Abstract: A DC/DC power converter comprises three or more capacitors connected in series between an output terminal and a ground terminal, the three or more capacitors being connected in series by means of two or more capacitor connection points, and an input voltage switching unit configured to connect an input terminal to one of a group of switching connection points, the group of switching connection points comprising the two or more capacitor connection points and the output terminal. With such a DC/DC power converter it is possible, for example, to convert a variable DC voltage at the input into a variable DC voltage at the output, wherein the voltage range of the output voltage is smaller than the voltage range of the input voltage.

Abstract: A DC/DC power converter comprises three or more capacitors connected in series between an output terminal and a ground terminal, the three or more capacitors being connected in series by means of two or more capacitor connection points, and an input voltage switching unit configured to connect an input terminal to one of a group of switching connection points, the group of switching connection points comprising the two or more capacitor connection points and the output terminal. With such a DC/DC power converter it is possible, for example, to convert a variable DC voltage at the input into a variable DC voltage at the output, wherein the voltage range of the output voltage is smaller than the voltage range of the input voltage.

Abstract: A DC/DC power converter comprises three or more capacitors connected in series between an output terminal and a ground terminal, the three or more capacitors being connected in series by means of two or more capacitor connection points, and an input voltage switching unit configured to connect an input terminal to one of a group of switching connection points, the group of switching connection points comprising the two or more capacitor connection points and the output terminal. With such a DC/DC power converter it is possible, for example, to convert a variable DC voltage at the input into a variable DC voltage at the output, wherein the voltage range of the output voltage is smaller than the voltage range of the input voltage.

Abstract: A DC/DC power converter has an input terminal, an output terminal, and a ground terminal. The DC/DC power converter includes two capacitors connected in series between the output terminal and the ground terminal, a boost converter having a first boost converter terminal connected to the input terminal, a second boost converter terminal connected to the output terminal, and a third boost converter terminal connected to a connection point between the capacitors, and a step-up converter having a first step-up converter terminal connected to the ground terminal, a second step-up converter terminal connected to the output terminal, and a third step-up converter terminal connected to the connection point.

Abstract: A DC/DC power converter comprises three or more capacitors connected in series between an output terminal and a ground terminal, the three or more capacitors being connected in series by means of two or more capacitor connection points, and an input voltage switching unit configured to connect an input terminal to one of a group of switching connection points, the group of switching connection points comprising the two or more capacitor connection points and the output terminal. With such a DC/DC power converter it is possible, for example, to convert a variable DC voltage at the input into a variable DC voltage at the output, wherein the voltage range of the output voltage is smaller than the voltage range of the input voltage.

Abstract: A DC/DC power converter has an input terminal, an output terminal, and a ground terminal. The DC/DC power converter comprises two capacitors connected in series between the output terminal and the ground terminal, a boost converter having a first boost converter terminal connected to the input terminal, a second boost converter terminal connected to the output terminal, and a third boost converter terminal connected to a connection point between the capacitors, and a step-up converter having a first step-up converter terminal connected to the ground terminal, a second step-up converter terminal connected to the output terminal, and a third step-up converter terminal connected to the connection point.

Abstract: The invention relates to a current-source power converter comprising, in a module thereof , switching legs having normally-on field effect transistors each controlled by a gate control device. A normally-open auxiliary switch is in series with the switching legs and connected to the positive line of the power supply bus. This auxiliary switch can prevent the mains from short-circuiting during start-up or during malfunction of the auxiliary power supply.

Abstract: The invention relates to a gate control device for a JFET-type transistor that has a gate, a drain and a source. The gate control device includes a voltage generation circuit comprising an output connected to the gate of the transistor, where the circuit is designed to generate at the output a reference gate-source voltage following a predetermined voltage ramp. A voltage limiting circuit is designed to limit the reference gate-source voltage to a predetermined maximum value when the gate-source voltage at the terminals of the JFET transistor has reached said maximum value.

Abstract: A method for managing the temperature implemented in a speed controller that includes several modules, each including a case containing a power semiconductor that provides a pulsed voltage to an electrical load, each module being characterized by a junction temperature, a heat sink, and a temperature sensor mounted on the heat sink. The method for a module includes estimating a case temperature based on a predetermined thermal model of the sink, a temperature measured by the sensor and average power losses that the module undergoes, the predetermined thermal model of the sink integrating the thermal transfer impedances representing the thermal influence of one module on another and vice versa; determining a junction-case temperature based on the case temperature of the module and a limiting value of the junction temperature; and limiting the junction-case temperature obtained to a predetermined limiting value of the junction-case temperature.

Abstract: The invention relates to a variable speed drive comprising a direct-current power bus having a positive line (16) and a negative line (17), and an inverter module (14) supplied by the direct-current bus in order to supply a variable voltage to an electric load (M). The drive comprises an energy-recovery device (10) comprising a first direct-current/direct-current converter (20), the output stage of the first converter (20) being connected in series to the positive line of the direct-current bus, a second direct-current/direct-current converter (30), the input stage of the second converter (30) being connected between the positive line and the negative line of the direct-current bus, and an electric energy storage module (Cs) connected in parallel with the input stage of the first converter (20) and with the output stage of the second converter (30).

