Gate-level current waveform simulation of CMOS integrated circuits

Injection-locked oscillators (ILO) have widespread use in wireline and wireless systems as fast-locking clock generators, phase noise filters, and frequency multipliers/ dividers, but their modeling and simulation typically resort to SPICE due to their nonlinear, time-varying characteristics. This paper presents a way to simulate ILOs in an event-driven logic simulator such as SystemVerilog, based on a perturbation projection vector (PPV) model. By expressing the continuous-time signals in analytical forms of which coefficients are updated as events, the nonlinear phase response of the ILO can be simulated in an algebraic fashion without numerical integration. The simulation methodology is demonstrated with the modeling examples of a phase-locked loop and a burst-mode clock recovery loop, each employing a injected-locked frequency divider and oscillator, respectively.

A new method is proposed to identify the location of transient events, including incipient faults, in power distribution systems, by using synchronized measurements from an emerging class of sensors, called waveform measurement units (WMUs). WMUs capture the voltage and current waveforms in time domain. The proposed method consists of three steps. The first step is to characterize the oscillatory modes of the transient components of all the captured synchronized voltage and current waveforms from all WMUs, by conducting a multi-signal modal analysis. The second step is to construct a circuit model for the underlying distribution feeder at the identified dominant mode(s) of the transient event. The final step is to identify the location of the transient event with the means of a method that involves certain forward and backward analyses of the constructed circuit model. The proposed method requires installing as few as only two WMUs. It can also utilize several synchronized waveform measurements when several WMUs are available. The performance of the proposed method is assessed on the IEEE 33-bus test system; for different cases of transient events, such as sub-cycle incipient faults, multi-cycle incipient faults, permanent faults, as well as benign yet informative events such as capacitor bank switching. Both the accuracy and the robustness of the proposed method are verified. The analysis and results in this paper provide new insights on possible applications of synchronized WMU measurements; while they also address a highly challenging problem in power distribution networks.

A new method is proposed to identify the location of events in distribution networks using data from waveform measurement units (WMUs). When an event occurs, WMUs provide GPS-synchronized measurements of voltage and current waveforms in time-domain that are captured during the event. Given such data, the proposed method identifies the bus number where the event occurred. Here, an event is defined rather broadly as any major change in the voltage or current waveforms. An event may have various causes, such as capacitor bank switching, load switching, a minor fault, etc. The first step in the proposed method is to characterize the oscillatory modes of the captured waveform; namely their frequency, damping rate, magnitude, and angle. The next step is to model the underlying circuit at the dominant mode of the event. The final step is to locate the cause of the event based on certain forward and backward calculations on the obtained circuit model. As few as only two WMUs, one at the beginning of the feeder and one at the end of the feeder, are sufficient to identify the location of the event. The performance of the developed method is verified on the IEEE 33-bus test system. The results verify the accuracy and robustness of the proposed method in identifying the location of events in distribution networks.

This paper uses big data technology to extract the electromechanical fault characteristics of metro vehicles and analyze the current situation under different fault conditions to ensure the operation quality and safety of metro operations. It also establishes a simulation model to simulate the current waveform of metro vehicles under different fault conditions and analyze the fault phenomenon. The simulation test results show that: (1) The current waveform of a single transistor with the hard fault is compared with the simulated current waveform under a normal state. The upper part of the A phase current waveform is lost when T1 fails. When T2 fails, the current waveform in the lower half of the C phase current is lost. When T3 fails, the upper half of the B phase current waveform is lost. (2) The current waveform in the hard fault’s upper and lower bridge arms will have phase loss. In the T25 fault, the C phase current is completely lost. In the T14 fault, the phase A current waveform is completely lost. In the T36 fault, the phase B current is completely lost. (3) The current waveform of a single transistor with a soft fault is complete, but the overall current amplitude is reduced. When a T1 fails, the A phase current tends to rise first and then fall. Compared to normal, the amplitude of the current decreases, and the peak decreases slightly. (4) The current values of phase B and phase C of the two transistors on the same bridge above and below the soft fault are mostly the same. The phase A current output value decreases in both the positive and negative half cycles. This paper aims to improve the monitoring ability of the monitoring system of electromechanical equipment of metro vehicles, which plays a specific role in maintaining the safety of subway operations and improving the quality of subway operations.

