A black start grid-connected switch non-pressure closing device and method

Abstract

The invention discloses a black start grid-connected switch voltage-free closing device, comprising a power supply, a closing switch, a relay module and a closing signal output module; the device controls the working state of a relay in the relay module through the closing switch, thereby realizing the switching of the relay between a normally open contact state and a normally closed contact state; the normally open contact is connected to the closing signal output module, and the closing signal output module is further connected to a grid-connected switch closing input signal channel of a synchronization device; when the relay is working, the normally open contact is closed, that is, the grid-connected switch closing input signal of the synchronization device is turned on, thereby realizing the voltage-free closing function of the grid-connected switch; after the grid-connected switch is closed, the closing switch controls the relay to lose power, the normally open contact is disconnected, the normally closed contact is closed, and the synchronization device is restored to a normal control state; the device can simplify the black start closing operation process, and reduce the inconvenience and safety hazards of manually operating the grid-connected switch closing.

Description

Technical Field

[0001] The invention belongs to the technical field of black start, and in particular relates to a black start grid-connected switch voltage-free closing device and method. Background Art

[0002] As an important link in the field of power system, black start involves a series of equipment status adjustments that are different from conventional operations during the start-up process. Each measure is crucial to the start-up. During the black start, the power grid is in normal operation and is on standby. Once the power station is ordered to black start, a major accident must have occurred in the power system, causing the power grid to lose power. Black start is the first lighter for the power grid to restore power supply and the first lifeline to ignite the entire power grid. Black start can prevent a major power outage from causing a huge impact on people's livelihood, industry, and national defense, and in serious cases, cause losses to people's lives and property. As an essential basic energy source in today's society, electricity must ensure its normal continuous and stable operation, and also ensure that it can restore power supply in an orderly manner in the face of major accidents. When the power system grid-connected switch is in normal state, no one has the authority to operate it. Only the synchronization device can find the synchronization point and close the switch to send out power. Some power plant grid-connected switches are not equipped with the on-site closing function. During black start, the switch must be manually short-circuited to access the signal to complete the closing. The first problem is that it is easy to click the wrong position, causing a DC short circuit. The second is that the DC short-circuit current after the short circuit is not smaller than the AC short-circuit current, and there is a risk of injury to the staff. The third is that the signal must be manually short-circuited during each black start, which is cumbersome and requires multiple people to monitor, low efficiency, and the risk of error. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a black start grid-connected switch no-voltage closing device and method, which can enable the grid-connected switch to have single-side no-voltage closing and double-side no-voltage closing functions, simplify the black start closing operation process, and reduce the inconvenience and safety hazards of manual operation of grid-connected switch closing.

[0004] The present invention is achieved through the following technical solutions:

[0005] A black start grid-connected switch pressure-free closing device, comprising a closing switch, a relay module and a closing signal output module, wherein the closing switch is connected to a control end of the relay module, the closing switch controls the energized and de-energized states of the relay in the relay module by turning on and off, the normally open contact of the relay in the relay module is connected to the closing signal output module, the closing signal output module is connected to a closing signal port of a synchronous device grid-connected switch, and the closing signal output module introduces the normally open contact of the relay in the relay module to the closing signal port of the synchronous device grid-connected switch;

[0006] The closing switch adopts two key-rotating self-locking switches, the common end of the first key-rotating self-locking switch is connected to the positive pole of the power supply, the normally open end is connected to the common end of the second key-rotating self-locking switch, and the normally open end of the second key-rotating self-locking switch is connected to the control port of the relay module. When the normally open ends of the first key-rotating self-locking switch and the second key-rotating self-locking switch are both closed, the positive pole of the power supply is transmitted to the control port of the relay module, driving the relay in the relay module to operate. When the normally open ends of either or both of the first key-rotating self-locking switch and the second key-rotating self-locking switch are disconnected, the relay in the relay module is in a power-off and non-operating state, and the normally closed ends of the first key-rotating self-locking switch and the second key-rotating self-locking switch are in a suspended state.

[0007] Preferably, it also includes a power supply, which provides a control voltage for the closing switch and a working power supply for the relay module coil, and the power supply is used to power the entire device.

[0008] Furthermore, the power supply is composed of three 1.5V rechargeable batteries and a battery box.

[0009] Preferably, the normally open ports of the first key-rotating self-locking switch and the second key-rotating self-locking switch are both in the closing position, and the normally closed ports are in the exit position.

