Diesel engine parallel type generator and control system

Abstract

The invention provides a diesel engine parallel generator and a control system, and belongs to the technical field of machinery. The parallel generator control system of the diesel engine comprises a # 1 diesel generator, and an outlet of the # 1 diesel generator is connected with a B4001 switch. A # 1 diesel generator and a # 2 diesel generator are mutually standby, and standby power supplies of a # 1 security 400V PC (IA and IB) section and a # 2 security 400V PC (IIA and IIB) section are recovered into two paths; and a standby power supply automatic input device with high reliability is used for replacing a low-voltage relay loop with low reliability to realize a switching function of the main power supply and the standby power supply, so that a first machine security 400V PC (IA, IB) section and a second machine security 400V PC (IIA, IIB) section can reliably and stably run under the condition of a power loss accident of the station service.

Description

Technical Field

[0001] The present application relates to the field of 400V PC segment backup power supply for thermal power plants, and more specifically, to a diesel parallel generator and control system. Background Art

[0002] The second safety power supply of the power plant is out of service, and the only backup power supply for the #1 and #2 safety 400V PC sections is the diesel generator. In the event of a unit tripping accident, if the plant power is lost, resulting in the loss of power in the boiler 400V PC section and the diesel generator co-start fails, the safety 400V PC section will lose power, and the important loads on the section, such as the emergency lighting, turbine cranking, top shaft oil pump, and AC lubricating oil pump, will all be shut down. At this time, the cylinder temperature is high and the turbine speed is high, and the cranking cannot be engaged, and the top shaft oil and lubricating oil are lost, which will cause uneven heating of the turbine rotor and loss of lubrication of the bearing, which may eventually lead to serious accidents such as burning of the turbine bearing, seriously threatening the safe and stable operation of the unit.

[0003] At the same time, in the original design, the main and backup power supply switching of the 400V PC section of the security system is realized through a low-voltage relay. The voltage monitoring sensitivity is insufficient and the reliability of the relay contacts is low, which can easily cause false operation or refusal to operate, seriously affecting the reliability and stability of the main and backup power supply switching. Summary of the invention

[0004] In order to make up for the above shortcomings, the present application provides a diesel parallel generator and control system, which aims to solve the problem of power loss of the safety 400V PC section in the event of a unit tripping accident.

[0005] In a first aspect, an embodiment of the present application provides a diesel engine parallel generator control system, comprising:

[0006] #1 diesel generator, the outlet of the #1 diesel generator is connected to the B4001 switch, and the outlet of the B4001 switch is connected to the #1 machine security 400V PC (IA, IB) segment;

[0007] #2 diesel generator, the outlet of the #2 diesel generator is connected to the B4002 switch, and the outlet of the B4002 switch is connected to the #2 machine security 400V PC (IIA, IIB) section;

[0008] A parallel circuit, the parallel circuit is connected to the outlets of the #1 diesel generator and the #2 diesel generator, and the parallel circuit is provided with a B4101 switch and a B4102 switch;

[0009] DCS configuration, the DCS configuration controls the #1 diesel generator and the #2 diesel generator to serve as backup for each other.

[0010] In a specific implementation scheme, the incoming switches of the #1 machine security 400V PC (IA, IB) section and the #2 machine security 400V PC (IIA, IIB) section are both equipped with automatic power supply switching devices for power supply switching.

[0011] In a specific implementation scheme, the #1 machine security 400V PC (IA, IB) section includes the #1 machine security 400VPC IA section and the #1 machine security 400V PC IB section, and the #1 machine security 400VPC IA section and the #1 machine security 400V PC IB section are respectively connected to the #1 machine boiler 400V PC IA section and the #1 machine boiler 400V PC IB section, and both are connected to the #1 diesel generator.

[0012] In a specific implementation scheme, the outlets of the #1 boiler 400V PC IA section and the #1 boiler 400V PC IB section are respectively connected to the B412a switch and the B412b switch, and the incoming lines of the #1 machine security 400V PC IA section and the #1 machine security 400VPC IB section are provided with B411a switch and B411b switch, the B411a switch and the B412a switch are located on the same line, and the B411b switch and the B412b are located on the same line.

