CN203690941U - Ternary converter system based on distributed power generation system - Google Patents

Abstract

The utility model discloses a ternary current conversion system based on distributed power generation system. Wherein, this system includes: the distributed power generation system, the load system, the power grid system, the converter device and the controller are respectively connected with the distributed power generation system, the load system and the power grid system; the current conversion device includes: the inverter is connected with the rectification inverter through a first group of direct current buses; the distributed power generation system is connected with the converter device through a second group of direct current buses, and the first group of direct current buses and the second group of direct current buses are connected in parallel; the controller controls the connection states of the distributed power generation system, the load system and the power grid system and the converter device respectively, and the connection states comprise connection or disconnection. Through the utility model discloses, can realize realizing the nimble control that can realize multi-end direct current system.

Description

Ternary change of current system based on distributed generation system

Technical field

The utility model relates to power electronics and household appliance technical field, in particular to a kind of ternary change of current system based on distributed generation system.

Background technology

Along with the upsurge that regenerative resource develops, development rapidly and application that the regenerative resource interconnection technologies such as photovoltaic generation obtain.The scheme that is widely used at present photovoltaic energy feedback grid system is: first convert solar energy into electrical energy, then electric energy is converted to the direct voltage that meets DC/AC converter and carry out pulse-width modulation or space vector pulse width modulation by DC/DC converter, finally by DC/AC converter, photovoltaic energy is fed back to AC network.Load electricity consumption is that photovoltaic energy imports after network system, is dispatched and is provided by network system unification.

According to the difference of load power taking point, collimation stream interconnection technology is also comparatively fast developed in recent years, as the grid-connected scheme of Sanyo, the brand such as beautiful.Its energy-feedback power grid mode of collimation stream interconnection technology is identical with the grid-connected feedback scheme of conventional AC, and it is distinguished and is only that load electricity consumption, directly from the direct current power taking after DC/DC converter, then carries out load control by other change of current measures.

Exchange in grid-connected system or collimation stream grid-connected system in, topmost link is exactly inverter (DC/AC converter), what it adopted is SPWM inversion transformation technique or SVPWM inversion transformation technique.In theory and practice, this scheme can meet the requirement of photovoltaic energy feedback grid system, and guarantee the two-way flow of the stable and energy of electrical network, but due to this scheme circuit complexity, control loaded down with trivial details, and by two-stage or above HF switch conversion, cause larger energy loss, reduced the efficiency of parallel network reverse device.

Full direct current interconnection technology is the DC bus that the direct current of photovoltaic module output is directly incorporated into frequency converter, carry out driving control and the electrical network feedback of load, utilize novel trend Prediction and Control Technology and flexible direct current power transmission and distribution technology to realize the two-way flow of direct current energy simultaneously.

But the realization of above-mentioned full direct current interconnection technology, is difficult to control the two-way flow commutation of DC energy; And current conversion station need to access the active AC network with enough capacities of short circuit and realize; In addition, current conversion station need to absorb a large amount of reactive powers, needs filtering and the reactive power compensator of larger capacity; Trend is difficulty oppositely, is unfavorable for building MTDC transmission system flexibly.

The problem that cannot realize at present the flexible control of MTDC transmission system for the full direct current interconnection technology of correlation technique, not yet proposes effective solution at present.

Utility model content

Cannot realize the problem of the flexible control of MTDC transmission system for the full direct current interconnection technology of correlation technique, effective solution is not yet proposed at present, for this reason, main purpose of the present utility model is to provide a kind of ternary change of current system based on distributed generation system, to address the above problem.

To achieve these goals, according to an aspect of the present utility model, a kind of ternary change of current system based on distributed generation system is provided, and this system comprises: distributed generation system, load system, network system, the current converter and the controller that are connected with distributed generation system, load system and network system respectively; Current converter comprises: inverter and commutation inversion device, and inverter is connected with commutation inversion device by first group of DC bus; Distributed generation system is connected with current converter by second group of DC bus, and first group of DC bus and second group of DC bus are connected in parallel; Wherein, controller control distributed generation system, load system and network system separately with the connection status of current converter, connection status comprises and is communicated with or turn-offs.

