Automatic Asynchronous Drive Efficiency Control with Soft-Starter Function

Digital models of pulse-width voltage control system with step switching of power supply frequency and automatic control of induction motor are developed and built, the recommendations on the algorithm of their control and circuit solution for the implementation of smooth start modes, nominal and frequency-step control from low-power -variable load schedule are provided. The novelty of the work lies in the substantiated sequence and conditions of control and originality of the structure of the automatic system of smooth start-up and activation of the effective mode of the asynchronous drive. The introduction of the conversion system will create an automatic system of asynchronous drive, due to which it is possible to achieve energy conservation at all levels of the electromechanical system, with minimum capital investment.

Experimental output regulation of permanent magnet synchronous motor position servo system: An internal model-based two-step control approach

It is well known that the position tracking control problem of permanent magnet synchronous motor (PMSM) is a challenging task when parameter uncertainties and time-varying load torque disturbances are taken into account. In this paper, a two-step controller design strategy composed of triple-loop control and internal model control is proposed to achieve a wide range of position tracking control of PMSM, where the reference position can be a relatively large value. In contrast, only local position tracking control problem has been solved by an internal model approach from output regulation theory in the recent work. In addition to the simulation results, the first experimental study is conducted to demonstrate the effectiveness of the proposed two-step control method. It is worth mentioning that our design can guarantee precise position tracking with a wide position range despite parameter uncertainties and time-varying load torque disturbances.

Variable step control to improve scanning speed of gene sequencing stage

High-speed scanning is a huge challenge to the motion control of step-scanning gene sequencing stage. The stage should achieve high-precision position stability with minimal settling time for each step. The existing step-scanning scheme usually bases on fixed-step motion control, which has limited means to reduce the time cost of approaching the desired position and keeping high-precision position stability. In this work, we focus on shortening the settling time of stepping motion and propose a novel variable step control method to increase the scanning speed of gene sequencing stage. Specifically, the variable step control stabilizes the stage at any position in a steady-state interval rather than the desired position on each step, so that reduces the settling time. The resulting step-length error is compensated in the next acceleration and deceleration process of stepping to avoid the accumulation of errors. We explicitly described the working process of the step-scanning gene sequencer and designed the PID control structure used in the variable step control for the gene sequencing stage. The simulation was performed to check the performance and stability of the variable step control. Under the conditions of the variable step control where the IMA6000 gene sequencer prototype was evaluated extensively. The experimental results show that the real gene sequencer can step 1.54 mm in 50 ms period, and maintain a high-precision stable state less than 30 nm standard deviation in the following 10 ms period. The proposed method performs well on the gene sequencing stage.

Modeling Control and Robustness Assessment of Multilevel Flying-Capacitor Converters

When performing AC/DC-DC/AC power conversions, multilevel converters provide several advantages as compared to classical two-level converters. This paper deals with the dynamic modeling, control, and robustness assessment of multilevel flying-capacitor converters. The dynamic model is derived using the Power-Oriented Graphs modeling technique, which provides the user with block schemes that are directly implementable in the Matlab/Simulink environment by employing standard Simulink libraries. The performed robustness assessment has led to the proposal of a divergence index, which allows for evaluating the voltage balancing capability of the converter using different voltage vector configurations for the extended operation of the converter, namely when the number of output voltage levels is increased for a given number of capacitors. A new variable-step control algorithm is then proposed. The variable-step control algorithm safely enables the converter extended operation, which prevents voltage balancing issues, even under particularly unfavorable conditions, such as a constant desired output voltage or a sudden load change. The simulation results showing the good performances of the proposed variable-step control as compared to a classical minimum distance approach are finally provided and commented in detail.

Parallel One-Step Control of Parametrised Boolean Networks

Boolean network (BN) is a simple model widely used to study complex dynamic behaviour of biological systems. Nonetheless, it might be difficult to gather enough data to precisely capture the behavior of a biological system into a set of Boolean functions. These issues can be dealt with to some extent using parametrised Boolean networks (ParBNs), as this model allows leaving some update functions unspecified. In our work, we attack the control problem for ParBNs with asynchronous semantics. While there is an extensive work on controlling BNs without parameters, the problem of control for ParBNs has not been in fact addressed yet. The goal of control is to ensure the stabilisation of a system in a given state using as few interventions as possible. There are many ways to control BN dynamics. Here, we consider the one-step approach in which the system is instantaneously perturbed out of its actual state. A naïve approach to handle control of ParBNs is using parameter scan and solve the control problem for each parameter valuation separately using known techniques for non-parametrised BNs. This approach is however highly inefficient as the parameter space of ParBNs grows doubly exponentially in the worst case. We propose a novel semi-symbolic algorithm for the one-step control problem of ParBNs, that builds on symbolic data structures to avoid scanning individual parameters. We evaluate the performance of our approach on real biological models.