Electromagnetic Contactor Voltage Control for Power Conditioners
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electromagnetic contactors require large control power sources due to uncontrolled current in the electromagnetic coil, leading to increased costs and instability during temporary blackouts or unstable control power sources, which can cause the solar power conditioner to stop operating.
Innovation Solution
A power conditioner design that includes an energization switch, an electromagnetic coil, a current-limiting resistor, and an auxiliary contact point, allowing for controlled voltage application and reduced power consumption by limiting current through the resistor, and a configuration with multiple resistors to manage voltage during energization and maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a common electromagnetic contactor operates at full voltage application without current control, then the electromagnetic coil can reliably close and maintain the circuit path, but the control power source capacity must be large, leading to increased cost and device size
Solution Approach 1:
The patent applies dynamic control to the electromagnetic coil by switching between two operational modes: a first mode with higher voltage for reliable path closing, and a second mode with reduced voltage for maintaining the closed state. This dynamic voltage adjustment allows the system to achieve reliable operation initially while reducing power consumption during maintenance, thereby enabling a smaller control power source.
Solution Approach 2:
The patent changes the voltage parameter applied to the electromagnetic coil over time. Initially, a first voltage sufficient for path closing is applied, then after the path is closed, a second voltage lower than the first is applied to maintain the closed state. This parameter change reduces the power source capacity requirement while maintaining operational reliability.
2Loss of energy
If a resistor is inserted in the electromagnetic coil immediately after energization to reduce power consumption, then power loss is reduced, but heat loss by the resistor is uneconomic and problematic
Solution Approach 1:
The patent performs preliminary action by closing the circuit path first using full voltage before introducing the resistor for power reduction. The controller closes the switch to apply full voltage to the electromagnetic coil, waits for the path to close, then inserts the resistor in series to reduce power consumption. This sequencing avoids immediate heat loss while achieving long-term energy efficiency.
Solution Approach 2:
The patent employs periodic action by switching between different circuit configurations: initially applying full voltage for path closing, then switching to a reduced voltage configuration with the resistor inserted for power reduction. This periodic switching between high-power and low-power states achieves energy efficiency without sustained heat generation.
3Weight of stationary object
If the voltage applied to the electromagnetic coil is lowered after energization to miniaturize the control power source, then the power source size is reduced, but the electromagnetic contactor may not reliably close the path initially
Solution Approach 1:
The patent applies preliminary action by first closing the switch to apply full voltage to the electromagnetic coil, ensuring reliable path closing before any power reduction occurs. Only after the path is confirmed closed does the controller insert the resistor to reduce voltage and power consumption. This preliminary full-voltage application guarantees reliable operation.
Solution Approach 2:
The patent uses dynamic control to switch between two voltage levels: a higher first voltage for reliable path closing and a lower second voltage for power reduction. The controller dynamically adjusts the voltage based on the operational state, ensuring that full voltage is applied when needed for reliability, then reduced for efficiency.
4Productivity
If an electromagnetic contactor is used in a solar power conditioner during temporary blackout or unstable control power source, then the system should continue operation, but the contactor opens due to power instability, stopping the solar power conditioner
Solution Approach 1:
The patent applies beforehand cushioning by using a capacitor connected in parallel with the electromagnetic coil. This capacitor stores electrical energy and provides cushioning voltage when the control power source becomes unstable or experiences temporary blackout. The capacitor discharge maintains the electromagnetic coil energization, preventing contactor opening and ensuring continuous operation during power disturbances.
5Ease of operation
If multiple electromagnetic coils are provided separately for closing and maintaining the path state, then the control is precise, but the device complexity and cost increase
Solution Approach 1:
The patent merges the functions of path closing and path maintaining into a single electromagnetic coil. By controlling the voltage applied to this single coil through switching between different voltage levels (using the resistor and capacitor network), the system achieves the control precision that would otherwise require separate coils, while reducing device complexity and cost.
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
This design miniaturizes the control power source, reduces power loss, and maintains the energized state during unstable conditions, providing a cost-effective and efficient power conditioner that can continue operation during temporary blackouts.
Implementation Method 1
applying a voltage to an electromagnetic coil closes a path in a circuit, and interrupting the applied voltage opens the path in the circuit
Implementation Method 2
a capacitor connected in parallel with the electromagnetic coil, thereby when a control power source becomes unstable or a temporary blackout of an alternating current occurs, the capacitor can hold a voltage
Implementation Method 3
a controller that controls supply of power to the electromagnetic coil, and a resistor connected in series with the electromagnetic coil
Data Source
Figure 1~2
Figure 3~4
AI summary
In an electromagnetic contactor in the open path state, the electromagnet gap is wide and the magnetic resistance is high, so a large amount of magnetomotive force is needed at the start of path-closing. In the closed path state, the gap is narrower, so the closed path state can be maintained with a weak magnetomotive force. However, since the current flowing in the electromagnetic coil cannot be controlled at full voltage application, a power source having the capacity needed for energizing the electromagnetic contactor is necessary. Therefore, this has resulted in larger sizes for control power sources, leading to the problem of increase in costs. Therefore, the present invention provides a power conditioner provided with a power conversion device and an electromagnetic contactor connecting an alternating current power source to the power conversion device, this power conditioner being characterized in that the power conditioner is further provided with a resistor connected in series with the coil of the electromagnetic contactor and a contact point connected in series with the electromagnetic contactor, the resistor and the switch are connected in parallel, and a capacitor is connected in parallel with the coil and the contact point of the electromagnetic contactor.