Compact combined energy router with electric energy quality adjusting capability

Abstract

The invention provides a compact combined energy router with electric energy quality adjusting capability, which relates to the technical field of power systems and comprises a three-phase power supply, a high-voltage side main winding, a first low-voltage side winding, a second low-voltage side winding, a front-stage voltage source converter VSC, a nine-switch converter and a three-phase nonlinear load, the three-phase power supply is connected with the high-voltage side main winding; the high-voltage side main winding, the first low-voltage side winding and the second low-voltage side winding are subjected to magnetic reaction coupling through winding the iron core; the first low-voltage side winding is connected with a three-phase nonlinear load; the second low-voltage side winding is connected with a front-stage voltage source converter VSC, the front-stage voltage source converter VSC is connected with a nine-switch converter, and the nine-switch converter is connected with a three-phase nonlinear load. The power quality of the power distribution tail end can be remarkably improved, and the system structure complexity and the equipment cost are reduced.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a compact combined energy router with power quality regulation capabilities. Background Technology

[0002] As the link most closely connected to users among the five stages of power generation, transmission, transformation, distribution, and consumption, the power distribution system directly serves end users and is a vital public infrastructure for serving people's livelihoods. Driven by the "dual carbon goals," massive amounts of new energy sources such as wind / solar power and electric vehicles will continue to flood into medium- and low-voltage power distribution systems. These new sources and loads are characterized by randomness, fluctuation, impulsiveness, and disorder, posing power quality challenges to the power distribution system, including high / low voltage, harmonic amplification, and three-phase imbalance. Especially for critical loads within the power supply area that are sensitive to power quality, such as precision instrument manufacturing enterprises and large data centers, even higher requirements are placed on power quality.

[0003] User-oriented power technology for power distribution systems is a key technology for addressing power quality issues today. The main content of user-oriented power technology is to use various power electronic devices in the power distribution network and apply control technology, power electronics technology and microcomputer processing technology to effectively solve various power quality problems that occur in the system.

[0004] However, existing power quality management devices are mostly single-function devices, which are difficult to comprehensively manage various power quality problems such as voltage harmonics, voltage fluctuations, current distortion, and three-phase imbalance. Moreover, they often require multiple sets of equipment to be used in combination, resulting in power quality management devices that are large in size, high in cost, and complex in structure. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a compact combined energy router with power quality regulation capability, which can solve the technical problem that the prior art has difficulty in comprehensively managing multiple power quality problems such as voltage harmonics, voltage fluctuations, current distortion and three-phase imbalance.

[0006] This invention proposes a compact combined energy router with power quality regulation capability, comprising: a three-phase power supply, a high-voltage side main winding, a first low-voltage side winding, a second low-voltage side winding, a front-end voltage source converter (VSC), a nine-switch converter, and a three-phase nonlinear load.

[0007] The three-phase power supply is connected to the high-voltage side main winding;

[0008] The high-voltage side main winding is magnetically coupled to the first low-voltage side winding and the second low-voltage side winding through a wound iron core.

[0009] The first low-voltage side winding is connected to the three-phase nonlinear load;

[0010] The second low-voltage side winding is connected to the preceding voltage source converter VSC, the preceding voltage source converter VSC is connected to the nine-switch converter, and the nine-switch converter is connected to the three-phase nonlinear load;

[0011] The three-phase power supply supplies power to the high-voltage side main winding, and the high-voltage side main winding generates low-voltage AC voltages on the first low-voltage side winding and the second low-voltage side winding respectively through electromagnetic induction.

[0012] The first low-voltage side winding provides AC voltage to the three-phase nonlinear load, drives the three-phase nonlinear load to operate, and forms a load current;

[0013] The second low-voltage side winding inputs three-phase voltage and current to the front-stage voltage source converter VSC. The front-stage voltage source converter VSC converts the three-phase voltage into a DC bus voltage and inputs the DC bus voltage to the nine-switch converter. The nine-switch converter inputs compensation voltage and compensation current to the three-phase nonlinear load through the upper and lower ports.

