The interests on energy storage schemes, bidirectional dc-dc converter and uninterruptible power supplies have been increasing nowadays as there wide researches are undertaken in the area of electric vehicles. A modif...The interests on energy storage schemes, bidirectional dc-dc converter and uninterruptible power supplies have been increasing nowadays as there wide researches are undertaken in the area of electric vehicles. A modified bi directional class-E resonant dc-dc converter is introduced here in this proposed topology for the application in electric vehicles. The advantages of soft switching techniques have been utilized for making analysis simple. The main advantage here in this system is that it can operate in a wide range of frequencies with minimal switching loss in transistors. This paper elaborates a detailed analysis on converter design and the same has been simulated and verified in Matlab/Simulink.展开更多
In order to meet the requirement of reliably running which is by Electric Vehicle for motor controller, the paper is focused on a sensorless brushless DC motor controller design and a commutation point method. By util...In order to meet the requirement of reliably running which is by Electric Vehicle for motor controller, the paper is focused on a sensorless brushless DC motor controller design and a commutation point method. By utilizing the saturation effect of stator iron core, six short voltage pulses are employed to estimate the initial rotor position. After that a series of voltage pulses are used to accelerate the motor. When the motor reaches a certain speed at which the back-electromotive force (EMF) method can be applied, the running state of the motor is smoothly switched at the moment determined by the relationship between the terminal voltage waveform and the commutation phases. “Lagging 90?-α commutation” is bring forward to overcome the shortages existing in the traditional method. The experimental results verify the feasibility and validity of the proposed method.展开更多
A power system structure composed of a brushless DC motor and a cycloidal reducer for electric balanced vehicle has been proposed, and the temperature of important components in this structure would be discussed. The ...A power system structure composed of a brushless DC motor and a cycloidal reducer for electric balanced vehicle has been proposed, and the temperature of important components in this structure would be discussed. The loss generated by the cycloid reducer is negligible, it’s only need to analyze the thermal field of motor. Since the temperature change will affect the material properties of the target motor, the electromagnetic and temperature fields, involved in the motor, are selected for coupling calculation to determine whether the final temperature distribution can meet the requirements of vehicle for use.展开更多
With rapid growth of power demand, transmission capacity is also in urgent need of upgrading. In some cases, converting existing AC transmission lines to DC lines can Improve the transmission capacity and reduce the c...With rapid growth of power demand, transmission capacity is also in urgent need of upgrading. In some cases, converting existing AC transmission lines to DC lines can Improve the transmission capacity and reduce the construction investment. In this paper, the upstream finite element method was expanded to calculate the total electric field of same tower multi-circuit DC lines converted from double-circuit AC lines, and the validity of the algorithm was confirmed by experiments. Taking a DC line converted from a typical same tower 500 kV double-circuit AC transmission line as an example, the surface electric field and the ground total electric field in different pole conductor arrangement schemes were calculated and analyzed, and the critical height of pole conductors for DC lines in residential and non-residential area were determined. Then, the corridor width of DC and AC lines at critical height in residential and non-residential areas before and after AC-DC line transformation were compared. The results indicate that for DC lines converted from common 500 kV double-circuit AC lines, the ground total electric field can meet the requirements of corresponding standard with appropriate pole conductor arrangement schemes.展开更多
The line side winding is under the fundamental frequency AC voltage, while the valve side winding contains not only fundamental AC voltage component, but also the DC voltage component, fundamental AC voltage component...The line side winding is under the fundamental frequency AC voltage, while the valve side winding contains not only fundamental AC voltage component, but also the DC voltage component, fundamental AC voltage component, and higher harmonic voltage components when the converter transformer is at its normal operating condition, and the electric field of converter transformer is a non-sinusoidal steady one. To analyze the non-sinusoidal steady electric field containing the DC component, fundamental AC and higher harmonic components, the voltage spectrum of the valve winding in a ±500 kV converter transformer is firstly analyzed, and the non-sinusoidal periodic steady electric field is obtained by the fast discrete Fourier transform. Different resistivity of the oil and oil-immersed paper is adopted to simulate the aging of oil paper insulation at operation, and get the non-sinusoidal steady electric field.展开更多
The paper describes the various energy management techniques that can be implemented for a modern electric vehicle by using MATLAB/SimuUnk. The Renault Twizy vehicle is considered for MATLAB simulation. Regenerative b...The paper describes the various energy management techniques that can be implemented for a modern electric vehicle by using MATLAB/SimuUnk. The Renault Twizy vehicle is considered for MATLAB simulation. Regenerative braking technique is discussed, in which the kinetic energy is converted to electricity to charge the battery of the vehicle when the brakes are applied or when the vehicle is moving down the hill. A solar photovoltaic （PV） on the roof-top of the vehicle is implemented to charge the battery used in the vehicle. The simulation results are highlighted and energy management strategies are presented. The results showed that the speed control of direct current （DC） motor during the motoring mode and regenerative braking mode was successfully achieved by using a bi-directional DC-DC converter and a proportional-integral （PI） controller at various reference speeds set by the user by applying a variable load torques to the motor. The size of solar PV on roof-top of the vehicle was found to be 280 W that charged the 48 V battery of the vehicle by using a bi-directional DC-DC converter, which was evaluated by using MATLAB/Simulink.展开更多
