Mesh construction type doubly salient direct current generator set and control system

Abstract

The invention discloses a network construction type doubly salient direct current generator set and a control system, and belongs to the technical field of network construction type generators. The grid-forming type double-salient-pole direct-current generator set comprises a fan rotating shaft, a double-salient-pole direct-current generator, a DC / DC converter and a direct-current bus. The doubly salient direct-current generator comprises a stator, a rotor, an excitation winding, a first armature winding and a second armature winding, the exciting windings are uniformly wound on the stator poles at a winding angle of 0 degree relative to the stator pole center, the first armature windings are wound on the corresponding stator poles at intervals of two poles at a winding angle of 10-20 degrees relative to the stator pole center, and the second armature windings and the first armature windings are arranged adjacently; and the winding wires are wound on the corresponding stator poles every two poles at a winding angle of 25-35 degrees relative to the stator pole center. A control system of the generator set comprises a double-closed-loop rotating speed control system and a DC / DC converter control system. The magnetic field distribution of the generator set is more uniform, the magnetic leakage is effectively reduced, and the energy conversion efficiency is improved; the control system improves the dynamic response capability of the generator set.

Description

Technical Field

[0001] The present invention belongs to the technical field of grid-type generators, and in particular relates to a grid-type double-salient-pole DC generator set and a control system. Background Art

[0002] With the rapid development of renewable energy generation technologies, the penetration of power electronics equipment in power grids is gradually increasing, and power systems are shifting toward weak grids with low inertia and low damping. Grid-connected generators can effectively combine with wind and solar energy and support grid-connected operation. They adjust power generation through rapid dynamic response to meet the power quality requirements of weak grids.

[0003] Currently, the design of grid-type generators faces numerous challenges. For example, in terms of structure, existing grid-type generators generally use AC motors such as permanent magnet synchronous generators for power supply, which increases the number of power conversion steps and results in energy loss during the conversion process, hindering efficient energy utilization. Secondly, traditional grid-type generators typically have a 6N / 4n pole structure, meaning the number of stator poles is 1.5 times the number of rotor poles. This reduces the stator slot width, increases magnetic flux leakage, and increases excitation power loss. Regarding control, in the droop control of a grid-type DC / DC converter, when the load changes, the converter's output voltage and frequency may deviate, especially under high load conditions, which can affect power supply stability. In motor speed control, traditional dual closed-loop control is not flexible enough to handle the system's complexity and nonlinear characteristics, resulting in insufficient control performance, especially under dynamically changing loads. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention aims to solve the technical problem of proposing a grid-type doubly salient DC generator set and a control system.

[0005] The present invention solves the technical problem by adopting the following technical solutions: On the one hand, the present invention provides a meshed doubly salient DC generator set, comprising a fan shaft, a doubly salient DC generator, a DC / DC converter and a DC bus; characterized in that the doubly salient DC generator comprises a stator, a rotor, an excitation winding, a first armature winding and a second armature winding; the excitation winding is evenly wound on each stator pole at a winding angle of 0° relative to the stator pole core, the first armature winding is wound on the corresponding stator pole every two poles at a winding angle of 10~20° relative to the stator pole core, the second armature winding is arranged adjacent to the first armature winding, and is wound on the corresponding stator pole every two poles at a winding angle of 25~35° relative to the stator pole core; the positive ends of the first armature winding and the second armature winding serve as the negative end of the doubly salient DC generator, and the negative ends of the first armature winding and the second armature winding serve as the positive end of the doubly salient DC generator.

[0006] Furthermore, the stator includes 9 stator poles and the rotor includes 12 rotor poles.

[0007] On the other hand, the present invention also provides a control system for a meshed doubly salient DC generator set, including a dual closed-loop speed control system and a DC / DC converter control system; the dual closed-loop speed control system includes a speed setting circuit, a speed detector, a first subtractor, a fuzzy speed controller, a second subtractor, a BP neural network current controller, a current detector and a generator starting circuit; the speed detector is connected to the doubly salient DC generator, the output ends of the speed setting circuit and the speed detector are simultaneously connected to the input end of the first subtractor, the output end of the first subtractor is connected to the input end of the fuzzy speed controller, the output end of the fuzzy speed controller and the output end of the current detector are simultaneously connected to the input end of the second subtractor, the output end of the second subtractor is connected to the input end of the BP neural network current controller, the output end of the BP neural network current controller is connected to the input end of the generator starting circuit, and the output end of the generator starting circuit is respectively connected to the doubly salient DC generator and the current detector.

