Design and Implementation of On-board Electrical Power ... - OUFTI-1
Design and Implementation of On-board Electrical Power ... - OUFTI-1 Design and Implementation of On-board Electrical Power ... - OUFTI-1
Parameter SLPB723870H4 SLPB554374HNominal Capacity TYP 1,500 mAh TYP 1,250 mAhNominal Voltage 3.7V 3.7VCharge ConditionMax. Current 1C(1,500mAh) 1C(1,250mAh)Voltage 4.20 ± 0.03V 4.20 ± 0.03VDischarge ConditionMax. Current 20C(30,000mAh) 15C(18,750mA)Cut-Off Voltage 2.7V 2.7VAC-Impedance.(mΩ ) MAX. 9.0 (1kHz) MAX. 16.0 (1kHz)Operating T ◦ Charge 0 ◦ C to 45 ◦ C 0 ◦ C to 45 ◦ CDischarge -20 ◦ C to 60 ◦ C -20 ◦ C to 60 ◦ CWeight(Max.) 41.0 g 34.0 gEnergy DensityVolumetric 278 Wh/l 287 Wh/lGravimetric 145 Wh/kg 152 Wh/kgTable 3.3: Characteristics of two candidate KOKAM batteries [20].Figure 3.17: Dimensions of the KOKAM SLPB554374H battery [20].to 4,720mW with the power budget worksheet (Chapter 4). The corresponding maximumconsumed current is 1.75A at 2.7V and 1.12A at 4.2V. This corresponds respectively todischarge rates of 1.4C and 0.9C. Figure 3.18 shows the charge characteristics of KOKAMbatteries. Figure 3.19 and 3.20 show their discharge characteristics.Figure 3.18 shows that the batteries are not fully charged when their voltage reaches 4.2V.The dissipation system on the EPS is a shunt regulator (Chapter 5). Another system couldbe to disconnect the batteries when their voltage reaches 4.2V. The use of a shunt regulatorwill allow the batteries to reach the full charge. This is still to be confirmed by tests.32
Figure 3.18: Charge characteristics of KOKAM SLPB554374H (KOKAM Datasheet).Figure 3.19 shows that, for a DoD of 13% (which corresponds to 162 mAh) and a dischargerate under 1C, the voltage should stay between 4V and 4.2V (at 23 ◦ C and begin of life).Figure 3.19: Variation of voltage of KOKAM SLPB554374H during discharge for severaldischarge rates [20].The temperature of the batteries during charge must be between 0 ◦ C and 45 ◦ C or theycould suffer permanent damages. The spacers between the batteries card and the EPS cardwill have a high thermal resistance. Simulations show that, with this solution, the temperature33
- Page 2 and 3: AcknowledgementsI want to thank the
- Page 4 and 5: Contents1 Introduction 91.1 Cubesat
- Page 6 and 7: 4.4.2 Mean case . . . . . . . . . .
- Page 8 and 9: B Power budget worksheet 106C Pictu
- Page 10 and 11: design and the tests are delegated
- Page 12 and 13: Chapter 2Requirements of the EPS2.1
- Page 14 and 15: • The Single-Event Upset (SEU)Thi
- Page 16 and 17: the P-POD. RBF pins must fit within
- Page 18 and 19: Figure 2.6: Top view of the PC104 c
- Page 20 and 21: Chapter 3Design of EPS architecture
- Page 22 and 23: • Voltage (4) and current (5) at
- Page 24 and 25: Figure 3.6: The equivalent circuit
- Page 26 and 27: of our Lithium-Polymer batteries va
- Page 28 and 29: Figure 3.12: I-V curve of a solar p
- Page 30 and 31: 3.3.3 CapacityA important value to
- Page 34 and 35: of the batteries is kept between -2
- Page 36 and 37: Over Charge Prohibition 4.275 ± 0.
- Page 38 and 39: supplied in 5V. The circuit will be
- Page 40 and 41: Chapter 4The Power Budget4.1 Introd
- Page 42 and 43: Figure 4.1: P-V curve of a solar pa
- Page 44 and 45: 4.3.2 Efficiency of convertersTo at
- Page 46 and 47: Figure 4.3: Consumptions in % in me
- Page 48 and 49: Chapter 5Electrical Design of EPS5.
- Page 50 and 51: V outV in= D. (5.1)Since D ≤ 1, t
- Page 52 and 53: The power losses in the inductor ar
- Page 54 and 55: ∆i L,1 + ∆i L,2 = 0, (5.16)V in
- Page 56 and 57: Using the value of ∆i L given by
- Page 58 and 59: There is no data about the case to
- Page 60 and 61: Capacitor selectionFour 10µF ceram
- Page 62 and 63: • Output voltage: 5V.• Maximum
- Page 64 and 65: Figure 5.12: Burst mode operation (
- Page 66 and 67: Figure 5.14: Simplified schematics
- Page 68 and 69: Figure 5.15: Worksheet for 3.3V con
- Page 70 and 71: sequently, the k was chosen above 0
- Page 72 and 73: where G 1 is the initial control-to
- Page 74 and 75: Figure 5.21: Measured Bode diagram
- Page 76 and 77: Figure 5.26: Equivalence between th
- Page 78 and 79: C f =12πf f R 0f,L f = R 2 0f C f
- Page 80 and 81: Figure 5.37: Schematics of the firs
Parameter SLPB723870H4 SLPB554374HNominal Capacity TYP 1,500 mAh TYP 1,250 mAhNominal Voltage 3.7V 3.7VCharge ConditionMax. Current 1C(1,500mAh) 1C(1,250mAh)Voltage 4.20 ± 0.03V 4.20 ± 0.03VDischarge ConditionMax. Current 20C(30,000mAh) 15C(18,750mA)Cut-Off Voltage 2.7V 2.7VAC-Impedance.(mΩ ) MAX. 9.0 (1kHz) MAX. 16.0 (1kHz)Operating T ◦ Charge 0 ◦ C to 45 ◦ C 0 ◦ C to 45 ◦ CDischarge -20 ◦ C to 60 ◦ C -20 ◦ C to 60 ◦ CWeight(Max.) 41.0 g 34.0 gEnergy DensityVolumetric 278 Wh/l 287 Wh/lGravimetric 145 Wh/kg 152 Wh/kgTable 3.3: Characteristics <strong>of</strong> two c<strong>and</strong>idate KOKAM batteries [20].Figure 3.17: Dimensions <strong>of</strong> the KOKAM SLPB554374H battery [20].to 4,720mW with the power budget worksheet (Chapter 4). The corresponding maximumconsumed current is 1.75A at 2.7V <strong>and</strong> 1.12A at 4.2V. This corresponds respectively todischarge rates <strong>of</strong> 1.4C <strong>and</strong> 0.9C. Figure 3.18 shows the charge characteristics <strong>of</strong> KOKAMbatteries. Figure 3.19 <strong>and</strong> 3.20 show their discharge characteristics.Figure 3.18 shows that the batteries are not fully charged when their voltage reaches 4.2V.The dissipation system on the EPS is a shunt regulator (Chapter 5). Another system couldbe to disconnect the batteries when their voltage reaches 4.2V. The use <strong>of</strong> a shunt regulatorwill allow the batteries to reach the full charge. This is still to be confirmed by tests.32