[0014] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0015] In this embodiment of the invention, by constructing a magnetic reaction coupling structure between the high-voltage side main winding and the two sets of low-voltage side windings, and adopting a dual-channel power quality compensation system composed of a front-end voltage source converter and a nine-switch converter, the load power supply and compensation energy acquisition are made independent of each other. At the same time, the nine-switch converter can provide compensation voltage and compensation current to the load respectively, thereby achieving comprehensive management of various power quality problems such as voltage fluctuations, harmonic distortion, and current distortion, making the load-side voltage more stable and the load current more sinusoidal, significantly improving the power quality at the end of the distribution line and reducing the system structure complexity and equipment cost. Attached Figure Description

[0016] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0017] Figure 1 This is a schematic diagram of a compact combined energy router with power quality regulation capability provided in an embodiment of the present invention.

[0018] Figure 2This is a schematic diagram of a dq voltage and current integrated detection based on Park transformation provided in an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the voltage waveform of phase A before compensation provided in an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of a compensated phase A voltage waveform provided in an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the A-phase waveform of the load current before compensation provided in an embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of the compensated load phase A current waveform provided in an embodiment of the present invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0024] Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts disclosed in this invention.

[0025] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention.

[0026] Reference manual attached Figures 1 to 6 The present invention provides a structure for a compact combined energy router with power quality regulation capability, comprising: a three-phase power supply, a high-voltage side main winding, a first low-voltage side winding, a second low-voltage side winding, a front-end voltage source converter (VSC), a nine-switch converter, and a three-phase nonlinear load.

[0027] In this context, three-phase power supply refers to the power source in the power distribution system that provides three-phase AC power, typically consisting of phases A, B, and C, used to input three-phase AC voltage and current to the high-voltage side main winding. The high-voltage side main winding refers to the high-voltage coil mounted on the transformer core, used to receive the three-phase power input and transfer electrical energy to the low-voltage side winding through magnetic coupling. The low-voltage side winding refers to the low-voltage coil magnetically coupled to the high-voltage side main winding. The front-end voltage source converter (VSC) is a three-phase AC / DC converter used to convert the three-phase AC power output from the second low-voltage side winding into DC bus power, providing a stable DC voltage for the nine-switch converter. The nine-switch converter is a multi-port power electronic converter composed of nine switching devices, with two independent AC output ports. It can simultaneously output control signals for voltage and current compensation, achieving comprehensive regulation of the load power quality. Three-phase nonlinear loads refer to three-phase loads whose current waveforms do not change linearly with the voltage waveforms, such as rectifiers, frequency converters, and power electronic equipment. Their operation can cause power quality problems such as harmonics and current distortion.

[0028] The three-phase power supply is connected to the high-voltage side main winding.

[0029] The high-voltage side main winding is magnetically coupled to the first low-voltage side winding and the second low-voltage side winding through a wound iron core.

[0030] The first low-voltage side winding is connected to the three-phase nonlinear load.

[0031] The second low-voltage side winding is connected to the preceding voltage source converter VSC, which is connected to the nine-switch converter, which is connected to the three-phase nonlinear load.

[0032] The three-phase power supply supplies power to the high-voltage side main winding, and the high-voltage side main winding generates low-voltage AC voltages on the first low-voltage side winding and the second low-voltage side winding respectively through electromagnetic induction.

[0033] The first low-voltage side winding provides AC voltage to the three-phase nonlinear load, drives the three-phase nonlinear load to operate, and forms the load current.

[0034] The second low-voltage side winding inputs three-phase voltage and current to the front-stage voltage source converter (VSC). The front-stage voltage source converter (VSC) converts the three-phase voltage into DC bus voltage and inputs the DC bus voltage to the nine-switch converter. The nine-switch converter inputs compensation voltage and compensation current to the three-phase nonlinear load through the upper and lower ports.

[0035] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0036] In this embodiment of the invention, by constructing a magnetic reaction coupling structure between the high-voltage side main winding and the two sets of low-voltage side windings, and adopting a dual-channel power quality compensation system composed of a front-end voltage source converter and a nine-switch converter, the load power supply and compensation energy acquisition are made independent of each other. At the same time, the nine-switch converter can provide compensation voltage and compensation current to the load respectively, thereby achieving comprehensive management of various power quality problems such as voltage fluctuations, harmonic distortion, and current distortion, making the load-side voltage more stable and the load current more sinusoidal, significantly improving the power quality at the end of the distribution line and reducing the system structure complexity and equipment cost.

