CN102005778A

CN102005778A - Intelligent switch for series inverter equipment

Info

Publication number: CN102005778A
Application number: CN 201010540132
Authority: CN
Inventors: 冯兴田; 韦统振; 霍群海
Original assignee: Institute of Electrical Engineering of CAS
Current assignee: Institute of Electrical Engineering of CAS
Priority date: 2010-11-10
Filing date: 2010-11-10
Publication date: 2011-04-06
Anticipated expiration: 2030-11-10
Also published as: CN102005778B

Abstract

The invention discloses an intelligent switch for series inverter equipment, which comprises a series inverter (10), a filter (20), a switching network (30), a load (40), a power grid (50) and a control system (60). The output of the series inverter (10) is connected with the filter (20) through an alternating-current bus (101); the filter (20) is connected with the switching network (30) through an electric interface (102); the switching network (30) is connected with the load (40) and the power grid (50) through electric interfaces (103) respectively; and the control system (60) is connected with the switching network (30) through an electric interface (104) and connected with the series inverter (10) through an electric interface (105). The series inverter (10) can enter or quite the functions of the load (40) and the power grid (50) by controlling the switching network (30).

Description

A kind of tandem type inverter apparatus intelligent switch

Technical field

The present invention relates to a kind of switch that is used for the tandem type inverter apparatus.

Background technology

The tandem type inverter apparatus is connected with electrical network, is used for quality of voltage problem in the improvement system.The switchgear that control tandem type inverter apparatus is connected with electrical network must can be controlled at interior connection of short as far as possible time or disconnection electrical network, and require switchgear must allow big electric current normally by and guarantee reliable turn-off.Therefore, the selection of switchgear is mainly determined based on operate time and two indexs of current capacity that allow to pass through.In the alternating electromotive force circuit, present research uses A.C. contactor or AC circuit breaker to realize the break-make of circuit usually.Though A.C. contactor and AC circuit breaker can be worked under big current conditions, because they are all based on mechanical contact, responsiveness is slower, needs several usually even tens power frequency periods, is difficult to satisfy the rapidity requirement of switchgear.

Japan Patent 03108668 provides a kind of switching device, at the movable contact of circuit breaker electric field is set and relaxes electrode, changes the position that this electric field relaxes electrode when open-circuit condition and during closed circuit state, thereby can connect movable contact and fixed contact.Like this, can improve insulation against ground intensity, electrode insulation intensity, make device miniaturization, realize cost degradation in the open-circuit condition position.In addition, by improving charging current interrupting performance, exciting current interrupting performance, can enlarge the scope of application on device systems.Although the related switching device of this patent has improved the switch performance of circuit breaker, its speed issue is not resolved yet, does not reach the rate request of tandem type inverter apparatus with switch.

(Series Static Transfer Switch---SSTS) be made up of semiconductor switch device contactless, that do not have the machinery action usually, responsiveness is very fast for the tandem type static switch.The full-control type semiconductor power device of using in present numerous occasion, such as GTR, IGBT etc., use as static switch, though have very high switching speed, but its power level has certain limitation, the two-way turn-off capacity that does not have voltage and current, proof voltage rush of current ability relatively a little less than, and cost is very high.And the electric current of make-and-break ability of thyristor (or being called controllable silicon SCR) is the strongest, and is shock-resistant and cheap, but as half control type device, thyristor can only be controlled conducting by gate signal, can not utilize gate signal control to turn-off.In the alternating current circuit, adopt bidirectional thyristor (being equivalent to two thyristor inverse parallels) when using as switch, two SCR alternate conduction of bidirectional thyristor in each power frequency period, all there is the periodically zero passage moment in the electric current that flows through every SCR.After the gate pole triggering signal that removes SCR, the SCR that is in conducting state can not turn-off immediately, still continues conducting, has only when electric current is reduced to and keeps electric current (approach zero a certain numerical value) when following, SCR just can become blocking-up by conducting, and this turn off process of SCR is commonly referred to nature and turn-offs.Naturally the time of Guan Duaning is depended on the moment that removes trigger impulse, and between 1/3rd to 1/2nd power frequency periods, maximum time needs half power frequency period 10ms usually.

