VSI Inverter Research Articles

PSO and GA designed Pareto of Fuzzy Controller in AC Motor Drive

In electric vehicles EV, can be implemented a controller has highest extend of battery’s lifetime meet a superior dynamic speed behavior? This research offer multi-objective approaching planned by a Particle Swarm Optimization (PSO) complementary with Genetic Algorithm (GA). This hybrid evolutionary learning is utilized as an automated method to generate the optimal parameters of fuzzy logic controller (FLC) type Mamdani. The Pareto front characterizes the speed controller of an Induction Motor (IM). where the first function is the error between the actual speed and desired speed, and the other function is the energy dissipated from the electrical supply during (10 sec), in present work the multi-objective optimization of PSO and GA have been implemented separately using two M-file/MATLAB, and compacted the results to sketch the global Pareto, while the evaluation of “fitness functions” of the two computational algorithms have been determined using SIMULINKMATLAB, the simulation has a completely mathematical model of induction motor IM, voltage source inverter VSI and FLC. The FLC have been implemented using RSLogix 5000. The empirical results demonstrate that the proposed method realized a limited disbursed energy as possible as better dynamic behavior of the IM speed along the Pareto front.

A New Concept of Two-Stage Multi-Element Resonant-/Cyclo-Converter for Two-Phase IM/SM Motor

The paper deals with a new concept of power electronic two-phase system with two-stage DC/AC/AC converter and two-phase IM/PMSM motor. The proposed system consisting of two-stage converter comprises: input resonant boost converter with AC output, two-phase half-bridge cyclo-converter commutated by HF AC input voltage, and induction or synchronous motor. Such a system with AC interlink, as a whole unit, has better properties as a 3-phase reference VSI inverter: higher efficiency due to soft switching of both converter stages, higher switching frequency, smaller dimensions and weight with lesser number of power semiconductor switches and better price. In comparison with currently used conventional system configurations the proposed system features a good efficiency of electronic converters and also has a good torque overloading of two-phase AC induction or synchronous motors. Design of two-stage multi-element resonant converter and results of simulation experiments are presented in the paper.

An Optimal Energy Utilization Self Adjusting Variable Speed Drive Scheme for Large Locomotive Drives

The paper presents a novel GA/PSO self regulating diesel driven AC induction motor controlled drive system using the common AC-DC-AC bus interface for industrial applications and electric vehicle EV-locomotion. The proposed control scheme utilizes the dual regulation multi loop error driven controller using the novel modified proportional plus integral plus derivative PID structure with the added error rate compensating auxiliary loop. The EV-drive is fed from the AC-DC-AC interface of a six-pulse controlled rectifier –DC link and six-pulse voltage source inverter VSI using a coordinated dual action control scheme for firing angle control. The diesel engine is controlled to ensure dynamic of power demand with dynamic voltage and current tracking. A dynamic error driven control scheme is proposed to regulate the motor current to limit any inrush currents and overloading conditions, in addition to motor speed dynamic reference tracking. The Proposed tri loop dynamic error driven self regulated-tuned controllers are also utilized to ensure dynamic energy efficiency, control loop decoupling, drive stability and the unified system efficient energy utilization while maintaining accurate speed reference tracking. The paperpresents soft-computing application of both Multi Objective Particle Swarm Optimization (MOPSO) and Genetic search MOGA optimization and search techniques for dynamic online gain-tuning to optimally adjust the settings of the proposed controllers.

Micro-Stepping Control of a Two-Phase Linear Stepping Motor With Three-Phase VSI Inverter for High-Speed Applications

This paper presents a synchronous frame current control scheme for micro-stepping a two-phase linear stepping motor drive using a three-phase voltage-source inverter. Because of the wide operating frequency, the frequency-dependent voltages are decoupled from the controller to reduce the current-following errors and preserve the dynamic characteristics as the frequency varies. A motor cogging force compensation scheme performed in the synchronous frame is proposed to reduce the positioning error and velocity ripple caused by the cogging force. A space-vector pulse width modulation scheme is used for motor voltage modulation. This scheme is based on the harmonic injection principle originally derived for three-phase motor drives. Good static and dynamic performance is obtained in the experimental verifications.

Single-phase three-level regular-sampled selective harmonic elimination PWM

A new harmonic elimination PWM strategy for single-phase VSI and CSI inverters is presented which closely approximates the exact switching angles produced offline for the harmonic elimination PWM (HEPWM) strategy. The new strategy is developed using well known regular-sampled techniques which enable the calculation of the switching angles in real-time, allowing a simple and efficient digital signal processor implementation. Experimental and computed results are presented in terms of total harmonic distortion and harmonic performance to highlight the advantages of the strategy and to confirm the theoretical developments.

Starting characteristics of motor in inverter-motor drive system

When the induction motor is fed from the PWM VSI inverter, with and without torque enhancing function, the variations of the starting torque and the starting current versus the starting frequency are analyzed, based on the steady state equivalent circuit of the induction motor. The corresponding expressions are derived, and the corresponding curves are also drawn, from which the initial starting frequency range can be determined properly and easily. The initial starting frequency range is the common range, in which the starting torque should be high enough and the starting current low enough. Some other useful formulas are also derived. These results are significant for electrical drive designers to make the starting schemes. The effects of the increase of the stator and the rotor resistances on the starting torque and the initial starting frequency range are also discussed, which is caused by the skin effects of the high order harmonics present in the PWM inverter output voltage.

A new low-cost, fully fault-protected PWM-VSI inverter with true phase-current information

This paper proposes a new topology for a low-cost three-phase pulse width modulation (PWM) VSI inverter where a true phase current information exists with the use of only one current sensor in the DC link. The topology also has the benefits of full protection of the inverter such as short circuits in the DC link, output phase faults, and output earth faults. Previously suggested methods have problems at low speed in detecting the phase current, but by the use of space vector modulation in a double-sided implementation, the PWM-pulses are adjusted so true information about the phase current exists even at very low speed. The DC link current is sampled twice during one switching period, and it is proposed to sample in the center of the PWM-pulses to obtain a real average phase current. The effects of blanking-time and overmodulation are also discussed. The strategy is implemented in a 16-b microcontroller, and the test results show the technique is useful in the whole speed range. It is concluded by the use of the proposed topology that only one current sensor will be necessary in the future for PWM-VSI inverters.

Improved constant-frequency hysteresis current control of VSI inverters with simple feedforward bandwidth prediction

An improved implementation of the constant-frequency hysteresis current control of three-phase voltage-source inverters is presented. A simple, self-adjusting analog prediction of the hysteresis band is added to the phase-locked-loop control to ensure constant switching frequency, even at a high rate of output voltage change, such as required in active filters, fast drives and other highly demanding applications. This provision also improves the relative position of phase modulation pulses, thus reducing the current ripple. The prediction method is robust and uses a small number of inexpensive components. It does not require trimming or tuning, giving the whole system the capability to adjust itself to different load conditions. Thus, the control becomes suitable for hybrid or monolithic integration. In this paper, the basic principles are described, and a detailed stability analysis is carried out. The control performance is illustrated, both by simulated and experimental results.