CN204441903U - A kind of clean energy resource system of alternating current-direct current mixing - Google Patents

Abstract

The utility model discloses an AC-DC hybrid clean energy system, which comprises a plurality of doubly-fed asynchronous generators, the stator windings of which are connected to the AC busbar, and the rotor windings are connected to the DC busbar through a converter; directly output AC after voltage and/or connect DC converter to output DC after stepping up by transformer. The electric power output by the stator winding is merged into the AC transmission line through the AC bus and transformer; when the doubly-fed asynchronous generator is running in a super-synchronous state, the rotor winding outputs the electric power to the DC bus through the converter; when the doubly-fed asynchronous generator is in sub-synchronous Or synchronous state operation, the rotor winding absorbs electric power from the DC bus through the converter; this system makes full use of the space-time complementarity between double-fed asynchronous, synchronous, DC generators, photovoltaic power generation, etc., to reduce the impact of unstable clean energy power fluctuations Power grid impact, reduce power grid reserve capacity, improve power grid operation stability.

Description

An AC-DC hybrid clean energy system

technical field

The utility model relates to a clean energy system, in particular to an AC-DC mixed clean energy system.

Background technique

With the current shortage of energy sources, more and more attention has been paid to the development of various new energy sources such as wind energy, solar energy, tidal energy and wave energy. In the development of these new energy sources, double-fed asynchronous generators, synchronous Generators, DC generators and photovoltaic power generation equipment. In order to improve the energy conversion efficiency of the prime mover driven by wind energy, tidal energy and wave energy, etc., the speed of the prime mover will change within a certain range, and the speed of the doubly-fed asynchronous generator and synchronous generator driven by it will change accordingly , the frequency of its electric power also changes, and it needs to be connected to the grid through a converter, resulting in unstable electric power and high harmonic content. New energy has the characteristics of instability and randomness, which makes the quality of the electric energy it emits low. After being integrated into the grid, it will have a greater impact on the grid, and sometimes even these energies have to be abandoned, resulting in greater waste. Due to the insufficient capacity of the power grid and the instability of new energy sources, some generators are suspended, and power cuts lead to a decline in the economy of the electric field. The main reason for the power cuts is the difficulty of grid connection, and the output of new energy sources is unstable, and other power sources are needed. To provide free peak-shaving services, it is necessary to build peak-shaving and frequency-regulating power sources such as pumped storage and gas-fired power generation. When the peak-shaving capacity is in short supply, power cuts are particularly severe. Optimizing the planning of power supply structure and grid layout and expanding the wind power consumption market also need to pass Technological innovation promotes the coordination of wind power production and consumption.

Contents of the invention

The purpose of the utility model is to overcome the above-mentioned shortcomings and deficiencies of the prior art, and to provide an AC-DC hybrid clean energy system. Reduce the impact of the output power of power generation equipment on the power grid when the new energy power fluctuates, reduce the harmonic injection to the power grid, and improve the stability of the power grid operation; while the unstable power output achieves power balance through load switching, and the unstable Energy is converted into other forms for storage or consumption, and replaces firewood, straw, coal, and oil to reduce carbon emissions and environmental pollution.

The utility model is realized through the following technical solutions:

An AC-DC hybrid clean energy system, including an AC bus, a DC bus, and a power generation system, the power generation system includes a plurality of double-fed asynchronous generators, prime movers for driving each double-fed asynchronous generator;

The stator winding of the doubly-fed asynchronous generator is connected to the AC bus, and the rotor winding is connected to the DC bus through a converter;

The alternating current output by the alternating current bus bar is directly output alternating current after being boosted by a transformer and/or is connected to a direct current converter to output direct current after being stepped up by a transformer.

The power generation system also includes a plurality of synchronous generators and DC generators driven by prime movers; the synchronous generators convert AC to DC through AC/DC and then connect to the DC bus; the DC generators convert DC to DC through DC/DC The DC voltage is converted into a stable DC voltage and then connected to the DC bus.

The power generation system also includes a photovoltaic power generation system. The photovoltaic power generation system converts the DC voltage into a stable DC voltage through DC/DC and then connects to the DC bus.

Between the AC bus and the DC bus, there is also connected an AC/DC converter for exchanging bidirectional electric energy between the DC bus and the AC bus.

The DC bus is also connected with water electrolysis equipment and electric heating equipment; the water electrolysis equipment is connected with hydrogen and oxygen supply equipment, and the electric heating equipment is connected with heating equipment.

The clean energy system also includes a DC transmission line, and a DC/DC converter is connected between the DC bus and the DC transmission line for DC voltage conversion and bidirectional exchange of electric energy between the DC bus and the DC transmission line.

