Inverter Motor Research Articles

Three-Phase Motor Inverter and Current Sensing GaN Power IC.

A three-phase GaN-based motor inverter IC with three integrated phase current mirror sensors (sense-FETs or sense-HEMTs, 1200:1 ratio), a temperature sensor, and an amplifier is presented and experimentally operated. The three low-side currents are read out by virtual grounding transimpedance amplifiers. A modified summed DC current readout circuit using only one amplifier is also discussed. During continuous 24 V motor operation with space-vector pulse width modulation (SVPWM), the sensor signal is measured and a bidirectional measurement capability is verified. The measured risetime of the sensor signal is 51 ns, indicating around 7 MHz bandwidth (without intentional optimization for high bandwidth). The IC is operated up to 32 V on DC-biased semi-floating substrate to limit negative static back-gating of the high-side transistors to around -7% of the DC-link voltage. Analysis of the capacitive coupling from the three switch-nodes to the substrate is calculated for SVPWM based on capacitance measurement, resulting in four discrete semi-floating substrate voltage levels, which is experimentally verified. Integrated advanced power converter topologies with sensors improve the power density of power electronics applications, such as for low-voltage motor drive.

Auxiliary Power Supply System with Parallel-Connected DC–AC Inverters for Low-Floor Light Rail Vehicle

This research proposes a roof-mounted auxiliary power supply (APS) system for 600 VDC low-floor light rail vehicles (LRVs). The proposed APS system consists of five parallel-connected dc–ac inverter modules (modules 1–5). Inverter modules 1 and 2 are three-phase dc–ac inverters for the compressor motors of the air conditioning system, and inverter modules 3 and 4 are three-phase dc–ac inverters for the air pump motors of the air supply system. Inverter module 5 is a single-phase dc–ac inverter for the 220 VAC power supply of onboard electric loads. Simulations and experiments were carried out under variable load torques and output frequencies for modules 1–4 and under full and no resistive loads for module 5. The measured total input current and total input power of the proposed APS system under the full-load condition are 114.36 A and 68.84 kW. The total efficiency of the proposed APS system (modules 1–5) is 97.05%. The proposed APS system is suitable for 600 VDC low-floor LRVs. The novelty of this research lies in the use of five parallel-connected inverter modules, as opposed to the three-phase output transformer or isolated dc–dc converter in the early and conventional APS systems. Specifically, the proposed APS system requires neither a three-phase output transformer nor an isolated dc–dc converter.

Neutral-point voltage control of the three-level inverter in permanent magnet synchronous motor based direct-drive belt conveyor

Combined with the operation condition of belt conveyor and the running state of low speed direct-drive permanent magnet synchronous motor (PMSM), the reason for the high fluctuation of the neutral-point voltage (NPV) in the three-level inverter with the conventional method is analyzed. An improved NPV control strategy based on self-optimization of the switching sequence is proposed to ensure that the NPV could be completely controlled with the minimal number of switching times. A test platform with a 800 kW low speed PMSM is built, where the proposed NPV control strategy is implemented on a digital processor using the programming language C. Compared with the conventional method, the experimental results show that the NPV fluctuation of the proposed method can be reduced by a ratio of 46.3% to 89.5% at the least cost of the switching loss increase and the low-frequency harmonics in the output current can also be mitigated.

Application of novel double-layer micro-jet heat sinks for energy-efficient thermal management of motor inverters in electric vehicles

