An adaptive method for main bus voltage regulation in large hydropower stations

Abstract

A self-adaptive main bus voltage regulation method for a large hydropower station includes the following steps: Step 1, combining the main bus of the power station into different operation modes, and presetting the main bus voltage value range in AVC; Step 2, when AVC is running, determining the power station operation mode according to the power station operation parameters; Step 3, AVC reads the upper and lower limit values ​​of the main bus voltage under the current operation mode, and compares them with the current main bus voltage setting value, and adjusts the main bus voltage setting value according to the comparison result; Step 4, AVC calculates the power station target reactive value, and distributes it to each unit, and sends it to each unit LCU for execution through the upper and lower computer communication program. The self-adaptive setting of the main bus voltage of a large hydropower station is realized, and the AVC automatically adjusts it to ensure that the bus voltage is always within the range required by the power grid. Especially when the power system operation suddenly changes, the main bus voltage of the power station can be adjusted instantly, and the safety, stability and economy of the power station and power grid operation can be improved; and the requirements for the construction of new power systems can be better met.

Description

Technical Field

[0001] The invention relates to the technical field of main bus voltage control of a hydropower station, and in particular to an adaptive main bus voltage regulation method for a large hydropower station. Background Art

[0002] The operation mode of large hydropower stations is complex, and the main bus voltage control requirements are many. The bus voltage is controlled by the AVC program (automatic voltage control program). The conventional AVC voltage control mode is based on the changes in the flow, the number of units in operation, the operation mode of the main bus of the power station, the total load of the plant, etc. The voltage range required by the power grid is different, and the power station operators need to set the target voltage value to ensure that the voltage is within the range required by the power grid. With the continuous advancement of the construction of new power systems, the auxiliary service role of large hydropower stations in the system is becoming more and more important, and the operation mode will change more frequently. The number of times operators need to set the target voltage according to the changes in the range required by the power grid will increase significantly. However, the manual setting of the target voltage to participate in voltage regulation has lag and a large workload, which is not conducive to the safe and stable operation of the power grid.

[0003] At present, the main bus voltage control of large hydropower stations is carried out by the AVC program according to the voltage target value given by the power station operator, and the target reactive power of the AVC grid-connected units is calculated and sent to the LCU for execution. The power grid dispatcher puts forward different range requirements for the power plant bus voltage according to the split-bus operation mode, the number of unit generating stations, different transmission methods, etc. When the mode changes, the voltage set value may not meet the new range requirements. At this time, a new voltage set value needs to be set manually. The existing main bus voltage control method requires the operator to set the voltage target value. When the mode changes, the required limit range requirements also change and need to be reset. However, human participation in voltage regulation has lag, and increases the workload of operators. It is easy for the voltage set value to exceed the limit, which poses a great hidden danger to the safe and stable operation of the power grid. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an adaptive large-scale hydropower station main bus voltage regulation method to ensure that the power station main bus voltage is controlled within a predetermined range, thereby improving the safety, stability and economy of the power station and power grid equipment operation.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] An adaptive large-scale hydropower station main bus voltage regulation method comprises the following steps:

[0007] Step 1. Combine the main bus denominator / combined denominator, the number of power stations in operation, the total load of the power station, etc. into different operation modes, and pre-set the main bus voltage value range under the corresponding operation mode in AVC;

[0008] Step 2: When AVC is running, the power plant operation mode is determined according to the power plant operation parameters;

[0009] Step 3, AVC reads the upper and lower limit values ​​of the main bus voltage under the current operation mode, compares them with the current main bus voltage setting value, and adjusts the main bus voltage setting value according to the comparison result;

[0010] Step 4. AVC calculates the target reactive power value of the power station according to the new main bus voltage setting value, distributes it to each unit, and sends it to each unit LCU for execution through the upper and lower computer communication program.

[0011] The specific method for adjusting the main bus voltage setting value according to the comparison result in the above Step 3 is:

[0012] If the current main bus voltage setting value is higher than the upper limit of the main bus voltage under the current operation mode, the "upper limit of the main bus voltage under the current operation mode - 1" will be used as the new main bus voltage setting value;

[0013] If the current main bus voltage setting value is lower than the main bus voltage lower limit value under the current operation mode, the "main bus voltage lower limit value under the current operation mode + 1" will be used as the new main bus voltage setting value;

[0014] If the current main bus voltage setting value meets the current operating mode requirements, keep the main bus voltage setting value unchanged.

[0015] The above-mentioned AVC adds a "bus voltage set value automatic assignment function soft connection". When the "bus voltage set value automatic assignment function soft connection" is put into operation, if the bus voltage set value exceeds the required limit range, the bus voltage set value is automatically assigned using the Step 3 method. When the "bus voltage set value automatic assignment function soft connection" is exited, the bus voltage set value can only be set by the operator or the superior dispatcher.

