506results about "Generation protection through control" patented technology

An electric power supply apparatus includes a distributed power generator such as a gas turbine generator and a power converter such as an inverter apparatus for converting electric power generated by the distributed power generator into AC electric power (alternating-current power) having a required frequency and a required voltage and supplying the AC electric power to a load. The electric power supply apparatus further includes a control unit having output voltage vs. output current characteristics for determining an output voltage corresponding to an output current of the power converter. The output voltage vs. output current characteristics has a first dropping characteristic for causing output electric power of the electric generator to be limited, between a first output current exceeding a power generation capability of the electric generator and a second output current exceeding a power converting capability of the power converter.

An integrated fault and personnel protection system and method for a multi-thread converter in a wind turbine power system is provided. The structure and method provide for system optimization, as well as, arc flash protection. Fault sensing with means of removing power applied to the converter minimizes the energy available to produce an arc flash event. Sensing and disconnects devices for the protections are provided close to the source of energy to protect more of the system. Converter controls detect, identify and isolate faults selecting the best combinations of the novel specific fault isolation devices. Components are distributed into separate physical to enhance protection.

A wind turbine generator system can regulate the rotational velocity of the wind turbine within an operation range even when the wind velocity suddenly changes and can perform continuous operation of the wind turbine. The wind turbine generator system includes a generator connected to the shaft of the wind turbine and a converter connected to the generator. When the rotational velocity of the wind turbine is within a predetermined range, power outputted from the generator is controlled so as to follow the instruction concerning the generator output given from the wind turbine to the converter. When the rotational velocity of the wind turbine is out of the predetermined range, the power outputted from the generator is controlled without following the instruction concerning generator output given from the wind turbine to the converter.

An electromechanical generator comprising an electromechanical device for converting mechanical vibrational energy into electrical energy, the electromechanical device having a vibratable mass adapted to resonate with an oscillation amplitude at a frequency and a regulator for regulating the oscillation amplitude to a value not greater than a maximum threshold.

A protection system and a protection method are provided for protecting a double fed induction generator and a gearbox during a grid fault. The protection system includes a plurality of controlled impedance devices. Each of the controlled impedance devices is coupled between a respective phase of a stator winding of the double fed induction generator and a respective phase of a grid side converter. The protection system also includes a controller configured for coupling and decoupling impedance in one or more of the plurality of controlled impedance devices in response to changes in at least one of a utility grid voltage and a utility grid current.

A control apparatus for a vehicle generator includes a switch, a regulator, a fault condition detector, and a PWM signal generator. The switch is selectively turned on and off so as to intermittently excite the generator. The regulator controls on / off operation of the switch so as to bring an output of the generator into agreement with a target value. The fault condition detector detects a fault condition of the generator. The PWM signal generator generates and outputs a PWM signal that has a duty determined as a function of a duty of the on / off operation of the switch and a frequency determined based on if the fault condition of the generator is detected by the fault condition detector. Consequently, the control apparatus can inform an external control apparatus of the duty of the on / off operation of the switch and the fault condition of the generator with the single PWM signal.

A system and method for protecting a motor drive unit from an associated motor includes a motor drive unit protection system. The motor drive unit protection system includes at least one switch configured to be connected between a motor drive unit and a plurality of motor leads of the motor driven by the motor drive unit. The motor drive unit protection system also includes a controller configured to monitor the motor drive unit or the motor to determine a fault condition indicative of the motor potentially operating as a generator. Upon determining the fault condition, the controller is configured to cause the at least one switch to connect the plurality of motor leads together to protect the motor drive unit from the motor when the motor is operating as a generator.

A protection system and a protection method are provided for protecting a double fed induction generator and a gearbox during a grid fault. The protection system includes a plurality of controlled impedance devices. Each of the controlled impedance devices is coupled between a respective phase of a stator winding of the double fed induction generator and a respective phase of a grid side converter. The protection system also includes a controller configured for coupling and decoupling impedance in one or more of the plurality of controlled impedance devices in response to changes in at least one of a utility grid voltage and a utility grid current.

A fault protection system and method of fault protection for permanent magnet machine (PMM)-based systems that utilize machine neutral decoupling (MND) to shut down a shorted winding and / or to isolate a short-circuit fault to prevent damage to a permanent magnet machine and to any downstream components are provided. The invention may be used for high-reactance and / or high current PMM-based systems, such as are commonly found in industrial and aviation applications.

