KCZ6.2 thyristor three-phase full control (half control) bridge intelligent control board

I. Main design features
  KCZ6.2 thyristor three-phase full control (semi-control) bridge intelligent control board is developed by our company KCZ6.0 and KCZ6.1 thyristor three-phase full control(semi-control)Bridge Control< /SPAN>
is developed on the basis of the board system to further improve and improve the performance. It absorbs the advantages of KCZ6.0 and KCZ6.1 boards, and discards Its shortcomings are more complete in performance and stronger functions. It can be used in three-phase bridge-type full-control, three-phase bridge-type half-control or three-phase half-wave (or double reverse star) thyristor rectifier circuit and three-phase AC voltage regulation As the phase shift trigger control unit of the thyristor in the system, it integrates a given integrator, a closed-loop regulator, and overvoltage and overcurrent protection into one, making it more convenient for users to apply. Its core chip is still TC787. In a nutshell, the board has the following main features:
1. The synchronization filter network can eliminate the distortion and interference in the synchronization signal, provide a 30-degree phase shift, and fine-tune the three-phase synchronization signal, so that the control board and the working system have a good cooperation.
2. The circuit uses a centralized constant current source with small relative error, good linearity of the three-phase sawtooth wave, and good slope consistency.
  3. A function selection point is designed on the circuit board. If the 6-pin of TC787 is connected to its 17-pin in the circuit, the output is a double pulse mode. 6 feet Ru and 3 feet
Connected, the output is single pulse mode.
  4. The output is a modulated pulse train, adapted to a pulse transformer to trigger a thyristor (SCR), with adjustable width, which is particularly reliable for triggering the working system of an inductive load.
   5. There is a pulse output control terminal. This terminal can be used as a pulse-sealing protection for over-current or over-voltage. It can also be used as a logic switch for a positive and negative group reversible system and a switch control terminal for a zero-crossing trigger system. This end is pin 5 of TC787, high level prohibits pulse output.
   6. A slight modification of the output circuit can be used in a three-phase AC voltage regulation system where the main power device is a bidirectional thyristor.
  7. The board comes with a working rectifier and stabilized power supply. Users only need to connect a dual 18V/0.5A AC power supply to work. Because the TC787 works with a single power supply, but considering the needs of the user, the board has a \15V dual-channel stabilized output and 24V output.
8. There is a closed-loop regulator in the board. As the user's external feedback signal is different in voltage or current, the user can easily form a voltage stabilization or current stabilization system to achieve constant voltage or constant current control.
9. There is an overvoltage and overcurrent protection unit in the board, which can be used for protection under fault conditions. After the protection, in addition to blocking the trigger pulse output by the KCZ6.2 board, it also provides a 380V/0.5A or 220V/1A normally open contact The point is used to disconnect the main circuit of the user system.

Two. Conditions of use
1. Altitude: +1500m;
2. Ambient temperature: -10≧゛+45≧;
  3. Maximum air humidity: +90%;
  4. There is no conductive and explosive dust around, no gas that corrodes metals and damages insulation;
   5. No severe vibration and shock.

3. How to use KCZ6.2 board
  3.1 The overall dimensions of the KCZ6.2 board are: length〜width〜height=145mm〜105mm〜30mm. The positions of the main components on the board, component labels, external lead connectors and signal names are shown in Figure 1. The installation dimensions are also shown in Figure 1, which is four-hole installation, with a hole diameter of φ4, and the hole distance is shown in Figure 1

 


