Synchronous grid-connected power generation control circuit and gas turbine generator set adopting same

Abstract

The utility model discloses a kind of synchronous grid-connected power generation control circuit and gas turbine generator set using it, the circuit uses intermediate relay KA31 to replace synchronous switching knob SA2, uses manual synchronous closing switch UCP102 to replace closing knob SA3, by the gain-loss power state of each relay and switch on HMI, manual synchronous grid-connected power generation control of gas turbine generator set can be realized on HMI interface, operation is simpler, and, the size, weight of relay and switch are less than knob, it is beneficial to realize the miniaturization and integration design of synchronous grid-connected control circuit.

Description

Technical Field

[0001] This utility model relates to the field of gas turbine generator set technology, and in particular, to a synchronous grid-connected power generation control circuit. Furthermore, it also relates to a gas turbine generator set using the aforementioned synchronous grid-connected power generation control circuit. Background Technology

[0002] A gas turbine generator set uses a gas turbine as a prime mover to convert the thermal energy of fuel into mechanical energy, which is then converted into electrical energy by a synchronous generator driven by the gas turbine. For the electrical energy generated by the gas turbine generator set to be connected to the power grid, a closing operation is performed through the generator's output circuit breaker 52G to connect the generator to the power grid system. Figure 1 As shown. In order to reduce the inrush current to the generator set at the moment of synchronous grid connection, it is required that the voltage, frequency and phase angle of the generator power supply are the same as those of the grid system when the grid is closed. However, in actual operation, the most ideal conditions are often not achieved, and there is no need to be so demanding in actual operation. It is sufficient for the generator and the system voltage, frequency and phase angle to be close.

[0003] Among them, such as Figure 2 and Figure 3As shown, the process of manual synchronization and grid connection of the gas turbine generator set is as follows: The synchronizing switch knob SA2 is manually rotated to the "manual synchronization" mode, i.e., contacts 3 and 4 of knob SA2 are connected, and contacts 7 and 8 are connected. The independent generation enable knob SA7 is then rotated to the disabled state. At this time, the coils of intermediate relays KA16 and KA16.1 are energized, and their normally open contacts close. Then, the dual voltmeter PV, dual frequency meter Hz, and synchronizing meter S begin monitoring the voltage, frequency, and phase angle difference between the generator side and the system side. When the voltage and frequency measured by the dual voltmeter PV and dual frequency meter HZ are basically the same, the manual synchronization is initiated by the operator at HM. Clicking "Synchronous Start" on the interface controls the closing switch SS1 to the closed state, while the output circuit breaker 52G is in the open state. This de-energizes the intermediate relay KA6.1, causing its normally closed contact to close. When the pointer of the synchronizing meter S points to the top triangle momentarily, manually rotate the closing knob SA3 to close the circuit. This connects contacts 3 and 4 of the closing knob SA3, closing the synchronizing relay TK and energizing the intermediate relay KA4. After energizing, KA4's normally open contact closes, directly sending power to the closing coil circuit of the output circuit breaker 52G, thus driving 52G to close and enabling the generator to connect to the power grid. The process of independently powering the gas turbine generator set is as follows: The synchronizing switch SA2 is manually rotated to manual synchronizing mode, and the independent power generation enable switch SA7 is simultaneously rotated to the enable state. At this time, intermediate relays KA16 and KA16.1 are activated. Overvoltage relay KA30 judges the voltage values ​​of grid-side A603 and C603. When the grid voltage is less than the set value, overvoltage relay KA30 does not operate, and its normally closed contact remains closed. At this time, synchronizing relay TK is in the open state, while the closing switch SS1 is in the closed state. Since the generator output circuit breaker 52G is in the open state, intermediate relay KA6.1 is not energized, and its normally closed contact remains closed. The closing switch SA3 is manually rotated to close the circuit, energizing intermediate relay KA4. After energizing, KA4's normally open contact closes and directly sends power to the closing coil circuit of output circuit breaker 52G, thereby driving output circuit breaker 52G to close, realizing independent power supply for the gas turbine generator set.Therefore, when the gas turbine generator set is manually synchronized and connected to the grid, the control current passes sequentially through contacts 7 and 8 of the synchronization switching knob SA2, contacts 3 and 4 of the closing knob SA3, the synchronization relay TK, the closing permission switch SS1, the normally closed contact of the intermediate relay KA6.1, and the normally open contact of the intermediate relay KA16.1 before being delivered to the intermediate relay KA4. This controls the normally open contact of the intermediate relay KA4 to close, thereby driving the outlet circuit breaker 52G to close. When the gas turbine generator set is generating electricity independently, the control current passes sequentially through contacts 7 and 8 of the synchronization switching knob SA2, contacts 3 and 4 of the closing knob SA3, contacts 3 and 4 of the independent generation enable knob SA7, the overvoltage relay KA30, the closing permission switch SS1, the intermediate relay KA6.1, and the intermediate relay KA16.1 before being delivered to the intermediate relay KA4. This controls the normally open contact of the intermediate relay KA4 to close, thereby driving the outlet circuit breaker 52G to close.

