A device reduces its energy consumption using a relatively lower frequency and lower power secondary oscillator to maintain timing information when a higher frequency and higher power primary oscillator is inactivated. The secondary oscillator maintains timing information at a higher resolution than the period of the oscillator, so as to conserve synchronization when the higher frequency, higher power primary oscillator is inactivated. In some embodiments, a microsequencer is programmably configured to control an integrated radio receiver and transmitter using less power than an associated microprocessor would use to perform the same functions. In other embodiments, flexible event timing facilitates the merging of wake-up events to reduce the energy consumed by wake-up operations in the device.

A method of operating a cold atom clock to maintain a highly homogeneous microwave field is provided. The method includes: driving a subset of microwave feed lines to excite a microwave field in a resonator, while a power and a phase of at least one microwave feed line in the subset is held constant, and while the power or the phase of at least one other microwave feed line in the subset is changed; measuring a strength of the atomic transition excited by the microwave field; extracting a relative power and a relative phase between or among the subset of microwave feed lines by processing the strength of the atomic transitions excited by the microwave field measured in at least one auxiliary-measurement sequence; and determining if an adjustment to one or more of the microwave feed lines is needed to improve the homogeneity of the microwave field phase and amplitude.

A method of operating a cold atom clock to maintain a highly homogeneous microwave field is provided. The method includes: driving a subset of microwave feed lines to excite a microwave field in a resonator, while a power and a phase of at least one microwave feed line in the subset is held constant, and while the power or the phase of at least one other microwave feed line in the subset is changed; measuring a strength of the atomic transition excited by the microwave field; extracting a relative power and a relative phase between or among the subset of microwave feed lines by processing the strength of the atomic transitions excited by the microwave field measured in at least one auxiliary-measurement sequence; and determining if an adjustment to one or more of the microwave feed lines is needed to improve the homogeneity of the microwave field phase and amplitude.

Various examples are provided for feedback control of power systems. The feedback control can provide simultaneous frequency regulation and economic operation of a power system. In one example, a method includes obtaining a frequency difference associated with a generator of a power system; determining an output power adjustment based at least in part upon the frequency difference and a cost function associated with the generator; and providing a power command to a secondary frequency control of the generator, the power command based upon the output power adjustment. In another example, a generator control system includes a primary frequency controller configured to control frequency droop of a generator of a power system; and a secondary frequency controller configured to adjust output power of the generator based at least in part upon a frequency difference associated with the generator and a cost function associated with the generator.

Various examples are provided for feedback control of power systems. The feedback control can provide simultaneous frequency regulation and economic operation of a power system. In one example, a method includes obtaining a frequency difference associated with a generator of a power system; determining an output power adjustment based at least in part upon the frequency difference and a cost function associated with the generator; and providing a power command to a secondary frequency control of the generator, the power command based upon the output power adjustment. In another example, a generator control system includes a primary frequency controller configured to control frequency droop of a generator of a power system; and a secondary frequency controller configured to adjust output power of the generator based at least in part upon a frequency difference associated with the generator and a cost function associated with the generator.

A voltage regulator includes a programming interface via which programming instructions may be applied to a processor of the voltage regulator. The voltage regulator operates the processor according to the programming instructions to select one of multiple active internally-generated analog voltage levels to determine an output voltage level of the voltage regulator.

A voltage regulator includes a programming interface via which programming instructions may be applied to a processor of the voltage regulator. The voltage regulator operates the processor according to the programming instructions to select one of multiple active internally-generated analog voltage levels to determine an output voltage level of the voltage regulator.

A power system stabilizing device includes an arithmetic unit that constructs a system model by collecting various kinds of system information, calculates a transient stability under an assumed accident condition beforehand, and selects, for each assumed accident in advance, a target solar power generator for shutdown and a target power generator to be disconnected to stabilize a power system, and a control unit that shutdowns the shutdown target solar power generator and disconnects the disconnection target power generator from the power system which are selected by the arithmetic unit when a system accident occurs.

A power system stabilizing device includes an arithmetic unit that constructs a system model by collecting various kinds of system information, calculates a transient stability under an assumed accident condition beforehand, and selects, for each assumed accident in advance, a target solar power generator for shutdown and a target power generator to be disconnected to stabilize a power system, and a control unit that shutdowns the shutdown target solar power generator and disconnects the disconnection target power generator from the power system which are selected by the arithmetic unit when a system accident occurs.

An oscillator circuit comprises a crystal oscillator and an inverter. The input of the inverter is connected to the first terminal of the crystal oscillator and the output of the inverter is connected to the second terminal of the crystal oscillator, oscillator circuit is arranged to operate the inverter in its linear operating region. An amplitude regulator has an input connected to the input of the inverter, arranged to provide a first supply current I.sub.AREG to the inverter, where the magnitude of the first supply current is inversely dependent on a magnitude of a voltage at the inverter input. A digital-to-analogue converter is arranged to provide a second supply current I.sub.DAC to the inverter having a magnitude determined by a digital signal applied to a digital input of the digital-to-analogue converter.