Figure 1 KCZ6.2 board outline dimensions and component layout    

                
  3.1.1  a, GND, b, GND, c, GND of the connector S1 are respectively connected to the corresponding three-phase A, B, and C of the three-phase synchronous transformer Of three 30V windings,
When the main circuit does not have a transformer, if the KCZ6.2 board is used in a three-phase controllable rectifier system, it is recommended to connect the synchronous transformer to Δ/Y-11. If the KCZ6.2 board is used in a three-phase AC voltage regulating system, it is recommended The synchronous transformer is connected to Y/Y-12; when the user's main circuit has a transformer, a, GND, b, GND, c, and GND in S1 are respectively connected to the secondary side of the three-phase synchronous transformer that matches the connection of the main circuit Three windings with a phase voltage of 30V, and Ug, +V, and GND are respectively connected to the middle tap and two fixed ends of a potentiometer with a resistance of 10K half a watt. It is recommended that one fixed end of the potentiometer is connected to GND. The other fixed end is connected to +V through a quarter-watt 2K resistor.
3.1.2  Between A* and B* in the connector S2 is a normally open contact with a contact capacity of 220V/2A or 380V/1A, which can be used to break the main circuit of the user system in a fault condition .
3.1.3  +24V, g1; +24V, g2; +24V, g3; +24V, g4; +24V, g5; +24V, g6 in connector S3 are three-phase six-way pulse output terminals respectively, which are used to Connected with the trigger pulse final board or pulse transformer of the user system, the user can directly select the trigger pulse final board of our company according to different power requirements. When the KCZ6.2 board is used in a three-phase full-control bridge or a three-phase AC voltage regulation system, g1゛g6 are respectively connected to the trigger pulse final board of the six thyristors in the main circuit or the primary side of the pulse transformer, and when the KCZ6 .2 When the board is used for three-phase half-controlled bridge thyristor common cathode connection, controllable rectification or three-phase half-wave common cathode system, only g1, g3, g5 and the trigger pulse final stage of the three thyristors in the corresponding main circuit are required Board or pulse transformer primary side connection, g2, g4, g6 are suspended. Similarly, when KCZ6.2 board is used for three-phase bridge-type semi-controlled thyristor common anode connection or three-phase half-wave common anode system, only g2, g4 , G6 is connected to the trigger pulse final board of the three thyristors in the main circuit or the primary side of the pulse transformer, while g1, g3, and g5 are suspended.
  3.1.4  18V, GND, 18V in the connector S4 are respectively connected to the three connecting ends of the secondary side of the power transformer whose secondary side voltage is dual AC 18V, and its GND is connected to the middle tap end of the dual AC 18V.
  3.2  There are 9 potentiometers in the KCZ6.2 board. The arrangement position of each potentiometer can be referred to Figure 1. Their respective functions and adjustment methods are as follows:
3.2.1  W1, W2, W3 are the synchronization signal amplitude adjustment potentiometers. Their function is not only to change the amplitude of the synchronization signal added to the TC787 18#, 1#, 2# pin, but also to adjust the synchronization signal at the same time. Carry on T-filter, when adjusting clockwise, TC787 The equivalent synchronization signal amplitude of 18#, 1#, 2# pins decreases, and the time constant of the T-type filter network increases. When adjusting counterclockwise, the equivalent synchronization signal amplitude of TC787 18#, 1#, 2# pins As it increases, the time constant of the T-filter network decreases.
3.2.2  W4 is a given adjustment potentiometer in the board. When KCZ6.2 is used as a given in the board, W4 is adjusted clockwise, the amplitude of the given signal increases, and the amplitude of the given signal decreases counterclockwise, in KCZ6. When board 2 is used for external reference, please disconnect the neutral line of W4. At this time, W4 has no effect, and the external reference signal is DC +0゛12V.
3.2.3  W5 is the maximum α angle when the given signal is zero? Wmax limit adjustment potentiometer, clockwise adjustment? Wmax decreases, counterclockwise adjustment? Wmax increases, in practice, it should be set to zero, Adjust W5 so that the angle α is 150< (resistive load) or 90< (inductive load), and no adjustment is needed after one adjustment.
3.2.4 When W6 is the maximum given signal, the smallest α angle? Wmin limiter adjustment potentiometer, clockwise adjustment? Wmin increases, counterclockwise adjustment? Wmin decreases, generally when the given signal is the maximum, adjust W6 to make ?Wmin=0<, no need to adjust after setting once.
  3.2.5  W7 is the feedback coefficient adjustment potentiometer, the clockwise adjustment feedback coefficient increases, and the counterclockwise adjustment feedback coefficient decreases.
  3.2.6  W8 is the feedback signal Uf protection threshold adjustment potentiometer, the overvoltage protection threshold value is adjusted clockwise to decrease, and the overvoltage protection threshold value is adjusted counterclockwise to increase.
  3.2.7  W9 is the protection signal If protection threshold adjustment potentiometer, clockwise adjusts the overcurrent protection threshold to increase, and counterclockwise adjusts the overcurrent protection to decrease.


