
Ⅰ. Background at IEE-Business and Pain Points
Ang mga renewable energy stations (photovoltaic/wind power) ay nakakaharap sa mga komplikadong transient processes dahil sa malawakang paggamit ng mga power electronic devices, kabilang dito ang: inverter shutdown surges, broadband resonance, at DC component interference. Ang mga conventional PTs/CTs ay limitado sa bandwidth, response speed, at anti-saturation capability, kaya hindi sila makakapagtamo ng maayos ng mga transient voltage waveforms. Ito ay nagdudulot ng protection misoperations, hirap sa fault location, at pagbaba ng lifespan ng mga equipment.
Ⅱ. Transient Response Monitoring Solution para sa Renewable Energy Stations
Ang solusyon na ito ay espesyal na idinisenyo para sa mga transient processes sa renewable energy stations, na may core capability na wide-bandwidth, high-precision voltage measurement mula DC hanggang 5kHz.
- Technical Focus: Wide-Band Measurement Capability (DC-5kHz)
Nagbibigay ng pagsisikat sa bandwidth limitations ng mga conventional transformers, kasama ang mga key transient signals tulad ng sub-synchronous oscillation (SSO), switching-frequency harmonics, high-frequency resonance, at slow DC offsets.
- Key Technologies
Resistive-Capacitive Divider + Rogowski Coil Integration:
• Resistive-Capacitive Divider: Nagbibigay ng precise wide-band voltage measurement (10Hz-5kHz) na may mabilis na transient response at matibay na anti-interference.
• Rogowski Coil: Nagsusukat ng high-frequency current rate-of-change (di/dt). Ang integrated complementary signals ay gumagawa ng isang buong wide-band voltage signal, na nagpapalawak ng effective bandwidth hanggang 5kHz at naggugol sa single-sensor limitations.
0.5Hz Low-Frequency Phase Compensation Circuit:
Para sa system ultra-low-frequency sub-synchronous oscillations (hal. <1Hz), ginagamit ang dedicated compensation algorithms at low-noise analog circuits upang panatilihin ang phase error <0.1° sa 0.5Hz, na nag-uugnay sa phase authenticity at amplitude accuracy ng sub-synchronous components.
Anti-DC Component Saturation Design (120% DC Offset):
Ginagamit ang high-Bsat nanocrystalline magnetic cores kasama ang active bias compensation technology. Makakataas ng sustained DC offsets hanggang 120% ng rated voltage nang walang saturation, na nagpapahinto sa measurement distortion dahil sa DC components mula sa inverter faults o grid asymmetry.
- Dynamic Performance Specifications
Step Response Time: <20μs – Sinisiguro ang mabilis na capture ng instantaneous overvoltages dahil sa switching actions (hal. IGBT turn-off).
Harmonic Measurement Accuracy: Hanggang 51st order (2500Hz@50Hz) – THD accuracy ±0.5% – Nakakasunod sa requirements para sa precise power quality assessment at resonance analysis.
Transient Overvoltage Recording Resolution: 10μs/point (equivalent to 100ksps sampling) – Nagbibigay ng high-resolution waveform recording para sa millisecond-level transient events (hal. lightning strikes, ground faults).
- Application Scenarios
PV Inverter Turn-off Overvoltage Monitoring: Precisely measures voltage spikes during IGBT turn-off (dv/dt >10kV/μs), locates the source of reflected wave overvoltages, and optimizes RC snubber parameters and cable layout.
Wind Farm Collection Line Resonance Analysis: Captures broadband resonance (e.g., 2-5kHz) caused by interactions between long cable distributed capacitance and SVGs/generator sets. Provides characteristic harmonic spectra and attenuation characteristics to guide active damping parameter tuning.
Sub-Synchronous Oscillation (SSO/SSR) Monitoring: Accurately records phase and amplitude changes of sub-synchronous oscillation voltages within the 0.5-10Hz range, providing core data for oscillation source localization and suppression strategies.
Protection Misoperation Analysis Due to DC Components: Provides accurate fundamental component measurements even under significant DC offset conditions, preventing protection device misjudgments caused by transformer saturation.