An electrical energy router power module and an electrical energy router

Abstract

The application discloses a kind of electric energy router power module and electric energy router, electric energy router power module includes multi-winding high-frequency transformer, buffer branch, high-frequency converter, DC interface circuit and AC interface circuit, the AC positive and negative terminals of DC interface circuit on n1 windings in multi-winding high-frequency transformer constitute DC port;The AC positive and negative terminals of AC interface circuit on n2 windings constitute AC port;The number of AC port and DC port is arbitrary, and the power of each AC port or DC port is bidirectional flow.The electric energy router is composed of one or more electric energy router power modules, and the AC and DC ports of each power module are connected in series or parallel in different combination forms to form a medium-voltage DC port, a low-voltage DC port, a three-phase medium-voltage AC port and a three-phase low-voltage AC port, which can be applied to different voltage levels and power levels.The application can meet various functional requirements as a power network hub.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of power electronic power conversion, and relates to a power module of an electric energy router and the electric energy router. BACKGROUND

[0002] With the access of renewable energy power generation devices, energy storage devices and various types of electric energy loads, the traditional power system devices cannot meet the requirements of power supply diversity, energy multi-directional flow and active regulation of power flow, and cannot adapt to the needs of future power marketization. The power system is also developing towards the new stage of coordinated and optimized operation of "source-grid-load-storage", and will become the core and link of future energy internet. The electric energy router based on power electronic conversion technology not only can provide flexible and diversified interface electrical forms for different new energy power generation devices and different types of loads, but also can realize the ability of energy multi-directional flow and active control of power flow. Moreover, the integration with information technology enables the electric energy router to have communication and intelligent decision-making capabilities, and can realize the active management of energy flow in the power network according to the network operation state and the instructions of users and control centers. The electric energy router can become the hub of future power network, responsible for managing and controlling the energy flow within the sub-network and the energy exchange between the sub-network and the backbone network.

[0003] Currently, there are three typical electric energy router topologies, namely, the series-parallel topology composed of series H-bridges, the topology composed of modular multilevel technology and the topology based on the mixing modulation method. The series-parallel topology composed of series H-bridges can not only meet the demand of high voltage and large capacity, but also provide DC ports, has the basic requirement of multi-port for electric energy routing, can form a flexible networking form for energy internet, and meets the requirements of energy internet. However, this structure cannot provide medium voltage DC ports, and the use of a large number of transformers makes the device volume and weight very large and the cost high. Moreover, the single-phase structure of series connection causes the existence of twice frequency components of grid voltage in the transient power exchange process of each phase circuit, which further causes the low-frequency fluctuation of the capacitor voltage on the DC side, and makes the DC side capacitor value very large. The electric energy router topology of modular multilevel structure can not only provide higher voltage level ports, but also have higher power quality and conversion efficiency. However, the overall modularization degree is not high, the reliability is low, and there are problems such as circulating current and capacitor voltage fluctuation. The topology based on the mixing modulation method reduces the number of transformers and switching tubes by reducing the number of power conversion stages, and improves the power density. However, this topology, like the series H-bridge topology, cannot provide higher voltage level ports, and the ports do not have scalability. In addition, the above three topologies also have the problems of large DC side capacitor value, low module integration degree and non-expandable ports, which are difficult to realize large-scale popularization and use. SUMMARY

[0004] In view of the problems of the prior art, the purpose of the present application is to provide an electric energy router power module and an electric energy router, aiming to solve the problems of the current electric energy router circuit structure, such as the inability to provide a medium-voltage DC port, a large DC side capacitor, a low degree of module integration, and the difficulty in expanding the port.

[0005] The purpose of the present application is achieved by the following technical solutions:

[0006] An electric energy router power module, comprising a multi-winding high-frequency transformer, a buffer branch, a high-frequency converter, a DC interface circuit, and an AC interface circuit;

[0007] In n1 (n1 ≥ 0) windings of the multi-winding high-frequency transformer, one terminal of each winding is connected to one terminal of a buffer branch, the other terminal of the buffer branch is connected to an AC positive terminal of the high-frequency converter, an AC negative terminal of the high-frequency converter is connected to the other terminal of the winding, DC positive and negative terminals of the high-frequency converter are respectively connected to positive and negative poles of a DC capacitor C, and the positive and negative poles of the DC capacitor C are respectively connected to DC positive and negative terminals of the DC interface circuit, and the other two terminals of the DC interface circuit constitute a DC port.

[0008] In n2 (n2 ≥ 0) windings of the multi-winding high-frequency transformer, one terminal of each winding is connected to one terminal of a buffer branch, the other terminal of the buffer branch is connected to an AC positive terminal of the high-frequency converter, an AC negative terminal of the high-frequency converter is connected to the other terminal of the winding, DC positive and negative terminals of the high-frequency converter are respectively connected to positive and negative poles of a DC capacitor C, and the positive and negative poles of the DC capacitor C are respectively connected to DC positive and negative terminals of the AC interface circuit, and AC positive and negative terminals of the AC interface circuit constitute an AC port.

[0009] As a further improvement of the present application, the total number of windings n of the multi-winding high-frequency transformer can be two windings, three windings, or N windings; n = n1 + n2; the frequency of the multi-winding high-frequency transformer is any frequency in the range of several hundred hertz to several hundred kilohertz;

[0010] The number of phases of the high-frequency converter is single-phase, two-phase, or m-phase, and each phase is sequentially phase-shifted by 360° / m; m ≥ 1; the high-frequency converter is a half-bridge or full-bridge circuit; the high-frequency converter is two-level, three-level, or multi-level;

[0011] The buffer branch is an LC series resonance branch or a single L branch, and the inductance in the buffer branch can be the leakage inductance of the transformer winding.

[0012] As a further improvement of the present application, the DC interface circuit comprises a direct connection wire and a DC / DC converter; the DC / DC converter is a two-level single-phase half-bridge, a three-level or multi-level single-phase half-bridge;

[0013] The AC interface circuit comprises an AC / DC converter; the AC / DC converter is a two-level single-phase full-bridge, a three-level or multi-level single-phase full-bridge, an m-1 phase m-wire half-bridge, which can be two-level, three-level or multi-level.

