摘要:
An electrical configuration contains at least one submodule which has a first and a second outer electrical terminal. The configuration further has a bypass switching device, which is electrically connected between the first and second terminals and in the on-state causes an electrical short-circuit in at least one current flow direction between the two outer terminals. The bypass switching device has a thyristor with an anode terminal, a cathode terminal and a trigger terminal and is connected by its anode terminal to one of the two outer terminals and by its cathode terminal to the other of the two outer terminals. A triggering device is connected to the trigger terminal of the thyristor for triggering the thyristor, and a switch is provided which in the on-state connects the anode terminal of the thyristor to the trigger terminal of the thyristor.
摘要:
A two-wire load control device (such as, a dimmer switch or an electronic switch) for controlling power delivered from an AC power source to an electrical load includes a thyristor for controlling the power to the load, a gate coupling circuit electrically coupled to a gate terminal of the thyristor, a control circuit configured to control the thyristor to turn the load on or off, and a power supply configured to conduct current through the electrical load to generate a supply voltage across a capacitor when the thyristor is non-conductive. When the electrical lead is on, the control circuit is configured to maintain the thyristor non-conductive after a beginning of each half-cycle until the magnitude of the supply voltage exceeds a predetermined threshold.
摘要:
An apparatus for controlling a converter has an ignition unit connected to power semiconductors in the converter and provides control signals for actuating the semiconductors. The apparatus has a control unit whose input is connected to measuring sensors providing actual values and whose output side is connected to the ignition unit. The control unit provides a reference variable for the ignition unit based on setpoint values and the actual values and the ignition unit actuates the power semiconductors such that the actual value corresponds to at least one of the setpoint values. A pilot unit has an output connected to the ignition unit and measures for calculating a step change reference variable for the ignition unit on the basis of at least one of the setpoint values. The ignition unit actuates the power semiconductors based on the step change reference variable.
摘要:
An auxiliary quasi-resonant dc tank (AQRDCT) power converter with fast current charging, voltage balancing (or charging), and voltage clamping circuits is provided for achieving soft-switched power conversion. The present invention is an improvement of the invention taught in U.S. Pat. No. 6,111,770, herein incorporated by reference. The present invention provides faster current charging to the resonant inductor, thus minimizing delay time of the pulse width modulation (PWM) due to the soft-switching process. The new AQRDCT converter includes three tank capacitors or power supplies to achieve the faster current charging and minimize the soft-switching time delay. The new AQRDCT converter further includes a voltage balancing circuit to charge and discharge the three tank capacitors so that additional isolated power supplies from the utility line are not needed. A voltage clamping circuit is also included for clamping voltage surge due to the reverse recovery of diodes.
摘要:
An inductance in a path (R1) from a gate electrode (3G) of a GTO (3) through a gate driver (4) and a node (13) to a cathode electrode (3K) is determined so that a turn-off gain may be not more than 1. At a turn-off, a main current (I.sub.A) is entirely commutated from the gate electrode (3G) towards the node (13) through the gate driver (4) in a direction reverse to a turn-off control current (I.sub.G) A peak voltage suppressing circuit (5) clamps an anode-cathode voltage (V.sub.A-K) which rises on, to a prescribed voltage value for a prescribed time. This prevents losses caused by a snubber circuit. Commutation of a main current to the gate prevents locally concentrating in the cathode side of the semiconductor switching element, to thereby increase the turn off capability of the semiconductor switching element. Further, this prevents or reduces dissipation of large amount produced by a discharge of the electric charges from a snubber capacitor. Thus, reduction in dissipation and in size of the whole apparatus can be achieved.
摘要:
A commutating circuit in combination with a snubber circuit are employed to switch a thyristor from a conducting state to a non-conducting state. The snubber circuit is connected across the cathode and anode of the thyristor to absorb system energy when the thyristor is switched. The commutating circuit is coupled in series with the cathode of the thyristor by means of a current transformer for increasing the cathode resistance, causing the cathode current to immediately transfer to the gate.
摘要:
This invention concerns a procedure to operate a turn-off thyristor which can be set to a current-conducting state or a current-blocking state as a function of a switch-on command or a switch-off command. To permit particularly reliable and optimal operation of the turn-off thyristor, the voltage between its gate terminal, G, and its cathode terminal, K, is detected and when it drops below a negative threshold current value U.sub.GKS, a status signal, Z, is generated which indicates the current-blocking state of the turn-off thyristor. A further embodiment detects the gate current of the turn-off thyristor and after the appearance of the switch-off command, the status signal is generated as the polarity changes in accordance with the time derivative of the gate current. An overload of the turn-off thyristor is best recognized by having simultaneous to the appearance of the switch-off command, a time function with a preset expiration time initiated, and having a malfunction notification signal, F, generated for protective ignition of the turn-off thyristor if the time function expires prior to the appearance of the status signal.
摘要:
A power converter including a plurality of serially connected self-turn-off semiconductor elements, including a first control circuit for producing a plurality of control signals, and a plurality of second control circuits is connected to receive respective of the control signals to supply a non-conduction control signal to a respective of the self-turn-off semiconductor elements to turn off the respective semiconductor element. The power converter further includes a plurality of failure detectors and blocking circuits. Each of the failure detectors is connected to a respective of the self-turn-off semiconductor elements for detecting a fault thereof to produce a fault detection signal when the respective self-turn-off semiconductor elements has failed. Each of the blocking circuits is connected to the respective failure detector and to the first control circuit for blocking either the respective control signal or the respective non-conduction control signal based on the respective fault detection signal.
摘要:
A parallel connected gate turn-off thyristor device including an additional short circuiting conductor connected between the gate terminals of the respective gate turn-off thyristors so as to bypass a part of the turn-on and turn-off gate currents of one gate turn-off thyristor to other gate turn-off thyristors to increase the turn-on and turn-off gate currents of the other gate turn-off thyristors thereby hastening the turn-on and turn-off operations of the other gate turn-off thyristors.
摘要:
An integratable circuit for controlling the turn-off time-rate-of-voltage-change of a non-regenerative power switching device (such as a field-effect transistor, an insulated gate transistor and the like) uses a single capacitive element, in conjunction with a first current source, to provide a ramp voltage generator which is operative only if a ramp generator terminal is disconnected from a circuit common potential. The circuit uses a second current source and a controlled-conduction device to provide a control electrode drive signal to the at least one power switching device, controlling the flow of current through a load from a unipolarity or bipolarity source. The voltage across the controlled-conduction circuit of the power switching device then active is applied in attenuated form to another input of the ramp voltage generator to control the load voltage time-rate-of-change during load current turn-off.