Method for operating a power generating device comprising a charge air compressor, control device for carrying out such a method and power generating device with such a control device

Abstract

Method for operating a power generating device (1) comprising a charge air compressor (7), wherein - a charge air pressure downstream of the charge air compressor (7) is detected and checked for a pressure drop, wherein - at least one further operating parameter of the power generation device (1) correlated with the charge air pressure is recorded, wherein - which evaluates at least one further operating parameter for the plausibility of a pumping event as the cause of a pressure drop in the charge air pressure, whereby - a pumping event of the charge air compressor (7) is detected when a drop in the detected charge air pressure is detected and, based on the evaluation of at least one other operating parameter, a pumping event is considered plausible as the cause of the pressure drop in the charge air pressure, wherein - it is checked whether the power generating device (1) is operated within a predetermined operating range, whereby a pumping event is only detected if the power generating device (1) is operated within the predetermined operating range, wherein - it is checked whether a transient operating state exists for the power generating device (1), whereby a pumping event is only detected if no transient operating state exists for the power generating device (1), wherein - it is checked whether a time-dependent torque gradient (M) of the power generation device (1) is greater than a predetermined torque gradient limit value (Ṁ grenz ) is, where a pumping event is only detected if the time torque gradient (M) is greater than the predetermined torque gradient limit (Ṁ grenz ) is.

Description

[0001] The invention relates to a method for operating a power generating device having a charge air compressor, a control device for carrying out such a method and a power generating device with such a control device.

[0002] During operation of a charge air compressor, various influences can cause flow stall at the compressor wheel blades, also known as compressor surge, or simply surge. This leads to critical conditions for a power generation device incorporating the charge air compressor, for example, a drop in charge air pressure, noise generation, heating of a charge path, and possibly even flame formation in critical components such as an air filter. Furthermore, the compressor wheel and surrounding structures, such as stationary guide vanes, suffer severely from surge, which shortens the service life of the charge air compressor. The compressor wheel can even be destroyed, which can cause further problems and, in particular, poses significant risks to people in the vicinity.Since it appears virtually impossible to completely rule out the occurrence of compressor surge, it is all the more important to be able to reliably detect such conditions. However, this has proven difficult, with both the disadvantage of not detecting actual surge events (false negative result) and the disadvantage of incorrectly concluding that a surge event is occurring when no compressor surge is occurring (false positive result). In the first case, the charge air compressor suffers, resulting in the problems described above. In the second case, it is possible that the power generation device operates suboptimally due to incorrectly detected compressor surge, which negatively impacts its efficiency and potentially emissions.

[0003] Known operating methods for power generation devices with a charge air compressor are disclosed, for example, in DE 3544821 A1, DE 69708319 T2 and DE 10237416 A1.

[0004] The invention is therefore based on the object of providing a method for operating a power generation device having a charge air compressor, a control device for carrying out such a method and a power generation device with such a control device, wherein the aforementioned disadvantages are at least reduced, preferably avoided.

[0005] The object is achieved by providing the present technical teaching, in particular the teaching of the independent claims as well as the preferred embodiments disclosed in the dependent claims and the description.

