Development of a Kind of Synchronous Generator Microcomputer Excitation Device Wang Xinyuan, Cui Yulong, Sun Jianguang Digital Trigger and other circuits The device is stable in operation and proves that the design is reasonable and reliable. At present, a large number of synchronous genset excitation systems are running in China's power system for maintenance. The function of the safe operation of the unit and the stability of the power grid is getting more and more important. The existing excitation devices have different advantages and disadvantages. In general, the proportion of the microcomputer excitation device in the power system is increasing year by year to meet the large In the technical transformation of the excitation system of the small and medium-sized synchronous generators, the excitation device with the combination of the chip machine and the pseudo-excited circuit has been designed. It has been successfully applied to the 5 000-step generator of a factory. Downtime test, operational safety can be achieved along, and achieved good economic benefits, 1 basic composition in the excitation device, in the process, after the mountain's original magnetic element åž adjustment shoulder discrete components or large-scale integrated circuits, and finally is now common The micro-machine excitation of the application should be based on the two-channel hardware that is adjusted from the measurement to the trigger stage. The performance and reliability of the single-channel structure can be used to the extent that the overall excitation device microcomputer excitation regulator has the advantages of powerful system programming and flexible software configuration. However, there are some inadequacies in some small and medium-sized units. Such as hardware circuit complex anti-interference ability is low, which is to solve the problem of improving the integration of hardware circuit design, but it will increase the cost of the system. Using the microcomputer to study the digital algorithm of control law and the data acquisition operation of Dajing, also It will reduce the adjustment speed of the system and the high cost. Considering the user's excavation and maintenance, as well as the improvement and application of the whole device, this static excitation device suitable for small and medium-sized units is developed. Its single-channel structure is only composed of the switch interface unit, and the small-yuan card-empty unit is composed of the circuit board. The test transmission and the control unit are each composed of an 8-bit single machine as the core, which can be programmed to垆The voltage regulation mode of the generator, that is, or the excitation current adjustment mode, that is, only the cabinet 1 is the frame of the excitation device of the single-turn structure, and the responsible date of the collection of 200 hearts 09 is Chen Shuxin and the ratio is changed by the unit. The parameters are determined. 1 is the phase voltage transformer connected to the generator outlet, the current transformer power circuit connected to the generator phase adopts the phase-controlled thyristor rectification mode, the synchronization signal is taken from the excitation transformer, and the elbow current sensor is used to measure the generator. Excitation current. The elbow ruler is the demagnetization mode of the generator de-excitation switch. In the normal shutdown, the phase-controlled bridge inverter is used. In the accident state, the magnetic switch is de-excited, which is a linear de-excitation resistor. The excitation circuit is taken from a factory AC or DC power supply. The conversion and isolation of the multi-channel control command and the output signal with the remote control device are composed of the optocoupler and the power elbow 031 operating in the switching mode. Compared with the relay of the conventional application, the utility model has the advantages of small volume, long electrical life and reliability. The advantage of high performance is especially the low power consumption of the MOSFET, so that there is no heat in the whole unit. The core of the measurement transmission unit is a chip. The 16074 single-chip microcomputer has a Harvard structure along the structure. It has separate program memory and data memory. It uses two stages of pipeline instructions to fetch data and execute. The running speed is 8 channels and 8 bits on the hardware. , conversion pin and two-way position, elbow output, suitable for data measurement and conversion of the unit's analog circuit part to achieve generator stator voltage, frequency, excitation current active power household, reactive power 2 measurement, converted to design The standard value, the excitation current, the active power, and the reactive power are collected by the single-chip microcomputer. After the internal software calculation, the over-excitation and under-excitation limits are implemented. The elbow pins are separately output, and the filter circuit is converted into the corresponding limit signal voltage. Superimposed to, the regulator realizes that the single-chip microcomputer also realizes the high-precision set value generator according to the control signal transmitted by the switch 10 interface unit. The main functions of the control unit include the generator stator voltage and excitation current, closed-loop regulation, synchronization signal filtering and phase-locked conversion, and digital trigger and pulse forming and amplifying circuits realized by MCS8031 microcontroller and external device 2764ADC0804. The unit also completes digital display interface control. The control logic can realize the two-channel structure that is usually mentioned, and each channel can be individually configured to work only by human or human. 