MATLAB Examples

Ni-MH Battery Model

This example shows a 200 V, 6.5 Ah Ni-MH battery model during charge and discharge process.

Olivier Tremblay, Louis-A. Dessaint (Ecole de technologie superieure, Montreal)

Contents

Description

The battery is connected to a constant load of 50 Amps. The DC machine is connected in parallel with the load and operates at no load torque. When the State-Of-Charge (SOC) of the battery goes under 0.4 (40%), a negative load torque of 200 Nm is applied to the machine so it acts as a generator to recharge the battery. When the SOC goes over 80%, the load torque is removed so only the battery supplies the 50 amps load.

Battery voltage, SOC, Motor speed and Motor current signals are available at the output of the block.

Simulation

At t = 0 s, the DC machine is started with the battery power. The speed increases to 120 rad/s. The battery is also discharged by the constant DC load of 50 amps. At t = 280 s, the SOC drops under 40%. A mechanical torque of -200 Nm is applied to the machine so it acts as a generator and provides a current of 100 amps. Hence, 50 amps goes to the load and 50 amps goes to recharge the battery. At t = 500 s, the SOC goes over 80%. The mechanical torque is removed and the machine operates free. And the cycle restarts.

References

1. O. Tremblay, L.-A. Dessaint, A.-I. Dekkiche, "A Generic Battery Model for the Dynamic Simulation of Hybrid Electric Vehicles", 2007 IEEE® Vehicle Power and Propulsion Conference, September 9-13, 2007, Arlington/Texas, USA