Auxiliary Contactor Module With Zero-Crossing Arc Control
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Solution Overview
Problem
Contactor-type electrical devices face issues with electric arc generation during contact closure and opening, energy dissipation, and inrush currents, which affect their lifespan and efficiency, and existing solutions fail to address these problems effectively.
Innovation Solution
An auxiliary module with a control unit and sensors that coordinates the activation and deactivation of the electromagnetic actuator based on zero crossing times of voltage and current signals to minimize electric arcs and inrush currents, allowing for remote control and energy management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If contactor contacts are closed randomly for network voltage values, then the contactor can respond quickly with a predetermined response time, but electric arcs are generated which affect lifespan
Solution Approach 1:
The control unit delays activation of the electromagnetic actuator until the voltage signal reaches zero crossing, preparing the system in advance to close contacts at the optimal moment. This preliminary timing adjustment ensures contacts close when voltage is minimal, reducing electric arcs while maintaining quick response capability.
2Speed
If contactor contacts are closed immediately upon receiving control signal, then the response time is minimized, but inrush currents are generated which may push contacts apart and damage the contactor
Solution Approach 1:
The control unit performs preliminary analysis of the voltage signal to detect zero crossing points before activating the electromagnetic actuator. By anticipating the optimal closing moment and preparing in advance, the system closes contacts when voltage is at zero, eliminating inrush currents while maintaining fast response.
3Reliability
If the contactor coil is powered continuously to maintain contactor operation, then the contactor is ready to operate, but energy dissipation increases and the coil heats up
Solution Approach 1:
Instead of continuous powering, the control unit implements periodic control by activating the electromagnetic actuator only at specific moments when voltage reaches zero crossing. This periodic action maintains operational readiness while dramatically reducing energy dissipation and coil heating.
4Device complexity
If existing solutions use simple relay control without zero crossing detection, then the device complexity is low, but they cannot manage and reduce contactor consumption or limit inrush currents
Solution Approach 1:
The control unit continuously monitors the voltage signal and uses this feedback to detect zero crossing points. This feedback mechanism enables intelligent control decisions that reduce contactor consumption and eliminate inrush currents, justifying the added complexity through significant energy savings and protection benefits.
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 electric arc generation and inrush currents, extends the lifespan of contactor-type devices, and enables efficient energy management by optimizing the timing of contact operations and reducing energy dissipation.
Implementation Method 1
a voltage sensor (14) electrically connected to said control unit (8) by a second input (15) which said control unit (8) comprises, said voltage sensor (14) being arranged to measure a voltage signal VS coming from said power supply
Implementation Method 2
a current sensor (17), said current measuring circuit (16) being electrically connected to said control unit (8) by a third input (18) which said control unit (8) comprises, said current sensor (17) being arranged to measure a current signal flowing in the phase current line P
Implementation Method 3
at least one electromagnetic actuator (4) configured to control at least the position of said first pair of contacts between the open position and the closed position
Data Source
Figure 1
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Figure 3
AI summary
The invention relates to an auxiliary module (1) for an electrical device (2), said electrical device (2) comprising: - a phase current line (P) comprising at least one first pair of contacts, - a neutral current line (N), - an electromagnetic actuator (4), said auxiliary module (1) comprising: - a control circuit (7) comprising a control unit (8), comprising a first input (9) arranged to receive a first control signal or a second control signal, - an activation and deactivation circuit (11) comprising a control element (12), - a voltage measurement circuit (13) for measuring a voltage signal from said power supply, - a current measurement circuit (16) for measuring a current signal flowing in the phase current line (P) downstream of said first pair of contacts,said auxiliary module (1) is characterized in that: the control unit (8) is configured such that if and only if the first control signal is received by said first input (9) and the voltage signal is between VS-15 percent and VS+10 percent, then said control unit (8) is configured to generate a timed activation signal for the control element (12); the control unit (8) is configured such that if and only if the second control signal is received by said at least one first input (9) and the current signal is equal to zero, then said control unit (8) is configured to generate a timed deactivation signal for the control element (12).