RU2789737C1 - Hybrid helicopter drive system - Google Patents

Abstract

FIELD: aircraft.

SUBSTANCE: invention relates to aircraft. A hybrid drive system with control systems and a helicopter main shaft with a main rotor connected to a gearbox contains pilot controls, an internal combustion engine (ICE) and an electric engine (EE), which affect the main shaft. The internal combustion engine control system may independently reach the set speed of the main shaft at any time and stabilize it for any flight mode set by the pilot's controls. The engine control system additionally drives or brakes the main shaft. The EE control system stores the first directive in order to always be able to apply driving or braking force to the main shaft, which causes the engine, if it has reached or maintains the adequate main shaft speed, to automatically generate torque on the main shaft, at which the engine reaches the adequate power.

EFFECT: invention provides for increasing helicopter operation safety.

9 cl, 2 dwg

Description

The invention relates to a hybrid drive system with control systems and the main shaft of a helicopter with a main rotor connected to a gearbox that can stabilize a flight mode specified by a pilot, comprising pilot controls, an internal combustion engine (ICE) and an electric motor (EM), both of which act directly onto the main shaft (3). The ICE is connected to the ICE control system, which can regulate the fuel supply from the fuel tank to the ICE to provide the required driving force on the main shaft, and the EM is connected to the EM control system, which, by discharging the battery, can drive the EM or charge the battery due to mechanical power generated by the EM, as a result of which the main shaft is either set in motion or, accordingly, braked. The invention also relates to a method for operating such a hybrid drive system.

State of the art

As in the automotive industry, a drive with an additional electric motor is also known for helicopters, in particular with a hybrid drive.

A system similar to that described above is known from US 2017/0225573 A1. It includes an internal combustion engine and an electric motor located between the internal combustion engine and the main rotor gearbox. The same applies to US 2018/0354635 A1. The indicated document describes the method of regulation through various computer distribution systems between the internal combustion engine and the electric motor.

From EP 3162713 another hybrid system is known which propels a helicopter with an electric motor and an internal combustion engine. The purpose of the regulation described in said document is to absorb power peaks by means of the electric motor, so that the internal combustion engine is operated as far as possible in the "steady state" mode, also known as "moving average power". To achieve this, the control signal used is split into a high frequency and a low frequency signal component, with the faster high frequency signal being transmitted to the electric motor and the slower low frequency signal to the internal combustion engine. Thus, the electric motor takes over the rapid changes, while the internal combustion engine only has to take over the power changes slowly, so to speak, "damped". The disadvantage of this separation is to reduce safety in the event of failure of one of the engines. Since none of these engines receives the entire signal, the remaining engine cannot take over the flight requirements on its own. An additional monitoring system should detect engine failure and immediately ensure that the remaining engine receives the entire signal. Any additional command or control system required is again a risk to flight safety.

Disclosure of the essence of the invention

The object of the present invention is to describe a hybrid drive system by which the operation of a helicopter can be made as safe as possible. Another object of the invention is to propose a method according to which said safe operation can be carried out. In addition, safe operation should be provided with a minimum fuel consumption.

These problems are solved thanks to the signs of the first points of the formula for the invention of the corresponding categories. Additional preferred embodiments are described in the dependent claims.

According to the invention, in the hybrid drive system, at least one torque sensor and one tachometer are located on the main shaft, and both the internal combustion engine control system and the EM control system during operation can receive the values of the current rotation frequency DZ and the current torque DM.

In addition, the memory stores the specified values of the rotation frequency DZ ₀ and torque DM ₀ , which provide the optimum efficiency of the internal combustion engine. The indicated values can be requested by the EM control system, and the first of the indicated values - DZ ₀ - can also be requested for the internal combustion engine control system.

The control system of the internal combustion engine by matching the power of the internal combustion engine at any time can independently reach and stabilize the given frequency DZ ₀ of rotation of the main shaft, which makes it possible to stabilize any flight mode set by the pilot's controls. In addition, the EM control system, through the use of the EM, can additionally drive or brake the main shaft, as a result of which the rotation frequency DZ changes, and the ICE control system automatically adjusts the ICE power in order to again achieve and maintain the specified main shaft rotation frequency DZ ₀ .

