor and the second capacitor in the output filter module provided by an alternative embodiment of the present invention. Detailed Embodiment

[0025] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order different from those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0027] Embodiment 1

[0028] According to an embodiment of the present invention, an embodiment of a voltage regulation device is provided.

[0029] Figure 1 is a schematic diagram of a voltage regulation device according to an embodiment of the present invention, as Figure 1 shown, the device is connected between a three-phase AC voltage source and a DC-side device, and includes: a high-frequency signal injection module, a rectification module, a first input filter module, a second input filter module, and an output filter module.

[0030] As an optional embodiment, the voltage regulation device includes: a high-frequency signal injection module, a rectification module, a first input filter module, a second input filter module, and an output filter module, wherein the first input terminal, the second input terminal, and the third input terminal of the first input filter module are respectively connected to the first phase, the second phase, and the third phase of the three-phase AC voltage source, the first output terminal, the second output terminal, and the third output terminal of the first input filter module are respectively connected to the first input terminal, the second input terminal, and the third input terminal of the second input filter module, the first output terminal, the second output terminal, and the third output terminal of the second input filter module are respectively connected to the first input terminal, the second input terminal, and the third input terminal of the rectification module, one output terminal of the first input filter module is connected to one input terminal of the high-frequency signal injection module through an inductor, the other two output terminals of the first input filter module are respectively connected to the other two input terminals of the high-frequency signal injection module, the first output terminal and the second output terminal of the rectification module are respectively connected to the first input terminal and the second input terminal of the DC-side device, the third output terminal of the rectification module is connected to the output terminal of the high-frequency signal injection module, the third output terminal of the rectification module is connected to the input terminal of the output filter module, and the first output terminal and the second output terminal of the output filter module are respectively connected to the first input terminal and the second input terminal of the DC-side device. Through this voltage regulation device, the midpoint voltage balance of the output filter module can be quickly achieved.

[0031] As an optional embodiment, the first input filter module includes: a first inductor, a second inductor, and a third inductor, wherein the first end of the first inductor, the first end of the second inductor, and the first end of the third inductor are respectively the first input terminal, the second input terminal, and the third input terminal of the first input filter module, and the second end of the first inductor, the second end of the second inductor, and the second end of the third inductor are respectively the first output terminal, the second output terminal, and the third output terminal of the first input filter module. Through the first inductor, the second inductor, and the third inductor in the first input filter module, the three-phase AC voltages input from the three-phase AC voltage source can be filtered and boosted respectively, so as to provide a better AC voltage for the second input filter module.

[0032] As an alternative embodiment, the second input filtering module includes: a fourth inductor, a fifth inductor, and a sixth inductor. Wherein, the first ends of the fourth inductor, the fifth inductor, and the sixth inductor are respectively the first input terminal, the second input terminal, and the third input terminal of the second input filtering module, and the second ends of the fourth inductor, the fifth inductor, and the sixth inductor are respectively the first output terminal, the second output terminal, and the third output terminal of the second input filtering module. Through the fourth inductor, the fifth inductor, and the sixth inductor in the second input filtering module, the three AC voltages input by the first input filtering module can be filtered and further boosted, so as to provide a better AC voltage for the rectification module.

[0033] As an alternative embodiment, the output filtering module includes: a first capacitor and a second capacitor. Wherein, the first ends of the first capacitor and the second capacitor are respectively the first output terminal and the second output terminal of the output filtering module, and the second end of the first capacitor is connected to the second end of the second capacitor to obtain point O, where point O is the input terminal of the output filtering module. Through the output filtering module, the voltages injected by the rectification module and the high-frequency signal injection module can be filtered, improving the quality of the voltage output to the DC-side device.

