CN103513136B - A transformer transmission characteristic testing device and method - Google Patents

Abstract

A transformer transmission characteristic test device and method, the test device includes a single-phase AC voltage regulator (1), a single-phase full-bridge uncontrolled rectifier circuit (2), a filter capacitor (3), a single-phase full-bridge inverter device (4), PWM pulse width modulator circuit (5), DC blocking capacitor (6) and segmented adjustable inductance (7). The tested transformer is connected in series to the loop composed of the DC blocking capacitor (6) and the segmented adjustable inductance (7), using the resonant frequency and single The relationship between the working frequency of the phase-to-phase full-bridge inverter can continuously obtain 1kHz-50kHz sine, square wave and sine distortion waveforms in the primary and secondary sides of the transformer, which can be used for testing the transmission characteristics of high-frequency and high-voltage transformers.

Description

A transformer transmission characteristic testing device and method

technical field

The invention relates to a high-frequency transformer transmission characteristic testing device and method, in particular to a high-frequency high-voltage transformer transmission characteristic testing device and testing method in the field of high-frequency and high-voltage power supplies.

Background technique

High-frequency high-voltage transformers are an important part of high-frequency high-voltage power supplies. With the development of high-frequency high-voltage power supply technology and the expansion of application fields, the operating frequency, output voltage, and output power of high-frequency high-voltage transformers are getting higher and higher, resulting in transformers. Parasitic and distribution parameters are more and more affected by the magnetic core, winding material, transformer structural parameters, winding process, etc., and directly affect the design and performance of high-frequency high-voltage power supply, so the transmission characteristics of high-frequency high-voltage transformers are increasingly affected One of the technical parameters of concern.

The transformer comprehensive tester in the patent 201220325692.3 includes a three-phase DC resistance tester, a transformation ratio tester, an on-load comprehensive tester, and automatically controls the three-phase DC resistance tester, transformation ratio tester, and on-load comprehensive tester by controlling the relay on and off. Switching and integration of tester functions; utility model 201220298644.X discloses a high-power high-frequency transformer testing system with a working frequency of 5-50kHz. The output waveform is controlled; patent 200910181695.7 discloses a transformer comprehensive parameter tester calibration device, which measures multiple parameters of power frequency transformers, only discloses the test function module, and does not disclose the specific test method used; A transformer comprehensive testing device, which integrates three single instruments including a transformer no-load load tester, a transformation ratio group tester and a DC resistance tester, and is mainly used for testing power frequency transformers.

Contents of the invention

The purpose of the present invention is to propose a transformer transmission characteristic testing device and method, cooperate with the tested transformer to generate square wave voltage signals of different frequencies, sinusoidal voltages, current signals and sinusoidal voltages and current signals of different degrees of distortion on the transformer input side winding, It is used to test the transmission characteristics of transformers.

The present invention includes seven components: a single-phase AC voltage regulator, a single-phase full-bridge uncontrolled rectifier circuit, a filter capacitor, a single-phase full-bridge inverter, a PWM pulse width modulator circuit, a DC blocking capacitor, and a segmented Adjustable inductance. The two input terminals of the single-phase AC voltage regulator are respectively connected to the 220V AC live wire and neutral wire, and the two output terminals of the single-phase AC voltage regulator are connected to the two AC input terminals of the single-phase full-bridge uncontrolled rectifier circuit. The output high voltage terminal of the uncontrolled rectification circuit is connected to the positive pole of the filter capacitor, the output low voltage terminal of the single-phase full-bridge uncontrolled rectifier circuit is connected to the negative pole of the filter capacitor, the positive pole of the filter capacitor is connected to the positive pole of the single-phase full-bridge inverter bus, and the negative pole of the filter capacitor is connected to The negative pole of the single-phase full-bridge inverter busbar; one end of the output of the single-phase full-bridge inverter is connected in series with a DC blocking capacitor and a segmented adjustable inductance, and then one end of the test transformer winding is accepted, and the other end of the output of the single-phase full-bridge inverter is accepted Test the other end of the transformer winding. The PWM pulse width modulator circuit is used as the driving circuit of the single-phase full-bridge inverter to connect to the driving end of the single-phase full-bridge inverter. bridge inverter output. By adjusting the voltage adjustment knob of the single-phase AC voltage regulator, the DC voltage rectified by the single-phase full-bridge uncontrolled rectifier circuit and filtered by the filter capacitor can be adjusted, and the DC voltage output by the filter capacitor can be adjusted from 0 to 300V. The single-phase full-bridge inverter is composed of 4 high-frequency controllable switching devices and 4 high-frequency diodes. The frequency of the high-frequency switching devices and high-frequency diodes should meet the test frequency requirements of the transformer under test. In the present invention, the test frequency of the device is 1kHz～50kHz, so the IGBT module is used as the controllable switch device, and the anti-parallel diode parasitic inside the IGBT module is used as the high-frequency diode of the full-bridge inverter; the PWM pulse width modulator circuit output frequency The controllable PWM wave signal, after being amplified and isolated, is given to the controllable switching device of the single-phase full-bridge inverter to control the single-phase full-bridge inverter to output an inverter voltage signal of the same frequency. This frequency is called the working frequency. The present invention The medium working frequency is 1kHz～50kHz. The generation of PWM wave in PWM pulse width modulator circuit can be realized by analog or digital circuit. The present invention adopts PWM pulse width modulator UG3525 to cooperate with IGBT driver board to realize; the DC blocking capacitor is a high frequency capacitor, and the capacity needs to be much larger than the distributed capacitance of the tested transformer. The value is generally greater than 1uF; the segmented adjustable inductance can be divided into multiple segments, the minimum value is 0uH, and the maximum value depends on the minimum test frequency of the device.

