CN117713250A - Parallel operation control system for multiple diesel generator sets - Google Patents

Abstract

The invention provides a parallel operation control system of a plurality of diesel generator sets, which comprises a diesel generator set and a control system, wherein the control system comprises a controller, a UPS (uninterrupted power supply), a double PLC (programmable logic controller), an industrial photoelectric converter and an HMI (human-machine interface); the control mode is divided into an automatic mode and a semi-automatic mode, when any commercial power is in voltage loss, the double PLCs output remote control start-stop signals to each diesel generating set, the outlet breaker switches are automatically switched on after the voltage and the frequency reach rated values at first, and the rest of automatic adjustment power generation voltages and frequencies are synchronous with the busbar, and the corresponding outlet breaker switches are switched on; the invention fully utilizes the inherent redundancy of the parallel operation of a plurality of diesel generators, one unit fails, the key load is redistributed among other units in the system according to the priority, and the reliability is higher; the system has accurate power management, reduces the damage of light load to the engine and the fuel consumption of heavy load, optimizes the system, has good expansibility and reduces the total operation cost.

Description

Parallel operation control system for multiple diesel generator sets

Technical Field

The invention relates to the technical field of diesel generator sets, in particular to a parallel operation control system of a plurality of diesel generator sets.

Background

In the prior art, most of application modes of the diesel generators are single large-capacity or parallel connection of a plurality of generators, and the situation that a single diesel generator fails or is checked regularly is frequently encountered in the application process, so that power failure accidents can be caused. The influence of the individual load on the grid-connected system is very small, the capacity of the grid-connected system is large, the investment and the shutdown of the machine set after grid connection are large, the voltage and the frequency for measuring the power supply quality can be regarded as constant, the problem can be solved by the intervention of the parallel operation system of the diesel generator, the power supply reliability and the power supply quality of the diesel generator are improved, and a reasonable control system is needed.

In the current control system of the diesel generator set, when the generator is adjusted to match the load requirement, it is generally difficult to accurately predict the increase of the load and fully plan the expected additional requirement. If the load prediction is too aggressive, the initial cost of the generator may be exceeded. On the other hand, if the load prediction is insufficient, reliable backup power may be lost, or expensive generator upgrades may have to be resorted to, even if another piece of equipment is purchased completely, without good expansibility. In addition, in the control of the generator set, the logic program has the conditions of unreasonable design, single start-stop mode, lack of system monitoring and temporary decision making capability and the like, and has low intelligent level, low operation efficiency and low cost.

Disclosure of Invention

In order to improve the reliability, expansibility and serviceability of diesel-electric power generation and reduce the cost benefit at the same time, the invention provides a multi-diesel-generator-unit parallel operation control system, which comprises a smoke exhaust system, an oil supply system, a grounding system, a diesel generator set and a control system, wherein the control system comprises a diesel generator set controller, a UPS (uninterrupted power supply), a double PLC (programmable logic controller), an industrial photoelectric converter and an HMI (human-machine interface);

the control system adopts a double PLC and HMI human-machine interface to communicate with an external interface of the diesel generating set system, and carries out logic control and state monitoring;

the control mode of the parallel operation control system is divided into an automatic mode parallel operation main control system and a semi-automatic mode parallel operation main control system;

the automatic mode parallel operation main control system monitors the states of four paths of commercial power in real time, when any path of commercial power is in voltage loss, after the delay setting time is reached, the double PLC outputs remote control start-stop signals to each diesel generator set, each diesel generator set has three start opportunities, and when the three start opportunities fail, the diesel generator set is withdrawn from the start sequence; the voltage and the frequency of the diesel generating set which is successfully started reach rated values first and then are automatically switched on to the outlet breaker switch, the other diesel generating sets which are successfully started automatically adjust the generating voltage and the frequency to be synchronous with the busbar, the corresponding outlet breaker switches are switched on after the synchronous operation, after the diesel generating set is successfully started, the number of the diesel generating sets is set, the parallel operation is successfully realized, the double PLC outputs a feeder cabinet switching-on signal, and the diesel generating set supplies power to a load according to power management.

