A realization method of a high-voltage arbitrary waveform generator

Abstract

The application relates to the technical field of voltage generators, in particular to an implementation method of a high-voltage arbitrary waveform generator. A front-stage linear power amplification mode and a rear-stage IGBT series mode of a digital power amplifier are adopted to realize the amplification output of the arbitrary waveform high voltage. The test system composed of an upper computer, a signal generation system, a positive and negative signal transmission isolation module, a positive and negative signal amplification module, an IGBT series module and a positive and negative power supply module is constructed, so that the arbitrary voltage output can be realized; the high voltage is isolated from the control signal, so that the control signal is not disturbed; the front-stage and rear-stage amplification design ensures that the front stage guarantees the amplification output of the arbitrary waveform, the rear stage improves the amplification efficiency while considering the waveform output and the efficiency; the voltage amplification loop is uniformly distributed when the IGBT series amplification is guaranteed, so that the voltage resistance safety of the power tube is guaranteed; the positive and negative separation amplification mode is adopted, so that the zero point output abnormality during the positive and negative signal switching is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of voltage generator, in particular, to a realization method of high-voltage arbitrary waveform generator. BACKGROUND

[0002] DC voltage transformer is an important primary equipment in the construction and operation process of DC power transmission system, which provides accurate and reliable measurement information for DC control and protection system. Its operation reliability and measurement accuracy is directly related to the safe and stable operation of DC power transmission system. At present, China has mastered the core technology of design, test, debugging and production of complete sets of DC power transmission equipment, but the research on DC electronic transformer is relatively backward. Compared with DC power transmission equipment, the nationalization process of DC electronic is relatively slow, especially the domestic rate of DC voltage transformer is still relatively low, and the DC voltage divider is mainly the DC voltage divider of Sniwen Technology Co., Ltd. The secondary part has basically been domesticized in order to cooperate with the control and protection, which brings great trouble to the field test. In recent years, occasional system failures in various converter stations have caused the response time of DC voltage transformer to be too long, resulting in slow action of DC control and protection and causing accidents. And because there is a coupling channel between AC and DC in the commutation process of the converter, the DC voltage contains a large amount of high-frequency signal, so the frequency response test of the DC voltage transformer must be carried out in the field.

[0003] At present, the test method of DC voltage transformer mainly adopts closed-loop test mode, as shown in Figure 1 , a small voltage control signal is sent to control the arbitrary waveform high voltage generator by the DC electronic transformer tester, a test high voltage signal is sent, and the standard voltage divider adopts pure resistance voltage division to divide the high voltage into a small voltage signal that can be sampled by the tester. The DC electronic transformer tester collects the small voltage signal output by the standard voltage divider, and synchronously collects the digital signal output by the DC voltage transformer, and then completes the test of the DC voltage transformer.

[0004] The rated voltage of ultra-high voltage DC voltage transformer can reach 800kV voltage at present. According to the test specification, the high frequency and step response can reach 5% of the rated voltage, so an arbitrary waveform voltage generator with a maximum voltage of more than 40kV must be designed.

[0005] The existing voltage type power amplifier mainly has two implementation methods of analog and digital. However, the above methods still have some defects in the application process, such as: the linear power amplifier is subject to the voltage resistance level and efficiency problem of the MOS tube, it is difficult to make the voltage very high, and it is impossible to output higher voltage; the input signal of the digital power amplifier is a pulse modulation signal, and a specific waveform needs to be modulated according to the output waveform characteristics, and then the signal is filtered, so many waveforms cannot be output, and it is impossible to realize the effect of arbitrary waveform amplification according to the input signal. In view of this, an implementation method of a high-voltage arbitrary waveform generator is proposed. SUMMARY

[0006] The purpose of the present application is to provide an implementation method of a high-voltage arbitrary waveform generator to solve the problems in the background art.

