Author: Site Editor Publish Time: 2021-10-11 Origin: Site
Toyota Prius hybrid battery, as the world's No. 1 hybrid (HV) model, has matured its hybrid technology development and application. Prius Ni-MH batteries are a very important part of Prius models and most hybrid vehicles. This article takes the Prius HV battery system as an example to analyze the working principles of system main relay (SMR) control and battery ECU control.
Here is the content list:
l System main relay (SMR) control analysis
l Battery ECU control analysis
The main relay of the system receives information from the HV ECU and is used to connect or disconnect the high-voltage circuit between the Prius hybrid battery and the inverter assembly. There are 3 relays of this kind, among them, 1 on the negative side and 2 on the positive side. These 3 relays work together to ensure that the system is in normal operation.
To control the current flowing through the main resistance, protect the contacts in the circuit, and avoid the relay from being damaged by the strong current, the SMR system circuit is controlled in the following way: When the power is ON, the coils of SMR1 and SMR3 in the circuit are energized, the contact is closed; next, the SMR2 contact is closed, and then the SMR1 contact is opened again.
The battery ECU monitors the Prius hybrid battery in real-time through the temperature sensor, current sensor, HV battery leakage detection circuit, and voltage detection circuit inside the HV battery and sends this information to the HV ECU, and exchanges information with other modules through the CAN bus.
The principle of the battery ECU control system, the Prius hybrid battery ECU determines the SOC value by identifying the size of the charge/discharge current. The temperature sensor of the HV battery detects the temperature signal and converts it into a voltage signal and transmits it to the battery ECU as a reference signal for the battery ECU.
The temperature change inside the HV battery will directly affect the battery's performance and the charge/discharge capacity of the storage battery temperature detection circuit. A serious situation can also cause the HV battery system to malfunction. The Prius hybrid battery system uses three battery temperature sensors installed at the bottom of the battery to detect temperature changes. There is a thermistor in the battery temperature sensor, and its resistance will change with the temperature of the Prius Ni-MH battery assembly. The lower the battery temperature, the higher the thermistor resistance. Conversely, the higher the battery temperature, the lower the resistance of the thermistor. According to this negative temperature coefficient (NTC type thermistor characteristics, the temperature information change status will be converted into a voltage signal change and sent to the battery ECU to achieve the purpose of real-time detection of battery temperature. Battery temperature detection circuit, TB terminal is the signal voltage terminal, The GB terminal is the ground terminal. After the detection information of the three temperature sensors is received by the battery ECU, it makes judgments and controls the operation of the cooling fan based on the information provided by the current sensor, the battery system intake temperature sensor, and the voltage detection signal.
GK International Enterprises Co., Ltd. has developed a variety of Prius hybrid batteries and conducted a lot of tests before leaving the factory to ensure quality. Prius hybrid batteries have many advantages over other products. If you want to know more about our professional Prius hybrid battery and Honda hybrid battery products, you can contact us at any time.