[0013] In a specific implementation scheme, the #1 machine security 400V PC IA section and the #1 machine security 400V PCIB section incoming lines are respectively connected with a B401a switch and a B401b switch, and the B401a switch and the B401b switch are located on the same line as the B4001 switch.

[0014] In a specific implementation scheme, the #2 machine security 400V PC (IIA, IIB) section includes the #2 machine security 400V PC IIA section and the #2 machine security 400V PC IIB section, and the #2 machine security 400V PC IIA section and the #2 machine security 400V PC IIB section are respectively connected to the #2 machine boiler 400V PC IIA section and the #2 machine boiler 400V PC IIB section, and are both connected to the #2 diesel generator.

[0015] In a specific implementation scheme, the outlets of the #2 boiler 400V PC IIA section and the #2 boiler 400V PCIIB section are respectively connected to the B422a switch and the B422b switch, and the incoming lines of the #2 machine security 400V PC IIA section and the #2 machine security 400V PC IIB section are respectively provided with B421a switch and B421b switch, the B421a switch and the B422a switch are located on the same line, and the B421b switch and the B422b switch are located on the same line.

[0016] In a specific implementation scheme, the #2 machine security 400V PC IIA section and the #2 machine security 400V PCIIB section incoming lines are respectively connected with a B402a switch and a B402b switch, and the B402a switch and the B402b switch are located on the same line as the B4002 switch.

[0017] In a specific implementation scheme, AC contactors (1ZJ, 2ZJ) are installed in the B4101 switch and the B4102 switch, respectively.

[0018] In a second aspect, the present application further provides a diesel engine parallel generator, comprising

[0019] The above-mentioned diesel engine parallel generator control system is adopted; and a diesel generator applied to the above-mentioned diesel engine parallel generator control system.

[0020] The beneficial effects of the present application are as follows: by realizing that the #1 diesel generator and the #2 diesel generator serve as backup for each other, the backup power supplies of the #1 machine safety 400V PC (IA, IB) section and the #2 machine safety 400V PC (IIA, IIB) section are restored to two routes; and a high-reliability backup power automatic input device is used instead of a low-voltage relay circuit with low reliability to realize the main and backup power supply switching function, ensuring that the #1 machine safety 400V PC (IA, IB) section and the #2 machine safety 400V PC (IIA, IIB) section can operate reliably and stably in the event of a power outage in the factory, providing power for important loads such as emergency lighting, steam turbine turning, top shaft oil pump, AC lubricating oil pump, etc., effectively ensuring the safety of important equipment such as steam turbines and generators. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the drawings required for use in the implementation methods will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a circuit diagram of a diesel engine parallel generator and a control system provided in an embodiment of the present application;

[0023] Figure 2 The B4101 switch automatic and manual closing logic diagram of the diesel parallel generator and control system provided in the embodiment of the present application;

[0024] Figure 3 The B4102 switch automatic and manual closing logic diagram of the diesel parallel generator and control system provided in the embodiment of the present application;

[0025] Figure 4 Schematic diagram of 1ZJ and 2ZJ connection of a diesel engine parallel generator and control system provided in an embodiment of the present application;

[0026] Figure 5 A schematic diagram of two pairs of normally open and three pairs of normally closed contacts of 1ZJ and 2ZJ of a diesel parallel generator and control system provided in an embodiment of the present application;

[0027] Figure 6 A schematic diagram of a pair of normally closed contacts 1ZJ and 2ZJ of a diesel parallel generator and control system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0029] See also Figure 1-6 The present application provides a diesel engine parallel generator control system, comprising

[0030] #1 diesel generator, the outlet of #1 diesel generator is connected to the B4001 switch, and the outlet of B4001 switch is connected to the 400V PC (IA, IB) section of #1 machine security;

[0031] #2 diesel generator, the outlet of #2 diesel generator is connected to the B4002 switch, and the outlet of B4002 switch is connected to the 400V PC (IIA, IIB) section of #2 machine security;

[0032] Parallel circuit, the parallel circuit is connected to the outlets of #1 diesel generator and #2 diesel generator, and the parallel circuit is provided with B4101 switch cabinet and B4102 switch cabinet;

[0033] DCS configuration, DCS configuration controls #1 diesel generator and #2 diesel generator as backup for each other.

