A Space Vector Modulation Method for Converter

Abstract

The present invention proposes a converter space vector modulation method, which virtually synthesizes the vectors in a specific area in the traditional space vector diagram (for the convenience of discussion, it is called "vector virtualization in a specific area"), thereby realizing the midpoint voltage and floating capacitance The balance control of the voltage, the vector virtualization of a specific area is compared with the whole vector virtualization, which reduces the complexity of the space vector modulation method and reduces the switching loss. The invention proposes that the vector virtualization of a specific area re-virtually synthesizes the vectors that affect the balance of the midpoint voltage, and redefines some cells. Through the redundant characteristics of the vector itself, it solves the unbalance of the midpoint voltage in some regions under the traditional space vector control strategy. To solve the problem, the synchronous control of the midpoint voltage of the whole region and the suspension capacitor voltage can be realized. At the same time, the traditional space vector synthesis rule is adopted in the area where the neutral point voltage and the floating capacitor voltage can achieve balanced control, which avoids the problem of increasing the switching times and switching loss when all virtual space vectors are used.

Description

A converter space vector modulation method technical field The present invention relates to the technical field of converters, particularly the field of five-level inverters, specifically a kind of ANPC A space vector modulation method for a five-level inverter. Background technique Active neutral point clamped (Active neutral point clamped, ANPC) converter topology effectively solves The problem of unbalanced loss of switching devices in midpoint clamp topology is solved. ANPC five-level converters rely on low switching device stress and The advantages of low output current harmonic content and other advantages have attracted extensive attention in the fields of high-voltage frequency conversion and new energy. Due to the floating capacitance Existing, the ANPC five-level converter must not only control the balance of the midpoint voltage during operation, but also ensure the floating capacitance Therefore, it is important to study the synchronous control of the...

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Problems solved by technology

[0022] where t1 is V (20-2) action time, so using the prior art vector V (20-2) The generated mid-point current cannot be eliminated, and the mid-point voltage in A12, A13, and A14 cells cannot achieve balanced control, and other large areas are similar

[0023] That is to say, the disadvantage of the existing technology is that in each large area, there are areas where the midpoint voltage cannot be balanced and controlled by using the traditional space vector modulation strategy, such as A12, A13, and A14 in the A large area.

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