2 The main function realization principle 2.1 Generator active power only reactive power 0 measurement In the microcomputer excitation device, the active power household and reactive power 2 measurement have two methods of DC sampling and AC sampling. AC sampling is a multi-point sampling of the generator stator voltage and stator current in the same phase during the weekly period, and then according to the shortcomings of the length. The use of DC sampling basically does not occupy the time of the microcontroller, and can meet the needs of the excitation device. 2 is to measure the circuit principle box and corresponding waveform of the generator household and 0. In 2, the left side is the corresponding circuit waveform on the right side of the circuit principle box, which is the generator phase voltage, the artificial generator phase current, and the generator line voltage is the power factor angle. In order to measure the active power, the modulation of the wave Wang Wangyuan and other kinds of synchronous generators, the development of the microcomputer excitation device is amplified and then sent to the input of the subsequent electronic switch. First, after passing through the 岑 comparator, two mutually inverted signals are obtained, and the electrons are controlled, so that the human phase current is operated in the same phase and in the reverse phase according to the fixed angle in the period of one line voltage, and the operation of the latter stage. The amplifier works in coordination. Finally, the modulated waveform of the point is transformed into a flat DC voltage reflecting the average value of the waveform through a low-pass filter, which is in a proportional relationship with the reactive power of the generator 2. The next 1 fly 2 measurement of the circuit principle of the generator corpse 2 ThetestingcircuitfoiPandQ, f the same, in the measurement of the generator active power corpse, the difference is only the switch, the signal from the line voltage first through the delay phase 90 phase shift ring 1 Then go to the zero-crossing comparator to ensure the accurate phase shift angle shift phase when the generator frequency changes. The 0 touch 03 device 4046 phase-locked loop realizes that the modulated waveform 2 is recognized as the calculated waveform. The formula of the average bit. 2.2 analog pm regulator adopts 1 analog circuit to realize adjustment 1 has mature technology, simple debugging, easy to master and so on. Especially in the application of small and medium-sized generator sets. Unlike numbers, that requires a higher theoretical level. 3 is used on the device, 0 circuit principle box, feedback value, 6+ is the input reverse voltage input irj from the given value generator, and the output voltage is simulated after operation. After the circuit person 000804, it becomes the circuit corresponding to the voltage range of the team. The static amplification factor that determines the accuracy of the generator voltage adjustment determines the integral time constant by changing the current potentiometer of the resistor 1. The heart potentiometer determines the integral gain, the electric melon Capacitance, 1 determines the differential, the inter-constant and the increase, these parameters are the same. Independently set, seven effects, both to capture the high precision of the season, the righteousness can be obtained. The dynamic response can be combined with a given voltage splitting link to achieve a stable zero rise of the generator. 2.3 Digital given circuit gives a fixed value to the actuator. The sliding contact is easy to contact and does not. In the occasion of adjustment, large-scale digital circuits are used, and there are complicated lines and flexible calculations. In this case, the numerical control potentiometer chip introduced by Shanguanguowei Company was designed, and the 9241 and the touch one company's single-chip microcomputer, 6, 4 relied on Two-wire 120 serial bus communication, while assisting a given value generator implemented by analog circuit combination. With the help of the software of the single-chip microcomputer, the programmable function can be realized. The 9241 is used to meet the high-precision step size requirement of the given value generator. The sister circuit of the analog circuit makes this design scheme have a humiliating search. Passing private, 6 gamtan. , this toe, which. 