[0008] Furthermore, the fuzzy speed controller includes a fuzzy controller and a PI controller; the input of the fuzzy controller is the generator voltage deviation and the generator voltage deviation change rate, and the output is the proportional coefficient correction value and the integral coefficient correction value; the BP neural network current controller includes a BP neural network and a PID controller, the input of the BP neural network is the generator starting circuit voltage deviation change rate, and the output is the proportional coefficient correction value, the integral coefficient correction value and the differential coefficient correction value; the input of the PID controller is the generator starting circuit voltage deviation, and the output is the voltage acting on the generator starting circuit.

[0009] Furthermore, the DC / DC converter control system includes a third subtractor, a droop controller, a fourth subtractor, a first voltage controller, a first current controller, a fifth subtractor, a current loop, a voltage loop, a second voltage controller, and a second current controller; wherein the input end of the droop controller is connected to the output end of the doubly salient DC generator, the output end of the droop controller is connected to the input end of the third subtractor, and the input end of the third subtractor also inputs the voltage reference value and the output of the secondary controller; the output end of the third subtractor and the output end of the voltage loop are simultaneously connected to the input end of the fourth subtractor, the output end of the fourth subtractor is connected to the input end of the first voltage controller, the output end of the first voltage controller and the output end of the current loop are simultaneously connected to the input end of the fifth subtractor, the output end of the fifth subtractor is connected to the input end of the first current controller, the output end of the first current controller is connected to the input end of the second current controller, one output end of the second current controller is connected to the input end of the second voltage controller, another output end of the second current controller is connected to the input end of the current loop, one output end of the second voltage controller directly outputs voltage, and another output end of the second voltage controller is connected to the input end of the voltage loop.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. In terms of generator structure, a 9 / 12-pole doubly salient DC generator is used, with a stator pole to rotor pole ratio of 3:4. This optimizes the magnetic circuit design, reduces magnetic leakage losses, and overcomes the increased magnetic leakage problem of traditional 6N / 4n generators, thereby improving energy conversion efficiency. The generator consists of one excitation winding and two armature windings. Each stator pole is wound with one excitation winding and two armature windings, and the winding angles form a certain angle difference between the windings. This not only improves the uniformity of the magnetic field, but also fully utilizes the multi-angle winding of the windings to optimize the output of the electromotive force. This effectively reduces the imbalance problem caused by traditional focusing of multiple windings on a small number of stator poles, while also enhancing adaptability to different load conditions.

[0011] 2. In terms of the control system, fuzzy logic and BP neural networks are introduced in generator speed control to achieve intelligent control of the outer loop speed and inner loop current. Fuzzy control dynamically generates control signals through real-time analysis of speed errors and their rate of change, improving the dynamic response capability of the generator set and the accuracy of speed control. Simultaneously, the BP neural network adaptively adjusts PID parameters to ensure current stability during rapid dynamic response. Compared with traditional fixed-parameter control methods, this significantly reduces complexity and improves system adaptability and stability. In DC / DC converter control, a combination of droop control and zero-level control maintains output voltage stability even under varying load conditions. Droop control adjusts the ratio of output voltage to load current in real time, ensuring stable converter output even with rapid load changes. Zero-level control simplifies system design, promotes smoother and more efficient power distribution, improves power quality, and accelerates dynamic response, overcoming the difficulties of traditional systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a structural diagram of a grid-type doubly salient DC generator set according to the present invention; Figure 2 is a structural diagram of a doubly salient DC generator of the present invention; Figure 3 Schematic diagram of the dual closed-loop speed control system of the present invention; Figure 4 A schematic diagram of a DC / DC converter control system according to the present invention; Explanation of reference numerals: 1. fan shaft; 2. doubly salient DC generator; 3. DC / DC converter; 4. dual closed-loop speed control system; 5. DC / DC converter control system; 6. DC bus; 11. Stator; 22. Rotor; 33. Field winding; 44. First armature winding; 55. Second armature winding; 66. Stator pole; 77. Rotor pole. DETAILED DESCRIPTION

[0013] Specific embodiments are given below in conjunction with the accompanying drawings. The specific embodiments are only used to introduce the technical solutions of the present invention in detail and are not intended to limit the scope of protection of the present application.

