Doubly-fed asynchronous power generation system and method for intelligently adjusting converter module

Abstract

The invention relates to the technical field of power generation control, and discloses a doubly-fed asynchronous power generation system and method for intelligently adjusting a converter module, and the system comprises a generator set, a dynamic converter, a converter controller, and a DC excitation controller. The generator set is a doubly-fed asynchronous generator in a synchronous generator state or an asynchronous generator state and a driving prime mover of the doubly-fed asynchronous generator; the dynamic converter sets the working mode of the generator according to the rotating speed value of the generator set; the variable current controller is used for performing power generation adjustment on the generator set according to the power generation mode and determining an excitation control scheme of the generator set; and the direct current excitation controller is used for carrying out direct current excitation on the doubly-fed asynchronous generator which is in a synchronous generator state and runs in a full-power conversion mode according to the excitation control scheme. Different power generation modes are adopted according to the operation rotating speed value of the doubly-fed asynchronous generator, the excitation control scheme is generated in the power generation process according to the power generation modes, and the power generation efficiency and the operation flexibility of a unit can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power generation control, and in particular to a double-fed asynchronous power generation system and method with intelligent regulation of a converter module. Background Art

[0002] The double-fed asynchronous generator is one of the mainstream devices in variable speed power generation. It can maintain the stability of output voltage and frequency by adjusting the frequency of rotor current when the speed of the prime mover changes. This variable speed constant frequency control technology enables the generator to operate efficiently within a wider speed range, thereby improving power generation efficiency. At the same time, stable output voltage and frequency also help to ensure the stable operation of the power grid.

[0003] By setting a suitable control strategy, the doubly-fed asynchronous generator can achieve optimal speed operation. That is, under different speed conditions, the operating parameters of the generator are automatically adjusted so that the generator set can obtain as much energy as possible and convert it into electrical energy. Therefore, power generation control of the doubly-fed asynchronous generator is an important means to improve power generation efficiency, enhance grid adaptability, improve energy utilization, and meet grid and power generation needs.

[0004] In the existing generator control technology, a fixed power conversion system design is often adopted. Such a design method often makes it difficult to adjust the appropriate power conversion capacity according to changes in the power generation state, which leads to increased cost of the power conversion system, reduced flexibility, and difficulty in handling faults in a timely manner, resulting in an impact on electricity consumption. At the same time, the existing technology often makes it difficult to achieve voltage compensation in power conversion control to improve the stability of generator operation. Summary of the invention

[0005] In view of this, the present invention proposes a double-fed asynchronous power generation system and method with intelligent regulation of converter modules to solve the problems existing in the above-mentioned prior art.

[0006] On the one hand, to achieve the above-mentioned purpose, the present invention proposes a double-fed asynchronous power generation system with intelligent regulation of converter modules, comprising a generator set, a dynamic converter, a converter controller, and a DC excitation controller connected in sequence;

[0007] The generator set is a double-fed asynchronous generator in a synchronous generator or asynchronous generator state;

[0008] The dynamic converter is used to set the power generation mode according to the speed value of the generator set during power generation;

[0009] The current converter controller is used to adjust the power generation of the generator set according to the power generation mode and determine the excitation control scheme for the generator set;

[0010] The DC excitation controller is used to perform DC excitation on the double-fed asynchronous generator operating in a full-power conversion mode in a synchronous generator state according to the excitation control scheme.

[0011] Optionally, the dynamic converter controls the power generation mode by setting a speed threshold:

[0012] When the speed value of the generator is lower than the speed threshold, the dynamic converter controls the generator set to generate electricity in a DC excitation synchronous power generation mode with full power conversion;

[0013] When the speed value of the generator is higher than the speed threshold, the dynamic converter controls the generator to generate electricity by adopting an AC excitation double-fed asynchronous power generation method with partial power conversion.

[0014] Optionally, the converter controller calculates the real-time power factor and electromagnetic torque of the generator set according to the working state of the double-fed asynchronous power generation system;

[0015] The average power factor of the generator set is obtained according to the real-time power factor, and the given active power and reactive power of the generator set are set according to the average power factor.

