DC Grid Fault Current Controller with Segmented Feeder Isolation
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Solution Overview
Problem
In direct current power grids, temporary feeder faults cause the main power supply to lock, leading to immediate power failure and shutdown of the entire network, resulting in unnecessary power outages for other loads.
Innovation Solution
A fault current controller with a primary circuit comprising an inductor, filter capacitor, resistors, IGBT switch, diodes, contactors, and a Hall current sensor, which switches between different modes to manage normal, instantaneous, permanent fault, and bypass shutdown conditions, allowing for selective disconnection of faulty feeders and limiting current to prevent network-wide power failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the main power supply detects a fault current and locks immediately, then the fault protection is achieved, but the whole direct current power distribution network is powered off
Solution Approach 1:
The power distribution network is segmented into multiple independent feeders, each equipped with its own fault current controller. When a fault occurs in one feeder, only that specific feeder is isolated while other feeders continue to operate normally, preventing network-wide power outages
Solution Approach 2:
A fault current controller is introduced as an intermediary device between the power supply and the load. This controller detects fault currents and selectively disconnects only the faulty feeder through contactors, acting as a mediator that prevents fault propagation to the entire network
2Speed
If the main power supply locks immediately upon detecting fault current, then the fault is detected quickly, but other loads are forced to be powered off
Solution Approach 1:
The network is divided into independent feeder sections with individual fault detection and control capabilities. Each segment can be isolated independently, allowing fast fault detection without affecting other segments' operation
Solution Approach 2:
Each feeder is equipped with localized fault detection and control functionality. The fault response is localized to only the affected feeder, maintaining normal operation quality in unaffected areas
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 controller effectively protects the direct current power grid by isolating faulty feeders, preventing network-wide power failures and ensuring normal operation resumes after temporary faults are cleared, thereby maintaining power supply to unaffected loads.
Implementation Method 1
a Hall current sensor; the inductor, a first resistor and a second contactor are connected in series to form a series circuit
Implementation Method 2
The primary circuit includes an inductor, a filter capacitor, a resistor, an IGBT switch, a diode, a contactor and a Hall current sensor
Implementation Method 3
the filter capacitor, the IGBT switch and the first resistor are connected in parallel
Implementation Method 4
the filter capacitor, the IGBT switch and the first resistor are connected in parallel
Data Source
AI summary
Disclosed is a fault current controller for a direct current power grid, which includes a primary circuit and a controller. The primary circuit includes an inductor, a filter capacitor, a resistor, an IGBT switch, a diode, a contactor and a Hall current sensor. The inductor, a first resistor and a second contactor are connected in series and are connected to a first contactor in parallel. A first branch including a second resistor and a first diode, a second branch including a third resistor and a second diode, and the inductor are connected in parallel; the filter capacitor, the IGBT switch and the first resistor are connected in parallel. The Hall current sensor is arranged in the series circuit. The controller controls the IGBT switch and the two contactors in the primary circuit to form different on-off combinations.