Multi-machine parallel system based on droop characteristic control, and control method of multi-machine parallel system

Abstract

The invention provides a multi-machine parallel system based on droop characteristic control. The multi-machine parallel system comprises a synchronizing signal generator, multiple inverter modules and a monitoring module, wherein the synchronizing signal generator is used for generating a synchronizing signal, the multiple inverter modules are connected in parallel and connected with the synchronizing signal generator, each inverter module captures the synchronizing signal, converts the synchronizing signal into a voltage phase signal and meanwhile samples the voltage and the current of the inverter module, and then phase coincidence is achieved according to the voltage phase signals. The monitoring module is used for calculating the output power of each inverter module according to the voltage and the current of the inverter module and calculating the average output power of the system, and an inverter controller conducts droop control according to the difference between the output power and the average power so as to modify the reference voltage target quantities of the inverter modules. According to the system, phase height synchronization can be achieved, it can be ensured that the modules are independent of one another and no circulation exists between the modules, power supply quality is greatly improved, and reliability is high. The invention further provides a control method of the multi-machine parallel system based on droop characteristic control.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a multi-machine parallel system based on droop characteristic control and a control method for the multi-machine parallel system based on droop characteristic control. Background technique [0002] With the development and demand of society, the capacity of electrical equipment with uninterrupted power supply continues to expand, and the scalability and reliability of a single inverter are greatly restricted. The power system with multiple inverters connected in parallel has been widely used. Applications. Multiple power modules are connected in parallel to share the load power, the current stress of the main circuit switching device is greatly reduced, and the power density is greatly improved, which can fundamentally improve reliability and reduce costs. However, the parallel connection of inverters also brings new problems. Multiple inverters cannot guarantee comple...

AI Technical Summary

Problems solved by technology

Compared with the first scheme, this scheme avoids the dependence on the host and adopts equal control. Compared with the second scheme, it does not need to carry out phase synchronization control, but because of the increase of the synchronous phase signal processing circuit, the complexity of the system is increased, and because the processing circuit The speed is limited, and the high precision of the synchronization signal cannot be guaranteed, making the system response slower

[0007] Therefore, the disadvantage of the existing technology is that the existing inverter parallel connection method cannot guarantee the phase height synchronization of each inverter module or the mutual independence between the modules, and the reliability is low.

Images