4 monument 8 micro 661. Qiu 01 chip pin connection, other similar, 9241 is a non-volatile digital potentiometer chip. Each slice includes a potentiometer that can be individually addressed and accessed. Each chip communicates with the microcontroller through the bus and accepts control. Among them, the 3-wire control data is transferred to the scale, and the 1 line transmits the specific data and status code. In addition, each piece is marked with human 0, address, and 4 addresses. The method of pure software can greatly simplify the hardware of the 4 digital given circuit principle. The clamps in the same chip work in series, all of which are called chips to work in parallel. The sliding ends of the chips are connected to the input of the in-phase adder, and the voltage output of the given value is obtained. After the reverse phase, the accuracy of the set value generator of the reverse polarity is obtained, and the control signal of the total number of steps is not less than 1000, and the output of the DC voltage is controlled by the bus. In addition, the 0-port external 8-bit DIP switch can set the reset 伉 and change speed of the setpoint generator. Conventional settings are widely used in precision multi-turn clamps or by digital integrated circuit combinations. The mechanical potentiometer has low instability and low reliability. The 2.4 digital trigger is in the thyristor rectifier circuit. The trigger pulse is the key to ensure the normal and stable operation of the mounting. When the phase control bridge is used as the main circuit in the excitation device, the double is required. Narrow pulse or wide pulse. Considering the volume of the pulse transformer, double narrow pulses are used. It is obtained by charging and discharging the integral capacitor to obtain a pulse of a constant electric angle, and after being amplified, the thyristor is triggered. It is also necessary to add a pulse monitoring circuit, which leads to a complicated circuit and a reduced achievable. To this end, the digital trigger designed by PCT and the 031 contention machine was designed. 5 is the synchronous power signal to which the circuit principle is framed. 1 First pass the band-pass filter circuit to eliminate the distortion caused by the influence of the thyristor rectifier circuit when working on the thyristor rectifier circuit, to ensure wide, pocket æ·– å•¡ å”· å”· 没 没 没 没 没 , , , , , , , , Therefore, the D-static excitation is 50 out and then the phase-locked loop circuit 4046 and the frequency dividing circuit 4040 of the mountain stage are used to interrupt the logic control signal and the multi-frequency signal locked to the power frequency. The interrupt logic control signal is a square wave caused by the power frequency, and the external interrupt input terminal of the single chip microcomputer 8031 ​​is taken as a synchronous phase recognition signal. The 2 multiplier signal is pulsed, and the output of the human digital flip-flop principle chip is introduced into the counter input of the factory machine. In the software, the phase shift angle of the trigger pulse is controlled by the formula of the signal, and the design is taken = 768. The triggering precision is controlled within 5, and the control voltage generated by the adjustment is recognized by the 0,804 after being converted by the single-chip microcomputer as the six-phase phase-controlled trigger pulse required for each thyristor counted by the single-chip output of the single-chip microcomputer. The wide pulse signal of 90 is superimposed with the multiplied signal in the pulse forming and amplifying sections, and the thyristor is directly triggered after being amplified by the stage MOSFET. Due to the high frequency trigger pulse modulation, the frequency is about 3.8 kHz. The volume and inductance of the pulse transformer is small, which reduces its leakage reactance, improves the steepness and amplitude of the pulse, and the circuit is very simple. Considering the additional pulse monitoring loop 3 Conclusion The mature analog and digital chirp circuit is used to realize the high-integration of the single-chip microcomputer and the flexibility of the software. The microcomputer excitation device has perfect functions, high control precision, reliable hardware circuit and debugging maintenance. Simple and other advantages, and the device has been running stably in the field for a long time, and the expected design has to be farmed 1 Fan Jun. Synchronous generator semiconductor excitation principle Beijing Water and Electric Power Press, 1991, connected to the 39th Yangyang-shaped combustion preheater, because the heat transfer capacity of the special-shaped grooved swirl tube is 23.5 times that of the same smooth tube, can be greatly The heat transfer area of ​​the heat exchange valley is reduced and the consumption of the low metal material, especially the copper pipe, is reduced, and the swirling flow is used to improve the heat transfer effect. The technical approach. The swirl tube and its swirl tube heat exchanger are new technology products for efficient heat transfer and energy saving. They can be widely used in the petrochemical industry, such as the ship and other industrial production fields. 1I South China Institute of Technology Thermal process research room. Research on heat transfer and fluid resistance of grooved tubes. Chemical Engineering, 1980, 5214.2 Cui Haiting. The research status and development direction of high-efficiency heterogeneous tubes. Petroleum Machinery, 1999, 277450.3 Yao Zhongpeng, Wang Ruijun, Zhang Xijun. Heat transfer is awkward. Beijing Institute of Technology Press, 1995713.
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