KC-13A DC screen control board

I. Main design features
The KC-13A DC screen control board adopts the latest three-phase phase-shifting integrated circuit TC787 developed by our company and digital and analog circuits to complete functions such as constant current charging, voltage stabilization maintenance, timing floating charging, overcurrent protection, etc., easy to debug and easy to use , Reliable work. The control board has the following characteristics:
1. Three-phase synchronous transformer inputs synchronous signals and provides on-board power supply;
2. The sync signal input has a 30 lag phase shift filter, and the potentiometer can fine-tune the three-phase balance.
3. With the function of soft start and power up;
4. Single closed loop proportional integral control;
5. Battery voltage sampling <210V for constant current charging, or manual intervention of constant current charging (<270V);
6. Battery voltage sampling > 270V for constant voltage charging, and then transfer to floating charging after 7 hours;
7. The battery voltage and voltage sampling threshold and timing are realized by the on-board circuit without adjustment; constant current, over-current current sampling, and stable floating charge voltage sampling are all adjusted by the on-board potentiometer;
8. The board is equipped with a pulse power amplifier and isolation unit transformer, which can directly trigger the thyristor;
9. The output pulse will be blocked after over-current protection;
10. The input and output wiring is fixed with screws, which has good reliability.

Second, the electrical parameters and load capacity of the control board

1. The three-phase synchronous transformer inputs synchronous signals (phase voltage 17V, alternating current 0.5A), and provides on-board power after being rectified by the on-board rectifier circuit.
2. The synchronization signal input can be used to fine-tune the three-phase balance through the potentiometer in the board, and can achieve the effect of 060 phase shift filtering, so as to better meet the needs of different connection methods of the main circuit.
3. It has a soft start function to prevent the impact on the rectifier circuit when the battery is seriously lacking.
4. There is a single closed-loop proportional integral regulator in the board, which can meet the function of steady current or steady voltage charging.
5. Fully automatic logic program control, the control board automatically patrols the working state of the system, when the battery voltage is lower than 210V, it will charge with constant current, and the constant current charge will reach the upper limit set by the user (240270V by the user). It is recommended to set it to 260V) automatically transfer to timing constant voltage charging. The timing time of constant voltage charging and the voltage value of constant voltage charging can be set by the user between 7 hours, 8 hours, 10 hours and 220270V. When the constant voltage charging time is over, it will automatically enter the floating charging state.
6. The current cut-off value for floating charging and constant voltage charging can be set by the user.
7. It can be artificially dry and enter the constant current charging state from constant voltage or floating charge.
8. The battery sampling threshold and constant current charging current sampling, constant voltage charging and floating charging state voltage sampling are all set by the potentiometer on the board, no external potentiometer is required.
9. The over-current protection threshold and the given value of the constant current and constant voltage state are all given by the potentiometer on the board, and no external given potentiometer is required.
10. The voltage setting of the floating charge state can be given by the potentiometer on the board, or by the user external potentiometer, both of which are optional by the user (it is recommended to generally use the setting on the board, so it is convenient to use.)
11. The constant current, constant voltage, and floating charge are given in the same potentiometer, and the given value is the same voltage value. The user only needs to adjust the feedback value under the constant current, constant voltage, and floating charge states to achieve different controls. effect.
12. It has the functions of overcurrent protection and interception protection, the protection threshold is adjustable, and the output trigger pulse is blocked after overcurrent protection.
13. The board contains a pulse power amplifier and a shaping network, which can directly trigger six thyristors below 1650A.
14. The current signal sampling value is +075mV.
15. The battery voltage and charging voltage are not more than 270V.
16. Can provide user system with +15V, -15V and +24V power supply (load capacity is not more than 15mA).
17. In order to facilitate the user to observe the charging status, a normally closed contact signal is given during constant current charging, and a normally open contact signal is given in other states. The contact capacity is 220V/1A or (380V/0.5A).
18. It is suitable for the control of 20Ah, 40Ah, 60Ah, 100Ah, 200Ah series cadmium nickel DC screen system.
19. It can be used to control the cadmium-nickel DC panel system whose main circuit is three-phase half-wave, three-phase half-controlled bridge, three-phase full-controlled bridge and other circuit topologies.
20. The input and output connectors are fixed by screws, and the reliability is good. The entire control board is installed on a flat surface. The overall size is only 233mm212mm30mm. The installation hole size is lengthwidth=216mm191mm, four holes 4.3mm.

