35results about "Emergency protective arrangements for automatic disconnection" patented technology

Systems and methods are disclosed for detecting balanced electrical leakage between a power source and a machine frame. In one embodiment, a balanced fault detection system for a machine includes a power source that is electrically insulated from a machine frame and a leakage detection switch that is connected to a ground. The balanced fault detection system also includes a leakage detection resistor that is interposed between a power source terminal and the switch having a leakage detection resistance. The balanced fault detection system further includes a voltage measuring device that measures voltages of the power source at positive and negative voltage sides of the ground and a leakage calculator that calculates a leakage resistance of the machine based on the measured voltages at the positive and negative voltage sides and the leakage detection resistance.

In accordance with various aspects of the present invention, a method and circuit for reducing power consumption of a power strip is provided. In an exemplary embodiment, a power strip is configured for reducing or eliminating power during idle mode by disengaging an outlet from power input. A power strip may include two or more outlets and two or more outlet circuits, with AC power input connected to the outlets through the outlet circuit(s), which may include a current transformer, a control circuit, and a switch. The current transformer secondary winding provides an output power level signal proportional to the outlet load. If behavior of the current transformer secondary winding indicates that the outlet is drawing substantially no power from the AC power input, the switch facilitates disengaging of the current transformer primary from the outlet.

A closing phase that produces the smallest energization flux error at a connection input point is calculated based upon a residual flux of the first closing phase and the preliminarily given pre-arc characteristic and closing time deviation characteristic of a three-phase circuit breaker, so that the calculated phase value is set as a target closing phase of the first closing phase. A closing phase that produces the smallest energization flux error when a residual flux of zero is calculated, so that the calculated phase value is set as a target closing phase of the remaining two phases. The total time required from the reference point to the target closing phases of the remaining two phases and a delay time corresponding to an integer multiple of a given cycle of the three-phase power supply is set as a target closing time of the remaining two phases.

An electric vehicle includes a control unit having overcurrent generation judgment unit, inverter selection unit, and inverter drive control unit. The overcurrent generation judgment unit judges whether an overcurrent is generated in an inverter for generation or an inverter for travel. When an overcurrent is generated in one of the inverters, the inverter selection unit selects the other inverter to be driven. The inverter drive control unit stops the driving of the one inverter and drives the other inverter to drive a travel motor or a generator.

The invention relates to a reactance relay and a re-closing method, the reactance relay is based on the current of a fault point of a mixed circuit of a high-voltage cable and a trolley wire, the reactance relay based on the current of the fault point is the reactance relay based on information of momentary current on two sides of the circuit, the momentary current on two sides of the circuit is utilized, capacitance current of a trolley wire circuit and a cable circuit and the current of a shunt reactor of the trolley wire are compensated, and the precise current of the fault point can be obtained by calculation. As for the mixed circuit of the high-voltage cable and the trolley wire without the shunt reactor, a protector on the trolley wire side is used for judging whether the re-closing is started or not, the protector on the trolley wire side always adopts the synchronous check way for superposition, the action range of the reactance relay is set to the junction of the trolley wire and the cable, if the reactance relay acts, a fault occurs in the trolley wire circuit, the re-closing is started, otherwise, the re-closing is locked. The re-closing is started when the fault occurs in the trolley wire of the mixed circuit, and the re-closing is locked when the fault occurs in the cable.

The invention discloses a leakage protection device which can prevent electric shock accidents caused by faults of electric equipment and also can prevent the electric shock accidents caused by the fact that an earth wire is electrified accidently. The leakage protection device is also provided with a weak current detection sensor, a voltage comparator circuit and a one-way output circuit; an iron core of the weak current detection sensor is wound by a primary winding and a secondary winding; a detection circuit which is formed by serially connecting the primary winding with a current-limiting capacitance resistance element is connected between the earth wire and a neutral wire; a standard voltage obtained from a stable-voltage power supply is input into an input end of the voltage comparator circuit; an output end of the secondary winding of the weak current detection sensor and the other output end thereof are respectively connected with the other input end of the voltage comparatorcircuit and a cathode of the output end of a rectifying circuit; and the output end of the voltage comparator circuit is connected with a driving circuit of an electromagnetic coil through the one-way output circuit.

