A kind of fault protection system of short circuit current experimental rig
Technical field
The invention belongs to electric and electronic technical field, be specifically related to a kind of fault protection system of short circuit current experimental rig.
Background technology
Voltage-source type high voltage direct current transmission VSC-HVDC (Voltage Sourced Converter-High Voltage DerectCurrent) is with turn-off devices such as IGBT, IGCT, GTO, the technology such as pulse-width modulation (PWM) are the VSC-HVDC technology of feature, present actual VSC-HVDC engineered capacity does not wait to hundreds of MW from several MW, the maximum engineering of having gone into operation is the Cross Sound Cable engineering of the U.S., rated capacity is 346MVA/ ± MVAr, electric pressure/± 150kV, capacity can rise to thousands of MW now.
Voltage-source type high voltage direct current transmission VSC-HVDC has a wide range of applications in the high-voltage dc transmission electrical domain, VSC-HVDC based on modularization multi-level converter (MMC), be to realize utilizing the IGBT valve to carry out a kind of mode of direct current transportation, its core component is called modularization multi-level converter.
The short circuit current experimental rig all might break down in charging stage and experimental stage, and contingent fault type and consequence are as shown in table 1.
Table 1
Sequence number |
Experimental stage |
Possible breakdown |
Failure effect (the most serious) |
1. |
Charging stage |
Capacitor breakdown |
Charge power supply 1 overcurrent |
2. |
Charging stage |
K
f1、K
f2、K
f3Malfunction
|
Discharge resistance is overheated, charge power supply 1 overcurrent |
3. |
Charging stage |
Charging voltage surpasses set point |
Overvoltage of capacitor, charge power supply 0 short circuit |
4. |
Experimental stage |
The diode valve reverse breakdown |
Capacitor short-circuit |
5. |
Experimental stage |
IGBT triggers unsuccessfully |
The overvoltage of IGBT valve was lost efficacy |
6. |
Experimental stage |
V1 triggers unsuccessfully |
The test product valve wave distortion |
7. |
Experimental stage |
V21 triggers unsuccessfully |
The test product valve wave distortion |
8. |
Experimental stage |
V22 triggers unsuccessfully |
The test product valve wave distortion |
9. |
Experimental stage |
V3 triggers unsuccessfully |
High back voltage can't apply |
Summary of the invention
In order to overcome above-mentioned the deficiencies in the prior art, the invention provides a kind of fault protection system of short circuit current experimental rig, be applicable to MMC valve short circuit current operating test device, can the guarantee test process in the safety of each equipment and carrying out smoothly of test.
In order to realize the foregoing invention purpose, the present invention takes following technical scheme:
A kind of fault protection system of short circuit current experimental rig is provided, and described system comprises charge circuit I, charge circuit II, test product valve, exponential damping electric current infusion circuit, sinusoidal current infusion circuit and high voltage infusion circuit; Described charge circuit I is in parallel with test product valve; Described exponential damping electric current infusion circuit, sinusoidal current infusion circuit and high voltage infusion circuit are in parallel with described charge circuit II respectively, and in parallel with test product valve respectively; The low-pressure end of charge circuit I, charge circuit II, test product valve, exponential damping electric current infusion circuit, sinusoidal current infusion circuit and high voltage infusion circuit all is connected to the ground.
Described charge circuit I provides energy by the 380V power supply, behind isolating switch, circuit breaker, voltage regulator and transformer, obtain testing the ac high voltage that needs, obtain testing again the direct current of required 0~40KV electric pressure through rectifying device, to the capacitor charging of test product valve.
Described charge circuit II provides energy by the 380V power supply, behind isolating switch, circuit breaker, voltage regulator and transformer, obtain testing the ac high voltage that needs, obtain testing again the direct current of required 0~5KV electric pressure through rectifying device, to the capacitor charging of exponential damping electric current infusion circuit, sinusoidal current infusion circuit and high voltage infusion circuit.
Described test product valve is formed by a plurality of submodule cascades, and wherein each submodule comprises that direct current capacitor, two igbt chips, two grading resistors and thyristor form; Wherein, two igbt chip series connection form the igbt chip series arm, two grading resistor series connection form the equalizing capacitance branch road, described igbt chip series arm, equalizing capacitance branch road and direct current capacitor are in parallel, described thyristor is in parallel with one of igbt chip, the negative pole of its anodic bonding direct current capacitor, and negative electrode connects the positive pole of direct current capacitor, the negative electrode of thyristor is drawn the positive pole output of submodule, and the anode utmost point of thyristor is drawn the negative pole output of submodule.
