CN205429765U - Little grid system of hybrid AC/DC based on distributing type bus structure - Google Patents

Abstract

The utility model discloses an AC-DC hybrid microgrid system based on a distributed busbar structure. Each sub-DC microgrid, sub-AC microgrid, distributed power supply, energy storage system and distributed first-level DC bus constitute an AC-DC hybrid microgrid. The neutron AC and DC microgrids in the system are connected to the second section of the first-level DC bus, and other units are connected to the first section of the first-level DC bus. Power exchange is performed between the two bus sections through bidirectional DC-DC converters. The microgrids are connected by converters to form a circular power supply area of AC/DC hybrid microgrids, which can realize direct power supply of high and low voltage loads. It can flow in both directions, which can improve the reliability, economy and diversity of power supply of the system, and realize the efficient utilization of renewable energy.

Description

AC-DC Hybrid Microgrid System Based on Distributed Bus Structure

technical field

The utility model relates to an AC-DC hybrid micro-grid system. In particular, it relates to an AC/DC hybrid micro-grid system with distributed multi-level radial busbars and power can be reasonably exchanged between sub-micro-grids.

Background technique

In recent years, with the development of the economy and the advancement of science and technology, the energy crisis and environmental problems have become more and more prominent, and have gradually attracted the attention and attention of the country and people. It is necessary to find ways to widely apply renewable energy to replace fossil fuels as soon as possible. consumption is the only way for people's sustainable development. At the same time, with the improvement of people's living standards, electricity consumption has increased year by year, resulting in the power system showing the characteristics of increasing electricity load and gradually increasing transmission capacity. However, the current large-capacity centralized power generation and long-distance high-voltage transmission The problems of high operating costs, difficult operation, and weak regulation ability of the large interconnected power grid have become increasingly prominent, and it is difficult to meet the increasingly high safety, reliability, diversity, and flexibility power supply needs of users. With the continuous maturity of new power electronics technology, distributed power generation technology based on wind, light, heat, storage and other green energy sources is booming. Distributed power generation has the advantages of high energy utilization rate, low environmental pollution, strong power supply flexibility, and low input cost. The development and utilization of efficient and economical distributed power generation technology is an effective way to solve energy crisis and environmental problems.

Distributed power sources dominated by renewable energy have obvious intermittency, randomness and volatility. When a large-scale distributed power source is connected to a large power grid alone, it will have a great impact on the large power grid. Therefore, large power grids often isolate distributed power sources, so that the advantages of distributed power sources cannot be fully utilized, and renewable energy cannot be used efficiently. In order to alleviate the impact of large-scale distributed power single-unit network access on the large power grid, to make up for the lack of power system's extensive penetration and carrying capacity of distributed power, and to give full play to the advantages of distributed power generation technology, the concept of micro-grid came into being. Microgrid is an intensive new power network with independent management, protection and control capabilities composed of distributed power sources, load units and energy storage devices according to a specific topology. A multi-constraint, multi-state, multi-dimensional autonomous power system dominated by The microgrid has two operating modes: grid-connected and islanded, and can switch smoothly and seamlessly between the two modes. Generally, it is connected to the main grid through a single point, and has "plug and play" flexibility and controllability. An important part of the smart grid of the future. When the micro-grid is in the grid-connected mode, it can realize the integrated and coordinated operation of the public grid, distributed power sources and loads, and the cascade efficient utilization of various energy resources; when the large power grid fails, the micro-grid enters the island mode through decoupling control , to supply power to sensitive loads alone, fully meeting the user's needs for power supply security and reliability.

In order to cope with the severe challenges faced by the utilization of distributed power sources in terms of power supply quality, continuity, and stability, an efficient and reliable energy storage system is a guarantee for the normal operation of a micro-grid dominated by new energy sources and low-inertia power electronic devices. . The application of energy storage system in microgrid is as follows: 1) Through reasonable and orderly energy storage system control strategy, it can make up for the randomness, intermittent and uncontrollable defects of distributed power generation, and enhance the stability and dispatchability of distributed power generation ; 2) Charging when the load is low and discharging when the load is peak, as a micro-grid energy buffer link to realize load shaving and valley filling, improving the economy and reliability of the micro-grid; 3) Based on the fast response characteristics of the energy storage system, Slow down the transient impact of mode switching transition, realize the seamless and smooth switching of microgrid, and provide voltage and frequency support for the island operation of microgrid; 4) provide active power support or reactive power compensation for microgrid, and smooth the voltage fluctuation of microgrid , to improve the power quality of the microgrid.

