阅读说明：本技术 开关型正弦波形输出的局部放电测量试验用变频调压电源 (Frequency conversion voltage regulation power supply for partial discharge measurement test of switch type sine waveform output ) 是由 刘晓庄 张文忠 仇永军 戴大春 于 2021-09-01 设计创作，主要内容包括：本发明提供开关型正弦波形输出的局部放电测量试验用变频调压电源,涉及高压电气试验设备领域。该开关型正弦波形输出的局部放电测量试验用变频调压电源,包括SPWM变频调压电源和控制-显示-测量-保护单元,所述SPWM变频调压电源的输入端连接有输入EMC滤波单元,所述SPWM变频调压电源的输出端连接有输出EMC滤波单元,所述输出EMC滤波单元的输出端连接有隔离滤波单元,所述隔离滤波单元的输出端连接有低通滤波单元,所述低通滤波单元的输出端连接有输出测量单元。通过采取多种局放抑制装置和技术措施,以及多种元件的搭配,能够有效控制系统输出的局放水平,实现数字化数据传输,提高系统抗干扰能力,并有效保证系统测量准确度。(The invention provides a variable-frequency voltage-regulating power supply for a partial discharge measurement test of switch type sine waveform output, and relates to the field of high-voltage electrical test equipment. This frequency conversion voltage regulation power for partial discharge measurement test of switch type sinusoidal waveform output, including SPWM frequency conversion voltage regulation power and control-show-measure-protection unit, SPWM frequency conversion voltage regulation power's input is connected with input EMC filtering unit, SPWM frequency conversion voltage regulation power's output is connected with output EMC filtering unit, output EMC filtering unit's output is connected with isolation filtering unit, isolation filtering unit's output is connected with low pass filtering unit, low pass filtering unit's output is connected with output measurement element. By adopting various partial discharge suppression devices and technical measures and matching of various elements, the partial discharge level output by the system can be effectively controlled, digital data transmission is realized, the anti-interference capability of the system is improved, and the measurement accuracy of the system is effectively ensured.)

1. The frequency conversion and voltage regulation power supply for the partial discharge measurement test of the switch type sine waveform output comprises an SPWM frequency conversion and voltage regulation power supply (1) and a control-display-measurement-protection unit (7), and is characterized in that: the input of SPWM variable frequency voltage regulation power (1) is connected with input EMC filtering unit (2), the output of SPWM variable frequency voltage regulation power (1) is connected with output EMC filtering unit (3), the output of output EMC filtering unit (3) is connected with isolation filtering unit (4), the output of isolation filtering unit (4) is connected with low pass filtering unit (5), the output of low pass filtering unit (5) is connected with output measuring unit (6), control-show-measure-protection unit (7) is including controller (10), touch screen display panel (9) and radio communication ware (8), controller (10) electric connection has communication serial ports (11).

2. The variable frequency voltage-regulating power supply for the switch type sine wave output partial discharge measurement test according to claim 1, characterized in that: the control-display-measurement-protection unit (7) is respectively connected with an SPWM variable-frequency voltage-regulating power supply (1), an isolation filtering unit (4), a low-pass filtering unit (5) and an output measuring unit (6) through transmission control lines.

3. The variable frequency voltage-regulating power supply for the switch type sine wave output partial discharge measurement test according to claim 1, characterized in that: the controller (10) is electrically connected with a touch screen display board (9) and a radio communicator (8) respectively.

4. The variable frequency voltage-regulating power supply for the switch type sine wave output partial discharge measurement test according to claim 1, characterized in that: the output measuring unit (6) comprises a voltmeter (12), an ammeter (13) and an automatic power phase measuring instrument (14).

5. The variable frequency voltage-regulating power supply for the switch type sine wave output partial discharge measurement test according to claim 1, characterized in that: the controller (10) can be a microcomputer, and a memory is arranged in the controller (10).

6. The variable frequency voltage-regulating power supply for the switch type sine wave output partial discharge measurement test according to claim 1, characterized in that: the output form of the SPWM variable-frequency voltage-regulating power supply (1) can be three-phase and single-phase, and can also be both three-phase and single-phase output.

7. The variable frequency voltage-regulating power supply for the switch type sine wave output partial discharge measurement test according to claim 1, characterized in that: the low-pass filtering unit (5) is a multi-order LC filter.

