Hybrid Electric Vehicle Battery Protection System Through Capacitor Bank Energy Buffer

• US 20120037438A1
• Filed: 08/16/2010
• Published: 02/16/2012
• Est. Priority Date: 08/16/2010
• Status: Abandoned Application

• Current Assignee: Howard Dan Enslow, James Monroe Schultz
• Original Assignee: Howard Dan Enslow, James Monroe Schultz
• Inventors: Schultz, James Monroe, Enslow, Howard Dan
• Application Number:
  US12/856,966
• Publication Number:
  US 20120037438A1
• Time in Patent Office: Days
• US Class Current: 180/65.22
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60Y 2400/114 Super-capacities
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Delivery Truck/Bus Hybrid Vehicles, experiencing frequent starts, rapidly load their batteries with pulse surges during the first hundredths of a second of acceleration. Traditionally, battery life is maximized by minimizing initial discharge pulses and sustained discharge rates, with initial surges two to three times battery capacity (2C to 3C). Early Lead-acid or Lithium-ion batteries in hybrid buses with 3C discharges had their life expectancies reduced 50-75%. Recent “Lithium Ion/Nano Phosphate” batteries reportedly increase durability to 100C. If these 100C expectations are not met, battery life can be extended with a capacitor bank “floating in parallel” with the hybrid batteries. This helps dampen acceleration surges, as well as initial charging energy impulses, which extends battery life. Others have proposed parallel battery and capacitor banks but this patent uniquely focuses on matching capacitor energy, and thereby equipment, to the greatest surge demand, during the initial few hundredths of a second of acceleration.

Claims

1. A hybrid vehicle system comprising:

an internal combustion engine {ICE} (either gas or diesel), an electrical generator/motor coupled to the ICE (both the engine and motor as per the design of others), a “

battery bank”

(an array of batteries in either/or parallel or series connection) of predefined voltage as per the design of the vehicle manufacturer, a capacitor bank (the primary object of this patent) of the same or greater predefined voltage as the battery bank and a means of electrically tying these together, commonly referred to as a “

bus bar/line”

.

2. The hybrid system according to claim 1 wherein the batteries of the battery hank are selected from the group consisting of a range of Lithium and Lithium-Ion batteries, Nickel-metal-hydride batteries, Nickel-Cadmium batteries, Lead-acid batteries or other appropriate batteries yet to be designed in the future as per the design of “

others”

, the vehicle manufacturer.

3. The hybrid system according to claim 1 wherein the capacitors are selected from the group consisting of super capacitors, double layer capacitors, ultra-capacitors and/or other similar construction as per the design of others and per the specifications of the vehicle manufacturer.

4. The hybrid system according to claim 1 wherein all of the capacitors in the capacitor bank are preferentially rated at, or above, the specified voltage of the Battery Bank. Alternatively, if the specified voltage is very high the above basic concept can also be achieved by connecting several capacitors in series to achieve the desired voltage, while a number of series strings would then be attached in parallel to affect the equivalent power capability. Whenever possible the design is much more robust if the capacitor'"'"'s energy can be achieved by a parallel configuration as the failure of one capacitor in series eliminates the usefulness of the other capacitors in the string.

5. The hybrid system according to claim 1 where in the capacitors in the capacitor bank are connected via circuitry in parallel as much as possible within design and component capabilities.

6. The hybrid system according to claim 1 wherein the battery bank and the capacitor bank are connected in parallel via the bus bar/line.

7. The hybrid system according to claim 1 wherein the capacitors provide most of the power needed during the first few hundredths of a second of acceleration thus ameliorating the energy surge initially encountered by the battery bank which could be one, two or three times greater than normal operating currents and battery capacity (typically referred to as 1C, 2C or 3C rated current draw).

8. The hybrid system according to claim 1 wherein the energy capacity (technically, capacitance) of the capacitor bank, measured in kilo-Watt-Seconds, is sized to cover the first 0.05 to 0.10 of a second. Providing capacitance in this time frame covers the first surge energy spike which is the most damaging to a battery'"'"'s life expectancy. Providing capacitance for more than a few hundredths of a second would increase cost, weight and size of the system beyond an optimum range without added benefit in terms of battery protection. This is because very quickly energy transfer to the battery pack would need to occur for the sustained 30 to 120+ seconds of typical acceleration. This is the unique feature of this patent, the sizing of a parallel capacitor bank to cover only the first few hundredths of a second of acceleration. Others have proposed batteries and capacitors working in parallel in hybrid vehicles but without the above optimizing specificity.

9. The hybrid system according to claim 1 wherein the capacitors and the batteries “

float”

at the same voltage, discharging and being charged at the same time as per a parallel circuit.

10. The hybrid system according to claim 1 further comprising a DC traction motor system electrically coupled to the power bus bar/line, said motor system providing a voltage on the power bus bar/line during regenerative braking for recharging the battery and the capacitors as per the design of others.

11. The hybrid system according to claim 1 further comprising a switch in series with the capacitor bank so, the capacitors and the battery system can be isolated from each other for repairs or service.

12. The hybrid system according to claim 1 in which, at the customer'"'"'s request, electrical circuitry is included to enable indicator lights to identify the state of charge or functionality of the individual capacitors.

13. The hybrid system according to the claim 1 in which, at the customer'"'"'s request, electrical circuitry and/or electronic circuitry is included to enable the capacitor bank to be connected to a vehicle'"'"'s electronic or computer monitoring system to identify the state of charge or functionality of the individual capacitors.

14. The hybrid system according to claim 1 in which the capacitor bank is enclosed in an electrically isolated container as per appropriate governmental, professional and safety code requirements, and customer specifications that may vary from customer to customer. At the customer'"'"'s request, these containers may be hermetically sealed.

15. The hybrid system according to claim 1 in which the capacitor bank enclosure is also isolated from vibrations in a manner to be agreed upon by the customers.

16. A hybrid vehicle system comprising:

an electrical power bus bar/line;

an internal combustion engine driving an electric motor/generator coupled to the bus bar/line;

a battery bank electrically coupled to the power bus bar/line; and

a super capacitor bank electrically coupled to the power bus bar/line sized and optimized to handle the energy requirements of the first few hundredths of a second of operation, all being in parallel and common voltage so that together they provide energy matching the initial surge requirements of the motor/generator during start up acceleration.