[0014] As a further improvement of the application, the two-level single-phase half-bridge circuit comprises two power switch tubes S1 and S2, the power switch tubes S1 and S2 are connected in series to form a bridge arm, the middle point and the lower end of the bridge arm are respectively led out to constitute an AC positive terminal and an AC negative terminal, and the upper end and the lower end of the bridge arm are respectively led out to constitute a DC positive terminal and a DC negative terminal.

[0015] The two-level single-phase full-bridge circuit is composed of two single-phase half-bridges connected in parallel, the DC positive and negative terminals of the two single-phase half-bridges are respectively connected in parallel, and the middle points of the two half-bridges are respectively led out to constitute AC positive and negative terminals.

[0016] The three-level single-phase half-bridge circuit comprises four power switch tubes S1, S2, S3 and S4 and two diodes D1 and D2, the power switch tubes S1 and S2 are connected in series to form a bridge arm 1, the power switch tubes S3 and S4 are connected in series to form a bridge arm 2, the bridge arm 1 and the bridge arm 2 are connected in series to form a bridge arm 3, the middle point of the bridge arm 3 is led out to constitute an AC negative terminal, the positive electrode of the diode D1 is connected with the negative electrode of the diode D2 to form a bridge arm 4, the middle point of the bridge arm 4 is led out to constitute an AC negative terminal, the positive and negative electrodes of the bridge arm 4 are respectively connected with the middle points of the bridge arm 2 and the bridge arm 1, the negative electrode of a DC capacitor C1 is connected with the positive electrode of a DC capacitor C2, and the connection point is connected with the middle point of the bridge arm 4, and the upper and lower ends of the bridge arm 3 are respectively connected with the positive electrode of the DC capacitor C1 and the negative electrode of the DC capacitor C2 and then led out to constitute DC positive and negative terminals.

[0017] The three-level single-phase full-bridge circuit is composed of two three-level single-phase half-bridges connected in parallel, the DC positive and negative terminals of the two three-level single-phase half-bridges are respectively connected in parallel, the middle points of the bridge arm 4 of the two three-level half-bridges and the connection points of the two DC capacitors are connected together, and the middle points of the bridge arm 3 are respectively led out to constitute AC positive and negative terminals.

[0018] The power switch tube can be a diode or an IGBT, a MOSFET or any other arbitrary fully-controlled switch device.

[0019] As a further improvement of the application, when the buffer branch is an LC series resonant branch and the switching frequency of the high-frequency converter is close to the resonant frequency, the DC ports are directly constituted by the capacitors at the DC side of the high-frequency converter, and the high-frequency converter is a half-bridge or a full-bridge circuit; the power among the windings is decoupled, and then the phase shift angle of the square wave voltage generated by the high-frequency converter of each winding is adjusted to realize free distribution of power and energy routing among the windings.

[0020] When the buffer branch is an LC series resonant branch, and the switching frequency of the high-frequency converter is equal to the resonant frequency, the high-frequency converter is a half-bridge or full-bridge circuit; the direct current port is formed by connecting a direct current / direct current converter to the capacitor at the direct current side of the high-frequency converter; the power is freely distributed among the windings and the energy is routed by controlling the inductor current of the direct current / direct current converter of the direct current port and the power of the alternating current / direct current converter of the alternating current port.

[0021] When the buffer branch connected to the winding constituting the direct current port is a single L branch, the buffer branch connected to the winding constituting the alternating current port is an LC series resonant branch, and the switching frequency of the high-frequency converter is equal to the resonant frequency, the high-frequency converter is a full-bridge circuit; the direct current port is directly led out by the capacitor at the direct current side of the high-frequency converter; the power is freely distributed among the windings and the energy is routed by decoupling the power of the winding of the direct current port and controlling the power of the alternating current / direct current converter of the alternating current port.

[0022] An electrical energy router comprises one, two to k electrical energy router power modules; the alternating current / direct current ports of each electrical energy router power module are connected in series or parallel in different combinations to form a medium-voltage direct current port, a low-voltage direct current port, a three-phase medium-voltage alternating current port and a three-phase low-voltage alternating current port.

[0023] The number of the medium-voltage direct current port, the low-voltage direct current port, the three-phase medium-voltage alternating current port and the three-phase low-voltage alternating current port is zero, one to n.

[0024] As a further improvement of the present application, the medium-voltage direct current port is a single-polarity medium-voltage direct current port or a bipolar medium-voltage direct current port.

[0025] When the medium-voltage direct current port is bipolar, one electrical energy router power module leads out two direct current ports (H0, L0) and (H1, N1), and the positive and negative poles of the ports (H0, N0) of the k electrical energy router power modules are connected in series to form a medium-voltage direct current port (H, N), and the positive and negative poles of the ports (H1, N1) are connected in series to form a medium-voltage direct current port (N, L), and the neutral points N are connected together, and the ports (H, N) and (N, L) form a bipolar medium-voltage direct current port, and two ports are connected to a filter capacitor respectively.

[0026] When the medium-voltage direct current port is single-polarity, one electrical energy router power module leads out one direct current port (H0, L0), and the positive and negative poles of the ports (H0, L0) of the k electrical energy router power modules are connected in series to form a single-polarity medium-voltage direct current port (H, L), and the port (H, L) is connected to a filter capacitor.

[0027] As a further improvement of the present application, the low-voltage direct current port is a single-polarity low-voltage direct current port or a bipolar low-voltage direct current port.

[0028] When the low-voltage DC port is bipolar, one power module of the electric energy router leads out two DC ports (h0, n0) and (n0, l0), the ports (h0, n0) of the k power modules of the electric energy router are connected in parallel in sequence to form a low-voltage DC port (h, n), the ports (n0, l0) are connected in parallel in sequence to form a low-voltage DC port (n, l), the neutral points n are connected together, and the ports (h, n) and (n, l) form a bipolar low-voltage DC port, and the two ports are connected with a filter capacitor respectively;

[0029] When the low-voltage DC port is unipolar, one power module of the electric energy router leads out one DC port (h0, l0), the ports (h0, l0) of the k power modules of the electric energy router are connected in parallel in sequence to form a unipolar low-voltage DC port (h, l), and the port (h, l) is connected with a filter capacitor.