Chinese patent 98102694 proposes a kind of contactless intelligent switch; comprise a series of parts compositions such as signal sampler, control circuit board, controllable silicon combination; by contactless deciliter of silicon controlled deciliter realization switch; can carry out the short circuit judgement automatically, transship to delay time and judge, leak electricity judgement, temperature protection judgement; and send controllable silicon branch/close and blower fan closes/open signal; can carry out electric energy metrical and electric current, voltage and electric energy automatically and switch demonstration; and can get in touch with other switch; realize uninterrupted power supply; also can be connected, realize monitoring in real time and control with the observing and controlling computer.Though this patent has been used controllable silicon, turn-off the problem that remains for silicon controlled, and because its limitation of design is difficult to be applied to the occasion that the tandem type inverter connects electrical network.

Switchgear at present commonly used mostly is difficult to take into account high-speed switch characteristic and high-power characteristic, and general inverse type static switch is primarily aimed at the switching in circuit, and is not suitable for the occasion that the tandem type inverter connects or disconnect electrical network.At the problems referred to above, this patent adopts bidirectional thyristor (being equivalent to two thyristor inverse parallels) to cooperate the tandem type inverter to constitute intelligent switch equipment, the ingenious main circuit of tandem type inverter and the control circuit of utilizing carries out suitable control, realized that the tandem type inverter apparatus connects or disconnect the function of electrical network, can satisfy rapidity and powerful performance requirement simultaneously.

Summary of the invention

The object of the invention is to overcome the shortcoming that the tandem type inverter apparatus connects the switchgear of electrical network, a kind of intelligent switch equipment that adopts bidirectional thyristor to cooperate the tandem type inverter to constitute is proposed, the present invention utilizes the main circuit of tandem type inverter and control circuit to carry out suitable control, in order to realize that the tandem type inverter apparatus connects or disconnect the function of electrical network, can satisfy rapidity and powerful performance requirement simultaneously.

The present invention includes tandem type inverter, filter, switching network, load, electrical network and control system, and ac bus interface and electric interfaces.The tandem type inverter is the voltage-type or the current source inverter of series connection access electrical network, and the output of tandem type inverter is connected with filter by ac bus; Filter is connected with switching network by electric interfaces; Switching network is connected with load with electrical network respectively by electric interfaces; Control system is connected the turn-on and turn-off of control switch network with switching network respectively by electric interfaces with the tandem type inverter.

The control switch network can realize that the tandem type inverter connects or disconnect the function of electrical network load rapidly.Line voltage just often, the tandem type inverter is in online holding state, promptly by the conducting of control system output triggering signal control switch network, flows through load current; Line voltage occurs rising temporarily, falls temporarily and during power quality problem such as fluctuation, at first remove the triggering signal of control system, the main circuit of tandem type inverter output simultaneously and the voltage that flows through the switching network current opposite in direction, make it possible to rapid stopcock network, keep one very short period, the tandem type inverter is exported the compensation network change in voltage immediately to improve quality of voltage subsequently, guarantee the stable of supply power voltage, switching network can satisfy rapidity switching and powerful performance requirement simultaneously.

The present invention compared with prior art, advantage is:

1. solved at the tandem type inverter apparatus and connected under the situation of electrical network, the shortcoming that the switching speed of mechanical switch such as A.C. contactor, AC circuit breaker is slower, and full-control type semiconductor device proof voltage, rush of current ability are weak and be mainly used in the deficiency of circuit switched aspect, have realized rapidity and powerful dual performance requirement.

