A Novel 100 kW Power Hardware-in-the-Loop Emulation Test Bench for Permanent Magnet Synchronous Machines with Nonlinear Magnetics

This paper presents a high dynamic power hardware-inthe-loop (PHIL) emulation test bench to mimic arbitrary permanent magnet synchronous machines with nonlinear magnetics. The proposed PHIL test bench is composed of a high performance real-time simulation system to calculate the machine behaviour and a seven level modular multiphase multilevel converter to emulate the power flow of the virtual machine. The PHIL test bench is parametrized for an automotive synchronous machine and controlled by a motor converter using a predictive trajectory dead-beat current controller. Measurements of high dynamic current steps and phase current ripples at the real machine are reproduced precisely at the PHIL test bench. Thus, the validity of the used machine model as well as the excellent performance of the PHIL test bench is proven

Power Hardware-in-the-Loop Emulation of Permanent Magnet Synchronous Machines with Nonlinear Magnetics - Concept & Verification

This paper presents a power hardware-in-the-loop emulation test bench (PHIL), based on a modular multiphase multilevel converter (MMPMC), to mimic arbitrary permanent magnet synchronous machines with nonlinear magnetics as they are used in automotive applications. Measurements in stationary operation as well as high dynamic torque steps are conducted at a real automotive machine and precisely reproduced at the PHIL system to demonstrate the excellent performance of the PHIL test bench. Moreover, the superiority of a PHIL test bench over conventional motor test benches is proven by the unproblematic emulation of a blocking rotor or a cracking shaft

Real-Time Hardware-in-the-Loop Simulation of Permanent Magnet Synchronous Motor Drives under Stator Faults

Hardware-in-the-loop (HIL) testing methods can facilitate the development of control strategies in a safe and inexpensive environment particularly when extreme operating conditions such as faults are considered. HIL methods rely on accurate real-time emulation of the equipment under investigation. However, no validated tools for real-time emulation of electrical drives under fault conditions are available. This paper describes the implementation of a high-fidelity real-time emulator of a Permanent Magnet Synchronous Motor (PMSM) drive in a platform suitable for HIL tests. The emulator is capable of representing the drive operation under both healthy conditions and during inter-turn stator winding faults. Nonlinearities due to saturation, higher order harmonics, slotting effects, etc. are accounted for using fourdimensional look-up tables obtained by finite element analysis (FEA). The proposed model is computationally efficient and capable of running in real-time in a FPGA platform and is validated against simulations and experimental results in a wide range of operating conditions. Potential applications of the proposed emulation environment to the development of drive control, fault detection and diagnostic algorithms are proposed

Design, Modelling and Verification of Distributed Electric Drivetrain

The electric drivetrain in a battery electric vehicle (BEVs) consists of an electric machine, an inverter, and a transmission. The drivetrain topology of available BEVs, e.g., Nissan Leaf, is centralized with a single electric drivetrain used to propel the vehicle. However, the drivetrain components can be integrated mechanically, resulting in a more compact solution. Furthermore, multiple drivetrain units can propel the vehicle resulting in a distributed drive architecture, e.g., Tesla Model S. Such drivetrains provide an additional degree of control and topology optimization leading to cheaper and more efficient solutions. To reduce the cost, the drivetrain unit in a distributed drivetrain can be standardized. However, to standardize the drivetrain, the drivetrain needs to be dimensioned such that the performance of a range of different vehicles can be satisfied. This work investigates a method for dimensioning the torque and power of an electric drivetrain that could be standardized across different passenger and light-duty vehicles. A system modeling approach is used to verify the proposed method using drive cycle simulations. The laboratory verification of such drivetrain components using a conventional dyno test bench can be expensive. Therefore, alternative methods such as power-hardware-in-the-loop (PHIL) and mechanical-hardware-in-the-loop (MHIL) are investigated. The PHIL test method for verifying inverters can be inexpensive as it eliminates the need for rotating electric machines. In this method, the inverter is tested using a machine emulator consisting of a voltage source converter and a coupling network, e.g., inductors and transformer. The emulator is controlled so that currents and voltages at the terminals resemble a machine connected to a mechanical load. In this work, a 60-kW machine emulator is designed and experimentally verified. In the MHIL method, the real-time simulation of the system is combined with a dyno test bench. One drivetrain is implemented in the dyno test bench, while the remaining are simulated using a real-time simulator to utilize this method for distributed drivetrain systems. Including the remaining drivetrains in the real-time simulation eliminates the need for a full-scale dyno test bench, providing a less expensive method for laboratory verification. An MHIL test bench for verification of distributed drivetrain control and components is also designed and experimentally verified

Hochdynamische Power Hardware-in-the-Loop Emulation hoch ausgenutzter Synchronmaschinen mit einem Modularen-Multiphasen-Multilevel Umrichter

Um die gestiegenen Anforderungen an elektrische Antriebe im Hinblick auf Zuverlässigkeit und Sicherheit zu erfüllen, wurden in den letzten Jahren PHIL-Emulatoren für elektrische Maschinen entwickelt. Aufgrund funktionaler Einschränkungen können diese Emulatoren das Verhalten einer realen Maschine jedoch bisher nicht äquivalent nachbilden. Die vorliegende Arbeit setzt an diesem Punkt an und zeigt auf, wie ein PHIL-Prüfstand konzipiert sein muss, um eine Synchronmaschine ganzheitlich nachzubilden

