A kind of DC voltage transformer on-site calibration device
Technical field
The present invention relates to a kind of DC voltage transformer on-site calibration device, belong to calibration, calibrating and detection field to power equipment.
Background technology
DC voltage transformer is the major equipment of measuring DC voltage in DC transmission system, for safety, the stable operation of DC transmission system provides control, guard signal.In order to guarantee the DC voltage transformer measuring-signal accurately and reliably, need to carry out field-checking to DC voltage transformer.
The DC voltage transformer on-site calibration device is comprised of direct voltage source, standard voltage divider, secondary measuring system three parts.Direct voltage source provides high voltage for field-checking, by control desk, I.F.T., multiplication of voltage tower, high direct voltage voltage divider four parts, formed, the effect of high direct voltage voltage divider wherein is to provide feedback signal for the voltage-regulation of direct voltage source and voltage show, accuracy requirement is not high.Standard voltage divider provides the standard value for field-checking, and accuracy requirement is higher.Secondary measuring system is carried out synchronous acquisition, measurement to the low-voltage signal of standard voltage divider and the output of tested DC voltage transformer.
While carrying out field-checking, DC high-voltage source is applied to DC high voltage the high-pressure side of tested DC voltage transformer and standard voltage divider, tested DC voltage transformer and standard voltage divider are exported low-voltage signal at low pressure end, secondary measuring system is carried out synchronous acquisition, measurement to the low-voltage signal of output, and, according to the marked ratio of standard voltage divider, obtain the actual no-load voltage ratio of tested DC voltage transformer.
The electric pressure of tested DC voltage transformer is generally all more than 400kV, so the electric pressure of DC voltage transformer on-site calibration device also will be more than 400kV.Electric pressure is higher, and the volume of DC voltage transformer on-site calibration device is larger, weight is heavier, and the site area that cause the cost of calibration equipment long-distance transport to increase, lengthens, takies the time of verification platform building increases.In order to save transportation cost, reduce the workload of field-checking, a kind of have more small size and lighter weight DC voltage transformer on-site calibration device and necessitate.
Summary of the invention
Deficiency for background technology, the invention provides a kind of DC voltage transformer on-site calibration device, traditional standard voltage divider and the high direct voltage voltage divider in direct voltage source are combined in a voltage divider, this voltage divider adopts double-deck resistance cascaded structure, for internal layer, the precision resistance of high precision, high stability, low-temperature coefficient is connected into the voltage divider with high accuracy and replaces standard voltage divider, for field-checking provides the standard value; Outer with performance is relatively poor but low-cost resistance is connected into the relatively low voltage divider of accuracy replaces the high direct voltage voltage divider in direct voltage source, for showing, the voltage-regulation of direct voltage source and voltage provides feedback signal; Simultaneously, make internal layer resitstance voltage divider and outer resitstance voltage divider there is identical Potential distribution, allow outer resitstance voltage divider the internal layer resitstance voltage divider be played to the effect of equivalent potential screen, further to improve the accuracy of internal layer resitstance voltage divider.Device of the present invention has less volume, and lighter weight has been saved the cost of transportation, has facilitated the installation of device, has reduced the site area that field-checking takies.
Technical scheme of the present invention is: a kind of DC voltage transformer on-site calibration device, comprise that direct voltage source, double-deck resistance cascaded structure voltage divider and secondary measuring system form, it is characterized in that: described direct voltage source comprises control desk, I.F.T. and multiplication of voltage tower; Double-deck resistance cascaded structure voltage divider comprises internal layer resitstance voltage divider and outer resitstance voltage divider, and described control desk is connected with outer resitstance voltage divider, and the internal layer resitstance voltage divider is connected with secondary measuring system, and the multiplication of voltage tower is connected with double-deck resistance cascaded structure voltage divider.Its beneficial effect is: because the volume and weight of DC voltage transformer on-site calibration device mainly concentrates on high direct voltage dividing potential drop and these three parts of the multiplication of voltage tower in direct voltage source in standard voltage divider, direct voltage source, high direct voltage voltage divider in standard voltage divider and direct voltage source is replaced with the voltage divider of a double-deck resistance cascaded structure, can reduce by a high-tension apparatus, thereby the volume and weight of a whole set of calibration equipment is reduced to 30% left and right, save trucking costs and test site, reduced the workload of field-checking.
DC voltage transformer on-site calibration device as above is characterized in that: described outer resitstance voltage divider and internal layer resitstance voltage divider have identical Potential distribution, and outer resitstance voltage divider provides equivalent potential screen for the internal layer resitstance voltage divider.Its beneficial effect is: reduced corona and the Leakage Current of internal layer resitstance voltage divider, made the accuracy of internal layer resitstance voltage divider obtain further raising.
The accompanying drawing explanation
Accompanying drawing 1 is apparatus structure sketch of the present invention.
Embodiment
Description of reference numerals: 1-direct voltage source, 2-control desk, 3-I.F.T., 4-multiplication of voltage tower, 5-double-deck resistance cascaded structure voltage divider, 6-internal layer resitstance voltage divider, 7-outer resitstance voltage divider, 8-secondary measuring system.
Below in conjunction with accompanying drawing, embodiments of the present invention is further illustrated.
As shown in Figure 1, this device is comprised of direct voltage source 1, double-deck resistance cascaded structure voltage divider 5 and secondary measuring system 8.Direct voltage source 1 comprises control desk 2, I.F.T. 3 and multiplication of voltage tower 4; Double-deck resistance cascaded structure voltage divider 5 comprises internal layer resitstance voltage divider 6 and outer resitstance voltage divider 7.
As shown in Figure 1, control desk 2 of the present invention is connected with outer resitstance voltage divider 7, and internal layer resitstance voltage divider 6 is connected with secondary measuring system 8, and multiplication of voltage tower 4 is connected with double-deck resistance cascaded structure voltage divider 5.
The course of work of the present invention is, the control platform 2 processed of operation direct voltage source 1, make the alternating voltage of I.F.T. 3 output amplitudes higher (hundreds of volts ~ tens of kilovolt), frequency higher (number kHz ~ tens of kHz), the DC voltage that multiplication of voltage and the rectified action of the alternating voltage of I.F.T. 3 outputs by multiplication of voltage tower 4 becomes amplitude very high (more than hundreds of kilovolts).High direct voltage is applied on double-deck resistance cascaded structure voltage divider 5, the DC low-voltage signal of the internal layer resitstance voltage divider 6 output accuracy very high (class of accuracy is better than 0.05 grade) of double-deck resistance cascaded structure voltage divider 5 also is transferred to secondary measuring system 8, for field-checking provides the standard value; The DC low-voltage signal of outer resitstance voltage divider 7 outputs of double-deck resistance cascaded structure voltage divider 5 is transferred to the control desk 2 of direct voltage source 1, both, for direct voltage source 1 provides feedback signal to improve the stability of output voltage, provided the voltage display for direct voltage source 1 again.In addition, because outer resitstance voltage divider 7 and internal layer resitstance voltage divider 6 have identical Potential distribution, outer resitstance voltage divider 7 provides equivalent potential screen for internal layer resitstance voltage divider 6, reduced corona and the Leakage Current of internal layer resitstance voltage divider 6, made the accuracy of internal layer resitstance voltage divider 6 obtain further raising.
High direct voltage voltage divider in standard voltage divider and direct voltage source is replaced with a double-deck resistance cascaded structure voltage divider 5, make the DC voltage transformer on-site calibration device reduce by a high-tension apparatus, greatly reduced the volume and weight of calibration equipment, saved the trucking costs of calibration equipment, reduce the site area that field-checking takies, alleviated the workload of field-checking.