[0004] In certain specific scenarios or projects, such as mobile vehicle-mounted power supplies and offshore platform power generation projects, gas turbine generator sets, especially their electrical control systems, require a high degree of integration. Strict control over the overall size and weight of the unit is necessary, necessitating optimized design of the entire gas turbine generator set's synchronization and grid connection control circuit to achieve synchronization and grid connection control with the fewest possible components and circuits. However, existing manual synchronization and grid connection control circuits for gas turbine generator sets have multiple knobs, such as the synchronization switching knob SA2, the closing knob SA3, and the independent generation enable knob SA7. These knobs are large and heavy, making it difficult to miniaturize and integrate the synchronization and grid connection control circuit. Furthermore, current manual synchronization and grid connection closing and independent generation closing require multiple manual knob operations, which can easily lead to operational errors and failures in either grid connection or independent generation. In addition, the existing synchronous grid-connected control circuit detects the bus voltage through an overvoltage relay KA30 when performing independent generator closing. Only when the bus voltage is less than the set value (generally, bus voltage value < 2V, voltage frequency < 0.5Hz), it means there is no voltage on the bus side, and the overvoltage relay KA30 will not operate, thus ensuring smooth independent generator closing. However, since the internal coil of the synchronous relay TK is connected to both the generator side and the bus side, although there is no voltage on the bus side during independent generator operation, there is voltage on the generator side. The internal coil of the synchronous relay TK will generate an induced voltage on the bus side due to electromagnetic induction. Once the induced voltage exceeds the set value, it will cause the overvoltage relay KA30 to operate and disconnect, making it impossible to achieve independent generator closing. Utility Model Content

[0005] This utility model provides a synchronous grid-connected power generation control circuit and a gas turbine generator set using the same. It enables manual synchronous grid-connected power generation control of the gas turbine generator set on the HMI interface, making operation simpler. Furthermore, the size and weight of the relays and switches are smaller than those of the knobs, which is beneficial for the miniaturization and integration of the synchronous grid-connected control circuit.

[0006] According to one aspect of this utility model, a synchronous grid-connected power generation control circuit is provided, including a manual synchronizing enable switch UCP101, intermediate relays KA31, KA16, and KA16.1, a manual synchronizing closing switch UCP102, a synchronizing relay TK, an overvoltage relay KA30, an independent power generation closing switch UCP100, a closing switch UCP105, intermediate relays KA6.1 and KA4. The manual synchronizing enable switch UCP101 is disposed on the power supply circuit of intermediate relay KA31. The normally open contact of intermediate relay KA31 is disposed on the power supply circuits of intermediate relays KA16 and KA16.1, and the power supply branches of intermediate relays KA16 and KA16.1 are connected in parallel. The normally open contact of intermediate relay KA31 is also connected to the manual synchronizing closing switch UCP102. The manual synchronizing switch UCP102 is connected to the synchronizing relay TK and the overvoltage type voltage relay KA30. The synchronizing relay TK and the overvoltage type voltage relay KA30 are set in parallel. The independent generator closing switch UCP100 is set in series with the overvoltage type voltage relay KA30. The synchronizing relay TK and the independent generator closing switch UCP100 are both connected to the allowable closing switch UCP105. The allowable closing switch UCP105 is connected in series with the normally closed contact of intermediate relay KA6.1, the normally open contact of intermediate relay KA16.1, and intermediate relay KA4 in sequence. The normally open contact of intermediate relay KA4 is connected to the drive circuit of the output circuit breaker 52G. The synchronizing relay TK is connected to the generator side through the normally open contact of intermediate relay KA16 and to the bus side through the normally open contact of intermediate relay KA16.1. The overvoltage type voltage relay KA30 is also connected to the bus side.