Described exponential damping electric current infusion circuit is by K switch
1, unidirectional control isolating valve V
1, reactor L
1, diode D, turn-off device valve G, capacitor C
1With decay controlling resistance R
1Form; Described turn-off device valve G, diode D and decay controlling resistance R
1Rear and capacitor C connect
1Parallel connection, the negative electrode of the anodic bonding turn-off device valve G of diode D, the negative electrode of diode D and capacitor C
1Positive pole and reactor L
1One end connects respectively, the anode of turn-off device valve G and decay controlling resistance R
1One end connects, decay controlling resistance R
1The other end connects capacitor C
1Negative pole, reactor L
1The other end and unidirectional control isolating valve V
1Anode link to each other unidirectional control isolating valve V
1Negative electrode pass through K switch
1Connect test product valve.
Described sinusoidal current infusion circuit is by capacitor C
2, reactor L
2With two-way control isolating valve V
2Form; Described capacitor C
2By reactor L
2With two-way control isolating valve V
2Link to each other described two-way control isolating valve V
2The other end pass through K switch
2Connect test product valve, described two-way control isolating valve V
2By thyristor V
21With thyristor V
22Inverse parallel forms; Its turn-on cycle is 7~10 power frequency periods, and each cycle continues 20ms.
Described high voltage infusion circuit is by capacitor C
3, reactor L
3With two-way control isolating valve V
3Form; Described capacitor C
3By reactor L
3With two-way control isolating valve V
3Link to each other described two-way control isolating valve V
3The other end pass through K switch
3Connect test product valve, described two-way control isolating valve V
3By thyristor V
31With thyristor V
32Inverse parallel forms, described thyristor
V 31 Forward conduction continues 1~3ms, described thyristor V
32At thyristor V
31Always conducting of negative sense after conducting finishes.
Compared with prior art, beneficial effect of the present invention is:
1, the present invention is applicable to MMC valve short circuit current operating test device, and protection range is comprehensive, designs three test loops, corresponding charge circuit and test product valves;
2, the present invention is applicable to MMC valve short circuit current operating test device, and highly sensitive, the whole process of the test duration is hundred Milliseconds, and protection system operate time is Microsecond grade;
3, the present invention is applicable to MMC valve short circuit current operating test device, and reliability is high, and a link goes wrong in the system, and all the other links still can guarantee the normal operation of system;
4, the present invention is applicable to MMC valve short circuit current operating test device, can the guarantee test process in the safety of each equipment and carrying out smoothly of test.
Description of drawings
Fig. 1 is the electrical structure diagram of test product valve in the embodiment of the invention;
Fig. 2 is the fault protection system circuit topological structure figure of short circuit current testing device in the embodiment of the invention.
Embodiment
Below in conjunction with accompanying drawing the present invention is described in further detail.
Such as Fig. 1 and Fig. 2, a kind of fault protection system of short circuit current experimental rig is provided, described system comprises charge circuit I, charge circuit II, test product valve, exponential damping electric current infusion circuit, sinusoidal current infusion circuit and high voltage infusion circuit; Described charge circuit I is in parallel with test product valve; Described exponential damping electric current infusion circuit, sinusoidal current infusion circuit and high voltage infusion circuit are in parallel with described charge circuit II respectively, and in parallel with test product valve respectively; The low-pressure end of charge circuit I, charge circuit II, test product valve, exponential damping electric current infusion circuit, sinusoidal current infusion circuit and high voltage infusion circuit all is connected to the ground.
Described charge circuit I provides energy by the 380V power supply, behind isolating switch, circuit breaker, voltage regulator and transformer, obtain testing the ac high voltage that needs, obtain testing again the direct current of required 0~40KV electric pressure through rectifying device, to the capacitor charging of test product valve.
Described charge circuit II provides energy by the 380V power supply, behind isolating switch, circuit breaker, voltage regulator and transformer, obtain testing the ac high voltage that needs, obtain testing again the direct current of required 0~5KV electric pressure through rectifying device, to the capacitor charging of exponential damping electric current infusion circuit, sinusoidal current infusion circuit and high voltage infusion circuit.
