Voltage regulation circuit and system for traction battery and control method thereof

A voltage regulation circuit for traction battery, comprising:

• a traction battery;
• a heating module;
• a charge/discharge interface;
• and
• a voltage regulation module;
• wherein
• the heating module comprises a power storage element and a switch module;
• the traction battery is connected in parallel to the switch module, and an external charging and discharging device is connected in parallel to the traction battery through the charge/discharge interface;
• the voltage regulation module comprises a plurality of switches and a power storage regulation element, and the plurality of switches and the power storage regulation element are disposed between the charge/discharge interface and the traction battery;
• and
• the voltage regulation module and the switch module are configured to regulate, in response to a voltage regulation control signal, a charge/discharge voltage between the traction battery and the power storage element and a charge voltage of the external charging and discharging device for the traction battery;
• wherein
• the voltage regulation module comprises a first switch, a second switch, a third switch, a fourth switch, and the power storage regulation element;
• the first switch is disposed between the power storage element and the switch module;
• the second switch is disposed between the power storage element and the charge/discharge interface;
• the third switch and the fourth switch are respectively disposed on a negative electrode side and a positive electrode side of the charge/discharge interface;
• and
• the power storage regulation element is disposed between the power storage element and the switch module and also between the power storage element and the charge/discharge interface;
• wherein a fifth switch is provided on the positive electrode side of the traction battery, and a sixth switch is provided on the negative electrode side of the traction battery;
• and
• wherein the fifth switch is connected in parallel to a branch, and the branch comprises a resistor and a seventh switch connected in series.