阅读说明：本技术 一种发电厂电动机的辅助控制方法 (Auxiliary control method for power plant motor ) 是由 陈铁 汪长林 张彬桥 胡文斌 甘辉霞 甘露 于 2018-06-06 设计创作，主要内容包括：一种发电厂电动机的辅助控制方法,它包括以下步骤：1)启动电动机启动的模拟过程；2)厂用电拓扑分析模块分析电动机启动后厂用电的拓扑结构和电动机的启动属性；3)厂用电运行状态分析模块根据厂用电拓扑分析模块的信息计算启动电动机所在的厂用母线负荷和负荷裕度。4)决策模块综合厂用电拓扑分析模块和厂用电运行状态分析模块的信息,判定是否同意操作,并将意见传递给执行模块；5)执行模块确定启动或停止电动机。本发明的目的是要解决现有技术中,在电厂中,在使用互为备用的电动机时,容易出现厂用母线负荷分配严重不平衡,甚至会对厂用电造成严重冲击,危及厂用电的供电安全,甚至可能导致机组发生事故的技术问题。(An auxiliary control method for a power plant motor, comprising the steps of: 1) starting a simulation process of starting the motor; 2) the service topology analysis module analyzes the topology structure of service power and the starting attribute of the motor after the motor is started; 3) and the service power running state analysis module calculates the service bus load and the load margin where the starting motor is located according to the information of the service power topology analysis module. 4) The decision-making module integrates the information of the service topology analysis module and the service running state analysis module, judges whether to agree to the operation or not, and transmits the opinion to the execution module; 5) the execution module determines to start or stop the motor. The invention aims to solve the technical problems that in the prior art, when motors which are mutually standby are used in a power plant, the load distribution of a service bus is seriously unbalanced, even the service bus can be seriously impacted, the power supply safety of the service bus is endangered, and even the unit can be possibly caused to have accidents.)

1. An auxiliary control method for a power plant motor, comprising the steps of:

1) after receiving a signal for automatically starting and stopping the motor, the motor starting and stopping signal receiving end (5) sends a starting and stopping signal to the service topology analysis module (1) and starts a simulation process of starting the motor;

2) the service topology analysis module (1) analyzes the topology structure of service after the motor is started and the starting attribute of the motor; then, the result of the topology analysis and the starting attribute are respectively transmitted to an auxiliary power running state analysis module (2) and a decision module (3);

3) the service power running state analysis module calculates service bus load and load margin where the starting motor is located according to the information of the service power topology analysis module;

4) the decision module (3) integrates the information of the service power topology analysis module (1) and the service power running state analysis module (2), judges whether to agree to the operation or not, and transmits the opinion to the execution module (4);

5) and the execution module (4) integrates the signal of the automatic start-stop and the signal of the decision module (3) to determine to start or stop the motor.

2. The method for assisting control of a power plant motor according to claim 1, wherein in step 2), the result of the topology analysis includes two communication structures, the first structure being: a factory high-voltage transformer, a factory high-voltage bus, a high-voltage auxiliary motor, a factory low-voltage transformer, a factory low-voltage bus and a low-voltage auxiliary motor; the second structure is as follows: the starting properties of the motor comprise 2 types: long term startup and short term startup.

3. The auxiliary control method of a power plant motor according to claim 1, characterized in that: in step 3), specifically, the load of the service bus is counted, and the load calculation is started from the low-voltage bus, and the load of the low-voltage bus is counted according to the number of the motors working on the low-voltage bus; estimating the loss of the low voltage bus according to the load of the low voltage bus, and adding the loss and the load of the low voltage bus to obtain the total load of a low voltage bus low voltage loop of the high voltage bus; and adding the loads of all the low-voltage variable loops of the factory on the high-voltage bus and the load of the running high-voltage auxiliary motor to obtain the load of the high-voltage bus.

4. The auxiliary control method for a power plant motor according to claim 3, characterized in that in step 3), specifically, a load margin is calculated from the statistical load, the load margin = maximum capacity allowed for start-up — current load; safety margin = (load margin-capacity of starting motor)/maximum capacity allowed for self-starting.

5. The auxiliary control method for the motor of the power plant according to claim 3 or 5, wherein if the motor is a low-voltage auxiliary motor, the load and the safety margin of the plant-used low-voltage bus and the plant-used high-voltage bus are calculated; and if the high-voltage auxiliary motor is adopted, calculating the load and the safety margin of the factory high-voltage bus.

