Design method of microsecond pulse excitation voltage source with variable parameters

Abstract

The invention discloses a variable-parameter microsecond pulse excitation voltage source design method, and relates to the technical field of power equipment power supplies, and the method comprises the steps: generating a double-exponential type impulse voltage and an oscillation type impulse voltage; automatic repetition frequency pulse voltage excitation output is realized; the rising time and the falling time of the output double-exponential impulse voltage can be adjusted by adjusting the sizes of the wavefront resistor, the discharging resistor and the charging capacitor; on the basis of a double-exponential impulse voltage circuit, the output of oscillation type impulse voltage is realized by connecting an inductor between a wavefront resistor and a test object in series, and the wavefront time, the half-peak time and the oscillation frequency of the output oscillation type impulse voltage can be adjusted by adjusting the values of the resistor, the capacitor and the inductor. According to the variable-parameter microsecond pulse excitation voltage source design method provided by the invention, the controllable high-voltage half-bridge module is adopted to replace a traditional spark sphere gap device to realize automatic repetition frequency pulse voltage excitation.

Description

Technical Field

[0001] The invention relates to the technical field of power supply for electric equipment, in particular to a design method for a microsecond pulse excitation voltage source with variable parameters. Background Art

[0002] In recent years, with the improvement of my country's industrial level and the requirements of large-scale power grid construction for the development of power equipment production technology, power equipment has gradually been localized. However, due to quality problems in the production process of power equipment (such as material defects and main and accessory assembly errors) and potential defects in transportation and installation (such as loose and falling parts, electrode scratches, misalignment and insulation cracks, etc.), the failures and accidents caused by them are increasing year by year. Statistics from relevant research institutions show that AC withstand voltage tests and AC partial discharge tests can generally expose most defects in power equipment, but for potential defects such as electrode scratches and spikes with abnormal electric fields, their detection effectiveness is limited. In order to prevent the occurrence of power equipment accidents and ensure the safety of the power system, more reliable means are urgently needed to improve the insulation diagnosis level of power equipment.

[0003] Generally speaking, the insulation AC withstand voltage test and impulse withstand voltage test have certain assessment equivalence. Therefore, in the withstand voltage or partial discharge test conducted at the factory or on site, AC voltage excitation is often used instead of impulse voltage excitation, thereby reducing the requirements of the partial discharge test on the power supply and test system. However, practical experience and related research have shown that AC tests have limitations in discovering potential insulation defects, especially steep front pulse voltage, and its insulation assessment effect is no longer equivalent to that of AC tests. Studies have shown that the action mechanisms of different types of applied voltages are quite different. Compared with power frequency voltage, the "transient" high field strength under impulse voltage excitation is more conducive to limiting the corona stabilization phenomenon, and is easy to stimulate latent defects to produce partial discharge or pre-breakdown discharge, promoting the generation and development of discharge. Therefore, the partial discharge test under impulse voltage is a more sensitive and strict assessment and diagnosis method. From the perspective of insulation diagnosis, partial discharge detection during impulse withstand voltage test can more effectively discover insulation defects such as abnormal electric field in power equipment, thereby better understanding the insulation status of power equipment. Therefore, studying the partial discharge characteristics of power equipment under impulse voltage and the effectiveness of this method are of great academic and engineering significance.

[0004] Through investigation, it is found that most of the impulse voltage generator devices currently made by various universities or sold on the market have some shortcomings. For example, the commonly used 1.2 / 50μs dual exponential impulse voltage generator is bulky, difficult to move, and complex to install. When used on site, it is difficult to adjust the wave due to the influence of the stray inductance of the loop, making it difficult to carry out the on-site lightning impulse withstand voltage test. Based on this, this paper introduces a design method for a microsecond pulse excitation voltage source with variable parameters. By using a controllable high-voltage half-bridge module to replace the traditional spark ball gap device to achieve automatic repetition frequency pulse voltage excitation output, it not only realizes the lightweight and miniaturization of the experimental device, but also effectively reduces the loop inductance. At the same time, the pulse voltage source designed by this method can easily replace the wavefront and wavetail resistors, making it more convenient to adjust the rise time and fall time of the output waveform. In addition, the frequency and duty cycle of the pulse voltage excitation output can be adjusted by adjusting the frequency and duty cycle of the output signal of the signal generator, thereby meeting the needs of various scenarios. In summary, this design not only helps the laboratory to conduct experiments related to pulse voltage excitation output and study the partial discharge characteristics of power equipment under impulse voltage, but also provides equipment support for insulation verification of power equipment such as medium-frequency transformers and special power supplies, which helps to more effectively discover insulation defects such as abnormal electric fields in power equipment, thereby better understanding the insulation status of power equipment. Summary of the invention

[0005] In view of the above-mentioned problems, the present invention is proposed.