By the utility model, adopt distributed generation system, load system, network system, the current converter and the controller that are connected with distributed generation system, load system and network system respectively; Current converter comprises: inverter and commutation inversion device, and inverter is connected with commutation inversion device by first group of DC bus; Distributed generation system is connected with current converter by second group of DC bus, and first group of DC bus and second group of DC bus are connected in parallel; Wherein, controller control distributed generation system, load system and network system separately with the connection status of current converter, connection status comprises and is communicated with or turn-offs, the full direct current interconnection technology that has solved related art cannot be realized the problem of the flexible control of MTDC transmission system, and then realizes the effect of the flexible control that can realize MTDC transmission system.

Accompanying drawing explanation

Accompanying drawing described herein is used to provide further understanding of the present utility model, forms the application's a part, and schematic description and description of the present utility model is used for explaining the utility model, does not form improper restriction of the present utility model.In the accompanying drawings:

Fig. 1 is according to the structural representation of the ternary change of current system based on distributed generation system of the utility model embodiment;

Fig. 2 is according to the structural representation of commutation inversion device embodiment illustrated in fig. 1;

Fig. 3 is according to the structural representation of the preferred ternary change of current of the first of the utility model embodiment system;

Fig. 4 is according to the structural representation of the preferred ternary change of current of the second of the utility model embodiment system;

Fig. 5 is according to the structural representation of the third preferred ternary change of current system of the utility model embodiment;

Fig. 6 is according to the structural representation of the 4th of the utility model embodiment the kind of preferred ternary change of current system;

Fig. 7 is according to the structural representation of the 5th of the utility model embodiment the kind of preferred ternary change of current system;

Fig. 8 is according to the structural representation of the preferred ternary change of current system of the support multiterminal direct current of the utility model embodiment; And

Fig. 9 realizes the control of load system and the electric power-feeding structure schematic diagram of coherent detection unit according to two DC buss of the utility model embodiment.

Embodiment

It should be noted that, in the situation that not conflicting, the feature in embodiment and embodiment in the application can combine mutually.Describe below with reference to the accompanying drawings and in conjunction with the embodiments the utility model in detail.

In its most basic configuration, Fig. 1 is according to the structural representation of the ternary change of current system based on distributed generation system of the utility model embodiment.

As shown in Figure 1, ternary change of current system that should be based on distributed generation system can comprise: distributed generation system 10, load system 30, network system 50, the current converter 70 and the controller 90 that are connected with distributed generation system, load system and network system respectively.

Wherein, current converter 70 can comprise: inverter 701 and commutation inversion device 702, and inverter 701 is connected with commutation inversion device 702 by first group of DC bus; Distributed generation system 10 is connected 70 by second group of DC bus with current converter, and first group of DC bus and second group of DC bus are connected in parallel; Wherein, controller 90 control distributed generation system 10, load system 30 and network system 50 separately with the connection status of current converter 70, connection status comprises and is communicated with or turn-offs.

The above embodiments of the present application have been set up distributed generation system, load is (including but not limited to determining frequency, frequency conversion load) ternary change of current model between system and utility network system three, realize the full direct current interconnection technology that electric energy mixes in DC side two-way flow multichannel, when system load flow upset, be that system capacity is overturn, be negative energy or be converted to by power consumption in the process of power supply by positive energy upset, direct current reverse transfer, and direct voltage polarity remains unchanged, being conducive to form to facilitate load disturbance to have again the MTDC transmission system in parallel of higher reliability.Thereby the full direct current interconnection technology that has solved related art cannot be realized the problem of the flexible control of MTDC transmission system, and then realization can realize the effect of the flexible control of MTDC transmission system.

Concrete, above-mentioned ternary change of current system can take the grid-connected system of photovoltaic hair electricity one, (load variable frequency centrifuge group rated power be as 380Kw, photovoltaic generating system nominal power 400Kw) be example, the above-mentioned ternary change of current of the application system can comprise: distributed generation system, load system and network system ternary.