6. The power plant motor support control method according to claim 2, wherein in step 3), the bus bar safety determination rule is stored as: setting a threshold value of the load margin and a corresponding judgment standard, wherein the threshold value at least comprises the following 3 grades: a threshold value of 1, above which startup is not authorized; a threshold 2, greater than this value, less than threshold 1 agrees to a short-term start; less than threshold 2 agrees to start; making a decision on the starting of the motor, wherein the decision result comprises the following steps: agreeing to start, agreeing to short-term start and not agreeing to start; the rules are as follows: when the safety margin of the decision module (3) is less than the threshold value 2, the start is agreed; when the service topology analysis module (1) is started for a long time and the safety margin of the decision module (3) is smaller than the threshold value 2, the service topology analysis module agrees to start; when the service topology analysis module (1) is started in a short period, when the safety margin of the decision module (3) is larger than a threshold value 2 and smaller than the threshold value 1, the service topology analysis module agrees to be started in the short period; if the auxiliary motor is a low-voltage auxiliary motor, evaluating the safety margins of the factory low-voltage bus and the factory high-voltage bus; and if the high-voltage auxiliary motor is adopted, evaluating the safety margin of the factory high-voltage bus.

7. The auxiliary control method of a power plant motor according to claim 2, characterized in that in step 5), the execution module (4) employs the steps of:

1) the decision module (3) agrees to start, and when the comprehensive automatic start-stop signal is started, the starting is executed;

2) when the decision module (3) is started for a short time and the comprehensive automatic start-stop signal is started, starting is executed, and timing is started; if the comprehensive automatic start-stop signal is changed into stop within the timing range, stopping resetting; if the comprehensive automatic start-stop signal does not have a stop signal within the timing, sending a stop command to stop the motor and resetting the timing;

3) if the decision module (3) is not approved to be started, the module is not started.

8. The auxiliary control method of the power plant motor according to claim 1, characterized in that it employs an auxiliary control device of the power plant motor, the device comprises an auxiliary power topology analysis module (1), an auxiliary power running state analysis module (2), a decision module (3) and an execution module (4), the motor start/stop signal receiving end (5) is connected with the input ends of the auxiliary power topology analysis module (1) and the execution module (4), respectively, the auxiliary power topology analysis module (1) is connected with the input ends of the auxiliary power running state analysis module (2) and the decision module (3), the auxiliary power running state analysis module (2) is connected with the input end of the decision module (3), the output end of the decision module (3) is connected with the input end of the execution module (4), the output end of the execution module (4) is connected with the control end of the power plant auxiliary motor, the power station auxiliary motor comprises a high-voltage auxiliary motor and a low-voltage auxiliary motor; the service power topology analysis module (1) comprises a service power topology analysis module (8) and a service motor starting attribute analysis module (9) and is used for analyzing the service power topology structure and the starting attribute of the motor, wherein the starting attribute comprises 2 types: long-term startup and short-term startup; the service power running state analysis module (2) comprises a load calculation module (6) of the service bus and a safety margin calculation module (7) of the service bus, and is used for calculating the load and the safety margin of the service bus; the decision module (3) integrates the information of the service power topology analysis module (1) and the service power running state analysis module (2), judges whether to agree to the operation or not, and transmits the opinion to the execution module (4); and the execution module (4) integrates the signal of the automatic start-stop and the signal of the decision module (3) to determine to start or stop the motor.

Technical Field

The invention belongs to the technical field of motor control, and particularly relates to an auxiliary control method for a power plant motor.

Background

Auxiliary systems of hydraulic power plants such as oil, water and gas generally use 2 or more motors, and the motors are automatically started and stopped and work in turn under the control of an independent auxiliary control device or an automatic process. In general, the "main" motor works, and the "standby" motor stops; when the main motor can not finish work independently or has fault, the standby motor is started. In order to balance the working time of a plurality of motors in the same system, the auxiliary control system can alternate the mode of primary use or standby use according to the running time and the starting times of the motors; or the fixed primary or standby mode and the timing rotation. The former mode has higher automation degree and higher working efficiency, and is widely applied to large-scale hydraulic power plants at present.

The motors are powered by service buses, the motors in the same auxiliary machine system are mutually standby motors, and power supplies of the motors come from different service buses. Because each auxiliary engine system is independent from each other, the relevance of each system in the aspect of power supply is not considered, after long-time operation, the condition that the motor is supplied with power by a plurality of sections of buses in a centralized mode can occur, so that the load distribution of the service bus is seriously unbalanced, at the moment, if the motor is automatically started from the bus with heavier load, the service bus can be seriously impacted, the power supply safety of the service bus is endangered, and even the unit accident can be caused.

