Quantum mechanics

Control (management)

Voltage

Engineering

Space vector

Modulation index

Modulation (music)

Operating system

Power (physics)

Pulse-width modulation

Computer science

Acoustics

Operating point

Physics

AC power

Mathematics

Artificial intelligence

Geometry

Generator (circuit theory)

Point (geometry)

Ripple

Space vector modulation

Control theory (sociology)

Converters

Space (punctuation)

Electrical engineering

IEEE Transactions on Industrial Electronics

This paper describes a high-performance neutral point voltage balancing technique for a neutral point clamped (NPC) converter. Conventional neutral point voltage balancing methods do not function well under low power factor, low pulse ratio, and near-unity modulation index operation conditions. These conditions are essentially dominant operation conditions for aircraft starter/generator systems. This paper introduces an alternative space vector modulation technique for three-level NPC converters in an aircraft starter generator system. The selection of voltage space vectors is optimized for high modulation index and low power factor operation. Disturbances caused by a low pulse ratio are also compensated. The proposed method maintains neutral point voltage balance and ripple minimization over the full range of operating conditions. This paper also provides a detailed analysis of the sources of neutral point voltage imbalances and ripples in high-speed drives with deep flux weakening. Simulation results obtained from a Simulink/PLECS model and experimental results obtained from a 45 kVA, 32 krpm aircraft starter generator test rig prove that the proposed method eliminates the neutral point voltage imbalance and significantly reduces the neutral point voltage ripple.

A Modified Neutral Point Balancing Space Vector Modulation for Three-Level Neutral Point Clamped Converters in High-Speed Drives