146results about How to "Reliable shutdown" patented technology

A stator arrangement for an electric motor. The stator arrangement including a laminated stator core with stator windings running through stator grooves and forming winding overhangs at each end face of the laminated stator core. The stator arrangement also includes an interconnection unit having a switching disk covering the winding overhangs on one end face of the stator. The switching disk further including at least one temperature monitor mounted thereon for monitoring the temperature of the stator windings. The temperature monitor being seated in a holding pocket that is resiliently connected to the switching disk in such a manner that, when positioned in one of the stator grooves, it is resiliently biased into engagement with a stator winding.

A switching apparatus includes a first transistor, a second transistor, a first circuit module, a first current sensor and a control circuit. The first transistor includes first, second and third terminals. The first terminal of the first transistor is coupled to a first power terminal. The third terminal of the first transistor includes a gate or base of the first transistor. The second transistor includes first, second and third terminals. The first terminal of the second transistor is coupled to a second power terminal. The second terminal of the second transistor is coupled to the second terminal of the first transistor. The third terminal of the second transistor includes a gate or base of the second transistor. The first circuit module includes an inductor in parallel with a diode. The first circuit module is connected between the first terminal of the second transistor and the second power terminal.

The invention provides an insulated gate bipolar transistor drive protective circuit. The protective circuit mainly comprises a VB+ power source, a VB- power source, an insulated gate bipolar transistor IGBT, an input impulse control circuit, an optocoupler P1, a primary amplifying circuit, a secondary amplifying circuit, a Vce monitoring protective circuit and an output circuit. The output circuit is mainly composed of a bipolar transistor circuit and a power source circuit and can output positive 15V impulse voltage and negative 15V impulse voltage. The positive 15V impulse voltage and the negative 15V impulse voltage output by the output circuit can enable the insulated gate bipolar transistor IGBT to be effectively communicated under different conditions of communication rising time and cutoff falling time. On application occasions with high interference, the negative 15V impulse voltage provided by the output circuit can enable the insulated gate bipolar transistor IGBT to be cut off reliably, and working reliability of the insulated gate bipolar transistor IGBT is improved.

The invention discloses an over temperature protection circuit used for a power device, and the over temperature protection circuit specifically comprises a temperature detection module, a cutoff control module, a delay temperature setting module and an electrifying module. The over temperature protection circuit requires no separate reference voltage source and can be electrified both from input signals and from a protected power device. The thermal induction source for temperature detection is a current source with the current value being direct proportional to the temperature. When the temperature reaches the over temperature point, the current path between a pre-driver and the power device is cut off by the cutoff control module, the power device can be reliably cut off and the overall power consumption under over temperature is the lowest. According to the invention, the delay temperature can be set by adjusting the proportion of the two current sources, and the protection can be relieved after the temperature is lower for one delay temperature than the over temperature point, so oscillation near the over temperature point can be effectively avoided and the power device can not be turned on by mistake.

The invention discloses a three-level inverter narrow pulse suppression method and device; the method comprises the following steps of S1, determining the minimum pulse width by combining factors suchas minimum turn-on time and turn-off time, dead zone time, switching frequency and the like of an IGBT, and calculating the duty ratio; S2, calculating the amplitude of a voltage vector, carrying outper-unit treatment, and comparing the amplitude with an upper limit value, and then carrying out correction and amplitude limiting on the vector amplitude when the amplitude is greater than the upperlimit; S3, calculating the duty ratio of the three-phase modulating waves; S4, making compassion between the duty ratio of the three-phase modulating waves and the duty ratio corresponding to the minimum pulse width, wherein if the absolute value of the duty ratio of any one phase of modulating wave is smaller than the duty ratio corresponding to the minimum pulse width, the duty ratio of the modulating wave of the phase is assigned to an intermediate variable temp, and the temp is subtracted from the duty ratio of the three-phase modulating waves; and S5, updating a PWM register. According to the method, an additional hardware circuit does not need to be added, and the method is easy to implement; and compared with a method for restraining a narrow pulse by using a hardware circuit and the like, the size can be effectively reduced, and the cost is saved.

The invention discloses an optical fiber trigger type high-voltage solid-state switch. The optical fiber trigger type high-voltage solid-state switch comprises a high-voltage direct-current power source, an FPGA control system, an optical fiber driving signal transmission part, an optical fiber fault signal transmission part, an IGBT series circuit, a plurality of IGBT driving modules and a plurality of IGBT voltage-sharing circuits; the optical fiber driving signal transmission part comprises a first optical fiber transmission module and a first optical fiber receiving module, the optical fiber fault signal transmission part comprises a second optical fiber transmission module and a second optical fiber receiving module, a plurality of series IGBT switches are arranged in the IGBT series circuit, and the number of the IGBT driving modules is the same as the number of the IGBT switches; the positive pole of the high-voltage direct-current power source is connected with the collector of the first IGBT switch in the IGBT series circuit through a load, and the negative pole of the high-voltage direct-current power source is connected with the emitter of the final IGBT switch in the IGBT series circuit. The optical fiber trigger type high-voltage solid-state switch is high in integration level, small in circuit board size and low in cost, effective electric isolation is provided, and the optical fiber trigger type high-voltage solid-state switch has the overcurrent and short circuit protection function and is flexible and convenient to use.

The invention discloses a multi-electrode rotary spark gap switch used for a high-voltage pulse powder supply, and belongs to the technical field of pulse power. The switch comprises a stator (8), a rotor (7), a rotor needle electrode (9), a stator needle electrode (10) and a drive motor (1). The stator (8) and the rotor (7) are respectively provided with 2N layers of the needle electrodes, each layer of the stator (8) is provided with M stator needle electrodes (10), the stator needle electrodes are connected with a lead to keep the same electric potential, one rotor needle electrode (9) is arranged at each layer of the rotor (7), the rotor needle electrodes of two adjacent layers keep a 180-degree mechanical angle, and are directly connected with a lead to keep the same electric potential, and the switch is turned on when the motor drives the rotor to rotate until the rotor needle electrode and the stator needle electrode are opposite. The switch has the advantages of high switching voltage, high switching power and high frequency of repetitive work, fast switching speed less than 10ns, simple insulation structure, long service life, convenient maintenance, low cost, etc.

The invention discloses a high-voltage IGBT driving and protecting circuit. A signal processing circuit, an isolation transformer transmission circuit, an isolation power supply circuit, an undervoltage protecting circuit, a gate pole clamping circuit, a short-circuit protecting circuit, an IGBT dynamic fault detecting circuit, an insulated gate bipolar transistor and a power supply are included. The high-voltage IGBT driving and protecting circuit has the advantages that working under a high-voltage operation environment can be achieved, high power can be output, high working efficiency is achieved, quick response is achieved, low-input-output delay time is at the microsecond level, high anti-jamming capability is achieved, input 1800V bus voltages can achieve driving isolation capacity of above 4000V, the safety of a system is well guaranteed, meanwhile, working state information transmitted through feedback signals can be monitored and controlled by a central control unit in real time, system reliability is greatly improved, and the high-voltage IGBT driving and protecting circuit can be widely used in the industrial control field where power conversion is needed.

The invention discloses a high-power insulated gate bipolar transistor (IGBT) redundancy driving protection circuit, which comprises a controlled IGBT, a basic isolation driving unit U1, a redundancy isolation driving unit U2 and a switching tube unit U3, wherein the input end of U1 is connected with a driving signal Vin, and the output end of U1 is connected with the gate of the IGBT by a gate resistor R1; the input end of U2 is connected with the driving signal Vin, and the output end of U2 is connected with the input end of U3; and the two output ends of U3 are connected with the gate of the IGBT and the internal negative bias voltage end of U1 respectively. The high-power IGBT redundancy driving protection circuit provided by the invention has the advantages of reducing the internal impedance of a driving circuit in the off-state of the IGBT, rapidly releasing surging current, reducing gate voltage, preventing the false switching-on of the IGBT and ensuring the reliable switching-off of the IGBT; and when the switching frequency of the driving signal is 25,000Hz, the threshold voltage of the IGBT can be reduced within 500ns.

The invention, which is suitable for the electrical switch and switch power source fields, provides a power switch tube drive circuit with a negative pressure turn-off function. According to the embodiment of the invention, a negative pressure turn-off circuit is added on the basis of a traditional drive circuit; and an N type MOSFET can be reliably turned off on the condition that a gate level voltage is substantially reduced. Besides, diodes that are in obverse and inverse connection as well as in parallel connection are utilized, so that it is ensured that a driving chip has a normal switch speed on the MOSFET on the condition that there is a negative turn-off circuit.

The invention provides a forced commutation bridge circuit. A one-phase semi-bridge arm of the commutation bridge circuit comprises two thyristor strings which are connected in parallel, and each thyristor string comprises 2N thyristors which are connected in series, wherein N is at least equal to 1; the midpoints of the two thyristor strings are connected through a capacitor by which each thyristor string is divided into two symmetric segments of thyristor strings. Compared with the prior art, the forced commutation bridge circuit provided by the invention is suitable for traditional high-voltage direct-current power transmission, and not only can be used for realizing the reliable cutoff of the thyristors under a fault condition, but also can ensure that the capacitor is not used when a converter valve is normally used, so that no great number of harmonic waves are generated, and the service life of the capacitor is prolonged; moreover, the capacitor can be self-charged without an external power source.

The invention discloses a safety chain control system for a wind generating set. The system comprises a safety power steering relay (PSR1) and an over-speed monitoring special mark relay (SM1), wherein the over-speed monitoring SM1 transmits a wind speed signal to a programmable logic controller (PLC) through an analogue output channel and accesses an output switching value which is calculated by the PLC to a safety chain. The safe operation of the system is guaranteed and the reliability of operation of the set is improved.

The invention discloses a coordination and protection method and device of DC grid having a resistive type superconductive current limiter. The resistive type superconductive current limiter is put into a fault discharging loop. The method comprises the steps of obtaining a first impedance scope of the resistive type superconductive current limiter when the fault discharging loop reaches to the over-damping state; obtaining a second impedance scope of the resistive type superconductive current limiter when the fault current of the fault discharging loop begins to be attenuated; obtaining a third impedance scope of the resistive type superconductive current limiter based on the movement time of a master breaker in a DC breaker; obtaining the impedance value of the resistive type superconductive current limiter based on the first impedance scope, the second impedance scope, and the third impedance scope. The invention is advantageous in that through selecting the impedance value of the superconductive current limiter, the fault current can be effectively inhibited; it can be guaranteed that the DC breaker can reliably turn off the fault current, and the voltage and current stress ofa switch member can be reduced.

The invention relates to a submodule structure and MMC topology structure with an AC-DC fault removing capability; two control switches are arranged; the first control switch is connected the submodule topology structure in parallel; the second control switch is connected in series on a connecting line between a voltage anode port or a voltage cathode port of the submodule and the submodule topology structure; when the submodule structure steadily operate, the first control switch is closed, and the second control switch is conducted; when the AC side has faults, the first control switch is triggered to conduct, and the fault current injected in the a MMC can be induced to the ground; when the DC side has faults, the second control switch is controlled to close. Therefore, the submodule structure can realize isolation of AC-DC faults, and can effectively reduce the voltage stress and current stress of the submodule power device. In addition, the scheme is the secondary design reconstruction of an existing submodule, and only small influences can be caused on existing valve tower and valve hall designs; the submodule structure and MMC topology structure is very low in cost, and simple in a realization process.

The invention provides a direct-current circuit breaker and a control method. The direct-current circuit breaker comprises at least one circuit breaker module, wherein the circuit breaker module comprises a through-flow unit, an energy consumption unit, a controlled oscillation unit and a grounding unit, and the through-flow unit is connected in series in a power line; the controlled oscillation unit is connected with the through-flow unit in parallel; one end of the energy consumption unit is connected with one end of the through-flow unit and one end of the controlled oscillation unit respectively, and the other end of the energy consumption unit is connected with the controlled oscillation unit; and one end of the grounding unit is connected with the controlled oscillation unit, and the other end is grounded. According to the direct-current circuit breaker and the control method, the technical and economical dual requirements of large-scale direct-current power grid construction on the direct-current circuit breaker are met.

The invention discloses a hybrid high-voltage direct-current circuit breaker based on a bidirectional current limiting module, which comprises a through-current branch and a fault removal branch connected in parallel, wherein the through-current branch comprises a mechanical switch and m bidirectional current limiting sub modules which are connected in series with each other; the fault removal branch comprises n bidirectional current limiting sub modules which are connected in series, and m is smaller than n; the bidirectional current limiting sub module comprises a first current limiting branch and a second current limiting branch; the first current limiting branch comprises a power electronic module M1, a current limiting inductor L1 and a power electronic module M3 which are sequentially connected in series; and the second current limiting branch comprises a power electronic module M4, a current limiting inductor L2 and a power electronic module M2 which are sequentially connected in series. The requirement for the over-current capability is low, reliable turn-off of the power device can be guaranteed, the number of the power devices connected in parallel can be correspondinglyreduced, and the cost is reduced; and the amplitude of the switched-off fault current is small, the technical requirement on the circuit breaker is lower, and meanwhile, the damage of the fault current to the power supply system is smaller.