Charging power supply current-sharing control system and method of parallel three-path output

Abstract

The invention discloses a charging power supply current-sharing control system and a charging power supply current-sharing control method used for parallel three-path output of an electric vehicle charging station / a battery swapping station. Each circuit is formed by connecting an electro-magnetic interference filter, a power factor corrector, a half-bridge LLC (Logical Link control) resonant converter in series, each power factor corrector and the converter are all connected with a CPU (central processing unit) control circuit, and each CPU control circuit is connected with a monitoring unit by a CAN (Controller Area Network) bus; any power supply module unit is appointed as a main module, and the others are auxiliary modules; and output currents of B and C phase circuits of the main module follow a circuit A, an output current reference value of the A phase circuit is transmitted to the rest auxiliary modules by CAN buses, the current reference values received by the auxiliary modules are taken as the target current value output by the signal circuit, and the output current values of the three phase circuits of the auxiliary module is controlled by CPU to follow the A phase circuit of the main module. According to the charging power supply current-sharing control system, the fault and error states of the main module can be avoided, the fault-tolerant capability is improved, and the expansion capability is favorable.

Description

technical field [0001] The invention relates to the technical field of electric vehicle charging station / swapping station, in particular to the current sharing technology in and between charging power supply modules. Background technique [0002] Electric vehicles are energy-saving and pollution-free vehicles, and the charging technology of electric vehicles is also developing continuously. Electric vehicle charging power usually uses multiple power modules connected in parallel to achieve high power output. Parallel operation of charging power supply is an effective method for modularization and large capacity of power supply products. On the one hand, parallel operation can make small power modules easily combined into a high-power power supply system, and its capacity can be expanded arbitrarily. [0003] It can be combined freely according to the needs of the use occasions, which is convenient and flexible. However, in practice, due to various reasons such as the lim...

AI Technical Summary

Problems solved by technology

The output impedance method is the simplest method of current sharing, the current balance is poor, and it is easy to be affected by the tolerance of components, aging and physical conditions; the master-slave control method has high current sharing accuracy, but the biggest disadvantage is that once the main control power module appears fault, the entire system is completely out of control; the average current method can also achieve accurate current sharing, but in specific applications, once a module fails to work or the current sharing bus is short-circuited, the power system will fail

The maximum current sharing method is currently the most widely used hardware current sharing method, but it requires relatively more hardware and cost

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