8. The variable frequency voltage-regulating power supply for the switch type sine wave output partial discharge measurement test according to claim 1, characterized in that: the SPWM variable-frequency voltage-regulating power supply (1), the input EMC filtering unit (2), the output EMC filtering unit (3), the isolation filtering unit (4), the low-pass filtering unit (5), the output measuring unit (6) and the control-display-measurement-protection unit (7) are all provided with grounding devices.

Technical Field

The invention relates to the technical field of high-voltage electrical test equipment, in particular to a variable-frequency voltage-regulating power supply for a partial discharge measurement test of switch type sine waveform output.

Background

At present, when high voltage electrical equipment such as transformers and the like in the field of electrical engineering and the like are used for partial discharge measurement and induction voltage withstand test, a power supply device in the used test equipment mainly adopts a linear power amplification type variable frequency voltage regulating power supply. The variable frequency power supply has the advantages of good output waveform and low partial discharge, and has a plurality of defects.

The internal inverter of the power supply is a triode (transistor) and works in a linear power amplification state. The commercially available triodes which are purchased in batches are only available, the available equivalent inversion power is generally only dozens of watts, the maximum equivalent inversion power is usually difficult to exceed one hundred watts, and the power is relatively low. In order to meet the power requirement of hundreds of kilowatts or even nearly thousands of kilowatts which are frequently used in the test, thousands or even tens of thousands of triodes are used in parallel. Due to the fact that the number of the used devices is large, parameter dispersion and individual difference exist, the power supply is poor in working reliability and weak in impact resistance. In actual use, the phenomenon of triode damage appears occasionally, which causes the forced interruption of the test, needs to wait for equipment repair, or provides a standby machine for use to continue the test, and possibly causes the delay of the test period of a user. Users often complain that the equipment is unreliable and not stable in operation. Meanwhile, in order to balance the power of the device, a current-sharing resistor is connected in series with the collector of each triode of the variable frequency power supply, and the resistor flows through working current, so that the overall heat productivity of the system is huge and the efficiency is low during operation. Under the condition of good design and control, the highest efficiency of the system is only about 65%, and huge electric energy is wasted in self heating; in order to reduce the temperature, a large electric power needs to be additionally provided for the heat dissipation fan, and the noise pollution of the heat dissipation fan is often unacceptable on site. Moreover, the reactive load capability of the variable frequency power supply is weak, and if the variable frequency power supply is forcibly provided with a reactive load, the output efficiency is reduced, the waveform distortion and the partial discharge are obviously increased, and even the equipment is damaged. In addition, the power supply is complex in production process, thousands of transistors need to be welded manually, labor is intensive, intensity is high, mechanical production degree is low, and welding quality is not easy to guarantee. There is a need for new and improved embodiments that can replace such power supplies.

Therefore, aiming at the defects of using more linear power amplification type variable frequency power supplies in the measurement of partial discharge quantity of current high-voltage electrical equipment such as a transformer and the like and an induction withstand voltage test, the high-capacity variable frequency voltage regulating power supply device which is realized by adopting a high-power electronic device and works in a switching state, has sine waveform low partial discharge output and has high reliability is provided.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a variable-frequency voltage-regulating power supply for a partial discharge measurement test of switch type sine waveform output, and solves the problems of the defects of a linear power amplification type variable-frequency power supply.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme: the utility model provides a partial discharge of switch type sinusoidal waveform output is frequency conversion voltage regulation power for measurement test, including SPWM frequency conversion voltage regulation power and control-demonstration-measure-protection unit, SPWM frequency conversion voltage regulation power's input is connected with input EMC filtering unit, SPWM frequency conversion voltage regulation power's output is connected with output EMC filtering unit, output EMC filtering unit's output is connected with isolation filtering unit, isolation filtering unit's output is connected with low pass filtering unit, low pass filtering unit's output is connected with the output measurement unit, control-show-measure-protection unit includes controller, touch screen display panel and radio communication ware, controller electric connection has the communication serial ports.

Preferably, the control-display-measurement-protection unit is respectively connected with the SPWM variable-frequency voltage-regulating power supply, the isolation filtering unit, the low-pass filtering unit and the output measuring unit through a transmission control line.

Preferably, the controller is electrically connected to the touch screen display panel and the radio communicator, respectively.

Preferably, the output measuring unit comprises a voltmeter, an ammeter and an automatic power phase measuring instrument.

Preferably, the controller may be a microcomputer, and a memory is provided in the controller.

