초록 ▼

A power supply system for processing current and voltage faults is disclosed. Each phase of a first power source (12) and each phase of a second power source (28) has a pair of switches (60, 64) for controlling the conduction of current from the phase of the power source to a phase load (29). In eac

A power supply system for processing current and voltage faults is disclosed. Each phase of a first power source (12) and each phase of a second power source (28) has a pair of switches (60, 64) for controlling the conduction of current from the phase of the power source to a phase load (29). In each of the phases of the first power source (12), a first switch (60) is controlled by a first control signal which has a high level when a voltage fault or current fault condition does not exist. When either a voltage fault or a current fault condition exists, the first switch (60) is turned off. The second switch (64) is turned on by a second control signal during a determination of whether a current fault exists. Furthermore, a logic network causes the first control signal to assume the second level in response to any one of an RMS over/under voltage fault, an instantaneous overcurrent fault, an I2t fault, or an instantaneous voltage fault occurring in the phase to which the switches are connected or in any one of the other phases in the first power source. Upon the detection of a voltage fault condition, the first power source (12) is disconnected from the load and a second power source is connected to the load. All of the phases of the first power source are disconnected either immediately in response to the detection of a fault in any one of the phases or, alternatively, the phase with the fault is immediately disconnected and the remaining phases without a fault are disconnected at the zero current crossing points of the AC signal of the phases. The phases of the second source are connected at a point when the voltage of the phase is zero.

대표청구항 ▼

A current and voltage fault processing system for disconnecting an electrical load from a first power source upon the detection of a current fault in the load and disconnecting the first power source from the load and connecting a second power source to the load upon the detection of a voltage fault

A current and voltage fault processing system for disconnecting an electrical load from a first power source upon the detection of a current fault in the load and disconnecting the first power source from the load and connecting a second power source to the load upon the detection of a voltage fault in the first power source comprising: (a) a first switching means disposed in series with the load and the first power source, conduction of the first switching means being controlled by a first control signal having first and second levels and passing current to the load when the first control signal is at the first level and blocking current flow when the first control signal is at the second level; (b) a shunt circuit, coupled in parallel with the first switching means, the shunt circuit containing a second switching means coupled to an impedance which limits the amount of current drawn by the load when the impedance is in series with the load, conduction of the second switching means being controlled by a second control signal having first and second levels and passing current to permit current flow through the impedance of the shunt circuit when the second control signal has the first level and blocking current flow when the second control signal has the second level; (c) means for generating the first control signal, responsive to a voltage level of the first power source, the means for generating the first control signal generating the first level of the first control signal in response to not detecting a voltage fault condition in the first power source and generating the second level of the first control signal in response to detecting a voltage fault condition in the first power source; and (d) means for generating the second control signal, responsive to a current level drawn from the first power source by the load, the means for generating the second control signal generating the first level of the second control signal in response to detection of a current flow between the first power source and the electrical load exceeding a maximum amount and generating the second level of the second control signal in response to detection of a current flow between the first power source and the electrical load not exceeding the maximum amount.