Patent classifications
H02J3/1864
Detection and mitigation of instability of synchronous machines
Methods and systems for stabilizing a power system include receiving a set point for a power system that includes the compensation circuitry controlled by the control system. A firing angle for the power system is set based at least in part on the set point. An angle between a generator terminal of a generator of the power system and a bus of the power system is calculated. A determination is made whether the angle is within a threshold value of the firing angle. When the angle is not within the threshold value of the firing angle, compensation circuitry is engaged to stabilize the power system.
High-power conversion system
A high-power conversion system includes a switching circuit and at least one reactor, the at least one reactor being electrically connected to the switching circuit, and the core of the at least one reactor being electrically connected to a potential point of the high-power conversion system.
HIGH-POWER CONVERSION SYSTEM
A high-power conversion system includes a switching circuit and at least one reactor, the at least one reactor being electrically connected to the switching circuit, and the core of the at least one reactor being electrically connected to a potential point of the high-power conversion system.
Reactive power compensation system and method thereof
The present disclosure relates to a reactive power compensation system includes a first measurement unit, a second measurement unit, a reactive power compensation unit, and a controller. The first measurement unit measures impedance of each of at least one load. The second measurement unit measures a voltage and current provided to the at least one load. The reactive power compensation unit compensates the leading reactive power or the lagging reactive power. The controller monitors a change of the impedance in real time, checks a change of the voltage or current according to the change of the impedance, and controls the reactive power compensation unit according to a result of the check to compensate the leading reactive power or the lagging reactive power.
Methods and devices for power compensation
A method is performed in a control device for controlling a power compensation arrangement including a voltage source converter and one or more power compensation branches, each power compensation branch including a thyristor controlled reactor, a thyristor switched reactor or a thyristor controlled capacitor. The voltage source converter and the one or more power compensation branches are connected to a same busbar. The method includes: detecting a request in an electrical power system to which the power compensation arrangement is connected; determining, based on the request, a need for reactive power supply to the electrical power system; providing reactive power by means of the voltage source converter and/or by one or more of the power compensation branches; and compensating, by means of the voltage source converter, any disturbances caused by the power compensation branches when providing the reactive power to the electrical power system. Corresponding devices are also disclosed.
CONTROL APPARATUS AND METHOD IN STATIC VAR COMPENSATOR SYSTEM
A control apparatus in a static VAR compensator (SVC) system includes a plurality of current supply units for supplying phase currents configuring three-phase current of a power system, a plurality of current sensors for measuring the phase currents, and a controller for determining whether unbalance occurs in the three-phase current based on the phase currents, calculating an error corresponding to the unbalance according to the phase currents if unbalance occurs, and individually controlling at least one of the plurality of current supply units so as to compensate for the error.
Mixed signal controller
A mixed signal controller for a power quality compensator includes an analog circuit, an analog-to-digital converter (ADC), and a digital circuit. The analog circuit amplifies an input signal from the power quality compensator by a gain factor and outputs an analog signal, which is converted to a digital signal by the ADC. The digital circuit receives the digital signal, calculates the reference compensating current of each phase and then generates a trigger signal via hysteresis PWM to the power quality compensator. The digital circuit includes an evaluation circuit that calculates a value of the system total harmonic distortion after the power quality compensator compensates power and adjusts the gain factor when the value of the system total harmonic distortion reaches a predetermined threshold.
MIXED SIGNAL CONTROLLER
A mixed signal controller for a power quality compensator includes an analog circuit, an analog-to-digital converter (ADC), and a digital circuit. The analog circuit amplifies an input signal from the power quality compensator by a gain factor and outputs an analog signal, which is converted to a digital signal by the ADC. The digital circuit receives the digital signal, calculates the reference compensating current of each phase and then generates a trigger signal via hysteresis PWM to the power quality compensator. The digital circuit includes an evaluation circuit that calculates a value of the system total harmonic distortion after the power quality compensator compensates power and adjusts the gain factor when the value of the system total harmonic distortion reaches a predetermined threshold.
CONTINUOUSLY VARIABLE SATURABLE SHUNT REACTOR
A continuously variable saturable shunt reactor includes a laminated core having two wound limbs for each phase connected by yokes. A network winding branch is disposed on each limb, high-voltage ends of winding branches of a phase are connected to a phase conductor and low-voltage ends of winding branches are connected to a DC voltage source, to reduce power of the DC voltage sources, degree of distortion of the operating current and control error, and to reduce the number of DC voltage sources. The DC voltage source includes two stabilized, single-pole-grounded power converters with opposite polarities and two electronic transistor changeover switches controlled by a control system, for each phase. The control system feeds direct current to the winding branches of a phase in pulses using the switches and the direct current is fed into the winding branches at opposite poles from different power converters.
METHOD AND DEVICE FOR REDUCING VOLTAGE FLUCTUATIONS IN A SUPPLY NETWORK
Voltage fluctuations in a supply network are intended to be reduced efficiently and cost-effectively. According to the method, a current flowing into a load is measured and a corresponding current measurement signal is obtained. The voltage fluctuations are reduced with the aid of a TCR, which constitutes a thyristor-controlled reactance, and a VSC, which constitutes a voltage source converter. The current measurement signal or a corresponding variable is divided into a first portion and a second portion depending on a predefined absolute limit value. The TCR is controlled on the basis of the first portion and the VSC is controlled on the basis of the second portion. Alternatively, the TCR can be controlled with the load current measurement signal and the VSC can be controlled with a sum of the load current measurement signal and a TCR current measurement signal.