Preferably, the negative sense active power that the active power that can define network system input is its output, the active power sum of the active power of network system output and distributed generation system output equals the active power that load system consumes.

Preferably, as shown in Figure 2, the commutation inversion device 702 in the above embodiments of the present application can comprise: entirely control converter bridge 4, such as electrical network of DC bus capacitor device 5(), converter reactor 1 and alternating current filter 2.Can also comprise: DC transmission line 3 and impedance 6.

Wherein, entirely control converter bridge, comprise the topological structure that adopts three-phase two level, and each brachium pontis forms by IGBT, for direct current and alternating current are changed mutually.

DC bus capacitor device, is connected in parallel with full control converter bridge, be used to full control converter bridge that voltage support is provided and cushion brachium pontis turn-off time impulse current, reduce DC side harmonics.

Converter reactor, is communicated with full control converter bridge, for the electric current of DC side is carried out to filtering processing.

Alternating current filter, is connected in parallel with converter reactor, for the harmonic wave of filtering AC.

Concrete, the commutation inversion device 702 in the above embodiments of the present application can be converter, the critical piece of this converter can comprise: entirely control converter bridge, DC bus capacitor device, converter reactor (or AC converter transformer) and alternating current filter.Wherein entirely control the topological structure that converter bridge adopts three-phase two level, each brachium pontis forms by IGBT, and DC bus capacitor device provides voltage support and cushions brachium pontis impulse current while turn-offing, reduces DC side harmonics for converter; Converter reactor be and AC system between the tie of energy exchange, play filter action simultaneously; The effect of wave filter on AC side is filtering AC harmonic wave.

As illustrated in fig. 1 and 2, the trend prediction that the application provides and the main structure figure of flexible direct current electrical power trans mission/distribution system, identical with airborne converter (as the selected four-quadrant frequency converter) topology in above-mentioned photovoltaic hair electricity one grid-connected system, can directly share.

Preferably, in the above embodiments of the present application, can, by controlling the pulse signal of commutation inversion device, regulate fundamental component amplitude and the phase place of commutation inversion device output voltage.Can adopt novel trend PREDICTIVE CONTROL and flexible direct current power transmission and distribution technology to carry out independent control to active power and reactive power, realize four quadrant running, have advantages of that control is flexible, its hardware circuit can share with frequency converter four-quadrant converter, thereby can improve level of integrated system, simplied system structure.Above-mentioned flexible direct current power transmission and distribution technology VSC-HVDC(Voltage Source Converter-HVDC) core be trend prediction.

In above-described embodiment, can adopt the modulation system such as space vector pulse width modulation (SVPWM) or sinusoidal pulse width modulation (SPWM), fundamental component amplitude and the phase place of the output voltage to full control converter bridge regulate, and can in to the control of conveying active power, carry out the control of reactive power.In the time of the normal steady operation of system, the essential balance that keeps of common power of three-membered ring flow model, be that the active power of electrical network output equals distributed generation system and load system and consumes active power sum (suppose that distributed generation system is negative sense load, its consumption active power equals self power output of negative sense).Hence one can see that, and the active power of DC network must keep balance, and the active power that the active power of exporting DC network must equal DC network output adds the active power loss of converter bridge and DC network.If there is any difference, all will cause rising or the reduction of direct voltage, and the unstable stable operation that will affect rear end load system of DC bus.Trend prediction and flexible direct current power transmission and distribution control are by various PWM debud modes, and the fundamental frequency amplitude of regulation output voltage and phase place guarantee the stable of DC bus, the idle independent regulation of gaining merit in real time.

Concrete, voltage source converter model as shown in Figure 2, can comprise following processing method:

$P_c=U_s{U}_{c}Y\sin (\mathrm{\δ}+\mathrm{\α})-U_c^{2}Y\sin \mathrm{\α}$ Formula 1

$Q_c=U_s{U}_{c}Y\cos (\mathrm{\α}+\mathrm{\δ})-U_c^{2}Y\cos \mathrm{\α}$ Formula 2

$P_s=U_s{U}_{c}Y\sin (\mathrm{\δ}-\mathrm{\α})+U_s^{2}Y\sin \mathrm{\α}$ Formula 3

$Q_s=-U_s{U}_{c}Y\cos (\mathrm{\δ}-\mathrm{\α})+U_s^{2}Y\cos \mathrm{\α}$ Formula 4

Wherein: known in conjunction with Fig. 2, the corresponding parameter of subscript c refers to converter bridge AC signal, and the corresponding parameter of subscript s refers to power network signal; Wherein, X=ω L,

δ is power network signal voltage phase angle; P active power, Q reactive power.

