Disclosure of Invention
Aiming at the problems, the invention provides a redundant trigger circuit for a bypass switch of a flexible direct current converter valve, which mainly solves the problems of the background technology, detects the on-off state of a trigger coil of the bypass switch and realizes the redundant trigger function.
In order to solve the technical problems, the technical scheme of the invention is as follows:
a redundant trigger circuit for a bypass switch of a flexible direct current converter valve comprises a first charging resistor, a second charging resistor, a first energy storage capacitor, a second energy storage capacitor, a first thyristor, a second thyristor, a first thyristor trigger circuit, a second thyristor trigger circuit, a first diode, a second diode, a third diode, a fourth diode, a bypass switch trigger coil, a second voltage detection circuit and a first voltage detection circuit, wherein the anodes of the first charging resistor and the second charging resistor are connected in parallel to the anode of a power supply, the cathode of the first charging resistor is connected with the first energy storage capacitor and the first voltage detection circuit which are connected in parallel, the cathode of the first charging resistor is connected with the anode of the second thyristor, the gate of the second thyristor is connected with one end of the second thyristor trigger circuit, the cathode of the second thyristor is connected with the other end of the second thyristor trigger circuit and the anode of the second diode, the negative electrode of the first energy storage capacitor is connected with the negative electrode of the third diode, and in a similar way, the negative electrode of the second charging resistor is connected with the second energy storage capacitor and the second voltage detection circuit which are connected in parallel, the negative electrode of the second charging resistor is connected with the positive electrode of the first thyristor, the gate electrode of the first thyristor is connected with one end of the first thyristor trigger circuit, the negative electrode of the first thyristor is connected with the other end of the first thyristor trigger circuit and the positive electrode of the first diode, the negative electrode of the second energy storage capacitor is connected with the negative electrode of the fourth diode, the positive electrode of the first diode is connected with the negative electrode of the third diode, the positive electrode of the second diode is connected with the negative electrode of the fourth diode, the negative electrode of the first diode and the second diode is connected with one end of the bypass switch trigger coil, and the other end of the bypass switch trigger coil is connected with the negative electrode of the power supply in parallel.
The invention has the beneficial effects that:
1. the redundancy trigger circuit for the bypass switch of the flexible-direct converter valve, which is designed by the invention, realizes the function of detecting the on-off state of the bypass switch trigger coil by setting the charging current of the energy storage capacitor to be uniform and passing through the bypass switch trigger coil.
2. The invention only uses a single power supply to supply power, has low requirement on engineering power supply, adopts a redundant bypass switch trigger circuit and has high reliability.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer and clearer, the following detailed description of the present invention is provided with reference to the accompanying drawings and detailed description. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some but not all of the relevant aspects of the present invention are shown in the drawings.
According to fig. 1, the present embodiment provides a redundant trigger circuit for a bypass switch of a soft dc converter valve, which includes a first charging resistor 1, a second charging resistor 2, a first energy-storing capacitor 3, a second energy-storing capacitor 4, a first thyristor 5, a second thyristor 6, a first thyristor trigger circuit 7, a second thyristor trigger circuit 8, a first diode 9, a second diode 10, a third diode 11, a fourth diode 12, a bypass switch trigger coil 13, a second voltage detection circuit 14, and a first voltage detection circuit 15, wherein the anodes of the first charging resistor 1 and the second charging resistor 2 are connected in parallel to the anode of a power supply, the cathode of the first charging resistor 1 is connected to the first energy-storing capacitor 3 and the first voltage detection circuit 15 which are connected in parallel, the cathode of the first charging resistor 1 is connected to the anode of the second thyristor 6, the gate of the second thyristor 6 is connected to one end of the second thyristor trigger circuit 8, the cathode of the second thyristor 6 is connected with the other end of the second thyristor trigger circuit 8 and the anode of the second diode 10, the cathode of the first energy-storage capacitor 3 is connected with the cathode of the third diode 11, similarly, the cathode of the second charging resistor 2 is connected with the second energy-storage capacitor 4 and the second voltage detection circuit 14 which are connected in parallel, the cathode of the second charging resistor 2 is connected with the anode of the first thyristor 5, the gate of the first thyristor 5 is connected with one end of the first thyristor trigger circuit 7, the cathode of the first thyristor 5 is connected with the other end of the first thyristor trigger circuit 7 and the anode of the first diode 9, the cathode of the second energy-storage capacitor 4 is connected with the cathode of the fourth diode 12, the anode of the first diode 9 is connected with the cathode of the third diode 11, the anode of the second diode 10 is connected with the cathode of the fourth diode 12, the cathodes of the first diode 9 and the second diode 10 are connected with one end of the bypass switch trigger coil 13, the other end of the bypass switch trigger coil 13 is connected in parallel with the anodes of the third diode 11 and the fourth diode 12 to the negative electrode of the power supply.
The first thyristor trigger circuit 7 and the second thyristor trigger circuit 8 both comprise an isolation transformer 16, a rectifier diode 17, a current limiting resistor 18 and an anti-parallel diode 19, the power transformer 16 receives a trigger signal, one end of the output side of the power transformer drives the first thyristor 5 or the second thyristor 6 through the rectifier diode 17 and the current limiting resistor 18, the anode of the anti-parallel diode 19 is connected with the other end of the output side, and the cathode of the anti-parallel diode 19 is connected with the current limiting resistor 18.
