Parallel-series dual-purpose harmonic suppression device, active filter and rectifier

Abstract

The utility model discloses a parallel-series dual-purpose harmonic suppression device, an active filter and a rectifier, relates to the technical field of power electronics, is used for solving the defects of a three-level APF (Active Power Filter) scheme, and provides a driving unit aiming at the problem caused by the use of excessive power devices in the three-level APF scheme. Based on a topological structure in which double silicon carbide IGBTs are connected in parallel, single-tube overcurrent can be effectively reduced, so that the heating value of a power device is reduced, and the heating problem caused by using a two-level scheme in a high-power scene is solved. Moreover, the driving unit formed by connecting the two silicon carbide IGBTs in parallel can also effectively reduce the switching loss requirement of a single tube, so as to meet the switching loss of a hardware topological structure of a two-level scheme in an actual application scene. On the basis, the driving unit can adopt a hardware topological structure of a two-level scheme, and the number of IGBT tubes used in the driving unit is reduced. Therefore, a series of problems caused by excessive use of the IGBT tubes are solved.

Description

Technical Field

[0001] This utility model relates to the field of power electronics, and in particular to a dual-purpose harmonic mitigation device, an active filter, and a rectifier. Background Technology

[0002] Currently, active power filter (APF) devices are mainly developing towards smaller size and modularity, but this also brings problems with the overcurrent capacity of power devices and overall heat generation in APFs. In related technologies, a common approach is to reduce switching losses by adding an intermediate voltage level, i.e., proposing a three-level scheme, distinct from the two-level scheme, to overcome the aforementioned problems. In the process of developing this application, the inventors discovered that the prior art has at least the following problems:

[0003] Three-level schemes require the use of more Insulated-Gate Bipolar Transistors (IGBTs). For example, a common three-level APF requires 18 IGBTs. This excessive use of IGBTs due to the three-level scheme leads to a series of problems, including excessive circuit area, complex control logic, complex protection logic, and high cost, ultimately resulting in long-term product instability.

[0004] Therefore, those skilled in the art urgently need a driving unit to solve a series of problems caused by using too many IGBTs in a three-level APF scheme. Utility Model Content

[0005] The purpose of this invention is to provide a dual-purpose harmonic mitigation device, active filter, and rectifier that can be used in parallel and series.

[0006] To solve the above-mentioned technical problems, this utility model provides a driving unit, including: multiple sets of silicon carbide IGBT transistors;

[0007] Each group of silicon carbide IGBTs consists of two silicon carbide IGBTs connected in parallel, and the layout and wiring of the two silicon carbide IGBTs in the same group are symmetrical.

[0008] The silicon carbide IGBTs in each group are connected by a two-level hardware topology.

[0009] In one possible embodiment, the silicon carbide IGBTs are arranged in a line.

[0010] To solve the above-mentioned technical problems, this utility model also provides a parallel-series dual-purpose harmonic mitigation device, including: the driving unit as described above, as well as a pre-charging unit, an energy storage unit, a control unit and a sampling unit;

[0011] Wherein, the input terminal of the pre-charging unit serves as the input terminal of the parallel-series dual-purpose harmonic mitigation device, the output terminal of the energy storage unit serves as the output terminal of the parallel-series dual-purpose harmonic mitigation device, and the input terminal of the sampling unit serves as the sampling input terminal of the parallel-series dual-purpose harmonic mitigation device;

[0012] The output terminal of the pre-charge unit is connected to the power supply terminal of the control unit and the input terminal of the energy storage unit, respectively.

[0013] The input terminal of the drive unit is connected to the energy storage unit, the output terminal of the drive unit is connected to the input terminal of the pre-charge unit, and the controlled terminal of the drive unit is connected to the control unit.

[0014] The control unit is connected to the output terminal of the sampling unit and is used to control the switching state of the silicon carbide IGBT in the driving unit according to the current value collected by the sampling unit.

[0015] In one possible embodiment, it further includes: a filtering unit and an extended capacitor board;

[0016] The filter unit is disposed between the output terminal of the pre-charge unit and the power supply terminal of the control unit; the extended capacitor plate is connected in parallel between the output terminals of the energy storage unit.