Disclosure of Invention

The invention aims to solve the technical problem that in the prior art, motors which are mutually standby in a power plant are automatically started to neglect the current unbalance of the load of a station bus, so that the power supply safety of station power is endangered.

The purpose of the invention is realized by the following steps: an auxiliary control method for a power plant motor, comprising the steps of:

1) after receiving a signal of automatically starting and stopping the motor, the motor starting and stopping signal receiving end sends a starting and stopping signal to the service topology analysis module, and starts a simulation process of starting the motor;

2) the service topology analysis module analyzes the topology structure of service after the motor is started and the starting attribute of the motor, and then transmits the topology analysis result and the starting attribute to the service operation state analysis module and the decision module respectively;

3) and the service power running state analysis module calculates the service bus load and the load margin where the starting motor is located according to the information of the service power topology analysis module.

4) The decision-making module integrates the information of the service topology analysis module and the service running state analysis module, judges whether to agree to the operation or not, and transmits the opinion to the execution module;

5) and the execution module integrates the signal of the automatic start-stop and the signal of the decision module to determine to start or stop the motor.

In step 2), the result of the topology analysis includes two connected structures, the first structure is: a factory high-voltage transformer, a factory high-voltage bus, a high-voltage auxiliary motor, a factory low-voltage transformer, a factory low-voltage bus and a low-voltage auxiliary motor; the second structure is as follows: the high-voltage transformer of factory-high-voltage bus-high-voltage auxiliary motor. The starting attributes of the motor include class 2: long-term startup and short-term startup;

in the step 3), counting loads and calculating load margins, wherein the load counting starts from the low-voltage bus, and the load of the low-voltage bus is counted according to the number of the motors working on the low-voltage bus; estimating the loss of the low voltage bus according to the load of the low voltage bus, and adding the loss and the load of the low voltage bus to obtain the total load of a low voltage bus low voltage loop of the high voltage bus; the load of all factory low transformer loops on the high-voltage bus is added with the load of the running high-voltage auxiliary motor to obtain the load of the high-voltage bus;

load margin-maximum capacity allowed for start-current load; safety margin is (load margin-capacity of starting motor)/maximum capacity allowed for self-starting.

If the voltage is the low-voltage auxiliary motor, calculating the load and the safety margin of the factory low-voltage bus and the factory high-voltage bus; and if the high-voltage auxiliary motor is adopted, calculating the load and the safety margin of the factory high-voltage bus.

The judgment rule for saving the bus safety is as follows: setting a threshold value of the load margin and a corresponding judgment standard, wherein the threshold value at least comprises the following 3 grades: a threshold value of 1, above which startup is not authorized; a threshold 2, greater than this value, less than threshold 1 agrees to a short-term start; less than threshold 2 agrees to start; making a decision on the starting of the motor, wherein the decision result comprises the following steps: agreeing to start, agreeing to short-term start and not agreeing to start; the rules are as follows: when the safety margin of the decision module is less than a threshold value 2, the decision module agrees to start; when the service topology analysis module is started for a long time and the safety margin of the decision module is smaller than a threshold value 2, the service topology analysis module agrees to start; when the service power topology analysis module is started in a short period, when the safety margin of the decision module is larger than a threshold value 2 and smaller than a threshold value 1, the service power topology analysis module agrees to the short-period starting; if the auxiliary motor is a low-voltage auxiliary motor, evaluating the safety margins of the factory low-voltage bus and the factory high-voltage bus; and if the high-voltage auxiliary motor is adopted, evaluating the safety margin of the factory high-voltage bus.

In step 5), the execution module synthesizes the signal of the automatic start-stop and the signal of the decision module, and adopts the following steps:

1) the decision module agrees to start, and when the comprehensive automatic start-stop signal is started, the starting is executed;

2) when the decision-making module is started for a short time and the comprehensive automatic start-stop signal is started, starting is executed and timing is started; if the comprehensive automatic start-stop signal is changed into stop within the timing range, stopping resetting; if the integrated automatic start-stop signal has no stop signal in the timing, a stop command is sent to stop the motor, and the timing is reset.

3) And if the decision module is not approved to be started, the decision module is not started.

When the motor is started in an automatic mode, the device simulates the starting of the motor in advance, evaluates the safety margin of the station service power after the starting, analyzes whether the starting of the motor can damage the power supply safety of the station service power, and can be started only when the power supply safety of the station service power is not damaged, otherwise, the motor is not started.

