dSPACE Digital Signal Processor Research Articles

DSPACE Implementation of Motor Drives using Asymmetric Converter

This paper deals with the dSPACE DS1104 based implementation of closed-loop motor drive system using asymmetric converter. The mathematical model of the drive has been simulated in the MATLAB/Simulink environment to analyze the performance of the drive system. The simulated results are then validated with the experimental investigation. For experimental work, the pulse width modulation (PWM) has been implemented in MATLAB environment with Simulink real-time interface. Meanwhile, the hardware implementation consisting of dSPACE digital signal processor, voltage source inverter and generator-coupled motor. Variable speed test was performed on the loaded motor in open loop and closed-loop design to obtain speed tracking response parameter as well as speed ripple. Overall performance of developed system is satisfactory where in low-speed operation, experimental results show good speed tracking performance with ripple within 20%.

A Novel DPC Approach for DFIG-Based Variable Speed Wind Power Systems Using DSpace

The integration of wind energy systems into the electric grid has become inevitable despite the many problems associated with this integration. Most of these problems are due to variations in wind speed. The problems are for example oscillations in the power generated, which implies the lack of guarantee of obtaining the maximum energy and the ripple in the electromechanical torque of the generator. This work aims at mitigating these problems for wind energy conversion system-driven doubly-fed induction generator (DFIG), which is the main wind turbine utilized for energy applications. This mitigation is performed through direct reactive and active powers control of the DFIG using an artificial neural network. A DSP (Digital Signal Processor-dSPACE DS1104) was used to experimentally test the proposed strategy. The dynamic performances of the controlled generator are analyzed by using the designed intelligent control strategy in the case of variable wind speeds and upon sudden change of the active power demand. Based on the obtained experimental results, it can be said that the designed intelligent control strategy outperforms traditional methods like direct power (DPC) and vector control in terms of reducing the current harmonics, and torque ripples, and enhancing dynamic response.

Modeling, Parameter Measurement, and Control of PMSG-based Grid-connected Wind Energy Conversion System

The design of reliable controllers for wind energy conversion systems (WECSs) requires a dynamic model and accurate parameters of the wind generator. In this paper, a dynamic model and the parameter measurement and control of a direct-drive variable-speed WECS with a permanent magnet synchronous generator (PMSG) are presented. An experimental method is developed for measuring the key parameters of the PMSG. The measured parameters are used in the design of the controllers. The generator-side converter is controlled using a vector control scheme that maximizes the power extraction under varying wind speeds. A model predictive controller (MPC) is designed for the grid-side voltage source converter (VSC) to regulate the active and reactive power flows to the power grid by controlling the $d$ - and $q$ -axis currents in the synchronous reference frame. The MPC predicts the future values of the control variables and takes control actions based on the minimum value of the cost functions. To comply with the grid code requirement, a modified design approach for an LCL filter is presented and incorporated into the system. The design process is simple and incorporates significant filter parameters while avoiding iterative calculations. The comparative analysis of the designed filter with conventional L, LC, and iterative LCL filters demonstrates the effectiveness of the modified design approach. The proposed wind energy system with MPC and LCL filter is simulated in MATLAB/Simulink and experimentally implemented in the laboratory using the dSpace digital signal processor (DSP) system. The simulation and experimental results validate the efficacy of the designed controllers using the measured parameters and show dynamic and steady-state performance under varying wind speeds.

Port Controlled Hamilton With Dissipation-Based Speed Control of IPMSM Drive

This paper presents a port controlled Hamilton with dissipation (PCHD) based control technique for high precision speed regulation of interior permanent magnet synchronous motor (IPMSM) drive. The PCHD controller is designed by assigning proper interconnection and damping matrix for multivariate, nonlinear, and time-varying IPMSM system to prove its passivity and ensure its global stability. A torque observer is also designed based on pole placement method to monitor the external load. The stability analysis of the proposed PCHD and uniformity between the proposed controller and proportional-integral (PI) controller are analyzed subsequently. The performance of the proposed controller is investigated in both simulation and experimental environment using MATLAB-Simulink and dSPACE digital signal processor board DS1104, respectively, at different operating conditions for a laboratory 5 hp motor. It is found that the proposed PCHD controller shows better performance than that of the conventional benchmark tuned PI controller in terms of speed tracking capability with load variations.

