CN219322086U - Grid-connected power generation micro-light control system - Google Patents

Abstract

The utility model discloses a grid-connected power generation micro-light control system, which relates to the technical field of photovoltaic power generation and comprises a voltage detection circuit, an A/D conversion circuit, a comparator and an inversion boosting circuit; the voltage detection circuit is connected with the A/D conversion circuit, the A/D conversion circuit is connected with the comparator, and the comparator is connected with the inversion booster circuit. The utility model can prolong the daily effective working time of the photovoltaic array, effectively utilize the solar energy resource in weak light and low light level and improve the photovoltaic power generation efficiency.

Description

Grid-connected power generation micro-light control system

Technical Field

The utility model relates to the technical field of photovoltaic power generation, in particular to a grid-connected power generation micro-light control system.

Background

With the development of social economy, solar power generation is a reliable way for providing energy sources for production and living and improving the problem of environmental pollution. The roof distributed solar power station is a form of distributed photovoltaic power generation, and the distributed solar power is used for realizing solar grid-connected power generation by using an idle roof and an internal power grid of a building, so that extra available space and extra land resources of the building are not occupied, and the aesthetic feeling of the building is improved. However, when the sunlight irradiation is insufficient, the voltage of the photovoltaic output array is often lower than 250V, so that the minimum input requirement of grid-connected equipment is difficult to reach, and the power generation efficiency of the photovoltaic power generation system is affected. Therefore, it is a problem to be solved in urgent need for those skilled in the art how to effectively utilize the solar energy resource in weak light and low light so as to improve the photovoltaic power generation efficiency.

Disclosure of Invention

In view of the above, the present utility model provides a grid-connected micro-light control system for generating power to solve the problems mentioned in the background art.

In order to achieve the above purpose, the present utility model adopts the following technical scheme: a grid-connected power generation micro-light control system comprises a voltage detection circuit, an A/D conversion circuit, a comparator and an inversion boosting circuit; the voltage detection circuit is connected with the A/D conversion circuit, the A/D conversion circuit is connected with the comparator, and the comparator is connected with the inversion boosting circuit.

Optionally, the inversion boosting circuit comprises an inverter, an alternating current breaker, a boosting device and a rectifier; the inverter is connected with the comparator, the alternating current breaker is connected with the inverter, the alternating current breaker is connected with the boosting device, and the boosting device is connected with the rectifier.

By adopting the technical scheme, the method has the following beneficial technical effects: considering that the alternating current boosting cost is lower than the direct current boosting cost, the output electric energy of the photovoltaic array is firstly converted into single-phase alternating current through an inverter, the output voltage is then raised to 250-300V by a boosting device, and finally the rectified high-voltage direct current is sent to a grid-connected inverter.

Optionally, the device further comprises a microcontroller, wherein the microcontroller is connected with the alternating current breaker and is used for controlling the on and off of the alternating current breaker.

Optionally, the comparator is configured to compare the output voltage with a preset threshold.

Optionally, the rectifier is a single-phase rectifier bridge.

Optionally, the inverter and the rectifier are pulse width modulated.

Compared with the prior art, the utility model discloses a grid-connected power generation micro-light control system, which has the following beneficial technical effects:

(1) More electric energy can be sent to the grid-connected inverter, so that solar energy resources can be fully utilized, and the energy is saved and the environment is protected;

(2) When the output voltage of the photovoltaic array is 150-250V, the input voltage supplied to the grid-connected inverter device is raised, the daily effective working time of the photovoltaic array is prolonged, the effective utilization of solar energy resources in low light and low light level is realized, the progress of energy saving and emission reduction work is promoted, and obvious economic benefits can be brought.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present utility model, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of the structure of the present utility model;

fig. 2 is a schematic diagram of the operation of the present utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The embodiment of the utility model discloses a grid-connected power generation micro-light control system, which is shown in figure 1 and comprises a voltage detection circuit, an A/D conversion circuit, a comparator and an inversion boosting circuit; the voltage detection circuit is connected with the A/D conversion circuit, the A/D conversion circuit is connected with the comparator, and the comparator is connected with the inversion boosting circuit.

Further, the inversion boosting circuit comprises an inverter, an alternating current breaker, a boosting device and a rectifier; the inverter is connected with the comparator, the alternating current breaker is connected with the inverter, the alternating current breaker is connected with the boosting device, and the boosting device is connected with the rectifier.

Further, the device also comprises a microcontroller which is connected with the alternating current breaker and controls the on and off of the alternating current breaker.

Further, the rectifier is a single-phase rectifier bridge.

Further, the inverter and the rectifier are pulse width modulated.

