Motor driving apparatus
First Claim
1. A motor driving apparatus for driving an AC motor using a regenerative electric power as well as an electric power from an AC power source, comprising:
- a converter section for rectifying and converting an alternating current from the AC power source into a direct current;
an inverter section connected to an AC motor, for converting the converted direct current into an alternating current to drive the AC motor;
a DC link for connecting said converter section and said inverter section;
a power storage device connected to said DC link, for charging a capacitor with regenerative electric power in a decelerating drive of the AC motor and discharging the electric power stored in the capacitor to be supplied to said DC link in an accelerating drive of the AC motor; and
regeneration control means for detecting a voltage of said DC link and performing a regeneration control of feeding the regenerative electric power to the AC power source when the detected voltage of said DC link is equal to or higher than a regeneration control start voltage, said regeneration control means having regeneration control start voltage altering means for altering the regeneration control start voltage to avoid the regeneration control when the electric power stored in the capacitor is supplied to said DC link.
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Accused Products
Abstract
A motor driving apparatus including a regeneration control function and a power storage device for accumulating a regenerative current and for supplying an inverter section with electric power during acceleration. The inverter section is connected to a converter section by a DC link to which regeneration start detecting means and the power storage device are connected. When the regeneration start detecting means detects that a voltage at the DC link reaches a regeneration control start voltage, a controller controls switching elements and starts regeneration control. The regenerative current is accumulated in the capacitor through a diode. When a motor is in a power running state, the switching elements are turned on to apply the voltage at the power storage device to the DC link, and the charged power is utilized for motor acceleration. At that time, the regeneration control start voltage for the regeneration start detecting means is made higher, thereby preventing regeneration control from being activated due to application of the capacitor'"'"'s voltage. Not only the regenerative current is effectively utilized by the power storage device, but also the regeneration control function can be utilized.
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Citations
9 Claims
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1. A motor driving apparatus for driving an AC motor using a regenerative electric power as well as an electric power from an AC power source, comprising:
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a converter section for rectifying and converting an alternating current from the AC power source into a direct current;
an inverter section connected to an AC motor, for converting the converted direct current into an alternating current to drive the AC motor;
a DC link for connecting said converter section and said inverter section;
a power storage device connected to said DC link, for charging a capacitor with regenerative electric power in a decelerating drive of the AC motor and discharging the electric power stored in the capacitor to be supplied to said DC link in an accelerating drive of the AC motor; and
regeneration control means for detecting a voltage of said DC link and performing a regeneration control of feeding the regenerative electric power to the AC power source when the detected voltage of said DC link is equal to or higher than a regeneration control start voltage, said regeneration control means having regeneration control start voltage altering means for altering the regeneration control start voltage to avoid the regeneration control when the electric power stored in the capacitor is supplied to said DC link.
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2. A motor driving apparatus for driving an AC motor using a regenerative electric power as well as an electric power from an AC power source, comprising:
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a converter section for rectifying and converting an alternating current from the AC power source into a direct current;
an inverter section connected to an AC motor, for converting the converted direct current into an alternating current to drive the AC motor;
a DC link for connecting said converter section and said inverter section;
a power storage device connected to said DC link, for charging a capacitor with regenerative electric power in a decelerating drive of the AC motor and discharging the electric power stored in the capacitor to be supplied to said DC link in an accelerating drive of the AC motor; and
regeneration control means for detecting a voltage of said DC link and performing a regeneration control of feeding the regenerative electric power to the AC power source when the detected voltage of said DC link is equal to or higher than a regeneration control start voltage, said regeneration control means having altering means for altering the regeneration control start voltage to be a voltage higher than a voltage of the electric power supplied from said power storage device to said DC link when said power storage device is connected to said DC link. - View Dependent Claims (3)
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4. A motor driving apparatus for driving an AC motor using a regenerative electric power as well as an electric power from an AC power source, comprising:
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a converter section for rectifying and converting an alternating current from the AC power source into a direct current;
an inverter section connected to an AC motor, for converting the converted direct current into an alternating current to drive the AC motor;
a DC link for connecting said converter section and said inverter section;
regeneration control means for detecting a voltage of said DC link and performing a regeneration control of feeding the regenerative electric power to the AC power source when the detected voltage of said DC link is equal to or higher than a regeneration control start voltage; and
a power storage device connected to said DC link, for charging a capacitor with regenerative electric power in a decelerating drive of the AC motor and discharging the electric power stored in the capacitor, said power storage device having electric power supply means for supplying the stored electric power to said DC link at a voltage lower than the regeneration control start voltage in an accelerating drive of the AC motor. - View Dependent Claims (5, 6, 7, 8, 9)
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Specification