A kind of IGBT series connection valve triggers supervisory control system and communication means thereof
Technical field
The invention belongs to power electronics and field of power, be specifically related to a kind of IGBT series connection valve and trigger supervisory control system and communication means thereof.
Background technology
20th century the mid-80 occur the semiconductor power switching device---insulated gate bipolar power tube IGBT (Insulated Gate Biploar Transistor) is a kind of multiple device, its input control section is the MOSFET pipe, output stage is a bipolar junction transistor; Have the advantage of MOSFET pipe and power transistor concurrently: high input impedance, voltage control, driving power is little; Switching speed is fast, and operating frequency can reach 10-40kHz, and saturation pressure reduces; Voltage, current capacity are bigger; The safety operation area broad still owing to the voltage that single IGBT device can bear is preferential, is difficult to satisfy the demand in high pressure, high-power field.In order to improve the electric pressure that IGBT uses, adopt the method for IGBT series connection usually.The progressively popularization of in electric power system, using along with power electronic technology; Becoming the core component of various novel high-power power electronic equipments, for example voltage source converter type DC transmission system VSC-HVDC (Voltage Vource Converter Based HVDC), STATCOM STATCOM (Static Synchronous Compensator), THE UPFC UPFC (Unified Power Flow Controller) etc. based on the high pressure valve of IGBT series average-voltage technology.
The cascaded structure of IGBT requires the strict synchronism that turns on and off of all IGBT in the valve, otherwise turn-offs in advance or the device that postpones to open will bear overvoltage, causes device failure.For realizing opening synchronously, turn-offing of IGBT, must between valve control and IGBT gate-drive unit, increase a valve base electronic device, the triggering control signal that valve control produces is distributed to each IGBT in the valve synchronously.In addition, IGBT gate-drive unit directly connects and is installed on the IGBT, be in the high-pressure side, and valve base electronic device is in the earth potential side, and considered is the transmission of information between the two.
IGBT type of drive commonly used is through the direct-connected gate pole to IGBT of necessary shaping processing and amplifying with the pulse width modulation (PWM) triggering signal.The characteristics of pwm signal itself have determined it only to comprise and have turned on and off two kinds of triggering control informations, and shown as continuous high-low level checker.This has just determined this PWM communication mode, and circuit is to transmit low-down amount of information with higher expense, causes communication efficiency low big with line loss.In high pressure IGBT series connection valve; Except distributing link, the valve trigger impulse to turn on and off the signal to IGBT driver element transmission PWM; The IGBT driver element also need be to the operating state repayment signal of valve trigger impulse transmission IGBT; The state reporting signal comprises whether IGBT is in overvoltage, crosses dv/dt, positive voltage is lost and information such as short trouble, and this will consider the transmission of signal.Through increasing the order wire way; Various signals to be passed are transmitted according to parallel mode, can head it off, but in the high-power application; The corresponding valve base electronic device of each series connection valve; Each IGBT quantity of comprising of series connection valve is then more, generally includes the series connection of up to a hundred IGBT and every corresponding driver element of IGBT like series connection valve in the 300kV converter.Simple dependence increases the circuit number and improves communication information capacity and can cause that equipment room circuit number of connection increases, interface circuit is in large scale and line cost rises.
Summary of the invention
The objective of the invention is to equipment room circuit number of connection increase, interface circuit is in large scale and line cost rising problem, propose to supply a kind of IGBT series connection valve to trigger supervisory control system and the triggering that proposes to this supervisory control system and the communication means of state reporting signal.This communication means is encoded various state reporting signals according to certain rule, on a circuit, accomplish the timesharing transmission.Because the asynchronism(-nization) that the various faults of IGBT occur adopts this communication means when having increased communication information amount, can not influence the real-time of communication, and can improve communication efficiency, reduces line loss.Its communication party's ratio juris mainly be according to IGBT in when work each switch periods overvoltage with cross dv/dt fault, positive voltage and lose the diverse location and the various fault of appearance such as fault and short trouble and can not occur simultaneously; The time that occurs according to fault is divided into several working hours with each IGBT switch periods; Carry out corresponding fault detect in each working hour, and fault detect information is transmitted through same optical fiber timesharing as the state reporting signal.