In this paper, application of a portable instrument to gain impulse grounding impedance (IGI) characteristics for grounding device (GD) of ultra-high-voltage (UHV) 1000 kV transmission towers is introduced. The test currents of 8/20 $\mu$ s and 10/350 $\mu$ s were chosen as the injection signal sources to the grounding device respectively, while the response transient voltage waveforms in time domain were simultaneously measured. Then the corresponding IGI can be calculated with processing of the impulse current and voltage waveforms. In order to obtain the transient characteristics of the whole test process, the transient grounding resistance in time domain (TGRT) and transient grounding resistance in frequency domain (TGRF) are also analyzed and compared abased on the measured current and voltage waveforms of 8/20 $\mu$s and 10/350$\mu$ s respectively. All of that provides a reference for basic research of lightning protection for the UHV 1000 kV transmission towers and a better understanding of transient characteristics of GD under the lightning stroke.

Understanding the causes of a power device’s defect plays a crucial role in failure and reliability analyses, and hence, the need of health diagnosis. Health diagnosis involves the measurement of predefined electrical parameters of a power device under its usual operating condition and the analyses of their deviations from their norms. Instead of the conventional direct measurements of voltage and current waveforms in time domain, this paper proposes a nonintrusive measurement method that measures the ON-state impedance of a power device in frequency domain. The proposed method eliminates direct electrical contact with the device-under-test, and it has the ability to detect the deviation of the ON-state impedance from its norm for health diagnosis purpose.

The paper presents an analysis of overvoltages caused by a direct lightning strike in intrusion detection system equipped with underground radiating cable sensors. Waveforms of currents and voltages in the system components are calculated using analytical formulas basing on a transmission-line model in the frequency domain. The time-domain waveforms are computed using the inverse fast Fourier transform (IFFT). Three network configurations of the intrusion detection system are analyzed.

This study aims to present a two‐output three‐level series‐resonant inverter together with an implementation and experiments for an induction melting application. A three‐level circuit is applied for each branch of inverter in order to decrease the voltage stress on switching devices. A phase‐shifted pulse‐width modulation (PSPWM) with variable frequency control is applied for providing and maintaining a zero‐voltage switching condition over a wide load range. In addition, the PSPWM could provide symmetrical output voltage and current waveforms that result in decreasing the THD v and THD i of output waveforms and harmonic losses of high‐frequency transformer cores comparing to other PWM schemes. Finally, the prototype was designed, built, and tested to verify the consistency between the experimental results and theories of the proposed inverter.

Hard switching specifies the stressful switching behavior of the controlled switches. During the turn-off and turn-on processes, the power electronic device has to withstand high current and voltage simultaneously, resulting in high stress and switching losses. The switching loss is directly proportional to the switch frequency, thus reducing the maximum switch frequency of the power electronic converter. The concept was to incorporate resonant tanks in the converters to create oscillatory (usually sinusoidal) voltage and/or current waveforms, so the zero current switching (ZCS) or zero voltage switching (ZVS) conditions can be achieved for the power control switches. The Soft-switched power converters are generally utilizing the resonance condition. Resonance condition is generally occurred just during the turn-off and turn-on processes, so as to create ZCS and ZVS across each switch. The Regulated three and five multiple-output dc-dc converter under zero-voltage switching (ZVS) condition is proposed. The converter is consists of three outputs altogether. With the help of two asymmetric half bridge converters, the first and second outputs are controlled. Based on the phase shift between two asymmetric half bridge converters, the third output is controlled. At high switching frequency, these multiple-output dc–dc converters can give higher efficiency. The various stages of operation, soft switching condition and controlling schemes are also explained. A closed loop and open loop control techniques of the three multiple output converter is explained.

