Simultaneous DC-Link and Stator Current Ripple Reduction With Interleaved Carriers in Multiphase Controlled Integrated Modular Motor Drives

Abstract

To meet the demand for increasingly high power density in electric drives, the concept of a so-called integrated modular motor drive has emerged. The machine is composed of multiple identical modules, which receive individual control signals for multiphase control, to reduce unwanted stator current harmonics. Each module is equipped with its own power electronic converter, which is integrated in the machine housing. This integration imposes strict constraints on the dc-link capacitor design. To reduce the dc-link current ripple, and hence relax the design constraints on the dc-link capacitor, without compromising the possibility to eliminate unwanted stator current harmonics by means of multiphase control, a new interleaving strategy is proposed in this article. The n modules of the machine are split into p subgroups of m modules for interleaving, while the n-phase control is preserved. An analytical model, simulations and experimental results are provided for a 4 kW test setup, confirming that multiphase control can be combined with interleaving. As a result, both the stator current harmonic distortion and the dc-link current ripple can be reduced simultaneously.

Multiphase Traction Inverters: State-of-the-Art Review and Future Trends

“…7a. This strategy was implemented and reported in [53] on a 15-phase inverter. Implementation of such interleaving technique in [54] resulted in a 60% volume reduction in the dc-bus capacitor for a 55 kW six-phase inverter.…”

“…Furthermore, enhanced EMC is achieved, thanks to the direct connection between the two components. Researchers have been interested in combining the merits of IMDs with the merits of multiphase drives, such as higher torque density, lower torque ripple and improved fault tolerance, to yield a highly competitive motor drive for traction applications [53], [150]- [152]. A five-phase IMD with a disk-shaped, air-cooled inverter was proposed in [151].…”

Multi‐agent control in modular motor drives by means of gossip consensus

“…It is assumed that for any two communication edges of the communication network, the Bernoulli processes are independent and have the same probability to fail. When a communication link fails at time instant k, algorithm (7) is not executed, and the parameters γ x , i * q;x and e x are not updated during one update period T c of the consensus algorithm. At the next time instant k + 1, the edge(s) that follow next in the communication sequences S are activated.…”

“…The basic idea of algorithm (7) is that each agent makes a local estimate of the discrepancy between the total reference T A B L E 1 Overview of the parameters used in the general gossip consensus algorithm (7) for the different communication strategies illustrated in Figure 1 x y α β δ ξ η…”

Multi-Agent Position Estimation in Modular Motor Drives Using Low-Resolution Sensors

“…As the agents do not predict the effects of their actions, but just reactively convert their low-resolution sensor inputs into a position estimate that can be used in a field-oriented control loop, they are reactive agents. They can decide for themselves whether or not to make use of the communicated VTO position estimates of their neighbors based on validity check (5), which makes them autonomous, flexible and communicative. However, the agents cannot change their behavior based on previous experience, so they are non-adaptive.…”