Further preferably, the automatic mode parallel operation master control system is further provided with a power management module;

after the diesel generating set is loaded for 10min, the automatic mode parallel operation main control system automatically activates the power management module, and performs power management according to logic;

when the other line of commercial power fails, all the diesel generating sets which are not started are started, and the power management module is restarted after the parallel operation is successful in stabilizing the load;

when the automatic mode is stopped, the automatic mode parallel operation main control system receives all commercial power recovery signals, after delay confirmation, the load is automatically and stably transferred to the commercial power, and all started diesel generator sets enter a stopping sequence.

Further preferably, the power monitoring system of the data center is connected with the power system of the diesel generator set to perform remote data acquisition and monitoring, the diesel generator set controller and the HMI human-computer interface are accessed through a data transmission protocol port, and any diesel generator set is remotely monitored.

Further preferably, the industrial photoelectric converter uses optical fibers as transmission media to establish communication connection with the unit controller, and the industrial photoelectric converter is in communication connection with the double PLC and the HMI human-computer interface through network cables in a parallel operation master control cabinet monitoring room.

Further preferably, the dual PLCs comprise a first PLC and a second PLC, wherein the first PLC and the second PLC are connected by a switch in real time through ethernet communication, and the first PLC has on/off monitoring control authority for each switch of the feeder cabinet; the second PLC only has monitoring authority to the states of all the switches of the feeder cabinet, does not participate in control output, and only after the first PLC fails, the second PLC takes over the first PLC to participate in the monitoring control output of the feeder cabinet.

Further preferably, the dual PLCs of the automatic mode parallel operation master control system monitor the switch state of the incoming line cabinet of each diesel generating set, and when the automatic mode parallel operation master control system reaches the set parallel operation number, the dual PLCs can judge the switch state of each feeder line cabinet, and automatically complete the feeder line cabinet switch meeting the closing condition.

Further preferably, after the feeder cabinet switch is switched on, the automatic mode parallel operation main control system automatically distributes load power to all online units; the double PLCs monitor the position signals of the feeder cabinet switch at the same time, and the position states of the feeder cabinet switch can be synchronously displayed on the HMI in real time;

when the unit power of the automatic mode parallel operation main control system is lower than a set value, a unit incoming line cabinet switch is automatically disconnected, a double PLC of the automatic mode parallel operation main control system can automatically disconnect the feeder switches which are already switched on, and when all the feeder switches are switched off, the generator unit is disconnected;

the separated diesel generator set enters a cooling shutdown sequence, and the diesel generator set enters the next startup preparation sequence after shutdown.

Further preferably, the automatic mode parallel operation main control system is further provided with an emergency shutdown module, when the parallel operation main control system is in emergency shutdown or is triggered by an external emergency shutdown signal, all diesel generator sets enter a cooling shutdown sequence, and after shutdown, the sets enter a next parallel operation preparation sequence;

when an emergency stop signal of a single diesel generating set is triggered, the automatic mode parallel operation main control system immediately opens a corresponding set incoming line cabinet switch, and then cools and stops.

Further preferably, in the semi-automatic mode parallel operation master control system, the diesel generator set controller needs to be switched to a semi-automatic mode, and all actions of the diesel generator set need to be completed by manual operation;

whether the mains supply fails or not is surveyed; if the mains supply power failure accident occurs, starting all diesel generators;

when the diesel generator set needs to be started, a corresponding generator set starting button is pressed on an HMI human-machine interface of the parallel operation control system, when the generating voltage and the generating frequency of the diesel generator set are stable, a wire inlet cabinet switch of the diesel generator set is manually pressed, a wire inlet cabinet switch which needs to be closed is manually closed, the parallel operation control system cannot be automatically stopped in a semi-automatic mode, and manual operation is needed on the HMI human-machine interface;

the emergency shutdown process of the semi-automatic mode parallel operation master control system is the same as that of the automatic mode parallel operation master control system.

