SXTY three-phase AC voltage regulation (closed loop) trigger board circuit

The SXTY three-phase AC voltage regulation (closed-loop) trigger board is used as the phase-shift trigger unit of the silicon controlled thyristor in the three-phase AC voltage regulation system. The trigger board contains synchronization signal detection, closed-loop PI regulator and pulse transformer output unit. It can form a three-phase AC voltage regulation system with voltage stabilization output function. SXTY three-phase AC voltage regulator board technical parameters 1. AC input voltage: dual 18 V (AC, 50Hz); input current ≤ 200 mA; 2. Main circuit rated operating voltage: 380 V (AC, 50Hz); 3. Three-phase Synchronization signal input range: line voltage 30 V; input current ≤5 mA; 4. Trigger pulse width: 1.5 mS; 5. Pulse phase shift range: 0~180°; 6. Input DC control voltage: 0~10 V; input Current ≤1 mA; 7. Pulse imbalance of each phase: <±3°; 8. Manual control potentiometer: 10 KΩ; 9. Voltage feedback parameters: AC feedback voltage input ≤10 VAC; 10. Working environment: ambient temperature : -10℃～+45℃; Environmental humidity: ≤80﹪. Dimensions of SXTY three-phase AC voltage regulator: length × width × height = 176 × 132 × 25 Unit: mm Working principle of SXTY three-phase AC voltage regulator. SXTY three-phase AC voltage regulator (closed-loop) trigger board adopts high Performance phase shift trigger circuit TC787. It is a trigger control unit for a three-phase AC voltage regulation system that integrates synchronization signal detection, closed-loop PI regulator and pulse transformer output unit, and has a constant voltage output function. . The synchronization signal input of the trigger board is taken from the AC signal in the same phase as the main circuit (signal input range: line voltage 30VAC, 50Hz). When the phase-shift control voltage changes in the range of 0 to 10V, the output voltage will change accordingly in the range of 0V to full voltage. When the output voltage is set at a certain fixed value, the output voltage can be constant within a certain input range. The trigger board is also equipped with a "pulse output prohibition control terminal". When the operation is abnormal, the control terminal is connected to a low level, and the trigger board stops sending trigger pulses to the thyristor. Terminal description and connection of SXTY three-phase AC voltage regulation (closed loop) trigger board (as shown in the figure below) 1, 2, 3, ⑴, ⑵, and ⑶ pins are the input terminals of the AC power supply (dual 18V, 200mA), among which pin ⑵ For the ground terminal of the trigger board, connect it to the center tap of the power transformer. ⑷, ⑸, and ⑹ pins are the input terminals of the three-phase synchronization signal, which are synchronized with the thyristor main circuit operating voltage U, V, and W; ⑺ pin is the pulse output prohibition control terminal S. It is left floating during normal operation. When the pulse output is prohibited, , this end is connected to the ground; ⑻ and ⑿ are the grounding terminals; ⑼ is the manual adjustment potentiometer to provide positive control voltage; ⑽ is the voltage adjustment input terminal; ⑾ is the voltage feedback positive input terminal, connected to the UF terminal. Pins G1, K1, G2, K2, G3, K3, G4, K4, G5, K5, G6, and K6 are trigger pulse output terminals and are connected to the corresponding thyristors. The application circuit of SXTY three-phase AC voltage regulation (closed-loop) trigger board The picture above shows a three-phase AC voltage regulation system with voltage stabilization output function. The load can be connected in Y-shaped or △-shaped connection. The voltage adjustment input terminal ⑽ pin is manually controlled by an external potentiometer, or can be automatically controlled by applying an external control voltage. During manual control, the center tap of the potentiometer is connected to pin ⑽, and the other two ends of the potentiometer are connected to pins ⑼ and ⑻ respectively; during automatic control, pin ⑽ is the positive input terminal of the control voltage, and pin ⑻ ​​is the negative input terminal of the control voltage. . The feedback signal is taken from the voltage dividing resistor network between the two phases at the output end of the main circuit. The value of the voltage dividing resistor should be such that when the system outputs full voltage, the feedback voltage value should be ≤10V. (Reference value: If the full voltage output is 380V, R0 can be 200K/0.25W, and RF can be 8.2K/0.25W.) Precautions for SXTY three-phase AC voltage regulation (closed loop) trigger board 1. In-board given potentiometer The value has been adjusted with special testing equipment and does not need to be adjusted, otherwise the control board will not work properly; 2. Before powering on the system, the manual adjustment potentiometer should be adjusted to zero.