Utilization of a Piezoelectric Polymer to Sense Harmonics of Electromagnetic Torque

In this paper, the use of a piezoelectric polymer material to measure the harmonics of electromagnetic torque produced by a permanent magnet synchronous machine is described. The advantages of the polymer include low cost, durability, and flexibility. In addition, wide-bandwidth sensors are relatively easy to design and couple to drive system hardware for harmonic evaluation or to use in feedback-based control. To illustrate the use of the polymer, the electrical and mechanical properties of three sensors are described. The results of time-domain simulation and hardware experiments are used to validate that the voltage obtained from the sensors is linearly related to the torque ripple produced by the machine

Measurement and Control of Torque Ripple-Induced Frame Torsional Vibration in a Surface Mount Permanent Magnet Machine

A sensor to measure the stator torsional vibration due to torque ripple produced by a surface mount permanent magnet machine is first described. The sensor is relatively inexpensive and is straight forward to incorporate into a drive system. Experiments are performed to validate that the voltage produced by the sensor is linearly related to torque ripple amplitude. Closed-loop controllers are then described that adjust the stator current harmonics applied to the machine to achieve a commanded average torque while mitigating measured torsional vibration. Simulation and experimental results are used to demonstrate the effectiveness of the control techniques

Torque Ripple Sensor and Mitigation Mechanism

A torque ripple sensor and method for torque ripple sensing and/or mitigation. A piezoelectric sensor is positioned relative to a motor so that torque fluctuations due to torque ripple of the motor are transmitted to the sensor, resulting in strain of a piezoelectric element. A resulting signal can be amplified and conditioned for determining a magnitude of the torque ripple and/or fed into a feedback loop for applying current control or a counter-torque to the motor for torque ripple mitigation

A Comparison of Diode-Clamped and Cascaded Multilevel Converters for a STATCOM with Energy Storage

The progression of distributed generation within a bulk power system will lead to the need for greater control of transmission-line power flows. Static synchronous compensators (STATCOMs) provide a power-electronics-based means of embedded control of transmission-line voltage and power flows. The integration of energy storage with a STATCOM can extend traditional STATCOM capabilities to four-quadrant power flow control and transient stability improvement. This paper discusses energy storage systems (ESSs) integrated with conventional and multilevel bidirectional power converters for a hybrid STATCOM/ESS. Conventional, diode-clamped, and cascaded multilevel converter-based STATCOM/ESSs are developed, and their performances for a variety of power system applications are compared using battery energy storage. The advantages and disadvantages of each topology are presented. Both simulation and experimental results are provided to validate the conclusions

Feasibility Study and Design of In-Road Electric Vehicle Charging Technologies

Electric Roadways (ERs) or Dynamic Wireless Charging (DWC) lanes offer an alternative dynamic and wireless charging method that has the potential of giving electric vehicles (EV) limitless range while they are moving. Heavy-duty vehicles (HDVs) are expected to be early adopters of the DWC technology due to the higher benefits offered to these vehicles that are traveling on fixed routes. The goal of this project was to assess the feasibility of ERs in Indiana and design a test bed for in-road EV charging technologies. The most suitable locations for implementing DWC lanes were identified on interstates that are characterized by high truck traffic. Using I-65 S as a case study, it was found that DWC can be economically feasible for the developer and competitive for the EV owner at high and medium future projections of EV market penetration levels. However, the existing substations are unlikely to serve future DWC needs for HDVs. Thus, consideration should be given to substation expansion to support EVs as market penetration expands. Implementing the DWC technology on interstates and jointly with major pavement preservation activities is recommended. Large scale deployment can significantly reduce the high initial investment. Renewable energy resources (solar and wind) deployed in the vicinity of ERs can reduce the electricity costs and associated greenhouse gas emissions

Comparison of 3-, 5-, and 6-Phase Machines for Automotive Charging Applications

In this paper, the performance of a 5-phase claw-pole machine/converter system is compared with those of 3-phase and 6-phase systems of the same volume. It is shown that the acoustic output of the 5-phase machine compares favorably with that of the 6-phase machine and is much lower than that of the 3-phase machine over a majority of the operating range. In addition, the output current produced by the 5-phase machine Is, in general, 6-8% higher than those of the 3-phase and 6-phase machines. These results suggest that for maximizing power density while minimizing cost and acoustic noise, 5-phase machines provide a competitive alternative to 6-phase machines of identical volume

Incorporating the Effects of Magnetic Saturation in a Coupled-Circuit Model of a Claw-Pole Alternator

A method of representing the effects of magnetic saturation in a coupled-circuit model of a claw-pole alternator is presented. In the approach considered, the airgap flux density produced by each winding is expressed as a function of magnetic operating point. A challenge in the implementation is that the airgap flux densities consist of several significant harmonics, each of which changes at a distinct rate as iron saturates. Despite this complication, it is shown that relatively simple measurements can be used to determine model parameters. The model is implemented in the analysis of several alternator/rectifier systems using a commercial state-model-based circuit analysis program. Comparisons with experimental results over a wide range of speeds and operating conditions demonstrate its accuracy in predicting both the steady state and transient behavior of the systems

Analytical Derivation of a Coupled-circuit Model of a Claw-pole Alternator with Concentrated Stator Windings

A lumped-parameter coupled-circuit model of a claw-pole alternator is derived. To derive the model, analytical techniques are used to define a three-dimensional (3-D) Fourier-series representation of the airgap flux density. Included in the series expansion are the harmonics introduced by rotor saliency, concentrated stator windings, and stator slots. From the airgap flux density waveform, relatively simple closed-form expressions for the stator and rotor self- and mutual-inductances are obtained. The coupled-circuit model is implemented in the simulation of an alternator/rectifier system using a commercial state-model-based circuit analysis program. Comparisons with experimental results demonstrate the accuracy of the model in predicting both the steady-state and transient behavior of the machin

Self-powered mobile sensor for in-pipe potable water quality monitoring

Traditional stationary sensors for potable-water quality monitoring in a wireless sensor network format allow for continuous data collection and transfer. These stationary sensors have played a key role in reporting contamination events in order to secure public health. We are developing a self-powered mobile sensor that can move with the water flow, allowing real-time detection of contamination in water distribution pipes, with a higher temporal resolution. Functionality of the mobile sensor was tested for detecting and monitoring pH, Ca2+, Mg2+, HCO3-/CO32-, NH4+, and Clions. Moreover, energy harvest and wireless data transmission capabilities are being designed for the mobile sensor