2. the present invention is applicable to that any series connection inserts the inverter apparatus of electrical network, can be voltage-type or current source inverter, also extensiblely is applied to being connected of parallel-type converter equipment and electrical network.

3. the present invention also can be used for three-phase system both applicable to single phase system.

4. the flexible in size of tandem type converter main circuit output back-pressure was regulated the turn-off time of intelligent switch equipment when the present invention can turn-off according to intelligent switch, can reduce the influence to tandem type inverter output compensation effect.

5. the present invention utilizes the output of tandem type converter main circuit and control circuit to carry out work, does not need to be equipped with separately the pressure breaking circuit.

Description of drawings

Fig. 1 is principle of the invention figure;

Fig. 2 is a structural representation of the present invention;

Fig. 3 is a specific embodiment of the present invention schematic diagram.

Embodiment

Further specify the present invention below in conjunction with the drawings and specific embodiments.

As shown in Figure 1, tandem type inverter apparatus of the present invention comprises tandem type inverter 10, filter 20, switching network 30, load 40, electrical network 50 and control system 60 with intelligent switch.The 10 single-phase outputs of tandem type inverter are connected with filter 20 by ac bus 101; Filter 20 is connected with switching network 30 by first electric interfaces 102; Switching network 30 is connected with electrical network 50 with load 40 respectively by second electric interfaces 103; Control system 60 is connected with switching network 30 by the 3rd electric interfaces 104, is connected with tandem type inverter 10 by the 4th electric interfaces 105.

The present invention can realize that by control switch network 30 tandem type inverter 10 seals in or withdraw from the function of load 40 and electrical network 50.Electrical network 50 voltages just often, tandem type inverter 10 is in online holding state, promptly by 30 conductings of control system 60 output triggering signal control switch networks, flows through load current; Electrical network 50 voltages occur rising temporarily, fall temporarily and during power quality problem such as fluctuation, control system 60 is at first removed the triggering signal of control conducting, control the main circuit output and the voltage that flows through switching network 30 current opposite in direction of tandem type inverter 10 simultaneously, make it possible to rapid stopcock network 30, keep one very short period, tandem type inverter 10 is exported compensation network 50 change in voltage immediately to improve quality of voltage subsequently, guarantee the stable of supply power voltage, switching network 30 can satisfy rapidity switching and powerful performance requirement simultaneously.

As shown in Figure 2, switching network 30 of the present invention comprises bidirectional thyristor 302 and current limiting element 301, and the first port 302a of bidirectional thyristor 302 is connected in series with the younger brother two port 301b of current limiting element 301 (can select inductance, resistance or resistance sense); Control system 60 comprises CPU601, current sample module 602, power quality problem judge module 603, triggering signal module 604, driver module 605, back-pressure signaling module 606, current sample module 602 output current signals are sent into CPU601, power quality problem judge module 603 output digital signals are sent into CPU601, CPU601 output digital signal is sent into back-pressure signaling module 606, CPU601 output digital signal is sent into triggering signal module 604, and triggering signal module 604 output digital signals are sent into driver module 605.The driver module 605 of control system 60 is connected with the 3rd port 302c of bidirectional thyristor 302 by the 3rd electric interfaces 104, and the back-pressure signal 606 of control system 60 is connected with tandem type inverter 10 by the 4th electric interfaces 105.The triggering signal of the voltage at control switch network 30 two ends and the 3rd port 302c of bidirectional thyristor 302 can realize the break-make of switching network 30, and realization is connected with electrical network 50.The impulse current of current limiting element 301 in order to control bidirectional thyristor 302 conductings or when turn-offing.