[0007] Furthermore, it also includes an independent power generation enable switch UCP103 and an intermediate relay KA22. The independent power generation enable switch UCP103 is installed on the power supply circuit of the intermediate relay KA22. The normally closed contact of the intermediate relay KA22 is installed on the power supply branch of the intermediate relay KA16. The normally open contact of the intermediate relay KA22 is installed on the branch where the overvoltage type voltage relay KA30 and the independent power generation closing switch UCP100 are connected in series.

[0008] Furthermore, it also includes an intermediate relay KA22.1. The power supply circuit of the intermediate relay KA22.1 is set in parallel with the power supply circuit of the intermediate relay KA22. Both are controlled by an independent power generation enable switch UCP103. The normally closed contact of the intermediate relay KA22.1 is set on the branch where the synchronous relay TK is located.

[0009] Furthermore, it also includes an automatic synchronizing switch SPM-D10, the normally closed contact of intermediate relay KA31 is connected to the automatic synchronizing switch SPM-D10, the automatic synchronizing switch SPM-D10 is connected to the synchronizing relay TK and the overvoltage type voltage relay KA30, the normally closed contact of intermediate relay KA31 and the automatic synchronizing switch SPM-D10 form an automatic synchronizing closing control branch, the normally open contact of intermediate relay KA31 and the manual synchronizing closing switch UCP102 form a manual synchronizing closing control branch, and the automatic synchronizing closing control branch and the manual synchronizing closing control branch are set in parallel.

[0010] Furthermore, the power supply circuit of the intermediate relay KA6.1 is also equipped with an output circuit breaker status feedback switch 53G, which is used to provide feedback on whether the output circuit breaker 52G is in a closed or open state.

[0011] Furthermore, the normally closed contact of intermediate relay KA31 is also set on the power supply circuit of intermediate relay KA2 for controlling automatic synchronization, and the normally open contacts of intermediate relay KA2 and intermediate relay KA31 are connected in parallel on the power supply circuits of intermediate relay KA16 and intermediate relay KA16.1.

[0012] Furthermore, the power supply circuit of intermediate relay KA2 is also equipped with a synchronous start switch UCP106, a normally closed contact of intermediate relay KA6, and a normally open contact of intermediate relay KA1.

[0013] Furthermore, the power supply circuit of intermediate relay KA6 is connected in parallel with the power supply circuit of intermediate relay KA6.1, and both are controlled by the status feedback switch 53G of the output circuit breaker.

[0014] Furthermore, a synchronization control switch UCP104 is provided on the power supply circuit of the intermediate relay KA1.

[0015] In addition, this utility model also provides a gas turbine generator set, which adopts the synchronous grid-connected power generation control circuit described above.

[0016] This utility model has the following beneficial effects:

[0017] The synchronous grid-connected power generation control circuit of this utility model uses an intermediate relay KA31 to replace the synchronous switching knob SA2 and a manual synchronous closing switch UCP102 to replace the closing knob SA3. By controlling the on / off state of each relay and switch on the HMI, manual synchronous grid-connected power generation control of the gas turbine generator set can be realized on the HMI interface. The operation is simpler. In addition, the size and weight of the relays and switches are smaller than the knobs, which is conducive to the miniaturization and integration design of the synchronous grid-connected control circuit.

[0018] In addition, the gas turbine generator set of this utility model also has the above-mentioned advantages.

[0019] In addition to the objectives, features, and advantages described above, this utility model has other objectives, features, and advantages. The present utility model will now be described in further detail with reference to the figures. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0021] Figure 1 This is a schematic diagram of the circuit structure connecting the generator to the power grid via the output circuit breaker;

[0022] Figure 2 This is a schematic diagram of the circuit structure of an existing synchronous grid-connected power generation control circuit;

[0023] Figure 3 This is a schematic diagram of the circuit structure connecting the synchronous circuit breaker to the generator side and the bus side in the existing synchronous grid-connected power generation control circuit.

