RU2730245C1 - Method for determination of inoperative generator unit - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to the field of electric engineering, in particular to technical diagnostics, and can be used for determination of inoperative generating unit (GU) in ship power plants. Technical result is achieved due to the fact that loading of each operating GU is measured, arithmetic mean value of working GU loading is calculated, determining the GU, loading of which decreases, determining deviation value of loading of this GU from the arithmetic mean value of loadings and at the moment when this value begins to increase and exceed the allowable value, the diagnosed GU is identified as inoperative.

EFFECT: reduced time for diagnosing the unit.

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Description

The invention relates to the field of technical diagnostics and can be used to determine an inoperative generator unit (GA) in ship power plants.

There is a known method for determining an inoperative GA (Yakovlev G.S. Ship electric power systems: Textbook-5th ed., Revised. And additional - Leningrad, Shipbuilding, 1987.-272s. Ill. (P. 132), according to which, with parallel the operation of several sources of electricity, the source of electricity is identified, which has passed into the motor mode of operation, and after a time delay it is recognized as inoperative.

The method as a whole provides for the determination of an inoperative HA with the parallel operation of several HA, but since the identification of an inoperable HA is carried out not at the moment of failure and transition to the motor mode, but with a predetermined time delay, this method allows a great inaccuracy in determining the moment of a change in the technical state with operable to inoperative, which, when applied, for example, in protective equipment, can lead to untimely shutdown of the GA, overload of the operating GA and de-energization of the vessel. In this case, the value of the time delay is determined, as a rule, by the time of energy recuperation into the network during the operation of ship cranes, cargo winches and other lifting and transport equipment on board the vessel and can reach, according to the Rules of the Russian Maritime Register of Shipping, 10 seconds (Rules for the classification and construction of marine courts, 2016, p56, clause 8.2.4).

Closest to the proposed invention is a method for determining an inoperative generator set according to patent No. 2686103, publ. 04/24/2019, according to which, during the parallel operation of several GAs, the load of each of the GAs is measured, the amount of uneven loading of the generating sets is determined, the moment of deviation of the latter beyond the set tolerance limits and the moment of transition of the GA into the motor mode is determined units outside the tolerance limits, the GA, which has switched to the motor mode, is recognized as inoperative.

This method as a whole provides the definition of an inoperative GA when several GAs work in parallel. However, since the identification of an inoperative HA is carried out at the moment of the transition of an inoperative HA to the motor mode, the diagnostic time includes the interval during which the HA load decreases from the load at the time of the defect to the complete unloading of the HA and its transition to the motor mode.

The proposed invention makes it possible to solve the problem of reducing the time for diagnosing the unit by identifying an inoperative HA before the transition to the motor mode of operation.

To solve this problem, the following set of essential features is used: in the method for determining an inoperable GA, which consists in measuring the load of each GA, additionally calculating the arithmetic mean value of the load of working GAs, determining the GA, the load of which decreases, determining the deviation of the load of this GA from the arithmetic mean loads, and at the time when this deviation value is positive, starts to increase and exceeds the allowable value, this GA is identified as inoperative.

The essence of the invention lies in the fact that the definition of an inoperative HA is carried out not when it is completely unloaded and switched to the motor mode, but somewhat earlier, when, after the occurrence of a defect, its load and the power it develops begins to decrease, and the load of the remaining operable units begins to increase. In this case, the arithmetic mean of the loads of the working HA is determined and the deviation of the HA load is calculated, the load of which decreases from the arithmetic mean of the HA loads. Since the arithmetic mean of the GA loads remains constant, and the load of the inoperative GA will decrease, the load deviation value will begin to increase and exceed the allowable value, then if the deviation value is positive, then this GA will be defined as inoperative.

Comparison of the proposed method and the prototype showed that the task - to reduce the diagnosis time by identifying an inoperative HA until the transition to the motor mode of operation is solved as a result of a new set of features, which proves the compliance of the proposed invention with the "novelty" criterion of patentability.

In turn, the conducted information search in the field of power supply and technical diagnostics did not reveal solutions containing individual distinctive features of the claimed invention, which allows us to conclude that the method meets the criterion "inventive step".

The essence of this method is illustrated by an image of a functional diagram of a device that implements the proposed method, using the example of parallel operation of "n" GA.

