Distributed generation system based on the direct current local area network (LAN)
Technical field
The utility model relates to the distributed power generation technology.The utility model is a kind of distributed generation system of novelty, is applied to the generating of small-size wind power-generating and photovoltaic generation (solar cell), is particularly suitable for the big-and-middle-sized grid-connected system of being made up of small-size wind power-generating and photovoltaic power generation array.
Background technology
Generation of electricity by new energy has from net and is incorporated into the power networks two kinds and utilizes mode, and generating electricity by way of merging two or more grid systems is the extensive effective ways of utilizing of new forms of energy, generates electricity from net and then can embody the advantage that new forms of energy disperse generating.According to the characteristics of natural resources natural endowment, new forms of energy generate electricity by way of merging two or more grid systems and itself often take the distributed form that is incorporated into the power networks, and also are a kind of trend that the net generating is left in scale by many common networkings of TRT.
For generating electricity by way of merging two or more grid systems; Miniature inverter is the current practical approach that can realize that small-sized new forms of energy generate electricity by way of merging two or more grid systems; Still the important means that makes full use of the natural resources in many areas; And the large-scale grid-connected system of forming by small-size wind power-generating and photovoltaic power generation array, a kind of new energy development mode of extremely well-adapted especially.
On the other hand because that new forms of energy are incorporated into the power networks is very strict for the requirement of combining inverter, wherein the control of miniature combining inverter can't than in, large-scale combining inverter simple what.Therefore, miniature combining inverter obviously is not so good as large-scale combining inverter at aspects such as reliability, high-performance and cost constraints.Form big-and-middle-sized grid-connected system by miniature combining inverter at present,,, all also have a lot of problems still from installation cost, maintainability no matter from operational reliability, system cost.
Electric energy through a plurality of middle-size and small-size generation of electricity by new energy devices are sent is pooled to the DC local area network (LAN); Send to civil power through big-and-middle-sized combining inverter then; Can simplify distributed system configuration of generating electricity by way of merging two or more grid systems, can think relatively easily also that under the net situation load provides AC power simultaneously; DC local area network (LAN) itself just can provide electric power to DC load, thereby improves power consumption efficiency.
The utility model content
The technical problem that the utility model will solve is; How to overcome in the prior art and form technology and the economic bottleneck problem that big-and-middle-sized grid-connected system must use miniature inverter by small-sized generation of electricity by new energy device; Thereby provide a kind of and can make full use of little little generation of electricity by new energy crowd resource, can avoid the use of the big-and-middle-sized grid-connected system technology of miniature inverter again.
For solving this technical problem, the solution that the utility model proposes is:
A kind of distributed generation system based on the direct current local area network (LAN) is provided, comprises many TRTs of apart arrangement; This system also comprises direct current local area network (LAN) (the following DC local area network (LAN) that all is called), and the direct current local area network (LAN) comprises the dc bus with positive and negative cable; Said TRT is at least a in direct-current generating device or the ac power generation, and inserts the DC local area network (LAN) through telegon parallel connection one to one;
For direct-current generating device, said telegon is made up of the DC/DC current transforming unit, reaches the purpose of controlling input power through voltage up-down or the input current of controlling between its input and the output; For ac power generation, said telegon is made up of rectification unit and DC/DC current transforming unit, the input of the DC termination DC/DC current transforming unit of rectification unit, and the AC end of rectification unit and the output of DC/DC current transforming unit are respectively the input and the output of telegon.
In the utility model, said DC local area network (LAN) is connected to AC network or AC load through inverter; Perhaps, said DC local area network (LAN) directly and DC load join.
In the utility model, also comprise at least one energy storage device; Said energy storage device is the dc energy storage device or exchanges at least a in the energy storage device; For the dc energy storage device, said DC local area network (LAN) joins through telegon and energy storage device one to one, and said telegon is two-way DC/DC current transforming unit, and the input and output of telegon connect dc energy storage device and DC local area network (LAN) respectively; For exchanging energy storage device, said DC local area network (LAN) joins through telegon and energy storage device one to one, and said telegon is two-way AC/DC current transforming unit, and the input and output of telegon connect interchange energy storage device and DC local area network (LAN) respectively.