[0037] In one possible implementation, the high-voltage side main winding specifically includes: a first high-voltage winding W A1 Second high voltage winding W B1 and the third high-voltage winding W C1 .

[0038] First high-voltage winding W A1 The first end and the third high voltage winding W C1 The ends are connected. The second high-voltage winding W B1 The first end and the first high voltage winding W A1 The ends are connected. The third high-voltage winding W C1 The first end and the second high voltage winding W B1 The ends are connected.

[0039] It should be noted that by connecting the first, second, and third high-voltage windings sequentially at their beginning and end to form a triangular connection structure, a balanced voltage distribution and stable magnetic coupling relationship can be achieved between the windings. This not only improves the overall power transmission efficiency of the windings but also enhances the system's adaptability to three-phase imbalance and grid disturbances, thereby ensuring the stability and reliability of subsequent low-voltage power supply and compensation processes.

[0040] In one possible implementation, the first low-voltage side winding specifically includes: a low-voltage winding W. a1 Low-voltage winding W b1 and low-voltage winding W c1 .

[0041] low voltage winding W a1 Low-voltage winding W b1 and low-voltage winding W c1 The first end is connected in a star configuration to form the first node, and the low-voltage winding W... a1 Low-voltage winding W b1 and low-voltage winding W c1 The second end is connected to phases A, B, and C of the three-phase nonlinear load, respectively.

[0042] It should be noted that by using the low-voltage winding W a1 Wb1 and W c1 The first end is star-connected to form a unified node, which not only ensures that the three-phase output voltage amplitude is consistent and the phase is symmetrical, but also effectively improves the voltage stability and power supply balance on the load side. This ensures that the three-phase nonlinear load can obtain a stable and reliable low-voltage AC power supply under different operating conditions, and reduces current distortion and equipment loss caused by unbalanced power supply.

[0043] In one possible implementation, the second low-voltage side winding specifically includes: a low-voltage winding W. a2 Low-voltage winding W b2 and low-voltage winding W c2 .

[0044] low voltage winding W a2 Low-voltage winding W b2 and low-voltage winding W c2 The first end is connected in a star configuration to form the second node, and the low-voltage winding W... a2 Low-voltage winding W b2 and low-voltage winding W c2 The second terminal is connected to phase A, phase B, and phase C of the preceding voltage source converter VSC, respectively.

[0045] It should be noted that by using the low-voltage winding W a2 W b2 and W c2 The first end is connected in a star configuration to form the second node, which ensures that the three-phase input voltages are in phase and have equal amplitude. This provides a stable and symmetrical three-phase AC input to the upstream voltage source converter (VSC), which not only improves the rectification efficiency of the VSC and the stability of the DC bus voltage, but also reduces the conversion losses caused by three-phase imbalance, which is beneficial to the efficient and reliable operation of the compensation system.

[0046] In one possible implementation, the first high-voltage winding W A1 The low-voltage winding W is coupled together by winding the iron core. a1 and low voltage winding W a2 .

[0047] Second high voltage winding W B1 The low-voltage winding W is coupled together by winding the iron core. b1 and low voltage winding W b2 .

[0048] Third high voltage winding W C1 The low-voltage winding W is coupled together by winding the iron core. c1 and low voltage winding W c2 .

[0049] It should be noted that by magnetically coupling each high-voltage winding with the two sets of low-voltage windings of the corresponding phase on the same iron core, the load power supply channel and the compensation energy acquisition channel can be made independent while ensuring good energy transfer efficiency. This not only improves the compactness and electromagnetic utilization of the overall transformer structure, but also ensures that the transmission characteristics between each phase are consistent, thereby improving the stability and reliability of the system under voltage fluctuation and load change conditions.

[0050] In one possible implementation, the input terminal of the front-end voltage source converter Input end and input terminal Each is connected to the output terminal of the second low-voltage side winding. Output terminal and output end connect.

