The present invention relates to a system for increasing efficiency of an Electric Vehicle.
More particularly, it relates to a system and method for increasing ideal efficiency of an
electric truck.
5
BACKGROUND OF THE INVENTION
[002] In recent years, due to a rise in the environmental pollution in countries such as India and
an increasing concern in depletion of petroleum resources in the future and cost factor of
the petroleum resources, a reduction the fuel consumption of the vehicle was much
10 needed. Keeping in view of the above, many of the companies internationally and in
India, spent a huge amount in Research & Development and filed number of patents
relating to a vehicle which can run by means of any source of energy and more
specifically by means of electricity.
15 [003] One of the types is an electric vehicle, which uses one or more electric motors or traction
motors for propulsion. The electric vehicle may be powered through a collector system
by electricity from off-vehicle sources, or may be self-contained with a battery, solar
panels or an electric generator to convert fuel (petrol, diesel or compressed natural gas)
to electricity.
20 [004] In the Conventional pure electric vehicles, while emission "free," can't go the distances
or provide the power (for any extended length of time) as that of the Internal Combustion
Engine Vehicles. The Internal combustion engines hazardously pollute the environment.
Further the Hybrid Electric Vehicles used both the characteristics in combination, so the
vehicle could go as far and as long as most people would want with emitting lesser
25 pollution. On the highway, when internal combustion engines (I.C.E) would work more
efficiently, and where the battery would be depleted very quickly in an electric car, the
I.C.E is being used. Whereas for shorter, city driving trips, the electric motor is either
used exclusively, or in such a manner that the I.C.E also runs, at its peak efficiency.
Although the existing knowledge and the arrangement relating to the electric vehicle
3
works well, there is a need for a Pure Electric vehicle that has high mileage and efficient
battery system to provide energy for longer period.
[005] Thereby the present invention provides a heavy Electric Vehicle that focusses on the
improvement in terms of efficiency of the vehicle, ideal functioning of a motor at its peak
5 efficiency, visualizing the battery temperature and its operating condition and capturing
80% of the energy consumed in acceleration and inclination.
OBJECTIVE OF THE INVENTION
[006] The primary objective of the present invention is to provide a system and method for
10 improving the efficiency of an electric vehicle working at variable speed and torque limit.
[007] Another objective of the present invention is to improve the energy efficiency and
mileage of this electric vehicle wherein the regenerative braking (regenerative braking)
method is being used to recover a part of the braking energy into electrical energy.
15
[008] Yet another objective of the present invention is to continuously monitor the battery
system to prolong the battery life and health through the pulse width modulation based
efficient battery water cooling system that runs continuously around the motor surface.
20 BRIEF DESCRIPTION OF DRAWINGS
[009] A complete understanding of the present invention may be obtained by reference to the
accompanying drawings, when taken in conjunction with the detailed description thereof
and in which:
25 [010] Fig. 1 illustrates the Control Area Network (CAN) communication between various
components in the vehicle;
[011] Fig. 2 illustrates the motor torque and speed curve.
30
4
SUMMARY OF THE INVENTION
[012] The present invention discloses an electric vehicle with improved energy efficiency and
mileage by using regenerative braking (regenerative braking) method to recover a part of
the braking energy into electrical energy. The pulse width modulation based efficient
5 battery water cooling system is being used that runs continuously around the motor
surface so as to provide continuous monitoring of the battery to prolong the life and health
of the said battery.
[013] An electric vehicle of the present invention includes at least one battery for storing electric
10 energy, at least one motor for generating a driving force from the electric energy of the
battery, a motor control unit to control the operation between the battery and the motor ,
a vehicle control unit that controls all the signals and monitors the state of the components
thereon, a transmission control unit that measures the propeller shaft speed and shifts the
gear in the gearbox, a battery management system to monitor the individual cell
15 temperature in battery while charging or discharging to protect it as a protection layer , a
battery cooling system for controlling and monitoring the individual cell temperature to
optimize the battery temperature according to the change in the state of the said battery.