In the utility model, said DC/DC current transforming unit is made up of the LLC circuit.
In the utility model, said direct-current generating device is photovoltaic power generation apparatus, fuel cell or DC generator; Said ac power generation is a wind-driven generator.
The control method of the utility model is to utilize telegon that the electric energy of a plurality of direct-current generating devices or ac power generation is pooled to the DC local area network (LAN), forms direct current supply; Perhaps further realize the Alternating Current Power Supply or the power supply of being incorporated into the power networks through inverter.
When system generated electricity by way of merging two or more grid systems, the input current of every telegon was controlled according to its maximum power point of TRT realization of correspondence, and inverter is stablized the voltage of DC local area network (LAN) to the electrical network power output through control;
System is when the net generating, and the input current of every telegon is controlled according to its maximum power point of TRT realization of correspondence, prescribes a time limit in case the voltage of DC local area network (LAN) reaches on it, then stablizes the voltage of DC local area network (LAN) through the input power of restriction telegon; Be connected to AC load like the DC local area network (LAN) through inverter, then through control inverter output stable AC voltage.
The beneficial effect of the utility model:
The utility model has significantly improved the technical and economic performance of being made up of system many miniature generation of electricity by new energy devices:
(1) Function Decomposition with the distributed device that generates electricity by way of merging two or more grid systems is many telegons and separate unit (or several) combining inverter, simplifies also web frame, raising reliability;
(2) system adopts modular construction, conveniently produces and safeguards, is easy to the change system scale that is incorporated into the power networks;
(3) the application coordination device is tackled numerous small new forms of energy power supplys, significantly reduces the electricity generation system cost;
(4) system configuration adaptability is strong, is convenient to constitute the independent of wind-powered electricity generation, photovoltaic or the electricity generation system of mixing;
(5) can utilize the power supply of DC local area network (LAN), improve power consumption efficiency, simplify load circuit;
(6) from when net, it is simple to form interchange local area network (LAN) electric power system by separate unit or several big-and-middle-sized inverters.
(7) the distributed honourable mixed DC generating/electric power system of band energy storage device, system is succinct.
Based on above-mentioned valuable characteristics, the utility model belongs to the technological innovation of the distributed power generation of new forms of energy, very helps the scale collecting and the development and use of wind-force and photovoltaic generation resource.
Description of drawings
Fig. 1 is the distributed grid-connected system of the utility model;
Fig. 2 is the telegon that is used for direct-current generating device;
Fig. 3 is the telegon that is used for ac power generation;
Fig. 4 is a three-phase commutation bridge;
Fig. 5 is a half-bridge isolated form DC/DC current transforming unit;
Fig. 6 is a kind of LLC type DC/DC current transforming unit;
Fig. 7 is a kind of two-way DC/DC current transforming unit;
Fig. 8 is a kind of two-way AC/DC current transforming unit;
The distributed generation system of Fig. 9 band energy storage device;
Figure 10 is a kind of distributed honourable mixed power generation road lamp system with energy storage device.
Embodiment
The realization principle of the utility model:
The utility model provides a kind of distributed generation system of novelty, utilizes telegon that the electric energy of a plurality of photovoltaics or wind power generation plant is pooled to the DC local area network (LAN), forms direct current supply; Or through big-and-middle-sized inverter Alternating Current Power Supply; Or incorporate civil power into through big-and-middle-sized inverter.So-called DC local area network (LAN) is exactly the dc bus that comprises positive and negative cable, and it provides an intermediate link platform to distributed energy and DC load or AC network.
