The converter valve is the core equipment of the DC transmission project. By sequentially connecting the three-phase AC voltage to the DC terminal to obtain the desired DC voltage and realize power control, its value accounts for about 22-25% of the total price of the complete set of equipment in the converter station.
The design of the converter valve applies the latest technology and research results of power electronics technology, light-controlled conversion technology, high-voltage technology, control technology and pressure equalization technology, cooling technology, and high-voltage insulating materials.
1. Introduction of converter valve
The main technical difficulties are: the establishment of the transient simulation model of the converter valve; the research on the overall shielding and shielding performance of the high potential of the converter valve; the insulation coordination of the converter valve and the control and suppression technology of the partial discharge level; Development and research; integration of converter valve cooling, photoelectric conversion technology, control and pressure equalization technology; research on converter valve type test methods.
2. Composition of converter valve
The converter valve is composed of thyristors, damping capacitors, voltage equalizing capacitors, damping resistors, voltage equalizing resistors, saturated reactors, thyristor control units and other components. Among them, the thyristor is the core component of the converter valve, which determines the flow capacity of the converter valve (at present, a 6-inch thyristor has been developed in China, with a rated flow capacity of 4000 amperes). The desired flow rate can be obtained by connecting multiple thyristor elements in series. system voltage.
3. Water cooling radiator for converter valve
The water-cooled radiator required for the thyristor, the core component of the converter valve, not only needs to dissipate heat for the thyristor, but also act as a structural part to bear pressure, conduct electricity, and have a lifetime warranty. Its strict quality requirements make this water-cooled radiator an ideal choice. The top product for water cooling radiators in the power electronics industry. The water-cooled radiator used in the independent research and development of the world's first ±800kV/4750A UHV DC converter valve by China Electric Power Research Institute was produced by Wuhan Renuo Metal.