CN207339720U - Photovoltaic energy storage power station - Google Patents

Abstract

It the utility model is related to energy-accumulating power station, there is provided a kind of photovoltaic energy storage power station.The photovoltaic energy storage power station includes photovoltaic system, energy-storage system and photovoltaic energy storage all-in-one machine, and energy-storage system includes super capacitor and the storage battery being connected with super capacitor, photovoltaic energy storage all-in-one machine are connected with photovoltaic system and super capacitor respectively；Photovoltaic system is used to collect solar energy, and collected solar energy is converted to electric energy；Photovoltaic energy storage all-in-one machine supplies AC load and power grid after being used for after the electric energy of photovoltaic system is converted to stable DC, being stored in storage battery or being converted to alternating current, and control storage battery is powered to DC load.The utility model can not only quick response charge-discharge power demand, and be remarkably improved energy storage speed and discharge and recharge number by using super capacitor.

Description

Photovoltaic energy storage power station

technical field

The utility model relates to an energy storage power station, in particular to a photovoltaic energy storage power station.

Background technique

As the world's energy supply continues to be tense and people pay more and more attention to environmental issues, the rational development and utilization of renewable energy has become an important issue. The development and utilization of renewable energy is an important measure to increase the sustainable supply of energy, improve the energy structure, ensure energy security, and gradually restore the natural environment. It is very important for building a resource-saving and environment-friendly society and realizing comprehensive, coordinated and sustainable economic and social development. meaning.

In recent years, renewable energy, especially solar energy, has been vigorously developed in the field of power generation. However, solar energy is greatly affected by seasons, time periods and the environment, and has defects such as intermittent, unstable and uncontrollable. In order to ensure the balance and continuity of its power supply, it is necessary to use an energy storage system to store the electric energy converted from solar energy. However, the charging and discharging speed of the battery energy storage system is slow and the number of charging and discharging is small, which makes it unable to achieve fast dynamic power compensation, suppress dynamic oscillation, and smooth rapid changes in wind power output.

Contents of the invention

The utility model aims to solve the technical problems of slow charging and discharging speed and less charging and discharging times of the energy storage system in the prior art.

In order to solve the above problems, the utility model provides a photovoltaic energy storage power station, the photovoltaic energy storage power station includes a photovoltaic system, an energy storage system and a photovoltaic energy storage integrated machine, the energy storage system includes a super capacitor and a A connected storage battery, the integrated photovoltaic energy storage machine is connected to the photovoltaic system and the supercapacitor respectively;

The photovoltaic system is used to collect solar energy and convert the collected solar energy into electrical energy;

The photovoltaic energy storage integrated machine is used to convert the electric energy of the photovoltaic system into stable direct current, store it in the storage battery or convert it into alternating current and supply it to the AC load and power grid, and control the storage battery to supply power to the DC load.

Wherein, the photovoltaic system includes a plurality of solar panels.

Wherein, the photovoltaic energy storage integrated machine includes a controller and a DC/DC converter, a DC/AC converter and a filter respectively connected to the controller; the DC/DC converter is used to convert the photovoltaic system The electric energy is converted into stable direct current; the DC/AC converter is used to convert the direct current output by the DC/DC converter into alternating current; the filter is used to convert the alternating current output by the DC/AC converter into a sine wave .

Wherein, the filter is connected to the power grid through a transformer and an AC distributor in sequence.

Wherein, the topology of the DC/DC converter is a non-isolated bidirectional DC/DC conversion topology.

Wherein, the topology of the DC/AC converter is a three-phase two-level half-bridge topology.

The utility model has simple structure and low cost. After converting solar energy into electric energy by using the photovoltaic system, the photovoltaic energy storage integrated machine can convert the electric energy of the photovoltaic system into stable direct current and store it in the storage battery, and control the storage battery to supply power to the direct current load; Or the photovoltaic energy storage integrated machine converts the electric energy of the photovoltaic system into a stable direct current, and then continues to convert the direct current into alternating current to supply the alternating current load and the grid, so that it can not only quickly respond to the charging and discharging demand, but also can significantly improve the energy consumption by using supercapacitors. Energy storage speed and charge and discharge times.

Description of drawings

Fig. 1 is a schematic diagram of a photovoltaic energy storage power station in an embodiment of the utility model;

Fig. 2 is the circuit topology diagram of the photovoltaic energy storage integrated machine in the embodiment of the utility model;

Fig. 3 is a low-voltage ride-through curve diagram of the photovoltaic energy storage power station in the embodiment of the utility model.

Detailed ways

In order to make the purpose, technical solutions and advantages of the utility model clearer, the technical solutions in the utility model will be clearly described below in conjunction with the accompanying drawings in the utility model. Obviously, the described embodiments are a part of the utility model Examples, not all examples. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

It should be noted that, unless otherwise clearly stipulated and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or through Intermediaries are indirectly connected. Those of ordinary skill in the art can understand the specific meanings of the above terms in the utility model in specific situations.

