Energy-based modeling of electric motors

We propose a new approach to model electrical machines based on energy considerations and construction symmetries of the motor. We detail the approach on the Permanent-Magnet Synchronous Motor and show that it can be extended to Synchronous Reluctance Motor and Induction Motor. Thanks to this approach we recover the usual models without any tedious computation. We also consider effects due to non-sinusoidal windings or saturation and provide experimental data

Permanent Magnet Synchronous Motors are Globally Asymptotically Stabilizable with PI Current Control

This note shows that the industry standard desired equilibrium for permanent magnet synchronous motors (i.e., maximum torque per Ampere) can be globally asymptotically stabilized with a PI control around the current errors, provided some viscous friction (possibly small) is present in the rotor dynamics and the proportional gain of the PI is suitably chosen. Instrumental to establish this surprising result is the proof that the map from voltages to currents of the incremental model of the motor satisfies some passivity properties. The analysis relies on basic Lyapunov theory making the result available to a wide audience

A Passivity-Based Controller Under low sampling for speed control of PMSM

LGEP 2014 ID = 1517International audienceController performances are strongly limited by the switching frequency of the converter and the computa- tional capacity of the target board. The refore, in such a context the design of controllers that provide good performances Under possible large sampling period length is necessary. To tackle these limitations, a digital design is described for speed control of permanent magnet synchronous machines. It is based on the interconnection and the damping assignment passivity-based contro l(IDA-PBC) techniques extensions to the sampled-data context

Energy-based modelling and simulation of a series hybrid electric vehicle propulsion system

This paper presents an energy-based model of a series hybrid electric vehicle. The proposed propulsion system has a new configuration using a wound-rotor synchronous generator (WRSM) and a doublyfed induction machine (DFIM). From the classic dq dynamical equations of the WRSM and DFIM the port-controlled Hamiltonian models of each machine is described. One of the abilities of the port-based models is that the complete model is easy to obtain by means of interconnection rules. Following this, the Hamiltonian model of the whole system is obtained. Similarly, the bond graph approach allows to build a complex model by interconnecting several subsystems. This paper also contains bond graph models of the machines and the propulsion system. Numerical simulations are also presented in order to validate the proposed models.Peer ReviewedPostprint (author’s final draft

Interconnection and damping assignment passivity-based non-linear observer control for efficiency maximization of permanent magnet synchronous motor

The permanent magnet synchronous motor (PMSM) has several advantages over the DC motor and is gradually replacing it in the industry. The dynamics of the PMSM are described by non-linear equations; it is sensitive to unknown external disturbances (load), and its characteristics vary over time. All of these restrictions complicate the control task. Non-linear controls are required to adjust for non-linearities and the drawbacks mentioned above. This paper investigates an interconnection and damping assignment (IDA) passivity-based control (PBC) combined with a non-linear observer approach for the PMSM using the model represented in the dq-frame. The IDA-PBC approach has the inherent benefit of not canceling non-linear features but compensating them in a damped manner. The suggested PBC is in charge of creating the intended dynamic of the system, while the non-linear observer is in charge of reconstructing the recorded signals in order to compel the PMSM to track speed. The primary objective of this study is to synthesize the controller while accounting for the whole dynamic of the PMSM and making the system passive. It is performed by restructuring the energy of the proposed strategy and introducing a damping component that addresses the non-linear elements in a damped instead of deleted way, so providing a duality concept between both the IDA-PBC and the observer There are three methods for computing IDA-PBC: parametric, nonparametric, and algebraic. The parameterized IDA-PBC method is used to control the speed of the PMSM. This method uses the energy function in parameterized closed-loop in terms of some functions depending on the system’s state vector, such that the energy formation step is satisfied. Then, the original port-controlled Hamiltonian (PCH) dynamics in open-loop (OL) are equalized with the desired one in closed-loop (CL). The equalization process allows obtaining a set of solutions of the partial differential equations. The latter must be solved in terms of the parameters of the energy function of the closed-loop. Finally, the stability properties are studied using the Lyapunov theory. Generally, the proposed candidate offers high robustness, fast speed convergence, and high efficiency over the conventional benchmark strategies. The effectiveness of the proposed strategy is performed under extensive numerical investigation with MATLAB/Simulink software

Global adaptive linear control of the permanent-magnet synchronous motor

International audienceWe contribute with a linear time-varying controller for the permanent magnet synchronous motor. We solve the open problem of speed-tracking control by measuring only stator currents and the rotor angular positions, under parametric uncertainty. Integral action is used to compensate for the effects of the unknown load-torque and adaptation is employed to estimate the unknown parameters. In the case that parameters are known (except for the load) we show that the origin of the closed-loop system is uniformly globally exponentially stable. For the case of unknown parameters we prove uniform global asymptotic stability hence, we establish parametric convergence. In contrast to other adaptive control schemes for electrical machines, we use a reduced-order adaptive controller. Indeed, adaptation is used only for the electrical dynamics equations. Moreover, not surprisingly, the closed-loop system has a structure well-studied in adaptive-control literature. Performance is illustrated in a numerical settin

Port-Hamiltonian model and load balancing for DC-microgrid lift systems

This paper considers the problem of modeling a multi-source lift system where power balancing-realized through a power DC bus-should be optimally controlled. The system includes the mechanical part, a Salient Permanent Magnet Synchronous Machine (SPMSM), a battery energy storage unit, a super-capacitor, a solar panel (PV) generation unit as well as the corresponding converters to DC-links. This microgrid is connected to a three-phase utility (external) grid. A port-Hamiltonian model is proposed for the system. It includes the descriptions of nonlinear characteristics and the limitations for each components as well as some typical operation demands. Then, different optimization objectives are formulated in view of an efficient energy management within the microgrid system

Linear robust output−feedback control for permanent−magnet synchronous motors with unknown load

International audienceWe solve the problem of set-point (respectively, tracking) control of a permanent-magnet synchronous motor via linear time-invariant (respectively, time varying) control. Our control approach is based on the physical properties of the machine: inherent stability and robustness to external disturbances. Our analysis is carried out under mild conditions, using cascaded systems theory. For all cases: constant operating point, trajectory tracking, and with known and unknown load, we show uniform global asymptotic stability of the closed-loop system with a linear controller that uses only velocity measurements. Furthermore, we explore natural extensions of our results to improve robustness with respect to external disturbances and parametric uncertainties

Integral control of port-Hamiltonian systems: non-passive outputs without coordinate transformation

In this paper we present a method for the addition of integral action to non-passive outputs of a class of port-Hamiltonian systems. The proposed integral controller is a dynamic extension, constructed from the open loop system, such that the closed loop preserves the port-Hamiltonian form. It is shown that the controller is able to reject the effects of both matched and unmatched disturbances, preserving the regulation of the non-passive outputs. Previous solutions to this problem have relied on a change of coordinates whereas the presented solution is developed using the original state vector and, therefore, retains its physical interpretation. In addition, the resulting closed loop dynamics have a natural interpretation as a Control by Interconnection scheme.Comment: 8 pages, 2 figure