Effective power transfer scheme for a grid connected hybrid wind/photovoltaic system

A new topology and effective power transfer scheme with minimum number of converters is proposed for a grid connected wind/photovoltaic (PV) system. Distributed generation sources considered are permanent magnet synchronous generator (PMSG)-based wind energy conversion system and PV array system. Two voltage source converters with a common DC-link serve as wind side converter (WSC) and grid side converter (GSC), respectively. The PV array is directly tied to the DC link without any power converter providing variable DC-link voltage. The Perturb and Observe technique extracts the maximum power from PV and the DC-link voltage is set to the maximum power point (MPP) voltage of the PV array. The output DC voltage of WSC is regulated to an MPP PV voltage using an outer proportional–integral voltage control loop. The maximum power from the PMSG and stator voltages is utilised to generate the reference currents for WSC to make stator currents to follow stator voltages. With unity power factor control, the overall VA of the WSC would contribute to the active power transfer and thereby reduce the kVA rating of the WSC in the proposed configuration. GSC tracks the maximum power from wind and PV array, and serves as a shunt active power filter to compensate for the current unbalance due to the connection of non-linear loads at the grid. All these functions are accomplished simultaneously. Various power transfer modes of operation are simulated through MATLAB/Simulink software and its results are validated through dSPACE Digital Signal Processor.

Real-time implementation of a maximum power point tracking algorithm based on first order sliding mode strategy for photovoltaic power systems

This paper focuses on a maximum power point tracking (MPPT) algorithm based on the first order sliding mode approach. This work is aimed at systems that are fed with a photovoltaic (PV) generator. The main objective is to act on the panel to ensure that the energy collected is always at its maximum. Because a PV panel frequently suffers from non-linearity of its P-V curves, we propose to work with MPPT controllers based on the first order sliding mode approach; indeed, this approach in general is recognized as one of the efficient tools to design robust controllers. It has received much more attention within the last two decades, and many researchers are dealing with this type of robust controller to ensure optimal operating point of a PV system. The proposed MPPT algorithm has been implemented using a DSPACE DSP (digital signal processor) controller. To demonstrate the efficiency and the validity of the developed algorithm in real time, an experimental setup around a boost converter and a resistive load is experimentally studied and successfully implemented. The real-time validation and the experimental results show that the proposed algorithm can effectively improve the efficiency of PV array output under climatic variation and load change. It is a favorable algorithm that is easy to realize.

Diseño e Implementación de un Sistema de Control estable basado en Lógica Borrosa para optimizar el rendimiento de un sistema de Generación Fotovoltaico

This paper presents a new control scheme for a standalone photovoltaic (PV) system based on a fuzzy-logic (FLC). The proposed control system provides good tracking for the optimal reference voltage, at which the maximum power generation is obtained. The photovoltaic system is connected to a load through a DC/DC boost converter. The FLC controller provides the appropriate duty cycle (D) to the DC/DC converter in order to get the maximum power from the PV system. A method for the stability analysis of the closed-loop system is also proposed. The stability analysis is based on the Lyapunov methods and is a semi-qualitative analysis because there is no closed loop system model available for the analytical analysis. Both simulation results and experimental tests on a real PV system show that the FLC provides good tracking for the maximum power point (MPP).Finally, the performance of the FLC on a real PV system consisting of a commercial solar panels Atersa model A55 is analyzed. To perform the experimental tests the proposed control strategy has been implemented on the dSPACE digital signal processor model DS1104. The experimental results demonstrate the good performance of the proposed FLC control scheme over a commercial photovoltaic system

Hybrid Fuzzy Bang–Bang Mode Controller With Switching Function for Electric Motor Drive Applications

This paper proposes a real-time hybrid fuzzy bang–bang (BB) controller with switching function, in order to implement a full nonlinear control law. The controller consists of a fuzzy-BB controller in parallel with a BB controller while the system is in operation. In order to circumvent the shortcomings of fuzzy-BB and BB-based controllers, a hybrid fuzzy-BB controller is proposed, in which the output can be either the outputs of the two, i.e., the fuzzy-BB or BB units that are being switched as per the absolute error signal. Normally, the BB controller operates in general; the fuzzy-BB controller is activated when the drive system experiences oscillatory behavior. The choice between the fuzzy-BB and BB controllers is based on a set of simple if–then rules; the overshoot and the oscillatory behavior have to be detected by the absolute errors. Trajectory tracking of nonlinear motor drives in position mode serves as a test bed for the control law, and a real-time experiment allows for the assessment of its practical applicability. The hybrid fuzzy-BB controller has been implemented on hardware with a dSPACE digital signal processor, and it is observed that the performance of the controlled brushless dc motor drive with the hybrid fuzzy-BB controller is assuring. Noticeably, experimental results demonstrate that the proposed controller is capable of significantly cultivating the motor performance under random disturbance and different loading conditions.

