Power Switching Control Device for Surge Voltage Suppression
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Solution Overview
Problem
Conventional circuit breakers with input resistance still generate surge voltage or inrush current due to potential differences between electrodes, even after the switch for the resistor is closed, before the main contact is closed, due to current flowing through the resistor before the circuit breaking unit is activated.
Innovation Solution
A power switching control device that includes a voltage measurement unit, an interelectrode-voltage calculation unit, a target closing time-point determination unit, and a closing control unit to calculate and control the closing time of the circuit breaker, minimizing the interelectrode voltage and thus suppressing surge voltage or inrush current by determining the optimal closing time based on the phase modifier's impedance and resistance value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed resistance value is used in the pre-charging circuit, then the circuit structure is simple, but the surge voltage cannot be effectively suppressed
Solution Approach 1:
The patent changes the resistance value from fixed to variable/dynamic. A variable resistor or switched resistor configuration is used that provides high resistance during the pre-charging phase to limit current flow, then switches to low resistance after the main contact closes. This parameter change enables effective suppression of both inrush current and surge voltage without significantly increasing circuit complexity.
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
Effectively suppresses surge voltage or inrush current by precisely controlling the closing time of the circuit breaker, reducing the risk of voltage spikes and current surges during the switching process.
Implementation Method 1
a voltage measurement unit to measure a power-supply-side voltage of the circuit breaker
Implementation Method 2
calculate a current that flows through the resistor after the switch is turned on and before the circuit breaking unit is turned on by using a measurement value of the power-supply-side voltage, a resistance value of the resistor, and an impedance of the phase modifier
Implementation Method 3
calculate a current that flows through the resistor after the switch is turned on and before the circuit breaking unit is turned on by using a measurement value of the power-supply-side voltage, a resistance value of the resistor, and an impedance of the phase modifier
Implementation Method 4
A power switching control device according to an aspect of the present invention that controls opening and closing of a circuit breaker including a circuit breaking unit, a resistor connected in parallel to the circuit breaking unit, and a switch connected in parallel to the circuit breaking unit and connected in series to the resistor to be turned on prior to the circuit breaking unit
Data Source
AI summary
A power switching control device includes a unit to measure a power-supply-side voltage of a circuit breaker, a unit to calculate a current that flows through a resistor after a switch is turned on and before a circuit breaking unit is turned on, and to calculate an interelectrode voltage of the circuit breaking unit after the switch is turned on and before the circuit breaking unit is turned on, a unit to determine a target closing time point for the circuit breaking unit so that a target turn-on phase for the circuit breaking unit becomes a phase that is set in accordance with the capacitor, and to output a control signal such that the circuit breaking unit is closed at the target closing time point.