Implementation Of A New Fast Direct Torque Control Algorithm For Induction Motor Drive

TM4, the industrial partner, is a leading manufacturer and supplier of traction motors and drives for electric vehicle industry in Canada. As a drive manufacturer, they always aim to provide solution which is energy efficient with small footprint. In order to achieve this, they always look for alternative software and hardware solutions. Software modifications, which may improve the system performance in comparison to their existing drive control strategy without increasing the size of the system, are always sought after for continuous improvement of their system. In this regards, the internship is relevant to them for exploring alternative control strategies.

The parameters of this controller (PI- 1) can be decreased during the voltage sag in order to improve the performance of the proposed method.

The impact of the proposed sequences has been simulated for 0.4 modulation index with a 0.5 lagging power factor load (power factor angle 60°). The simulation setup consists of the following software: 1) MATLAB/Simulink – used to implement the modulation strategies and switching sequences, and 2) PSIM – used to simulate the T-NPC inverter running with an R-L load and to provide conduction and switching losses of each switch. The inverter switching pulses were generated within Simulink and were fed to PSIM through sim-coupler module which provides a link between PSIM and simulink for the purpose of co-simulation [29].

Starting Current of both motors were different, when analyzed using ETAP. Starting current of Induction motor was more than that of the synchronous motor. However Induction motor is used for Stable operation in running condition [1]

This paper is organized as follows: Section II describes the three phase BLDC motor and mathematical modeling of BLDC. Section III describes the four quadrant operation of the three phase BLDC motor and its features. The controller PI and its features are explained in Section IV. In section V, the simulation results are presented. Section VI concludes the proposed work.

This career episode is the creation of my thesis during my final year in engineering. The project is called “Microcontroller Based Three Phase Induction Motor Controls”. This is a partial fulfillment for my bachelor’s degree in Electrical Engineering at Mindanao University of Science and Technology. This project commenced on June 2011 and ended on March 2012. I was under the supervision of Engr. Reuel C. Pallugna, one of the instructors in the Electrical Engineering department.

This paper presents a simulation for the sensorless operation of a BLDC motor drive with the estimation of initial rotor position at standstill. The system determines the actual rotor position of the motor at standstill and provides appropriate starting pulses to inverter switches to turn on. Once the motor starts to rotate, it then directly extracts the back EMF from the motor terminals between the floating phase and the midpoint of DC link. Inductance variation sensing method is used for estimating the initial rotor position of the motor followed by a sensorless operation by back EMF sensing method. The principle behind the rotor position estimation is detection and comparison of phase voltage and dc link current responses and relating it with stator inductances.

ABSTRACT: Power flow control in a long transmission line plays a vital role in electrical power system. This paper uses the shunt connected STATCOM for the control of voltage and power flow. The proposed device is used in different locations such as sending end, middle and receiving end of the transmission line. The PWM control is used to generate the firing pulses of the controller circuit. Simulation modeling of the system is carried out using MATLAB/SIMULINK. Based on a voltage-source converter, the STATCOM regulates system voltage by absorbing or generating reactive power. This paper deals with a cascaded multilevel converter model, which is a 48-pulse (three levels) GTO converter. The simulation studies are carried for sending end, middle and receiving end of the transmission line. The objective is to define the reactive power generated and voltage control at different locations (at sending end, middle, receiving end) of transmission line using STATCOM. KEYWORDS: FACTS device, STATCOM, SVC, PWM, MATLAB /Simulink.

In the grid new renewable resources are added to extract more power. This adds more power quality issues to grid connection. A Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that results in a failure or a mis-operation of end user equipment. This paper investigates the use of a static synchronous compensator (STATCOM) is connected at a point of common coupling with Battery Energy Storage System(BESS)to overcome of a power quality issues of a wind farm equipped with variable speed wind turbines driving Double – Fed Induction Generators (DFIG). A physical control scheme, including four control loops: ac voltage, dc voltage, ac active current and ac reactive current controllers, is pre-specified for the STATCOM. A synthetic algorithm is proposed to embed these physical control loops in the output feedback path. The simulation results demonstrated that under various system disturbances, the proposed mode decoupling STATCOM is effective in regulating IG terminal voltage.

2Control & Mechatronics Engineering, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 Skudai Johor Bahru, Malaysia

NOMENCLATURE d-q stator voltages of induction generator d-q stator currents of induction generator d-q rotor currents of induction generator , stator and rotor resistances per phase of induction generator stator, rotor and magnetizing inductances of induction generator self excitation capacitance per phase of induction generator Angular stator frequency of the induction generator Angular rotor speed (electrical rads/s) of the induction generator moment of inertia friction coefficient, differential operator d/dt DC-link inductance DC-link resistance firing angles of the converter and inverter d-q input voltage of the converter d-q input current of the converter DC-link current inverter output voltage d-q stator voltages of synchronous generator d-q damper winding voltages of synchronous generator field winding voltage of synchronous generator d-q stator currents of synchronous generator d-q damper winding currents of synchronous generator field winding current of synchronous generator stator resistance of synchronous generator d and q damper winding resistances d and q mutual inductances d and q self inductances rotor speed (electrical rads/s) of the synchronous generator torque input from diesel engine applied and actual fuel flow rate of diesel engine combustion delay time constant time constant and gain of fuel rack position actuator prediction horizon.

For the systems where high switching efficiency is needed, it is required and desirable to keep switching frequency much lower. In this state,

A few recent papers [53]-[56] have demonstrated a virtual synchronous machine (VSM) concept, particularly for microgrid applications and usually for distributed generators utilizing the same ac-dc-ac conversion stages. The same concept applied on flywheel based energy storage is discussed in [57]. Given the similarities existed in the MEA power grid and motor controlled thermal storage, it is deemed feasible to implement the VSM concept in this research. A high-level description is shown in Fig. 3. For a synchronous machine in the rotating reference frame, the d-q voltage and current relationship is shown in (1a-b), where vg is the grid voltage, R is the stator resistance, M is the magnetizing, and Ld = Lq = L is assumed. On the other hand, the active front end (i.e., the hex-bridge converter connected to the gird) follows (2a-b) in d-q reference frame at ωc rotating speed, where Rg and Lg are grid tied resistance and inductance, and vc is the output voltage at the converter controlled by modulation index from the dc voltage bus []. The analogy between (1a-b) and (2a-b) is straightforward. By equating the first three terms and varying the modulation indices, md and mq, the active front end mimics the VSM proposed in [ZhongQC]. The purpose of the ac motor-tied inverter (i.e., the left hex-bridge converter in Fig. 3) is to main a constant 270 V dc bus by adjusting the motor speed and torque using conventional vector controls. Given the limited

The problem of the reactive power compensation in the conventional HVDC LCC transmission is a nagging issue in the subject of the Line Commutated Converter tech-nique of HVDC transmission

In recent years, Permanent Magnet Synchronous Motor (PMSM) has significantly attracted the attention of researchers due to its simplicity of design, ability of operation at wide range speeds, high efficiency and high power/torque density. Hence it has been increasingly used not only in several industrial sectors but also in household appliance and electrical vehicle applications [1-3], [10]. However, a conventional PMSM control needs a sensor to measure the rotor position and rotor speed for ensuring the precision Field Oriented Control (FOC) and speed control, but such sensor presents some disadvantages such as drive cost, machine size, reliability and noise immunity.