Electric Vehicle OBC System Analysis and Comparison BYD Song Plus DM-i

Hello everyone, today we will continue to analyze the electric vehicle OBC (On-board Charger) system, focusing on the OBC design features of BYD Song Plus DM-i.

I will give you an in-depth explanation of the OBC power specifications, technical features, and working principles of this model in combination with its super hybrid system. I hope that through today's explanation, I can help you better understand the differentiated applications of electric vehicle OBC systems in different models.

First of all, the BYD Song Plus DM-i's OBC system has a power specification of 6.6 kW, which mainly supports conventional AC charging. This means that the Song Plus DM-i can be charged at a relatively moderate speed on a home charging pile or a public slow charging pile, but it does not support high-speed fast charging mode.

The design positioning of this power specification is very clear: mainly slow charging, especially for those users who can use the night time to charge at home.

Although this 6.6 kW power is not high, it is enough to fully charge the battery in 8-10 hours, which is very suitable for daily urban commuting needs. Compared with high-power charging systems, the charging efficiency at this power is lower, but it is more friendly to the battery life and reduces the loss of overheating and fast charging to the battery.

The biggest highlight of Song Plus DM-i is its DM-i super hybrid system, which not only improves the fuel economy of the whole vehicle, but also affects the design of OBC.

On Song Plus DM-i, OBC is closely integrated with its hybrid system, and the overall design is relatively simple. Unlike some pure electric vehicles, Song Plus DM-i does not rely on high-power OBC for fast charging, because its fuel engine can intervene to provide power support when the battery is low.

This also explains why the model uses a medium-power OBC of 6.6 kW instead of a high-power fast charging system.

Although the OBC power is not high, the vehicle's charging efficiency is optimized thanks to the DM-i system. The hybrid system can provide a certain amount of energy to the battery through the internal combustion engine, so the battery does not need to rely entirely on an external charging source.

For users who frequently drive in the city, the vehicle can almost self-maintain the battery in hybrid mode.

Since the DM-i system plays an important role in energy management, the structure of OBC is relatively simple. It does not need a complex power conversion and control system like pure electric vehicles. Its main task is to provide additional power for the battery to meet daily charging needs.

This design not only reduces costs, but also reduces dependence on OBC hardware, making the entire vehicle system more stable and reliable.

Let's further analyze the working principle of BYD Song Plus DM-i's OBC. Its OBC design is different from traditional electric vehicles, mainly because it does not rely on a high-power charging system.

Since Song Plus DM-i is equipped with a super hybrid system, the vehicle does not completely rely on external charging stations to keep the battery charged.

The main role of OBC is to recharge the battery through regular AC power, especially to perform slow charging when the battery power level is below a certain level.

Most of the time, the battery charge can be maintained by the energy recovery of the hybrid system or the power generation function of the engine, so the frequency of use of OBC is relatively low.

The OBC process of Song Plus DM-i is relatively simple. AC power is input through the charging port, passes through the EMC filter to eliminate electromagnetic interference, and then enters the power factor correction (PFC) circuit to ensure efficient use of electrical energy.

Finally, the AC power is converted into DC power suitable for the battery through the DC-DC converter. During this process, the OBC control circuit will also monitor the voltage, current and battery status in real time to ensure the safety of the charging process.

Compared with high-power OBC, Song Plus DM-i's OBC design does not require complex multi-level power conversion and management, and focuses on serving daily slow charging scenarios. This simplified design not only reduces the cost and weight of the OBC, but also reduces the impact of high-power fast charging on battery life.

Now we can compare the OBC of Song Plus DM-i with other models to see what features the OBC designs of cars with different technical types have:

Song Plus DM-i's OBC supports standard single-phase AC input with a power of 6.6 kW, which is suitable for home charging piles. In contrast, models like Tesla Model 3 support higher-power three-phase AC charging, which can achieve faster charging speeds.

This is because pure electric vehicles usually need to rely on faster charging to maintain efficient use, while Song Plus DM-i does not need to pursue fast charging excessively.

Whether it is BYD Song Plus DM-i or other high-end electric models, EMC filters are standard configurations to eliminate electromagnetic interference generated during the charging process.

The difference is that higher-power OBCs often require more complex EMC filter designs to handle higher-power currents, while the Song Plus DM-i has a simpler EMC filter design due to its relatively low charging power.

The PFC circuit of Song Plus DM-i is relatively simple and is mainly used to improve the efficiency of power utilization within the power range of 6.6 kW.

In contrast, the PFC circuits of models such as Tesla are more complex and can be optimized at higher power, which is closely related to their high-power OBC requirements.

Song Plus DM-i's DC-DC converter is mainly used to convert AC power into DC power suitable for battery charging, with low power and simple structure.

In comparison, models like the Wenjie M7, which have bidirectional OBC functions, have DC-DC converters that can not only support higher-power charging, but can also reversely power external devices, and their structural complexity is much higher.

The OBC control circuit of Song Plus DM-i is responsible for real-time monitoring of various parameters during the charging process to ensure the safety and efficiency of charging. Compared with Tesla's highly intelligent control system, Song Plus's control logic is relatively simple and is mainly used in daily slow charging scenarios.

Through today's explanation, we can see that the OBC design of BYD Song Plus DM-i is simple and efficient, suitable for daily slow charging scenarios.

The OBC power of this model is 6.6 kW, combined with the DM-i super hybrid system, which can maintain efficient charging while reducing the dependence on high-power fast charging. This design is very suitable for urban commuting and daily use, which can effectively reduce charging costs and extend battery life.

In summary, the OBC system of Song Plus DM-i has the following features:

It does not rely on high-power fast charging, but instead maintains the battery status through slow charging and hybrid system.

The OBC structure is relatively simple, suitable for daily slow charging scenarios, and has high charging efficiency.

By simplifying the OBC design, the cost of the entire vehicle is reduced while ensuring the stability of the system and the health of the battery.

I hope today's sharing can help you better understand the design ideas of electric vehicle OBC systems and the differentiated applications of different models. If you have more questions, please discuss them on the message board or send private messages in the following time. Thank you!