[0006] The object is achieved, in particular, by providing a method for operating a power generation device having a charge air compressor. A charge air pressure downstream of the charge air compressor is detected—in particular continuously—and checked for a pressure drop. Furthermore, at least one further operating parameter of the power generation device correlated with the charge air pressure is detected—in particular continuously.The at least one further operating parameter is evaluated - in particular continuously - for the plausibility of a pumping event as the cause of a pressure drop in the charge air pressure, and a pumping event of the charge air compressor is detected if a drop in the detected charge air pressure is detected and, based on the evaluation of the at least one further operating parameter, a pumping event is assessed as plausible as the cause of the pressure drop in the charge air pressure, i.e. is detected as a plausible cause of the pressure drop in the charge air pressure.In this case, it is checked whether the power generating device (1) is operated within a predetermined operating range, wherein a pumping event is only detected if the power generating device (1) is operated within the predetermined operating range, wherein it is checked whether a transient operating state exists for the power generating device (1), wherein a pumping event is only detected if there is no transient operating state for the power generating device (1), and wherein it is checked whether a temporal torque gradient (M) of the power generating device (1) is greater than a predetermined torque gradient limit value (Ṁ. grenz ), whereby a pumping event is only detected if the temporal torque gradient (M) is greater than the predetermined torque gradient limit (Ṁ grenz). Advantageously, compressor surge can be detected very reliably in this way, so that both the number of false positive and false negative results can be at least reduced, whereby incorrect results and assignments of events are preferably completely avoided. In this respect, it has been recognized that the pressure drop in the charge air pressure in itself is at least not always a sufficient criterion for the reliable diagnosis of compressor surges. However, by additionally recording and evaluating at least one further operating parameter correlated with the charge air pressure, the reliability of detection can be significantly increased. This in turn allows suitable targeted measures to be taken to at least reduce the adverse effects of surge events.

[0007] In one embodiment, the charge air pressure downstream of the charge air compressor is continuously detected during operation of the power generation device and checked for a pressure drop.

[0008] In one embodiment, it is possible for the detection of a pressure drop to initiate or trigger the further method steps, wherein in this embodiment, in particular the at least one further operating parameter is only recorded and evaluated if a pressure drop in the charge air pressure is previously detected.

[0009] In another embodiment, the at least one further operating parameter is also continuously recorded and, in particular, continuously evaluated. The recording of the at least one further operating parameter and, in particular, its evaluation thus occurs independently of whether a pressure drop is detected. However, to determine whether a pumping event is present, the condition of the pressure drop, on the one hand, and the evaluation of the at least one further operating parameter, on the other hand, are considered together, in particular linked to one another by a logical AND.

[0010] In one embodiment, a pressure drop in the charge air pressure is detected when a second time derivative of the charge air pressure falls below a predetermined negative derivative limit. This represents a particularly reliable criterion for detecting a pressure drop, particularly relevant with regard to a surge event.

[0011] In particular, a pumping event of the charge air compressor is always detected, i.e. every time a drop in the recorded charge air pressure is detected and, in addition, the evaluation of at least one other operating parameter returns a pumping event as a plausible cause for the pressure drop in the charge air pressure.

[0012] In one embodiment, based on the evaluation of the at least one further operating parameter, a pumping event is assessed as plausible as the cause of the pressure drop if the evaluation does not identify any other cause for the charge air pressure drop. In particular, in this embodiment, a pumping event of the charge air compressor is detected if a drop in the detected charge air pressure is detected and the evaluation of the at least one further operating parameter does not identify any other cause for the charge air pressure drop. Thus, in particular, detection occurs by excluding other possible causes.

[0013] Alternatively or additionally, based on the evaluation of the at least one further operating parameter, a pumping event is assessed as plausible as the cause of the pressure drop if the evaluation establishes at least one specific temporal progression or a specific behavior of the at least one further operating parameter, wherein, in particular, the specific temporal progression or the specific behavior of the at least one further operating parameter suggests a pumping event or is characteristic of a pumping event. In this case, in particular, a positive identification of a pumping event occurs.

[0014] According to a further development of the invention, a characteristic value is determined that indicates how many surge events are detected within a predetermined time window, with at least one first measure being initiated if the determined characteristic value exceeds a predetermined first characteristic value limit. This advantageously enables targeted measures to be taken, in particular to reduce the effects of surge events occurring with a higher temporal frequency.

[0015] In particular, the key figure is recorded continuously during operation of the power generation device. In one embodiment, the key figure is recorded for the predetermined time window, then for a subsequent predetermined time window, and so on, i.e., in particular, from time window to time window. In this case, the key figure is incremented, in particular, within a time window and reset, in particular, to zero, at the end of the time window. In another embodiment, the key figure is determined as a floating value. In particular, it is possible for the key figure to be incremented when a pumping event occurs, wherein the time at which the pumping event occurred is noted, and wherein the key figure is decremented again at a time interval of a predetermined time window from the pumping event.In this embodiment, the key figure indicates at each instantaneous point in time the number of pumping events in a period extending into the past from the instantaneous point in time by subtracting the predetermined time window.