Preferably, the output form of the SPWM variable-frequency voltage-regulating power supply can be three-phase or single-phase, and can also be both three-phase and single-phase output.

Preferably, the low-pass filter unit is a multi-order LC filter.

Preferably, the SPWM variable-frequency voltage-regulating power supply, the input EMC filtering unit, the output EMC filtering unit, the isolation filtering unit, the low-pass filtering unit, the output measuring unit and the control-display-measurement-protection unit are all provided with grounding devices.

The working principle is as follows: the input end of the SPWM variable frequency voltage-regulating power supply is connected with an input EMC filtering unit, the output end of the SPWM variable frequency voltage-regulating power supply is connected with an output EMC filtering unit for ensuring the electromagnetic compatibility of the system and reducing the interference to an input power supply system, so that the device meets the EMC related standard requirements, simultaneously is favorable for improving the waveform quality of the output of the device and reducing the local discharge amount of an output voltage signal, the output end of the output filtering unit is connected with an isolation filtering unit for isolating and filtering, improving the waveform quality of the output and reducing the output local discharge amount, the output end of the isolation filtering unit is connected with a multi-stage LC low-pass filtering unit, the multi-stage LC low-pass filtering unit and the isolation filtering unit are used for improving the waveform and reducing the local discharge amount of the device, then the output end of the low-pass filtering unit is connected with an output measuring unit for outputting electrical parameters of the measuring device, the SPWM variable-frequency voltage-regulating power supply, the isolation filtering unit, the low-pass filtering unit and the output measuring unit are all controlled by the control-display-measurement-protection unit in a centralized manner, state, data and information display, storage and man-machine interaction are carried out, digital data transmission can be realized, the anti-interference capability is improved, and the measuring accuracy is effectively ensured.

(III) advantageous effects

The invention provides a variable-frequency voltage-regulating power supply for a partial discharge measurement test of switch type sine waveform output. The method has the following beneficial effects:

1. according to the invention, through the mutual cooperation of the SPWM variable-frequency voltage-regulating power supply, the input EMC filtering unit, the output EMC filtering unit, the isolation filtering unit, the low-pass filtering unit and the output measuring unit, a high-capacity variable-frequency voltage-regulating power supply device which adopts a high-power electronic device and works in a switching state, a sine-wave-shaped low partial discharge output and high reliability can be used in a partial discharge measurement and induction voltage withstand test of high-voltage electrical equipment and the like, and meanwhile, the control of the SPWM variable-frequency voltage-regulating power supply, the isolation filtering unit, the low-pass filtering unit and the output measuring unit is centralized through the control-display-measurement-protection unit, so that the states, data and information display, processing, storage and man-machine interaction are carried out, the digital data transmission can be realized, the anti-jamming capability is improved, and the measuring accuracy is effectively ensured.

2. The high-quality low partial discharge sine waveform voltage output is realized by comprehensively applying measures such as isolation, filtering, grounding, shielding, carrier control and the like based on a mature SPMW frequency conversion technology adopting a high-power electronic device, so that the engineering application requirements of partial discharge measurement and induction withstand voltage test of high-voltage electrical equipment such as a transformer can be met. The power supply device has the advantages of mature and stable system, strong impact resistance, high efficiency, strong load including reactive power capability and reliable operation, and overcomes the defects of low efficiency, easy damage, poor reliability and the like of the traditional linear power amplification type variable frequency power supply for partial discharge tests.

3. According to the invention, through the arrangement and application of the SPWM variable-frequency voltage-regulating power supply, the isolation filtering unit and the low-pass filtering unit, the reactive load capacity of the complete device is extremely strong, which is incomparable with the traditional power amplifier type linear power supply and has outstanding advantages. The output carrier frequency design of SPWM variable frequency voltage regulating power supply is adjustable, helps improving the final waveform quality of output of integrated equipment, and core component SPWM variable frequency voltage regulating power supply, the technology is mature, uses extensively, and the stable performance has decided that integrated equipment has high reliability, the stable characteristics of operation, and the practicality is strong, and like product has a great deal of advantage and fills up its not enough relatively tradition, can effectively replace, has wide market space, is worth widelys popularization.

