Series Z-Source Circuit Breaker with Delayed Reverse-Bias Fault Interruption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing series Z-source circuit breakers for DC circuits face challenges such as high resistive power losses, increased size and cost due to cooling requirements, and inability to interrupt faults immediately or effectively handle slow-rising fault currents.
Innovation Solution
The proposed series Z-source circuit breaker incorporates an electromechanical switch in parallel with a semiconductor switch, a delay circuit, and capacitors to manage fault currents. This design allows for controlled reverse biasing of the semiconductor switch and provides time for the electromechanical switch to open, ensuring effective fault interruption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a semiconductor switch is used in a series Z-source circuit breaker, then the circuit breaker can operate in DC circuits, but high resistive power losses occur and cooling systems are required
Solution Approach 1:
The circuit breaker is segmented into two distinct switches: a semiconductor switch (IGBT) for fast fault detection and initiation of fault current redirection, and an electromechanical switch (VCB) for sustained fault current interruption. This segmentation allows each component to operate in its optimal regime, reducing overall power losses while maintaining DC circuit operation capability.
Solution Approach 2:
The electromechanical switch acts as an intermediary that takes over the fault current interruption task from the semiconductor switch. The semiconductor switch initiates the protection sequence by detecting faults and activating the electromechanical switch, which then handles the high current interruption, reducing the semiconductor switch's exposure to high power losses.
2Adaptability or versatility
If a semiconductor switch is used in a series Z-source circuit breaker, then the circuit breaker can operate in DC circuits, but cooling systems are required which increase size and cost
Solution Approach 1:
The circuit breaker is segmented into two distinct switches: a semiconductor switch (IGBT) for fast fault detection and initiation of fault current redirection, and an electromechanical switch (VCB) for sustained fault current interruption. This segmentation allows each component to operate in its optimal regime, reducing overall power losses while maintaining DC circuit operation capability.
Solution Approach 2:
The electromechanical switch acts as an intermediary that takes over the fault current interruption task from the semiconductor switch. The semiconductor switch initiates the protection sequence by detecting faults and activating the electromechanical switch, which then handles the high current interruption, reducing the semiconductor switch's exposure to high power losses.
3Reliability
If the breaker semiconductor switch is opened immediately upon overcurrent detection, then fault interruption is achieved, but the electromechanical switch cannot open in time due to its slower operation
Solution Approach 1:
The semiconductor switch performs a preliminary action by detecting the fault condition first and initiating the fault current redirection before the electromechanical switch operates. This preliminary action sets up the conditions for successful fault interruption, allowing the slower electromechanical switch to complete the interruption process effectively.
Solution Approach 2:
The semiconductor switch acts as a fast intermediary that detects faults and activates the electromechanical switch, which then serves as a slower intermediary for sustained fault current interruption. This two-stage intermediary approach combines the speed advantage of semiconductor devices with the sustained interruption capability of electromechanical switches.
4Speed
If reverse bias current is provided immediately to the breaker semiconductor switch, then the switch turns off quickly, but the electromechanical switch does not have time to open
Solution Approach 1:
The semiconductor switch performs a preliminary action by detecting the fault condition first and initiating the fault current redirection before the electromechanical switch operates. This preliminary action sets up the conditions for successful fault interruption, allowing the slower electromechanical switch to complete the interruption process effectively.
Solution Approach 2:
The semiconductor switch acts as a fast intermediary that detects faults and activates the electromechanical switch, which then serves as a slower intermediary for sustained fault current interruption. This two-stage intermediary approach combines the speed advantage of semiconductor devices with the sustained interruption capability of electromechanical switches.
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
The solution reduces power losses, minimizes the need for cooling systems, and enables immediate and effective fault interruption, even in the presence of slow-rising fault currents, thereby enhancing the reliability and efficiency of the circuit breaker.
Implementation Method 1
A first capacitor is electrically coupled between the positive and negative buses at an output side of the breaker semiconductor switch
Implementation Method 2
A delay circuit is electrically coupled in series with the first capacitor between the positive and negative buses. The delay circuit is controlled to delay when reverse bias current is provided from the first capacitor to the breaker semiconductor switch
Data Source
AI summary
A series Z-source circuit breaker including a semiconductor switch that breaks source power being provided to a load in response to overcurrent. An electromechanical switch is electrically coupled in parallel with the semiconductor switch, a first capacitor is electrically coupled to an output side of the semiconductor switch, a second capacitor is electrically coupled in parallel with the semiconductor switch, and a delay circuit is electrically coupled in series with the first capacitor. The semiconductor switch is in an open position and the electromechanical switch is in a closed position when overcurrent is not present. Upon detection of overcurrent the semiconductor switch is closed, the electromechanical switch is opened and the delay circuit is controlled to delay when reverse bias current is provided from the first capacitor to the semiconductor switch to prevent source power from being provided to the load to give the electromechanical switch time to open.