[0017] In one possible embodiment, the pre-charging unit, the energy storage unit, the control unit, the sampling unit, and the filtering unit are disposed on the motherboard;

[0018] The drive unit is mounted on a heat sink aluminum plate for the switching transistors, which is independent of the motherboard.

[0019] The heat sink aluminum plate of the switching transistor is fixedly connected to the motherboard.

[0020] In one possible embodiment, it further includes: a spacer column;

[0021] The heat dissipation aluminum plate of the switching tube is provided with through holes. The shape and size of the through holes are adapted to the cross-section of the spacer column. The spacer column is fixedly connected to the heat dissipation aluminum plate of the switching tube through the through holes.

[0022] The motherboard is fixedly connected to the spacer post by screws.

[0023] In one possible embodiment, it further includes: a first heat dissipation device and a second heat dissipation device;

[0024] The first heat dissipation device is fixedly connected to the heat dissipation aluminum plate of the switching tube through the spacer column;

[0025] The second heat dissipation device is fixedly connected to the motherboard via the spacer post.

[0026] In one possible embodiment, both the first heat dissipation device and the second heat dissipation device include: a heat dissipation aluminum plate and a heat dissipation fin;

[0027] The second heat dissipation device further includes a thermally conductive silicone pad, which is in physical contact with the filter unit.

[0028] To solve the above-mentioned technical problems, this utility model also provides an active filter, including: the parallel-series dual-purpose harmonic control device as described above;

[0029] The dual-purpose harmonic mitigation device is connected in parallel between the power grid and the load.

[0030] The sampling input terminal of the dual-purpose harmonic mitigation device is connected in the path between the power grid and the load, located at any position between the power grid and the parallel connection point of the dual-purpose harmonic mitigation device.

[0031] To solve the above-mentioned technical problems, this utility model also provides a rectifier, including: the parallel and series dual-purpose harmonic mitigation device as described above;

[0032] The parallel-series dual-purpose harmonic mitigation device is connected in series between the power grid and the load. Its input terminal is connected to the power grid, and its output terminal is connected to the load via a DC bus.

[0033] This application provides a driving unit that uses silicon carbide IGBTs as switching transistors, with the switches connected in parallel. Based on this parallel topology of two silicon carbide IGBTs, the overcurrent of each switching transistor in the APF device can be effectively reduced, thereby significantly reducing the heat generation of the power devices in the APF device and solving the heat generation problem of switching transistors using two-level schemes in high-power scenarios. Simultaneously, the parallel dual silicon carbide IGBT driving unit provided in this application can also effectively reduce the switching loss requirements of a single transistor, allowing the driving unit to meet the switching loss requirements of practical application scenarios using a two-level hardware topology.

[0034] In summary, the driving unit provided in this application uses silicon carbide IGBTs as switching transistors to address the switching loss problem of the two-level scheme in high-power scenarios, and employs a dual-transistor parallel connection scheme to also address the switching loss problem of the two-level scheme in high-power scenarios. This allows for the use of a two-level scheme as the topology of the driving unit, significantly reducing the number of IGBTs required. Typically, the number can be reduced to 2 / 3 of that of a three-level scheme. That is, for a three-level scheme that originally required 18 IGBTs, this application only requires 12 IGBTs to meet the same application requirements. This effectively solves a series of problems caused by using too many IGBT devices, such as large circuit area occupation, complex control logic, complex protection logic, and high cost. Attached Figure Description

[0035] To more clearly illustrate the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 A circuit schematic diagram of a driving unit provided by this utility model;

[0037] Figure 2 A structural diagram of a parallel-to-serial dual-purpose harmonic mitigation device provided by this utility model;

[0038] Figure 3 A functional block diagram of a parallel-series dual-purpose harmonic mitigation device provided by this utility model;

[0039] Figure 4 Exploded view of the structure of a parallel-to-serial dual-purpose harmonic mitigation device provided by this utility model;

[0040] Figure 5 A schematic diagram illustrating the application of a parallel-series dual-purpose harmonic mitigation device as an active filter, provided by this utility model.