Drawings

FIG. 1 is a block diagram of the system of the present invention;

FIG. 2 is a system block diagram of a control-display-measurement-protection unit of the present invention;

FIG. 3 is a system block diagram of an output measurement unit of the present invention

FIG. 4 is a waveform diagram of the SPWM inversion principle of the SPWM variable frequency voltage-regulating power supply of the present invention;

FIG. 5 is an actual measurement waveform diagram of the SPWM inversion output of the SPWM variable frequency voltage-regulating power supply of the present invention;

fig. 6 is a waveform diagram of the filtered output of the output EMC filtering unit according to the present invention.

Wherein, 1, SPWM frequency conversion voltage regulation power supply; 2. inputting an EMC filtering unit; 3. an output EMC filter unit; 4. an isolation filtering unit; 5. a low-pass filtering unit; 6. an output measurement unit; 7. a control-display-measurement-protection unit; 8. a radio communicator; 9. a touch screen display panel; 10. a controller; 11. a communication serial port; 12. a voltmeter; 13. an ammeter; 14. automatic power phase measuring instrument.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example (b):

as shown in fig. 1-6, the embodiment of the present invention provides a variable frequency voltage-regulating power supply for a partial discharge measurement test of switch type sinusoidal waveform output, which includes an SPWM variable frequency voltage-regulating power supply 1 and a control-display-measurement-protection unit 7, the SPWM variable frequency voltage-regulating power supply 1 is used for realizing frequency conversion and voltage regulation of system output, adopts an SPWM (sinusoidal pulse width modulation) inversion technique with mature technology and application, uses a large capacity integrated power module as an inversion device of a core, has strong impact resistance, is a SPWM inversion principle waveform schematic diagram as shown in fig. 4, the SPWM inversion output is a sinusoidal pulse width modulation wave, an actually measured waveform is shown in fig. 5, is a non-sinusoidal wave, has large self partial discharge amount and cannot be directly output for a test, an input end of the SPWM variable frequency voltage-regulating power supply 1 is connected with an input EMC filtering unit 2, an output end of the SPWM variable frequency voltage-regulating power supply 1 is connected with an output EMC filtering unit 3, the output end of the output EMC filtering unit 3 is connected with an isolation filtering unit 4 for isolation, filtering and improving the quality of output waveforms. According to the SPWM principle, the output waveform has high fundamental wave content and less low-order harmonic content, so that the sine wave type output can be realized through filtering. The input EMC filter unit 2 and the output EMC filter unit 3 also contribute to improving the quality of the output waveform. By adopting a filter with a pertinence design and combining the comprehensive application of various technical measures such as isolation, grounding, shielding, carrier control and the like, more ideal sine wave voltage output can be obtained, and the actually measured waveform is shown in fig. 6. Particularly, the output waveform apparent partial discharge amount can be controlled at a quite low level, the actual measurement can be as low as 20-10 pC, and the engineering application requirements can be completely met, the output end of the isolation filter unit 4 is connected with a multi-order LC low-pass filter unit 5, the multi-order LC low-pass filter unit 5 and the isolation filter unit 4 are used for filtering and improving the waveform and reducing the partial discharge amount of the device, then the output end of the low-pass filter unit 5 is connected with an output measurement unit 6 for outputting, the output measurement unit 6 is used for measuring the electrical parameters output by the device, including voltage, current, phase angle, capacity and the like, for large current and high voltage, the control-display-measurement-protection unit 7 comprises a controller 10, a touch screen display panel 9 and a radio communicator 8 after conversion, and the controller 10 is electrically connected with a communication serial port 11, wherein the SPWM variable frequency voltage regulation power supply 1, The isolation filtering unit 4, the low-pass filtering unit 5 and the output measuring unit 6 are all controlled by the control-display-measurement-protection unit 7 in a centralized manner, and state, data and information display, processing, storage and man-machine interaction are carried out, so that digital data transmission can be realized, the anti-interference capability is improved, and the measuring accuracy is effectively ensured.

The control-display-measurement-protection unit 7 is respectively connected with an SPWM variable-frequency voltage-regulating power supply 1, an isolation filter unit 4, a low-pass filter unit 5 and an output measurement unit 6 through a transmission control line, the core component of the isolation filter unit 4 is an isolation transformer, and the electrical isolation of the primary side and the secondary side is realized by using magnetic coupling, so that the secondary side output and a circuit connected behind the secondary side output can be grounded at one point for fixing the potential; meanwhile, the filter is realized by matching with an alternating current filter capacitor and assisting with an inductor when necessary, and the quality of an output waveform is improved. If necessary, the filter devices (capacitors, inductors) are preferably designed to be selectively switched. In addition, the capacity and type (such as phase number) of the isolated transformer can be determined according to the output requirement of the device; moreover, the transformer realizes impedance matching by configuring a proper transformation ratio, so that the output voltage and power of the complete set of equipment meet the specific use requirements of the complete set of equipment.