Generate electricity by way of merging two or more grid systems for distributed; Utilize DC local area network (LAN) notion; The grid-connected inverting system of routine is decomposed into a plurality of telegons and big-and-middle-sized combining inverter two parts; Connect together through the DC local area network (LAN), constitute the big-and-middle-sized grid-connected system that small-size wind power-generating or photovoltaic power generation array are formed.
The utility model will significantly improve by the technical and economic performance of many miniature generation of electricity by new energy systems that device is formed, simplify the control of being incorporated into the power networks requires, improves the reliability that is incorporated into the power networks, and very helps the scale collecting and the development and use of wind-force and photovoltaic generation resource.
TRTs such as photovoltaic, fuel cell, DC generator provide DC power supply, and TRTs such as wind-driven generator provide AC power.The distributed generation system that the utility model proposes is by many TRTs and many telegons, DC local area network (LAN) and one or more inverters constitute one to one; Many TRTs by direct-current generating device or ac power generation separately or both constitute jointly; The input of telegon connects DC local area network (LAN), AC network or AC load with output difference sending and receiving electric installation and DC local area network (LAN), the input of inverter respectively with output.
For direct-current generating device, its corresponding telegon is made up of the DC/DC current transforming unit, reaches the purpose of controlling input power through voltage up-down or the input current of controlling between its input and the output; For alternating current generator, its corresponding telegon is made up of rectification unit and DC/DC current transforming unit, the input of the DC termination DC/DC current transforming unit of rectification unit, and the AC end and the output of DC/DC current transforming unit of rectification unit is respectively the input and the output of telegon.
When system generated electricity by way of merging two or more grid systems, the input current of every telegon was controlled according to its maximum power point of TRT realization of correspondence, and inverter is stablized the dc voltage of DC local area network (LAN) to the electrical network power output through control;
System is when the net generating; The input current of every telegon is controlled according to its maximum power point of TRT realization of correspondence; Prescribe a time limit in case the voltage of DC local area network (LAN) reaches on it, system will stablize the dc voltage of DC local area network (LAN) through the input power of restriction telegon.Be connected to AC load like the DC local area network (LAN) through inverter, then through control inverter output stable AC voltage.The input power of so-called here restriction telegon is realized by telegon.Distributed system for the band energy storage hangs up energy storage equipment through telegon on the DC local area network (LAN).
Telegon outputs all in the system all are attempted by on the DC local area network (LAN), that is to say that a plurality of telegons are to belong to the parallel connection relation each other.This point has greatly been simplified the formation of system, helps system and realizes modular construction.
The distributed generation system of the utility model goes for photovoltaic generating system and wind generator system; Also can be applied to hybrid power system; Different only be to select corresponding telegon for use; This has significantly simplified the structure of distributed generation system, and has improved the performance of producing I&M.Fig. 1 is the distributed generation system signal of the utility model.
Fig. 2,3 is structural representations of two types of telegons, be respectively applied for direct-current generating device and ac power generation, Fig. 2 is the DC/DC current transforming unit, Fig. 3 is the cascade of rectification unit and DC/DC current transforming unit.Fig. 4 is an example of rectification unit, is common three-phase commutation bridge.
The DC local area network (LAN) only needs to connect an inverter usually in the above-mentioned distributed generation system; But under the situation that electricity generation system is not suitable for cutting apart in that the DC lan capacity is very big; Then can adopt many inverters, its energy control all is to carry out according to the voltage that keeps the DC local area network (LAN) is stable.Inverter can adopt single-phase or three-phase.When many combining inverters were connected the DC local area network (LAN), many inverters in the electricity generation system needed coordinated management, for example take sharing control.
The output of photovoltaic generation is direct current; Though the output that wind-powered electricity generation is one type is to exchange, pilot process often is a DC link.Form the DC local area network (LAN) by the generation of electricity by new energy array, carry out direct current supply and also be a kind of high efficiency of new forms of energy and utilize form.