Further preferably, the shutdown operation steps of the parallel operation control system in the semiautomatic mode are as follows:

step 1, pressing a switch-off button of a wire inlet cabinet of a diesel generating set, and automatically transferring loads to other parallel operation generating sets by a parallel operation system when the switch of the wire inlet cabinet is disconnected;

and step 2, pressing a stop button of the diesel generating set, wherein the diesel generating set enters a cold cut stop sequence.

The invention provides a multi-mode parallel operation control system for a plurality of diesel generator sets, which is controlled in a full-automatic or semi-automatic mode, fully utilizes the inherent redundancy of parallel operation of a plurality of diesel generators, has a fault in one unit, and redistributes key loads among other units in the system according to priorities, thereby providing higher reliability. The parallel operation control system has accurate power management, reduces the damage of light load to the engine and the fuel consumption of heavy load, can accurately predict the increase of the load and fully plan the expected additional demand when adjusting the size of the generator to match the load requirement, avoids unnecessary waste, optimizes the system, reduces the cost and has good expansibility. The generator in the system of the present invention fails or requires maintenance, and the individual units can be disassembled and serviced without disrupting the function of the other units. The redundancy inherent in parallel systems provides multiple layers of protection and ensures uninterrupted power to critical circuits. Furthermore, in connection with monitoring solutions such as remote monitoring, the usage and performance data can be monitored for further analysis and intelligent decisions made regarding the optimal setting of the generators in parallel operation, thereby further reducing the overall operation costs during the whole operation.

Drawings

FIG. 1 is a flow chart of an automatic mode parallel operation master control system of the invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention provides a parallel operation control system of a plurality of diesel generator sets, which is applied to the parallel operation of the plurality of diesel generator sets, wherein the control mode is divided into an automatic mode parallel operation main control system and a semi-automatic mode parallel operation main control system, and aims to improve the intelligent level of control, realize good reliability and expansibility and improve the cost benefit and the control service. The parallel operation control system of the multiple diesel generator sets also comprises the diesel generator sets and a control system, and the parallel operation control system of the diesel generators of the data center by means of double PLC+HMI human-machine interfaces can complete centralized monitoring and redundant control of the sets.

The control system comprises a diesel generating set controller, a UPS power supply, a double PLC, an industrial photoelectric converter and an HMI human-computer interface; the control system adopts a double PLC and HMI human-machine interface to communicate with an external interface of the diesel generating set system, logic control and state monitoring. The industrial photoelectric converter uses optical fiber as transmission medium to establish communication connection with the unit controller, and the industrial photoelectric converter is in communication connection with the double PLC and HMI human-machine interface through network cable in the parallel operation master control cabinet monitoring room. The double PLCs comprise a first PLC and a second PLC, real-time Ethernet communication connection is established between the first PLC and the second PLC through a switch, and the first PLC has on/off monitoring control authority for each switch of the feeder cabinet; the second PLC only has the monitoring authority for each switch state of the feeder cabinet, does not participate in control output, and only after the first PLC fails, the second PLC takes over the first PLC to participate in the monitoring control output of the feeder cabinet.

Referring to the flow chart of the automatic mode parallel operation master control system of the invention in combination with the attached figure 1, in two control modes, the automatic mode parallel operation master control system monitors the state of four paths of mains supply in real time, judges that any path of mains supply is out of voltage (the out-of-voltage signal is on) in the state of being started and connected by a remote key in a monitoring center, after the set time of delay is reached, the double PLC outputs a remote control start-stop signal to each diesel generator set, the generator set receives a start-up signal to start up the generator set, judges whether the generator set is successfully started up or not, and each diesel generator set has three starting opportunities, and restarts if the generator set fails, and the diesel generator set exits the start-up sequence when the three starting fails; and judging whether the successfully started diesel generator set reaches a rated value, if the successfully started diesel generator set does not reach the rated value, the outlet breaker cannot be switched on, and when the voltage and the frequency reach the rated value at first, the outlet breaker switch is automatically switched on, and the rest successfully started diesel generator sets automatically adjust the generating voltage and the frequency to be synchronous with the busbar, and switch on the corresponding outlet breaker switch after synchronization. After the starting is successful, the diesel generator sets the number of the parallel machines to realize the parallel machines, the double PLC outputs a feeder cabinet closing signal, and the diesel generator sets supply power to the load according to power management.