DETAILED DESCRIPTION OF INVENTION
20 [001] The following detailed description is merely exemplary in nature and is not intended to
limit the invention or the application and uses of the invention. The detailed description
of the appended drawings is construed as a description of the currently preferred
embodiment of the present invention and does not represent the only form in which the
present invention may be practiced. This is to be understood that the same or equivalent
25 functions may be accomplished, in any order unless expressly and necessarily limited to
a particular order, by different embodiments that are intended to be encompassed within
the scope of the present invention. Furthermore, there is no intention to be bound by any
expressed or implied theory presented in the preceding technical field, background, brief
summary or the following detailed description.
30
5
[002] Accordingly, those of ordinary skill in the art will recognize that various changes and
modifications of the embodiments described herein can be made without departing from
the scope of the invention. In addition, descriptions of well-known functions and
constructions are omitted for clarity and conciseness.
5
[003] Features that are described and/or illustrated with respect to one embodiment may be used
in the same way or in a similar way in one or more other embodiments and/or in
combination with or instead of the features of the other embodiments.
10 [004] The terms and words used in the following description and claims are not limited to the
bibliographical meanings, but, are merely used to enable a clear and consistent
understanding of the invention. Accordingly, it should be apparent to those skilled in the
art that the following description of exemplary embodiments of the present invention are
provided for illustration purpose only and not for the purpose of limiting the invention.
15
[005] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents
unless the context clearly dictates otherwise.
[006] It should be emphasized that the term “comprises/comprising” when used in this
20 specification is taken to specify the presence of stated features, integers, steps or
components but does not preclude the presence or addition of one or more other features,
integers, steps, components or groups thereof.
[007] The present invention is applicable not only to a pure electric vehicle but also to a hybrid
25 vehicle. However, an embodiment in which the spirit of the present invention thereof is
applied to a hybrid vehicle is obvious from an embodiment described hereinafter, in
which the spirit of the present invention is applied to a pure electric vehicle. Therefore,
an embodiment in which the spirit of the present invention is applied to a pure electric
vehicle is hereinafter described in detail.
30
[008] The invention described herein is an electric vehicle that may be a truck or any heavy
vehicle using electric energy stored in the battery as a power source.
6
[009] In accordance with the present invention FIG. 1 shows a system for optimizing efficiency
of an electric truck. The various components of the system are shown in FIG. 1 , which
includes a transmission control unit (1), a motor control unit (2), a vehicle control unit
(3), a battery management system (4), plurality of batteries (4.1-4.10), and a battery
5 cooling unit (5.1-5.3):
• Vehicle Control Unit (VCU) (3) acts as a switch that controls all the signals and
monitors the state of the components. Further whenever there is a fault, VCU (3)
communicates it to other components and takes necessary actions. Vehicle
Control Unit (VCU) (3) acts as a mediator between two Control Area Network
10 (CAN) busses.
• A Transmission Control Unit (TCU)(1) measures the propeller shaft speed and
shifts the gear in the gearbox. It calculates the vehicle speed according to the
changes between motor control mode and torque control mode.
• Battery Management System (BMS)(4) is a control unit for the batteries where it
15 monitors the individual cell temperature while charging or discharging to protect
it as a protection layer to the batteries. It calculates the Battery voltage and Battery
current and further calculates schedule of charge corresponding to voltage and
current. It also generates faults emerging the battery.
• Motor Control Unit (MCU)(2) is placed between the battery and the motor. It
20 converts the direct current to alternating current for running of the motor. In the
case of regeneration, it acts as a rectifier where it converts alternating current to
direct current.
• Battery Cooling System (BCS) (5.1-5.3) is a pulse width modulation based water
cooling system. The system is optimized to maintain the temperature of the battery
25 during charging and discharging state to enhance the mileage of the electric
vehicle.
[010] In accordance with the present invention the vehicle control unit (3) may comprise
plurality of sensors, further each of the sensors may comprise a plurality of sensor
30 elements, A/D converters for converting outputs of the plurality of sensor elements to
digital values, a match checking function for a plurality of A/D-converted values, a filter
7
function, and/or a communication interface.The sensors may include a steering angle
sensor for measuring a steering wheel rotational angle, a brake pedal position sensor for
measuring a brake pedal step-down amount, and/or an accelerator pedal position sensor
for measuring an accelerator pedal step-down amount.