Formula 1-formula 4 is active power and the same U of reactive power everywhere in Fig. 2 _cand fundamental relation formula between δ; In formula, voltage quantities is line voltage, and power and variable is three phase power.From formula 1-formula 4, regulate U _ccan control size and the flow direction of active power and reactive power with δ.

U _cvalue again by DC bus-bar voltage U _ddetermine with M, the direct voltage utilance of supposing adopted PWM modulation technique is 1, i.e. there is following relation 0≤M≤1:

$U_c=\frac{M}{\sqrt{2}}{U}_d$ Formula 5

For P _s, Q _sindependent regulation, decoupling zero can obtain:

$Q_s=-U_s\mathrm{YA}+U_s^{2}Y\cos \mathrm{\α}$ Formula 6

$P_s=U_s\mathrm{YB}+U_s^{2}Y\sin \mathrm{\α}$ Formula 7

Wherein: $\left\{\begin{array}{c}A=U_c\cos (\mathrm{\δ}-\mathrm{\α})\\ B=U_c\sin (\mathrm{\δ}-\mathrm{\α})\end{array}\right.$ Formula 8

Convert and can obtain according to formula 5, formula 8:

$\left\{\begin{array}{c}A=\frac{M}{\sqrt{2}}{U}_d\cos (\mathrm{\δ}-\mathrm{\α})\\ B=\frac{M}{\sqrt{2}}{U}_d\sin (\mathrm{\δ}-\mathrm{\α})\end{array}\right.$ Formula 9

Known accordingly, the maximum of parameter A, B is proportional to U _d, do not change system voltage U _stime, P _c, Q _sadjustable range be subject to U _drestriction.Can obtain (A, B are the intermediate variable in order to draw duty ratio M) by formula 6, formula 7:

$A=\frac{U_s^{2}Y\cos \mathrm{\α}-Q_s}{U_{s}Y}$ Formula 10

$B=\frac{P_s-U_s^{2}Y\sin \mathrm{\α}}{U_{s}Y}$ Formula 11

Can obtain according to above formula:

$\mathrm{\&delta;}=\left\{\begin{array}{cc}\mathrm{arctg}\left(\frac{B}{A}\right)+\mathrm{\&alpha;}-\mathrm{\&pi;}& A\&le;0,B<0\\ \mathrm{arctg}\left(\frac{B}{A}\right)+\mathrm{\&alpha;}+\mathrm{\&pi;}& A\&le;0,B\&GreaterEqual;0\\ \mathrm{arctg}\left(\frac{B}{A}\right)+\mathrm{\&alpha;}& A>0\end{array}\right.$ Formula 12

$M=\frac{\sqrt{2}A}{U_d\cos (\mathrm{\&delta;}-\mathrm{\&alpha;})}$ Formula 13

Preferably, as shown in Figure 3, in the above embodiments of the present application, when controller control distributed generation system and current converter shutoff, and when network system is communicated with load system by current converter, commutation inversion device is operated in rectification pattern, and the alternating current that network system is produced is converted to direct current and flows to inverter, and flows to load system after the direct current of the conversion of network system being converted into alternating current by inverter.

Concrete, the load take distributed generation system as negative sense, all energy unifications are scheduling to example by network system, above-described embodiment provides the commutating mode of the first ternary change of current model, under this pattern, overall load only comprises load system, entirely controls converter bridge and is operated in rectification pattern, and network system energy is converted to the DC bus-bar voltage of rear end load demand for control by converter bridge; Carry out trend prediction and direct current transmission and distribution control by various PWM modulator approaches, make network system energy dispatch, change by energy, realize the stable operation of rear end load;

Preferably, as shown in Figure 4, in the above embodiments of the present application, when controller control load system and current converter shutoff, and when distributed generation system is communicated with network system by first group of DC bus being connected in parallel and second group of DC bus, if distributed generation system is negative sense load, commutation inversion device is operated in inverter mode, and the direct current that distributed generation system is produced is converted to alternating current and flows to network system.

