SU1721703A1 - Method of automatic regulation of transfer of power between two power systems - Google Patents

Abstract

The invention relates to the current dynamic control range of power plants, which satisfies the requirements for the effective suppression of power flow oscillations, limited by the technological features of the thermal power plant. The method involves the use of consumer controllers to extend the adjustment range needed to suppress irregular power flow fluctuations. This determines the desired value of the adjustment range based on the expected level of power flow fluctuations. The setpoint of the flow regulator varies depending on the entered adjusting range of power plants and consumers-regulators, which increases the use of transmission capacity. 1 il.

Description

The invention relates to power engineering and can be used to automatically regulate the flow of power through a power line connecting the two power systems.

There is a known method for regulating the power flow over power transmission, according to which, in order to increase the stability of power transmission, the deviation of the controlled parameter is summed up with the parameter characterizing the excess moment of the power system 1.

However, this method does not take into account the magnitude of the predicted deviation of the flow when determining the control action of the regulating power plants (RES) connected to the flow control system. This reduces the use of transmission capacity.

There is also known a method for regulating the flow in which the selection of a control action is made taking into account the impending change in the random component of the power flow 2.

The disadvantage of this method is the lack of correction of the setpoint of the regulator of the overflow in it depending on the current dynamic range of the regulation of the RES, which reduces the reliability and efficiency of transmission.

The known method of automatic control of the flow, carried out by the impact on the change in the task of testing the power of the RES as a function of the deviation of the flow from the specified value and

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changing the setpoint of the flow regulator by the amount of the sum of the products of the current dynamic control range (TDRM) of each RES on the coefficient of influence of the RES power change on the power flow, on the factor of the RES share and on the reliability coefficient. At the same time, the magnitude of the TDRD of each RES is limited according to the conditions of operation of the heating and mechanical equipment. The magnitude of the TDRD is reduced if the increment of the power of the EFR occurs at a speed exceeding the planned 3.

The disadvantage of this method is the lack of orientation of the control system to effectively suppress the deviations of the power flow from the specified value. The speed of the system and the adjustment range for the change in the power of the RES should correspond to the parameters of the deviation of the flow. Failure to analyze the current values of the rate and depth of change of the flow can lead to an unreasonable increase in the setpoint of the flow regulator, which reduces the reliability of the power system.

The purpose of the invention is to increase the reliability and cost-effectiveness of the power system by determining the magnitude of the RADD, taking into account the required response rate of the change in the power of the RES, corresponding to the current values of the speed and depth of the flow change.

With insufficient TDRM of RES, corresponding to the required speed of flow control, it is necessary to expand it by introducing under the control of the controller of mobile objects capable of maintaining the balance of active power in the power system. Such objects should include consumer-regulators, which can significantly expand the DDR, used to suppress flow deviations. The latter allows, quite reasonably, to increase the setpoint of the flow regulator, which increases the use of transmission capacity.

To achieve this goal, the intersystem power transmission power is measured, compared to the setpoint and, in proportion to the sum of the received deflection of the power flow, its integral and differential components change the power of the regulatory power plants. In this case, the current dynamic range of adjustment is determined at each regulatory power plant and multiplies the specified range by the coefficient of influence

power changes for power flow and reliability factor. Then, the setpoint of the regulator of the flow is changed by the amount of the sum of these products Rd. For the preceding time interval, the rate of change of the power flow is determined by the expression

ten

vp Ci

where Ci is the proportionality coefficient; PI is the power load of the power system in the foregoing time interval, and the range implemented with the speed vp is used as the current dynamic control range of power plants. The value of the required control range of the flow is then determined from

20

Reg 6S2 GRG + DROP (t) + A RoP (t).

where C2 is a proportionality coefficient depending on the time of day;

DRop (t) is the magnitude of the prediction error of the regular component of the load on the power system in the preceding time interval; Lro p (t) - the magnitude of the prediction error irregular component

power system loads in the upcoming time interval.

After that, the value of the current dynamic control range of the consumer-controller is determined.

DRPR (Reg-Rd) / K8 Kn,

where K8 is the ratio of the power change of the consumer-regulator to the power flow; KN - the reliability coefficient, and develop the control

impact. on the introduction of the adjustment range DRPR. At the same time, the performance of the flow regulator is increased and the setpoint is additionally increased by the value of the RADU - Rd.

The drawing shows a scheme for implementing a method for automatically controlling power flow between two power systems.

The circuit contains a sensor 1 for power flow, setpoint adjuster 2 for flow control setpoint, element 3 for comparing flow with setpoint, differentiator 4, integrator 5, proportional organ 6, adder 7, distribution unit 8

controlling flow control regulator, remote control channel 9, regulating power station (RES) 10, system 11 for controlling the power of the consumer-regulator, consumer-regulator (PR) 12, setpoint 13 of the PR power, sensor 14 of the PR power, element 15 comparison, channel 16 for information transfer, adder 17 for TDRR RES, device 18 for fixing the load curve of the power system, block 19 for determining the magnitude of the rate of change of the power flow, block 20 for determining the magnitude of the span of irregular oscillations of the power flow, block 21 for determining the power flow bki forecast a regular grid load component unit 22 for determining the magnitude of the prediction error irregular load component, the adder 23, the block 24 for determining correction amount setting flow regulator unit 25 determine the magnitude TDDR consumer -regul torus.

The system of automatic control of power flow works as follows.

