Introduction

The invention concerns a system that heats the batteries on board an electric vehicle, without specific heaters and exploiting the modulation of the efficiency of the power converters, already present on board. That system uses a special control circuit of the electronic devices and the electronics and the battery are placed in the same cooling circuit.

Technical features

The converters on board electric vehicles are modified in the control of electronic devices, in order to be able to temporarily and reversibly lower their efficiency. The converters become on-demand heat sources, which can be used to heat the batteries in adverse thermal or cold start conditions. The converters are placed on the same fluid cooling circuit as the batteries, controlled by a special unit. Thermal control is obtained acting on: modulation of the efficiency of the converters, variation of the flow rate of the pump circulating the fluid, heat extraction capacity of the radiator.​

Once the optimal operating temperature has been reached, the efficiency is restored to maximum levels and the converter operates normally. The circuit used for heating can also cool the batteries.

Possible Applications

• Hybrid and electric vehicles;​
• Electric boats;
• Engines and machinery operating in cold environments;
• Energy conversion systems with battery storage.

Advantages

• Improved powertrain density;​
• E-waste reduction;​
• More accurate thermal control;​
• Rapid availability of full battery power;​
• No loss of efficiency under normal operating conditions;​
• Possibility of using the system also for cooling.