摘要:
A circuit for monitoring the voltage stress of a capacitor which produces an over-stress indicator signal responsive to the over-voltage history of the capacitor. If the measured voltage stress of the capacitor exceeds a predetermined over-voltage value, a characteristic-curve generator, having a predetermined transfer function, produces an output signal which is responsive to the measured voltage stress of the capacitor and the transfer function of the characteristic-curve generator. This signal is combined with a further signal which is responsive to a predetermined permissible continuous operation voltage value. The combined signals are conducted to an integrator having a predetermined integration time constant for producing an overload signal. The overload signal at the output of the integrator is a measure of the state of stress of the capacitor. Circuitry may be provided for disconnecting the capacitor from a transmission line in response to the output signal of the integrator. Also, plural capacitor voltage stress monitoring stages may be combined to monitor the capacitor voltage stress in a plurality of over-voltage ranges.
摘要:
A monitoring system for measuring the phase currents of a filter circuit, the monitoring system having current measuring transformers coupled to respective filter sections for suppressing the harmonic content. Voltage measuring transformers are provided for measuring the network phase voltages, each such voltage measuring transformer being coupled to an electronic filter simulator and a filtering section for suppressing harmonic content. The fundamental frequency component of the measured phase currents and the simulated phase currents are conducted to transient comparator circuitry which is coupled to indicating and triggering circuitry having individual counter stages. Only rapid variations between the measured and simulated phase currents will result in fault indications, thereby preventing false indications resulting from variations in temperature.
摘要:
A monitoring system for detecting earth contact of at least one phase of a polyphase network. Each of the phases in the network is connected by a capacitive-inductive filter to a neutral node which is connected to earth. In one embodiment of the invention, the current flowing from the neutral node to earth is detected by an induction current transformer which provides a signal responsive to said earth current. The output signal of the induction current transformer is conducted through at least one low pass filter for suppressing harmonics, and rectified to produce a direct current voltage signal, the amplitude of which is proportional to the amplitude of the fundamental frequency component of said signal. A fault indicating signal is produced when the direct voltage signal exceeds a predetermined value.
摘要:
A system for monitoring the capacitor batteries of a three-phase filter circuit. Each capacitor battery is formed of a plurality of parallel legs each having a plurality of sectional capacitors which are connected in series with fuses. Adjacent ones of the sectional capacitors are coupled to one another. In a three-phase system, three capacitor batteries are coupled to one another in a Y-circuit configuration, the Y-circuit node being coupled to a reference potential, illustratively ground. The magnitude and phase of the fundamental frequency component of the current flowing from the Y-circuit node to the reference potential is monitored, variations therein being evaluated to identify defective sectional capacitors. Only variations in the Y-circuit node current which occur rapidly will trigger fault signals, thereby preventing false indications resulting from variations in temperature.
摘要:
A method for the transmission of DC current via a DC network between at least one rectifier station and several inverter stations wherein reference inputs are formed on the basis of a fixed predetermined current-voltage characteristic and a fixed predetermined voltage-current characteristic matched to the aforesaid current-voltage characteristic for the voltage controller of the rectifier of the rectifier station and for the current controller of each inverter station, respectively. The formed reference input for each current controller is released to that current controller when the maximum value of the formed reference input exceeds a value determined for the reference input corresponding to the power demand associated with the inverter station which includes that current controller. When the maximum value of the formed reference input is less than the latter determined value, such value is released as the reference input to the current controller.
摘要:
A circuit arrangement is disclosed having an odd number of Y-connected frequency converters. The control units of the frequency converters are associated with current regulators, all of which are addressed by an additional common reference value. In accord with the invention, the aforesaid reference value is derived by generating a difference voltage corresponding to the difference of the voltages at the neutral point of the frequency converter circuit and the neutral point of the load. This difference voltage is then passed through a delay member whose time constant corresponds to the time constant of the load to develop the reference value.
摘要:
A circuit for damping hunting oscillations of controlled electric machines. The circuit is provided with a measuring circuit for determining the hunting oscillations and an identifier circuit for determining the angle components of such hunting oscillations. A phase shifter circuit is provided for receiving the angle components produced by the identifier circuit and forming a hunting oscillation correction signal which is shifted in phase from the hunting oscillations by a predetermined phase angle. The hunting oscillation correction signal is conducted to a control unit of the electric machine. The invention is particularly useful in damping hunting by the rotors of voltage controlled synchronous generators.
摘要:
In order to compensate for the effects of mechanical oscillations of the salient pole rotor in a synchronous machine in a simple manner, control coils are provided which generate a controllable quadrature-axis magnetic field. The control coils are arranged on the salient pole rotor in such a way that the quadrature-axis magnetic field generated by the control coils is superimposed in the air gap on the controllable direct-axis magnetic field generated by exciting coils enclosing each pole body of the salient pole rotor.
摘要:
Device for monitoring the service life of the shaft of a turbine-generator set includes an analog computer circuit having a pair of inputs and an output, means for feeding to the inputs of the analog computer circuit electrical quantities proportional to the voltage and the current of the generator, the analog computer circuit having means for converting the electrical quantities that are proportional to the generator voltage and current to an electrical quantity proportional to the electrical torque in the air gap of the generator, a simulation circuit having an input connected to the output of the analog computer circuit for receiving therefrom the electrical quantity proportional to the electrical torque in the air gap of the generator, the simulation circuit comprising means for determining the torques in individual sections of the shaft of the turbine-generator set and having a multiplicity of outputs corresponding to the number of individual sections of the shaft, an analog-to-digital converter having an output and having inputs connected to the outputs of the simulation circuit for receiving therefrom analog data corresponding to the torques in individual sections of the shaft and converting them to corresponding digital data, a digital computer having an input connected to the output of the analog-to-digital converter and connected therethrough to the simulation circuit, a trouble-monitoring device connected parallel to the analog-to-digital converter, and having means for restricting the analog-to-digital converter to feed the digital data through the output thereof to the input of the digital computer only if a torque of extreme value is present in a section of the shaft, the digital computer having means for converting the digital data into signals proportional to the service life of the shaft.
摘要:
A pharmaceutical comprising a therapeutic protein that hinds to a therapeutic target, the protein being modified with a compound that inhibits binding of the protein to the therapeutic target, the modified protein being effective for reducing an immune response against the protein and for producing a therapeutic effect by binding to the therapeutic target. The therapeutic protein may be an antibody that includes an antibody combining site that binds to the therapeutic target.