Instantaneous power‐based current control scheme for VAR compensation in hybrid AC/DC networks for smart grid applications

An important feature of grid-connected DC microgrids is the ability to inject or suck power from the grid based on the generation and loading conditions. Power flow from the AC to DC grid is important to cover any deficiency in the demand in DC grid. Power flow from the DC to AC grid is needed when there is an excess power from renewable energy sources on the DC bus. To allow this bidirectional power flow, a pulse-width modulation controlled voltage source converter is used as an interface between the DC microgrid and the AC main grid. The bidirectional converter controls the active power transferred in both directions while operating at unity power factor. In this study, a current control approach based on the instantaneous synchronous detection theory has been used to control the power flow in both directions. The proposed current control scheme is verified through MATLAB simulation and the simulated results are also validated experimentally using a prototype controlled by dSPACE digital signal processor. The simulated and the experimental results show that the proposed scheme offers regulated DC grid voltage and nearly unity power factor for wide load variations. Results have proven excellent performance in steady and transient states.

A Novel Wavelet-Neural-Network-Based Robust Controller for IPM Motor Drives

This paper presents a novel wavelet-neural-network (NN) (WNN)-based speed controller for interior permanent-magnet (IPM) motor drives. The speed error and its change are used as inputs to the proposed controller. The WNN controller parameters such as weights, translation, and dilation of the wavelet functions are regulated adaptively with speed and load. The back-propagation-based training algorithm is used for updating the WNN parameters. The Lyapunov stability is used for stable learning and robustness of the WNN controller. The IPM motor is operated above the rated speed using the flux-weakening control. The maximum-torque-per-ampere control is used below the rated speed. The proposed WNN-controller-based IPM drive is implemented using the MATLAB/Simulink software and the dSPACE digital signal processor hardware. The performance of the WNN controller is compared to those of the conventional proportional–integral (PI)-, PI–derivative-, and NN-based speed controllers. The WNN controller is found more robust and quicker than conventional controllers.

Design and control of the humanoid robot SURALP

SURALP is a 29 degrees-of-freedom full-body walking humanoid robot designed and constructed at Sabanci University - Turkey. The human-sized robot is actuated by DC motors, belt and pulley systems and Harmonic Drive reduction gears. The sensory equipment consists of joint encoders, force/torque sensors, inertial measurement systems and cameras. The control hardware is based on a dSpace digital signal processor. This paper reviews the design of this robot and presents experimental walking results. A posture zeroing procedure is followed after manual zeroing of the robot joints. Controllers for landing impact reduction, early landing trajectory modification, foot-ground orientation compliance, body inclination and Zero Moment Point (ZMP) regulation, and independent joint position controllers are used in zeroing and walking. A smooth walking trajectory is employed. Experimental results indicate that the reference generation and control algorithms are successful in achieving a stable and continuous walk.

Load Disturbance Resistance Speed Controller Design for PMSM

This paper presents an linear-quadratic-regulator-based proportional–integral–differential equivalent controller design method for a permanent-magnet synchronous motor. The disturbance rejection is achieved based on a multi-objective observer in which observation error is purposely retained and utilized in load disturbance compensation. This makes disturbance rejection tuning independent of the adjustment for speed command tracking; and the disturbance compensation is an integrated part of the controller output, which reduces the chance of input or state saturation. A robust stability analysis is also included for the modeling error. The proposed methodology is implemented through the dSPACE digital signal processor system, and the experimental result confirms its effectiveness.

DSP-Based PID Controller Design for the PMDC Motor

This paper presents a robust proportional-integral-derivative (PID) controller design method for permanent magnetic DC (PMDC) motor. The PID controller parameters are systematically developed through the linear quadratic regulator (LQR) approach, such that satisfactory performance with guaranteed closed-loop stability is achieved. In order to deal with modelling error and input saturation, an internal model control (IMC) structure is utilized, such that system robustness is improved, without the need for an observer. The proposed method is implemented through the dSPACE digital signal processor (DSP) system, and the experimental result confirms its effectiveness.