[0016] Optionally, the current converter controller constructs a vector relationship between the current value and the voltage value during the power generation process of the generator set, calculates the current vector that needs to be compensated for the generator set according to the vector relationship between the current value and the voltage value, calculates the voltage vector according to the current vector, and simultaneously calculates the phase difference between the voltage vector and the current vector to obtain the power factor angle;

[0017] The power factor required by the generator is calculated according to the power factor angle and the voltage vector, and then the active power and reactive power control scheme of the generator set is constructed.

[0018] Optionally, the current converter controller sets the output voltage of the DC excitation controller to control the operating voltage of the generator.

[0019] On the other hand, to achieve the above-mentioned purpose, the present invention proposes a double-fed asynchronous power generation method with intelligent regulation of a converter module, comprising:

[0020] Acquire the speed value of the generator set during power generation, and set the power generation mode according to the speed value;

[0021] Adjusting the power generation of the generator set according to the power generation mode and determining the excitation control scheme for the generator set;

[0022] According to the excitation control scheme, a doubly-fed asynchronous generator in a synchronous generator state and operating in a full-power conversion mode is subjected to DC excitation, and a doubly-fed asynchronous generator in an asynchronous generator state and operating in a partial-power conversion mode is subjected to AC excitation.

[0023] Optionally, the process of setting the power generation mode according to the rotation speed value includes:

[0024] Setting a speed threshold, when the speed value is lower than the speed threshold, adopting a full-power-converted DC excitation synchronous power generation mode to generate electricity;

[0025] When the speed value is higher than the speed threshold, power generation is performed using an AC excitation double-fed asynchronous power generation method with partial power conversion.

[0026] Optionally, the process of regulating power generation of the generator set according to the power generation mode and the current distribution scheme includes:

[0027] Calculate the real-time power factor and electromagnetic torque of the generator set according to the working state of the double-fed asynchronous generator system;

[0028] The average power factor of the generator set is obtained according to the real-time power factor, and the given active power and reactive power of the generator set are set according to the average power factor.

[0029] Optionally, the process of generating an excitation control scheme for a generator set includes:

[0030] Construct a vector relationship between the current value and the voltage value during the power generation process of the generator set, calculate the current vector that the generator set needs to compensate based on the vector relationship between the current value and the voltage value, calculate the voltage vector based on the current vector, and simultaneously calculate the phase difference between the voltage vector and the current vector to obtain the power factor angle, thereby constructing the active power and reactive power control scheme of the generator set.

[0031] Optionally, the process of performing DC excitation on a doubly-fed asynchronous generator operating in a full-power conversion mode in a synchronous generator state and performing AC excitation on a doubly-fed asynchronous generator operating in a partial-power conversion mode in an asynchronous generator state according to the excitation control scheme includes:

[0032] Perform DC excitation on the doubly-fed asynchronous generator in full-power conversion mode in the synchronous generator state, set the output voltage of the DC excitation controller, and control the generator operating voltage;

[0033] The double-fed asynchronous generator in the asynchronous generator state and operating in partial power conversion mode is subjected to AC excitation, and the DC excitation controller is exited.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention adopts different power generation modes according to the operating speed value of the generator. When the generator speed is lower than the preset speed, it operates in a DC excitation synchronous or asynchronous power generation mode with full power conversion. When the generator speed is higher than the preset speed, it operates in an AC excitation double-fed asynchronous power generation mode with partial power conversion, thereby reducing the conversion capacity of the power generation system and improving the system stability.

[0036] The present invention generates an excitation control scheme according to the power generation mode during the power generation process, effectively adjusts the voltage output by the generator, and improves the power generation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0038] Figure 1 It is a structural schematic diagram of a double-fed asynchronous power generation system with intelligent regulation of a converter module in an embodiment of the present invention;

[0039] Figure 2 The figure is a flow chart of a double-fed asynchronous power generation method with intelligent regulation of a converter module in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0041] Embodiment 1

[0042] This embodiment proposes a double-fed asynchronous power generation system with intelligent regulation of the converter module, such as Figure 1 As shown, it includes a generator set, a dynamic converter, a converter controller, and a DC excitation controller connected in sequence;

[0043] The generator set is a double-fed asynchronous generator in a synchronous generator or asynchronous generator state;

[0044] The dynamic converter is used to set the power generation mode according to the speed value of the generator set during power generation;

[0045] The current converter controller is used to adjust the power generation of the generator set according to the power generation mode and determine the excitation control scheme for the generator set;

[0046] The DC excitation controller is used to perform DC excitation on the double-fed asynchronous generator operating in a full-power conversion mode in a synchronous generator state according to the excitation control scheme.

