0000000000082392
AUTHOR
Jose Jordan
Power system consumption model using SPICE
Space missions have very stringent mass, volume and also power budgets. This requires very precise knowledge of the power consumption of the whole satellite, not only peak power but also static and long term dynamic power. This calculation becomes very complex if all the operational modes (long term dynamic changes) are taken into account, including the different environmental situations. The power budget of any Power Converter Module (PCM), which includes not only the DC/DC converter but also the distribution unit, depends on the power it delivers and on external factors like temperature and input voltage. We propose to use a linear SPICE model using electronic models of discrete component…
On the design of a multiple-output DC/DC converter for the PHI experiment on-board of solar orbiter
Power converters for experiments that have to fly on board space missions (satellite, launchers, etc.) have very stringent requirements due to its use in a very harsh environment. The selection of a suitable topology is therefore not only based on standard requirements but additional more strict ones have also to be fulfilled. This work shows the design procedure followed to build the Power Converter Module (PCM) for the Polarimetric and Helioseismic Imager (SO/PHI), experiment on board the Solar Orbiter Satellite. The selected topology has been a Push-Pull, for a power level of approximately 35 W and with seven output voltages. Galvanic isolation is needed from primary to secondary, but no…
Novel test bed for induction heating power supplies
Power supplies used in induction heating industrial applications must be entirely tested after its manufacturing in order to assure its security and reliability by means of a full power running test of several hours of duration. Nowadays this test is done with a dissipative load which implies a large waste of energy. This paper proposes a new high efficiency test system for induction heating generators. It incorporates a regenerative electronic load which allows an extraordinary improvement of the efficiency of this test with an important economical and ecological benefit.
Efficiency comparison between SiC- and Si-based active neutral-point clamped converters
This paper presents an efficiency comparison between silicon-carbide technology and silicon technology. In order to achieve this, the efficiency of an active neutral-point clamped converter built up with silicon carbide power-devices is compared with the efficiency of an active neutral-point clamped converter built up with silicon power-devices, under a particular operating mode and a particular selection of devices. Firstly, overall losses of both converters are estimated. Then, experimental tests are carried out to measure their overall losses and efficiency. Finally, experimental results are compared with the estimations to support the analysis. The efficiency of the SiC converter is hig…
Failure Rate Measurement on Silicon Diodes Reverse Polarized at High Temperature
This paper calculates the failure rate on reversed polarized silicon diodes with the aim to justify, experimentally, the rules of the European Space Agency (ESA) which are referred to the component life’s extension, the reliability increase and the end of life performance enhancement, by using oversized devices (derating rules). In order to verify the derating rules, 80 silicon diodes are used, which are reverse polarized in a high temperature environment. The diodes are divided in 4 groups of 20 diodes, applying a different voltage to each group, in order to relate the failure rate to the applied derating rule. The experiment described in this paper is developed using a temperature acceler…
Optimized Topology for High Efficiency Battery Discharge Regulator
In the following years power levels of 20 kW to 50 kW will be demanded by the telecommunication satellites. It is not possible to keep 0.5 kW modules with up to 100 modules in parallel and, therefore, higher power modules must be used. A higher bus voltage seems also necessary and any voltage below 150 V and above 100 V could meet the needs. In addition, new optimized topologies that process only a part of the total power delivery can be employed to improve the efficiency. In this article, design guidelines and experimental results of a high efficiency battery discharge regulator (BDR) module based on parallel power processing are given.
Output Impedance Improvement Using Coupled Inductors
When using a single DC/DC converter with multiple outputs and having a buck topology, which has one filter inductor per output, the designer can choose to couple these outputs together. This paper demonstrates additional benefits of coupling output inductors together. Apart from saving mass and volume, and due to an improved small signal behaviour it also reduces the output impedance of the regulated output. The paper will analyse a seven output push-pull converter used as a space power converter module and verify the theoretical results with experimental measurements.
