Uninterruptible power supply
DCFirst Claim
Patent Images
1. An uninterruptible power supply comprising:
- a controlled rectifier having an input coupled to receive AC power and an output coupled to a DC bus;
a battery coupled to the DC bus;
an inverter having an input coupled to the DC bus and an output coupled to a load; and
a control system coupled to the controlled rectifier and the inverter the control system comprising three microprocessors, wherein a first microprocessor functions as an overall controller, a second microprocessor controls the rectifier, and a third microprocessor controls the inverter;
wherein the three microprocessors communicate via a common global memory.
9 Assignments
Litigations
0 Petitions
Accused Products
Abstract
An uninterruptible power supply is disclosed that includes a digital controller comprising a plurality of microprocessors. These microprocessors are programmed and arranged to provide various control features heretofore unavailable using analog controllers of the prior art.
-
Citations
21 Claims
-
1. An uninterruptible power supply comprising:
-
a controlled rectifier having an input coupled to receive AC power and an output coupled to a DC bus;
a battery coupled to the DC bus;
an inverter having an input coupled to the DC bus and an output coupled to a load; and
a control system coupled to the controlled rectifier and the inverter the control system comprising three microprocessors, wherein a first microprocessor functions as an overall controller, a second microprocessor controls the rectifier, and a third microprocessor controls the inverter;
wherein the three microprocessors communicate via a common global memory. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method of controlling the output current of a controlled rectifier having its output connected to a DC bus with a battery coupled thereto, the method comprising:
-
sensing the DC bus voltage;
comparing the sensed voltage to a voltage setpoint;
adjusts the firing signal timing to minimize a difference between the sensed voltage and the voltage setpoint;
determining whether an input current of the rectifier or a charging current of the battery is above a predetermined limit; and
switching control to a different control loop to maintain the input current or the charging current within the predetermined limit. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
-
-
18. A method of operating a plurality of uninterruptible power supplies in parallel comprising:
-
adjusting a phase angle of a voltage generated by each uninterruptible power supply to eliminate real power unbalances among the plurality of uninterruptible power supplies;
adjusting a magnitude of a voltage generated by each uninterruptible power supply to eliminate reactive power unbalances among the plurality of uninterruptible power supplies; and
shifting a location of a harmonic servo compensator pole to reduce the bandwidth of the controller for each harmonic.
-
-
19. An uninterruptible power supply comprising:
-
a controlled rectifier having an input coupled to receive AC power and an output coupled to a DC bus;
a battery coupled to the DC bus;
an inverter having an input coupled to the DC bus and an output coupled to a load; and
a control system coupled to the controlled rectifier and the inverter, the control system comprising three microprocessors, wherein a first microprocessor functions as an overall controller, a second microprocessor controls the rectifier, and a third microprocessor controls the inverter; and
a plurality of components interconnected by a peer-to-peer controller area network, wherein the network accommodates fragmented messaging.
-
-
20. An uninterruptible power supply comprising:
-
a controlled rectifier having an input coupled to receive AC power and an output coupled to a DC bus;
a battery coupled to the DC bus;
an inverter having an input coupled to the DC bus and an output coupled to a load; and
a control system coupled to the controlled rectifier and the inverter, the control system comprising three microprocessors, wherein a first microprocessor functions as an overall controller, a second microprocessor controls the rectifier, and a third microprocessor controls the inverter;
a three-phase input and independent zero-crossing detection circuits for each input phase wherein the second microprocessor independently determines a phase shift introduced by each zero cross detection circuit and adjusts the firing signal timing for each rectifier phase to negate the phase shift; and
wherein the second microprocessor is configured to change the firing sequence of the rectifier to compensate for a phase rotation of the three-phase input.
-
-
21. An uninterruptible power supply comprising:
-
a controlled rectifier having an input coupled to receive AC power and an output coupled to a DC bus;
a battery coupled to the DC bus;
an inverter having an input coupled to the DC bus and an output coupled to a load; and
a control system coupled to the controlled rectifier and the inverter, the control system comprising three microprocessors, wherein a first microprocessor functions as an overall controller, a second microprocessor controls the rectifier, and a third microprocessor controls the inverter;
a three-phase input and independent zero-crossing detection circuits for each input phase, wherein the second microprocessor independently determines a phase shift introduced by each zero cross detection circuit and adjusts the firing signal timing for each rectifier phase to negate the phase shift; and
wherein the second microprocessor qualifies the input voltage by measuring the voltage on a first phase of said three-phase input, the frequency on a second phase of said three-phase input, and the phase sequence between either said first phase or said second phase and a third phase of said three-phase input.
-
Specification