34 results about "Thyristor rectifier" patented technology

The invention provides a PWM / Buck cascade circuit auxiliary electrolytic hydrogen production rectification power supply and a control method, and relates to the technical field of electrolytic hydrogen production power supply and intelligent power grids, and the power supply comprises a main power loop and an auxiliary power loop; the main power loop comprises a multi-pulse thyristor rectifier, the power supply side of the multi-pulse thyristor rectifier is connected with an alternating-current power grid, the load side of the multi-pulse thyristor rectifier is connected with one end of a direct-current smoothing reactor, and the other end of the direct-current smoothing reactor is connected with the electrolytic bath; the auxiliary power loop comprises a PWM rectifier and a Buck circuit which are connected in series, the output end of the Buck circuit is connected to the output end of the main power loop in parallel through a direct-current LC filter, the output end of the Buck circuit and the output end of the main power loop are jointly connected into an electrolytic bath for ripple compensation, the multi-pulse rectifier adopts PI control, the PWM rectifier adopts voltage and current double-closed-loop control and SVPWM modulation, Buck adopts PI and feedforward compound control, and the output end of the Buck circuit and the output end of the main power loop are connected in parallel. The system has the advantages of improving the grid-side electric energy quality, the voltage utilization rate, the water electrolysis hydrogen production efficiency and the operation stability.

The invention discloses a hybrid hydrogen production power supply and a control method thereof. The hybrid hydrogen production power supply comprises a transformer, a main power rectifier and an auxiliary converter, wherein three-phase alternating current is connected to the input end of the main power rectifier after passing through the transformer, the output end of the main power rectifier leads out a positive electrode to be connected to an electrolytic bath, and the output end of the main power rectifier leads out a negative electrode to be connected to a power ground; the input end of the auxiliary converter is connected to a three-phase alternating current; an output end lead-out anode of the auxiliary converter is connected to an output anode of the main power rectifier; and the output end of the auxiliary converter leads out a cathode and is connected to the output cathode of the main power rectifier. According to the invention, on the basis of satisfying electrolytic hydrogen production, the harmonic current is compensated, and the alternating current side current harmonic distortion rate of the thyristor rectifier is reduced.

An energy conversion device 100 for an electrolysis system (150) comprises: an adjustable transformer (101) having a primary side (102) connectable to an AC grid (103) via a point of common coupling, a secondary side (104) and a tap switch (105); a rectifier transformer (106, 107) having a primary side (108, 109) configured to provide a secondary side voltage differing by a predetermined phase shift; a thyristor rectifier unit (114, 115, 116, 117) forming a multi-pulse rectifier system (118) that receives the secondary side voltage and provides a DC current to the electrolyser unit (119, 120, 121, 122); and a protection controller unit 133 for connecting / disconnecting the device to / from the power grid as a function of a comparison of the secondary-side voltage to a corresponding secondary-side threshold voltage, where the multi-pulse rectifier system comprises a synchronization control circuit (123, 124, 125, 126) providing thyristor gate pulses at an emission angle synchronized with the secondary-side voltage, and a protection controller unit 133 for connecting / disconnecting the device to / from the power grid as a function of a comparison of the secondary-side voltage to a corresponding secondary-side threshold voltage. And wherein the respective secondary-side threshold voltage is determined from a nominal threshold voltage specified by a grid guideline at the point of common coupling and a physical transformer parameter adjusted according to tap switch position information (129).

The invention discloses an efficient silicon controlled rectifier, and relates to the technical field of rectifiers, the efficient silicon controlled rectifier comprises a circuit board, a radiator is arranged at the top end of the circuit board, a placement bin is arranged at the top end of the circuit board, the silicon controlled rectifier is arranged in the placement bin, and a heat-resistant motor is arranged in the placement bin; the output end of the heat-resistant motor is in transmission connection with a speed change mechanism through a coupler, a bimetallic strip is arranged in the containing bin, and a push rod is arranged at one end of the bimetallic strip. The silicon controlled rectifier is pushed in along a sliding groove of a placement bin to complete installation, a toothed plate of the rectifier drives a gear to rotate, so that a first connecting rod pushes a second connecting rod to make contact with a power-on socket to achieve electricity conduction, and the temperature rises when the rectifier works; according to the structure, heat dissipation can be automatically adjusted according to the temperature, maintenance is easy and convenient, and a plurality of components do not need to be detached during replacement.