[0034] As an alternative embodiment, the high-frequency signal injection module includes: a third capacitor, a fourth capacitor, and a fifth capacitor. Wherein, the first ends of the third capacitor, the fourth capacitor, and the fifth capacitor are respectively the first input terminal, the second input terminal, and the third input terminal of the high-frequency signal injection module, and the second ends of the third capacitor, the fourth capacitor, and the fifth capacitor are connected to obtain the output terminal of the high-frequency signal injection module. Since one output terminal of the first input filtering module is connected to one input terminal of the high-frequency signal injection module through an inductor, the other two output terminals of the first input filtering module are respectively connected to the other two input terminals of the high-frequency signal injection module, and the inductor is a resonant inductor. Through this resonant inductor, a series resonance with twice the switching frequency can be formed, so as to quickly achieve the voltage balance between the first capacitor and the second capacitor in the output filtering module.

[0035] As an alternative embodiment, the rectification module includes a first rectification unit, a second rectification unit, and a third rectification unit. The first end of the first rectification unit is connected to the first input terminal of the rectification module, the second end of the first rectification unit is connected to the first output terminal of the rectification module, the third end of the first rectification unit is connected to the third output terminal of the rectification module, and the fourth end of the first rectification unit is connected to the second output terminal of the rectification module. The first end of the second rectification unit is connected to the second input terminal of the rectification module, the second end of the second rectification unit is connected to the first output terminal of the rectification module, the third end of the second rectification unit is connected to the third output terminal of the rectification module, and the fourth end of the second rectification unit is connected to the second output terminal of the rectification module. The first end of the third rectification unit is connected to the second input terminal of the rectification module, the second end of the third rectification unit is connected to the first output terminal of the rectification module, the third end of the third rectification unit is connected to the third output terminal of the rectification module, and the fourth end of the third rectification unit is connected to the second output terminal of the rectification module. Through the first rectification unit, the second rectification unit, and the third rectification unit in the rectification module, the effect of voltage division can be achieved, and the AC voltage input by the second input filter module can be converted into a DC voltage.

[0036] As an alternative embodiment, the first rectification unit, the second rectification unit, and the third rectification unit each include a first diode, a second diode, a first switching tube, and a second switching tube. Among them, the positive electrode of the first diode is the first end of the corresponding rectification unit, the negative electrode of the first diode is the second end of the corresponding rectification unit, the negative electrode of the second diode is connected to the positive electrode of the first diode, the positive electrode of the second diode is the fourth end of the corresponding rectification unit, the drain of the first switching tube is connected to the positive electrode of the first diode, the source of the first switching tube is connected to the source of the second switching tube, and the drain of the second switching tube is the third end of the corresponding rectification unit. By opening and closing the diodes and switching tubes in the rectification unit, the effect of voltage division can be achieved. Combining with the high-frequency signal injection module and the inductor, it can ensure that the voltage balance of the neutral point of the output filter module is quickly achieved and the voltage balance state can be maintained.

[0037] As an alternative embodiment, the first rectification unit, the second rectification unit, and the third rectification unit each include a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode, and a switching transistor. Among them, the negative electrode of the first diode is the second terminal of the corresponding rectification unit, the negative electrode of the second diode is connected to the negative electrode of the fourth diode, the positive electrode of the second diode is the first terminal of the corresponding rectification unit, the negative electrode of the third diode is connected to the positive electrode of the second diode, the positive electrode of the third diode is connected to the positive electrode of the fifth diode, the negative electrode of the fifth diode is the third terminal of the corresponding rectification unit, the positive electrode of the fourth diode is connected to the negative electrode of the fifth diode, the source electrode of the switching transistor is connected to the negative electrode of the sixth diode, the drain electrode of the switching transistor is connected to the positive electrode of the first diode, and the positive electrode of the sixth diode is the fourth terminal of the corresponding rectification unit. By opening and closing the diodes and the switching transistor in the rectification unit, a voltage division effect can be achieved. Combining with the high-frequency signal injection module and the inductor can ensure that the voltage balance of the neutral point of the output filter module is quickly achieved and the voltage balance state can be maintained.