The design of a bidirectional dc-dc power converter specifically for a distributed energy application is presented. The existing two different DC voltage battery bank of the distributed generation needs to interlink e...The design of a bidirectional dc-dc power converter specifically for a distributed energy application is presented. The existing two different DC voltage battery bank of the distributed generation needs to interlink each other using a bi-directional dc-dc converter in order to minimize the unbalance of the output load currents of the three inverters connected to electric grid system. Through this connection, a current can flow from one system to another or vice versa depending on which systems need the current most. Thus, unbalanced currents of the grid line have been minimized and the reliability and performance of the DER grid connected system has been increased. A detailed mathematical analysis of the converter under steady state and transient condition are presented. Mathematical models for boost and buck modes are being derived and the simulink model is constructed in order to simulate the system. Moreover, the model has been validated on the actual operation of the converter, showing that the simulated results in Matlab Simulink are consistent with the experimental ones.展开更多
The rise in the price of oil and pollution issues has increased the interest on the development of electric vehicles. This paper discusses about the application of solar energy to power up the vehicle. The basic princ...The rise in the price of oil and pollution issues has increased the interest on the development of electric vehicles. This paper discusses about the application of solar energy to power up the vehicle. The basic principle of solar based electric vehicle is to use energy that is stored in a battery to drive the motor and it moves the vehicle in forward or reverse direction. The Photo Voltaic (PV) module may be connected either in parallel or series, and the charge controllers direct this solar power to the batteries. The DC voltage from the PV panel is then boosted up using a boost DC-DC converter, and then an inverter, where DC power is converted to AC power, ultimately runs the Brushless DC motor which is used as the drive motor for the vehicle application. This paper focuses on the design, simulation and implementation of the various components, namely: solar panel, charge controller, battery, DC-DC boost converter, DC-AC power converter (inverter circuit) and BLDC motor for the vehicle application. All these components are modeled in MATLAB/SIMULINK and in real-time, the hardware integration of the system is developed and tested to verify the simulation results.展开更多
This paper presents a controller for fast and ultrafast electric vehicle(EV)charging stations.Without affecting the charging efficiency,the proposed controller enables the charger to provide support to the interconnec...This paper presents a controller for fast and ultrafast electric vehicle(EV)charging stations.Without affecting the charging efficiency,the proposed controller enables the charger to provide support to the interconnection voltage to counter and damp its transients.Existing solutions are either hardware-based such as using supercapacitors and flywheels which increase the cost and bulkiness of the charging station,or software-based such as P/V droop methods which are still unable to provide a robust and strong voltage support.This paper proposes an emulated supercapacitor concept in the control system of the ultra-fast EV charger in an islanded DC microgrid.Thus,it converts the EV from a static load to a bus voltage supportive load,leading to reduced bus voltage oscillations during single and multiple ultra-fast EV charging operations,and rides through and provides supports during extreme external disturbances.Detailed analysis and design guidelines of the proposed controller are presented,and its effectiveness and improved performance compared with conventional techniques are shown for different case studies.展开更多
文摘The interests on energy storage schemes, bidirectional dc-dc converter and uninterruptible power supplies have been increasing nowadays as there wide researches are undertaken in the area of electric vehicles. A modified bi directional class-E resonant dc-dc converter is introduced here in this proposed topology for the application in electric vehicles. The advantages of soft switching techniques have been utilized for making analysis simple. The main advantage here in this system is that it can operate in a wide range of frequencies with minimal switching loss in transistors. This paper elaborates a detailed analysis on converter design and the same has been simulated and verified in Matlab/Simulink.
文摘In order to meet the requirement of reliably running which is by Electric Vehicle for motor controller, the paper is focused on a sensorless brushless DC motor controller design and a commutation point method. By utilizing the saturation effect of stator iron core, six short voltage pulses are employed to estimate the initial rotor position. After that a series of voltage pulses are used to accelerate the motor. When the motor reaches a certain speed at which the back-electromotive force (EMF) method can be applied, the running state of the motor is smoothly switched at the moment determined by the relationship between the terminal voltage waveform and the commutation phases. “Lagging 90?-α commutation” is bring forward to overcome the shortages existing in the traditional method. The experimental results verify the feasibility and validity of the proposed method.
文摘A power system structure composed of a brushless DC motor and a cycloidal reducer for electric balanced vehicle has been proposed, and the temperature of important components in this structure would be discussed. The loss generated by the cycloid reducer is negligible, it’s only need to analyze the thermal field of motor. Since the temperature change will affect the material properties of the target motor, the electromagnetic and temperature fields, involved in the motor, are selected for coupling calculation to determine whether the final temperature distribution can meet the requirements of vehicle for use.
