New energy power generation system

Abstract

The invention relates to a new energy power generation system which comprises a multi-source complementary input device, a converter, a motor group and a generator which are connected in sequence. The multi-source complementary input device is used for converting various energy sources and then generating current; the converter is used for converting current into alternating current to drive the motor group, the motor group is coaxially connected with the generator to generate power, and the alternating current generated by the generator is used for grid connection; the multi-source complementary input device comprises a wind power generation module, a light energy power generation module and an energy storage module. And the energy storage module is used for storing residual energy when the wind energy and the light energy are excessive, and is used as a standby power supply when the wind energy and the light energy are insufficient. Convergence is carried out on the input side of the converter, and multiple energy sources are supported, so that new energy power generation has the advantages of power generation of a traditional hydro-thermal power generating unit, the inertia supporting and voltage supporting capacity of a new energy station is improved, and safe operation of a power grid is more facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric power market, and in particular relates to a new energy power generation system. Background Art

[0002] A high proportion of new energy power grid is an inevitable development trend in the energy and power sector in the future. After a high proportion of new energy is connected to the power grid, a large number of new energy converters will replace synchronous generators, reducing system inertia, causing the power grid to present a high degree of power electronics characteristics, resulting in fundamental changes in the power supply characteristics of the power grid, and bringing huge challenges to the stable operation of the power system.

[0003] In the related technologies, the existing renewable energy sources have the following problems after being connected to the power grid: the renewable energy sources lack reliable inertial response and have low frequency tolerance, which results in a decrease in the frequency anti-disturbance capability of the power grid; the transient voltage and current support capabilities of the renewable energy converters are insufficient, which results in a decrease in the fault ride-through capability of the renewable energy sources; and the operation control of renewable energy sources and their interaction with the power grid lead to new oscillation problems.

[0004] Therefore, there is an urgent need for a new energy power generation system to solve the above problems. Summary of the invention

[0005] In view of this, the purpose of the present invention is to overcome the deficiencies of the prior art and provide a new energy power generation system to solve the problem in the prior art that the frequency anti-disturbance capability of the power grid is reduced due to the lack of inertial support when new energy is connected to the grid.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a new energy power generation system, the system comprising: a multi-source complementary input device, an inverter, a motor set and a generator, the multi-source complementary input device, the inverter, the motor set and the generator are connected in sequence.

[0007] The multi-source complementary input device is used to convert multiple energy sources and then generate current;

[0008] The converter is used to convert the current into alternating current to drive the motor group, the motor group is coaxially connected to the generator to generate electricity, and the alternating current generated by the generator is used for grid connection;

[0009] Among them, the multi-source complementary input device includes a wind power generation module, a solar power generation module and an energy storage module; the energy storage module is used to store the remaining energy when wind energy and solar energy are in excess, and to serve as a backup power supply when wind energy and solar energy are insufficient.

[0010] Further, it also includes: a voltage converter;

[0011] The output end of the multi-source complementary input device is connected to the input end of the voltage converter, and the output end of the voltage converter is connected to the input end of the converter;

[0012] The voltage converter is used to perform voltage step-up and voltage stabilization processing on the received voltage.

[0013] Furthermore, an input switch is provided between the multi-source complementary input device and the converter;

[0014] An output switch is provided between the converter and the motor group.

[0015] Further, the converter includes: a first inverter module, a second inverter module and a controller, and the first inverter module and the second inverter module are connected to the controller;

[0016] The controller is used to control the first inverter module or the second inverter module to perform inversion conversion on the received current according to the received current;

[0017] The first inverter module is used to invert the received direct current into alternating current, and change the frequency and amplitude of the alternating current to drive the motor group;

[0018] The second inverter module is used for inverting the received AC power / DC / AC hybrid power into AC power, and changing the frequency and amplitude of the AC power to drive the motor set.

[0019] Furthermore, the second inverter module includes a rectifier circuit and an inverter circuit;

[0020] The rectifier circuit is used to rectify the received AC power / DC mixed power into DC power;

[0021] The inverter circuit is used to invert the direct current into alternating current, and change the frequency and amplitude of the alternating current to drive the motor set.

[0022] Furthermore, the motor group and the generator are coaxially connected.