[0014] The present invention provides a grid-type double-salient DC generator set (referred to as the generator set, see Figures 1 and 2), including a fan shaft 1, a doubly salient DC generator 2, a DC / DC converter 3 and a DC bus 6; one end of the fan shaft 1 is coaxially connected to the air compression device at the front end, and the other end is connected to the rotor of the doubly salient DC generator 2, used to drive the rotor of the doubly salient DC generator 2 to rotate; one side of the DC / DC converter 3 is connected to the output end of the doubly salient DC generator 2, and the other side is connected to the DC bus 6. The DC power generated by the doubly salient DC generator 2 is converted into 400V high-voltage stable DC power by the DC / DC converter 3, and then output to the DC bus 6.

[0015] like Figure 2 As shown, the doubly salient DC generator 2 includes a stator 11, a rotor 22, an excitation winding 33, a first armature winding 44, and a second armature winding 55; wherein the stator 11 includes 9 stator poles 66, and the rotor 22 includes 12 rotor poles 77; the excitation winding 33 is uniformly wound on each stator pole 66 at a winding angle of 0° relative to the stator pole core, and the first armature winding 44 is wound on the corresponding stator pole 66 every two poles at a winding angle of 10-20° relative to the stator pole core, with the excitation winding 33 and the first armature winding 44. The windings 33 are staggered at a small angle, allowing for proper interaction between the first armature winding 44 and the field winding 33. This improves output current stability while maintaining power generation efficiency. The second armature winding 55 is arranged adjacent to the first armature winding 44 and wound around every other stator pole 66 at a winding angle of 25-35° relative to the stator pole core. This creates a certain angle difference with the first armature winding 44, enabling the armature coils to respond quickly to varying magnetic flux changes, further improving output current stability. The positive terminals (A and A') of the first and second armature windings 44, 55, are directly connected to the generator's negative terminal, while the negative terminals (X and X') of the first and second armature windings 44, 55, are directly connected to the generator's positive terminal. A DC excitation current flows through the field winding 33 to generate the main magnetic field, while DC current flows through the first and second armature windings 44, 55.

[0016] The doubly salient DC generator 2 uses a centralized excitation method. Compared to traditional distributed excitation, centralized excitation evenly distributes the excitation winding 33 on each stator pole 66, resulting in a more compact structure. This solves the magnetic circuit asymmetry and imbalance problems of distributed excitation, enables better control of the excitation current, quickly responds to load changes, and helps effectively manage the output voltage. The first armature winding 44 and the second armature winding 55 are arranged adjacent to each other, and there is a certain angle difference between the winding angles. This allows the generator to produce a more uniform magnetic field distribution, thereby effectively reducing the electromagnetic noise and vibration generated by the motor during operation, and can improve the motor's operating stability and comfort. At the same time, the voltage waveform output by the generator is smoother, and the ripple of the output current is reduced, which helps to extend the service life of the motor and load and reduce the impact on the load drive power supply. Moreover, this arrangement makes the magnetic flux generated by the armature winding more uniform, thereby improving the overall efficiency of the generator, especially under high load conditions, and can achieve a higher energy conversion rate.

[0017] The stator 11 is made of silicon steel sheets with high magnetic permeability and low loss. The rotor 22 is made of high-performance permanent magnet materials, such as Ni-Fe-B.

[0018] The present invention also provides a control system for a grid-type doubly salient DC generator set (hereinafter referred to as the control system, see Figures 3 and 4 ), including a dual closed-loop speed control system 4 and a DC / DC converter control system 5; the dual closed-loop speed control system 4 is used to control the speed of the doubly salient DC generator 2, and the DC / DC converter control system 5 is used to control the DC / DC converter 3.

[0019] like Figure 3 As shown, the dual closed-loop speed control system 4 includes a speed setting circuit, a speed detector, a first subtractor, a fuzzy speed controller, a second subtractor, a BP neural network current controller, a current detector and a generator starting circuit; wherein the speed detector is connected to the doubly salient DC generator 2 for detecting the speed of the generator; the output ends of the speed setting circuit and the speed detector are simultaneously connected to the input end of the first subtractor, the output end of the first subtractor is connected to the input end of the fuzzy speed controller, the output end of the fuzzy speed controller and the output end of the current detector are simultaneously connected to the input end of the second subtractor, the output end of the second subtractor is connected to the input end of the BP neural network current controller, the output end of the BP neural network current controller is connected to the input end of the generator starting circuit, and the output end of the generator starting circuit is respectively connected to the doubly salient DC generator 2 and the current detector.

