Passenger vehicles are generally used together with other power, mainly playing the role of starting output high power and braking energy recovery. In the field of urban rail transit, ultracapacitors can be used for braking energy recovery.
For vehicles with large inertia, the braking power is very large; for general batteries, the proportion of recovered energy is limited; and only ultracapacitors are most suitable for such applications. The bus is completely powered by ultracapacitor as agv power supply, which is charged once every 3-5 km, mainly relying on the ability of fast charging.
Due to the high power density and low energy density, there are a few application cases of ultracapacitor as the main power supply in electric passenger vehicles. The application of ultracapacitor combined with lithium battery has also been proposed.
The ultra capacitor bank is connected in parallel with the power battery pack, and the circuit is controlled separately. When the starting, acceleration, climbing and other systems need instantaneous high power, connect the ultracapacitor circuit; when the system is in normal operation, connect the power battery circuit.
The voltage of ultracapacitor is relatively low, which is generally lower than that of lithium battery. Therefore, the application form of ultracapacitor also needs to be used in series-parallel connection. In this way, it brings the need of ultracapacitor for management systems. The general situation is also very similar to that of lithium battery, where the current, voltage and temperature should be monitored. The controller needs to estimate SOC, SOH and other parameters.
The voltage capacity characteristic curve of ultracapacitor is similar to the first-order function curve when the ambient temperature is stable. However, if the external environment changes, the relationship between voltage and electricity will change. Another difficulty is that the voltage and quantity of ultracapacitor change rapidly, which also puts forward new requirements for the monitoring and control system.
JINZHOU KAIMEI POWER CO.,LTD is a professional super capacitor manufacturer. For more information, please visit our website at http://www.kamcappower.com.
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