High Frequency AC Series Voltage Regulator with Current Direction Sensing
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Solution Overview
Problem
Traditional AC voltage regulators rely on large and heavy magnetic structures at low frequency, which are inefficient and prone to 'shoot-through' issues due to ambiguous input voltage polarity control, leading to semiconductor damage and inefficiency.
Innovation Solution
A high-frequency AC series voltage regulator topology using bidirectional power semiconductors and power inductors with PWM control, which avoids 'shoot-through' by incorporating current direction sensing to ensure safe and efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional low frequency magnetic structures are used in AC voltage regulators, then voltage regulation can be achieved, but the size and weight of the magnetic structures become large
Solution Approach 1:
The patent changes the operating frequency parameter from traditional low frequency (50/60 Hz) to high frequency (20 kHz or higher). This parameter change allows the magnetic structures to be significantly smaller and lighter while maintaining voltage regulation capability, as magnetic component size is inversely proportional to operating frequency.
Solution Approach 2:
The patent replaces traditional electro-mechanical adjustment mechanisms (carbon brushes, motors) with fully electronic high-frequency switching control. This substitution eliminates mechanical wear and reduces the need for large magnetic structures, achieving both weight reduction and improved reliability.
2Device complexity
If simple voltage polarity control is used in HF PWM regulation, then control simplicity is maintained, but shoot-through conditions occur causing semiconductor damage
Solution Approach 1:
The patent introduces current direction sensing feedback to detect the actual current flow direction in the power inductor. This feedback mechanism provides critical information that prevents shoot-through conditions by ensuring proper sequencing of semiconductor switch activation, thereby protecting the devices while maintaining controlled operation.
Solution Approach 2:
The patent performs preliminary detection of current direction before activating semiconductor switches. By sensing the current flow direction in advance, the control system can prevent shoot-through conditions by ensuring that switches are activated only when safe, thus preventing damage before it occurs.
3Reliability
If traditional AC switching devices are used, then voltage regulation can be achieved, but mechanical wear and maintenance are required
Solution Approach 1:
The patent replaces all electro-mechanical switching devices (carbon brushes, motors, relays) with solid-state high-frequency semiconductor switches controlled by PWM. This substitution eliminates mechanical wear components entirely, resulting in a maintenance-free system while achieving superior voltage regulation performance.
4Weight of stationary object
If high frequency PWM control is implemented, then size of magnetic structures is reduced, but shoot-through issues arise causing energy loss
Solution Approach 1:
The patent uses current direction sensing feedback to monitor the actual current flow and prevent shoot-through conditions. By detecting current direction in real-time, the control system can sequence semiconductor switch activation to avoid simultaneous conduction of opposing switches, thereby preventing energy-wasting shoot-through while maintaining high-frequency operation and small magnetic structure size.
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 significantly reduces the size, weight, and cost of magnetic structures while preventing semiconductor damage and improving efficiency by eliminating 'shoot-through' conditions, allowing for safe operation with lower losses and reduced heat generation.
Implementation Method 1
power inductors with PWM control
Data Source
AI summary
A bidirectional AC series voltage regulator that regulates an output AC voltage level regardless of the varying AC input voltage utilizing high frequency series inductors that only process a proportion of the total output power. The AC series voltage regulator detects the power inductor current direction data signal and can generate power inductor current direction data signals for its control to determine the AC input voltage polarity at all time; wherein the determination of the AC input voltage polarity is unambiguous during the AC input voltage zero crossover and near zero points; and wherein the determination of the AC input voltage polarity allows normal switching sequence of the AC bidirectional switches during the AC input voltage zero crossover and near zero points to prevent power “shoot-through.”