[0030] As a further improvement of the application, one power module of the electric energy router leads out three AC ports A0(A 0+ ,A 0- ), B0(B 0+ ,B 0- ) and C0(C 0+ ,C 0- ), the positive and negative poles of the AC ports A0(A 0+ ,A 0- ) of the k power modules of the electric energy router are connected in series in sequence to form an A phase, and then form a B phase and a C phase, and then connect an AC three-phase LC filter to form a three-phase medium-voltage AC port (A, B, C), and the negative poles of the three AC ports of the last power module connected in series are connected together to form a neutral point N.

[0031] As a further improvement of the application, there are three ways to form a three-phase low-voltage AC port, which are:

[0032] One power module of the electric energy router leads out three AC ports a0(a 0+ ,a 0- ), b0(b 0+ ,b 0- ) and c0(c 0+ ,c 0- ), the positive poles of the AC ports a0(a 0+ ,a 0- ) of the k power modules of the electric energy router are connected in series with an inductor first, and then connected in parallel in sequence to form an a phase, and then form a b phase and a c phase, and then connect an AC three-phase LC filter to form a three-phase low-voltage AC port (a, b, c), and the negative poles of the three AC ports of each power module are connected together to form a neutral point n; or,

[0033] One DC port of one power module of the electric energy router is connected with four terminals a, b, c and n of the three-phase four-bridge inverter to form a three-phase low-voltage AC port and a low-voltage DC port, and electrical isolation is realized; or when the low-voltage DC port is formed, one DC port (h0, l0) of one power module of the electric energy router is connected with four terminals a, b, c and n of the three-phase four-bridge inverter, and finally a three-phase low-voltage AC port and a low-voltage DC port are formed to realize electrical isolation; a, b and c terminals of k power modules of the electric energy router are connected in series with an inductor, and then connected in parallel to form a three-phase low-voltage AC port (a, b, c), and n terminals are directly connected in parallel to form a neutral point n; or,

[0034] One DC port (p, q) of one power module of the electric energy router is connected with the three-phase four-bridge inverter and the three-phase LC filter to form a three-phase low-voltage AC port (a, b, c) and a neutral point n, and electrical isolation is realized; or the low-voltage DC bus provided by the low-voltage DC port (h, l) of the k power modules of the electric energy router is connected with the three-phase four-bridge inverter and the three-phase LC filter to form a three-phase low-voltage AC port (a, b, c) and a neutral point n, and electrical isolation is not realized.

[0035] Compared with the prior art, the electric energy router has the following beneficial effects:

[0036] The electric energy router has multiple AC / DC ports, including a medium-voltage three-phase AC port, a high-voltage DC port, a low-voltage DC port and a low-voltage three-phase AC port; each port of the electric energy router is electrically isolated through a multi-winding high-frequency transformer; the electric energy router can offset the two-frequency power fluctuation of each phase of the AC port through a magnetic circuit, reduce the power buffered by the DC side capacitor, and thus reduce the capacitance value of the DC side capacitor; the electric energy router can realize arbitrary expansion of the port by increasing the number of windings of the multi-winding high-frequency transformer; the electric energy router has module integration and high integration, clear structure, simple control, is conducive to industrial production, easy to design in series and flexibly control power flow. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0038] Figure 1 is a structural schematic diagram of a power module of the electric energy router of the present application;

[0039] Figure 2 is a structural schematic diagram of a medium-voltage DC port of the electric energy router of the present application;

[0040] Figure 3 is a structural schematic diagram of a low-voltage DC port of the electric energy router of the present application;

[0041] Figure 4 is a structural schematic diagram of a three-phase medium-voltage AC port of the electric energy router of the present application;

[0042] Figure 5 is a structural schematic diagram of a three-phase low-voltage AC port of the electric energy router of the present application;

[0043] Figure 6 is a structural schematic diagram of a ten-winding medium / low-voltage AC / DC hybrid four-port electric energy router of an embodiment of the present application;

[0044] Figure 7 is a four-port voltage, current and power simulation waveform diagram of an embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to make the purpose and technical solutions of the present application clearer and more convenient to understand, the present application is further described in detail below in combination with the drawings and embodiments, and the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0046] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more. In the description of the present application, it needs to be explained that, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0047] The technical solutions of the present application will be described clearly and completely in combination with the drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of the present application.

[0048] The power module of the electric energy router of the present application is described in Figure 1 , Figure 1 The structure diagram of the power module of the electric energy router of the present application is shown in Figure 1 As shown in (a) of Fig. 1, the power module of the electric energy router is composed of five parts, which are multi-winding high-frequency transformer, buffer branch, high-frequency converter, DC interface circuit and AC interface circuit.

[0049] Specifically, n1 (n1≥0) windings in the multi-winding high-frequency transformer are used to construct the DC port. One terminal of each winding is connected with one terminal of a buffer branch, the other terminal of the buffer branch is connected with the AC positive terminal of the high-frequency converter, the AC negative terminal of the high-frequency converter is connected with the other terminal of the winding, the DC positive and negative terminals of the high-frequency converter are connected with the positive and negative poles of the DC capacitor C respectively, the positive and negative poles of the DC capacitor C are connected with the DC positive and negative terminals of the DC interface circuit respectively, and the other two terminals of the DC interface circuit constitute the DC port.

[0050] The n2 (n2≥0) windings in the multi-winding high-frequency transformer are used to construct an AC port. One terminal of each winding is connected to one terminal of a buffer branch, the other terminal of the buffer branch is connected to an AC positive terminal of the high-frequency converter, an AC negative terminal of the high-frequency converter is connected to the other terminal of the winding, and DC positive and negative terminals of the high-frequency converter are connected to positive and negative terminals of a DC capacitor C respectively, and the positive and negative terminals of the DC capacitor C are connected to DC positive and negative terminals of an AC interface circuit respectively, and the AC positive and negative terminals of the AC interface circuit constitute an AC port.

[0051] Specifically, the total number of windings n of the multi-winding high-frequency transformer can be two windings, three windings, or N windings; n=n1+n2; the frequency of the multi-winding high-frequency transformer is any frequency in the range of several hundred hertz to several hundred kilohertz.

[0052] Specifically, the structure of the high-frequency converter can be any one of (c)-(g) shown in Figure 1 , including a single-phase half-bridge, a single-phase full-bridge, a three-level or multi-level single-phase half-bridge, a three-level or multi-level single-phase full-bridge, an m-1 phase m-wire half-bridge, which can be two-level, three-level or multi-level.