5
[011] The vehicle control unit (3) operates and generates a command value based on driver's
demand signals and vehicle status signals from sensors, and/or motor driving nodes each
controlling a motor thereby enabling driving, steering and braking a vehicle.
10 [012] These command values are generated through the nodes of the Control area Network
(CAN)(6) Bus. Each of these nodes may have a failure detecting function and operate
such that, when a failure is detected in itself with the failure detecting function, the
relevant node does not make any action externally of the relevant node except for
notifying that the relevant node is in a failed state. When a failure occurs in any node,
15 the control is switched over to the normal nodes, thereby continuing normal operation as
an entire system. Each of the driver's demand detecting sensors may be connected to a
communication network, and when a failure of the relevant sensor is detected, it notifies
that the relevant sensor is in a failed state.
20 [013] In accordance with the present invention the transmission control unit (1) includes a
motor for directly converting electric energy to usable mechanical energy and a
transmission connected to the motor without clutch. A motor speed sensor detects motor
speed and a wheel speed sensor detects wheel speed. An inverter controls the motor and
a control unit controls the inverter in accordance with the motor speed sensor signal and
25 the wheel speed sensor signal. The transmission control unit measures the propeller shaft
speed and shifts the gear in the gearbox.
[014] In accordance with the present invention the battery management system(4) may
comprise a plurality of batteries packs(4.1- 4.10) wherein the battery pack further
30 comprises a plurality of battery control units (5.1-5.3) corresponding to the respective
batteries packs and communicating with the charger control unit. A switch is provided
8
between each battery and the charger. The battery and charger are connected to each other
by a power line, and the charger control unit calculates the charging power of the battery
calculated from the battery state transmitted from each battery control unit or the
calculated charging power transmitted from the battery control unit.
5
[015] Accordingly, the battery may be charged from an external power source and supplies
power to the motor when the vehicle is traveling. During charging state it is disconnected
from the motor. A battery control unit (5) monitors the input of voltage signal to the
battery control unit(4), and activates the charging of battery after the battery control unit
10 is activated.
[016] In accordance with the present invention the battery cooling system(5) is a pulse width
modulation based water cooling system. The system is optimized to maintain the
temperature of the battery during charging and discharging state to enhance the mileage
15 of the electric vehicle.
[017] Accordingly, the battery cooling system may comprise plurality of compressors, plurality
of condensers, plurality of condenser fans, plurality of expansion valves, plurality of
pumps, plurality of piping, and plurality of piping refrigerated plate heat exchangers.
20
[018] Accordingly, on the operation of battery cooling system, the compressor takes the
refrigerant gas and compresses it to become a high-temperature and high-pressure gas,
and then discharges it to the condenser to exchange heat with the low-temperature inlet
air generated by the condenser fan through the condenser to lower the high temperature
25 of the compressed gas. The high-pressure refrigerant gas is condensed into a liquid at a
normal temperature and high pressure, and at the same time, the low-temperature air inlet
is discharged into a high-temperature air outlet. After the normal temperature and high
pressure refrigerant liquid passes through the expansion valve, it is throttled by the
expansion valve into a low temperature and low pressure liquid into the refrigerating plate
30 heat exchanger, and heat exchange is performed in the plate heat exchanger with water
entering the higher temperature at the same time, so that the low temperature and low
9
pressure are the liquid refrigerant that evaporates to a low temperature and low pressure
gas, and is finally recirculated by the compressor.
[019] During the operation of the battery cooling system, the water pump works 30 second
ahead of time. The high temperature water in the battery cools down after the plate heat
5 exchanger of the unit, re-flows into the battery pack, and circulates to dissipate heat for
the battery.
[020] During discharge condition of the battery, the battery cooling system is optimized to
maintain the temperature upto 40˚C.