The invention relates to an overtemperature detection circuit and an overtemperature protection circuit used for a heater. Beneficial effects are achieved as follows: the overtemperature detection circuit and the overtemperature protection circuit do not need to use a temperature sensor, and instead, can judge whether the heater suffers from an overtemperature condition or not by detecting the power supply voltage and the voltage difference between the two ends of the heater. In addition, in a condition that only an external circuit and a protection switch are needed, overtemperature protection on the heater can be realized; therefore, the size of the heater can be obviously reduced, and the single fault protection function is not lost; and on the aspect of a micro heater, a novel thoughtis provided, and quite high practical value and economic value are achieved.

The present invention discloses a fan protection apparatus and related method thereof. The fan protection apparatus has a control circuit and a counter. According to the fan protection method, the user can set the acceptable restart number and the special time for auto restart. The fan protection apparatus and method can force to stop the fan when the fan encounters an abnormal situation. When the stop time has passed, the fan is automatically restarted. The present invention counts the number of restarts. If the number of restarts equals the set number and the abnormal situation also cannot be eliminated, the present invention cuts off power to the fan

The invention provides an over-voltage protection (OVP) protection line of multiple groups of voltage. The OVP protection line of the multiple groups of voltage comprises a multivoltage sampling circuit, a voltage detecting circuit and a delayed self-locking protection circuit, wherein the multivoltage sampling circuit, the voltage detecting circuit and the delayed self-locking protection circuit are connected in series in sequence. The multivoltage sampling circuit is used for inputting the highest voltage of multiple groups of voltage into the voltage detecting circuit. The voltage detecting circuit judges whether the received voltage exceeds critical voltage. When the actual voltage exceeds the critical voltage, the delayed self-locking protection circuit is triggered. When the delayed self-locking protection circuit is triggered, a whole system is powered off, and the whole line is in a protection state. Compared with the prior art, the OVP protection line of the multiple groups of voltage can detect multiple groups of voltage, and meanwhile has delayed and self-locking functions, and can effectively save cost.

The invention discloses a convenient-to-judge detection type over-current protection device which comprises a box body. An electrifying plate is embedded in the inner wall of the top of the box body,a conductive column is rotatably connected to the inner wall of the bottom of the box body through a bearing, and a rotating plate made of an insulating material is coaxially welded to the upper end of the conductive column. Memory metal is fixedly connected between the rotating plate and the electrifying plate, and a circular connecting plate is coaxially welded to the lower end of the conductivecolumn. The device has the advantages that overload current in a household circuit and a short circuit problem of an electric appliance can be timely responded, the household circuit and the electricappliance are protected, the storage battery electric appliances in the box body are connected in series, by utilizing the characteristic that the phase resistance value of the internal circuit of the short-circuited electric appliance is small, the current of the storage battery enables the indicating lamp to emit a comparative amount of light, a user can quickly discover which electrical appliance is short-circuited, so that the problem can be conveniently solved in time.

A system and method for mitigating overvoltage on a DC link of a power converter of an electrical power system connected to a power grid includes receiving a voltage feedback signal from the DC link for a predetermined time period. The method also includes determining a rate of change of the voltage feedback signal during the predetermined time period. Further, the method includes predicting a future voltage value on the DC link as a function of the voltage feedback signal and the rate of change of the voltage feedback signal. Moreover, the method includes controlling the electrical power system based on the future voltage value.

The invention relates to a power supply protection system and a magnetic levitation blower. The system comprises a power supply conversion module of which the input end is used for connecting an external input power supply; an uninterruptible power supply of which the input end is connected with the output end of the power conversion module; a seamless power supply converter of which the first input end is connected with the output end of the uninterruptible power supply, the second input end is connected with the output end of the power supply conversion module and the detection end is used for connecting a controller; and a first DC stabilized power supply of which the input end is connected with the output end of the seamless power supply converter and the output end is used for connecting the magnetic levitation system for maintaining the suspension of the motor spindle. The system can generate a warning effect in time when the uninterruptible power supply fails and can seamlesslyswitch the power supply so as to enhance the power supply protection mechanism of the power supply and improve the power supply reliability.

