Tula Technology, Inc.

Tula Etechnology, Inc.

Tripath Technology, Inc.

Cirrus Logic Inc.

Adya S Tripathi

Chester Silvestri

Mohammad R Pirjaberi

Louis Joseph Serrano

Cary L Delano

Paul Carvell

Joshua P Switkes

Farzad Sahandiesfanjani

Christopher W Chandler

Mark A Wilcutts

Babak Mazda

Matthew Aaron Younkins

Christopher C Hand

Xin Yuan

Steven E Carlson

Li-Chun Chien

Bhupendra K Ahuja

Chris Hand

Mark A Shost

Robert W Dibble

Biswa R Ghosh

Ronald D Yuille

Kar Shing Chiu

Gurmail Kandola

Delon Hanson

Ming-Tak Leung

Raman Dakshinamurthy

Ki Chun Fu

Asit Tripathi

Chester J Silvestri

Modulated pulse control of electric machines to deliver a desired output in a more energy efficient manner by either (a) operating the electric machine in a continuous mode when a requested torque demand is greater than the peak efficiency torque of the electric machine or (b) in a pulsed modulation mode when the requested torque demand is less than the peak efficiency torque of the electric machine. When operating in the pulsed modulation mode, the inverter may be deactivated to further improve the system efficiency when field weakening is not required to mitigate or eliminate generation of a retarding torque in situations when Back Electromagnetic Force (BEMF) exceeds a supply voltage for the inverter of the machine.

Pulse modulated control with field weakening for improved machine efficiency

Methods, controllers and electric machine systems are described that facilitate pulsed control of electric machines (e.g., electric motors and generators) to improve the machine's energy conversion efficiency. Under selected operating conditions, the electric machine is intermittently driven (pulsed). The pulsed operation causes the output of the electric machine to alternate between a first output level and an off state. The output levels are selected such that the electric machine has a higher energy conversion efficiency during the pulsed operation than the electric machine would have when operated at a third output level that would be required to drive the electric machine in a continuous manner to deliver the desired output. In some embodiments, the power converter it turned off during at least portions of the time that the electric machine is pulsed off.

Pulsed electric machine control

A variety of methods, controllers and electric machine systems are described that facilitate pulsed control of electric machines (e.g., electric motors and generators) to improve the machine's energy conversion efficiency. Under selected operating conditions, the electric machine is intermittently driven (pulsed). The pulsed operation causes the output of the electric machine to alternate between a first output level and a second output level that is lower than the first output level. The output levels are selected such that at least one of the electric machine and a system that includes the electric machine has a higher energy conversion efficiency during the pulsed operation than the electric machine would have when operated at a third output level that would be required to drive the electric machine in a continuous manner to deliver the desired output. In some embodiments, the second output level is zero torque.

A boost circuit is arranged to reduce rise and fall times of pulsed power used for pulsed control operation of electric machines. Magnetic energy present in the electric machine at the end of a pulse is extracted by the boost circuit to reduce the pulse fall time. The energy is stored by the boost circuit and then applied at the beginning of a subsequent pulse to reduce the rise time. By reducing rise and fall times compared to not using such a boost circuit, machine efficiency is improved.

Boosted converter for pulsed electric machine control

Pulse modulated control with field weakening for improved motor efficiency

Engine controllers and methods are described that facilitate skip fire control of an internal combustion engine. An engine controller determines a skip fire firing fraction and (as appropriate) associated engine settings that are suitable for delivering a requested output. The engine controller selects an operational firing fraction from a set of available firing fractions. A firing controller then directs cylinder firings in a skip fire manner that delivers the selected operational firing fraction. The firing controller includes an accumulator that helps smooth transitions between different firing fractions.

Firing fraction management in skip fire engine control

A variety of methods, controllers and electric machine systems are described for pulse control of electric machines (e.g., electric motors and generators). To improve the energy conversion efficiency of the machine, pulse control involves determining if the machine should operate in a continuous mode or pulse mode, and if the latter, defining a magnitude, duty cycle, and frequency for the pulses. One or more tables, indexing by a wide range of speeds and torque requests, is/are used to define the pulsing frequency or a pulsing frequency pattern.

Pulsed electric machine control using tables

Skip fire engine control using a first order sigma delta based firing controller is described. An engine controller determines a skip fire firing fraction and (as appropriate) associated engine settings that are suitable for delivering a requested output. The operational firing fraction is selected from a set of available firing fractions. The engine controller uses a first order sigma delta based converter to direct working cycle firings in a skip fire manner that delivers the selected firing fraction. The converter includes or functions substantially equivalent to a first order sigma delta converter and may be implemented any of: algorithmically using a processor; using digital, analog or hybrid components; using a lookup table; or using other appropriate techniques. In some embodiments firing decisions are made on a working cycle by working cycle basis. The described approach may be used in gasoline engines, diesel engines, turbocharged or supercharged engines, or others.

In various described embodiments skip fire control is used to deliver a desired engine output. A controller determines a skip fire firing fraction and (as appropriate) associated engine settings that are suitable for delivering a requested output. In one aspect, the skip fire controller is arranged to select a base firing fraction that has a repeating firing cycle length that will repeat at least a designated number of times per second at the current engine speed. Such an arrangement can be helpful in reducing the occurrence of undesirable vibrations.

A variety of methods and arrangements for improving the fuel efficiency of internal combustion engines based on skip fire operation of the engine are described. In one aspect the skip fire decisions are made on a working cycle by working cycle basis. During selected skipped working cycles, the corresponding cylinders are deactivated such that air is not pumped through the cylinder during the selected skipped working cycles. In some implementations, the cylinders are deactivated by holding associated intake and exhaust valves closed such that an air charge is not present in the working chamber during the selected skipped working cycles.

Internal combustion engine control for improved fuel efficiency

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San Jose, CA, United States of America

Adya S Tripathi