The first directive is stored in the EM control system, according to which the EM must always act on the main shaft with such a driving or braking force, which leads to the fact that the internal combustion engine, if it has reached or, accordingly, maintains the optimal frequency DZ ₀ of rotation of the main shaft, automatically creates on the main shaft torque DM ₀ at which the internal combustion engine reaches the optimum engine power.

Preferably, the EM is located between the internal combustion engine and the main rotor gearbox 1. The rotational speed DZ can be measured anywhere in the main shaft, it is the same everywhere. At least one of the sensors of the rotating moment should be located between the internal combustion engine and ED to determine the load of the ICE on the main shaft. Other torque sensors may be located between the motor and gearbox to determine the total load on the main shaft. However, the torque sensor between the internal combustion engine and the electric motor is, first of all, the determining factor for regulating the control system of the electric motor, since it shows the power of the internal combustion engine, which, according to the first directive, must operate with maximum efficiency.

Between the pilot's controls and the internal combustion engine control system, a direct data signal transmission line can be made, used for takeoff and landing of the helicopter. At these stages, the first directive should not be applied. Indirect communication always exists due to the helicopter flight mode. If the pilot sets the main rotor blade angle higher to increase the height, due to the higher load, the main shaft speed DZ immediately drops, after which, in the normal mode, the power demand is set according to the first directive.

Additionally, a level indicator can be located on the fuel tank, and on the battery - an indicator of the degree of battery charge, which, during operation, can transmit their measurement data to the ED control system. By means of the calculation unit, the respective still available energies can be calculated. If necessary, the ED management system can act in accordance with the second directive, which differs from the first directive. The purpose of the second directive may be to protect the battery from overcharging and undercharging, to save fuel and/or to periodically operate the internal combustion engine at lower power to reduce emissions.

It is important that the ICE management system, together with the internal combustion engine at any time, can independently achieve the necessary frequency of DZ of the main shaft rotation in order to achieve or, accordingly, stabilize the flight mode set by the pilot management. This means that the helicopter with its ICE can be retrofitted with an EM and an EM control system without the need to interfere with the existing ICE control system. The consequence of this is that in the event of a system malfunction, when the EM and/or the EM control system fails, the helicopter can be normally controlled only from the internal combustion engine.

The method of operation of the hybrid drive system for the main shaft of the helicopter, proposed by the invention, provides the flight mode required by the pilot by applying the invention of the hybrid drive system with control systems. This method performs the following steps.

The current values of rotation frequency DZ and torque DM are continuously measured on the main shaft and transmitted both to the EM control system and to the internal combustion engine control system. The specified values of rotation frequency DZ ₀ and torque DM ₀ are stored in memory, and both values DZ ₀ , DM ₀ can be requested by the EM control system, and at least the rotation frequency DZ ₀ can be requested by the internal combustion engine control system. Both control systems constantly determine the deviations of the measured values DZ, DM from the set values DZ ₀ , DM ₀ known to them.

As soon as the pilot, through the pilot's controls, creates a changed power demand on the main shaft in order to achieve the required flight mode, this also causes a change in the main shaft speed DZ. On the basis of the deviation of the current speed DZ from the set speed DZ ₀ , the ICE control system slowly changes the power of the ICE so that the set speed DZ ₀ is reached again.

This is explained more precisely in the following example. The internal combustion engine control system is configured in such a way that the internal combustion engine always creates a load that allows reaching and stabilizing the optimal speed DZ ₀ of rotation. If the pilot adjusts the rotor blades to increase the altitude, then this results in a decrease in the rotational speed DZ. The internal combustion engine responds to said reduction in speed DZ with increased power and the torque DM generated by it is increased. This in turn causes the rotational speed DZ to increase. As soon as the engine speed reaches the setpoint DZ ₀ again and stabilizes, there is no reason for the internal combustion engine control system to change the engine power. The ICE continues to operate unchanged, but with a higher torque DM than before the adjustment of the main rotor blades. As the helicopter descends, the opposite happens accordingly, and the torque DM generated by the internal combustion engine drops.