文摘With rapid growth of power demand, transmission capacity is also in urgent need of upgrading. In some cases, converting existing AC transmission lines to DC lines can Improve the transmission capacity and reduce the construction investment. In this paper, the upstream finite element method was expanded to calculate the total electric field of same tower multi-circuit DC lines converted from double-circuit AC lines, and the validity of the algorithm was confirmed by experiments. Taking a DC line converted from a typical same tower 500 kV double-circuit AC transmission line as an example, the surface electric field and the ground total electric field in different pole conductor arrangement schemes were calculated and analyzed, and the critical height of pole conductors for DC lines in residential and non-residential area were determined. Then, the corridor width of DC and AC lines at critical height in residential and non-residential areas before and after AC-DC line transformation were compared. The results indicate that for DC lines converted from common 500 kV double-circuit AC lines, the ground total electric field can meet the requirements of corresponding standard with appropriate pole conductor arrangement schemes.
文摘The line side winding is under the fundamental frequency AC voltage, while the valve side winding contains not only fundamental AC voltage component, but also the DC voltage component, fundamental AC voltage component, and higher harmonic voltage components when the converter transformer is at its normal operating condition, and the electric field of converter transformer is a non-sinusoidal steady one. To analyze the non-sinusoidal steady electric field containing the DC component, fundamental AC and higher harmonic components, the voltage spectrum of the valve winding in a ±500 kV converter transformer is firstly analyzed, and the non-sinusoidal periodic steady electric field is obtained by the fast discrete Fourier transform. Different resistivity of the oil and oil-immersed paper is adopted to simulate the aging of oil paper insulation at operation, and get the non-sinusoidal steady electric field.
文摘The paper describes the various energy management techniques that can be implemented for a modern electric vehicle by using MATLAB/SimuUnk. The Renault Twizy vehicle is considered for MATLAB simulation. Regenerative braking technique is discussed, in which the kinetic energy is converted to electricity to charge the battery of the vehicle when the brakes are applied or when the vehicle is moving down the hill. A solar photovoltaic （PV） on the roof-top of the vehicle is implemented to charge the battery used in the vehicle. The simulation results are highlighted and energy management strategies are presented. The results showed that the speed control of direct current （DC） motor during the motoring mode and regenerative braking mode was successfully achieved by using a bi-directional DC-DC converter and a proportional-integral （PI） controller at various reference speeds set by the user by applying a variable load torques to the motor. The size of solar PV on roof-top of the vehicle was found to be 280 W that charged the 48 V battery of the vehicle by using a bi-directional DC-DC converter, which was evaluated by using MATLAB/Simulink.
文摘The design of a bidirectional dc-dc power converter specifically for a distributed energy application is presented. The existing two different DC voltage battery bank of the distributed generation needs to interlink each other using a bi-directional dc-dc converter in order to minimize the unbalance of the output load currents of the three inverters connected to electric grid system. Through this connection, a current can flow from one system to another or vice versa depending on which systems need the current most. Thus, unbalanced currents of the grid line have been minimized and the reliability and performance of the DER grid connected system has been increased. A detailed mathematical analysis of the converter under steady state and transient condition are presented. Mathematical models for boost and buck modes are being derived and the simulink model is constructed in order to simulate the system. Moreover, the model has been validated on the actual operation of the converter, showing that the simulated results in Matlab Simulink are consistent with the experimental ones.
文摘The rise in the price of oil and pollution issues has increased the interest on the development of electric vehicles. This paper discusses about the application of solar energy to power up the vehicle. The basic principle of solar based electric vehicle is to use energy that is stored in a battery to drive the motor and it moves the vehicle in forward or reverse direction. The Photo Voltaic (PV) module may be connected either in parallel or series, and the charge controllers direct this solar power to the batteries. The DC voltage from the PV panel is then boosted up using a boost DC-DC converter, and then an inverter, where DC power is converted to AC power, ultimately runs the Brushless DC motor which is used as the drive motor for the vehicle application. This paper focuses on the design, simulation and implementation of the various components, namely: solar panel, charge controller, battery, DC-DC boost converter, DC-AC power converter (inverter circuit) and BLDC motor for the vehicle application. All these components are modeled in MATLAB/SIMULINK and in real-time, the hardware integration of the system is developed and tested to verify the simulation results.
文摘This paper presents a controller for fast and ultrafast electric vehicle(EV)charging stations.Without affecting the charging efficiency,the proposed controller enables the charger to provide support to the interconnection voltage to counter and damp its transients.Existing solutions are either hardware-based such as using supercapacitors and flywheels which increase the cost and bulkiness of the charging station,or software-based such as P/V droop methods which are still unable to provide a robust and strong voltage support.This paper proposes an emulated supercapacitor concept in the control system of the ultra-fast EV charger in an islanded DC microgrid.Thus,it converts the EV from a static load to a bus voltage supportive load,leading to reduced bus voltage oscillations during single and multiple ultra-fast EV charging operations,and rides through and provides supports during extreme external disturbances.Detailed analysis and design guidelines of the proposed controller are presented,and its effectiveness and improved performance compared with conventional techniques are shown for different case studies.