[0041] Figure 6 A schematic diagram illustrating the application of a parallel-to-series dual-purpose harmonic mitigation device as a rectifier, provided by this utility model;

[0042] In this design, 1 is the motherboard, 2 is the heat sink aluminum plate for the switching transistor, 3 is a through hole, 4 is a spacer post, 5 is the first heat sink, 51 is the first heat sink aluminum plate, 52 is the first heat sink fin, 6 is the second heat sink, 61 is the second heat sink aluminum plate, 62 is the second heat sink fin, and 63 is a thermally conductive silicone pad. Detailed Implementation

[0043] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0044] The core of this utility model is to provide a dual-purpose harmonic mitigation device (parallel and series), an active filter, and a rectifier.

[0045] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] In related technologies, active power filters (APFs) are gradually developing towards smaller size and modularity. However, the focus is usually on the compensation capability of APFs, which is generally described by the compensable current capacity. The larger the target power to be compensated, the larger the current required for compensation. Due to the excessive operating power of the power devices in APFs, the industry has proposed adding an intermediate level to the original two-level scheme to reduce the switching losses of the power devices in APFs, i.e., a three-level scheme.

[0047] However, the three-level scheme requires more Insulated-Gate Bipolar Transistors (IGBTs) compared to the two-level scheme. For example, a common three-level APF requires 18 IGBTs. This excessive use of IGBTs due to the three-level scheme leads to a series of problems, such as excessive circuit area, complex control logic, complex protection logic, and high cost, resulting in long-term product instability.

[0048] To address the aforementioned problems, this application provides a driving unit, such as... Figure 1 As shown, it includes: multiple sets of silicon carbide IGBT transistors.

[0049] Each group of silicon carbide IGBTs consists of two silicon carbide IGBTs connected in parallel, and the layout and routing of the two silicon carbide IGBTs in the same group are symmetrical. The silicon carbide IGBTs in each group are connected by a two-level hardware topology.

[0050] It should be noted that the aforementioned driving unit uses silicon carbide IGBTs to meet the switching loss requirements of high-power scenarios in practical applications. Furthermore, silicon carbide IGBTs also have advantages such as high temperature resistance, low loss, and small size, making them suitable for the current trend of miniaturization and modularization in APF (Automatic Power Filter) systems. They also address the issue of device overheating caused by the trend towards miniaturization but increased operating power.

[0051] Furthermore, the drive unit provided in this application uses multiple silicon carbide IGBTs in parallel to share the current, thereby reducing single-transistor overcurrent and lowering the heat generated by the switching transistors. However, it should be noted that the number of parallel transistors is not limited only from the perspective of reducing single-transistor overcurrent. That is, the specific number of silicon carbide IGBTs in a group of silicon carbide IGBTs is not limited; as long as it exceeds one, the purpose can be achieved. The drive unit provided in this application is based on the goal of reducing the number of power devices required. After multiple simulation experiments and tests, it was found that using two silicon carbide IGBTs in parallel can meet the general needs of APF in practical applications. The circuit structure of the dual-transistor parallel drive unit based on a two-level scheme is as follows: Figure 1 As shown, only 12 silicon carbide IGBTs are needed, compared to the 18 IGBTs typically required in a three-level scheme. This reduces the number of IGBTs used by one-third, effectively solving a series of problems caused by using too many IGBT devices, such as excessive circuit area, complex control logic, complex protection logic, and high cost.

[0052] It should also be noted that parallel connection of multiple IGBTs may lead to uneven current distribution, which can seriously affect the lifespan and safety of the drive unit. Therefore, in the drive unit provided in this application, the layout and routing of the two silicon carbide IGBTs connected in parallel in the same group are completely symmetrical to reduce the uneven current distribution caused by parallel connection.

[0053] Furthermore, it should be noted that the symmetrical layout required in the above embodiments only applies to parallel silicon carbide IGBTs within the same group; there is no such mandatory requirement for parallel silicon carbide IGBTs between different groups, and a suitable layout can be selected based on the actual circuit design needs. However, in one possible embodiment, such as Figure 2 As shown, this embodiment also provides a layout scheme for each silicon carbide IGBT transistor in the driving unit: the silicon carbide IGBT transistors are arranged in a straight line.

