CN-122001229-A - Improved generation C-dump converter can be trusted and is passed tactics simultaneously

Abstract

The invention discloses an improved C-dump converter energy-signal simultaneous transmission strategy. Aiming at the problems that energy in the follow current stage of the traditional C-dump converter can only be fed back to an excitation power supply and can not realize output of generated energy, the invention constructs a follow current loop suitable for a power generation state by adjusting the connection position of an energy storage capacitor in a circuit, thereby realizing effective output of the generated energy on the premise of keeping the control independence of each phase and not increasing the use of devices. The flyback converter can widen the voltage output range and reduce the output voltage fluctuation. In order to realize synchronous transmission of energy and signals, the invention uses a frequency shift keying modulation method to embed ripple signals containing communication data in output voltage, and a receiving end uses fast Fourier change to demodulate information, thereby simplifying an information transmission system. The scheme obviously reduces the complexity of the system and effectively improves the output power quality of the switched reluctance generator.

Inventors

• YU DONGSHENG
• YANG JIAHAO
• LIU WENLONG
• YU JUN

Assignees

• 中国矿业大学

Dates

Publication Date

20260508

Application Date

20260128

Claims (4)

1. 1. An improved C-dump converter energy signal simultaneous transmission strategy is characterized in that an improved C-dump converter is used as a driving circuit of an SRG, an improved C-dump converter is used for realizing effective output of power generation energy by adjusting connection positions of an energy storage capacitor and exciting positive and negative buses to construct a follow current loop adapting to current flow characteristics of the SRG in a power generation stage, the improved C-dump converter controls switching tubes of corresponding phases to be conducted in an excitation section to enable a phase winding and an excitation power supply to establish a passage to enter an excitation state, the switching tubes of the corresponding phases to be turned off in the power generation section to enable the phase winding to enter the power generation stage, current generated by the winding flows to the energy storage capacitor through the follow current buses to form a loop through the excitation buses and returns to the phase winding to form a closed follow current loop, and in order to realize synchronous transmission of energy and signals on the basis of not affecting the output efficiency of the SRG, a BFSK modulation method is introduced into an output voltage, and a voltage signal is demodulated by an FFT method to obtain transmission information.
2. 2. The improved C-dump converter of claim 1, wherein the control of the SRG winding output current is achieved by constructing a freewheel loop that conforms to the current flow characteristics of the SRG power generation phase, in particular comprising: Each phase of the converter consists of a switching tube and a freewheeling diode, wherein the switching tube realizes the control of the phase, the diode is responsible for constructing a freewheeling path to guide the output current of a winding to an energy storage capacitor, the SRG is assumed to share N phases, the corresponding switching tube of the kth phase is S k , the freewheeling diode is D k , and the improved C-dump converter comprises N switching tubes, N diodes, an excitation power supply and an energy storage capacitor; The improved C-dump converter comprises three buses, namely an excitation positive bus, an excitation negative bus and a follow current bus, wherein the excitation positive bus is connected with the positive electrode of an excitation power supply, one end of a k-phase winding is connected with the excitation positive bus, the other end of the k-phase winding is connected with S k , the other end of the k-phase winding is connected with the excitation negative bus, the excitation negative bus is connected with the negative electrode of the excitation power supply, and in the operation process, switching devices of corresponding phases are controlled to act according to rotor angle position information, and when the switching devices are in an excitation interval of a k-phase, S k is conducted, and a passage is formed between the k-phase winding and the excitation power supply to enter an excitation state; One end of the k-phase winding connected with the S k is simultaneously connected with the D k , the other end of the D k is connected with a freewheeling bus, the freewheeling bus is connected with the positive electrode of the energy storage capacitor, the freewheeling diode of each phase is connected with the freewheeling bus, the current of the freewheeling bus charges the energy storage capacitor, and the negative electrode of the energy storage capacitor is connected to the excitation positive bus through the diode to form a freewheeling loop; In order to achieve the improvement of the output voltage level, a flyback converter is connected with an output capacitor in parallel, the flyback converter is controlled by a high-frequency driving signal, the improved C-dump converter supplies energy to the flyback converter, and the effect of inhibiting output voltage fluctuation can be achieved while the voltage level is improved.
3. 3. The improved C-dump converter of claim 2, wherein the freewheel mechanism is characterized in that S k is turned off when the k-phase excitation phase is finished according to rotor angle position information, output current of the phase winding enters a freewheel bus through D k , the freewheel bus collects generated current of each alternately generated freewheel current to form continuous fluctuation to charge an energy storage capacitor, and the energy storage capacitor is connected to an excitation positive bus through a diode to form a freewheel loop leading to each phase, so that continuous transmission of winding energy is realized.
4. 4. The energy simultaneous transmission strategy of the improved C-dump converter of claim 1, wherein the energy simultaneous transmission strategy is characterized in that a BFSK modulation method is adopted to realize synchronous transmission of energy and signals, and a switching tube in a flyback converter is used as a modulation object for modulation in order to perform energy simultaneous transmission modulation on the premise of not influencing SRG output efficiency; The carrier generation, namely, adopting triangular waves with two different frequencies as carriers of binary information '1' and '0', constructing a gating function c (t) according to a binary information sequence to be transmitted, wherein the gating function value is 1 when the binary information is transmitted as '1', the triangular carrier frequency is f 1 , the gating function value is 0 when the binary information is transmitted as '0', and the triangular carrier frequency is f 2 , so that the carrier S c (t) is obtained as follows: a is carrier amplitude; PWM generates, wherein a given duty ratio signal is used as a modulation wave, the modulation wave is compared with a carrier wave, the output is 0 when the carrier wave is larger than the given duty ratio and is 1 when the carrier wave is smaller than the duty ratio, a PWM control signal is obtained, and a switching device in a flyback converter is controlled by PWM; And information demodulation, namely generating ripple signals with frequencies f 1 and f 2 on the output voltage after modulation, wherein the ripple with the frequency f 1 exists on the output voltage when the information is transmitted as 1 according to the modulation principle, the ripple amplitude of f 2 is 0, and the situation is opposite when the information is transmitted as 0.