The controller 10 is electrically connected to the touch screen display panel 9 and the radio communicator 8, respectively.

The output measuring unit 6 comprises a voltmeter 12, an ammeter 13 and an automatic power phase measuring instrument 14.

The controller 10 may be a microcomputer or a server for controlling the received signals, and a memory is disposed in the controller 10 and used for storing data such as the result received and processed by the controller 10.

The output form of the SPWM variable-frequency voltage-regulating power supply 1 can be three-phase and single-phase, and can also be three-phase and single-phase output, namely, a three-phase output device can be used for single-phase output (using two output lines), which determines which inverse deformation form is adopted inside the SPWM variable-frequency voltage-regulating power supply 1, and uses corresponding auxiliary circuits and inversion devices in a matched manner, and correspondingly sets different protection forms. And a filter of a corresponding type is selected, a mature SPWM technology is adopted in the design of the SPWM variable-frequency voltage-regulating power supply 1, a core inverter device is adopted, and a high-power switch type power electronic Integration Power Module (IPM) with single body capacity of tens of even hundreds of kilowatts is adopted, and the module is commonly used but not limited to an IGBT module. Because the module device has large capacity, high insulation level and large rated current, the module device has strong working current impact resistance and stable and reliable performance. The inverter circuit is designed to work in a switching state, SPWM signals can be generated by means of CPU running software calculation, natural sampling and the like, and the SPWM signals are driven by the driving circuit. The inversion device is of a field control type, so that the driving current is small, the working switching frequency is high, the system loss is small, the efficiency can reach more than 90% -95%, the efficiency of linear power amplification type inversion formed by a far-exceeding triode parallel network is high, the SPWM inversion directly outputs a width-modulated square wave pulse sequence with symmetric positive and negative half cycles, the pulse sequence is non-sinusoidal wave, the partial discharge is large, and the pulse sequence cannot be directly used for tests. But the fundamental wave content is high, sinusoidal waveform output can be realized through a subsequent filtering unit, and the partial discharge of the sinusoidal waveform is controlled at a lower level by matching with other technical measures, so that the related test requirements are met.

The low-pass filter unit 5 is a multi-order LC filter for filtering, improving the quality of output waveforms and reducing the amount of amplification, and may be in a T-type or Π -type configuration. The main components of the filter are an inductor, a capacitor and a resistor, parameter design and order matching are required to be performed in a targeted manner, and harmonic waves of a specific frequency band can be effectively filtered, so that the waveform quality and the release quantity output by the filter are ensured. If necessary, the multi-stage LC filter unit device needs to be designed into a selective switching mode and operated by the control-display-measurement-protection unit 7 so as to adapt to the output requirements of different parameters.

The SPWM variable frequency voltage-regulating power supply 1, the input EMC filtering unit 2, the output EMC filtering unit 3, the isolation filtering unit 4, the low-pass filtering unit 5, the output measuring unit 6 and the control-display-measurement-protection unit 7 are all provided with grounding devices. The specifications of the input EMC filtering unit 2 and the output EMC filtering unit 3 specifically adopted EMC filters can be determined according to the specifications and the types of the SPWM variable-frequency voltage-regulating power supply 1, and the components can be purchased from the market. In addition, the functional circuits or the whole of the input EMC filtering unit 2 and the output EMC filtering unit 3 can be integrated in the SPWM variable frequency voltage-regulating power supply 1 as required, and are not independent, and can be used wholly or partially or even not used according to the specific use environment requirements and the filtering effect that can be achieved by the designed or adopted subsequent filter. The control-display-measurement-protection unit 7 is a control center of a complete set of equipment, realizes on-off control, parameter setting and variable frequency and voltage regulation control of the SPWM variable frequency and voltage regulation power supply 1, switching control of a filter device of the isolation filter unit 4, switching control of a filter device of the low-pass filter unit 5, communication with the output measurement unit 6, display and monitoring of system state information, measurement results, operation parameters and the like, and functions of data storage, processing, transmission, man-machine interaction, on-line communication and the like.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.