Disclosure of Invention
The invention aims to provide a soft start circuit of an alternating current servo driver and a working method thereof, which can play a role of soft start when a user carries out abnormal power-on operation, protect a power supply system of the user from being influenced by power-on current impact and improve the reliability of the system.
The technical solution for realizing the purpose of the invention is as follows: a soft start circuit of an alternating current servo driver comprises an input voltage detection circuit, an isolation diode circuit, a soft start unit, a bus capacitor filter circuit and a bus voltage detection circuit;
the input voltage detection circuit comprises a first divider resistor, a first sampling resistor and an input voltage sampling circuit, and the input voltage detection circuit is connected with a user power supply system and an isolation diode circuit, is used for detecting the voltage value of an input power supply and outputs the voltage value to the microcontroller circuit;
the isolation diode circuit comprises an isolation diode which is connected with the input voltage detection circuit and the soft start unit and is used for isolating in the circuit and preventing energy feedback;
the soft start unit comprises a soft start relay and a current-limiting resistance circuit, is connected with the isolation diode circuit and the bus capacitor filter circuit, and is used for executing the action of soft start;
the bus capacitor filter circuit comprises a driver bus filter capacitor, is connected with the soft start unit and the bus voltage detection circuit and is used for filtering and storing energy for a driver bus;
the bus voltage detection circuit comprises a second divider resistor, a second sampling resistor and a bus voltage sampling circuit, and the bus voltage detection circuit is connected with the bus capacitor filter circuit and is used for detecting the bus voltage of the driver and outputting the bus voltage to the microcontroller circuit.
Further, an input power supply of the alternating current servo driver adopts a direct current power supply mode or an alternating current power supply mode, which is determined by a user power supply mode, wherein a direct current power supply unit is adopted when the user power supply mode adopts the direct current power supply, and a rectification unit is adopted when the user power supply mode adopts the alternating current power supply mode.
Furthermore, the first voltage dividing resistor and the first sampling resistor are connected with an input power supply, the voltage of the input power supply is sampled in a resistor voltage dividing mode and then is sent to the micro-control circuit through the input voltage sampling circuit, the sampling result is compared with the soft start unit reset voltage U2 and serves as a judgment basis for resetting the soft start unit, and the micro-control circuit controls the soft start relay to act according to the judgment result.
Furthermore, the isolation diode is connected in series between the input power supply and the soft start unit, the anode of the isolation diode is connected with the input power supply, so that the input power supply is isolated from the driver bus in a single direction, when the user power supply is cut off, the value of the input voltage sampling circuit is zero, and the value of the bus voltage sampling circuit is still kept as the driver bus voltage and is continuously reduced.
Furthermore, when the driver is powered on, the initial state of the soft start relay is disconnected, the driver input power supply charges the bus filter capacitor of the driver through the current-limiting resistance circuit, after the soft start is finished, the soft start relay is closed after time delay, the current-limiting resistance circuit is short-circuited, and the soft start is finished.
Furthermore, the driver bus filter capacitor is formed by combining one or more electrolytic capacitors in a series-parallel mode, is connected to the driver bus in parallel, and stores energy and filters the driver bus.
Furthermore, the second voltage division resistor and the second sampling resistor are connected with the driver bus, the voltage of the driver bus is sampled in a resistor voltage division mode and then is sent to the micro control circuit through the bus voltage sampling circuit, the sampling result is compared with the soft start threshold voltage U1 to serve as a judgment basis for judging whether the soft start is finished, and the micro control circuit controls the soft start relay to act according to the judgment result.
A working method of a soft start circuit of an alternating current servo driver comprises the following steps:
step 1, setting a soft start ending voltage U1, a soft start resetting voltage U2 and a driver undervoltage alarm voltage U3;
step 2, the driver monitors the value of the bus voltage Udc in real time, compares the bus voltage detection value Udc with a soft start threshold voltage U1, controls a soft start relay to pull in when the bus voltage is higher than U1 for the first time and then passes through the delay time set by software, and finishes the soft start;
step 3, the driver monitors the input voltage Udc2 in real time, compares the detected value Udc2 of the input voltage with the soft start reset voltage U2, and judges that the user cuts off the power supply and the software enters the interruption of the soft start unit reset when the voltage value of the input power supply is less than U2;
step 4, comparing the bus voltage detection Udc with a soft start reset voltage U1, and disconnecting a soft start relay when the bus voltage value is greater than U3; if the bus voltage value is smaller than U3, performing undervoltage alarm and shutdown operation on the driver;
step 5, comparing the detected value Udc2 of the input end voltage with the soft start reset voltage U2, and when the voltage value of the input power supply is greater than U2, judging that the user is electrified again; and if the voltage value of the input power supply is not greater than U2, judging that the user is not electrified again, and performing undervoltage alarm and shutdown operation on the driver when the bus voltage Udc is less than the undervoltage alarm threshold U3.