[0024] Figure 4 This is a schematic diagram of the circuit structure of the synchronous grid-connected power generation control circuit according to a preferred embodiment of this application;

[0025] Figure 5 This is a schematic diagram of the circuit structure of the synchronous relay connected to the generator side and the power grid side according to a preferred embodiment of this application. Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] Reference Figure 4 and Figure 5As shown, a preferred embodiment of this application provides a synchronous grid-connected power generation control circuit, including a manual synchronization enable switch UCP101, intermediate relays KA31, KA16, and KA16.1, a manual synchronization closing switch UCP102, a synchronization relay TK, an overvoltage type voltage relay KA30, an independent power generation closing switch UCP100, a closing switch UCP105, intermediate relays KA6.1 and KA4. The manual synchronization enable switch UCP101 is located in the power supply circuit of intermediate relay KA31 and is used to control the energization or de-energization of intermediate relay KA31. When intermediate relay KA31 is energized, its normally open contact closes and its normally closed contact opens; when intermediate relay KA31 is de-energized, its normally open contact opens and its normally closed contact closes. The normally open contact of intermediate relay KA31 is located on the power supply circuit of intermediate relays KA16 and KA16.1, used to control the simultaneous de-energization or simultaneous energization of intermediate relays KA16 and KA16.1. The power supply branches of intermediate relays KA16 and KA16.1 are connected in parallel. The normally open contact of intermediate relay KA31 is also connected to the manual synchronizing switch UCP102. The manual synchronizing switch UCP102 is connected to the synchronizing relay TK and the overvoltage relay KA30. The synchronizing relay TK and the overvoltage relay KA30 are connected in parallel. The independent generator closing switch UCP100 is connected in series with the overvoltage relay KA30. Both the synchronizing relay TK and the independent generator closing switch UCP100 are connected to the closing switch UCP105. The closing switch UCP105 is connected in series with the normally closed contact of intermediate relay KA6.1, the normally open contact of intermediate relay KA16.1, and intermediate relay KA4. The normally open contact of intermediate relay KA4 is connected to the drive circuit of the output circuit breaker 52G. When intermediate relay KA4 is energized, its normally open contact closes, energizing the drive circuit of output circuit breaker 52G and thus driving output circuit breaker 52G to close. Synchronous relay TK is connected to the generator side through the normally open contact of intermediate relay KA16 and to the bus side through the normally open contact of intermediate relay KA16.1. When the normally open contacts of both intermediate relays KA16 and KA16.1 are closed, synchronous relay TK collects the voltages from the generator side and the bus side. When the phase angle difference between the two sides is within a preset range (generally 15°), synchronous relay TK closes. Overvoltage relay KA30 is also connected to the bus side to collect the bus side voltage.

[0028] It is understood that the PLC of the control system can monitor and collect the voltages on the generator side and the grid bus side through communication, and display the voltage difference, frequency difference, and phase angle difference between the two on the human-machine interface (HMI). Operators can observe these differences in real time through the HMI. The principle of the PLC monitoring and displaying the voltage difference, frequency difference, and phase angle difference between the generator side and the grid bus side through communication is existing technology and will not be elaborated here. For example, the real-time voltages on the generator side and the grid bus side can be collected by the generator's excitation regulator and transmitted to the PLC via communication. This eliminates the need for dual voltmeters, synchronization meters, and dual frequency meters, saving cost and space, and reducing potential sources of failure. However, this is not the innovation of this application; the innovation of this application lies in the circuit structure.