10
[021] During charging due to high current from the fast charger the temperature of the battery
increases rapidly. In the present invention the battery cooling system is optimized to
maintain the temperature between 35˚C to 40˚C.
15 [022] The battery cooling system is optimized and monitored via battery management system
and instructs the cooling system control unit to run the cooling system according to the
requirement of the system.
[023] A simple electrically driven truck powered only by electrical batteries has the
20 disadvantages that the batteries may become depleted while the truck is far from a battery
charging station, and even long-distance travel is not possible.
[024] The advantage in fuel mileage arises from the use of regenerative dynamic braking, which
converts kinetic energy of motion into electrical power during at least a portion of braking
25 and returns the energy to the battery. It has been found that braking losses account for
somewhere near half of all the frictional losses experienced by a vehicle in an urban
transit setting. The recovery of this atleast 60 percent of energy, and returning it to the
batteries for further use, permits to cut-off the need for "secondary" fuel-operated
electrical generator.
30
10
[025] The motor in the electric truck on running develops counter voltage higher than the
battery voltage and inverts the current direction thereby feeding current into the battery,
while developing a counter torque that acts as a brake. This phase is called regeneration.
5 [026] In accordance with the present invention in the electric truck (power source), the electric
energy stored in the battery is used as a power source. To improve the electric truck
mileage and energy efficiency, the regenerative braking (regenerative braking) method is
being used to recover a part of the braking energy into electrical energy. Thereby
increasing the mileage of the said Electric Truck.
10
[027] In accordance with the present invention Table 1 shows various efficiency values at which
the motor can work corresponding to its speed and torque values. Further, Fig. 2 illustrates
the motor curve with the varying efficiency as signified by the contour lines. The X-axis
of the graph depicts the varying speed of the motor in rpm and the Y-axis depicts the
15 torque in N.m.
Table 1
Motor
speed
(rpm)
Output
torque
(Nm)
Output
power(k
w)
System
efficiency
(％)
Bus
volta
ge
(V)
Bus
Curre
nt (A)
Input
power
(KW)
Line
voltag
e (V)
Phase
curren
t (A)
Motor
efficienc
y (％)
Controll
er
efficienc
y(％)
200 200.5 4.2 85.80% 576 8.6 4.9 163 52.5 93.63% 91.65%
200 400 8.4 85.87% 576 17 9.8 172 98.8 92.79% 92.54%
200 601 12.6 85.32% 576 25.7 14.7 179 142.2 91.50% 93.24%
200 801.6 16.8 84.04% 576 34.7 19.9 184 185.1 89.98% 93.39%
201 1003.2 21.1 82.84% 575 44.3 25.4 188 228.9 88.99% 93.08%