However, in the method according to the invention with a hybrid drive system, the EM control system comes into action according to its first directive. Based on the deviation of the current values of the speed DZ of rotation and/or torque DM from the corresponding preset values DZ ₀ , DM ₀ it changes the power of the electric motor in a faster way than the internal combustion engine in such a way that the internal combustion engine, after adjusting its power, until reaching the set rotation frequency DZ ₀ creates a given torque DM ₀ at which it reaches the optimum efficiency. The EM control system achieves this by either charging the battery due to the mechanical power of the EM or actuating the EM by means of a charge in the battery.

Thus, in the above example, the ED control system also comes into play. It knows the setpoints for speed DZ ₀ and torque DM ₀ and can determine corresponding differences from the current values DZ, DM on the basis of the measured values transmitted to it.

First, the ED control system works according to its first directive. Thus, if the pilot adjusts the rotor blades to increase altitude, the RPM first drops as described above. However, before the internal combustion engine increases its power due to the increase in torque, the EM, which reacts much faster, creates an additional required load, so that the required speed DZ ₀ of rotation is immediately reached again. The internal combustion engine control system, which also constantly monitors the speed, at best perceives a short-term, slight deviation of the set speed DZ ₀ of rotation, which is immediately compensated by the EM, since the EM immediately creates the necessary load for this. Due to the longer response time of the internal combustion engine, it does not increase its power, but retains its originally created torque DM.

The same thing happens in descent flight when the pilot decreases the angle of the rotor blades. The battery ED is charged by the fact that Ed inhibits the main shaft before the ICE can compensate for the increase in the speed and lower the power created by them.

Therefore, the said first directive of the EM control system, on the one hand, regulates and stabilizes the rotation frequency DZ ₀ of the main shaft due to the fact that it controls the EM accordingly. Thus, it prevents changes in the load of the internal combustion engine, its torque remains constant. This is desirable as long as the specified torque corresponds to the specified torque DM ₀ . As long as this is the case, the efficiency is always optimal.

In addition, on the other hand, the EM control system also constantly monitors the compliance of the torque DM generated on the main shaft at the moment with the specified torque DM ₀ . Deviations can occur, for example, after takeoff, during climb or descent flight, or after a motor failure, for example, due to a too low battery charge. Therefore, when setting the torque deviation, the first directive of the EM control system also adjusts the specified measured torque DM to the set value DM ₀ as follows. If the measured torque is too high, the EM control regulates DZ to always a slightly increased value. The internal combustion engine control system reacts to this by reducing power, as a result of which the torque generated by the internal combustion engine is continuously reduced. The EM control system maintains a slightly increased speed until the measured torque DM matches the set torque DM ₀ . As soon as this is achieved, the power of the EM again rapidly decreases until the set rotation frequency DZ ₀ is again reached. As a result, the set torque DM ₀ is also maintained. After that, the ICE operates at its optimum efficiency, and the EM control system stabilizes DZ again so that the ICE always provides its optimum power.

Thus, during operation, the EM control system on the basis of too low a rotation speed, if DZ < DZ ₀ , and/or on the basis of an increased torque, if DM > DM ₀ , increases the EM power, and vice versa.

According to the invention, in the event of a failure of the EM control system, the ICE control system based on speed control to a predetermined value DZ ₀ automatically provides a stable flight mode, since the required driving force is provided by the ICE. This does not require coordination and additional control.

In a preferred embodiment of the method, the EM control system, based on the measurement data of the fuel tank level indicator and / or the battery charge indicator, can determine the energies still available and, as a result, periodically deviate from the first directive and act according to the second directive. Under said second directive, the battery may be purposefully charged or discharged to protect the battery, conserve fuel, and/or periodically operate the internal combustion engine at lower power to reduce emissions.

Due to this, for example, a deep discharge or overcharging of the battery can be prevented. On the other hand, when located at high altitudes, ED can be purposefully used to a greater extent, since fuel consumption increases relatively strongly there. In addition, at the stage of take -off and/or landing, depending on the need, it can be operated exclusively by ED for reducing noise and emissions of exhaust gases, or exclusively by the ICE.