[0038] As an alternative embodiment, the switching transistors included in the rectification module each include at least one of the following: an insulated gate bipolar transistor with an anti-parallel diode, a metal oxide semiconductor field effect transistor. The insulated gate bipolar transistor with an anti-parallel diode and the metal oxide semiconductor field effect transistor have good performance. Using such transistors as switches can ensure that the rectifier has better performance.

[0039] As an alternative embodiment, the rectifier is a Vienna rectifier. The Vienna rectifier is a pulse width modulation rectifier that can receive a three-phase AC power supply and is also a power factor correction circuit. The Vienna rectifier has the advantages of low complexity and low implementation cost. Therefore, when applied in a voltage regulation device, it can make the voltage regulation device have better performance.

[0040] Based on the above embodiments and alternative embodiments, an alternative implementation manner is provided, which is specifically described below.

[0041] In the related art, when achieving the voltage balance between the first capacitor and the second capacitor in the output filter module, there are technical problems of long implementation time and inability to maintain the voltage balance.

[0042] In view of this, an alternative implementation manner of the present invention provides a voltage regulation device that can quickly achieve the voltage balance of the neutral point of the output filter module and can maintain the voltage balance state for a period of time.

[0043] Figure 1 is a schematic diagram of a voltage regulation device according to an embodiment of the present invention, Figure 1In the figure: The three-phase AC voltage is equivalent to the three-phase AC voltage source in the above text. ia, ib, and ic are the currents flowing through the second input filtering module respectively. Lr is equivalent to the inductor in the above text. The DC side is equivalent to the DC side device in the above text. As Figure 1 shown, the first input terminal, the second input terminal, and the third input terminal of the first input filtering module are respectively connected to the first phase, the second phase, and the third phase of the three-phase AC voltage source. The first output terminal, the second output terminal, and the third output terminal of the first input filtering module are respectively connected to the first input terminal, the second input terminal, and the third input terminal of the second input filtering module. The first output terminal, the second output terminal, and the third output terminal of the second input filtering module are respectively connected to the first input terminal, the second input terminal, and the third input terminal of the rectifying module. One output terminal of the first input filtering module is connected to one input terminal of the high-frequency signal injection module through an inductor. The other two output terminals of the first input filtering module are respectively connected to the other two input terminals of the high-frequency signal injection module. The first output terminal and the second output terminal of the rectifying module are respectively connected to the first input terminal and the second input terminal of the DC side device. The third output terminal of the rectifying module is connected to the output terminal of the high-frequency signal injection module. The third output terminal of the rectifying module is connected to the input terminal of the output filtering module. The first output terminal and the second output terminal of the output filtering module are respectively connected to the first input terminal and the second input terminal of the DC side device.

