Intelligent Switch Delay Control for Grid Fault Ride-Through
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Solution Overview
Problem
Conventional power generation systems lack sufficient time to perform detection and control during grid fault ride-through and islanding events due to rapid tripping of controllable switch devices, failing to meet time period requirements in some regions.
Innovation Solution
An intelligent switch device with a control unit that keeps the switch unit turned on for a predetermined time period when the first power supply is in abnormal operation, utilizing a delay power supply unit to ensure the switch unit remains operational during grid fault ride-through and islanding isolation, thereby meeting the required time period standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the controllable switch device is arranged at the grid-connection position to enable rapid tripping, then the system response speed is improved, but the time period for detection and control becomes insufficient
Solution Approach 1:
The patent applies preliminary action by pre-charging a capacitor through a charging circuit during normal operation. When abnormal operation is detected, the pre-charged capacitor immediately powers the control unit, enabling detection and control actions to commence without waiting for power supply establishment. This resolves the time period insufficiency by having the system ready in advance.
Solution Approach 2:
The patent introduces a capacitor as an intermediary energy storage element between the power supply and the control unit. This capacitor acts as a buffer that can quickly deliver the necessary power for detection and control operations during abnormal conditions, bridging the time gap between switch tripping and full system response.
2Reliability
If the switch unit is rapidly tripped during abnormal operation, then system safety is improved, but the device cannot meet time period requirements for grid fault ride-through and islanding isolation
Solution Approach 1:
The control unit performs detection and initiates control actions during the delay period before the switch unit is actually tripped. This preliminary detection and control preparation ensures that the system meets the required time period durations for grid fault ride-through and islanding isolation while maintaining safety through the eventual tripping action.
Solution Approach 2:
The patent implements a dynamic response strategy where the switch unit's tripping is not immediate but delayed for a predetermined time period. This dynamic adjustment allows the system to balance safety requirements with the need to maintain operation long enough to complete detection and control functions, adapting the tripping timing to system needs.
3Loss of time
If a delay power supply unit with capacitor is introduced to provide power during abnormal operation, then the time period for detection and control is sufficient, but the device complexity increases
Solution Approach 1:
The patent extracts the power supply function for the control unit from the main power supply system by using a separate capacitor-based delay power supply unit. This extracted subsystem independently handles power delivery during abnormal operations, simplifying the overall control architecture while ensuring sufficient time period for detection and control.
Solution Approach 2:
The capacitor in the delay power supply unit is automatically charged during normal operation through the charging circuit and automatically discharges to power the control unit when abnormal operation occurs. This self-service mechanism reduces the need for complex external power management while ensuring timely power delivery.
Data Source
AI summary
An intelligent switch device and a power generation system are provided. The intelligent switch device includes a first power port, a second power port, a switch unit and a control unit. A first end of a switch unit is connected to a first power supply via a first power port, and a second end of the switch unit is connected to a second power supply via a second power port. The control unit is configured to control the switch unit to be turned on for a first time period when the first power supply is in abnormal condition, where the abnormal condition causes the switch unit to be tripped. The first time period is greater than or equal to a time period required for a device to respond to the abnormal condition.