Abstract: A variable-frequency drive that includes a DC power supply bus with a positive line and a negative line, and an inverter module powered by the DC bus for supplying a variable voltage to an electric load. The inverter includes a first DC/DC converter including output terminals connected in series on the positive line of the DC bus, a second DC/DC converter including input terminals connected between the positive line and the negative line of the DC bus, a filtering capacitor connected in parallel to the input terminals of the first converter and to the first output terminals of the second converter, and an electric power storage module connected in parallel to the second output terminals of the second converter.

Abstract: The invention relates to a power converter comprising, in particular, a rectifier comprising at least one switching leg provided with two transistors (T1-T6) connected in series. The transistors (T1-T6) are of the normally ON field-effect type, for example JFETs, and are each controlled by a gate control device (CT1-CT6). Each gate control device comprises, in particular: an output (OUT1) connected to the gate (G) of the controlled transistor, a voltage rectifier element connected between the output of the control device and an input (in1, in3) of the converter, a capacitor (C11) connected between the source (S) of the transistor and a point situated between the output of the control device and the voltage rectifier element.

Abstract: A variable-frequency drive that includes a DC power supply bus with a positive line and a negative line, and an inverter module powered by the DC bus for supplying a variable voltage to an electric load. The inverter includes a first DC/DC converter including output terminals connected in series on the positive line of the DC bus, a second DC/DC converter including input terminals connected between the positive line and the negative line of the DC bus, a filtering capacitor connected in parallel to the input terminals of the first converter and to the first output terminals of the second converter, and an electric power storage module connected in parallel to the second output terminals of the second converter.

Abstract: The invention relates to a current-source power converter comprising, in its rectifier module (20) and/or its inverter module, switching legs equipped with normally-on field effect transistors (T1-T6, Q1-Q6) each controlled by a gate control device (CT1, CT2). The invention has the particular feature of a normally-open auxiliary switch (SW) placed in series with the switching legs and connected to the positive line (10) of the power supply bus. This auxiliary switch is intended to prevent the mains (R) from short-circuiting during start-up or during malfunction of the auxiliary power supply (AUX).

Abstract: The invention relates to a variable speed drive comprising a direct-current power bus having a positive line (16) and a negative line (17), and an inverter module (14) supplied by the direct-current bus in order to supply a variable voltage to an electric load (M). The drive comprises an energy-recovery device (10) comprising a first direct-current/direct-current converter (20), the output stage of the first converter (20) being connected in series to the positive line of the direct-current bus, a second direct-current/direct-current converter (30), the input stage of the second converter (30) being connected between the positive line and the negative line of the direct-current bus, and an electric energy storage module (Cs) connected in parallel with the input stage of the first converter (20) and with the output stage of the second converter (30).

Abstract: The invention relates to a gate control device for a JFET-type transistor comprising a gate, a drain and a source, said device comprising: a voltage generation circuit (11) comprising an output (out2) connected to the gate (G) of the transistor, said circuit being designed to generate at the output a reference gate-source voltage (VREF) following a predetermined voltage ramp, a voltage limiting circuit (12) designed to limit the reference gate-source voltage (VREF) to a predetermined maximum value (VGS—max) when the gate-source voltage (VGS) at the terminals of the JFET transistor has reached said maximum value.

Abstract: The invention relates to a power converter comprising, in particular, a rectifier comprising at least one switching leg provided with two transistors (T1-T6) connected in series. The transistors (T1-T6) are of the normally ON field-effect type, for example JFETs, and are each controlled by a gate control device (CT1-CT6). Each gate control device comprises, in particular: an output (OUT1) connected to the gate (G) of the controlled transistor, a voltage rectifier element connected between the output of the control device and an input (in1, in3) of the converter, a capacitor (C11) connected between the source (S) of the transistor and a point situated between the output of the control device and the voltage rectifier element.

Abstract: The invention relates to a switched-mode power supply system comprising two buffer capacitors connected in series and connected between the two input terminals of a DC input voltage source, two switches connected in series, a primary inductive assembly connected in series with the two switches, and a secondary winding magnetically coupled to the primary inductive assembly in order to deliver a DC output voltage. A current injection module injects current at a mid-point of the two buffer capacitors in order to generate a current imbalance at this mid-point. A balancing circuit for balancing the leakage currents of the capacitors, one end of said balancing circuit being connected to the mid-point of the buffer capacitors, maintains this imbalance at a predetermined value. The invention also relates to a speed variator using such a power supply system.

Abstract: The present invention relates to a method for managing the temperature implemented in a speed controller (1), said speed controller comprising: several semiconductor power modules (M1, M2, M3); a heat sink (2) to dissipate the heat generated by each module (M1, M2, M3); a temperature sensor (SN) mounted on the heat sink (2); said method being characterized in that for a module (M1) it consists in: estimating the case temperature (TC—U) of the module based on a predetermined thermal model of the sink (2), a temperature (TSN) measured by the sensor (SN) and average power losses (PAV) that the module undergoes; determining a junction-case temperature (TJC); and limiting the junction-case temperature (TJC) obtained to a predetermined limiting value (TJCmax) of the junction-case temperature.

Abstract: A variable speed drive for a three-phase electric motor, including a rectifier module supplying a rectified voltage from a single-phase alternating current network, a voltage step-up module supplying a regulated bus voltage, and an inverter module supplying a control voltage to the motor. The variable speed drive includes a hybrid power-factor correction device that drives the voltage step-up module and that includes a digital circuit including a voltage step-up module supplying a correction signal based on a measurement signal of the bus voltage and an analog circuit supplying a driver signal to the step-up module based on a measurement signal of the rectified voltage and based on the correction signal.