[0044] Figure 2 Figure 1 is the first schematic diagram of the voltage regulating device provided by an optional embodiment of the present invention. Figure 2 In the figure: The three-phase AC voltage is equivalent to the three-phase AC voltage source in the above text. Lga is equivalent to the first inductor in the above text. Lgb is equivalent to the second inductor in the above text. Lgc is equivalent to the third inductor in the above text. La is equivalent to the fourth inductor in the above text. Lb is equivalent to the fifth inductor in the above text. Lc is equivalent to the sixth inductor in the above text. ia is the current flowing through La. ib is the current flowing through Lb. ic is the current flowing through Lc. C1 is equivalent to the first capacitor in the above text. C2 is equivalent to the second capacitor in the above text. The DC side is equivalent to the DC side device in the above text. Lr is equivalent to the inductor in the above text. Ca is equivalent to the third capacitor in the above text. Cb is equivalent to the fourth capacitor in the above text. Cc is equivalent to the fifth capacitor in the above text. The high-frequency signal injection device includes Ca, Cb, and Cc. As Figure 2As shown, the first ends of the first inductor, the second inductor, and the third inductor are respectively the first input terminal, the second input terminal, and the third input terminal of the first input filtering module, and the second ends of the first inductor, the second inductor, and the third inductor are respectively the first output terminal, the second output terminal, and the third output terminal of the first input filtering module. The first ends of the fourth inductor, the fifth inductor, and the sixth inductor are respectively the first input terminal, the second input terminal, and the third input terminal of the second input filtering module, and the second ends of the fourth inductor, the fifth inductor, and the sixth inductor are respectively the first output terminal, the second output terminal, and the third output terminal of the second input filtering module. The first ends of the first capacitor and the second capacitor are respectively the first output terminal and the second output terminal of the output filtering module, and the second end of the first capacitor is connected to the second end of the second capacitor to obtain point O, where point O is the input terminal of the output filtering module. The first ends of the third capacitor, the fourth capacitor, and the fifth capacitor are respectively the first input terminal, the second input terminal, and the third input terminal of the high-frequency signal injection module, and the second ends of the third capacitor, the fourth capacitor, and the fifth capacitor are connected to obtain the output terminal of the high-frequency signal injection module. The first output terminal of the first input filtering module is connected to the first input terminal of the high-frequency signal injection module through an inductor, and the second output terminal and the third output terminal of the first input filtering module are respectively connected to the second input terminal and the third input terminal of the high-frequency signal injection module. It should be noted that the parameters of the inductor Lr should satisfy:

[0045]

[0046] x = a, b, c;

[0047] fc is the carrier frequency.

[0048] Figure 3 is the second schematic diagram of the voltage regulating device provided by an alternative embodiment of the present invention, Figure 3 wherein: the three-phase AC voltage is equivalent to the three-phase AC voltage source in the above text, Lga is equivalent to the first inductor in the above text, Lgb is equivalent to the second inductor in the above text, Lgc is equivalent to the third inductor in the above text, La is equivalent to the fourth inductor in the above text, Lb is equivalent to the fifth inductor in the above text, Lc is equivalent to the sixth inductor in the above text, ia is the current flowing through La, ib is the current flowing through Lb, ic is the current flowing through Lc, C1 is equivalent to the first capacitor in the above text, C2 is equivalent to the second capacitor in the above text, the DC side is equivalent to the DC side device in the above text, Lr is equivalent to the inductor in the above text, Ca is equivalent to the third capacitor in the above text, Cb is equivalent to the fourth capacitor in the above text, Cc is equivalent to the fifth capacitor in the above text, and the high-frequency signal injection device includes Ca, Cb, and Cc. As Figure 3As shown in the figure, the first ends of the first inductor, the second inductor, and the third inductor are respectively the first input terminal, the second input terminal, and the third input terminal of the first input filtering module, and the second ends of the first inductor, the second inductor, and the third inductor are respectively the first output terminal, the second output terminal, and the third output terminal of the first input filtering module. The first ends of the fourth inductor, the fifth inductor, and the sixth inductor are respectively the first input terminal, the second input terminal, and the third input terminal of the second input filtering module, and the second ends of the fourth inductor, the fifth inductor, and the sixth inductor are respectively the first output terminal, the second output terminal, and the third output terminal of the second input filtering module. The first ends of the first capacitor and the second capacitor are respectively the first output terminal and the second output terminal of the output filtering module. The second end of the first capacitor is connected to the second end of the second capacitor to obtain point O, where point O is the input terminal of the output filtering module. The first ends of the third capacitor, the fourth capacitor, and the fifth capacitor are respectively the first input terminal, the second input terminal, and the third input terminal of the high-frequency signal injection module. The second ends of the third capacitor, the fourth capacitor, and the fifth capacitor are connected to obtain the output terminal of the high-frequency signal injection module. The second output terminal of the first input filtering module is connected to the second input terminal of the high-frequency signal injection module through an inductor. The first output terminal and the third output terminal of the first input filtering module are respectively connected to the first input terminal and the third input terminal of the high-frequency signal injection module. It should be noted that the parameters of inductor Lr should satisfy:

[0049]

[0050] x = a, b, c;

[0051] fc is the carrier frequency.