[0016] The present invention provides an adaptive main bus voltage regulation method for a large hydropower station, which automatically identifies the current operation mode and reads the upper and lower limit values ​​of the main bus voltage under the corresponding mode, and reassigns the main bus voltage setting value after comparing the current voltage setting value with the upper and lower limit values, and then automatically adjusts it by the AVC program to achieve adaptive regulation of the main bus voltage of the large hydropower station. The bus voltage set value automatic assignment function and the manual setting function can be switched through the "bus voltage set value automatic assignment function soft connection". In terms of power station and power grid operation: the main bus voltage of the large hydropower station is adaptively set, and is automatically adjusted by the AVC to ensure that the bus voltage is always within the range required by the power grid, especially when the power system operation suddenly changes, the main bus voltage of the power station can be instantly adjusted to improve the safety, stability and economy of the power station and power grid operation; better meet the requirements for the construction of new power systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0018] Figure 1 This is a flow chart of the adaptive regulation of the main bus voltage of a power station according to the present invention;

[0019] Figure 2 It is a schematic diagram of the software interface of AVC in the present invention. DETAILED DESCRIPTION

[0020] like Figure 1 As shown in , an adaptive large-scale hydropower station main bus voltage regulation method includes the following steps:

[0021] Step 1. Combine the main bus denominator / combined denominator, number of power plant units in operation, total load of the power plant into different operation modes, and pre-set the main bus voltage value range under the corresponding operation mode in AVC;

[0022] Step 2: When AVC is running, the power plant operation mode is determined according to the power plant operation parameters;

[0023] Step 3, AVC reads the upper and lower limit values ​​of the main bus voltage under the current operation mode, compares them with the current main bus voltage setting value, and adjusts the main bus voltage setting value according to the comparison result;

[0024] Step 4. AVC calculates the target reactive power value of the power station according to the new main bus voltage setting value, distributes it to each unit, and sends it to each unit LCU for execution through the upper and lower computer communication program.

[0025] The specific method for adjusting the main bus voltage setting value according to the comparison result in the above Step 3 is:

[0026] If the current main bus voltage setting value is higher than the upper limit of the main bus voltage under the current operation mode, the "upper limit of the main bus voltage under the current operation mode - 1" will be used as the new main bus voltage setting value;

[0027] If the current main bus voltage setting value is lower than the main bus voltage lower limit value under the current operation mode, the "main bus voltage lower limit value under the current operation mode + 1" will be used as the new main bus voltage setting value;

[0028] If the current main bus voltage setting value meets the current operating mode requirements, keep the main bus voltage setting value unchanged.

[0029] The above-mentioned AVC adds a "bus voltage set value automatic assignment function soft connection". When the "bus voltage set value automatic assignment function soft connection" is put into operation, if the bus voltage set value exceeds the required limit range, the bus voltage set value is automatically assigned using the Step 3 method. When the "bus voltage set value automatic assignment function soft connection" is exited, the bus voltage set value can only be set by the operator or the superior dispatcher.

[0030] Example:

[0031] like Figure 2 As shown in the figure, it is the software interface of AVC, where:

[0032] Station control setting: The abbreviation of the main bus voltage station control setting value, which is the main bus voltage control target value. It can be automatically assigned by the AVC program or manually assigned by the staff.

[0033] Bus voltage setpoint automatic assignment function soft link: AVC program function soft link. When this link is put into operation, if the bus voltage setpoint exceeds the required limit range, the AVC program can automatically adjust the main bus voltage station control setting value to within the limit range.

[0034] According to the method of the present invention, the adjustment test is carried out:

[0035] Program offline test record

[0036] Test purpose: To check whether the program can automatically set the voltage limit according to the current plant operating conditions.

[0037] Test steps: 1) AVC open loop;

[0038] 2) “AVC enablement” investment;

[0039] 3) “Full voltage control” is put into use;

[0040] 4) "Voltage setting" is turned on;

[0041] 5) Simulate the modification of power station operating conditions to observe whether the voltage setting value of the entire plant meets the requirements;

[0042]

[0043] Test results: correct .

Claims

1. An adaptive method for regulating the main bus voltage of a large hydropower station, characterized in that: The steps include: Step 1. Combine the main bus denominator / combined denominator, number of power plant units, total load of the power plant into different operating modes, and pre-set the main bus voltage value range under the corresponding operating mode in AVC, and follow the table below: The XXXXXX in the total load of the power station is set according to the needs; Step 2: When AVC is running, the power plant operation mode is determined according to the power plant operation parameters; Step 3, AVC reads the upper and lower limit values ​​of the main bus voltage under the current operation mode, compares them with the current main bus voltage setting value, and adjusts the main bus voltage setting value according to the comparison result; Step 4. AVC calculates the target reactive power value of the power station according to the new main bus voltage setting value, distributes it to each unit, and sends it to each unit LCU for execution through the upper and lower computer communication program.

2. The adaptive main bus voltage regulation method of a large hydropower station according to claim 1, characterized in that: The specific method of adjusting the main bus voltage setting value according to the comparison result in Step 3 is as follows: If the current main bus voltage setting value is higher than the upper limit of the main bus voltage under the current operation mode, "the upper limit of the main bus voltage under the current operation mode - 1" is used as the new main bus voltage setting value; If the current main bus voltage setting value is lower than the main bus voltage lower limit value under the current operation mode, "the main bus voltage lower limit value under the current operation mode + 1" is used as the new main bus voltage setting value; If the current main bus voltage setting value meets the current operating mode requirements, keep the main bus voltage setting value unchanged.

3. The adaptive main bus voltage regulation method of a large hydropower station according to claim 2 is characterized in that: The AVC adds a "bus voltage set value automatic assignment function soft connection piece". When the "bus voltage set value automatic assignment function soft connection piece" is put into operation, if the bus voltage set value exceeds the required limit range, the bus voltage set value is automatically assigned using the Step 3 method. When the "bus voltage set value automatic assignment function soft connection piece" is exited, the bus voltage set value can only be set by the operator or the superior dispatcher.

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