ELECTRODINAMÓMETRO EXPERIMENTAL PARA EMULAR CARGAS NO LINEALES EN EL LABORATORIO

Abstract

This paper presents the simulation and implementation of a electrodynamometer to be enabled in the laboratory to emulate different dynamic mechanical loads. The simulation uses the model of permanent magnet synchronous machine to simulate the driving machine and the machine load, the two MSIP have a power of 7.5 kW. The driving machine use the field oriented control with constant torque to control the speed, therefore the control system has a speed control loop and two current control loops, the PI controller used in the simulation was a AW PI tracking controller which has a satisfactory performance in the speed control response by eliminating the phenomenon of overshoot in speed that occurs when the saturated output drivers to avoid exceeding the rated voltage of the machine. The loading machine also uses the field-oriented control but has only two current control loops because the electrodynamometer just need the electromagnetic torque control so that does not include the loop speed control, thus the loading machine has the ability to emulate different types of mechanical loads and this is achieved using a torque reference signal that is seting in a block of MATLAB / Simulink. To achieve emulate the load of the vehicle using an equation that models the charge state of a vehicle. Another element that is part of the simulation is the voltage source inverter that used the average model [5] because this model eliminates the effects of switching inverter which produces a reduction in simulation time since it only takes into account the fundamental frequency this means that inverter output signals are sinusoidal. In the part where implementation occurs electrodynamometer shows the connection diagrams of power and control of the regenerative system, the system regenerative consists of two Unidrive SP 3201, one of these drives is configured as a regen drive and the other like servo mode, the Unidrive used in servo mode is controlled by two analog input terminals which are admitted by the reference signals of torque and speed with which it manipulates the machine load. These signals are sent through the data acquisition card NI USB 6211 which is controlled by a program developed in LabView, the control software was implemented in order to the electrodynamometer operate in three modes: manual, automatic and vehicle mode, each of these modes has its own characteristics and the user is the responsible for setting the type of load wants to emulate. Finally, a comparison of experimental and simulation results that were obtained through testing in the laboratory and simulation results, in order to make the comparison in the simulation set up the same reference signals used in implementation resulting in a satisfactory performance test platform.