One winding of the transformer under test is connected to the output end of the single-phase full-bridge inverter in series with the DC blocking capacitor and segmented adjustable inductance. The winding of the transformer under test connected to the test device is called the input side winding. The other winding is called the output side winding. The segmented adjustable inductance and the distribution parameters of the tested transformer are mainly distributed capacitance. There is a resonance point, which is called the resonance frequency. have a big impact. When the operating frequency of the single-phase full-bridge inverter is approximately equal to the resonant frequency, the voltage and current waveforms on the input side of the transformer under test are approximately sine waves, and the tested Transformer voltage and current transfer characteristics. By adjusting the operating frequency of the single-phase full-bridge inverter, you can adjust the winding voltage, current waveform and frequency of the input side of the transformer under test, and obtain the voltage and current transmission characteristics of the transformer under different frequencies and waveforms. When the operating frequency is adjusted away from the resonance frequency, the voltage and current waveforms on the input side of the transformer under test will be distorted, so the transmission characteristics of the transformer under different distorted input signals can be tested. When adjusting the operating frequency of the single-phase full-bridge inverter, it is still impossible to obtain a sinusoidal waveform at both ends of the winding on the input side of the transformer under test, the segmented adjustable inductance can be adjusted, so that the segmented adjustable inductance and the distribution parameters of the tested transformer The determined resonant frequency is equal to or approximately equal to the target test frequency, and the operating frequency of the single-phase full-bridge inverter is also adjusted to the target test frequency, and a sinusoidal waveform can be obtained at the input side winding of the transformer under test. When the segment adjustable inductance value is 0, the voltage waveform of the winding on the input side of the tested transformer is a square wave, and the frequency of the square wave is equal to the operating frequency of the single-phase full-bridge inverter. When the voltage or current amplitude at the input terminal of the transformer under test is too large or too small, adjust the voltage adjustment handle of the single-phase AC voltage regulator and adjust the DC voltage on the filter capacitor to change the voltage or current amplitude at the input terminal of the transformer under test. value.

The present invention adopts the test method of the transformer transmission characteristic testing device, and utilizes the relationship between the resonant frequency determined by the segmented adjustable inductance and the distribution parameters of the tested transformer and the operating frequency of the single-phase full-bridge inverter to generate a standard 1kHz~ 50kHz sinusoidal waveform, sinusoidal distortion waveform, test the transmission characteristics of the transformer under the excitation of 1kHz ~ 50kHz sinusoidal signal and sinusoidal distortion signal. When the segmented adjustable inductance in the device of the present invention is 0uH, a high-frequency square-wave voltage signal can be generated on the input side of the transformer under test, which is used for testing the transmission characteristics of the transformer under the excitation of the high-frequency square-wave voltage signal.

The positive effect of the present invention is:

1. Using the segmented adjustable inductance in the device and the relationship between the resonant frequency determined by the distributed parameters of the tested transformer and the operating frequency of the single-phase full-bridge inverter, voltage waveforms of different waveforms and frequencies are generated for testing high-frequency transformers voltage transfer characteristics.

2. Using the segmented adjustable inductance in the device and the relationship between the resonant frequency determined by the distributed parameters of the tested transformer and the operating frequency of the single-phase full-bridge inverter, current waveforms of different waveforms and frequencies are generated for testing high-frequency transformers current transfer characteristics.

3. The segmented wave-modulating inductor is used to expand the resonant frequency range generated by the distribution parameters of the inductor and the transformer in the device, and effectively measure the transmission characteristics of the transformer under different frequency signal excitations.