[0010] Preferably, the relay module includes a power port, a relay, a diode, a first resistor and a transistor, one end of the relay coil is connected to a port of the power port, the diode anode and the positive electrode of the power supply, the other end of the relay coil is connected to the diode cathode and the transistor emitter, the transistor collector is connected to the other port of the power port and the negative electrode of the power supply, the closing switch is connected to the transistor base via the first resistor, the power port is used to connect the positive and negative electrodes of the power supply to the device, the relay is used to control the opening and closing states of the normally open and normally closed contacts, the diode is used to maintain the residual capacity in the coil after the relay loses power, the transistor is used to drive whether the relay is energized to work, and the first resistor is used to divide the voltage so that the transistor base obtains a bias voltage.

[0011] Furthermore, the relay adopts a single-position relay with a normally open contact and a normally closed contact, the rated working voltage is 5V, and the transistor adopts a PNP type 9012 transistor. When there is no voltage signal input to the base, the transistor is in a cut-off state, and after the base is input with a bias voltage, the transistor is in a conducting state.

[0012] Preferably, the closing signal output module uses a single-row two-port output terminal, one of the two bottom pins of the output terminal is connected to the common contact of the relay, and the other pin is connected to the normally open contact, and the two ports of the two top screw-fixed ports of the output terminal are respectively connected to the two input ports of the closing signal of the synchronization device grid-connected switch.

[0013] A method for non-pressure closing of a black start grid-connected switch, based on any one of the above-mentioned devices, comprises the following steps:

[0014] 1) Check and confirm that the unit to be started is in the shutdown state, the transmission line and the main transformer are in the power-off state, and proceed to step 2);

[0015] 2) Install the black start grid-connected switch no-pressure closing device on the guide rail of the synchronous device grid-connected switch closing signal channel, and proceed to step 3);

[0016] 3) Connect the two ports of the closing signal output module to the two standby channels of the closing signal of the grid-connected switch of the synchronization device through wires, and proceed to step 4);

[0017] 4) Use a multimeter to measure the secondary voltage of the PT voltage transformer on both sides of the grid-connected switch. Once again confirm that there is no voltage on one or both sides of the grid-connected switch, the device can be operated and go to step 5);

[0018] 5) The first staff member operates the first key to rotate the self-locking switch to the closed position, and the second staff member operates the second key to rotate the self-locking switch to the closed state, and then proceeds to step 6);

[0019] 6) The first staff member and the second staff member confirm that the grid-connected switch is in the closed state. The first staff member operates the first key to rotate the self-locking switch to the exit position, and the second staff member operates the second key to rotate the self-locking switch to the exit state. The black start commander is notified that the grid-connected switch is closed. The first key rotation self-locking switch and the second key rotation self-locking switch are both in the exit state.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects:

[0021] The present invention controls the working state of the relay in the relay module through a closing switch, thereby realizing the switching of the relay between the normally open and normally closed contact states. The normally open contact is connected to the closing signal output module, and the closing signal output module is further connected to the grid-connected switch closing input signal channel of the synchronization device. When the relay is working, the normally open contact is closed, that is, the grid-connected switch closing input signal of the synchronization device is turned on, thereby realizing the pressure-free closing function of the grid-connected switch. After the grid-connected switch is closed, the closing switch controls the relay to lose power, the normally open contact is disconnected, and the normally closed contact is closed, thereby restoring the synchronization device to a normal control state.

[0022] Furthermore, the closing switch of the present invention is composed of two key-rotating self-locking switches connected in series. When in use, both persons need to rotate the key to the closing position to perform the voltage-free closing operation of the grid-connected switch. The two-person operation reduces the risk of accidental closing. As an important grid-connected switch, the two-person closing can play a role in mutual monitoring. After the closing is completed, both persons rotate the key to the closing position and the exit position, ensuring a smooth black start.

[0023] Furthermore, the power supply of the present invention uses rechargeable No. 5 batteries connected in series to form a 4.5V, which is convenient for on-site recycling and reduces the cost of use. The power supply provides a control voltage signal for the closing switch on the one hand, and provides a working power supply for the coil of the relay on the other hand, without the need to set the control voltage separately.