[0029] Specifically, the manual synchronization and grid-connected power generation control process of this utility model's synchronization and grid-connected power generation control circuit is as follows: The operator selects "Manual Synchronization" and "Independent Power Generation Enable / Disable" on the HMI, manually controlling the generator to perform synchronized grid-connected power generation. The PLC controls the manual synchronization enable switch UCP101 to close, and simultaneously controls the independent power generation closing switch UCP100 to open. Intermediate relay KA31 is energized, its normally open contact closes, and its normally closed contact opens. Intermediate relay KA22.1 is de-energized, its normally open contact opens, and its normally closed contact closes. When the normally open contact of intermediate relay KA31 closes, intermediate relays KA16 and KA16.1 are simultaneously energized, their normally open contacts close, and their normally closed contacts open. Synchronization relay TK then collects the voltages from the generator side and the bus side. When the phase angle difference between the two voltages meets the requirement (i.e., the phase angle difference is less than 15°), synchronization relay TK closes. When the PLC detects that the voltage and frequency differences between the generator side and the bus side meet the requirements, the HMI will display "Synchronization Allowed". After the operator clicks "Synchronization Start" on the HMI, the PLC will control the closing switch UCP105 to close. Then, the operator observes the phase angle difference value on the HMI. When the observed phase angle difference value is 0°, the operator manually clicks the "Close" button on the HMI to close the circuit. The PLC will control the manual synchronizing closing switch UCP102 to close. At this time, the intermediate relay KA6.1 is not energized, and its normally closed contact closes. Therefore, the circuit provided by the 24V DC power supply will sequentially flow through intermediate relay KA31, manual synchronizing switch UCP102, synchronizing relay TK, normally closed contact of intermediate relay KA22.1, allow closing switch UCP105, normally closed contact of intermediate relay KA6.1, and normally open contact of intermediate relay KA16.1 before being delivered to intermediate relay KA4. When intermediate relay KA4 is energized, its normally open contact closes, controlling the drive circuit of the output circuit breaker 52G to work, thereby driving the output circuit breaker 52G to close, and the generator to connect to the grid to generate electricity, thus realizing the manual synchronizing grid connection and power generation of the gas turbine generator set.

[0030] It is understood that in this embodiment, the synchronous grid-connected power generation control circuit uses an intermediate relay KA31 to replace the synchronous switching knob SA2 and a manual synchronous closing switch UCP102 to replace the closing knob SA3. By controlling the power-on and power-off states of each relay and switch on the HMI, manual synchronous grid-connected power generation control of the gas turbine generator set can be realized on the HMI interface, making the operation simpler. Furthermore, the size and weight of the relays and switches are smaller than those of the knobs, which is conducive to the miniaturization and integration design of the synchronous grid-connected control circuit.

[0031] In addition, the synchronous grid-connected power generation control circuit also includes an independent power generation enable switch UCP103 and an intermediate relay KA22. The independent power generation enable switch UCP103 is set on the power supply circuit of the intermediate relay KA22. The normally closed contact of the intermediate relay KA22 is set on the power supply branch of the intermediate relay KA16. The normally open contact of the intermediate relay KA22 is set on the branch where the overvoltage type voltage relay KA30 and the independent power generation closing switch UCP100 are connected in series.

[0032] It is understandable that when the operator selects the "Manual Synchronization" and "Independent Generation Enable" buttons on the HMI, they manually control the generator to generate electricity independently. The PLC will control the manual synchronization enable switch UCP101 to close and the independent generation enable switch UCP103 to close. Both intermediate relays KA31 and KA22 will be energized. The normally closed contact of intermediate relay KA22 will open and the normally open contact will close. At this time, intermediate relay KA16 will be de-energized and intermediate relay KA16.1 will be energized. At this time, the synchronizing relay TK is only connected to the bus side through intermediate relay KA16.1, and not to the generator side. The coil in the synchronizing relay TK will not generate an induced voltage. The overvoltage relay KA30 detects the actual bus voltage. When the grid is de-energized, the voltage on the bus side will be lower than the set value. The overvoltage relay KA30 will not operate and will remain closed. At this time, the synchronizing relay TK will be in the open state. When the PLC detects that the voltage and frequency differences between the generator side and the bus side meet the requirements (generator side voltage is rated voltage and frequency is rated frequency, while bus voltage is <2V and frequency is <0.5Hz), the PLC will control both the independent generator closing switch UCP100 and the independent generator closing switch UCP105 to close. At the same time, the HMI will display "Independent generator closing allowed". The operator manually clicks the "Close" button on the HMI to close the circuit. The PLC will then control the manual synchronizing closing switch UCP102 to close. At this time, the intermediate relay KA6.1 will not be energized, and its normally closed contact will close. Therefore, the circuit provided by the 24V DC power supply will sequentially flow through the normally open contact of intermediate relay KA31, the manual synchronizing switch UCP102, the normally open contact of intermediate relay KA22, the overvoltage type voltage relay KA30, the independent power generation closing switch UCP100, the closing switch UCP105, the normally closed contact of intermediate relay KA6.1, and the normally open contact of intermediate relay KA16.1 before being delivered to intermediate relay KA4. When intermediate relay KA4 is energized, its normally open contact closes, controlling the drive circuit of the output circuit breaker 52G to work, thereby driving the output circuit breaker 52G to close, and the generator to connect to the grid to generate electricity, thus realizing the independent grid-connected power generation of the gas turbine generator set.

