Direct Current Chopper Research Articles

Performance Analysis of DC Motors With Integrated Proportional-Integral and Artificial Neural Network Control

Direct current (DC) motors are frequently utilized in various applications, and the motor's pace is affected by applied loads as it fluctuates. A power converter must be employed to control the velocity of the motor by varying the armature voltage. One of the options for the power converter is the one-quadrant DC chopper. In this case, the investigation will turn the one-quadrant chopper into a system by merging velocity and current control into the DC motor. The speed is regulated by controlling the armature voltage. This may be accomplished using a controlled rectifier. The contribution of the research is to test the effectiveness of Artificial Neural Network Control (ANN) and Proportional-Integral (PI) controllers to control the speed of a DC motor using a one-quadrant DC chopper. Therefore, due to technological advancements, the authors will utilize the training data of the artificial neural network of Proportional- Integral controllers in MATLAB's Simulink. Test results demonstrate the artificial neural network (ANN's) superior ability to regulate system response, showing enhancements in delay time, rise time, overshoot, and steady-state error compared to the PI controller. These findings underscore the potential of ANN as a more sophisticated choice for DC motor control, although further research is required to finetune its performance through rigorous training.

Kendali Kecepatan Motor DC Menggunakan Chopper DC Dua Kuadran Berbasis Kontroller PI

DC (Direct Current) motor is one of drive which is widely used in industry. DC motor as a drive has several advantages compared with AC (Alternating Current) motor. One of the advantages use DC motor as drive in industry because has a starting big torque and rotation speed motor can be set up easily in the range wide variation of rotation. One of speed setting DC motor can use DC Chopper two quadrant. Speed control DC motor with DC Chopper two quadrant is a method for speed control motor DC can operate for two condition which can be stated in the quadrant system. For one quadrant DC motor can operate for forward motoring and the second quadrant DC motor can operate for renegerative breaking. DC Chopper is a electronic circuits can change value voltage and current DC source, and can using for speed control and operate DC motor. For system control used controller PI (proportional integral) for feedback parameter mechanics and electrick DC motor. For controller PI can work for system control used Simulink software for programming, and also works for interfece to displays real times condition parameters work operate DC motor.

Coordinated Optimization of DFIG Rotor Crowbar and DC-chopper Resistances Based on NSGA-II

Abstract Low voltage ride-through (LVRT) scheme of doubly-fed induction generator (DFIG) will affect the transient stability of power system since it will change the operation state of wind turbine. The LVRT scheme combining rotor crowbar circuit and Direct Current chopper (DC-chopper) circuit is effective, but the resistances of crowbar and DC-chopper are set separately and the impact on the system transient stability is usually ignored, which makes it difficult to gain optimum control effect. In this paper, the relation between rotor crowbar and DC-chopper in LVRT duration is analyzed in theory, which shows the effect of DC-chopper circuit can be considered as the variation of crowbar in equivalent circuit. Furthermore, by analyzing the effect of crowbar on the LVRT performance and power system transient stability, a coordinated resistance optimization method of crowbar and DC-chopper is proposed. Based on this method, a multi-objective optimization model for crowbar and DC-chopper resistance considering both LVRT performance and system transient stability is established, and the non-dominated sorting genetic algorithms-II (NSGA-II) is applied to solve this multi-objective optimization problem. The simulation results verify that the coordinated optimization scheme will not only achieve better LVRT characteristics, but also improve the transient stability of power system.

A Comparisson of Synchronous And Nonsynchronous Boost Converter

Modern electronic systems require resources with high efficiency. The efficiency of direct current to dicrect current converters as a power source can be increased by replacing a diode with MOSFET. The use of MOSFET is expected to reduce power loss as the internal resistance of MOSFET is lower than a diode. To implement the propossed idea, a boost type direct current chopper and TL494 as PWM generator circuit were applied in this work. MOSFET is used in synchronization mode to replace diode at conventional topology of chopper. The proposed circuit and conventional topology were made and their performance were observed. The efficiency of both circuit were compared and analyzed. The result of the experiments showed that the efficiency of converter within MOSFET at synchronization mode is proportional with the increment of duty cycle, while at conventional topology the efficiency remain stable at any duty cycle. Synchronous boost converter is more efficient than nonsynchronous boost converter at duty cycle over than 40%.

A Comparisson of Synchronous and Nonsynchronous Boost Converter

Modern electronic systems require resources with high efficiency. The efficiency of direct current to dicrect current converters as a power source can be increased by replacing a diode with MOSFET. The use of MOSFET is expected to reduce power loss as the internal resistance of MOSFET is lower than a diode. To implement the propossed idea, a boost type direct current chopper and TL494 as PWM generator circuit were applied in this work. MOSFET is used in synchronization mode to replace diode at conventional topology of chopper.. The proposed circuit and conventional topology were made and their performance were observed. The efficiency of both circuit were compared and analyzed. The result of the experiments showed that the efficiency of converter within MOSFET at synchronization mode is proportional with the increment of duty cycle, while at conventional topology the efficiency remain stable at any duty cycle. Synchronous boost converter is more efficient than nonsynchronous boost converter at duty cycle over than 40%.

Fast Coordinated Control of DFIG Wind Turbine Generators for Low and High Voltage Ride-Through

This paper presents a fast coordinated control scheme of the rotor side converter (RSC), the Direct Current (DC) chopper and the grid side converter (GSC) of doubly fed induction generator (DFIG) wind turbine generators (WTGs) to improve the low voltage ride through (LVRT) and high voltage ride through (HVRT) capability of the DFIG WTGs. The characteristics of DFIG WTGs under voltage sags and swells were studied focusing on the DFIG WTG stator flux and rotor voltages during the transient periods of grid voltage changes. The protection schemes of the rotor crowbar circuit and the DC chopper circuit were proposed considering the characteristics of the DFIG WTGs during voltage changes. The fast coordinated control of RSC and GSC were developed based on the characteristic analysis in order to realize efficient LVRT and HVRT of the DFIG WTGs. The proposed fast coordinated control schemes were verified by time domain simulations using Matlab-Simulink.

Short‐circuit analysis of a doubly fed induction generator wind turbine with direct current chopper protection

ABSTRACTModern doubly fed induction generator (DFIG) wind turbines can ride through a symmetrical fault in the network by using a chopper protection on the direct current (DC) link without triggering a crowbar protection. A novel method to model the DC link system of such wind turbines as an equivalent resistance during symmetrical faults is presented in this paper. The method allows looking at the DFIG with chopper protection as to one with an equivalent crowbar protection and, hence, to apply to the former type of DFIG short‐circuit calculation methods developed for a DFIG with crowbar protection. This may be a valid help in short‐circuit calculations, for example, for protection settings. It also allows simulating for short‐circuit studies a DFIG with chopper protection, often not available in a standard power system simulation software, by using an equivalent DFIG with crowbar protection, which is a standard model in power system simulation software. The results for the short‐circuit current obtained through the proposed method are compared with simulations of a detailed model of a DFIG with chopper protection under different conditions, which showed good agreement. It is also shown that the DFIG with chopper protection delivers lower short‐circuit current than a DFIG with standard crowbar protection, especially for low initial loading. Copyright © 2011 John Wiley & Sons, Ltd.