Simplified Space Vector Pulse Width Modulation Algorithm Research Articles

A Simplified Space Vector Pulse Width Modulation Algorithm of a High-Speed Permanent Magnet Synchronous Machine Drive for a Flywheel Energy Storage System

A space vector pulse width modulation (SVPWM) algorithm is an important part of the permanent magnet synchronous machine (PMSM) drive to achieve direct current (DC) to alternating current (AC) conversion. The execution of the conventional SVPWM algorithm is a complex process which will limit the sampling frequency of the high-speed PMSM drive. Low sampling frequency will cause high current total harmonic distortion (THD) and eddy current loss. To increase the sampling frequency, this paper proposes a novel simplified SVPWM algorithm. The proposed SVPWM algorithm turns the vector composition problem of the conventional SVPWM algorithm into an optimization problem of the dwell time of the basic vector. The proposed SVPWM algorithm has an optimal vector dwell time (OVDT). The dwell time of the basic vector can be directly calculated by solving the optimization problem. The proposed SVPWM algorithm does not need sector identification compared to the conventional algorithm. The experiments of the proposed SVPWM algorithm are performed in a high-speed PMSM drive of a flywheel energy storage system (FESS). Compared to the conventional SVPWM algorithm, the execution time of the proposed SVPWM algorithm is reduced by 38%. By using the proposed SVPWM algorithm, the sampling frequency can be increased from 33 kHz to 40 kHz. With the higher sampling frequency, the current THD is reduced by 25.6%. The effectiveness of the proposed simplified SVPWM algorithm is verified experimentally.

Design and implementation of three-level T-type inverter based on simplified SVPWM using cost-effective STM32F4 board

This paper investigates the design and validation of simplified space vector pulse width modulation (SVPWM) as a switching control for a three-phase three-level T-type inverter using STM32F4 board interfaced with MATLAB/Simulink environment. Usually, the SVPWM algorithm implemented using either DSP card or Dspace platform, which affects the cost of the system. On the contrary, the proposed algorithm offers a great reduction of computations compared with the conventional one, which grants an easy digital implementation. Thanks to the geometrical symmetry of six sectors, in which exists a close relationship between on-time calculations and on-time arrangement of the switching states. This can be exploited for the remaining sectors based on a single computation that relies on the first sector only. The proposed algorithm has been validated in both simulation and experimental tests. The results show the ability and the flexibility of using the STM32F4 board to drive a three-level T-type inverter.

Design and implementation of three-level T-type inverter based on simplified SVPWM using cost-effective STM32F4 board

This paper investigates the design and validation of simplified space vector pulse width modulation (SVPWM) as a switching control for a three-phase three-level T-type inverter using STM32F4 board interfaced with MATLAB/Simulink environment. Usually, the SVPWM algorithm implemented using either DSP card or Dspace platform, which affects the cost of the system. On the contrary, the proposed algorithm offers a great reduction of computations compared with the conventional one, which grants an easy digital implementation. Thanks to the geometrical symmetry of six sectors, in which exists a close relationship between on-time calculations and on-time arrangement of the switching states. This can be exploited for the remaining sectors based on a single computation that relies on the first sector only. The proposed algorithm has been validated in both simulation and experimental tests. The results show the ability and the flexibility of using the STM32F4 board to drive a three-level T-type inverter.

Power Device Thermal Fault Tolerant Control of High-Power Three-Level Explosion-Proof Inverter Based on Holographic Equivalent Dual-Mode Modulation

It is necessary for three-level explosion-proof inverters to have high thermal stability and good output characteristics avoiding problems caused by power devices, such as IGBT, so it becomes a hot and difficult research point using only one control algorithm to guarantee both output characteristics and high thermal stability. Firstly, the simplified SVPWM (Space Vector Pulse Width Modulation) algorithm was illustrated based on the NPC (neutral-point-clamped) three-level inverter, and then the quasi-square wave control was brought in and made into a novel holographic equivalent dual-mode modulation algorithm together with the simplified SVPWM. The holographic equivalent model was established to analyze the relative advantages comparing with the two single algorithms. Finally, the dynamic output and steady power device losses were analyzed, based on which the power loss calculation and system simulation were conducted as well. The experiment proved that the high-power three-level explosion-proof inverter has good output characteristics and thermal stability.

A new simplified SVPWM algorithm based on modified carrier signal

This paper presents a simplified algorithm of space vector pulse width modulation (SVPWM) for a two-level three-phase inverter, which can operate in undermodulation and overmodulation modes. In other simplifications founded in literature, the reference voltages are modified and compared with a triangular carrier to estimate the switching states of the inverter. However, this paper proposes the modification of the carrier signal instead of the references. This procedure reduces the number of mathematical operations and increases the execution speed of SVPWM algorithm in DSPs or FPGAs. The reference voltages are sinusoidal, even for overmodulation mode. Simulation and experimental results proves that the proposed simplification produces the same switching patterns than conventional SVPWM, is simpler and is faster than other simplifications.

Novel Control Strategy for Multi-Level Active Power Filter without Phase-Locked-Loop

Active power filter (APF) using novel virtual line-flux-linkage oriented control strategy can not only realizes no phase-locked-loop (PLL) control, but also achieves a good inhibitory effect to interfere. However, there are some problems in the conventional method, such as the error of amplitude, the shift of phase angle and the non-determinacy of initial oriented angle. In this paper, two one-order low-pass filters are adopted instead of the pure integrator in the virtual line-flux-linkage observer, which can steady the phase and amplitude. Furthermore, an original scheme of harmonics detection under the rotating coordinate is advanced based on the simplified space vector pulse width modulation (SVPWM) strategy. Meanwhile, by using the new SVPWM algorithm, the voltage space vector diagram of the three-level inverter can be simplified and applied into that of two-level inverter, and this makes the control for Neutral Point potential easier.