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.

Description

TECHNICAL FIELD [0001] The present invention relates to a control device and a voltage conversion method for a voltage conversion device, a recording medium, a program, a driving system, and a vehicle carrying the driving system. In particular, the present invention relates to a device having a reactor for temporary storage of energy based on a current from a power source, for converting a voltage of the power source, which is input using the reactor, into a desired voltage through switching of a switching element to output. BACKGROUND ART [0002] As a conventional driving system of the above-described kind, there is proposed a system comprising, for example, a battery serving as a power source of the driving system, a DC / DC converter for applying DC / DC conversion to an input voltage from the battery, a load having an inverter for converting an output from the DC / DC converter into a multi-phase AC current and a motor for rotation driving while receiving the multi-phase AC current fro...

AI Technical Summary

Benefits of technology

[0006] With control by a voltage conversion device according to another aspect of the present invention, a ratio range setting means sets a range of ratios each between a period with an upper switching element remaining in an ON state and a period with a lower switching element remaining in an ON state, or a ratio range, based on output characteristics of the power source corresponding to the condition of the power source, which is determined by the condition detection means, and a control means controls the ratio between the periods with the respective switching elements remaining in an ON state so as to remain within the ratio range set by the ratio range setting means. This arrangement enables more appropriate extraction of an output from the power source based on the output characteristics of the power source depending on the condition of the power source. Here, “output characteristics of a power source” refers to correlation between an output of the power source and a ratio between periods with the respective switching elements remaining in an ON state.

Problems solved by technology

However, there may be situations in which, depending on the condition of the battery, a battery cannot supply an amount of power corresponding to a load requiring output when, for example, the battery inner resistance has increased due to low battery temperature.

Were the DC / DC converter be, in such a case, given driving control simply such that an amount of power corresponding to a load requiring output is fed to the load, power consumption due to inner resistance of the battery may increase, resulting in a drop in power supplied to the load.

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