Optimized Switching Pattern Generator Embedded into an SOC | Consortium for Embedded Systems | SIU

Abstract: The project will be the continuation of a previous project funded by the I/UCRCES under the title: ‘Ground Work for Embedding a Field Oriented Motor Controller (FOC) into a Single System on a Chip’, 2012-13. The previous project developed and integrated FOC into a SoC applicable to motor drives of the PM type. The new project proposes to embed an optimized switching pattern generator (SPG) for the inverter gates. The SPG will generate the gating signals for the inverter valves in order to minimize the harmonic output of the inverter, especially at operations with a high modulation index. The project will investigate the design and implementation of such generator using the system-on-chip (SoC) approach. The proposed SPG will be integrated into the SoC along with the already developed elements of the FOC thereby providing a complete integrated system for the control of the PM motor. The project will benefit the industry because it will significantly reduce the size of filter components, which are otherwise needed to deal with increased harmonic and EMI at the output of the inverter.

Problem: The project proposes to embed an optimized switching pattern generator (SPG) into the field-orienting controller (FOC) of permanent magnet (PM) motors. The SPG will generate the gating signals for the (3-phase) inverter valves in order to minimize the harmonic output of the inverter, especially at operations with a high modulation index. The project will investigate the design and implementation of such generator using the system-on-chip (SoC) technology. The proposed SPG will be integrated into the SoC along with the already developed elements of the FOC thereby providing a complete integrated system for the control of the PM motor.

Rationale / Approach: The rational of the project is minimize the harmonics of the motor drive by designing a optimum switching pattern for the inverter. The proposed optimized SPG will be based on a combination of the techniques including sigma/delta modulation and spread spectrum modulation. Modeling of the entire drive system under the proposed SPG will be done in MATLAB in order to simulate the harmonic response of the inverter and fine-tune the design. The optimized SPG will be integrated into the SoC previously design to complete the drive control.

Novelty: The proposed project will result in a complete motor drive controller integrated into a SoC. The novelty of the proposed project is in the investigation of suitable switching patterns within the constraints imposed by the present SoC technology and the all-digital implementation of the algorithms.

Potential Member Company Benefits: The proposed project will result in significant reduction of hardware, which is needed to filter current harmonics from the motor. In addition, this project will complete the previous effort to produce a complete integrated drive controller into the SoC, which further reduces the hardware requirements compared to similar schemes using discrete and analogue components.

Deliverables for the proposed year: The project deliverables are:
1. An optimized SPG based on combining delta modulation with randomized modulation techniques;
2. Integration of the SPG into the previously developed SoC including the complete controller of a PM motor.

Milestones for the proposed year: The proposed project will produce a standalone controller integrated into an SoC for the permanent magnet motor.