[0052] Figure 4 is the third schematic diagram of the voltage regulating device provided by an alternative embodiment of the present invention, Figure 4 wherein: the three-phase AC voltage is equivalent to the three-phase AC voltage source in the above text, Lga is equivalent to the first inductor in the above text, Lgb is equivalent to the second inductor in the above text, Lgc is equivalent to the third inductor in the above text, La is equivalent to the fourth inductor in the above text, Lb is equivalent to the fifth inductor in the above text, Lc is equivalent to the sixth inductor in the above text, ia is the current flowing through La, ib is the current flowing through Lb, ic is the current flowing through Lc, C1 is equivalent to the first capacitor in the above text, C2 is equivalent to the second capacitor in the above text, the DC side is equivalent to the DC side device in the above text, Lr is equivalent to the inductor in the above text, Ca is equivalent to the third capacitor in the above text, Cb is equivalent to the fourth capacitor in the above text, Cc is equivalent to the fifth capacitor in the above text, and the high-frequency signal injection device includes Ca, Cb, and Cc. As Figure 4As shown, the first ends of the first inductor, the second inductor, and the third inductor are respectively the first input terminal, the second input terminal, and the third input terminal of the first input filtering module, and the second ends of the first inductor, the second inductor, and the third inductor are respectively the first output terminal, the second output terminal, and the third output terminal of the first input filtering module. The first ends of the fourth inductor, the fifth inductor, and the sixth inductor are respectively the first input terminal, the second input terminal, and the third input terminal of the second input filtering module, and the second ends of the fourth inductor, the fifth inductor, and the sixth inductor are respectively the first output terminal, the second output terminal, and the third output terminal of the second input filtering module. The first ends of the first capacitor and the second capacitor are respectively the first output terminal and the second output terminal of the output filtering module. The second end of the first capacitor is connected to the second end of the second capacitor to obtain point O, where point O is the input terminal of the output filtering module. The first ends of the third capacitor, the fourth capacitor, and the fifth capacitor are respectively the first input terminal, the second input terminal, and the third input terminal of the high-frequency signal injection module. The second ends of the third capacitor, the fourth capacitor, and the fifth capacitor are connected to obtain the output terminal of the high-frequency signal injection module. The third output terminal of the first input filtering module is connected to the third input terminal of the high-frequency signal injection module through an inductor. The first output terminal and the second output terminal of the first input filtering module are respectively connected to the first input terminal and the second input terminal of the high-frequency signal injection module. It should be noted that the parameters of inductor Lr should satisfy:

[0053]

[0054] x = a, b, c;

[0055] fc is the carrier frequency.