[0024] Furthermore, the relay module of the present invention adopts the normally open contact of the relay to be connected to the closing channel of the synchronization device. The normally open contact is closed only when the relay is actuated. When the device is not in use, the normally closed contact is closed, and there is no signal input to the closing channel of the synchronization device, which does not affect the normal operation of the synchronization device.

[0025] Furthermore, the present invention can be installed on the terminal fixing rail of the synchronization device, and connected to the closing channel of the synchronization device through the closing signal output line. The on-site installation and wiring are simple and fast. The device does not work during normal operation and does not require frequent wiring. The closing operation is only performed during black start, which does not affect the original control method of the parallel switch.

[0026] Furthermore, when the present invention is operated, it is first confirmed that there is no pressure on one side or both sides of the grid-connected switch before operation, and the device with pressure on both sides cannot be operated to avoid asynchronous closing.

[0027] Furthermore, the present invention uses very few electronic components, which reduces the cost of the device, enriches the black start closing means, is easy to promote and use on site, and is convenient for operators to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a principle block diagram of the device of the present invention.

[0029] Figure 2 The schematic diagram of the circuit of the device of the present invention is shown in FIG.

[0030] In the figure: power supply 1; closing switch 2; relay module 3; closing signal output module 4. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0032] The present invention can solve the problem and hidden danger that the closing of the switch can only be completed by manually short-circuiting the switch access signal during black start.

[0033] The present invention provides a black start grid-connected switch non-pressure closing device, such as Figure 1 As shown, it includes a closing switch 2, a relay module 3 and a closing signal output module 4, the closing switch 2 is connected to the control end of the relay module 3, the closing switch 2 controls the energized and de-energized states of the relay in the relay module 3 by turning on and off, the normally open contact of the relay in the relay module 3 is connected to the closing signal output module 4, the closing signal output module 4 is further connected to the closing signal port of the synchronous device grid-connected switch, and the closing signal output module 4 introduces the normally open contact of the relay in the relay module 3 to the closing signal port of the synchronous device grid-connected switch.

[0034] In this embodiment, a power supply 1 is also included, and the power supply 1 provides a control voltage for the closing switch 2 and provides a working power supply for the coil of the relay module 3. The power supply 1 is used to power the entire device.

[0035] In this embodiment, the power supply 1 is composed of three 1.5V rechargeable batteries and a battery box.

[0036] In this embodiment, the closing switch 2 adopts two key-rotating self-locking switches, the common end of the first key-rotating self-locking switch is connected to the positive pole of the power supply 1, and the normally open end is connected to the common end of the second key-rotating self-locking switch, and the normally open end of the second key-rotating self-locking switch is connected to the control port of the relay module 3. When the normally open ends of the first key-rotating self-locking switch and the second key-rotating self-locking switch are both closed, the positive pole of the power supply 1 can be transmitted to the control port of the relay module 3, driving the relay in the relay module 3 to operate. When the normally open ends of either or both of the first key-rotating self-locking switch and the second key-rotating self-locking switch are disconnected, the relay in the relay module 3 is in a power-off and non-operating state, and the normally closed ends of the first key-rotating self-locking switch and the second key-rotating self-locking switch are in a suspended and unconnected state.

[0037] In this embodiment, the first key rotary self-locking switch and the second key rotary self-locking switch are kept by different persons. When operating the grid-connected switch to close the switch without pressure, two persons need to supervise each other to close the switch. The normally open ports of the first key rotary self-locking switch and the second key rotary self-locking switch are both in the closing position, and the normally closed ports are in the exit position.

[0038] In this embodiment, the relay module 3 includes a power port, a relay, a diode, a first resistor and a transistor. One end of the relay coil is connected to a port of the power port, the diode anode and the positive electrode of the power supply 1, the other end of the relay coil is connected to the diode cathode and the transistor emitter, the transistor collector is connected to the other port of the power port and the negative electrode of the power supply 1, the closing switch 2 is connected to the transistor base via the first resistor, the power port is used to connect the positive and negative electrodes of the power supply 1 to the device, the relay is used to control the opening and closing states of the normally open and normally closed contacts, the diode is used to maintain the residual capacity in the coil after the relay loses power, the transistor is used to drive whether the relay is energized to work, and the first resistor is used to divide the voltage so that the transistor base obtains a bias voltage.

