Fuel pump boost system

Abstract

A fuel delivery system includes a fuel pump, a controller, and a boost circuit. The fuel pump has an electric motor that includes a winding configured to operate with a maximum efficiency at a first voltage for an expected load. The controller includes a pulse width modulator for generating a driving signal for the electric motor. Under normal operating conditions, the boost circuit acts as a pass-through and the driving signal is modulated at the first voltage to control the pump output. However, when a load greater than the expected load is applied to the electric motor, the boost circuit acts to scale the driving signal to a second voltage that is greater than the first voltage. The second voltage drives the electric motor at a voltage beyond the maximum efficiency but provides overall improved system efficiency.

1 . A fuel delivery system comprising: 
 a fuel pump having an electric motor, the electrical motor includes a winding configured to operate with a maximum efficiency at a first voltage for an expected load;    a controller configured to generate a driving signal for the electric motor, the driving signal corresponding to a fuel demand; and    wherein the controller is configured to operate the electric motor at a second voltage when a load greater than the expected load is applied to the electric motor, the second voltage being greater than the first voltage, and the electric motor is configured operate at an efficiency less than the maximum efficiency at the second voltage.    
   
   
       2 . The fuel delivery system according to  claim 1 , wherein the controller includes a pulse width modulator for controlling the driving signal, and the pulse width modulator is configured to vary the duty cycle of the driving signal based on the fuel demand.  
   
   
       3 . The fuel delivery system according to  claim 1 , further comprising a boost circuit in electrical communication with the controller to receive the driving signal, the boost circuit being configured to scale the driving signal to the second voltage when the load greater than the expected load is applied to the electric motor.  
   
   
       4 . The fuel delivery system according to  claim 1 , further comprising a power supply having a supply voltage, is in selective communication with the motor to scale the driving signal to the second voltage.  
   
   
       5 . The fuel delivery system according to  claim 4 , wherein the first voltage is lower than the supply voltage.  
   
   
       6 . The fuel delivery system according to  claim 4 , wherein the second voltage is equal to the supply voltage.  
   
   
       7 . The fuel delivery system according to  claim 1 , wherein the controller is configured to receive a feedback signal and configured to operate the motor at the second voltage based on the feedback signal.  
   
   
       8 . The fuel delivery system according to  claim 7 , wherein feedback signal is a fuel pressure feedback signal.  
   
   
       9 . A fuel delivery system comprising: 
 a fuel pump having an electric motor, the electrical motor includes a winding configured to operate with a maximum efficiency at a first voltage for an expected load;    a controller including a pulse width modulator for generating a driving signal for the electric motor, the pulse width modulator being configured to vary the duty cycle of the driving signal based on a fuel demand; and    a boost circuit in electrical communication with the controller to receive the driving signal, the boost circuit being configured to scale the driving signal to a second voltage when a load greater than the expected load is applied to the electric motor and the electric motor operating at an efficiency less than the maximum efficiency, and wherein the second voltage is greater than the first voltage.    
   
   
       10 . The fuel delivery system according to  claim 9 , further comprising a power supply having a supply voltage, is in selective communication with the motor to scale the driving signal to the second voltage.  
   
   
       11 . The fuel delivery system according to  claim 10 , wherein the first voltage is lower than the supply voltage.  
   
   
       12 . The fuel delivery system according to  claim 10 , wherein the second voltage is equal to the supply voltage.  
   
   
       13 . The fuel delivery system according to  claim 9 , wherein the controller is configured to receive a feedback signal and configured to operate the motor at the second voltage based on the feedback signal.  
   
   
       14 . The fuel delivery system according to  claim 13 , wherein feedback signal is a fuel pressure feedback signal.