[0016] In particular, the determined key figure is continuously compared with the predetermined first key figure limit value during operation of the power generation device. This allows the first measure to be initiated quickly and in a targeted manner.

[0017] In particular, no action will be taken if the determined key figure does not exceed the predetermined first key figure threshold.

[0018] According to a further development of the invention, at least one second measure is initiated if the determined characteristic value exceeds a predetermined second characteristic value limit, wherein the predetermined second characteristic value limit is greater than the predetermined first characteristic value limit. Thus, different cases of surge events can advantageously be distinguished. Depending on the frequency with which the surge events occur, different measures, in particular measures of varying severity, can be taken to mitigate or avert the negative consequences of compressor surge as far as possible.

[0019] In particular, the determined key figure is continuously compared with the predetermined second key figure limit value during operation of the power generation device. This allows the second measure to be initiated quickly and in a targeted manner.

[0020] According to the invention, it is provided that a check is carried out to determine whether the power generating device is operating within a predetermined operating range, wherein a surge event is only detected if - in particular in addition to the other aforementioned criteria - the power generating device is operating within the predetermined operating range. This advantageously allows resources, in particular computing power, to be conserved in particular by not detecting a surge event if the power generating device is operating outside the predetermined operating range and thus in particular in an operating range in which the occurrence of compressor surge is impossible or at least improbable. At the same time, the accuracy of the detection is increased by expressly excluding such operating ranges from the detection of surge events.

[0021] In particular, no pumping event is detected if the power generating device is not operated within the predetermined operating range.

[0022] The predetermined operating range is defined, in particular, in a characteristic map, in particular as a predetermined characteristic map range. The characteristic map is spanned, in particular, by a rotational speed and a torque of the power generating device. Alternatively, the characteristic map is spanned by an electrical voltage and an electrical current of the power generating device.

[0023] According to the invention, it is provided that a check is carried out to determine whether a transient operating state exists for the power generation device, whereby a surge event is only detected if—in particular, in addition to the other criteria mentioned—no transient operating state exists for the power generation device. This is based on the idea that compressor surge cannot be reliably detected in a transient operating range, particularly during a power drop or load shedding. By excluding transient operating states for the detection of surge events, the accuracy of the detection is advantageously further increased.

[0024] In particular, no pumping event is detected when there is transient operation for the power generating device.

[0025] According to a further development of the invention, it is provided that the at least one first measure is selected from a group consisting of a first alarm, a change in a flow cross-section of a compressor bypass path around the charge air compressor, and a change in a flow cross-section of a charging path in which the charge air compressor is arranged.

[0026] In the context of the present technical teaching, a first alarm is understood to mean, in particular, a first, particularly less urgent, warning to an operator of the power generation device, in particular a yellow alarm, in particular a request for inspection. The first warning can be issued acoustically, visually, haptically, or in any other suitable manner, as well as in combinations of the aforementioned ways.

[0027] The flow cross-section in the compressor bypass path is changed, in particular, by changing a flap position or valve setting of a bypass path adjusting device in the compressor bypass path. The compressor bypass path is, in particular, a compressor bypass. In particular, a bypass path adjusting device, in particular a bypass valve or a bypass flap, is arranged in the compressor bypass, via which the flow cross-section of the compressor bypass path can be changed.

[0028] The flow cross-section in the charging path is changed, in particular, by changing a flap position or valve position of a charging path adjusting device in the charging path. The charging path is, in particular, an air path or charge air path of the power generation device, in which the charge air compressor is arranged. In particular, a charging path adjusting device, in particular a throttle valve or a throttle flap, is arranged in the charging path, via which the flow cross-section of the charging path can be changed.

