公开(公告)号：US5315533A

公开(公告)日：1994-05-24

申请号：US702733

申请日：1991-05-17

Applicant: Frederick A. Stich ,  Donald K. Zahrte, Sr. ,  Richard V. Baxter, Jr. ,  Douglas C. Folts ,  Thomas G. Hubert ,  Juan M. Medina ,  William J. Hazen ,  Edward G. Beistle

Inventor： Frederick A. Stich ,  Donald K. Zahrte, Sr. ,  Richard V. Baxter, Jr. ,  Douglas C. Folts ,  Thomas G. Hubert ,  Juan M. Medina ,  William J. Hazen ,  Edward G. Beistle

IPC: G06F1/26 ,  H02J9/06 ,  G06F15/20

CPC classification number: H02J9/062 ,  Y10T307/625

Abstract: A back-up uninterruptible power system has a power supply path from input terminals connected to AC power system lines to normally supply power to a load. Upon the occurrence of a line fault, a static switch in the power supply path interrupts the connection between the AC power lines and the load and an inverter is turned on to provide power derived from an auxiliary battery through a transformer to the power supply path to supply AC power to the load. By using the static switch, switching from line connection to backup power can be done quickly, within a half cycle, so that substantially no interruption of the output waveform is observed. The inverter can be operated to provide a commutation pulse to the SCRs in the static switch to commutate an SCR which might otherwise continue conducting after the triggering signals to the gates are cut off and before the inverter supplies the AC power to the load. A relay connected between the input terminals and the static switch is controlled to open relay contacts after the static switch has interrupted the current flow to the load, thereby providing positive electrical isolation of the AC power system from the uninterruptible power system while allowing the mechanical relay contacts to switch only during times of no current. Line fault detection is carried out by creating a digital waveform composed of an average of prior cycles of the AC input waveform, converting the stored waveform to an analog signal, and comparing it with the present input signal in phase lock therewith to detect deviation of the input signal from the reference waveform.

Abstract translation: 备用的不间断电力系统具有从连接到AC电力系统线路的输入端子的电源路径，以正常地向负载供电。 在发生线路故障时，电源路径中的静态开关中断交流电力线与负载之间的连接，并且逆变器接通，以通过变压器提供从辅助电池获得的功率到电源路径 为负载提供交流电源。 通过使用静态开关，可以在半个周期内快速地进行从线路连接切换到备用电源，从而观察到输出波形基本上不会中断。 可以对逆变器进行操作，以向静态开关中的SCR提供换向脉冲，以便在切断对门的触发信号之后以及在逆变器将AC电力提供给负载之前换向可能继续导通的SCR。 连接在输入端子和静态开关之间的继电器被控制以在静态开关中断到电流到负载的电流之后打开继电器触点，从而提供交流电力系统与不间断电力系统的正电隔离，同时允许机械继电器 触点仅在无电流时才切换。 线路故障检测通过产生由AC输入波形的先前周期的平均值组成的数字波形，将存储的波形转换成模拟信号，并将其与当前输入信号进行相位锁定，以检测其中的偏差 来自参考波形的输入信号。