Showing papers on "Dynamic braking published in 2021"

Synthesis of a Regulator Recuperation Mode a DC Electric Drive by Creating a Process of Finite Duration

Abstract: Analytical dependences describing the conditions for the implementation of finite duration processes in the regulation of armature and excitation windings of the DC motor in the modes of traction and regenerative braking are established. The synthesis of regulators of the two-circuit automatic control system which allows to realize the maximum speed is executed. Analytical expressions describing the dependences of the value of the pulsation factors of the step-down pulse converter depending on the value of the transfer functions of the regulators of the double-circuit automatic control system and the value of the duty cycle of the pulse-width modulation are established. An automatic control system has been developed that can be used in the practical design of dynamic braking systems by DC motors. The presented technique in Matlab simulation allows to determine power losses and temperature of power transistors of any types as a part of any semiconductor converter

Optimisation of train speed to limit energy consumption

Abstract: The speed profile of a train plays an important role in energy consumption and resulting costs. The industrial objective of this work is thus to develop a method to reduce the energy consumed by a train over a journey by playing on the driver commands (traction and braking forces) while respecting punctuality constraints. A coupling between measured data and simulation is proposed to solve this optimization problem. First, a rigid body approach (Lagrangian formalism) is introduced to characterize the dynamics of each element of the train and their interactions with their environment. In particular, the aerodynamic (including the wind effect), traction, and braking forces are taken into account, and a special attention is paid to the vertical and lateral characteristics of the track as they play a key role on the train dynamics. Secondly, a model for energy consumption and recovery (thanks to dynamic braking) is introduced. Experimental measurements of a high-speed line are then used to estimate the parameters on which the two previous models are based and to validate their predictive capacities. The optimization problem under constraints is finally solved using an evolutionary algorithm where the constraints are implemented using an augmented Lagrangian formalism. The performance of the proposed method in terms of speed optimization and energy consumption reduction is compared to measurements associated with commercial trains.

Dynamic braking circuit for electric motor, and dynamic braking method for electric motor

Abstract: Disclosed are a dynamic braking circuit for an electric motor, and a dynamic braking method for an electric motor. After being rectified by a rectifier bridge module, an alternating current is converted, after being subjected to the filtering of a bus capacitor, into a direct current bus P/N with a stable voltage, and a direct current is then converted, by means of an inverter bridge module, into an alternating current to drive an electric motor; one end of a power-on soft start module is connected to the positive side P of the bus, and the other end thereof is connected to one end of a bus capacitor module and one end of a regenerative braking module, and the other end of the bus capacitor module and the other end of the regenerative braking module are connected to the negative side N of the bus; and a dynamic braking module is directly connected to the direct current bus P/N. The dynamic braking circuit of the present invention completely multiplexes body diodes of the inverter bridge module to realize rectification, without the need to add three additional diodes per shaft, such that system costs are reduced, and the PCB area is reduced; and multi-axis common bus systems sharing a dynamic braking module can be supported without the need to add any additional wiring, such that the system wiring is simplified, and the costs of the wiring terminals and cables are reduced.