• Journal of Electrical Engineering and Technology
• /
• v.6 no.2
• /
• pp.215-225
• /
• 2011

In this paper, a buck DC-DC bridge converter is used as a power factor correction (PFC) converter for feeding a voltage source inverter (VSI) based permanent magnet brushless DC motor (PMBLDCM) drive. The front end of the PFC converter is a diode bridge rectifier (DBR) fed from single phase AC mains. The PMBLDCM is used to drive the compressor of an air conditioner through a three-phase voltage source inverter (VSI) fed from a variable voltage DC link. The speed of the air conditioner is controlled to conserve energy using a new concept of voltage control at a DC link proportional to the desired speed of the PMBLDC motor. Therefore, VSI operates only as an electronic commutator of the PMBLDCM. The current of the PMBLDCM is controlled by setting the reference voltage at the DC link as a ramp. The proposed PMBLDCM drive with voltage control-based PFC converter was designed and modeled. The performance is simulated in Matlab-Simulink environment for an air conditioner compressor load driven through a 3.75 kW, 1500 rpm PMBLDC motor. To validate the effectiveness of the proposed speed control scheme, the evaluation results demonstrate improved efficiency of the complete drive with the PFC feature in a wide range of speed and input AC voltage.

• Journal of Electrical Engineering and Technology
• /
• v.3 no.4
• /
• pp.546-551
• /
• 2008

In this paper, a flux-lock type superconducting fault current limiter(SFCL) integrated with a voltage-controlled voltage source inverter(VC-VSI) is proposed. The suggested equipment, which consists of a flux-lock type SFCL and a VCVSI, can perform the fault current limiting operation from the occurrence of a short-circuit. In addition, it can compensate the reactive power that the non-linear load requires and also perform the uninterruptible power supply(UPS) as well as the load voltage stabilization by controlling the amplitude and the phase of the inverter's output voltage. The specification for a test model was determined and its various functions such as the fault current limiting and the power conditioning operations were presented and analyzed via computer simulation. Through the analytical results based on the computer simulation, the validity of the analysis was confirmed and its multi-operation was discussed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.17 no.2
• /
• pp.58-65
• /
• 2003

The conventional single phase PFC converter can control DC voltage to steady standard value but control system is system is complex and expensive and has rapidity problems because of controlled by detecting DC voltage, AC voltage and current. In order to solve those problems, this paper proposes senseless PFC converter circuit. The proposed circuit can control the whole system by detecting AC voltage waveform And it directly controlled DC output voltage by the controlled voltage value Kd(Ed/Ea). The fluctuation ratio of DC output voltage is changed by the circuit characteristics These characteristics are confirmed by some experimental results.

• Journal of Advanced Marine Engineering and Technology
• /
• v.41 no.1
• /
• pp.70-75
• /
• 2017

In this paper, we studied the RF characteristics of a voltage-controlled artificial transmission line employing periodically arrayed diodes for application to highly miniaturized wireless communication systems on an MMIC (monolithic microwave integrated circuit). According to the results, the novel voltage-controlled artificial transmission line employing periodically arrayed diodes exhibited a short wave length, which was only 35.2% that of the conventional transmission line, owing to increasing capacitance. In addition, it's effective permittivity and effective propagation constant exhibited considerably higher values than those of the conventional transmission line. Furthermore, attenuation constant of the voltage-controlled artificial transmission line was far higher than that of the conventional transmission line. Using the closed-form equation, we theoretically analyzed the equivalent circuit of the voltage-controlled artificial transmission line.

• Journal of Power Electronics
• /
• v.5 no.2
• /
• pp.104-108
• /
• 2005

This paper presents the performance improvement of voltage-mode controlled interleaved synchronous buck converters. This is a voltage-mode controlled scheme, where the controllers do not need an external saw-tooth generator for PWM generation and the loop design is easier. The controller implementation requires only a single error amplifier and gives almost current mode control performance. The control scheme uses voltage feedback with two loops similar to current mode control: one for the slow outer loop and the other for the faster inner PWM control loop. To improve the performance of the converter system a coupled inductor is used. This coupled inductor reduces the magnetic size and also improves the converter's transient performance without increasing the steady-state current ripple. The effectiveness of the proposed control scheme is demonstrated through PSIM simulations.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.6 no.6
• /
• pp.891-896
• /
• 2002

In this paper, a new voltage-controlled tunable integrator for low-voltage applications is proposed. The proposed active element is composed of the CMOS complementary cascode circuit which can extend transconductance of an element. Therefore, the unity gain frequency which is determined transcon-ductance is increased than that of the conventional element. And then these results are verified by the $0.25{\mu}m$ CMOS n-well parameter HSPICE simulation. As a result, the gain and the unity gain frequency are 42dB and 200MHz respectively in the element on 2V supply voltage. And power dissipation of the designed circuit is 0.32mW.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.4
• /
• pp.871-876
• /
• 2011

In this paper, a voltage-controlled frequency tunable current-mode integrator and a 3rd-order current-mode Chebyshev filter in 1.8V-$0.18{\mu}m$ CMOS is realized for software radio applications in system-on-chips. This filter is used for reconstruction purposes between a current-steering DAC and a current-mode mixer. Power consumption of the designed filter can be reduced by using a current-mode small size integrator. And also, cutoff frequency of this filter is variable between 1.2MHz and 10.1MHz, the power consumption is 2.85mW. And the voltage bias compensated circuit is used to control the voltage variation.in the designed filter.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.242-243
• /
• 2012

In this paper, 200 W power supply for LED driver has been designed, analyzed, simulated and tested. Input AC voltage of 100VAC-240VAC was converted to DC voltage by high power factor converter. Output voltage was controlled, and output current was controlled by constant current when output current was reached to LED maximum rated current. By simulation and experimental test, voltage and current control and high power factor characteristics are verified.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.2
• /
• pp.127-132
• /
• 2003

This paper presents a new model that can precisely simulate the attenuation characteristics of the voltage-controlled PIN diode attenuators. After carefully investigating the problems in the conventional PIN diode models, a new PIN diode model was proposed and verified with experimental data. The proposed model is well operated when it is used in the voltage-controlled mode as well as current-controlled mode, and is simple and straightforward model, since the PN junction diode of this model has the same curve as that of the PIN diode. This model is very effective to design voltage-controlled attenuator and its implementation in commercial simulators is simple and accurate. This model will allow RF and Microwave designers to better use the PIN diodes in various circuits.

• Journal of Power Electronics
• /
• v.19 no.4
• /
• pp.869-880
• /
• 2019

Due to the inherent feedforward of load current, capacitor current (CC) control shows a fast transient response that makes it suitable for the power supplies used in various portable electronic devices. However, considering the effect of the outer voltage loop, the stable range of the duty-cycle is significantly diminished in CC controlled buck converters. To investigate the stability effect of the outer voltage loop on buck converters, a CC controlled buck converter with a proportion-integral (PI) compensator is taken as an example, and its second-order discrete-time model is established. Based on this model, the instability caused by the duty-cycle is discussed with consideration of the outer voltage loop. Then the dynamical effects of the feedback gain of the PI compensator and the equivalent series resistance (ESR) of the output capacitor on the CC controlled buck converter with a PI compensator are studied. Furthermore, the design-oriented closed-loop stability criterion is derived. Finally, PSIM simulations and experimental results are supplied to verify the theoretical analyses.