[0006] Therefore, the technical problem solved by the present invention is that the generation of repetitive frequency pulse voltage can be realized by using a high-voltage solid-state switch instead of a ball gap. In addition, the frequency and duty cycle of the output pulse voltage can be adjusted by adjusting the drive signal, and different pulse waveforms can be generated by adjusting the circuit elements, which can meet the needs of various situations. In addition, compared with the traditional high-efficiency Marx circuit to generate impulse voltage, the pulse excitation voltage source has a simple structure, small size, light weight, and is easy to disassemble.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for designing a microsecond pulse excitation voltage source with variable parameters, comprising:

[0008] The impulse voltage generator circuit is used to generate double exponential impulse voltage and oscillating impulse voltage;

[0009] The controllable high-voltage half-bridge module is used to replace the traditional spark ball gap device to achieve automatic repetition frequency pulse voltage excitation output;

[0010] The rise time and fall time of the output double exponential impulse voltage can be adjusted by adjusting the wavefront resistance, discharge resistance and charging capacitor.

[0011] On the basis of the double exponential impulse voltage circuit, the output of the oscillating impulse voltage is realized by connecting an inductor in series between the wavefront resistor and the test piece. The wavefront time, half-peak time and oscillation frequency of the output oscillating impulse voltage can be adjusted by adjusting the values ​​of the resistor, capacitor and inductor.

[0012] As a preferred solution of the design method of the variable parameter microsecond pulse excitation voltage source described in the present invention, the impulse voltage generator circuit is charged in parallel through capacitors and then discharged in series.

[0013] As a preferred solution of the variable parameter microsecond pulse excitation voltage source design method described in the present invention, the AC voltage is rectified into DC power through a high-voltage silicon stack and converted into pulse excitation through a controllable high-voltage half-bridge module.

[0014] As a preferred solution of the variable parameter microsecond pulse excitation voltage source design method described in the present invention, the controllable high-voltage half-bridge module is powered by a 5V DC source, and a square wave control signal is input into the module through a signal generator to realize automatic repetition frequency pulse voltage excitation output.

[0015] As a preferred solution of the variable parameter microsecond pulse excitation voltage source design method of the present invention, wherein: the rise time refers to the time required for the pulse voltage to rise from 10% of the maximum value to 90% of the maximum value;

[0016] The fall time refers to the time required for the pulse voltage to fall from 90% of the maximum value to 90% of the maximum value.

[0017] As a preferred solution of the variable parameter microsecond pulse excitation voltage source design method described in the present invention, the rise time, fall time and target output waveform of the output voltage are adjusted by changing the parameters of the electrical components in the circuit.

[0018] As a preferred solution of the variable parameter microsecond pulse excitation voltage source design method described in the present invention, the frequency of the output voltage of the controllable high-voltage half-bridge module is changed by changing the frequency of the square wave signal output by the signal generator, thereby realizing automatic repetition frequency pulse voltage excitation output.

[0019] As a preferred solution of the variable parameter microsecond pulse excitation voltage source design method described in the present invention, the duty cycle of the output voltage of the controllable high-voltage half-bridge module is changed by changing the duty cycle of the square wave signal output by the signal generator to meet the needs of different scenarios.

[0020] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method for designing a microsecond pulse excitation voltage source with variable parameters as described above are implemented.

[0021] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the method for designing a microsecond pulse excitation voltage source with variable parameters as described above.