[0039] In this embodiment, the relay is a single-position relay, that is, it has a normally open contact and a normally closed contact, and the rated working voltage is 5V. The transistor is a PNP type 9012 transistor. When there is no voltage signal input to the base, the transistor is in the cut-off state, and after the base is input with a bias voltage, the transistor is in the on state.

[0040] In this embodiment, the closing signal output module 4 uses a single-row two-port output terminal, one of the two bottom pins of the output terminal is connected to the common contact of the relay, and the other pin is connected to the normally open contact, and the two ports of the two top screw-fixed ports of the output terminal are respectively connected to the two input ports of the closing signal of the synchronization device grid-connected switch.

[0041] like Figure 2As shown, a black start grid-connected switch pressure-free closing device comprises a power supply port D1, a relay U1, a diode Dio1, a first resistor R1, a transistor Q1, a closing signal output terminal H1, a first key rotation self-locking switch S1, and a second key rotation self-locking switch S2. The closing switch (2) comprises the first key rotation self-locking switch S1 and the second key rotation self-locking switch S2. The relay module (3) comprises the power supply port D1, the relay U1, the diode Dio1, the first resistor R1, and the transistor Q1. The closing signal output module (4) is the closing signal output terminal H1. The positive electrode of the power supply (1) is connected to the first pin of the power supply port D1, and the negative electrode of the power supply (1) is connected to the second pin of the power supply port D1. The control port of the relay module (3) is a pair of terminals connected to the first resistor R1 and the transistor Q1. At the side end, the output port of the relay module (3) is a common terminal and a normally open contact; one end of the relay U1 coil is connected to the first pin of the power port D1, and the other end is connected to the emitter of the transistor Q1, the collector of the transistor Q1 is connected to the second pin of the power port D1, the anode of the diode Dio1 is connected to the emitter of the transistor Q1, the cathode of the diode Dio1 is connected to the first pin of the power port D1, the common terminal of the first key rotation self-locking switch S1 is connected to the first pin of the power port D1, the normally open terminal is connected to the common terminal of the second key rotation self-locking switch S2, and the normally open terminal of the second key rotation self-locking switch S2 is connected to the base of the transistor Q1 via the first resistor R1; the second pin of the closing signal output terminal H1 is connected to the common terminal contact of the relay U1, and the first pin of the closing signal output terminal H1 is connected to the normally open contact of the relay U1.

[0042] A method for closing a black start grid-connected switch without voltage, comprising the following steps:

[0043] 1) Check and confirm that the unit to be started is in the shutdown state, the transmission line and the main transformer are in the power-off state, and proceed to step 2);

[0044] 2) Install the black start grid-connected switch no-pressure closing device on the guide rail of the synchronous device grid-connected switch closing signal channel, and proceed to step 3);

[0045] 3) Connect the two ports of the closing signal output module 4 to the two standby channels of the closing signal of the grid-connected switch of the synchronization device through wires, and go to step 4);

[0046] 4) Use a multimeter to measure the secondary voltage of the PT voltage transformer on both sides of the grid-connected switch. Once again confirm that there is no voltage on one or both sides of the grid-connected switch, the device can be operated and go to step 5);

[0047] 5) The first staff member operates the first key to rotate the self-locking switch to the closed position, and the second staff member operates the second key to rotate the self-locking switch to the closed state, and then proceeds to step 6);

[0048] 6) The first staff member and the second staff member confirm that the grid-connected switch is in the closed state. The first staff member operates the first key to rotate the self-locking switch to the exit position, and the second staff member operates the second key to rotate the self-locking switch to the exit state. The black start commander is notified that the grid-connected switch is closed. The first key rotation self-locking switch and the second key rotation self-locking switch are both in the exit state.