200 1202.9 25.2 81.18% 575 54.1 31.1 193 274 86.91% 93.41%
200 1403.3 29.5 79.41% 575 64.6 37.1 197 320.9 85.34% 93.06%
200 1603.3 33.6 77.42% 575 75.6 43.4 200 371 83.34% 92.89%
200 1803.6 37.8 75.06% 575 87.6 50.3 204 425 81.00% 92.66%
200 2004.8 42 72.50% 575 101.1 58 207 484.6 78.74% 92.07%
200 2206.1 46.2 69.30% 575 116.4 66.7 210 553 75.51% 91.78%
200 2406.3 50.5 65.44% 574 134.7 77.1 215 632.2 71.46% 91.58%
400 199.1 8.3 90.06% 576 16.1 9.3 227 52.4 94.55% 95.25%
400 399.3 16.7 91.06% 576 32 18.4 239 98.7 94.77% 96.08%
401 599.6 25.2 90.89% 575 48.2 27.7 247 142.1 94.42% 96.26%
400 798.8 33.5 90.24% 575 64.6 37.1 254 185 93.68% 96.32%
11
400 999.1 41.9 89.48% 575 81.5 46.8 258 228.8 92.91% 96.31%
400 1199 50.3 88.54% 575 98.9 56.8 263 273.7 91.96% 96.29%
400 1397.7 58.5 87.43% 575 116.6 67 268 320.6 91.00% 96.07%
400 1597.6 67 86.19% 575 135.4 77.7 273 370.7 89.80% 95.99%
401 1797.6 75.4 84.75% 574 155.2 89 277 424.7 88.58% 95.67%
400 1997 83.7 82.96% 574 176 100.9 281 484.1 86.88% 95.49%
400 2197.8 92.1 80.75% 574 199.3 114.1 285 552.5 84.94% 95.06%
401 2397.5 100.6 78.87% 574 222.8 127.5 290 631.5 83.30% 94.69%
600 197.8 12.4 91.54% 576 23.6 13.6 277 52.3 94.56% 96.80%
600 397.7 25 92.92% 575 46.8 26.9 290 98.6 95.56% 97.24%
600 597.7 37.6 93.05% 575 70.3 40.4 299 141.8 95.53% 97.41%
600 796.4 50 92.73% 575 93.9 53.9 306 184.7 95.19% 97.41%
600 996.8 62.7 92.27% 575 118.3 67.9 312 228.4 94.75% 97.38%
600 1195.8 75.1 91.63% 575 142.8 82 318 273.2 94.17% 97.30%
600 1394.7 87.7 90.89% 574 168.1 96.5 324 320.1 93.44% 97.27%
600 1593.7 100.2 89.99% 574 194.1 111.3 330 370.1 92.73% 97.04%
600 1793.2 112.7 88.94% 574 221.1 126.7 334 424 91.72% 96.97%
600 1992.4 125.2 87.64% 573 249.5 142.9 338 483.4 90.72% 96.60%
600 2192.7 137.9 86.01% 573 280.2 160.3 343 551.6 89.25% 96.37%
600 2389.7 150.2 83.82% 573 313.9 179.2 350 630.7 87.20% 96.13%
800 196.6 16.5 92.33% 576 31.1 17.8 318 52.3 94.69% 97.50%
800 395.8 33.2 93.90% 575 61.5 35.3 333 98.4 96.02% 97.80%
800 594.7 49.8 94.14% 575 92.1 52.9 344 141.6 96.09% 97.97%
800 793 66.5 93.95% 575 123.2 70.7 352 184.3 95.92% 97.95%
801 992.9 83.3 93.63% 574 154.9 88.9 358 228 95.57% 97.97%
800 1191.2 99.8 93.16% 574 186.8 107.2 365 272.8 95.23% 97.82%
800 1389.2 116.4 92.57% 574 219.4 125.8 372 319.5 94.66% 97.79%
801 1587.8 133.1 91.87% 574 252.9 144.9 378 369.4 94.10% 97.62%
800 1787.3 149.8 91.01% 573 287.6 164.6 383 423.4 93.27% 97.58%
800 1988.5 166.6 89.95% 573 324 185.3 388 483.5 92.32% 97.43%
800 2198.1 184.2 88.50% 572 364.7 208.1 393 555.5 91.04% 97.21%
800 2349 196.9 87.11% 572 397 226 399 615.5 89.90% 96.90%
1000 195.3 20.5 92.80% 576 38.5 22 355 52.2 94.84% 97.85%
1000 393.8 41.2 94.56% 575 76 43.6 371 98.1 96.25% 98.25%
1000 592.1 62 94.92% 575 113.8 65.3 383 141.1 96.51% 98.36%
1000 789.5 82.7 94.86% 575 151.9 87.2 392 183.6 96.45% 98.36%