The intelligent control system comprises a three-phase thyristor rectifier bridge, a sampling unit and a master controller, the input end of the three-phase thyristor rectifier bridge is connected with a three-phase alternating current power supply, and the output end of the three-phase thyristor rectifier bridge is connected with the lifting electromagnetic chuck through a switch S1 and connected with a storage battery pack through a switch S2; and the storage battery pack is connected in series with the lifting electromagnetic chuck through the IGBT power switch Q1. According to the invention, the technical problems of unreliable magnetic retention intervention, uncontrollable magnetic force, logic conflict risk, huge volume, storage battery maintenance deficiency and the like of a traditional discrete system are solved, seamless switching between magnetic retention and excitation is realized, and accurate magnetic force control under all working conditions and intelligent maintenance of a storage battery in a full life cycle can be realized; the device has the advantages of high safety, strong reliability, compact structure, low cost and the like.

The invention discloses a 12 pulse wave / PWM hybrid rectifier based on multi-winding phase-shifting transformer power supply and a control method thereof, and relates to the technical field of hydrogen production equipment, and the 12 pulse wave / PWM hybrid rectifier comprises a three-phase AC power grid, a multi-winding phase-shifting transformer, a 12 pulse wave / PWM hybrid rectifier and an electrolytic cell. Wherein the additional winding of the multi-winding phase-shifting transformer adopts a type connection method, and provides a winding internal circulation path of harmonics of three times and multiple times of three; the control method comprises the steps of 12-pulse thyristor rectifier control, PWM rectifier control and DC-DC converter control, and a phase compensation mechanism is introduced for the phase difference generated by the main winding and the additional winding of the multi-winding phase-shifting transformer due to the structure. Through topology integration and an advanced coordination control strategy, the problems that in the prior art, water electrolysis equipment is complex, high in cost, large in harmonic wave and ripple wave, low in power factor, slow in dynamic response and the like are effectively solved.

The invention discloses a high-voltage and low-voltage direct-current dual-output three-stage generator system and a design method. The system comprises a three-stage generator and a controller. The three-stage generator is composed of a permanent magnet auxiliary exciter, a main exciter, a main motor, a rotary transformer and a rotary rectifier. The controller comprises a voltage regulating circuit, a thyristor rectifier bridge, a diode rectifier bridge, a control circuit, a power generation control relay and a current sensor. The main motor is provided with a low-voltage three-phase winding and a high-voltage three-phase winding which respectively meet the requirements of low-voltage direct current and high-voltage direct current. According to the invention, the exciting current of the exciting winding of the main exciter is regulated through the voltage regulating circuit, so that the low-voltage direct-current voltage is stabilized at an expected voltage value; by means of phase-controlled rectification control, the output high-voltage direct-current voltage is stabilized at an expected voltage value, meanwhile, the switching frequency which is the same as the output electric frequency of the generator is adopted for power generation and voltage stabilization of the thyristor rectifier bridge, and the thyristor rectifier bridge has the advantages of being low in loss, low in high-frequency ripple frequency spectrum component, weak in high-frequency conduction and radiation interference, high in power density and the like.

A 36-pulse hydrogen production converter based on a controllable pulse multiplication balancing reactor belongs to the field of power electronics technology. It addresses the problems of high input current THD and output voltage ripple, as well as the large number of high-current thyristors required in existing 24-pulse thyristor-rectified hydrogen production converters. The present invention constructs a 36-pulse hydrogen production converter consisting of a nine-phase half-wave thyristor bridge, an auxiliary single-phase thyristor rectifier bridge, and a balancing reactor with a secondary side. The controllable pulse multiplication balancing reactor is composed of the balancing reactor with a secondary side and the auxiliary single-phase thyristor rectifier bridge. By controlling the thyristors in the nine-phase half-wave thyristor bridge and the auxiliary single-phase thyristor rectifier bridge and rationally designing the primary and secondary winding turns ratios of the balancing reactor with a secondary side, a 36-pulse hydrogen production converter can be achieved. The rectifier solution of the present invention requires only 18 high-current thyristors and is primarily suitable for renewable energy hydrogen production applications with high power quality requirements.

The invention discloses an electrolytic hydrogen production hybrid rectifier control system for fluctuating power input, and the system comprises a three-phase multi-winding transformer which is used for achieving the transformation of voltage and supplying power through a network side; the output end of the thyristor rectifier is connected with the electrolytic bath and used for supplying power to the electrolytic bath; the output end of the IGBT rectifier is connected with the electrolytic bath, and the IGBT rectifier is used for supplying power to the electrolytic bath; and the controller is used for adjusting the running state of the three-phase multi-winding transformer and the running power of the thyristor rectifier and the IGBT rectifier according to a two-stage power fluctuation range by receiving a power instruction sent by the energy management system. Through innovative circuit design and control strategies, accurate control over the electrolytic hydrogen production process is achieved, the hydrogen production efficiency is improved, the cost is reduced, and harmonic pollution to a power grid is reduced. The hybrid rectifier can better adapt to the volatility of renewable energy power generation, and an efficient, stable and economical solution is provided for the field of electrolytic hydrogen production.

The static discharge protection device of the present application including thyristor rectifier comprises: a substrate of a first conductive type; a ring disposed in the substrate, belonging to a second conductive type different from the first conductive type, comprising a first part and a second part spaced apart from each other; a first well of the first conductive type disposed in the substrate and disposed between the first part of the ring and the second part of the ring, spaced apart from the first part of the ring and the second part of the ring; a second well of the first conductive type disposed in the substrate and disposed between the first part of the ring and the second part of the ring, spaced apart from the first well, the first part of the ring and the second part of the ring; a third well of the first conductive type disposed in the substrate and disposed between the first well and the second well, spaced apart from the first well and the second well; and a cathode electrode connected between the first well and the third well, connected to the third well, and connected between the second well and the third well.

This invention discloses an apparatus including a silicon controlled rectifier (SCR). The apparatus includes: a substrate; a plurality of floating wells disposed within the substrate and spaced apart from each other, belonging to a first conductivity type; a plurality of electrodes disposed on the substrate; a ring disposed within the substrate and surrounding the plurality of floating wells, belonging to a second conductivity type; a peripheral well disposed within the substrate and surrounding the ring, belonging to the first conductivity type; and a first buried layer disposed within the substrate and connected to the ring, belonging to the second conductivity type. The plurality of floating wells are interconnected at their respective ends and disposed between the first buried layer and the upper surface of the substrate.

The utility model provides a silicon controlled rectifier equipment flushing device and cooling system relates to silicon controlled rectifier equipment field. This silicon controlled rectifier equipment flushing device includes: liquid inlet pipeline has at least first main pipe section and shunt pipe row, be provided with liquid inlet total valve and monitoring component on first main pipe section, shunt pipe row with first port intercommunication of a plurality of silicon controlled rectifier cooling flow channel, and liquid return pipeline is connected with second port intercommunication of a plurality of silicon controlled rectifier cooling flow channel, be provided with liquid return total valve and blow-off pipe on liquid return pipeline, wherein, monitoring component can show the impurity content of fluid in liquid inlet pipeline, a plurality of shunt branch pipes of shunt pipe row all are provided with branch valve, be provided with blow-off valve on blow-off pipe, the utility model can show in time and fast processing the impurity in silicon controlled rectifier equipment cooling flow channel, avoid the cooling water circulation pipeline blockage and cause the heat dissipation efficiency and production stability to reduce.

This application provides an icing monitoring device and method for power transmission lines, relating to the field of circuit technology. The device includes an icing monitoring module and an icing melting module. The icing melting module includes: a first thyristor rectifier bridge, the input of which is connected to an AC power source, and a first output of which is equipped with a first disconnecting switch, used to connect to a first end of the power transmission line via the first disconnecting switch; a second output of which is used to connect to a second end of the power transmission line; and a second thyristor rectifier bridge, the input of which is connected to an AC power source, the first output of which is used to connect to the first end of the power transmission line, and a second output of which is equipped with a second disconnecting switch. This application can reduce the damage rate of related components of power transmission lines.

The invention provides a hydrogen production rectifier transformer, and relates to the technical field of transformers. The main voltage regulating winding and the auxiliary voltage regulating winding are arranged, the main voltage regulating winding and the high-voltage winding are connected through the on-load voltage regulating switch, and the auxiliary voltage regulating winding and the high-voltage winding pass through the non-excitation voltage regulating switch. The access proportion of the main voltage regulating winding is adjusted through the on-load voltage regulating switch, so that variable flux voltage regulation is realized; when the hydrogen production rectifier transformer is the power supply of the IGBT rectifier equipment, the access proportion of the auxiliary voltage regulation winding is adjusted through the non-excitation voltage regulation switch, and constant magnetic flux voltage regulation is realized; the thyristor rectification and the IGBT rectification are matched at the same time, the investment cost can be reduced, meanwhile, the occupied area is reduced, and the problems that when the thyristor rectification and the IGBT rectification are used in a combined mode, the investment cost is high, and the occupied area is large are solved.

A high-power four-quadrant converter system includes a double-secondary-side oil-immersed rectifier transformer with an output connected to four three-phase bridge type thyristor rectifiers, wherein every two rectifier bridges share a group of rectifier transformer secondary sides; two rectifier bridges sharing a group of rectifier transformer secondary sides are inversely connected in parallel, one of the two rectifier bridges realizes a forward output, and the other one realizes a reverse output; two groups of rectifier bridges which output in the same direction can operate independently or in parallel; when the two groups of rectifier bridges operate in parallel, reactors are connected in parallel to realize current sharing; and the rectifier bridges for the forward output and the reverse output realize free smooth transition under control of a controller, so that a four-quadrant operation of an output current is realized. When the system operates, the electromagnetic compatibility of sensitive components is high.

The utility model discloses a solve the problem that the structure of wiring terminal is more complex in the existing thyristor rectifier module, provide a kind of thyristor module that intermediate trigger maintains lead-out, including thyristor structure, shell, cover;Wherein thyristor structure includes bottom plate and circuit board, and circuit board is fixed on bottom plate;Bottom plate is fixedly installed in the bottom of shell, and the top of shell is also fixedly connected with cover;Still include first electrode, second electrode and mounting seat;Mounting seat is fixedly arranged in shell interior;Mounting seat is provided with the plug-in hole, and the opening direction of plug-in hole is towards cover, and first electrode is inserted into plug-in hole;First electrode is also connected with circuit board through wiring;The other end of first electrode passes through cover, and is exposed on the upper surface of cover;One end of second electrode is directly connected with circuit board, and the other end of second electrode passes through cover, and is exposed on the upper surface of cover;Overall structure is simple, and connection is stable.

The invention discloses a thyristor rectification system control method based on power grid voltage zero crossing point detection. The method comprises the following steps: S1, sampling a first voltage, a second voltage and a charging current; s2, according to the effective value of any phase voltage, judging whether the three-phase alternating-current power grid has a fault or not, if the fault occurs, entering step S3, and if the fault does not occur, entering step S4; s3, a trigger pulse signal of the thyristor rectifier bridge is filled with a dead zone, and a high-magnification energy storage unit is started to supply power to a load; s4, performing zero-crossing detection according to the voltage value of any phase voltage at the current moment and the voltage value of any phase voltage at the previous moment so as to judge whether the voltage of the power grid is in a forward zero-crossing state, if so, entering step S5, and if not, entering step S5; and S5, performing phase compensation and boundary limitation on the initial trigger angle, and finally generating a trigger pulse signal of the thyristor rectifier bridge according to the trigger angle after phase compensation and boundary limitation so as to perform charging management on the high-magnification energy storage unit. The method has the advantages of high real-time performance, high robustness and high reliability.

An electrical power system for supplying a ship (120) with a DC voltage from the shore side, the electrical power system comprising: a transformer (101), the primary side of which is connectable to a shore-side AC voltage network (130); a diode or thyristor rectifier (102), the AC voltage terminals of which are connected to the secondary side of the transformer; the electric connector (103) is used for being connected to the ship; and a DC voltage link (104) for transmitting a DC voltage from the DC voltage terminals of the rectifier to the electrical connector. The transformer comprises an on-load tap changer (105) for changing the transformation ratio. The power system includes a controller (106) for controlling the on-load tap changer to control a DC voltage supplied to the vessel. Natural switching of rectifier diodes or thyristors does not cause potentially detrimental high frequency common mode voltages and currents. In addition, the number of power conversions is minimized, which provides energy efficient power transfer.

The invention discloses an electrostatic protection device of a silicon controlled rectifier. The electrostatic protection device comprises a first conductive type substrate; a first conductivity type epitaxial layer (PEPI); and a first conductivity type well region (PW) and a second conductivity type well region (NW) disposed within the PEPI. The device is characterized by further comprising a floating first conductive type heavily doped region (P +) which is arranged in the PW and at least partially stretches across the PW / PEPI junction region, and a floating second conductive type heavily doped region (N +) which is arranged in the NW and at least partially stretches across the NW / PEPI junction region. According to the floating heavily doped region, the current amplification coefficient of the floating heavily doped region is reduced by increasing base region doping of a corresponding parasitic transistor, so that the maintaining voltage (Vh) of the device is improved, and latch-up is inhibited. Moreover, the floating heavily doped region forms a parasitic diode structure in the PEPI, and the parasitic diode structure is used for determining the trigger voltage (Vt1) of the device. The device has the advantages of high maintaining voltage, settable trigger voltage, high robustness and bidirectional protection.

The invention discloses a silicon controlled rectifier for core particle electrostatic pulse rapid clamping. The silicon controlled rectifier comprises a substrate P-Sub, a first DN-Well region, a second DN-Well region, a first P-Well region, a second P-Well region, a first N-Well region, a second N-Well region, a first field oxygen isolation region, a second field oxygen isolation region, a third field oxygen isolation region, a fourth field oxygen isolation region, a fifth field oxygen isolation region, a sixth N + injection region, a third P + injection region, a fourth P + injection region, a fifth P + injection region, a sixth P + injection region and a second polysilicon gate. According to the invention, a silicon controlled rectifier structure with self-gain and rapid electrostatic pulse clamping is formed, and the protection level of chip core particle bonding electrostatic discharge can be improved; a polysilicon gate is controlled to open a channel, current is injected to conduct a parasitic NPN triode, and a low-trigger silicon controlled rectifier is further coupled, so that an electrostatic protection structure with a multi-channel parallel path is formed, the current discharge capacity of the device per unit area is remarkably enhanced, and the purpose of realizing rapid clamping of electrostatic voltage in a core particle is achieved.

The invention relates to an energy conversion device (100) for an electrolysis system (150). It comprises a tunable transformer (101) having a primary side (102) connectable to an electrical network (103) and a secondary side (104), a sensor device (105) sensing an alternating primary side voltage of the tunable transformer, a rectifier transformer (106, 107) having a primary side (108, 109) connected to the secondary side of the tunable transformer and providing an alternating secondary side voltage differing from a predefined phase shift on the secondary side (110, 111, 112, 113), and a thyristor rectifier unit (114, 115, 116, 117) forming a multi-pulse rectifier system (118) that receives the secondary side voltage and provides a DC current to the electrolyzer unit (119, 120, 121, 122). The multi-pulse rectifier system includes a synchronization control circuit (123, 124, 125, 126) to provide thyristor gate pulses to the thyristor rectifier unit at an emission angle that is synchronized with a synchronization voltage signal (130) differing from a predefined phase shift and varies in accordance with an electrolyzer DC current request, where the synchronization control circuit (123, 124, 125, 126) is activated before the predefined phase shift is applied. The synchronous voltage signal (130) directly corresponds to an AC primary side voltage sensed at the adjustable transformer primary side (102).

A method for operating a hybrid rectifier includes an AC input, a DC output and a thyristor rectifier arranged in a first path, and a transistor rectifier arranged in a second, parallel path. The method includes when a DC voltage at the DC output of the hybrid rectifier is below a voltage threshold value, operating the hybrid rectifier in a first operating state in which the transistor rectifier is isolated from the DC output and connected to the AC input and the thyristor rectifier is connected both to the AC input and to the DC output. When the DC voltage at the DC output of the hybrid rectifier reaches or exceeds the voltage threshold value, operating the hybrid rectifier in a second operating state in which the thyristor rectifier and the transistor rectifier are each connected to the AC input and to the DC output.

The invention discloses a metallurgical efficient energy-saving integrated special direct current power supply device which comprises a box body, the interior of the box body is divided into a transformation rectification area and an oil storage area which are arranged up and down, the transformation rectification area is divided into a transformation area and a rectification area which are arranged left and right, and the transformation area is communicated with the oil storage area through a pipeline; an air bellow is arranged at the upper part of the rectification area, a copper bar is arranged in the air bellow, the air bellow is provided with a connecting hole communicated with the transformation area, the copper bar is connected with a thyristor rectifier, one end of the air bellow is provided with a fan for blowing air into the air bellow, the other end of the air bellow is provided with an air outlet, a cooling channel is arranged in the copper bar, and the cooling channel is communicated with the oil storage area through a pipeline; an oil pump and a cooler are arranged in the oil storage area, and the output end of the oil pump is communicated with the variable pressure area and the cooling channel through pipelines to form a closed loop from the oil storage area to the variable pressure area and then to the oil storage area and from the oil storage area to the cooling channel and then to the oil storage area. The LED lamp is good in heat dissipation effect, compact in overall structure, small in occupied space and convenient to install and maintain.

The application discloses a control method and system for realizing soft starting of a thyristor rectifier bridge, and belongs to the technical field of power generation, power transformation or power distribution. According to the real-time obtained power grid voltage parameters and the power grid voltage frequency, the application introduces specific logic to accurately identify the half-cycle position of the power grid voltage, reduces the frequency measurement error caused by power grid voltage distortion, accurately generates the thyristor driving pulse according to the obtained power grid voltage frequency, introduces a thyristor turn-off point automatic correction algorithm, automatically adjusts the phase of the thyristor driving pulse cycle by cycle, avoids the failure of the thyristor slow starting, and thus ensures the reliable and accurate generation of the thyristor driving pulse.

The invention relates to the technical field of black-start auxiliary excitation, in particular to a black-start auxiliary excitation circuit and a wire connecting device. The system comprises an excitation silicon controlled rectifier bridge, an alternating current magnetic field circuit breaker and a direct current magnetic field circuit breaker which are electrically connected with the excitation silicon controlled rectifier bridge, an excitation transformer electrically connected with the alternating current magnetic field circuit breaker, and a generator and an alternating current branch which are electrically connected with the excitation transformer, the device comprises an AC power switch electrically connected with the excitation silicon controlled rectifier bridge, an excitation transformer electrically connected with the AC power switch, a first diode rectifier bridge electrically connected with the excitation transformer, and an auxiliary excitation control switch electrically connected with the first diode rectifier bridge. According to the black-start auxiliary excitation circuit, the problem that a conventional direct-current power supply cannot be adopted for auxiliary excitation in the excitation black-start process of a large generator set is solved, and the installation and maintenance efficiency of the black-start auxiliary excitation circuit is improved.

The invention relates to a thyristor rectifier driving synchronous triggering time sequence processing method and system, and the method comprises the following steps: carrying out the differential comparison of three-phase AC voltage through three hysteresis comparators, and generating three digital pulse signals; performing high-frequency sampling on the three paths of digital pulse signals by using a DSP with an EPWM module, wherein the sampling frequency is not lower than 10kHz; continuously sampling each path of signal for 16 times, and carrying out software filtering according to a sampling result to filter out high-frequency interference pulses with the width less than 1.6 ms; carrying out edge detection based on the filtered signal, and identifying an effective zero-crossing event under the positive sequence of the power grid in combination with phase relation verification, state machine index matching and time threshold verification; and according to the identified effective zero-crossing event, generating a thyristor trigger pulse, and controlling the rectifier to work.

The utility model provides an energy-adjustable high-energy igniter which comprises an on-off switching assembly, a voltage conversion assembly, a power supply trimming assembly, a discharge ignition assembly, a power supply sampling assembly, a discharge control assembly and a charge and discharge control assembly. Charging and discharging durations can be dynamically adjusted according to the power supply fluctuation state, accurate control over ignition energy is achieved, different application requirements are met, accurate discharging control over the discharging control assembly is achieved through a photoelectric triode and a silicon controlled rectifier, the accuracy of ignition time and energy is ensured, continuous adjustment of charging and discharging energy can be achieved, and the application range is wide. The applicability and flexibility of the product are improved, optical isolation of a high-voltage circuit and a control loop is realized, and the reliability of the product is improved.

The invention relates to the technical field of direct-current ice melting, in particular to a low-voltage dynamic simulation test platform for a control and protection system of a direct-current ice melting device, which comprises an alternating-current power supply access unit which forms an alternating-current input loop through a main circuit breaker, an electric reactor and a contactor; the first alternating current transformer is arranged in the alternating current input loop; the first thyristor rectifier module and the second thyristor rectifier module are connected with the first rectifier transformer and the second rectifier transformer in a one-to-one correspondence mode; the first circuit breaker and the second circuit breaker are used for switching rectification modes, the first circuit breaker controls the second rectifier transformer to be connected with the direct current side of the second thyristor rectifier module, and the second circuit breaker controls the direct current side of the first thyristor rectifier module and the direct current side of the second thyristor rectifier module to be connected in parallel. According to the invention, the rectification mode is switched through the first circuit breaker and the second circuit breaker, so that two functions and performance tests of the control and protection system of the DC deicing device can be realized.

The present invention discloses a drilling motor DC contactor disconnection protection system and method based on current detection. The DC contactor is respectively connected in series with a thyristor rectifier and a motor, and the thyristor rectifier is respectively connected in series with an incoming line circuit breaker and a programmable DC speed regulator, and the programmable DC speed regulator is connected to the incoming line circuit breaker; the output end of the DC contactor is connected to the input end of a programmable PLC through a current detection device, and the programmable DC speed regulator and the stop conversion switch are also connected to the input end of the programmable PLC. The output end of the programmable PLC is respectively connected to the motor and the alarm device, and the programmable PLC is connected to a host computer. The present invention compares the external detection loop current Current1 and the internal acquisition current Current2 of the DC speed regulator in real time, and disconnects the DC contactor after the load current is reduced to a safe value through the control of the programmable PLC, which can effectively prevent the damage of the main contacts of the DC contactor, reduce equipment maintenance costs, reduce equipment accidents, and extend the life of the DC contactor.

The invention discloses a bidirectional silicon controlled rectifier device. The device is of a symmetrical structure, comprises a central first conductive type well region (connected with a first end) and flank first conductive type well regions (connected with a second end) at two sides, and is provided with inner side and outer side second conductive type well regions. The key point is that a floating first conductive type heavily doped region is arranged in the first conductive type well region and is used for improving the maintaining voltage; a first trigger pitch (S2) between the inner second conductive type well region and the central first conductive type well region and a second trigger pitch (S3) between the inner second conductive type well region and the flank first conductive type well region are defined. The trigger voltage can be set by adjusting the S2 and the S3, and symmetric or asymmetric bidirectional protection can be realized by controlling the relative size of the S2 and the S3. The device is high in maintaining voltage, adjustable in trigger voltage and flexible in protection characteristic, effectively improves ESD protection performance and widens the application range.