[0023] Furthermore, a plurality of inertia adjustment units are arranged on one end of the shaft of the motor group away from the generator;

[0024] The plurality of inertia adjustment units are used to change the mass of the rotating shaft and thus adjust the rotational inertia of the generator according to the linear positive correlation between the rotational inertia of the generator and the mass of the rotating shaft and the radius of the rotating shaft.

[0025] Furthermore, the rotational inertia of the generator is adjusted by adjusting the number or size of the inertia adjustment units.

[0026] Furthermore, the motor group adopts a single-winding motor or a multi-winding motor.

[0027] Furthermore, the generator is a direct-mounted generator.

[0028] The present invention adopts the above technical solution, and the beneficial effects that can be achieved include:

[0029] The present invention provides a new energy power generation system, which converges on the input side of the converter and supports multiple energy sources, such as photovoltaic, wind power, energy storage, hydrogen production, etc. Under normal circumstances, the wind and solar power generation output is collected through the DC bus and connected to the grid through the converter, motor and generator. When the wind and solar power output is in excess, the energy storage is charged. If the energy storage is full, green electricity hydrogen production is considered. When the wind and solar power are insufficient, the energy storage system emits electrical energy to make the transmission capacity of the entire system more stable. In addition, the present application increases or decreases the mechanical inertia at the generator shaft end to adjust the inertia of the entire system to match the multi-scenario inertia requirements of the source network.

[0030] The present invention converges at the input side of the converter and supports multiple energy sources, so that the new energy power generation also has the advantages of traditional water and thermal power generation units, improves the inertia support and voltage support capabilities of the new energy station, and is more beneficial to the safe operation of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 The structure of the new energy power generation system of the present invention is shown in FIG. Figure 1 ;

[0033] Figure 2 The structure of the new energy power generation system of the present invention is shown in FIG. Figure 2 ;

[0034] Figure 3 The structure of the new energy power generation system of the present invention is shown in FIG. Figure 3 ;

[0035] Figure 4 The structure of the new energy power generation system of the present invention is shown in FIG. Figure 4 ;

[0036] Figure 5 The schematic diagram of the working method of the new energy power generation system of the present invention is as follows Figure 1 ;

[0037] Figure 6 The schematic diagram of the working method of the new energy power generation system of the present invention is as follows Figure 1 . DETAILED DESCRIPTION

[0038] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0039] A specific new energy power generation system provided in an embodiment of the present application is described below in conjunction with the accompanying drawings.

[0040] like Figure 1 As shown, the new energy power generation system provided in the embodiment of the present application comprises: a multi-source complementary input device 1, a converter 2, a motor group 3 and a generator 4, and the multi-source complementary input device 1, the converter 2, the motor group 3 and the generator 4 are connected in sequence.

[0041] The multi-source complementary input device 1 is used to convert multiple energy sources and then generate current;

[0042] The converter 2 is used to convert the current into alternating current to drive the motor group 3. The motor group 3 is coaxially connected to the generator 4 to generate electricity. The alternating current generated by the generator 4 is used for grid connection.

[0043] Among them, the multi-source complementary input device 1 includes a wind power generation module, a solar power generation module and an energy storage module; the energy storage module is used to store the remaining energy when wind energy and solar energy are in excess, and to serve as a backup power supply when wind energy and solar energy are insufficient.

[0044] The multi-source complementary device in this application belongs to the energy input link, supports the access of multiple energy sources, and provides green energy input for this system; the converter 2 belongs to the conversion link, covers a variety of types, such as DC / AC, AC / DC / AC, etc., usually adopts DC to AC inverter to provide the required pulse for driving the motor; the motor is driven by the converter 2 to rotate, providing the motive force for the generator 4; the generator 4 is driven by the motor to rotate, emits AC power and connects to the grid. The present invention can stabilize the overall power generation of the system through the input of multiple energy complementarity, reduce the randomness of new energy power generation, and improve the power generation efficiency of the motor. The introduction of the motor and the generator 4 makes the new energy power generation also have the advantages of traditional water and thermal power generation, improves the inertia support and voltage support capabilities of the new energy station, and is more beneficial to the safe operation of the power grid.