1000 988.1 103.5 94.63% 574 190.7 109.4 399 227.1 96.23% 98.33%
1000 1185.7 124.2 94.27% 574 229.8 131.7 407 271.6 96.00% 98.20%
1000 1383.1 144.9 93.83% 573 269.5 154.4 414 318.2 95.60% 98.15%
1000 1580.9 165.6 93.26% 573 310.3 177.5 421 367.9 95.13% 98.04%
1000 1785.6 187.1 92.55% 573 353.6 202.1 426 423.2 94.54% 97.90%
12
1001 2005.1 210.1 91.57% 572 401.9 229.4 432 489.4 93.64% 97.78%
1000 2142.9 224.5 90.76% 572 433.7 247.3 435 536 92.97% 97.63%
1000 2266.6 237.4 90.09% 571 462.7 263.6 436 584.2 92.28% 97.62%
1000 2283.9 239.2 89.83% 571 467.6 266.3 437 591 92.13% 97.50%
1200 193.5 24.3 92.94% 576 45.6 26.2 389 52 94.61% 98.24%
1201 391.3 49.2 94.95% 575 90.3 51.8 406 97.8 96.38% 98.52%
1200 589.4 74.1 95.38% 575 135.3 77.7 419 140.8 96.75% 98.58%
1200 789.6 99.2 95.44% 574 181.3 104 428 183.8 96.80% 98.59%
1200 992.1 124.7 95.30% 574 228.3 130.8 436 228.1 96.67% 98.58%
1200 1198.8 150.7 95.02% 573 276.9 158.6 445 274.8 96.49% 98.48%
1200 1412 177.5 94.60% 573 328.3 187.6 452 325.4 96.12% 98.42%
1200 1618 203.4 94.06% 572 378.7 216.2 452 378.8 95.65% 98.33%
1200 1777.6 223.5 93.40% 572 419.4 239.3 451 429 95.11% 98.21%
1200 1926 242.1 92.39% 571 459.8 262 450 491.1 94.29% 97.99%
1200 1955.8 245.8 92.02% 571 469 267.1 450 507.9 93.96% 97.93%
1400 152.7 22.4 91.76% 576 42.5 24.4 416 41.8 94.06% 97.55%
1401 309.2 45.4 94.44% 575 83.6 48 431 79.3 96.22% 98.15%
1400 473.9 69.5 95.26% 575 127.1 73 445 115.9 96.82% 98.39%
1400 642.2 94.2 95.54% 574 172.3 98.6 449 152.5 96.98% 98.51%
1400 803.9 117.9 95.53% 574 215.8 123.4 448 189.9 97.01% 98.48%
1400 962.3 141.1 95.33% 573 258.9 148 447 229.3 96.82% 98.47%
1400 1119.1 164.1 95.01% 573 302.2 172.7 447 271.8 96.61% 98.35%
1400 1276.5 187.2 94.52% 573 346.8 198 446 319.6 96.29% 98.16%
1400 1449.6 212.6 93.52% 572 398.4 227.3 443 389.2 95.40% 98.03%
1400 1527.4 224 92.62% 572 424.5 241.8 442 437.1 94.74% 97.76%
1600 115.9 19.4 90.14% 576 37.5 21.6 441 32.7 92.21% 97.76%
1601 233.3 39.1 93.87% 575 72.7 41.7 450 61.7 95.47% 98.32%
1600 349.5 58.6 94.98% 575 107.7 61.7 450 90 96.45% 98.48%
1600 465.2 78 95.42% 575 142.9 81.7 449 119.3 96.83% 98.55%
1601 582.4 97.6 95.53% 574 178.9 102.2 449 149.8 96.94% 98.55%
1600 700.3 117.4 95.52% 574 215.3 122.9 448 181 96.94% 98.54%
1600 818.4 137.2 95.36% 574 252 143.8 447 213.8 96.84% 98.47%
1600 937.3 157.1 95.14% 573 289.2 165.1 447 249 96.64% 98.44%
1601 1064 178.3 94.73% 573 329.8 188.2 446 290.4 96.36% 98.32%
1600 1174.1 196.8 94.24% 572 366 208.8 445 332.4 95.92% 98.25%
1601 1243.1 208.4 93.64% 572 390.1 222.5 443 368.9 95.51% 98.04%
1600 1287.3 215.7 93.09% 572 406.8 231.7 442 397.8 95.02% 97.97%
1800 103.9 19.6 89.15% 576 38.4 22 451 34.6 91.13% 97.82%
1801 192.8 36.4 93.02% 575 68.3 39.1 451 58.8 94.63% 98.30%
1800 283.5 53.5 94.38% 575 99 56.6 450 84 95.87% 98.45%
1801 378.2 71.3 94.98% 575 131.4 75.1 450 110.4 96.36% 98.56%
13