Under the demand of large-scale grid-connection of distributed power sources and increasing load levels, micro-grid technology is developing vigorously. The future smart grid will be a hybrid AC-DC system with high penetration of new energy, two-way flow of trends, and excellent flexibility and integration. Multi-microgrid system. The AC-DC hybrid microgrid contains both DC bus and AC bus, which can directly supply power to DC loads and AC loads, which solves many problems caused by multiple commutations and reduces the energy loss caused by power conversion. , with higher efficiency and flexibility, is the most potential form of distribution network in the future. It has three operating modes: independent operation of the DC part, independent operation of the AC part, and coordinated operation of the AC and DC part. It includes the advantages of the AC microgrid and the DC microgrid, and has good compatibility with both AC and DC distributed power sources.

The current micro-grid is in its infancy, and there are relatively few types of micro-grid architectures. Most of the commonly used micro-grid architectures are centralized single-bus type. The power supply form in the micro-grid is relatively single, resulting in economy and stability. To poor. For a centralized single-bus microgrid, when the common bus fails, the equipment connected to the bus needs to be separated from the fault by disconnecting, which will lead to poor stability and low efficiency of the system. At the same time, a single type of energy storage device can no longer meet the development requirements of a microgrid, and a hybrid energy storage system will gradually replace a single energy storage device in a microgrid. The future power grid will be a grid with mixed AC and DC, and highly permeable distributed power sources. If the research only focuses on DC microgrids or AC microgrids, the application effect of microgrids in actual distribution networks will be greatly reduced. In addition, with the development of the economy and the improvement of people's living standards, the requirements for the diversity and reliability of power supply are getting higher and higher, and more power supply forms and structures need to appear.

Contents of the invention

The technical problem to be solved by the utility model is to propose an AC-DC hybrid micro-grid system based on a distributed busbar structure, by setting a distributed busbar , Radial three-level DC bus, which improves the power supply flexibility, diversity and reliability of the system. At the same time, the interaction of each unit in the system is improved by utilizing the bidirectional flow characteristics of power between sub-DC microgrids and sub-AC microgrids. Using the hybrid energy storage system improves the power supply quality of the microgrid, thereby realizing the efficient cascade utilization of renewable energy and alleviating the pressure of environmental pollution and energy crisis.

The technical solution adopted by the utility model is: including public power grid unit, hybrid energy storage unit, distributed power supply unit, bidirectional direct current-direct current (DC-DC) converter, sub-microgrid unit, first-stage DC bus section and first-stage The second section of the DC bus, wherein: the public grid unit, the public grid is connected to a transformer, and the other side of the transformer is correspondingly connected to a bidirectional AC-DC (AC-DC) converter, and the bidirectional AC-DC (AC-DC) conversion The other side of the converter is connected to a section of the primary DC bus; the hybrid energy storage unit, the hybrid energy storage system is connected to a primary bidirectional direct current-direct current (DC-DC) converter, and the primary bidirectional direct current-direct current (DC-DC ) The other side of the converter is correspondingly connected to one section of the first-level DC bus; the distributed power supply unit includes a fuel cell, a photovoltaic cell, a micro-gas turbine and a wind generator, wherein the fuel cell and the photovoltaic cell each pass a The direct-current (DC-DC) converter is connected to a section of the first-level DC bus, and the micro-turbine and the wind generator are respectively connected to a section of the first-level DC bus through an AC-DC (AC-DC) converter; The sub-microgrid unit described above includes a sub-DC microgrid, a sub-AC microgrid, a bidirectional direct current-direct current (DC-DC) converter and a bidirectional alternating current-alternating current (AC-AC) converter. The sub-AC microgrids are connected through bidirectional AC-AC (AC-AC) converters, and each sub-DC microgrid and each sub-AC microgrid are connected at the same time. The second section of the first-level DC bus, thereby forming a ring-shaped power supply structure; the bidirectional DC-DC (DC-DC) converter is connected between the first section of the first-level DC bus and the second section of the first-level DC bus.