Compared with the prior art, the invention has the remarkable advantages that: (1) the driver can judge whether the power supply is cut off by the user or not due to the detection of the state of the power supply input by the user, so that the action of starting a circuit relay is controlled, and the power-on operation of the user can be adapted; (2) the impact of the power supply of the user by the power-on current is avoided, and the adaptability of the driver and the reliability of a user system are improved.
Detailed Description
The invention relates to a soft start circuit of an alternating current servo driver, which comprises an input voltage detection circuit, an isolation diode circuit, a soft start unit 3, a bus capacitor filter circuit and a bus voltage detection circuit;
the input voltage detection circuit comprises a first voltage dividing resistor 13, a first sampling resistor 14 and an input voltage sampling circuit 12, and the input voltage detection circuit is connected with a user power supply system and an isolation diode circuit, is used for detecting the voltage value of an input power supply and outputs the voltage value to the microcontroller circuit 5;
the isolation diode circuit comprises an isolation diode 11 which is connected with the input voltage detection circuit and the soft start unit 3 and is used for isolating in the circuit and preventing energy feedback;
the soft start unit 3 comprises a soft start relay 9 and a current limiting resistance circuit 10, is connected with an isolation diode circuit and a bus capacitor filter circuit, and is used for executing the action of soft start;
the bus capacitor filter circuit comprises a driver bus filter capacitor 8 which is connected with the soft start unit 3 and the bus voltage detection circuit and is used for filtering and storing energy for a driver bus;
the bus voltage detection circuit comprises a second voltage dividing resistor 6, a second sampling resistor 7 and a bus voltage sampling circuit 4, and the bus voltage detection circuit is connected with the bus capacitor filter circuit and used for detecting the bus voltage of the driver and outputting the bus voltage to the microcontroller circuit 5.
Further, the input power supply of the alternating current servo driver adopts a direct current power supply mode or an alternating current power supply mode, which is determined by a user power supply mode, wherein the user power supply mode adopts a direct current power supply unit 1 when adopting the direct current power supply mode, and adopts a rectification unit 2 when adopting the alternating current power supply mode.
Furthermore, the first voltage dividing resistor 13 and the first sampling resistor 14 are connected to the input power supply, the input power supply voltage is sampled in a manner of resistor voltage division, and then the sampled voltage is sent to the micro control circuit 5 through the input voltage sampling circuit 12, the sampling result is compared with the reset voltage U2 of the soft start unit 3 and is used as a judgment basis for resetting the soft start unit 3, and the micro control circuit 5 controls the soft start relay 9 to operate according to the judgment result.
Further, the isolation diode 11 is connected in series between the input power supply and the soft start unit 3, the anode of the isolation diode 11 is connected with the input power supply, so that the input power supply is isolated from the driver bus in a single direction, when the user power supply is cut off, the value of the input voltage sampling circuit 12 is zero, and the value of the bus voltage sampling circuit 4 is still kept as the driver bus voltage and continuously decreases.
Further, when the driver is powered on, the soft start relay 9 is in an off state initially, the driver input power supply charges the driver bus filter capacitor 8 through the current limiting resistor circuit 10, after the soft start is completed, the soft start relay 9 is closed after time delay, the current limiting resistor circuit 10 is short-circuited, and the soft start is completed.
Further, the driver bus filter capacitor 8 is formed by combining one or more electrolytic capacitors in a series-parallel connection mode, and is connected to the driver bus in parallel to store energy and filter the driver bus.
Further, the second voltage dividing resistor 6 and the second sampling resistor 7 are connected with the driver bus, the voltage of the driver bus is sampled in a resistor voltage dividing mode, then the sampled voltage is sent to the micro control circuit 5 through the bus voltage sampling circuit 4, the sampling result is compared with the soft start threshold voltage U1 to serve as a judgment basis for judging whether the soft start is finished, and the micro control circuit 5 controls the soft start relay 9 to act according to the judgment result.