[0053] Specifically, the buffer branch can be any one of (h)-(i) shown in Figure 1 , including an LC resonant branch and a single-L branch, and the inductance in the buffer branch can be the leakage inductance of the transformer winding.

[0054] Specifically, the DC interface circuit includes a direct connection wire and a DC / DC converter, and the structure of the direct connection wire is (b) shown in Figure 1 , and the structure of the DC / DC converter can be any one of (c)-(d) shown in Figure 1 , including a two-level single-phase half-bridge, a three-level or multi-level single-phase half-bridge.

[0055] Specifically, the structure of the AC interface circuit includes an AC / DC converter, and the structure of the AC / DC converter can be any one of (e)-(g) shown in Figure 1 , including a two-level single-phase full-bridge, a three-level or multi-level single-phase full-bridge, and an m-1 phase m-wire half-bridge, which can be two-level, three-level or multi-level.

[0056] Specifically, as shown in (c) in Figure 1 , the two-level single-phase half-bridge circuit includes two power switch tubes S1 and S2, the power switch tubes S1 and S2 are connected in series to form a bridge arm, the midpoint of the bridge arm and the lower end of the bridge arm are respectively led out to constitute an AC positive terminal and an AC negative terminal, and the upper end of the bridge arm and the lower end of the bridge arm are respectively led out to constitute a DC positive terminal and a DC negative terminal.

[0057] Specifically, as shown in Figure 1 The two-level single-phase full-bridge circuit is composed of two single-phase half-bridge circuits in parallel. The positive and negative DC terminals of the two single-phase half-bridge circuits are connected in parallel, and the midpoints of the two half-bridge circuits are respectively led out to form the positive and negative AC terminals.

[0058] Specifically, as shown in Figure 1 The three-level single-phase half-bridge circuit includes four power switching tubes S1, S2, S3 and S4 and two diodes D1 and D2. The power switching tubes S1 and S2 are connected in series to form a bridge arm 1, the power switching tubes S3 and S4 are connected in series to form a bridge arm 2, the bridge arm 1 and the bridge arm 2 are connected in series to form a bridge arm 3, the midpoint of the bridge arm 3 is led out to form an AC negative terminal, the positive electrode of the diode D1 is connected with the negative electrode of the diode D2 to form a bridge arm 4, the midpoint of the bridge arm 4 is led out to form an AC negative terminal, the positive and negative electrodes of the bridge arm 4 are respectively connected with the midpoints of the bridge arm 2 and the bridge arm 1, the negative electrode of the DC capacitor C1 is connected with the positive electrode of the DC capacitor C2, and the connection point is connected with the midpoint of the bridge arm 4, and the upper and lower ends of the bridge arm 3 are respectively connected with the positive electrode of the DC capacitor C1 and the negative electrode of the DC capacitor C2 and then led out to form the positive and negative DC terminals.

[0059] Specifically, as shown in Figure 1 The three-level single-phase full-bridge circuit is composed of two three-level single-phase half-bridge circuits in parallel. The positive and negative DC terminals of the two three-level single-phase half-bridge circuits are connected in parallel, the midpoints of the bridge arm 4 of the two three-level half-bridge circuits and the connection points of the two DC capacitors are connected together, and the midpoints of the bridge arm 3 are respectively led out to form the positive and negative AC terminals.

[0060] Specifically, the power switching tubes used in each component structure of the power router power module can be IGBT, MOSFET or any other fully controlled switching device.

[0061] Specifically, when the buffer branch is an LC series resonant branch and the switching frequency of the high-frequency converter is equal to the resonant frequency, the DC side capacitor of the high-frequency converter is connected with a DC / DC converter at both ends to form a DC port, and the high-frequency converter can be a half-bridge or a full-bridge circuit; by controlling the inductance current of the DC / DC converter of the DC port and the power control of the AC / DC converter of the AC port, the power free distribution and energy routing among windings are realized.

[0062] Specifically, when the buffer branch connected with the winding constituting the DC port is a single L branch, the buffer branch connected with the winding constituting the AC port is an LC series resonant branch, and the switching frequency of the high-frequency converter is equal to the resonant frequency, the DC side capacitor of the high-frequency converter is directly led out to form a DC port, and the high-frequency converter is a full-bridge circuit; by decoupling the power of the winding of the DC port and controlling the power of the AC / DC converter of the AC port, the power free distribution and energy routing among windings are realized.

[0063] The composition of the low-voltage AC / DC four ports in the electric energy router is specifically described as follows:

[0064] The electric energy router is composed of one, two to k electric energy router power modules, the AC / DC ports of each electric energy router power module are connected in series or parallel in different combination forms to form a medium-voltage DC port, a low-voltage DC port, a three-phase medium-voltage AC port and a three-phase low-voltage AC port, which are applied to occasions with different voltage levels and power levels. The number of the medium-voltage DC port, the low-voltage DC port, the three-phase medium-voltage AC port and the three-phase low-voltage AC port is zero, one to n.

[0065] The composition method of the medium / low-voltage AC / DC mixed four ports of the electric energy router is as follows.

[0066] The medium-voltage DC port is shown in Figure 2 , Figure 2 is a schematic diagram of the composition of the medium-voltage DC port of the electric energy router. The medium-voltage DC port can be a single-polarity medium-voltage DC port and a bipolar medium-voltage DC port.

[0067] When the medium-voltage DC port is bipolar, a positive and negative pole of a DC port of one electric energy router power module is connected in series to form a DC port (H0, L0), a positive and negative pole of a DC port (H1, N1) is connected in series to form a DC port (H1, N1), and (H0, L0) and (H1, N1) are led out as two DC ports of one electric energy router power module.

[0068] Specifically, as shown in Figure 5 (H0, N0) ports of k electric energy router power modules are connected in series in positive and negative poles to form a medium-voltage DC port (H, N), (H1, N1) ports are connected in series in positive and negative poles to form a medium-voltage DC port (N, L), the neutral point N is connected together, (H, N) and (N, L) form a bipolar medium-voltage DC port, and two ports are connected with a filter capacitor respectively.

[0069] When the medium-voltage DC port is single-polarity, a positive and negative pole of a DC port of one electric energy router power module is connected in series to form a DC port (H0, L0), and (H0, L0) is led out as one DC port of one electric energy router power module.

