Effect of Magnetic Properties of Magnetic Composite Tapes on Motor Losses

Abstract

Alternating current (AC) copper losses in motors increase with carrier frequency of the pulse width modulation (PWM) and are further increased by leakage flux of the permanent magnet. Therefore, AC copper losses increase with motor speed. Conventional techniques for reducing AC copper losses tend to increase other losses. In this paper, AC copper loss was reduced by wrapping a magnetic tape made of a magnetic composite material around the winding. This method controlled the flux path through the winding. Magnetic composite materials are mixtures of magnetic powders and liquid resins whose magnetic properties can be manipulated by changing the combination and other factors. When Fe–Si–Al magnetic tape was wrapped around the winding, the AC copper loss was reduced by 40%. The loss was further reduced by optimizing the magnetic properties of the magnetic composite material. The AC copper loss was maximally reduced when the specific permeability was 100 and the saturation flux density was 1.6. Magnetic tapes composed of magnetic composite materials with high saturation flux density and specific permeability reduce the AC copper losses without increasing other losses in the motor.

High-Power-Factor LC Series Resonant Converter Operating Off-Resonance with Inductors Elaborated with a Composed Material of Resin/Iron Powder

“…For the experimental tests, current (TCP0020) and differential voltage (THDP0200) probes and a digital oscilloscope (DPO2014B) from TEKTRONIX were used. Figures [19][20][21] show the oscilloscope captures taken during the corresponding measurements in the experimental tests to validate the operation of the circuit. Figure 19 shows the output voltage, output current, and output power measurements, which comply with the design parameters in Table 1.…”

“…For this, a power subtraction was performed between the power coming out of the inverter Pout(inver) and the power entering the output rectifier Pin(bridge). The equation to determine the losses in the resonant tank is defined as follows: Figures [19][20][21] show the oscilloscope captures taken during the corresponding measurements in the experimental tests to validate the operation of the circuit. Figure 19 shows the output voltage, output current, and output power measurements, which comply with the design parameters in Table 1.…”

“…As a method for evaluating the performance of this magnetic material, the resonant converter shown in Figure 1 was implemented, operating off-resonance at different switching frequencies from 300 kHz to 800 kHz to feed a resistive load of 19 watts at the output, where the inductor "La" was built with a toroidal core made of this soft magnetic material composed of resin and iron powder. The reason the experimental tests were performed at different operating frequencies was to check if the permeability of the magnetic cores composed of resin/iron powder varied with the frequency since it is well known that one of the problems of magnetic components is the changes in the permeability of their magnetic cores in applications where high operating frequencies are required [20][21][22]. To further stress the test magnetic cores, it was decided that the converter should operate off-resonance to obtain higher peak currents circulating in the resonant tank since, by operating off-resonance, the peak currents are higher compared to operating at resonance.…”

Penerapan Kawat Litz Pada Motor BLDC Untuk Peningkatan Gaya Dorong Per Daya

“…Kawat Litz yang menurut definisi memiliki subkonduktor yang diisolasi dalam pola yang seragam sehingga setiap subkonduktor menggabungkan medan yang sama dan membawa jumlah arus yang sama, memberikan solusi untuk mengurangi rugi pada belitan yang berlebihan [10]. Oleh karena itu, kawat Litz dapat digunakan untuk mengurangi copper loss [11].…”