The insulation ag(e)ing test unit that is used for the frequency conversion high voltage pulse equipment
Affiliated technical field
The present invention relates to a kind of insulation ag(e)ing test unit that is used for the frequency conversion high voltage pulse equipment
Background technology
Frequency conversion high voltage pulse equipment such as ac variable frequency speed regulation kinematic train are used widely in industry, and output has the high pressure continuous impulse square wave of steep rising edge during its inverter work.This inverter output pulse square wave voltage that wherein drives the inverter-fed traction motor is up to more than the 5.2kv, and frequency is 300Hz~20kHz.Pulse square wave produces the vibration superpotential through cable at the Terminal of motor place, its amplitude can reach 2 times of pulse square wave amplitude; Simultaneously, pulse square wave also can cause between machine winding coil, turn-to-turn voltage skewness, the voltage that end coil (insulated conductor) is born reaches motor terminal superpotential 80%, and first circle bears 40% of whole winding in the end coil, and high like this pulse voltage very easily makes the failure of insulation of coil; Simultaneously, the variable-frequency motor winding bears the effect of too high pulse voltage for a long time, causes motor windings insulation premature failure, influences the normal serviceable life of timing gearing system.
Therefore, need to test the voltage performance of anti-pulse square wave of the insulating material that uses in the frequency conversion high voltage pulse equipment, i.e. simulation produces pulse voltage and acts on the insulating material, the insulating material ageing properties of test under this operating mode is beneficial to the selection of insulating material and design, the making of insulation system.And existing this type of insulation ag(e)ing test unit is primarily aimed at the variable-frequency motor Insulation Test of low-voltage grade and develops.Directly export pulse square wave by switching device, then this pulsating wave is acted on the sample, test.Owing to adopt switching device directly to export pulse square wave, be subjected to the restriction of on-off element electric pressure, pulse amplitude can not be too high, is no more than 4KV.And as mentioned above, pulse square-wave voltage amplitude is very high during some frequency conversion high voltage pulse equipment actual condition, pulse square wave peak-to-peak value as inverter-fed traction motor actual condition is 5.2kV, consider the vibration and the skewness of voltage in winding of square-wave voltage, the crest value of impulse voltage that winding reality is born during work is also much larger than 5.2kV.Therefore existing proving installation can not satisfy the needs that the insulating material in the frequency conversion high voltage pulse equipment carried out insulation accelerated aging test.
Summary of the invention
Purpose of the present invention just provides a kind of insulation ag(e)ing test unit that is used for the frequency conversion high voltage pulse equipment, this device can be exported high power CW high-voltage pulse square wave, to carry out the aging test of insulating material under high-voltage pulse square wave operating mode in the frequency conversion high voltage pulse equipment.The insulating material that it is particularly suitable for the high-power high voltage variable-frequency motor carries out aging test.
The present invention solves its technical matters, the technical scheme that is adopted is: a kind of insulation ag(e)ing test unit that is used for the frequency conversion high voltage pulse equipment, comprise the isolating transformer that is connected with power frequency supply, be connected the pulse producer of isolating transformer output terminal, and the insulating sleeve of the baking oven that links to each other with the pulse producer output terminal.Its design feature is, the concrete mode that the pulse producer output terminal links to each other with lead in the baking oven insulating sleeve is: the output terminal of pulse producer links to each other with the former limit of high-frequency step-up transformer, and the inferior limit of high-frequency step-up transformer links to each other with the lead in the insulating sleeve.This high-frequency step-up transformer is: alternately the frequency of operation that inserts is respectively four high-frequency step-up transformers of 300Hz~1kHz, 1kHz~5kHz, 5kHz~10kHz and 10kHz~20kHz.
Compared with prior art, the invention has the beneficial effects as follows:
Output terminal adjunction high-frequency step-up transformer at pulse producer, the square wave of pulse producer output is boosted, keeping under the distortionless condition of square wave, the amplitude of the pulse voltage of output can reach the requirement of the frequency conversion high voltage pulse equipment being carried out the insulation ag(e)ing test.