[0033] It is understood that the synchronous grid-connected power generation control circuit of this embodiment, by setting an intermediate relay KA22 on the power supply branch of the intermediate relay KA16, and setting an independent power generation enable switch UCP103 on the power supply circuit of the intermediate relay KA22, replaces the independent power generation enable knob SA7 with the independent power generation enable switch UCP103. Independent grid-connected power generation can be controlled by controlling the on / off state of the switch and relay, making operation simpler and facilitating the miniaturization and integration of the synchronous grid-connected control circuit. Furthermore, during independent grid-connected power generation, the coil of the synchronous relay TK no longer generates induced voltage, and the overvoltage relay KA30 detects the actual bus voltage, thereby eliminating the interference of induced voltage and ensuring the reliability and accuracy of the independent power generation closing control.

[0034] In addition, the synchronous grid-connected power generation control circuit also includes an intermediate relay KA22.1. The power supply circuit of intermediate relay KA22.1 is connected in parallel with the power supply circuit of intermediate relay KA22, and both are controlled by the independent power generation enable switch UCP103. The normally closed contact of intermediate relay KA22.1 is located on the branch where the synchronous relay TK is located. When independent grid-connected power generation is performed, after the independent power generation enable switch UCP103 is closed, intermediate relays KA22.1 and KA22 are energized simultaneously. After intermediate relay KA22.1 is energized, its normally closed contact opens and its normally open contact closes, ensuring that the branch where the synchronous relay TK is located is in an open state. This prevents short circuits to the branch where intermediate relay KA22, overvoltage relay KA30, and the independent power generation closing switch UCP100 are located if the synchronous relay TK fails to disconnect, thus improving the reliability of the circuit operation.

[0035] In addition, the synchronous grid-connected power generation control circuit also includes an automatic synchronizing switch SPM-D10 for controlling the start and stop of the automatic synchronizing switch. The normally closed contact of the intermediate relay KA31 is connected to the automatic synchronizing switch SPM-D10. The automatic synchronizing switch SPM-D10 is connected to the synchronizing relay TK and the overvoltage relay KA30. The normally closed contact of the intermediate relay KA31 and the automatic synchronizing switch SPM-D10 form an automatic synchronizing closing control branch. The normally open contact of the intermediate relay KA31 and the manual synchronizing closing switch UCP102 form a manual synchronizing closing control branch. The automatic synchronizing closing control branch and the manual synchronizing closing control branch are connected in parallel.

[0036] It is understandable that when performing manual synchronizing power generation closing control and independent power generation closing control, the manual synchronizing enable switch UCP101 is closed, the intermediate relay KA31 is energized, its normally open contact is closed and its normally closed contact is open. At this time, the manual synchronizing closing control branch is working, while the automatic synchronizing closing control branch is not working. When automatic synchronizing generator closing control is performed, the PLC controls the manual synchronizing enable switch UCP101 and the independent generator enable switch UCP103 to open. The intermediate relay KA31 is de-energized, with its normally open contact open and normally closed contact closed. At this time, the automatic synchronizing closing control branch is working. When the generator voltage and frequency meet the requirements, the PLC controls the closing allow switch UCP105 to close and the synchronizing start switch UCP106 to close. The automatic synchronizing synchronizer will start working and will automatically match the voltage difference, frequency difference, and phase angle difference between the generator side and the grid bus side. When all three meet the requirements, the automatic synchronizing synchronizer control switch SPM-D10 closes, the intermediate relay KA4 is energized, its normally open contact closes, and the drive circuit of the output circuit breaker 52G is controlled to work, thereby driving the output circuit breaker 52G to close, and the generator is connected to the grid to generate electricity, thus realizing the automatic synchronizing grid-connected power generation of the gas turbine generator set.

