Voltage converter control apparatus and method

Abstract

By using a target voltage Vc* of a capacitor connected to the output side of a DC/DC converter and a voltage Vb of a battery connected to the input side of the DC/DC converter, a duty ratio D as a drive instruction of the DC/DC converter is calculated. By using the voltage Vb, the electromotive force Vbo of the battery, and the charge/discharge current Ib of the battery, an internal resistance Rb is calculated. According to the internal resistance Rb and the electromotive force Vbo, the current value when the battery output becomes maximum is set as the upper limit value of the optimal current range IR, the DC/DC converter is driven/controlled by limiting the duty ratio D so that the current Ib is within the range of the optimal current range IR. Thus, it is possible to appropriately convert the battery input voltage.

1 . A voltage conversion device having a reactor for temporarily storing energy based on a current from a power source, for converting a voltage of the power source, which is input while utilizing the reactor, into a desired voltage through switching of a switching element to output, comprising: 
 a voltage detection circuit for detecting a voltage of the power source; and    a control circuit for applying switching control to the switching element such that the detected voltage remains within a predetermined range which is determined based on the electromotive voltage of the power source, and further, such that an output voltage of the voltage conversion device becomes equal to a target voltage which is determined based on a target output amount of a load which is driven based on the output of the voltage conversion device,    wherein the power source is chargeable and dischargeable, and,    an output obtained through conversion into the desired voltage is supplied to a load.    
   
   
       2 . A voltage conversion method for converting a voltage of a power source, which is input while utilizing a reactor for temporarily storing energy based on a current from the power source, into a desired voltage through switching of a switching element to output, comprising: 
 detecting a voltage of the power source; and    applying switching control to the switching element such that the detected voltage remains within a predetermined range which is determined based on the electromotive voltage of the power source, and further, such that an output voltage of the voltage conversion device becomes equal to a target voltage which is determined based on a target output amount of a load which is driven based on the output of the voltage conversion device,    wherein the power source is chargeable and dischargeable, and,    an output obtained through conversion into the desired voltage is supplied to a load.    
   
   
       3 . A computer readable recording medium storing a control program for controlling a voltage conversion device having a reactor for temporarily storing energy based on a current from a power source which is chargeable and dischargeable, for converting a voltage of the power source, which is input while utilizing the reactor, into a desired voltage through switching of a switching element to output to a load, the program having a computer to execute switching control of the switching element such that the voltage of the power source remains within a predetermined range which is determined based on the electromotive voltage of the power source, and further, such that an output voltage of the voltage conversion device becomes equal to a target voltage which is determined based on a target output amount of a load which is driven based on the output of the voltage conversion device.  
   
   
       4 . A control program for controlling a voltage conversion device having a reactor for temporarily storing energy based on a current from a power source which is chargeable and dischargeable, for converting a voltage of the power source, which is input while utilizing the reactor, into a desired voltage through switching of a switching element to output to a load, the program having a computer to execute: 
 switching control of the switch element such that the voltage of the power source remains within a predetermined range which is determined based on the electromotive voltage of the power source, and further, such that an output voltage of the voltage conversion device becomes equal to a target voltage which is determined based on a target output amount of a load which is driven based on the output of the voltage conversion device.