The objective of the invention is to adopt following technical proposals to realize:
A kind of IGBT series connection valve triggers supervisory control system, and its improvements are that said supervisory control system comprises valve base electronic device VBE, IGBT driver element; Said valve base electronic device is connected through optical fiber with the IGBT driver element; Said IGBT driver element is electrically connected with insulation bipolar-type power pipe IGBT.
A kind of optimized technical scheme provided by the invention is: said valve base electronic device VBE comprises coding module, decoder module, optical transmitting set and optical receiver; Said coding module and decoder module are realized through the FPGA control circuit.
Second optimized technical scheme provided by the invention is: said IGBT driver element comprises optical receiver, optical transmitting set, decoder module, circuits for triggering, state detection module and guard mode back-reporting module; Said optical transmitting set is connected with optical transmitting set with the optical receiver of valve base electronic device respectively through optical fiber with optical receiver; Said decoder module, state detection module and guard mode back-reporting module realize through the FPGA control circuit.
The present invention is based on a kind of communication means like above-mentioned said supervisory control system that another purpose provides, its improvements are that said method is divided at least one working hour according to the time that fault occurs with each IGBT switch periods; Said method comprises the steps:
A, said valve base electronic device VBE receive the PWM start pulse signal that produces in higher level's valve control;
B, said coding module convert said PWM start pulse signal and IGBT working hour information to IGBT driver element discernible pulse signal according to coded system; Said discernible pulse signal is given the IGBT driver element through Optical Fiber Transmission;
The discernible pulse signal that decoder module in C, the said IGBT driver element will receive is decoded, and makes the form before said pulse signal is reduced to coding, and the form before the said coding is PWM start pulse signal and IGBT working hour information;
The PWM start pulse signal that D, said IGBT driver element parse from coding is accomplished the triggering to IGBT through circuits for triggering; Said IGBT working hour information is used for the IGBT driver element and opens and corresponding failure detector circuit of working hour; To the IGBT working state real-time monitoring, and convert testing result to state reporting coding and feed back to valve base electronic device VBE through the guard mode back-reporting module; Said the IGBT working state real-time monitoring is realized by state detection module;
E, said state reporting coding is represented the fault detect result with impulse form, said valve base electronic device VBE accepting state repayment coding, and promptly valve base electronic device VBE decodes the operating state of IGBT according to the period that whether receives pulse and pulse appearance.
A kind of optimized technical scheme provided by the invention is: the coded system of said start pulse signal and IGBT working hour information comprises the mode of valve base electronic device VBE and the time-delay of IGBT driver element counting.
Compared with prior art, the beneficial effect that reaches of the present invention is:
1, in supervisory control system provided by the invention and the communication means thereof, IGBT series connection valve triggering signal is synchronous, and overvoltage damages owing to asynchronous triggering to avoid device.
2, in supervisory control system provided by the invention and the communication means thereof, IGBT series connection valve operating state real-time repaying is avoided device because damage.
3, supervisory control system provided by the invention and communication means thereof utilize the transmission medium of optical fiber as triggering signal and state reporting signal between valve base electronic device and IGBT driver element; Guarantee the reliability and the rapidity of communication, and realized the electrical isolation of high-low pressure equipment room.
4, supervisory control system provided by the invention and communication means thereof only use two optical fiber between triggering allocation units and IGBT driver element, have saved fiber count and interface circuit scale, have reduced equipment cost and complexity.
Description of drawings
Fig. 1 is the overall hardware formation sketch map that IGBT series connection valve triggers supervisory control system;
Fig. 2 is IGBT series connection valve triggering signal and IGBT working hour information encoding-decoding sketch map;
Fig. 3 is an IGBT series connection valve state reporting signal encoding sketch map.
Embodiment
Do further detailed description below in conjunction with the accompanying drawing specific embodiments of the invention.
