Showing papers by "Juan Carlos Balda published in 1990"
TL;DR: In this article, a set of standstill measurements that allow time-domain identification of linear model parameters for direct and quadrature axes of a synchronous machine is proposed, where the models are obtained directly in parametric form (in per unit or measured units).
Abstract: A set of standstill measurements that allow time-domain identification of linear model parameters for direct and quadrature axes of a synchronous machine is proposed. The advantages of this method over conventional standstill frequency response testing include the simplicity of test equipment, the higher current levels achieved, the speed with which the measurements can be obtained, and the fact that the models are obtained directly in parametric form (in per-unit or measured units). The proposed method is illustrated by results measured on a 3 kVA, 220 V microalternator. >
50 citations
07 Oct 1990
TL;DR: In this paper, the Nichols chart is used in conjunction with quantitative feedback theory (QFT) for the design of fixed-structure controllers for parameter-sensitive plants, where the parameter variations are included at the outset of the design task.
Abstract: When classical techniques are used for designing fixed-structure speed controllers for AC drives, the design is normally done around a nominal value of the controlled plant. Generally, a sensitivity analysis is subsequently done to ensure that the design specifications are met when the plant parameters change. An alternative is proposed where the parameter variations are included at the outset of the design task. The Nichols chart lends itself rather well to this application since it represents both magnitude and phase information on a single diagram. By using this alternative, it may be possible to reduce the overall time needed to complete the design. The particular technique, quantitative feedback theory (QFT), is used in conjunction with the Nichols chart. The basics of QFT are presented, and it is shown how it can be used for the design of fixed-structure controllers for parameter-sensitive plants. A design is presented and verified experimentally. >
12 citations
11 Jun 1990
TL;DR: In this paper, the authors evaluate two adaptive control methods for vector-controlled AC drives under parameter variations, namely a minimum variance controller (MVC) and a model reference exact-matching (MREM) method.
Abstract: The authors evaluate two adaptive control methods for vector-controlled AC drives under parameter variations, namely a minimum variance controller (MVC) and a model reference exact-matching (MREM) method. They compare them to a nonadaptive model reference complementary controller (MRCC) and address their potential impact on designing PWM (pulse width modulation) inverters. Digital simulation results indicate that although all the methods considered had similar responses for nominal conditions, the MVC and MREM exhibited a higher performance than the MRCC under variations of the rotor time constant. However, the MVC PWM signal placed a more severe burden on the PWM stage. It is concluded that a comprehensive solution for the problem of parameter variations should include a combination of an identification method for the rotor parameters and adaptive control method to meet the desired specifications (rise time, bandwidth, speed range, etc.). >