While in EP 3162713 the signal from the pilot is separated into a high frequency and a low frequency component of the signal from the pilot in order to achieve the desired power distribution of the two engines, in the present invention the power distribution in normal mode is controlled by the first directive of the EV control system by that the measured frequency DZ the rotation and the measured torque DM are adjusted to the stored preset values DZ ₀ and DM ₀ . During the normal phase of flight, with the exception of takeoff and landing, the control systems of the two engines receive no control signals from the pilot. EM and ICE regulate their power to stabilize the given rotational speed DZ ₀ , and any deviation in the first place compensates for the more quickly responding EM, before the inertial ICE can respond to it. In addition, according to the first directive, ED, by additionally providing positive or negative power, regulates the torque DM generated by the internal combustion engine to a predetermined value DM ₀ . Thus, the hybrid drive system described here is very easy to operate and functionally reliable, even in the event of a sudden failure of the internal combustion engine.

Thus, the hybrid drive system is constantly operated with a load distribution that allows the most efficient use of the available fuel. However, this is not achieved by the fact that complicated calculations are carried out, but directly and only due to the fact that the respective current values of the speed DZ of rotation and torque DM, as well as their set values DZ ₀ , DM ₀ are known.

In case of failure of the EM, the hybrid drive system according to the invention becomes a conventional drive with an internal combustion engine, since the control system of the internal combustion engine through the internal combustion engine with a certain delay in each case accurately provides the required torque on the main shaft, which is necessary to achieve and, accordingly, maintain the flight mode specified by the pilot.

If the internal combustion engine fails, the rotational speed drops, which is immediately compensated by the ED through additional power. Thanks to the stabilization of the rotation frequency DZ, flight safety is ensured. In addition, the EM control system determines that there is no torque DM generated by the internal combustion engine, which can only mean that the internal combustion engine is not working. Thus, the EM takes over all power supply until the ICE starts up again, or until landing. A safe flight is ensured at all times.

Since each of the two control systems receives the same data generated directly depending on the flight mode, each of the engines can autonomously provide the required flight mode. The distribution of loads between the two engines is completely automatic due to the fact that the ED very quickly determines and performs its part of the work, so that the internal combustion engine can constantly operate in the optimal range.

In addition, when the fuel level is low, the EM control system can load the EM more to save fuel. To prevent deep discharge or reloading of the battery, deviation from the first directive is also possible. Also, an ED can be connected as a booster to provide additional power, for example, when flying a high mountain. On the other hand, at high temperatures and/or extreme altitudes, in which ICE power is severely reduced due to rarefied air, ED can be applied more intensively, if the battery charge allows, to increase the available power limit or save fuel. In addition, at the stage of takeoff and / or landing, to reduce noise and emissions of exhaust gases in the area of \u200b\u200btakeoff or, accordingly, landing, only ED can be operated.

As soon as the exception ends, the first directive is activated again.

Brief description of the drawings

The invention is described in more detail below with reference to the drawings. The drawings show the following:

fig. 1 is a schematic representation of a hybrid drive system according to the invention;

fig. 2 are graphs for describing load distribution in various flight modes such as climb, cruise and descent.

Implementation of the invention

In FIG. 1 Details, as necessary to describe the invention, a hybrid system of the 4th drive is shown according to the invention. Said drawing shows part of a helicopter with a transmission 3, a gearbox 1 with a main rotor and, in addition, a tail rotor 2, which is irrelevant for the subject matter of the invention. On the transmission 3, an internal combustion engine (ICE) 6 and an electric motor (EM) 10 are located in parallel, with the EM 10 being preferably located between the ICE 6 and the main rotor gearbox 1. Other arrangements are also possible.

The pilot controls 5 receive control signals from the pilot for adjusting the rotor blades, whereby the adjustable engine power to be set is obtained indirectly, in the form of the desired speed DZ ₀ of rotation of the main shaft 3. If necessary, the data signal line 19, passing from the pilot's controls to the internal combustion engine control system 7, can be used for takeoff and landing.