When the output voltage of the photovoltaic array is 150-250V, the AC circuit breaker in the circuit is in a closed conduction state under the control of the microcontroller, and the inversion boosting device works. The 150V-250V direct current is changed into 50Hz alternating current through a series-type inverter (the maximum input power of a single inverter is 3.1 kW), and the voltage is raised to 250V-300V by using an alternating current booster device. And converting the alternating current into direct current through a rectifier, and finally conveying the direct current into a grid-connected inverter.

The working principle of the utility model is shown in figure 2, and the specific steps comprise the following steps:

s1, obtaining photovoltaic output voltage;

s2, detecting photovoltaic output voltage, and carrying out A/D conversion on the detected output voltage to obtain output voltage digital quantity;

s3, comparing the output voltage digital quantity with a first threshold value, and if the output voltage digital quantity is smaller than the first threshold value, not performing grid-connected power generation; if the voltage is larger than the first threshold and smaller than the second threshold, performing boosting operation on the photovoltaic output voltage; and if the threshold value is larger than the second threshold value, performing grid-connected operation.

Further, the specific steps of the boosting operation are as follows:

inverting the photovoltaic output voltage to obtain a first alternating current;

lifting the voltage of the first alternating current by using a booster device to obtain a second alternating current;

the second alternating current is changed into direct current through rectification, and the direct current is transmitted to a grid-connected system.

When the sunlight is insufficient, the voltage of the photovoltaic output array is often lower than 250V, and the minimum input requirement of grid-connected equipment is difficult to achieve. Therefore, in the present embodiment, the first threshold is set to 150V, and the second threshold is set to 250V.

And judging the output voltage of the photovoltaic through the voltage detection device, and closing a circuit breaker in the booster circuit when the output voltage of the photovoltaic array of the roof is between 150 and 250V, so that the circuit is conducted. Considering that the alternating current boosting cost is lower than the direct current boosting cost, firstly, the output electric energy of the photovoltaic array is converted into 50Hz single-phase alternating current through an inverter, then the output voltage is raised to 250-300V by a boosting device, and finally, the rectified high-voltage direct current is sent to a grid-connected inverter, and the whole process is controlled by an external microprocessor.

Furthermore, the project data is adopted to verify that the utility model can realize the beneficial effects of effectively utilizing solar energy resources in dim light and dim light:

1. work efficiency of direct-alternating-direct boosting system

The overall efficiency coefficient of the system is divided into three parts: inverter loss K1, ac booster loss K2, single-phase rectifier bridge loss K3.

The loss of the inverter takes the european efficiency, k1=97.1%. The ac boost device takes the lowest efficiency tested, k2=95%. The loss of the single-phase rectifier bridge is within 3%, and K3=97% is adopted. Thus, the overall efficiency of the system: k=k1×k2×k3=97.1% ×95% ×97% = 89.47%.

2. Lifting of power generation

The capacity of the installation machine in an actual project is 36.69kWp, the average power on line in a theoretical month is 3015kWh, the sunlight intensity meeting the working condition of the device (the output voltage of the photovoltaic array is 150-250V) is 13% of the total power generation time, and the power generation capacity in the stage is 5-8% of the total power generation time in normal operation. The micro-light control system device is additionally arranged, the average power on the network in theory month can be improved by 150-241 kWh, which is equivalent to saving 50-80.5 kg of standard coal for the power grid more per year (the consumption of thermal power coal is calculated according to the average value 334g/kWh in the whole country in 2007), and the micro-light control system device has obvious energy-saving benefit.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the utility model. Thus, the present utility model is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (6)

1. The grid-connected power generation micro-light control system is characterized by comprising a voltage detection circuit, an A/D conversion circuit, a comparator and an inversion boosting circuit; the voltage detection circuit is connected with the A/D conversion circuit, the A/D conversion circuit is connected with the comparator, and the comparator is connected with the inversion boosting circuit.

2. The grid-connected power generation micro-light control system according to claim 1, wherein the inversion boosting circuit comprises an inverter, an alternating current circuit breaker, a boosting device and a rectifier; the inverter is connected with the comparator, the alternating current breaker is connected with the inverter, the alternating current breaker is connected with the boosting device, and the boosting device is connected with the rectifier.

3. The grid-tie power micro-light control system of claim 2, further comprising a microcontroller connected to the ac circuit breaker for controlling the on and off of the ac circuit breaker.

4. The grid-tie power micro-light control system of claim 1, wherein the comparator is configured to compare the output voltage with a preset threshold.

5. The grid-tie power micro-light control system of claim 2, wherein the rectifier is a single-phase rectifier bridge.

6. The grid-tie power micro-light control system of claim 2, wherein the inverter and the rectifier are pulse width modulated.

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