Tc787 chips in a single chip and three-phase half-controlled rectifier circuit

Rectifier circuit is widely used in DC motor speed, DC voltage and other occasions. Three-phase half-controlled rectifier bridge circuit is a common rectifier circuit, and its easy to control and reduce costs. This paper introduces a microcomputer PIC690 specific integrated three-phase half-controlled rectifier trigger circuit, which combines specific integrated chip and digital trigger trigger the advantages of high performance and highly symmetrical trigger pulse chip TC787. It fully utilizes the MCU internal resources, adaptive phase sequence sets, voltage regulators, and various protection functions in one, system parameters can be used to load the constant voltage control. Three-phase main circuit
Rectifier circuit is widely used in DC motor speed, DC voltage and other occasions. Three-phase half-controlled rectifier bridge circuit is a common rectifier circuit, and its easy to control and reduce costs. This paper introduces a microcomputer PIC690 specific integrated three-phase half-controlled rectifier trigger circuit, which combines specific integrated chip and digital trigger trigger the advantages of high performance and highly symmetrical trigger pulse chip TC787. It fully utilizes the MCU internal resources, adaptive phase sequence sets, voltage regulators, and various protection functions in one, system parameters can be used to load the constant voltage control. Three-phase main circuit DC output voltage of LC filter structure of semi-controlled bridge structure and improve quality.
System design as the main control chip by the microcontroller PIC690 system as the main switch thyristor. Design goal is to maintain the output DC voltage, output voltage ripple, low THD AC output current measurement, reliable performance and stability.

Main circuit system includes: Three-phase half-controlled rectifier, synchronous signal sampling circuit, microprocessor control circuit, thyristor trigger circuit. First, the synchronous signal sampling circuit trigger signal is sent simultaneously to the detection of an integrated chip TC787 zero, the further delay in order to achieve the appropriate phase shift. ADC is responsible for collecting micro-controller DC bus voltage, the PI operation by voltage setpoint and actual value of the deviation, adjusted for a given output. PIC MCU's voltage reference value output to the TC787, TC787 implementation phase triggered thyristor, to achieve a rectifier regulator. Overall hardware block diagram shown in Figure 1.

Overall hardware block diagram in Figure 1
Main circuit design the main circuit three-phase half-controlled rectifier bridge, LC filter structure shown in Figure 2 Schematic diagram of the main current DC current measurement. Half-controlled bridge select SEMIKRON 140A SKDH146/120-L100 module rated current, rated voltage of 1200V's. DC LC circuit filter, filter capacitor than single effective. In addition, you can increase the AC input current total harmonic distortion of the side. DC 6 times and 6 times the main contents of the entire design, the harmonic frequency of LC low-pass filter, in order to avoid resonance of the harmonic content is higher. In this design, select the inductor 5mH, filter capacitor 480

Figure 2 circuit structure to obtain the power grid phase voltage, the synchronous circuit plastic, due to integrated chip TC787 18AT trigger pin, pin and pin 1CT 2BT. TC787 has three zero and polarity detection unit, three serrated forming units, 3 comparator, pulse generator, interference lock circuit and the pulse distribution and the drive circuit for a given number of phase-shifted control voltage, phase sequence can automatically identify an internal integration.
Control of the controller circuit design using PIC16F690. PIC16F690 microcontroller with an internal 10-bit AD; Wide operating voltage (2.0 ~ 5.5V), the low power consumption, with the PWM output; own internal crystal oscillator. With an on-chip 10-bit AD, AD collected on the DC voltage conversion. In order to reduce hardware costs, some of the pressure, rather than directly through the sensor to collect resistance voltage DC voltage divider ratio through two reverse the resistance of the circuit to the microcontroller. Microcontroller and analog signal directly connected (through the beads can also be connected to reduce interference.) PIC16F690 microcontroller IO port through the TC787 chip enable or disable the output shown in Figure 3. When the PIC microcontroller's I / O port RC3 output high (+5 V) when the lock port is low; when the MCU I / O port RC3 output is low, locking in a high (+15 V) number. I use a given signal a IO TC787 reference voltage, the use of PWM pulse mode, adjust the duty cycle to adjust the output voltage, PWM wave through the RC low-pass filter similar to the DC signal as a reference voltage to the signal set Uref, its the range of 0 to 5V,. Because the chip TC787 required for a given input range of 0 - 15V, so the PWM wave through a level translator shown in Figure 3, couplers.