The hybrid energy storage system includes two secondary bidirectional direct current-direct current (DC-DC) converters, batteries and supercapacitors, wherein one side of the two secondary bidirectional direct current-direct current (DC-DC) converters corresponds to The storage battery and the supercapacitor are connected, and the other side is connected in parallel with the primary bidirectional direct current-direct current (DC-DC) converter.

The sub-DC microgrid includes a radial secondary DC bus connected to the second section of the primary DC bus through a bidirectional DC-DC converter, a unidirectional DC-DC (DC-DC) The radial three-level DC bus with the converter connected to the radial two-level DC bus, the low-voltage DC load connected to the radial three-level DC bus through a DC-DC converter, and the low-voltage DC load connected to the radial three-level DC bus through a DC-AC (DC -AC) converters connected to low-voltage AC loads on the radial three-level DC bus, batteries, photovoltaic cells, fuel cells, and high-voltage DC connected to the radial two-level DC bus through DC-DC converters Load, in which photovoltaic cells and fuel cells are respectively connected to the radial secondary DC bus through a DC-DC converter, and the storage battery is connected to the radial secondary DC bus through a bidirectional DC-DC converter. on the DC bus.

The sub-AC microgrid includes a radial secondary AC bus connected to the second section of the primary DC bus through a bidirectional DC-AC (DC-AC) converter, a storage battery, a wind power generator, a micro-gas turbine, and an AC -The AC (AC-AC) converter is connected to the high-voltage AC load on the radial secondary AC busbar, wherein the wind turbine and the micro-turbine are respectively connected to the radial secondary AC through the AC-AC (AC-AC) converter On the AC bus, the battery is connected to the radial secondary AC bus through a bidirectional AC-DC (AC-DC) converter.

The bidirectional DC-DC (DC-DC) converter is connected between the radial secondary DC buses of the two sub-DC microgrids, and the bidirectional AC-AC (AC-AC) converter is connected between the two sub-AC microgrids. between radial secondary AC buses.

The utility model provides an AC-DC hybrid micro-grid system based on a distributed busbar structure, which has the beneficial effects of: realizing the orderly operation of distributed power sources and efficient cascade utilization of renewable energy, alleviating the pressure of environmental pollution and energy crisis; utilizing The hybrid energy storage system composed of batteries and supercapacitors can stabilize power fluctuations and improve power supply quality; the hybrid energy storage system adopts a two-level controller to increase power dispatchability; the two-way power between sub-DC microgrids and sub-AC microgrids is used The flow characteristics improve the interaction of each unit in the system; the distributed bus architecture including two first-stage DC buses, the radial two-stage AC-DC bus, and the radial three-stage DC bus improve the power supply flexibility of the system. Diversity and reliability, and improve energy utilization efficiency through the reasonable setting of micro-power sources and loads; through the setting of distributed bus architecture, improve the reliability and stability of power supply, and the mixed sub-microgrid units are connected in a specific way The AC-DC hybrid micro-grid ring power supply area with multi-radial busbars improves the economy of the system.

Description of drawings

Figure 1 is a schematic structural diagram of an AC-DC hybrid microgrid system based on a distributed bus structure;

Fig. 2 is a schematic structural diagram of a sub-DC microgrid and a sub-AC microgrid;

Fig. 3 is a schematic structural diagram of a hybrid energy storage system;

Fig. 4 is a schematic structural diagram of the connection mode between sub-microgrids.

in the picture

1: Public grid unit 2: Hybrid energy storage unit

3: Distributed Power Unit 4: Bidirectional DC-DC Converter

5: sub-microgrid unit 6: first-level DC bus section

7: The second section of the first-level DC bus 11: Public power grid

12: Transformer 13: Bidirectional AC-DC Converter

21: Hybrid Energy Storage System 22: Primary Bidirectional DC-DC Converter

31: Fuel cell 32: Photovoltaic cell

33: micro-combustion engine 34: wind power generator

35: DC-DC Converter 36: DC-DC Converter

37: AC-DC Converter 38: AC-DC Converter

51: Sub-DC microgrid 52: Sub-AC microgrid

53: Bidirectional DC-DC Converter 54: Bidirectional AC-AC Converter

detailed description

The AC/DC hybrid microgrid system based on the distributed bus structure of the present invention will be further described below in conjunction with the accompanying drawings.