The clean energy system also includes multiple sets of synchronous generators, DC generators and photovoltaic power generation systems;

The synchronous generator converts the AC into DC through AC/DC and then connects to the DC transmission line; the DC generator and the photovoltaic power generation system respectively convert the DC voltage into a stable DC voltage through DC/DC and then connect to the DC transmission line;

The direct current transmission line is also connected with electrolytic plating equipment for absorbing electric power from the direct current transmission line, and switching according to the electric power input to the direct current transmission line to achieve power balance;

The direct current transmission line is also connected with a direct current load for absorbing electric power from the direct current transmission line and switching according to the electric power input to the direct current transmission line to achieve power balance;

The direct current transmission line is also respectively connected with a rural micro-distributed air supply and heating subsystem, an urban community air supply and heating subsystem, an urban centralized air supply and heating subsystem, and a hydrogen energy vehicle hydrogen supply subsystem.

The prime mover includes a wind turbine, a thermal engine, and a water turbine.

The control method of the AC-DC hybrid clean energy system is as follows:

The prime mover drives the double-fed asynchronous generator to rotate, and the electric power output by the stator winding is merged into the AC transmission line through the AC busbar and the transformer, or merged into the DC transmission line after being commutated by the DC converter;

When the doubly-fed asynchronous generator is running in a super-synchronous state, the rotor winding outputs electric power to the DC bus through the converter; when the doubly-fed asynchronous generator is running in a sub-synchronous or absorb electric power;

At this time, the alternating current output by the alternating current bus bar is directly incorporated into the alternating current transmission line after being boosted by the transformer, and/or converted into direct current by the direct current converter and then incorporated into the direct current transmission line.

Compared with the prior art, the utility model has the following advantages and effects:

The control (or operation) method of the utility model is simple and easy to realize.

According to the operating state of the doubly-fed asynchronous generator, the utility model incorporates the relatively stable active power output by the stator winding (coil) of the engine into the AC power grid (AC busbar), and connects the rotor winding (coil) into the DC system (DC busbar) , and exchange power with it, realize power balance through load switching, convert unstable electric energy into other forms of energy for storage or consumption, and replace firewood, straw, coal and oil and other energy sources, reduce carbon emissions, and reduce environmental pollution. Pollution, reduce the impact of new energy power generation output power on the grid, reduce harmonic injection to the grid, and even make double-fed wind turbines as the basic power supply of the grid to improve the stability of the grid operation.

When the doubly-fed asynchronous generator is running in synchronous and sub-synchronous state, the rotor absorbs electric power from the DC part (DC bus); when the doubly-fed asynchronous generator set is running in a super-synchronous state, the electric energy output by the rotor is output to the DC part. Since the output power fluctuation of the stator winding of the doubly-fed asynchronous generator is small, the stator side of the doubly-fed asynchronous generator outputs stable electric power in a relatively wide speed range, while the electric power with large fluctuations passes through the rotor winding through the converter Swap with DC section. The power balance of the DC part is achieved through the switching of water electrolysis equipment, electric heating equipment, electrolytic plating equipment and other DC loads.

As mentioned above, the system and its control method are simple and easy to implement, and can make full use of the space-time complementarity among doubly-fed asynchronous generators, synchronous generators, DC generators, and photovoltaic power generation in the system to reduce unstable cleaning The impact of energy power fluctuations on the power grid reduces the reserve capacity of the power grid and improves the stability of the power grid operation; DC loads such as water electrolysis equipment and electric heating equipment in the DC part replace firewood straw with rural micro-distributed hydrogen supply heating, and urban And the centralized hydrogen supply heating method in urban areas instead of coal gas, hydrogen energy instead of vehicle fuel, etc. to reduce carbon emissions and reduce environmental pollution.

Description of drawings

Fig. 1 is a structural block diagram of the utility model and a schematic flow chart of a control (or operation) method.

Detailed ways

Below in conjunction with specific embodiment the utility model is described in further detail.

Example

As shown in Figure 1. The utility model AC-DC mixed clean energy system includes an AC bus, a DC bus and a power generation system, the power generation system includes a plurality of double-fed asynchronous generators, prime movers for driving each double-fed asynchronous generator to run;

The stator winding of the doubly-fed asynchronous generator is connected to the AC bus, and the rotor winding is connected to the DC bus through a converter;

The alternating current output by the alternating current bus bar is directly output alternating current after being boosted by a transformer and/or is connected to a direct current converter to output direct current after being stepped up by a transformer. Realize the voltage conversion and power exchange between the AC busbar and the AC output (AC output line), realize the AC-DC conversion and power exchange between the AC busbar and the DC converter, and the DC output (DC output line).