Because the operating frequency range of frequency conversion high voltage pulse equipment is very wide, when working as the ac variable frequency speed regulation kinematic train, the operating frequency range of its square wave is: 300Hz~20kHz.In the insulation ag(e)ing test, need the insulation characterisitic of test sample in whole frequency.But a high-frequency step-up transformer can not satisfy the requirement of the frequency change of wide region like this.Adopt many (group) high-frequency transformers respectively correspondence work in 300Hz~1kHz, 1kHz~5kHz, 5kHz~10kHz, 10kHz~20kHz band limits.Four frequency range alternately testings make the present invention can adopt the mode of step-up transformer to carry out the simulation test of broadband working range, can simulate and measure the aging characteristics of insulating material under ac variable frequency speed regulation kinematic train actual condition.
Above-mentioned high-frequency step-up transformer is to be composed in series by 2-10 transformer former limit parallel connection, inferior limit.
When required voltage pulse output is higher, select for use a plurality of transformers to link to each other in the mode of the parallel connection of former limit, the series connection of inferior limit, voltage magnitude can be brought up to the high pressure of desirable value; Simultaneously, compare with the single transformer that uses the hypermutation ratio, the number of windings in unit space reduces, distribution parameters such as stray capacitance, distributed inductance have been reduced, make the pulse square wave wave form distortion little, square-wave form can better be kept, and can simulate the working condition of the insulating material in the variable-frequency motor more realistically, and its test result is more accurate, more reliable.Whole transformer group is placed in the transformer oil, can improve dielectric strength and prolong physical life.
Above-mentioned transformer voltage ratio≤2, former limit winding is 1 layer with time limit winding, and soaks and place transformer oil.
The minimizing of no-load voltage ratio I is former, the distribution parameter on inferior limit, and Single-layer Windings has been avoided the interlayer interference of multilayer winding.Guaranteed so further that after high-frequency transformer boosts the pulse square wave waveform distortion of output is little, simulates the working condition of the insulating material in the frequency conversion high voltage pulse equipment more realistically.Whole transformer group is placed on compound inslation in the transformer oil, can improve dielectric strength and prolong native system serviceable life.
An above-mentioned 2-10 transformer evenly distributes in the form of a ring, and secondly the series connection line on limit distributes in the form of a ring, and the line in parallel on former limit is spoke-like distribution.
Ring-shaped distributed transformer group, the interference between each transformer is little; Connect mutually in inferior limit, the series connection line distributes in the form of a ring, and the parallel connection of former limit and its line that is connected in parallel are spoke-like distribution, and the inferior limit lead-in wire of whole like this transformer is in vertical distribution with former limit lead-in wire, almost can not form distributed capacitance.Further reduce the distortion of output pulse square wave waveform, can simulate the working condition of the insulating material in the frequency conversion high voltage pulse equipment more realistically.
The invention will be further described below in conjunction with the drawings and specific embodiments.
Description of drawings
Fig. 1 illustrates the system architecture diagram of the embodiment of the invention one.
Fig. 2 illustrates the circuit theory synoptic diagram of the high-frequency step-up transformer of the embodiment of the invention one.
Fig. 3 illustrates the space distribution and former, the inferior limit lead-in wire synoptic diagram of each transformer in the high-frequency step-up transformer of the embodiment of the invention one.
Embodiment
Embodiment one
Fig. 1 illustrates, a kind of embodiment of the present invention is: a kind of insulation ag(e)ing test unit that is used for the frequency conversion high voltage pulse equipment, comprise the isolating transformer 1 that is connected with power frequency supply, be connected the pulse producer 2 of isolating transformer 1 output terminal, the lead in pulse producer 2 output terminals and baking oven 5 insulating sleeves 4 links to each other.The concrete mode that lead in pulse producer 2 output terminals and baking oven 5 insulating sleeves 4 links to each other is: the output terminal of pulse producer 2 links to each other with the former limit of high-frequency step-up transformer 3, and the inferior limit of high-frequency step-up transformer 3 and insulating sleeve 4 interior leads link to each other.High-frequency step-up transformer 3 is: alternately the frequency of operation that inserts is respectively four high-frequency step-up transformers 3 of 300Hz~1kHz, 1kHz~5kHz, 5kHz~10kHz and 10kHz~20kHz.When using with segmentation, in turn mode simulation test frequency is the ageing properties of the insulation of the variable-frequency motor under the high-frequency pulse square wave operating mode of 300Hz~20kHz.