The relentless advancement in electronics miniaturization and performance has birthed a tremendous amount of heat flux, demanding effective dissipation techniques. Thermal effects pose a significant hurdle in the thermal management of electric vehicles (EVs) and having advanced cooling techniques in place is vital. To tackle this, the present study numerically evaluates the cooling attributes of two novel double-layer micro-jet heat sinks (DLMJHSs) to address the thermal management of insulated-gate bipolar transistors (IGBTs) in the motor inverters of EVs. The numerical analyses are carried out for Reynolds numbers ranging from 5000 to 25,000, IGBT heat fluxes of 100, 200, and 300 W/cm2, and different configurations of DLMJHSs. The potential of using nanofluids is assessed by employing Al2O3–water nanofluid with different volume fractions of 0.8% and 1.7%. The finite volume technique is implemented to solve the equations and the turbulence closure is modeled using the k-ԑ model. Results show that HS #2 provides a 10.2% higher convective heat transfer coefficient leading to a 7.44 ℃ lower baseplate temperature than HS #1. Besides, HS #2 prevents the occurrence of high-temperature spots owing to a more uniform temperature distribution in comparison with HS #1. HS #2 demonstrates the most uniform temperature distribution, with a Coefficient of Variation of only 0.00993 and a maximum heat transfer coefficient of 80.5 kW/m2 ℃. The heat sink’s baseplate temperature drops by increasing either the Reynolds number or the volume fraction. The baseplate temperature declines by up to 6.94 ℃ using a nanofluid volume fraction of 1.7% compared with only the base fluid. A minimum Reynolds number of 15,700 is required to prevent overheating at the peak heat flux. The performance evaluation criterion (PEC) is higher than 1 for Re ≤ 15,000.

Open-circuit fault diagnosis in voltage source inverter for motor drive by using deep neural network

Open-circuit fault diagnosis in voltage source inverter for motor drive by using deep neural network

Solar cell split source inverter for induction motor with computer control

<span lang="EN-US">The electrical energy is necessary for daily life, but there is a continuous increase in the usage rate of electric energy. Such an increase is a big problem, which makes us think about using alternative energy for conventional energy, in addition to the problem of pollution resulting from the use of energy generation. Solar energy is a solution for energy in terms of consumption, besides there is no environmental risk in the use of solar energy. In this work, an integrated solar system operating in the daytime has been designed to operate a 3-phase induction motor (IM). The study begins by simulating the system in the MATLAB/Simulink program in order to find out the results and verify them using the same components of the proposed algorithm. The system with photovoltaic (PV) modules 1080 W, whereas the PV array is a direct source of the designed split source inverter (SSI). This SSI is controlled by sine pulse width modulation (SPWM). The maximum power point tracking (MPPT) incremental conductance (INC) method is monitored by a computer connected to the system via a Wi-Fi connection, the 3-phase IM (373) W. The results reveal the efficiency of the system and that it can be versatile.</span>

Design and implementation of a driver circuit for three-phase induction motor based on STM32F103C8T6

A three-phase induction motor is an electrical machine that can be used for many industrial applications. A three-phase driver circuit, also known as a three-wire series circuit or three-wire delta circuit is an electrical power system. These motors typically rely on power supplied using electric cables, which carry alternating currents. The three-phase motor inverter driver circuit is a simple circuit consisting of three half-wave rectifiers, which are connected in a bridge. When the input voltage level of the DC power supply to the inverter is high enough, this arrangement can provide a large current through the induction motor. This paper will show how to build a three-phase inverter driver circuit from scratch for a threephase induction motor by using (transistors and diodes) for photovoltaic application. The paper will guide people through each step with diagrams and schematics that make it easy for anyone to understand every part of this project and ensure people's safety by learning how these components work before putting them into their own design. The focus of this project will be on the use of STM32F103C8T6 as microcontrollers to generate the pulse width modulation (PWM) signals.

Design and Analysis of a 54-Pulse Converter and 7-Level Hybrid Inverter for Medium Voltage Induction Motor Drive

Design and Analysis of a 54-Pulse Converter and 7-Level Hybrid Inverter for Medium Voltage Induction Motor Drive

Selection of PWM Methods for Common-Mode Voltage and DC-Link Capacitor Current Reduction of Three-Phase VSI

This paper evaluates several important pulse-width modulation (PWM) methods developed to reduce the common-mode voltage (CMV) or DC-link capacitor current (DCC) of two-level three-phase voltage source inverter (VSI) in motor drive applications. In addition, a PWM selection criterion is introduced to properly utilize these advanced PWM methods in the VSI system. In the motor drive systems, the high CMV generates the large common-mode current, which may cause electromagnetic emissions and motor damages. Also, the large DCC may have an adverse effect on the life expectancy and increase the volume of DC-link capacitor. Therefore, reducing the CMV and DCC is required in modern VSI systems. So far, various PWM methods have been studied to reduce these CMV and DCC. However, they need to be fairly compared and evaluated together under the same condition to provide information so that power electronics engineers can select the appropriate PWM method when designing their motor drive systems. In this paper, the principle of these PWM methods is reviewed and their performance is analytically evaluated. Then, the PWM selection criterion is described based on the comprehensive evaluation studies. Lastly, the simulation and experimental results with an interior permanent magnet synchronous motor (IPMSM) drive system are presented to validate the presented PWM selection criterion.

