SU1647758A1 - Method of control of power transfers between power systems - Google Patents

Abstract

The invention relates to power engineering and can be used to automatically regulate power flows through interconnection lines. To determine the location of the disturbance, the magnitude of the derivative of the voltage frequency on the power system tires and the derivative of the power flow are compared. If the first of the compared values is greater than the second disturbance takes place in the given power system. When the first value is less than the second disturbance occurred in the neighboring power system. The increment of the task to the regulating power plants, produced by the flow regulator, is made according to the parameters of a step change in the power of a number of power stations of the power system caused by the unbalance of the active power. This makes it possible to increase the speed of power flow control, which provides the basis for a more complete use of transmission capacity. 1 il. THX

Description

The invention relates to power engineering and can be used to automatically regulate power flows through interconnection lines.

The purpose of the invention is to increase the reliability and efficiency of the energy systems, achieved by using the new principle of quickly determining the location of the disturbance caused by the unbalance of the active power, and the increment value of the task for developing power at the regulatory power plants.

The drawing shows a diagram of the device that implements the method.

The device contains power system bus 1, which is adjoined by inter-system power transmission 2, power transmission 3. connected to the power system node, generator 4 of the power plant, active power control system 5 with unit 6 of the new power plant load, sensor 7 step change in power in the power system element, block 8 multiplying, adder 9, block 10 discrete increments of the task for power testing, regulator 11 of the power flow, block 12 of agreement, block 13 of the distribution of the task for power tests between the regulator the PV power plant yuschimi E, telecontrol channel 14, channel 15 Telemetering sensor 16 interconnection transmission power, the differentiator 17, the transmitter 18 frequency voltage on the buses 1 and comparison unit 19.

The method is carried out as follows.

With insignificant unbalances of active power in the power system, the regulation of the flow is carried out in the traditional way, according to which the power 16 is measured by the sensor 16 J 44 VJ

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power transmission 3, compare it with a predetermined value and change the power of regulatory power plants in proportion to the deviation of the power flow and its integral component. The magnitude of the power flow measured by sensor 16. is fed to the input of controller 11, which produces an increment of the task for power development at regulating power plants. The task increment is distributed by block 13 between the regulating power stations of the power system. Signals proportional to the increment of the task are transmitted via telecontrol channels 14 to the inputs of the setting units 6 of the unplanned load of the regulatory power plants.

The occurrence of a significant unbalance of power (for example, a shortage of power in the power system) causes a sharp change in the frequency of the voltage on tires 1, which is measured by sensor 18 and fed to the input of differentiator 17. At the same time, the power of power transmission 3 (sensor 16) is measured and fed to the input of the differentiator 17. The signals from the outputs of both differentiators are fed to the input of the device 19 of the comparison. Since a case of disturbance (power shortage) in this power system is considered, the voltage frequency on the tires is derived

Idf / dt is greater than the derivative of the power transmission flow 3 dPsn / dt, and the comparison device 19 generates a resolution signal, which is fed to the input of the flow controller 11 and the discrete increment block 10 of the task. The fulfillment of the df / dt dP3n / dt inequality confirms the fact of the unbalance of power in this power system .. Therefore, the regulator

I1 forms at its output a signal proportional to the deviation of the power flow and its integral component. Simultaneously with this, in the block. 10, a discrete increment signal of the reference is generated, which is summed with the output of the controller 11 in the adder 9.

If df / dt Rap / dt, which confirms the occurrence in the neighboring power system, device 19 generates a inhibitory signal. In this case, in the controller 11, the increment of the integral component of the flow deflection is blocked, and in block 10, the discrete increment of the reference is blocked. This ensures the selectivity of the controller in case of disturbance in the neighboring power system.

The formation of a discrete task in the event of a significant unbalance of power (deficit) is performed as follows.

The power imbalance is distributed between the power plants of the power system in proportion to their synchronizing power with respect to the point of disturbance. Each power station at the moment of disturbance experiences a stepped increment of power, which is detected by sensor 7. Through the telemetry channels 15, the recorded power increments are transmitted to multiplication units 8, multiplying the input parameter by the coefficient Ki (, m), reflecting the ratio of the magnitude of the step change in the power of the power stations in the energy system region topics to change this power station where this change is determined. The number of power plants hl (areas of the power system), which are installed sensors 7

stepwise change in power, less than the total number of power plants in the power grid n (t n), therefore Kj 1.0.

The output signals of blocks 8, proportional to the product of a stepwise change in the power of the power plant in the region of the power supply system L Pi by the coefficient Ki, are summed up in block 9. The block 10 of the discrete task increment produces a control action on the control power plants in accordance with the expression

 Kiapi

i 1

When the condition df / dt dP3n / dt is fulfilled, the increment signal of the value of D Pp is transmitted to the adder 9, where it is summed with the signal of the regulator 11. The amplification factors of the integral and proportional components of the regulator of the overflow are selected according to the conditions of stability of the overflow system. To increase the stability of this system, a differential component of the deflection flow can be used. The speed of regulation of the system for significant power imbalances is provided by the discrete generation unit 10.

increments of the task, proportional to the amount of unbalance. The specified increment of the task is formed after the disturbance and is ahead of the process of forming the task by the flow regulator. However, in spite of the high speed of the incremental development D Pp, there is a certain delay in the remote control channel 14 and the power plant control system 5. Even in the case of exact correspondence of the discrete task to the value

the actual unbalance of power due to the specified reasons there is a deviation of the flow from the specified value. In this case, the flow regulator forms its own task, which can lead to overshoot. To eliminate this discrepancy, a matching block 12 is installed at the input of the controller 11, which implements a prevented deviation of the controlled parameter

The output signals of the Yuiregul block 11 are summed (adder 9) and transmitted to the block 13 for the distribution of the task between the control power plants.

To fine-tune the generation of a task increment for random power fluctuations. not associated with significant unbalances, block 10 is supplied with a threshold element that prevents the formation of a task increment with the indicated power changes.

The emergence of unbalance of power causes a step change in the power of not only the power plants of the power grid, but also of the intersystem electricity transmissions. For example, if there is a shortage in the proposed power system, the condition df / dt Rap / dt must be met,

However, when a power shortage is formed at the first moment, the power is impacted, which leads to the violation of this inequality. Therefore, the differentiator 17, which differentiates the power flow, must be rebuilt from stepwise changes in the signals at its input using special filters.

Claims (1)

Invention Formula The method of regulating power flows between power systems containing regulating power plants and a power line connecting the power system bus, according to which power flows are measured, is compared with a predetermined value and proportional to the ratio of power flow and regulating power plants each power system, the frequency f of the voltage on the tires of each power system is measured, its df is determined derivative dt fix unbalance power in the adjacent power system and change the power of the regulating power plants in proportion to the deviation of the flow, characterized in that, in order to improve reliability and efficiency, the derivative of the flow transmission power .p and record the imbalance of power in the adjacent power system when -t-: measure the capacity of part of the regulatory power plants of the power grid areas, determine the stepwise change in their power A PI when the power imbalances, ep fix power imbalance in df d P: dt dt this power system, form when this value  iAPi, i - 1 where Ki is the proportionality coefficient reflecting the ratio of the magnitude of the step change in the power of the power plants in the region of the power grid to the change in this power of the power station where this change is determined; m - h, the number of areas of the power system, summarize this value with the deviation of the overflow and its integral component and change the power of the regulatory power plants in proportion to the amount received. sk Ihikex I I // 1-4 1-4 I PMZ "