CN203301166U - Device for suppressing photovoltaic power generation output power fluctuation - Google Patents

Abstract

The utility model discloses a device for suppressing output power fluctuations of photovoltaic power generation, which comprises more than one set of photovoltaic array components (1), and is characterized in that: the photovoltaic array components (1) are connected with an energy storage device (3), and the energy storage The output of the device (3) is connected to the grid load (5) through the bidirectional inverter (4). The principle is to use the capacity of the energy storage device to stabilize the photovoltaic output power, ensure the stability of the output power, improve the reliability of power supply, and deliver qualified quality electric energy to users. Photovoltaic power generation first enters energy storage, and then converts it into AC power through a bidirectional inverter to supply power to the load; when the energy storage capacity is full, the controller switches to "float charging" mode to directly supply power to the load, and the energy storage acts as Replenish.

Description

A device for suppressing output power fluctuations of photovoltaic power generation

technical field

The utility model relates to a device for suppressing output power fluctuations of photovoltaic power generation, which belongs to the technical field of solar photovoltaics. the

Background technique

At present, solar photovoltaic power generation systems can be divided into grid-connected methods: off-grid power generation systems and grid-connected power generation systems. According to the bus form, there are two ways: DC bus and AC bus. The DC bus mode is that the photovoltaic array components are first collected into the DC bus, and then converted into AC power by a DC/AC inverter to supply the load. The AC bus mode is that the photovoltaic array components are converted into AC power by the DC/AC inverter and collected to the AC bus, and then supplied to the load. At present, photovoltaic power generation adopts the maximum power point tracking technology (MPPT) to realize the maximum utilization of solar energy, but it does not have power adjustment capabilities; at the same time, photovoltaic power generation systems are greatly affected by conditions such as light and temperature. When the DC output is interrupted, the AC side output It presents a fast turn-off characteristic, and the current fluctuation rate is large. According to relevant literature reports, in cloudy weather, the power fluctuation of photovoltaic power generation can reach 25% of the installed capacity, and the maximum fluctuation rate can reach 10% of the rated output per second. the

In order to solve the problem of large power fluctuations and non-adjustable control of photovoltaic power generation, the current method is to add energy storage devices (usually batteries), install them on the DC bus or AC bus, and control the input and output of energy storage according to the system power balance. , but affected by the control system, and its control strategy is controlled according to voltage fluctuations, there are factors such as time lag, resulting in large fluctuations in output power and large fluctuations in system voltage. the

Contents of the invention

The technical problem to be solved by the utility model is to provide a device with a simple system, which can effectively solve the problem of large power fluctuations of photovoltaic power generation and unadjustable control, so that its power output can be stable and suppress the fluctuation of photovoltaic power generation output power, which can overcome the existing Insufficient technology. the

The technical solution of the present utility model is: a device for suppressing fluctuations in output power of photovoltaic power generation, which includes more than one set of photovoltaic array components, the photovoltaic array components are connected to an energy storage device, and the output of the energy storage device is connected to the power grid through a bidirectional inverter load connection. the

More than one set of photovoltaic array components are connected to each other through series, parallel or combination of series and parallel. the

A DC/DC charging device is provided between the photovoltaic array assembly and the energy storage device. the

The bidirectional inverter is a DC/AC bidirectional inverter. the

Compared with the prior art, the utility model connects the photovoltaic array components in series and parallel, charges the energy storage (battery) through a DC/DC charging device, and then converts it into AC power through a bidirectional inverter to supply power to the load. In the evening or when there is no sunshine, the electricity price in the valley of the power grid is cheap, and the power of the grid is charged through the DC/AC bidirectional inverter to charge the energy storage device, which plays the role of peak-shaving and valley-filling of the power grid. The principle is: use the capacity of the energy storage device to stabilize the photovoltaic output power, ensure the stability of the output power, improve the reliability of power supply, and deliver qualified quality electric energy to users. Photovoltaic power first enters energy storage, and then converts it into AC power through a bidirectional inverter to supply power to the load; when the energy storage capacity is full, the controller switches to "float charging" mode to directly supply power to the load, and the energy storage acts as Replenish. the

Description of drawings

Fig. 1 is the structural representation of the utility model. the

Detailed ways

The connection structure of each part of the device is shown in Figure 1. More than one set of photovoltaic array components 1 are connected in series and in parallel to charge the energy storage device 3 through the DC/DC charging device 2, and then through the bidirectional inverter 4 to convert into The AC power supply supplies power to the grid load 5 . the

The specific power supply method is:

At night or during a set time period, the energy storage device 3 is charged through the bidirectional inverter 4 by using the energy of the power grid, making full use of the peak-valley electricity price difference, and playing a role in peak-shaving and valley-filling of the power grid until the energy storage device 3, that is, the battery is fully charged. After charging, charging stops.

When the photovoltaic array component 1 outputs energy, and the energy emitted by the photovoltaic array component 1 is greater than the energy required by the grid load 5, and the energy storage device 3 can also be charged, let the DC/DC charging device 2 work at the MPPT power point, and the energy storage device 3 charging, and at the same time supplying excess electric energy to the load 5 through the bidirectional inverter 4. the

When the energy output by the photovoltaic array assembly 1 is greater than the power required by the load 5, and the charging voltage of the energy storage device 3 has reached the overcharge voltage, the load 5 is directly powered by "float charging". the

When the energy output by the photovoltaic array module 1 is less than the energy required by the load 5, the insufficient energy needs to be supplemented by discharging the battery, the DC/DC charging device 2 works at the MPPT power point, and the bidirectional inverter 4 works in the discharge mode. the

Claims (4)

1. A device for suppressing fluctuations in output power of photovoltaic power generation, which includes more than one set of photovoltaic array components (1), characterized in that: photovoltaic array components (1) are connected to energy storage devices (3), and the energy storage devices (3) ) is connected to the grid load (5) through a bidirectional inverter (4). 2. A device for suppressing fluctuations in output power of photovoltaic power generation according to claim 1, characterized in that: more than one set of photovoltaic array components (1) are connected to each other through series and parallel. 3. A device for suppressing fluctuations in output power of photovoltaic power generation according to claim 1, characterized in that: a DC/DC charging device (2) is provided between the photovoltaic array assembly (1) and the energy storage device (3) . 4. The device for suppressing fluctuations in output power of photovoltaic power generation according to claim 1, characterized in that: the inverter (4) is a DC/AC bidirectional inverter.

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