[0047] As a preferred embodiment, the dynamic converter described in this embodiment includes a power type power electronic device, a multi-way switching switch, a grid-connected contactor and a conversion auxiliary module, wherein the power type power electronic device is composed of an IGBT fully controlled power electronic device, which is used to realize AC / DC rectification and DC / AC inversion between AC and DC buses, DC / DC conversion between DC buses, and freewheeling, switching, isolation and other functions, and connects different AC buses and DC buses through a multi-way switching module under the control of the measurement control module to realize unidirectional or bidirectional power transmission from the AC bus AC to the DC bus DC, and dynamically adjusts the topology of the converter according to the operating state. When the withstand voltage and current of a single device are When the requirements are not met, multiple devices of the same model can be connected in series or in parallel, and voltage and current equalization circuits can be added; the grid-connected contactor connects the generator stator winding with the AC power grid, and is used to isolate the stator winding from the power grid when the generator is running at full power conversion at low speed, and connects the stator winding to the power grid when the generator is running at partial power conversion at high speed, and directly sends the power of the stator winding to the power grid; the multi-way switching switch module is used to connect the power ports of the power electronic devices to each phase of each AC bus and each DC bus; the power conversion auxiliary module includes DC filtering, AC filtering, electromagnetic compatibility EMC filtering, transformers and optoelectronic coupling or electromagnetic coupling, which are used to cooperate with the filtering, voltage regulation, freewheeling, isolation, etc. required in the power conversion process.

[0048] Based on the above power generation structure and principle, this embodiment discusses the optimal solution at different speeds during the power generation process of the doubly-fed asynchronous generator, and judges the operating state of the motor by setting a speed threshold. When the generator set is running at a low speed, its speed value is lower than the speed threshold, and a full-power-converted electric excitation synchronous or asynchronous power generation method is used to generate electricity to ensure that the operating requirements of the generator are met. When running at a high speed, the output power of the doubly-fed asynchronous generator increases and gradually reaches the rated power of the motor, and the generator is controlled to generate electricity using a partial-power-converted doubly-fed asynchronous power generation method.

[0049] In summary, when the speed value of the generator is lower than the speed threshold, the dynamic converter controls the generator set to generate electricity using a full-power-converted DC excitation synchronous power generation method;

[0050] When the speed value of the generator is higher than the speed threshold, the dynamic converter controls the generator to generate electricity by adopting an AC excitation double-fed asynchronous power generation method with partial power conversion.

[0051] As a preferred embodiment, the current converter controller calculates the real-time power factor and electromagnetic torque of the generator set;

[0052] The average power factor of the generator set is obtained according to the real-time power factor, and the given active power and reactive power of the generator set are set according to the average power factor.

[0053] Furthermore, the real-time power factor calculation method of the generator set is as follows:

[0054]

[0055] Where K represents the salient pole ratio of the generator, and K = L d / L q , x = sin 2 γ, L d is the direct-axis inductance, L q is the quadrature-axis inductance, and γ is the current angle.

[0056] The calculation method of the electromagnetic torque is as follows:

[0057]

[0058] Among them, T e is the electromagnetic torque of the generator, L d is the direct-axis inductance, L q is the quadrature-axis inductance, I s is the current vector of the generator set, p n is the number of magnetic poles of the generator.

[0059] Furthermore, in the process of generating the excitation control scheme, the current converter controller constructs a vector relationship between the current value and the voltage value during the power generation process of the generator set, calculates the current vector that needs to be compensated for the generator set according to the vector relationship between the current value and the voltage value, calculates the voltage vector according to the current vector, and simultaneously calculates the phase difference between the voltage vector and the current vector to obtain the power factor angle;

[0060] The power factor required by the generator is calculated according to the power factor angle and the voltage vector, and then the active power and reactive power control scheme of the generator set is constructed.

