Insulation coordination method for modular multi-level voltage source converter module unit

Abstract

The invention provides an insulation coordinating method of a module unit of a modularized multi-level voltage source converter, and belongs to the field of alternating current/direct current conversion and power transmission and distribution of a voltage source converter. A voltage source converter (VSC) is adopted as the module unit; when the insulating method provided by the invention is adopted, all equipment of the module unit can meet the insulating requirement of the system and exert self characteristics of the equipment to the maximum extent simultaneously, the cost of the module unit and the structural design difficulty are reduced, and the running robustness of the VSC system is improved; and the electric field of the module unit is distributed uniformly, and the influence of primary main equipment on a secondary control and protection system is reduced. The insulating method comprises the steps of: selecting insulating equipment and metal equipment according to the parameters of the module unit in various working conditions, and performing the structural design and electric design on the module unit to ensure the module unit to operate safely, reliably and economically under the voltage stress.

Description

technical field [0001] The invention belongs to the fields of AC-DC conversion and power transmission and distribution of voltage source converters, and specifically relates to an insulation coordination method for modular multilevel voltage source converter module units. Background technique [0002] In order to alleviate problems such as energy shortage and environmental pollution, the large-scale development and utilization of renewable energy such as wind energy and solar energy has become the general trend. However, renewable energy such as wind energy and solar energy have the disadvantages of being dispersed and intermittent. When wind power and photovoltaic power generation are connected to the grid using traditional AC transmission technology or conventional DC transmission technology, they will bring a series of problems to the power system, and this This problem will become increasingly prominent as the scale of renewable energy utilization expands. [0003] Flex...

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Problems solved by technology

However, the design of insulation coordination is very professional and technical. It is not only necessary to comprehensively analyze the maximum steady-state voltage stress of the module unit under steady-state conditions, the maximum transient and loss overvoltage characteristics under transient conditions, and the high-speed switching of devices. complex electromagnetic environment, etc., it is also necessary to repeatedly adjust the protection logic and protection configuration parameters of the system with the designer

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