The second voltage detection circuit 14 and the first voltage detection circuit 15 both include an up-sampling resistor 20, a down-sampling resistor 21 and a hysteresis comparator 22, the up-sampling resistor 20 and the down-sampling resistor 21 are connected in series and then connected in parallel at two ends of the first energy storage capacitor 3 or the second energy storage capacitor 4, a connection point between the up-sampling resistor 20 and the down-sampling resistor 21 is connected to an input end of the hysteresis comparator 22, and an output end of the hysteresis comparator 22 is an output end of the voltage detection circuit
The working principle is as follows:
the positive electrode of the power supply supplies power to the first energy storage capacitor 3 through the first charging resistor 1, the first energy storage capacitor 3 will charge gradually to the voltage close to the power supply; the power supply charges the second energy storage capacitor 4 through the second charging resistor 2, and the second energy storage capacitor 4 is gradually charged to a voltage close to the power supply.
The charging path of the first energy storage capacitor 3 is: the positive pole of the power supply passes through the first charging resistor 1, the first energy storage capacitor 3, the first diode 9, the bypass switch trigger coil 13 and the negative pole of the power supply.
The charging path of the second energy storage capacitor 4 is: the positive pole of the power supply passes through the second charging resistor 2, the second energy storage capacitor 4, the second diode 10, the bypass switch trigger coil 13 and the negative pole of the power supply.
The discharge path of the first energy storage capacitor 3 is: the high-voltage switch comprises the upper end of a first energy storage capacitor 3, a second thyristor 6, a second diode 10, a bypass switch trigger coil 13, a third diode 11 and the cathode of the first energy storage capacitor 3.
The discharge path of the second energy storage capacitor 4 is: the upper end of the second energy storage capacitor 4, the first thyristor 5, the first diode 9, the bypass switch trigger coil 13, the fourth diode 12 and the cathode of the second energy storage capacitor 4.
The first energy storage capacitor 3 is connected in parallel with a first voltage detection circuit 15, which can detect the charging voltage state of the first energy storage capacitor 3.
The second energy storage capacitor 4 is connected in parallel with a second voltage detection circuit 14, which can detect the charging voltage state of the second energy storage capacitor 4.
When the bypass switch trigger coil 13 in the circuit is in a conducting state, a redundant trigger circuit for the bypass switch of the flexible direct current converter valve of the embodiment works as follows:
1) before a redundant trigger circuit for a bypass switch of a flexible direct current converter valve is started, the voltage of a first energy storage capacitor 3 and the voltage of a second energy storage capacitor 4 are 0V, a first thyristor trigger circuit 7 and a second thyristor trigger circuit 8 have no trigger signals, and a first thyristor 5 and a second thyristor 6 are in a cut-off state;
2) after the power supply is powered on, the power supply charges the first energy storage capacitor 3 through the first charging resistor 1, the first energy storage capacitor 3, the first diode 9 and the bypass switch trigger coil 13; the power supply charges the second energy storage capacitor 4 through the second charging resistor 2, the second energy storage capacitor 4, the second diode 10 and the bypass switch trigger coil 13.
3) Because the first thyristor 5 and the second thyristor 6 are both in a cut-off state, no current flows, and the voltage of the first energy storage capacitor 3 and the voltage of the second energy storage capacitor 4 are continuously charged to be close to the voltage of the power supply. Via the first voltage detection circuit 15 and the second voltage detection circuit 14, the charging state of the first energy storage capacitor 3 and the second energy storage capacitor 4 can be recognized.
4) When the first thyristor trigger circuit 7 or the second thyristor trigger circuit 8 receives a trigger signal, the first thyristor 5 or the second thyristor 6 is turned on, so that the first energy storage capacitor 3 or the second energy storage capacitor 4 discharges to the bypass switch trigger coil 13 to trigger the bypass switch to be closed.
A redundant trigger circuit for a bypass switch of a limp-to-dc converter valve according to this embodiment operates when the bypass switch trigger coil 13 in the circuit is in an open fault condition as follows:
1) before a redundant trigger circuit for a bypass switch of a flexible direct current converter valve is started, the voltage of a first energy storage capacitor 3 and the voltage of a second energy storage capacitor 4 are 0V, a first thyristor trigger circuit 7 and a second thyristor trigger circuit 8 have no trigger signals, and a first thyristor 5 and a second thyristor 6 are in a cut-off state;
2) after the power supply is powered on, the bypass switch trigger coil 13 is in an open-circuit fault state, the first energy storage capacitor 3 and the second energy storage capacitor 4 cannot be charged, and the voltage is always 0V. Can be identified by the first voltage detection circuit 15 and the second voltage detection circuit 14 and alarms.
The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention accordingly, and not to limit the protection scope of the present invention accordingly. All equivalent changes or modifications made in accordance with the spirit of the present disclosure are intended to be covered by the scope of the present disclosure.