P. Delarue

The Ultracapacitor-Based Controlled Electric Drives With Braking and Ride-Through Capability: Overview and Analysis

Two issues are still a great challenge in design and application of advanced controlled electric drives: 1) recovery of the braking energy and 2) ride-through capability of the drive system. Apart from ordinary solutions, such as back-to-back and matrix converters, the ordinary drive converter equipped with an energy storage element is used in specific applications such as traction and lift drives. This approach came into focus recently with rapid development of electrochemical double-layer capacitors, so-called ultracapacitors. The ultracapacitor is an electrochemical capacitor having energy density much greater than that of standard electrolytic capacitors. Additionally, the ultracapacitor power density is much higher than that of the existing electrochemical batteries. In this paper, a regenerative controlled electric drive having extended ride-through capability is discussed. The basic principle has been extensively analyzed, including a detailed analysis of all operational modes. A bidirectional three-level dc-dc converter has been considered as the interface power converter. The ultracapacitor design guideline is given. A control algorithm that allows control of the dc bus voltage and the ultracapacitor voltage and current has been presented and briefly analyzed. The regenerative controlled drive system has been tested, and the results are presented and discussed.

Modeling and Control of the Ultracapacitor-Based Regenerative Controlled Electric Drives

Two issues are still a great challenge in the design and application of advanced controlled electric drives, namely, recovery of the braking energy and ride-through capability of the drive system. Apart from the ordinary solutions, such as back-to-back and matrix converters, an approach based on the ordinary diode front-end-drive converter equipped with an energy-storage element is used in some applications, such as traction and lift drives. This approach has come into focus recently with the rapid development of electrochemical double layer capacitors, so-called ultracapacitors. To achieve system flexibility and better efficiency, the ultracapacitor is connected to the drive via a dc-dc converter. The converter is controlled in such a way as to fulfill the control objectives: the control of the dc-bus voltage, the ultracapacitor state of charge, and peak-power filtering. In this paper, we have discussed the modeling and control aspects of the regenerative controlled electric drive using the ultracapacitor as energy-storage and emergency power-supply device. The presented model and control scheme have been verified by simulation and a set of experiments on a 5.5-kW prototype. The results are presented and discussed in this paper.

The Ultracapacitor-Based Regenerative Controlled Electric Drives With Power-Smoothing Capability

Modern controlled electric drive applications, such as lifts, port rubber tyred gantry cranes, and tooling machines, are characterized by high ratio of the peak to average power. Moreover, such applications have a need for braking at rated power. In ordinary drives, the braking energy, which represents 30%-40% of the consumed energy, is dissipated on a brake resistor. Apart from this “energetic” issue, the mains interruption, the input current quality, and the mains peak power are additional issues to be addressed. A novel ultracapacitor-based controlled regenerative electric drive with peak power-smoothing function is presented in this paper. The ultracapacitor with an interconnection dc-dc converter is used to store and recover the braking energy. In addition, the dc-dc converter controls and smooths the rectifier input power. In comparison to state-of-the-art solutions, the new solution has better performance regarding size, cost, and efficiency. The presented solution is theoretically analyzed and experimentally verified. The results are presented and discussed.

A Three-Terminal Ultracapacitor-Based Energy Storage and PFC Device for Regenerative Controlled Electric Drives

Most of modern controlled electric drive applications, such as lifts, cranes, and tooling machines, are characterized by a high ratio of the peak to average power. In addition, such applications have high demand for braking at the full rated power. In ordinary drives, the braking energy, which represents 30%-50% of the consumed energy, is dissipated on a brake resistor. Apart from this “energetic” issue, power supply interruption and the input current quality are two additional issues to be solved. A novel regenerative controlled electric drive based on an ultracapacitor as energy storage is presented in this paper. The ultracapacitor with an interface dc-dc converter is used to store and recover the braking energy. In addition, the dc-dc converter controls the rectifier current and reduces the drive input current total-harmonic-distortion factor down to 30%. Moreover, the dc bus voltage is boosted and controlled to be constant and ripple free regardless of the load and the mains voltage variation. In comparison to state-of-the-art solutions, the new solution has better performance regarding size, cost, and efficiency. The presented solution is theoretically analyzed and experimentally verified. The results are presented and discussed.

