Double-fed asynchronous power generation device with multiple variable flow modes

Abstract

The utility model relates to the technical field of power generation devices, and discloses a doubly-fed asynchronous power generation device with multiple variable-current modes, which comprises a power grid, a doubly-fed asynchronous power generator, a machine-side converter, a grid-side converter, a variable-current controller and a direct-current excitation controller, a stator winding of the doubly-fed asynchronous generator is connected with a power grid, a rotor winding of the doubly-fed asynchronous generator is connected with the machine-side converter, the machine-side converter is connected with the grid-side converter, and the grid-side converter is connected with the power grid. The variable-current controller is connected with the direct-current excitation controller, the machine-side converter, the grid-side converter, the stator grid-connected switch and the converter grid-connected switch; the variable-current controller is used for controlling the running states of the machine-side converter, the grid-side converter, the stator grid-connected switch and the converter grid-connected switch; the direct current excitation controller is connected with the doubly-fed asynchronous generator, and the direct current excitation controller is used for performing direct current excitation on the doubly-fed asynchronous generator. The operation efficiency and stability of the power generation device under different working conditions can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power generation devices, in particular to a double-fed asynchronous power generation device with multiple flow conversion modes. Background Art

[0002] Doubly-fed asynchronous generators play an important role in modern power systems. They can maintain the stability of output voltage and frequency by adjusting the frequency of the rotor current when the speed of the prime mover changes. Although traditional doubly-fed asynchronous generators have met the needs of variable speed operation to a certain extent, their performance and efficiency still need to be improved when facing grid fluctuations and load changes. Existing generator control technologies often adopt a fixed converter system design. Such a design approach often makes it difficult to adjust the appropriate converter capacity according to changes in power generation status, resulting in increased converter system costs, reduced flexibility, and difficulty in timely handling of faults, which affects electricity consumption. At the same time, existing technologies often find it difficult to achieve voltage compensation in converter control to improve the stability of generator operation.

[0003] Therefore, it is particularly important to study a doubly fed asynchronous generator that can adapt to multiple power conversion modes. Utility Model Content

[0004] The purpose of the utility model is to provide a doubly-fed asynchronous generator with multiple conversion modes, so as to solve the problem that the existing generator adopts a fixed conversion mode and is difficult to adjust the appropriate conversion capacity according to the change of power generation state, thereby increasing the cost of the conversion system, reducing flexibility, and making it difficult to handle faults in a timely manner, resulting in an impact on electricity consumption. At the same time, it is difficult to achieve voltage compensation in the conversion control to improve the stability of the generator operation.

[0005] The utility model provides a double-fed asynchronous power generation device with multiple current conversion modes, comprising: a power grid, a double-fed asynchronous generator, a machine-side converter, a grid-side converter, a current conversion controller and a DC excitation controller;

[0006] The stator winding of the doubly-fed asynchronous generator is connected to the power grid via a stator grid-connected switch, the rotor winding of the doubly-fed asynchronous generator is connected to the machine-side converter, the machine-side converter is connected to the grid-side converter via a DC bus, and the grid-side converter is connected to the power grid via a converter grid-connected switch;

[0007] The current converter controller is connected to the DC excitation controller, the machine-side converter, the grid-side converter, the stator grid-connected switch and the converter grid-connected switch, and is used to control the operating states of the machine-side converter, the grid-side converter, the stator grid-connected switch and the converter grid-connected switch;

[0008] The DC excitation controller is connected to the doubly-fed asynchronous generator, and is used to perform DC excitation on the doubly-fed asynchronous generator in a synchronous power generation state.

[0009] Preferably, the rotor of the doubly-fed asynchronous generator is connected to the prime mover and its transmission device.

[0010] Preferably, the doubly-fed asynchronous generator is provided with a rotor encoder, which is connected to the converter controller. The rotor encoder is used to detect the real-time speed of the doubly-fed asynchronous generator, and the converter controller is used to set the power generation mode according to the real-time speed and control the machine-side converter and the grid-side converter.

[0011] Preferably, the converter controller is provided with two working modes. When the real-time speed of the doubly fed asynchronous generator is lower than the speed threshold, it is a DC excitation synchronous power generation mode with full power conversion; when the real-time speed of the doubly fed asynchronous generator is higher than the speed threshold, it is an AC excitation doubly fed asynchronous power generation mode with partial power conversion.