[0029] According to a further development of the invention, the at least one second measure is selected from a group consisting of a second alarm and a shutdown of the power generation device. Thus, the measures to be taken can advantageously be escalated depending on the frequency of occurrence of surge events, with the higher escalation level, in particular a shutdown of the power generation device, only being reached if the surge events occur at the predetermined, higher frequency.

[0030] In the context of the present technical teaching, a second alarm is understood to mean, in particular, a second, particularly more urgent warning, in particular a request to take action, to an operator of the power generation device, in particular a red alarm. The second warning can be issued acoustically, visually, haptically, or in any other suitable manner, as well as in combinations of the aforementioned ways.

[0031] According to a further development of the invention, a compressor of an exhaust gas turbocharger of the power generation device is operated as the charge air compressor, wherein an operating parameter that is correlated—in particular positively—with an exhaust gas mass flow of the power generation device is used as the at least one further operating parameter. In addition to the pressure drop in the charging path, the exhaust gas mass flow via a turbine that is drive-connected to the charge air compressor is a highly suitable criterion for accurately detecting compressor surges. This is advantageously utilized by evaluating the operating parameter that is correlated—in particular positively—with the exhaust gas mass flow.

[0032] In particular, an operating parameter is used as the at least one further operating parameter that is functionally linked to the exhaust gas mass flow of the power generation device, either such that the exhaust gas mass flow depends on the operating parameter, or such that the operating parameter depends on the exhaust gas mass flow. In one embodiment, an operating parameter is used as the at least one further operating parameter whose value increases when the exhaust gas mass flow increases and whose value decreases when the exhaust gas mass flow decreases. In particular, the value of the operating parameter remains the same when the exhaust gas mass flow remains the same.

[0033] According to a further development of the invention, it is provided that a torque of the power generation device is detected as the at least one further operating parameter, in particular when the power generation device is designed as an internal combustion engine. The torque of the power generation device represents a particularly suitable further operating parameter for detecting the presence of compressor surge. In particular, the torque is correlated - in particular positively - with the exhaust gas mass flow via the turbine of the exhaust gas turbocharger. In one embodiment, the torque is measured at the power generation device. In another embodiment, the torque is calculated in particular from operating data of the power generation device, in particular in a control device.In particular, the torque can be calculated based on injection data of the power generation device, in particular a fuel pressure and an opening duration of an injector.

[0034] Alternatively, it is possible for the at least one further operating parameter to be detected as an output power of the power generation device and / or an electrical current output by the power generation device, particularly if the power generation device is configured as a fuel cell. In this case, the output power or the output electrical current is correlated—in particular positively—with an exhaust gas mass flow of the fuel cell.

[0035] In particular, it is checked whether the at least one further operating parameter, in particular the torque, the output power or the output electrical current, drops. In particular, based on the evaluation of the at least one further operating parameter, a pumping event is assessed as plausible as the cause of the pressure drop in the charge air pressure if it is determined that the at least one further operating parameter does not drop. In particular, in this case there is no drop in power or torque, which would otherwise explain the pressure drop in the charge air pressure even without a pumping event. Thus, in particular there is no other cause for the pressure drop than a pumping event, so that a pumping event can be concluded with a high degree of certainty.

[0036] Additionally or alternatively, a check is carried out to determine whether at least one other operating parameter, in particular the torque, the output power, or the output electrical current, is increasing. In particular, if at least one other operating parameter increases, any other cause for the pressure drop other than a surge event can be almost certainly ruled out. In particular, in such a case, in the absence of compressor pumps, an increase in the charge air pressure would actually be expected. Therefore, if the charge air pressure drops in such a situation, a surge event must almost certainly be present.

[0037] In one embodiment, the evaluation of the at least one further operating parameter is implicitly included in the test for transient operation. This means, in particular, that a pumping event is assessed as plausible as the cause of the pressure drop if no transient operation is detected. If, however, transient operation is detected for the power generation device, it is assumed that no pumping event is present, since the transient operation is a possible cause of the pressure drop.