[0022] The beneficial effects of the present invention are as follows: the variable parameter microsecond pulse excitation voltage source design method provided by the present invention realizes automatic repetition frequency pulse voltage excitation output by adopting a controllable high-voltage half-bridge module to replace the traditional spark ball gap device; the rapid conversion of double exponential impulse excitation and oscillation impulse excitation can be realized by adjusting the distribution of circuit elements; the output voltage rise time and fall time can be adjusted by adjusting the parameters of the circuit elements; the frequency of the output voltage can be adjusted by adjusting the frequency of the input signal of the controllable high-voltage half-bridge module; the duty cycle of the output voltage can be adjusted by adjusting the duty cycle of the input signal of the controllable high-voltage half-bridge module.

[0023] Compared with the traditional impulse voltage generator using a spark ball gap device, the pulse excitation voltage source designed by this design method has the advantages of simple structure, small size, light weight, and easy disassembly of circuit components. It not only greatly reduces the loop stray inductance, but also is suitable for a variety of real-life scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0025] Figure 1 An overall flow chart of a method for designing a microsecond pulse excitation voltage source with variable parameters provided by an embodiment of the present invention.

[0026] Figure 2 A diagram showing the arrangement of electrical components of a method for designing a microsecond pulse excitation voltage source with variable parameters provided by an embodiment of the present invention.

[0027] Figure 3 A double exponential pulse voltage waveform diagram of a method for designing a microsecond pulse excitation voltage source with variable parameters provided by an embodiment of the present invention.

[0028] Figure 4 A physical circuit diagram of a microsecond oscillation pulse excitation voltage source with variable parameters, which is a design method for a microsecond pulse excitation voltage source with variable parameters provided by one embodiment of the present invention.

[0029] Figure 5An oscillation pulse voltage waveform diagram of a method for designing a microsecond pulse excitation voltage source with variable parameters provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] Example 1

[0033] Reference Figure 1-Figure 5 , as an embodiment of the present invention, provides a method for designing a microsecond pulse excitation voltage source with variable parameters, comprising:

[0034] The impulse voltage generator circuit is used to generate double exponential impulse voltage and oscillating impulse voltage;

[0035] The controllable high-voltage half-bridge module is used to replace the traditional spark ball gap device to achieve automatic repetition frequency pulse voltage excitation output;

[0036] The rise time and fall time of the output double exponential impulse voltage can be adjusted by adjusting the wavefront resistance, discharge resistance and charging capacitor.

[0037] On the basis of the double exponential impulse voltage circuit, the output of oscillating impulse voltage can be achieved by connecting an inductor in series between the wavefront resistor and the test piece. The wavefront time, half-peak time and oscillation frequency of the output oscillating impulse voltage can be adjusted by adjusting the values ​​of the resistor, capacitor and inductor.

[0038] The impulse voltage generator circuit preferably uses a high-efficiency Marx circuit, and the working principle can be summarized as "capacitors are charged in parallel and then discharged in series".

[0039] The traditional high-efficiency Marx circuit uses a ball gap trigger to generate pulses. This paper uses a high-voltage solid-state switch instead of a ball gap trigger.

[0040] The AC voltage is first rectified into DC through a high-voltage silicon stack, and then converted into pulse excitation through a controllable high-voltage half-bridge module.

[0041] The controllable high-voltage half-bridge module is powered by a 5V DC source. By inputting a square wave control signal into the module through a signal generator, an automatic repetition frequency pulse voltage excitation output can be achieved.

[0042] The rise time refers to the time required for the pulse voltage to rise from 10% of the maximum value to 90% of the maximum value. The fall time refers to the time required for the pulse voltage to fall from 90% of the maximum value to 90% of the maximum value.

[0043] Double exponential shock Figure 3 As shown, assuming that the test capacitance is 0.3nF, the main capacitance is 22nF, the wavefront resistance is 20kΩ, the rise time of the output double exponential impulse voltage is about 0.8μs, and the fall time is about 22μs.

[0044] Oscillating shock Figure 5 As shown, assuming that the test capacitance is 0.3nF, the main capacitance is 22nF, the wavefront resistance is 1kΩ, and a 1mH inductor is connected in series between the wavefront resistance and the test capacitance, the rise time of the output oscillation impulse voltage is about 0.3μs, the fall time is about 22μs, and the oscillation frequency is about 650kHz.