[0012] Preferably, a first voltage detector is provided between the doubly-fed asynchronous generator and the power grid, a current detector is provided between the doubly-fed asynchronous generator and the machine-side converter, and a second voltage detector is provided between the grid-side converter and the power grid.

[0013] Preferably, the stator grid-connected switch and the converter grid-connected switch are both provided with a switch state detection device, and the switch state detection device is connected to the converter controller.

[0014] Preferably, the stator grid-connected switch and the converter grid-connected switch are both AC contactors.

[0015] Preferably, the machine-side converter and the grid-side converter both adopt a three-phase full-bridge IGBT topology structure.

[0016] Compared with the prior art, the present invention offers the following advantages: The multi-mode, double-fed asynchronous generator, by integrating multiple converter modules and combining them with an intelligent control system, can improve power generation efficiency and stability, thus possessing broad application prospects. This application features both a full-power conversion DC-excited synchronous generator mode and a partial-power conversion AC-excited double-fed asynchronous generator mode, flexibly switching between them based on real-time speed, improving the adaptability and efficiency of the generator. The converter controller precisely controls the operating status of the generator-side converter, grid-side converter, stator grid-connected switch, and converter grid-connected switch, enabling fine-grained regulation of the power generation process. The DC excitation controller provides DC excitation for the double-fed asynchronous generator. The voltage detector, current detector, and switch status detection device provide real-time monitoring of the generator's operating status, facilitating timely problem detection and adjustment. The connection between the double-fed asynchronous generator and the prime mover and its transmission, along with the provision of a rotor encoder, ensures efficient energy transfer and accurate speed detection. The generator-side converter and grid-side converter utilize a three-phase full-bridge IGBT topology, improving converter performance and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0018] Figure 1 The utility model is a structural schematic diagram of a double-fed asynchronous power generation device with multiple flow conversion modes.

[0019] Among them, 1. Power grid; 2. Doubly fed asynchronous generator; 3. Machine-side converter; 4. Grid-side converter; 5. Converter controller; 6. DC excitation controller; 7. Stator grid-connected switch; 8. Converter grid-connected switch; 9. Prime mover and its transmission device; 11. Rotor encoder; 12. First voltage detector; 13. Current detector; 14. Second voltage detector. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0021] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0024] like Figure 1 As shown, the utility model provides a doubly-fed asynchronous power generation device with multiple current conversion modes, including: a power grid 1, a doubly-fed asynchronous generator 2, a machine-side converter 3, a grid-side converter 4, a current conversion controller 5 and a DC excitation controller 6.

[0025] The stator winding of the doubly-fed asynchronous generator 2 is connected to the grid 1 through the stator grid-connected switch 7, the rotor winding of the doubly-fed asynchronous generator 2 is connected to the machine-side converter 3, the machine-side converter 3 is connected to the grid-side converter 4 through the DC bus, and the grid-side converter 4 is connected to the grid 1 through the converter grid-connected switch 8.

[0026] The converter controller 5 is connected to the DC excitation controller 6, the generator-side converter 3, the grid-side converter 4, the stator grid-connected switch 7 and the converter grid-connected switch 8. The converter controller 5 is used to control the operating status of the generator-side converter 3, the grid-side converter 4, the stator grid-connected switch 7 and the converter grid-connected switch 8.

[0027] The DC excitation controller 6 is connected to the doubly-fed asynchronous generator 2 , and is used to perform DC excitation on the doubly-fed asynchronous generator 2 in a synchronous power generation state.

[0028] In some embodiments of the present application, the rotor of the doubly-fed asynchronous generator 2 is connected to the prime mover and its transmission device.

[0029] In this embodiment, the rotor of the doubly-fed asynchronous generator 2 is connected to the prime mover and its transmission device via a mechanical connection device, ensuring efficient power transmission between the two. This structural design not only ensures efficient operation of the power generation system but also adapts to power generation requirements under different prime mover driving conditions.

[0030] In some embodiments of the present application, the doubly fed asynchronous generator 2 is provided with a rotor encoder 11, which is connected to the converter controller 5. The rotor encoder 11 is used to detect the real-time speed of the doubly fed asynchronous generator 2. The converter controller 5 is used to set the power generation mode according to the real-time speed and control the machine-side converter 3 and the grid-side converter 4.