[0056] Figure 5 is the fourth schematic diagram of the voltage regulating device provided by an alternative embodiment of the present invention, Figure 5In the figure: The three-phase AC voltage is equivalent to the three-phase AC voltage source in the above text. Lga is equivalent to the first inductor in the above text. Lgb is equivalent to the second inductor in the above text. Lgc is equivalent to the third inductor in the above text. La is equivalent to the fourth inductor in the above text. Lb is equivalent to the fifth inductor in the above text. Lc is equivalent to the sixth inductor in the above text. ia is the current flowing through La. ib is the current flowing through Lb. ic is the current flowing through Lc. C1 is equivalent to the first capacitor in the above text. C2 is equivalent to the second capacitor in the above text. The DC side is equivalent to the DC side device in the above text. Lr is equivalent to the inductor in the above text. Ca is equivalent to the third capacitor in the above text. Cb is equivalent to the fourth capacitor in the above text. Cc is equivalent to the fifth capacitor in the above text. The high-frequency signal injection device includes Ca, Cb, and Cc. The first rectification unit includes D1, D2, S1, and S2. The second rectification unit includes D3, D4, S3, and S4. The third rectification unit includes D5, D6, S5, and S6. D1 is equivalent to the first diode in the first rectification unit in the above text. D2 is equivalent to the second diode in the first rectification unit in the above text. S1 is equivalent to the first switching transistor in the first rectification unit in the above text. S2 is equivalent to the second switching transistor in the first rectification unit in the above text. D3 is equivalent to the first diode in the second rectification unit in the above text. D4 is equivalent to the second diode in the second rectification unit in the above text. S3 is equivalent to the first switching transistor in the second rectification unit in the above text. S4 is equivalent to the second switching transistor in the second rectification unit in the above text. D5 is equivalent to the first diode in the third rectification unit in the above text. D6 is equivalent to the second diode in the third rectification unit in the above text. S5 is equivalent to the first switching transistor in the third rectification unit in the above text. S6 is equivalent to the second switching transistor in the third rectification unit in the above text. As Figure 5 shown, the positive electrode of the first diode is the first end of the corresponding rectification unit, the negative electrode of the first diode is the second end of the corresponding rectification unit, the negative electrode of the second diode is connected to the positive electrode of the first diode, the positive electrode of the second diode is the fourth end of the corresponding rectification unit, the drain of the first switching transistor is connected to the positive electrode of the first diode, the source of the first switching transistor is connected to the source of the second switching transistor, and the drain of the second switching transistor is the third end of the corresponding rectification unit.

[0057] Figure 6 This is the fifth schematic diagram of the voltage regulation device provided by an alternative embodiment of the present invention. Figure 6Among them, the three-phase AC voltage is equivalent to the three-phase AC voltage source in the above text, Lga is equivalent to the first inductor in the above text, Lgb is equivalent to the second inductor in the above text, Lgc is equivalent to the third inductor in the above text, La is equivalent to the fourth inductor in the above text, Lb is equivalent to the fifth inductor in the above text, Lc is equivalent to the sixth inductor in the above text, ia is the current flowing through La, ib is the current flowing through Lb, ic is the current flowing through Lc, C1 is equivalent to the first capacitor in the above text, C2 is equivalent to the second capacitor in the above text, the DC side is equivalent to the DC side device in the above text, Lr is equivalent to the inductor in the above text, Ca is equivalent to the third capacitor in the above text, Cb is equivalent to the fourth capacitor in the above text, Cc is equivalent to the fifth capacitor in the above text, the high-frequency signal injection device includes Ca, Cb and Cc, the first rectification unit includes D1, D2, D3, D4, D5, D6 and S1, the second rectification unit includes D7, D8, D9, D10, D11, D12 and S2, the third rectification unit includes D13, D14, D15, D16, D17, D18 and S3, D1 is equivalent to the first diode in the first rectification unit in the above text, D2 is equivalent to the second diode in the first rectification unit in the above text, D3 is equivalent to the third diode in the first rectification unit in the above text, D4 is equivalent to the fourth diode in the first rectification unit in the above text, D5 is equivalent to the fifth diode in the first rectification unit in the above text, D6 is equivalent to the sixth diode in the first rectification unit in the above text, S1 is equivalent to the switching tube in the first rectification unit in the above text, D7 is equivalent to the first diode in the second rectification unit in the above text, D8 is equivalent to the second diode in the second rectification unit in the above text, D9 is equivalent to the third diode in the second rectification unit in the above text, D10 is equivalent to the fourth diode in the second rectification unit in the above text, D11 is equivalent to the fifth diode in the second rectification unit in the above text, D12 is equivalent to the sixth diode in the second rectification unit in the above text, S2 is equivalent to the switching tube in the second rectification unit in the above text, D13 is equivalent to the first diode in the third rectification unit in the above text, D14 is equivalent to the second diode in the third rectification unit in the above text, D15 is equivalent to the third diode in the third rectification unit in the above text, D16 is equivalent to the fourth diode in the third rectification unit in the above text, D17 is equivalent to the fifth diode in the third rectification unit in the above text, D18 is equivalent to the sixth diode in the third rectification unit in the above text, S3 is equivalent to the switching tube in the third rectification unit in the above text, such as Figure 6As shown, the negative electrode of the first diode is the second end of the corresponding rectifying unit. The negative electrode of the second diode is connected to the negative electrode of the fourth diode. The positive electrode of the second diode is the first end of the corresponding rectifying unit. The negative electrode of the third diode is connected to the positive electrode of the second diode. The positive electrode of the third diode is connected to the positive electrode of the fifth diode. The negative electrode of the fifth diode is the third end of the corresponding rectifying unit. The positive electrode of the fourth diode is connected to the negative electrode of the fifth diode. The source electrode of the switching transistor is connected to the negative electrode of the sixth diode. The drain electrode of the switching transistor is connected to the positive electrode of the first diode. The positive electrode of the sixth diode is the fourth end of the corresponding rectifying unit.