[0054] It is easy to understand that the linear arrangement of the silicon carbide IGBTs allows for symmetrical layout and routing between silicon carbide IGBTs in the same group within the drive unit, as well as between different groups of silicon carbide IGBTs, resulting in better performance in current sharing and other aspects.

[0055] In summary, the driving unit provided in the above embodiments of this application, by using silicon carbide IGBTs and a circuit design with two IGBTs connected in parallel, allows the use of a two-level scheme as the hardware topology to meet the requirements of actual high-power applications regarding switching losses of power devices and single-transistor overcurrent. Furthermore, to address the uneven current problem caused by the parallel connection of two IGBTs, the driving unit provided in this application also mitigates this problem through a symmetrical layout and wiring method. Based on the above settings, the driving unit provided in this application can still use a two-level scheme as the hardware topology while meeting practical application requirements. Compared to a three-level scheme, this reduces the number of power devices used by 1 / 3, thereby simplifying the hardware topology of the driving unit, reducing the overall circuit size, and reducing production and design costs.

[0056] On the other hand, this application also provides an embodiment of a parallel-to-serial dual-purpose harmonic mitigation device, such as... Figure 3 As shown, the dual-purpose harmonic mitigation device in series includes: a drive unit as provided in the above embodiment, as well as a pre-charging unit, an energy storage unit, a control unit, and a sampling unit.

[0057] Among them, the input terminal of the pre-charge unit serves as the input terminal of the parallel-series dual-purpose harmonic mitigation device, the output terminal of the energy storage unit serves as the output terminal of the parallel-series dual-purpose harmonic mitigation device, and the input terminal of the sampling unit serves as the sampling input terminal of the parallel-series dual-purpose harmonic mitigation device.

[0058] The output of the precharge unit is connected to the power supply terminal of the control unit and the input terminal of the energy storage unit, respectively.

[0059] The input terminal of the drive unit is connected to the energy storage unit, the output terminal of the drive unit is connected to the input terminal of the pre-charge unit, and the controlled terminal of the drive unit is connected to the control unit.

[0060] The control unit is connected to the output of the sampling unit and is used to control the switching state of the silicon carbide IGBT in the drive unit according to the current value collected by the sampling unit.

[0061] It should be noted that the pre-charging unit in the above-mentioned parallel-series dual-purpose harmonic mitigation device can be implemented through a pre-charging circuit; the energy storage unit can be implemented through an energy storage device or circuit containing a capacitor; the control unit can be implemented through a device with processing and control functions, such as a microcontroller; and the sampling unit, since it specifically collects the current value between the power grid and the load, can be implemented through a current transformer and its matching circuit.

[0062] The structure of the actual parallel-series dual-purpose harmonic mitigation device obtained through welding is as follows: Figure 2 As shown, the wiring of each electrical component in the dual-purpose harmonic mitigation device, as well as the external input and output terminals, are hidden on the back and not directly shown.

[0063] The parallel-series dual-purpose harmonic mitigation device provided in this embodiment can be used as an APF (Automatic Power Filter). When used as an APF, the workflow between the units is as follows: First, the input terminal is connected to an external power source (such as the power grid, in this case, three-phase power). The electrical energy input from the external power source passes through the pre-charging unit, on one hand being output to the power supply terminal of the control unit to power the control unit, and on the other hand, the pre-charging unit stores energy in the energy storage unit. After energy storage is completed, the control unit controls the pre-charging relay in the pre-charging circuit to engage. At this time, the parallel-series dual-purpose harmonic mitigation device can function normally as an APF. Specifically, the control unit obtains the current value collected by the sampling unit, calculates it, and controls the switching state of the silicon carbide IGBT in the drive unit to control the energy stored in the energy storage unit to output it with a certain waveform, thereby achieving the effect of harmonic mitigation.

[0064] It is easy to understand that when the parallel-series dual-purpose harmonic mitigation device provided in this embodiment is used as an APF, since the driving unit therein adopts the driving unit provided in the above embodiment, it can bring the same technical effect as the driving unit described above, that is, it can reduce the use of power devices and alleviate a series of problems caused by the excessive use of power devices.