The automatic mode parallel operation main control system is also provided with a power management module; after the diesel generator set is loaded for 10min, the automatic mode parallel operation main control system automatically activates the power management module, carries out power management according to logic, and the parallel operation system automatically adds and subtracts the number of machine sets according to the size of an output load, wherein the adding power percentage is 50%, the subtracting power percentage is 30%, and can obtain detailed adding and subtracting machine start-stop parameter data, the power of fourteen diesel generators is 1800KW, and the formula of a machine start flow is as follows: (n-1) ×pe×50%, specifically:

starting the second station: 1800×50% = 900KW, i.e. when the total load is greater than 900KW, starting the second station;

starting from the third stage: 1800×2×50% =1800 KW, i.e. the total load is greater than 1800 KW: 1800×3×50% =2700kw, i.e. when the total load is greater than 2700kw, the fourth stage is started;

starting with the fifth station: 1800×4×50% =3600 KW, i.e., when the total load is greater than 3600KW, the fifth table is started;

starting with the sixth station: 1800×5×50% =4500 KW, i.e. when the total load is greater than 4500KW, the sixth table is started;

starting from the seventh stage: 1800×6×50% =5400 KW, i.e. when the total load is greater than 5400KW, the seventh stage is started;

starting with the eighth station: 1800×7×50% =6300 KW, i.e. when the total load is greater than 6300KW, the eighth station is started;

starting with the ninth station: 1800×8×50% =7200 KW, i.e. when the total load is greater than 7200KW, starting with the ninth stage;

starting with the tenth station: 1800×9×50% =8100 KW, i.e. when the total load is greater than 8100KW, the tenth table is started;

starting from the eleventh station: 1800×10×50% =9000kw, i.e. when the total load is greater than 9000KW, starting at the eleventh station;

starting with the twelfth station: 1800×11×50% =9900 KW, i.e. when the total load is greater than 9900KW, the twelfth stage is started;

starting with thirteenth stage: 1800×12×50% =10800 KW, i.e. when the total load is greater than 10800KW, starting from thirteenth station;

starting at fourteenth: 1800×13×50% =11700 KW, i.e., the total load is greater than 11700KW, the fourteenth stage is started.

The shutdown flow formula: (n-1) ×pe×30%, specifically:

14 steps back to 13: (14-1) ×1800×30% =7020 KW, i.e., when the total load is less than 7020KW and each average is less than 501, 14 pieces are retracted to 13 pieces;

13 to 12: (13-1) x 1800 x 30% = 6480KW, i.e. when the total load is less than 6480KW, each average is less than 498, 13 stations are retracted to 12 stations;

12 to 11: (12-1) ×1800×30% =5940 KW, i.e., total load is less than 5940KW, and when each is less than 495 on average, 12 pieces are retracted to 11 pieces;

11 to 10: (11-1) ×1800×30% =5400 KW, i.e., when the total load is less than 5940KW and each of the average is less than 491, 11 pieces are retracted to 10 pieces;

10 to 9: (10-1) x 1800 x 30% = 4860KW, i.e. when the total load is less than 5940KW, and each of the average is less than 486, 10 pieces are retracted to 9 pieces;

9, backing to 8: (9-1) x 1800 x 30% = 4320KW, i.e. the total load is less than 5940KW, 9 are retracted to 8 when each is less than 480 on average;

8, backing to 7: (8-1) ×1800×30% =3780 KW, i.e., total load less than 5940KW, average each less than 473, 8 stations are retracted to 7 stations;

7, backing to 6: (7-1) x 1800 x 30% = 3240KW, i.e. total load less than 5940KW, average each less than 463, 7 were retracted to 6;

6, backing to 5: (6-1) ×1800×30% =2700kw, i.e., total load is less than 5940KW, and when each is less than 450 on average, 6 pieces are retracted to 5 pieces;

5 backing to 4: (5-1) ×1800×30% =2160kw, i.e., total load is less than 5940KW, 5 pieces are retracted to 4 pieces when each is less than 432 on average;

4, backing to 3: (4-1) ×1800×30% =1620 KW, i.e., when the total load is less than 5940KW and each of the average is less than 405, 4 pieces are retracted to 3 pieces;

3 back to 2: (3-1) x 1800 x 30% = 1080KW, i.e. the total load is less than 5940KW, 3 stations are retracted to 2 stations when each is less than 360 on average;

2 back to 1: (2-1) ×1800×30% =540 KW, i.e., the total load is less than 5940KW, and when each of the average is less than 270, 2 pieces are retracted to 1 piece.

