Abstract: A method, device and computer program product for providing improved control of power or voltage oscillation damping in a power transmission system. The device includes a magnitude obtaining element configured to obtain an instantaneous magnitude of a signal representing a deviating oscillation in at least one element of the power transmission system, a slope investigating element configured to determine the rate of change of the signal, and a first processing block including an integrating element configured to integrate the instantaneous magnitudes with an integrating factor that is based on the determined rate of change. The first processing block is further configured to form a phase compensation angle based on the integrated instantaneous magnitude for use in a damping control signal generating unit in order to provide power or voltage oscillation damping of the system.

Abstract: An apparatus (14/18) for controlling a voltage on a transmission line (10). The apparatus (14/18) comprises a first voltage sourced converter controller (18) connected to a first node (22) of the transmission line (10); a second voltage sourced converter controller (14) connected to a second node (20) of the transmission line (10), the second node (20) spaced apart from the first node (22) wherein the first voltage sourced converter controller (18) supplies capacitive reactive current and the second voltage sourced converter controller (14) absorbs inductive reactive current to control the voltage.

Abstract: The present disclosure relates to power system sensitivities as computed from power flow parameters and control parameters of a Power Flow Control Device (PFC). To this end, control parameter variations are applied to or generated by a PFC, and comprise variations in a control input u, a control effort e (injected series voltage, inserted series reactance), or a control effect q (power flow, active power transfer, phase-shift, current). A power flow response measuring unit measures a variation of a power flow response such as current, active or apparent power, in a way sufficiently synchronized with the control parameter variation to allow establishing an unambiguous causal relationship or correspondence in the form of a power system sensitivity.

Abstract: A control apparatus for a controlled series compensator including a plurality of reactance elements each having a rapid switch for connecting and disconnecting the reactance in series with an electric power transmission line. The apparatus also includes a steady state power flow controller. A damping controller is provides on the presence of an oscillation on the transmission line a first reactance insertion on the transmission line having a first duration of time trigged by a time instant that coincides with a peak in the power oscillation.

Abstract: A flux control system for a three-phase active voltage conditioner that utilizes an injection transformer to apply calculated compensation voltage to a mains supply. The flux control system is configured to modify the compensation voltage to be applied to at least one primary terminal of the injection transformer so as to avoid magnetic saturation of the injection transformer. The flux control system includes magnetic flux model modules that are configured to calculate a core flux level of the injection transformer, flux offset modules that are configured to apply a first modification to the compensation voltage to gradually reduce any flux offset in the injection transformer, and peak flux modules that are configured to apply a second modification to the compensation voltage to prevent the core flux level from exceeding a preset range.

Abstract: A cancellation signal generation section generates a cancellation signal which cancels an alternating-current component of a power supply terminal voltage of a digital signal processing circuit section, and a synthesis section synthesizes the generated cancellation signal and a power supply voltage of an analog signal processing circuit section to cancel noise superimposed on the power supply voltage.

Abstract: Exemplary embodiments of the present disclosure provide a method and controller for damping multimode electromagnetic oscillations in electric power systems which interconnect a plurality of generators and consumers. The controller for damping such oscillations includes a phasor measurement unit (PMU) and a power oscillation damper (POD) controller. Each oscillating mode signal is damped and then superposed to derive a control signal. A feedback controller is used to feedback the control signal to a power flow control device in the power system.

Abstract: A power system oscillation detection device is provided for use in an electric power system. A plurality of sample signals are acquired from the electrical power system via a plurality of intelligent electronic devices (IEDs) in communication with the power system. The power system oscillation detection device includes a real-time modal analysis module, a real-time mode identification module, and real-time decision and control logic. The real-time modal analysis module calculates modes of at least one of the signals, each mode including mode information. The real-time mode identification module together with the real-time decision and control logic determines, from the mode information, whether there is an undesirable oscillation in the electric power system and activates a remedial action.

