Arrangement with rotating drive machine and operating method

Abstract

A method of operating an arrangement includes using a rotating drive machine, wherein a value characteristic of a change of a power output of the arrangement is provided by measuring at least one parameter and/or calculation. The rotating drive machine is open and/or closed loop controlled depending on the value characteristic of the change of the power output of the arrangement and/or a load of the rotating drive machine is changed depending on the value characteristic of the change of the power output of the arrangement, such that the change of the power output of the arrangement is substantially compensated.

Claims

1. A method for operating an arrangement comprising a load driven by a rotating drive machine having an internal combustion engine with a plurality of cylinders, the method comprising: providing a load change value (P) which is characteristic of a change in a power output of the arrangement by measuring at least one parameter and/or performing a calculation; selecting at least one measure from a plurality of different measures for controlling the at least one load or the rotating drive machine as a function of the load change value (P), wherein the at least one measure being selected is different as the load change value (P) changes; and controlling at least one of the load or the rotating drive machine of the arrangement with the at least one measure being selected such that the change in the power output of the arrangement is substantially compensated, wherein the plurality of different measures comprises at least one of: controlling a bypass of air to circumvent a compressor of a turbocharger of the rotating drive machine; or shutting off a fuel supply to the rotating drive machine for a duration of time during operation of the rotating drive machine; or changing the load with a braking resistor comprising a load bank.

2. The method according to claim 1, wherein the plurality of different measures comprises controlling the bypass of the air to circumvent the compressor of the turbocharger of the rotating drive machine.

3. The method according to claim 1, wherein the plurality of different measures comprises shutting off the fuel supply to the rotating drive machine for the duration of time during the operation of the rotating drive machine.

4. The method according to claim 1, wherein the plurality of different measures comprises suspending an ignition in one or more cylinders, but less than all of the plurality of cylinders of the internal combustion engine, during operation of the rotating drive machine.

5. The method according to claim 1, wherein the plurality of different measures comprises controlling the bypass of the air to circumvent the compressor of the turbocharger of the rotating drive machine, and wherein the plurality of different measures comprises shutting off the fuel supply to the rotating drive machine for the duration of time during the operation of the rotating drive machine.

6. The method according to claim 1, wherein providing the load change value (P) comprises measuring at least one parameter comprising a rotational speed and/or an angular speed of a shaft driven by the rotating drive machine.

7. The method according to claim 6, wherein providing the load change value (P) comprises performing the calculation of the load change value (P) using a formula, $P=J\frac{d}{dt}$ wherein J denotes an effective moment of inertia from inputs of all moved masses and denotes the angular speed of the driven shaft.

8. The method according to claim 6, wherein the rotational speed and/or the angular speed of the shaft driven by the rotating drive machine is measured at a crankshaft of the rotating drive machine.

9. The method according to claim 6, wherein a measurement signal is filtered from the measuring of the rotational speed and/or the angular speed of the shaft driven by the rotating drive machine by a low-pass filter.

10. The method according to claim 1, wherein the plurality of different measures comprises changing the load with the braking resistor comprising the load bank.

11. An arrangement comprising the rotating drive machine and a control unit for closed loop controlling of the arrangement with the at least one measure, operated according to claim 1, wherein the control unit has an input interface where the load change value (P) which is characteristic of the change in the power output of the arrangement and/or the at least one parameter is transmittable, wherein the load change value (P) of the change in the power output of the arrangement is calculated from the at least one parameter, and in that the control unit is designed to closed loop control at least one of the load or the rotating drive machine with the at least one measure being selected such that the change of the power output of the arrangement is substantially compensated.

12. The arrangement according to claim 11, comprising a sensor connected to the control unit for measuring the at least one parameter, wherein the at least one parameter comprises the rotation of a shaft driven by the rotating drive machine, wherein the control unit is configured to calculate the load change value (P) of the change in the power output of the arrangement from a temporal change of the rotation of the driven shaft measured by the sensor.

13. The arrangement according to claim 11, comprising the load, wherein the load comprises an electrical generator driven by the rotating drive machine.

14. A method, comprising: measuring a speed of rotation of an arrangement having an electrical generator driven by an internal combustion engine having one or more cylinders; calculating a load change value (P) based on a change in the measured speed of rotation, wherein the load change value (P) is characteristic of a change in a power output of the electrical generator; selecting at least one measure from a plurality of different measures for controlling the arrangement as a function of the load change value (P), wherein the at least one measure being selected is different as the load change value (P) changes; and controlling the arrangement with the at least one measure being selected to compensate for the change in the power output to reduce frequency shifts or phase shifts in the power output.

15. The method of claim 14, wherein the plurality of different measures comprises controlling a bypass of air to circumvent a compressor of a turbocharger of the internal combustion engine.

16. The method of claim 14, wherein the plurality of different measures comprises shutting off a fuel supply to the internal combustion engine for a duration of time during operation of the internal combustion engine.

17. The method of claim 14, wherein the plurality of different measures comprises changing a load on the internal combustion engine with a braking resistor having a load bank electrically coupled to the electrical generator.

18. A system, comprising: a control unit configured to: measure a speed of rotation of an arrangement having an electrical generator driven by an internal combustion engine having one or more cylinders; calculate a load change value (P) based on a change in the measured speed of rotation, wherein the load change value (P) is characteristic of a change in a power output of the electrical generator; select at least one measure from a plurality of different measures for controlling the arrangement as a function of the load change value (P), wherein the at least one measure being selected is different as the load change value (P) changes; and control the arrangement with the at least one measure being selected to compensate for the change in the power output to reduce frequency shifts or phase shifts in the power output.