Therefore, the power of start-stop operation of the diesel generating set can be obtained, and reasonable power management is realized.

In order to avoid the condition that the load is suddenly added to cause the generator set to swing, under the normal load condition, when the other line of commercial power fails, all the diesel generator sets which are not started are started, and the power management module is restarted after the load is successfully stabilized.

When the automatic mode is stopped, the automatic mode parallel operation main control system receives all commercial power recovery signals, after delay confirmation, the load is automatically and stably transferred to the commercial power, and all started diesel generator sets enter a stopping sequence.

The double PLC of the automatic mode parallel operation master control system monitors the switch state of the incoming line cabinet of each diesel generating set, and when the automatic mode parallel operation master control system reaches the set parallel operation number, the double PLC can judge the switch state of each feeder line cabinet, and automatically completes the feeder line cabinet switch meeting the closing condition. After the feeder cabinet switch is switched on, the automatic mode parallel operation main control system can automatically distribute load power to all online units; the double PLCs monitor the position signals of the feeder cabinet switch at the same time, and the position states of the feeder cabinet switch can be synchronously displayed on the HMI human-machine interface in real time.

When the unit power of the automatic mode parallel operation main control system is lower than a set value, a unit incoming line cabinet switch is automatically disconnected, a double PLC of the automatic mode parallel operation main control system can automatically disconnect the feeder switches which are already switched on, and when all the feeder switches are switched off, the generator unit is disconnected; the separated diesel generator set enters a cooling shutdown sequence, and the diesel generator set enters the next startup preparation sequence after shutdown.

The automatic mode parallel operation main control system is also provided with an emergency stop module, when the parallel operation main control system is in emergency stop or is triggered by an external emergency stop signal, all diesel generator sets enter a cooling stop sequence, and after the parallel operation main control system is stopped, the diesel generator sets enter a next parallel operation preparation sequence;

when an emergency stop signal of a single diesel generating set is triggered, the automatic mode parallel operation main control system immediately opens a corresponding set incoming line cabinet switch, and then cools and stops. All alarm information of the parallel operation control system can be dynamically displayed on a touch screen of the parallel operation main control monitoring system in real time.

In another semi-automatic mode parallel operation master control system, the diesel generator set controller is required to be switched to a semi-automatic mode, and all actions of the diesel generator set are required to be completed by manual operation.

Whether the mains supply fails or not is surveyed; if the mains supply power failure accident occurs, all diesel generators are started.

When the diesel generator set needs to be started, a corresponding generator set starting button is pressed on an HMI human-machine interface of the parallel operation control system, when the generating voltage and the generating frequency of the diesel generator set are stable, a wire inlet cabinet switch of the diesel generator set is manually pressed, a wire inlet cabinet switch which needs to be closed is manually closed, the parallel operation control system cannot automatically stop in a semi-automatic mode, and manual operation is needed on the HMI human-machine interface.

The emergency shutdown process of the semi-automatic mode parallel operation master control system is the same as that of the automatic mode parallel operation master control system.

The shutdown operation steps of the parallel operation control system under the semi-automatic mode are as follows:

step 1, pressing a switch-off button of a wire inlet cabinet of a diesel generating set, and automatically transferring loads to other parallel operation generating sets by a parallel operation system when the switch of the wire inlet cabinet is disconnected;

and step 2, pressing a stop button of the diesel generating set, wherein the diesel generating set enters a cold cut stop sequence.

