Abstract:
A voltage source converter (30) comprises: a converter limb (36) extending between first and second DC terminals (32,34) and having first and second limb portions (38,40) separated by an AC terminal (42), the first and second DC terminals (32,34) being connectable to a DC electrical network (44) and the AC terminal (42) being connectable to an AC electrical network (46), each limb portion (38,40) including a primary switching element (48), the primary switching element (48) of each limb portion (38,40) being switchable to switch the corresponding limb portion (38,40) into and out of circuit between the corresponding DC terminal (32,34) and the AC terminal (42) to control the configuration of an AC voltage at the AC terminal (42); an auxiliary limb (50) including an auxiliary converter, the auxiliary converter including at least one auxiliary switching element, the auxiliary limb (50) being connected to the AC terminal (42), the primary switching element (48) of each limb portion (38,40) being switchable to switch the auxiliary limb (50) into and out of circuit with the corresponding limb portion (38,40) and thereby switch the auxiliary limb (50) into and out of circuit with the corresponding DC terminal (32,34); and a control unit to selectively control the switching of the or each auxiliary switching element of the auxiliary converter to control the auxiliary limb (50) as a current source in a primary operating mode to inject a circulation current (68) that flows in one direction in one of the first and second limb portions (38,40) to minimise a limb portion current (66) flowing in the opposite direction in that limb portion (38,40), wherein each primary switching element (48) switches the respective limb portion (38,40) into or out of circuit between the corresponding DC terminal (32,34) and the AC terminal (42), following the minimisation of the limb portion current (66) by the circulation current (68), when a minimal or zero current flows through the corresponding primary switching element (48) during the commutation of current from one of the first and second limb portions (38,40) to the other of the first and second limb portions (38,40).
Abstract:
A dimmer switch (110-x, 200, 400, 600, 700A, 700B,1200) adapted to be coupled to an alternating current (AC) source and to a load so as to control an amount of power delivered from the AC source to the load, the dimmer switch may include: a triode for AC (TRIAC) (208, 408, 612) coupled between the AC source and the load, and which when triggered conducts to deliver a controlled amount of power from the AC source to the load for a corresponding half-cycle of one or more half cycles of the AC source. The dimmer switch may include first and second triggering circuits (606, 608) configured to trigger the TRIAC when charged after being enabled. One or more of the triggering circuits may be a self-balancing triggering circuit. The dimmer switch may further include a controller (412, 602, 1210) which selects and thereafter enables one or more of the first or second triggering circuits.
Abstract:
The present invention discloses a method for controlling the turning-off process of a soft switch, when any of the main power switching tubes in the soft switch need to be turned off, comprising: turning on the auxiliary switching tube located in a different position on the bridge arm from the main power switching tube to be turned off, inputting energy to the LC second-order resonant circuit, and determining the energy inputting end moment satisfying the condition that the maximum value of resonant current equals the present load current; when the energy inputting end moment comes, stopping the energy input and turning off the auxiliary switching tube located in a different position on the bridge arm from the main power switching tube to be turned off, and turning on the auxiliary switching tube located in the same position on the bridge arm as the main power switching tube to be turned off; determining the moment when the resonant current is zero, and after 1/4 resonance cycle from this moment, simultaneously turning off the auxiliary switching tube located in the same position on the bridge arm as the main power switching tube to be turned off and the main power switching tube to be turned off. The present invention also discloses a soft switch. Use of the technical solution of the present invention can reduce the extra loss during the turning-off process of the soft switch.
Abstract:
The invention relates to a circuit arrangement for a converter (1) with switches (S1, S2) for chopping a DC voltage U1 into a chopped DC voltage U3, comprising control means for controlling the switch-on times of the switches (S1, S2), in which switch-on times of the switches (S1, S2) alternate with each other and are separated from each other by dead-time phases Ttot, and circuit elements comprising a resonant circuit having at least one capacitor (Cr) and at least one coil (Lr) for converting the chopped DC voltage U3 into an output voltage U2. To ensure a reliable and interference-free ZVS operation of such a circuit, a circuit arrangement and a method of operating such a circuit arrangement are proposed in which a value for the energy/charge remaining in the resonant circuit for switching the switch in the inductive mode of operation is determined and compared with a threshold value by means of a comparator (24), and in which the switches (S1, S2) are controlled in dependence upon the comparison result.