The AC-DC hybrid micro-grid system based on the distributed bus structure of the utility model, through the distributed power supply, the hybrid energy storage system, the first-level DC bus of the distributed architecture, the radial second- and third-level The AC microgrid forms an AC/DC hybrid microgrid system with a distributed bus structure. The system is equipped with three levels of buses, including distributed first-level DC bus, second-level DC bus, second-level AC bus and third-level DC bus. DC-DC) converter connection, the voltage level is 500V, the secondary DC bus is a medium-voltage DC bus with a voltage level of 380V, the secondary AC bus is a medium-voltage AC bus with a voltage level of 220V, and the third-level DC bus is a voltage A low-voltage DC bus with a rating of 48V. Through the setting of multi-level busbars and distributed busbars, the functional diversity of the system is increased and the power supply efficiency is improved. A public grid unit, a hybrid energy storage unit, and a distributed power unit are installed on the first section of the first-level DC bus, and a sub-DC micro-grid and a sub-AC micro-grid are installed on the second section of the first-level DC bus, and a ring power supply is formed through a specific connection method Area, in which: the AC/DC hybrid microgrid system can control the grid-connected or island operation status through the on-off connection with the public grid unit; the hybrid energy storage unit can balance the system power fluctuation through charge and discharge control, so as to maintain the stability of the DC bus voltage; The distributed power supply unit includes micro-gas turbines and wind generators that output AC power, fuel cells and photovoltaic cells that output DC power, so as to make full use of renewable energy; the sub-DC micro-grid and the sub-AC micro-grid are connected to the second section of the first-level DC bus, Each sub-microgrid can also independently control the operating state of the system to improve the stability of power supply. The secondary DC bus and the secondary AC bus are respectively set in the sub-DC microgrid and the sub-AC microgrid. In order to increase the power supply efficiency of the system and improve the economy of the system, the photovoltaic cells and fuel cells that output DC are connected to the secondary DC bus. , the wind power generator and the micro gas turbine that output AC power are connected to the secondary AC busbar, and batteries are installed on both busbars to stabilize power fluctuations at the same time. The three-level DC bus is connected with low-voltage AC loads and low-voltage DC loads.

As shown in Figure 1, the AC-DC hybrid microgrid system based on the distributed bus structure includes a public grid unit 1, a hybrid energy storage unit 2, a distributed power supply unit 3, a bidirectional direct current-direct current (DC-DC) converter 4, The sub-microgrid unit 5, the first-stage DC bus section 6 and the first-stage DC bus section 7, wherein: the public grid unit 1, the public grid 11 is connected to a transformer 12, and the other side of the transformer 12 is connected to a bidirectional AC - DC (AC-DC) converter 13, the other side of the bidirectional AC-DC (AC-DC) converter 13 is connected to the first-stage DC bus section 6; the hybrid energy storage unit 2 is a hybrid energy storage system 21 is connected to a primary bidirectional direct current-direct current (DC-DC) converter 22, and the other side of the primary bidirectional direct current-direct current (DC-DC) converter 22 is correspondingly connected to a section 6 of the primary DC bus; the distributed The power supply unit 3 includes a fuel cell 31, a photovoltaic cell 32, a micro-combustion engine 33 and a wind generator 34, wherein the fuel cell 31 and the photovoltaic cell 32 are connected to each other through a direct current-direct current (DC-DC) converter 35/36. On the section 6 of the first-level DC bus, the micro-gas turbine 33 and the wind generator 34 are respectively connected to the section 6 of the first-level DC bus through an AC-DC (AC-DC) converter 37/38; the sub-microgrid Unit 5 includes a sub-DC microgrid 51, a sub-AC microgrid 52, a bidirectional direct current-direct current (DC-DC) converter 53 and a bidirectional alternating current-alternating current (AC-AC) converter 54, wherein each sub-DC microgrid 51 Each sub-AC microgrid 52 is connected through a bidirectional AC-AC (AC-AC) converter 54. Each sub-DC microgrid 51 and each sub-AC microgrid The power grid 52 is connected to the second section 7 of the first-level DC bus at the same time, thereby forming a ring power supply structure; the described bidirectional DC-DC (DC-DC) converter 4 is connected to the first section 6 of the first-level DC bus and the second section of the first-level DC bus. Between segment 7.