Abstract: A method for measuring a capacitance using a capacitance meter. The capacitance meter includes an AC power source with a controllable frequency which is fed to a capacitor to measure its capacitance. A first measurement of the capacitance is performed by the capacitance meter using a first frequency. When the first measurement of the capacitance indicates the capacitance is below a threshold capacitance a lower capacitance measurement is performed in the capacitance meter, using a second measurement of the capacitance using a second frequency. When the first measurement of the capacitance indicates the capacitance is above a threshold capacitance, a higher capacitance measurement is performed in the capacitance meter, using a second measurement of the capacitance using a third frequency, the third frequency being lower than the second frequency.

Abstract: An islanding detection apparatus for a distributed generation power system and a detection method therefor operates a power converter to act as a virtual capacitor or inductor at a frequency close to but unequal to that of a utility power system under abnormal condition of the utility power system. When power failure occurs in the utility power system, only the distributed generation power system supplies power to a load so that a load voltage has been changed in at least one of amplitude and frequency which can be immediately detected islanding phenomenon.

Abstract: Systems, apparatus, and methods are provided for maintaining the state of charge of energy storage devices such as batteries, flywheel, capacitors, or other technologies that are energetically coupled with the electricity grid to support ancillary services. To reliably respond to requests to regulate the grid, the charge on the energy storage device is sustained or restored to a specified range in a manner that optimizes the readiness of the energy storage device to supply ancillary services in light of the condition of the grid. A state of charge (SOC) of the energy storage device and the grid frequency may be monitored. When a request from the operator to regulate the grid frequency is not being serviced, the charge of the energy storage device may be increased or decreased so that the charge may be sustained within the specific range. Once the SOC falls outside of the first range, charge may be added to or removed from the energy storage device when the grid frequency has appropriate values, e.g.

Abstract: An apparatus for controlling a thyristor controlled series capacitor connected to a power transmission line. A thyristor firing control includes a unit for effectuating a desired capacitor voltage zero crossing in dependence of a line current and a capacitor voltage in response to a command signal. A command control provides the command signal to the thyristor firing control. The command control includes a damping control including a damper configured to damp at a least one discrete frequency.

Abstract: In a control system for a static var compensator that performs phase control of a current of a reactor for each phase by a thyristor and thus controls reactive power, a detecting unit that detects a tertiary harmonic current flowing through each phase of the static var compensator is provided, and on the basis of the tertiary harmonic current flowing through each phase detected by the detecting unit, the thyristor of each phase is controlled so that the quantity of generated tertiary harmonic current of each phase becomes equal, and therefore an outflow of the tertiary harmonic current toward a system can be restrained by an inexpensive method.

Abstract: A power compensator for an electric power transmission line. The power compensator includes a voltage source converter, a capacitor and an energy storage device. The energy storage device includes a high voltage battery having a short circuit failure mode, a first main switch and second main switch for disconnecting the battery from the capacitor, and a control unit for operating the first and second switch.

Abstract: A flicker improvement effect evaluating system evaluates an effect of improvement of voltage flicker in a power system to which a static reactive power compensator is to be introduced. A system voltage operating unit operates a compensation current and a system impedance of the power system, based on actually measured data of system voltage and load current read from a data reading unit. Based on the results of operations and the actually measured data, a not-yet-improved system voltage at present and an improved system voltage attained when the static reactive power compensator is provided on a bus are simulated. By a flicker meter, flicker values of the not-yet-improved system voltage and improved system voltage amplified by an amplifying circuit are measured, and from the flicker values, the rate of improvement attained by the static reactive power compensator is operated.

Abstract: A control apparatus for a controlled series compensator including a plurality of reactance elements each having a rapid switch for connecting and disconnecting the reactance in series with an electric power transmission line. The apparatus also includes a steady state power flow controller. A damping controller is provides on the presence of an oscillation on the transmission line a first reactance insertion on the transmission line having a first duration of time trigged by a time instant that coincides with a peak in the power oscillation.

Abstract: The voltage stabilizer for stabilizing a voltage of a circuit includes a first resistor, a second resistor, a voltage controller, and a current supply unit. The voltage controller keeps a voltage of the first resistor constant. The current supply unit supplies a first current to between the first resistor and the second resistor when a second current in the circuit becomes equal to or larger than a predetermined value.