A wind turbine having a rotor, at least one rotor blade, and a plurality of generators, of which a first generator is configured to provide power to an electric grid and a second generator is configured to provide power to the wind turbine during times of grid loss. The wind turbine is configured to utilize power provided by the second generator to reduce loads on the wind turbine during times of grid loss.

The present invention relates to a method and an apparatus for controlling a power-grid connected wind turbine generator during grid faults. During grid faults, the stator windings of the wind turbine generator are disconnected from the power grid and impedances for dissipating at least part of the power generated by the wind turbine during grid fault condition are connected to the stator windings. In this way, a certain magnetisation of the generator can be maintained and after removal of the grid fault condition, the generator is synchronised to the power grid and the impedances are disconnected and the stator windings are reconnected to the power grid. In this way, it is possible to keep the wind turbine generator at least partly magnetised during grid faults and thus ready for delivering power to the power grid, as soon as the grid voltage is re-established after the fault.

The present invention relates to a method and an apparatus for controlling a power-grid connected wind turbine generator during grid faults. During grid faults, the stator windings of the wind turbine generator are disconnected from the power grid and impedances for dissipating at least part of the power generated by the wind turbine during grid fault condition are connected to the stator windings. In this way, a certain magnetisation of the generator can be maintained and after removal of the grid fault condition, the generator is synchronised to the power grid and the impedances are disconnected and the stator windings are reconnected to the power grid. In this way, it is possible to keep the wind turbine generator at least partly magnetised during grid faults and thus ready for delivering power to the power grid, as soon as the grid voltage is re-established after the fault.

A vehicle power generation control apparatus that has a power supply circuit, a rotation detecting circuit, an exciting current detecting circuit, an exciting current control circuit, a torque detecting / maximum exciting current determining circuit and a power transistor. When a speed of rotation of a vehicle generator is detected by the rotation detecting circuit and an exciting current flowing through an exciting winding of the vehicle generator is detected by the exciting current detecting circuit, the torque detecting / maximum exciting current determining circuit calculates an upper limit value of the exciting current so that a rate of change of a generator torque does not exceed a predetermined value, and the exciting current control circuit controls the exciting current so that the exciting current becomes below the limit value. This can prevent the engine revolution from becoming unstable due to variation of load or variation of engine revolution.

A typical power plant has a plurality of generators; at least one load; at least one bus interconnecting the generators and the at least one load. The plant is operated on an uncorrected droop configuration for speed control and voltage control. The plant further includes a monitoring module for monitoring at least one of a plurality of signals; a calculating module for calculating a fault based on a comparison of predefined values expected from normal droop operation with respect to monitored values obtained from the monitored signals; and a control module for providing an order to bring additional generating capacity on line, for tripping a generator if a fault has been identified with respect to a single generator or for tripping a tie breaker to provide bus to bus isolation if an identified fault cannot be isolated to a single generator.

A method and a device for determining the rotor temperature in a permanent-magnet-excited synchronous machine are described, in which field-oriented regulation takes place. An estimator is provided which is supplied with the manipulated variables for the direct-axis current and the cross current made available by a direct-axis current controller and a cross current controller. The estimator determines an estimate for the rotor temperature using the manipulated variables mentioned and a temperature model of the synchronous machine.

Method and system are provided for operating a generator using a dynamic capability curve. In one embodiment, the method allows providing a family of static capability curves corresponding to nominal reference levels of pressure of a fluid for cooling the generator. The method further allows acquiring data indicative of the actual pressure of the cooling fluid. A dynamic capability curve is generated to be responsive to the actual pressure of the cooling fluid. The family of static capability curves may be displayed relative to the dynamic capability curve, thereby allowing the operator to monitor and control the operation of the generator based on the actual pressure of the cooling fluid and further in view of at least one of the nominal reference levels of pressure for the cooling fluid.

Methods and system are provided for operating an energy producing device when a utility grid is unavailable. The energy producing device includes a power system receiving power from a generator of the energy producing device. The power system includes a main power component and an accessory power component, where the received power is provided to the main power component and accessory power component depending upon the availability of the utility grid. The main power component provides the received power to the utility grid and the accessory power component provides power to accessories of the energy producing device, wherein the power includes the received power and power from an energy storage device included within the accessory power component.

According to the present invention, there is provided a control apparatus for an automotive alternator which includes a switch, a target voltage setter, a voltage regulator, and a disconnection detector. The switch is configured to be selectively turned on and off so as to intermittently excite the alternator. The target voltage setter works to set a target voltage. The voltage regulator works to regulate an output voltage of the alternator to the target voltage through controlling on / off operation the switch. The disconnection detector works to detect disconnection between the alternator and an on-board battery to be charged by the alternator. The disconnection detector is configured to detect the disconnection, when the target voltage is changed from a lower value to a higher value, based on a time required for the voltage regulator to bring the output voltage of the alternator from the lower value to the higher value.

A renewable energy extraction device, such as a wind turbine generator includes a turbine driving a hydraulic pump and a variable displacement hydraulic motor driving an electrical generator connected directly to an electricity grid. The hydraulic motor employs electronically controlled valves operated to select the net displacement of working chambers of the hydraulic motor on each successive cycle of working chamber volume. In the event of an electric grid fault causing the maximum absorbable torque of the electrical generator to collapse, the electronically controlled valves are controlled to substantially reduce the rate of displacement of working fluid by the hydraulic motor, rapidly reducing the torque exerted on the generator rotor. This has the benefit of avoiding pole slip which could otherwise cause serious damage. During the fault, the rate of displacement of working fluid by the hydraulic motor is controlled to maintain the phase and frequency of rotation of the generator rotor in synchrony with the electricity grid so that electricity generation can resume rapidly once the grid failure is rectified. Excess working fluid displaced by the hydraulic pump is stored in an accumulator. When the maximum amount has been stored pressurised fluid is discharged through a throttle to avoid damage but maintain pressure within the hydraulic transmission so that electricity generation can resume rapidly if the grid failure is rectified. If the fault persists, the turbine blades are feathered to reduce power input and if the fault persists for a further period of time, the energy extraction device shuts down.

In a power-generator control apparatus, a control circuit intermittently controls the supply of a field current from a battery to a field winding of a power generator in normal mode so as to adjust power induced in an output winding of the power generator. The control circuit interrupts the supply of the field current from the battery to the field winding in transient mode when a transient voltage occurs. An energy absorbing circuit absorbs magnetic energy stored in the field winding independently of magnetic-energy consumption by a resistance of the field winding itself.

The invention provides an excitation fault fault-tolerant power generation system of a double-salient electro-magnetic motor and a control method of the system. According to the control method, when the system detects an excitation fault, an excitation circuit is disconnected and a fault-tolerant mode is switched to for operation, and in the fault-tolerant operation mode, a fault-tolerant power generation function of the excitation fault of the motor is achieved through a novel six-beat power generation control strategy that positive-direction exciting current and negative-direction exciting current are led to each phase of a three-phase four-arm convertor. The control method of the system makes full use of the three-phase four-arm convertor of the double-salient electro-magnetic motor, enables the motor to continue to generate power under the conditions of faults, is suitable for brake feedback motors, starter generators and other multi-quadrant operation double-salient electro-magnetic motors in the aerospace industry, automobile industry and other industries.

A control apparatus for a vehicle generator includes a switch, a regulator, a fault condition detector, and a PWM signal generator. The switch is selectively turned on and off so as to intermittently excite the generator. The regulator controls on / off operation of the switch so as to bring an output of the generator into agreement with a target value. The fault condition detector detects a fault condition of the generator. The PWM signal generator generates and outputs a PWM signal that has a duty determined as a function of a duty of the on / off operation of the switch and a frequency determined based on if the fault condition of the generator is detected by the fault condition detector. Consequently, the control apparatus can inform an external control apparatus of the duty of the on / off operation of the switch and the fault condition of the generator with the single PWM signal.

A fault-tolerant control system and method for variable-speed variable-pitch wind turbines with an inverter-fed generator. When generator faults are detected, the generator torque and / or flux is limited to prevent propagation of the faults and possible failure and shutdown of the generator. The control system and method improves on two-loop control methods for variable-speed variable-pitch wind turbines and provides improved power delivery under fault conditions.

A vehicle generating system includes a generator for a vehicle, a voltage regulator that supplies field current to the field coil at a variable duty ratio, a field current sensor that detects field current amount, a signal transmitting circuit that transmits a signal representing the detected field current amount and the duty ratio and an electronically controlling unit that receives the signal representing the detected field current amount and the duty ratio and controls the engine according to one of the detected field current amount and the duty ratio.