[0058] Figure 7 It is a schematic diagram of the relationship curve between voltage and time during the process of achieving voltage balance at the neutral point between the first capacitor and the second capacitor in the output filtering module in the prior art.

[0059] Figure 8 It is a schematic diagram of the relationship curve between voltage and time during the process of achieving voltage balance at the neutral point between the first capacitor and the second capacitor in the output filtering module provided by an alternative embodiment of the present invention.

[0060] As Figure 7 and Figure 8 shown, the time required for the voltage regulating device in the present invention to achieve voltage balance at the neutral point between the first capacitor and the second capacitor in the output filtering module is shortened to 20% or even more of the prior art, and the voltage balance at the neutral point of the rectifier can be achieved more quickly.

[0061] Through the above alternative embodiments, at least the following beneficial effects can be achieved:

[0062] (1) Achieve voltage balance at the neutral point of the rectifier quickly;

[0063] (2) Maintain the voltage balance state at the neutral point for a period of time.

[0064] It should be noted that for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0065] Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present invention, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions for causing a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods of the various embodiments of the present invention.

[0066] In the embodiments provided in the present application, it should be understood that the disclosed technical content can be implemented in other ways.

[0067] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A voltage regulating device is connected between a three-phase AC voltage source and a DC-side device, characterized in that, Including: a high-frequency signal injection module, a rectification module, a first input filtering module, a second input filtering module, and an output filtering module, where the first input terminal, the second input terminal, and the third input terminal of the first input filtering module are respectively connected to the first phase, the second phase, and the third phase of the three-phase AC voltage source, the first output terminal, the second output terminal, and the third output terminal of the first input filtering module are respectively connected to the first input terminal, the second input terminal, and the third input terminal of the second input filtering module, the first output terminal, the second output terminal, and the third output terminal of the second input filtering module are respectively connected to the first input terminal, the second input terminal, and the third input terminal of the rectification module, one output terminal of the first input filtering module is connected to one input terminal of the high-frequency signal injection module through an inductor, and the other two output terminals of the first input filtering module are respectively connected to the other two input terminals of the high-frequency signal injection module, the first output terminal and the second output terminal of the rectification module are respectively connected to the first input terminal and the second input terminal of the DC-side device, the third output terminal of the rectification module is connected to the output terminal of the high-frequency signal injection module, the third output terminal of the rectification module is connected to the input terminal of the output filtering module, the first output terminal and the second output terminal of the output filtering module are respectively connected to the first input terminal and the second input terminal of the DC-side device; wherein, the high-frequency signal injection module includes: a third capacitor, a fourth capacitor, and a fifth capacitor, where the first end of the third capacitor, the first end of the fourth capacitor, and the first end of the fifth capacitor are respectively the first input terminal, the second input terminal, and the third input terminal of the high-frequency signal injection module, the second ends of the third capacitor, the fourth capacitor, and the fifth capacitor are connected to obtain the output terminal of the high-frequency signal injection module.

