Category | Protection Measures

Safety Characteristics of Film Capacitors

Posted on 01 July 2013

                    Self-healing The most important reliability feature of film capacitors is their self-healing capability, i.e. their ability to clear faults (such as pores or impurities in the film) under the influence of a voltage. The metal coatings, vacuum-deposited directly onto the plastic film, are only 20 [...]

DC link voltage with optimised dynamic feedback

Overvoltage Limitation for Power Transistors

Posted on 03 June 2013

                    Overvoltage limitation between main terminals Measures to limit overvoltages between main terminals (collector-emitter voltage, DC link voltage) can be divided into passive snubber networks, active clamping, and dynamic gate control. Irrespective of the type of overvoltage limitation, the avalanche operation mode of a MOSFET can [...]

Fault Current Detection and Reduction in Converter Circuits

Posted on 08 May 2013

              Errors in converter circuits may be detected at various points. The responses to detected errors, however, may be very different. The term fast protection is used if an error signal is detected in the switch or in close vicinity to the switch and the respective switch is turned [...]

Basic Considerations for Semiconductor Protection with Fuses

Posted on 23 April 2013

              Solid state devices have progressed through several generations of sophistication since their introduction in the 1940s. Fuse designs have changed to match solid state protection demands. The protection task seems simple - choose a fuse of correct voltage and ampere rating which will protect a solid state device [...]

Solar Power System Control and Safety

Posted on 20 March 2013

  The Copenhagener climatic conference in 2009 and the earlier Kyoto protocol (adopted in 1997 and enforced as of 2005) committed different national governments to decrease their CO2 emissions. One of the possible ways to achieve these goals is to increase the production of sustainable energy and to issue a grant for every initiative taken. [...]

Epcos PTC thermistor

PTC Thermistors for Overcurrent Protection

Posted on 15 March 2013

              As to their possibilities of application, PTC thermistors (Positive Temperature Coefficient thermistors) can be divided in the following manner: 1. By Function 2. By Application Ceramic PTC thermistors are used instead of conventional fuses to protect loads such as motors, transformers, etc., or electronic circuits against overcurrent. They [...]

Switching Loss Reduction Networks - Snubber Circuits

Posted on 06 March 2013

              Power electronic switches with conventional thyristors or GTOs require snubber circuits in order to guarantee operation within the safe operating area, i.e., these networks are indispensable if the components are to live up to their basic functions during switching. In contrast to this, the SOA (Safe Operating Area) [...]

Protection and monitoring functions for IGBT and MOSFET modules

Posted on 14 February 2013

              To protect MOSFET or IGBT modules in the event of malfunction/errors, the use of different efficient, quick-response protection functions in the driver is recommended; for example, overcurrent and short circuit protection, protection from excessive drain-source or collector-emitter voltage, gate overvoltage protection, overtemperature protection and monitoring of the gate [...]

Types of Faults for IGBT and MOSFET Modules

Posted on 06 February 2013

              Power semiconductors have to be protected from non-permissible stress in every operational state. Leaving SOAs (Safe Operating Areas) leads to damage and therefore reduces component's life. In the worst case scenario, the component will be immediately destroyed. This is why it is important to detect critical states and [...]

SC II characteristics of an IGBT with external dynamic gate voltage limitation

Overload and Short Circuit Behavior of IGBTs and MOSFETs

Posted on 28 January 2013

                    Overload Essentially, the switching and on-state behavior of IGBTs and MOSFETs under overload does not differ from "standard operation" under rated conditions. In order not to exceed the maximum junction temperature and to ensure safe operation, the overload range has to be restricted since increased [...]