Impact of Current Pulsation on BLDC Motor Parameters

Abstract

BrushLess Direct-Current (BLDC) motors are characterized by high efficiency and reliability due to the fact that the BLDC motor does not require power to the rotor. The rotor of the BLDC motor consists of permanent magnets. When examining the waveform of the current supplied to the motor windings, significant current ripple was observed within one power cycle, where the optimum value would be the constant value of this current during one power cycle. The variability of this current in one motor supply cycle results from the variability of the electromotive force induced in the motor winding. The paper presents a diagram of the power supply system consisting of an electronic commutator and a DC/DC converter made by the authors, and a proposed modification of the power supply system reducing the current pulsation of the motor windings and thus the possibility of reducing energy losses in the motor windings. The paper presents numerous results of measurements which showed a significant reduction in energy losses in the case of low-load operation.

Minimization of Energy Losses in the BLDC Motor for Improved Control and Power Supply of the System under Static Load

“…This board was also made as an evaluation circuit allowing additional elements to be connected, for example to filter the signals supplied from the hall sensors. For an illustration of the PCB design, see [ 9 ]. The ready circuit dedicated to the tested solution is shown in the photo in Figure 22 .…”

“…The basic idea behind controlling power transistors is to switch the transistors sequentially based on the rotor position. The control process is discussed in detail in [ 9 ]. At this point, it should be noted that a very important aspect of control is the use of current limitations at the stage of engine start-up, reversal, braking and during engine operation.…”

“…Thanks to this design, the current flow is not needed to generate the magnetic field (no excitation winding), it eliminates energy losses in the excitation winding automatically [ 7 , 8 ]. The use of strong magnets to excite electrical machines allows for the construction of more efficient machines [ 9 ]. Electric machines excited by permanent magnets can be divided into two groups due to the placement of magnets: Machines in which permanent magnets are placed on the stator.…”

Sensorless LC Filter Implementation for Permanent Magnet Machine Drive Using Observer-Based Voltage and Current Estimation

“…However, considering PWM voltage control, visible switching-reflected current harmonics occur on these low-inductance machines [ 4 ]. Although the bus voltage usage is improved at high speed, PWM inverter-reflected current harmonics increase the machine iron loss and cause rotor thermal issues [ 5 , 6 ].…”

“…Similar to Equation(6), theÎ Cdq estimation accuracy can be analyzed in the S-domain based on the definition of the capacitor current error,Î Cdq_err = I Cdq −Î Cdq . It is shown to be…”