[0045] The new energy power generation system provided by the present application, the multi-source complementary input device 1 in the present application can generate wind power and solar power, and can also store the remaining energy when there is excess wind energy and solar energy. If the energy storage is full, consider green electricity hydrogen production, etc. When the wind and light are insufficient, the energy storage system emits electrical energy, so that the transmission capacity of the entire system is more stable. Then the multi-source complementary input device 1 inputs the current after energy conversion into the converter 2. It can be understood that the multi-source complementary input device 1 can output both direct current and alternating current. The AC converter can convert the received current into alternating current, thereby using alternating current to drive the motor group 3, the motor group 3 is coaxially connected to the generator 4 to generate electricity, and the generator 4 emits alternating current for grid connection.

[0046] It is understandable that the present application is compatible with a generator 4 of multiple voltage levels, and the generator 4 supports power grids of different voltage levels such as 690V, 1140V, 3kV, 10kV, 35kV, etc. It supports high-voltage direct-hanging grid connection, saves the cost of step-up transformers, and improves the reliability of the system.

[0047] The new energy power generation system provided in the present application converges on the input side of the converter 2 and supports multiple energy sources, so that new energy power generation also has the advantages of traditional hydro-thermal power generation, improves the inertia support and voltage support capabilities of the new energy station, and is more beneficial to the safe operation of the power grid.

[0048] Some optional embodiments further include: a voltage converter (not shown in the figure);

[0049] The output end of the multi-source complementary input device 1 is connected to the input end of the voltage converter, and the output end of the voltage converter is connected to the input end of the converter 2;

[0050] The voltage converter is used to perform voltage step-up and voltage stabilization processing on the received voltage.

[0051] It is understandable that after the multi-source complementary input device 1 outputs a voltage, a voltage converter is required to perform voltage boosting and voltage stabilization processing on the received voltage, and finally output current, and the output current can be a direct current or an alternating current.

[0052] In some optional embodiments, an input switch 5 is provided between the multi-source complementary input device 1 and the converter 2.

[0053] An output switch 6 is provided between the converter 2 and the motor group.

[0054] In some optional embodiments, the converter 2 includes: a first inverter module 21, a second inverter module 22 and a controller 23, and the first inverter module 21, the second inverter module 22 are connected to the controller 23;

[0055] The controller 23 is used to control the first inverter module 21 or the second inverter module 22 to perform inversion conversion on the received current according to the received current;

[0056] The first inverter module 21 is used to invert the received direct current into alternating current, and change the frequency and amplitude of the alternating current to drive the motor group 3;

[0057] The second inverter module 22 is used to invert the received AC power / DC / AC hybrid power into AC power, and change the frequency and amplitude of the AC power to drive the motor group 3 .

[0058] In the present application, the converter 2 includes two types of input: DC input and DC and AC mixed input;

[0059] like Figure 2 As shown, when DC is input, the first inverter module 21DC / AC inverts the new energy connected in DC form, and the controller 23 controls the conduction and shutdown of the switching devices in the inverter circuit, inverts the DC power generated by the new energy into AC, and drives the subsequent motor by changing the frequency and amplitude of the AC power. The motor drives the subsequent AC generator 4 to produce AC power without harmonic voltage.

[0060] In some optional embodiments, the second inverter module 22 includes a rectifier circuit (not shown in the figure) and an inverter circuit (not shown in the figure);

[0061] The rectifier circuit is used to rectify the received AC power / DC mixed power into DC power;

[0062] The inverter circuit is used to invert the direct current into alternating current, and change the frequency and amplitude of the alternating current to drive the motor group 3 .

[0063] like Figure 3 As shown, when the new energy is connected in pure AC form, it is connected to the AC side of the front end, first converted into DC through the rectifier circuit, and then the DC is converted into AC through the inverter circuit, and the subsequent motor is driven by changing the frequency and amplitude of the AC power.

[0064] When DC and AC are mixed input, the AC power generated by the new energy is still connected through the AC side of the front end, while the DC power generated by the new energy is connected at the output of the AC / DC, and is combined with the DC power obtained through the rectifier circuit, and is converted into AC power through the DC / AC inverter, which drives the subsequent motor in this system by changing the frequency and amplitude of the AC power. The motor drives the subsequent AC generator 4 to generate AC power without harmonic voltage.

