Capacitance mask resistance sensor

Abstract

A resistance transducer of capacity-shielding type is prepared as parallel-connecting and jacketing capacity-shielding layer at external of high voltage resistance column on resistance transducer, forming said capacity-shielding layer by fixing a numbers of cylindrical media-along being superposed to each other and being isolated to each other in insulation media along axial direction from top tobottom for shielding off interference current caused by stray capacitance between high voltage conductor and high voltage resistance column so as to raise accuracy of voltage measurement.

Description

technical field [0001] It belongs to the field of high-voltage electrical appliances. As a voltage sensor of a photoelectric voltage transformer, it collects high-voltage signals and converts them into low-voltage signals, and is used for high-voltage measurement and relay protection of power systems. Background technique [0002] The voltage transformers in the prior art have the following types: (1) electromagnetic transformers insulated with oil paper; (2) electromagnetic voltage transformers filled with SF6 gas; (3) electromagnetic voltage transformers with casting insulation; (4) ) oil-paper insulated capacitive voltage transformer; (5) electronic voltage transformer. [0003] Types (1) and (4) belong to electromagnetic voltage transformers and capacitive voltage transformers using oil paper as the main insulating material, and type (2) is electromagnetic voltage transformers using SF6 as the main insulating material. All have problems such as leakage, environmental po...

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Problems solved by technology

[0003] Types (1) and (4) belong to electromagnetic voltage transformers and capacitive voltage transformers using oil paper as the main insulating material, and type (2) is electromagnetic voltage transformers using SF6 as the main insulating material. There are problems such as leakage, environmental pollution, heavy maintenance workload, high accident rate, large volume and heavy weight to varying degrees.

[0004] The (3) epoxy resin casting insulated electromagnetic voltage transformer, due to many reasons such as material, structure and process, in addition to the low voltage level, there are also problems such as large partial discharge and dielectric loss factor.

[0005] Types (1), (2) and (3) belong to electromagnetic voltage transformers, and all electromagnetic voltage transformers have the following problems: ① Each transformer needs to be configured with multiple different functions according to user requirements For the secondary winding, in order to prevent signal distortion caused by iron core saturation, the capacity of the iron core needs to be made larger, so the volume is large and the weight is heavy; ② Improper matching of the excitation inductance and line capacitance parameters of the electromagnetic voltage transformer can easily cause ferromagnetic resonance , thus endangering the system security

Under such parameters, the stray capacitance of high-voltage conductors, adjacent equipment, and grounding equipment and the earth will cause interference currents to high-voltage resistors, which will affect the uncertainty of resistive sensors, making it difficult to meet the accuracy of voltage measurement.

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