The parallel operation control system of the multiple diesel generator sets can remotely monitor the parallel operation control system, the power monitoring system of the data center is connected with the power supply system of the diesel generator sets to remotely collect and monitor data, the diesel generator set controller and the HMI human-machine interface are accessed through a data transmission protocol port, the ModbusRTU485/TCP-IP data transmission protocol is adopted, and a user can remotely access the HMI human-machine interface and the diesel generator set controller through the ModbusRS485 or/TCP-IP port, so that the state and various parameters of the system can be remotely monitored, and any diesel generator set can be remotely monitored, including but not limited to the running/standby state and parameters, such as the running parameters, the state parameters, the parallel system state parameters, the running parameters, the alarm information and other real-time running parameters of the engine and the generator sets.

The invention provides a multi-mode parallel operation control system for a plurality of diesel generator sets, which is controlled in a full-automatic or semi-automatic mode, fully utilizes the inherent redundancy of parallel operation of a plurality of diesel generators, has a fault in one unit, and redistributes key loads among other units in the system according to priorities, thereby providing higher reliability.

The parallel operation control system has accurate power management, reduces the damage of light load to the engine and the fuel consumption of heavy load, can accurately predict the increase of the load and fully plan the expected additional demand when adjusting the size of the generator to match the load requirement, avoids unnecessary waste or loss of standby power supply caused by insufficient prediction, optimizes the system, reduces the cost and has good expansibility.

The generator in the system of the present invention fails or requires maintenance, and the individual units can be disassembled and serviced without disrupting the function of the other units. The redundancy inherent in parallel systems provides multiple layers of protection and ensures uninterrupted power to critical circuits.

Furthermore, in connection with monitoring solutions such as remote monitoring, the usage and performance data can be monitored for further analysis and intelligent decisions made regarding the optimal setting of the generators in parallel operation, thereby further reducing the overall operation costs during the whole operation.

Claims (10)

1. The parallel operation control system of the multiple diesel generator sets comprises a smoke exhaust system, an oil supply system and a grounding system, and is characterized by further comprising a diesel generator set and a control system, wherein the control system comprises a diesel generator set controller, a UPS (uninterrupted power supply), a double PLC (programmable logic controller), an industrial photoelectric converter and an HMI (human-machine interface);

the control system adopts a double PLC and HMI human-machine interface to communicate with an external interface of the diesel generating set system, and carries out logic control and state monitoring;

the control mode of the parallel operation control system is divided into an automatic mode parallel operation main control system and a semi-automatic mode parallel operation main control system;

the automatic mode parallel operation main control system monitors the states of four paths of commercial power in real time, when any path of commercial power is in voltage loss, after the delay setting time is reached, the double PLC outputs remote control start-stop signals to each diesel generator set, each diesel generator set has three start opportunities, and when the three start opportunities fail, the diesel generator set is withdrawn from the start sequence; the voltage and the frequency of the diesel generating set which is successfully started reach rated values first and then are automatically switched on to the outlet breaker switch, the other diesel generating sets which are successfully started automatically adjust the generating voltage and the frequency to be synchronous with the busbar, the corresponding outlet breaker switches are switched on after the synchronous operation, after the diesel generating set is successfully started, the number of the diesel generating sets is set, the parallel operation is successfully realized, the double PLC outputs a feeder cabinet switching-on signal, and the diesel generating set supplies power to a load according to power management.

2. The parallel operation control system of a plurality of diesel generator sets according to claim 1, wherein the automatic mode parallel operation main control system is further provided with a power management module;

after the diesel generating set is loaded for 10min, the automatic mode parallel operation main control system automatically activates the power management module, and performs power management according to logic;

when the other line of commercial power fails, all the diesel generating sets which are not started are started, and the power management module is restarted after the parallel operation is successful in stabilizing the load;

when the automatic mode is stopped, the automatic mode parallel operation main control system receives all commercial power recovery signals, after delay confirmation, the load is automatically and stably transferred to the commercial power, and all started diesel generator sets enter a stopping sequence.

3. The parallel operation control system of a plurality of diesel generator sets according to claim 1, wherein a power monitoring system of a data center is connected with a power supply system of the diesel generator sets for remote data acquisition and monitoring, and a data transmission protocol port is used for accessing a diesel generator set controller and an HMI man-machine interface for remote monitoring of any diesel generator set.