The CPU601 of control system 60 judges by power quality problem 603 obtain to occur power quality problem whether information, when not having power quality problem, CPU601 control output triggering signal 604, the 3rd port 302c via driving the 605 and the 3rd electric interfaces 104 control bidirectional thyristors 302 makes switching network 30 conductings; When having power quality problem, triggering signal 604 is removed in CPU601 control, current sample 602 is judged the sense of current and size that flows through bidirectional thyristor 302, CPU601 control output back-pressure signal 606, the reverse voltage that drives tandem type inverter 10 output adjustable size imposes on switching network 30, keep a period of time, after the electric current of judgement bidirectional thyristor 302 is reduced to zero, the back-pressure signal 606 of cancellation CPU601 output, tandem type inverter 10 is exported normal bucking voltage at once, and completion status is switched rapidly.After power quality problem disappears, tandem type inverter 10 quits work, and CPU601 control output triggering signal 604 is via the 3rd port 302c that drives the 605 and the 3rd electric interfaces 104 control bidirectional thyristors 302, make switching network 30 conducting once more, so periodic duty.

Be illustrated in figure 3 as a kind of embodiment of the present invention.

Tandem type inverter 10 output PWM ripples are connected with first port 201a of the filter inductance 201 of filter 20 and the second port 202b of filter capacitor 202 respectively through two port one 01a of ac bus 101 and 101b.The first port one 02a of the second port 201b of filter inductance 201 and the first port 202a of filter capacitor 202 and first electric interfaces 102 is connected, and the second port 202b of filter capacitor 202 is connected with the second port one 02b of first electric interfaces 102.Current-limiting inductance 301 and bidirectional thyristor 302 are composed in series switching network 30; The first port 301a of current-limiting inductance 301 is connected with the first port one 02a of first electric interfaces 102, and is connected with electrical network 50 via the first port one 03a of second electric interfaces 103; The second port 301b of current-limiting inductance 301 is connected with the first port 302a of bidirectional thyristor 302; The second port 302b of bidirectional thyristor 302 is connected with the second port one 02b of first electric interfaces 102, and is connected with load 40 via the second port one 03b of second electric interfaces 103; The 3rd port 302c of bidirectional thyristor 302 is connected via the 3rd electric interfaces 104 with the output signal of control system 60, and another road output signal of control system 60 is connected with tandem type inverter 10 by the 4th electric interfaces 105.

Electrical network 50 voltages just often, tandem type inverter 10 is in online holding state, promptly triggers the 3rd port 302c of control bidirectional thyristors 302 by control system 60 output, makes switching network 30 conductings, flows through load current; Electrical network 50 voltages occur rising temporarily, fall temporarily and during power quality problem such as fluctuation, at first remove the triggering signal of the 3rd port 302c of the control bidirectional thyristor 302 of control system 60, sample streams is crossed the size and Orientation of bidirectional thyristor 302, the voltage of the adjustable size of the current opposite in direction of 10 outputs of driving tandem type inverter and bidirectional thyristor 302, constant amplitude, keep a period of time, after the electric current of judgement bidirectional thyristor 302 is reduced to zero, the shutoff measure is forced in cancellation, be that tandem type inverter 10 is exported normal bucking voltage at once, devote oneself to work.After power quality problem disappeared, tandem type inverter 10 quit work, and control system 60 outputs trigger the 3rd port 302c of control bidirectional thyristor 302, make switching network 30 conducting once more, so move in circles, and realized that on off state switches.

Claims

1. tandem type inverter apparatus intelligent switch, it is characterized in that: described intelligent switch comprises tandem type inverter (10), filter (20), switching network (30), load (40), electrical network (50) and control system (60), and ac bus (101), first electric interfaces (102), second electric interfaces (103), the 3rd electric interfaces (104) and the 4th electric interfaces (105); The output of tandem type inverter (10) is connected with filter (20) by ac bus (101); Filter (20) is connected with switching network (30) by first electric interfaces (102); Switching network (30) is connected with electrical network (50) with load (40) respectively by second electric interfaces (103); Control system (60) is connected with switching network (30) by the 3rd electric interfaces (104), and control system (60) is joined by the 4th electric interfaces (105) and tandem type inverter (10).