Description of drawings

Fig. 1 is a topological structure block diagram of the present invention, in the figure: 1 single-phase AC voltage regulator, 2 single-phase full-bridge uncontrolled rectification circuits, 3 filter capacitors, 4 single-phase full-bridge inverters, 5PWM pulse width modulator circuit , 6 DC blocking capacitors, 7 segmented adjustable inductance.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1: the present invention includes a single-phase AC voltage regulator 1, a single-phase full-bridge uncontrolled rectifier circuit 2, a filter capacitor 3, a single-phase full-bridge inverter 4, a PWM pulse width modulator circuit 5, a DC blocking Capacitor 6 and segmented adjustable inductance 7. The two input terminals of the single-phase AC voltage regulator 1 are respectively connected to the live wire and neutral wire of 220V AC, and the two output terminals of the single-phase AC voltage regulator 1 are connected to the two AC input terminals of the single-phase full-bridge uncontrolled rectifier circuit 2. The output of the phase full bridge uncontrolled rectifier circuit 2 is connected to the positive pole of the filter capacitor 3 at the high voltage end, the output voltage of the single phase full bridge uncontrolled rectifier circuit 2 is connected to the negative pole of the filter capacitor 3, and the positive pole of the filter capacitor 3 is connected to the single phase full bridge inverter 4 The positive pole of the busbar, the negative pole of the filter capacitor 3 is connected to the negative pole of the single-phase full-bridge inverter 4, the negative pole of the busbar, the output end of the single-phase full-bridge inverter 4 is connected in series with the DC blocking capacitor 6 and the segmented adjustable inductor 7, and then one end of the transformer winding is tested , the other end of the output of the single-phase full-bridge inverter 4 accepts the other end of the test transformer winding.

The specific implementation of the present invention takes a 1kW testing device as an example. The single-phase AC voltage regulator 1 adopts a 2kW single-phase AC voltage regulator, and the adjustment range is 0-220V. The single-phase full-bridge uncontrolled rectifier circuit 2 adopts the 30A/1200V rectifier bridge of Ximenkang Company, and the filter capacitor 3 adopts 1100uF/450V electrolysis Capacitor, single-phase full-bridge inverter 4 uses Infineon F4-50R12KS4IGBT, PWM pulse width modulator circuit 5 uses UG3252 as PWM wave generation and frequency adjustment chip, UG3252 output is connected to Luomuyuan company DA962D4 drive circuit, DC blocking capacitor 6 Using 1uF/3000V high-frequency capacitors, segmented adjustable inductance 7 external processing, each inductance is 0, 107uH, 543uH, 1.2mH, 2.6mH, 5.4mH, 11mH, 30mH.

The working process of the present invention is as follows: the tested transformer is connected in series to the resonant circuit, as shown in Figure 1, the segmented adjustable inductance can choose a grade of inductance value at will; the normal power supply for the PWM pulse width modulator circuit 5; Phase AC voltage regulator 1 input terminal is connected to 220V AC; 2 sets of voltage and current test probes are used to measure the input side winding voltage and current of the tested transformer and the output side winding voltage and current respectively, and the voltage and current probes are connected to the oscilloscope. First adjust the voltage, current probe and oscilloscope settings, start the power supply of the PWM pulse width modulator circuit 5, and adjust the PWM pulse width modulator circuit 5 to the target test frequency, and slowly adjust the voltage adjustment handle of the single-phase AC voltage regulator. The voltage and current waveforms are measured on the input side and output side of the transformer. When the waveforms are not ideal, the power supply system is powered off and the segmented adjustable inductance is adjusted to other segments until the waveforms are ideal. After obtaining the ideal waveforms, continue to adjust the single-phase AC regulator. The voltage and current amplitudes of the input side and output side windings of the tested transformer can be adjusted by using the voltage adjustment handle of the transformer until satisfactory. The voltage and current waveforms of the windings on the input side of the transformer under test are determined by the relative relationship between the operating frequency and the resonant frequency. When the frequency deviates far from the resonant frequency, the voltage and current waveforms of the input side winding of the tested transformer are distorted and become other non-standard waveforms. When the resonant inductance is 0, the tested transformer input side winding voltage waveform is a square wave. After obtaining the winding voltage and current waveforms of the input side and output side of the tested transformer, the voltage and current transmission characteristics of the transformer can be calculated according to the needs.

The invention is used for testing the transmission characteristics of high-frequency and high-voltage transformers. In the invention, high-voltage and high-current are used to test the transmission characteristics of transformers. At the same time, due to the simple circuit structure and convenient control, test waveforms of different amplitudes and frequencies can be generated according to needs. More accurate and realistic calculation of the transfer characteristics of the transformer.