[0070] Specifically, as shown in Figure 5 (H0, L0) ports of k electric energy router power modules are connected in series in positive and negative poles to form a single-polarity medium-voltage DC port (H, L), and (H, L) is connected with a filter capacitor.

[0071] Specifically, when the buffer branch is an LC series resonance branch, the switching frequency of the high-frequency converter is equal to the resonance frequency, and the DC interface circuit is a DC / DC converter. At this time, when the medium-voltage DC port is bipolar, the positive pole of each (H0, N0) port of the k electric energy router power modules is first connected in series with an inductor, and then the positive and negative poles are connected in series to form the medium-voltage DC port (H, N); the negative pole of each (H1, N1) port is first connected in series with an inductor, and then the positive and negative poles are connected in series to form the medium-voltage DC port (N, L), and the neutral points N are connected together, (H, N) and (N, L) form a bipolar medium-voltage DC port, and two ports are respectively connected with a filter capacitor; when the medium-voltage DC port is unipolar, the positive pole of each (H0, L0) port of the k electric energy router power modules is first connected in series with an inductor, and then the positive and negative poles are connected in series to form the unipolar medium-voltage DC port (H, L), and (H, L) is connected with a filter capacitor.

[0072] The low-voltage DC port is shown in Figure 3 , Figure 3 is a schematic diagram of the low-voltage DC port of the electric energy router of the application. The medium-voltage DC port can be a unipolar low-voltage DC port and a bipolar low-voltage DC port.

[0073] When the low-voltage DC port is bipolar, the positive and negative poles of d DC ports of one electric energy router power module are connected in series to form the DC port (h1, n1), the positive and negative poles of e DC ports are connected in series to form the DC port (n1, l1), and other DC ports formed in this way (h2, n2), (h3, n3) are connected in parallel with (h1, n1) to form the DC port (h0, n0), (n2, l2), (n3, l3) are connected in parallel with (n1, l1) to form the DC port (n0, l0), and (h0, n0) and (n0, l0) are led out as two DC ports of one electric energy router power module.

[0074] Specifically, as shown in Figure 3 (h0, n0) ports of the k electric energy router power modules are connected in parallel to form the low-voltage DC port (h, n), and (n0, l0) ports are connected in parallel to form the low-voltage DC port (n, l), and the neutral points n are connected together, (h, n) and (n, l) form a bipolar low-voltage DC port, and two ports are respectively connected with a filter capacitor.

[0075] When the low-voltage DC port is unipolar, the positive and negative terminals of the 2f+1 DC ports of a power router module are connected in series to form DC port (h1,l1). Other DC ports (h2,l2), (h3,l3), etc., which are composed of 2f+1 DC ports, are connected in parallel with (h1,l1) to form DC port (h0,l0). (h0,l0) is led out as a DC port of a power router module.

[0076] Specifically, such as Figure 5 As shown in Figure (b), the (h0,l0) ports of the k power modules of the power router are connected in parallel to form a unipolar low-voltage DC port (h,l), and a filter capacitor is then connected to (h,l).

[0077] Specifically, when the buffer branch is an LC series resonant branch, the switching frequency of the high-frequency converter is equal to the resonant frequency, and the DC interface circuit is a DC / DC converter, then, when the medium-voltage DC port is bipolar, the positive terminals of the (h0,n0) ports of the k power router modules are first connected in series with an inductor, and then connected in parallel to form a low-voltage DC port (h,n). The negative terminals of the (n0,l0) ports are first connected in series with an inductor, and then connected in parallel to form a low-voltage DC port (n,l). The neutral points n are connected together, and (h,n) and (n,l) form a bipolar low-voltage DC port. Each port is then connected to a filter capacitor. When the medium-voltage DC port is unipolar, the positive terminals of the (h0,l0) ports of the k power router modules are first connected in series with an inductor, and then connected in parallel to form a unipolar low-voltage DC port (h,l). (h,l) is then connected to a filter capacitor.

[0078] 3. Three-phase medium-voltage AC port

[0079] Please see Figure 4 , Figure 4 This is a schematic diagram of the three-phase medium-voltage AC port configuration of the power router of this invention.

[0080] The positive and negative terminals of the g AC ports of a power router module are connected in series to form AC port A0 (A 0+ A 0- Similarly, this forms the AC port B0 (B 0+ B 0- ) and C0(C 0+ C 0- A0, B0, and C0 are the three AC ports of a power router module.

[0081] Specifically, such as Figure 4 As shown, the AC ports A0 (A) of the power modules of the k power routers are... 0+ A 0-The positive and negative poles of the k electric energy router power modules are connected in series to form phase A, and phases B and C are formed in the same way. After being connected with an AC three-phase LC filter, a three-phase medium-voltage AC port (A, B, C) is formed. The negative poles of the three AC ports of the last electric energy router power module are connected together to form a neutral point N.

[0082] The three-phase low-voltage AC port can be seen from Figure 5 , Figure 5 The three-phase low-voltage AC port of the electric energy router is shown in the schematic diagram. The three-phase low-voltage AC port has three forms, which are:

[0083] 1) The positive and negative poles of the h AC ports of one electric energy router power module are connected in series to form an AC port a0 (a 0+ ,a 0- ), and AC ports b0 (b 0+ ,b 0- ) and c0 (c 0+ ,c 0- ) are formed in the same way. a0, b0 and c0 are three AC ports of one electric energy router power module.

[0084] Specifically, as shown in (a) of Figure 5 , the positive poles of the AC ports a0 (a 0+ ,a 0- ) of the k electric energy router power modules are connected in series with an inductor, and then connected in parallel to form phase A, and phases B and C are formed in the same way. After being connected with an AC three-phase LC filter, a three-phase low-voltage AC port (a, b, c) is formed. The negative poles of the three AC ports of each electric energy router power module are connected together to form a neutral point n.

[0085] 2) One DC port of one electric energy router power module is connected with a three-phase four-bridge inverter to form a, b, c and n terminals. At this time, the three-phase low-voltage AC port and the low-voltage DC port finally formed realize electrical isolation; or when forming a low-voltage DC port, the DC port (h0, l0) of one electric energy router power module is connected with a three-phase four-bridge inverter to form a, b, c and n terminals. At this time, the three-phase low-voltage AC port and the low-voltage DC port finally formed have no electrical isolation.