The device comprises an auxiliary power utilization topology analysis module, an auxiliary power utilization running state analysis module, a decision module and an execution module, wherein a motor start-stop signal receiving end is respectively connected with the auxiliary power utilization topology analysis module and the input end of the execution module, the output end of the auxiliary power utilization topology analysis module is respectively connected with the input ends of the auxiliary power utilization running state analysis module and the decision module, the output end of the auxiliary power utilization running state analysis module is connected with the input end of the decision module, the output end of the decision module is connected with the input end of the execution module, the output end of the execution module is connected with the control end of a power station auxiliary motor, and the power station auxiliary motor comprises a high-voltage auxiliary motor.

The service power topology analysis module comprises a service power topology analysis module and a service motor starting attribute analysis module, and the service power topology analysis module is used for analyzing a service power topology structure; the factory motor starting attribute analysis module is used for analyzing starting attributes of the motor.

The service power running state analysis module comprises a load calculation module of the service bus and a safety margin calculation module of the service bus, and is used for calculating the load and the safety margin of the service bus.

By adopting the technical scheme, the following technical effects can be brought:

1) when the motor needs to be started, before formal starting, the starting process of the motor is simulated in advance, and the safety margin of auxiliary power after the motor is started is calculated.

2) The impact of the starting to the service power is evaluated through the pre-starting simulation, the evaluation effect is used as a necessary condition for starting the motor, and the starting of the motor is allowed only when the starting cannot damage the power supply safety of the service power.

3) The device can be flexibly added into the original system and used together with the existing automatic device. The automatic device guarantees that the original automatic control function can be normally implemented, and when the automatic device sends an instruction to start the motor, the device is started to evaluate the safety margin of the service power, so that the safety of service power operation is effectively improved.

Drawings

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

fig. 1 is a schematic structural diagram of a control device in the present invention.

FIG. 2 is a schematic diagram of a service power topology.

Detailed Description

As shown in fig. 1, an auxiliary control device for a power plant motor includes an auxiliary power topology analysis module 1, an auxiliary power running state analysis module 2, a decision module 3 and an execution module 4, wherein a motor start/stop signal receiving terminal 5 is connected to the input terminals of the auxiliary power topology analysis module 1 and the execution module 4, the output terminal of the auxiliary power topology analysis module 1 is connected to the decision module 3 and the input terminal of the auxiliary power running state analysis module 2, the output terminal of the auxiliary power running state analysis module 2 is connected to the input terminal of the decision module 3, the output terminal of the decision module 3 is connected to the input terminal of the execution module 4, the output terminal of the execution module 4 is connected to the control terminal of a power station auxiliary motor, and the power station auxiliary motor includes a high-voltage auxiliary motor and a low-voltage auxiliary motor.

Specifically, the service topology analysis module 1 includes a service topology analysis module 8 and a service motor start attribute analysis module 9, and the service topology analysis module 8 and the service motor start attribute analysis module 9 are configured to analyze a service topology structure and a start attribute of the motor.

Specifically, the service power operation state analysis module 2 includes a load calculation module 6 of the service bus and a safety margin calculation module 7 of the service bus, and is configured to count the load of the service bus and calculate the safety margin.

When in use, the following steps are adopted:

(1) when the motor is started or stopped, a motor start-stop signal receiving end receives a signal of automatic start-stop of the motor, sends a start-stop signal to the service topology analysis module 1, and starts the service topology analysis module 1;

(2) and if the motor is stopped, the service topology analysis module 8 in the service topology analysis module 1 updates the current topology structure and directly exits.

(3) If the motor is started, a plant motor starting attribute analysis module 9 in the service power topology analysis module 1 determines the starting attribute of the motor according to the method in the step 2), and the step (4) is carried out;

(4) the service topology analysis module 8 in the service topology analysis module 1 forms a communication relation;

(5) transmitting the starting attribute of the motor in the step (3) to a decision module 3;

(6) transmitting the communication relation in the step (4) to a service power running state analysis module 2;

(7) after the load calculation module 6 of the service bus in the service power operation state analysis module 2 receives the communication relation in the step (6), the load of the bus is counted;

(8) a safety margin calculation module 7 of the service bus in the service power operation state analysis module 2 calculates a load margin according to the result of the step (7);

(9) transmitting the load margin obtained in the step (8) to a decision module 3;

(10) the decision module 3 integrates the starting attribute of the motor in the step (5) and the load margin in the step (8), integrates rules to evaluate the safety margin of the bus and determines whether to approve the starting;

(11) sending the evaluation opinions in the step (10) to an execution module 4;

(13) and (4) integrating the opinion of the step (11) and the signal execution of automatic start-stop.