Figure 3, the control circuit of the hardware structure
Transformer through the sync input to the TC787, TC787 6-foot-high output double-pulse or low pulse width alone. 12,11,10 feet are the A, B, C of the trigger output, after a pulse transformer output to the thyristor.

Trigger Trigger driving circuit chip select high-performance three-phase thyristor phase triggering IC TC787. TC787 single power supply, dual power can work, the main three-phase thyristor phase and three-phase power transistor trigger pulse width modulation circuit, and the formation of a VVVF inverter devices. TC787 internal structure shown in Figure 4.
Figure 4 TC787 chip architecture in the design, TC787 and 15V power supply, 4-pin method (VR): the phase control voltage input. Input voltage directly determines the end of the output pulse relative to the output of a given part of the scope of the applications received TC787/TC788 level. Pin 5 (skin): prohibitions side of the output pulse. The final state is used to block TC787/TC788 fault output, high efficiency, the application, then the output protection circuit. Synchronous voltage input: pin 1 (VC) pin 2 (VB) and three-phase synchronous input interface 18-pin (VA). The application, receive a synchronization input filter voltage, synchronous peak voltage shall not exceed TC787/TC788 supply voltage VDD.

Triggered mainly by the power driver circuit voltage synchronization circuit, TC787 integrated isolation trigger circuit and the pulse amplifier drive circuit. Figure 5 shows the synchronization circuit and peripheral circuits TC787. Synchronization circuit voltage of the first part of this design method will need more accessories. The three potentiometers RP1 ~ RP3 adjustment can be achieved with different phase shift of 0 to 60 in order to meet the needs of different transformer connections. Figure 5, the midpoint of the transformer to receive a direct sync (1 / 2) power supply voltage, so that the components used to simplify. TC787-pin micro-controller output for a given voltage 4 (0 ~ +15 V), the blockade of the foot 6-pin to trigger pulse. 10 feet for the trigger pulse output pins 12, respectively, the circuit received C, B, a phase separation.

Figures 5 and synchronization circuit pulse circuit
Figure 6, the voltage detection circuit voltage detection circuit

In order to reduce hardware costs, the DC bus voltage detection circuit and a resistor divider design tools, and not by the voltage sensor

 output voltage of LC filter structure of semi-controlled bridge structure and improve quality.
System design as the main control chip by the microcontroller PIC690 system as the main switch thyristor. Design goal is to maintain the output DC voltage, output voltage ripple, low THD LCD LCM output current measurement, reliable performance and stability.

Main circuit system includes: Three-phase half-controlled rectifier, synchronous signal sampling circuit, microprocessor control circuit, thyristor trigger circuit. First, the synchronous signal sampling circuit trigger signal is sent simultaneously to the detection of an integrated chip TC787 zero, the further delay in order to achieve the appropriate phase shift. ADC is responsible for collecting micro-controller DC bus voltage, the PI operation by voltage setpoint and actual value of the deviation, adjusted for a given output. PIC MCU's voltage reference value output to the TC787, TC787 implementation phase triggered thyristor, to achieve a rectifier regulator. Overall hardware block diagram shown in Figure 1.

