Controllable interphase power transfer method and system

Abstract

The invention discloses a controllable interphase power transfer method and system which are implemented through the following steps that: a digital signal processor (DSP) acquires four paths of voltage / current signals, calculates the balance degree of loads of three phases, and carries out comparative analysis on the balance degree of loads of three phases, the imbalance degree of a load current set by the system, and the upper and lower thresholds of a neutral current so as to obtain the optimal interphase power transfer control decision scheme at the moment; through controlling a fling-cut switch to extract power from a phase line with the lightest load in A, B and C phases, after boosting, rectifying and filtering by an isolation transformer, the DSP realizes the dynamic allocation of power transmission among the A, B and C phases so as to reduce the electric energy loss of neutral lines and power transmission lines as far as possible through controlling the output power of a BUCK converter and an inverter, controlling the fling-cut switch to transfer the output power to the phase line with the lightest load, then carrying out acquisition and analysis on the four paths of voltage / current signals again, and carrying out dynamic control on the output power of the inverter; and related control information such as the dynamic allocation of power transfer among the A, B and C phases and the like can be subjected to remote transmission through a wireless GPRS (general packet radio service) network.

Description

technical field [0001] The invention belongs to the technical field of electric energy transmission and power electronic conversion, and in particular relates to a method and a system for controlling interphase power transfer to realize neutral line current management. Background technique [0002] In my country's urban and rural power grids, the three-phase four-wire power distribution system is mostly used. Most of the current distribution networks operate under the condition of unbalanced three-phase. Especially in recent years, medium and high-end, high-power electrical appliances (high-power air conditioners, washing machines with drying drums, etc.) have entered the homes of ordinary people. In the case of rapid growth of single-phase high-power users, the three-phase unbalance phenomenon is becoming more and more serious due to the inconsistent probability of users using electrical equipment at the same time. [0003] Since the unbalanced three-phase load exists at ...

AI Technical Summary

Problems solved by technology

Excessive neutral current will accelerate the aging of the winding insulation of the distribution transformer due to overheating and reduce the life of the equipment

Excessive neutral current flowing through the grounding resistance will generate heat, which poses a threat to the safe operation of the transformer

According to a survey by a power supply bureau, only the loss caused by the neutral current causes each transformer to lose more than 30,000 kilowatt-hours of electricity every year, causing huge economic losses to the national economy.

Images