[0034] The incoming switches of the #1 machine security 400V PC (IA, IB) section and the #2 machine security 400V PC (IIA, IIB) section are both equipped with automatic power supply switching devices for power supply switching.

[0035] The #1 machine security 400V PC (IA, IB) section includes the #1 machine security 400V PC IA section and the #1 machine security 400V PC IB section. The #1 machine security 400V PC IA section and the #1 machine security 400V PC IB section are respectively connected to the #1 machine boiler 400V PC IA section and the #1 machine boiler 400V PC IB section, and both are connected to the #1 diesel generator.

[0036] The outlets of #1 boiler 400V PC IA section and #1 boiler 400V PC IB section are connected to B412a switch and B412b switch respectively. The incoming lines of #1 machine security 400V PC IA section and #1 machine security 400V PC IB section are equipped with B411a switch and B411b switch. The B411a switch and B412a switch are located on the same line, and the B411b switch and B412b are located on the same line.

[0037] The B401a switch and the B401b switch are respectively connected to the incoming lines of the #1 machine security 400V PC IA section and the #1 machine security 400V PC IB section. The B401a switch and the B401b switch are located on the same line as the B4001 switch.

[0038] The #2 machine security 400V PC (IIA, IIB) section includes the #2 machine security 400V PC IIA section and the #2 machine security 400V PCIIB section. The #2 machine security 400V PC IIA section and the #2 machine security 400V PC IIB section are respectively connected to the #2 machine boiler 400V PCIIA section and the #2 machine boiler 400V PC IIB section, and are both connected to the #2 diesel generator.

[0039] The outlets of #2 boiler 400V PC IIA section and #2 boiler 400V PC IIB section are connected to B422a switch and B422b switch respectively, and the incoming lines of #2 machine security 400V PC IIA section and #2 machine security 400V PC IIB section are equipped with B421a switch and B421b switch respectively. The B421a switch and B422a switch are located on the same line, and the B421b switch and B422b switch are located on the same line.

[0040] The B402a switch and the B402b switch are respectively connected to the incoming lines of the #2 machine security 400V PC IIA section and the #2 machine security 400V PC IIB section. The B402a switch and the B402b switch are located on the same line as the B4002 switch.

[0041] Power switching logic:

[0042] ① When the #1 machine's 400V PC (IA, IB) section working power supply boiler 400V PC section (i.e. #1 machine's 400V PC IA section, #1 machine's 400V PC IB section) loses power:

[0043] a. The 400V PC (IA, IB) section of the #1 generator loses power, and the automatic standby power supply device determines that the busbar voltage is low, trips the B411a switch and the B411b switch, closes the B401a switch and the B401b switch, and starts the #1 diesel generator;

[0044] b. If the #1 diesel generator starts successfully, the B4001 switch will automatically close after 15 seconds, and the #1 generator's 400V PC (IA, IB) section will resume power supply from the #1 diesel generator;

[0045] c. If the #1 diesel generator fails to start, or the B4001 switch does not close automatically, restore the #1 generator's 400V PC (IA, IB) power supply in the following way:

[0046] (a) When the DCS determines that the bus voltage of the #1 generator safety 400V PC (IA, IB) section is low and the B411a switch and the B411b switch are in the open position and delayed for 30s, the #1 diesel generator has no voltage and the frequency is lower than 45Hz, and the backup power supply interlocking logic of the #1 generator safety 400V PC (IA, IB) section and the #2 generator safety 400V PC (IIA, IIB) section are enabled, the DCS issues a closing command to close the B4101 switch;

