Advantages And Disadvantages Of PFC Transverter

Fig.3. shows algorithm for the proposed method. This algorithm uses voltage and current of the PV module. A permitted error of 0.06 as shown in (8) is used in modified algorithm to eliminate the steady state oscillation in the system. The permitted error is written as  I + V dI/dV   0.06 Using the permitted error of 0.06, the steady state error is approximately 0.7% based on the duty cycle step size of 0.005.

15. Load transient response is simulated under load variations from 0mA to 50mA that step load current has 100ns rise/fall times. The maximum overshoot and undershoot is 45.2mV and 30mV, respectively. It is evident from Fig. 15 which settling time is less than 5.65µs which provides fast settling time in compare with previous works. Line transient response is demonstrated in Fig. 16. As it is evident that the maximum variations at the LDO output are less than 7.4mV under loading condition of 50mA with the step voltage source from 1.8V to 2.2V with 500ns rise/fall

A phase-locked loop (PLL) generates a signal that has a fixed relation to the phase of a reference signal and is given in Fig. 4. A phase locked loop responds to both the frequency and the phase of the input signals, automatically raising or lowering the frequency of the controlled oscillator until it is matched to the reference in both frequency and phase. Here three phase PLL was implemented with three basic functional blocks: the phase detector, a PI controller and a voltage controlled oscillator. The phase detector is a circuit capable of delivering an output signal that is proportional to the phase difference between its two input signals. The PI controller is a low pass filter and used to suppress high frequency component and provide dc controlled signal to voltage controlled oscillator which acts as an integrator. The output of the PI controller is the inverter output frequency that is integrated to obtain inverter phase angle θ. When the difference between grid phase angle and inverter phase angle is equal, Vq =

Efficiency increases due to low energy consumption 3. It provide battery backup for about one hour 7.2 Application 1. To reduce cost, size and weight of a power supply 2. CCTV cameras, TV’s, monitor, PC’s, laptop and camcorder power packs, printers, fax machine, VCRs, portable CD players, microelectronics based devices in automotive, computing, communication, consumer electronics and industrial applications use SMPS. Controllable output power analysis of SMPS using PWM technique for DC appliances Sigma, Matar Page XXXVII CHAPTER 8 CONCLUSION Controllable output power analysis of SMPS using PWM technique for DC appliances Sigma, Matar Page XXXVIII  Suitable components were selected and tested for desired performance.

It is observed that the power factor is maintained closer to unity when the input voltage is reduced from 230V to 110Vrms. Figure 11 (a) and (b) shows the power factor correction of controller for various load condition such as 20% (60W) and 75% (230W). The power factor for the system is found to be 0.84 for light load condition and 0.99 for full load condition. The THD of input current at full load with predominant third and fifth harmonic components are shown in Figure 12(a) and (b).Third harmonics is found to be 4.8% and fifth harmonic component is 4.9% which are well within IEC 61000-3-2 standard during wide range of load variations. The variation in power factor with load is shown graphically in Figure 13(a). It can be inferred from the graph that improved resettable control operates at high power factor for all load condition whereas the conventional PI control has poor power factor under light load conditions. Figure 13(b) shows the comparison between the efficiency of the converter for varying load conditions with the conventional control method and the resettable integrator control. The converter’s efficiency is maintained at 92% for light load conditions and 96% for fully loaded condition with integrator control technique. Thus the improved resettable integrator controller provides a very simple and reliable solution for power factor correction and

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

The impact of the proposed sequences has been simulated for 0.4 modulation index with a 0.5 lagging power factor load (power factor angle 60°). The simulation setup consists of the following software: 1) MATLAB/Simulink – used to implement the modulation strategies and switching sequences, and 2) PSIM – used to simulate the T-NPC inverter running with an R-L load and to provide conduction and switching losses of each switch. The inverter switching pulses were generated within Simulink and were fed to PSIM through sim-coupler module which provides a link between PSIM and simulink for the purpose of co-simulation [29].

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.

Switching power converters offer an easy way to regulate both the frequency and magnitude of the voltage and current applied to a motor shown in fig(1). As a result much higher efficiency and performance can be achieved by these motor drives with less generated noises[3].

With the advent of modern controls theory and in the semiconductor technology, the use of high sophisticated technologies, advance digital controllers and embedded systems which include microprocessors, DSPs (digital signal processors), ASICs (application-specific integrated circuits), and FPGAs (field-programmable gate arrays).in the area of AC power control have become global challenges nowadays[1]. Recently FPGAs have become a good alternative answer and have been generally accepted as a tool for the controller`s platform in high performance embedded control system[2]. This device completely give inventors the ad-liberty to use their design customs

And are fundamental frequency positive-, negative-, and zero-sequence components, respectively, and is the harmonic component of the bus voltage. According to control objectives of the MC-UPQC, the load voltage

DBR followed by a filter and an isolated zeta converter. The filter is designed to avoid any switching ripple in the DBR and thesupply system. An isolated zeta converter is designed to operate in DCM to act as an inherent power factor corrector. This combinationof DBR and PFC converter is used to feed a BLDC motor drive via a three-phase VSI as shown in Fig. 1. The dc link voltage of the VSI is controlled by varying the duty ratio of the PWM pulses of PFC converter switch. However, VSI is operated in a low frequency switching to achieve an electronic commutation of BLDC motor for reduced switching losses. A single voltage sensor is used at the front-end converter for the control of dc link voltage for speed control of BLDC motor. The proposed drive is designed and its performance is validated on a developed prototype for improved power quality at ac mains for a wide range of speed control and supply voltage variations.

The main advantage of sliding mode is low sensitivity to plant parameter variations and disturbances which reduces the need of precise modeling. Sliding mode control allows the decoupling of the overall system motion into independent partial components of lower dimension and, as a result, decreases the difficulty of feedback design. Sliding mode control implies that control actions are discontinuous state functions which may simply be applied by straight power converters with “on-off” as the only permissible operation mode. Due to these properties sliding mode control has been proved to be valid to a wide range of problems in robotics, electric drives and generators, process control, vehicle and motion control.

Abstract—In this paper, A bidirectional full-connected dc–dc converter with a change proportion around nine times, delicate start-up, and delicate exchanging elements for PMDC motor drive is proposed in this paper. The converter is furnished with a dynamic flyback and two inactive capacitor–diode snubbers, which can diminish voltage and current spikes and lessen voltage and current burdens, while it can accomplish almost zero-voltage-exchanging and zero-present exchanging delicate exchanging element. Simulation results are presented using MATLAB/ SIMULINK software.