US 8,027,181 B2 · Load drive device and vehicle equipped with the same

Abstract

A surge voltage generated by the switching operation of an IGBT element and voltage variation generated in an equivalent series resistance of a capacitor are superimposed on an input voltage of an inverter. The equivalent series resistance has a temperature dependence that a resistance value increases with a decrease in a capacitor temperature. The IGBT element has a temperature dependence that an element withstand voltage decreases with a decrease in an inverter temperature. When capacitor temperature is lower than a predetermined threshold value, a control device reduces an upper limit value of the input voltage by an amount corresponding to the voltage variation from its upper limit value at a high temperature, and controls a target voltage of a boost converter such that an output voltage does not exceed the upper limit value. Consequently, the allowable range of the surge voltage can be ensured.

Claims11

Dependent claims

A load drive device comprising:

a DC power supply configured to allow an output voltage to be variably controlled;
a drive circuit converting a DC voltage from said DC power supply into an AC voltage by a switching operation of a switching element to drive-control an electric load;
a capacity element provided between said DC power supply and said drive circuit and smoothing the output voltage of said DC power supply for inputting to said drive circuit;
and
a control device controlling said DC power supply,
said capacity element having a temperature dependence such that a resistance value of an equivalent series resistance increases with a decrease in temperature of said capacity element, and
said control device setting an upper limit value of an input voltage of said drive circuit to a lower value depending on the decrease in the temperature of said capacity element, and, in response to a request from said electric load, setting the output voltage of said DC voltage to a value of less than the set upper limit value of said input voltage.

4 more elements

A load drive device comprising:

a DC power supply configured to allow an output voltage to be variably controlled;
a drive circuit converting a DC voltage from said DC power supply into an AC voltage by a switching operation of a switching element to drive-control an electric load;
a capacity element provided between said DC power supply and said drive circuit and smoothing the output voltage of said DC power supply for inputting to said drive circuit;
and
a control device controlling said DC power supply,
said switching element having a temperature dependence such that an element withstand voltage decreases with a decrease in temperature of said switching element, and
in response to a request from said electric load, said control device to set the output voltage of said DC voltage to a value of less than an upper limit value of an input voltage of said drive circuit set depending on the temperature of said switching element.

4 more elements

A load drive device comprising:

a DC power supply configured to allow an output voltage to be variably controlled;
a drive circuit converting a DC voltage from said DC power supply into an AC voltage by a switching operation of a switching element to drive-control an electric load;
a capacity element provided between said DC power supply and said drive circuit and smoothing the output voltage of said DC power supply for inputting to said drive circuit;
and
a control device controlling said DC power supply,
said capacity element having a temperature dependence such that a resistance value of an equivalent series resistance increases with a decrease in temperature of said capacity element,
said switching element having a temperature dependence such that an element withstand voltage decreases with a decrease in temperature of said switching element, and
in response to a request from said electric load, said control device setting the output voltage of said DC voltage to a value of less than an upper limit value of an input voltage of said drive circuit set depending on the temperature of each of said capacity element and said switching element.

5 more elements

Dependencies are inferred from the claim text.

Load drive device and vehicle equipped with the same

Life of this patent

Load drive device and vehicle equipped with the same

Life of this patent

Abstract

Claims11