The invention discloses a working method of a soft start circuit of an alternating current servo driver, which comprises the following steps:
step 1, setting a soft start ending voltage U1, a soft start resetting voltage U2 and a driver undervoltage alarm voltage U3;
step 2, the driver monitors the value of the bus voltage Udc in real time, compares the bus voltage detection value Udc with a soft start threshold voltage U1, controls the soft start relay 9 to attract when the bus voltage is higher than U1 for the first time and passes through the delay time set by software, and the soft start is finished;
step 3, the driver monitors the input voltage Udc2 in real time, compares the detected value Udc2 of the input voltage with the soft start reset voltage U2, and judges that the power supply is cut off by the user and the software enters the interruption of the soft start unit 3 reset when the voltage value of the input power supply is less than U2;
step 4, comparing the bus voltage detection Udc with the soft start reset voltage U1, and disconnecting the soft start relay 9 when the bus voltage value is greater than U3; if the bus voltage value is smaller than U3, performing undervoltage alarm and shutdown operation on the driver;
step 5, comparing the detected value Udc2 of the input end voltage with the soft start reset voltage U2, and when the voltage value of the input power supply is greater than U2, judging that the user is electrified again; and if the voltage value of the input power supply is not greater than U2, judging that the user is not electrified again, and performing undervoltage alarm and shutdown operation on the driver when the bus voltage Udc is less than the undervoltage alarm threshold U3.
The invention is described in further detail below with reference to the figures and specific examples.
Examples
With reference to fig. 2, the ac servo driver soft start circuit of this embodiment includes a user input voltage detection circuit, an isolation diode circuit, a soft start unit 3, a bus capacitor filter circuit, and a bus voltage detection circuit;
the input voltage detection circuit comprises a first voltage dividing resistor 13, a first sampling resistor 14, an input voltage sampling circuit 12 and a microcontroller circuit 5, is connected with a user power supply system and an isolation diode circuit, and is used for detecting the voltage value of a user input power supply;
the isolation diode circuit comprises an isolation diode 11 which is connected with the input voltage detection circuit and the soft start unit 3 and is used for isolating in the circuit and preventing energy feedback;
the soft start unit 3 comprises a soft start relay 9 and a current limiting resistance circuit 10, is connected with an isolation diode circuit and a bus capacitor filter circuit, and is used for executing the action of soft start;
the bus capacitor filter circuit comprises a driver bus filter capacitor 8 which is connected with the soft start unit 3 and the bus voltage detection circuit and is used for filtering and storing energy for a driver bus;
the bus voltage detection circuit comprises a second divider resistor 6, a second sampling resistor 7, a bus voltage sampling circuit 4 and a microcontroller circuit 5, is connected with the bus capacitor filter circuit and is used for detecting the bus voltage of the driver.
Further, the input power supply of the alternating current servo driver adopts a direct current power supply mode or an alternating current power supply mode, which is determined by a user power supply mode, wherein the user power supply mode adopts a direct current power supply unit 1 when adopting the direct current power supply mode, and adopts a rectification unit 2 when adopting the alternating current power supply mode.
Furthermore, the first voltage dividing resistor 13 and the first sampling resistor 14 are connected to the input power supply, the input power supply voltage is sampled in a manner of resistor voltage division, and then the sampled voltage is sent to the micro control circuit 5 through the input voltage sampling circuit 12, the sampling result is compared with the reset voltage U2 of the soft start unit 3 and is used as a judgment basis for resetting the soft start unit 3, and the micro control circuit 5 controls the soft start relay 9 to operate according to the judgment result.
Furthermore, the isolation diode 11 is connected in series between the input power supply and the soft start unit 3, the anode of the isolation diode is connected with the input power supply, so that the input power supply is isolated from the driver bus in a single direction, when the user power supply is cut off, the value of the input voltage sample 12 is zero, and the value of the bus voltage sample 4 is still kept as the driver bus voltage and slowly decreases. The isolation diode also plays a role in preventing energy feedback, when the power supply is the direct current power supply unit 1, the load is generally not allowed to perform energy feedback, when the driving system brakes, the bus voltage of the driver can rise, the higher feedback voltage can cause the fault protection or damage of the power supply, and the isolation diode 11 in the system can prevent the problems.
Further, when the driver is powered on, the soft start relay 9 is in an off state initially, the driver input power supply charges the driver bus filter capacitor 8 through the current limiting resistor circuit 10, after the soft start is completed, the soft start relay 9 is closed after time delay, the current limiting resistor circuit 10 is short-circuited, and the soft start is completed.
Further, the driver bus filter capacitor 8 is formed by combining one or more electrolytic capacitors in a series-parallel connection mode, and is connected to the driver bus in parallel to store energy and filter the driver bus.
Further, the second voltage dividing resistor 6 and the second sampling resistor 7 are connected with the driver bus, the voltage of the driver bus is sampled in a resistor voltage dividing mode, then the sampled voltage is sent to the micro control circuit 5 through the bus voltage sampling circuit 4, the sampling result is compared with the soft start threshold voltage U1 to serve as a judgment basis for judging whether the soft start is finished, and the micro control circuit 5 controls the soft start relay 9 to act according to the judgment result.
