EPS design quick reference · cells · chemistries · bus voltages · power classes
| Cell电池片 | Efficiency效率 | Power temp coeff功率温度系数 | Degradation (LEO)退化（LEO） | Notes备注 |
|---|---|---|---|---|
| Silicon硅 | 14–17% | −0.45%/°C | ~3%/yr | Legacy, cheap, radiation-soft传统工艺、便宜、抗辐照差 |
| GaAs single单结 | 19–20% | −0.22%/°C | ~2%/yr | Rare today现已少用 |
| Triple-junction GaAs三结砷化镓 | 29–31% | −0.21%/°C | 1–2%/yr | Current workhorse当前主力 |
| Four/next-gen junction四结/下一代 | 32–34% | −0.20%/°C | ~1%/yr | Emerging, higher cost新兴、成本更高 |
Solar constant 1361 W/m² (1322 at aphelion, 1414 at perihelion). Inherent degradation I_d ≈ 0.72–0.80 (packing, wiring, UV, mismatch).太阳常数 1361 W/m²（远日点 1322，近日点 1414）。固有退化 I_d ≈ 0.72–0.80（填充、布线、UV、失配）。
| Chemistry体系 | Cell voltage单体电压 | Specific energy比能量 | DoD (LEO) | DoD (GEO) | Notes备注 |
|---|---|---|---|---|---|
| Li-ion | 3.6 V | 120–180 Wh/kg | 20–30% | 60–80% | Standard today; needs cell balancing当前标准；需均衡管理 |
| NiH₂ | 1.25 V | 40–60 Wh/kg | ~40% | ~80% | Long GEO heritage, robust overchargeGEO 长期飞行经历、耐过充 |
| NiCd | 1.2 V | 25–35 Wh/kg | 15–25% | ~55% | Legacy, memory effect传统体系、有记忆效应 |
Round-trip energy efficiency: Li-ion ~90–95%, NiH₂ ~70–80%. Keep Li-ion between ~20–90% SoC for calendar life; temperature sweet spot 10–25 °C.充放循环效率：锂离子约 90–95%，氢镍约 70–80%。锂电日历寿命宜保持约 20–90% SoC，温度最佳区间 10–25 °C。
| Bus母线 | Typical use典型应用 |
|---|---|
| 3.3 / 5 / 12 V | CubeSat rails (1–50 W)立方星电源轨（1–50 W） |
| 28 V unregulated不调节 | Smallsats & LEO missions (100 W – 2 kW)小卫星与 LEO 任务（100 W – 2 kW） |
| 50 V regulated全调节 | Mid-size platforms (2–8 kW)中型平台（2–8 kW） |
| 100 V regulated全调节 | GEO comsats & large LEO (8–30 kW)GEO 通信卫星与大型 LEO（8–30 kW） |
| 300 V+ | Electric propulsion direct-drive studies电推进直接驱动方案研究 |
Rule of thumb: keep bus current under ~50 A per feeder — raise the voltage as power grows. Harness mass scales with current, not power.经验法则：单路馈线电流控制在约 50 A 以内——功率增大时应提高母线电压。线缆质量随电流而非功率增长。