[0007] In order to solve the above technical problems, the present application provides an implementation method of a high-voltage arbitrary waveform generator, which adopts a front and rear stage amplification mode, the front stage adopts a linear power amplification mode, and the rear stage adopts an IGBT series mode of a digital power amplifier to realize the amplification output of arbitrary waveform high voltage; the specific implementation method includes the following steps:

[0008] S1, a test system composed of an upper computer, a signal generation system, a positive and negative signal transmission isolation module, a positive and negative signal amplification module, an IGBT series module and a positive and negative power supply module is constructed;

[0009] S2, after the upper computer generates test voltage waveform data, the data is transmitted to the signal generation system;

[0010] S3, the signal generation system converts the digital signal into a small analog voltage signal as the input voltage of the power amplifier;

[0011] S4, the positive and negative signal transmission isolation module isolates the input small voltage signal and the output high voltage signal;

[0012] S5, the small voltage signal is amplified by two stages through the positive and negative signal amplification module;

[0013] S6, the highest voltage of the whole system is provided by the positive and negative power supply module, and finally the voltage signal amplified by step S5 drives the IGBT series module to output high voltage with energy.

[0014] As a further improvement of the technical solution, in the test system, the upper computer is programmed by C language, which is used to generate direct current voltage signal, high frequency voltage signal, step voltage signal and alternating current superimposed voltage signal, and can also import and replay the recorded wave data according to the on-site recorded wave data to realize the output of special waveforms under complex faults.

[0015] As a further improvement of the technical solution, in the test system, the signal generating system adopts a dual-CPU architecture of FPGA and PowerPC.

[0016] The PowerPC is used for being responsible for communication with the upper computer, generating new discrete digital signals for testing according to the upper computer, and sending the discrete digital signals to the FPGA after being packed.

[0017] The FPGA is used for controlling the DAC chip to convert the digital signals into small voltage analog signals.

[0018] As a further improvement of the technical solution, in the test system, the positive and negative signal transmission isolation module is used for realizing the isolation between the input small voltage signal and the output high voltage signal, adopts an optical device input end electro-optical conversion, an output end photoelectric conversion, an optical fiber transmission in the middle, and an operational amplifier added to the output end for signal amplification and certain driving capacity, so as to effectively realize the transmission isolation driving of the analog small voltage signal.

[0019] As a further improvement of the technical solution, in the test system, the positive and negative signal amplification module adopts a front-stage amplification mode, and adopts a linear power amplifier to realize the amplification and driving of the voltage signal by adjusting the input and output resistance values.

[0020] As a further improvement of the technical solution, in the test system, the IGBT series module adopts a rear-stage amplification mode, and adopts a multi-stage high-speed IGBT series mode composed of a plurality of IGBT series power tubes.

[0021] As a further improvement of the technical solution, in the test system, the positive and negative power module adopts a 220V alternating power input, rectifies the power to convert into 48V direct current, and realizes the positive and negative 60kV voltage direct current output through a high-frequency isolation amplification series mode.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] 1. In the implementation method of the high-voltage arbitrary waveform generator, the upper computer programming and the signal generating system are used to realize the control generation of the signal source, so as to realize the function of arbitrary voltage output.

[0024] 2. In the implementation method of the high-voltage arbitrary waveform generator, the optical isolation and optical fiber transmission analog voltage are used to realize the isolation of the high voltage and the control signal, so as to ensure that the control signal is not disturbed.

[0025] 3. The implementation method of the high-voltage arbitrary waveform generator adopts two-stage amplification design, the front stage adopts a linear power amplifier to ensure the amplification output of the arbitrary waveform, and the rear stage adopts an IGBT series module of a digital power amplifier to improve the amplification efficiency of the power tube while considering the waveform output and efficiency;

[0026] 4. In the implementation method of the high-voltage arbitrary waveform generator, a resistance-capacitance parallel voltage divider is adopted to ensure that the voltage amplification loop during IGBT series amplification can be evenly distributed, thereby ensuring the voltage withstand safety of the power tube;

[0027] 5. In the implementation method of the high-voltage arbitrary waveform generator, a positive and negative separation amplification mode is adopted to separate the positive and negative signals from the signal source end, thereby avoiding abnormal zero output during positive and negative signal switching. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A DC voltage transformer closed-loop test circuit diagram is shown in the present application;

[0029] Figure 2 A linear power amplifier structure schematic diagram is shown in the present application;

[0030] Figure 3 A digital power amplifier structure schematic diagram is shown in the present application;