[0086] Specifically, as shown in (b) of Figure 5 , the a, b and c terminals of the k electric energy router power modules are connected in series with an inductor, and then connected in parallel to form a three-phase low-voltage AC port (a, b, c) after being connected with an AC three-phase LC filter. The n terminals are directly connected in parallel to form a neutral point n.

[0087] 3) One DC port of one electric energy router power module is connected to form a DC port (p, q).

[0088] Specifically, as shown in (c), the DC ports (p, q) of the k electric energy router power modules are connected in parallel to connect a three-phase four-leg inverter, and then an AC three-phase LC filter is connected to form a three-phase low-voltage AC port (a, b, c) and a neutral point n, at this time, the three-phase low-voltage AC port and the low-voltage DC port are electrically isolated. Figure 5

[0089] Specifically, as shown in (d), the low-voltage DC bus provided by the low-voltage DC port (h, l) of the aforementioned k electric energy router power modules is connected to connect a three-phase four-leg inverter, and then an AC three-phase LC filter is connected to form a three-phase low-voltage AC port (a, b, c) and a neutral point n, at this time, the three-phase low-voltage AC port and the low-voltage DC port are not electrically isolated. Figure 6

[0090] Based on the various constitutions of the AC / DC low-voltage four-port proposed in the present application, all other constitutions obtained by those skilled in the art without creative labor, such as various combinations between different constitutions and methods derived from the various constitutions proposed in the present application, all belong to the scope of protection of the present application.

[0091] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0092] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application herein only for the purpose of describing specific embodiments and is not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0093] Embodiments

[0094] Please refer to Figure 6 , Figure 6 is a ten-winding low-voltage AC / DC hybrid four-port electric energy router topology of an embodiment of the present application. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not intended to limit the present application.

[0095] Specifically, as shown in (c), the DC ports (p, q) of the k electric energy router power modules are connected in parallel to connect a three-phase four-leg inverter, and then an AC three-phase LC filter is connected to form a three-phase low-voltage AC port (a, b, c) and a neutral point n, at this time, the three-phase low-voltage AC port and the low-voltage DC port are electrically isolated. Figure 6 ​​As shown in (a), in one power module of the power router, the high-frequency transformer has ten windings, the DC interface circuit is a single-phase half-bridge circuit, and the AC interface circuit is a single-phase full-bridge circuit. The ten windings form four DC ports and six AC ports. The first DC port forms a DC port O1, and the second DC port forms a DC port O2. The third DC port and the fourth DC port are connected in series to form a bipolar DC port (h0, l0), and a neutral point n0 is formed from the center point.

[0096] Specifically, as shown in (a) and (b), the positive poles of the O1 ports of the ten power modules are connected in series with an inductor, and then connected in series in order to form a medium-voltage DC port (H, N) of the (+10kV) voltage level. The negative poles of the O2 ports are connected in series with an inductor, and then connected in order to form a medium-voltage DC port (N, L) of the (-10kV) voltage level. The neutral point N is connected together, and the (H, N) and (N, L) form a bipolar medium-voltage DC port of the (+10kV, -10kV) voltage level. Figure 6

[0097] Specifically, as shown in (a) and (b), the positive poles of the O1 ports of the ten power modules are connected in series with an inductor, and then connected in series in order to form a medium-voltage DC port (H, N) of the (+10kV) voltage level. The negative poles of the O2 ports are connected in series with an inductor, and then connected in order to form a medium-voltage DC port (N, L) of the (-10kV) voltage level. The neutral point N is connected together, and the (H, N) and (N, L) form a bipolar medium-voltage DC port of the (+10kV, -10kV) voltage level. Figure 7

[0098] Specifically, the bipolar medium-voltage DC port (H, L) and the bipolar low-voltage DC port (h, l) are connected to a (+10kV, -10kV) medium-voltage DC source and a (+375V, -375V) low-voltage DC source, respectively. The three-phase medium-voltage AC port (A, B, C) and the three-phase low-voltage AC port (a, b, c) are connected to a three-phase load, respectively.

[0099] Through the control of the inductor current of the DC / DC converter of the DC port and the control of the AC / DC converter of the AC port, the power is freely distributed among the windings and the energy is routed.​​

[0100] The simulation parameters of the electric energy router model designed in the above idea are collected in Table 1, and the simulation model of the ten-winding medium and low voltage AC-DC hybrid four-port electric energy router constructed by Matlab / Simulink achieves the expected design goal and realizes the control function according to the simulation parameters. The simulation waveforms are collected in Figure 7 .

[0101] Figure 7 is the four-port voltage, current and power simulation waveform diagram of the embodiment of the present application. As shown in ​ , (a) is the ±10kV medium voltage DC port voltage waveform; (b) is the ±375V low voltage DC port voltage waveform; (c) is the ±10kV medium voltage DC port current waveform; (d) is the ±375V low voltage DC port current waveform; (e) is the three-phase medium voltage AC port voltage waveform; (f) is the three-phase medium voltage AC port current waveform; (g) is the three-phase low voltage AC port voltage waveform; (h) is the three-phase low voltage AC port current waveform; (i) is the medium and low voltage AC-DC hybrid four-port power change waveform.

[0102] When the simulation model is normally started, the ±10kV medium voltage DC port outputs 1MW of power, the ±375V low voltage DC port does not output power, and the three-phase medium voltage AC port and the three-phase low voltage AC port each absorbs 50% of the power. At t=1s, the ±10kV medium voltage DC port power command changes from 100% output power to 50% output power, and the ±375V low voltage DC port changes from no power output to 50% output power; the three-phase medium voltage AC port power command changes from 50% absorption power to 100% absorption power, and the three-phase low voltage AC port power command changes from 50% absorption power to no absorption power. The power of the four ports is distributed and kept stable according to the power command. In the entire simulation process, the present application can quickly control the power of each port according to the command, proving its good energy routing function.

[0103] Table 1 Simulation parameters of the electric energy router model

[0104]

[0105] The above only describes the preferred embodiments of the present application, but not all embodiments, and does not limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application are included in the protection scope of the present application.

[0106] It should be noted that in the description of the present application, the terms "first", "second", etc. are only used for the purpose of description and distinguishing similar objects, and there is no sequence between them, nor can it be understood as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise stated, the meaning of "multiple" is two or more.

