Reverse Wiring Protection Circuit for DC Solid-State Breakers
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Solution Overview
Problem
In DC microgrids, reverse wiring of solid-state circuit breakers can cause damage due to reverse voltage, leading to potential breakdown and safety hazards, which existing technologies have not adequately addressed.
Innovation Solution
A reverse wiring self-protection circuit for solid-state circuit breakers that includes an auxiliary power module, a reverse wiring determination module, and a driving circuit module to detect and prevent reverse wiring by tripping the circuit before the isolating switch is closed, using rectified voltage and tripping energy storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reverse wiring protection is not implemented, then the circuit breaker can operate normally under correct wiring conditions, but the circuit breaker may be damaged by reverse voltage under wrong wiring conditions
Solution Approach 1:
The patent applies preliminary action by detecting reverse wiring conditions before the isolating switch closes and the main circuit becomes conductive. The control circuit monitors the voltage polarity across the main circuit terminals in advance, and if reverse wiring is detected, it prevents the isolating switch from closing or triggers immediate tripping. This proactive approach protects the circuit breaker from reverse voltage damage before the harmful condition can take effect, rather than responding after damage occurs.
Solution Approach 2:
The patent introduces a control circuit as an intermediary between the main circuit and the isolating switch. This control circuit includes voltage detection units that monitor the polarity of the main circuit terminals and a control unit that processes this information to determine whether reverse wiring exists. The control circuit acts as a mediator that intercepts and analyzes the electrical conditions before they can affect the main circuit, enabling safe operation or protective tripping based on the detected conditions.
2Object-affected harmful factors
If reverse wiring detection is added, then the circuit breaker can prevent damage from reverse voltage, but the device complexity and cost increase
Solution Approach 1:
The control circuit serves multiple functions: it detects reverse wiring conditions, monitors the operational state of the isolating switch, controls the tripping mechanism, and provides overall protection logic. By making the control circuit multi-functional, the patent avoids adding separate dedicated components for each function, thereby limiting the increase in device complexity while achieving comprehensive protection against reverse voltage damage.
Solution Approach 2:
The circuit breaker performs its own reverse wiring detection and protection using its built-in control circuit, eliminating the need for external protection devices or separate monitoring systems. The control circuit uses the existing voltage detection capabilities and control mechanisms already present in the circuit breaker design, allowing the device to protect itself without requiring additional external components or systems.
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 effectively protects the circuit breaker and improves safety by detecting and preventing reverse wiring, thereby safeguarding the solid-state circuit breaker and the connected DC system from damage.
Implementation Method 1
a rectifier configured to rectify the DC power and provide the rectified voltage to an auxiliary power circuit
Implementation Method 2
an isolating switch connected between the solid-state circuit breaker and the DC power and configured to isolate or close the connection
Data Source
Figure 1A~1B
Figure 1C
Figure 2
AI summary
A reverse wiring self-protection circuit for a solid-state circuit breaker for DC power is disclosed, comprising an auxiliary power module (211) configured to provide tripping electric energy for tripping the solid-state circuit breaker to a tripping coil (220) of the solid-state circuit breaker before an isolating switch (301) of the solid-state circuit breaker is closed; a reverse wiring determination module (213) configured to determine whether DC power connected to the solid-state circuit breaker is reversely wired, and output a first driving enable signal enabling a driving circuit module (212) in response to reverse wiring of the DC power; the driving circuit module is configured to, transmit a driving signal indicating tripping operation to the tripping coil, in response to the first driving enable signal. The reverse wiring self-protection circuit according to the present disclosure can protect the elements included in the solid-state circuit breaker itself and improve the personal safety of the DC system to which the solid-state circuit breaker is connected. Fig. 3A