Over-current Protection Circuit Research Articles

Design of Laser-Powered Opto-Electrical Current Transformer and Its Application in Electrical Automation of Substations

The novel power equipment represented by the Opto-Electrical Current Transformer (OECT) possesses unparalleled advantages compared to traditional Current Transformers (CTs), rendering it with vast potential in power systems. In the design of OECT, this study employs laser power supply and focuses on the overall perspective, particularly the design of the laser power supply module and the optical fiber digital transmission module. The laser power supply module selects a high-power semiconductor laser to provide power to the circuit, incorporating line filters, thermistor resistors, and a laser overcurrent protection circuit. An automatic temperature control circuit based on PI regulation is utilized to stabilize the working temperature of the laser diode (LD). The photoelectric conversion device PPC-6E achieves a maximum photoelectric conversion efficiency of 40%, and the MAX639 DC–DC conversion chip ensures stable output voltage. The optical fiber digital transmission module adopts a circuit composed of multiple NOR gate logic for electro-optical conversion, a low-power driving circuit based on the 74LVC1G07 chip, and the HFBR-2412 photoelectric converter to simplify the circuit board design. To achieve a higher communication baud rate, a quartz multimode optical fiber with a diameter of 62.5 μm is chosen. In the experimental phase, a simulation of high-power AC power with equal turns is conducted. The linearity/temperature test results demonstrate that the designed OECT in this study meets expectations. In the electrical automation test of substations, a comparison between traditional CTs and the designed OECT is carried out using traditional protection algorithms and optical differential protection algorithms. The results indicate that, compared to traditional protection algorithms, the optical differential algorithm using the designed OECT achieves faster protection times.

Design and modeling of an all-solid-state high power bidirectional DC switch

In order to improve the reliability of the aircraft ring network power distribution system for the future development needs of advanced multi-power and all-power aircraft, a design scheme of an all-solid-state high-power bidirectional DC switch is proposed to upgrade the aircraft power distribution system originally composed of traditional mechanical switches and some low-power solid-state power controllers to an all-solid-state aircraft power distribution system. The solid-state high-power bi-directional DC switch uses SiC MOSFETs as switching elements is modeled and simulated by Saber simulation software and uses reverse time overcurrent protection and short circuit protection design to realize high voltage control distribution, circuit protection, and fault isolation functions. The simulation verifies that the designed all-solid-state high-power bidirectional DC switch has short-circuit protection and overcurrent protection intelligent protection functions. Applying the design to the aircraft distribution loop network greatly enhances the reliability of the aircraft distribution system drives the development of aircraft multi-electricity-all-electricity technology, and also promotes the application of digital solid-state series modular switches in civil transportation and high-voltage power supply fields.

High Performance SiC Power Module Based on Repackaging of Discrete SiC Devices

Increased adoption of electric vehicles (EV), photovoltaic (PV), and battery energy storage systems (BESS) is driving the need for high-current SiC power modules. The state-of-the-art multichip module is substantially more expensive than the IGBT module. This paper proposes a cost-effective packaging methodology for high-power SiC intelligent power modules (IPMs) with discrete SiC devices. The proposed IPM integrates the gate drivers, decoupling capacitors, snubbers, discrete SiC devices, direct bond copper (DBC), base plate, temperature sensors, and overcurrent protection circuits, achieving very low loop inductance and thermal resistance, and more than 50% cost reduction. A 1200V/480A/2.15mΩ half-bridge IPM is presented for comparison with commercial counterparts. A 1200V/240A/4.3mΩ six-phase IPM is developed, and its performance is experimentally verified.

Design of reduced-current overcurrent protection circuit based on GBDT model

Abstract To address the problems of slow response and insufficient protection sensitivity of existing overcurrent protection techniques, this paper verifies the feasibility of the design of reduced-current overcurrent protection circuits by using the GBDT model. Firstly, the regression tree is used as a circuit learner for iteration, and the CART algorithm is applied to calculate circuit splitting characteristics and optimal splitting points to obtain the gain of splitting. Then the line loss rate is calculated using the differential evolution method to derive the objective function of the minimized line and the optimal value of the circuit. Finally, the mean value is extracted by calculating the optimal line’s statistical characteristics, the regression tree nodes are calculated using the GBDT model, and the root means the square error is used to verify the effectiveness of the circuit protection design proposed in this paper. The experimental results show that the overcurrent protection value of the circuit sample is around 1.35A and the current limit protection time is around 13ms by verifying the current reduction protection function and indication function of the circuit in the full temperature range. This shows that the GBDT model enables the reduced-current overcurrent protection circuit to perform timely and accurate overcurrent detection actions, and the circuit can be reliably protected under different overcurrent conditions.

