CN207200300U

CN207200300U - A kind of photovoltaic combining inverter of impedance remodeling

Info

Publication number: CN207200300U
Application number: CN201720896931.3U
Authority: CN
Inventors: 孔祥炜
Original assignee: Shenzhen Meinuo Di Technology Co Ltd
Current assignee: Shenzhen Meinuo Di Technology Co Ltd
Priority date: 2017-07-24
Filing date: 2017-07-24
Publication date: 2018-04-06
Anticipated expiration: 2027-07-24

Abstract

The utility model discloses a kind of photovoltaic combining inverter of impedance remodeling, including photovoltaic array, the voltage output end of photovoltaic array is connected with DC booster converter by wire, the control terminal of switching tube is connected with maximal power tracing controller by wire in DC booster converter, the voltage output end of DC booster converter is parallel with filter capacitor, three-phase full-bridge inverting circuit is parallel with by filter capacitor, the drive end of three-phase full-bridge inverting circuit is connected with inverse changing driving circuit by wire, three-phase full-bridge inverting circuit exports sinusoidal ac, output current to LCL filter, LCL filter is used for filtering clutter output burning voltage, and it is also associated with PLL phase-locked loop circuits between the output end and inverse changing driving circuit of LCL filter.The utility model effectively realizes the resonance suppression for higher harmonic current, improves the purpose that power network damping reaches network impedance remodeling, reduces circuit loss and improves reliability.

Description

A kind of photovoltaic combining inverter of impedance remodeling

Technical field

Technical field of electric equipment is the utility model is related to, specially a kind of photovoltaic combining inverter of impedance remodeling.

Background technology

In recent years, global energy crisis and environmental problem are increasingly sharpened, and the regenerative resource such as photovoltaic has obtained more and more Concern, with the continuous reduction of photovoltaic cell cost, grid-connected photovoltaic power generation system is expected to obtain more in Future Power System Add and be widely applied.However, along with the continuous improvement of photovoltaic permeability, safety and stability of the photovoltaic combining inverter to power distribution network No small challenge is brought with the quality of power supply etc..Particularly, constantly found in distributed photovoltaic grid-connected system：More grid-connected inverse The interaction become between device can cause the connection in series-parallel harmonic resonance of power distribution network, in combining inverter autoprotection or distribution protection Under participation, in some instances it may even be possible to the fault-free trip of combining inverter can be caused, reduce ability and supply user that it generates electricity by way of merging two or more grid systems The reliability of electricity.

Existing photovoltaic combining inverter for the miscellaneous function such as power network power quality controlling research mainly for fundamental wave and Low-order harmonic electric current, suppress for the resonance of higher harmonic current, and the grinding key issues of remodeling of power distribution network network impedance Study carefully and also compare shortage.

The content of the invention

In order to overcome the shortcomings of prior art, the utility model provides a kind of photovoltaic grid-connected inversion of impedance remodeling Device, the resonance suppression for higher harmonic current is effectively realized, improve the purpose that power network damping reaches network impedance remodeling, drop Low circuit loss improves reliability.

Technical scheme is used by the utility model solves its technical problem：A kind of photovoltaic grid-connected inversion of impedance remodeling Device, including photovoltaic array, the photovoltaic array are used to solar energy being converted into direct current energy, the voltage output end of photovoltaic array DC booster converter is connected with by wire, the control terminal of switching tube is connected with by wire in the DC booster converter Maximal power tracing controller, the maximal power tracing controller output MPPT controls waveform control DC booster converter are defeated Go out prominent DC voltage under specified criteria；The voltage output end of the DC booster converter is parallel with filter capacitor, Three-phase full-bridge inverting circuit is parallel with by filter capacitor, the drive end of the three-phase full-bridge inverting circuit is connected with by wire Inverse changing driving circuit, the inverse changing driving circuit are used to export SPWM wave control signals, the three-phase full-bridge inverting circuit output Sinusoidal ac, LCL filter is outputed current to, the LCL filter is used for filtering clutter output burning voltage, and LCL is filtered PLL phase-locked loop circuits are also associated between the output end and inverse changing driving circuit of ripple device.

As a kind of technical scheme for having choosing of the utility model, the DC booster converter uses typical Boost liters Topological structure is pressed, and optical coupling isolator is in series between DC booster converter and photovoltaic array.

As a kind of technical scheme for having choosing of the utility model, the core of the inverse changing driving circuit uses IR2110 cores Piece, external microcontroller controller introducing control signal is connected at pin 7, serial coupling capacitor between pin 5 and pin 6, is drawn Pin 10 exports the gate pole of SPWM ripple signals switching tube into three-phase full-bridge inverting circuit.

As a kind of technical scheme for having choosing of the utility model, the LCL filter shares three and uses typical Y types knot Structure, it is connected respectively with the single armed of three-phase full-bridge inverting circuit, and resistance is in series with the capacitive branch of LCL filter.