ICE 6 is connected to the fuel tank 8, connected to the system of the ICE, which can adjust the supply of fuel from the fuel tank 8 to DIC 6 to provide the necessary driving force on the main shaft 3. In addition, ED 10 is connected to the battery 14, preferably through static The 12 current converter and charger 13, which can be equipped with buffering for protection against current peaks. The EM 10 may be powered by the charge of the battery 14, or the battery 14 may be charged by the mechanical power on the EM 10, whereby the main shaft 3 may either be driven or braked. The EM control system 11 is at least indirectly, for example, through a static current converter 12, connected to the EM 10 and can regulate it to provide the necessary driving or braking force on the main shaft 3.

In addition, a level indicator 9 can be located on the fuel tank 8, and a battery charge indicator 15 on the battery 14, which, during operation, can transmit their measurement data to the computing unit 16.

At least one torque sensor 17 and a tachometer 18 are located on the main shaft 3. During operation, the internal combustion engine control system 7 and the EM control system 11 receive data from at least one torque sensor 17 and at least one tachometer 18.

The computing unit 16 is connected to the EM control system 11 and the internal combustion engine control system 7. It is used to calculate the energy still available, the required torque on the main shaft 3 and/or to control the EM control system 11 . It contains a data memory 20 in which the values of the set speed DZ ₀ of rotation and the set torque DM ₀ are stored, and at the specified values, the optimal power input of the internal combustion engine 6 is achieved, and the efficiency of the internal combustion engine is maximum at the specified values.

During operation, the distribution of loads on the internal combustion engine 6 and ED 10 is caused by the control system 11 ED. This is shown schematically in Fig. 2.

The dotted curve in the upper diagram shows the flight mode as a function of time, in each case required by the pilot's controls 5, in particular the flight altitude H. Here, the flight altitude "0" should be understood as the ground. The solid line shows the actual height H of the flight, it is slightly delayed. In the first step (I), the helicopter continuously climbs until it reaches the desired flight altitude H ₁ . In the second stage (II) it constantly continues to fly at the indicated altitude, and in the third stage (III) it descends again. Between all stages of the flight, some time passes until the newly set goal is reached.

The curves in the middle diagram show schematically the total load P _H , i.e. the total torque on the rotor (dashed line), the load P _VM on the internal combustion engine 6 (dash-dotted line) and the load P _EM on the ED 10 (dashed line). The bottom diagram shows the DZ rotation frequency.

After the takeoff process, the ICE 6 operates at a consistently high level. At the first stage I ED 10 works as an additional drive, as soon as the internal combustion engine 6 reaches a predetermined optimum load P _VM due to the fact that it applies the torque DM ₀ . It maintains the ICE 6 in climb flight during phase I until the desired flight altitude H ₁ is reached, i. e. until the pilot slightly reduces the pitch angle of the rotor blades. The takeoff process may deviate from the first directive until the helicopter is airborne in a safe position.

As a result of the reduction in the pitch angle of the rotor blades at the beginning of stage II, the speed DZ increases slightly for a short time, as can be seen from the lower diagram. ED 10 immediately responds to this and reduces its power until the speed DZ again corresponds to the set value DZ ₀ . Thereafter, the flight altitude remains constant during the entire phase II. ICE 6 is inertial and therefore does not respond to the specified short-term change. In the example shown, at stage II, the load on the ED 10 is negative, thus, as a generator, it again charges the battery 14 with energy additionally available due to excess power from the internal combustion engine 6. At stage II, the internal combustion engine 6 does not change its load either.

At the beginning of the descending flight, at the beginning of stage III, the pilot again reduces the angle of the rotor blades, the speed DZ increases again briefly, and the ED 10 again reacts to this by reducing its power. However, this time, according to its second directive, it regulates up to a speed DZ that is slightly higher than the set value DZ ₀ . Now the energy on the EM 6 is immediately recuperated even more as the EM 10 brakes the main shaft 3 even more. While ED 10 maintains an increased speed DZ rotation, as shown by the lower curve in step III. The solid line showing the current rotation frequency DZ is located above the dotted line representing DZ ₀ .