[0065] It can be understood that the controller 23 controls the on and off of the input switch 5 and the output switch 6, and inverts the DC power or AC power and DC mixed current generated by the new energy into AC power, and drives the subsequent motor by changing the frequency and amplitude of the AC power. The motor drives the subsequent AC generator 4 to generate AC power without harmonic voltage.

[0066] In some optional embodiments, a plurality of inertia adjustment units are provided on the end of the shaft of the motor group 3 away from the generator 4;

[0067] The plurality of inertia adjustment units are used to change the mass of the rotating shaft and thus adjust the rotational inertia of the generator 4 according to the linear positive correlation between the rotational inertia of the generator 4 and the mass of the rotating shaft and the radius of the rotating shaft.

[0068] The rotational inertia of the generator 4 is adjusted by adjusting the number or size of the inertia adjustment units.

[0069] It should be noted that the motor and generator 4 in the present invention adopt a coaxial design, the shaft mass of the coaxial motor can be changed, the motor has multiple windings, and the generator 4 supports high-voltage direct connection to the grid. Compared with traditional motors, this application considers reducing losses and adopts a design in which the generator 4 and the motor share a mechanical shaft. The new energy drives the motor through the converter 2, and uses the coaxial power to drive the generator 4 to rotate and then generate electricity and connect to the grid. The motor in the present invention is equivalent to the prime mover of the generator 4.

[0070] In this application, the inertia adjustment unit adopts the generator 4 inertia formula, J = mr 2 , where J is the moment of inertia, m is the mass of the shaft, and r is the radius of the shaft. According to the inertia formula of the generator 4, the motor moment of inertia is linearly positively correlated with the mass of the shaft and the radius of the shaft. Since the generator 4 and the motor of the present application adopt a coaxial design, it is possible to set a number of inertia adjustment units on the motor or the coaxial end of the motor to change the mass of the shaft and thus adjust the moment of inertia of the generator 4, such as Figure 4 The inertia can be adjusted by adjusting the number or size of the inertia adjustment units.

[0071] In some optional embodiments, the motor group 3 is a single-winding motor or a multi-winding motor.

[0072] Taking into account different power levels, the motor in this application can be designed with single / multi-windings, which can support multiple converters 2 to be directly connected to the motor, thereby expanding the capacity of the entire system from the converter 2 level.

[0073] In some optional embodiments, the generator 4 is a direct-mounted generator.

[0074] Compared with the traditional new energy stations connected to the grid via transformers, the present invention adopts a high-voltage generator 4 design, omitting the intermediate transformer, and the generator 4 is directly connected to the 10kV or 35kV power grid.

[0075] The new energy power generation system provided in this application has the advantages of harmonic-free voltage power generation, inertial support, adjustable inertia, and flexible grid-connected voltage.

[0076] The working modes of the new energy power generation system provided in this application include two modes: active / reactive power generation mode and phase modulation mode.

[0077] like Figure 5 As shown in the figure, when the system is operating in active / reactive power generation, it can generate power by receiving dispatching instructions, and can generate capacitive reactive power or inductive reactive power at the same time, achieving the dual functions of green power generation and grid voltage support. The specific process is as follows:

[0078] Close the input switch 5 of converter 2 to make the DC voltage of multi-source input ready; close the output switch 6 of converter 2 to open the path; start the inverter module in converter 2, that is, the inverter drives the motor frequency to be basically synchronized with the grid frequency, so that the motor sends excitation pulses, establishes the terminal voltage of generator 4, and dynamically adjusts the voltage of generator 4 so that it meets the grid connection conditions with the grid voltage amplitude and phase, closes the grid connection switch, and generator 4 is connected to the grid, and receives the dispatching instructions to send active and reactive power.

[0079] like Figure 6 As shown, when the system operates in the phase-shifting mode, the generator 4 does not generate active power, but only generates reactive power. It can generate capacitive reactive power or inductive reactive power according to the dispatching instruction to achieve the purpose of supporting the grid voltage. The specific process is as follows:

[0080] Close the input switch 5 of converter 2 to make the DC voltage of multi-source input ready; close the output switch 6 of converter 2 to open the path; start the inverter module in converter 2, that is, the inverter drives the motor frequency to be basically synchronized with the grid frequency, so that the motor sends excitation pulses, establishes the terminal voltage of generator 4, and dynamically adjusts the voltage of generator 4 so that it meets the grid connection conditions with the grid voltage amplitude and phase, closes the grid connection switch, generator 4 is connected to the grid, disconnects the output switch 6 of converter 2, and accepts the dispatching instruction to adjust the reactive power.

