Power Distribution System

The go-kart mechatronics system is designed as a modular system, consisting of several subsystems that are responsible for different tasks. There are six major subsystems: Power Distribution (PD), Main Control (MC), Throttle-by-Wire (TBW), Brake-by-Wire (BBW), and Steerby-Wire (SBW). The “x-by-wire” system design approach has been gaining popularity in the automotive industry which is to replace conventional mechanical and hydraulic control systems with electronic signals. The elimination of traditional mechanical components could increase control stability, increase design flexibility, reduce cost, and improve efficiency. In our go-kart drive-by-wire design, all subsystems except the PD use an STM32 Nucleo development board on a standalone PCB as the electronic control unit (ECU). Like modern vehicle design, communication is achieved using the controller area network (CAN) to allow efficient information exchange between nodes. These modular control systems are integrated with the original go-kart chassis in a nonintrusive manner and are easy to understand, build, and modify.

PDU Subsystem video

1. Feature

Dual Input:

2x 12V battery input with XT90 connectors, offering flexibility in battery selection and redundancy for increased reliability.

Fuse Protection:

Each component has an individual fuse, ensuring protection against overcurrent and short circuits.

Multiple DC-DC Converters:

High-Current 24V Converter	Laptop Charger 19V Converter
Auxiliary 12V Converter	Isolated 5V Converter
Isolated LIDAR 24V Converter	Isolated LIDAR 12V Converter
Isolated 3.3V Converter

2. Description

The Power Distribution Unit (PDU) V3, designed for the Autoware Autonomous Gokart Team at the University of Pennsylvania, is a highly efficient and versatile power distribution board. The PDU V3 takes input from two 12V batteries and distributes power through various voltage outputs to various devices. The board features a combination of external and in-board isolated DC-DC converters, fuses for overcurrent protection, and XT60 connectors for secure power distribution.

3. Specification of Board

Board Size	230.00mmx150.00mm
Components on board	78
Routing completion	100.00%
Connections	163
Connections routed	163
Layer / Sq.mm
Top Layer	9891.453
Bottom Layer	32700.357

4. Layout

Figure 1. Layout of Power Distrubution Board

This product should be installed and operated by qualified personnel only. Ensure proper input voltage is supplied to the board to avoid damage to the components. For additional protection, use a separate surge protector or voltage regulator. Do not exceed the maximum output current for each output. Disconnect power before making any adjustments or modifications to the board. Use proper wiring and connectors to ensure secure connections and reduce the risk of short circuits or other electrical hazards. Keep the board in a dry and well-ventilated area to prevent condensation and overheating.

5. Devices

Name	Unit price ($)	Purchasing Link
EEU- TA1J221S C apacitor	2.67	https ://www.digikey.com/en/products/detail/panason ic-electronic-components/EEU-TA1J221S/2689962
EEU- TA1H101B C apacitor	0.96	https ://www.digikey.com/en/products/detail/panason ic-electronic-components/EEU-TA1H101B/2689918
C FR16J1K0 Resistor	0.09	https://www.digikey.com/en/products/detai l/te-connectivity-passive-product/CFR16J1K0/3 317907?s=N4IgTCBcDaIMIDEBKBGAbAKRQaQAwgF0BfIA
O VLAW4CB7 LED	0.44	https://www.digikey.com/en/products/detail /tt-electronics-optek-technology/OVLAW4CB7/18 43572?s=N4IgTCBcDaIPIDUAyBBA6gFgMICEDsIAugL5A
3557-2 Fuse	1.10	https://www.digikey.com/en/produc ts/detail/keystone-electronics/3557-2/2137305
PDQE20- Q24-S5-D c onverter	23.67	https://www.digikey.com/en/prod ucts/detail/cui-inc/PDQE20-Q24-S5-D/10230156? s=N4IgTCBcDaIAoBECKBRMAGAtEsAWTAygKyYIgC6AvkA
PDQE10- Q24-S3-D C onverter	17.07	https://www.digikey.com/en/pr oducts/detail/cui-inc/PDQE10-Q24-S3-D/9521937
PYBE30 -Q24-S24 C onverter	33.83	https://www.digikey.com/en/p roducts/detail/cui-inc/PYBE30-Q24-S24/9859976
PDQ30-Q 24-S12-D c onverter	42.50	https://www.digikey.com/en/pro ducts/detail/cui-inc/PDQ30-Q24-S12-D/6165425? s=N4IgTCBcDaIAoBECKBmADAWiWALBgygIxgYIgC6AvkA
24V10A Bulk C onverter	49.99	https ://www.amazon.com/Stabilizer-Converter-Waterp roof-Regulator-Transformer/dp/B097CYG8HG?th=1
12V20A Buld C onverter	54.99	https ://www.amazon.com/Stabilizer-Converter-Waterp roof-Regulator-Transformer/dp/B097BLH4HC?th=1
19V15A Bulk C onverter	21.00	https://www.amazon.com/dp/B08J7M BJ7B?psc=1&ref=ppx_yo2ov_dt_b_product_details
XT30 C onnector	12.99	htt ps://www.amazon.com/gp/product/B0875MBLNH/ref =ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
XT90 C onnector	9.58	htt ps://www.amazon.com/gp/product/B09QJRHC19/ref =ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
XT60 C onnector	7.99	htt ps://www.amazon.com/gp/product/B07VRZR5TL/ref =ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
XT60 E xtension Cable	7.98	htt ps://www.amazon.com/gp/product/B08GPRGQZX/ref =ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Table 2. PDU Device and Purchasing Link

6. Battery Recommendation

Input Voltage: Dual 12V batteries

Nerwak Model 1250 LIFEP04

• Capacity: 12V, 50Ah

• Weight: 4.8 kg

• Dimension: 7.59 x 5.11 x 6.14 inches

• Price: $169.99

• Power Connectors: XT90

7. Schematic

Figure 2. External non-isolated DC-DC converter (24V, 10A) with 4 ports for Peplink LTE and three additional unused ports

Figure 3. External non-isolated DC-DC converter (19V, 15A) with 1 port for Laptop Charger.

Figure 4. External non-isolated DC-DC converter (12V, 20A) with 4 ports for PWM-VCC Converter, Brake Pressure Sensor, and two unused ports.

Figure 5. In-board isolated DC-DC converter (5V, 4A) with 6 ports for MC, USBW, LSBW, BBW, UI, and Ethernet Switch.

Figure 6. In-board isolated DC-DC converter (24V, 1.25A) with 1 port for Ouster LIDAR system.

Figure 7. In-board isolated DC-DC converter (12V, 2.5A) with 1 port for Velodyne LIDAR system.

Figure 8. In-board isolated DC-DC converter (3.3V, 2.4A) with 2 unused ports for future expansion.