Phase change assisted heat sink

Details Phase change assisted heat sink Phase change assisted heat sink

1999-11-22

2001-05-29

Ponomarenko, Nicholas (Department: 2834)

Prime-mover dynamo plants

Miscellaneous

Drive gearing

C361S700000

Reexamination Certificate

active

06239502

ABSTRACT:

FIELD OF THE INVENTION
This invention relates to the cooling of power electronic components, and more particularly to the use of phase-change heat transducers to aid in such cooling.
BACKGROUND OF THE INVENTION
Modern electrically driven power machines such as industrial and domestic air conditioners, electrical and hybrid-electric vehicles, and the like, are controlled in more sophisticated manners than in the past. More particularly, many such power machines are driven from sources which synthesize the electrical drive waveforms in order to provide improved efficiency and performance by comparison with simple on-off application of the raw source energy. For example, in the traction motor drive of an electrical vehicle energized at least in part from a direct-voltage battery (also known as a direct-current or DC battery), high efficiency and controllability is attainable by using a multiphase alternating-voltage motor operated in a field-oriented control mode. A controllable switched electrical converter/inverter converts the direct voltage from the battery (or other source) into three-phase alternating voltage or current for driving the traction motor.
Hybrid electric vehicles are widely viewed as being among the most practical of the low-polluting vehicles. A hybrid electric vehicle includes an electric “traction” battery which provides electric power for an electric traction motor, which in turn drives the wheels of the vehicle. The “hybrid” aspect of a hybrid electric vehicle lies in the use of a secondary or supplemental source of electrical energy for recharging the traction battery during operation of the vehicle. This secondary source of electrical energy may be solar panels, a fuel cell, a generator driven by an internal combustion engine, or generally any other source of electrical energy. When an internal combustion engine is used as the secondary source of electrical power, it commonly is a relatively small engine which uses little fuel, and produces little pollution. A concomitant advantage is that such a small internal combustion engine can be operated within a limited RPM range, so that pollution controls of the engine may be optimized. The terms “primary” and “secondary” when used to describe the sources of electrical energy merely relate to the way energy is distributed during operation, and are not of fundamental importance. A simple electrically driven vehicle powered only by electrical batteries has the disadvantages that the batteries may become depleted while the vehicle is far from a battery charging station, and even when such a vehicle successfully returns to its depot after a day's use, the batteries must then be recharged. The hybrid electric vehicle has the significant advantage over a simple electrically powered vehicle that the hybrid electric vehicle recharges its own batteries during operation, and so should not ordinarily require any external battery charging. Thus, the hybrid electric vehicle can be used much like an ordinary vehicle powered by internal combustion engines, requiring only replenishing of the fuel.
Another major advantage of the hybrid electric vehicle is its good fuel mileage. 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, 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 50% of energy, and returning it to the batteries for further use, permits the use of a much smaller “secondary” fuel-operated electrical generator than would be the case if regenerative braking were not used. In turn, the smaller secondary electrical source results in less fuel used per unit time, or per mile. Yet another advantage of a hybrid electric vehicle is that under many conditions, the power which is available for accelerating the vehicle is the sum of the maximum power which can be supplied by the batteries plus the maximum power which can be generated by the secondary electrical generator. When the electrical generator is a diesel-powered internal combustion engine, the combination of the battery power and the diesel power can result in a total motive force which is quite substantial, notwithstanding the good fuel mileage.
In
FIG. 1
, an electric vehicle
10
, as described in U.S. Pat. No. 5,929,595, issued Jul. 27, 1999 in the name of Lyons et al., includes at least one drive wheel
12
connected to an alternating voltage electric traction motor
40
, which in one embodiment is a three-phase alternating-current motor. Motor
40
is preferably a motor-generator, as known, so that kinetic energy of motion can be transduced into electrical energy during dynamic braking. A power controller
14
is connected by power-handling paths to traction motor
40
, to a traction battery illustrated as
20
, and to an auxiliary source of electrical energy illustrated as a block
16
. As illustrated in block
16
, the auxiliary source may include an internal combustion engine such as a diesel engine
18
driving an electrical generator
22
, or it may include a fuel cell
24
. A command controller illustrated as a block
50
is connected by means of information paths to power controller
14
, auxiliary source
16
, and to traction motor
40
, for controlling the operation of the power controller
14
, auxiliary source
16
, and to traction motor
40
in accordance with appropriate control laws.
One of the most common and least expensive types of batteries which is capable of storing relatively high power includes the common lead/H
2
SO
4
battery. This type of battery is suitable for use in an electric vehicle, if some care is taken to prevent application of a charging current thereto when the battery is at full charge, to prevent gassing of the electrolyte and undesired heat generation, and if sulfation can be avoided. U.S. Pat. No. 5,828,201, issued Oct. 27, 1998 in the name of Hoffman, Jr., et al., and entitled METHOD FOR EOUALIZING THE VOLTAGE OF TRACTION BATTERY MODULES OF A HYBRID ELECTRIC VEHICLE, and U.S. Pat. No. 5,869,950, issued Feb. 9, 1999, also in the name of Hoffman, Jr., et al., and entitled METHOD FOR MAINTAINING THE CHARGE CAPACITY OF TRACTION BATTERY MODULES OF A HYBRID ELECTRIC VEHICLE, describe control arrangements by which lead-acid batteries can be maintained to optimize their useful life and capacity, and describe various aspects of the care and use of such batteries.
FIG. 1
, the displays and operator controls of vehicle
10
are illustrated as a block
30
. Block
30
is illustrated as being connected by a bidirectional data path
31
to command control block
50
, for applying driving commands to command controller
50
, which command controller
50
can then convert into appropriate commands to the various power elements, such as power controller
14
, auxiliary source
16
, and traction motor
40
. Block
30
is also illustrated as being connected by a path
32
to friction brakes
36
a
and
36
b
, for direct control of the friction brakes by a conventional hydraulic braking system connected to a brake pedal.
FIG. 2
represents the interconnection of some of the elements of power controller
14
of
FIG. 1
with other elements of FIG.
1
. More particularly, power controller
14
includes a rectifier arrangement
26
connected to auxiliary source
16
, for (if necessary) converting alternating-current output of the auxiliary source
16
into direct voltage. Power controller
14
also includes a bidirectional propulsion control system, which further includes a dc-to-ac inverter
28
coupled by power connections to battery
20
, to rectifier arrangement
26
, and to traction motor
40
. The operations of the inverter
28
, the auxiliary source
16
, and traction motor
40
are controlled, as mentioned above, by command controller
50
. It should be noted that in addition to the dc-to-ac inverter
28
, the propulsion control system inclu

Affiliated with

Also associated with

Rating

Phase change assisted heat sink does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Phase change assisted heat sink, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phase change assisted heat sink will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2480674