[0065] It should be further noted that the functional units in the parallel-series dual-purpose harmonic mitigation device provided in the previous embodiment are only a basic implementation scheme to achieve the APF function. If other needs arise in practical applications, other functional units or circuits can be added to the parallel-series dual-purpose harmonic mitigation device provided in the above embodiments. For example, in one possible implementation scheme provided in this embodiment, such as... Figure 3 As shown, the above-mentioned parallel-series dual-purpose harmonic mitigation device also includes: a filter unit and an extended capacitor board.

[0066] The filter unit is located between the output of the pre-charge unit and the power supply of the control unit. An extended capacitor plate is connected in parallel between the outputs of the energy storage unit.

[0067] It should also be noted that the above Figure 2 The illustrated physical structure diagram of the welded parallel-series dual-purpose harmonic mitigation device includes the filtering unit in this embodiment. The filtering unit is mainly composed of components such as inductors. In this embodiment, the filtering unit is located between the output terminal of the pre-charge unit and the power supply terminal of the control unit, and is used to filter the power input provided by the pre-charge unit to the control unit, thereby improving the stability and reliability of the control unit's operation.

[0068] For extended capacitor boards, since they serve as an extension device based on a dual-purpose parallel and series harmonic mitigation device, Figure 2The diagram does not explicitly show the capacitors. However, it's easy to understand that capacitors are deployed on the expansion capacitor board. The expansion capacitor board can be fixed to the main board 1, and then the capacitors on the expansion capacitor board are connected in parallel to the output terminal of the energy storage unit. This expands the capacitance of the energy storage unit, allowing the parallel-series dual-purpose harmonic mitigation device to adapt to higher power application scenarios. The energy storage unit capacitor expansion implemented using this solution does not require modification of the circuit layout and wiring on the main board 1. It can be achieved by connecting an expansion board, making implementation more flexible and better adaptable to different operating power requirements in different application scenarios.

[0069] On the other hand, this embodiment also provides a possible implementation scheme for the production and design of the parallel-series dual-purpose harmonic mitigation device described in the above embodiments, such as... Figure 4 As shown:

[0070] The pre-charge unit, energy storage unit, control unit, sampling unit, and filtering unit are mounted on the motherboard 1; the drive unit is mounted on the switching transistor heat sink 2, which is independent of the motherboard 1; the switching transistor heat sink 2 is fixedly connected to the motherboard 1.

[0071] In this embodiment, the drive unit is designed separately from other functional units in the integrated board. This design is adapted to the characteristic of the parallel-to-serial dual-purpose harmonic mitigation device in this embodiment, which uses the improved drive unit described in the previous embodiment. The modular design facilitates the design and production of the parallel-to-serial dual-purpose harmonic mitigation device. In this embodiment, the drive unit, composed of silicon carbide IGBTs, is pre-locked onto an aluminum substrate (i.e., the aforementioned switch tube heat sink 2) using a fixture, and then soldered onto the main board 1 as a large plug-in. That is, in this embodiment, the main board 1 and the switch tube heat sink 2 can be designed separately, and finally, an electrical connection is established through soldering or other methods.

[0072] Furthermore, this embodiment also provides a possible implementation scheme for how to achieve a fixed connection between the motherboard 1 and the switching transistor heat sink 2, which are designed in a split form in the above embodiments. For example... Figure 4 As shown, the dual-purpose harmonic mitigation device in series also includes: spacer column 4.

[0073] The heat sink aluminum plate 2 of the switching tube is provided with a through hole 3. The shape and size of the through hole 3 are adapted to the cross-section of the spacer 4. The spacer 4 is fixedly connected to the heat sink aluminum plate 2 of the switching tube through the through hole 3. The main board 1 is fixedly connected to the spacer 4 by screws.

