Testing method for dynamic inductance of saturable reactor of direct-current converter valve

Abstract

The invention relates to a testing method for dynamic inductance, and in particular relates to the testing method for the dynamic inductance of a saturable reactor of a direct-current converter valve. The testing method comprises the following steps of: A. setting up a testing circuit of the saturable reactor; B. testing the voltage of a dynamic inductance end of an iron core of the saturable reactor; C. applying low frequency sinusoidal steady state excitation to the saturable reactor; D. testing the electric current of a dynamic inductance branch of the iron core; E. determining the electromagnetic parameter of the dynamic inductance of the iron core; and F. determining the dynamic inductance of the iron core. According to the testing method, the circuit characteristic measurement for determining the dynamic inductance of the iron core is converted into a electromagnetic field parameter through strict test and calculation on the basis of the dynamic inductance definition, thereby reducing the computational complexity and numerical errors; the physical property of the dynamic inductance is expressed by adopting the parameter of the port of the saturable reactor through a reasonable physical hypothesis, thereby avoiding the direct measurement on the parameters of the two ends of the dynamic inductance and greatly reducing the test complexity; and equipment needed for tests is simple and frequently-used; and the test process is easy to operate.

Description

technical field [0001] The invention relates to a testing method for dynamic inductance, in particular to a testing method for dynamic inductance of a DC converter valve saturated reactor. Background technique [0002] The saturable reactor is an important protection element in the DC transmission converter valve, which is composed of an iron core and a coil. At the initial stage of the converter valve opening, the saturable reactor has the function of delaying the current rising rate and protecting the thyristor. This process generally only takes a few microseconds, and the saturable reactor appears as a dynamic inductance during this process. [0003] The iron core and the coil interlink constitute the dynamic inductance of the saturable reactor, denoted as L m There are hysteresis loss and eddy current loss in the iron core during operation. At both ends of the iron core of the saturable reactor, as the excitation current rises, the iron core tends to be saturated. At th...

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Problems solved by technology

From the physical definition of dynamic inductance, the dynamic performance of a saturable reactor is mainly determined by the voltage and current characteristics at both ends, but in the actual physical entity, the iron core and the coil are arranged orthogonally and fixedly assembled, and the coil port is connected to the external circuit , it is difficult to directly test the performance of the iron core for a formed saturable reactor

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