19. The system of claim 18, comprising the internal combustion engine.

20. The system of claim 18, comprising the electrical generator.

Description

(1) Further advantages and details of the invention emerge by way of the figures as well as the associated figure description. In this regard, they show:

(2) FIG. 1 a schematic depiction of a device according to the invention

(3) FIG. 2 a flow diagram of a method according to the invention and

(4) FIG. 3 two diagrams for regulating or controlling a fuel valve.

(5) The arrangement 1 according to the invention depicted in FIG. 1 comprises a combustion engine 2, in this case a gas engine, which drives a generator 7. In this configuration, the arrangement is denoted as a Genset.

(6) The combustion engine 2 has a plurality of cylinders 5. In this exemplary embodiment, eight cylinders 5 are specifically depicted, wherein the exact number of cylinders is not significant for the present invention. It can be used, in particular for a cylinder number of 8 to 24.

(7) The combustion engine 2 has a fuel source T and a fuel valve 3. Fuel T and air L are supplied via this valve to a mixing device 14. The mixture produced is supplied to cylinders 5 via a throttle valve 4. The crankshaft 6 driven by cylinders 5 in turn drives a rotor of the generator 7. The electrical energy provided in the generator 7 is supplied to one or a plurality of consumers 15.

(8) A sensor 11 is positioned on the crankshaft 6 or on the rotating unit, which measures the rotational speed N in this exemplary embodiment. The measurement signals are initially supplied via an input interface 10 to a control unit 9. The measurement signal is initially filtered by means of a filter 8, in this case a bandpass filter, and supplied to a calculation unit 12. The calculation unit 12 calculates the load change value P according to the formula,

(9) $P=J\frac{d}{dt}$
wherein is the angular speed calculated from the filtered measurement signal N_filt and J denotes the effective moment of inertia of all rotating or moving masses (

(10) $(\frac{d}{dt}$
of course denotes the temporal derivative).

(11) In case the arrangement cannot be represented with only one mass system, this must be calculated with an expansion through the combination of a plurality of moments of inertia and angular speeds.

(12) The load change value is supplied to an open and/or closed loop control unit 13, 10 which takes different measures as a function of the load change value P. To this end, the open and/or closed loop control unit 13 is connected with the fuel valve 3, the throttle valve 4 and optionally with a braking resistor 16 (load bank), which is downstream of the generator 7.

(13) Alternatively or additionally, different actuators can be used to open and/or closed loop control, for example, the load pressure. Examples are a bypass value or a so-called waste gate. The first allows a partial air flow to circumvent a compressor of a turbo charger. The second functions analogously to a turbine of a turbo charger.

(14) FIG. 2 shows a flow diagram of an exemplary embodiment of a method according to the invention. Following a change of the power output of the arrangement, the rotating drive machine reacts with a change of the rotational speed. This is measured and filtered. The gradient of the change of rotational speed can be calculated from the filtered measurement signal. With the help of the same, a load change value can be determined. This is supplied to a response logic which takes different measures as a function of the load change value. Examples of the measures would be the open and/or closed loop control of the throttle valve and/or a (main) fuel valve. Alternatively or additionally, actions of the ignition system can be changed and/or further measures taken.

(15) In the case of a high power reduction (load shedding), the fuel valve can be immediately closed and remain closed for a time (100 ms to 5 s) depending on the degree of the power change, the rotational power or other operational parameters (e.g. rotational speed curve).

(16) Regulating elements for influencing the load pressure (in FIG. 2 abbreviated as actuators) can also be used for open and/or closed loop control. These would be, for example, the already mentioned throttle valves, bypass valves or waste gates. The throttle valve can, for example be set to a position, which corresponds to the new power level present after the load change.

(17) In FIG. 3, a comparison between a method of the prior art and a method according to the invention is lastly presented by way of two diagrams. In the top diagram of FIG. 3, the rotational speed of the rotating drive machine is depicted, in the bottom diagram the target value for a fuel valve. The two values are plotted there against time in each case. At a time t.sub.L, a change of the power output of the arrangement occurs, in this case a reduced power output. The rotational speed of the rotating drive machine is thereby increased.

(18) In this example, it is assumed that the mixture composition remains constant, whereby due to the increased rotational speed and the mixture quantity increased thereby, a short-term increase of the fuel quantity can take place.

(19) Through the relatively quick response time, the response time t.sub.R is relatively close to the time t.sub.L of the change of the load output (around 100 to 300 ms in this exemplary embodiment). In the case of a relatively large load shedding, the fuel supply can be immediately closed, as can be seen in the bottom diagram of the figure. The duration of the shutdown is around 2 s in this special example.

(20) This is the situation for the approach according to the invention, illustrated by the curves B in FIG. 3.

(21) For an approach according to the prior art (curves A in FIG. 3), a limit value N.sub.L is predetermined. As soon as the rotational speed reaches this limit value, different measures can be taken (in this example a safety-related shutdown of the machine). Due to residual fuel still present in the supply system of the rotating drive machine, the rotational speed still increases for a short time, but then falls again. As soon as the rotational speed is again close to the desired rotational speed, the fuel supply can be turned on again.

(22) As is visible from the diagram, this limit value N.sub.L is further from the target value. for the rotational speed than the rotational speed N.sub.R, for which a response can take place according to the invention. A more robust operation of the rotating drive machine is thus provided.