### I. Introduction

### II. Spacecraft Power System Modeling

### 1. Battery Model

*L*is the inductor linked to the electrode current collectors,

*R*is the series resistance of the cells, which mainly functions as temperature,

*R*

*is called the charge transfer resistance,*

_{ct}*C*

*is the double-layer capacitance of the electrode material/electrolyte interfaces [9].*

_{dl}Battery type: Lithium-ion

Battery dimension: 855 × 425 ×210 mm

^{3}maxBattery capacity: 104 AH @ BOL

Battery mass: 58 kg

Cell connection: 4 cells parallel and 13 cells serial connected

Cell length: 5.4 cm

### 2. Power Control and Distribution Unit Model

Solar array regulator,

28 V Power regulator,

Low voltage converter,

Bus filter,

Battery interface,

Power distribution module,

Bus bar, board interconnection, internal wiring.

#### 2.1 Modeling of solar array regulator

#### 2.2 Modeling of power (28 V) regulator

#### 2.3 Modeling of low voltage converters

#### 2.4 Modeling of the bus filter

#### 2.5 Modeling of battery interface and power distribution boards

### 3. Connection Model between Battery and PCDU

### 4. Proposed Power System Model

### III. Experimental Verification

*I*

_{NOISE}into the power bus using an independent current source, voltage perturbation

*V*

_{NOISE}occurred according to its impedance characteristics. From these current and voltage results, the dynamic impedance of the power bus can be calculated.

### IV. Results and Analysis

*RLC*network consisting of unit input filters, internal wiring, and unit function. The PPD output was connected to electrical ground support equipment (EGSE) made of resistors. Therefore, the PPD output was modeled as a resistor, taking power consumption into account.