Aree Wangsupphaphol

Improved EKF-based direct torque control at the start-up using constant switching frequency

A sensorless extended Kalman filter (EKF) based direct torque control (DTC) with the use of a constant switching frequency control (CSFC) of induction machine is proposed in this research work. This paper is meant to investigate the dynamic performance for DTC-CSFC and DTC with a hysteresis torque controller by applying different speed step changes from three different low speed operations. The dynamic performance results show that the sensorless EKF-based DTC-CSFC is superior to the conventional EKF-based DTC when reference speed change is applied from 0 to 59 rad/s. Additionally, improvement in the reduction of torque ripples is achieved for all step changes of speed. The effectiveness of the proposed EKF-based DTC-CSFC is confirmed by experimental validation.

Acceleration-based design of electric vehicle auxiliary energy source

The battery electric vehicle (BEV) has disadvantages of high power loss during acceleration and poor regenerative braking energy recapture. Moreover, the battery is frequently exposed to repetitive high power demand, which consequently shortens the battery lifetime [1]. To overcome these problems, many parallel connections of energy sources have been proposed by scientists with the aim to reduce high peak power supply and repetitive power, as well as to save battery energy and lengthen its use [2], [3]. In this article, a parallel supercapacitors (SCs)- batteries scheme for battery hybrid electric vehicle (BHEV) and its control are proposed. The configuration consists of a parallel connection of batteries and SCs, which are connected to the inverter via a bidirectional dc-dc converter, as shown in Figure 1. This scheme intends to save braking energy for extending the driving range. In order to control the voltage and current of SCs, the control algorithms, composed of cascaded voltage and current loops based on the acceleration-based design (ABD), are developed. For efficiency validation, comparison of the core features between 3 different system configurations are proposed: the proposed BHEV with acceleration-based design (BHEV-ABD), BHEV with load-based design (BHEV-LBD) [4], and a pure BEV.

Energy and power control strategy for battery electric vehicle with supercapacitors

This paper presents a new energy and power management control strategy for battery electric vehicle (BEV) with supercapacitors (SCs) based on speed command and acceleration estimation. The purpose of the control strategy is to increase the capability of regenerative braking energy capturing and to improve DC bus voltage regulation. The control strategy uses cascade voltage and current control of SCs. The voltage and current references are calculated based on the speed command and acceleration including the power losses of the system. The whole electrical drive system is mathematically modelled and the core features of the control strategy are presented. Numerical simulation demonstrates the benefits of the proposed control strategy in term of energy saving and DC bus voltage regulation improvement compared to the BEV without SCs.