Soft switched interleaved boost converters used as high-power battery discharge regulator for space power systems
In the following years the telecommunication satellites will have a much greater power demand than nowadays. One reason for this is that the geostationary orbit required by this kind of satellites is becoming too crowded. Probably power levels of l0 kW to l00 kW will be the standard and with life duration of 25 years. It is not possible to keep 0.5 kW modules with more than 100 in parallel and therefore higher power modules (5 kW) must be used. A higher bus voltage seems also necessary and keeping a safety limit of 150 V, any voltage below it and above 100 V could meet the needs. In this paper we will propose a topology that fits the application: two soft switched interleaved boost converte…
Bidirectional High-Efficiency Nonisolated Step-Up Battery Regulator
The design and results of a high-efficiency high-power (5 kW) nonisolated bidirectional dc-dc converter is presented. High stability due to minimum phase behavior is an additional benefit of the topology. The converter is a new boost with output filter where input and output inductors are coupled. This converter is useful with any system that needs to charge and discharge backup batteries and can be applied in space, automotive, and telecom power systems.
Unstable behaviour of normally-off GaN E-HEMT under short-circuit
The short-circuit capability of power switching devices plays an important role in fault detection and the protection of power circuits. In this work, an experimental study on the short-circuit (SC) capability of commercial 600 V Gallium Nitride enhancement-mode high-electron-mobility transistors (E-HEMT) is presented. A different failure mechanism has been identified for commercial p-doped GaN gate (p-GaN) HEMT and metal-insulator-semiconductor (MIS) HEMT. In addition to the well known thermal breakdown, a premature breakdown is shown on both GaN HEMTs, triggered by hot electron trapping at the surface, which demonstrates that current commercial GaN HEMTs has requirements for improving the…
Study of the Audio Susceptibility in Parallel Power Processing With a High-Power Topology
In this paper, the audio susceptibility characteristic of a high-efficiency nonisolated topology that processes only a part of the total power delivery is analyzed. Since the proposed topology presents a direct path from input to output, the effect of the input voltage ripple at the output voltage has been studied. The effect on the audio susceptibility of the values and disposition of the components and the effect of their parasitic elements must be taken into account. Due to this study, the analytical expression of the audio susceptibility and the design criteria to improve it have been obtained.
Bidirectional high-power high-efficiency non-isolated step-up DC-DC converter
This paper presents the results of a high-efficiency high-power (5kW) non-isolated bidirectional DC-DC converter. High efficiency, high stability and simplicity are the main goals, and no galvanic isolation is required. The proposed topology is a new BOOST converter with output filter where input and output inductors are coupled together which can be designed to be a minimum phase system. This topology provides therefore input and output current filtering, reducing noise and need of additional filters. Its bidirectionality reduces mass in many applications like in charge/discharge subsystems and lowers cost and component count. This converter is useful with any system that needs backup batt…
Stability improvement of isolated multiple-output DC/DC converter using coupled inductors
Coupling output inductors is a very popular solution when designing a multiple-output DC/DC system. Space-borne circuits are one of the areas where a custom DC/DC converter design with coupled inductors could be preferred to have a detailed design of all variables. Output voltage regulation can be improved using coupled output inductors on a multiple-output DC/DC converter, and, as demonstrated in this paper, it provides an enhanced stability. This paper presents the small signal analysis of a push-pull converter with seven outputs having all its output inductors coupled together and compares it theoretically to the uncoupled version to demonstrate the stability improvement. The theoretical…
A Comparative Performance Study of a 1200 V Si and SiC MOSFET Intrinsic Diode on an Induction Heating Inverter
This paper presents a comparison of the behavior of the intrinsic diode of silicon (Si) and silicon carbide (SiC) MOSFETs. The study was done for 1200 V Si and SiC MOSFETs. The data sheet from manufacturers shows the characteristics of MOSFET' intrinsic diode when gate source voltage (VGS) is 0 V. There are applications where the MOSFET' intrinsic diode is used while VGS is different than 0 V. One of these applications is induction heating, where depending on the load and the regulation system, the diode can conduct a significant part of the inverter current. In most applications which use the MOSFET' intrinsic diode, the turn ON of the intrinsic diode happens at VGS = 0 V. After a blanking…
