3.2.3. EV Module

The EV module consists of four parts: a drive module (DRIVE MODEL), a DC circuit (DC INSTALLATION), a harmonic filter (H.F. FILTER) and a central controller (EV CONTROLLER). They are described below.

DRIVE MODEL is based on the equation of rotary motion dynamics:

$$J\frac{dw}{dt} = T\_t - T\_m(w) \tag{3}$$

where:

*J*—moment of machine inertia brought to the machine shaft,

*w*—instantaneous value of the angular velocity of the machine rotor,

*Te*, *Tm*—electromagnetic torque and mechanical torque in the function of *w*.

The EV engine is represented by the module of a synchronous machine with permanent magnets. The integral part imitates the car inertia brought to the machine shaft. The input of this block is the sum of torques: electromagnetic driving *Te* depended on the current generated by the inverter and provided to the vehicle engine and mechanical *Tm* braking the car's movement. The output is the value of the machine's angular velocity *w*. It is assumed that the resistance to the movement and so the torque *Tm* are proportional to the angular velocity *w* of the car.

DC INSTALLATION represents EV battery and DC/AC motor inverter. The battery is represented by the DC source. The inverter is built as three-phase (6T) bridge of gate turn-off (GTO) thyristors. Firing pulses to thyristors are generated using pulse-width modulation (PWM) technique in the block of Inverter Current Controller. Hysteresis control is applied, in which the inverter AC current *iinv* reproduces the reference current vector *iref* determined in the block of EV CONTROLLER.

In the EV module passive filter (H.F.FILTER) and the remaining R, L, C elements visible in the simulator diagram are used to reduce current harmonics of high frequencies resulting from thyristor switches operation.

Two EV operation modes are modelled in the simulator: Driving and Parking. They can be selected by the position of MODE switch in EV CONTROL panel. For the first mode the switch should be set to the DRIVE position. It results in opening BRKpark switch and closing BRKev switch. With BRKev closed the EV inverter is connected to the stator of the synchronous machine and the EV is ready to drive. For the parking mode the position PARK at the control panel should be selected—it causes BRKpark switch to close. As a result, the connection between the EV inverter and EVSE (user installation) is established.