Abstract: The disclosure relates to a converter control unit or power system stabilizing unit for counteracting oscillations in electric power systems that is equipped and employed to provide and processes information for system-wide monitoring, protection, control and metering. It comprises means for synchronized (e.g. via GPS or another absolute/global time reference) sampling of voltages and/or currents, means for down-sampling in order to decrease the number of samples, and means for calculating phasors, i.e. time stamped amplitude and phase angle of the voltages and/or currents.

Abstract: A method for measuring a stability margin at a node of a polyphase power grid injects suppressed-carrier stimulus into a node of the power grid by low-level amplitude modulation of the output voltage of a pre-exiting generator connected to the node. Response signals are obtained and product demodulated on a per-phase basis and summed in three-phase groups. Demodulated and summed responses contain signals that represent the suppressed-carrier impedance upstream and downstream of the stimulus injection point, and are processed to determine the stability margin at the node.

Abstract: Power flow models of Interline Power Flow Controllers (IPFC) for large-scale power systems are studied, in details. Mathematical models of the IPFC, using the d-q axis decompositions of control parameters are derived. In this framework, for each IPFC, only two control parameters are added to the unknown vector in the iteration formula and the quadratic convergence characteristic is preserved. Simulations results from several practical large-scale power systems embedded with multiple Convertible Static Compensators (CSCs) demonstrate the effectiveness of the proposed models. Comparisons with existing models are made to elucidate the performance of the convergence.

Abstract: The invention relates to a voltage stabilization system for power supply lines, comprising a variable inductance, an autotransformer and a system for controlling the variable inductance to automatically compensating for voltage variations of the power supply lines. The system can include a control system that includes a processor unit, a setpoint adjustment unit, a feedback unit and a rectifier circuit.

Abstract: A stabilization circuit wherein voltages of the secondary winding of a transformer are stabilized with respect to mains voltage fluctuations and load fluctuations, an auxiliary voltage is derived either from a secondary winding of the transformer or an auxiliary transformer. Together with the mains voltage portion of this auxiliary voltage acquired by pulse-width modulation forms the primary voltage of the transformer such that the desired stabilization is achieved.

Abstract: A method and apparatus for regulating resonance in a computer system I/O interface is provided. A shunting impedance/resistance is arranged across a power supply of the I/O interface. The shunting impedance/resistance is controlled by circuitry that is arranged to detect voltage overshoot conditions in the I/O interface. The circuitry has (1) an analog front end that is arranged to detect power supply oscillations relative to a grounded terminal, (2) an amplifier (or logic conversion circuit) that is arranged to convert an output signal from the analog front end to a digital signal, and (3) a shunting apparatus arranged to modify power supply behavior in the I/O interface dependent on the digital signal.

Abstract: A direction and a magnitude of a current flowing between an external alternating current power source (20) and a load (30) are detected by a current transformer (11). A voltage generated to a secondary winding (11B) of the current transformer as a result of detection is superimposed upon a voltage of the alternating current power source (20), and is supplied to the synchronous power source (S). The synchronous power source (S) generates a voltage having an instantaneous value which is the same as that of the voltage supplied thereto, and applies the generated voltage to the load (30) in parallel. Since the voltage applied by the synchronous power source (S) has a value for lowering the current detected by the current transformer (11), there is substantially no current flowing between the alternating current power source (20) and the load (30).

Abstract: The present invention was achieved in order to provide an antitheft device, which can prevent unauthorized intrusion into a car even if an engine is started by remote control, to be mounted on a vehicle having a remote engine starting system which starts the engine based on a command from a remote control transmitter, comprising a controller to control the state of door windows so as to prohibit at least the opening out of the opening and closing of the door windows when the engine is started by the remote engine starting system.

Abstract: A method and apparatus for reducing an impedance of a power supply path of an integrated circuit is provided. The power supply path includes a first power supply line and a second power supply line to provide power to the integrated circuit. At least one resistive element connected between the first power supply line and the second power supply line is adjusted to reduce the impedance of the power supply path.

Abstract: A method for reduction of natural system oscillations in an electric motor which is operated using a converter with a voltage intermediate circuit, by periodically decoupling the voltage intermediate circuit (UZK) from the supply mains system (N) at times which are synchronized to triggering equipment for the input converter (E), in particular for as long as current is flowing through the mains system input inductor (LK).