[0031] In this embodiment, the doubly-fed asynchronous generator 2 is equipped with a rotor encoder 11. This rotor encoder 11 is closely connected to the converter controller 5. Its primary function is to monitor and detect the rotational speed of the doubly-fed asynchronous generator 2 in real time. Using the precise data provided by the rotor encoder 11, the converter controller 5 can set the optimal power generation mode based on the real-time rotational speed of the doubly-fed asynchronous generator 2. Furthermore, the converter controller 5 is responsible for precisely controlling the generator-side converter 3 and the grid-side converter 4, ensuring efficient and stable operation of the entire power generation system. This design enables precise control of the doubly-fed asynchronous generator 2, thereby improving power generation efficiency and overall system performance.

[0032] In some embodiments of the present application, the converter controller 5 is provided with two working modes. When the real-time speed of the doubly-fed asynchronous generator 2 is lower than the speed threshold, it is a DC excitation synchronous power generation mode with full power conversion; when the real-time speed of the doubly-fed asynchronous generator 2 is higher than the speed threshold, it is an AC excitation doubly-fed asynchronous power generation mode with partial power conversion.

[0033] In this embodiment, two operating modes are designed in the converter controller 5 to adapt to different operating conditions and requirements. Specifically, when the actual operating speed of the doubly fed asynchronous generator 2 is lower than a preset speed threshold, the converter controller 5 will switch to a full-power conversion operating mode. In this mode, the generator can operate in a DC-excited synchronous power generation state to ensure efficient power generation even under low speed conditions. This mode is particularly suitable for scenarios where high power generation efficiency is maintained under low speed conditions. On the other hand, when the actual operating speed of the doubly fed asynchronous generator 2 is higher than the preset speed threshold, the converter controller 5 will switch to an AC-excited doubly fed asynchronous power generation mode with partial power conversion. In this mode, the generator will operate in a doubly fed asynchronous power generation mode. This means that partial power will be exchanged between the rotor and stator of the generator, thereby achieving more efficient energy conversion and utilization. This mode is suitable for high speed conditions and can fully utilize the performance of the generator, improving power generation efficiency and stability.

[0034] By flexibly switching between these two operating modes, the converter controller 5 can select the most appropriate power generation mode based on the actual operating state of the doubly-fed asynchronous generator 2, thereby maintaining efficient and stable power generation performance under various operating conditions. This design not only improves the overall efficiency of the power generation system, but also enhances its adaptability and reliability in various environmental conditions.

[0035] In some embodiments of the present application, a first voltage detector 12 is provided between the doubly-fed asynchronous generator 2 and the power grid 1, a current detector 13 is provided between the doubly-fed asynchronous generator 2 and the machine-side converter 3, and a second voltage detector 14 is provided between the grid-side converter 4 and the power grid 1.

[0036] In this embodiment, a first voltage detector 12 is provided between the doubly-fed asynchronous generator 2 and the power grid 1 to monitor and adjust the voltage between them in real time. Similarly, to ensure stable and reliable current transmission between the doubly-fed asynchronous generator 2 and the generator-side converter 3, a dedicated current detector 13 is also provided between them. Furthermore, a second voltage detector 14 is provided between the grid-side converter 4 and the power grid 1 to ensure voltage stability in the power grid 1 and the normal operation of the converter. The provision of these detectors makes the entire system safer and more reliable, and enables timely response to changes in various operating conditions.

[0037] In some embodiments of the present application, both the stator grid-connected switch 7 and the converter grid-connected switch 8 are provided with a switch state detection device, and the switch state detection device is connected to the converter controller 5 .

[0038] In this embodiment, both the stator grid-connected switch 7 and the converter grid-connected switch 8 are equipped with corresponding switch status detection devices. The primary function of these switch status detection devices is to monitor and detect the operating status of their respective switches in real time, ensuring proper operation. To achieve this, each switch status detection device is connected to the converter controller 5, enabling real-time data transmission and processing. In this way, the converter controller 5 can accurately obtain switch status information, enabling appropriate control and adjustments to ensure stable operation of the entire system.