[0038] The object is also achieved by providing a control device for a power generation device, which is configured to carry out a method according to the invention or a method according to one or more of the previously described embodiments. In connection with the control device, in particular, those advantages arise that were already explained above in connection with the method.

[0039] The object is also achieved by providing a power generation device having a charging path in which a charge air compressor is arranged. The power generation device further comprises a control device according to the invention or a control device according to one or more of the previously described embodiments. In connection with the power generation device, in particular, those advantages arise that were already explained above in connection with the method or the control device.

[0040] The control device is in particular operatively connected to a charge air pressure sensor arranged in the charging path downstream of the charge air compressor.

[0041] In particular, the control device is configured to detect and evaluate the at least one additional operating parameter. In one embodiment, the control device is operatively connected to at least one operating parameter sensor to detect the at least one additional operating parameter. Alternatively or additionally, the control device is configured to calculate the at least one additional operating parameter.

[0042] According to a further development of the invention, the charge air compressor is drive-connected to a turbine arranged in an exhaust path of the power generation device. In particular, the charge air compressor is designed as a compressor of an exhaust gas turbocharger of the power generation device.

[0043] According to a further development of the invention, the power generation device is designed as an internal combustion engine. Alternatively, the power generation device is designed as a fuel cell.

[0044] The invention is explained in more detail below with reference to the drawings, which show: Fig. 1 is a schematic representation of an embodiment of a power generation device with an embodiment of a control device; Fig. 2 a first schematic representation of an embodiment of a method for operating the power generating device according to Fig. 1, and Fig. 3 a second schematic representation of an embodiment of the method.

[0045] Fig. 1 shows a schematic representation of an embodiment of a power generation device 1 with an embodiment of a control device 3.

[0046] The power generation device 1 has a charging path 5 in which a charge air compressor 7 is arranged. The charge air compressor 7 is, in particular, part of an exhaust gas turbocharger 9 of the power generation device 1 and is drive-connected to a turbine 13 arranged in an exhaust gas path 11 of the power generation device 1.

[0047] In the exemplary embodiment shown here, the power generation device 1 is designed in particular as an internal combustion engine and has an engine block 15. In another exemplary embodiment not shown, it is possible for the power generation device 1 to be designed as a fuel cell.

[0048] The control device 3 is in particular operatively connected to a first charge air pressure sensor 17 arranged in the charging path 5 downstream of the charge air compressor 7 in order to be able to detect the charge air pressure in the charging path 5 downstream of the charge air compressor 7.

[0049] In the exemplary embodiment illustrated here, the control device 3 is additionally operatively connected to a second charge air pressure sensor 19 arranged in the charging path 5 upstream of the charge air compressor 7 in order to be able to detect the charge air pressure in the charging path 5 upstream of the charge air compressor 7. This can advantageously contribute, in particular, to greater accuracy or plausibility in detecting a pressure drop in the charge air pressure downstream of the charge air compressor 7.

[0050] In the exemplary embodiment illustrated here, the control device 3 is also configured to detect and evaluate at least one further operating parameter of the power generation device 1, in particular of the internal combustion engine and especially of the engine block 15. For this purpose, the control device 3 is operatively connected to an operating parameter sensor 21. Alternatively or additionally, it is possible for the control device 3 to be configured to calculate the at least one further operating parameter, in particular based on additional parameters detected on the power generation device 1 and in particular on the engine block 15.

[0051] As the at least one further operating parameter, an operating parameter is preferably used that is positively correlated with an exhaust gas mass flow in the exhaust path 11 of the power generation device 1. Preferably, as the at least one further operating parameter, a torque of the power generation device 1 is detected, in particular measured or calculated, wherein in particular it is checked whether the torque is decreasing or increasing, and wherein in particular a pumping event is assessed as plausible as the cause of the pressure drop in the charge air pressure if it is determined that the torque is not decreasing or if it is determined that the torque is increasing.

[0052] In the exemplary embodiment illustrated here, the control device 3 is also configured to change a flow cross-section in a compressor bypass path 23. For this purpose, it is operatively connected, in particular, to a bypass flap 25 in order to change a flap position of the bypass flap 25 as a bypass path adjusting device in the compressor bypass path 23.

