CN202333838U

CN202333838U - Isolated grid-connected inverter power supply

Info

Publication number: CN202333838U
Application number: CN2011204722920U
Authority: CN
Inventors: 张世桐; 咸立坤; 黄耀林; 申云献
Original assignee: HUIZHOU SANHUA INDUSTRIAL Ltd
Current assignee: HUIZHOU SANHUA INDUSTRIAL Ltd
Priority date: 2011-11-23
Filing date: 2011-11-23
Publication date: 2012-07-11
Anticipated expiration: 2021-11-23

Abstract

The utility model discloses an isolated grid-connected inverter power supply, which comprises a direct current (DC) input current correction module, an input power type identify module, a DC/DC isolated conversion module, a DC/alternating current (AC) bridge-type conversion module, a wind/light energy and battery grid-connected control module, a grid voltage, current and phase sampling module, a digital signal processor (DSP) main control module and a communication interface, wherein a wind energy, photovoltaic or lead-acid battery is used as direct current input, after the operating mode is determined by the input power type identify module, the direct current is converted into a sine wave or a steamed bread wave which has the same frequency and phase as a grid through the DC/DC isolated conversion module, and finally, the phase of the direct current is converted by the DC/ AC bridge-type conversion module and then is merged with the grid. The isolated grid-connected inverter power supply has a wide use scope, and is safe, reliable, convenient to install, lower in cost, and very suitable for building a household and small grid-connected inverter generating system.

Description

Isolation type grid-connected inverter

Technical field

The utility model relates to a kind of parallel network reverse power technology, specifically is meant a kind of isolation type grid-connected inverter.

Background technology

Nowadays energy problem has become world today's problem demanding prompt solution, and each state all utilizes regenerative resource at active development, comprises solar energy, wind energy, water ability, geothermal energy, tidal energy etc. in these regenerative resources; Its main energy obtain manner is exactly that various form of energy is converted into electric energy, be a kind of mode relatively more commonly used and these elementary electric energy are connected to the grid through conversion, and the parallel network reverse power supply is exactly a kind of device for converting electric energy that is connected to the grid these elementary electric energy through conversion; Existing parallel network reverse power supply is mainly high-power product; Can only adapt to the input of photovoltaic panel high voltage, its circuit adopts the design of not isolating with civil power, and input is charged; Need the professional to safeguard; Relative cost is high, therefore is more suitable for the large-sized photovoltaic power station, is not suitable for the use of family and small-sized grid-connected system.

The utility model content

The purpose of the utility model is to overcome above-mentioned weak point of the prior art, and a kind of isolation type grid-connected inverter is provided, and it is higher to be used to solve existing parallel network reverse power supply cost, is inappropriate for the use problem of family and small-sized grid-connected system.

The purpose of the utility model realizes through following technical scheme:

Isolation type grid-connected inverter comprises DC input current correction module, input power supply type identification module, DC/DC isolated variable module, DC/AC bridge-type conversion module, wind/luminous energy and battery generate electricity by way of merging two or more grid systems control module, line voltage electric current and phase sample module, DSP (Digital Signal Processor digital signal processor) master control module and communication interface;

The direct current that is provided by photovoltaic, wind energy or lead-acid battery is introduced in the DC input current correction module and carries out treatment for correcting; And through DC/DC isolated variable module converts one-tenth and the sinusoidal wave perhaps steamed bun ripple of electrical network with the frequency homophase; At last by being connected to the grid after the DC/AC bridge-type conversion module conversion phase place; Said input power supply type identification module is discerned the power supply type of input automatically and is confirmed mode of operation; Simultaneously the input power supply is sampled and import and carry out A/D conversion in the DSP master control module; Said line voltage electric current and phase sample module be to carrying out the A/D conversion in the voltage of grid side, current signal sampling and the input DSP master control module, produces SPWM (Sinusoidal pulse Width Modulation Sine Wave Pulse Width Modulation) control signal and realize that through wind/luminous energy and the battery control module control DC/DC isolated variable module of generating electricity by way of merging two or more grid systems single-stage isolates through the processing of DSP master control module.

The utility model compares that prior art has the following advantages and beneficial effect:

DC/DC isolated variable module single-stage makes input not charged after accomplishing the isolation to input current, uses safelyr, and the single-stage translation circuit is simple and reliable, cost is lower, and I&M makes things convenient for, and is more suitable for the use of family and small-sized grid-connected system.

Description of drawings

Shown in Figure 1 is the overall construction drawing of the utility model

Fig. 2 is the circuit theory diagrams of DC input current correction module

Fig. 3 is a photovoltaic cell V/A curve chart

Fig. 4 is a lead-acid battery V/A curve chart

Embodiment

Below in conjunction with embodiment and accompanying drawing the utility model is described in further detail, but the execution mode of the utility model is not limited thereto.