The invention relates to a control circuit which serves for security-critical control of a consumer with an inductive load portion, to be connected to a direct voltage source, and a method for failure control. It is in this case assumed that the control circuit has a power driving assembly, a free-wheeling assembly and a reverse-connection protected assembly. In order to increase the probability of failure recognition, this control circuit is extended by a method for failure control. For this purpose the semiconductor switches of the assemblies, each formed by a MOSFET, are individually driven. The different switching statuses are checked by a diagnostic device which processes voltage values to be read out at outputs of the control circuit. In this way failure-free functionality and also possible causes of failure in the control circuit can be diagnosed.

The invention relates to the technical field of power protection and discloses an overvoltage control terminal and a distributed management system and method based on equal potential. The overvoltagecontrol terminal comprises an overvoltage control module, a discharge monitoring module, a fatigue monitoring module, a self-disengagement module, and a communication module. The overvoltage control terminal realizes voltage monitoring and management. The overvoltage control terminal distributed arrangement based on equal potential realizes the overall control and protection of the power supply and consumption equipment under the equal potential of a power supply network. The management system realizes visualized and centralized monitoring and management of the overvoltage control terminal ofthe entire power supply and consumption network, and has a high practical value and broad application prospects.

The invention provides a method and device for controlling power-on/off of a solar component and a curtain wall system of adopting the device. The method comprises the steps of collecting an environment characteristic signal related to the environmental safety in an environment of the solar component; judging whether the environment characteristic signal is matched with a preconfigured trigger signal or not; and if the environment characteristic signal is matched with the preconfigured trigger signal, cutting off connection of the solar component and external equipment. When emergencies, suchas a fire occur, disconnection of the solar component and the external equipment can be determined according to the characteristics of the monitored environment characteristic signal. The environmentcharacteristic signal is directly related to the emergencies, such as the fire and the probability that the environment characteristic signal is disturbed by the emergencies is relatively low, so thatthe security of adopting the environment characteristic signal as a corresponding control signal is relatively high.

The invention relates to the technical field of power supply protection circuits, in particular to a control system of a battery protection circuit, which is characterized in that the input end of a battery protection unit is connected with a battery pack; an electronic switch unit is respectively connected with the battery pack and the battery protection unit and is used for cutting off the battery pack when the battery pack works abnormally; the input end of the control unit is connected with the power supply unit, and the output end of the control unit is connected with the electronic switch unit for controlling start and stop of the electronic switch unit; the control unit specifically comprises a key switch, a control circuit and a micro-control chip, and the micro-control chip controls the electronic switch unit to be started and stopped according to the pressing state of the key switch after being powered on. The advantages are that the starting and stopping of the battery protection circuit are controlled so as to reduce static power consumption of an electronic product and prolong service time of a battery; in addition, the control system has a reset function, so that the system can be forcibly reset through the key switch when the system crashes or breaks down.

The present invention provides an arrangement and method for a galvanically insulated, AC/DC sensitive differential current measurement. The arrangement is an electric circuit arrangement having a high resolution having: a toroid current transformer having at least one secondary winding for detecting a differential current; a driver circuit for powering the secondary winding; a first oscillator circuit for controlling the driver circuit and for generating a time-modulated binary oscillator signal having dwell times in a state 1 and a state 2; a second oscillator circuit for determining the corresponding dwell time in the states 1 and 2 in high resolution by means of a clock signal having a clock rate independent of the oscillator signal; an evaluation device for evaluating the dwell time; and a data interface for outputting a differential-current measuring value; the driver circuit and the second oscillator circuit each being realized as structurally individual, integrated circuits.

An apparatus and method for circuit interruption, with auto-power on and fault memory. The interrupter includes first and second locks in series with one another, and in series between the circuit driving source and load. The first lock is in communication with the circuit driving source. Control circuitry may be disposed between the circuit driving source and the first lock. When either lock is open the circuit is open; with both locks closed the circuit is closed. Actuating one lock does not change the state of the other lock. While closing input such as a power signal is applied to the first lock it is closed, and while the closing input is not applied it is open. When an opening input such as a fault signal is applied the second lock opens, and when a closing input such as a reset signal is applied the second lock closes.

The invention discloses a rapid protection method for a tap switch of a converter transformer, and the method comprises the steps: collecting the voltage and current of each side of the converter transformer, and forming a rapid differential protection criterion of the converter transformer; relay signals of high oil temperature, on-load light gas, on-load gas, pressure release and the like of the converter transformer are collected to form non-electrical quantity anomaly detection criteria of the converter transformer; monitoring signals of oil temperature, body pressure, oil chromatography and the like at a tap switch of the converter transformer are collected to form abnormal criteria of the body monitoring signals of the converter transformer. And when the rapid differential protection criterion of the converter transformer is satisfied and the non-electrical quantity anomaly detection criterion or the body monitoring signal anomaly criterion is satisfied, performing protection action on the tap switch of the converter transformer. The method can sensitively and effectively identify the slight fault of the converter transformer tap switch and quickly act, thereby effectively protecting the converter transformer tap switch.

An electrical appliance sharing singlechip embedded-type chip with various anti-electric wall devices comprises a singlechip chip and a control software. The chip is characterized in that the input terminal of the singlechip chip respectively provides eight types of potential difference detecting device and a soft-touch switch bridged between an earth wire and a null line, an infrared transmitting and receiving device, a pyroelectricity transmitting and receiving device, a remote receiving device, a sensor, a temperature controller and other digital and non-digital signal input ports, and the output terminal of the singlechip chip respectively provides a crystal liquid display interface and a terminal control circuit interface. The chip has the advantages that the output signals from the potential difference detecting device connected thereof between the earth wire and the null line, etc. are received when the earth wire and basic insulation fail simultaneously, so that the executive circuit connected therewith is controlled to cut off the earth wire and the power supply of a heating unit on a real-time basis, and other control functions of the related electrical appliance are performed. The chip is applicable to various electric appliances sharing such as an electric water heater, a shower room with electric heating water supply, a flushing toilet with electric heating warming, an electric heating boiled water boiler, a sterilizing cabinet and a range hood, etc.

The invention discloses a speed limiting circuit for an electric bicycle. The base of the transistor T1 is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the speedometer of the electric bicycle, and the emitter of the transistor T1 is connected to the base of the transistor T2. Connection, the collector of transistor T1 is connected with the anode of diode D1 and the other end of relay K1 coil respectively, the collector of transistor T2 is connected with the other end of relay K1 coil, the collector of transistor T2 is also connected with the negative pole of light-emitting diode D3 The positive pole of the light-emitting diode D3 is connected to the other end of the resistor R2, one end of the normally closed contact switch of the relay K1 is connected to the positive pole of the supply voltage terminal J1, and the other end of the normally closed contact switch of the relay K1 passes through the ignition switch S2 Connect to the negative pole of the supply voltage terminal J1. The invention has simple control, simple circuit, easy realization and good application prospect.

The invention discloses a heating control circuit with a short-circuit protection function. The heating control circuit comprises a switching circuit unit, an overcurrent detection unit, a signal extension unit and an overcurrent feedback unit, wherein the first input end of the switching circuit unit is connected with an MCU output control signal, and the second input end of the switching circuit unit is connected with the output end of the overcurrent feedback unit; a sampling resistor of the detection unit is connected in series with the negative electrodes of the heating interface and the temperature sensing interface, and the output end of the detection unit is connected with the input end of the signal extension unit; and the output end of the signal extension unit is connected with the input end of the overcurrent feedback unit. The circuit is good in working effect and safe to use.