[0061] Furthermore, the setting of the output voltage of the DC excitation controller can be adjusted according to the actual power generation state of the generator set. When the speed of the generator set is low, a higher output voltage is required to increase the operating voltage of the generator. When the speed of the generator set increases, the output voltage of the DC excitation controller is reduced to achieve dynamic control of the power generation state.

[0062] Embodiment 2

[0063] This embodiment proposes a double-fed asynchronous power generation method with intelligent regulation of the converter module, such as Figure 2 As shown, the following steps are included:

[0064] Acquire the speed value of the generator set during power generation, and set the power generation mode according to the speed value;

[0065] Adjusting the power generation of the generator set according to the power generation mode and determining the excitation control scheme for the generator set;

[0066] According to the excitation control scheme, a doubly-fed asynchronous generator in a synchronous generator state and operating in a full-power conversion mode is subjected to DC excitation, and a doubly-fed asynchronous generator in an asynchronous generator state and operating in a partial-power conversion mode is subjected to AC excitation.

[0067] As a preferred embodiment, the process of setting the power generation mode according to the speed value includes:

[0068] Setting a speed threshold, when the speed value is lower than the speed threshold, adopting a full-power-converted direct current excitation synchronous or asynchronous power generation mode to generate electricity;

[0069] When the speed value is higher than the speed threshold, power generation is performed using an AC excitation double-fed asynchronous power generation method with partial power conversion.

[0070] As a preferred embodiment, the process of adjusting power generation of the generator set according to the power generation mode and the current distribution scheme includes:

[0071] Calculating the real-time power factor and electromagnetic torque of the generator set according to the current distribution scheme;

[0072] The average power factor of the generator set is obtained according to the real-time power factor, and the given active power and reactive power of the generator set are set according to the average power factor.

[0073] As a preferred embodiment, the calculation method of the real-time power factor is as follows:

[0074]

[0075] Where K represents the salient pole ratio of the generator, and K = L d / L q , x = sin 2 γ, L d is the direct-axis inductance, L q is the quadrature-axis inductance, and γ is the current angle.

[0076] As a preferred embodiment, the calculation method of the electromagnetic torque is as follows:

[0077]

[0078] Among them, T e is the electromagnetic torque of the generator, L d is the direct-axis inductance, L q is the quadrature-axis inductance, I s is the current vector of the generator set, p n is the number of magnetic poles of the generator.

[0079] As a preferred embodiment, the process of generating an excitation control scheme for a generator set includes:

[0080] Construct a vector relationship between the current value and the voltage value during the power generation process of the generator set, calculate the current vector that the generator set needs to compensate based on the vector relationship between the current value and the voltage value, calculate the voltage vector based on the current vector, and simultaneously calculate the phase difference between the voltage vector and the current vector to obtain the power factor angle, thereby constructing the active power and reactive power control scheme of the generator set.

[0081] As a preferred embodiment, according to the excitation control scheme, a process of performing DC excitation on a doubly-fed asynchronous generator in a synchronous generator state and operating in a full-power conversion mode, and performing AC excitation on a doubly-fed asynchronous generator in an asynchronous generator state and operating in a partial-power conversion mode includes:

[0082] Perform DC excitation on the doubly-fed asynchronous generator in full-power conversion mode in the synchronous generator state, set the output voltage of the DC excitation controller, and control the generator operating voltage;

[0083] The double-fed asynchronous generator in the asynchronous generator state and operating in partial power conversion mode is subjected to AC excitation, and the DC excitation controller is exited.

[0084] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. As for the method disclosed in the embodiment, since it corresponds to the system disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0085] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can still modify the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or perform equivalent replacements on some of the technical features thereof; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. They should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A double-fed asynchronous power generation system with intelligent regulation of converter modules, characterized in that: It includes a generator set, a dynamic converter, a converter controller, and a DC excitation controller connected in sequence; The generator set is a double-fed asynchronous generator in a synchronous generator or asynchronous generator state and its driving prime mover; The dynamic converter is used to set the power generation mode according to the speed value of the generator set during power generation; The current converter controller is used to adjust the power generation of the generator set according to the power generation mode and determine the excitation control scheme of the generator set; The DC excitation controller is used to perform DC excitation on the double-fed asynchronous generator operating in a full-power conversion mode in a synchronous generator state according to the excitation control scheme.