An Elimination Scheme of Long and Short Periods for Flyback Converter

For small size, low cost, and wide power range, the constant current (CC) control scheme suitable for both discontinuous conduction mode and continuous conduction mode (CCM) is prevalent in low and medium power applications. However long and short periods (LSP) emerge due to the inner control relationship of conventional flyback converter especially in CCM. An adaptive over current protection (OCP) control scheme is adopted to eliminate LSP. A threshold regulator and a calibrated protector are used to correct the OCP threshold dynamically in the proposed OCP circuit. To verify the feasibility and performance, the proposed scheme has been implemented in 0.18lm BCD process. The experimental results show that the LSP is eliminated and deviation of the CC is within ±1.04% under different input and load conditions.

Design of a Rectangular Wave High Voltage Generator for the Evaluation of Inverter-Fed Motor Insulation

The urgent need for the safer operation of inverter-fed motors is leading research to the qualification tests under high frequency rectangular wave voltages. Consequently, the generation of rectangular wave voltages with adjustable parameters has become a major concern for manufacturers and researchers. This paper presents a design of high frequency and high voltage pulse generator able to provide unipolar or bipolar pulses up to 20 kV peak-to-peak with variable rise and fall time that can be tuned down to 40 ns. Such a generator is performant enough for testing a large part of motors following standards and with more stressful conditions for research of new winding technologies. Resorting to high voltage push-pull solid-state switches and dielectrics liquid & air-cooling technique, the tested capacitance load can reach up to 3000 pF. Also, the over-current protection circuit is carefully designed and verified by using real-time logic control hardware. The proposed generator has been successfully used for endurance tests and partial discharge inception voltage (PDIV) detection at repetitive impulsive voltages for capacitive, inductive insulation structures and windings during the qualification evaluation of inverter-fed motors.

Development of the radiation and magnetic field tolerant DC/DC converter system for the ATLAS ITk Strip Detector

The radiation and magnetic field tolerant step-down DC/DC converter system is developed to supply low-voltage power for the ATLAS ITk Strip Detector. The system is modular and consists of custom designed crates with embedded cooling plates, backplane, and DC/DC converter modules. Each converter module comprises two or four power channels. Each channel comprises a 48-to-11 V DC/DC converter, hardware overcurrent and overvoltage protection circuits, correction circuitry to compensate for voltage drops along the cables, and control and monitoring functionality based on the AMACStar chip. We present the design and performance of such a DC/DC converter system, including evaluation of its radiation tolerance.

Application of a small transformer for designing current detection and overcurrent protection circuit for laboratory tables

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An Integrated GaN Overcurrent Protection Circuit for Power HEMTs Using SenseHEMT

GaN power high-electron-mobility transistors (HEMTs), with their fast switching transients and poor overcurrent tolerance, require overcurrent protection (OCP) circuits that can respond in under <inline-formula><tex-math notation="LaTeX">$\text{0.5}\, \mu \text{s}$</tex-math></inline-formula>. Monolithically integrating digital and analog circuits with GaN power devices is enabled by recent advancements in high-voltage GaN integrationplatforms. Thus, integrated OCP designs can be used to reduce the protection response time, the area penalty, and the assembly complexity. This work presents the first fully integrated, senseHEMT-based GaN OCP integrated circuit (IC) with an adjustable current limit and programmable blanking time, suitable for a wide range of power applications. The IC, implemented on a 200-V GaN-on-Silicon-on-Insulator (GaN-on-SOI) process, contains a power HEMT with a senseHEMT for current sensing, a totem-pole-based gate driver, an analog comparator, and a set of logic circuits to enable high-speed closed-loop OCP. The fabricated design is tested in both a clamped switching setup and a 12&#x2013;48 V boost converter. The minimum OCP response time is estimated to be 36 ns with <inline-formula><tex-math notation="LaTeX">$dI_{D}/dt\geq \text{30}\,\text{A}/\mu \text{s}$</tex-math></inline-formula>, one of the fastest amongst state-of-the-art OCP circuits for GaN.

