Method for synchronously controlling parallel connection of three-phase inverter

Abstract

The invention provides a method for synchronously controlling parallel connection of a three-phase inverter. The method for synchronously controlling the parallel connection of the three-phase inverter comprises that a carrier wave counter, a modulating wave counter, a pulse generator, a signal output arbiter and a wire and drive, wherein synchronous enable signals are sent to the signal output arbiter through a control system of the inverter, a symmetrical triangular wave which is identical to a triangular carrier wave period of an inverter module is generated by the carrier wave counter, the modulating wave counter records the amount of falling edges of pulses on a synchronous bus received in a carrier wave period, the input of the pulse generator is triangular waves coming from the carrier wave counter and modulating wave reset pulse signals coming from the modulating wave counter, the input of the signal output arbiter is carrier wave grade synchronous pulse signals coming from the synchronous bus and the synchronous enable signals sent from a controller of the inverter module, a wire and drive module amplifies the power of quasi-synchronous pulse signals of the pulse generator, and the amplified power is output to the synchronous bus after passing by the ware and drive.

Description

technical field [0001] The invention relates to a control method for distributed parallel operation inverters with interconnection lines. Background technique [0002] With the development of information processing technology, the requirements for the capacity, performance and reliability of the power system are getting higher and higher. Multi-module parallel connection to realize large-capacity power supply is the development direction of power supply technology. For the parallel operation system with interconnected inverters, the synchronous circuit is one of the key technologies to realize the reliable and stable operation of the system. In an ideal free parallel system, each module can be operated as a single machine or multiple units can be directly connected in parallel. Some redundant parallel systems need to be hot-swappable. Patent application number 200410000213.0 discloses a genlock method. Although the method of using competition to obtain bus control rights s...

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Problems solved by technology

Patent application number 200410000213.0 discloses a genlock method. Although the method of using competition to obtain bus control rights solves the problem of high risk of single point failure (master) in the master-slave synchronization method, it still needs to set different The waiting time for the inverters to compete for control of the bus

And when the inverter that obtains the bus control line exits, the bus has an idle time of three synchronous cycles, which poses a safety hazard

The patent document with the patent application number 200810220118.8 discloses a synchronous control method. Although it achieves the purpose of having no master-slave in each inverter, it can only realize the function of synchronizing the modulated wave and not the function of carrier synchronization.

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