[0045] The method of the present invention can generate both double exponential shock and oscillatory shock.

[0046] The pulse excitation voltage source designed by this method can adjust the rise time, fall time and target output waveform of the output voltage by changing the parameters of the electrical components in the circuit.

[0047] The pulse voltage source designed by this method can change the frequency of the output voltage of the controllable high-voltage half-bridge module by changing the frequency of the square wave signal output by the signal generator, thereby realizing automatic repetition frequency pulse voltage excitation output.

[0048] The pulse voltage source designed by this method can change the duty cycle of the output voltage of the controllable high-voltage half-bridge module by changing the duty cycle of the square wave signal output by the signal generator to meet the needs of different scenarios.

[0049] The pulse excitation voltage source has a simple structure, a small size, a light weight and is easy to disassemble.

[0050] The traditional high-efficiency Marx circuit uses a ball gap trigger to generate a pulse waveform, so each time the ball gap is triggered, a waveform is output. The present invention uses a high-voltage solid-state switch to replace the ball gap, and controls the charging and discharging process of the capacitor in the circuit by controlling the on and off of the switch, thereby controlling the output waveform. When the high-voltage solid-state switch is working, a drive signal needs to be input to it, so adjusting the drive signal (i.e., the signal generator) can adjust the on and off speed of the switch, thereby controlling the output of the voltage waveform.

[0051] By adjusting the duty cycle of the driving signal, the on-off time of the solid-state switch is adjusted, and the charging and discharging process of the capacitor is controlled, and finally the duty cycle of the output signal is regulated.

[0052] Example 2

[0053] Reference Figure 2-Figure 5 , as an embodiment of the present invention, provides a method for designing a microsecond pulse excitation voltage source with variable parameters, comprising:

[0054] A controllable high-voltage half-bridge module is used to replace the traditional spark ball gap device. The driving signal input end of the high-voltage half-bridge module is connected to a DC voltage source and a signal generator. The output voltage of the DC voltage source is set to 5V, the output signal of the signal generator is a square wave signal, the bias voltage is set to 8V, and the frequency of the signal generator output signal and the frequency of the final pulse excitation source output voltage.

[0055] For electrical components, the charging capacitor is 22nF, the wavefront resistor is 20kΩ, the wave tail resistor is 500Ω, the filter capacitor is 0.5μF to filter out interference noise, and the protection resistor is 1kΩ to protect the circuit from overcurrent, etc. The arrangement of electrical components is as follows: Figure 2 As shown, the voltage input is the DC power after the AC power is rectified by the high-voltage silicon stack, and the voltage output is connected to the test product. Figure 3 This is the output voltage waveform of the double exponential pulse excitation under the design parameters. The rise time of the double exponential pulse excitation of this design is about 0.8μs, and the fall time is about 22μs.

[0056] Oscillating shock pulse excitation physical circuit such as Figure 5 As shown, a controllable high-voltage half-bridge module is used to replace the traditional spark ball gap device, and the driving signal input end of the high-voltage half-bridge module is connected to a DC voltage source and a signal generator. The output voltage of the DC voltage source is set to 5V, the output signal of the signal generator is a square wave signal, the bias voltage is set to 8V, and the frequency of the signal generator output signal and the frequency of the final pulse excitation source output voltage.

[0057] For electrical components, the charging capacitor is 22nF, the wavefront resistor is 1kΩ, the wavetail resistor is 500Ω, the filter capacitor is 0.5μF to filter out interference noise, and the protection resistor is 1kΩ to protect the circuit from overcurrent, etc. A 1mH inductor is directly connected in series between the wavefront resistor and the test piece to achieve oscillation pulse excitation output. The arrangement of electrical components is as follows: Figure 4 As shown, the voltage input is the DC power after the AC power is rectified by the high-voltage silicon stack, and the voltage output is connected to the test product. Figure 5is the output voltage of the oscillation shock pulse excitation under this design parameter. Under this parameter, the rise time of the oscillation shock pulse excitation is about 0.3μs, the fall time is about 22μs, and the oscillation frequency is about 650kHz.