Three. The layout diagram of the main components of the KC-13A board is shown in Figure 1.


4. The function of each potentiometer and how to use it

(1) Potentiometers P1P3 are three-phase synchronous voltage adjustment potentiometers. The role of the three-phase potentiometer is shown when the user's power grid is seriously unbalanced. The adjustment can use TC787 to output six pulses with a mutual difference of 60. Another function of the three potentiometers is to adjust them to make the equivalent synchronous voltage applied to the TC787 pins 18#, 1#, and 2# have a delay of 0-60 relative to the phases a, b, and c of the secondary windings of the synchronous transformer. , in order to adapt to the different needs of the trigger pulse of the rectifier or other circuit structure with the main transformer connection method, adjust clockwise to reduce the synchronous voltage amplitude added to the TC787 pins 18#, 1#, 2#, (that is, add to The equivalent synchronous voltage of TC787 pins 18#, 1#, 2# is increased relative to the delay angles of the phases a, b, and c of the secondary winding of the synchronous transformer), and the counterclockwise adjustment is added to the TC787 pins 18#, 1#, 2# The amplitude of the synchronous voltage increases (that is, the equivalent synchronous voltage added to the TC787 pins 18#, 1#, and 2# reduces the delay angle of the phases a, b, and c of the secondary windings of the synchronous transformer). Generally, the three-potentiometer has been adjusted before leaving the factory, and no further debugging is required (it is recommended that both the main transformer and the synchronous transformer are connected to /Y-11). The equivalent synchronous voltage amplitudes of 18#, 1#, and 2# added to the TC787 pins can be measured from points a1, b1, and c1 on the board.
(2) Potentiometer P4 is a bias potentiometer at the non-inverting end of the differential. The voltage at the midpoint of the potentiometer determines that when the midpoint of the given potentiometer P6 is zero, the phase of the output trigger pulse is the highest of the TC787 pin 4# (P6 midpoint voltage is adjusted to zero) and minimum voltage (P6 midpoint voltage is adjusted to maximum), clockwise adjust the voltage drop of TC787 pin 4# (when P6 midpoint is set to zero), adjust TC787 pin counterclockwise The voltage of 4# increases (when the midpoint of P6 is set to zero). The potentiometer has been adjusted before leaving the factory, and generally does not need to be adjusted by the user. The set value of the P4 midpoint can be measured from the PZ point on the board.
(3) Potentiometer P5 is the equivalent proportional coefficient adjustment potentiometer of the proportional integral regulator. Clockwise adjustment of the proportional integral regulator reduces the equivalent amplification factor, and counterclockwise adjustment of the proportional integral regulator increases the equivalent amplification factor. Generally The user does not need to adjust.
(4) Potentiometer P6 is a common set adjustment potentiometer under constant current, constant voltage, and floating charge states. It adjusts the absolute value of the equivalent set voltage in a clockwise direction to decrease, and adjusts the absolute value of the equivalent set voltage in a counterclockwise direction to increase. Use First, set the potentiometer to a fixed value (such as 6V), and the test point of the P6 setting value is the gd point on the board.
(5) Potentiometer P7 is the current feedback value adjustment potentiometer during constant current charging. Clockwise adjusts the equivalent current feedback value to decrease, and counterclockwise adjusts the equivalent current feedback value to increase. The test point of the current feedback value is the if on the board. point.
(6) Potentiometer P8 is a current-limiting adjustment potentiometer under the condition of floating charge state, the current limit value decreases when the float state is adjusted clockwise, and the current limit value increases when the float state is adjusted counterclockwise. Generally, the adjustment of P8 should be in the floating state Under the conditions, the maximum charging current is 1/31/4 of the rated input current (for example, the value of the 20Ah DC screen is 75A), and the midpoint setting value of P8 can be measured from the id point on the board.
(7) Potentiometer P9 is the actual sampling value adjustment potentiometer of the overcurrent protection current. The equivalent overcurrent protection threshold is adjusted clockwise to increase, and the equivalent overcurrent protection threshold is adjusted counterclockwise to decrease. The midpoint setting value of P9 can be read from the board. Measured at the iV point.
(8) P10 is the charging voltage regulator potentiometer in the floating charge state, which adjusts the floating charge voltage increase counterclockwise (equivalent to the feedback voltage decrease in the floating charge state), and adjusts the float charge voltage decrease clockwise (equivalent to the float charge state) The lower feedback voltage increases), and the midpoint setting value of P10 can be measured from the FF point on the board.
(9) P11 is the voltage feedback value adjustment potentiometer during constant voltage charging. The counterclockwise adjustment voltage feedback value decreases (equivalent to the constant voltage charging voltage value increase), and the clockwise adjustment voltage feedback value increases (equivalent to the constant voltage charging voltage Value decreases), the set value of the midpoint of P11 can be measured from the Vf point on the board.
(10) P12 is the adjustment potentiometer for the switching point of constant current charging to constant voltage charging. The voltage at the switching point is adjusted clockwise (that is, the voltage at the midpoint of the potentiometer decreases), and the voltage at the switching point is adjusted counterclockwise to decrease (that is, the potential The midpoint voltage of the device rises), the midpoint voltage of P12 can be measured from the rr point on the board.
(11) P13 is a threshold adjustment potentiometer that automatically performs constant current charging when the battery voltage drops to a certain lower limit. The threshold voltage is adjusted clockwise to increase (equivalent to the potentiometer's midpoint voltage decrease), and the threshold voltage is adjusted counterclockwise. Decrease (equivalent to an increase in the midpoint voltage of the potentiometer), the set value of the midpoint of P13 can be measured from point qq on the board.