[0047] (b) The operator manually starts the #2 diesel generator, and 15 seconds after the successful start, the B4002 switch automatically closes;

[0048] (c) The operator manually closes the B4102 switch remotely on the DCS screen. When the DCS determines that the three conditions of "the backup power supply interlocking logic of the #1 machine safety 400V PC (IA, IB) section and the #2 machine safety 400V PC (IIA, IIB) section is activated", "the #2 diesel generator has a voltage or frequency higher than 45Hz (indicating that the #2 diesel generator has started)" and "there is a manual closing command for the B4102 switch", the DCS issues a closing command to close the B4102 switch;

[0049] (d) The #1 machine security 400V PC (IA, IB) section is restored to power by the #2 diesel generator.

[0050] ②When the #2 machine safety 400V PC (IIA, IIB) section working power supply boiler 400V PC section (i.e. #2 machine boiler 400V PCIIA section, #2 machine boiler 400V PC IIB section) loses power:

[0051] a. The 400V PC (IIA, IIB) section of the #2 generator loses power, and the automatic standby power supply device determines that the busbar voltage is low, trips the B421a switch and the B421b switch, closes the B402a switch and the B402b switch, and starts the #2 diesel generator;

[0052] b. If the #2 diesel generator starts successfully, the B4002 switch will automatically close after 15 seconds, and the #2 generator's 400V PC (IIA, IIB) section will resume power supply from the #2 diesel generator;

[0053] c. If the #2 diesel generator fails to start, or the B4002 switch does not close automatically, restore the #2 generator's 400V PC (IIA, IIB) section power supply in the following manner:

[0054] (a) When the DCS determines that the bus voltage of the #2 generator safety 400V PC (IIA, IIB) section is low and the B421a switch and the B421b switch are in the open position and delayed for 30s, the #2 diesel generator has no voltage and the frequency is lower than 45Hz, and the #1 generator safety 400V PC (IA, IB) section and the #2 generator safety 400V PC (IIA, IIB) section standby power supply interlocking logic are enabled, it issues a closing command to close the B4102 switch;

[0055] (b) The operator manually starts the #1 diesel generator, and 15 seconds after the successful start, the B4001 switch automatically closes;

[0056] (c) The operator manually closes the B4101 switch remotely on the DCS screen. When the DCS determines that the three conditions of "the backup power supply interlocking logic of the #1 machine safety 400V PC (IA, IB) section and the #2 machine safety 400V PC (IIA, IIB) section is activated", "the #2 diesel generator has a voltage or frequency higher than 45Hz (indicating that the #2 diesel generator has started)" and "there is a manual B4101 switch command issued" are met, the DCS issues a closing command to close the B4101 switch;

[0057] (d) The #2 generator's 400V PC (IIA, IIB) section is restored to power by the #1 diesel generator.

[0058] Refer to the figure, AC contactors (1ZJ, 2ZJ) are installed in the B4101 switch cabinet and the B4102 switch cabinet respectively.

[0059] When #1 diesel generator and #2 diesel generator are running at the same time, their voltage is asynchronous voltage. At this time, if the B4101 switch and the B4102 switch are closed at the same time, the asynchronous power supply will be connected in parallel, causing impact on the system. Therefore, measures must be taken to prevent different power supplies from running in parallel. The logic is as follows:

[0060] Install AC contactors (1ZJ, 2ZJ) in the B4101 switch and B4102 switch respectively: the coil is connected to the C and N phases of the busbar on the #1 diesel generator side of the B4101 switch to monitor the outlet voltage of the #1 diesel generator; the 2ZJ coil is connected to the C and N phases of the busbar on the #2 diesel generator side of the B4102 switch to monitor the outlet voltage of the #2 diesel generator.

[0061] ② Take two pairs of normally open and three pairs of normally closed contacts of AC contactor 1ZJ and AC contactor 2ZJ, and connect them to the closing circuits of switch B4101 and switch B4102 respectively. When #1 diesel generator and #2 diesel generator have voltage at the same time, lock switch B4101 and switch B4102 from closing.