[0020] The speed setting circuit outputs the given speed and converts the given speed into the generator given voltage U n *; The speed detector detects the speed of the doubly salient DC generator and converts the speed into the generator measurement voltage Un The first subtractor makes a difference between the given voltage of the generator and the measured voltage to obtain the generator voltage deviation e=U n *-U n The generator voltage deviation e is optimized by the fuzzy speed controller to obtain the output of the fuzzy speed controller, that is, the given voltage U of the generator starting circuit. i *; The current detector detects the current of the generator starting circuit and converts the current into the generator starting circuit measurement voltage U i The second subtractor makes a difference between the given voltage and the measured voltage of the generator starting circuit to obtain the voltage deviation e of the generator starting circuit t =U i *-U i ; Generator starting circuit voltage deviation e t After optimization of the BP neural network current controller, the voltage U c ; Set the voltage U c It acts on the generator starting circuit, thereby controlling the rotation of the doubly salient DC generator.

[0021] The fuzzy speed controller includes a fuzzy controller and a PI controller; the fuzzy controller uses fuzzy control rules to generate a fuzzy control quantity according to the generator voltage deviation and the generator voltage deviation change rate, and the fuzzy control quantity obtains an output quantity through fuzzy reasoning, including a proportional coefficient correction value ΔK p And the integral coefficient correction value ΔK i , used to modify the parameters of the PI controller. The output of the PI controller is the given voltage U of the generator starting circuit. i *.

[0022] The BP neural network current controller includes a BP neural network and a PID controller; the input of the BP neural network is the voltage deviation change rate of the generator starting circuit, and the output is the proportional coefficient correction value ΔK p , integral coefficient correction value ΔK i and differential coefficient correction value ΔK d , used to dynamically modify the parameters of the PID controller to achieve precise control of the current loop; the input of the PID controller is the voltage deviation of the generator starting circuit, and the output is the voltage U c .

[0023] Furthermore, the generator starting circuit utilizes a symmetrical half-bridge circuit. By controlling the on and off switching of switches within the symmetrical half-bridge circuit, the generator output voltage is regulated, reducing current surges. Furthermore, compared to a full-bridge structure, the symmetrical half-bridge circuit requires only two switches, simplifying circuit design. The current detector includes a rectifier circuit and a current transformer. The current transformer is connected to the generator starting circuit, and the output of the current transformer is connected to the rectifier circuit.

[0024] like Figure 4 As shown, the DC / DC converter control system 5 includes a third subtractor, a droop controller, a fourth subtractor, a first voltage controller, a first current controller, a fifth subtractor, a current loop, a voltage loop, a second voltage controller, and a second current controller; wherein the input end of the droop controller is connected to the output end of the doubly salient DC generator 2, the output end of the droop controller is connected to the input end of the third subtractor, and the input end of the third subtractor also inputs the voltage reference value and the output of the secondary controller; the output end of the third subtractor and the output end of the voltage loop are simultaneously connected to the input end of the fourth subtractor, the output end of the fourth subtractor is connected to the input end of the first voltage controller, the output end of the first voltage controller and the output end of the current loop are simultaneously connected to the input end of the fifth subtractor, the output end of the fifth subtractor is connected to the input end of the first current controller, the output end of the first current controller is connected to the input end of the second current controller, one output end of the second current controller is connected to the input end of the second voltage controller, another output end of the second current controller is connected to the input end of the current loop, one output end of the second voltage controller directly outputs the voltage, and another output end of the second voltage controller is connected to the input end of the voltage loop.