Energetic Macroscopic Representation of a Fuel Cell-Supercapacitor System

This paper presents a model of a fuel cell- supercapacitor system which represents the electric power supply device of a hybrid electric vehicle (HEV). The fuel cell and the supercapacitors are coupled with a DC bus and a common cooling system. The first part of this paper deals with the modeling of the elements of the system (fuel cell system (FCS), supercapacitors, power electronics, and temperature regulation system). The second part deals with the design of a control structure which regulates the DC bus voltage, the fuel cell power, and the power source temperature. Simulation and experimental results are provided and analyzed.

Influence of Control Design on Energetic Performances of an Electric Vehicle

The influence of the choice of controller design on the efficiency of an EV is discussed in this paper. A classical 2-driven-wheels traction with a permanent magnet synchronous machine (PMSM) is studied. Energetic macroscopic representation (EMR) is used for the modeling of the system with different losses. A simplified model is used to define the control scheme. In order to find out the influence of control design on energetic performance, the model taking losses into account is used to assess this control. Simulation results and comparative studies are provided.

An energetic based method leading to merged control loops for the stability of input filters

In most of applications, power converters are controlled to allow their output current/voltage to follow the required reference values. For DC/DC and DC/AC converters, the control must take into account their input voltage, which must be rejected. In such conditions, the converters can be modeled as negative impedance, causing the instability of their feeding 2nd order input filter. This paper presents an original method for the stabilization of the input filter. A merged control scheme is defined using an Energetic based method. A first control scheme is defined to control the output current. A second independent control scheme is defined to control the filter stability. Both control loops are merged using a weighing criterion. Simulation results are provided and the stability issue is discussed.

Validation of Mechanical Transmission with Clutch using Hardware-In-the-Loop Simulation

A hardware-in-the-loop (HIL) simulation of a conventional vehicle system is developed for experimental validations of clutch modelling. Two different states have to be taken into account in this system: clutch locked and slipping. Two different models are then used and a specific condition defines the commutation between both models with respect to the physical energy flow. Energetic macroscopic representation (EMR) is used to organize the numerous blocks required. A Petri net is employed to activate a model according to clutch state (lock and slip). The HIL is based on a controlled IM drive, which imposes the same behaviour of the mechanical power-train to the clutch. A flexible and dynamical model of the whole system is used and simulation results are provided with regard to the experimental results.

A Novel Approach for Simulating the Control of the Traction System of an Automatic Subway

The present paper deals with the simulation and control design of the traction system of the VAL subway. The traction system is ensured by two DC machines connected in series. A common chopper supplies the armature windings and a double-chopper supplies the field windings. The novelty consists on modeling the physical system using Bond Graph, a structural formalism, whereas the control structure is deduced from the Energetic Macroscopic Representation which is a functional formalism. The combination of Bond Graph and Energetic Macroscopic Representation in the same simulation environment allows exploiting the advantages of both approaches. Simulation results are provided in order to illustrate the proposal and to analyze the performance of the closed-loop system.

Voltage Stabilization System for Stop - Start Vehicles: Systemic Approach

This article presents a new Linear Voltage Stabilization System (LVSS) specially meant for 181;- hybrid vehicles using the Stop-Start function. The LVSS stabilizes the battery voltage mainly during the start-up of the ICE limiting the load current using parallels MOSFETs working in linear mode. The Energetic Macroscopic Representation (EMR) is used to model the system and to design its control system. The main advantages of the LVSS are the low price, small volume and the fact of avoiding EMC perturbation. The concept is validated testing the prototype in a real car.