The device for determining an inoperative GA (Fig.) Contains: by the number of GA: load sensors GA1.1, 1.2 ... 1.n, control units for the operation of the corresponding GA 2.1, 2.2 ... 2.n, load reduction control units 3.1, 3.2 ... 3.n ,, subtraction units 4.1, 4.2,… 4.n, controlled keys 5.1, 5.2,… 5.n, signal increase control units 6.1, 6.2,… 6.n, threshold units 7.1, 7.2,… 7.n, logic gates "I" 8.1, 8.2, ... 8.n, as well as a block for calculating the arithmetic mean value 9, and the outputs of the GA load sensors 1.1, 1.2 ... 1.n are connected to the inputs of the corresponding load reduction control units 3.1, 3.2 ... 3.n, with the second the inputs of the corresponding subtraction blocks 4.1, 4.2, ... 4.n, and corresponding from the first inputs of the arithmetic mean value calculation unit 9, the outputs of the GA operation control units 2.1, 2.2 ... 2.n are connected to the corresponding from the second inputs of the arithmetic mean value calculation unit 9, the output of which connected to the first inputs of subtraction blocks 4.1, 4.2, ... 4.n, the outputs of the block subtraction covs 4.1, 4.2,… 4.n are connected to the information inputs of the corresponding controlled keys 5.1, 5.2,… 5.n, the outputs of the load reduction control units 3.1, 3.2 ... 3.n are connected to the control inputs of the corresponding controlled keys 5.1, 5.2, ... 5.n, whose outputs are connected to the inputs of the corresponding signal increase control units 6.1, 6.2, ... 6.n and threshold blocks 7.1, 7.2, ... 7.n, the outputs of which are connected to the second inputs of the corresponding logical elements "AND" 8.1, 8.2, ... 8.n, the outputs of the signal increase control units 6.1, 6.2, ... 6.n are connected to the first inputs of the corresponding logical elements "AND" 8.1, 8.2, ... 8.n.

GA load sensors 1.1, 1.2 ... 1.n are well-known functional blocks that generate at their output signals in the form of a DC voltage proportional to the load of the GA (the load of the network that this GA takes on). Blocks for monitoring the operation of GA 2.1, 2.2 ... 2.n are known functional blocks that generate a logical "1" signal at their output, if this GA is working and a logical "0" signal in the opposite case. As these blocks can be used a block of contacts of generator automatic machines of the corresponding GA. Load reduction control units 3.1, 3.2 ... 3.n are known functional blocks that generate a logical "1" signal at their outputs when the signal in the form of a voltage at their inputs decreases and a logical "0" signal in the opposite case. Subtraction blocks 4.1, 4.2, ... 4.n are known functional blocks that generate signals at their outputs in the form of voltage proportional to the difference between the signals at the first and second inputs. They can be based on operational amplifiers. Controlled keys 5.1, 5.2, ... 5.n are known functional blocks, at the output of each of which, at the moment of the appearance of a logical "1" signal, at its control input, a signal appears at its information input (Volovikov V.A. automation. Textbook. 1986. p. 61, fig. 27). Signal increase control units 6.1, 6.2, ... 6.n are known functional blocks that generate logic "1" signals at their outputs if the signals at their inputs increase. They can be based on operational amplifiers. Threshold blocks 7.1, 7.2, ... 7.n are known functional blocks that generate a logical "1" signal at their outputs, if their inputs contain signals that exceed the threshold (permissible) value and a logical "0" signal in the opposite case. They can be based on operational amplifiers. Logic elements "AND" 8.1, 8.2, ... 8n are known functional blocks that generate logic "1" signals at their outputs if logic "1" signals are received at all their inputs and signals of logic "0" in the opposite case. The arithmetic mean calculator 4 is a well-known functional block that generates at its output a signal proportional to the value of the sum of signals in the form of voltages arriving at its first inputs, divided by the number of second inputs to which the logical "1" signals were received. It can be based on operational amplifiers.