[0039] In some embodiments of the present application, the stator grid-connected switch 7 and the converter grid-connected switch 8 are both AC contactors.

[0040] In this embodiment, the stator grid-connected switch 7 and the converter grid-connected switch 8 are actually devices such as AC contactors. AC contactors are electrical switching devices used to control and switch AC circuits and are widely used in power systems and industrial automation. Their primary function is to enable grid-connected operation of equipment within the power system, ensuring that electrical equipment can be safely and reliably connected and disconnected from the power grid 1. By using AC contactors, the on-off flow of current can be effectively controlled, thereby achieving precise control and protection of the power system.

[0041] In some embodiments of the present application, both the generator-side converter 3 and the grid-side converter 4 adopt a three-phase full-bridge IGBT topology structure.

[0042] In this embodiment, both the generator-side converter 3 and the grid-side converter 4 employ a three-phase full-bridge IGBT topology. This structure consists of six IGBT switches, one connected to each phase of the three-phase power supply, forming a complete bridge circuit. Each IGBT switch can control the direction and magnitude of the current in its corresponding phase, thereby achieving efficient conversion and control of electrical energy. This topology is widely used in converters due to its high reliability and excellent performance. By precisely controlling the switching states of the IGBTs, the generator-side converter 3 and the grid-side converter 4 can achieve efficient conversion of electrical energy, meeting the needs of various power systems.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A double-fed asynchronous power generation device with multiple current conversion modes, characterized in that: include: Power grid, doubly-fed asynchronous generator, generator-side converter, grid-side converter, converter controller and DC excitation controller; The stator winding of the doubly-fed asynchronous generator is connected to the power grid via a stator grid-connected switch, the rotor winding of the doubly-fed asynchronous generator is connected to the machine-side converter, the machine-side converter is connected to the grid-side converter via a DC bus, and the grid-side converter is connected to the power grid via a converter grid-connected switch; The current converter controller is connected to the DC excitation controller, the machine-side converter, the grid-side converter, the stator grid-connected switch and the converter grid-connected switch, and is used to control the operating states of the machine-side converter, the grid-side converter, the stator grid-connected switch and the converter grid-connected switch; The DC excitation controller is connected to the doubly-fed asynchronous generator, and is used to perform DC excitation on the doubly-fed asynchronous generator in a synchronous power generation state.

2. The doubly-fed asynchronous power generation device with multiple conversion modes according to claim 1, characterized in that: The rotor of the double-fed asynchronous generator is connected to the prime mover and its transmission device.

3. The doubly-fed asynchronous power generation device with multiple conversion modes according to claim 2, characterized in that: The doubly-fed asynchronous generator is provided with a rotor encoder, which is connected to the converter controller. The rotor encoder is used to detect the real-time speed of the doubly-fed asynchronous generator. The converter controller is used to set the power generation mode according to the real-time speed and control the machine-side converter and the grid-side converter.

4. The doubly-fed asynchronous power generation device with multiple conversion modes according to claim 3, characterized in that: The converter controller is provided with two working modes. When the real-time speed of the doubly-fed asynchronous generator is lower than the speed threshold, it is a DC excitation synchronous power generation mode with full power conversion; when the real-time speed of the doubly-fed asynchronous generator is higher than the speed threshold, it is an AC excitation doubly-fed asynchronous power generation mode with partial power conversion.

5. The doubly-fed asynchronous power generation device with multiple conversion modes according to claim 4, characterized in that: A first voltage detector is provided between the doubly-fed asynchronous generator and the power grid, a current detector is provided between the doubly-fed asynchronous generator and the generator-side converter, and a second voltage detector is provided between the grid-side converter and the power grid.

6. The doubly-fed asynchronous power generation device with multiple conversion modes according to claim 5, characterized in that: The stator grid-connected switch and the converter grid-connected switch are both provided with a switch state detection device, and the switch state detection device is connected to the converter controller.

7. The doubly-fed asynchronous power generation device with multiple conversion modes according to claim 6, characterized in that: The stator grid-connected switch and the converter grid-connected switch are both AC contactors.

8. The doubly-fed asynchronous power generation device with multiple conversion modes according to claim 7, characterized in that: The machine-side converter and the grid-side converter both adopt a three-phase full-bridge IGBT topology structure.

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