Wind Power Network News: The converter system is the main electrical system of the wind turbine. Its function is to connect the generator and the grid, and convert the non-power frequency AC power output by the generator into the power frequency AC power through the converter system and transmit it to the grid. Its cooling system provides heat dissipation for the power unit in the converter cabinet to keep the temperature of the power unit within the normal range.
Nowadays, the converter system of 1.5MW unit, which has been in service for many years, has various operations such as excessively high network temperature, high humidity in the converter cabinet, shutdown of the inverter module, frequent damage of the inverter filter contactor, and unstable signal transmission of the inverter. Problems, these problems can cause wind turbines to operate with limited power, or cause serious safety accidents such as blowing up modules and burning cabinets.
In the 1.5MW double-fed unit, the frequency conversion system is one of the core systems of the unit. Its main function is to realize the control and grid connection of the output power of the wind turbine by exciting the generator. It is understood that after many years of service, the high procurement cost of inverter power modules of 1.5MW doubly-fed units, frequent damage of inverter filter contactors, and converter failures have repeatedly plagued wind power owners under the pressure of reducing costs and increasing efficiency. NS.
Structure diagram of doubly-fed wind power generation system So, what solutions are there in the industry for the above problems?
Case 1: Localized substitution to achieve seamless replacement of inverter power modules
Since the purchase cost of imported modules is high, can we consider replacing them with domestic modules of the same quality? In this regard, the technical innovation expert of Beijing Jinfeng Huineng Technology Co., Ltd. said that in fact, the domestic industry has already put this assumption into practice. It is understood that in the design of the replacement product for the inverter module of the 1.5MW double-fed unit, the size and interface definition of the domestic product power unit have been completely consistent with the original power unit. Moreover, the product has been rigorously tested and verified, all performance indicators meet the requirements of use, and the technology and quality have reached a mature level.
From the design drawing to the actual power unit, the size and interface definition of the self-developed product are consistent with the original power unit, and the performance is stable and reliable
It can be said that localized substitution perfectly solves the problems of long procurement cycle and high maintenance cost of imported power modules. It is worth mentioning that the current localized products can achieve module replacement of multiple brands.
In addition, in the special transformation of 1.5MW double-fed units, Jinfeng Hui Energy has almost formed technical transformation services covering most models of filtering optimization, comprehensive converter management, etc., effectively reducing the frequency converter failure rate and ensuring the safety of the unit. Reliable operation.
Case 2: 90% failure rate! Solution to high converter temperature and mis-engagement of stator contactor
In addition to frequency converters, imported converters are also widely used in 1.5MW double-fed units. In summer, high temperature failures of some converters account for about 90% of the annual failure rate of converters, which seriously affects the safe operation of wind turbines.
The misalignment of the converter stator contactor is one of the widespread problems currently. Disturbance of the controller program or hardware damage will directly cause the wind turbine to be integrated into the power grid in the standby state and burn the key components of the converter.
In view of the above two faults of high temperature and accidental suction, the current common solution in the industry is to solve the overtemperature problem by using the tower structure to design upward exhaust; the DC bus is not pre-charged, the stator contactor is not closed, and the stator The contactor is disconnected when it loses power to prevent the stator contactor from being pulled in by mistake, so as to solve the problem of the stator contactor being pulled in by the damage of the control circuit board.
Post time: Dec-24-2021