[0107] It should be understood that the above description is for illustration only and not for limitation. Many embodiments and many applications other than those provided in the examples will be apparent to those skilled in the art from the foregoing description. The scope of the present teachings should not be determined with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. The omission in the foregoing description of any aspect of the subject matter disclosed herein is not a disclaimer of such subject matter, nor should it be construed as a disavowal of such subject matter as part of the disclosed application. The power system is developing towards a new stage of "source-grid-load-storage" coordinated optimization operation, and will become the core and link of future energy internet. As the future power network hub, the electric energy router has great economic potential. The electric energy router of the present application has multiple AC / DC ports, each port realizes electrical isolation, the DC side capacitor has small capacity, the port can be arbitrarily expanded, has module integration and high integration, clear structure, simple control, is conducive to industrial production, easy to design series and flexible flow control, etc. It can meet the various functional requirements of the power network hub and has expected economic benefits.

[0108] The energy internet is the future development trend of the power system, and the electric energy router can become the hub of the future power network, responsible for managing and controlling the energy flow within the subnetwork and the energy exchange between the subnetwork and the backbone network. However, the circuit structure of the electric energy router proposed so far has some technical problems. The electric energy router of the present application proposes a new circuit structure, which can solve the problems of not being able to provide medium-voltage DC ports, large DC side capacitor capacity, low module integration, and not easy to expand the port of the current typical electric energy router circuit structure, and has the potential to become the preferred choice in the future domestic technology market. Specifically, when the buffer branch is an LC series resonant branch, and the switching frequency of the high-frequency converter is close to the resonant frequency, the DC port is directly formed by the DC side capacitor of the high-frequency converter, and the high-frequency converter can be a half-bridge or full-bridge circuit; by decoupling the power between the windings, and then adjusting the phase shift angle of the square wave voltage generated by the high-frequency converter of each winding, the power between the windings can be freely distributed and the energy can be routed.

[0109] The above merely illustrates the preferred embodiments of the present application, and does not limit the present application in any way. Any simple modification, change, and equivalent structural change of the above embodiments according to the technical essence of the present application are still within the protection scope of the technical solution of the present application.

[0110] The above embodiments are merely used for illustrating the technical solution of the present application but not limiting the present application. Although the present application is described in detail with reference to the above embodiments, the ordinary skilled in the art can still modify or equivalently replace the specific implementation of the present application without departing from the spirit and scope of the present application, and these modifications or equivalent replacements are still within the protection scope of the claims of the present application.

Claims

1. An electrical energy router power module, characterized by, The power module comprises a multi-winding high-frequency transformer, a buffer branch, a high-frequency converter, a DC interface circuit and an AC interface circuit. Multi-winding high-frequency transformer Each of the windings is connected to one terminal of a buffer branch, the other terminal of the buffer branch is connected to an AC positive terminal of the high-frequency converter, an AC negative terminal of the high-frequency converter is connected to the other terminal of the winding, DC positive and negative terminals of the high-frequency converter are respectively connected to positive and negative poles of a DC capacitor C, the positive and negative poles of the DC capacitor C are respectively connected to DC positive and negative terminals of a DC interface circuit, and the other two terminals of the DC interface circuit constitute a DC port. Multi-winding high-frequency transformer Each of the windings is connected to one terminal of a buffer branch, the other terminal of the buffer branch is connected to an AC positive terminal of the high-frequency converter, an AC negative terminal of the high-frequency converter is connected to the other terminal of the winding, DC positive and negative terminals of the high-frequency converter are respectively connected to positive and negative poles of a DC capacitor C, the positive and negative poles of the DC capacitor C are respectively connected to DC positive and negative terminals of an AC interface circuit, and AC positive and negative terminals of the AC interface circuit constitute an AC port. When the buffer branch is an LC series resonant branch and the switching frequency of the high-frequency converter is close to the resonant frequency, the DC port is directly formed by the capacitor at the DC side of the high-frequency converter, and the high-frequency converter is a half-bridge or full-bridge circuit; the power among the windings is decoupled, and the phase shift angle of the square wave voltage generated by the high-frequency converter is adjusted to realize free distribution of power among the windings and energy routing. When the buffer branch is an LC series resonant branch and the switching frequency of the high-frequency converter is equal to the resonant frequency, the DC port is formed by connecting the DC / DC converter to the capacitor at the DC side of the high-frequency converter, and the high-frequency converter is a half-bridge or full-bridge circuit; the inductance current of the DC / DC converter of the DC port and the power control of the AC / DC converter of the AC port are controlled to realize free distribution of power among the windings and energy routing. When the buffer branch connected to the winding forming the DC port is a single-L branch and the buffer branch connected to the winding forming the AC port is an LC series resonant branch, and the switching frequency of the high-frequency converter is equal to the resonant frequency, the DC port is directly formed by the capacitor at the DC side of the high-frequency converter, and the high-frequency converter is a full-bridge circuit; the power of the winding of the DC port is decoupled, and the power control of the AC / DC converter of the AC port is controlled to realize free distribution of power among the windings and energy routing.

2. The power module of claim 1, wherein: The total number of windings of the multi-winding high-frequency transformer is two windings, three windings or windings; The frequency of the multi-winding high-frequency transformer is any frequency in the range of several hundred hertz to several hundred kilohertz. The phase number of the high-frequency converter is single-phase, two-phase or m-phase, each phase is sequentially phase-shifted ; m≥1; the high-frequency converter is a half-bridge or full-bridge circuit; the high-frequency converter is two-level or multi-level; the buffer branch is an LC series resonant branch or a single-L branch, and the inductance in the buffer branch is the leakage inductance of the transformer winding.

3. The power module of claim 1, wherein: the DC interface circuit comprises a direct connection wire and a DC / DC converter; the DC / DC converter is a two-level single-phase half-bridge circuit or a multi-level single-phase half-bridge circuit; the AC interface circuit comprises an AC / DC converter; the AC / DC converter is a two-level single-phase full-bridge circuit, a multi-level single-phase full-bridge circuit, an m-1 phase m-wire half-bridge circuit, and the m-1 phase m-wire half-bridge circuit is a two-level half-bridge circuit or a multi-level half-bridge circuit.