Overall hardware block diagram in Figure 1
Main circuit design the main circuit three-phase half-controlled rectifier bridge, LC filter structure shown in Figure 2 Schematic diagram of the main current DC current measurement. Half-controlled bridge select SEMIKRON 140A SKDH146/120-L100 module rated current, rated voltage of 1200V's. DC LC circuit filter, filter capacitor than single effective. In addition, you can increase the AC input current total harmonic distortion of the side. DC 6 times and 6 times the main contents of the entire design, the harmonic frequency of LC low-pass filter, in order to avoid resonance of the harmonic content is higher. In this design, select the inductor 5mH, filter capacitor 480

Figure 2 circuit structure to obtain the power grid phase voltage, the synchronous circuit plastic, due to integrated chip TC787 18AT trigger pin, pin and pin 1CT 2BT. TC787 has three zero and polarity detection unit, three serrated forming units, 3 comparator, pulse generator, interference lock circuit and the pulse distribution and the drive circuit for a given number of phase-shifted control voltage, phase sequence can automatically identify an internal integration.
Control of the controller circuit design using PIC16F690. PIC16F690 microcontroller with an internal 10-bit AD; Wide operating voltage (2.0 ~ 5.5V), the low power consumption, with the PWM output; own internal crystal oscillator. With an on-chip 10-bit AD, AD collected on the rs232 lcd voltage conversion. In order to reduce hardware costs, some of the pressure, rather than directly through the sensor to collect resistance voltage DC voltage divider ratio through two reverse the resistance of the circuit to the microcontroller. Microcontroller and analog signal directly connected (through the beads can also be connected to reduce interference.) PIC16F690 microcontroller IO port through the TC787 chip enable or disable the output shown in Figure 3. When the PIC microcontroller's I / O port RC3 output high (+5 V) when the lock port is low; when the MCU I / O port RC3 output is low, locking in a high (+15 V) number. I use a given signal a IO TC787 reference voltage, the use of PWM pulse mode, adjust the duty cycle to adjust the output voltage, PWM wave through the RC low-pass filter similar to the DC signal as a reference voltage to the signal set Uref, its the range of 0 to 5V,. Because the chip TC787 required for a given input range of 0 - 15V, so the PWM wave through a level translator shown in Figure 3, couplers.

Figure 3, the control circuit of the hardware structure
Transformer through the sync input to the TC787, TC787 6-foot-high output double-pulse or low pulse width alone. 12,11,10 feet are the A, B, C of the trigger output, after a pulse transformer output to the thyristor.

Trigger Trigger driving circuit chip select high-performance three-phase thyristor phase triggering IC TC787. TC787 single power supply, dual power can work, the main three-phase thyristor phase and three-phase power transistor trigger pulse width modulation circuit, and the formation of a VVVF inverter devices. TC787 internal structure shown in Figure 4.
Figure 4 TC787 chip architecture in the design, TC787 and 15V power supply, 4-pin method (VR): the phase control voltage input. Input voltage directly determines the end of the output pulse relative to the output of a given part of the scope of the applications received TC787/TC788 level. Pin 5 (skin): prohibitions side of the output pulse. The final state is used to block TC787/TC788 fault output, high efficiency, the application, then the output protection circuit. Synchronous voltage input: pin 1 (VC) pin 2 (VB) and three-phase synchronous input interface 18-pin (VA). The application, receive a synchronization input filter voltage, synchronous peak voltage shall not exceed TC787/TC788 supply voltage VDD.

Triggered mainly by the power driver circuit voltage synchronization circuit, TC787 integrated isolation trigger circuit and the pulse amplifier drive circuit. Figure 5 shows the synchronization circuit and peripheral circuits TC787. Synchronization circuit voltage of the first part of this design method will need more accessories. The three potentiometers RP1 ~ RP3 adjustment can be achieved with different phase shift of 0 to 60 in order to meet the needs of different transformer connections. Figure 5, the midpoint of the transformer to receive a direct sync (1 / 2) power supply voltage, so that the components used to simplify. TC787-pin micro-controller output for a given voltage 4 (0 ~ +15 V), the blockade of the foot 6-pin to trigger pulse. 10 feet for the trigger pulse output pins 12, respectively, the circuit received C, B, a phase separation. serial lcd

Figures 5 and synchronization circuit pulse circuit
Figure 6, the voltage detection circuit voltage detection circuit

In order to reduce hardware costs, the DC bus voltage detection circuit and a resistor divider design tools, and not by the voltage sensor