Fig. 2 illustrates, and the high-frequency step-up transformer 3 of present embodiment is the former limit parallel connection by 5 transformer 3a.Inferior limit is composed in series, and transformer 3a no-load voltage ratio is 2, and turn ratio also promptly former, inferior limit is 2.Former limit winding is 1 layer with time limit winding, and soaks and place transformer oil.
Fig. 3 illustrates, and 5 transformer 3a evenly distribute in the form of a ring, and secondly connect mutually in the limit, and series connection line 11 distributes in the form of a ring, and the parallel connection of former limit and its line 12 that is connected in parallel are spoke-like distribution.
In this example, what transformer 3a was more specifically detailed constitutes: the winding enameled wire coiling of 0.31mm outsourcing dacron thread, layer insulation insulating paper and mylar compound inslation.Simultaneously, in order to adapt to the needs of different frequency, the iron core that constitutes 5 transformer 3a of 10kHz-20kHz high-frequency step-up transformer 3 adopts E type ferrite iron core, and the number of turn is former limit 42 circles, inferior limit 84 circles; The transformer 3a iron core that constitutes 5kHz-10kHz high-frequency step-up transformer 3 adopts non-crystaline amorphous metal, and the number of turn is former limit 250 circles, inferior limit 500 circles.The transformer 3a iron core that constitutes 1kHz-5kHz high-frequency step-up transformer 3 also adopts non-crystaline amorphous metal, and the number of turn is former limit 350 circles, inferior limit 700 circles.The transformer 3a iron core that constitutes 300Hz-1kHz high-frequency step-up transformer 3 adopts 0.2mm silicon sheet core, former limit 158 circles, inferior limit 316 circles.
It is that 300Hz~20kHz is adjustable continuously that the pulse producer 2 of present embodiment produces frequency range, with the high-frequency step-up transformer 3 of exporting to four different frequency ranges respectively.Pulse producer 2 output peak-to-peak value scopes are 0~1kV, and dutycycle is 50%, and rising edge is less than the pulse square wave of 50 nanoseconds.High-frequency transformer 3 promotes 10 times to pulse square wave amplitude, makes the square-wave voltage amplitude rise to 10kV, and keeps rising edge less than 500 nanoseconds, and promptly the output square-wave waveform of high-frequency transformer 3 is constant substantially, can simulate the actual condition of variable-frequency motor more exactly.
In the present embodiment, insulating sleeve 3 adopts porcelain bushing, and withstand voltage is 50kV.Baking oven 4 adopts air dry ovens, range of temperature room temperature to 500 ℃.
Embodiment two
Present embodiment and embodiment one are basic identical, and different is: high-frequency step-up transformer 3 is made up of 2 transformer 3a.
Embodiment three
Present embodiment and embodiment one are basic identical, and different is: high-frequency step-up transformer 3 is made up of 10 transformer 3a.
Embodiment four
Fig. 1 illustrates, the structure of present embodiment is: a kind of insulation ag(e)ing test unit that is used for the frequency conversion high voltage pulse equipment, comprise the isolating transformer 1 that is connected with power frequency supply, be connected the pulse producer 2 of isolating transformer 1 output terminal, the lead in pulse producer 2 output terminals and baking oven 5 insulating sleeves 4 links to each other.The concrete mode that lead in pulse producer 2 output terminals and baking oven 5 insulating sleeves 4 links to each other is: the output terminal of pulse producer 2 links to each other with the former limit of high-frequency step-up transformer 3, and the inferior limit of high-frequency step-up transformer 3 and insulating sleeve 4 interior leads link to each other.High-frequency step-up transformer 3 is: alternately the frequency of operation that inserts is respectively four high-frequency step-up transformers 3 of 300Hz~1kHz, 1kHz~5kHz, 5kHz~10kHz and 10kHz~20kHz.When using with segmentation, in turn mode simulation test frequency is the ageing properties of the insulation of the variable-frequency motor under the high-frequency pulse square wave operating mode of 300Hz~20kHz.This example is applicable to the occasion lower to the voltage magnitude requirement.