[0058] In the process of building this pulse excitation voltage source circuit, it is necessary to explain:

[0059] When designing a pulse excitation voltage source to output the target waveform using this method, it is necessary to reasonably select the parameters of the electrical components in combination with the target waveform parameters. After determining the parameters of the electrical components, the circuit can be built according to the loop structure of this design method to achieve the output of the waveform. Before applying the voltage, first adjust the signal generator and the DC voltage source. After the adjustment is completed, it is input into the controllable high-voltage half-bridge module as a driving signal. When the controllable high-voltage half-bridge module shows normal operation, apply AC voltage through the voltage regulator.

[0060] When conducting the test, it is necessary to pay attention to the voltage regulation to be uniform and smooth, and the change of each voltage level should be small to ensure that the voltage regulation is in a stable working state. When conducting long-term high-power tests, it is necessary to dissipate heat from the controllable high-voltage half-bridge module to prevent the module from overheating and damage. During the test, the applied voltage cannot exceed the rated working voltage of the module to avoid damage to the module. After the test, first return the voltage regulator to zero, and then turn off the drive signal of the module. After powering off, pay attention to discharging the main capacitor and filter capacitor in the circuit to avoid electric shock.

[0061] Example 3

[0062] An embodiment of the present invention is different from the first two embodiments in that:

[0063] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0064] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0065] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0066] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0067] It should be noted that the above embodiments are only used to illustrate the technical solutions 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 the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for designing a microsecond pulse excitation voltage source with variable parameters, characterized in that: include: The impulse voltage generator circuit is used to generate double exponential impulse voltage and oscillating impulse voltage; The controllable high-voltage half-bridge module is used to replace the traditional spark ball gap device to achieve automatic repetition frequency pulse voltage excitation output; The rise time and fall time of the output double exponential impulse voltage can be adjusted by adjusting the wavefront resistance, discharge resistance and charging capacitor. On the basis of the double exponential impulse voltage circuit, the output of the oscillating impulse voltage is realized by connecting an inductor in series between the wavefront resistor and the test piece. The wavefront time, half-peak time and oscillation frequency of the output oscillating impulse voltage can be adjusted by adjusting the values ​​of the resistor, capacitor and inductor.

2. The method for designing a microsecond pulse excitation voltage source with variable parameters as claimed in claim 1, characterized in that: The impulse voltage generator loop is charged in parallel through a capacitor and then discharged in series.

3. The method for designing a microsecond pulse excitation voltage source with variable parameters as claimed in claim 2, characterized in that: The AC voltage is rectified into DC through a high-voltage silicon stack and converted into pulse excitation through a controllable high-voltage half-bridge module.

4. The method for designing a microsecond pulse excitation voltage source with variable parameters as claimed in claim 3, characterized in that: The controllable high-voltage half-bridge module is powered by a 5V DC source, and a square wave control signal is input into the module through a signal generator to realize automatic repetition frequency pulse voltage excitation output.

5. The method for designing a microsecond pulse excitation voltage source with variable parameters as claimed in claim 4, characterized in that: The rise time refers to the time required for the pulse voltage to rise from 10% of the maximum value to 90% of the maximum value; The fall time refers to the time required for the pulse voltage to fall from 90% of the maximum value to 90% of the maximum value.

6. The method for designing a microsecond pulse excitation voltage source with variable parameters as claimed in claim 5, characterized in that: The rise time, fall time and target output waveform of the output voltage are adjusted by changing the parameters of the electrical components in the circuit.

7. The method for designing a microsecond pulse excitation voltage source with variable parameters as claimed in claim 6, characterized in that: The frequency of the output voltage of the controllable high-voltage half-bridge module is changed by changing the frequency of the square wave signal output by the signal generator, thereby realizing automatic repetition frequency pulse voltage excitation output.

8. The method for designing a microsecond pulse excitation voltage source with variable parameters as claimed in claim 7, characterized in that: By changing the duty cycle of the square wave signal output by the signal generator, the duty cycle of the output voltage of the controllable high-voltage half-bridge module can be changed to meet the needs of different scenarios.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for designing a microsecond pulse excitation voltage source with variable parameters as claimed in any one of claims 1 to 8 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for designing a microsecond pulse excitation voltage source with variable parameters as claimed in any one of claims 1 to 8 are implemented.

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