Claims (3)

1. a transformator measuring transmission loss method, the test device applied includes single phase ac regulation device (1), single-phase Full-bridge uncontrollable rectifier circuit (2), filter capacitor (3), single-phase full-bridge inverter (4), PWM pulse-width modulation circuit (5), Capacitance (6) and stagewise controllable impedance (7)；Two inputs of single phase ac regulation device (1) meet 220V respectively and hand over Stream electricity live wire and zero line, (1) two outfan of single phase ac regulation device connects two friendships of single-phase full bridge uncontrollable rectifier circuit (2) Stream input, the positive pole of single-phase full bridge uncontrollable rectifier circuit (2) output high pressure termination filter capacitor (3), single-phase full bridge is not controlled The negative pole of rectification circuit (2) output low pressure termination filter capacitor (3), the positive pole order phase full-bridge inverting of filter capacitor (3) Device (4) bus positive pole, filter capacitor (3) negative pole connects single-phase full-bridge inverter (4) bus negative pole, single-phase full-bridge inverter (4) output one end series connection capacitance (6) and stagewise controllable impedance (7) are followed by tested transformator input side winding Wherein one end, the other end that single-phase full-bridge inverter (4) exports accepts the other end of examination transformator input side winding,

It is characterized in that, described method of testing is by regulation single-phase full-bridge inverter operating frequency and the electricity of stagewise controllable impedance Inductance value, utilizes single-phase full-bridge inverter operating frequency and is determined by stagewise controllable impedance (7) and tested transformator distributed constant The pass of resonant frequency tie up to tested Transformer Winding input and produce 1kHz～50kHz high frequency sinusoidal, square wave, sinusoidal distortional wave Shape, is carried out by the way of testing tested transformator input side winding and the voltage of tested transformator output side winding, current waveform Measuring transmission loss under transformator 1kHz～50kHz sine, square wave, sinusoidal distortion pumping signal.

Transformator measuring transmission loss method the most according to claim 1, it is characterised in that when described single-phase full bridge When inverter operating frequency is equal to the resonant frequency determined by stagewise controllable impedance and tested transformator distributed constant, tested transformation The voltage of device input side, current waveform are sinusoidal wave, by testing tested transformator input side and the voltage of output side winding and electricity Stream waveshape goes out transformator voltage under sinusoidal excitation, current transmission characteristic；When regulation single-phase full-bridge inverter operating frequency Time near resonant frequency, tested transformator input side voltage, current waveform approximate sine wave, defeated by testing tested transformator The voltage and current waveform entering side and output side winding can calculate the transformer voltage under near sinusoidal waveform, electric current transmission Characteristic；When regulating single-phase full-bridge inverter operating frequency away from resonant frequency, tested transformator input side voltage, current waveform It is distorted, it is possible to the voltage of transformator, current transmission characteristic under test distortion sinusoidal input signal；When regulation single-phase full bridge is inverse Become device operating frequency and still cannot regulate stagewise controllable impedance when tested transformator input side winding two ends acquisition sinusoidal wave form, The resonant frequency determined by stagewise controllable impedance and tested transformator distributed constant is made to be equal to target detection frequency, by single-phase full bridge Inverter operating frequency also regulates to target detection frequency, i.e. obtains sinusoidal wave form at tested transformator input side winding；Segmentation can When tune inductance value is 0, tested transformator input side winding voltage waveform is square wave, and square wave frequency is equal to single-phase full-bridge inverter work Working frequency, its frequency range is operating frequency 1kHz～the 50kHz scope of device, it is possible to test 1kHz～50kHz square wave is defeated Enter the voltage of tested transformator, current transmission characteristic under signal；When tested transformer inputs voltage or current amplitude is excessive or mistake Hour, regulate DC voltage size on single phase ac regulation device voltage-regulation swing handle, i.e. regulation filter capacitor, just change tested change Depressor input terminal voltage or current amplitude.

Transformator measuring transmission loss method the most according to claim 1, it is characterised in that described method can be real Existing transformator 1kHz～50kHz zonal cooling frequency test；By changing single-phase full bridge in transformer transmission characteristic test device The switching device used in inverter, improves single-phase full-bridge inverter operating frequency, simultaneously the refinement low inductance value of stagewise adjustable electric The segmentation of section, i.e. can test the transformator transmission characteristic under higher frequency；By increasing stagewise adjustable electric inductance value, i.e. can Measure the transmission characteristic of transformator under lower frequency.