2. The device according to claim 1, characterized in that, The first input filtering module includes: a first inductor, a second inductor, and a third inductor, where the first end of the first inductor, the first end of the second inductor, and the first end of the third inductor are respectively the first input terminal, the second input terminal, and the third input terminal of the first input filtering module, the second ends of the first inductor, the second inductor, and the third inductor are respectively the first output terminal, the second output terminal, and the third output terminal of the first input filtering module.

3. The device according to claim 1, characterized in that, The second input filtering module includes: a fourth inductor, a fifth inductor, and a sixth inductor, where the first end of the fourth inductor, the first end of the fifth inductor, and the first end of the sixth inductor are respectively the first input terminal, the second input terminal, and the third input terminal of the second input filtering module, the second ends of the fourth inductor, the fifth inductor, and the sixth inductor are respectively the first output terminal, the second output terminal, and the third output terminal of the second input filtering module.

4. The device according to claim 1, wherein The output filtering module includes: a first capacitor and a second capacitor, where The first ends of the first capacitor and the second capacitor are respectively the first output end and the second output end of the output filtering module. The second ends of the first capacitor and the second capacitor are connected to obtain point O, where point O is the input end of the output filtering module.

5. The device according to claim 1, characterized in that, The rectifying module includes a first rectifying unit, a second rectifying unit, and a third rectifying unit. The first end of the first rectifying unit is connected to the first input end of the rectifying module, the second end of the first rectifying unit is connected to the first output end of the rectifying module, the third end of the first rectifying unit is connected to the third output end of the rectifying module, and the fourth end of the first rectifying unit is connected to the second output end of the rectifying module. The first end of the second rectifying unit is connected to the second input end of the rectifying module, the second end of the second rectifying unit is connected to the first output end of the rectifying module, the third end of the second rectifying unit is connected to the third output end of the rectifying module, and the fourth end of the second rectifying unit is connected to the second output end of the rectifying module. The first end of the third rectifying unit is connected to the second input end of the rectifying module, the second end of the third rectifying unit is connected to the first output end of the rectifying module, the third end of the third rectifying unit is connected to the third output end of the rectifying module, and the fourth end of the third rectifying unit is connected to the second output end of the rectifying module.

6. The device according to claim 5, characterized in that The first rectifying unit, the second rectifying unit, and the third rectifying unit each include a first diode, a second diode, a first switching tube, and a second switching tube, where the positive electrode of the first diode is the first end of the corresponding rectifying unit, the negative electrode of the first diode is the second end of the corresponding rectifying unit, the negative electrode of the second diode is connected to the positive electrode of the first diode, the positive electrode of the second diode is the fourth end of the corresponding rectifying unit, the drain of the first switching tube is connected to the positive electrode of the first diode, the source of the first switching tube is connected to the source of the second switching tube, and the drain of the second switching tube is the third end of the corresponding rectifying unit.

7. The device according to claim 5, characterized in that, The first rectifying unit, the second rectifying unit, and the third rectifying unit each include a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode, and a switching tube, where the negative electrode of the first diode is the second end of the corresponding rectifying unit, the negative electrode of the second diode is connected to the negative electrode of the fourth diode, the positive electrode of the second diode is the first end of the corresponding rectifying unit, the negative electrode of the third diode is connected to the positive electrode of the second diode, the positive electrode of the third diode is connected to the positive electrode of the fifth diode, the negative electrode of the fifth diode is the third end of the corresponding rectifying unit, the positive electrode of the fourth diode is connected to the negative electrode of the fifth diode, the source of the switching tube is connected to the negative electrode of the sixth diode, the drain of the switching tube is connected to the positive electrode of the first diode, and the positive electrode of the sixth diode is the fourth end of the corresponding rectifying unit.

8. The device according to claim 6 or 7, characterized in that The switching tubes included in the rectification module all include at least one of the following: insulated gate bipolar transistor with anti-parallel diode, metal oxide semiconductor field effect transistor.

9. The device according to claim 1, characterized in that, including: The rectification module is a Vienna rectifier.

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