[0074] In this embodiment, the motherboard 1 and the heat sink 2 of the switching transistor are fixedly connected by a spacer post 4. The heat sink 2 of the switching transistor has through holes 3, the shape and size of which are adapted to the spacer post 4, allowing for a snap-fit ​​connection. The motherboard 1 can be threadedly connected to the spacer post 4 using screws, thus achieving a fixed connection between the motherboard 1 and the heat sink 2 of the switching transistor through the spacer post 4. It is clear that both the connection between the spacer post 4 and the through hole 3 of the heat sink 2, and the connection between the spacer post 4 and the motherboard 1 using screws, are detachable fixing solutions, offering greater flexibility and facilitating production, quality inspection, and maintenance needs in practical applications. Furthermore, the length, shape, and size of the spacer post 4 can be adaptively adjusted based on the needs of different production processes. Besides fixing the motherboard 1 and the heat sink 2 of the switching transistor, the spacer post 4 can also be used for fixing other components or boards; this embodiment does not limit this.

[0075] For example, this embodiment provides a possible implementation scheme in addition to the parallel-series dual-purpose harmonic mitigation device of the above embodiments, which includes a motherboard 1 and a switching transistor heat sink aluminum plate 2. For example... Figure 4 As shown, the dual-purpose harmonic mitigation device in series also includes: a first heat dissipation device 5 and a second heat dissipation device 6.

[0076] The first heat dissipation device 5 is fixedly connected to the heat dissipation aluminum plate 2 of the switching tube via a spacer post 4; the second heat dissipation device 6 is fixedly connected to the main board 1 via a spacer post 4.

[0077] More specifically, the first heat dissipation device 5 is used to improve the heat dissipation capacity of the silicon carbide IGBT transistor on the heat sink aluminum plate 2. The second heat dissipation device 6 is used to improve the heat dissipation capacity of various electrical components on the motherboard 1. In one possible implementation, the second heat dissipation device 6 is mainly used to improve the heat dissipation capacity of the inductors on the motherboard 1. Therefore, in this scenario, the second heat dissipation device 6 can be fixed to the motherboard 1 by the spacer post 4 and cover the inductors arranged on the motherboard 1.

[0078] It should be noted that both the first heat dissipation device 5 and the second heat dissipation device 6 described above are devices for dissipating heat from electrical components. In a further embodiment, the first heat dissipation device 5 and the second heat dissipation device 6 are devices for dissipating heat from the IGBT transistor and the inductor, respectively. Currently, there are various mature technical solutions for dissipating heat from electrical components (IGBT transistor and inductor), and this embodiment does not limit these solutions. Appropriate heat sinks can be freely selected as the first heat dissipation device 5 and the second heat dissipation device 6 according to actual needs.

[0079] However, this embodiment also provides a possible implementation scheme for the first heat dissipation device 5 and the second heat dissipation device 6 described above, such as... Figure 4 As shown:

[0080] Both the first heat dissipation device 5 and the second heat dissipation device 6 include: a heat dissipation aluminum plate and a heat dissipation fin.

[0081] The second heat dissipation device 6 also includes a thermally conductive silicone pad 63. The thermally conductive silicone pad 63 is in physical contact with the filter unit.

[0082] Specifically, the heat dissipation aluminum plate is also an aluminum substrate, used to provide a heat dissipation medium for the target object, thereby improving the heat dissipation capacity of the target object. For ease of explanation, the heat dissipation aluminum plate in the first heat dissipation device 5 is referred to as the first heat dissipation aluminum plate 51, and the heat sink in the first heat dissipation device 5 is referred to as the first heat sink 52. The heat dissipation aluminum plate in the second heat dissipation device 6 is referred to as the second heat dissipation aluminum plate 61, and the heat sink in the second heat dissipation device 6 is referred to as the second heat sink 62. The first heat dissipation device 5 is mainly used to dissipate heat from the silicon carbide IGBT transistors arranged on the switching transistor heat dissipation aluminum plate 2. Therefore, the first heat dissipation aluminum plate 51 can be fixedly connected to the switching transistor heat dissipation aluminum plate 2 through the spacer 4. The second heat dissipation device 6 is mainly used to dissipate heat from the inductors in the filter unit on the motherboard 1. Therefore, the second heat dissipation aluminum plate 52 can be fixedly connected to the motherboard 1 through the spacer 4. It is particularly important to note that the second heat dissipation device 6 also includes a thermally conductive silicone pad 63. The thermally conductive silicone pad 63 is used to make direct physical contact with the inductor, thereby increasing the contact area between the inductor and the second heat dissipation device 6, further improving the heat dissipation capacity. In addition, the thermally conductive silicone sheet 63 can also provide fixed support for the inductor, which helps to improve the stability and safety of the filter unit operation.

