Transformerless Power Converter with Dynamic Switching Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transformerless power conversion apparatuses are inefficient due to power wastage, particularly with capacitive types which consume more than ten to twenty times the output power, and are limited by inrush current limiting resistors and Zener diodes that reduce efficiency regardless of load conditions.
Innovation Solution
The power conversion apparatus employs a high voltage capacitor in series with the input and utilizes switches to control current flow in both positive and negative parts of the AC signal, with a switch control circuit to manage the flow based on a low voltage DC signal, reducing power dissipation and improving efficiency by allowing load-demand-based control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of stationary object
If transformerless power conversion apparatus is used, then device size and cost are reduced, but power efficiency deteriorates significantly
Solution Approach 1:
The patent applies dynamic switching control where switches (transistors) are controlled to conduct during specific portions of the AC cycle based on load requirements. The switch control circuit dynamically adjusts the switching timing and duration to match load demand, enabling the system to operate efficiently at variable power levels without the continuous power dissipation inherent in resistive and Zener-based transformerless designs.
Solution Approach 2:
The invention utilizes periodic switching action where the switches are turned on and off in synchronization with the AC input signal cycles. The switch control circuit generates control signals that cause the switches to conduct during specific phases of each AC cycle, creating a periodic energy transfer mechanism that improves efficiency compared to continuous conduction schemes.
2Stability of the object's composition
If Zener diode is used for voltage regulation, then voltage stability is improved, but power consumption increases regardless of load conditions
Solution Approach 1:
The patent replaces the static Zener diode voltage regulation with dynamic switching control. The switch control circuit monitors the output voltage and dynamically adjusts the switching duty cycle and timing to maintain voltage stability. This allows the system to provide voltage regulation only when needed and at the appropriate power level, eliminating the continuous power dissipation of Zener diodes.
Solution Approach 2:
The invention incorporates feedback control where the switch control circuit monitors the output voltage conditions and adjusts the switching control signals accordingly. This closed-loop control mechanism maintains voltage stability by compensating for load variations, replacing the open-loop Zener diode clamping approach that wastes power regardless of actual voltage requirements.
3Reliability
If inrush current limiting resistor is used, then capacitor protection is improved, but power efficiency deteriorates
Solution Approach 1:
The patent implements preliminary protection measures where the switch control circuit monitors input conditions and controls the switching timing to prevent inrush currents. The switches are controlled to turn on at appropriate moments in the AC cycle, and the control circuit can implement soft-start sequences that gradually increase power transfer, protecting capacitors without continuous resistive current limiting.
4Device complexity
If capacitive transformerless power conversion is used, then device complexity is reduced, but power wastage increases ten to twenty times the output power
Solution Approach 1:
The patent maintains the simple capacitive transformerless topology but adds dynamic switching control to overcome the power wastage issue. The switches and control circuit enable the system to transfer power efficiently by controlling the timing and duration of energy transfer cycles, allowing the simple topology to operate efficiently at variable power levels rather than continuously dissipating power.
Solution Approach 2:
The invention changes the operational parameters of the capacitive transformerless circuit by introducing controlled switching. The switches modify the effective impedance and energy transfer characteristics dynamically, enabling efficient power conversion without requiring the continuous power dissipation that characterized traditional capacitive transformerless designs.
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 configuration significantly reduces power wastage and improves efficiency by allowing for load-demand-based control, reducing the size of components and voltage drops, and enhancing the tolerance of the low voltage DC signal compared to traditional Zener diode circuits.
Implementation Method 1
a capacitor coupled to a converter circuit, where the capacitor is configured to harvest energy from an electric field through capacitive coupling
Data Source
AI summary
A power conversion apparatus or system can be configured to receive a high voltage alternating current (AC) signal at an input and to provide in dependence thereon a low voltage direct current (DC) signal from an output stage. The power conversion apparatus can include a main path comprising a high voltage capacitor in series with the input. In an example, the capacitor comprises a portion of an electric field energy harvesting system.