As a kind of technical scheme for having choosing of the utility model, the PLL phase-locked loop circuits use MCI4046 and two piece CD4017 chip cascades form, after the pin 7 of one of CD4017 chips access NAND gate in parallel with next piece of pin 11 Sampled signal is introduced, MCI4046 pin 4 exports VCO signal to the feedback end of inverse changing driving circuit.

Compared with prior art, the beneficial effects of the utility model are：

(1) the utility model is controlled by setting maximal power tracing controller using power tracking, realizes peak power Output, conversion efficiency is improved under the conditions of equal ambient, reduce system loss；

(2) the utility model is by setting LCL filter to carry out output filtering so that circuit has more for high-frequency harmonic Good attenuation characteristic, so as to effectively reduce circuit loss and size, while by capacitive branch series resistance, effectively increasing Circuit damped coefficient, realize impedance remodeling function；

(3) the utility model controls the extraction of PLL phase-locked loop circuits progress electric network voltage phase parameter by setting, with reference to Inverse changing driving circuit realizes that phase factor corrects, and improves the phase stability of output voltage, and then improve the ability generated electricity by way of merging two or more grid systems With the reliability to customer power supply.

Brief description of the drawings

Fig. 1 is overall structure diagram of the present utility model；

Fig. 2 is DC booster converter circuit theory diagrams；

Fig. 3 is inverse changing driving circuit schematic diagram；

Fig. 4 is three-phase full-bridge inverting circuit and LCL filter circuit theory diagrams；

Fig. 5 is PLL phase-locked loop circuit schematic diagrams.

In figure：1- photovoltaic arrays；2- DC booster converters；3- maximal power tracing controllers；4- three phase full bridge inversions Circuit；5- inverse changing driving circuits；6-LCL wave filters；7-PLL phase-locked loop circuits；8- optical coupling isolators.

Embodiment

Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the embodiment of the utility model is carried out Clearly and completely describing, it is clear that described embodiment is only the utility model part of the embodiment, rather than whole Embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are not under the premise of creative work is made The every other embodiment obtained, belong to the scope of the utility model protection.

The explanation of following embodiment is refer to the attached drawing, can be to the particular implementation implemented to example the utility model Example.The direction and position term that the utility model is previously mentioned, for example, " on ", " in ", " under ", "front", "rear", "left", "right", " It is interior ", " outer ", " side " etc., be only the direction and position with reference to annexed drawings.Therefore, the direction and position term used is to use To illustrate and understand the utility model, and it is not used to limit the utility model.

Embodiment：

As depicted in figs. 1 and 2, the utility model provides a kind of photovoltaic combining inverter of impedance remodeling, including photovoltaic Array 1, the photovoltaic array 1 are used to solar energy being converted into direct current energy, and the voltage output end of photovoltaic array 1 passes through wire It is connected with DC booster converter 2, the control terminal of switching tube is connected with maximum work by wire in the DC booster converter 2 Rate tracking control unit 3, the maximal power tracing controller 3 export MPPT control waveform control DC booster converters 2 and exported Prominent DC voltage under specified criteria；The voltage output end of the DC booster converter 2 is parallel with filter capacitor, leads to Cross filter capacitor and be parallel with three-phase full-bridge inverting circuit 4, the drive end of the three-phase full-bridge inverting circuit 4 is connected with by wire Inverse changing driving circuit 5, the inverse changing driving circuit 5 are used to export SPWM wave control signals, and the three-phase full-bridge inverting circuit 4 is defeated Going out sinusoidal ac, output current to LCL filter 6, the LCL filter 6 is used for filtering clutter output burning voltage, and PLL phase-locked loop circuits 7 are also associated between the output end and inverse changing driving circuit 5 of LCL filter 6；

The photovoltaic array 1 can change into solar energy direct current energy, but one piece of photovoltaic through photovoltaic effect Module (photovoltaic panel) can caused by electric current not general enough residential usage, so several piece photovoltaic module is linked together and formed Array, the DC voltage that photovoltaic array 1 exports are sent to DC booster converter 2；

As shown in Fig. 2 the DC booster converter 2 uses typical Boost boost topologies, and DC boosting becomes Optical coupling isolator 8 is in series between parallel operation 2 and photovoltaic array 1, the optical coupling isolator 8 connects into push-pull driver circuit structure； The optical coupling isolator 8 realizes that the voltage between photovoltaic array 1 and DC booster converter 2 is isolated, and reduces front stage circuits to rear The influence of level, the working frequency of the adjusting switch pipe of DC booster converter 2, the amplitude of adjustment output boosting；Further illustrate It is that maximal power tracing controller 3 is controlled by external microcontroller controller, according to the size of boost output voltage, realizes Maximal power tracing is controlled, and control photovoltaic, which is contributed, to be exported；