[0051] It should be noted that by connecting the three-phase input terminals of the front-stage voltage source converter to the corresponding output terminals of the second low-voltage side winding, it is possible to ensure that the converter obtains a three-phase AC input with consistent phase and stable amplitude, thereby improving the power factor and voltage utilization rate of the AC / DC conversion process, further ensuring the stability of the DC bus voltage, and enabling the subsequent nine-switch converter to perform power quality compensation under more reliable DC conditions.

[0052] In one possible implementation, it also includes: capacitor C dc

[0053] The DC input terminal of the nine-switch converter and capacitor C dc connect.

[0054] Capacitor C dc The positive terminal of the capacitor is connected to the positive terminal P of the DC bus, and the capacitor C dc The negative terminal is connected to the negative terminal N of the DC bus.

[0055] A DC bus voltage Ud is formed between the positive and negative terminals of the DC bus. The DC bus voltage Ud is used to provide DC energy storage for the nine-switch converter and stabilize the DC side voltage.

[0056] It should be noted that by introducing a capacitor C on the DC side of the nine-switch converter... dc Energy storage and filtering can effectively smooth DC bus voltage fluctuations during converter operation, improve the stability of DC side voltage Ud, and avoid voltage transient deviations caused by source-side disturbances or load changes. This ensures that the nine-switch converter can generate accurate compensation voltage and compensation current under stable DC power supply conditions, thereby improving the reliability and dynamic performance of the entire power quality regulation system.

[0057] In one possible implementation, the nine-switch converter specifically includes: phase A arm, phase B arm, and phase C arm.

[0058] Phase A bridge arm specifically includes switch modules S1, S2, and S3 connected in sequence. Phase B bridge arm specifically includes switch modules S4, S5, and S6 connected in sequence. Phase C bridge arm specifically includes switch modules S7, S8, and S9 connected in sequence.

[0059] It should be noted that by dividing the nine-switch converter into three bridge arms, namely A-phase, B-phase, and C-phase, and using three switch modules connected in series in each bridge arm to form a multi-stage switching structure, not only can independent and precise control of three-phase power be achieved, but also dual-port output capability can be obtained while reducing the number of components. This reduces the overall converter size and cost, and improves control flexibility and power quality compensation effect.

[0060] In one possible implementation, switch modules S1, S2, S3, S4, S5, S6, S7, S8, and S9 are all composed of an insulated gate bipolar transistor T. k And an anti-parallel diode D k composition.

[0061] Diode D k Anode and Insulated Gate Bipolar Transistor T k The emitters are connected.

[0062] Diode D k Cathode and Insulated Gate Bipolar Transistor T k The collectors are connected.

[0063] It should be noted that by uniformly designing each switching module to consist of an insulated gate bipolar transistor (IGBT) T... k With anti-parallel diode D k This structure not only enables bidirectional power conduction and efficient switching control simultaneously, but also effectively provides a freewheeling path when handling inductive loads, reducing voltage spikes and energy losses during switching. The structure is simple and reliable, facilitating modular design and contributing to improved overall stability, efficiency, and lifespan of the nine-switch converter.

[0064] In this embodiment of the invention, the switching module is represented by the symbol k, and the insulated gate bipolar transistor in the switching module is represented by the symbol T. k A diode is indicated by the symbol D. k The symbol T represents... k and symbol D kThe subscript symbol k indicates the switch module in which it is located, where k∈{1,2,3,4,5,6,7,8,9}.

[0065] In one possible implementation, phase A bridge arm has an upper output terminal A and a lower output terminal X, phase B bridge arm has an upper output terminal B and a lower output terminal Y, and phase C bridge arm has an upper output terminal C and a lower output terminal Z.

[0066] The upper output terminals A, B, and C together form the first inverter stage.

[0067] The lower output terminals X, Y, and Z together form the second inverter stage.

[0068] The A, B, and C ports of the first inverter stage are connected to an LC filter, which is then connected in series with the output terminal of the first low-voltage side winding via a transformer. Output terminal and output end connect.

[0069] The X, Y, and Z ports of the second inverter stage are connected to an L-type filter, which is then connected in series to the input terminals A3, B3, and C3 of the three-phase nonlinear load.

