Compensation method for voltage transformer secondary circuit pressure drop and compensation arrangement

Abstract

The invention relates to a compensation method for voltage mutual inductor secondary circuit recession, which comprises: putting in series resistance at voltage mutual inductor secondary circuit, making secondary circuit access to open circuit by controlling the resistance's recession to access to zero, extracting sample voltage from both ends of resistance and doing voltage isolation amplify and power amplify to it and outputting it by output transformer which is paralleled with charge. The invention also relates to a compensation device, which comprises classification resistance, voltage isolation amplifying circuit, power amplifying circuit, output inverter and power circuit, wherein both ends of resistance is used as input end connection of voltage sample end and isolation amplifying circuit, output end of voltage isolation amplifying circuit is in touch with input end of power amplifying circuit, while output end of power amplifying circuit is connected with inverter. The invention does second recession compensation by transforming secondary charge aroused by cutting off electric current of secondary circuit.

Description

technical field [0001] The invention relates to a method and a compensation device capable of compensating the voltage drop of a voltage transformer secondary circuit. Background technique [0002] So far, high-precision voltage transformers and secondary circuit voltage drop compensation devices are two completely different products. Due to the existence of the no-load current voltage drop and the load current voltage drop, the voltage error of the uncompensated voltage transformer is usually negative, and the error is relatively large. In order to improve the accuracy of the voltage transformer, the method of error compensation is usually used ( Turns compensation or series winding compensation), but the uncertainty of the load makes it impossible for the accuracy of the voltage transformer after error compensation to reach a very high value. Usually, the voltage of the secondary load is within the range of 0.25 to 1.0 rated value The error is greater than 0.1%, and the p...

AI Technical Summary

Problems solved by technology

In order to reduce the measurement error of the secondary circuit, many secondary circuit voltage drop compensation devices have appeared at present. Most of these devices are implemented by connecting a series transformer between the secondary circuit of the voltage transformer (PT) and the electric energy meter to increase the voltage. Voltage drop compensation, this voltage drop compensation method is likely to cause metering disputes between users and power departments, and it is difficult to promote; some people also propose to perform voltage drop compensation by switching loads, but although this compensation method can transfer loads, it does not The secondary (because it must provide excitation for the low-voltage voltage transformer) circuit cannot be cut off, the measurement error of the low-voltage detection unit will affect the compensation result, and at the same time, the large reduction of the secondary load current of the voltage transformer (PT) will cause voltage mutual inductance The further increase of the instrument measurement error

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