IPH Input Impedance Control for Safe Power Draw Regulation
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Solution Overview
Problem
Induction Power Harvester (IPH) systems face challenges in efficiently drawing power at low line currents while preventing excessive power draw during high line currents, leading to increased complexity and cost due to high impedance and voltage spikes, and pose safety risks during installation due to magnetic flux and voltage spikes.
Innovation Solution
The system incorporates an impedance controller to match the reactive part of the IPH's impedance, uses a shorting switch to limit power supply during high currents, and employs a power TRIAC to safely install and remove the IPH by shorting the magnetic flux, thereby reducing the risk of high voltage spikes and attractive forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the extraction circuit draws power from the IPH during high line currents, then the electronic devices can be powered, but the IPH voltage increases to open circuit EMF which is very high, requiring the entire power path to be designed to withstand high voltage, greatly increasing complexity and cost
Solution Approach 1:
The control circuit preemptively detects high line current conditions and activates the shorting switch to short the winding terminals before the extraction circuit would cause voltage to rise to dangerous levels. This preliminary action prevents the high voltage condition from developing, allowing the power path components to be designed for lower voltage ratings.
Solution Approach 2:
The shorting switch acts as an intermediary element between the IPH winding and the extraction circuit. When high line currents are detected, the shorting switch provides a low-impedance path that limits the voltage across the winding, thereby protecting the extraction circuit and other power path components from high voltage stress without requiring them to be designed for open circuit EMF ratings.
2Reliability
If a resistive load is used to clamp the IPH voltage during high line currents, then the voltage is limited, but the excess energy is dissipated as heat, greatly increasing the complexity and cost of capturing energy using the IPH
Solution Approach 1:
The invention extracts or removes the harmful high voltage condition from the system by using the shorting switch to create a controlled short circuit path. Instead of allowing the voltage to rise to dangerous levels (which would then need to be clamped by a resistive load), the shorting switch proactively limits the voltage by providing an alternative current path, thereby eliminating the need for energy-dissipating clamping resistors.
Solution Approach 2:
The IPH system serves itself by using the shorting switch to automatically limit its own voltage output during high line current conditions. The control circuit monitors the line current and activates the shorting switch when needed, allowing the system to self-regulate its voltage output without requiring external resistive loading to clamp the voltage and dissipate excess energy.
3Ease of manufacture
If the two halves of the core are brought close together during installation, then the magnetic flux through the core increases rapidly, resulting in a large attractive force that draws the two halves together in a dangerous manner
Solution Approach 1:
The shorting switch is activated in advance during the installation process to create a short circuit across the winding terminals. This preliminary action generates a magnetic field that opposes the attractive force between the core halves, counteracting thesnap-together effect before it can occur. The control circuit detects the installation condition and activates the shorting switch to prevent the harmful attractive force.
Solution Approach 2:
The invention converts the potentially harmful high magnetic flux condition into a beneficial effect by using the shorting switch to create a controlled short circuit. The short circuit current generates a magnetic field that produces a repulsive force between the core halves, counteracting the attractive force. Thus, the high magnetic flux that would normally cause dangerous attraction is transformed into a protective repulsive force during installation.
4Object-affected harmful factors
If the IPH is designed to withstand high voltages to protect against voltage spikes during installation, then safety is improved, but the size and cost of the IPH increases
Solution Approach 1:
The shorting switch serves as an intermediary protective element that is activated during installation to limit voltage spikes at the winding terminals. By shorting the terminals when high magnetic flux conditions occur during installation, the switch prevents dangerous voltage spikes from developing, allowing the IPH components to be designed for lower voltage ratings rather than requiring high voltage withstand capability.
Solution Approach 2:
The control circuit activates the shorting switch in advance during the installation process, before voltage spikes can occur. This preliminary action ensures that the winding terminals are shorted and protected from high voltage conditions during the critical installation phase, allowing the use of lower voltage-rated components throughout the IPH design.
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 solution enhances power draw efficiency at low currents, reduces complexity and cost by minimizing power dissipation and hardware requirements, and ensures safe installation and operation by managing impedance and magnetic forces.
Implementation Method 1
An Induction Power Harvester (IPH) can capture energy from an alternating current (AC) high power line
Implementation Method 2
uses a shorting switch to limit power supply during high currents, and employs a power TRIAC to safely install and remove the IPH by shorting the magnetic flux
Implementation Method 3
employs a power TRIAC to safely install and remove the IPH by shorting the magnetic flux, thereby reducing the risk of high voltage spikes and attractive forces
Data Source
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AI summary
A method for regulating input impedance of a switching regulator, the method comprising: obtaining, at an impedance controller: (a) a measured voltage value that is indicative of an input current of the switching regulator and (b) an input voltage of the switching regulator, wherein a ratio of the input voltage to the input current defines an actual input impedance of the switching regulator; generating a control signal by the impedance controller, in accordance with a difference between the actual input impedance of the switching regulator and a desired input impedance of the switching regulator, wherein the desired input impedance is a predefined impedance; and controlling a feedback node feeding the switching regulator, in accordance with the control signal, to realize an output voltage of the switching regulator for achieving the desired input impedance, wherein the feedback node is external to the switching regulator, thereby regulating the input impedance of the switching regulator externally to the switching regulator.