As shown in Figure 1, an embodiment of the utility model provides a photovoltaic energy storage power station, the photovoltaic energy storage power station includes a photovoltaic system, an energy storage system and a photovoltaic energy storage integrated machine, the energy storage system includes a super capacitor and is connected to the super capacitor The storage battery and the integrated photovoltaic energy storage machine are connected to the photovoltaic system and the supercapacitor respectively;

Photovoltaic systems are used to collect solar energy and convert the collected solar energy into electrical energy;

The photovoltaic energy storage integrated machine is used to convert the electric energy of the photovoltaic system into stable direct current, store it in the battery or convert it into alternating current to supply the AC load and the grid, and control the battery to supply power to the DC load.

Therefore, after the photovoltaic system converts solar energy into electrical energy, the photovoltaic energy storage integrated machine converts the electrical energy of the photovoltaic system into stable DC and stores it in the battery, or the photovoltaic energy storage integrated machine converts the electrical energy of the photovoltaic system into stable DC. ,Continue to convert the direct current into alternating current to supply the alternating current load and the power grid. When the direct current load needs power supply, the photovoltaic energy storage integrated machine will control the battery to supply power to the direct current load. It can be seen that the photovoltaic energy storage power station can not only quickly respond to charging and discharging demands, but also significantly improve the energy storage speed and charging and discharging times by using supercapacitors. In addition, as shown in Figure 3, when the voltage drops to 0pu, the time for the photovoltaic energy storage power station to remain connected to the grid is 0.15s; The grid-connected time for the photovoltaic energy storage power station is 0.625s; when the voltage drops to 0.9pu, that is, the lowest voltage value during normal operation, the photovoltaic energy storage power station needs to be kept grid-connected for 2s. It can be seen that the photovoltaic energy storage power station has a low-voltage ride-through function when supplying power to the grid.

Preferably, the photovoltaic system comprises a plurality of solar panels.

Preferably, the photovoltaic energy storage integrated machine includes a controller and a DC/DC converter, a DC/AC converter and a filter respectively connected to the controller; the DC/DC converter is used to convert the electric energy of the photovoltaic system into a stable direct current; The DC/AC converter is used to convert the direct current output by the DC/DC converter into alternating current; the filter is used to convert the alternating current output by the DC/AC converter into a sine wave. Since, for small-scale independent photovoltaic power generation systems, the tracking of the maximum output power point (MPPT) by the photovoltaic power generation system system depends on the clamping of the solar panel operating point by the energy storage system in most cases. If the charging characteristic curve of the energy storage system is relatively flat, the voltage difference of the DC/DC converter in the MPPT can be minimized, so the tracking efficiency will be improved, which will effectively improve the utilization efficiency of the solar panel. By combining supercapacitors with batteries, the charging characteristic curve of the energy storage system can be flattened, which in turn can significantly improve the utilization efficiency of solar panels.

Further, as shown in Figure 2, the integrated photovoltaic energy storage machine also includes an AC switch, a DC switch and a generator.

Preferably, the filter is connected to the grid through a transformer and an AC distributor in sequence.

Preferably, the topology of the DC/DC converter is a non-isolated bidirectional DC/DC conversion topology, so that the photovoltaic energy storage power station can charge and discharge at constant voltage and constant current.

Preferably, the topology of the DC/AC converter is a three-phase two-level half-bridge topology, so that constant voltage and constant frequency control can be achieved when the photovoltaic energy storage power station operates off-grid.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present utility model, and are not intended to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit of the technical solutions of the various embodiments of the present invention. and range.

Claims (6)

1. A photovoltaic energy storage power station, characterized in that it includes a photovoltaic system, an energy storage system and a photovoltaic energy storage integrated machine, the energy storage system includes a supercapacitor and a battery connected to the supercapacitor, and the photovoltaic energy storage The all-in-one machine is connected to the photovoltaic system and the supercapacitor respectively; The photovoltaic system is used to collect solar energy and convert the collected solar energy into electrical energy; The photovoltaic energy storage integrated machine is used to convert the electric energy of the photovoltaic system into stable direct current, store it in the storage battery or convert it into alternating current and supply it to the AC load and power grid, and control the storage battery to supply power to the DC load. 2. The photovoltaic energy storage power station according to claim 1, wherein the photovoltaic system comprises a plurality of solar panels. 3. The photovoltaic energy storage power station according to claim 1 or 2, wherein the photovoltaic energy storage integrated machine includes a controller, a DC/DC converter and a DC/AC converter respectively connected to the controller and a filter; the DC/DC converter is used to convert the electric energy of the photovoltaic system into a stable direct current; the DC/AC converter is used to convert the direct current output by the DC/DC converter into an alternating current; the The filter is used to convert the alternating current output by the DC/AC converter into a sine wave. 4. The photovoltaic energy storage power station according to claim 3, wherein the filter is connected to the power grid through a transformer and an AC distributor in sequence. 5. The photovoltaic energy storage power station according to claim 3, wherein the topology of the DC/DC converter is a non-isolated bidirectional DC/DC conversion topology. 6. The photovoltaic energy storage power station according to claim 3, wherein the topology of the DC/AC converter is a three-phase two-level half-bridge topology.