Wireless Power Receiver Overvoltage Protection via Isolated Gate Driver
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Solution Overview
Problem
Wireless power receivers are vulnerable to overvoltage conditions due to rapid changes in coupling factors during alignment or misalignment with the transmitter, which can lead to damage from excessive voltage.
Innovation Solution
A wireless power system that includes a Hall effect sensor to detect the distance between the receiver and transmitter, transient voltage suppression (TVS) diodes to divert transient current, and a processor to send a reset command to the transmitter when an overvoltage condition exceeds a threshold, ensuring the receiver is protected from excessive voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If clamping capacitance or short circuit switch is used to limit receiver voltage, then voltage protection is improved, but communication between receiver and transmitter is interrupted causing overcurrent or prolonged overvoltage transient
Solution Approach 1:
The patent introduces an isolated gate driver as an intermediary component between the receiver and transmitter. This driver uses an isolated controller that maintains communication capability while controlling the primary switch, preventing direct short-circuiting of the transmitter output. The isolation barrier allows control signals to pass while blocking harmful voltage transients and currents, thus protecting the transmitter from overcurrent conditions while maintaining receiver protection.
Solution Approach 2:
The patent segments the control system into isolated sections: the primary side (transmitter) and secondary side (receiver) are electrically isolated through the gate driver. This segmentation allows independent protection of each side while maintaining communication. The receiver controller and transmitter controller operate in isolated environments, preventing harmful effects from propagating across the boundary while still enabling coordinated operation.
2Reliability
If conventional clamping methods are used, then receiver voltage is limited, but receiver-to-transmitter communication is cut off creating abnormal system conditions
Solution Approach 1:
The isolated gate driver acts as a mediator that preserves communication pathways while providing voltage protection. The isolated controller within the gate driver maintains bidirectional communication between receiver and transmitter controllers, allowing normal operation and fault detection to continue even when voltage clamping is active. This eliminates the communication blackout experienced with conventional clamping methods.
Solution Approach 2:
The patent changes the electrical isolation parameter of the control system. By introducing galvanic isolation through the gate driver, the system allows control signals and communication data to pass while blocking harmful voltage transients. This parameter change enables simultaneous voltage protection and communication maintenance, as the isolation barrier selectively passes desired signals while blocking harmful voltage excursions.
3Power
If the receiver is surrounded by large electromagnetic field for power transfer, then power transmission capability is improved, but the receiver coil generates excessive voltage that can damage the receiver
Solution Approach 1:
The isolated gate driver serves as a protective intermediary between the high-power electromagnetic field and the receiver's sensitive electronics. The driver's isolated controller monitors voltage conditions and controls the primary switch to prevent excessive voltage from reaching the receiver coil, while still allowing sufficient power transfer. The isolation barrier protects the receiver control circuitry from the harsh electromagnetic environment.
Solution Approach 2:
The patent implements beforehand cushioning by pre-configuring the isolated gate driver and protected circuitry to withstand voltage transients before they occur. The isolated controller is designed with built-in protection mechanisms that activate automatically when voltage exceeds safe levels, cushioning the receiver from damage before the overvoltage can cause harm. This proactive protection allows the system to operate in high-power electromagnetic fields safely.
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
Effectively limits voltage to a safe level during overvoltage events, preventing damage to the receiver and ensuring safe operation by combining Hall effect sensor detection, TVS diode protection, and timely transmitter reset.
Implementation Method 1
A wireless power system providing protection from overvoltage conditions may be summarized as including a Hall effect sensor. The system further includes a wireless power receiver including one or more magnets to allow detection of a distance of the wireless power receiver from the wireless power transmitter using the Hall effect sensor
Implementation Method 2
one or more transient voltage suppression (TVS) diodes communicatively connected so that when an overvoltage condition occurs in which a determined operating voltage of a protected portion of the receiver is exceeded, the TVS diodes provide a low impedance path for transient current to divert the transient current away from the protected portion of the receiver
Implementation Method 3
Receiver overvoltage can arise in wireless power transfer systems. In some cases, a receiver can be surrounded by a large electromagnetic field and can be potentially damaged from the large voltage generated in the receiver coil
Data Source
AI summary
A wireless power system and method performs wireless power transmission with sensing to detect a distance and/or misalignment of a power receiver from the power transmitter. Power transmission is adjusted in response to the sensing detecting the distance and/or misalignment exceeding a determined threshold, or in response to instructions sent by the receiver based, at least in part, on a duration of the overvoltage condition exceeding a determined time period.