Concrete, the load take distributed generation system as negative sense, all energy unifications are scheduling to example by network system, above-described embodiment provides the commutating mode of the second ternary change of current model, under this pattern, overall load is distributed generation system, as shown in Figure 4.Because distributed generation system is the load of bearing, now energy flows into network system by full control converter bridge, entirely controls converter bridge and is operated in inverter mode.Trend prediction and direct current transmission and distribution control are modulated by PWM, and output voltage fundamental frequency amplitude and phase place after making distributed generation system output energy by full control converter bridge are synchronizeed with network system.

Preferably, as shown in Figure 5, in the above embodiments of the present application, when controller control network system and current converter shutoff, and when distributed generation system is communicated with load system by first group of DC bus being connected in parallel and second group of DC bus, commutation inversion device is cut off, and direct current distributed generation system being produced by inverter is converted to alternating current and flows to load system.

Preferably, in the above embodiments of the present application, in the time that distributed generation system is negative sense load, the power of the DC bus system of first group of DC bus and second group of DC bus formation is zero.

Concrete, the load take distributed generation system as negative sense, all energy unifications are scheduling to example by network system, above-described embodiment provides the commutating mode of the third ternary change of current model, under this pattern, overall load had both comprised distributed generation system, comprise again load system, now think that the power of DC bus system is zero, according to trend prediction and flexible direct current power transmission and distribution technology, the energy reserving dynamic equilibrium of direct current system, now, converter bridge is not worked, trend prediction and flexible direct current power transmission and distribution control pulse signals are blocked, now dispatching of power netwoks energy is zero, realize the shutoff certainly of electric current.By realizing electric current from turn-offing, said system can be operated in passive inverter mode, does not need additional commutation voltage.

Preferably, as shown in Figure 6, in the above embodiments of the present application, controller control distributed generation system, load system and network system are all connected states with the connection status of current converter separately, when the power providing when distributed generation system is less than the required power of load system, commutation inversion device is operated in rectification pattern dispatches the electric energy of network system, makes galvanic output energy superposed transmission that direct current that distributed generation system is provided and commutation inversion device provide to load system.

Concrete, the load take distributed generation system as negative sense, all energy unifications are scheduling to example by network system, above-described embodiment provides the commutating mode of the 4th kind of ternary change of current model, under this pattern, overall load comprises distributed generation system and load system, as shown in Figure 6.Two kinds of load stacks are in power consumption state, be that the power that distributed generation system provides is less than the required power of load system, need network system to carry out energy scheduling, now entirely control converter bridge and be operated in rectification state, busbar voltage energy is by dispatching of power netwoks energy and both stacks of distributed generation system output energy, need to entirely control according to trend prediction and flexible direct current power transmission and distribution control the working pulse of converter bridge, guarantee the balance of the stable and energy of both DC bus-bar voltage after superposeing.

Above-described embodiment has been realized the electrical integrated electric energy scheduling of hair, reaches the maximum utilization of solar energy.

Preferably, as shown in Figure 7, in the above embodiments of the present application, controller control distributed generation system, load system and network system are all connected states with the connection status of current converter separately, when the power providing when distributed generation system is greater than the required power of load system, commutation inversion device is operated in inverter mode, provides unnecessary direct current to feed back to network system by commutation inversion device distributed generation system.

Concrete, the load take distributed generation system as negative sense, all energy unifications are scheduling to example by network system, above-described embodiment provides the commutating mode of the 5th kind of ternary change of current model, under this pattern, overall load had both comprised distributed generation system, comprised again load system; After two kinds of load stacks, in electric energy feedback states, the power that distributed generation system provides is greater than the required power of load system, and excess energy need to feed back to network system by full control converter bridge.Now, full control converter bridge is operated in inverter mode, direct current energy electric current is reverse, and polarity of voltage remains unchanged, DC bus-bar voltage stable and entirely control converter bridge output voltage fundamental frequency amplitude and the synchronizeing for trend is predicted and the target of flexible direct current power transmission and distribution control of phase place and network system.