Since the current rotation speed DZ is greater than the set rotation speed DZ ₀ , the power to the internal combustion engine 6 drops and thus noise and exhaust emissions are reduced at the landing site. This is achieved by the fact that the ED 10 constantly reduces the electrically generated power and thus weakens its braking action.

According to the invention, the speed DZ of rotation of the main shaft 3 according to the first directive is regulated only by means of ED 10 in such a way that at DM ₀ ICE 6 it stabilizes at the level of the set speed DZ ₀ of rotation. According to the second directive, as shown in stage III, there is a deviation from this in order to purposefully reduce the load on the internal combustion engine 6. In addition to the above emission reduction, deviation from the first directive may have other reasons. In particular, such a basis can be a purposeful charge or, respectively, discharge of the battery 14, if the degree of its charge requires it. In addition, the ED 10 can be connected as a booster in order to provide increased power or save fuel for a short time, for example, at high altitudes.

The second directive can be regulated, for example, based on the fact that the energy reserves are known, if the EM control system 11 has data on the state of charge of the battery 14 and the fuel reserve, on the basis of the norms of permissible noise levels depending on the flight altitude and / or preliminary information about the planned flight paths.

List of reference symbols

1 gearbox with main rotor

2 tail rotor

3 main shaft

4 hybrid drive system

5 pilot controls

6 internal combustion engine (ICE)

7 engine control system

8 fuel tank

9 level indicator

10 electric motor (EM)

11 ED control system

12 static current converter

13 charger

14 battery

15 battery level indicator

16 computing unit

17 torque sensor

18 tachometer

19 data signal line

20 data memory with the value of the optimal engine speed

I first stage, climb flight

II second stage, constant flight altitude

III third stage, descent flight

t time

H current flight altitude

H ₁ flight altitude to be reached

P power (excessive in relation to torque)

P _H total power

P _EM power per EM

P _VM power on internal combustion engine

DZ main shaft speed measured

DZ ₀ optimum speed

DM torque on the main shaft, measured

DM ₀ set torque.

Claims (26)