The DC/DC current transforming unit of the utility model, can be isolated form with one of two kinds of non-isolation types or mix, the safety that relatively helps system and the reliability of isolated form usually.Fig. 5 is a kind of half-bridge isolated form DC/DC current transforming unit, and similarly common circuit has a lot, such as full-bridge, recommend, anti-sharp, two normal shocks etc.DC/DC current transforming unit in above-mentioned 1 or 2 the system can be made up of the LLC circuit, can obtain higher inversion efficiency thus, and reaches former secondary isolation purpose.Fig. 6 is a kind of LLC type DC/DC convertor circuit.DC/DC current transforming unit in above-mentioned 1 or 2 the system can be made up of the LLC circuit, can obtain higher inversion efficiency thus, and reaches former secondary isolation purpose.
System in the utility model can energy storage device be realized being incorporated into the power networks and from network operation, also can when being incorporated into the power networks, realize electric power energy storage regulatory function through increasing.Specific practice is to increase one or more energy storage device to reach one or more telegon one to one, and the input of every telegon is connected energy storage device and DC local area network (LAN) respectively with output.Said energy storage device is the dc energy storage device or exchanges at least a in the energy storage device.For one type of dc energy storage device of batteries, this telegon is two-way DC/DC current transforming unit, and Fig. 7 is the example of two-way DC/DC current transforming unit.Exchange energy storage device for one type for the flywheel inertial energy-accumulating, this telegon is two-way AC/DC current transforming unit, and Fig. 8 is the example of two-way AC/DC current transforming unit.
Use the technological thought of the utility model, can constitute multiple distributed generation system, for example:
(1) distributed photovoltaic power generation system.This system does not keep ac power generation and relevant with it telegon in Fig. 1; Direct-current generating device in the system is a N piece photovoltaic battery panel; The N relevant with a direct-current generating device telegon is made up of the LLC circuit of Fig. 6 respectively, and inverter is conventional unidirectional or three-phase grid-connected inverter.
(2) distributed wind power system.This system does not keep direct-current generating device and relevant with it telegon in Fig. 1; Ac power generation in the system is a N platform alternating current generator; The N relevant with an alternating current generator telegon is made up of the LLC circuit of Fig. 6 respectively, and inverter is conventional unidirectional or three-phase grid-connected inverter.
(3) distributed honourable hybrid power system.This main structure of system is as shown in Figure 1, is the mixing of above-mentioned two kinds of systems.
(4) the distributed honourable hybrid power system of band energy storage device, energy storage device wherein is a storage battery, storage battery hangs on the DC local area network (LAN) through the accent device (adopting two-way DC/DC current transforming unit) of corresponding association, can carry out to be incorporated into the power networks or to leave network operation.This main structure of system is as shown in Figure 9.
(5) the distributed honourable mixed power generation street lamp power supply, road lamp power supply system of band energy storage device, this main structure of system is shown in figure 10.Can constitute a kind of distributed honourable mixed power generation road lamp system through increasing DC loads such as energy storage device, electrical lighting with energy storage device; Specific practice is to increase one or more energy storage device to reach one or more telegon one to one; Some electrical lighting loads directly hang on the DC local area network (LAN); Telegon is two-way DC/DC current transforming unit, and the input of every telegon is connected dc energy storage device and DC local area network (LAN) respectively with output, and the dc energy storage device can adopt batteries.
The above; Only be some preferable case study on implementation of the utility model; Not being that the utility model is done any pro forma restriction, though the utility model with preferable case study on implementation announcement as above, yet is not in order to limit the utility model; Anyly be familiar with the professional and technical personnel; In not breaking away from the utility model technical scheme scope, when the structure of above-mentioned announcement capable of using and technology contents are made a little change or are modified to the equivalent case study on implementation of equivalent variations, but every content that does not break away from the utility model technical scheme; Any simple modification, equivalent variations and modification according to the technical spirit of the utility model is done above case study on implementation all still belong in the utility model technical scheme scope.