Above-described embodiment has also been realized the electrical integrated electric energy scheduling of hair, reaches the maximum utilization of solar energy.

As from the foregoing, above-mentioned five kinds of patterns that the application provides have formed this ternary change of current model jointly, predict and flexible direct current power transmission and distribution technology by trend, the pulse signal of controlled full control unsteady flow bridge, thus reach the target of controlling DC bus-bar voltage and output voltage fundamental frequency amplitude and phase place.

Preferably, as shown in Fig. 3-7, in the above embodiments of the present application, distributed generation system 10 can comprise:

Solar battery array 101, for generation of array direct current.

Collector-shoe gear 103, is connected with solar battery array, for array direct current is confluxed in device.

DC switchgear 105, is connected with collector-shoe gear, carries out distribution for the direct current after collector-shoe gear is confluxed, and the main flow electricity after distribution is transmitted by first group of DC bus.

It should be noted that, the distributed generation system in the above embodiments of the present application can be photovoltaic generating system, distributed wind-power generator system, wind light mutual complementing power generation formula system or fuel cell generation herein.Current converter can be arranged on air-conditioning unit, for example, in load, thereby can become airborne current converter.

In the said system providing in the application, novel trend Prediction and Control Technology and flexible direct current power transmission and distribution technology are adopted, initiate the grid-connected control technology of full direct current that electric energy closes in DC side two-way flow multichannel very much, set up the ternary change of current model between distributed generation system, centrifuge load and utility network three, realize the electrical integrated electric energy scheduling of hair, reach the maximum using of solar energy.According to principle and the realization of trend PREDICTIVE CONTROL and flexible direct current power transmission and distribution technology, can carry out according to load predictions different under the different working modes of this grid-connected system and energy consumption the Real-Time Scheduling of the electric energy in whole service process.

In view of the application of trend PREDICTIVE CONTROL and flexible direct current power transmission and distribution technology, the full direct current grid-connected system of this photovoltaic is supported MTDC transmission system, can realize DC bus sharing system or two DC bus and many DC bus system as shown in Figure 8, Figure 9.In native system, adopt two DC buss shown in Fig. 9 to realize the control of load system and the power supply of coherent detection unit.

From above description, can find out, the utility model has been realized following technique effect: the full direct current interconnection technology that has solved related art cannot be realized the problem of the flexible control of MTDC transmission system, and then realizes the effect of the flexible control that can realize MTDC transmission system.

As seen through the above description of the embodiments, those skilled in the art can be well understood to the mode that the application can add essential general hardware platform by software and realizes.Based on such understanding, the part that the application's technical scheme contributes to prior art in essence in other words can embody with the form of software product, this computer software product can be stored in storage medium, as ROM/RAM, magnetic disc, CD etc., comprise that some instructions (can be personal computers in order to make a computer equipment, server, or the network equipment etc.) carry out the method described in some part of each embodiment of the application or embodiment.

Each embodiment in this specification all adopts the mode of going forward one by one to describe, between each embodiment identical similar part mutually referring to, what each embodiment stressed is and the difference of other embodiment.Especially,, for system embodiment, because it is substantially similar in appearance to embodiment of the method, so description is fairly simple, relevant part is referring to the part explanation of embodiment of the method.

The application can be used in numerous general or special purpose computingasystem environment or configuration.For example: personal computer, server computer, handheld device or portable set, plate equipment, multicomputer system, system, set top box, programmable consumer-elcetronics devices, network PC, minicom, mainframe computer based on microprocessor, comprise distributed computing environment (DCE) of above any system or equipment etc.

