Analysis and comparison of electric vehicle OBC systems BYD Haishang

Hello everyone, today's science topic is the analysis of BYD Haiba's OBC (On-board Charger) system.

I will explain the BYD Seal's OBC system in detail from the perspectives of power specifications, technical features, working principles and circuit design, and compare and analyze it with other models.

Whether you are an electric car enthusiast or a technician engaged in maintenance work, today's content will help you gain a deeper understanding of the core technology of the OBC system.

BYD Haiba's OBC system has an AC charging power of 6.6Kw in China and 11 kW in Europe, which means it has strong charging capabilities and is suitable for a variety of charging scenarios.

Whether using single-phase power for slow charging at home, or using three-phase power for high-power charging on a public charging station, the SEAL OBC system can adapt effectively.

Compared with some low-power OBC models, the SEAL's 11 kW charging capacity gives it a significant advantage in charging speed, especially in daily use, and can replenish sufficient power for the vehicle in a shorter time.

In comparison, hybrid models like the BYD Song Plus DM-i have an OBC power of 6.6 kW, which is mainly suitable for daily slow charging scenarios, while the Seal is positioned as a pure electric model and requires faster charging efficiency to meet the needs of pure electric driving.

BYD Seal's OBC system has many technical highlights, especially in efficient charging and energy conversion.

The OBC system of Haibao adopts advanced PFC control technology to optimize the utilization of electric energy by improving the power factor.

When an electric vehicle draws electricity from the power grid, the asynchrony between current and voltage will cause power loss. The PFC circuit can correct the phase of current and voltage so that the electricity can be absorbed by the battery more efficiently.

This technology not only improves charging efficiency, but also reduces grid pressure and avoids the waste of reactive power.

Compared with traditional hard switching conversion, Haibao's OBC system uses soft switching technology, which improves efficiency by reducing switching losses and reduces heat generation during charging.

The advantage of soft switching technology is that it can maintain low loss and high efficiency under high power conditions. Especially at a high power of 11 kW, it can greatly improve the overall charging conversion efficiency.

Haibao's OBC system not only supports household single-phase power supply, but is also compatible with three-phase power grid, which enables the vehicle to be charged efficiently in different charging environments.

Single-phase power is suitable for slow charging in a home environment, while three-phase power can provide higher charging power and shorten charging time when used in public charging piles.

Next, we will explore the working process and circuit design of BYD Haibao OBC system. Haibao's OBC system adopts a full-bridge inverter topology, combined with PFC control technology and soft-switching DC-DC converter to form an efficient energy conversion system.

The AC power from the home power supply or charging station first enters the OBC system. At this stage, the current enters the filter through the AC input port to eliminate noise and electromagnetic interference in the current, ensuring that the subsequent circuit processes a stable current signal.

The current after the filter enters the PFC circuit for power factor correction. The main task of PFC is to optimize the input AC power, improve the power factor, ensure the synchronization of current and voltage, and maximize the charging efficiency.

This step is particularly important because it directly affects the efficiency of electricity utilization and charging speed.

The current processed by PFC enters the soft switching DC-DC converter. The core task of this stage is to convert AC power into DC power suitable for battery charging.

Compared with traditional hard-switching DC-DC converters, soft-switching technology can significantly reduce energy loss and improve overall efficiency, while reducing circuit heat and extending equipment life.

During the entire charging process, the OBC control circuit monitors parameters such as voltage, current and temperature in real time to ensure the safety of the charging process. If the system detects that the temperature is too high or the current is abnormal, the control circuit will automatically adjust the charging power or stop charging to protect the battery and circuit.

BYD Haibao's OBC system adopts a full-bridge inverter topology, which is a common circuit design in current high-efficiency OBC systems. The full-bridge inverter circuit can effectively reduce power loss and provide higher power conversion efficiency.

Combined with PFC control technology, this circuit can handle different types of grid inputs, ensuring efficient and stable power output under different charging environments. The advantage of the full-bridge inverter topology is that it performs particularly well in high-power charging scenarios and can meet high power requirements of 11 kW.

The addition of soft-switching DC-DC technology further improves the efficiency of OBC. Compared with hard switching, soft switching ensures a smoother power conversion process by reducing switching losses during current transient changes, especially suitable for operation at high power output.

Comparing BYD Seal's OBC with other models can better understand its uniqueness:

Tesla's OBC system also supports 11 kW high-power charging and has highly integrated PFC control technology. Tesla's advantage lies in the high integration of its software control system and hardware, and the user experience is more intelligent.

BYD Haibao emphasizes power conversion efficiency in hardware design, reducing losses through full-bridge inverter and soft switching technology. The common point between the two is that they can adapt to high-power charging scenarios, but Tesla relies on software, while BYD emphasizes circuit efficiency.

The OBC system power of Song Plus DM-i is only 6.6 kW, which is mainly suitable for slow charging scenarios. Compared with the seal, the OBC design of Song Plus is simpler and suitable for the needs of hybrid systems. As a pure electric vehicle, the seal must rely on a more efficient OBC system to shorten the charging time, so it adopts a more complex circuit design and higher power output.

The OBC system of the Wenjie M7 also supports 11 kW charging and has a two-way charging function, which can power external devices. In contrast, the OBC design of BYD Haibao focuses on efficient charging itself, without adding complex two-way functions, and the circuit structure is more optimized to improve charging efficiency.

In summary, BYD Haibao's OBC system is characterized by its high-efficiency PFC technology, soft-switching DC-DC converter, and full-bridge inverter topology circuit, forming an efficient and reliable charging system. It not only supports AC charging power up to 11 kW, but also can operate efficiently in single-phase and three-phase power grids to adapt to different charging scenarios.

Compared with other models, the OBC system of Haibao focuses on the efficiency optimization of high-power charging, reduces losses through soft switching technology, and adopts a full-bridge inverter topology to improve power utilization. This makes Haibao competitive in charging speed and energy efficiency, especially suitable for users who need fast charging.

I hope that through today's explanation, everyone has a deeper understanding of BYD Haibao's OBC system. If you are interested in the OBC system of other models, we can continue to discuss it in the message board at the bottom of the article. Thank you!