[0053] Alternatively or additionally, it is possible, in a manner not explicitly shown here, for the control device 3 to be configured to change a flow cross-section in the charging path 5, in particular by changing a flap position or valve position of a charging path actuating device (not shown) in the charging path 5.

[0054] The control device 3 is in particular designed to carry out a method described below.

[0055] Fig. 2 shows a first schematic representation of an embodiment of the method for operating the power generating device 1 according to Fig. 1.

[0056] Identical and functionally identical elements are provided with the same reference symbols in all figures, so that reference is made to the preceding description in each case.

[0057] In particular, the charge air pressure downstream of the charge air compressor 7 is detected by means of the first charge air pressure sensor 17 and checked for a pressure drop, wherein at least one further operating parameter of the power generation device correlated with the charge air pressure is detected - in particular by means of the operating parameter sensor 21. The at least one further operating parameter is evaluated for the plausibility of a pumping event as the cause of a pressure drop in the charge air pressure, and a pumping event of the charge air compressor 7 is detected if a drop in the detected charge air pressure is detected and, based on the evaluation of the at least one further operating parameter, a pumping event is assessed as plausible as the cause of the pressure drop in the charge air pressure.In particular, this makes it possible to detect compressor surges very reliably, so that both the number of false positive and false negative results can be at least reduced, and preferably incorrect classifications of events can be completely avoided.

[0058] In connection with Fig. 2, an embodiment of the method is explained below using computing modules. The various computing modules do not necessarily have to be distinguishable from one another as separate hardware or software components; therefore, the illustration based on the computing modules merely serves to explain the functionality of this embodiment of the method, without restricting its generality. However, an implementation of the method is certainly conceivable in which the various computing modules are configured, for example, as separate software functions.

[0059] In a first computing module A, a continuous check for a pumping event of the charge air compressor 7 is performed. The first computing module A continuously outputs, in particular at regular intervals, a first variable a, which indicates whether a pumping event is currently detected, in particular in the current time interval. For example, the variable a can have the value "0" if no pumping event is detected, whereas the variable a can assume the value "1" if a pumping event is detected.

[0060] In b), the test for a pumping event, which is carried out by the first calculation module A, is shown in more detail: In particular, the calculation module A checks whether the following conditions are currently met, in particular in the current time cycle: A pressure drop in the charge air pressure is detected, there is no transient operating state, a temporal torque gradient M of the power generation device 1 is greater than a predetermined torque gradient limit value Ṁ grenz, and the operation of the power generation device 1 is within a predetermined operating range. These conditions are all linked to one another in the first computing module A by a logical AND, so that the first computing module A only detects a pumping event, for example, outputs the value "1" for the variable a, if each of the listed conditions is met, whereas the first computing module A does not detect a pumping event and, for example, outputs the value "0" for the variable a if at least one of the listed conditions is not met.

[0061] In particular, a pressure drop in the charge air pressure is detected when a second time derivative of the charge air pressure falls below a predetermined negative derivative limit value.

[0062] In particular, a key figure is determined that indicates how many pumping events are detected within a predetermined time window.

[0063] In particular, returning to the illustration in a), the pumping events are counted in a second computing module B, with the second computing module B outputting the value of a counter b as a second variable and as the key figure, with counter b indicating the number of detected pumping events. In particular, counter b is always incremented when variable a indicates the detection of another pumping event, i.e., when it changes from the value "0" to the value "1," for example.

[0064] In one embodiment, it is possible for the counter b to be reset by the second computing module B every time a predetermined time window Δt has elapsed, i.e., in particular, set to the value "0." In another embodiment, the second computing module B assigns a time stamp to each individual pumping event and decrements the value of the counter b every time the predetermined time window Δt has elapsed, based on the time stamp of each pumping event. Thus, the counter b essentially indicates a moving time average of the pumping events over the predetermined time window Δt at any given time.