[0049] The above is only a preferred embodiment of the patent of the present invention, and does not impose any limitation on the patent of the present invention. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A black start grid-connected switch non-pressure closing device, characterized in that: The invention comprises a closing switch (2), a relay module (3) and a closing signal output module (4), wherein the closing switch (2) is connected to a control end of the relay module (3), the closing switch (2) controls the energized and de-energized states of the relay in the relay module (3) by turning on and off, the normally open contact of the relay in the relay module (3) is connected to the closing signal output module (4), the closing signal output module (4) is connected to a closing signal port of a synchronous device grid-connected switch, and the closing signal output module (4) introduces the normally open contact of the relay in the relay module (3) to the closing signal port of the synchronous device grid-connected switch; The closing switch (2) uses two key-rotating self-locking switches, the common end of the first key-rotating self-locking switch is connected to the positive pole of the power supply (1), the normally open end is connected to the common end of the second key-rotating self-locking switch, and the normally open end of the second key-rotating self-locking switch is connected to the control port of the relay module (3). When the normally open ends of the first key-rotating self-locking switch and the second key-rotating self-locking switch are both closed, the positive pole of the power supply (1) is transmitted to the control port of the relay module (3), driving the relay in the relay module (3) to operate. When the normally open ends of either or both of the first key-rotating self-locking switch and the second key-rotating self-locking switch are disconnected, the relay in the relay module (3) is in a power-off and non-operating state, and the normally closed ends of the first key-rotating self-locking switch and the second key-rotating self-locking switch are in a suspended state.

2. A black start grid-connected switch non-pressure closing device according to claim 1, characterized in that: It also includes a power supply (1), which provides a control voltage for the closing switch (2) and provides a working power supply for the relay module (3) coil. The power supply (1) is used to power the entire device.

3. A black start grid-connected switch non-pressure closing device according to claim 2, characterized in that: The power supply (1) is composed of three 1.5V rechargeable batteries and a battery box.

4. A black start grid-connected switch non-pressure closing device according to claim 1, characterized in that: The normally open ports of the first key rotation self-locking switch and the second key rotation self-locking switch are both in the closing position, and the normally closed ports are in the exit position.

5. A black start grid-connected switch non-pressure closing device according to claim 1, characterized in that: The relay module (3) comprises a power port, a relay, a diode, a first resistor and a transistor. One end of the relay coil is connected to a port of the power port, the anode of the diode and the positive electrode of the power supply (1). The other end of the relay coil is connected to the cathode of the diode and the emitter of the transistor. The collector of the transistor is connected to the other port of the power port and the negative electrode of the power supply (1). The closing switch (2) is connected to the base of the transistor via the first resistor. The power port is used to connect the positive and negative electrodes of the power supply (1) to the device. The relay is used to control the opening and closing states of the normally open and normally closed contacts. The diode is used to maintain the residual energy in the coil after the relay loses power. The transistor is used to drive whether the relay works with power. The first resistor is used to divide the voltage so that the base of the transistor obtains a bias voltage.

6. A black start grid-connected switch non-pressure closing device according to claim 5, characterized in that: The relay adopts a single-position relay with a normally open contact and a normally closed contact, and the rated working voltage is 5V. The transistor adopts a PNP type 9012 transistor. When no voltage signal is input to the base, the transistor is in a cut-off state, and after the base is input with a bias voltage, the transistor is in a conducting state.

7. A black start grid-connected switch non-pressure closing device according to claim 1, characterized in that: The closing signal output module (4) uses a single-row two-port output terminal, one of the two bottom pins of the output terminal is connected to the common contact of the relay, and the other pin is connected to the normally open contact, and two ports of the two top screw-fixed ports of the output terminal are respectively connected to the two input ports of the closing signal of the synchronous device grid-connected switch.

8. A method for closing a black start grid-connected switch without voltage, characterized in that: The device according to any one of claims 1 to 7 comprises the following steps: 1) Check and confirm that the unit to be started is in the shutdown state, the transmission line and the main transformer are in the power-off state, and proceed to step 2); 2) Install the black start grid-connected switch no-pressure closing device on the guide rail of the synchronous device grid-connected switch closing signal channel, and proceed to step 3); 3) Connect the two ports of the closing signal output module (4) to the two standby channels of the closing signal of the grid-connected switch of the synchronization device through wires, and proceed to step 4); 4) Use a multimeter to measure the secondary voltage of the PT voltage transformer on both sides of the grid-connected switch. Once again confirm that there is no voltage on one or both sides of the grid-connected switch, the device can be operated and go to step 5); 5) The first staff member operates the first key to rotate the self-locking switch to the closed position, and the second staff member operates the second key to rotate the self-locking switch to the closed state, and then proceeds to step 6); 6) The first staff member and the second staff member confirm that the grid-connected switch is in the closed state. The first staff member operates the first key to rotate the self-locking switch to the exit position, and the second staff member operates the second key to rotate the self-locking switch to the exit state. The black start commander is notified that the grid-connected switch is closed. The first key rotation self-locking switch and the second key rotation self-locking switch are both in the exit state.

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