5. External wiring method of each connector
(1) The +15V, -15V and +24V in the connector H1 are provided to the user system. If the user system selects the JV-13A type automatic voltage compensation board produced by our company, +15V, -15V Connect with +24V to the corresponding power terminal of the JV-13A type board, and the load current of +15V, -15V, +24V should not be greater than 15mA.
(2) A, b, c in the connector H1 and GND1 in H9 are respectively connected to the secondary phase voltage of the synchronous transformer 17V, the connection method is star connection corresponding to the three-phase synchronous voltage of the power supply A, B, and C. And its neutral point. It is recommended to connect both the rectifier transformer and the synchronous transformer to /Y-11. If the main transformer is / connection, the synchronous transformer should be changed to Y/Y-10 connection, that is, use -b of the synchronous transformer as the board. The upper phase a is synchronized, and -c is used as the on-board b-phase synchronization, and -a is used as the on-board c-phase synchronization (that is, the a, b, and c of the synchronization transformer are connected as the neutral point to lead to GND1 on the board, and Use x, y, and z as the synchronous voltages of the c-phase, a-phase, and b-phase on the board respectively).
(3) Connect the two ends of the main loop current sampling shunt between IT and GND2 in the connector H9. It is recommended that the sampling value is 5075mV and connected with positive polarity. Please note that the shunt should be connected in series on the negative bus of the main loop , And IT connects the shunt to the negative end of the battery, and GND2 connects to the shunt and the negative end of the thyristor rectifier bridge. A normally open button can be connected between CL and GND2. When the button is closed, the charging state can be artificially switched to the constant current state. The contact capacity of the button is greater than 0.1A. If the user system does not need to be involved in the working state of the system, this button can be left unconnected.
(4) VT in connector H9 is connected to the common cathode end of the main circuit thyristor bridge rectifier circuit, and PT is connected to the positive end of the battery. The remaining FI is directly short-circuited with the FF terminal when the user does not need an external floating state adjustment potentiometer; when the user needs an external floating state adjustment potentiometer, the terminal is connected to the middle end of the potentiometer (the resistance value of the potentiometer is not It should be less than 4.7k, and the power should not be less than 1W. One end of its two fixed ends is connected to GND2, and one end is connected to +15V through a 2k resistor. At this time, the FF end is suspended and not connected. (5) G1, K1G6, K6 in the connector H2H9 are numbered 1, 2, 3, 4, 5, 6 in the main circuit when the user application system is a three-phase bridge fully-controlled rectifier circuit. The gate cathodes of the six thyristors; and when the user system is a three-phase bridge-type half-controlled rectifier circuit (or a three-phase half-wave rectifier circuit), and the three thyristors have a common cathode connection, G1, K1; G3, K3; G5, K5 are respectively connected to the gate cathodes of the three thyristors on the secondary side of the main rectifier transformer A, B, and C in the main circuit, G2, K2; G4, K4; G6, K6 terminals are suspended, when the user system is When the three-phase bridge half-controlled rectifier circuit (or three-phase half-wave rectifier circuit) and the three thyristors have common anode connection, G2, K2; G4, K4; G6, K6 should be connected to the main rectifier transformer in the main circuit respectively. The three thyristor gates and cathodes of the three phases of the secondary side A, B, and C are connected. In this state, G1, K1; G3, K3; G5, K5 are suspended.
(6) Ao and Bo in the connector H9 are a contact signal for the user system to detect the charging state. The Ao and Bo are normally closed during constant current charging, and the Ao and Bo are normally open in other states. The contacts can be used to connect indicator lights or connect with other control circuits according to user needs.
5. Other instructions
(1) There are four light-emitting diodes on the board that indicate the working status of the rectifier system. Among them, L1 lights up (green) in the constant current state, and L2 lights up in the constant voltage state. Second-level flashing (red), L3 is the light-emitting diode (yellow) that indicates the floating charge state, and the light-emitting diode is on when the floating charge state; L4 is the protection fault indicator (red) after overcurrent protection.
(2) For over-current protection, there is a reset button K in the board. When the fault is removed, the user only needs to press K lightly, and the system will automatically reset.
(3) The debugging method of the whole control board