[0025] The given current I of the DC / DC converter i After the droop controller, a given voltage V* is generated; the third subtractor performs the subtraction of the given voltage V* and the reference voltage V ref and the output z of the secondary controller i Calculate and get the given reference voltage V* ref =V ref -V*+z i ; Output voltage v of the second voltage controller i After the voltage loop, the voltage calculation value v is obtained i *; The fourth subtractor performs a subtraction between the given reference voltage and the voltage calculation value to obtain the voltage deviation e v= V* ref— v i *; Voltage deviation e v After the first voltage controller, the reference current I is obtained. ref ; The output current i of the second current controller L After the current loop, the current calculation value I is obtained L * ; The fifth subtractor is for the reference current I ref and the calculated current value I L * Make the difference and get the current deviation e i = I ref— I L * ; Current deviation ei After passing through the first current controller and the second current controller in sequence, the output current i is obtained. L Output current i L After the second voltage controller, the output voltage v i .

[0026] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A grid-type doubly salient DC generator set, comprising a fan shaft, a doubly salient DC generator, a DC / DC converter and a DC bus; characterized in that: The double-salient-pole DC generator comprises a stator, a rotor, an excitation winding, a first armature winding and a second armature winding; the excitation winding is uniformly wound on each stator pole at a winding angle of 0° relative to the stator pole core, the first armature winding is wound on the corresponding stator pole every two poles at a winding angle of 10-20° relative to the stator pole core, the second armature winding is arranged adjacent to the first armature winding, and is wound on the corresponding stator pole every two poles at a winding angle of 25-35° relative to the stator pole core; the positive ends of the first armature winding and the second armature winding serve as the negative end of the double-salient-pole DC generator, and the negative ends of the first armature winding and the second armature winding serve as the positive end of the double-salient-pole DC generator.

2. A grid-type doubly salient DC generator set according to claim 1, characterized in that: The stator contains 9 stator poles and the rotor contains 12 rotor poles.

3. A control system for a grid-type doubly salient DC generator set according to claim 1 or 2, characterized in that: The control system includes a dual closed-loop speed control system and a DC / DC converter control system; The dual closed-loop speed control system includes a speed setting circuit, a speed detector, a first subtractor, a fuzzy speed controller, a second subtractor, a BP neural network current controller, a current detector and a generator starting circuit; the speed detector is connected to the double-pole DC generator, the output ends of the speed setting circuit and the speed detector are simultaneously connected to the input end of the first subtractor, the output end of the first subtractor is connected to the input end of the fuzzy speed controller, the output end of the fuzzy speed controller and the output end of the current detector are simultaneously connected to the input end of the second subtractor, the output end of the second subtractor is connected to the input end of the BP neural network current controller, the output end of the BP neural network current controller is connected to the input end of the generator starting circuit, and the output end of the generator starting circuit is respectively connected to the double-pole DC generator and the current detector.

4. The control system of a grid-type doubly salient DC generator set according to claim 3, characterized in that: The fuzzy speed controller includes a fuzzy controller and a PI controller; the input of the fuzzy controller is the generator voltage deviation and the generator voltage deviation change rate, and the output is the proportional coefficient correction value and the integral coefficient correction value; the BP neural network current controller includes a BP neural network and a PID controller, the input of the BP neural network is the generator starting circuit voltage deviation change rate, and the output is the proportional coefficient correction value, the integral coefficient correction value and the differential coefficient correction value; the input of the PID controller is the generator starting circuit voltage deviation, and the output is the voltage acting on the generator starting circuit.

5. A control system for a grid-type doubly salient DC generator set according to claim 3 or 4, characterized in that: The DC / DC converter control system includes a third subtractor, a droop controller, a fourth subtractor, a first voltage controller, a first current controller, a fifth subtractor, a current loop, a voltage loop, a second voltage controller and a second current controller; Among them, the input end of the droop controller is connected to the output end of the doubly salient pole DC generator, the output end of the droop controller is connected to the input end of the third subtractor, and the input end of the third subtractor also inputs the voltage reference value and the output of the secondary controller; the output end of the third subtractor and the output end of the voltage loop are simultaneously connected to the input end of the fourth subtractor, the output end of the fourth subtractor is connected to the input end of the first voltage controller, the output end of the first voltage controller and the output end of the current loop are simultaneously connected to the input end of the fifth subtractor, the output end of the fifth subtractor is connected to the input end of the first current controller, the output end of the first current controller is connected to the input end of the second current controller, one output end of the second current controller is connected to the input end of the second voltage controller, the other output end of the second current controller is connected to the input end of the current loop, one output end of the second voltage controller directly outputs voltage, and the other output end of the second voltage controller is connected to the input end of the voltage loop.

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