Papers by anders hultgren
Using MATLAB with dSPACE rapid prototyping system in power converter control
IFAC Proceedings Volumes, 1999
Operator interface for a controlled water tank process has been developed in Java. The task of th... more Operator interface for a controlled water tank process has been developed in Java. The task of the systeln is to control the water level in a tank, to give the user an opportunity to interact with the controller, and to present data in a lucid "vay. The P-, 1-and D-part of the control signal arc shown in a graph and thereby give a clear insight in the function of the controller. Taking use of the Java standard libraries has made the program small but at the same time powerful. (~opyright ((:) 1999 IFAC
Controller applied to a LCC-converter
Stability of a nonlinear Hamiltonian observer applied to a general electrical network
2004 43rd IEEE Conference on Decision and Control (CDC) (IEEE Cat. No.04CH37601), 2004
ABSTRACT A nonlinear Hamiltonian observer is defined and applied to a general switched electrical... more ABSTRACT A nonlinear Hamiltonian observer is defined and applied to a general switched electrical network. A design and analysis method is suggested. A proof is given for the stability of the observer error process. As an example, the observer is applied to a switched resonant power converter. Simulations indicate convergence properties.
Proceedings of the 2000. IEEE International Conference on Control Applications. Conference Proceedings (Cat. No.00CH37162), 2000
A switched power converter is a hybrid system and can be modelled by a switched linear model cons... more A switched power converter is a hybrid system and can be modelled by a switched linear model consisting of a set of linear differential equations and connected logic conditions. If the time instants of the switchings are known the system can be viewed as a linear time varying system. A switched Kalman filter is developed to meet the switched property and enable a state feedback control. The filter is tested in a high frequency resonant power converter. The filter is developed in a system for rapid prototyping offilter and control algorithms.
A structural flow for modeling of switched electrical circuits by means of an example a switched ... more A structural flow for modeling of switched electrical circuits by means of an example a switched DC/DC converter will be presented. The modeling flow has a minimal amount of hand calculations and is suitable for script implementation in suitable mathematical computer software such as Matlab or similar. Switched Hamiltonian Differential Algebraic Equation models and Differential Equation models are obtained which are suitable for analysis in the time domain. Linear models, which can be transformed to the frequency domain for analysis, are obtained from the Hamiltonian models. The duty cycle will be included in the input vector enabling the full system analysis considering the system transfer functions audio susceptibility, output impedance, and control, i.e., the duty cycle to output voltage.
Virtual Real Time Measurement System with a Switched
2 4 S2 # 1 # 3 # 2 # 4 Load # # 1:n Avt...r Tr...vr+y'hqrq...r+'h#p'o/oor...#r...#Uur... more 2 4 S2 # 1 # 3 # 2 # 4 Load # # 1:n Avt...r Tr...vr+y'hqrq...r+'h#p'o/oor...#r...#Uur...r+'h# pv...pv#p'+v+#+'s#urphfhpv#'...8hq#urvqp#'...G#Uur p'#...'yvf#'s#urp'o/oor...#r...v+trr...h#rqi'#ur+#v#pur+ T #'T##p'#...'yyvt#uro/oo'y#htr#W ## #Uur'#f#'s#ur pv...pv#v+#urp......r#v #### The power converter is a Teries Goaded Sesonant 8onverter, see figure 1. The SLRC has many advantages over the conventional fulse #idth odulation PWM converter such as low switching losses at higher switching frequencies ("ero-current +witching, ZCS, or "ero-o/oooltage<
When modelling complex computer systems, four primary modelling techniques are available to the s... more When modelling complex computer systems, four primary modelling techniques are available to the software engineer, i.e. abstraction, composition, functional decomposition and multiple client interfaces (views). Abstraction and composition can directly be expressed in traditional object oriented models and functional decomposition can often be expressed using subsystems. However, traditional object models provide no expressiveness for multiple client interfaces. This forces designers to either model all different views on a conceptual object as a large, complex implementation object or to model each view as an object and relate the different view objects. Both approaches suffer from problems of complexity, maintainability and reusability. As a solution, we propose the layered object model that allows for the expressive, flexible and extensible definition of multiple client interfaces. To illustrate the problems associated with views and our proposed solution, the domain of industrial...
Layering in Object-Oriented Control Systems
In order to make a dependable distributed computer system resilient to arbitrary failures of its ... more In order to make a dependable distributed computer system resilient to arbitrary failures of its processors, deterministic interactive consistency algorithms (ICAs) are required. Thus far, in order to guarantee interactive consistency, all ICAs found ...
Auto-test in situ of real time measurement system of SLRC
IMTC/98 Conference Proceedings. IEEE Instrumentation and Measurement Technology Conference. Where Instrumentation is Going (Cat. No.98CH36222), 1998
A method of in situ test of a real time measurement system, RTMS, is presented. The method involv... more A method of in situ test of a real time measurement system, RTMS, is presented. The method involves superposing a probing signal on one of the measurement signals of the RTMS, The RTMS is used in a control system of a series loaded resonant converter, SLRC. The power spectrum of a SLRC is specific, the energy is concentrated in narrow
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IEEE Transactions on Instrumentation and Measurement, 2001
A new method for achieving an automated in-situ impulse response test of resistance temperature s... more A new method for achieving an automated in-situ impulse response test of resistance temperature sensors is described in this paper. An implementation of the automated in-situ test and some experimental results are also given. The experimental setup is based on a signal processor board programmable directly from Matlab and Simulink. The suggested test can be built into the sensor system giving an intelligent or smart sensor.
2010 11th International Workshop on Variable Structure Systems (VSS), 2010
An industrially applied LCC power converter is modelled as a hybrid system. It is found that the ... more An industrially applied LCC power converter is modelled as a hybrid system. It is found that the hybrid system with three continuous states and one logic state given a parameter set up and different initial conditions has among other solutions one central closed trajectory and two types of limit cycles, on the left and the right side. The other solutions are indicated.
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Papers by anders hultgren