Method for detecting network-free reactor high voltage frequency converter electric network voltage phase

Abstract

The invention discloses a method for testing the electricnetwork pressure phase of the high pressure transducer without network side reactor, comprising: the high pressure input side pressure namely electricnetwork pressure being subjected to zero cross balancing by an analog comparator and obtaining a square wave in the same phase with the electricnetwork pressure by the main control system of the transducer; locking phase by a phase locked loop chip to obtain a stable square wave output; sending the square wave to each power unit by the optical fiber; each power unit receiving the optical fiber signal and obtaining the phase of the electricnetwork pressure by calculating the frequency and phase of the square wave. The high pressure transducer with energy feedback function without network side reactor after abolishing the network side reactor, still reliably operates at high performance, therefore the cost, volume and weight of the transducer can be greatly reduced.

Description

Technical field [0001] The present invention relates to a method for detecting the voltage phase of a power grid. Specifically, the present invention relates to a method for detecting a three-phase connected to a multi-level high-voltage inverter connected in series with a power unit without a grid-side reactor and with an energy feedback function. The method of the grid voltage phase. Background technique [0002] With the development of power electronics technology, high-voltage frequency converters, as the main means of energy saving and consumption reduction, have been widely used in various fields of the national economy, such as metallurgy, petrochemical, water supply, power and other industries, and are playing an increasingly important role. . [0003] Among the high-voltage inverters with many topologies, figure 1 The power unit shown in series with a multi-level high-voltage inverter, due to its strong voltage output capability, low harmonic pollution to the grid, and ...

AI Technical Summary

Problems solved by technology

During the development process, the inventors found that: after canceling the grid-side reactor between the grid side of each power unit 1 and the secondary winding of the transformer 2, the grid side of each power unit is its controllable rectifier bridge part The output side of the power supply, where the voltage is the output voltage of the controllable rectifier bridge part of the power unit rather than the grid voltage, the control part of each power unit cannot measure the phase and amplitude of the grid voltage, so the control part of each control unit cannot measure The calculation of the control algorithm can not control the on and off of each switching element that constitutes the rectifier bridge, and cannot realize energy feedback

Images