1800 476.1 89.8 95.23% 574 165.3 94.3 449 137.9 96.66% 98.5%
1800 576.4 108.7 95.32% 574 200.1 114 448 166.4 96.69% 98.58%
1800 675.3 127.3 95.29% 574 234.7 133.6 448 195.3 96.69% 98.56%
1801 775.1 146.1 95.12% 573 269.7 153.6 447 226.1 96.59% 98.47%
1800 875 165 94.88% 573 304.9 173.9 446 259.5 96.40% 98.42%
1800 978.4 184.5 94.48% 573 342.4 195.3 446 298.7 96.10% 98.31%
1800 1082.4 204.1 93.66% 572 381.9 217.9 443 353.1 95.46% 98.12%
1800 1128.6 212.8 92.96% 572 401.8 228.9 442 390.3 94.88% 97.98%
2000 81.4 17.1 85.91% 576 34.7 19.9 455 48.1 88.40% 97.19%
2001 177.7 37.2 91.96% 575 70.6 40.5 452 71.7 93.70% 98.14%
2000 276.8 58 93.84% 575 107.7 61.8 450 98.6 95.33% 98.44%
2000 375.4 78.6 94.58% 575 145.1 83.1 449 126.5 96.02% 98.50%
2001 476.2 99.8 94.87% 574 183.8 105.2 449 156 96.26% 98.56%
2001 577 120.9 94.96% 574 222.7 127.3 448 186.2 96.36% 98.55%
2000 675.6 141.5 94.87% 573 261.1 149.2 447 218.2 96.31% 98.50%
2001 776.6 162.7 94.68% 573 300.7 171.8 446 253.5 96.16% 98.46%
2000 885.3 185.5 94.23% 573 344.5 196.8 446 297.8 95.80% 98.36%
2000 974.7 204.2 93.35% 572 383.1 218.7 443 353.2 95.13% 98.14%
2201 61.8 14.2 81.12% 576 30.6 17.6 456 65.6 84.23% 96.31%
2200 140.6 32.4 89.87% 575 62.8 36 454 80.6 91.95% 97.74%
2201 219.2 50.5 92.43% 575 95.2 54.7 452 100 94.15% 98.18%
2200 378.7 87.3 94.20% 574 161.7 92.6 449 144.6 95.65% 98.48%
2200 458.9 105.8 94.47% 574 195.6 111.9 448 168.7 95.88% 98.53%
2201 539.4 124.3 94.58% 574 229.8 131.4 448 194 96.02% 98.49%
2200 618.6 142.6 94.54% 573 263.8 150.8 447 220.9 95.97% 98.51%
2200 699.5 161.2 94.36% 573 298.9 170.8 446 251.3 95.81% 98.48%
2200 781.1 180 94.04% 573 334.9 191.4 446 285.9 95.56% 98.40%
2201 860.5 198.3 93.34% 572 372 212.5 443 334.7 95.03% 98.21%
2200 892.1 205.6 92.66% 572 388.7 221.8 442 367.9 94.47% 98.08%
2401 66.8 16.8 79.93% 576 36.6 21 454 87.1 83.08% 96.21%
2400 98.7 24.8 85.22% 575 50.7 29.1 455 90.3 87.85% 97.01%
2401 160.8 40.4 89.79% 575 78.4 45 454 102.7 91.71% 97.91%
[028] From the above table 1 and the efficiency curve illustrated in Fig. 2 it is inferred that at
an input torque of 700-1000 N.m. and at a speed range of 800 to 1400 rpm the electric
motor attains the maximum efficiency. The efficiency curve is based on the formula:
5 TORQUE = HP x 9550 ÷ RPM
EFFICIENCY η= (0.7457×HP×load) ÷ Pi
14
[029] Here, HP = motor horsepower, load = Output power as a percentage of rated power, and
Pi = input power in kW, rpm = Speed
5 [030] In accordance with the present invention the control units (i.e. Vehicle control unit(VCU),
motor control unit(MCU), Transmission control unit(TCU), Battery management
system(BMS) discussed above are optimized in such a way that they all try to minimize
power consumption from the battery with the help of the highly efficient battery cooling
system, thereby increasing the overall efficiency of the electric vehicle.