Obviously, those skilled in the art should be understood that, above-mentioned of the present utility model each module or each step can realize with general calculation element, they can concentrate on single calculation element, or be distributed on the network that multiple calculation elements form, alternatively, they can be realized with the executable program code of calculation element, thereby, they can be stored in storage device and be carried out by calculation element, or they are made into respectively to each integrated circuit modules, or the multiple modules in them or step are made into single integrated circuit module to be realized.Like this, the utility model is not restricted to any specific hardware and software combination.

The foregoing is only preferred embodiment of the present utility model, be not limited to the utility model, for a person skilled in the art, the utility model can have various modifications and variations.All within spirit of the present utility model and principle, any modification of doing, be equal to replacement, improvement etc., within all should being included in protection range of the present utility model.

Claims (11)

1. the ternary change of current system based on distributed generation system, it is characterized in that, comprising: distributed generation system, load system, network system, the current converter and the controller that are connected with described distributed generation system, load system and network system respectively;

Described current converter comprises: inverter and commutation inversion device, and described inverter is connected with described commutation inversion device by first group of DC bus;

Described distributed generation system is connected with described current converter by second group of DC bus, and described first group of DC bus and described second group of DC bus are connected in parallel;

Wherein, described in described controller control distributed generation system, load system and network system separately with the connection status of described current converter, described connection status comprises and is communicated with or turn-offs.

2. system according to claim 1, it is characterized in that, the negative sense active power that the active power that defines described network system input is its output, the active power sum of the active power of described network system output and distributed generation system output equals the active power that load system consumes.

3. system according to claim 1, it is characterized in that, when distributed generation system described in described controller control and described current converter turn-off, and described network system is while being communicated with described load system by described current converter, and described commutation inversion device is operated in rectification pattern.

4. system according to claim 1, it is characterized in that, when load system described in described controller control and the shutoff of described current converter, and when described distributed generation system is communicated with described network system by described first group of DC bus of being connected in parallel and described second group of DC bus, if described distributed generation system is negative sense load, described commutation inversion device is operated in inverter mode.

5. system according to claim 1, it is characterized in that, when network system described in described controller control and the shutoff of described current converter, and when described distributed generation system is communicated with described load system by described first group of DC bus of being connected in parallel and described second group of DC bus, described commutation inversion device is cut off.

6. system according to claim 5, is characterized in that, in the time that described distributed generation system is negative sense load, the power of the DC bus system that described first group of DC bus and described second group of DC bus form is zero.

7. system according to claim 1, it is characterized in that, described in described controller control, distributed generation system, load system and network system are all connected states with the connection status of described current converter separately, when the power providing when described distributed generation system is less than the required power of described load system, described commutation inversion device is operated in rectification pattern dispatches the electric energy of described network system.

8. system according to claim 1, it is characterized in that, described in described controller control, distributed generation system, load system and network system are all connected states with the connection status of described current converter separately, when the power providing when described distributed generation system is greater than the required power of described load system, described commutation inversion device is operated in inverter mode.

9. according to the system described in any one in claim 1-8, described commutation inversion device comprises:

Full control converter bridge, comprises the topological structure that adopts three-phase two level, and each brachium pontis forms by IGBT, for direct current and alternating current are changed mutually;

DC bus capacitor device, is connected in parallel with described full control converter bridge, be used to described full control converter bridge that voltage support is provided and cushion brachium pontis turn-off time impulse current, reduce DC side harmonics;

Converter reactor, is communicated with full control converter bridge, for the electric current of described DC side is carried out to filtering processing;

Alternating current filter, is connected in parallel with described converter reactor, for the harmonic wave of AC described in filtering.

10. according to the system described in any one in claim 1-8, it is characterized in that, described distributed generation system is photovoltaic generating system, distributed wind-power generator system, wind light mutual complementing power generation formula system or fuel cell generation.

11. systems according to claim 10, is characterized in that, described photovoltaic generating system comprises,

Solar battery array, for generation of array direct current;

Collector-shoe gear, is connected with described solar battery array, for described array direct current is confluxed in device;

DC switchgear, is connected with described collector-shoe gear, carries out distribution for the direct current after described collector-shoe gear is confluxed, and the main flow electricity after distribution is transmitted by described first group of DC bus.

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