Abstract:
본 발명은 교류를 직류로 또는 직류를 교류로 변환하는 3-레벨 컨버터에서 매 스위칭 주기마다 직류측 전류가 평균적으로 일정하게 되도록 펄스폭 변조(PWM) 방식으로 제어할 수 있도록 하는, 3-레벨 컨버터의 직류측 전류를 일정하게 만드는 PWM 제어방법 및 장치에 관한 것이다. 이를 위한 PWM 제어장치는, 3-레벨 컨버터가 발생하기를 원하는 교류측 단자전압의 명령(command)에 해당하는 3상 기준파 신호를 입력받고, 입력받은 3상 기준파 신호로부터 각 상의 변조함수(d a , d b , d c )를 발생시키는 변조함수 발생기; 상기 변조함수 발생기에서 발생된 각 상의 변조함수(d a , d b , d c )로부터 각 상의 NP-스위치의 듀티비(duty ratio)(d a0 , d b0 , d c0 )의 범위를 산출하고, 산출된 범위들의 공통 교집합으로부터 d a0 =d b0 =d c0 =d 0 가 되는 d 0 값을 결정하는 d 0 발생기; 상기 각 상의 변조함수(d a , d b , d c )와, 상기 결정된 d 0 의 값을 이용해서 일의적으로 정해지는 각 상의 듀티비(d ap , d an , d bp , d bn , d cp , d cn )를 결정하는 듀티비 발생기; 및 상기 각 상의 듀티비로부터 각 상의 IGBT를 턴 온 및 턴 오프하기 위한 게이팅 신호를 발생시키는 케이팅 신호 발생기를 포함할 수 있다.
Abstract:
Gleichrichter-Vorrichtung (20) zum Gleichrichten eines m-phasigen Wechselsignals, die m Gleichrichterschaltungen (40. m) umfasst, mit m als ganze Zahl ≥ 1. Die m Gleichrichterschaltungen (40. m) sind parallel zueinander angeordnet und sie umfassen eine Serienschaltung eines positiven Schaltungsbereichs (14) und eines negativen Schaltungsbereichs (15). Knoten (a1, a2, a3) dienen zum Einspeisen einer Phase des m-phasigen Wechselsignals an einem Verbindungsleiter (16, 17, 18), der sich zwischen dem positiven Schaltungsbereich (14) und dem negativen Schaltungsbereich (15) befindet. Mindestens eine der m Gleichrichterschaltungen (40. m) umfasst: - mindestens einen Feld-Effekt-Transistor (Q1, Q2, Q3), der im negativen Schaltungsbereich (15) angeordnet und dessen Drain (d) mit dem Knoten (a1, a2, a3) und dessen Source (s) mit einem unteren Potentialpunkt (k5) verbunden ist, - einen autosynchronen Treiber (aASD), der analog aufgebaut ist und der mit dem Gate (g) des mindestens einen Feld-Effekt-Transistors (Q1, Q2, Q3) verbunden ist, wobei der autosynchrone Treiber (aASD) dazu ausgelegt ist die entsprechende Phase des m-phasigen Wechselsignals zu überwachen und selbstständig einen Schaltvorgang des mindestens einen Feld-Effekt-Transistors (Q1, Q2, Q3) auszulösen, - mindestens eine Diode (DS 1 , DS 2 , DS 3 ) die im positiven Schaltungsbereich (14) zwischen dem Knoten (a1, a2, a3) und einem oberen Potentialpunkt (k4) angeordnet ist, so, dass die Gleichrichter-Vorrichtung (20) ein Gleichsignal (+V D ) bereit stellt, das zwischen dem oberen Potentialpunkt (k4) und dem unteren Potentialpunkt (k5) abgreifbar/entnehmbar ist.
Abstract:
In accordance with the concepts, circuits and techniques described herein, a converter circuit is provided having multiple half-bridge switching cells that can be selectively controlled using one or more switching patterns to convert a source voltage to a desired output voltage over wide voltage and power ranges while maintaining zero-voltage switching and/or zero-current switching. The convert circuit includes capacitive elements disposed between center switching nodes of the half-bridge switching cells and fixed potentials and a magnetic energy storage element coupling the center switching nodes of first and second half-bridge switching cells. A controller is coupled to the converter circuit to monitor, control and apply one or more switching patterns the half-bridge switching cells such that components of the half-bridge switching cells are switched having a minimal or zero voltage (or current) across them.