4. The power module of claim 3, wherein: The two-level single-phase half-bridge circuit comprises two power switch tubes , power switch tubes and are connected in series to form a bridge arm, the bridge arm midpoint and the bridge arm lower end are respectively led out to constitute an AC positive terminal and an AC negative terminal, and the bridge arm upper end and the bridge arm lower end are respectively led out to constitute a DC positive terminal and a DC negative terminal; the two-level single-phase full-bridge circuit is formed by connecting two single-phase half-bridges in parallel; the DC positive and negative terminals of the two single-phase half-bridges are connected in parallel, and the midpoints of the two half-bridges are connected to form AC positive and negative terminals; The three-level single-phase half-bridge circuit comprises four power switch tubes and two diodes , the power switch tubes and are connected in series to form a bridge arm 1, the power switch tubes and are connected in series to form a bridge arm 2, the bridge arm 1 and the bridge arm 2 are connected in series to form a bridge arm 3, the midpoint of the bridge arm 3 is led out to form an alternating negative terminal, the positive electrode of the diode is connected with the negative electrode of the diode to form a bridge arm 4, the midpoint of the bridge arm 4 is led out to form an alternating negative terminal, the positive and negative electrodes of the bridge arm 4 are connected with the midpoints of the bridge arm 2 and the bridge arm 1 respectively, the negative electrode of a direct-current capacitor is connected with the positive electrode of a direct-current capacitor and the connecting point is connected with the midpoint of the bridge arm 4, the upper and lower ends of the bridge arm 3 are connected with the positive electrode of the direct-current capacitor and the negative electrode of a direct-current capacitor respectively and then led out to form direct-current positive and negative terminals; the three-level single-phase full-bridge circuit is formed by connecting two three-level single-phase half-bridges in parallel; the DC positive and negative terminals of the two three-level single-phase half-bridges are connected in parallel, the midpoint of bridge arm 4 of the two three-level half-bridges and the connection point of the two DC capacitors are connected together, and the midpoints of bridge arm 3 are connected to form AC positive and negative terminals; the power switch tube is a diode or an IGBT or MOSFET fully controlled switch device.

5. An electrical energy router, characterized by: The electric energy router power module comprises one, two to k electric energy router power modules as claimed in any one of claims 1 to 4, and the AC-DC ports of each electric energy router power module are connected in series or parallel in different combinations to form a medium-voltage DC port, a low-voltage DC port, a three-phase medium-voltage AC port and a three-phase low-voltage AC port. The number of the medium-voltage DC port, the low-voltage DC port, the three-phase medium-voltage AC port and the three-phase low-voltage AC port is zero, one to n.

6. The electric energy router according to claim 5, characterized in that: The medium-voltage DC port is a single-polarity medium-voltage DC port or a bipolar medium-voltage DC port. When the medium-voltage direct-current port is bipolar, a first direct-current port is led out by one power module of the electric energy router and a second direct-current port , the first direct-current ports of the k power modules of the electric energy router are connected in series in positive-negative order to form a first medium-voltage direct-current port , the second direct-current ports are connected in series in positive-negative order to form a second medium-voltage direct-current port , the neutral points N are connected together, and the first medium-voltage direct-current port and the second medium-voltage direct-current port form a bipolar medium-voltage direct-current port, and the two ports are respectively connected with one filter capacitor. When the medium voltage DC port is single polarity, one power module of the power router leads out one DC port Each DC port of the k power modules of the power router The positive and negative poles are connected in series to form a single polarity medium voltage DC port The medium voltage DC port And connect a filter capacitor again.

7. The electric energy router according to claim 5, characterized in that: The low-voltage DC port is a single-polarity low-voltage DC port or a bipolar low-voltage DC port. When the low-voltage DC port is bipolar, a power router power module leads out the first DC port. Second DC port The first DC port of each of the k power router power modules The first low-voltage DC port is formed by connecting them in parallel sequentially. Each second DC port The second low-voltage DC port is formed by connecting them in parallel. Neutral points n are connected together, first low-voltage DC port Second low voltage DC port This forms a bipolar low-voltage DC port, and a filter capacitor is then connected to each of the two ports. When the low-voltage DC port is single-polarity, one power module of the electric energy router leads out one DC port The DC ports of the k power modules of the electric energy router are connected in parallel in sequence to form a single-polarity low-voltage DC port The low-voltage DC port is connected with a filter capacitor again.

8. The electric energy router according to claim 5, characterized in that: An electric energy router power module leads out three alternating current ports , and The alternating current ports of the k electric energy router power modules are connected in series in order to form phase A, and further form phase B and phase C, and then connect an alternating current three-phase LC filter to form a three-phase medium voltage alternating current port The negative poles of the three alternating current ports of the last electric energy router power module in series are connected together to form a neutral point N.

9. The electric energy router according to claim 6, characterized in that: The three-phase low-voltage AC port is formed in three ways, respectively as follows: A power router's power module has three AC ports. , and Each AC port of the k power router modules An inductor is first connected in series with the positive terminal, and then connected in parallel to form phase a, followed by phases b and c. A three-phase AC LC filter is then connected to form a three-phase low-voltage AC port. The negative terminals of the three AC ports of each power router's power module are connected together to form a neutral point n; or, One DC port of one power module of the electric energy router is connected with four terminals a, b, c, n of the three-phase four-bridge inverter to form a three-phase low-voltage AC port and a low-voltage DC port, which realize electrical isolation; or when forming the low-voltage DC port, one DC port of one power module of the electric energy router is connected with four terminals a, b, c, n of the three-phase four-bridge inverter The three-phase four-bridge inverter is connected with four terminals a, b, c, n, and the three-phase low-voltage AC port and the low-voltage DC port formed finally realize electrical isolation; the terminals a, b, c of the k power modules of the electric energy router are connected in series with an inductor first, and then connected in parallel to form the three-phase low-voltage AC port The terminals n are directly connected in parallel to form the neutral point n; Or, One DC port is led out from one power module of the power router The DC ports of the k power routers are connected in parallel A three-phase four-leg inverter is connected, and an AC three-phase LC filter is further connected to form a three-phase low-voltage AC port and a neutral point n, at this time, the three-phase low-voltage AC and low-voltage DC ports formed achieve electrical isolation; or the low-voltage DC bus provided by the foregoing k power modules of the power router connects a three-phase four-leg inverter, and an AC three-phase LC filter is further connected to form a three-phase low-voltage AC port and a neutral point n, at this time, the three-phase low-voltage AC and low-voltage DC ports formed achieve electrical isolation.

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