2. The double-fed asynchronous power generation system with intelligent regulation of the converter module according to claim 1 is characterized in that: The dynamic converter controls the power generation mode by setting a speed threshold; When the speed value of the generator is lower than the speed threshold, the dynamic converter controls the generator set to generate electricity in a DC excitation synchronous power generation mode with full power conversion; When the speed value of the generator is higher than the speed threshold, the dynamic converter controls the generator to generate electricity by adopting an AC excitation double-fed asynchronous power generation method with partial power conversion.

3. The double-fed asynchronous power generation system with intelligent regulation of the converter module according to claim 1 is characterized in that: The converter controller calculates the real-time power factor and electromagnetic torque of the generator set according to the working state of the double-fed asynchronous power generation system; The average power factor of the generator set is obtained according to the real-time power factor, and the given active power and reactive power of the generator set are set according to the average power factor.

4. The double-fed asynchronous power generation system with intelligent regulation of the converter module according to claim 3 is characterized in that: The current converter controller constructs a vector relationship between the current value and the voltage value during the power generation process of the generator set, calculates the current vector that needs to be compensated for the generator set according to the vector relationship between the current value and the voltage value, calculates the voltage vector according to the current vector, and simultaneously calculates the phase difference between the voltage vector and the current vector to obtain the power factor angle; The power factor required by the generator is calculated according to the power factor angle and the voltage vector, and then the active power and reactive power control scheme of the generator set is constructed.

5. The double-fed asynchronous power generation system with intelligent regulation of the converter module according to claim 3 is characterized in that: The current converter controller sets the output voltage of the DC excitation controller to control the operating voltage of the generator.

6. A double-fed asynchronous power generation method with intelligent regulation of converter modules, characterized in that: include: Acquire the speed value of the generator set during power generation, and set the power generation mode according to the speed value; Adjusting the power generation of the generator set according to the power generation mode and determining the excitation control scheme for the generator set; According to the excitation control scheme, a doubly-fed asynchronous generator in a synchronous generator state and operating in a full-power conversion mode is subjected to DC excitation, and a doubly-fed asynchronous generator in an asynchronous generator state and operating in a partial-power conversion mode is subjected to AC excitation.

7. The double-fed asynchronous power generation method with intelligent regulation of converter modules according to claim 6 is characterized in that: The process of setting the power generation mode according to the speed value includes: Setting a speed threshold, when the speed value is lower than the speed threshold, adopting a full-power-converted DC excitation synchronous power generation mode to generate electricity; When the speed value is higher than the speed threshold, power generation is performed using an AC excitation double-fed asynchronous power generation method with partial power conversion.

8. The double-fed asynchronous power generation method with intelligent regulation of converter modules according to claim 6, characterized in that: The process of regulating the power generation of the generator set according to the power generation mode includes: Calculate the real-time power factor and electromagnetic torque of the generator set according to the working state of the double-fed asynchronous generator system; The average power factor of the generator set is obtained according to the real-time power factor, and the given active power and reactive power of the generator set are set according to the average power factor.

9. The double-fed asynchronous power generation method with intelligent regulation of converter modules according to claim 8, characterized in that: The process of generating an excitation control scheme for a generator set includes: Construct a vector relationship between the current value and the voltage value during the power generation process of the generator set, calculate the current vector that the generator set needs to compensate based on the vector relationship between the current value and the voltage value, calculate the voltage vector based on the current vector, and simultaneously calculate the phase difference between the voltage vector and the current vector to obtain the power factor angle, thereby constructing the active power and reactive power control scheme of the generator set.

10. The double-fed asynchronous power generation method with intelligent regulation of converter modules according to claim 9, characterized in that: The process of performing DC excitation on a doubly-fed asynchronous generator in a synchronous generator state and operating in a full-power conversion mode according to the excitation control scheme, and performing AC excitation on a doubly-fed asynchronous generator in an asynchronous generator state and operating in a partial-power conversion mode includes: Perform DC excitation on the doubly-fed asynchronous generator in full-power conversion mode in the synchronous generator state, set the output voltage of the DC excitation controller, and control the generator operating voltage; The double-fed asynchronous generator in the asynchronous generator state and operating in partial power conversion mode is subjected to AC excitation, and the DC excitation controller is exited.

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