Has anyone used Friendly Thai Visa’s airport safe entry service? Only real experiences plz
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JAPAN - Prof dr Yasufumi MURAKAMI: "The more doses you get, the sooner you’re likely to die"
well, people are blinded by Hollywood, strong healthy gladiators, Vikings, and settlers. Only Monty Python had some great graphics and correct stories of the ancient times. you can’t beat ignorance, it is impossible -
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Spanish Power Outage - The Official Report
The scenario describes a cascading series of power system disturbances with multiple events triggering protocolized actions and equipment tripping. A concise analysis of the events and their implications, based on power system dynamics and standard protocols: 1. **Forced Oscillation (0.6 Hz, Badajoz PV Plant, N-1)**: A photovoltaic (PV) power plant in Badajoz introduces a forced oscillation at 0.6 Hz, likely due to control system issues or equipment malfunction. This triggers system-altering actions, including operating shunt reactors to manage reactive power and coupling lines to stabilize the grid. Schedule modifications indicate adjustments to generation or load to dampen oscillations. This is classified as an N-1 contingency (single element failure). 2. **Natural Oscillation (0.2 Hz, N-2)**: A lower-frequency natural oscillation at 0.2 Hz emerges, possibly due to system-wide resonance or insufficient damping. Further shunt reactor operations and line coupling are enacted, with additional schedule adjustments. This N-2 event suggests a second contingency compounding the initial disturbance. 3. **Reactive Power Absorption Failure (P.O. 7.4, N-3)**: Generation units under operating condition P.O. 7.4 (likely a specific grid code or protocol) fail to absorb required reactive power, exacerbating voltage control issues. This indicates non-compliance or equipment limitations, further stressing the system. 4. **RCW Generation Issues (N-4)**: Renewable (likely wind or solar, RCW = Renewable Control Wind or similar) generation units exhibit variations during active power regulation, impacting voltage control. Many units fail to meet grid obligations, suggesting control or communication issues, adding to system instability. 5. **Conventional Generation Failure (N-5)**: Requested conventional generation (e.g., thermal or gas units) to mitigate oscillations does not come online, likely due to delays, outages, or scheduling errors, leaving the system vulnerable. 6. **Generation Loss in Distribution (N-5)**: A minor generation loss (P < 1 MW) and significant self-consumption (435 MW) before 12:32:57 indicate distributed energy resources (e.g., small-scale PV or loads) are not contributing as expected, further straining the grid. 7–14. **Multiple Inappropriate Trippings (N-6 to N-10, N-12 to N-14)**: A series of inappropriate trippings occur across various generation types and locations: - Granada generation transformer (N-6). - Solar thermal and PV plants in Badajoz (N-7, N-8, N-14). - PV plants in Seville and Cáceres (N-9, N-10). - Three wind farms in Segovia and one wind farm plus a PV plant in Huelva (N-10, N-11). Many lack point-of-interconnection data, indicating missing telemetry or communication with the transmission system operator (TSO), which complicates system monitoring and control. 15. **CCGT Unit Tripping (Valencia, N-11)**: A combined-cycle gas turbine (CCGT) unit trips, removing a significant dispatchable power source, further reducing system stability. 16. **Load Shedding and Voltage Increase**: Underfrequency triggers load shedding of pumping units and other loads, reducing demand but causing an unintended increase in system voltage due to reduced reactive power absorption. 17. **HVDC Link Operation**: The HVDC link to France continues exporting 1,000 MW in constant power mode, unaffected by local disturbances. This may exacerbate local instability by prioritizing export over domestic stabilization. 18. **Nuclear Power Plant Tripping (N-12)**: A nuclear plant trips, a critical event given its large capacity and baseload role, significantly worsening the system’s stability and capacity margin. ### System Implications - **Oscillations**: The 0.6 Hz forced and 0.2 Hz natural oscillations suggest poorly damped inter-area or local modes, likely exacerbated by high renewable penetration and inadequate reactive power support. - **Cascading Failures**: The sequence of events (N-1 to N-12) indicates a cascading failure, where initial disturbances (PV-related oscillations) trigger widespread equipment trippings due to protection settings, lack of coordination, or missing telemetry. - **Reactive Power and Voltage Issues**: Repeated failure to manage reactive power (N-3, N-4, N-16) points to insufficient voltage control resources or non-compliance with grid codes. - **Data Gaps**: Missing point-of-interconnection data for multiple tripped units (N-7, N-8, N-10, N-11, N-14) highlights a critical issue in TSO visibility, hindering real-time response. - **Export Strain**: The HVDC link’s constant 1,000 MW export reduces local flexibility, potentially worsening underfrequency and stability issues. ### Recommended Actions 1. **Oscillation Damping**: Deploy power system stabilizers (PSS) on remaining conventional units and tune renewable controllers to dampen 0.2–0.6 Hz oscillations. 2. **Reactive Power Management**: Enforce grid code compliance for renewable units (P.O. 7.4) and activate additional reactive power resources (e.g., SVCs or synchronous condensers). 3. **Telemetry Improvement**: Address missing point-of-interconnection data by mandating real-time telemetry for all generators, especially renewables. 4. **Protection Coordination**: Review and adjust protection settings to prevent inappropriate trippings, particularly for PV, wind, and thermal units. 5. **Contingency Planning**: Enhance N-1 and N-2 contingency plans to prioritize local stability over exports, including dynamic HVDC control adjustments. 6. **Load and Generation Balance**: Restore conventional generation and adjust load shedding schemes to balance frequency and voltage. 7. **Post-Event Analysis**: Conduct a root cause analysis of the Badajoz PV oscillation and subsequent trippings to prevent recurrence. -
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How long do 'The Shins' have left?
Now I know why you are the way you are.. Mark. -
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The weather in Thailand ain’t all that…
marin would be a good start to get some polishing practice.. Mark.
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