[0070] It should be noted that by setting two independent output terminals on each phase bridge arm and forming the first inverter stage and the second inverter stage respectively, the nine-switch converter can realize the separation of voltage compensation and current compensation functions. Then, through LC type filter and L type filter, stable compensation voltage and compensation current are output respectively, which improves the independence and accuracy of compensation control, and improves the voltage quality and current quality on the load side without adding additional power devices.

[0071] like Figure 2 The diagram shown is a schematic of a dq voltage and current integrated detection method based on Park transform provided by an embodiment of the present invention. This dq voltage and current integrated detection method based on Park transform is used to achieve effective control of a nine-switch converter. The method employs a dq voltage and current integrated detection method based on Park transform. A phase-locked loop (PLL) tracks the phase and frequency of the grid-side voltage and acquires the three-phase voltage and current u on the user side. a u b u c and i a i b i c The two-phase voltage and current u can be obtained through the dq transformation formula. d u q and i d i q The filtered two-phase voltage and current u are obtained through LPF. ld u lqand i ld i lq After dq inverse transformation and the three-phase voltage and current u a u b u c and i a i b i c The harmonic voltage and current u are obtained by subtraction. ah u bh u ch and i ah i bh i ch .

[0072] Let the reference voltages at the upper and lower output terminals of the nine-switch converter be respectively:

[0073]

[0074] in, This represents the reference voltage at the upper output terminal of the converter. This represents the reference voltage at the lower output terminal of the converter. This indicates the amplitude of the reference voltage at the upper output terminal. The lower output modulated wave represents the reference amplitude, and cos represents the cosine function. This represents the angular frequency of the output voltage. The frequency of the output voltage is represented by ω, and t represents time. This indicates the initial phase of the voltage at the upper output terminal. This indicates the initial phase of the output voltage. This indicates the offset of the voltage at the upper output terminal. This indicates the offset of the output voltage.

[0075] For the inverter to operate normally, the upper output reference voltage must always be no less than the lower output reference voltage, and the reference amplitude of the modulation wave must be...

[0076] V m1 V m2 The offsets m1 and m2 must satisfy the following:

[0077]

[0078] By using the SPWM modulation method, comparing the modulated wave with the triangular carrier wave, and selecting a suitable drive circuit, effective control of the nine-switch converter can be achieved.

[0079] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the preferred embodiments, while those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the protection scope of the present invention.

Claims

1. A compact, modular energy router with power quality regulation capabilities, characterized in that, include: Three-phase power supply, high-voltage side main winding, first low-voltage side winding, second low-voltage side winding, front-end voltage source converter (VSC), nine-switch converter, and three-phase nonlinear load; The three-phase power supply is connected to the high-voltage side main winding; The high-voltage side main winding is magnetically coupled to the first low-voltage side winding and the second low-voltage side winding through a wound iron core. The first low-voltage side winding is connected to the three-phase nonlinear load; The second low-voltage side winding is connected to the preceding voltage source converter VSC, the preceding voltage source converter VSC is connected to the nine-switch converter, and the nine-switch converter is connected to the three-phase nonlinear load; The three-phase power supply supplies power to the high-voltage side main winding, and the high-voltage side main winding generates low-voltage AC voltages on the first low-voltage side winding and the second low-voltage side winding respectively through electromagnetic induction. The first low-voltage side winding provides AC voltage to the three-phase nonlinear load, drives the three-phase nonlinear load to operate, and forms a load current; The second low-voltage side winding inputs three-phase voltage and current to the front-stage voltage source converter VSC. The front-stage voltage source converter VSC converts the three-phase voltage into a DC bus voltage and inputs the DC bus voltage to the nine-switch converter. The nine-switch converter inputs compensation voltage and compensation current to the three-phase nonlinear load through the upper and lower ports.

2. The compact combined energy router with power quality regulation capability according to claim 1, characterized in that, The high-voltage side main winding specifically includes: a first high-voltage winding W A1 Second high voltage winding W B1 and the third high-voltage winding W C1 ; The first high voltage winding W A1 The first end and the third high-voltage winding W C1 The ends are connected; the second high-voltage winding W B1 The first end is connected to the first high-voltage winding W A1 The end is connected; the third high-voltage winding W C1 The first end and the second high voltage winding W B1 The ends are connected.