Four. Electrical parameters and waveforms
   The waveform of each point of the output pulse of the KCZ6.2 board is shown in Figure 2. In the figure, P2 represents the waveform of the TC787 2# pin and so on. Its characteristic parameters are as follows
:


  Figure 2

 

    1. AC synchronous voltage: three-phase 30V (effective value of phase voltage);    

    2. External synchronization transformer connection: 380V/30V    Δ/Y-11 or Δ/Y-12;

    3. Phase shift control voltage: 0゛10V DC;          
 
    4. Phase shift range: 0゛177<;

    5. Trigger pulse form: pulse modulation type;          

 6. Modulation pulse train frequency: 5゛10KHz;

    7. The maximum pulse load current allowed by the output stage: <300mA;
   
    8. Pulse unbalance degree of each phase: <\3<;

    9. AC power input: dual AC 18V/0.5A;     

    10. Output regulated power supply: \15V/50mA;

    11. Power consumption current: <25mA;                   

    12. Operating temperature range: -10≧゛45≧.

Five. Application

  1. For three-phase rectification system
The KCZ6.2 board is equipped with a power transformer, a synchronous transformer and a 3-unit or 6-unit final trigger board produced by our company, which can adapt to three-phase full-control bridge, half-control bridge, three-phase zero-type double reverse star and three-phase Control of AC voltage regulation system.
The principle circuit of KCZ6.2 used in three-phase half-controlled bridge rectification system is shown in Figure 3. The main circuit is a half-controlled bridge rectification and voltage regulation system composed of three thyristors (SCR) and three diodes, KCZ6.2 board The principle circuit for the three-phase full-controlled bridge rectification system is shown in Figure 4. The main circuit is a full-controlled bridge rectification and voltage regulation system composed of six thyristors (SCRs).

 

Figure 3

                     Figure 4

   Considering that there is a 30< phase shift on the KCZ6.2 board, the three-phase synchronous transformer should be determined according to the connection of the main circuit transformer, and the KCZ6.2 board requires The three-phase synchronous input voltage is 30V, and the KCZ6.2 board can filter and fine-tune the phase of the three-phase synchronous voltage through three trimming potentiometers. The phase shift voltage can be manually adjusted by a potentiometer, or the main loop sampling current or voltage signal can be integrated and amplified, and added to a given voltage to obtain the phase shift voltage, and the system can be stabilized or stabilized through a closed loop. The adjustment range of the phase shift voltage should be determined according to the requirements of the system and the load conditions by changing the voltage divider resistance or external circuit up and down the potentiometer to obtain the corresponding phase shift angle range. The amplitude range of the phase shift voltage adjustment should be consistent with the amplitude of the sawtooth wave on the integrating capacitor; another
Taking into account the discrete nature of the circuit¨s discharge on the integrating capacitor, the zero potential of the phase shift voltage should be 0.2V more than the negative power supply of the TC787, that is, the adjustment amplitude of the phase shift voltage
The degree range should be around 0.2゛12V
.

   2. Used in three-phase AC voltage regulating system

Figure 5(a)  Load triangle connection                             Figure 5(b) Load star connection method

   The control part of the three-phase AC voltage regulation system is similar to the control part of the three-phase rectifier system, except that the main circuit of the control is different. Figure 5(a) shows the three-phase Half
Control voltage regulation. Figure 5(b) shows three-phase full control voltage regulation. The load can be delta or Y type. The control terminal of the TC787 can also be used as an AC zero-crossing switch. Adjust the phase-shifting voltage to 0.2V and change the potential of the control terminal to achieve the purpose of zero-crossing switch.
  3. Used for three-phase double reverse star DC stabilized power supply system
   The principle of the KCZ6.2 board used in this type of system is shown in Figure 6, where the gate trigger signals of the six thyristors S1゛S6 come from the output of the KCZ6.2 board.
Road pulse.


 Figure 6

VI. Output and input load capacity of KCZ6.2 board
  7.1  Input signal
   The dual AC 18V of the KCZ6.2 board requires a supply current of only 50mA, a three-phase synchronous signal requires a supply current of 50mA, and Vf, If requires a current amplitude of 20mA, and its amplitude is AC or DC, given The signal is 20mA, and the amplitude is 0-12V DC.
  7.2  Output load capacity 1. The maximum load capacity of +15V, -15V is 50mA, the maximum load capacity of +24V is 300mA pulse current, and the maximum allowable pulse current of g1゛g6 is 150mA.
  2. The AC voltage 220V/1A or 380V/0.5A is allowed to be applied between the protection contacts A* and B* provided to the user.