The power generation system also includes a plurality of synchronous generators and DC generators driven by prime movers; the synchronous generators convert AC to DC through AC/DC and then connect to the DC bus; sent to the DC bus.

The DC generator transforms the DC voltage into a stable DC voltage through DC/DC and then connects to the DC bus; the electric power output by the DC generator is sent to the DC bus through the DC/DC.

The power generation system also includes a photovoltaic power generation system. The photovoltaic power generation system converts the DC voltage into a stable DC voltage through DC/DC and then connects to the DC bus; the electric power output by the photovoltaic power generation system is sent to the DC bus through the DC/DC.

Between the AC bus and the DC bus, there is also connected an AC/DC converter for bidirectional power exchange between the DC bus and the AC bus, and is used to realize the bidirectional power exchange between the DC bus and the AC bus.

The DC bus is also connected to water electrolysis equipment and electric heating equipment; the water electrolysis equipment is connected to hydrogen and oxygen supply equipment, and the electric heating equipment is connected to heating and heating equipment; electric power is absorbed from the DC bus to generate heat energy and hydrogen and oxygen, and according to the input The electric power to the DC bus is switched to achieve power balance.

The electric energy output by the synchronous generator connected to the DC bus, the DC generator and the photovoltaic power generation system is converted into DC by AC/DC or DC/DC, and then shared with the converter on the rotor side of the doubly-fed asynchronous generator (not shown in the figure) ; Or share the bidirectional AC/DC (not shown in the figure) connected between the AC bus and the DC bus. These two schemes can reduce the total capacity of the converters of the system by utilizing the characteristics of the temporal and spatial distribution of clean energy according to the needs of the power grid.

The clean energy system also includes a DC transmission line, and a DC/DC converter is connected between the DC bus and the DC transmission line for DC voltage conversion and bidirectional exchange of electric energy between the DC bus and the DC transmission line.

The clean energy system also includes multiple sets of synchronous generators, DC generators and photovoltaic power generation systems;

The synchronous generator transforms the alternating current into direct current through AC/DC and then connects to the direct current transmission line, and is used for merging the electric energy generated by the synchronous generator into the direct current transmission line through AC/DC. The DC generator and the photovoltaic power generation system respectively convert the DC voltage into a stable DC voltage through DC/DC and then connect to the DC transmission line, and are used to merge the electric energy generated by the photovoltaic power generation system into the DC transmission line through DC/DC.

The direct current transmission line is also connected with electrolytic plating equipment for absorbing electric power from the direct current transmission line, and switching according to the electric power input to the direct current transmission line to achieve power balance;

The DC transmission line is also connected with DC loads (other loads) for absorbing electric power from the DC transmission line and performing switching according to the electric power input to the DC transmission line to achieve power balance;

The direct current transmission line is also respectively connected with a rural micro-distributed air supply and heating subsystem, an urban community air supply and heating subsystem, an urban centralized air supply and heating subsystem, and a hydrogen energy vehicle hydrogen supply subsystem.

The rural micro-distributed gas supply and heating subsystem is used to absorb electric power from the connected direct current transmission line to generate heat energy and hydrogen and oxygen, replacing firewood, straw, coal and other energy sources, and switching according to the electric power input to the direct current transmission line to achieve power balance.

The gas supply and heating subsystem for urban districts is used to absorb electric power from the connected direct current transmission line to generate heat energy and hydrogen and oxygen to replace firewood, straw, coal and other energy sources, and switch according to the electric power input to the direct current transmission line to achieve power balance.

The urban centralized gas supply and heating subsystem is used to absorb electric power from the connected direct current transmission line to generate heat energy and hydrogen and oxygen to replace coal, gas and other energy sources, and switch according to the electric power input to the direct current transmission line to achieve power balance.

The hydrogen supply subsystem of the hydrogen energy vehicle is used to absorb electric power generation and hydrogen and oxygen from the direct current transmission line to replace oil resources, and switch according to the electric power input to the direct current transmission line to achieve power balance.

The prime mover includes a wind turbine, a heat engine, a water turbine, and the like.

The control (or operation) method of the AC-DC hybrid clean energy system can be realized through the following steps:

The prime mover drives the double-fed asynchronous generator to rotate, and the electric power output by the stator winding is merged into the AC transmission line through the AC busbar and the transformer, or merged into the DC transmission line after being commutated by the DC converter;

When the doubly-fed asynchronous generator is running in a super-synchronous state, the rotor winding outputs electric power to the DC bus through the converter; when the doubly-fed asynchronous generator is running in a sub-synchronous or absorb electric power;

At this time, the alternating current output by the alternating current bus bar is directly incorporated into the alternating current transmission line after being boosted by the transformer, and/or converted into direct current by the direct current converter and then incorporated into the direct current transmission line.