1. Hybrid drive system (4) with control systems (5, 7, 11) and the main shaft (3) of a helicopter with a main rotor (1) connected to a gearbox, which is capable of stabilizing the flight mode set by the pilot, containing - pilot controls (5), - an internal combustion engine (ICE) (6) and an electric motor (EM) (10), both of which act directly on the main shaft (3), - moreover, the internal combustion engine (6) is connected to the internal combustion engine control system (7), which is able to regulate the supply of fuel from the fuel tank (8) to the internal combustion engine (6) to provide the required driving force on the main shaft (3); - and at the same time, ED (10) is connected to the ED system (11), which can actually drive ED (10) by the discharge of the battery (14) or the battery (14) by the mechanical power created by ED (10), as a result whereby the main shaft (3) is either driven or, respectively, braked, differing in that - that one or more torque sensors (17) and tachometers (18) are located on the main shaft (3), and both for the internal combustion engine control system (7) and the EM control system (11) during operation it is possible to obtain the current frequency value (DZ) rotation and current torque (DM), - moreover, the specified values of the frequency (DZ ₀ ) of rotation and torque (DM ₀ ), at which the internal combustion engine (6) is able to achieve its optimal efficiency, are stored in memory and requested for the EM control system (11), and the first (DZ ₀ ) of the indicated values is applicable for the request also for the internal combustion engine control system (7), - and that the ICE control system (7) by matching the power of the ICE (6) at any time is able to independently reach the specified frequency (DZ ₀ ) of rotation of the main shaft (3) and stabilize it to stabilize any flight mode specified by the controls (5) pilot, - moreover, the EM control system (11) through the use of EM (10) is able to additionally set in motion or brake the main shaft (3), due to which the ICE control system (7) based on the current frequency (DZ) of rotation is able to automatically match the power of the ICE (6 ) to achieve or, respectively, maintain a given frequency (DZ ₀ ) of rotation of the main shaft (3), - and at the same time, the first directive is stored in the EM control system (11), so that the EM (10) always acts on the main shaft (3) with such a driving or braking force that leads to the fact that the internal combustion engine (6), if it has reached the optimal frequency (DZ ₀ ) of rotation of the main shaft (3) or, accordingly, maintains it, automatically creates a torque (DM ₀ ) on the main shaft (3), at which the internal combustion engine reaches the optimum engine power. 2. Hybrid drive system (4) according to claim 1, characterized in that the ED (10) is located between the internal combustion engine (6) and the main rotor gearbox (1). 3. Hybrid drive system (4) according to claim 1 or 2, characterized in that between the pilot controls (5) and the internal combustion engine control system (7) there is a direct line (19) for transmitting data signals for helicopter takeoff and landing. 4. The hybrid system (4) of the drive according to one of the previous points, characterized in that, in addition, the indicator (9) of the level is located on the fuel tank (8), and on the battery (14) there is a pointer (15) of the battery charge, the battery, the battery. which, during operation, are capable of transmitting their measurement data to the EM control system (11). 5. Hybrid drive system (4) according to claim 4, characterized in that it contains a calculation unit (16) for calculating the energies still available and, if necessary, for calculating a second directive that differs from the first directive, to protect the battery from reloading and non -discharge, saving fuel and/or periodic operation of the internal combustion engine (6) with lower power to reduce emissions. 6. A method of operating a hybrid drive system (4) for the main shaft (3) of a helicopter to provide the flight mode required by the pilot using a hybrid drive system (4) with control systems (5, 7, 11) according to one of the previous paragraphs, differing in stages, where: - current values (DZ, DM) of speed and torque are continuously measured on the main shaft (3) and transmitted both to the EM control system (11) and to the internal combustion engine control system (7), - set values of frequency (DZ ₀ ) rotation and torque (DM ₀ ) are stored in memory, and it is possible to request both values (DZ ₀ , DM ₀ ) by the EM control system (11) and at least the frequency (DZ ₀ ) of rotation by the system (7) internal combustion engine control, and these control systems (7, 11) constantly determine the deviations of the measured values (DZ, DM) from the specified values (DZ ₀ , DM ₀ ), - as soon as the pilot through the pilot controls (5) creates a variable power demand on the main shaft (3) in order to achieve the desired flight mode, this also causes a change in the frequency (DZ) of rotation of the main shaft (3), - the internal combustion engine control system (7) based on the deviation of the current rotation frequency (DZ) from the preset rotation frequency (DZ ₀ ) slowly changes the power of the internal combustion engine (6) in such a way that the preset rotation frequency (DZ ₀ ) is reached, - the EM control system (11) according to its first directive based on the deviation of the current values of the frequency (DZ) of rotation and / or torque (DM) from the corresponding setpoints (DZ ₀ , DM ₀ ) in a faster manner than the internal combustion engine (6), changes the power of the EM (10) in such a way that the internal combustion engine (6) after slow regulation of its power until the specified frequency (DZ ₀ ) of rotation is reached, creates a specified torque (DM ₀ ), at which it reaches the optimum efficiency, - as a result of which either the battery (14) is charged due to the mechanical power on the EM (10), or the EM (10) is activated due to the charge of the battery (14), - and in case of failure of the EM control system (11), the internal combustion engine control system (7) on the basis of speed control to a predetermined value (DZ ₀ ) automatically by means of the internal combustion engine (7) provides the required driving force and thus a stable flight mode. 7. The method according to p. 6 using a hybrid drive system (4) according to p. ) the state of charge of the battery (14) determines the energy still available and therefore, according to the second directive, deviates from the regulation of the first directive in order to purposefully charge or discharge the battery (14) for battery protection, fuel economy and / or periodic operation of the internal combustion engine (6) with lower power to reduce emissions. 8. The method according to one of paragraphs. 6 or 7, characterized in that at the stage of take -off and/or landing, exclusively ED (10) is exploited to reduce noise in the area of planting and emissions of exhaust gases. 9. The method according to one of paragraphs. 6-8, characterized in that during operation, the EM control system (11) on the basis of too low rotational speed (DZ < DZ ₀ ) and/or increased torque (DM > DM ₀ ) increases the power of the EM (10), and vice versa.

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