First adjust P6 to a fixed value such as 56V, artificially make the system enter the constant current charging state (short-circuit CL and GND1 once), adjust P7 to make the charging current in this state It is the rated current value (20Ah is 20A, 40Ah is 40A, 60Ah is 50-60A, and 100Ah is 90-100A). Set P12 to make constant current charging until the battery voltage rises to the corresponding set value (between 240 and 270V). To constant voltage charging, adjust P11 so that the constant voltage charging voltage is 220V (or 230V). The system should automatically enter the floating charging state after 7 hours of operation. To facilitate debugging, the user can manually disconnect it after a certain period of time in the constant voltage state. The control board power supply (input is three-phase 17V) once, and then the system will directly enter the floating charge state. At this time, adjust P10 or the user's external potentiometer to make the float charge voltage at 220V (battery voltage), and set P8 to float charge The maximum charging current in the state is limited to 1/2 of the rated current (20Ah is 10A, 40Ah is 20A, 60Ah is 30A, and 100Ah is 50A). Finally, the artificial load is artificially added to make the charging current 1.5 times the rated charging current for a short time, and P9 is adjusted to make the protection circuit operate. At this time, the potentiometers of P6, P7, P8, P9, P10, P11, and P12 are all set to normal values.
Connect a load at both ends of the battery to discharge the battery at 1.5 times the rated current (the charging switch should be turned off at this time, but the control circuit should not be powered off), when the battery voltage is below 210V, adjust P13 to make constant current charging The LED and on-board relay J act, then the value of P13 is set!

VI. KC-13A type board peripheral wiring is extremely simple, so that it can be conveniently used in the main circuit structure for three-phase bridge full control, three-phase bridge half-control or three-phase half-control As the core control component in the DC panel system of wave rectification. For the users convenience and understanding of this board, an example is given to illustrate its use. Figure 2 shows the detailed principle wiring diagram of the KC-13A control board for the cadmium-nickel DC screen control system with the main circuit of the three-phase bridge type full control structure. The contact of the relay (in the board) J in the picture gives a constant Stream status indication.



figure 2