In addition, photovoltaic power generation systems, DC generators (such as DC power generation equipment) and other prime mover-driven synchronous generators can output electric energy to the DC part (DC bus) through AC/DC or DC/DC converters accordingly, for Synchronous and sub-synchronous doubly-fed asynchronous generator rotor windings, water electrolysis equipment, electrothermal equipment, electrolytic plating equipment and other DC loads provide electric power; it can also be directly connected to the power grid through a converter; water electrolysis equipment, electrothermal equipment, Electrolytic plating equipment and other DC loads are connected to the DC part to absorb electric power, and are switched in time according to the operating status of each power generation equipment to achieve the power balance of the DC part.

As mentioned above, the utility model can be better realized.

The doubly-fed asynchronous generator in the utility model is also applicable to the brushless doubly-fed generator. At this time, the stator coil corresponds to the power winding of the brushless doubly-fed generator, and the rotor coil corresponds to the control winding of the brushless doubly-fed generator.

The implementation of the present utility model is not limited by the above-mentioned examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present utility model should be equivalent replacement methods. Included within the protection scope of the present utility model.

Claims (9)

1. A mixed clean energy system of AC and DC, comprising an AC bus, a DC bus and a power generation system, characterized in that the power generation system includes a plurality of double-fed asynchronous generators, which are used to drive each double-fed asynchronous generator to run prime mover; The stator winding of the doubly-fed asynchronous generator is connected to the AC bus, and the rotor winding is connected to the DC bus through a converter; The alternating current output by the alternating current bus bar is directly output alternating current after being boosted by a transformer and/or is connected to a direct current converter to output direct current after being stepped up by a transformer. 2. The AC-DC hybrid clean energy system according to claim 1, wherein the power generation system also includes a plurality of synchronous generators and DC generators driven by prime movers; the synchronous generators are powered by AC/DC The AC is converted into DC and then connected to the DC bus; the DC generator transforms the DC voltage into a stable DC voltage through DC/DC and then connected to the DC bus. 3. The AC-DC hybrid clean energy system according to claim 2, wherein the power generation system also includes a photovoltaic power generation system, and the photovoltaic power generation system converts the DC voltage into a stable DC voltage through DC/DC and then connects to the DC bus . 4. The AC-DC hybrid clean energy system according to any one of claims 1 to 3, characterized in that, between the AC bus and the DC bus, there is also a connection for bidirectional electric energy exchange between the DC bus and the AC bus AC/DC converter equipment. 5. The AC-DC hybrid clean energy system according to claim 4, characterized in that, the DC bus is also connected to water electrolysis equipment and electric heating equipment; the water electrolysis equipment is connected to hydrogen and oxygen supply equipment, and the electric heating equipment Connect heating equipment. 6. According to claim 4, the AC-DC hybrid clean energy system is characterized in that, after the electric energy output by the synchronous generator connected to the DC bus, the DC generator and the photovoltaic power generation system is converted into DC by AC/DC or DC/DC The output of the converter on the rotor side of the doubly-fed asynchronous generator is shared to the AC bus; or the bidirectional AC/DC connected between the AC bus and the DC bus is shared, and the electric energy is output to the AC bus. 7. The AC-DC hybrid clean energy system according to claim 4, characterized in that, the clean energy system further comprises a DC transmission line, between the DC bus and the DC transmission line, there is also a connection for connecting the DC bus and the DC DC/DC converter for DC voltage conversion between transmission lines and bidirectional exchange of electric energy. 8. The AC-DC hybrid clean energy system according to claim 6, characterized in that, the clean energy system also includes multiple sets of synchronous generators, DC generators and photovoltaic power generation systems; The synchronous generator converts the AC into DC through AC/DC and then connects to the DC transmission line; the DC generator and the photovoltaic power generation system respectively convert the DC voltage into a stable DC voltage through DC/DC and then connect to the DC transmission line; The direct current transmission line is also connected with electrolytic plating equipment for absorbing electric power from the direct current transmission line, and switching according to the electric power input to the direct current transmission line to achieve power balance; The direct current transmission line is also connected with a direct current load for absorbing electric power from the direct current transmission line and switching according to the electric power input to the direct current transmission line to achieve power balance; The direct current transmission line is also respectively connected with a rural micro-distributed air supply and heating subsystem, an urban community air supply and heating subsystem, an urban centralized air supply and heating subsystem, and a hydrogen energy vehicle hydrogen supply subsystem. 9. The AC-DC hybrid clean energy system according to claim 4, wherein the prime mover is a wind turbine, a heat engine or a water turbine.