introduction
This article refers to the address: http://
Automotive designers are currently facing a new and old challenge: to develop efficient and economical new electric vehicle platforms. The history of electric cars is almost as old as traditional fuel cars, but for most people today they are still "new things."
In 1900, the US auto market was basically composed of three propulsion systems (see Figure 1). Gasoline cars ranked third with a market share of only 22%.
Figure 1: The electric car reached its peak around 1900, when it exceeded the internal combustion engine.
But 1900 was the culmination of electric cars. Soon, with the massive discovery of oil, gasoline became popular and cheap. The dominance of gasoline-powered cars was established and there was virtually no challenge in the next century.
Growing oil price pressures and environmental problems have forced the automotive industry to seriously consider electric propulsion systems. Designers need tools to accelerate the development of safe, reliable, and economical electric vehicles for the future market.
Everything starts with battery technology
Today's complex battery technology enables high energy density, reasonable quality and proper charging time. Many modern battery packs use chemical elements such as lithium ions, which increase mileage while reducing weight. However, if the gasoline energy density of 12 kWh/kg is compared with 0.12 kWh/kg 2 of a normal lithium-ion battery, even if the "best" battery drives a four-door passenger car, it can only run at most once per charge. 250 km (150 miles) 3.
Designing battery-powered vehicles (and ultimately achieving battery-driven targets for all electric vehicles) is a challenge that involves multiple areas—if there are no software tools to help engineers design lightweight, low-cost power distribution systems; Battery operation, charging and demand simulation models; predicting safety and electrical interference problems, and still meeting the urgent new product development schedule, this challenge is difficult to solve.
Hybrid electric vehicles bring design challenges
Consumers now have to weigh a significant trade-off compared to traditional fuel vehicles when buying electric vehicles. Relatively high purchase prices, battery replacement costs, and limited mileage are enough for consumers to pursue traditional fuel vehicles, and the disadvantages are not limited to these.
Many original equipment manufacturers have chosen to combine electric and conventional fuel engine technology to produce hybrid vehicles. These platforms also leverage the strengths of batteries and traditional technologies.
Hybrid cars have smaller batteries than pure electric cars because they are used intermittently. The smaller battery pack makes it easier for designers to design into the car while keeping the cost and weight of the car under control. The battery can also be charged while the car is running. However, the propulsion technology of hybrid electric vehicles (and many derivatives) and pure electric vehicles has significantly increased the electrical content and complexity of automobiles.
All electric vehicle platforms bring many new design challenges, including system simulation, electromagnetic interference (EMI), failure mode and effects analysis (FMEA), potential path analysis (SCA), and more.
Design data management is at the heart of solving the complexity of electrical design. The data-centric distribution system (EDS) design toolkit (shown in Figure 2) plays this central role, complemented by other tools selected based on their respective AC analysis capabilities.
Figure 2: The data-centric process provides a consistent data foundation from the product definition to the design of the service point.
Simulation, modeling, and parametric analysis work together
Hybrid and electric vehicles undoubtedly add to the complexity of the simulation. Traditional analog scenes are inseparable from qualitative logic type current or numerical DC motor, but cannot handle multiphase AC voltage and current and switching frequency up to 50 kHz. In addition, the strengthening of interactions between various automotive system domains has also made verification of multi-model systems a key consideration.
When a designer equips a car with a conventional gasoline engine and electric motor in a "similar" hybrid configuration, in addition to simulating common DC weak current circuit behavior, the designer also evaluates various interactions. , including the impact of DC-DC converters on the entire vehicle.
Multiphase AC power is used to power the motor. This requires new simulation and modeling techniques to maximize battery life, extend driving range, reduce weight and reduce charging time. Finally, the designer must also be able to study the interaction of the motor, gasoline engine, gearbox and drive system under different driving cycle conditions.
The versatile power distribution system design platform makes it easy to characterize and numerically analyze DC circuits. Battery and engine behavior can be described in formats such as VHDL-AMS to simulate effects such as temperature or charging effects. Engineers can create a "demand model" based on the driving cycle and determine the optimal combination of battery and engine by operating a series of scenarios.
When more detailed research is required, the power distribution system platform can send data to a compatible time domain/AC analysis tool to evaluate the multiple physical characteristics of the design (as shown in Figure 3). Advanced drivetrain control algorithm models, engine-driven power electronic component models using space vector modulation conversion strategies, and accurate mechanical models based on finite element analysis (FEA) can be assembled and modeled into a fully integrated system.
Figure 3: Leading distribution system tools can analyze DC phenomena, temperature effects, and more. Through efficient interoperability, a system modeling tool set can increase multiphysics analysis and prediction of time domain and AC behavior.
The pairing of the power distribution system platform with the system modeling tool solves the trade-off problem of high-level design, such as comparing the driving performance or battery life of induction motors and brushless DC motors. Again, this helps determine the trade-offs of low-level designs, such as motor drive efficiency and switching frequency or power device component selection.
In recent years, complex control systems (such as collision avoidance systems) have increased the traffic of the car network, so it is necessary to expand the corresponding network capacity. Electric and hybrid vehicles have also continued this trend. A simple hybrid vehicle stop/start engine system may involve communication between up to 26 independent electronic control units. Finally, technologies such as Flexray (10 Mbit/s) will replace the older, slower CAN (1 Mbit/s) network. Clearly, it is important to choose a power distribution system solution that builds a network architecture and protocol model with varying levels of abstraction and complexity.
Support security
For humans, DC power greater than 80 volts can be fatal. Since some electric and hybrid electric vehicles can reach 600 VDC, every imaginable safety hazard must be considered.
double split wire loom tube ,twin slitted conduits,Double Split Wire Loom,divisble Corrugated conduit,Double Slit Conduit
Dongguan Zhonghe Electronics Co., Ltd. , https://www.zhonghesleeving.com