25-kW/50-kHz generator for induction heating
The authors present the features, technology, and construction of a transistorized generator for induction heating operating over the 4-50 kHz frequency range. This type of 25 kW output-power generator allows replacement of the electronic tube generators for most of their applications. The advantages of this new generator are more energy efficiency, extended life, reduced size, separated heating station of the generator, and connection by flexible cable. In addition, the generator has incorporated a frequency automatic tracking system that allows operating without any adjustments over a wide frequency range. >
Phase Margin Degradation of a Peak Current Controlled Converter at Reduced Duty Cycle
An inner current loop is frequently used in many switching power supplies to achieve higher stability and a good current sharing. Nevertheless, some problems derived from its practical implementation can be encountered. One problem is related to the need of filtering of the sensed current and was discovered by the authors in the implementation of a 500 W converter, when peak current control was applied by sensing the switch current. This paper will demonstrate mathematically that an RC filter not only filters out the noise but also can cause a degradation of the phase margin, especially, if the needed duty cycle is close to zero. The main reason for it is the severe distortion of the curren…
Series and parallel resonant inverters for induction heating under short-circuit conditions considering parasitic components
Series and parallel resonant inverters are the common structures in high power industrial generators for induction heating applications. In practical working conditions, short-circuit of the heating coil is very common, normally producing overvoltages that can damage the power transistors of the inverter if no special precautions are taken. The aim of the paper is to show the mechanism of how overvoltages are generated under short-circuit conditions of the heating coil for series and parallel inverters.
High Temperature SiC Blocking Diodes for Solar Array
This paper presents the results of an experimental investigation of the performance of 300V-5A Silicon Carbide Ni and W Schottky diode operating in the range between -170°C to 270°C. We have developed these diodes as blocking diodes, for solar cell array protection in order to fulfill the BepiColombo mission specifications. An electro-thermal characterization has been performed taking into account the harsh condition of the mission (high temperature range and electrical stress). The destructive and non-destructive tests have assured that the designed SiC diodes are able to support the electro-thermal limits. A reliability test has also been performed to investigate the stability of forward …
Using Pulse Density Modulation to Improve the Efficiency of IGBT Inverters in Induction Heating Applications
This paper analyses a high power (50 kW), high frequency (150 kHz) voltage fed inverter with a series resonant load circuit for industrial induction heating applications which is characterized by a full bridge inverter made with IGBT and the power control based on pulse density modulation (PDM). This power control strategy allows that the inverter works close to the resonance frequency for all output power levels. In this situation zero-voltage switching (ZVS) and zero-current switching (ZCS) conditions are performed and the switching losses are minimized. The results are verified experimentally using a prototype for induction hardening applications. A comparative study between the PDM and …
Design considerations for transformerless series resonant inverters for induction heating
The aim of the paper is to present some preliminary ideas in order to overcome the output transformer in series resonant inverters for induction heating applications. By adding a third reactive element to the conventional two element resonant inverter, the output matching transformer can be eliminated, allowing accommodation of the resonant frequency and load with the only drawback being the need for an overdimensioning of the output capacitor bank, and benefiting from inherent short-circuit protection.
Test bench for coupling and shielding magnetic field
This paper describes a test bench for training purposes, which uses a magnetic field generator to couple this magnetic field to a victim circuit. It can be very useful to test for magnetic susceptibility as well. The magnetic field generator consists of a board, which generates a variable current that flows into a printed circuit board with spiral tracks (noise generator). The victim circuit consists of a coaxial cable concentric with the spiral tracks and its generated magnetic field. The coaxial cable is part of a circuit which conducts a signal produced by a signal generator and a resistive load. In the paper three cases are studied. First, the transmitted signal from the signal generato…