Monolithic Integration of Gate Driver and Protection Modules With P-GaN Gate Power HEMTs

The high-speed superiority of GaN power devices with silicon-based peripheral circuits is not yet fully leveraged, mainly due to the parasitic inductance of interconnections. In this article, we demonstrate a GaN-based gate driver with an overcurrent (OC) protection circuit and an undervoltage lockout (UVLO) circuit on a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -GaN gate power HEMT platform. The gate driver features a rail-to-rail output voltage, suppressed gate ringing, and tunable driving speed, all of which are highly desired in high-efficiency and high-speed GaN power systems. To offer timely but reliable protections, the OC protection and UVLO circuit are designed with reference to the switching speed and the threshold voltage of GaN power devices. The OC protection is implemented with a separated sensing branch and blanking time controller, and the response time to an OC event is reduced to 10 ns after the blanking time. The UVLO circuit has a fixed hysteresis of 0.5 V, and its threshold voltage is especially tailored for the GaN integrated circuits.

Overcurrent Protection Circuit for Engine Starting Mode of Range Extended Electric Vehicles

Overcurrent Protection Circuit for Engine Starting Mode of Range Extended Electric Vehicles

Research on Latching Current Limiter Circuit of Aerospace Power System

The input terminal of the aerospace power system is connected with surge suppression and overcurrent protection circuits. However, prior art methods have many demerits such as complex circuits, high surge currents, and slow response of overcurrent protection. Hence, this paper proposes a novel latching current limiter (LCL) circuit with both surge suppression and over-current protection functions. When over-current occurs, the circuit snap into the current limiting state within the adjustable time-delay period. When the over-current fault despairs during the time-delay period, the LCL circuit turns into the output lock state and rapidly lock down the output bus wire. Theoretical analysis of LCL circuit including the three operation states (i.e., the normal operation state, current limiting state and output lock state) and basic circuit equation derivation have been carried out. And the experimental platform is set up to validate the superior performance of the proposed LCL circuit. Results show that the proposed LCL circuit can effectively suppress the inrush current and sensitively respond the over-current fault of dc-link bus wire.

Open-source lab hardware: Driver and temperature controller for high compliance voltage, fiber-coupled butterfly lasers

This article describes the development of a compact, relatively low-cost, high compliance voltage laser driver that can provide the constant optical laser output required for a range of applications. The system contains an integrated, high-precision temperature controller that can be implemented with butterfly-style lasers containing an internal thermoelectric cooler. The laser parameters can be controlled manually or via an onboard microcontroller. Additionally, an adjustable over-current protection circuit safeguards the laser diode from potential damage.

Design a Half Bridge Inverter and a Full Bridge Inverter with Overload Protection Circuit Using IC555

Inverter is a power electronic circuit that converts the direct voltage (DC) to an alternating voltage (AC). Inverters are used in a range of applications from consumer electronics and industrial to renewable energy. The flexible capability to create an AC signal from a DC voltage, frequency and speed control are all accomplished from the use of Inverter. Inverter takes the voltage and passes it through switching elements which turn the DC signal into an AC square wave signal. This wave is then passes through filter which turns it into a sine wave signal of the required voltage. This paper presents design an inverter with overcurrent protection circuit without microcontroller, where the MOSFET gate driver is controlled by pulses generated from 555 timer, and with using a low pass filter and setup transformer, a low cost sine wave inverter has been obtained. The heart of the design is 555 timer. The design is achieved in Proteus 8. Simulation results demonstrated that a single phase sine wave (50 Hz) has been generated by a half bridge inverter and a full bridge inverter and protection circuit from current higher than 4.5A has been built. The reliability and accuracy of the system are verified through an experiment.

Design of new quick control power protection system of EAST

Aiming at the problems that may arise in the work of the AC-DC-AC converter of the new fast-control power system of the Experimental Advanced Superconducting Tokamak (EAST), a control and protection method for each link is proposed. Based on in-depth research on the protection mechanism of fast control power in the field of nuclear fusion, and combination with the needs of nuclear fusion devices, a surge current suppression circuit, a voltage protection circuit, an overcurrent protection circuit, an overt-emperature protection circuit, an energy leakage protection circuit, and a crowbar were designed. Compared with the traditional protection method, the scheme has a wide protection range, strong reliability and high security. The experimental results show that the power protection system can ensure safe and reliable exit of the power supply in the event of a sudden failure, and effectively protect the superconducting magnets and power components of the superconducting Tokamak experimental device from damage, verifying the correctness and effectiveness of the designed scheme.