2. tandem type inverter apparatus intelligent switch according to claim 1, it is characterized in that: switching network (30) comprises bidirectional thyristor (302) and current limiting element (301), and first port (302a) of bidirectional thyristor (302) directly is connected in series with second port (301b) of current limiting element (301); Control system (60) comprises CPU (601), current sample module (602), power quality problem judge module (603), triggering signal module (604), driver module (605), back-pressure signaling module (606), current sample module (602) output current signal is sent into CPU (601), power quality problem judge module (603) output digital signal is sent into CPU (601), CPU (601) output digital signal is sent into back-pressure signaling module (606), CPU (601) output digital signal is sent into triggering signal module (604), and triggering signal module (604) output digital signal is sent into driver module (605); The driver module (605) of control system (60) is connected with the 3rd port (302c) of bidirectional thyristor (302) by the 3rd electric interfaces (104), and the back-pressure signal (606) of control system (60) is connected with tandem type inverter (10) by the 4th electric interfaces (105); The impulse current of current limiting element (301) in order to control bidirectional thyristor (302) conducting or when turn-offing.

3. tandem type inverter apparatus intelligent switch according to claim 1, it is characterized in that: described tandem type inverter (10) output PWM ripple is connected with first port (201a) of the filter inductance (201) of filter (20) and second port (202b) of filter capacitor (202) respectively through two ports (101a, 101b) of ac bus (101); Second port (201b) of filter inductance (201) is connected with first port (102a) of first port (202a) of filter capacitor (202) and first electric interfaces (102), and second port (202b) of filter capacitor (202) is connected with second port (102b) of first electric interfaces (102); Current limiting element (301) and bidirectional thyristor (302) are composed in series switching network (30); First port (301a) of current limiting element (301) is connected with first port (102a) of first electric interfaces (102), and is connected with electrical network (50) via first port (103a) of second electric interfaces (103); Second port (301b) of current limiting element (301) is connected with first port (302a) of bidirectional thyristor (302); Second port (302b) of bidirectional thyristor (302) is connected with second port (102b) of first electric interfaces (102), and is connected with load (40) via second port (103b) of second electric interfaces (103); The 3rd port (302c) of bidirectional thyristor (302) is connected via the 3rd electric interfaces (104) with the output signal of control system (60), and another road output signal of control system (60) is connected with tandem type inverter (10) by the 4th electric interfaces (105).

4. tandem type inverter apparatus intelligent switch according to claim 1, it is characterized in that: the CPU (601) of described control system (60) obtains electrical network (50) by power quality problem judge module (603) and power quality problem whether information occurs, when not having power quality problem, CPU (601) control output triggering signal module (604), via three port (302c) of driver module (605), make switching network (30) conducting with second electric interfaces (104) control bidirectional thyristor (302); When electrical network (50) when having power quality problem, triggering signal module (604) is removed in CPU (601) control, current sample module (602) is judged the sense of current and size that flows through bidirectional thyristor (302), CPU (601) control output back-pressure signaling module (606), the reverse voltage that drives tandem type inverter (10) output adjustable size imposes on switching network (30), keep a period of time, after the electric current of judgement bidirectional thyristor (302) is reduced to zero, the back-pressure signaling module (606) of cancellation CPU (601) output, tandem type inverter (10) is exported normal bucking voltage at once, and completion status is switched rapidly; After electrical network (50) power quality problem disappears, tandem type inverter (10) quits work, CPU (601) control output triggering signal module (604), via three port (302c) of driver module (605), make switching network (30) conducting once more with the 3rd electric interfaces (104) control bidirectional thyristor (302).

5. tandem type inverter apparatus intelligent switch according to claim 1 is characterized in that: tandem type inverter (10) inserts the voltage-type or the current source inverter of electrical network (50) for series connection.

6. tandem type inverter apparatus intelligent switch according to claim 1 is characterized in that: current limiting element (301) is inductance, resistance or resistance sense.