The public grid unit 1, the hybrid energy storage unit 2, the distributed power supply unit 3, and the AC-DC mixed sub-microgrid unit 5 constitute an AC-DC hybrid micro-grid system. The AC-DC hybrid micro-grid has two operating states: grid-connected and islanded, and It can switch smoothly and seamlessly between the two modes. When the AC-DC hybrid microgrid is in the grid-connected mode, it can realize the integrated and coordinated operation of the public grid unit 1, the distributed power unit 3 and the load and the cascade of various energy resources Efficient utilization; when the public grid unit 1 fails, the AC-DC hybrid microgrid enters the island mode through decoupling control, and supplies power to the load independently, fully meeting the security and reliability requirements of power supply. The AC-DC hybrid microgrid system can adopt master-slave control mode, peer-to-peer control mode or hierarchical control mode to ensure the power balance of the system and the stability of each bus voltage. The bidirectional AC-DC converter 13 can adopt droop control, constant power control or constant voltage/constant frequency control, which controls the power exchange between the AC-DC hybrid microgrid and the public grid 11 . The hybrid energy storage unit 2 adopts a hybrid energy storage form composed of a battery with high energy density and a supercapacitor with high power density and long cycle life, so as to improve the power output capability and prolong the service life of the device. Each micro power source in the distributed power source unit 3 determines the control strategy and controls the output power through the scheduling requirements of the system and the instructions of the local controller. The first section 6 of the first-level DC bus and the second section 7 of the first-level DC bus are connected through a bidirectional DC-DC (DC-DC) converter. The two parts can exchange power, and when one part fails, the other part can still Normal connections run on the corresponding busbars. The number of sub-DC microgrids 51 and sub-AC microgrids 52 in the system can be determined according to actual load conditions. When any sub-DC microgrid 51 or sub-AC microgrid 52 in the system fails, it can be isolated by decoupling control to ensure the safe power supply of other loads. When other parts of the system fail, the sub-DC microgrid 51 or the sub-AC microgrid 52 can also enter the island operation state through decoupling control, so as to ensure the load power supply in the system, thus improving the reliability, safety and flexibility of power supply.

As shown in Figure 2, the sub-DC microgrid and the sub-AC microgrid are schematically shown. The sub-DC microgrid 51 includes a DC-DC (DC-DC) converter 514 connected to the second section of the primary DC bus 7 A radial secondary DC bus 513 on the top, a radial tertiary DC bus 511 connected to the radial secondary DC bus 513 through a unidirectional direct current-direct current (DC-DC) converter 512, a A low-voltage DC load 515 connected to the radial three-level DC bus 511 by a DC) converter 5111, a low-voltage AC load 516 connected to the radial three-level DC bus 511 through a DC-AC (DC-AC) converter 5112, A storage battery 517, a photovoltaic cell 518, a fuel cell 519, and a high-voltage DC load 5110 connected to a radial secondary DC bus 513 through a direct current-direct current (DC-DC) converter 5116, wherein the photovoltaic cell 518 and the fuel cell 519 pass through The DC-DC converter 5114/5115 is connected to the radial secondary DC bus 513, and the storage battery 517 is connected to the radial secondary DC bus 513 through the bidirectional DC-DC converter 5113.