Modellbildung, Parameteridentifikation und Regelung hoch ausgenutzter Synchronmaschinen

Was passiert, wenn permanentmagneterregte Elektromotoren bei gleicher Leistung immer kleiner und leichter werden? Wie verändert sich das elektromagnetische Verhalten? Was folgt daraus für die optimale Regelung der Motoren? Die vorliegende Arbeit beantwortet diese Fragen und behandelt die Modellbildung, Parameteridentifikation und Regelung wechselrichtergespeister, magnetisch anisotroper, hoch ausgenutzter, permanentmagneterregter Synchronmotoren

Advanced Fault Detection Methods for Permanent Magnets Synchronous Machines

The trend in recent years of transport electrification has significantly increased the demand for reliability and availability of electric drives, particularly in those employing Permanent Magnet Synchronous Machines (PMSM), often selected due to their high efficiency and energy density. Fault detection has been identified as one of the key aspects to cover such demand. Stator winding faults are known to be the second most common type of fault, after bearing fault. An extensive literature review has shown that, although a number of methods has been proposed to address this type of fault, no tool of general application, capable of dealing effectively with fault detection under transient conditions unrelated to the fault, has been proposed up to date. This thesis has made contributions to modelling, real-time emulation and stator winding fault detection of PMSM. Fault detection has been carried out through model-based and signal-based methods with a specific aim at operation during transient conditions. Furthermore, fault classification methods already available have been implemented with features computed by proposed signal-based fault detection methods. The main conclusion drawn from this thesis is that model-based fault detection methods, particularly those based on residuals, appear to be better suited for transient conditions analysis, as opposed to signal-based fault detection methods. However, it is expected that a combination of the two (model/signal) would yield the best results

An Investigation of Series and Parallel Configurations for Hybrid Power Amplifiers

Power Hardware-in-the-Loop (PHIL) is becoming increasingly popular for compartmentalized testing of electric power equipment in several areas such as in electric drive systems and distributed power generation systems. The fundamental idea of PHIL is to create flexible conditions for Devices under Test (DUT) to be properly assessed in real time and dynamic conditions with their rated power levels. Connected to the DUT is the Power Amplifier (PA), which is responsible for increasing the voltage and current levels, given from the Real-Time Simulator (RTS). The DUT is a physical equipment and high-complexity models are used to control the PAs to emulate necessary conditions for the DUT to be evaluated. One of the main benefits of PHIL is that it can provide a platform for conducting a number of severe tests without risking damaging the equipment that is being emulated, while testing the actual response of the DUT. It can also help with the preliminary design and performance assessment of new types of machines, drivers and controllers, thus significantly reducing the time to market of new equipment. The flexibility of PHIL is also one of its main assets, since the combination of the RTS and the PA can be used for various applications only by changing the model and/or parameters of the emulated element. This thesis will evaluate the main architectures, control strategies and PHIL applications of PAs. Linear Power Amplifiers (LPA) provide an overall great performance due to its high bandwidth but are expensive, mostly at increased power ratings. For high PAs with fast dynamic response and reduced waveform distortion, the Hybrid Power Amplifier (HPA) configuration provides a good cost-performance compromise. HPAs are built essentially with the association of a low-cost Switch Mode Power Amplifier (SMPA) and an LPA. The first configuration to be investigated is the series connected HPA intended for high voltage systems. The SMPA consists of a Cascaded H-Bridge Multilevel (CHBM) converter for increased modularity. A single-pulse per H-bridge modulation technique called Nearest Level of Control (NLC) is used for minimizing the switching losses. However, this leads to unbalanced power consumption by the H-bridges when the SMPA provides relatively low output voltages, thus compromising the reliability and power quality of the SMPA. A new modulation technique called Split-Voltage Fist-In First-Out (SV-FIFO) that mitigates this issue is proposed. Its implementation requires the use of a supplemental, but simple, control loop based on the magnitude and frequency of the reference output voltage. Experimental results are presented to validate the design approach and demonstrate the high performance achieved with SV-FIFO. The parallel connected HPA is also evaluated in this thesis. In a similar way to the series connected HPA, the LPA provides high bandwidth (BW) and active power filtering while the bulk of the power is provided by the SMPA. The SMPA is realized with a three-phase Voltage Source Converter (VSC) and three single-phase LPAs. The contribution relies on proposing a new topology and current control strategy that aims to reduce the size of the required LPA, which is costly. This is achieved by using the reference current of the HPA for the current control loop of the LPA, and the actual HPA current as the reference for the SMPA current loop. By making the bandwidth of the current loop of the LPA higher than that the SMPA one, the first provides the fast transient components and harmonic filtering while the second, the bulk of the HPA current. Additionally, this thesis also covers the evaluation of techniques for Amplitude, Phase Angle and Frequency (APAF) detection for single-phase systems. Amplitude, phase and frequency detection is a key feature for the control of the series HPA, but it is also useful for other important applications, such as the synchronization of renewable sources to Alternate Current (AC) grids, which is a largely growing practice. APAF for single-phase systems are more challenging since they require additional and more complex techniques to determine the phase angle. Usually, both single and three-phase systems are designed for a single and known frequency, usually the grid’s frequency. However, a wider range of frequencies is necessary for other applications such as HPAs. This thesis will examine two proposed techniques for APAF. The first is based on the combination of the integral and derivative actions and the second is based on the modification of a zero-crossing detection system. Both systems are discussed in detail and validated experimentally