[0031] Figure 4 A principle architecture diagram of the arbitrary waveform high-voltage generator is shown in the present application;

[0032] Figure 5 A signal generation system structure schematic diagram is shown in the present application;

[0033] Figure 6 A transmission isolation driving principle architecture diagram is shown in the present application;

[0034] Figure 7 A principle architecture diagram of IGBT series is shown in the present application. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0036] Embodiment 1

[0037] As Figures 1-7As shown, the embodiment provides a realization method of high-voltage arbitrary waveform generator, adopts front and rear stage amplification mode, the front stage adopts linear power amplification mode, the rear stage adopts IGBT series mode of digital power amplifier to realize the amplification output of arbitrary waveform high voltage together; the specific realization method includes the following steps:

[0038] S1, a test system composed of an upper computer (i.e. a test host), a signal generating system, a positive and negative signal transmission isolation module, a positive and negative signal amplification module, an IGBT series module and a positive and negative power supply module is constructed;

[0039] S2, after the upper computer generates test voltage waveform data, the data is transmitted to the signal generating system;

[0040] S3, the signal generating system converts the digital signal into a small analog voltage signal as the input voltage of the power amplifier;

[0041] S4, the positive and negative signal transmission isolation module isolates the input small voltage signal and the output high voltage signal;

[0042] S5, the small voltage signal is amplified by two stages through the positive and negative signal amplification module;

[0043] S6, the positive and negative power supply module provides the highest voltage of the entire system, and finally the voltage signal amplified by step S5 drives the IGBT series module to output high voltage with energy.

[0044] First, the existing voltage type power amplifier mainly has two kinds of realization methods of analog and digital.

[0045] Among them, the analog voltage type power amplifier is also called linear power amplifier, such as Figure 2 is a schematic diagram of linear power amplifier structure, mainly using the resistance at both ends of the operational amplifier to form a voltage proportional relationship U o / U i = R2 / R1, and P-type and N-type MOS tubes are used on the positive and negative electrodes to realize the conduction isolation of high voltage.

[0046] Further, the switching tube of the digital voltage type power amplifier works in saturation region and cutoff region, and its basic principle is as follows Figure 3As shown. Given the analog signal as a modulated signal, and the carrier signal after comparison, get SPWM pulse signal, to drive power switch device, output pulse power signal, and then use low-pass filter to filter high frequency components, get amplified output voltage. Digital power amplifier in the amplification process, the input analog signal through modulation into digital signal, has good anti-interference ability, will not appear crossover distortion and phase distortion and other phenomena, waveform distortion degree is low. Because the power device is always in the switch state, the loss is mainly the switching loss, so theoretically the efficiency of digital power amplifier can reach more than 80%, much higher than the linear power amplifier.

[0047] In summary, the pure linear power amplifier or digital voltage type power amplifier can not be very good to achieve the effect of arbitrary waveform amplification.

[0048] In this embodiment, in order to realize the purpose of DC voltage transformer test, the arbitrary waveform amplifier of the embodiment adopts the front and rear stage amplification mode, the front stage adopts the linear power amplification mode, and the rear stage adopts the IGBT series mode of the digital power amplifier to realize the amplification output of the peak value of 50kV of the arbitrary waveform; The two-stage amplification design is adopted, the linear power amplifier is used in the front stage to ensure the amplification output of the arbitrary waveform, and the IGBT series module of the digital power amplifier is used in the rear stage to improve the amplification efficiency of the power tube while considering the waveform output and efficiency.

[0049] Among them, the host computer is responsible for generating test voltage waveform data and transmitting the data to the signal generating system, the signal generating system converts the digital signal into small analog voltage signal as the input voltage of the power amplifier, the positive and negative signal amplification module drives the IGBT series power tube to output high voltage with energy after two-stage amplification, and the positive and negative power module is responsible for providing the highest voltage of the whole system.