Performance Evaluation of SiC-Based Two-Level VSIs with Generalized Carrier-Based PWM Strategies in Motor Drive Applications

Currently, silicon carbide (SiC) MOSFETs are several times higher in cost than the equivalent silicon (Si)-IGBTs; however, the gains in power conversion efficiency, simplification of thermal management, and energy savings in general bring the advantages of lower total cost of ownership. The implementation of discontinuous PWM (DPWM) techniques for controlling the motor drive brings further reductions for the semiconductor switching losses; however, most existing techniques have limited performance on the optimized clamping region, particularly at a low power factor, which is a common operation condition for motor drives employing the widely used V/f control, particularly at partial- or low-load conditions. This paper evaluates the performance of a SiC-based two-level voltage-source inverter (2L-VSI) motor drive operated with generalized carrier-based PWM methods. Theoretical analysis and experimental measurements are conducted in a 2.2 kW heatsink-less 2L-VSI prototype and induction machine, which demonstrates that the minimum switching losses DPWM (MSL-DPWM) is the most favorable solution in practice in terms of the achievable power conversion efficiency and harmonic distortions and also produces the least common-mode current, which is critical in motor drives.

AVsIs: An Analytical-Solution-Based Solver for Model-Predictive Control With Hexagonal Constraints in Voltage-Source Inverter Applications

The theory of a new analytical-solution-based algorithm for calculating the optimal solution in model-predictive control applications with hexagonal constraints is discussed in this article. Three-phase voltage-source inverters for power electronic and electric motor drive applications are the target of the proposed method. The indirect model-predictive control requires a constrained quadratic programming (QP) solver to calculate the optimal solution. Most of the QP solvers use numerical algorithms, which may result in unbearable computational burdens. However, the optimal constrained solution can be calculated in an analytical way when the control horizon is limited to the first step. A computationally efficient algorithm with a certain maximum number of operations is proposed in this article. A thorough mathematical description of the solver in both the stationary and rotating reference frames is provided. Experimental results on real test rigs featuring either an electric motor or a resistive–inductive load are reported to demonstrate the feasibility of the proposed solver, thus smoothing the way for its implementation in industrial applications. The name of the proposed solver is <monospace xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">aVsIs</monospace> , which is released under Apache License 2.0 in GitHub, and a free example is available in Code Ocean.

A Stacked Multilevel Inverter With Single DC Link for Open-End Winding Induction Motor Drive With Zero-Voltage Switching and Common-Mode Voltage Elimination

A switching-state selection scheme for a five-level stacked multilevel inverter for open-end winding motor drive is presented in this article. Using the proposed scheme, converter can be operated with a single dc supply and with zero common-mode voltage. In addition, the switching transition of high-voltage switches occurs at zero-voltage conditions. The degree of freedom provided by the redundant switching-states and voltage vectors of the inverter topology is utilized to design the modulation scheme. The proposed switching-state selection leads to inherent capacitor balancing without using any extra sensors and fundamental frequency switching of the high-voltage switches of the topology. The modulation scheme uses triangular carrier comparison and, hence, avoids the complexity of subsector identification and dwell time calculation. Half-wave symmetry in output waveforms is ensured by maintaining synchronous sampling with constant samples per fundamental cycle. The inverter topology and the effectiveness of the state selection scheme are experimentally validated on an open-end winding induction motor drive, and experimental results showing steady-state and dynamic operations are presented.