[0083] On the other hand, as described in the above embodiments, the parallel-to-serial dual-purpose harmonic control device provided in the above embodiments can be used as an active filter. Therefore, this application also provides an embodiment corresponding to an active filter, such as... Figure 5 As shown, the active filter provided in this embodiment includes the parallel-series dual-purpose harmonic mitigation device provided in the above embodiment.

[0084] Among them, the dual-purpose harmonic mitigation device is connected in parallel between the power grid and the load.

[0085] The sampling input terminal of the dual-purpose harmonic mitigation device is connected in the path between the power grid and the load, at any position between the power grid and the parallel connection point of the dual-purpose harmonic mitigation device.

[0086] In addition, when the parallel-series dual-purpose harmonic mitigation device is used as an active filter, the workflow of each functional unit has been described in some embodiments of the parallel-series dual-purpose harmonic mitigation device: the control unit, based on the current value collected by the sampling unit, calculates and controls the switching state of the silicon carbide IGBT tube in the drive unit to control the energy stored in the energy storage unit to be output with a certain waveform, thereby achieving the effect of harmonic mitigation. This embodiment will not repeat the details.

[0087] Furthermore, since the active filter provided in this embodiment includes the parallel-series dual-purpose harmonic mitigation device and driving unit provided in the above embodiments, it can achieve the same technical effects as the above-described parallel-series dual-purpose harmonic mitigation device and driving unit. For details, please refer to the above-described embodiments of the driving unit and the parallel-series dual-purpose harmonic mitigation device, which will not be repeated here.

[0088] Finally, in addition to being used as an APF, the parallel-series dual-purpose harmonic mitigation device provided in the above embodiments also offers another possible application. For example... Figure 6 As shown, this embodiment provides a rectifier (AFE) including the parallel-to-serial dual-purpose harmonic mitigation device provided in the above embodiment.

[0089] The dual-purpose harmonic mitigation device is connected in series between the power grid and the load. Its input terminal is connected to the power grid, and its output terminal is connected to the load via a DC bus.

[0090] In other words, this embodiment provides an implementation scheme for using a parallel-series dual-purpose harmonic mitigation device as an AFE. The parallel-series dual-purpose harmonic mitigation device is connected in series between the power grid and the load. Its input terminal draws three-phase power from the power grid, and its output terminal is connected to the DC bus of the load, thus realizing the function of a rectification / feedback unit.

[0091] The foregoing has provided a detailed description of the driving unit, the parallel-series dual-purpose harmonic mitigation device, the active filter, and the rectifier provided by this utility model. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section. It should be noted that those skilled in the art can make various improvements and modifications to this utility model without departing from its principles, and these improvements and modifications also fall within the protection scope of this utility model.

[0092] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A parallel and series dual-purpose harmonic management device, characterized by, The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device.

2. The dual-series harmonic management device of claim 1, wherein, The application relates to a parallel-serial dual-purpose harmonic treatment device.

3. The dual-series harmonic management device of claim 1, wherein, The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device.

4. The dual-series harmonic management device of claim 3, wherein, The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device.

5. The dual-series harmonic management device of claim 4, wherein, The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device.

6. The dual-series harmonic management device of claim 5, wherein, The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device.

7. The dual-series harmonic management device of claim 6, wherein, The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device.

8. An active filter, characterized by The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device.

9. A rectifier characterized by The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to a parallel-serial dual-purpose harmonic treatment device. The application relates to The parallel-serial dual-purpose harmonic control device is connected in series between a power grid and a load, an input end of the parallel-serial dual-purpose harmonic control device is connected with the power grid, and an output end of the parallel-serial dual-purpose harmonic control device is connected with the load through a DC bus.

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