Air Conditioner Power Supply Circuit for Short-Circuit Voltage Isolation
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Solution Overview
Problem
Existing power supply devices that receive AC power and drive electric motors face increased costs due to the need for high withstand voltage components in the power storage units, which are required to handle twice the normal voltage during semiconductor switch element short-circuit failures.
Innovation Solution
A power supply device design that includes a first rectifying unit, a power-factor improving unit, a first power storage unit, a second rectifying unit, and a second power storage unit, where the second rectifying unit converts AC power into DC power and stores it independently, allowing the control unit to interrupt the input unit during a short-circuit failure, thereby reducing the voltage applied to the second power storage unit and minimizing the need for high withstand voltage components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a noise filter with a capacitor is used to suppress harmonic noise in the input unit, then noise suppression is improved, but during a short-circuit failure the voltage superimposition causes the power storage unit to require twice the normal withstand voltage, increasing costs
Solution Approach 1:
The power supply device is divided into two independent power storage units: a first power storage unit (C1) connected to the input unit for noise filtering, and a second power storage unit (C2) for supplying power to the control unit. This segmentation isolates the voltage superimposition issue to only the first power storage unit, allowing the second power storage unit to use lower withstand voltage components and reducing overall costs.
Solution Approach 2:
The patent introduces a diode (D121) as an intermediary component between the input unit and the second power storage unit. This diode prevents the superimposition of input unit voltage onto the second power storage unit during short-circuit failures, thereby protecting the second power storage unit from high voltage stress and enabling the use of lower cost components.
2Reliability
If the withstand voltage of the power storage unit is increased to handle voltage superimposition during failures, then reliability is improved, but costs increase due to higher specification components
Solution Approach 1:
The power supply device is divided into two independent power storage units: a first power storage unit (C1) connected to the input unit for noise filtering, and a second power storage unit (C2) for supplying power to the control unit. This segmentation isolates the voltage superimposition issue to only the first power storage unit, allowing the second power storage unit to use lower withstand voltage components and reducing overall costs.
Solution Approach 2:
The patent introduces a diode (D121) as an intermediary component between the input unit and the second power storage unit. This diode prevents the superimposition of input unit voltage onto the second power storage unit during short-circuit failures, thereby protecting the second power storage unit from high voltage stress and enabling the use of lower cost components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design reduces costs by eliminating the need for high withstand voltage components in the second power storage unit, while ensuring continuous operation and noise suppression, even during semiconductor switch element failures.
Implementation Method 1
a first rectifying unit that converts the AC power passed through the input unit into DC power
Implementation Method 2
a second rectifying unit connected to a portion where the input unit is connected to the AC power supply, the second rectifying unit converting the AC power into the DC power
Implementation Method 3
a first power storage unit that stores the DC power passed through the power-factor improving unit and supplies the stored DC power to a load side
Implementation Method 4
a second power storage unit that stores the DC power passed through the second rectifying unit
Data Source
AI summary
A power supply device includes a first rectifying unit that converts the AC power passed through an input unit into DC power, a power-factor improving unit that improves a power factor of the DC power output from the first rectifying unit, a first power storage unit that stores the DC power passed through the power-factor improving unit and supplies the stored DC power to a load side, a second rectifying unit connected to a portion where the input unit is connected to the AC power supply, the second rectifying unit converting the AC power into the DC power, a second power storage unit that stores the DC power passed through the second rectifying unit, and a control unit that operates using the electric power stored in the second power storage unit and, when a short-circuit failure occurs in the power-factor improving unit, performs control for interrupting the input unit.