公开(公告)号：WO1990001826A1

公开(公告)日：1990-02-22

申请号：PCT/US1989003164

申请日：1989-07-21

Applicant: SUNDSTRAND CORPORATION

Inventor： SUNDSTRAND CORPORATION ,  SHEKHAWAT, Sampat, S. ,  DHYANCHAND, John

IPC: H02M01/12

CPC classification number: H02M7/487 ,  H02M1/12

Abstract: Prior types of neutral point clamped PWM inverters pulses in a PWM waveform having reference points which are evenly spaced. Such a control technique, however, accomplishes a significant reduction in output harmonics only for relatively low inverter output magnitudes. In order to overcome this problem, a control for a PWM inverter defines a series of reference points (alpha) spaced in time in accordance with an inverse trigonometric function of the number of pulses (9) to be produced in a portion (180 DEG ) of the inverter output wherein each reference point is associated with a pulse to be produced in the PWM waveform and determines rising (R1, R2...) and falling (F1, F2...) edges of each pulse of the AC output relative to the reference point associated with such pulse in dependence upon an output parameter of the inverter. Switch control signals are developed for each switch from the defined rising and falling edges. The control of the present invention accomplishes a significant reduction in the harmonics produced by the inverter at higher inverter output magnitudes.

Abstract translation: 先前的中性点钳位PWM逆变器脉冲在具有均匀间隔的参考点的PWM波形中。 然而，这种控制技术仅在相对较低的逆变器输出幅度下实现输出谐波的显着降低。 为了克服这个问题，PWM逆变器的控制根据在一部分（180°）中产生的脉冲数（9）的反三角函数来定义一系列时间间隔的参考点（α） 其中每个参考点与要在PWM波形中产生的脉冲相关联，并确定AC输出相对每个脉冲的上升沿（R1，R2 ...）和下降（F1，F2 ...） 根据逆变器的输出参数到与这种脉冲相关联的参考点。 从定义的上升沿和下降沿开始为每个开关开关开关控制信号。 本发明的控制在较高的逆变器输出幅度下实现了逆变器产生的谐波的显着降低。

公开(公告)号：WO1990007825A1

公开(公告)日：1990-07-12

申请号：PCT/US1989005634

申请日：1989-12-08

Applicant: SUNDSTRAND CORPORATION

Inventor： SUNDSTRAND CORPORATION ,  SHEKHAWAT, Sampat, S. ,  DHYANCHAND, John

IPC: H03K05/00

CPC classification number: H03K17/61 ,  H03K17/667

Abstract: A load (32) is controlled by a pulse waveform from a source (30). The source and load are electrically isolated by using two monostable circuits (11, 12) to detect the leading and trailing edge of the pulse waveform, two pulse transformers (T1, T2) to isolate the source and the load, and a bistable circuit (21) to reconstruct the original pulse waveform.

Abstract translation: 负载（32）由源（30）的脉冲波形控制。 源和负载通过使用两个单稳态电路（11,12）来检测脉冲波形的前沿和后沿被电隔离，两个脉冲变压器（T1，T2）隔离源极和负载，以及双稳态电路 21）重构原始脉冲波形。

公开(公告)号：WO1990007820A1

公开(公告)日：1990-07-12

申请号：PCT/US1989005658

申请日：1989-12-12

Applicant: SUNDSTRAND CORPORATION

Inventor： SUNDSTRAND CORPORATION ,  SHEKHAWAT, Sampat, S. ,  NG, Chai-Nam ,  DHYANCHAND, John

IPC: H02M07/538

CPC classification number: H02M1/40 ,  H02M1/38 ,  H02M7/538

Abstract: The problem of sensing current through inverter switches (SW1, SW2) is solved by a current transformer (21) which has windings (40, 41) connected with the flyback diodes (D1, D2) to demagnetize or reset the current transformer core. Size and weight of the transformer are minimized while avoiding a buildup of flux which would saturate the core.

公开(公告)号：WO1985002067A1

公开(公告)日：1985-05-09

申请号：PCT/US1984001764

申请日：1984-11-01

Applicant: SUNDSTRAND CORPORATION

Inventor： SUNDSTRAND CORPORATION ,  CHETTY, P., R., K. ,  DHYANCHAND, John ,  THOLLOT, Pierre

IPC: H02H07/20

CPC classification number: H02M3/3378

Abstract: A push-pull converter has transistor power switches (20, 21) which conduct alternately to connect a DC source (+V, -V) with the primary windings (16, 17) of an output transformer (15). A turn-off snubber circuit (31, 32) is connected with each power switch. When a power switch is turned on, snubber current pulses flow in the circuits connected with both switches. A switch current sensoring circuit has a current transformer with an output winding (45, 46 or 55) inductively coupled with each of the conductors (47, 48) connected between the power switches (20, 21) and the primary windings (16, 17) of the output transformer (15). The snubber current pulses (37, 50, 51) through the conductors are 180o out of phase and are suppressed in the current transformer output. The switch current signal from the secondary (55) of the current transformer (54) is free of snubber current pulses and is used in a flux balance circuit (68, 69, 70) and in a pulse-by-pulse current limiter (72).

公开(公告)号：EP0163691A1

公开(公告)日：1985-12-11

申请号：EP84904246.0

申请日：1984-11-01

Applicant: SUNDSTRAND CORPORATION

Inventor： CHETTY, P., R., K. ,  DHYANCHAND, John ,  THOLLOT, Pierre

IPC: H02H7 ,  H02M3

CPC classification number: H02M3/3378

Abstract: Un convertisseur push-pull possède des commutateurs de puissance à transistors (20, 21) qui conduisent en alternance pour relier une source de courant continu (+V, -V) aux enroulements primaires (16, 17) d'un transformateur de sortie (15). Un circuit d'amortissement de mise hors tension (31, 32) est relié à chaque commutateur de puissance. Lorsqu'un commutateur de puissance est mis sous tension, des impulsions de courant d'amortissement s'écoulent dans les circuits reliés aux deux commutateurs. Un circuit de détection de courant de commutation possède un transformateur de courant avec un enroulement de sortie (45, 46 ou 55) couplé de manière inductive avec chaque conducteur (47, 48) connecté entre les commutateurs de puissance (20, 21) et les enroulements primaires (16, 17) du transformateur de sortie (15). Les impulsions du courant d'amortissement (37, 50, 51) au travers des conducteurs sont déphasées de 180o et sont supprimées dans le courant de sortie du transformateur. Le signal de courant de commutation provenant du secondaire (55) du transformateur de courant (54) est exempt d'impulsions de courant d'amortissement et est utilisé dans un circuit d'équilibrage de flux (68, 69, 70) et dans un limiteur de courant impulsion par impulsion (72).