Described test product valve is formed by a plurality of submodule cascades, and wherein each submodule comprises that direct current capacitor, two igbt chips, two grading resistors and thyristor form; Wherein, two igbt chip series connection form the igbt chip series arm, two grading resistor series connection form the equalizing capacitance branch road, described igbt chip series arm, equalizing capacitance branch road and direct current capacitor are in parallel, described thyristor is in parallel with one of igbt chip, the negative pole of its anodic bonding direct current capacitor, and negative electrode connects the positive pole of direct current capacitor, the negative electrode of thyristor is drawn the positive pole output of submodule, and the anode utmost point of thyristor is drawn the negative pole output of submodule.
Described exponential damping electric current infusion circuit is by K switch
1, unidirectional control isolating valve V
1, reactor L
1, diode D, turn-off device valve G, capacitor C
1With decay controlling resistance R
1Form; Described turn-off device valve G, diode D and decay controlling resistance R
1Rear and capacitor C connect
1Parallel connection, the negative electrode of the anodic bonding turn-off device valve G of diode D, the negative electrode of diode D and capacitor C
1Positive pole and reactor L
1One end connects respectively, the anode of turn-off device valve G and decay controlling resistance R
1One end connects, decay controlling resistance R
1The other end connects capacitor C
1Negative pole, reactor L
1The other end and unidirectional control isolating valve V
1Anode link to each other unidirectional control isolating valve V
1Negative electrode pass through K switch
1Connect test product valve.
Described sinusoidal current infusion circuit is by capacitor C
2, reactor L
2With two-way control isolating valve V
2Form; Described capacitor C
2By reactor L
2With two-way control isolating valve V
2Link to each other described two-way control isolating valve V
2The other end pass through K switch
2Connect test product valve, described two-way control isolating valve V
2By thyristor V
21With thyristor V
22Inverse parallel forms; Its turn-on cycle is 7~10 power frequency periods, and each cycle continues 20ms.
Described high voltage infusion circuit is by capacitor C
3, reactor L
3With two-way control isolating valve V
3Form; Described capacitor C
3By reactor L
3With two-way control isolating valve V
3Link to each other described two-way control isolating valve V
3The other end pass through K switch
3Connect test product valve, described two-way control isolating valve V
3By thyristor V
31With thyristor V
32Inverse parallel forms,
Described thyristor V
31Forward conduction continues 1~3ms, described thyristor V
32At thyristor V
31Always conducting of negative sense after conducting finishes.
When capacitor occured to puncture, the charge power supply II can by direct short-circuit, cause overcurrent.If closed in charging stage discharge switch Kf1~Kf3 malfunction equally, can cause overcurrent equally, just overcurrent is less.Can adopt the control logic that interlocks between discharge switch Kf1~Kf3 and the KC11~KC32.Namely only have after charge switch disconnects, discharge just allows closed.Detect simultaneously the direct current of charge circuit, and the repayment control system, when electric current surpasses the action threshold value of setting, tripping circuit breaker 2 and 5.
Charging neutron module capacitance may overvoltage cause BOD action closes bypass switch, causes chain reaction, makes charge power supply by short circuit; safeguard measure is the detection sub-module condenser voltage; when BOD moves, repayment control system, separating brake charge power supply front end circuit breaker.
At capacitor C
1In the situation of charging, if diode valve D reverse breakdown can cause very large impulse current, safeguard measure is the overcurrent protection of configuration capacitor, and sets up the diode valve surge suppressor.
If when exponential damping electric current infusion circuit is worked, if turn-off device valve G does not trigger capacitor C
1Upper meeting produces back-pressure, threatens the safety of turn-off device valve G.Safeguard measure is to select the turn-off device valve G of higher level, optimizes the absorption circuit of turn-off device valve G.
Unidirectional control isolating valve V
1, thyristor V21, thyristor V22, two-way control isolating valve V
3Trigger unsuccessfully and can not bring overvoltage or overcurrent to whole device and test product valve, therefore need not to take extra safeguard measure.
Conclude through summing up, the safeguard measure of short circuit current experimental rig is as shown in table 1:
Table 1
Should be noted that at last: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit, although with reference to above-described embodiment the present invention is had been described in detail, those of ordinary skill in the field are to be understood that: still can make amendment or be equal to replacement the specific embodiment of the present invention, and do not break away from any modification of spirit and scope of the invention or be equal to replacement, it all should be encompassed in the middle of the claim scope of the present invention.