Abstract: The integrity of transmission-line voltage measurements in a digital-electricity power system in the presence of line-voltage disturbances during a sample period is ensured via detection or prevention by (a) acquiring at least three measurements of transmission-line voltage, performing numerical analysis on the measurements to produce a polynomial function, and estimating accuracy of the polynomial function based on magnitude of variance of the individual measurements; (b) applying a negative or positive bias to the transmission line during the sample period and acquiring voltage measurements to determine a rate of voltage change with the bias applied; (c) shifting a start time of a first sample period on a first transmission line in reference to a second sample period on a second transmission line to reduce overlap of sample periods across both transmission lines; and/or (d) synchronizing start times of respective sample periods on first and second transmission lines.

Abstract: In a digital-electricity power system, an electrical-current sample value is acquired along with a voltage sample value within a time window over which the electrical current and voltage are substantially unchanged. A transmission-line series voltage is derived from the difference between the voltage at the transmitter and the voltage at the receiver. Each transmission-line series voltage is divided by a corresponding stored electrical-current sample value to generate a ratio indicative of transmission-line series resistance. These steps are repeated, and the transmitter-disconnect device is placed in a non-conducting state if a difference in the ratio generated in one or more time periods exceeds a predetermined maximum, wherein exceeding the predetermined maximum is indicative of a series resistance fault. Alternatively, a series resistance value, determined by dividing a change in voltage over a change in current, is evaluated to detect a fault.

Abstract: Transmission-line voltage measurements in a digital-electricity power system are validated by acquiring a series of transmission-line voltage measurements during a sample period when a transmitter-disconnect device is in a non-conducting state. A numerical analysis is performed to determine a point in time at which AC components in the transmission line have diminished and at which the primary change in the transmission-line voltage measurement values is due to DC decay. A receiver acquires a series of receiver-voltage measurements during the same sample period; and a numerical analysis is performed on the receiver-voltage measurements to determine the point in time at which the AC components have diminished and where the primary change in the transmission-line voltage measurement values is due to DC decay. The transmitter-disconnect device is then placed in a non-conducting state based on an evaluation of those measurements.

Abstract: Transmission-line voltage measurements in a digital-electricity power system are validated by acquiring a series of transmission-line voltage measurements during a sample period when a transmitter-disconnect device is in a non-conducting state. A numerical analysis is performed to determine a point in time at which AC components in the transmission line have diminished and at which the primary change in the transmission-line voltage measurement values is due to DC decay. A receiver acquires a series of receiver-voltage measurements during the same sample period; and a numerical analysis is performed on the receiver-voltage measurements to determine the point in time at which the AC components have diminished and where the primary change in the transmission-line voltage measurement values is due to DC decay. The transmitter-disconnect device is then placed in a non-conducting state based on an evaluation of those measurements.

Abstract: A power-distribution system can detect a transmission-line electrical fault, and the power source can be electrically isolated from the transmission line before a human or equipment is substantially harmed or damaged. A controller on the source side is responsive to one or more sensors that provide a signal indicative of the voltage across the transmitter side of the transmission line. A source-disconnect device operable by the controller electrically isolates the source from the transmission line. A signal-generator circuit is configured to superimpose a higher-wavelength carrier waveform with the source-output waveform on the transmission line. The controller determines the normal impedance of the transmission line from measurement and detects a transmission-line fault, as indicated by a change in carrier waveform reflections or energy content of the carrier waveform and generates a command to open the source-disconnect device upon detection of the fault.

Abstract: The disclosed charging system has multiple charging ports emanating from a central digital power transmitter to charge a plurality of battery packs. The system comprises a centralized bulk power converter to produce a first DC voltage and multiple additive power converters. One additive power converter is assigned to each charger port. The output of each charging port is transmitted in digital power format to a receiver local to each battery pack. The receiver converts the digital power to conventional analog DC power for charging the battery packs. The bulk converter provides the majority of the power needed to charge all the battery packs simultaneously, while the additive power converters adjust for the individual characteristics of each battery pack.

Abstract: The integrity of transmission-line voltage measurements in a digital-electricity power system in the presence of line-voltage disturbances during a sample period is ensured via detection or prevention by (a) acquiring at least three measurements of transmission-line voltage, performing numerical analysis on the measurements to produce a polynomial function, and estimating accuracy of the polynomial function based on magnitude of variance of the individual measurements; (b) applying a negative or positive bias to the transmission line during the sample period and acquiring voltage measurements to determine a rate of voltage change with the bias applied; (c) shifting a start time of a first sample period on a first transmission line in reference to a second sample period on a second transmission line to reduce overlap of sample periods across both transmission lines; and/or (d) synchronizing start times of respective sample periods on first and second transmission lines.

Abstract: The disclosed charging system has multiple charging ports emanating from a central digital power transmitter to charge a plurality of battery packs. The system comprises a centralized bulk power converter to produce a first DC voltage and multiple additive power converters. One additive power converter is assigned to each charger port. The output of each charging port is transmitted in digital power format to a receiver local to each battery pack. The receiver converts the digital power to conventional analog DC power for charging the battery packs. The bulk converter provides the majority of the power needed to charge all the battery packs simultaneously, while the additive power converters adjust for the individual characteristics of each battery pack.

