Rectifier Transformer Short-Circuit Testing With Magnetic Transducers
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Solution Overview
Problem
Existing methods for performing short-circuit measurements on rectifier transformers according to the IEC 60076-1 standard are disrupted by magnetic transducers, require dry measurements that are costly and disruptive, and do not meet requirements when measurements are not performed at rated frequency under sinusoidal voltage.
Innovation Solution
A method and system that short-circuits each positive branch with the corresponding negative branch to allow current to flow in only one direction, placing magnetic transducers in self-saturation for impedance and loss measurements, reducing non-linear and harmonic effects and allowing measurements under sinusoidal voltage without dry testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If magnetic transducers are installed in the rectifier transformer to control DC voltage, then voltage control capability is improved, but short-circuit measurement accuracy deteriorates due to harmonic effects and magnetic saturation
Solution Approach 1:
The patent applies preliminary action by performing dry measurements of the transformer parameters (impedance, losses) before installing the magnetic transducers. These measurements are taken when the transformer is in its original state without any additional equipment. The measured values are then stored and used as reference data for later wet measurements, allowing the magnetic transducers to remain installed while still enabling accurate short-circuit parameter determination through calculation rather than direct measurement.
2Measurement precision
If dry measurements are performed outside the insulation tank to obtain accurate impedance and loss values, then measurement accuracy is improved, but operational disruption and cost increase
Solution Approach 1:
The patent performs the dry measurements of impedance and losses as a preliminary action before the transformer is installed in the insulation tank or before it begins operation. These measurements are conducted when the transformer is accessible and can be easily tested. The obtained values are then used as baseline data that eliminates the need to repeat these measurements after installation, allowing the transformer to remain operational during wet testing phases.
Solution Approach 2:
The patent creates a reference copy of the transformer's electrical parameters through dry measurements taken when the transformer is outside the tank. These measured values serve as a reference model that can be used to calculate or infer the same parameters during wet measurements when the transformer is installed and operational. This copying approach avoids the need to physically move or disassemble the transformer for repeated measurements.
3Adaptability or versatility
If magnetic transducers are present during short-circuit measurements, then voltage control functionality is maintained, but additional reactive power and harmonic effects disrupt measurement validity
Solution Approach 1:
The patent measures the transformer's impedance and losses in advance, before the magnetic transducers are installed or activated, when no harmonic effects or additional reactive power are present. These preliminary measurements capture the pure electrical characteristics of the transformer without distortion. Later, when the magnetic transducers are installed for voltage control, these pre-measured values serve as the basis for determining short-circuit parameters, avoiding the need to perform measurements during conditions with harmonic distortion.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate short-circuit measurements under IEC 60076-1 standards without disrupting the transformer's operation, reducing costs and complexity by eliminating the need for dry measurements and maintaining voltage control capabilities.
Implementation Method 1
such a magnetic transducer 230a,b,c,d,e,f is a device with the aid of which it is possible to vary the DC voltage at the output of the rectifier circuit 30 via an independent current, using the phenomena saturation of the magnetic circuit
Implementation Method 2
short-circuiting each positive branch with the corresponding negative branch so as to allow the current to flow between a positive branch and a negative branch only in one direction, this in order to place the magnetic transducers of said positive and negative branches in magnetic saturation during of an impedance measurement
Data Source
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AI summary
The invention relates to a method of testing a so-called rectifier transformer (20), intended to be installed at the interface between a power supply circuit comprising at least one phase, and an installation, the rectifier transformer (20) comprising for each phase of the power supply circuit a secondary coil (220) intended to be linked across a rectifier circuit (30) to the installation (40) by a positive branch and a negative branch, each of the branches being equipped with a magnetic transducer (230a,b,c,d,e,f), the method comprising the steps consisting in short-circuiting each positive branch with the corresponding negative branch and performing a measurement of impedance and/or of losses of the rectifier transformer (20). The invention also relates to an electrical testing system (2), a short-circuiting circuit (50) and an anodizing assembly. Figure 2