Proposed Pfc Based Bldc Motor Drive With High Frequency Isolation Essay

Fig. 5.12. Control of the dc–dc converter with FLC to produce less power under voltage sag: grid voltages, related grid currents, related dc-link

It is of great importance in our industries to cut the cost of power controlling with high efficiency and PWM satisfies this criteria. Therefore, it is

Using Field Oriented Control, current control is largely unaffected by speed of rotation of the motor[6].In the scheme of filed oriented control motor currents and voltages obtained from the motor are transformed into d-q reference frame. Measured currents from three stator phases these currents which are now in the stator reference frame are converted into two phase using Clarke transformations which are further converted into the corresponding rotor reference frame using Park transformation. The resultant current obtained is dc which is easier for the PI controllers to operate.

Brushless DC motors are a vital part of the technology we use today in many different aspects of life; a common being computers. This essay will study how a brushless DC motor works, it’s pros, cons and how it compares to a brushed DC motor. Throughout will be various physics concepts and terms in order to provide the most accurate and detailed explanation.

A dc Brushless Motor uses a permanent magnet external rotor, three phases of driving coils, one or more Hall Effect devices to sense the position of the rotor, and the associated drive electronics. The coils are activated, one phase after the other, by the drive electronics as cued by the signals from the Hall effect sensors, they act as three phase synchronous motors containing their own variable frequency drive electronics. A simplified current controlled modulation technique for BLDC motors is presented.

The objective of the control circuit for PFC converter are a near unity power factor should flow and a steady average voltage should maintain at the output. Literature is abounded with novel PFC control methods that address these objectives. These control methods can segmented into a few categories in terms of their implementation approach and structures. Such as the multi-loop multiplier approach, the cycle-by-cycle integration approach, the single-loop control approach and the sliding mode control approach. Under these categories, some common PFC converter control methods are discussed and their advantages and disadvantages of those methods [].

To study the impact of VSFPWM on switching loss reduction over the entire modulation index range, the simulations were carried out different speeds (modulation indices) for a constant load torque. Table II and Table III compares the current ripple, and the percentage change in the current distortion and the switching losses for CSFSVPWM-VSFSVPWM and CSFDPWM2-VSFDPWM2 techniques respectively. Similar to the analytical results at section II, there is higher switching loss reduction capability at higher speed due to higher variation in current ripple at higher speeds (modulation indices). For example, with VSFSVPWM, around 15% switching loss reduction is obtained, whereas with VSFDPWM2, around 7.2% switching loss reduction is obtained. The difference in switching loss reduction capability in comparison to analytical results is attributed to the

On the front end of the adjustable frequency drive, a series inductance on the DC side of the semiconductor bridge circuit is called a DC choke. An equivalent AC-side line reactor is comparable to the DC choke, except that the THD of DC choke is less than that of the AC counterpart. A greater reduction of the 5th and 7th harmonics, primarily, is provided by the DC

Nowadays, because of the fast evolution of electronic device, The recent developments in permanent magnet materials, solid state devices and microelectronic have led to the appearance of a new energy efficient drives using permanent magnet brushless direct current motors (PMBLDCM).

Abstract— Conventional three-level discontinuous pulse-width modulation (DPWM) techniques are typically employed in variable frequency drive applications to reduce inverter switching losses and provide maximum benefit for load power factor angles in the range from 30° lagging to 30° leading. This paper proposes a series of DPWM templates for lower power factors and a generalized DPWM strategy for three-level T-NPC inverters operating with modulation indices lower than 0.5. With a change in the power factor, the proposed strategy adapts the inverter pulse sequence by combining different portions of the proposed DPWM templates within one fundamental cycle and ensures minimum switching instances during transitions. Consequently, the strategy perfectly aligns the no-switching durations of the inverter pulse-patterns with the respective load-current peaks, achieving a 50% switching loss reduction for all operating power factor angles (90° lagging to 90° leading) at modulation indices lower than 0.5. The paper provides an analytical evaluation of the proposed strategy on the three-level T-NPC inverter switching losses. The simulation and experimental results demonstrate the effectiveness of the proposed three-level generalized

The development of power electronic converters is marked by demands for a simultaneous reduction in Size , losses and power related costs. Historically diode bridge rectifiers with a laSrge capacitor at the dc bus have been used to convert the ac voltage to a dc voltage. But diode bridge rectifiers draw a very high peak current from the ac utility, which is rich in harmonics and thus gives a very poor power factor. Modern AC-DC power supplies utilize power factor correction in order to minimize the harmonics in the input current drawn fiom the utility. The Boost topology is the most popular topology used for power factor correction today. In this paper, power factor correction using boost converters in single phase diode bridge rectifiers is presented.

This paper investigates adjustable speed induction motor drive using 2-level and 3-level PWM.The result obtained is verified using Matlab simulation.This result compares the hamonic contect in between 2-level and 3-level by FFT analysis tool.To analyse the resulta a carrier based pwm was taken using 2- level and 3- level topology and a threephase bridge convetor with internally generated capability SPWM/SVPWM was intrduced. Carrier freqency18*60Hz, modulation index 0.9, output voltage freqency 60 Hz and ouput voltage phase 0 degre Was fixed. So corresponing to above values,the motor speed was 1800 rpm. Or 188.5 radian/sec, hence torque is 11.87Nm. A two pole squirrel cage motor was taken subjected to 400V dc source with modulation index0.9 prduces 220v rms.when motor starts, at 0.5s it reaches its steady speed 181 radian/sec or 1728 rpm. Now by discretizing the FFT tool displays the frequency spectrum of voltage and current waveforms. These signals are stored in workspace in the ASM structure with time variable generated by the Scope block. As my model is discretized, the signal saved in this structure is sampled at a fixed step and consequently satisfies the FFT tool requirements.It was observed that value of total harmonic distortion(THD) was 65.77 percent in 2-level and 35.11 percent in 3- level for SPWM invertor and 56.77 percent for SVPWM invertor.

This thesis deals with the configuration and investigation of control framework structures for electric drives furnished with changeless magnet synchronous machines (PMSM) in car application. With the expanding prominence of multi-level inverters, the opportunity to get better of the execution of voltage source inverters has persistently been tried for different applications. The fast improvement of high exchanging recurrence power gadgets in the previous decade leads towards more extensive use of voltage source inverters in AC power era. In this way, this prompts the requirement for a regulation method with less aggregate symphonious bending, less exchanging misfortunes, and more extensive direct balance range. The present theory highlights the examination of the customary two-level inverter and the three-level diode cinched inverters for the application in car industry.

Power supplying mode is choose according to the position of the switch shown in the figure below:

Abstract—Different converter topologies have been introduced for high power applications in recent years. This paper shows Permanent Magnet Synchronous Motor in Hybrid electrical vehicle is proposed by an interface of boost converter, interleaved converter and inverter as an integrated circuit. An inverter/converter circuit is designed in such a way so as to operate or control the HEV during different modes of operation. The integrated circuit in HEV will operate as a boost converter or interleaved converter depending on the load condition. The proposed integrated circuit will reduce the current ripple and voltage ripple hence it will leads to reduction in switching, conduction losses, and thermal stress on the motor. The effectiveness of proposed integrated circuit is simulated in MATLAB/ Simulink. The simulation shows that the integrated circuit have a high efficiency and can be used at high power application.