Proteus/Simulink Analysis of Rectifier based E-Vehicle Charger Circuit

. In this paper, an AC to DC rectifier circuit has been discussed and the simulation results are provided. This converter is very useful for the upcoming development of the electric vehicles charging technology. For producing steady DC from a rectified AC supply requires a smoothing circuit or filter. The main purpose of the filter circuit is to remove the ripple or ac components from the output of the diode circuit. So, to make the output DC pure, the filter circuit is used. The filter circuit may be inductive (built with only inductors in series) or capacitive (built with only capacitors in parallel) or Inductive-Capacitive (built with both inductors and capacitors). A voltage regulator which is used to maintain the constant output DC voltage. Design of the controller is detailed for reference. The converter will operate in continuous conduction mode (CCM). Finally, some selected experimental results are presented to verify the proposed theory.


Introduction
These days, there are many purposes behind the advancement of electric vehicles (EVs). The most important reasons are increasing of fuel cost, lacking in energy resources and reduce the greenhouse gas emission [4]. The advantages of using the EVs can be stated as, being a source of the clean energy, having high efficiency when compared to the conventional vehicles and producing less noise than the conventional vehicles [13]. But the supply for the EV is from the battery. This paper provides a solution for charging of EV batteries.
L. Sri Sivani, Nagi Reddy B, K. Subba Rao, A. Pandian has proposed a paper on A New Single Switch AC/DC Converter with Extended Voltage Conversion Ratio for SMPS Application, which is an AC/DC converter having a buck-boost PFC circuit that operates in discontinuous conduction mode (DCM) to attain unity input power factor and a buck converter to achieve tightly regulated voltage along with wide conversion range [1]. The proposed converter doesn't require extra control technique to achieve unity power factor.
M. Bhaskara Rao, T. Lokanadha Rao, Nagalla Sowjanya, T. Jaganmohan Rao proposed a paper which titled as An Efficient AC-DC Step up Converter for Low voltage Harvesting Applications. In this paper, presents an efficient ac-dc power converter that avoids the bridge rectification and directly converts the low ac input voltage to the required high dc output voltage at a higher efficiency [18]. The proposed converter consists of a boost converter in parallel with a buck-boost converter, which are operated in the positive half cycle and negative half cycle, respectively.
Ching-Tsai Pan, and Tsung-Cheng Chen has proposed a paper on Modelling and Design of an AC to DC Converter. this paper, a step-up-down single-phase ac-to-dc converter without current sensor is proposed to achieve high performance and simple control logic. The converter adopts a front-end diode rectifier so that only one active switch is required [2]. Unlike the existing model, which is valid only for very low frequency range, namely below line frequency, the proposed model is applicable up to half switching frequency.

Block Diagram
The block diagram of rectifier that was built with four important parts such as step-down transformer, a diode circuit, a filter circuit, and a voltage regulator circuit.

Fig. 1. Block Diagram
The transformer is a device that steps up or steps up the voltage. The normal step-down transformer is used when it is a bridge rectifier circuit. Now coming to the diode circuit, that is a very important part of the rectifier. The diode circuit is made of four diodes. The full-wave bridge rectifier circuit is built with four PN junction diodes. The bridge rectifier is the most efficient among all and is nowadays mostly used.
The main purpose of the filter circuit is to remove the ripple or ac components from the output of the diode circuit. The diode circuit converts alternating current (AC) into Direct Current (DC) but it is not in pure form. So, to make the output DC pure, the filter circuit is used. The filter circuit may be inductive (built with only inductors in series) or capacitive (built with only capacitors in parallel) or Inductive-Capacitive (built with both inductors and capacitors).
The main objective to use a voltage regulator circuit is to keep the output voltage level constant even when the input voltage or output load fluctuates or changes. Generally, a Zener diode is connected in parallel with reverse for voltage regulation. Or the voltage regulator ICs.

Circuit Configurations
A rectifier is an electronic device or circuit that converts the Alternating Current (AC) into Direct Current (DC). The main component of a rectifier circuit is the PN Junction Diode. A rectifier circuit may use a four PN Junction Diodes (for bridge rectifier). Actually, the diode converts the AC into DC. The other parts of the rectifier are also important.

Fig. 2. Circuit Diagram
The proposed converter is designed for charging of E-Vehicle batteries. The output voltage of this converter will be remains constant and regulated by using the ICs. By using the smoothing capacitor at the end of the circuit. It will reduce the output ripple voltage.

Components Specifications
There are four main components used in this rectifier circuit. They are transformer, bridge rectifier, smoothing capacitor and voltage regulator. When an AC signal is applied across the bridge rectifier, we notice that the current flow across load resistor R L is the same during the positive and negative half-cycles. The output DC signal polarity may be either completely positive or negative. In this case, it is completely positive. If the diodes' direction is reversed, the obtained DC voltage is completely negative. Thus, a bridge rectifier allows electric current during both positive and negative half cycles of the input AC signal.

Simulation and Waveforms
The simulation work of this AC to DC rectifier is done with the help of proteus simulation application. By using this all the data of the converter is taken and displayed below.

Fig. 3. Simulation circuit
The output waveforms of the AC to DC rectifier are shown in the below figure, Fig-4 shows the input waveform from the supply which has the amplitude of 230 V in the supply. This supply is given to the bridge rectifier circuit.    Fig-7 shows the pure DC output voltage, the voltage from the filter capacitor will be oscillated. Because, the capacitor will keep on charging. So, the voltage from the capacitor will not be constant and not preferred to give to the battery. So, a voltage regulator is used to kept the output DC voltage constant. This is the DC output voltage waveform of the rectifier circuit which is given to the battery. So, these are the simulation and its waveforms of the AC to DC converter circuit. All the necessary data are collected.

Results and Discussions
From the above simulations and waveforms results, all the readings are taken and tabulated.  Table-2 show the output voltage and power factor of the rectifier circuit under the input AC voltage is varied. The frequency of the system is kept constant and the input AC voltage only varying. With respect to the input voltage the power factor of the system is varying. When the input AC voltage is decreased, the power factor is also decreased.  Table-3 In this table, the input AC voltage is kept constant and the system frequency is varied. Hence with respect to the frequency, the power factor and output DC voltage is varying. When the frequency of the system is decreased, the power factor is decreased and somehow the output DC voltage is also slightly decreased.

Conclusion
In this paper, the design and analysis of the AC to DC diode bridge rectifier circuit for the charging of batteries in E-Vehicles are discussed. The simulation of the circuit diagram is done in proteus simulation application and the different waveforms of the circuit from different components are collected and they are placed above in this paper. Finally, the simulation work for different input AC voltage and frequency and the changes in output DC voltage and power factor based on the change in input are noted and tabulated. The