Application Cases

【Overview】 This paper proposes a model for analyzing and calculating magnetic core losses based on vector magnetic circuit theory, intended for calculating core losses at high frequencies under non-sinusoidal waveform excitation. Through Fourier decomposition, a numerical mapping relationship between magnetic permeability and magnetic hysteresis under sinusoidal excitation is established. Based on the mechanisms of hysteresis loss and eddy current loss, under non-sinusoidal excitation, the losses can be directly calculated using the parameter values of magnetic permeability and magnetic hysteresis obtained under sinusoidal excitation. The accuracy and effectiveness of the proposed method have been verified by comparing predicted and measured data for three different magnetic cores: 3E6, N30, and N87.

Experiment Name: Application of Power Amplifier in High-Frequency Magnetic Core Loss Measurement

Research Direction: High-Frequency Magnetic Core Loss Measurement

Experimental Content: Measurement of ring-type magnetic core losses under sinusoidal and PWM waveform excitation, with frequencies ranging from 10 kHz to 500 kHz and magnetic flux density amplitudes from 0 to 0.2 T. The required waveforms are generated by a signal generator and then amplified by a power amplifier before being input to the primary side of the magnetic core. The core losses are measured using the two-winding method.

Testing Equipment: Signal generator, ATA-4052C high-voltage power amplifier, oscilloscope, high-frequency current and voltage probes, etc.

Experimental Procedure:

Figure 1: Photo of the Experimental Setup

According to the two-winding method, two voltage probes detect the voltages on the primary and secondary sides of the ring-type magnetic core, and one current probe detects the primary-side current. The detected signals are input to the oscilloscope. The signal generator produces the desired waveform with the required frequency, amplitude, and shape, which is then amplified by the power amplifier and input to the primary side of the ring-type magnetic core. The voltage and current data are acquired and converted into magnetic flux density and magnetic field strength, and the core losses are calculated from the B-H curve.

Experimental Results:

Figure: Experimental Results

As shown in the figure, the measured electrical signals are converted into magnetic circuit signals based on the full current law and the law of electromagnetic induction. By plotting the converted magnetic flux density B and magnetic field strength H, the effects of frequency f or magnetic flux density on the B-H loop can be obtained, respectively, thereby revealing the influence of B and f on magnetic core losses.

Recommended Product: ATA-4052C High-Voltage Power Amplifier

Figure: Specifications of the ATA-4052C High-Voltage Power Amplifier