[0050] As shown in Figure 4 The specific principle of the arbitrary waveform high voltage generator is as follows:

[0051] Firstly, the host computer generates test voltage waveform data and transmits the data to the signal generating system; wherein, the host computer programming and the signal generating system realize the control generation of the signal source, which can realize the function of arbitrary voltage output;

[0052] Secondly, the signal generating system converts the digital signal into small analog voltage signal as the input voltage U i of the power amplifier;

[0053] Then, the positive signal transmission isolation module realizes the isolation between the input small voltage positive signal and the output high voltage positive signal, and the small voltage positive signal is amplified by two stages through the positive signal amplification module, at the same time, the negative signal transmission isolation module realizes the isolation between the input small voltage negative signal and the output high voltage negative signal, and the small voltage negative signal is amplified by two stages through the negative signal amplification module; and then the positive and negative voltage signals amplified by two stages are respectively input into different IGBT series power tubes in series in the IGBT series module; the positive and negative separation amplification mode is adopted, the positive and negative signals are separated from the signal source end, and the abnormal zero point output when the positive and negative signals are switched is avoided;

[0054] At this time, the positive power module and the negative power module are also respectively connected to different IGBT series power tubes in series in the IGBT series module, so as to improve the highest voltage of the system, and finally the IGBT series module outputs high voltage U o .

[0055] In the test system, the host computer is programmed by using C language, and can generate direct current voltage signals, high frequency voltage signals, step voltage signals and alternating current superimposed voltage signals, and can also play back after wave recording data is recorded and imported according to the scene to realize special waveform output under complex fault, finally satisfying any waveform required by direct current voltage transformer test.

[0056] Further, the signal generating system adopts a dual-CPU architecture of FPGA and PowerPC.

[0057] The PowerPC is used for communicating with the host computer, generating new discrete digital signals for testing according to the host computer, and sending the discrete digital signals to the FPGA after being packaged.

[0058] The FPGA is used for converting the digital signals into small voltage analog signals by the DAC chip.

[0059] As Figure 5 The signal generating system structure diagram is shown in the figure. The FPGA processor preferably adopts Xilinx's Spartan3 series product XC3S1500, which contains 1.5 million system gates, 32 special multipliers, 4 digital clock management modules, rich logic resources and fast running speed. The FPGA utilizes precise timing control capability to complete the control of the DAC, and can also complete signal back sampling, high-speed serial data reception and switch value reception according to the test requirements.

[0060] At the same time, the digital-to-analog converter applied in the signal generating system is preferably ADI's AD5683R, which is a 16-bit single-channel converter with a relative accuracy of ±2LSB INL, a built-in 2ppm / ℃ 2.5V reference voltage source; At the same time, it adopts the space-saving 2mmx2mm 8-pin LFCSP and 10-pin MSOP package, which can realize more functions in smaller circuit board space; 2mV total non-adjustment error, no initial calibration or adjustment; 4kV HBM ESD rating, realizing system robustness.

[0061] Further, as Figure 6 The transmission isolation driving principle architecture diagram, since the highest output voltage of the system design is up to 60kV, the input signal is a small voltage signal of 10V or less, in order to realize the isolation between the input small voltage signal and the output high voltage signal, the positive and negative signal transmission isolation module adopts optical input end electro-optical conversion, the output end is optoelectronic converted, the middle adopts optical fiber transmission, and the output rear end is added with an operational amplifier to amplify the signal and has a certain driving ability, effectively realizing the transmission isolation driving of the analog small voltage signal. Among them, the optical isolation, optical fiber transmission analog voltage realizes the isolation of high voltage and control signal, which can ensure that the control signal is not disturbed.

[0062] Further, the positive and negative signal amplification module is a pre-stage amplification mode, which adopts a linear power amplifier to realize the amplification and driving of the voltage signal by adjusting the input and output resistance values, and the signal is amplified to a maximum of 300V.

[0063] Further, the IGBT series module is a post-stage amplification mode, which adopts a multi-stage high-speed IGBT series mode composed of a plurality of IGBT series power tubes.

[0064] Among them, since the maximum output voltage is 60kV peak value, the commonly used 1200V voltage tube is selected, and since the system is designed for IGBT to work in the amplification area, the actual single-sided 200 series mode is adopted, and the parallel resistance and capacitance of each IGBT are compatible with AC and DC voltage to make the voltage evenly distributed in each IGBT single tube, the single voltage drop is 300V, and the dissipation power is 75W, which can be cooled by a heat sink.