[0062] ③ Take a pair of normally closed contacts of AC contactor 1ZJ and AC contactor 2ZJ, and connect them to the closing circuits of switch B4001 and switch B4002 respectively. When the #2 diesel generator supplies power to the 400V PC (IA, IB) section of the #1 machine safety protection, the B4001 switch is locked for closing. When the #1 diesel generator supplies power to the 400V PC (IIA, IIB) section of the #2 machine safety protection, the B4002 switch is locked for closing.

[0063] (4) Locking logic verification.

[0064] ① Move the B4101 switch and B4102 switch to the test position and supply their control power.

[0065] ②B4101 switch locking logic verification:

[0066] a. Close the B4101 switch manually on site, and the switch should be able to close normally;

[0067] b. Press AC contactor 1ZJ to simulate #1 diesel generator with pressure, and close B4101 switch manually on site. The switch should be able to close normally.

[0068] c. Press AC contactor 2ZJ to simulate the pressure of #2 diesel generator, and close the B4101 switch manually. The switch should be able to close normally.

[0069] d. Press AC contactor 1ZJ and AC contactor 2ZJ at the same time to simulate that #1 diesel generator and #2 diesel generator are pressurized at the same time. Close the B4101 switch manually on site. The switch should be locked and cannot be closed.

[0070] ③B4102 switch locking logic verification:

[0071] a. Close the B4102 switch manually on site, and the switch should be able to close normally;

[0072] b. Press AC contactor 1ZJ to simulate #1 diesel generator with pressure, and close B4102 switch manually on site. The switch should be able to close normally;

[0073] c. Press AC contactor 2ZJ to simulate the pressure of #2 diesel generator, and close the B4102 switch manually. The switch should be able to close normally.

[0074] d. Press AC contactor 1ZJ and AC contactor 2ZJ at the same time to simulate that #1 diesel generator and #2 diesel generator are pressurized at the same time. Close the B4102 switch manually on site. The switch should be locked and cannot be closed.

[0075] ④B4001 switch locking logic verification:

[0076] a. Start the #1 diesel generator on the DCS. After 15 seconds, the B4001 switch should be able to close normally;

[0077] b. Press AC contactor 1ZJ to simulate the pressure on #2 diesel generator and start #1 diesel generator on DCS. After 15 seconds, switch B4001 should be locked and cannot be closed.

[0078] ⑤B4002 switch locking logic test

[0079] a. Start the #2 diesel generator on the DCS. After 15 seconds of pressure buildup, the B4002 switch should be able to close normally.

[0080] b. Press AC contactor 2ZJ to simulate the pressure on #1 diesel generator and start #2 diesel generator on DCS. After 15 seconds of pressure building up, switch B4002 should be locked and cannot be closed.

[0081] (5) Phase sequence check

[0082] In order to prevent the motor from reversing due to different phase sequences of the power supplies on each side, it is necessary to check the phase sequence of the power supplies on each side. The steps are as follows:

[0083] ①Disconnect switches B401a, B401b, B402a, B402b and B4101, and pull them out of the cabinet to expose the upper and lower static contacts inside the cabinet;

[0084] ② Use a phase sequence meter to measure the phase sequence of the static contacts on the 400V PC section side of the B401a, B401b, B402a, and B402b switches respectively;

[0085] ③ Start the #1 diesel generator and use a phase sequence meter to measure the phase sequence of the static contacts on the #1 diesel generator side of switch B401a, B401b, and B4101;

[0086] ④ Stop the #1 diesel generator, close the B4102 switch, start the #2 diesel generator, and use a phase sequence meter to measure the phase sequence of the static contacts on the #2 diesel generator side of the B402a, B402b, and B4101 switches;

[0087] ⑤All the above-mentioned measured phase sequences should be consistent, otherwise the phase sequence should be adjusted.