[0081] In summary, the present invention provides a new energy power generation system, including supporting the access of multiple energy sources to provide green energy input for the system; the converter belongs to the conversion link and covers multiple types, such as DC / AC, AC / DC / AC, etc., usually adopts DC to AC inverter to provide the required pulse for driving the motor; the motor is driven by the converter to rotate and provide the motive force for the generator; the generator is driven by the motor to rotate and generate AC power to connect to the grid. The present invention can stabilize the overall power generation of the system through the input in the form of multi-energy complementation, reduce the randomness of new energy power generation, and improve the power generation efficiency of the motor. The introduction of motors and generators makes new energy power generation also have the advantages of traditional water and thermal power generation, improves the inertia support and voltage support capabilities of new energy sites, and is more beneficial to the safe operation of the power grid.

[0082] Those skilled in the art will appreciate that the embodiments of the present application may be provided as a new energy power generation system, system, or computer program product. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0083] The present application is described with reference to the flowcharts and / or block diagrams of the new energy power generation system, device (system), and computer program product according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0084] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction for a new energy power generation system, wherein the instruction for a new energy power generation system is implemented in the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0085] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0086] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A new energy power generation system, characterized in that: The system comprises: a multi-source complementary input device, a converter, a motor group and a generator, wherein the multi-source complementary input device, the converter, the motor group and the generator are connected in sequence; The multi-source complementary input device is used to convert multiple energy sources and then generate current; The converter is used to convert the current into alternating current to drive the motor group, the motor group is coaxially connected to the generator to generate electricity, and the alternating current generated by the generator is used for grid connection; Among them, the multi-source complementary input device includes a wind power generation module, a solar power generation module and an energy storage module; the energy storage module is used to store the remaining energy when wind energy and solar energy are in excess, and to serve as a backup power supply when wind energy and solar energy are insufficient.

2. The new energy power generation system according to claim 1, characterized in that: Also includes: Voltage converter; The output end of the multi-source complementary input device is connected to the input end of the voltage converter, and the output end of the voltage converter is connected to the input end of the converter; The voltage converter is used to perform voltage step-up and voltage stabilization processing on the received voltage.

3. The new energy power generation system according to claim 1, characterized in that: An input switch is provided between the multi-source complementary input device and the converter; An output switch is provided between the converter and the motor group.

4. The new energy power generation system according to claim 1, characterized in that: The converter comprises: a first inverter module, a second inverter module and a controller, wherein the first inverter module and the second inverter module are connected to the controller; The controller is used to control the first inverter module or the second inverter module to perform inversion conversion on the received current according to the received current; The first inverter module is used to invert the received direct current into alternating current, and change the frequency and amplitude of the alternating current to drive the motor group; The second inverter module is used for inverting the received AC power / DC / AC hybrid power into AC power, and changing the frequency and amplitude of the AC power to drive the motor set.

5. The new energy power generation system according to claim 4, characterized in that: The second inverter module includes a rectifier circuit and an inverter circuit; The rectifier circuit is used to rectify the received AC power / DC mixed power into DC power; The inverter circuit is used to invert the direct current into alternating current, and change the frequency and amplitude of the alternating current to drive the motor set.

6. The new energy power generation system according to claim 1, characterized in that: A plurality of inertia adjustment units are arranged on an end of the shaft of the motor group away from the generator; The plurality of inertia adjustment units are used to change the mass of the rotating shaft and thus adjust the rotational inertia of the generator according to the linear positive correlation between the rotational inertia of the generator and the mass of the rotating shaft and the radius of the rotating shaft.

7. The new energy power generation system according to claim 6, characterized in that: The rotational inertia of the generator is adjusted by adjusting the number or size of the inertia adjustment units.

8. The new energy power generation system according to claim 1, characterized in that: The motor group adopts a single-winding motor or a multi-winding motor.

9. The new energy power generation system according to claim 1, characterized in that: The generator is a direct-mounted generator.

Images