This paper presents a simple soft-switching chopper scheme with fixed timing control. A near-zero-voltage transition (near-ZVT) switching condition is realized by adding one auxiliary resonant snubber branch to a full-bridge two-quadrant chopper. The turn-off loss is reduced by lossless snubber capacitors in parallel with the main switches. The proposed design approach is to realize true ZVT at the rated load and near-ZVT under all other load current conditions. Computer simulation and hardware experiments have been implemented to verify the proposed concept, and the resulting voltage and current waveforms are shown from 30% to 150% load conditions in this paper. Under near-ZVT switching, the switching loss and dv/dt of the power device can be significantly reduced, and the reverse recovery problem of main switches can be avoided as compared to the hard-switching case. The design criteria for the resonant components are described with a practical example that has been used in a commercial magnetic levitation system. Under different load current conditions, the proposed design methodology has been fully verified with simulation and experimental results.

This paper presents the modeling and simulation of a novel topology of quasi Z-Multilevel Inverter with stepped DC input. The proposed inverter incorporates a simple switching technique with reduced component count and is aimed at producing boosted multilevel output AC voltage. The inverter consists of two stages and the buck /boost operation is obtained by varying the shoot through period of the pulses obtained by maximum constant boost control with third harmonic injection. With all the advantages of the quasi Z-network, the proposed inverter eliminates the fly back diodes and capacitors present in a conventional Z-Multilevel Inverter. Further the stress on the devices is less which leads to reduction in component value and hence the cost. The novel stepped DC coupled Single Phase quasi Z-Multilevel Inverter is modeled and simulated in the MATLAB - SIMULINK environment and its performance is analyzed for varying input and switching conditions. The voltage and current waveforms across each stage of the inverter is analyzed and the results are presented for different levels of input.

This paper presents a complete design methodology of a Class-E inverter for capacitive wireless power transfer (CWPT) applications, focusing on the capacitance coupling influence. The CWPT has been investigated in this paper, because most of the literature refers to inductive power transfer (IWPT). However, CWPT in perspective can result in lower cost and higher reliability than IWPT, because it does not need coils and related shields. The Class-E inverter has been selected, because it is a single switch inverter with a grounded MOSFET source terminal, and this leads to low costs and a simple control strategy. The presented design procedure ensures both zero voltage switching (ZVS) and zero derivative switching (ZDS) conditions at an optimum coupling coefficient, thus enabling a high transmission and conversion efficiency. The novelties of the proposed method are that the output power is boosted higher than in previous papers available in the literature, the inverter is operated at a high conversion efficiency, and the equivalent impedance of the capacitive wireless power transfer circuit to operate in resonance is exploited. The power and the efficiency have been increased by operating the inverter at 100 kHz so that turn-off losses, as well as losses in inductor and capacitors, are reduced. The closed-form expressions for all the Class-E inverter voltage and currents waveforms are derived, and this allows for the understanding of the effects of the coupling coefficient variations on ZVS and ZDS conditions. The analytical estimations are validated through several LTSpice simulations and experimental results. The converter circuit, used for the proposed analysis, has been designed and simulated, and a laboratory prototype has been experimentally tested. The experimental prototype can transfer 83.5 W at optimal capacitive coupling with operating at 100 kHz featuring 92.5% of the efficiency, confirming that theoretical and simulation results are in good agreement with the experimental tests.

Battery/Supercapacitors combination offers superior performances for a hybrid electric energy storage system in Electric Vehicles. This paper, presents a frequency power sharing strategy to get the best use of complementarity between battery and supercapacitors. Storage devices are sized based on reduced scale specifications for the studied EV. Power and current waveform simulation results are shown for each storage device due to the use of a frequency power sharing policy. Various power split configurations are analyzed to study their effect on battery current waveforms. Optimal frequency sharing policy for the battery/SCs hybrid reducing RMS battery current is obtained. The best use of battery/SCs association provides significant improvements of Electric Vehicle performances in terms of battery lifetime and amortized cost.

Simulation of the transient current of radiation detector materials using the constrained profile interpolation method

Chapter 3 - Logic and Fault Simulation