3. The compact combined energy router with power quality regulation capability according to claim 1, characterized in that, The first low-voltage side winding specifically includes: low-voltage winding W a1 Low-voltage winding W b1 and low-voltage winding W c1 ; The low-voltage winding W a1 The low-voltage winding W b1 and the low-voltage winding W c1 The first end is star-connected to form the first node, and the low-voltage winding W a1 The low-voltage winding W b1 and the low-voltage winding W c1 The second end is connected to phase A, phase B and phase C of the three-phase nonlinear load, respectively.

4. The compact combined energy router with power quality regulation capability according to claim 1, characterized in that, The second low-voltage side winding specifically includes: low-voltage winding W a2 Low-voltage winding W b2 and low-voltage winding W c2 ; The low-voltage winding W a2 The low-voltage winding W b2 and the low-voltage winding W c2 The first end is star-connected to form the second node, and the low-voltage winding W a2 The low-voltage winding W b2 and the low-voltage winding W c2 The second terminal is connected to phase A, phase B and phase C of the preceding voltage source converter VSC, respectively.

5. The compact combined energy router with power quality regulation capability according to claim 2, characterized in that, The first high voltage winding W A1 The low-voltage winding W is coupled to the wound iron core. a1 and low voltage winding W a2 ; The second high-voltage winding W B1 The low-voltage winding W is coupled to the wound iron core. b1 and low voltage winding W b2 ; The third high-voltage winding W C1 The low-voltage winding W is coupled to the wound iron core. c1 and low voltage winding W c2 .

6. The compact combined energy router with power quality regulation capability according to claim 1, characterized in that, The input terminal of the front-stage voltage source converter Input end and input terminal The output terminals of the second low-voltage side winding are respectively connected to the output terminals of the second low-voltage side winding. Output terminal and output end connect.

7. The compact combined energy router with power quality regulation capability according to claim 1, characterized in that, Also includes: Capacitor C dc The DC input terminal of the nine-switch converter is connected to the capacitor C. dc connect; The capacitor C dc The positive terminal of the capacitor C is connected to the positive terminal P of the DC bus. dc The negative terminal is connected to the negative terminal N of the DC bus; A DC bus voltage Ud is formed between the positive and negative terminals of the DC bus. The DC bus voltage Ud is used to provide DC energy storage for the nine-switch converter and stabilize the DC side voltage.

8. The compact combined energy router with power quality regulation capability according to claim 1, characterized in that, The nine-switch converter specifically includes: phase A bridge arm, phase B bridge arm, and phase C bridge arm; The A-phase bridge arm specifically includes switch modules S1, S2, and S3 connected in sequence; the B-phase bridge arm specifically includes switch modules S4, S5, and S6 connected in sequence; and the C-phase bridge arm specifically includes switch modules S7, S8, and S9 connected in sequence.

9. The compact combined energy router with power quality regulation capability according to claim 8, characterized in that, The switching modules S1, S2, S3, S4, S5, S6, S7, S8, and S9 are all composed of an insulated gate bipolar transistor T. k And an anti-parallel diode D k composition; The diode D k The anode of the insulated gate bipolar transistor T k The emitters are connected; The diode D k The cathode and the insulated gate bipolar transistor T k The collectors are connected.

10. The compact combined energy router with power quality regulation capability according to claim 8, characterized in that, The A-phase bridge arm has an upper output terminal A and a lower output terminal X, the B-phase bridge arm has an upper output terminal B and a lower output terminal Y, and the C-phase bridge arm has an upper output terminal C and a lower output terminal Z; The upper output terminal A, the upper output terminal B, and the upper output terminal C together form the first inverter stage; The lower output terminal X, the lower output terminal Y, and the lower output terminal Z together form the second inverter stage; The A, B, and C ports of the first inverter stage are connected to an LC filter, which is then connected in series with the output terminal of the first low-voltage winding via a transformer. Output terminal and output end connect; The X, Y, and Z ports of the second inverter stage are connected to an L-type filter, which is then connected in series to the input terminals A3, B3, and C3 of the three-phase nonlinear load.

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