Abstract: In a method for damping power oscillations in a transmission line, at least one first angular-frequency signal is generated, representing a first angular frequency which is given by a prior knowledge of oscillation frequencies expected in the power system, and a first phase-reference signal is formed as the time integral of the angular-frequency signal. A power quantity in the transmission line characterizing the power is sensed and a first estimated power quantity is formed, representing for an oscillation of the first angular frequency, its amplitude and phase position relative to the first phase-reference signal. A first damping signal is formed with an amplitude dependent on the amplitude of the first estimated power quantity and with a first phase shift in relation to the phase position thereof, and the first damping signal is supplied to an actuator for influencing the power transmitted in the transmission line.

Abstract: A stabilization circuit wherein voltages of the secondary winding of a transformer are stabilized with respect to mains voltage fluctuations and load fluctuations, an auxiliary voltage is derived either from a secondary winding of the transformer or an auxiliary transformer. Together with the mains voltage portion of this auxiliary voltage acquired by pulse-width modulation forms the primary voltage of the transformer such that the desired stabilization is achieved.

Abstract: Disclosed is a circuit for stabilizing a high tension voltage of a CRT and a method thereof. A feedback unit receives a cutoff voltage from the CRT. A compensating unit calculates a variation quantity of the cutoff voltage on the basis of the cutoff voltage from the feedback unit. The variation quantity of the cutoff voltage is compared with a high tension voltage compensation data stored in a storing unit according to the variation quantity of the cutoff voltage. Accordingly, the circuit for stabilizing the high tension voltage of the CRT and the method thereof can overcome inaccuracy of the high tension voltage compensation due to delay, and cut down the production cost by removing an ABL circuit and a high tension voltage compensating capacitor. Since the ABL circuit is not used, it is also possible to perform partial compensation according to an alternating current variation quantity.

Abstract: The present invention discloses a system protection scheme comprising of at least two system protection terminals (18), introduced at suitable locations in an electric power system (1). The system protection terminals (18) are interconnected by a communication system (22), preferably using a substantially dedicated communication resource. At least-two of the system protection terminals (18) are equipped to collect measurement signals (72) associated with time stamped voltage or current values of the power system at that particular location or quantities derivable therefrom. The measurements are evaluated and related data is spread to other system protection terminals (18). At least one of the system protection terminals (18) is equipped to evaluate the existence of poorly damped power oscillations in the power network and if necessary provide control signals (74) to power system actuating units. The evaluation is preferably based on changes in the node angle differences between the measurement locations.

Abstract: A method and system for preventing sustained resonance conditions in a power system involves measuring voltage and current samples on a conductor to which a plurality of controlled capacitors are operatively coupled. The measured voltage and/or current is utilized to identify a resonance condition. The method or system determines whether the resonance condition is due to switching of a controlled capacitor and, if so a corrective switching operation is performed after a first time delay. If the resonance condition is determined not to be due to the switching of a capacitor, then a second switching operation, in which a second controlled capacitor is switched after a second time delay, is performed. The second time delay is preferably greater than the first time delay.

Abstract: In a power-electronic circuit arrangement for compensating for mains system voltage reductions and mains system disturbances, a second auxiliary voltage source is provided, whose voltage is chosen to be less than that of the first auxiliary voltage source. The second auxiliary voltage source can be coupled to the feeder converter with the aid of a switch. The circuit according to the invention can thus operate in two different modes: when the first auxiliary voltage source is coupled to the feeder converter, the available voltage is sufficiently high to compensate for mains system failures or mains system voltage reductions. However, when less severe disturbances occur, the second, lower auxiliary voltage source is coupled to the feeder converter, and mains system disturbances can in consequence be compensated for without any major switching losses.

Abstract: Pyroelectric detector systems may be used in vehicles for security applications, such as intrusion detection and anti-theft alarms. The pyroelectric detectors are small in size, highly reliable and consume very low power. They can be physically and electrically integrated with other vehicle components, including rear-view mirror assemblies in automobiles, without incurring additional installation costs. They can also be easily integrated into aircraft cockpits.