10
[031] While this invention has been described in connection with what is presently considered
to be the most practical and preferred embodiment, it is to be understood that the invention
is not limited to the disclosed embodiments, but, on the contrary, is intended to cover
various modifications and equivalent arrangements included within the spirit and scope
15 of the appended claims.

WE CLAIM:

1. A system for increasing efficiency of an electric vehicle, comprising:
- a transmission control unit (1);
- a motor control unit (2);
5 - a vehicle control unit (3);
- a battery management system (4);
- plurality of batteries (4.1-4.10);
- plurality of battery cooling unit (5.1-5.3);
wherein, the transmission control unit (1) including the motor in the electric vehicle
10 operates at variable speed (800-1400 rpm) and torque (700-1000 N.m.) to obtain 96-99
percent efficiency of the motor.
2. The system for increasing efficiency of an electric vehicle as claimed in claim1, wherein
the vehicle control unit (3), the transmission control unit (1) and the motor control unit
(2) are connected in a single Control Area Network Bus (6).
15 3. The system for increasing efficiency of an electric vehicle as claimed in claim 1, wherein
the said battery management system (4) comprises a first battery control unit (5.1), a
secondary battery control unit (5.2), and third battery control unit (5.3).
4. The system for increasing efficiency of an electric vehicle as claimed in claim 1, wherein
the said battery cooling system (5) is a pulse width modulation-based water cooling
20 system.
5. The system for increasing efficiency of an electric vehicle as claimed in claim 1, wherein
the said battery cooling system(5) comprising atleast one compressor, atleast one
condenser, plurality of condenser fans, plurality of expansion valves, plurality of piping
and atleast one refrigeration plate heat exchanger.
16
6. The system for increasing efficiency of an electric vehicle as claimed in claim 1, wherein
the electric vehicle is an electric truck.
7. A method for increasing efficiency of an electric vehicle, comprising:
- monitoring the safety of the vehicle by means of a a Vehicle Control Unit (3);
5 - controlling the gearbox and shifting of the gears by means of a Transmission
Control Unit (1);
- controlling and monitoring the individual cell temperature by means of a Battery
Management System (4);
- converting the DC current to AC current for motor operation by means of a Motor
10 Control Unit (3);
- optimizing the battery temperature at their optimal temperature range by means
of a Battery Cooling System (5);
8. The method for increasing efficiency of an electric vehicle, as claimed in claim 6, wherein
the temperature of the battery is regulated upto 40˚C for efficient functioning.
15 9. The method for increasing efficiency of an electric vehicle as claimed in claim 6, wherein
the plurality of batteries (4.1- 4.10) storing power generated from the movement of the
wheels in the electric truck when brakes are applied or accelerator pedal is not pressed.
10. The method for increasing efficiency of an electric vehicle as claimed in claim 6, wherein
the battery cooling unit (5) comprising:
20 - the compressor discharges a high-temperature pressure gas into the condenser and
exchanges the heat with the low-temperature inlet air;
- the high-pressure refrigerant gas is then condensed into a liquid at a normal
temperature and high pressure, and at the same time, the low-temperature air inlet
is discharged into a high-temperature air outlet.
17
- the normal temperature and high-pressure refrigerant liquid is throttled by the
expansion valve into a low temperature and low pressure liquid;
- the plate heat exchanger performing the heat exchange with the water entering the
higher temperature at the same time and is finally recirculated by the compressor.
5 11. The method for increasing efficiency of an electric vehicle, as claimed in claim 6, wherein
the battery cooling unit (5) is optimized to maintain the temperature between 35 ˚C and
40˚C of the battery during the discharge condition.
12. The method for increasing efficiency of an electric vehicle, as claimed in claim 6, wherein
the battery cooling unit (5) is optimized to maintain the temperature between 35 ˚C and
10 40˚C of the battery during the charging condition.