Design and Experimental Demonstration of Integrated Over-Current Protection Circuit for GaN DC–DC Converters

This article reports the design and the first experimental demonstration of the monolithically integrated over-current protection (OCP) circuit in GaN power converters. The design criteria and protection time estimation methods are proposed. Through the GaN integration platform based on normally-OFF AlGaN/GaN metal insulator semiconductor high electron mobility transistors (MIS-HEMTs), the OCP circuit is monolithically integrated with the gate driver and GaN switches. At the over-current incident, the current sensing signal is compared with over-current thresholds, and then the generated protection action signal is clamped to disable the high-side gate driver and shut down the GaN dc-dc buck converter. The analysis of current paths, SPICE-based simulations, and numerical description of the protection process are carried out to support the proposed design criteria and estimation methods. The experimental results show that the GaN dc–dc buck converter can be protected within one duty cycle period according to the desired preset over-current thresholds. The consistent results of the calculated and measured time periods in the OCP process have verified the proposed design criteria and estimation methods. The proposed OCP circuit together with the analysis can help researchers to design and estimate the OCP process in integrated GaN power converters.

All-GaN Power Integration: Devices to Functional Subcircuits and Converter ICs

This article reports the Au-free GaN power integration platform and a complete integration scheme from devices to functional subcircuits and to application-oriented GaN converter ICs. The design and experimental demonstration of all-GaN dc-dc converter IC with high level of integration is presented. Through the developed GaN power integration platform, devices are monolithically integrated and functional subcircuits are demonstrated, which have realized expected application-oriented functions and are feasible for high-level integration. The all-GaN converter IC with monolithically integrated high-side gate driver, pulse-width modulation (PWM) feedback controller, and overcurrent protection circuits are proposed, numerically analyzed, experimentally demonstrated, and characterized. It can realize stable 10-V output with constant output ripples below 4% from 15-30-V input line voltage. Stable output with constant ripples can be maintained according to the designed feedback control when input and load conditions are abruptly changed. When subjected to over-current incident, the converter IC can be protected according to the desired over-current threshold values within one duty cycle period. The developed all-GaN power integration platform, together with functional subcircuits and dc-dc converter IC, can be a practical verification of all-GaN IC scheme oriented toward power conversion application, and a useful reference for all-GaN IC designs.

A simple and versatile overcurrent protection circuit for power MOSFETs

ABSTRACTThis paper proposes an overcurrent protection (OCP) circuit for power MOSFETs employed in low voltage power converters. The proposed configuration requires only discrete components with a gate driver IC and uses the voltage drop across the device for overcurrent detection. It can operate independently in cycle-by-cycle shutdown and multiple cycle shutdown modes. In coordination with a micro-controller based driver IC input signal generator and controller, the proposed OCP circuit can also operate in a single cycle latch-up and hiccup OCP modes. The performance of the proposed scheme is evaluated experimentally at both, hard and soft fault conditions. By experimentation, it is shown that the proposed circuit can operate in various protection modes and capable of protecting a MOSFET in both, hard and soft fault conditions.

An ultrafast overcurrent protection scheme for power MOSFETs switches

ABSTRACT Ultrafast overcurrent protection (OCP) prevents peak fault current reaching at a very high level and hence peak power dissipation and turn-off transient voltage stress on the power device are reduced. In this paper, a direct driver shutdown technique is proposed for ultrafast over current protection for power MOSFETs. The key advantage of this technique is that, delay due to logic gates and input control flip-flop is avoided and the response time of the OCP circuit is reduced. The analysis is presented to prove the concept. By simulation and experimentation, it is shown that the response is ultrafast and there is no spurious or recurrence of switching pulses from the driver IC output when it is directly shutdown before the input control flip-flop is reset. The operation of the proposed OCP circuit is verified under short-circuit condition by simulation as well as by experimentation. Response time of less than 100 ns and fault current clearance time of less than 180 ns are obtained.

Gate Driver with Overcurrent Protection Circuit for GaN Transistors

The improvement of the gate driver for GaN transistor is presented in this paper. The proposed topology contains the overcurrent protectionwith the two-stage turning off and independent control of turn on and off time of the GaN transistor. The operation of driver and its application in thehalf-bridge converter are described using both simulation and prototype measurements. The overcurrent protection was tested in Double Pulse Test(DPT) conditions.