[0065] In a third calculation module C, the counter b is compared, on the one hand, with a predetermined first key figure limit value b1 and, on the other hand, with a predetermined second key figure limit value b2. The predetermined second key figure limit value b2 is, in particular, greater than the predetermined first key figure limit value b1. Depending on the result of the comparison, the third calculation module C outputs a third variable c. This can, for example, assume the value "0" if the counter b is not greater than the predetermined first key figure limit value b1, wherein it can assume the value "1" if the counter b is greater than the predetermined first key figure limit value b1 but not greater than the predetermined second key figure limit value b2, wherein it can assume the value "2" if the counter b is greater than the predetermined second key figure limit value b2.

[0066] In a fourth calculation module D, various measures are initiated depending on the value of the third variable c. In particular, at least one first measure is initiated when the counter b exceeds the predetermined first key figure limit b1. Preferably, at least one second measure is initiated when the counter b exceeds the predetermined second key figure limit b2. In particular, no measure is initiated if the counter b does not exceed the predetermined first key figure limit b1.

[0067] The at least one first measure is preferably selected from a group consisting of a first alarm, a change in the flow cross-section of the compressor bypass path 23, and a change in the flow cross-section of the charging path 5.

[0068] The at least one second measure is preferably selected from a group consisting of a second alarm and a shutdown of the power generating device 1.

[0069] In particular, the first computing module A, the second computing module B, the third computing module C and the fourth computing module D do not operate sequentially, but simultaneously, changing their respective internal states in particular depending on their respective calculations, in particular depending on the respective input variables.

[0070] Fig. 3 shows a second schematic representation of an embodiment of the method.

[0071] In a first step S1, a counter nP, which indicates the number of detected pumping events as the key figure, is initialized with the value zero, at the same time a time variable t is initialized with zero, and a time measurement with which the time variable t is incremented is started.

[0072] In a second step S2, a test for a pumping event is carried out, in particular the same test being carried out as in the test carried out in connection with Fig. 2, in particular in b), is carried out. In particular, in the second step S2, it is checked whether the following conditions are currently met, in particular in a current time cycle: A pressure drop in the charge air pressure is detected, there is no transient operating state, a temporal torque gradient M of the power generation device 1 is greater than a predetermined torque gradient limit value Ṁ grenz, and the operation of the power generation device 1 is within a predetermined operating range. These conditions are all linked together by a logical AND, so that a surge event is only detected if each of the enumerated conditions is met, and no surge event is detected if at least one of the enumerated conditions is not met.

[0073] In a third step S3, the result of the test of the second step S2 is checked: If a pumping event is detected, the method is continued in a fourth step S4; if, however, no pumping event is detected, a fifth step S5 checks whether the current value of the time variable t exceeds a predetermined time limit value t lim reaches or exceeds, whereby the predetermined time limit t limin particular the length of the predetermined time window Δt, calculated from time t = 0. If the instantaneous value of the time variable t reaches or exceeds the predetermined time limit t lim , the method jumps back to the first step S1, otherwise the method jumps back to the second step S2 and the test for a pumping event is carried out again.

[0074] In the fourth step S4, the counter nP is incremented. Subsequently, in a sixth step S6, it is checked whether the current value of the time variable t exceeds the predetermined time limit value t lim reached or exceeded. If this is the case, the method returns to the first step S1; otherwise, the method continues in a seventh step S7.

[0075] In the seventh step S7, it is checked whether the counter nP has a predetermined first pumping event limit value nP lim1reaches or exceeds, whereby the first predetermined pumping event limit nP lim1 in particular, is equal to the first characteristic limit b1. If the counter nP reaches or exceeds the predetermined first pumping event limit nP liml If not, the method returns to the second step S2, and the check for a pumping event is performed again. If the counter nP reaches or exceeds the predetermined first pumping event limit nP lim1 On the other hand, in an eighth step S8 it is checked whether the counter nP additionally has a predetermined second pumping event limit value nP lim2 reaches or exceeds, wherein the second predetermined pumping event limit nP lim2 in particular is equal to the second key figure limit value b2.

