Medium-Sized Electric Bus Platform

The EV research team has developed a prototype for a medium-sized electric bus platform as part of ongoing efforts to support Indonesia’s clean energy transition and strengthen national technology acquisition in electric vehicle development. The project is primarily funded by Lembaga Pengelola Dana Pendidikan (LPDP) and carried out in collaboration with multiple industry partners, reflecting a strong synergy between research institutions and the industrial sector.

The development of the electric bus platform was initiated based on the characteristics of the Indonesian electric bus market, where approximately 90% of the industry is centered on bus platforms and coach building. As of the latest report, there has been no domestically branded bus platform in Indonesia fully designed and developed by Indonesian engineers, including platforms for conventional internal combustion engine buses. Nevertheless, the country hosts a significant number of coach-building companies, indicating that local industries already possess the technical capabilities and manufacturing infrastructure required to produce bus body structures.

Figure 1. Electric bus prototype design

The electric bus platform is developed with Bus Rapid Transit (BRT) applications in mind, including systems such as Transjakarta and Transpasundan. The platform is designed to achieve a full charge within 2.5 hours and provide a maximum driving range of approximately 200 km, supporting daily urban public transportation operations.

The platform integrates several key technological features. An efficient liquid cooling system is designed and manufactured to maintain optimal operating temperature for three battery packs, supported by efficient cooling pipe routing to ensure stable thermal management. In addition, an independent liquid cooling system is implemented for the electric motor, controller, and control interface to maintain overall system performance and reliability during operation.

Figure 2. Liquid cooling design and implementation for three battery packs using a series arrangement

Figure 3. Liquid cooling design and implementation for electric motor controller, control interface, and electric motor using a series arrangement

The drive train adopts a high-power, high-torque configuration using a 180 kW / 600 V electric motor to generate strong traction performance. By leveraging the advantages of electric propulsion, the platform eliminates the need for conventional mechanical transmission, improving overall efficiency while reducing the number of components and vehicle weight. This simplified configuration significantly lowers maintenance requirements and provides more design flexibility for coach builders to develop body structures in accordance with Indonesian medium-sized bus standards.

Figure 4. A high-power PMSM electric motor installed with parking brake features, which is directly connected to the differential gear to simplify the mechanical component

The platform is also designed with a simple and robust architecture suitable for heavy-duty public transport operations in metropolitan environments. Its adaptive design considers the needs of local coach builders who may be transitioning to electric vehicle technology, allowing easier integration with various upper structures, exterior designs, and interior configurations.

Figure 5. Simple and robust electric bus platform adaptable to various body structures

To ensure operational safety and long-term reliability, the electric bus platform is developed in accordance with high safety standards, including safety testing and periodic design updates to maintain optimal performance and safety throughout its lifecycle.