Inverter system
First Claim
1. A PWM voltage type inverter system comprising:
- a rectifier connected to an AC power source to receive an AC power therefrom and convert it into a DC power,an inverter bridge connected to receive the DC power from the rectifier and converting it into an AC power of a variable frequency to supply it to an AC motor,a conduction control circuit for controlling the conduction of arms of the inverter bridge normally in a first mode wherein it operates at a frequency determined by a frequency reference signal,a control power circuit connected to receive the power from the AC power source and the regenerative AC power from the motor and to supply a constant voltage DC power to the conduction control circuit,power failure detecting means for detecting the power failure of the AC power source, andswitching means responsive to the power failure detecting means for switching, when power failure is detected, the conduction control circuit to a second mode, wherein it operates in such a manner as to maintain the regenerative voltage at a predetermined value.
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Accused Products
Abstract
In a PWM voltage type inverter system comprising: a rectifier converting an AC power from an AC power source into a DC power, an inverter bridge converting the DC power from the rectifier into an AC power of a variable frequency to supply it to an AC motor, and a conduction control circuit for controlling the conduction of arms of the inverter bridge normally in a first mode wherein it operates at a frequency determined by a frequency reference signal, a control power circuit is connected to receive the power from the AC power source and the regenerative AC power from the motor and to supply a constant voltage DC power to the conduction control circuit. When power failure is detected, the conduction control circuit is switched to a second mode, wherein it operates in such a manner as to maintain the regenerative voltage at a predetermined value. With the arrangement of the invention, the motor can be kept operating over a longer period of time upon occurrence of power failure.
53 Citations
8 Claims
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1. A PWM voltage type inverter system comprising:
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a rectifier connected to an AC power source to receive an AC power therefrom and convert it into a DC power, an inverter bridge connected to receive the DC power from the rectifier and converting it into an AC power of a variable frequency to supply it to an AC motor, a conduction control circuit for controlling the conduction of arms of the inverter bridge normally in a first mode wherein it operates at a frequency determined by a frequency reference signal, a control power circuit connected to receive the power from the AC power source and the regenerative AC power from the motor and to supply a constant voltage DC power to the conduction control circuit, power failure detecting means for detecting the power failure of the AC power source, and switching means responsive to the power failure detecting means for switching, when power failure is detected, the conduction control circuit to a second mode, wherein it operates in such a manner as to maintain the regenerative voltage at a predetermined value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification