54results about "Emergency protective circuit arrangements" patented technology

The invention relates to a ground electrode circuit grounding protective system of a high-voltage DC transmission system. The system is provided with two parallel ground electrode circuits respectively connected in series with a high-voltage DC breaker, sets an allowable range of current differences of two ground wires and an allowable range of the subtraction of the line current sum of the two ground wires from the line current difference of the two ground wires and then sequentially executes the following control program: (1), reading currents of the two ground wires; (2), judging and comparing whether an absolute value of the current difference of two ground wires is larger than the allowable range thereof, if the absolute value is not larger than the allowable range, returning to the step (1); if the absolute value is larger than the allowable range, (3) then, judging whether the subtraction of the line current sum of the two ground wires from the line current difference of the two ground wires is smaller than or equal to the allowable range; if the subtraction is smaller than or equal to the allowable range, returning to the step (1); and if the subtraction is not smaller than or equal to the allowable range, enabling the high-voltage DC breaker which is connected in series with the ground wire with larger line current to trip and terminate the program. The system can avoid the imbalance of the ground electrode circuits due to the failures of the ground electrode circuits and protects the caused DC transmission system to be closed down.

Provided is a method of localizing rack-mounted computing devices, the method comprising: receiving, with a direct current (DC) power bus or via an Ethernet control network or data network, a request from a control unit for a rack computing device location; generating, with a sensor, output signals conveying information related to a location of the rack-mounted computing device; and sending, with the direct current (DC) power bus or via an Ethernet control network or data network, location information of the rack-mounted computing device.

The invention provides a fault phase selection method of double transmission line protection on the same pole, comprising the steps that (1) a low voltage phase component criterion Uphi<Uset selects the fault phase firstly, in the formula, Uphi is any one voltage value of the three phases A, B and C, and the Uset is a set voltage threshold constant value; (2) the criterion FORMULA based on fault component direction distinguishes the fault type, among the formula, Delta Uphi and Delta Iphi are the fault component voltage and current of the fault phase selected by the low voltage phase selection component, and Theta phi is the phase angle difference of them; when step (1) and step (2) are fulfilled at the same time, the fault phase Phi is judged to be an internal fault phase, then the protection is implemented, if only the step (1) is fulfilled, the fault phase Phi is judged to be an external fault, then protection is not actuated.

A system and/or method for sensing the presence of moisture (e.g., rain) and/or other material(s) on a window such as a vehicle window (e.g., vehicle windshield, sunroof or backlite). In certain example embodiments of the invention, at least one sensing capacitor is supported by a window such as a vehicle windshield, the capacitor(s) having a field that is affected by moisture (e.g., rain) on a surface of the window. A sensing circuit outputs an analog signal that is based on and/or related to the capacitance(s) of the sensing capacitor(s). The analog output of the circuit may be converted to a digital signal via sigma-delta modulation, and subjected to processing (e.g., correlation) for determining whether moisture (e.g., rain, dew, fog, etc.) or the like is present on the surface of the window.

A half-open position holding apparatus for a vehicle opening and closing member includes an opening and closing member supported in a vehicle body to be openable and closable and has an opening and closing member driving unit that has a motor and a electromagnetic clutch that can put a power transmission path connecting the motor and the opening and closing member in a connected state and in a disconnected state, for driving the opening and closing member in opening and closing directions thereof, and an in-vehicle battery serving as a power source for the electromagnetic clutch. The apparatus includes a controller for controlling the opening and closing member driving unit, that, when the opening and closing member is held at a half-open position between a fully-closed position and a fully-opened position, holds the opening and closing member at the half-open position by stopping the motor, putting the electromagnetic clutch in a connected state, and controlling the electromagnetic clutch to a half-open position holding connection state such that a voltage applied to the electromagnetic clutch becomes a predetermined voltage lower than an output voltage of the in-vehicle battery.

A wind jet turbine with a housing that creates an air density deferential between the air within the housing and the wind passing outside the housing in order to generate the same or more electrical power in less space than traditional wind turbines.

The movable conductors of a three phase isolation switch are incorporated into the electrically insulative molded shaft, thereby mechanically supporting them and isolating them from the metal axle of the shaft. Movable contacts on the ends of each movable conductor are angularly spaced by α degrees, where α is less than 180° and is 90° in the exemplary embodiment. A common fixed load contact is located angularly between, and spaced α degrees from, both the fixed line and ground contacts so that the shaft is rotated only α degrees between a first, closed position, in which the movable conductors connect the fixed load contact for each phase to the corresponding fixed line contact, and a second, grounded position, where the fixed load contact of each phase is connected by the movable conductor to the corresponding fixed ground contact.

The invention discloses a multi-terminal flexible DC network longitudinal protection method and system based on current limiting inductor voltage polarity, which comprises the following steps: collecting voltage values of current limiting inductor at both ends of a DC line in real time; detecting voltage values of current limiting inductor at both ends of the DC line in real time; Voltage gradientalgorithm is used to deal with the voltage, and then to detect whether there is a fault; After the protection is started, the current-limiting inductor voltage in the sampling data window is integrated, and the current-limiting inductor voltage polarity is judged by comparing the integrated value S with the set threshold value. The current limiting inductor voltage polarity R at both ends of theline is compared, and if both polarities are positive, the fault is judged to be in-area fault, otherwise, the fault is judged to be out-of-area fault. The protection principle and algorithm of the invention are simple, and do not need mathematical tools such as fast Fourier transform, wavelet transform and the like for frequency division or traveling wave capture, and also do not need data synchronization at both ends of the line, and are easy to realize. The data window of the protection criterion is short, and no additional fault pole identification step is needed, so the protection criterion is fast.

The invention discloses a same-phase power supply equipment relay protection system. The system mainly consists of a microcomputer protection device, a breaker 1QF, a current transformer 1TA, a breaker 2QF, a current transformer 2TA, a voltage transformer 1TV and a voltage transformer 2TV, wherein the breaker 1QF and the current transformer 1TA are arranged between an alpha bus bar and same-phasepower supply equipment; the breaker 2QF and the current transformer 2TA are arranged between a beta bus bar and the same-phase power supply equipment; the voltage transformer 1TV is arranged on the alpha bus bar; the voltage transformer 2TV is arranged on the beta bus bar; and the current transformer 1TA, the current transformer 2TA, the voltage transformer 1TV and the voltage transformer 2TV areall connected with the microcomputer protection device. The invention also discloses a same-phase power supply equipment relay protection system-based protection method. By using the system and the method, the same-phase power supply equipment can be rapidly cut and isolated when fails, so that the same-phase power supply equipment is prevented from being damaged continuously and a failure-free part can recover normal operation rapidly; therefore, electrical energy can be continuously transmitted to an electrical locomotive safely and reliably.

Disclosed is a drive circuit for generating the drive current used to energize the windings of a motor. The drive circuit includes a data processing unit that produces two outputs used to control an H-bridge and generation of the drive current. One output, a commutation signal, controls the timing of generation of drive current. The drive current in turn is determined based on the other output, a speed signal. The speed signal waveform includes blanking portions to avoid occurrences of shoot through in the H-bridge.

A hybrid control system for controlling an electric machine coupled to a gas turbine engine is provided. The control system comprises: a primary analog control loop including an analog controller for controlling the electric machine based on a set point and a measured output of the electric machine; and a digital controller of the turbine engine operationally connected to the primary analog control loop to adjust at least one control parameter associated with the analog controller.

A DC circuit breaker is disclosed, the DC circuit breaker comprises n main branch circuits, a transfer current branch circuit, an energy dissipation branch circuit and 2n isolation units, the n main branch circuits are connected in parallel with each other, two ends of each main branch circuit are respectively connected with a transfer current branch circuit and an energy dissipation branch circuit through an isolation unit, the transfer current branch circuit is respectively connected in parallel with each main branch circuit, the energy dissipation branch circuit is connected in parallel with the transfer current branch circuit, and the system current flows through the n main branch circuits under the normal flow state; the transfer current branch circuit is not conducted; and the energydissipation branch circuit conduction threshold is higher than the system voltage, and no current flows through it. When one or more main branch circuits are short-circuited, the two isolation unitsof the main branch circuit are on, the main branch circuit is off, the transfer current branch circuit is on, and the fault current is quickly transferred to the transfer current branch circuit.

The invention discloses a torque limited permanent magnet coupler, which comprises a conductor rotor and a permanent magnet rotor. The conductor rotor and the permanent magnet rotor are provided with independent rotating axes. The conductor rotor is connected with the permanent magnet rotor through an air gap. The permanent magnet rotor can freely slide along the axial direction. When a load is overloaded or blocked, larger thrust is generated in the axis direction of the permanent magnet rotor according to the Li push and pull theory; the thrust pushes the permanent magnet rotor away from the conductor rotor and makes the action area of the permanent magnet rotor and the conductor rotor reduced so as to reduce the torque; and a motor is completely separated from the load so as to completely protect the motor and protect the whole motor dragging system.

The invention discloses an intelligent oil-immersed transformer comprising a box body filled with transformer insulating oil and a transformer installed in the box body. A transducer module and a protector are also installed in the box body, wherein the protector comprises a vacuum arc extinguish chamber, a control mechanism of the chamber and a control module; one end of the control mechanism is connected with a high-pressure bushing seat, and the other end thereof is connected with a movable contact of the vacuum arc extinguish chamber; a stationary contact of the vacuum arc extinguish chamber is connected with the high voltage line incoming end of the transformer; the control module is connected with the control mechanism and the transducer module respectively so as to perform circuit operation and transformation on the transformer operation electricity parameter data collected by the transducer module to transmit the data to a far end control center of a mass distribution network; meanwhile, the control module gives out a cut-off instruction to the control mechanism when circuit fails. The invention does not need additional breaker cabinet bodies, thus obviously reducing the installation space of the transformer and mating devices, and can greatly reduce installation and construction links and workload of the transformer, thus causing the transformer to be installed conveniently and quickly.

The present disclosure includes a compressor for use with an air-conditioner. The compressor includes a motor having a stator and a rotor. A compressing portion intakes gas, compresses gas and discharges gas. The compressor includes a protector located near the motor. The protector is connected in series to the circuit of the motor stator coil. The protector has a temperature sensitive element that trips the protector in response to the temperature sensitive element being heated to a predetermined drive temperature. A thermal resistance heater connects in parallel to the temperature sensitive element. The compressor can be includes with an air-conditioner, having an evaporator, a condenser, a throttling member and the compressor.

The invention consists of: switching power outputting the AC power to voltage generating device through width pulse modulation; feedback control unit outputting feedback signal to switching power; voltage detecting unit selecting standard input voltage from voltage outputted from voltage generating device and controlling feedback control unit according to control signal outputted from standard voltage; abnormal voltage detecting unit connecting to all outputs of voltage generating device in order to monitor abnormal voltage generated from each output contact, when abnormal voltage occurs, cut off control signal to feedback control unit outputted from voltage detecting unit.

A power converter and a control method thereof are provided. The power converter includes a primary side switching circuit, a secondary side switching circuit, a transformer, and a control circuit. The primary side switching circuit includes a first set of switches. The secondary side switching circuit includes a second set of switches. The transformer is coupled between the primary side switching circuit and the secondary side switching circuit. The control circuit is configured to control power transfer between the primary side switching circuit and the secondary side switching circuit by controlling the first and second sets of switches. The control circuit is adapted to enable and disable the first and second sets of switches in an enabling duration and a disabling duration respectively and alternatively.

The invention discloses a power grid circuit wide-area current protection method. The method includes the first step of synchronously measuring the voltage phasor and current phasor of each transformer substation of a power grid through an existing wide-area measuring system of the power grid so as to obtain power grid synchronous data; the second step of calculating an admittance variation matrix through a wide-area backup protection system when single-circuit trip of the power grid occurs, and further calculating a voltage variation matrix of each transformer substation and the current variation of each circuit after the single-circuit trip of the power grid occurs; the third step of establishing a current protection criterion according to the calculated circuit current variation and the circuit current variation measured through the existing wide-area measuring system. According to the power grid circuit wide-area current protection method, the function of protecting the power grid circuit wide-area current after the single-circuit trip occurs is achieved through the existing wide-area measuring system of the power grid; when the topological structure of the power grid changes after the single-circuit trip of the power grid occurs, the variation of current which flows through each circuit after the single-circuit trip of the power grid occurs can be directly calculated without modifying the power grid admittance matrix, and the whole calculation process can be completed within 200 microseconds.

The invention discloses a discriminating system and method for automatic putting and retreating of startup-shutdown protection of a generator. The discriminating system is composed of a generator outlet voltage transformer (2), a main transformer (3), a grid-connected circuit breaker (4), a bus (5), a system-side circuit breaker (6), an enclosed bus (8), a first group of overhead lines (9), a second group of overhead lines (10), a third group of overhead lines (11) and a fourth group of overhead lines (12). With the discriminating system and method disclosed by the invention, a problem that the states of the generator set and the grid system are determined inaccurately only based on the state of the grid-connected circuit breaker. The states of the generator set and the grid system are determined by using the generator-end voltage frequency sum and the grid-connected circuit breaker as criteria simultaneously to realized automatic putting of startup-shutdown protection. The discriminating system and method have advantages of accurate identification, high adaptability and high reliability.

The invention belongs to the technical field of energy storage battery management systems, and particularly relates to a safe BMS (Battery Management System) for rapidly protecting the abnormality of a battery energy storage system. The invention aims at the prior art and scheme, a relay on each battery operation parameter monitoring and sampling module is omitted, an electric control switch on-off driving electric signal and a terminal of each battery operation parameter monitoring and sampling module are directly connected with an electric control switch, connected with a direct-current bus, of a battery cluster respectively, that is, when it is monitored that a battery is abnormal, the battery operation parameter monitoring and sampling modules directly and electrically drive and disconnect the electric control switch, connected with the direct-current bus, of the battery cluster, and accidents are prevented. Therefore, the system structure and composition are simplified, the cost is saved, the beneficial effect of getting twofold results with half the effort is achieved, and meanwhile the response speed and reliability of the BMS to battery protection are improved.

The invention discloses a clock synchronization method for a medium-low voltage distribution network, and the method comprises the steps: injecting a time synchronization characteristic signal at a downstream protection device of a medium-low voltage distribution line, collecting a disturbance signal waveform at an upstream protection device, and recording a local time scale; enabling the downstream protection device to transmit a disturbance signal waveform through a carrier channel and print a local time scale when disturbance starts, and enabling the upstream protection device to determinethe time scale difference of devices at the two ends by calculating the relevancy of the two curves. By implementing the method, the current situation and characteristics of the medium-low voltage power distribution network are fully considered, the influence of channel delay is avoided, a special channel does not need to be additionally laid, and time unification and strict synchronization of sampling moments of two different places are realized at low cost.

The invention relates to a phase sequence detection device for a three-phase AC power supply, in particular to an energy-saving phase sequence protector, which includes an intermediate relay and a transfer switch; the intermediate relay includes an intermediate relay coil and an intermediate relay contact; the intermediate The relay coil is connected between the AC contactor coil and the start button switch; the normally closed contact of the transfer switch is connected in series in the intermediate relay coil circuit, the normally open contact of the transfer switch is connected in parallel on the intermediate relay contact, and the intermediate relay contacts One end of the point is connected to the three-phase power supply, and the other end of the intermediate relay contact is connected to the power input end of the phase sequence protector. The invention adds an intermediate relay on the basis of the existing phase sequence protector, which can make the phase sequence protector work together with the equipment to be protected, shorten online time, reduce power consumption and improve safety.

The embodiment of the invention provides a short-circuit accident protection processing system of a power distribution network. The short-circuit accident protection processing system comprises a current-limiting reactor and protection processing equipment, wherein the current-limiting reactor and the protection processing equipment are arranged in parallel at set positions of a power distributionnetwork line, the set positions comprise at least one or more of a position in an outgoing line switch cabinet of a substation, a switch position of an initial-stage column of an overhead line, a switch position of a power distribution network branch and a user grading switch position, the protection processing equipment is used for limiting a short current to be an overcurrent or overload levelwhen a short-circuit accident of the power distribution network occurs, so that multi-stage differential protection matching of an automatic system of the power distribution network is achieved. Sincethe current-limiting reactor and the protection processing equipment, which are arranged in parallel, are arranged at the set positions of the power distribution network line, voltage drop of other branches cannot be caused, the whole power distribution network system is stable, local accident isolation without dependent on multi-stage differential matching of the system is further achieved, theimpact of the accident to the power distribution network is effectively reduced, and the voltage of the power distribution network is stabilized.