Abstract: A vehicle theft prevention and recovery system is activated by a pager upon receiving a telephonic signal from a pager service, in response to a call from a vehicle owner or operator, to activate anti-theft means including a warning to a thief in the vehicle, means for disabling the vehicle engine, and visual and audible alarm signal devices to identify the vehicle as stolen. The means for disabling the vehicle engine preferably disables the engine after a predetermined count-down warning to any occupant in the vehicle. In addition, the theft prevention and recovery system includes a light display on the exterior of the vehicle to warn outsiders of an impending vehicle disoperation. In addition, an embodiment is disclosed in which radar can be used from another source as, for example, a law enforcement vehicle, to trigger the operation of the vehicle disablement.

Abstract: The device comprises a transmitter (7) transmitting ultrasound into a predetermined space (5), a sensor (8) which senses the echoes from the transmission by the transmitter into the space in order to deliver a signal representative of the echoes, and electronic device for processing the signal in order to diagnose the possible presence of a moving body in the space (5). It further comprises a) device (10) for scanning the space (5) with the ultrasound beam output by the transmitter (7) and (b) device (11) for simultaneously moving the echo sensor (8) so as to optimize the signal/noise ratio of the output of the sensor (8).

Abstract: An electrical control unit for a vehicle successively writes operation data of the vehicle in a transponder provided in a key used for starting the vehicle. At the same time, the electric control unit successively writes the same operation data in a memory area of a non-volatile memory corresponding to a key used for starting the engine. When the key is lost, the engine is started under the condition that the identification of the lost key is written in a replacement key. Then, the electric control unit of the vehicle writes operation data stored in the non-volatile memory corresponding to the lost key in the replacement key. At the same time, the electric control unit of the vehicle moves the operation data to a memory area corresponding to the replacement key. Accordingly, when the operation data is read from the replacement key, operation data stored in the lost key can be managed.

Abstract: An anti-vandalism detection and alarm system is disclosed for detecting and reporting the scratching of relatively hard materials such as glass and plastic which generate characteristic sound or vibration frequencies during scratching, and for detecting and reporting the cutting and slashing of relatively soft materials such as fabric, leather and plastic.

Abstract: A vehicle security system includes a first housing for positioning adjacent the front windshield area of the vehicle, and an antenna carried by the first housing for receiving signals from the at least one remote transmitter. The security system also includes a security controller positioned in spaced apart relation from the first housing and being operatively connected to the antenna to be responsive to signals from the remote transmitter. Moreover, an indicator is preferably carried by the first housing, and is driven by the security controller for a number of significant purposes. In one embodiment of the invention, the indicator is preferably an alphanumeric indicator. The indicator may be used to display a number of remote transmitters capable of operating the security controller. The system may also include a coded override feature for switching to the disarmed mode from the armed mode responsive to operation of the control switch in a predetermined pattern based upon a plurality of user override codes.

Abstract: A method and apparatus for providing a vehicle theft alarm using a handheld computing device. A handheld computing device is disclosed that includes an image capture device, a location determination system and a communication device. The handheld computing device can be used for capturing images and transmitting images to other locations via the communication device. The handheld computing device also includes a position determining system for determining position of the vehicle. The handheld computing device can be located within a vehicle and the alarm system activated such that, upon the occurrence of an alarm triggering event, the image capture device captures images of the driver's compartment of the vehicle and the location determination system determines the location of the vehicle. The captured images and the determined location are transmitted through the communication device to a designated remote location.

Abstract: The present invention relates to an apparatus and a method for a motor vehicle security system relating to immobilizing and enabling of a fuel pump for a motor vehicle engine. The system comprises data input means for receiving driver verification data, an engine control unit (ECU) including an ECU processor for controlling engine operation, a pump control unit (PCU) including a PCU processor for controlling the fuel pump, the PCU being separate from the ECU and integrally housed with the fuel pump. Communication links permit communication between the data input means and ECU, and between the ECU and PCU. The ECU processor is activated to control the PCU when valid driver verification data is received. The PCU processor is then activated to communicate a challenge code to the ECU. The ECU and PCU processors then compute respectively a first and a second response code associated with the challenge code.

