DCDC converter, on-board charger and electric vehicle

Abstract

The invention discloses a DCDC converter, an on-board charger and an electric vehicle. The DCDC converter comprises a first three-phase bridge module, a resonance module, a second three-phase bridge module and a controller, wherein the first three-phase bridge module is configured to adjust the frequency of an input signal during charging; the resonance module is configured to resonate an output signal of a first adjustment module during charging and resonate an output signal of a second adjustment module during discharging; the second three-phase bridge module is configured to adjust the frequency of an output signal of a battery module during discharging; and in a light load mode, the controller is used for controlling the first three-phase bridge module to switch to two-phase bridge arminput or one-phase bridge arm input and controlling the second three-phase bridge module to switch to two-phase bridge arm output during charging, and is used for controlling the second three-phase bridge module to switch to two-phase bridge arm input or one-phase bridge arm input and controlling the first three-phase bridge module to switch to three-phase bridge arm output during discharging. Thereby, the switching loss in the light load mode can be reduced.

Description

technical field [0001] The invention belongs to the technical field of vehicles, and in particular relates to a DC-DC converter, an on-board charger including the DC-DC converter, and an electric vehicle installed with the on-board charger. Background technique [0002] With the continuous development of electric vehicles, the capacity of battery modules of electric vehicles is increasing. In order to save charging and discharging time, a large-capacity battery module requires a more powerful bidirectional on-board charger (hereinafter referred to as on-board charger). At present, the power level of mainstream on-board chargers in the industry is single-phase 3.3KW / 6.6KW. With the further demand for high-power on-board chargers, there is a growing market for three-phase 10 / 20 / 40KW on-board chargers. [0003] The main power topology of the on-board charger generally includes two parts: PFC (Power Factor Correction, power factor correction) + bidirectional DCDC. . In order ...

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Problems solved by technology

[0004] However, for figure 1 In the scheme shown, there are some problems in the parallel connection of multiple modules. For example, the cost of multiple devices is high, and each module requires independent voltage and current sampling and drive control circuits. The redundancy is large, and the cost and volume are difficult to optimize. Another example is the output The large ripple current is still difficult to solve. In order to reduce the ripple current, each module still needs a large filter capacitor. Of course, there are multiple independent modules to perform phase interleaving to reduce the ripple current, but it also requires different modules to work together at the same time. A master Slave settings and high coordination requirements put forward high requirements for system hardware circuit design and software algorithms

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