Electric vehicle charging switch device for realizing three-phase load balance and charging method

Abstract

The invention belongs to the technical field of electric vehicle charging control, and in particular relates to an electric vehicle charging switch device for realizing three-phase load balance and a charging method for an electric vehicle by using the electric vehicle charging switch device. The device comprises a micro-measurement voltage converter, a signal conditioning module, an A / D sampling module, a CPU module, a one-out-of-three interlocking solid-state switch and a charger unit which are in sequence connected; the input end of the micro-measurement voltage converter is connected with a three-phase power supply; the three-phase power supply is a three-phase four-wire system which comprises a phase A, a phase B, a phase C and N wires respectively; the input end of the one-out-of-three interlocking solid-state switch is further connected with the phase A, the phase B and the phase C of the three-phase power supply; the charger unit is connected with the output end of the one-out-of-three interlocking solid-state switch and the N wires of the three-phase power supply respectively; according to the results of A / D conversion, the phase with the highest voltage is selected from the phase A, the phase B and the phase C, and the one-out-of-three interlocking solid-state switch breaks over the phase with the highest voltage to be used as a charging power supply of the electric vehicle to realize the three-phase load balance of a distribution network.

Description

technical field [0001] The invention belongs to the technical field of electric vehicle charging control, and in particular relates to an electric vehicle charging switch device and a charging method for realizing three-phase load balance. Background technique [0002] Energy crisis and environmental pollution are two major problems facing the development of the world today, and a large number of traditional vehicles have brought a non-negligible impact on energy crisis and environmental pollution. Electric vehicles do not directly consume primary energy, and because of their advantages of high efficiency and low pollution, they have incomparable advantages over traditional vehicles in solving the above problems. Household commuter electric vehicles (private electric vehicles) usually stop driving during the day and park in the garage of the community at night. They have a long charging period to choose from, and usually use the conventional slow charging method, that is, si...

AI Technical Summary

Problems solved by technology

Three-phase balance is the basis for the safe and economical operation of the power grid. Serious three-phase imbalance will not only lead to unqualified voltage quality, but also increase power grid loss (line, transformer loss), and even cause power grid safety accidents

[0004] When large-scale private electric vehicles are charged at a slow speed in the community garage, if no control measures are taken, the most obvious problems are: 1) increase the maximum load value of the regional power grid and further increase the load peak-valley difference; 2) cause three-phase load imbalance , so that the three-phase voltage unbalance of the local low-voltage distribution network is unqualified, the network loss increases, and even threatens the safe operation of electrical equipment

[0007] This low-voltage distribution network load imbalance management method has the following disadvantages: 1) When the load imbalance occurs in the system, the number of phase selection switches participating in the action is relatively large, and the phase selection switch operates frequently; There will be power supply interruption or voltage drop, which will affect the user's power supply reliability and electricity safety

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