Inverter Self-Heating Through Cooling Circuit for Battery Warmup
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Solution Overview
Problem
Existing warmup devices for vehicular storage batteries complicate control and are limited to vehicles with step-up converters, as they rely on complex calculations of switching frequency for self-heating, which is not applicable to vehicles without such converters.
Innovation Solution
A control device for vehicular storage batteries that includes an inverter, a cooling circuit, and an inverter heat generation unit, where a predetermined current is passed through the inverter to generate heat, which is then used to warm up the storage battery via the cooling circuit, simplifying the warmup control and making it applicable to vehicles without step-up converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If ripple temperature increase control is performed by decreasing switching frequency of step-up converter to increase ripple current, then heating in internal resistor of storage battery increases, but control becomes complicated and is only applicable to vehicles with step-up converters
Solution Approach 1:
The inverter serves as an intermediary heat generation device. Instead of directly controlling the storage battery to generate heat through complex ripple current control, the patent uses the inverter as a mediator that generates heat through IGBT conduction losses when passing AC current, which then transfers heat to the storage battery through the cooling circuit. This simplifies control while achieving the same warming effect.
Solution Approach 2:
The inverter uses its own operational characteristics (IGBT conduction losses) to generate heat for warming the storage battery. The cooling circuit, which normally serves to cool the inverter, is repurposed to transfer heat from the inverter to the storage battery, creating a self-service heating system that eliminates the need for separate heating control mechanisms.
2Temperature
If self-heating control of storage battery is performed by calculating switching frequency based on detected temperature, then warmup is achieved, but control becomes complicated
Solution Approach 1:
The inverter acts as an intermediary that simplifies the heating control process. Instead of calculating and controlling switching frequency based on temperature feedback, the system simply controls the inverter to pass AC current, which automatically generates heat through IGBT conduction losses. The cooling circuit then transfers this heat to the storage battery, eliminating complex temperature-based frequency calculations.
Solution Approach 2:
The patent replaces the mechanical/electrical control system (switching frequency calculation and ripple current control) with a thermal field approach. By utilizing the inverter's inherent IGBT conduction losses and the cooling circuit's heat transfer capability, the system achieves warming through thermal field interaction rather than complex electrical control, significantly simplifying the operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution simplifies the warmup control of storage batteries, broadens the chargeable/dischargeable electric power range, and prevents the deterioration mode called grease-missing deterioration by minimizing repeated heating and heat dissipation of the inverter, while being applicable to a wider range of vehicles.
Implementation Method 1
an inverter heat generation control unit configured to cause the inverter to emit heat by passing a predetermined current through the inverter for a predetermined time and to cause the storage battery to warm up via the cooling circuit
Implementation Method 2
a cooling circuit configured to cool the storage battery and the inverter by circulating a refrigerant
Data Source
AI summary
At least one inverter is heated by causing an inverter heat generation control unit to pass a predetermined current through the inverter for a predetermined time, and heating of the at least one inverter causes a high-voltage battery (storage battery) to warm up via a cooling circuit. Accordingly, control for warmup of the high-voltage battery (storage battery) is simply performed by passing the predetermined current through the inverter for a predetermined time. This inverter heat generation control can also be applied to a vehicle not including a step-up converter.