Super-power cascade type high-voltage inverter and method for surge inhibiting of super-power cascade type high-voltage inverter

Abstract

The invention discloses a super-power cascade type high-voltage inverter and a method for surge inhibiting of the super-power cascade type high-voltage inverter and relates to the field of high-voltage frequency conversion. The super-power cascade type high-voltage inverter comprises two or more phase-shifting transformer sets, 24 power units with the numbers of A1-A8, B1-B8 and C1-C8, a high-voltage 10 kV power source, a low-voltage 380 V power source and an excitation surge inhibiting circuit. The high-voltage 10 kV power source is connected with primary-side windings of phase-shifting transformers through the excitation surge inhibiting circuit. Secondary side windings of the phase-shifting transformers are connected with the 24 power units with the numbers of A1-A8, B1-B8 and C1-C8. The phase-shifting transformers are provided with low-voltage auxiliary windings. The excitation surge inhibitingcircuit comprises a first vacuum circuit breaker QF1, a second vacuum circuit breaker QF2 and a current-limiting resistor R0. The super-power cascade type high-voltage inverter and the method for surge inhibiting of the super-power cascade type high-voltage inverter can effectively inhibit excitation surges, the reliability and stability of products are improved, cost is reduced, the production difficulty of the phase-shifting transformers is lowered, and later-stage carrying and installing are convenient.

Description

technical field [0001] The invention relates to the field of high-voltage frequency conversion, in particular to an ultra-high-power cascaded high-voltage frequency converter and a method for suppressing surges thereof. Background technique [0002] The rapid development of my country's industrialization has promoted the development of motor manufacturing and application in the direction of high voltage and high power. Ultra-high-power cascaded high-voltage inverters are used to drive high-voltage and high-power motors, and are widely used in metallurgy, petrochemical, and chemical industries. In ultra-high-power applications, such as the power of blast furnace fans in the metallurgical industry is generally concentrated above 20 MW, two or more high-voltage inverters are often used in parallel to drive, see figure 1 As shown, the technical difficulty of paralleling is relatively high. If multiple high-voltage inverters are running at the same time, if any one of them fails...

AI Technical Summary

Problems solved by technology

In this method, charging resistors, charging contactors, and corresponding control circuits need to be installed inside each power unit, which not only increases the cost, but also increases the complexity of the process and reduces the reliability of the product.

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