A device for determining an inoperative GA, which implements the proposed method, operates as follows. Suppose that during the parallel operation of the generating sets, one of them failed, for example, the j-th one due to the failure of the fuel supply system. In this case, the load of the inoperative unit will begin to decrease, and the load of the rest of the operating HA will begin to increase. In this regard, the signal at the output of the load sensor 1.j decreases, and at the outputs of the remaining load sensors 1.1, 1.2 ... 1.n - increases. These signals are fed to the first inputs of the block for calculating the arithmetic mean value 9, to the second inputs of which the signals of logical "1" are received from the outputs of the blocks for monitoring the operation of the corresponding GA 2.1, 2.2 ... 2.n, if the generators are working and the signals of the logical "0", if they are not are working at the moment. At the output of block 9, a signal is generated that is proportional to the arithmetic mean of the load of the working HA (Rav.arithm.) And goes to the first inputs of subtraction units 4.1, 4.2, ... 4.n. Signals proportional to the load of the corresponding HA (P1, P2… Pj,… Pn) from the load sensors 1.1, 1.2… 1.n are fed to the inputs of the corresponding load reduction control units 3.1, 3.2… 3.n and the second inputs of the corresponding subtraction units 4.1, 4.2 ,… 4.n, at the outputs of which signals appear proportional to the deviation of the load of the corresponding GA from the arithmetic mean value. These signals are fed to the information inputs of the corresponding controlled keys 5.1, 5.2, ... 5.n. In this case, a logical "1" signal appears at the output of the load reduction control unit 3.j and is fed to the control input of the controlled key 5j, the information input of which receives a signal proportional to the value of the load deviation of the j-th GA from the arithmetic mean value Rotkl.j = Pavarithm ... - Pj from the output of the subtraction block 4j. At the output of the controlled key 5j, the signal Rotkl.j = Pav.arithm is generated. - Pj and is fed to the inputs of the signal increase control units 6j and the threshold unit 7j. Since Рj decreases, and Рav.arithm. does not change its value, then Rotkl.j increases. At the same time, a logical "1" signal appears at the output of the control unit for increasing the signal 6j and is fed to the first input of the logical element "AND" 8j. At the moment when Rav.arithm. will exceed the value of Pj and Rotkl.j will become greater than the permissible value, at the output of the threshold unit 7j, a logical "1" signal will appear and go to the second input of the logical element "AND" go GA.

Since the load of the rest of the GA increases, then at the outputs of all other control units for reducing the load 3.1, 3.2 ... 3.n - a logical "0" signal, the corresponding controlled keys are closed and signals from their information inputs to the outputs are not received, and, therefore, do not increase. Therefore, at the outputs of the corresponding control units for increasing the signal 6.1, 6.2, ... 6.n - signals of logical "0", which are fed to the first inputs of the corresponding logical elements "AND". At their outputs - signals of logical "0", informing about the operable state of the corresponding GA.

If at the same time with the j - th GA the fuel system also fails on the i - th GA, then its load will also begin to decrease. At the output of the corresponding control unit for reducing the load 3i, a logical “1” signal will appear and from its output it will be fed to the control input of the controlled key 5i, at the output of which a signal will appear proportional to the deviation of the load of the i-th GA from the arithmetic mean value Rotkl.i = Pav.arithm ... - Pi from the output of the subtraction block 4i. Since Рi decreases, and Рср.arithm. does not change its value, then Rotkl.i increases. In this case, at the output of the control unit for increasing the signal 6i, a logical "1" signal appears and enters the first input of the logical element "AND" 8i. At the moment when Rav.arithm. will exceed the value of Pi and Rotkl. i will become greater than the permissible value, a logical "1" signal will appear at the output of the threshold block 7i and will be fed to the second input of the logical element "AND" 8i, at the output of which a logical "1" signal will be generated, informing about the inoperability of i- go GA.

The device, the functional diagram of which is shown in Fig., Fully implements the proposed method for determining an inoperative GA:

Block 3 determines the GA, the load of which decreases;

Block 9 generates a signal proportional to the arithmetic mean of the load of the working HA;

Subtraction unit 4 determines the deviation of the GA load from the arithmetic mean;

Block 6 determines the moment when the deviation of the HA load from the arithmetic mean value increases;

Block 7 determines the moment when the deviation of the GA load from the arithmetic mean value will be greater than a positive allowable value;

Logic element "AND" generates at its output a signal of logical "1" informing about the inoperative state of the GA, at the time when its load decreases, when the deviation of the GA load from the arithmetic mean value increases and the deviation of the GA load from the arithmetic mean value will be greater than the allowable values.

An example of the implementation of the method.