As shown in figure 3, the core of the inverse changing driving circuit 5 uses IR2110 chips, outside monolithic is connected at pin 7 Machine controller introduces control signal, serial coupling capacitor between pin 5 and pin 6, and pin 10 exports SPWM ripples signal to three-phase The gate pole of switching tube in full bridge inverter 4；IR2110 chips in the inverse changing driving circuit 5 can under the control of single-chip microcomputer To export corresponding SPWM ripples according to the dutycycle of setting, so as to control the size of inversion output AC voltage；

As shown in figure 4, the LCL filter 6, which shares three, uses typical y-type structure, respectively with three phase full bridge inversion The single armed of circuit 4 is connected, and is in series with resistance on the capacitive branch of LCL filter 6；LCL filter 6 is relative to traditional L And LC wave filters have more preferable attenuation characteristic to high-frequency harmonic, so as under identical harmonic wave and switching frequency, be filtered using LCL The loss of the three-phase photovoltaic grid-connected inverting device of ripple device and size are smaller；In addition capacitive branch series resistance is hindered with increasing system Buddhist nun, suppress peak value of the LCL filter at resonant frequency；

As shown in figure 5, the PLL phase-locked loop circuits 7 are formed using MCI4046 and two piece of CD4017 chip cascade, wherein Sampled signal is introduced after the pin 7 of one piece of CD4017 chip access NAND gate in parallel with next piece of pin 11, MCI4046's draws Pin 4 exports VCO signal to the feedback end of inverse changing driving circuit 5；Phaselocked loop is used to extract electric network voltage phase, and will extraction The phase information arrived carries out process of frequency multiplication, is re-fed into inverse changing driving circuit 5, with reference to external microcontroller, is compared using comparator Whether current output phase and setting phase are consistent, so as to provide thermal compensation signal to ensure the phase-constant of output voltage.

In summary, it is of the present utility model to be mainly characterized by：

It is obvious to a person skilled in the art that the utility model is not limited to the details of above-mentioned one exemplary embodiment, and And in the case of without departing substantially from spirit or essential attributes of the present utility model, it can realize that this practicality is new in other specific forms Type.Therefore, no matter from the point of view of which point, embodiment all should be regarded as exemplary, and is nonrestrictive, this practicality is new The scope of type limits by appended claims rather than described above, it is intended that the equivalency fallen in claim is contained All changes in justice and scope are included in the utility model.Any reference in claim should not be considered as limitation Involved claim.

Claims

A kind of 1. photovoltaic combining inverter of impedance remodeling, it is characterised in that：Including photovoltaic array (1), the photovoltaic array (1) For solar energy to be converted into direct current energy, the voltage output end of photovoltaic array (1) is connected with DC boosting by wire and become Parallel operation (2), the control terminal of the interior switching tube of the DC booster converter (2) are connected with maximal power tracing controller by wire (3), the given bar of maximal power tracing controller (3) output MPPT control waveform control DC booster converters (2) output Prominent DC voltage under part；The voltage output end of the DC booster converter (2) is parallel with filter capacitor, passes through filter Ripple electric capacity is parallel with three-phase full-bridge inverting circuit (4), and the drive end of the three-phase full-bridge inverting circuit (4) is connected with by wire Inverse changing driving circuit (5), the inverse changing driving circuit (5) are used to export SPWM wave control signals, the three phase full bridge inversion electricity Road (4) exports sinusoidal ac, outputs current to LCL filter (6), it is steady that the LCL filter (6) is used for filtering clutter output Determine voltage, and PLL phase-locked loop circuits (7) are also associated between the output end of LCL filter (6) and inverse changing driving circuit (5).
A kind of 2. photovoltaic combining inverter of impedance remodeling according to claim 1, it is characterised in that：The DC boosting Converter (2) uses typical Boost boost topologies, and is connected between DC booster converter (2) and photovoltaic array (1) There is optical coupling isolator (8).
A kind of 3. photovoltaic combining inverter of impedance remodeling according to claim 1, it is characterised in that：The inversion driving The core of circuit (5) uses I R2110 chips, and external microcontroller controller is connected at pin 7 and introduces control signal, pin 5 The serial coupling capacitor between pin 6, pin 10 export the door of SPWM ripples signal switching tube into three-phase full-bridge inverting circuit (4) Pole.
A kind of 4. photovoltaic combining inverter of impedance remodeling according to claim 1, it is characterised in that：The LCL filtering Device (6) shares three and uses typical y-type structure, and the single armed with three-phase full-bridge inverting circuit (4) is connected respectively, and LCL is filtered Resistance is in series with the capacitive branch of ripple device (6).
A kind of 5. photovoltaic combining inverter of impedance remodeling according to claim 1, it is characterised in that：The PLL locks phase Loop circuit (7) is formed using MCI4046 and two piece of CD4017 chip cascade, the pin 7 of one of CD4017 chips with it is next Sampled signal is introduced after the access NAND gate in parallel of pin 11 of block, MCI4046 pin 4 exports VCO signal to inversion and drives electricity The feedback end on road (5).