With reference to fig. 3, a method for controlling a soft start circuit of an ac servo driver in this embodiment includes the following steps:
step 1, setting a soft start threshold voltage U1, a soft start reset voltage U2 and a driver undervoltage alarm voltage U3, specifically as follows:
setting the value of the soft start threshold voltage U1 to be about 80% of the power supply voltage of a user for judging whether the soft start is finished or not; the soft start reset voltage U2 is used for judging the power-off and power-on of a user, the input voltage has large change amplitude and short time, and is easy to judge, and the soft start reset voltage U1 is generally set slightly smaller than the soft start ending voltage in consideration of the power supply fluctuation of the user; the value of the undervoltage alarm voltage U3 of the driver depends primarily on whether the driver is operating properly below this bus voltage.
Step 2, the driver monitors the value of the bus voltage Udc in real time, compares the bus voltage detection value Udc with a soft start threshold voltage U1, and judges whether the soft start is finished, specifically as follows:
the driver monitors the value of the bus voltage Udc in real time, the detected value of the bus voltage Udc is compared with a soft start threshold voltage U1, when the bus voltage is higher than U1 for the first time, the driver is considered to be powered on for soft start to be completed, after the delay time t1 set by software, the soft start relay 9 is controlled to be attracted, the soft start is completed, the time length of t1 needs to be set in consideration of a user power supply mode, the capacity of the bus filter capacitor 8 of the driver and the resistance value of the current limiting resistor circuit 10, the fact that the bus filter capacitor 8 of the driver is charged after the delay time is over is ensured, and overlarge impact current cannot be generated when the soft circuit relay 9 is closed.
Step 3, the driver monitors the input voltage Udc2 in real time, compares the voltage value Udc2 obtained by detecting the voltage of the input terminal with the soft start reset voltage U2, and judges whether the user cuts off the input power supply, which is as follows:
the driver monitors the input voltage Udc2 in real time, compares the voltage value Udc2 obtained by detecting the voltage value of the input terminal with the soft start band reset voltage U2, and judges that the user cuts off the power supply and the software enters the interruption of the soft start unit 3 reset when the voltage value of the input power supply is less than U2.
Step 4, comparing the bus voltage detection Udc with the soft start reset voltage U1, and judging whether the soft start circuit needs to be reset, specifically as follows:
after the software enters the interruption of the soft start circuit reset, the bus voltage detection value Udc is compared with the undervoltage alarm voltage U3 of the driver, and when the bus voltage value is greater than U3, the soft start relay 9 is switched off; and if the bus voltage value is less than U3, performing an under-voltage alarm and shutdown operation of the driver.
Step 5, comparing the input end voltage detection value Udc2 with the soft start reset voltage U2, and judging whether the user is powered on again, wherein the steps are as follows:
after the soft start relay 9 is disconnected, comparing a voltage value Udc2 obtained by detecting the voltage of the input end with a soft start belt circuit reset voltage U2, and judging that the user is electrified again when the voltage value of the input power supply is greater than U2; and the condition that the voltage value of the input power supply is larger than U2 does not occur, namely when the user is not electrified again and the bus voltage Udc is smaller than the undervoltage alarm threshold U3, the driver performs undervoltage alarm and shutdown operation.
In this embodiment, the user supply voltage is DC540V, the soft-start ending voltage is set to 430V, the soft-start reset voltage is set to 400V, and the driver under-voltage alarm voltage is set to 350V. After the driver is powered on, when the bus voltage value Udc detected by the bus voltage is larger than 430V, the soft start is judged to be finished, after the delay of 1s, the soft start relay 9 is closed, the soft start power-on is finished, and the driver still monitors the input voltage and the bus voltage in real time. When the input voltage is less than 400V, the user is considered to cut off the power supply, and the action of the driver is judged according to the value of the bus voltage. When the bus voltage is greater than 350V, the microcontroller circuit 5 controls the soft start relay 9 to be switched off, if the input power supply is greater than 400V, the user is considered to be powered up again, the microcontroller circuit 5 controls the soft start relay 9 to be switched on after 1s of delay, the current limiting resistance circuit 10 is short-circuited, if the user is not powered up again, discharging is carried out after a period of time, and when the bus voltage is less than or equal to 350V, the driver carries out under-voltage alarm and shutdown operation.
In summary, according to the invention, since the state of the power input by the user is detected, the driver can judge whether the power is cut off by the user, and further control the action of the starting circuit relay, so that the method can adapt to any power-on operation of the user, avoid the impact of power-on current on the power supply of the user, and improve the adaptability of the driver and the reliability of a user system.