[0088] A diesel engine parallel generator, comprising

[0089] The above-mentioned diesel engine parallel generator control system is adopted; and a diesel generator applied to the above-mentioned diesel engine parallel generator control system.

[0090] The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

Claims

1. A diesel engine parallel generator control system, characterized in that: include #1 diesel generator, the outlet of the #1 diesel generator is connected to the B4001 switch, and the outlet of the B4001 switch is connected to the #1 machine security 400V PC (IA, IB) segment; #2 diesel generator, the outlet of the #2 diesel generator is connected to the B4002 switch, and the outlet of the B4002 switch is connected to the #2 machine security 400V PC (IIA, IIB) section; A parallel circuit, the parallel circuit is connected to the outlets of the #1 diesel generator and the #2 diesel generator, and the parallel circuit is provided with a B4101 switch and a B4102 switch; DCS configuration, the DCS configuration controls the #1 diesel generator and the #2 diesel generator to serve as backup for each other.

2. A diesel engine parallel generator control system according to claim 1, characterized in that: The incoming switches of the #1 machine safety 400V PC (IA, IB) section and the #2 machine safety 400V PC (IIA, IIB) section are both equipped with automatic power supply switching devices for power supply switching.

3. A diesel engine parallel generator control system according to claim 1, characterized in that: The #1 machine security 400V PC (IA, IB) section includes the #1 machine security 400V PC IA section and the #1 machine security 400V PC IB section. The #1 machine security 400V PC IA section and the #1 machine security 400V PC IB section are respectively connected to the #1 machine boiler 400V PC IA section and the #1 machine boiler 400V PC IB section, and are both connected to the #1 diesel generator.

4. A diesel engine parallel generator control system according to claim 3, characterized in that: The outlets of the #1 boiler 400V PC IA section and the #1 boiler 400V PC IB section are respectively connected to the B412a switch and the B412b switch, and the incoming lines of the #1 machine security 400V PC IA section and the #1 machine security 400V PC IB section are provided with B411 a switch and B411 b switch, the B411 a switch and the B412a switch are located on the same line, and the B411 b switch and the B412b are located on the same line.

5. A diesel engine parallel generator control system according to claim 3, characterized in that: The #1 machine security 400V PC IA section and the #1 machine security 400V PC IB section incoming lines are respectively connected with B401 a switch and B401 b switch, and the B401 a switch and the B401 b switch are located on the same line as the B4001 switch.

6. A diesel engine parallel generator control system according to claim 1, characterized in that: The #2 machine security 400V PC (IIA, IIB) section includes the #2 machine security 400V PC IIA section and the #2 machine security 400V PC IIB section. The #2 machine security 400V PC IIA section and the #2 machine security 400V PC IIB section are respectively connected to the #2 machine boiler 400V PC IIA section and the #2 machine boiler 400V PC IIB section, and are both connected to the #2 diesel generator.

7. A diesel engine parallel generator control system according to claim 6, characterized in that: The outlets of the #2 boiler 400V PC IIA section and the #2 boiler 400V PC IIB section are respectively connected to the B422a switch and the B422b switch, and the incoming lines of the #2 safety 400V PC IIA section and the #2 safety 400V PC IIB section are respectively provided with B421 a switch and B421 b switch, and the B421 a switch and the B422a switch are located on the same line, and the B421 b switch and the B422b switch are located on the same line.

8. A diesel engine parallel generator control system according to claim 6, characterized in that: The #2 machine security 400V PC IIA section and the #2 machine security 400V PC IIB section incoming lines are respectively connected with a B402a switch and a B402b switch, and the B402a switch and the B402b switch are located on the same line as the B4002 switch.

9. A diesel engine parallel generator control system according to claim 1, characterized in that: The B4101 switch and the B4102 switch are respectively equipped with AC contactors (1ZJ, 2ZJ).

10. A diesel engine parallel generator, characterized in that: include The above-mentioned diesel engine parallel generator control system is adopted; and a diesel generator applied to the above-mentioned diesel engine parallel generator control system.

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