As an example of the application of the method, consider the operation of a ship power plant consisting of two diesel generators DG1 and DG2 with a rated power of 100 kW each. Suppose that with parallel operation of these GA, the load of DG1 will be 64kW, and the load of DG2 will be 60kW. The permissible accuracy of the distribution of active loads (Pdop.) Is 10% of the nominal power of the DG, that is, Pdop. = 10 kW in this case. Signals proportional to the load of the first and second DG will be generated by load sensors 1.1 and 1.2, respectively, will be fed to the inputs of the load reduction control units 2.1 and 2.2, to the second inputs of subtraction units 4.1 and 4.2, the first and second of the first inputs of the arithmetic mean value calculation unit 9, to the first and second of the second inputs of which the logical "1" signals are received from the outputs of the operation control units 2.1 and 2.2. At the output of block 9, a signal is generated that is proportional to Rav arithm. = (64 + 60) / 2 = 62 kW, which is fed to the first inputs of subtraction units 4.1 and 4.2. A signal about the load value of the first GA from the output is sent to the second input of the subtraction unit 4.1. block 1.1 (64 kW), and to the second input of the subtraction block 4.2 - from the output of block 1.2 (60 kW). At the output of the first block of subtraction, a signal is generated that the load of the first HA deviates from the arithmetic mean value Rotkl. 1 = Rav.arithm. -P1 = 62-64 = -2kW, which is fed to the information input of the first controlled key 5.1, to the control input of which the signal from the output is received first load reduction control unit 3.1. At the output of the second block of subtraction, a signal is generated about the deviation of the load of the second GA from the arithmetic mean value Rotkl. 2 = Rav arithm. -P2 = 62-60 = 2 kW, which is fed to the information input of the second controlled key 5.2, to the control input of which a signal is received from output of the second load reduction control unit 3.2. Let us assume that there was a loss of performance of the DG2 prime mover caused by the failure of the fuel pump and the cessation of fuel supply to the diesel engine. Then the load of DG2 will begin to decrease, and the load of DG1 will increase. Suppose that the load of the second HA has decreased to 50 kW, then a signal proportional to 12 kW (62-50 = 12 kW) will appear at the output of the second subtractor and the information input of the second controlled key. In this case, the signal at the output of the load sensor of the first DG 1.1 will increase, and at the output of the sensor 1.2 - decrease, at the output of the load reduction control unit 3.1, the logical "0" signal will not change its value, and the logical "1" signal will be generated at the output of block 3.2 ... The logical "1" signal from the output of the load reduction control unit 3.2 will be fed to the control input of the second controlled key 5.2 and a signal from the information input will appear at its output, proportional to Rotkl.2 = 12 kW. This signal is fed to the inputs of blocks 6.2 and 7.2, at the outputs of which signals of a logical "1" are generated, since the value of Rotkl.2 increases and has exceeded the permissible value of 10 kW. When a logical "1" signal arrives at both inputs of the logical element "AND" 8.2, a logical "1" signal appears at its output, informing about the inoperative state of DG2. Since the load of DG1 increases and a logical "0" signal remains at the output of the load reduction control unit 3.1, the first controlled key 5.1 is closed, the signal at its output does not change and is less than the permissible value, at the outputs of blocks 6.1 and 7.2 - a logical "0" signal , at the output of the logical element "AND" 8.1 - a signal of the logical "0", informing about the operable state of DG1.

When implementing the method taken as a prototype, in this case, identification of an inoperative state does not occur, both units are defined as operable. By means of the method taken as a prototype, DG2 will be considered out of order only when it is unloaded and the load on DG1 is 124 kW, that is, later than in the proposed method.

The proposed invention was created in the process of developing a prototype device for diagnosing generator sets in the process of operation, carried out by the Department of Electric Drive and Electrical Equipment of Coastal Installations of the GUMRF named after Admiral S.O. Makarov. Calculations were carried out and a working model of a device that implements the claimed method was made, laboratory tests of which showed the possibility of using this method in systems for monitoring the technical condition of ship's electric power systems, which, taking into account the above, allows us to conclude about the possibility of its industrial application.

Claims (2)

1. A method for determining an inoperative generator unit (GA), which consists in measuring the load of each operating GA, characterized in that the arithmetic mean value of the load of the operating GA is additionally calculated, the GA is determined, the load of which decreases, the deviation of the load of this GA from the arithmetic mean value is determined downloads and at the time when this value begins to increase and exceeds the allowable value, this GA is identified as inoperative. 2. A method for determining an inoperative generator set (GA) according to claim 1, characterized in that for its implementation, a device is used containing, according to the number of GAs: GA load sensors, control units for the operation of the corresponding GA, load reduction control units, subtraction units, controlled keys , signal increase control blocks, threshold blocks, logical elements "AND", as well as a block for calculating the arithmetic mean value, and the outputs of the GA load sensors are connected to the inputs of the corresponding load reduction control units, with the second inputs of the corresponding subtraction blocks and corresponding from the first inputs of the arithmetic mean calculation block values, the outputs of the operation control units are connected to the corresponding from the second inputs of the arithmetic mean value calculation unit, the output of which is connected to the first inputs of the subtraction units, the outputs of the subtraction units are connected to the information inputs of the corresponding controlled keys, the outputs of the decrease control units downloads are connected to the control inputs of the corresponding controlled keys, the outputs of which are connected to the inputs of the corresponding signal increase control units and threshold blocks, the outputs of which are connected to the second inputs of the corresponding "AND" logic gates, the outputs of the signal increase control blocks to the first inputs of the corresponding "AND" logic gates ...

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