Electrical braking and energy storage for moving vehicles

• US 6,037,728 A
• Filed: 03/29/1999
• Issued: 03/14/2000
• Est. Priority Date: 03/29/1999
• Status: Expired due to Term

• Current Assignee: Peter M. Petkovic
• Original Assignee: Peter M. Petkovic
• Inventors: Petkovic, Peter M.
• Primary Examiner(s): Ip, Paul
• Application Number:
  US09/280,317
• Time in Patent Office: 351 Days
• Field of Search: 318/46-89, 318/140-159, 318/364-375, 318/723, 318/721, 318/805, 318/806, 318/799, 318/809, 320/40, 320/17, 320/43, 320/48, 364/483
• US Class Current: 318/364
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2220/44 Wheel Hub motors, i.e. integrated in the wheel hub
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/461 Speed
• CPC Class Codes: B60L 2260/28 Four wheel or all wheel drive
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 7/06 for vehicles propelled by ac motors
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: B60T 13/586 the retarders being of the electric type
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A system for electrical braking and the storage for reuse of the braking energy is disclosed using alternating current (AC) rather than direct current (DC) generators coupled to the wheels of the vehicle to be braked. Upon braking, the AC generators feed the primary coil of a transformer whose secondary coil can be tapped at one of a number of different turns. Means are provided for changing the tap points so as to increase the number of turns in the secondary as the speed of the braked wheel declines. The output from the secondary is fed to a rectifier and thereafter the direct current is fed to a battery energy storage device. By increasing the turns of the secondary as the wheel speed drops, more energy can be fed and stored in the battery and the range of effective braking by the alternating current generator can be extended to lower speeds.

Claims

1. In a vehicle having an energy storage device and at least one turning wheel, a system for electrically braking that wheel, in response to a braking signal, comprising:

tachometer means for approximately sensing the speed of the wheel;

a variable transformer having a primary coil and a secondary coil and means for varying the primary to secondary coil turn ratio from a lower to higher value in response so said tachometer means sensed speed;

a rectifier means connected to the secondary coil of said variable transformer to receive output of said variable transformer to produce direct current energy therefrom and feeding that direct current energy to the vehicle'"'"'s energy storage device;

an alternating current (AC) generator coupled to the wheel so as to generate AC output; and

means for effectively connecting, in response to the braking signal, said generator to said primary coil of said variable transformer whereby said AC generator brakes the wheel and provides energy which is fed to said transformer means and to said rectifier means and stored in the energy storage device.

2. A vehicle having wheels and having an improved braking system comprising:

alternating current generator means coupled to at least one of the wheels of the vehicle which, in response to a braking command, produces an alternating current output from the spinning wheels and applies braking forces to slow the spin of said wheels;

sensing means coupled to at least one of said wheels for providing an output signal related to the speed of the wheel;

an electric storage battery;

a rectifier which may charge said battery;

variable transformer means coupled to said generator means to receive its alternating current output and provide a transformed voltage alternating current transformer output, said transformer means being also coupled to receive the output signal of said sensing means and to vary the output voltage of the transformer in response thereto to keep the voltage thereof near and above the charging level for the battery for an extended range of speeds for the braking wheel; and

means for feeding the transformer output to said rectifier, whereby the voltage of the input to the battery is keep above the charging level for the battery as the speed of the wheels slows.

3. An electric braking system for a wheeled vehicle comprising:

an alternating current (AC) generator coupled to at least one wheel of the wheeled vehicle for producing alternating current electrical power and providing braking to the at least one wheel;

a variable turn ratio transformer having a primary coil for receiving an AC input and a secondary coil for producing an AC output;

an electrical load;

means for sensing the rotational speed of the at least one wheel and coupled to said transformer for varying the turn ratio of said transformer'"'"'s primary to secondary coils from a relatively low number to a relatively high number in response to a decrease in the rotational speed of the at least one wheel; and

means for selectively operationally connecting said transformer to said generator and for connecting said load to the output of said transformer when braking is desired.

4. The system of claim 3 wherein said electrical load includes means for storing electric power delivered to it.

5. The system of claim 3 wherein said electrical load includes a rectifier means and electric storage battery and wherein electric power derived from said generator is stored in said battery.