Description

Improved generation C-dump converter can be trusted and is passed tactics simultaneously Technical Field The invention belongs to the technical field of power electronics, and particularly relates to an energy-signal simultaneous transmission strategy of an improved C-dump converter. Background Under the background of rapid development of new energy power generation, the wind power generation technology becomes a major important field in the new energy power generation technology. The switched reluctance generator (Switched Reluctance Generator, SRG) has the advantages of firm structure, maximum allowable temperature rise, wide rotating speed range, flexible control method of multiple control parameters and the like, and has obvious advantages in wind power generation application. In the existing SRG driving system, the traditional asymmetric half-Bridge (AHB) driving circuit has the defects of large number of power devices, complex structure and high cost, and the energy storage capacitor (C-dump) driving circuit can obviously reduce the use of the power devices on the basis of ensuring the control independence of each phase and has obvious advantages in the aspects of cost and system integration. Because of the special freewheel characteristics of the SRG power generation phase, the conventional C-dump converter cannot directly provide a freewheel loop, and a freewheel loop for switching on a load needs to be constructed to realize power transmission. With the diversification of wind power generation application scenes, the output voltage level and stability requirements of the SRG are continuously improved. In the prior art, the voltage level is generally adjusted by adding a special boost circuit or adjusting excitation parameters and other methods, but the former can lead to the complexity of an output system structure, and the latter can have an influence on the operation efficiency of the motor. Therefore, realizing a wide range of voltage output and improving the stability of the output voltage are problems worthy of study on the premise that the additional structure is as simple as possible. The flyback converter has the advantages of simple circuit structure, electric isolation and flexible gain adjustment, and can play roles of expanding the voltage output range and inhibiting voltage fluctuation after the improved C-dump converter. In addition, in a distributed energy system such as wind power generation, the traditional communication mode relies on an independent communication line or a wireless communication module, and has the defects of complex wiring and easy interference. The energy communication technology can embed information into output voltage in a high-frequency ripple mode through a special modulation mode, and the synchronous transmission of energy and signals is realized by utilizing the power transmission line to transmit the information, so that an independent communication line or an attached wireless communication module is not required to be erected. The technology can not only use the power line as a communication line to reduce the consumption of the communication line part, but also has stronger anti-interference performance compared with the wireless communication technology, and is suitable for information transmission of a distributed power generation system. Disclosure of Invention The invention aims to provide an improved C-dump converter and a power co-transmission strategy thereof. The invention takes the improved C-dump converter as a driving circuit of the SRG, and the improved C-dump converter constructs a closed freewheel path of a motor phase winding, a freewheel bus, an energy storage capacitor, an excitation positive bus and a motor phase winding by adjusting a freewheel loop of the traditional C-dump converter, and the path accords with the current flow characteristic of a power generation stage, so that the effective output of electric energy in the power generation stage is ensured. On the basis, in order to further widen the range of the SRG output voltage and improve the stability of the output voltage, a flyback converter is cascaded behind the improved C-dump converter, so that the energy output by the improved C-dump converter is regulated and converted, and the voltage fluctuation is restrained while the output voltage level is improved. In addition, in order to realize synchronous transmission of energy and signals without affecting the working efficiency of the SRG, a binary frequency shift keying (Binary Frequency Shift Key, BFSK) method is used for modulating a switching device of a post-stage direct current conversion link, and a fast Fourier (Fast Fourier Transform, FFT) method is adopted at an output end for demodulation to obtain original data. The technical scheme of the invention is as follows: The whole system consists of a switch reluctance generator, an improved C-dump converter, a flyback converter and an energy communication and transm