Abstract: In the transfer of energy from a source to a load, a power distribution system is configured to detect unsafe conditions that include electrically conducting foreign objects or individuals that have come in contact with exposed conductors in the power distribution system. A responsive signal is generated in a source controller including source terminals. The responsive signal reverses a voltage on the source terminals. With the voltage on the source terminals reversed, a measurement of electrical current flowing through the source terminals is acquired; and the source controller generates signals to electrically disconnect the source from the source terminals if and when the electrical current falls outside of high or low limits indicating that there is a conducting foreign object or living organism making electrical contact with the source or load terminals or a failure in power distribution system hardware.

Abstract: A power distribution system (that can detect an unsafe fault condition where an individual or object has come in contact with the power conductors) regulates the transfer of energy from a source to a load. Periodically, the source controller opens an S1 disconnect switch, a and load controller opens an S2 disconnect switch. A capacitor represents the capacitance across the load terminals. If the capacitor discharges at a rate higher or lower than predetermined values after the S1 and S2 disconnect switches are opened, then a fault condition is registered, and the S1 and S2 switches will not be commanded to return to a closed position, thus isolating the fault from both the source and the load.

Abstract: Thermal runaway in battery packs is suppressed by inserting packages of hydrated hydrogel at physical interfaces between groups of one or more cells. The hydrogel acts to diffuse and absorb thermal energy released by the cells in the event of a cell failure. During extreme overheating of a battery cell, the water stored by the hydrogel will undergo phase change, that is, begin to vaporize, thus absorbing large amounts of thermal energy and preventing thermal runaway.

Abstract: Methods and systems for constructing a battery, the battery including at least two energy storage sections connected in parallel to a common module power bus, the energy storage sections including at least one battery cell and at least one section disconnect device capable of disconnecting the at least two energy sections from the module power bus, and, a section protection device to control the section disconnect device based on data from the energy storage sections. In an embodiment, the battery can include at least two battery modules connected in series using an interlock signal, where the battery modules include a module protection device having an interlock signal controller and fault logic for controlling the interlock signal controller, such that the modules can control the interlock signal and hence a disconnect device that receives the interlock signal and is connected between the modules and a load and/or charger.

Abstract: A large battery pack of specified voltage and capacity can be assembled from a plurality of identical small cells by dividing the specified capacity by a nominal battery module capacity to determine a desired number of parallel modules to be provided, dividing the nominal battery module capacity by a nominal cell card capacity, to determine the number of cell cards required in each module, connecting the call cards in parallel to a common buswork to form the battery module, and connecting the modules in parallel to obtain the specified battery pack capacity and in series to obtain the specified battery pack voltage Protection circuitry can be implemented at the module level, by disconnecting one or more modules or the entire battery pack if a fault at the module level is identified; at the cell card level, by disconnecting a cell card if a cell within it is determined to be faulty; and/or internally, in each cell.

Abstract: Methods and systems for constructing a battery, the battery including at least two energy storage sections connected in parallel to a common module power bus, the energy storage sections including at least one battery cell and at least one section disconnect device capable of disconnecting the at least two energy sections from the module power bus, and, a section protection device to control the section disconnect device based on data from the energy storage sections. In an embodiment, the battery can include at least two battery modules connected in series using an interlock signal, where the battery modules include a module protection device having an interlock signal controller and fault logic for controlling the interlock signal controller, such that the modules can control the interlock signal and hence a disconnect device that receives the interlock signal and is connected between the modules and a load and/or charger.

Abstract: In the embodiment described in the specification, a fault tolerant motor drive circuit arrangement includes a motor having three stator windings which are electrically isolated and are supplied by separate single phase drive circuits, each having a differential current sensor detecting current in both circuit conductors and an overcurrent sensor in one circuit conductor, along with a ground connection for each circuit having a ground conductor with an overcurrent sensor and a high resistance with a voltage sensor across the high resistance. A monitoring unit receives signals from all of the differential current sensors, overcurrent sensors and voltage sensors to provide indications of the location of insulation faults or incipient faults in the windings.

Abstract: A power distribution unit (PDU) for series connected multicell battery packs which uses a common hardware platform for both charging and providing power to an external load. Using switching circuitry (2), and tap points (5a,5b,5c,5d,5e) individual access to cells (4a,4b,4c,4d) or groups of series connected cells is accomplished. Under control of microcontroller circuitry (1), series connected cell groups of varying sizes are selected and prioritized for connection to a common power bus (29),(30) at real-time speeds. The PDU uses these groups to maintain balance over cells with varying characteristics, adapt to varying charge sources and to produce a regulated output voltage during discharge.

Abstract: An electronic counting device for counting the charge cycles accumulated on a battery. The counting device is mounted on a battery intercell connector and senses the reversal in current through the battery which corresponds to a charge cycle.