Abstract: To prevent a theft of a car with a forged key, the start of an engine is permitted irrespective of the result of judgement of start judging means for a predetermined time after a key switch is turned on and the engine is stopped after the passage of the predetermined time and when the start judging means judges that the start of the engine should be inhibited.

Abstract: A security device (2) of a security system which a user can unlock by means of a transmitter unit (1) normally can also be unlocked by unauthorized users utilizing the transmitter unit (1). The new procedure acording to the invention is to allow only authorized users to access the object (4) to be secured by means of a security system, even in the event of the transmitter unit (1) being lost or stolen. To this end, the transmitter unit (1) will generate an identification signal (3) characterizing the user, by means of a detector (10) scanning the user's own physical features, preferably a finger print. This identification signal (3) will then be transmitted to the security device (2). This security device can then be unlocked only if there is a match between the identification signal (3) and a stored identification signal provided by a user authorized to unlock the security device.

Abstract: In a current interrupter for a battery lead for motor vehicles, with a contact element between the two connecting parts for their electrical connection and with an auxiliary drive for separating the two connecting parts, contact element applies only a transverse force that is directed essentially perpendicularly to the connecting parts. A retaining force which is directed opposite to the action of the auxiliary drive is mainly applied at one point and is spatially separated from the contact element.

Abstract: The present invention provides an apparatus (10) for selectively enabling or disabling an actuatable vehicle occupant protection device (18). The apparatus (10) includes a cylindrical housing (80) having an inner sidewall portion (88), which has an annular ledge (90) adjacent the first end (82). A locking rib (102) extends axially a predetermined distance from the ledge (90) toward the second end (84) of the housing (80). The inner sidewall portion (88) has a pair of spaced apart locking channels (104 and 106) along opposed sides of the locking rib (102). An elongated shaft member (40) is disposed within and rotatable relative to the housing (80). The shaft member (40) has at least one slot (50) extending axially from a first end (42) portion of the shaft member (40). A blade member (56) is disposed within and axially movable relative to the shaft member (40). The blade member (56) has at least one arm (60) extending radially through the slot (50) and into one of the locking channels (104 or 106).

Abstract: When a control unit for controlling a 2-motor-3-relay type locking system makes a transition to, for example, an N/L (lock) state, the two motors are turned on or off such that operation timings of the motors are shifted from each other by a period of time longer than a shift amount (variation) of required operation times of the relays.

Abstract: Described herein is an in-dash automotive accessory having a detachable faceplate with a keypad and a medium resolution color graphics display. The graphic display has a rectangular array of addressable pixels. A serial interface is used to transfer data to and from the faceplate. Although the serial interface has a clock rate of only 7.5 MHz, it allows refreshing of a 64.times.256 pixel display panel at a 70 Hz pixel refresh rate. This is accomplished through a variety of techniques, including the use of efficient command code protocol, by packing or compressing pixel intensity data, and by double buffering incoming control messages.

Abstract: To prevent the engine from becoming able to be started by a cut-off of the communication line, for example, an engine control ECU 20 contains a reference code which is used to compare with a personal ID code transmitted from a transponder 12 of a key 10. A key insertion detecting switch 22 start this comparison when the insertion of the key is detected, and finishes the comparison before the engine is started. When a trouble of the key insertion detecting switch 22 is detected, a code collating section 20b collates the ID code with a reference code until the number of revolutions of the engine 30 exceeds 500 rpm. Therefore, even when the key insertion detecting switch 22 becomes out of order, it is possible to recognize the operation with a correct key, and give a permission to start the engine 30.

Abstract: An alarm device is provided in a car. A criminal act such as braking of a window of the car is detected and a criminal act signal is produced. In accordance with the criminal act signal, the alarm device is operated. When an ignition switch of the car is operated by an ignition key within a first predetermined time after opening of a door of the car, the production of the criminal act signal is stopped.

Abstract: The casing of a passive proximity transceiver includes a protrusion which extends from the main body of the casing to prevent metal objects from touching the main body, where they would otherwise be close enough to interfere with reception of signals transmitted between the passive proximity transceiver and another electronic device. The casing may be arranged to be mounted on a key ring, with the protrusion being in the form of a collar extending around the main body.