4. The parallel operation control system of a plurality of diesel generator sets according to claim 1, wherein the industrial photoelectric converter uses an optical fiber as a transmission medium to establish communication connection with a set controller, and the industrial photoelectric converter is in communication connection with a double PLC and an HMI man-machine interface through a network cable in a parallel operation master control cabinet monitoring room.

5. The parallel operation control system of a plurality of diesel generator sets according to claim 1, wherein the dual-PLC comprises a first PLC and a second PLC, real-time Ethernet communication connection is established between the first PLC and the second PLC through a switch, and the first PLC has on/off gate monitoring control authority for each switch of a feeder cabinet; the second PLC only has monitoring authority to the states of all the switches of the feeder cabinet, does not participate in control output, and only after the first PLC fails, the second PLC takes over the first PLC to participate in the monitoring control output of the feeder cabinet.

6. The parallel operation control system of a plurality of diesel generator sets according to claim 5, wherein the automatic mode parallel operation master control system is configured to monitor the switch states of the incoming line cabinets of the diesel generator sets, and when the automatic mode parallel operation master control system reaches a set number of parallel operation machines, the double PLCs determine the switch states of the incoming line cabinets, so as to automatically complete the switch of the incoming line cabinets meeting the closing condition.

7. The parallel operation control system of a plurality of diesel generator sets according to claim 6, wherein after the feeder cabinet switch is closed, the automatic mode parallel operation main control system automatically distributes load power to all online sets; the double PLCs monitor the position signals of the feeder cabinet switch at the same time, and the position states of the feeder cabinet switch can be synchronously displayed on the HMI in real time;

when the unit power of the automatic mode parallel operation main control system is lower than a set value, a unit incoming line cabinet switch is automatically disconnected, a double PLC of the automatic mode parallel operation main control system can automatically disconnect the feeder switches which are already switched on, and when all the feeder switches are switched off, the generator unit is disconnected;

the separated diesel generator set enters a cooling shutdown sequence, and the diesel generator set enters the next startup preparation sequence after shutdown.

8. The parallel operation control system of a plurality of diesel generator sets according to claim 1, wherein the automatic mode parallel operation main control system is further provided with an emergency shutdown module, when the parallel operation main control system is in emergency shutdown or an external emergency shutdown signal is triggered, all diesel generator sets enter a cooling shutdown sequence, and after shutdown, the diesel generator sets enter a next parallel operation preparation sequence;

when an emergency stop signal of a single diesel generating set is triggered, the automatic mode parallel operation main control system immediately opens a corresponding set incoming line cabinet switch, and then cools and stops.

9. The parallel operation control system of a plurality of diesel generator sets according to claim 1, wherein in the semi-automatic mode parallel operation master control system, the diesel generator set controller is required to be switched to a semi-automatic mode, and all actions of the diesel generator sets are required to be completed by manual operation;

whether the mains supply fails or not is surveyed; if the mains supply power failure accident occurs, starting all diesel generators;

when the diesel generator set needs to be started, a corresponding generator set starting button is pressed on an HMI human-machine interface of the parallel operation control system, when the generating voltage and the generating frequency of the diesel generator set are stable, a wire inlet cabinet switch of the diesel generator set is manually pressed, a wire inlet cabinet switch which needs to be closed is manually closed, the parallel operation control system cannot be automatically stopped in a semi-automatic mode, and manual operation is needed on the HMI human-machine interface;

the emergency shutdown process of the semi-automatic mode parallel operation master control system is the same as that of the automatic mode parallel operation master control system.

10. The parallel operation control system of a plurality of diesel generator sets according to claim 9, wherein the shutdown operation steps of the parallel operation control system in a semiautomatic mode are as follows:

step 1, pressing a switch-off button of a wire inlet cabinet of a diesel generating set, and automatically transferring loads to other parallel operation generating sets by a parallel operation system when the switch of the wire inlet cabinet is disconnected;

and step 2, pressing a stop button of the diesel generating set, wherein the diesel generating set enters a cold cut stop sequence.