Active Cancellation of Periodic CM EMI at the Input of a Motor Inverter by Injecting Synthesized and Synchronized Signals (S3-AEF)

Active electromagnetic interferences (EMI) cancellation is a promising solution to reduce the size of passive filters. Power electronic systems may generate periodic disturbances if they are controlled by periodic signals in steady-state operation. Periodic disturbances can be represented by a set of sine waves, according to the Fourier theory, and can be suppressed by an appropriate set of cancelling sine waves injected into the system. Since bothersome effects, like delay times or complex transfer functions, can be compensated by individually selecting the appropriate amplitude and phase for each cancelling sine wave, high EMI reductions can be achieved in a wide frequency range. In this contribution, this cancellation method is applied to the common-mode EMI of a three-phase motor inverter in stationary operation with periodic control signals in the frequency range from 150 kHz to 30 MHz. Approximately 2.4 million harmonics are suppressed. The characteristics of the overall system are discussed and the challenges for the cancellation system are elaborated. A method for the synthesis of the cancellation signal is introduced. The design of the cancellation system is described, and its signal processing is presented. The outstanding performance is proven by reference measurements in a laboratory setup. Extensions for practical applications are discussed.

Floating-capacitor based inverter for open-ended winding induction motor drive with fault-tolerance

ABSTRACT Floating-capacitor-based nine-level inverter topology for open-ended winding induction motor (OWIM) drive is presented in this paper. The proposed multilevel inverter topology (PMLIT) essentially consists of four three-phase two-level voltage source inverters (VSI), three isolated DC sources and a floating-capacitor (FC). Out of four inverters, three inverters are fed from DC sources, and the fourth inverter is connected with the FC. The advantage of the PMLIT is that the maximum output voltage will be twice the source voltage with nine levels across each phase winding. The PMLIT employs least number of components which makes the inverter cost-effective and has lowered control complexity. The PMLIT can deliver seven, five or three-level output voltage with a decrease in modulation index. Conventional sinusoidal pulse-width modulation (PWM) techniques can be employed to generate switch-gate pulses. The intermediate-voltage levels are realised by proper charging and discharging of the FC. The performance of the PMLIT under possible switch faults is investigated, and modified switching logics are proposed to deliver a balanced supply for the OWIM drive in post-fault operation. Simulations are performed in the MATLAB/Simulink environment, and an experimental setup is designed to validate the simulations, and the results are presented.

Verification of simplified model of inverter–Motor stator system

A simplified inverter–motor stator system model is presented in the paper. The model is based on elementary dynamic blocks described by differential equations. The paper presents the results of research aimed at verifying the model on different devices with different types of inverters and motors. Model accuracy coefficients have been developed for all examined cases, confirming the high conformity of the model to the measured speeds and torques of asynchronous motors. The model was also used to simulate the operation of a drive system with a synchronous motor, obtaining high compliance of speed and torque mapping. The presented cases of verification of a simplified model confirm the possibility of using it to model different devices fed by frequency inverters, controlled both manually and automatically. The presented model, using simple description, ensures high accuracy of speed and torque mapping. It should be emphasized that most parameters in the presented model are calculated for motors and inverters based on data sheets.

A Harmonic Mitigation Technique for Multi-Parallel Grid-Connected Inverters in Distribution Networks

Different harmonic mitigation techniques have been utilized in grid-connected inverters to suppress the effect of grid voltage distortion on the output current of these inverters. In practice, to scale up the injected current into the grid, a set of parallel grid-connected inverters are often utilized rather than a single high-power inverter in solar Photovoltaic or motor drive systems. Conventional Point of Common Coupling (PCC) feedforward approaches have been used for harmonic rejection of multi-parallel grid-connected inverters. However, these methods need to implement a separate feedforward scheme for each individual inverter. In this paper, a novel full PCC voltage feedforward strategy is proposed to reduce the cost investment, which is implemented only in one of the grid-connected inverters. The proposed strategy is based on cancelling the total parallel admittance of the system by adding a virtual negative admittance to the target inverter. It is shown that the proposed scheme causes no instability issue on the system since it does not affect the system phase margin. To verify the efficiency of the proposed strategy against emitted harmonics from the grid, simulations and experiments on a system with two parallel single-phase grid-tied inverters are performed.