[0076] If the test in the eighth step S8 shows that the counter nP exceeds the predetermined second pumping event limit value nP ıim2does not reach or exceed the predetermined second pumping event limit value nP, the at least one first measure is initiated in a ninth step S9, after which the method returns to the second step S2. If, however, the check in the eighth step S8 shows that the counter nP also exceeds the predetermined second pumping event limit value nP lim2 reaches or exceeds, the at least one second measure is initiated in a tenth step S10, whereupon the method preferably ends, in particular if the power generating device 1 is switched off due to the second measure.

Claims

[1] Method for operating a power generating device (1) having a charge air compressor (7), wherein - a charge air pressure downstream of the charge air compressor (7) is detected and checked for a pressure drop, whereby - at least one further operating parameter of the power generation device (1) correlated with the charge air pressure is detected, wherein - at least one further operating parameter is evaluated for the plausibility of a pumping event as the cause of a pressure drop in the charge air pressure, whereby - a pumping event of the charge air compressor (7) is detected when a drop in the detected charge air pressure is detected and, based on the evaluation of the at least one further operating parameter, a pumping event is assessed as plausible as the cause of the pressure drop in the charge air pressure, wherein - checking whether the power generating device (1) is operated within a predetermined operating range, wherein a pumping event is only detected if the power generating device (1) is operated within the predetermined operating range, wherein - checking whether a transient operating state exists for the power generating device (1), wherein a pumping event is only detected if there is no transient operating state for the power generating device (1), wherein - it is checked whether a temporal torque gradient (M) of the power generating device (1) is greater than a predetermined torque gradient limit value (Ṁ grenz ), whereby a pumping event is only detected if the temporal torque gradient (M) is greater than the predetermined torque gradient limit (Ṁ grenz ) is. [2] Method according to claim 1, wherein a characteristic number (b, nP) is determined which indicates how many pumping events are detected within a predetermined time window (Δt), and wherein at least one first measure is initiated if the determined characteristic number (b, nP) exceeds a predetermined first characteristic number limit value (b1, nP lim1 ) exceeds. [3] Method according to claim 2, wherein at least one second measure is initiated if the determined characteristic value (b, nP) exceeds a predetermined second characteristic value limit value (b2, nP lim2 ), wherein the predetermined second key figure limit value (b2, nP lim2 ) is greater than the predetermined first key figure limit value (b1, nP lim1 ). [4] Method according to one of the preceding claims, wherein the at least one first measure is selected from a group consisting of: a first alarm, a change in a flow cross-section of a compressor bypass path (23) around the charge air compressor (7), and a change in a flow cross-section of a charging path (5) in which the charge air compressor (7) is arranged. [5] Method according to one of the preceding claims, wherein the at least one second measure is selected from a group consisting of: a second alarm and a shutdown of the power generating device (1). [6] Method according to one of the preceding claims, wherein the charge air compressor (7) of an exhaust gas turbocharger (9) of the power generation device (1) is operated, and wherein the at least one further operating parameter is positively correlated with an exhaust gas mass flow of the power generation device (1). [7] Method according to one of the preceding claims, wherein a torque of the power generating device (1) is detected as the at least one further operating parameter, wherein in particular it is checked whether the torque drops, and wherein in particular a pumping event is assessed as plausible as the cause of the pressure drop in the charge air pressure if it is determined that the torque does not drop. [8] Control device (3) for a power generating device (1), arranged to carry out a method according to one of claims 1 to 7. [9] Power generation device (1) with a charging path in which a charge air compressor (7) is arranged, and with a control device (3) according to claim 8. [10] Power generation device (1) according to claim 9, wherein the charge air compressor (7) is drive-connected to a turbine (13) arranged in an exhaust gas path (11) of the power generation device (1). [11] Power generating device (1) according to one of claims 9 or 10, wherein the power generating device (1) is designed as an internal combustion engine or as a fuel cell.

Images