It is as shown in Figure 1 that the overall hardware of the IGBT series connection valve triggering supervisory control system that the present invention relates to constitutes sketch map.In Fig. 1, supervisory control system comprises valve base electronic device and IGBT driver element; Information channel between valve base electronic device and the IGBT driver element is a transport vehicle with two optical fiber, and being equipped with in valve base electronic device and the IGBT driver element that light is connected is optical transmitting set and optical receiver.Optical fiber connects the electrical isolation that has realized two equipment rooms on the one hand, and is anti-interference to by force because the signal transmission loss of transmitting on the optical fiber is little on the other hand, and transmission delay is little, has guaranteed the reliability of message transmission and IGBT triggering.
Valve base electronic device comprises coding module, decoder module, optical transmitting set and optical receiver, and optical transmitting set is connected with optical transmitting set with IGBT driver element optical receiver respectively through optical fiber with optical receiver; Coding module and decoder module can be realized its function through the FPGA control circuit, also can realize its function through other control circuits.
The IGBT driver element comprises optical receiver, optical transmitting set, decoder module, circuits for triggering, guard mode back-reporting module and state detection module; Optical transmitting set is connected with optical transmitting set with the valve base electronic device optical receiver respectively through optical fiber with optical receiver; Decoder module, guard mode back-reporting module and state detection module can be realized its function through the FPGA control circuit, also can realize its function through other control circuits; Circuits for triggering are to have some stable states or astable circuit, wherein have at least one to be stable state, and are designed to when applying a suitable pulse, can start required transformation.The FPGA control circuit is mainly realized by fpga chip.
Concrete operation principle: valve base electronic device VBE receives the PWM trigger impulse that higher level's valve control produces.Coding module converts PWM start pulse signal and IGBT working hour information coded system by appointment to pulse code that the IGBT driver element can be discerned; The pulse code that can discern is transferred to the IGBT driver element through optical-fibre channel; Decoder module in the IGBT driver element is decoded the pulse code that receives; Form before making it be reduced to coding, the form before the coding is PWM start pulse signal and IGBT working hour information.The PWM trigger impulse that the IGBT driver element parses from coding is accomplished the triggering to IGBT through circuits for triggering; IGBT working hour information is used for the IGBT driver element and opens and corresponding failure detector circuit of working hour; To the IGBT working state real-time monitoring; And the testing result transition status is repaid encoder feedback give valve base electronic device; Valve base electronic device VBE encodes through the repayment of optical fiber accepting state, and draws each IGBT state information in the series connection valve through decoder module.
IGBT series connection valve triggering signal and IGBT working hour information encoding-decoding sketch map are as shown in Figure 2.Valve base electronic device is divided into some working hours through mode such as time-delay counting etc. with switch periods, with working hour information synthesize triggering with pwm pulse signal and encode and send to the IGBT driver element; The IGBT driver element receives the coding back and decomposites PWM waveform and period information through decoder module.IGBT series connection valve state reporting signal encoding sketch map is as shown in Figure 3.State reporting coding is represented the fault detect result with impulse form, and the decoder module of valve base electronic device decodes the operating state of IGBT according to the period that whether receives pulse and pulse appearance; Wherein, failure detector circuit is to the overvoltage that possibly occur in the IGBT course of work, crosses dv/dt, under-voltage and circuit that short trouble detects, can realize with software and hardware.
Trigger impulse and working hour coded system can have multiplely, can adopt valve base electronic device and IGBT driver element to count the mode of time-delay respectively.
The invention provides triggering and state reporting signal communication method between a kind of valve base electronic device and the IGBT driver element; This communication means as communication media, has guaranteed the reliability of communication with optical fiber, and makes triggering signal and state reporting signal only need two optical fiber just can accomplish transmission through certain coded system; Thereby improved communication efficiency; Reduce loss of communications, and guaranteed circuit linking number minimum between the equipment, reduced the optical fiber cost.
Should be noted that at last: above embodiment is only in order to explanation the application's technical scheme but not to the restriction of its protection range; Although the application has been carried out detailed explanation with reference to the foregoing description; The those of ordinary skill in affiliated field is to be understood that: those skilled in the art still can carry out all changes, revise or be equal to replacement to the embodiment of application after reading the application; These changes, modification perhaps are equal to replacement, and it is all within the claim scope that its application is awaited the reply.