Challenge

Week-11 Challenge: Braking

CChaitanya Chavan14 Oct 2022

Driving cycle

Driving Cyle is define as Speed V/s time characteristics of electric vehicle which helps to calculate fuel consumption for motor

useful for vehicle model simulation

Performance analysis of electric vehicle

Battery state and energy consumption analysis

Breaking

Kinetic energy in the form of heat dissipation takes place when brakes are applied in electric vehicle which follows law of conservation of energy

E= 1/2 mv^2

m = mass of the vehicle in Kg

v = velocity of the vehicle in m/s

E = Kinectic energy in KJ

velocity will be (v-vo) where, V is the speed of the vehicle, Vi the speed of the vehicle which brought to standstill condition

To access matlab file for program 2 and 3

step 1) /MATLAB Drive/Breaking.m

step 2) Matlab Drive

step 3)Matlab Drive Online

step 4)select Braking option

Total Energy consumed during Braking is 0.000000 KJ
Total Energy consumed during Acceleration is 3.980957 KJ

Ans 2)

Electrical motor cant develope braking torque at the time of starting since it has to be applied in opposite direction to the motor

In case of Electric motor Breaking torque is less than accelerating torque hence regenerative braking is not possible where suppose to work in generating region

Rotor has to run greater than synchromous speed in order to have breaking which reverses power flow and recharges battery

Eback emf> Evmotor (For breaking application)

when speed is high enough and no extra load is there the torque cannot be incresed since Eback=Ev motor

at the time of starting most of the torque use to increase kinetical energy of the load(motor)

where operation in motorin region Ev motor> Evback emf

Ans 3)

The losses in the motor are classified into four types

1. Copper loss:

Copper losses are given by I^2 * R loss. Torque is proportional to the current. So the copper loss is given as:

Copper loss = Kc * T^2

2. Iron loss:

Iron losses are due to magnetic losses.

Iron loss = Ki * ω

3. Windage loss:

loss due to the friction between air and the rotor.

Windage loss = Kw * ω^3

4. Constant loss:

Constant losses in the motor are considered as C.

Total loss = (Kc * T^2) + (Ki * ω) + (Kw * ω^3) + C

Outpower can be calculated by multiplying the torque & velocity

Po = T * ω

So input power is sum of output power & losses.

Pi = Po + (Kc * T^2) + (Ki * ω) + (Kw * ω^3) + C

Week-11 Challenge: Braking

Ship work like this
in your own course.

Talk to a career counsellor

Ship work like thisin your own course.

Talk to a career counsellor

Ship work like this
in your own course.