[0037] The power supply circuit of intermediate relay KA6.1 is equipped with an output circuit breaker status feedback switch 53G, which is used to provide feedback on whether the output circuit breaker 52G is closed or open. When the output circuit breaker 52G is closed, the output circuit breaker status feedback switch 53G also closes accordingly, and when the output circuit breaker 52G is open, the output circuit breaker status feedback switch 53G also opens accordingly. When the output circuit breaker 52G is closed, the output circuit breaker status feedback switch 53G closes, the intermediate relay KA6.1 is energized, its normally closed contact opens and its normally open contact closes, thereby disconnecting the power supply circuit of intermediate relay KA4, preventing intermediate relay KA4 from being constantly energized, which helps to improve its service life and circuit safety. In addition, the drive circuit of output circuit breaker 52G only needs to provide a drive signal to output circuit breaker 52G to drive it to close, without requiring intermediate relay KA4 to be constantly energized. The specific principle is existing technology and will not be elaborated here.

[0038] In addition, the normally closed contact of intermediate relay KA31 is also set on the power supply circuit of intermediate relay KA2 for automatic synchronization control. The normally open contact of intermediate relay KA2 is connected in parallel with the normally open contact of intermediate relay KA31 on the power supply circuits of intermediate relays KA16 and KA16.1. When performing manual synchronization generator closing control and independent generator closing control, intermediate relay KA31 is energized, its normally open contact is closed and its normally closed contact is open, and the power supply circuit of intermediate relay KA2 is disconnected. After intermediate relay KA2 is de-energized, its normally open contact remains open, and the power supply circuits of intermediate relays KA16 and KA16.1 are controlled to conduct by intermediate relay KA31. When performing automatic synchronization generator closing control, the normally closed contact of intermediate relay KA31 is closed and its normally open contact is open, and the power supply circuit of intermediate relay KA2 is connected. After intermediate relay KA2 is energized, its normally open contact closes, and the power supply circuits of intermediate relays KA16 and KA16.1 are controlled to conduct by intermediate relay KA2.

[0039] The power supply circuit of intermediate relay KA2 is also equipped with a synchronizing start switch UCP106, intermediate relay KA6, and intermediate relay KA1. During automatic or manual synchronization, the PLC controls the synchronizing start switch UCP106 to close. The power supply circuit of intermediate relay KA6 is connected in parallel with that of intermediate relay KA16.1, and both are controlled by the output circuit breaker status feedback switch 53G. When the output circuit breaker status feedback switch 53G is not closed, intermediate relay KA6 is de-energized, its normally closed contact closes, and its normally open contact opens. After the output circuit breaker status feedback switch 53G closes, intermediate relay KA6 is energized, its normally closed contact opens, and its normally open contact closes, thus disconnecting the power supply circuit of intermediate relay KA2, eliminating the need for intermediate relay KA2 to be continuously energized. In addition, the power supply circuit of the intermediate relay KA1 is equipped with a synchronization preparation control switch UCP104. When the PLC detects that the synchronization preparation requirement is met, the PLC will control the synchronization preparation control switch UCP104 to close, the intermediate relay KA1 will be energized, its normally open contacts will close and its normally closed contacts will open. The synchronization preparation requirement is set according to the speed, and the specific rules are existing technology and will not be elaborated here.

[0040] In addition, another embodiment of this utility model provides a gas turbine generator set, which preferably adopts the synchronous grid-connected power generation control circuit described above.

[0041] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0042] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

[0043] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A synchronous grid-connected power generation control circuit, characterized in that, This includes a manual synchronizing enable switch UCP101, intermediate relays KA31, KA16, and KA16.1, a manual synchronizing closing switch UCP102, a synchronizing relay TK, an overvoltage relay KA30, an independent generator closing switch UCP100, a closing switch UCP105, intermediate relays KA6.1, and intermediate relay KA4. The manual synchronizing enable switch UCP101 is located on the power supply circuit of intermediate relay KA31. The normally open contact of intermediate relay KA31 is located on the power supply circuits of intermediate relays KA16 and KA16.1, and the power supply branches of intermediate relays KA16 and KA16.1 are connected in parallel. The normally open contact of intermediate relay KA31 is also connected to the manual synchronizing closing switch UCP102. The manual synchronizing closing switch UCP102...