Overview of Electric Scooter operating on Synchronous Reluctance Motor (SynRM)

this paper deals in research and review of a 3-phase motor inverter to run a designed synchronous reluctance motor which would be used in electric scooters. The synchronous reluctance motor falls in the category of rare earth free magnet motors, yet provides better efficiency and gives straight competition to other AC and DC motors. It also includes designing of swappable battery packs for mobility purposes which offers easy removal and installation of batteries. All the major components which are to be use in electric scooter powertrain have been discussed here.

Design method of wide‐band high‐current air‐core inductor EMI filter for high voltage DC power of motor inverter of electric vehicle

Passive filters are often used for electromagnetic interference (EMI) suppression of high voltage (HV) DC power supplies of electric vehicle (EV) motor controllers. The high current of the DC bus saturates the differential mode (DM) magnetic ring, while the leakage inductance of common mode (CM) inductor used as the DM inductance is usually very small, resulting in almost no suppression of DM EMI. A design method of broadband high-current air-core inductor passive filter is proposed. By using the air-core inductor as DM inductor, the problem of easy saturation of the DM inductor core and the small leakage inductance of the CM inductor is solved, and improves the low frequency DM EMI suppression. Through the calculation and selection of the turning frequency point of the multi-stage filter circuit, the effective frequency band can be improved. By analysing the influence of parasitic parameters, the problem of insufficient insertion loss of the filter at high frequency is solved. The experimental verification shows that the proposed air-core inductor filter achieves 50 dB of CM and DM insertion loss in frequency range of 150 kHz–108 MHz, and meets the requirements of system conducted disturbance voltage specified in CISPR25-2016Rd level 3.

Stabilizing Sets of Current PI Controllers for IM Drives With and Without LC Filter

Connection of an LC filter to the output of voltage source inverter (VSI) in squirrel cage induction motor (SQIM) drive converts the pulse-width modulated (PWM) voltages into smooth sinusoidal voltages. However, this connection may lead to closed-loop instability in the rotor flux-oriented (RFO) vector-controlled (VC) SQIM system. The closed-loop stability of the combined SQIM + LC filter (SQLC) system is complex and has not been analyzed properly in the literature. In this paper, a detailed closed-loop stability analysis of the SQLC system has been presented based on stability region (SR) and accordingly the PI gains of VC has been designed. The SR method is adopted to derive the common stability regions for the SQIM system and SQLC system. Thereby, the paper proves that connecting an LC filter in-between the VSI and the SQIM system does not always destabilize the closed-loop system. Further, for an SQLC system, the complete range of current controller gains is obtained at various operating points. The frequency-domain specifications have been used to select a proper stabilizing set and the effect of parametric variation of LC filter on the stabilizing set has also been discussed. The experimental results are provided to validate the analysis.

Accurate Electro-Thermal Computational Model Design and Validation for Inverters of Automotive Electric Drivetrain Applications

This paper proposes the fast and accurate electro-thermal model of the existing Simrod three-phase inverter for an electric vehicle (EV) application. The research focuses on analytical and dynamic electro-thermal models of inverters that can be applied for multi-applications. The optimal design approach of passive filters is presented for the DC and AC sides of the inverter. The analytical model has been established, including a mathematical representation of the inverter and induction motor (IM). The high-fidelity electro-thermal simulation model of an inverter with integrated power loss and thermal model is established. The state-space thermal model (for the IRFS4115PbF device) has been created and incorporated into the MATLAB simulation. The simulation model is then validated with the PLECS software-based thermal model to confirm the accuracy. Indirect field-oriented control (IFOC) is designed for squirrel-cage IM at a maximum power rating of 45 kW and implemented on MATLAB/Simulink. The comparative analysis between the real and simulated results is performed to validate the simulation model at a specific speed, torque, and current. Furthermore, the electro-thermal simulation model has been validated with experimental data using efficiency and temperature comparison. The developed simulation model is beneficial for designing, optimizing, and developing advanced technology-based inverters to achieve higher efficiency at a particular operating range of temperature and power quality. The new European driving cycle (NEDC) speed profile simulation results are demonstrated.