Power converter and vehicle driving system
First Claim
1. A power converter comprising:
- a power converting unit including a switching element, the power converting unit converting DC power into AC power; and
a control unit including a modulated-wave generating unit to generate a modulated wave synchronized with an output voltage command of the power converting unit and a carrier-wave generating unit to output a carrier wave having a frequency higher than a frequency of the modulated wave, the control unit controlling the power converting unit by comparing the modulated wave and the carrier wave to output a switching signal for driving the switching element, whereinwhen a modulation factor in converting the DC power into the AC power is equal to or higher than a mode switching modulation factor and is lower than π
/4, the power converting unit converts the DC power into the AC power in an over-modulation mode, in which switching of the switching element is stopped for a period longer than one cycle of the carrier wave and a ratio of the first period in one cycle of the AC output voltage increases as the modulation factor increases, in a first period in which an AC output voltage is positive and timing of a positive peak value of the AC output voltage is included.
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Accused Products
Abstract
A power converter includes a control unit that generates a modulated wave synchronized with an output voltage command and a carrier wave having a frequency higher than a frequency of the modulated wave, the control unit controlling the power converter by comparing the modulated wave and the carrier wave to output a switching signal for driving a switching element. When a modulation factor in converting DC power into AC power is equal to or higher than a mode switching modulation factor and is lower than π/4, the power converter converts the DC power into the AC power in an over-modulation mode, in which switching of the switching element is stopped for a period longer than one cycle of the carrier wave, in a first period in which an output voltage command is positive and timing of a positive peak value of the output voltage command is included.
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Citations
20 Claims
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1. A power converter comprising:
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a power converting unit including a switching element, the power converting unit converting DC power into AC power; and a control unit including a modulated-wave generating unit to generate a modulated wave synchronized with an output voltage command of the power converting unit and a carrier-wave generating unit to output a carrier wave having a frequency higher than a frequency of the modulated wave, the control unit controlling the power converting unit by comparing the modulated wave and the carrier wave to output a switching signal for driving the switching element, wherein when a modulation factor in converting the DC power into the AC power is equal to or higher than a mode switching modulation factor and is lower than π
/4, the power converting unit converts the DC power into the AC power in an over-modulation mode, in which switching of the switching element is stopped for a period longer than one cycle of the carrier wave and a ratio of the first period in one cycle of the AC output voltage increases as the modulation factor increases, in a first period in which an AC output voltage is positive and timing of a positive peak value of the AC output voltage is included. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A power converter comprising:
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a power converting unit including a switching element, the power converting unit converting DC power into AC power; and a control unit including a modulated-wave generating unit to generate a modulated wave synchronized with an output voltage command of the power converting unit and a carrier-wave generating unit to output a carrier wave having a frequency higher than a frequency of the modulated wave, the control unit controlling the power converting unit by comparing the modulated wave and the carrier wave to output a switching signal for driving the switching element, wherein when a modulation factor in converting the DC power into the AC power is lower than a mode switching modulation factor and is lower than π
/√
(12), the power converting unit outputs an AC voltage superimposed with 3n-th (n is a positive integer) order harmonics, andwhen the modulation factor is equal to or higher than the mode switching modulation factor, the power converting unit converts the DC power into the AC power in an over-modulation mode, in which switching of the switching element is stopped for a period longer than one cycle of the carrier wave and a ratio of the first period in one cycle of the AC output voltage increases as the modulation factor increases, in a first period in which an AC output voltage is positive and timing of a positive peak value of AC the output voltage is included. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification