CN207218264U - A kind of photovoltaic plant high-tension transformer no-flashy-flow switching circuit - Google Patents

Abstract

The utility model discloses a kind of photovoltaic plant high-tension transformer no-flashy-flow switching circuit, the circuit includes being used to form the Group of Silicon Controlled Rectifier of the multi-section serial of three-phase main circuit, and Group of Silicon Controlled Rectifier is parallel with by-pass knife switch；The circuit also includes singlechip controller, and the output end of controller is electrically connected with thyristor gating circuit；The output end of controller is electrically connected with by-pass knife switch operation drive circuit；The input of controller is electrically connected with alternating voltage zero-crossing point detection circuit and controllable silicon current detection circuit.The utility model can not produce excitation surge current when transformer is by electricity, transformer is set not to be hit when putting into every time, current techniques are eliminated when transformer is by electricity by the significant damage for the excitation surge current impact for being several times as much as rated current, high-tension transformer not linked network power consumption when not generating electricity at daily night of photovoltaic plant can be achieved, not only saved electric energy but also extended the life-span of transformer.

Description

A kind of photovoltaic plant high-tension transformer no-flashy-flow switching circuit

Technical field

It the utility model is related to a kind of photovoltaic plant high-tension transformer no-flashy-flow switching circuit.

Background technology

It is well known that the time that photovoltaic plant can generate electricity daily only has 10-11 hour, remaining 13-14 hour is not Generating electricity, the transformer (case change) for low-voltage AC to be boosted to high pressure effectively only has 10-11 hour using the time, its The remaining time all hangs over consumes electric energy in vain on power network；This just needs to exit transformer from power network when not generating electricity, sent out Put into again when electric.Because transformer in power system every time by electricity when, be all inevitably several times as much as transformer The excitation surge current impact of rated current, this impact easily damages transformer, if the transformer in photovoltaic plant daily by Once such impact, the probability of its transformer damage will be very big, and the life-span of transformer will be greatly shortened, while excitation is gushed Various higher hamonic waves caused by stream also have large effect to power network and communication；Therefore, although photovoltaic plant night does not generate electricity, this A little transformers can only also be hung on the net, but such consequence is：1st, hang over the transformer on power network and consume electricity in power network in vain Can, calculated according to every megawatt of transformer noload losses 1.5kW, every megawatt of transformer consumes about 20kWh electric energy more daily, entirely The current photovoltaic generation installation of state is about 77GW, therefore the high-voltaghe compartment change of annual national photovoltaic plant will consume 5.62 hundred million more altogether KWh electric energy, equivalent to one 12.5 ten thousand kW thermal power generation unit (year hours run 5000) generated energy of 1 year；2nd, due to becoming Depressor is also at running status when photovoltaic plant does not generate electricity, and night line voltage is higher and is easily disturbed and produces overvoltage, Therefore the probability of transformer insulated breakdown fault is added；If the 3, transformer not linked network when not generating electricity, during transformer station high-voltage side bus Between will reduce by more than 50, by contrast, its life-span has a larger extension, therefore the transformer longevity in continuous running status Life can not be extended.

The content of the invention

In order to solve defect present in above-mentioned prior art, the utility model provides a kind of photovoltaic plant high pressure transformation Excitation surge current can be reduced to far below the specified electricity of transformer by device no-flashy-flow switching circuit, the circuit when transformer is by electricity Stream, excitation surge current not being produced even, transformer is not hit when putting into every time, the high-tension transformer that photovoltaic plant can be achieved exists Not linked network power consumption when daily night does not generate electricity, had not only saved electric energy but also had extended the life-span of transformer.

The technical solution adopted in the utility model：A kind of photovoltaic plant high-tension transformer no-flashy-flow switching circuit, the circuit Include the Group of Silicon Controlled Rectifier of the multi-section serial for forming three-phase main circuit, described Group of Silicon Controlled Rectifier is parallel with by-pass knife switch；The electricity Road also includes singlechip controller, and the output end of described singlechip controller is electrically connected with thyristor gating circuit；It is described Singlechip controller output end be electrically connected with by-pass knife switch operation drive circuit；The input of described singlechip controller End is electrically connected with alternating voltage zero-crossing point detection circuit and controllable silicon current detection circuit.

Preferably, described Group of Silicon Controlled Rectifier is by two forward and reverse unidirectional controllable silicon S CR1 and unidirectional controllable silicon S CR2 in parallel Composition, realizes that electric current two-way circulates；Described thyristor gating circuit is triggered by triggering power supply dedicated transformer and independent merogenesis Circuit forms；Described independent merogenesis triggers circuit is connected with Group of Silicon Controlled Rectifier, for triggering Group of Silicon Controlled Rectifier conducting.

Preferably, secondary coil of the described independent merogenesis triggers circuit by triggering power supply dedicated transformer, the pole of rectification two Pipe D1, filter capacitor C1, triode Q1, triode Q3, phototriode Q5, resistance R1, resistance R2, resistance R3, resistance R5, electricity Hinder R7 and the trigger electrode of the section Group of Silicon Controlled Rectifier forms；Wherein：Commutation diode D1 positive pole connects secondary coil one end, negative pole connects filter Ripple electric capacity C1 positive pole, what the negative electrode of the other end and this section controllable silicon that filter capacitor C1 negative pole is connected to secondary coil was formed This pole common port, secondary coil, diode D1 and filter capacitor C1 collectively form the triggering power supply of this section；Phototriode Q5's Emitter stage connects triode Q3 base stage, and phototriode Q5 colelctor electrode is connected to triode Q1 base stage, three poles by resistance R5 Pipe Q3 colelctor electrode is connected to triode Q1 base stage by resistance R3, and triode Q3 emitter stage is connected to this section common port, three poles Pipe Q1 emitter stage is connected to the positive pole of triggering power supply, and triode Q1 colelctor electrode is connected to the triggering of controllable silicon SCR 1 by resistance R1 Pole, resistance R7 are connected in parallel between SCR1 and this section common port.

Preferably, described alternating voltage zero-crossing point detects circuit by current-limiting resistance R4, diode D2, diode D3, two Pole pipe D4, diode D5 and triode Q2 compositions；Wherein, diode D2 connects with diode D3, diode D4 and diode D5 Series connection, reverse parallel connection, one end are connected to the two of high-voltage system voltage transformer by current-limiting resistance R4 to the two-way diode of series connection again Secondary voltage Uab one end, another secondary voltage Uab for the being connected to voltage transformer other end, the end be used as with reference to " " electricity Position.

Preferably, described controllable silicon current detection circuit is by Current Transmit, commutation diode D6, commutation diode D7, filter capacitor C2, limiter diode D8-D12, resistance R6, R8, triode Q4 compositions；Wherein：Current Transmit secondary line One end of circle is connected to commutation diode D6 positive pole, and the another of Current Transmit secondary coil is connected to commutation diode D7 Positive pole, the midpoints of CT secondary coils be used as with reference to " " current potential, commutation diode D6, D7 negative pole, which link together, is connected to limit Width diode D8 positive pole, limiter diode D8-D12 series connection, limiter diode D12 negative pole ground connection, filter capacitor C2 are in parallel At limiter diode D8-D12 both ends, filter capacitor C2 positive pole is connected to triode Q4 base stage, triode by resistance R6 Q4 grounded emitter, is connected to parallel resistance R8 between triode Q4 base stage and emitter stage, and triode Q4 colelctor electrode connects To the input pin of singlechip controller.

Preferably, described singlechip controller and control machines order light drive circuit composition calculate control and output Drive circuit；The output end of described singlechip controller by described control machines order light drive circuit with it is described Thyristor gating circuit connects；Described control machines order light drive circuit includes infrarede emitting diode, three poles of driving Pipe Q5 and current-limiting resistance composition, the negative pole of described infrarede emitting diode are connected to triode Q5 colelctor electrode, triode Q5's The output end that base stage is connected to singlechip controller by resistance R0 receives trigger command, and triode Q5 emitter stage is connected to power supply and born Pole, current-limiting resistance are connected between positive source and the positive pole of infrarede emitting diode.

Preferably, the electrical contact of described by-pass knife switch and mechanical operation portion using insulated connecting rod enter horizontal high voltage every From.

The beneficial effects of the utility model：1. using the rapidity of thyristor trigger, controllable silicon can be precisely controlled Open time point, make its it is each mutually open controllable silicon in current zero-crossing point, transformer is not produced excitation surge current.

2. transformer can be made each in current over-zero such as characteristic that Triggerless controllable silicon just turns off using controllable silicon Mutually turn off, will not produce " cutting space-variant overvoltage " naturally in current over-zero.

3. according to the height of transformer primary voltage, using more piece group controllable silicon in serial connection, to meet to use common controllable silicon Demand in high voltage circuit, such as：It is most with 35kV voltage class in photovoltaic plant at present, and common one-way SCR electricity Pressure is no more than 2kV, according to the actual voltage that bears of 85% safety coefficient to be limited no more than 1.7kV, in 35kV electrical voltage systems Voltage magnitude is 49.5kV, considers voltage pulsation 10%, so at least needing 33 groups of series connection in 35kV circuits, often section group is by two The forward and reverse parallel connection of one-way SCR.

4. Group of Silicon Controlled Rectifier only makes it not produce excitation surge current when transformer puts into power network, but its overload capacity is poor, because This, immediately should be bypassed its short circuit with by-pass knife switch once Group of Silicon Controlled Rectifier completes the mission that transformer puts into operation, with full Foot straps load and the requirement of overload.Therefore in the both ends parallel connection by-pass knife switch of every phase Group of Silicon Controlled Rectifier, and in the work of control circuit With lower and controllable silicon coordination, respective task is completed.

Brief description of the drawings

Fig. 1 is the utility model principle block diagram.

Fig. 2 is the multi-section serial Group of Silicon Controlled Rectifier using independent merogenesis triggering mode.

Fig. 3 is alternating voltage zero-crossing point detection circuit.

Fig. 4 is controllable silicon current detection circuit.

Fig. 5 is control machines order light drive circuit.

Symbol description in figure：1st, Group of Silicon Controlled Rectifier, 2, by-pass knife switch, 3, thyristor gating circuit, 3-1, triggering power supply are special Transformer, 3-2, independent merogenesis triggers circuit, 4, alternating voltage zero-crossing point detection circuit, 5, controllable silicon current detection circuit, 6, Calculate control and output driving circuit, 6-1, singlechip controller, 6-2, control machines order light drive circuit, 7, bypass knife Lock operates drive circuit.

Embodiment

As shown in Figure 1：Transformer is by electricity：Transformer confirms step down side switch in off-state, exchange before by electricity Voltage over zero detection circuit 4 detects the high AC voltage Uab provided by voltage transformer zero crossing, is exchanged when detecting During voltage zero-cross, singlechip controller 6-1 calculates the time of A phase current zero passages and starts timing, when timing then, send A Phase trigger command, A phase control machines order light drive circuits 6-2 drive light emitting diode after trigger command is amplified, and will touch Send instructions each section light being transferred in a manner of light in the independent independent merogenesis triggers circuit 3-2 of merogenesis triggers circuit 3-2, A phase of A phases Quick triode turns on after receiving light instruction, by A touch that energy source dedicated transformer 3-1 provides it is rectified after each section it is straight Stream trigger voltage is respectively turned on to the trigger electrode of the corresponding section Group of Silicon Controlled Rectifier 1 of A, and each Group of Silicon Controlled Rectifier 1 of A phases turns on, transformer A by Electricity；Singlechip controller 6-1 detects Uab zero crossing again, calculates the time of B phase current zero passages and starts timing, works as timing Then, B phase trigger commands are sent, trigger command amplification is driven luminous two by B phase control machines order light drive circuit 6-2 Pole pipe, triggering command is transferred to the independent independent merogenesis triggers circuit 3-2 of merogenesis triggers circuit 3-2, B phase of B phases in a manner of light In each section phototriode receive the light instruction after turn on, by B touch energy source dedicated transformer 3-1 provide it is rectified Each section direct current trigger voltage afterwards is respectively turned on to the trigger electrode of the corresponding section Group of Silicon Controlled Rectifier 1 of B, each Group of Silicon Controlled Rectifier 1 of B phases and turned on, Transformer AB two-phases are by electricity；Singlechip controller 6-1 detects Uab zero crossing again, calculates the time of C phase current zero passages and opens Beginning timing, when timing then, send C phase trigger commands, C phase control machines order light drive circuits 6-2 puts trigger command Big driving light emitting diode, triggering command is transferred in a manner of light the independent merogenesis of independent merogenesis triggers circuit 3-2, the C phase of C phases Each section phototriode in triggers circuit 3-2 is turned on after receiving light instruction, and C is touched into energy source dedicated transformer 3-1 There is provided it is rectified after each section direct current trigger voltage be respectively turned on to the trigger electrode of the corresponding section Group of Silicon Controlled Rectifier 1 of C, C phases respectively may be used Control silicon group 1 turns on, and transformer ABC three-phases are all by electricity, and so far transformer has passed through controllable silicon input power network no-load running；Due to Singlechip controller 6-1 will calculate the phase current null time and open controllable silicon at this moment before every phase input, Therefore by that will not produce excitation surge current during electricity, transformer will not be impacted transformer by power network in theory.

Controllable silicon only makes it not produce excitation surge current when transformer puts into power network, but its overload capacity is poor, therefore, one Denier controllable silicon immediately should be bypassed its short circuit with by-pass knife switch 2 after completing the task of all turning on, to meet bringing onto load and excessively negative The requirement of load.Therefore need to be in the both ends parallel connection by-pass knife switch 2 of every phase Group of Silicon Controlled Rectifier 1, when transformer accesses power network by controllable silicon Afterwards, the no-load current of transformer flows through controllable silicon, and Current Transmit secondary coil produces electric current, controllable silicon current detecting electricity Road 5 detects the electric current and is sent to singlechip controller 6-1, and singlechip controller 6-1 detects that the current signal can determine Controllable silicon has turned on, and sends by-pass knife switch combined floodgate order, and by-pass knife switch operates drive circuit 7 and passes through electric operating part driving side The 2-in-1 lock of road disconnecting link, electric operating part are dielectrically separated from moving contact of disconnecting link using insulated connecting rod.

After by-pass knife switch 2-in-1 lock, electric current is just no longer flow through in controllable silicon, controllable silicon current detection circuit 5 just detects not To electric current, singlechip controller 6-1 detection electric currents are zero, can determine that by-pass knife switch 2 has been got togather, A, B, C three-phase are triggered Order is reset, each phase controllable silicon cut-off.So far, the powered all processes of transformer are completed.

Transformer has a power failure：Step down side switch is confirmed in off-state, and singlechip controller 6-1 is connected to transformer and stopped After electricity instruction, A, B, C three-phase trigger command are simultaneously emitted by, the Group of Silicon Controlled Rectifier 1 of each phase multi-section serial all turns on, single-chip microcomputer control Device 6-1 processed sends the instruction of by-pass knife switch separating brake, the separating brake of by-pass knife switch 2, when by-pass knife switch separating brake disconnects after certain delay Electric current is flowed through in controllable silicon afterwards, after singlechip controller 6-1 detects the electric current, A, B, C three-phase trigger command are reset, each phase Controllable silicon ends, and is turned off naturally in current over-zero, so far, completes all processes of transformer power failure.

Circuit as shown in Figure 2, often saved by two per phase using the Group of Silicon Controlled Rectifier 1 of the multi-section serial of independent merogenesis triggering mode The section of unidirectional controllable silicon S CR1 and unidirectional controllable silicon S CR2 composition one of reverse parallel connection, shows 4 sections in figure, in practical application Joint number should be determined by voltage class and pipe are pressure-resistant, the most universal with 35kV voltage class in photovoltaic plant at present, and it is common in Power one-way SCR voltage is no more than 2kV, according to the actual voltage that bears of 85% safety coefficient to be limited no more than 1.7kV, Voltage magnitude in 35kV electrical voltage systems is 49.5kV, considers voltage pulsation 10%, so at least needing 33 in 35kV circuits Section series connection, often saves forward and reverse by two one-way SCRs and is unified into one group.

Independent merogenesis triggers circuit 3-2 is by triggering power supply dedicated transformer 3-1 secondary coil, commutation diode D1, filter Ripple electric capacity C1, triode Q1, triode Q3, phototriode Q5, resistance R1, resistance R2, resistance R3, resistance R5, resistance R7 with The trigger electrode composition of the section Group of Silicon Controlled Rectifier；Wherein：Commutation diode D1 positive pole connects secondary coil one end, negative pole connects filtered electrical Hold C1 positive pole, this pole that the negative electrode of the other end and this section controllable silicon that filter capacitor C1 negative pole is connected to secondary coil is formed Common port, secondary coil, diode D1 and filter capacitor C1 collectively form the triggering power supply of this section；Phototriode Q5 transmitting Pole connects triode Q3 base stage, and phototriode Q5 colelctor electrode is connected to triode Q1 base stage, triode Q3 by resistance R5 Colelctor electrode triode Q1 base stage is connected to by resistance R3, triode Q3 emitter stage is connected to this section common port, triode Q1 Emitter stage be connected to the positive pole of triggering power supply, triode Q1 colelctor electrode is connected to the trigger electrode of controllable silicon SCR 1 by resistance R1, Resistance R7 is connected in parallel between SCR1 and this section common port.

Trigger power supply dedicated transformer 3-1 secondary coil, commutation diode D1, that filter capacitor C1 forms the section is independent Power supply is triggered, is turned on when phototriode Q5, which is received, touches light commands, so as to which triode Q3, triode Q1 are turned on, to controllable The trigger electrode of silicon group 1 provides trigger current, the triggering and conducting of Group of Silicon Controlled Rectifier 1, when phototriode Q5 does not receive tactile light commands Cut-off, Group of Silicon Controlled Rectifier 1 are ended；The tricks of independent merogenesis triggers circuit is determined by the joint number of controllable silicon in serial connection, according to forward and reverse The mode triggered respectively, then the tricks of triggers circuit is 2 times of controllable silicon in serial connection joint number, the utility model using it is forward and reverse simultaneously The form of triggering, the tricks of triggers circuit can so be greatly reduced, using it is forward and reverse and meanwhile triggering form, triggers circuit Tricks covers for n+1, and wherein n is the joint number of controllable silicon in serial connection；Experiment proves that in the form of forward and reverse while triggering be success , as long as the one-way SCR for being saved the unidirectional controllable silicon S CR2 of next section and upper one using forward and reverse while triggering method SCR1 trigger electrode triggers simultaneously；Triggering power supply dedicated transformer 3-1 primary voltage is the common civil powers of 220V, secondary side For each independent n+1 6V outputs, rectified diode D1 rectifications, the filtered dc sources of filter capacitor C1 are as each section The independent triggers power supply of controllable silicon, because secondary side is connected with high-pressure system, so as follows to insulating requirements：(1) each secondary line Circle and the insulation between iron core and primary winding will be designed by the high-pressure system class of insulation, exhausted between (2) each adjacent secondary coil Edge grade is designed by high-voltage system voltage divided by controllable silicon in serial connection joint number, and (3) first segment is with final section secondary coil according to height Press the design of system insulation grade.

The secondary side of triggering power supply dedicated transformer uses halfwave rectifier, to bear the positive and negative half cycle of dedicated transformer primary side Balance is carried, the connection of each coil of secondary side answers Same Name of Ends to stagger, i.e., the of the same name of a half-coil is connected into commutation diode, half The non-same polarity of coil is connected to commutation diode.

The resistance R11-R20 being connected in parallel in each section Group of Silicon Controlled Rectifier 1 is equalizing resistance, to ensure that each section Group of Silicon Controlled Rectifier is being ended The electric voltage equalization born under state.

As shown in figure 3, alternating voltage zero-crossing point detects circuit by current-limiting resistance R4, diode D2, diode D3, two poles Pipe D4, diode D5 and triode Q2 compositions；Wherein, diode D2 connects with diode D3, and diode D4 and diode D5 goes here and there Connection, reverse parallel connection, one end are connected to the secondary of high-voltage system voltage transformer to the two-way diode of series connection by current-limiting resistance R4 again Voltage Uab one end, another secondary voltage Uab for the being connected to voltage transformer other end, the end be used as with reference to " " current potential； Resistance R4 effect is the electric current that limitation flows into, and diode D2-D5 effect is that the voltage of input is limited in into below 1.4V to make It turns into square wave, and triode Q2 effect is reliably to detect the voltage amplification for single-chip microcomputer, when alternating voltage is positive half cycle, Output is zero, when alternating voltage is negative half period, is exported as just, single-chip microcomputer calculates the triggered time and sent out for basic point accordingly on time Phototriode of the trigger signal to light emitting diode by optical signal transmission to corresponding phase, phototriode conducting make triggers circuit Trigger controlled silicon conducting.

As shown in figure 4, controllable silicon current detection circuit 5 is by Current Transmit, commutation diode D6, commutation diode D7, filter capacitor C2, limiter diode D8-D12, resistance R6, R8, triode Q4 compositions；Wherein：Current Transmit secondary line One end of circle is connected to commutation diode D6 positive pole, and the another of Current Transmit secondary coil is connected to commutation diode D7 Positive pole, the midpoints of CT secondary coils be used as with reference to " " current potential, commutation diode D6, D7 negative pole, which link together, is connected to limit Width diode D8 positive pole, limiter diode D8-D12 series connection, limiter diode D12 negative pole ground connection, filter capacitor C2 are in parallel At limiter diode D8-D12 both ends, filter capacitor C2 positive pole is connected to triode Q4 base stage, triode by resistance R6 Q4 grounded emitter, is connected to parallel resistance R8 between triode Q4 base stage and emitter stage, and triode Q4 colelctor electrode connects To the input pin of singlechip controller；Limiter diode D8-D12 effect is：1 ensures triode Q4 when having electric current Can reliably it turn on, 2 are bypassed when controllable silicon electric current is excessive, ensure that triode Q4 base current is not excessive.

When controllable silicon all turns on, controllable silicon current detection circuit 5 detects that electric current turns on triode Q4, and control is single The controllable silicon current detecting pin of piece machine is changed into low potential from high potential, and single-chip microcomputer sends conjunction bypass knife after detecting this electric current The instruction of lock 2 makes the 2-in-1 lock of by-pass knife switch with short circuit controllable silicon.

As shown in figure 1, singlechip controller 6-1 output end by control machines order light drive circuit 6-2 with can Control silicon triggers circuit 3 connects, and realizes the conducting of control control machines and cut-off, the division of output end control by-pass knife switch in addition Lock operating mechanism is to realize the combined floodgate of by-pass knife switch, separating brake.

As shown in figure 5, control machines order light drive circuit 6-2 includes infrarede emitting diode and triode Q5, it is red UV light-emitting diode LED1-LEDn+1 negative pole is connected to triode Q5 colelctor electrode, and triode Q5 base stage is connect by resistance R0 Output end to singlechip controller 6-1 receives trigger command, and triode Q5 emitter stage is connected to power cathode；Infraluminescence Diode (LED) 1 to LEDn+1 positive pole are connected to positive source by current-limiting resistance A1 to An+1 respectively；When triode Q5 base stage Collector and emitter pole turns on when receiving the trigger command that singlechip controller 6-1 is sent, and drives infrarede emitting diode LED1-LEDn+1 sends centre wavelength with receiving phototriode identical infrared light, is transmitted into each section control machines respectively The phototriode of circuit, each phototriode for saving thyristor gating circuit, which receives the light order, leads control machines It is logical.

Examined as shown in figure 1, calculating control and output driving circuit 6 by single chip machine controlling circuit U1, alternating voltage zero-crossing point Survey input pin, controllable silicon current detecting input pin, A phase trigger commands output pin, B phase trigger commands output pin, C phases Trigger command output pin, by-pass knife switch combined floodgate order output pin, by-pass knife switch separating brake order output pin, triggering calculate and Controller forms；According to principle caused by excitation surge current during Transformer Close, when switching angle is in 0 °, excitation surge current is maximum, When switching angle is in 90 °, excitation surge current minimum zero, when alternating voltage zero-crossing point, for A phases, by surveying electricity To press as Uab, 30 ° of the advanced A phase voltages of the voltage, the angle passed through when A phase voltages are to maximum is 30+90=120 °, so Controller is set in the instruction that triggering A phases Group of Silicon Controlled Rectifier 1 is sent when 120 ° after measuring Uab voltage over zero；When A is conducted Afterwards, it is Uab on B phases fracture, controller sends the instruction of triggering B phases Group of Silicon Controlled Rectifier 1 at 90 ° after measuring Uab zero crossings again； Due to advanced Uab90 ° of C phase voltages, controller sends triggering C phases Group of Silicon Controlled Rectifier 1 at 180 ° after measuring Uab zero crossings again Instruction；After controllable silicon all turns on, single-chip microcomputer detects controllable silicon electric current, and controller is to send the instruction for closing by-pass knife switch Make the 2-in-1 lock of by-pass knife switch with short circuit controllable silicon；Single-chip microcomputer controls and output driving circuit 6 passes through Phototube Coupling mode and controllable silicon Triggers circuit connects, and the distance between its light emitting diode and photosensitive triode must are fulfilled for wanting for high-pressure system insulation distance Ask, the utility model uses 0.5m safe distance.

By-pass knife switch 2 respectively saves controllable silicon and is fully completed after conducting task to close a floodgate immediately and bypasses controllable silicon short circuit in three-phase, Because the accurate controllable silicon for calculating control only makes it not produce excitation surge current when transformer puts into power network, but it overloads energy Power is poor, therefore, immediately should be bypassed its short circuit with by-pass knife switch 2 after controllable silicon completes the task of all turning on, with full Foot straps load and the requirement of overload.Therefore need to be in the both ends parallel connection by-pass knife switch 2 of every phase Group of Silicon Controlled Rectifier 1, and in control circuit In the presence of with controllable silicon coordination, complete respective task.By-pass knife switch 2 is using the electronic behaviour controlled by MCU Instruction Make mode, the operation transmission between electric operating part and moving contact of disconnecting link is using the kind of drive of insulated connecting rod, its length of connecting rod Degree and dielectric level should meet the resistance to pressure request of high-pressure system insulation.

Claims (7)

1. A kind of 1. photovoltaic plant high-tension transformer no-flashy-flow switching circuit, it is characterised in that：The circuit includes being used to form three-phase The Group of Silicon Controlled Rectifier (1) of the multi-section serial of main circuit, described Group of Silicon Controlled Rectifier (1) are parallel with by-pass knife switch (2)；The circuit also includes Singlechip controller (6-1), the output end of described singlechip controller (6-1) are electrically connected with thyristor gating circuit (3)； The output end of described singlechip controller (6-1) is electrically connected with by-pass knife switch operation drive circuit (7)；Described single-chip microcomputer The input of controller (6-1) is electrically connected with alternating voltage zero-crossing point detection circuit (4) and controllable silicon current detection circuit (5)。
2. A kind of 2. photovoltaic plant high-tension transformer no-flashy-flow switching circuit according to claim 1, it is characterised in that：It is described Group of Silicon Controlled Rectifier (1) it is each section be made up of two forward and reverse unidirectional controllable silicon S CR1 in parallel and unidirectional controllable silicon S CR2, realize Electric current two-way circulates；Described thyristor gating circuit (3) triggers electricity by triggering power supply dedicated transformer (3-1) and independent merogenesis Road (3-2) forms；Described independent merogenesis triggers circuit (3-2) is connected with Group of Silicon Controlled Rectifier (1), for triggering Group of Silicon Controlled Rectifier (1) Conducting.
3. A kind of 3. photovoltaic plant high-tension transformer no-flashy-flow switching circuit according to claim 2, it is characterised in that：It is described Independent merogenesis triggers circuit (3-2) by the secondary coil of triggering power supply dedicated transformer (3-1), commutation diode D1, filtering Electric capacity C1, triode Q1, triode Q3, phototriode Q5, resistance R1, resistance R2, resistance R3, resistance R5, resistance R7 are with being somebody's turn to do Save the trigger electrode composition of Group of Silicon Controlled Rectifier；Wherein：Commutation diode D1 positive pole connects secondary coil one end, negative pole meets filter capacitor C1 Positive pole, the negative electrode of the other end and this section controllable silicon that filter capacitor C1 negative pole is connected to secondary coil formed this is extremely public End, secondary coil, diode D1 and filter capacitor C1 collectively form the triggering power supply of this section；Phototriode Q5 emitter stage connects Triode Q3 base stage, phototriode Q5 colelctor electrode are connected to triode Q1 base stage, triode Q3 collection by resistance R5 Electrode is connected to triode Q1 base stage by resistance R3, and triode Q3 emitter stage is connected to this section common port, triode Q1 hair Emitter-base bandgap grading is connected to the positive pole of triggering power supply, and triode Q1 colelctor electrode is connected to the trigger electrode of controllable silicon SCR 1, resistance by resistance R1 R7 is connected in parallel between SCR1 and this section common port.
4. A kind of 4. photovoltaic plant high-tension transformer no-flashy-flow switching circuit according to claim 1, it is characterised in that：It is described Alternating voltage zero-crossing point detection circuit (4) by current-limiting resistance R4, diode D2, diode D3, diode D4, diode D5 and Triode Q2 is formed；Wherein, diode D2 connects with diode D3, and diode D4 connects with diode D5, the two-way two of series connection Reverse parallel connection, one end are connected to the secondary voltage Uab of high-voltage system voltage transformer one end by current-limiting resistance R4 to pole pipe again, separately One end is connected to the secondary voltage Uab of the voltage transformer other end, the end be used as with reference to " " current potential.
5. A kind of 5. photovoltaic plant high-tension transformer no-flashy-flow switching circuit according to claim 1, it is characterised in that：It is described Controllable silicon current detection circuit (5) by Current Transmit, commutation diode D6, commutation diode D7, filter capacitor C2, limit Width diode D8-D12, resistance R6, resistance R8, triode Q4 compositions；Wherein：

   One end of Current Transmit secondary coil is connected to commutation diode D6 positive pole, Current Transmit secondary coil it is another One end is connected to commutation diode D7 positive pole, the midpoints of CT secondary coils be used as with reference to " " current potential, commutation diode D6, D7's Negative pole, which links together, is connected to limiter diode D8 positive pole, limiter diode D8-D12 series connection, limiter diode D12 negative pole Ground connection, filter capacitor C2 are connected in parallel on limiter diode D8-D12 both ends, and filter capacitor C2 positive pole is connected to three poles by resistance R6 Pipe Q4 base stage, triode Q4 grounded emitter are connected to parallel resistance R8 between triode Q4 base stage and emitter stage, and three Pole pipe Q4 colelctor electrode is connected to singlechip controller (6-1) input pin.
6. A kind of 6. photovoltaic plant high-tension transformer no-flashy-flow switching circuit according to claim 1, it is characterised in that：It is described Singlechip controller (6-1) and control machines order light drive circuit (6-2) composition calculate control and output driving circuit (6)；The output end of described singlechip controller (6-1) by described control machines order light drive circuit (6-2) with Described thyristor gating circuit (3) connection；Described control machines order light drive circuit (6-2) includes infraluminescence two Pole pipe, driving triode Q5 and current-limiting resistance composition, the negative pole of described infrarede emitting diode are connected to triode Q5 current collection Pole, triode Q5 base stage are connected to the output end reception trigger command of singlechip controller (6-1), triode Q5 by resistance R0 Emitter stage be connected to power cathode, current-limiting resistance is connected between positive source and the positive pole of infrarede emitting diode.
7. A kind of 7. photovoltaic plant high-tension transformer no-flashy-flow switching circuit according to claim 1, it is characterised in that：It is described Electrical contact and the mechanical operation portion of by-pass knife switch (2) high_voltage isolation is carried out using insulated connecting rod.