Sensor 1 measures the power flow, the value of which is compared in element 3 with a specified value (setpoint), which is set by unit 2. The flow deviation from element 3 is fed to differentiator 4, integrator 5 and proportional organ 6. Adder 7 forms a control effect on change power RES and PR, the implementation of the proportional-integral-differential law. The control action using block 3 is distributed between the RES

10 and PR 12 via remote control channels 9. The actual power of the PR is recorded by the sensor 14 and is compared on the device 15 with the value of the set power output by the setting unit 13. The system

11, the PR power control restricts the change in its power, which is determined by the control action of the flow regulator. The restriction is made according to the conditions of the PR operation technology and the possibility of compensating for undersupply (excessive consumption) of energy at subsequent time intervals.

The device 18 records a load graph of the power system Pi f (t). The ordinates of this graph (power load of the power system PI for the foregoing time interval) from device 18 arrive at blocks 19 and 20. In blocks 19, the magnitude of the change rate of the power flow vp is calculated, which depends on the coefficient Ci determined by the number of intersections of the irregular component its average flow. Since the number of intersections varies little from the power system mode, the rate of change of the flow Vp is determined almost exclusively by the power PL The value of the speed vp comes

to the adder 17, in which the TCDR of the RES is controlled at the required speed of adjustment. The magnitudes of the RDCs of the RES are transmitted over channels 16 and entered into the adder.

17. The latter produces the summation of only those values of TDRD, which can be implemented at the RES with the required speed Vp.

In block 20, a calculation is made

0 magnitude of the span of irregular oscillations

the power flow is Pp 6 Ca V P1, which is determined by the value of the power load of the power system in the previous time interval Pi and the coefficient C2, usually equal to 0.5 MW for the day period of the load curve and 0.25 MW 1/2 for the night period.

Block 21 calculates the error

0 is the prediction of the regular component of the load of the DRP (t) power system, which is determined in advance. The value of DP0 p (t) is a function of the ordinates of the load curve of the power system and varies throughout the day.

5 In block 22, the prediction error of the irregular component AP0n (t) is determined, which is also a function of the load pattern of the power system. The source of errors ДР0п (m.) And Л P0n (t)

0 is the fact that the rate of change of load within an hour of the load curve in five minute intervals in a series of cases is 3-4 times higher than the average hourly rate. This is especially true for sharp changes in the ordinate of the load graph. Under these conditions, power plants leading the load curve do not have time to track the increase (decrease) in power consumption, which is reflected in the change in overflow.

0 Forecast errors are calculated in advance, taking into account the analysis of the comparison of the predicted and actual load graphs for the past period.

In the adder 23, the value of the required control range of the flow Preg is determined as the sum of the parameters of the Pp, Pon W and AP0n (t) mode, which come to its input from the blocks 20-22.

Block 25 implements the operation of calculating the value of the current dynamic range of adjustment of the consumer-controller DRRp according to data received from adders 17 and 23. To obtain the parameter DRRr, it is necessary to take into account the influence factors Kv and

5 reliability KN (each of which is less than unity), increasing the power difference Reg-Pd to the required value. On channel 16, the control range DRR is transmitted to the power control system 11.

0

Consumer Regulator. The system 11 prepares an appropriate adjustment range for the ARC, sufficient to effectively suppress the deviation of the overflow caused by its irregular fluctuations and errors of load prediction.

In block 24, the correction value of the setpoint of the regulator of the flow of the switchgear unit is calculated according to the data obtained from adders 17 and 23. The difference of the parameters with its positive value is used to increase the setpoint of the regulator. At the same time, the setting device 2 performs an additional increase in the setpoint at the DU, which leads to an increase in the utilization of the capacity of the intersystem transmission. At the same time, an increase in the speed of the flow regulator along the control channel from block 25 to proportional 6, integral 5 and differential And regulator organs is made. The increase in speed is carried out by a corresponding change in the transmission coefficients of the indicated regulator organs. The transmission coefficients are determined based on the dynamic parameters of the control object — the consumer-controller and information transmission channels.

Thus, the implementation of the proposed method of automatic control of the flow makes it possible to increase the reliability and efficiency of the power system by increasing the use of transmission capacity. An additional increase in the setpoint of the flow regulator, leading to an increase in the power transmission load, is made possible by orienting the flow control system to effectively suppress flow deviations, including its irregular component. The latter is achieved by the fact that a consumer-regulator is introduced under the control of the flow regulator, which has a high response rate of power change and the required adjustment range. In addition, when determining the adjustment range, the RES takes into account only its component that, in terms of the speed of the change in power, meets the requirements for the effective suppression of flow deviations.

Claims (1)

Invention Formula Method for automatic control of power flow between two power sources five 0 five 0 The systems, according to which the intersystem power transmission power is measured, compare it with the setpoint and proportionally to the sum of the received deflection of the flow, its integral and differential components change the power of the regulating power plants, and the current dynamic range of control is determined at each regulating power plant, multiply the specified range on the coefficient of influence of the power change on the power flow and on the reliability coefficient, summarize these products for All regulatory power plants change the power flow setpoint by the sum of these products RD, characterized in that, in order to increase the reliability and efficiency in the operation of the power system, the rate of power flow change vp Cp V P, where Ci - coefficient of proportionality, Rc - power load of the power system in the foregoing time interval, as the current dynamic range of control of power plants use a range that is adjustable with speed vp, It determines the value of the required control range of the flow by the expression per  6С2 + APin (t) + DRop (T), where C2 is the proportionality coefficient, depending on the time of day; DRop (t) is the magnitude of the prediction error of the regular component of the load on the power system in the preceding time interval; DRop (t) is the value of the prediction error of an irregular component of the load of the power system in the preceding time interval, then the value of the current dynamic control range of the consumer-controller is determined DRP-p (1 / KVKn) (Reg-Rd), where KB is the coefficient of influence of the change in the power of the consumer-regulator on power flow; KN is the safety factor, and the power of the con- troller is changed by the value of the DRP, while the response time of the power change is increased and the power flow setpoint is further increased by the value of Py Reg-Rd.