The sub-AC microgrid 52 includes a radial secondary AC bus 521, a storage battery 523, a wind generator 524, The micro-gas turbine 525 and the high-voltage AC load 526 connected to the radial secondary AC busbar 521 through an AC-AC (AC-AC) converter 5210, wherein the wind power generator 524 and the micro-gas turbine 525 respectively pass AC-AC ( The AC-AC converters 528/529 are connected to the radial secondary AC bus 521, and the storage battery 523 is connected to the radial secondary AC bus 521 through a bidirectional AC-DC (AC-DC) converter 527 .

The topological form of sub-DC microgrid 51 and sub-AC microgrid 52 is radial, and the sub-DC microgrids and sub-AC microgrids are connected by converters, so that a ring-shaped AC-DC hybrid microgrid power supply area can be formed. The power supply flexibility can be improved while improving the power supply reliability. The setting of multi-level radial busbars increases the flexibility of power supply. The sub-DC microgrid 51 can directly supply power to low-voltage loads, and can also supply power to high-voltage DC loads 5110 at the same time. The sub-AC microgrid 52 can supply power to high-voltage AC loads 526. The battery in the sub-microgrid can balance the power fluctuations in the system and maintain the stability of the DC bus. Sub-DC microgrid 51 and sub-AC microgrid 52 exchange power with other units through bidirectional direct current-direct current (DC-DC) converter 514 and bidirectional direct current-alternating current (DC-AC) converter 522 respectively. 7 and the secondary DC bus 513 and the secondary AC bus 521 are bidirectional. It can flow in two directions, which greatly increases the interactivity of the system and improves the reliability of mutual support between the units.

In the hybrid energy storage system shown in Figure 3, one side of the secondary bidirectional direct current-direct current (DC-DC) converter 211 and the secondary bidirectional direct current-direct current (DC-DC) converter 212 are respectively connected to the storage battery 213 and the super The other side of the capacitor 214 is connected to the primary bidirectional direct current-direct current (DC-DC) converter 22 in parallel. When power fluctuations occur in the system, the storage battery 213 absorbs or releases low-frequency power, the supercapacitor 214 absorbs or releases high-frequency power, and the primary bidirectional direct-current (DC-DC) converter 22 controls the overall power flow of the hybrid energy storage system 21, while The secondary bidirectional direct current-direct current (DC-DC) converter 211 and the secondary bidirectional direct current-direct current (DC-DC) converter 212 respectively control the power flow of the storage battery 213 and the supercapacitor 214, through the setting of the two-stage controller, Increased power dispatchability.

As shown in Fig. 4, the connection mode between each sub-microgrid, the bidirectional DC-DC (DC-DC) converter 53 is connected between the radial secondary DC buses 513 of the two sub-DC microgrids 51, bidirectional An alternating current-alternating current (AC-AC) converter 54 is connected between the radial secondary AC busbars 521 of the two sub-AC microgrids 52 . Each sub-DC microgrid 51 and sub-AC microgrid 52 can be interconnected and operated in the form of a cluster, and each sub-microgrid can realize mutual support control through group power scheduling and group coordination control.

Claims (5)

1. alternating current-direct current mixing micro-grid system based on distributed bus structure, it is characterised in that include public electric wire net unit (1), Hybrid energy-storing unit (2), distributed power unit (3), two-way DC-DC (DC-DC) converter (4), sub-micro-capacitance sensor Unit (5), one-level dc bus one section (6) and one-level dc bus two sections (7), wherein:

Described public electric wire net unit (1), public electric wire net (11) connects a transformer (12), another of transformer (12) Side correspondence connects a two-way exchange-direct current (AC-DC) converter (13), two-way exchange-direct current (AC-DC) converter (13) Opposite side be connected on one-level dc bus one section (6)；

Described hybrid energy-storing unit (2), mixed energy storage system (21) connects a primary two-way DC-DC (DC-DC) Converter (22), it is female that the opposite side correspondence of primary two-way DC-DC (DC-DC) converter (22) is connected to one-level direct current On one section of line (6)；