[0065] Further, the power amplification preferably adopts NPT type IGBT, which has the characteristics of high saturation voltage drop, short turn-off time, small temperature influence, strong short-circuit current resistance and strong avalanche breakdown resistance, especially suitable for saturation voltage drop index of series-parallel mode without forced pairing; suitable for multi-stage series of the power supply; at the same time, the system preferably adopts infineon fast IGBT SGP02N120, which has a withstand voltage of 1200V, a current of 2A, and a typical value of turn-on delay time of 20nS. As Figure 7The principle architecture diagram of the IGBT series connection, the voltage amplification loop of the IGBT series connection amplification can be evenly distributed by using the resistance-capacitance parallel voltage division, so as to ensure the voltage withstand safety of the power tube.

[0066] Further, the positive and negative power modules adopt 220V AC power input, rectify the power to 48V DC, and then realize the positive and negative 60kV voltage DC output through the high-frequency isolation amplification series connection mode.

[0067] Those skilled in the art can understand that the process of implementing all or part of the steps of the above-mentioned embodiments can be completed by hardware, or by program to instruct relevant hardware, and the program can be stored in a computer readable storage medium, and the above-mentioned storage medium can be a read-only memory, a magnetic disk or an optical disk, etc.

[0068] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only preferred examples of the present application, and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A method of implementing a high voltage arbitrary waveform generator, characterized by: Adopting front and rear stage amplification mode, the front stage adopts linear power amplification mode, and the rear stage adopts IGBT series mode of digital power amplifier to realize amplification output of arbitrary waveform high voltage; the specific implementation method comprises the following steps: S1, a test system composed of an upper computer, a signal generation system, a positive and negative signal transmission isolation module, a positive and negative signal amplification module, an IGBT series module and a positive and negative power module is constructed; S2, after the upper computer generates test voltage waveform data, the data is transmitted to the signal generation system; S3, the signal generation system converts the digital signal into a small analog voltage signal as the input voltage of the power amplifier; S4, the positive and negative signal transmission isolation module isolates the input small analog voltage signal from the output high voltage signal; S5, the small analog voltage signal is amplified through the positive and negative signal amplification module; S6, the positive and negative power module provides the highest voltage of the entire system, and finally the voltage signal amplified in step S5 drives the IGBT series module to output high voltage with energy.

2. The method of implementing a high voltage arbitrary waveform generator according to claim 1, wherein: In the test system, the upper computer is programmed in C language to generate DC voltage signals, high-frequency voltage signals, step voltage signals and AC superimposed voltage signals, and can also import and replay recorded wave data according to field recorded wave data.

3. The method of claim 1, wherein: In the test system, the signal generation system adopts a dual-CPU architecture of FPGA and PowerPC; Among them, the PowerPC is responsible for communication with the upper computer, and generates new discrete digital signals for testing according to the upper computer configuration, and sends the discrete digital signals to the FPGA; The FPGA is used to control the DAC chip to convert the digital signal into a small voltage analog signal.

4. The method of claim 1, wherein: In the test system, the positive and negative signal transmission isolation module is used to realize the isolation between the input small voltage signal and the output high voltage signal, which adopts optical input end electro-optical conversion, optical output end photoelectric conversion, optical fiber transmission in the middle, and an operational amplifier at the output end to amplify the signal while having certain driving ability, for realizing transmission isolation and driving of the small voltage analog signal.

5. The method of claim 1, wherein: In the test system, the positive and negative signal amplification module is a front stage amplification mode, which adopts a linear power amplifier to realize voltage signal amplification and driving by adjusting input and output resistance values.

6. The method of implementing a high voltage arbitrary waveform generator of claim 1, wherein: In the test system, the IGBT series module is a rear stage amplification mode, which adopts a multi-stage high-speed IGBT series mode composed of a plurality of IGBT series power tubes.

7. The method of claim 1, wherein: In the test system, the positive and negative power module adopts 220V AC power input, rectifies the power to 48V DC, and realizes positive and negative 60kV voltage DC output through high-frequency isolation amplification series mode.

Images