2. Connected to synchronous relay TK and overvoltage type voltage relay KA30. Synchronous relay TK and overvoltage type voltage relay KA30 are set in parallel. Allowable independent generator closing switch UCP100 is set in series with overvoltage type voltage relay KA30. Synchronous relay TK and allowable independent generator closing switch UCP100 are both connected to allowable closing switch UCP105. Allowable closing switch UCP105 is connected in series with the normally closed contact of intermediate relay KA6.1, the normally open contact of intermediate relay KA16.1 and intermediate relay KA4 in sequence. The normally open contact of intermediate relay KA4 is connected to the drive circuit of the output circuit breaker 52G. Synchronous relay TK is connected to the generator side through the normally open contact of intermediate relay KA16 and to the bus side through the normally open contact of intermediate relay KA16.

1. Overvoltage type voltage relay KA30 is also connected to the bus side.

2. The synchronous grid-connected power generation control circuit as described in claim 1, characterized in that, It also includes an independent power generation enable switch UCP103 and an intermediate relay KA22. The independent power generation enable switch UCP103 is set on the power supply circuit of the intermediate relay KA22. The normally closed contact of the intermediate relay KA22 is set on the power supply branch of the intermediate relay KA16. The normally open contact of the intermediate relay KA22 is set on the branch where the overvoltage type voltage relay KA30 and the independent power generation closing switch UCP100 are connected in series.

3. The synchronous grid-connected power generation control circuit as described in claim 2, characterized in that, It also includes intermediate relay KA22.

1. The power supply circuit of intermediate relay KA22.1 is set in parallel with the power supply circuit of intermediate relay KA22. Both are controlled by independent power generation enable switch UCP103. The normally closed contact of intermediate relay KA22.1 is set on the branch where synchronous relay TK is located.

4. The synchronous grid-connected power generation control circuit as described in claim 1, characterized in that, It also includes an automatic synchronizing switch SPM-D10, the normally closed contact of intermediate relay KA31 is connected to the automatic synchronizing switch SPM-D10, the automatic synchronizing switch SPM-D10 is connected to the synchronizing relay TK and the overvoltage type voltage relay KA30, the normally closed contact of intermediate relay KA31 and the automatic synchronizing switch SPM-D10 form an automatic synchronizing closing control branch, the normally open contact of intermediate relay KA31 and the manual synchronizing closing switch UCP102 form a manual synchronizing closing control branch, and the automatic synchronizing closing control branch and the manual synchronizing closing control branch are set in parallel.

5. The synchronous grid-connected power generation control circuit as described in claim 1, characterized in that, The power supply circuit of the intermediate relay KA6.1 is also equipped with an output circuit breaker status feedback switch 53G, which is used to provide feedback on whether the output circuit breaker 52G is in a closed or open state.

6. The synchronous grid-connected power generation control circuit as described in claim 5, characterized in that, The normally closed contact of intermediate relay KA31 is also set on the power supply circuit of intermediate relay KA2 for controlling automatic synchronization. The normally open contact of intermediate relay KA2 is connected in parallel with the normally open contact of intermediate relay KA31 on the power supply circuit of intermediate relay KA16 and intermediate relay KA16.

1.

7. The synchronous grid-connected power generation control circuit as described in claim 6, characterized in that, The power supply circuit of intermediate relay KA2 is also equipped with synchronous start switch UCP106, normally closed contact of intermediate relay KA6 and normally open contact of intermediate relay KA1.

8. The synchronous grid-connected power generation control circuit as described in claim 7, characterized in that, The power supply circuit of intermediate relay KA6 is set in parallel with the power supply circuit of intermediate relay KA6.1, and both are controlled by the status feedback switch 53G of the output circuit breaker.

9. The synchronous grid-connected power generation control circuit as described in claim 7, characterized in that, The power supply circuit of intermediate relay KA1 is equipped with a synchronization control switch UCP104 that enables synchronization.

10. A gas turbine generator set, characterized in that, The synchronous grid-connected power generation control circuit as described in any one of claims 1 to 9 is adopted.

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