Described distributed power unit (3), including fuel cell (31), photovoltaic cell (32), miniature combustion engine (33) and wind Power generator (34), wherein fuel cell (31) and photovoltaic cell (32) are all each via a DC-to-dc (DC-DC) Converter (35/36) is connected on one-level dc bus one section (6), and miniature combustion engine (33) and wind-driven generator (34) are the most each It is connected on one-level dc bus one section (6) from by an AC-DC (AC-DC) converter (37/38)；

Described sub-micro-capacitance sensor unit (5), including sub-direct-current grid (51), sub-exchange micro-capacitance sensor (52), bidirectional, dc- Direct current (DC-DC) converter (53) and two-way exchange-exchange (AC-AC) converter (54), the most each sub-DC micro-electric Connected by two-way DC-DC (DC-DC) converter (53) between net (51), between each sub-exchange micro-capacitance sensor (52) Being connected by two-way exchange-exchange (AC-AC) converter (54), each sub-direct-current grid (51) sub exchanges micro-capacitance sensor with each (52) it is simultaneously connected with on one-level dc bus two sections (7), thus constitutes looply connected power supply framework；

Described two-way DC-DC (DC-DC) converter (4) is connected to one-level dc bus one section (6) and one-level direct current Between bus two sections (7).

Alternating current-direct current mixing micro-grid system based on distributed bus structure the most according to claim 1, it is characterised in that Described mixed energy storage system (21) includes secondary two-way DC-DC (DC-DC) converter (211), secondary bidirectional, dc -direct current (DC-DC) converter (212), battery (213) and super capacitor (214), wherein secondary two-way DC-DC (DC-DC) converter (211) is the most corresponding with the side of secondary two-way DC-DC (DC-DC) converter (212) even Connecing battery (213) and super capacitor (214), opposite side mode in parallel connects primary two-way DC-DC (DC-DC) Converter (22).

Alternating current-direct current mixing micro-grid system based on distributed bus structure the most according to claim 1, it is characterised in that Described sub-direct-current grid (51) includes that one is connected to one by two-way DC-DC (DC-DC) converter (514) Radial two grades of dc bus (513) in level dc bus two sections (7), one by Unidirectional direct-current-direct current (DC-DC) Radial three grades of dc bus (511) that converter (512) is connected on radial two grades of dc bus (513), by straight Stream-direct current (DC-DC) converter (5111) be connected to the low-voltage direct load (515) on radial three grades of dc bus (511), It is connected to the low-voltage alternating-current on radial three grades of dc bus (511) by DC-AC (DC-AC) converter (5112) Load (516), battery (517), photovoltaic cell (518), fuel cell (519), by DC-to-dc (DC-DC) Converter (5116) is connected to the HVDC load (5110) on radial two grades of dc bus (513), wherein, photovoltaic Battery (518) and fuel cell (519) are connected to spoke by DC-to-dc (DC-DC) converter (5114/5115) respectively Penetrating on two grades of dc bus (513) of shape, battery (517) passes through two-way DC-DC (DC-DC) converter (5113) It is connected on radial two grades of dc bus (513).

Alternating current-direct current mixing micro-grid system based on distributed bus structure the most according to claim 1, it is characterised in that Described son exchange micro-capacitance sensor (52) includes that one is connected to one by bidirectional, dc-exchange (DC-AC) converter (522) Radial two grades of ac bus (521) in level dc bus two sections (7), battery (523), wind-driven generator (524), Miniature combustion engine (525), it is connected to radial two grades of ac bus (521) by AC-AC (AC-AC) converter (5210) On high-voltage alternating load (526), wherein, wind-driven generator (524) and miniature combustion engine (525) are respectively by AC-AC (AC-AC) Converter (528/529) is connected on radial two grades of ac bus (521), and battery (523) passes through two-way exchange-direct current (AC-DC) converter (527) is connected on radial two grades of ac bus (521).

Alternating current-direct current mixing micro-grid system based on distributed bus structure the most according to claim 1, it is characterised in that Described two-way DC-DC (DC-DC) converter (53) is connected to radial two grades of two sub-direct-current grid (51) Between dc bus (513), two-way exchange-exchange (AC-AC) converter (54) is connected to two sons exchange micro-capacitance sensor (52) Radial two grades of ac bus (521) between.