Embodiment

As shown in Figure 1; Isolation type grid-connected inverter mainly comprises DC input current correction module 1, power supply type identification module 2, DC/DC isolated variable module 3, DC/AC bridge-type conversion module 4, wind/luminous energy and battery generate electricity by way of merging two or more grid systems control module 5, line voltage electric current and phase sample module 6, DSP master control module 7 and communication interface 8;

Be illustrated in figure 2 as the circuit diagram of DC input current correction module 1, the pi type filter of mainly being made up of capacitor C 1, inductance L 1, capacitor C 2 constitutes, and power is similar to passive PFC function; The direct current that the power supply that wind energy, photovoltaic cell or lead-acid battery are three types provides is introduced in the DC input current correction module 1 proofreaies and correct Filtering Processing, and wherein wind energy controller two-wire connected mode is adopted in the input of wind energy power supply; When the input power supply was wind energy, DSP master control module 7 was sent the identification data through communication interface 8 to the wind energy controller, and both sides carry out real-time exchange behind the identification data validation, realized that wind energy MPPT generates electricity by way of merging two or more grid systems.When the input power supply is photovoltaic cell or lead-acid battery, confirm that because of not having communication data DSP master control module 7 switches to V/A tracing analysis pattern.2 pairs of said power supply type identification modules input power supply carries out different capacity and loads, and through when the different loads, the different variable quantities of power supply Δ V (like Fig. 3 and shown in Figure 4) are realized the identification of photovoltaic cell and lead-acid battery.

Said DC/DC isolated variable module 3 comprises single-stage DC/DC converter; The input current of said single-stage DC/DC converter can be with the output current sinusoidal variations; Because the output internal resistance of wind energy controller and photovoltaic cell is relatively large; The internal resistance loss is very big when output current is non-linear, and 7 pairs of input current signals of DSP master control module carry out Δ I/ Δ T ratio calculation, if this numerical value will be regulated single-stage DC/DC converter PWM drive signal when excessive; After DC input current correction module 1 is proofreaied and correct, make the electric current approximately linear of input, make system works efficient bring up to 90% by about 83%.

Input current after overcorrect and Filtering Processing get in the DC/DC isolated variable module 3 isolate, boost, processings such as the control of frequency plot and amplitude, waveform transformation and convert to and electrical network with the sinusoidal wave perhaps steamed bun ripple of homophase frequently, at last by being connected to the grid after the DC/AC bridge-type conversion module 4 conversion phase places.

Import the sampling of 2 pairs of inputs of power supply type identification module power supply simultaneously; Parameters such as the electric voltage frequency of sampling, phase place input DSP master control module 7 is carried out the A/D conversion; Because in the parallel network reverse power supply; Requirement be incorporated into the power networks electric voltage frequency, that phase place must keep is consistent with electric voltage frequency, the phase place of electrical network; Therefore DSP master control module 7 through line voltage electric current and phase sample module 6 sample electrical network electric voltage frequency and phase signal and carry out A/D and change; One of output and all consistent SPWM control signal of mains frequency, phase place, amplitude after computing send to DC/DC isolated variable module 3 realization single-stage DC/DC single-stage isolated variables through wind/luminous energy and the battery control module 5 of generating electricity by way of merging two or more grid systems.

Said communication interface 8 is the RS232 communication interface, and said DSP master control module 7 connects external equipments such as display, PC or wind energy controller through communication interface 8.

The foregoing description is the utility model preferred implementation; But the execution mode of the utility model is not restricted to the described embodiments; Other any do not deviate from change, the modification done under spirit and the principle of the utility model, substitutes, combination, simplify; All should be the substitute mode of equivalence, be included within the protection range of the utility model.

Claims

1. isolation type grid-connected inverter is characterized in that: comprise DC input current correction module (1), input power supply type identification module (2), DC/DC isolated variable module (3), DC/AC bridge-type conversion module (4), wind/luminous energy and battery generate electricity by way of merging two or more grid systems control module (5), line voltage electric current and phase sample module (6), DSP master control module (7) and communication interface (8); The direct current that is provided by photovoltaic, wind energy or lead-acid battery is introduced in the DC input current correction module (1) and carries out treatment for correcting; Convert to and the sinusoidal wave or steamed bun ripple of electrical network by DC/DC isolated variable module (3) with the frequency homophase; At last by being connected to the grid after DC/AC bridge-type conversion module (4) the conversion phase place; Said input power supply type identification module (2) is power supply type and definite mode of operation of identification input automatically; Simultaneously the input power supply is sampled and import and carry out A/D conversion in the DSP master control module (7); Said line voltage electric current and phase sample module (6) be to carrying out the A/D conversion in the voltage of grid side, current signal sampling and the input DSP master control module (7), produce the SPWM control signal and realize that through wind/luminous energy and battery control module (5) the control DC/DC isolated variable module (3) of generating electricity by way of merging two or more grid systems single-stage isolates through the processing of DSP master control module (7).

2. isolation type grid-connected inverter according to claim 1 is characterized in that: said DSP master control module (7) connects display, PC external equipment or wind energy controller through communication interface (8).

3. isolation type grid-connected inverter according to claim 1 is characterized in that: the pi type filter of said DC input current correction module (1) for being made up of capacitor C 1, inductance L 1, capacitor C 2.