AT526560A1 - Emergency power device for a power generation system - Google Patents

Abstract

The present invention relates, inter alia, to an emergency power device (2) for an energy generation system (1), comprising a generator (21) which has a system interface (6) to the energy generation system (1), in particular to an inverter (5) of the energy generation system (1), a control device (25) which is connected to the generator (21) via a signal line (26), and a measuring device (23) assigned to the generator (21) which has an interface to the control device (23). In order to provide an emergency power device (2) in which the performance of the generator (21) can be adapted directly to changing conditions, it is provided that the measuring device (23) is designed to generate measured values relating to the operating point of the generator (21), for example to measure the electrical voltage and/or the electrical current and/or the ratio of electrical voltage to electrical current, and that the control device (25) is provided in such a way that it is able to regulate the operating point of the generator (21) based on the measured values generated.

Description

Emergency power device for a power generation system

The invention relates firstly to an emergency power device for an energy generation system, as well as to an energy generation system. Furthermore, the invention also relates to a method for controlling the operating point of a generator of an emergency power device for an energy generation system, as well as to a method for controlling a

energy generation system.

Energy generation systems themselves are known in various ways from the state of the art. In one embodiment, the energy generation system serves to generate and provide electrical energy, for example for an electrical network of a house. Such an energy generation system can, for example, serve as the sole energy source for the electrical network, or

as a supplement to an electrical supply network.

Such an energy generation system has, for example, a device for generating electrical energy, which can be a photovoltaic device or a device for generating electrical energy based on wind power. Furthermore, the energy generation system comprises a device for storing the generated electrical energy, such as a battery device. Finally, the energy generation system can also have an inverter, which is connected to the electrical network, in particular a

a domestic network. In normal operation of the energy generation system, electrical energy is generated by

the device for generating electrical energy and then fed into the electrical network and/or in the device for storing the

Energy can then be made available to the electrical grid when needed.

It is known to additionally equip such energy generation systems with an emergency power device. This is required, for example, if the device for generating electrical energy fails or if, for example, during peak times or when energy-intensive consumers in the electrical network are activated, more electrical energy is required than can be provided by the device for storing the electrical energy.

This will be illustrated using a specific application. If the energy generation system feeds the electrical energy into an electrical network, for example a house network, which is also connected to an electrical supply network, the power may fail for a variety of reasons, for example due to a thunderstorm, a violent storm, or the like. The power may fail for several hours, days or weeks, for example.

If the device for generating electrical energy is a photovoltaic device, the storage device can no longer be charged if there is no solar radiation. In the worst case scenario, the storage device for the electrical energy, for example the battery device, will only have a low storage level during a power failure. If, for example, there is no solar radiation for a long period of time, or if the photovoltaic device is covered in snow, damaged or very dirty, i.e. the storage device cannot be charged, the emergency power device is used. It is connected directly to the electrical grid, for example via an inverter, and recharges the storage device in the shortest possible time. Once the storage device is charged, the emergency power device can switch itself off again. This means that the energy generation system is completely autonomous at all times.

During operation, the control device monitors the environment of the generator via a measuring device in the form of a gas sensor and a temperature sensor.

rators to avoid damaging the generator.

The disadvantage of this known solution is that, in fact, appropriate protective measures are only taken when damage to the generator occurs or shortly before it occurs, for example by switching off the generator.

Based on the described prior art, the present invention is based on the object of improving an emergency power device so that the aforementioned disadvantages can be avoided. In particular, an emergency power device is to be provided in which the performance of the generator is immediately adapted to changing circumstances.

The invention solves the problem by the emergency power device with the features according to independent claim 1, which represents the first aspect of the invention, by the energy generation system with the features according to independent claim 12, which represents the second aspect of the invention

represents.

Further features and details of the invention emerge from the subclaims, the description and the drawings. Features and details that are described in connection with one aspect of the invention also apply in full in connection with the other aspects of the invention, and vice versa, so that with regard to the disclosure of one of the aspects of the invention, reference is also made in full to the disclosure of the other aspects of the invention.

and is referred to.

The individual aspects of the invention are based on the common inventive basic concept that the generator of an emergency power device is controlled via a suitable control circuit so that it is always at an adequate operating point. In the sense of the present invention, the operating point is in particular a certain point in the characteristic field or on the characteristic curve of the generator, which is determined based on the system properties and the external influences.

influences and parameters are taken into account.

According to the first aspect of the invention, an emergency power device is provided which has the features of independent claim 1.

The emergency power device is intended for an energy generation system. This means that the emergency power device can supply the energy generation system with electrical energy when required. In this regard, in order to avoid repetition, reference is also made to the explanations regarding the energy generation system according to the invention.

generation system is fully referred to and referenced below.

Invention aspect is explained in detail below.

For this purpose, the generator has a system interface to the energy generation system. For example, as described in more detail below, the generator can be connected to an MPP charge controller via the system interface, or if necessary,

be connected to an inverter of the energy generation system.

Depending on the design, the generator can be connected directly to the energy generation system via the system interface. Alternatively, other components can be connected between the generator and the energy generation system. In a preferred embodiment, the emergency power device has a rectifier, which is connected to the generator on the input side via a line and which is connected to the generator on the output side via the system interface.

connected to the energy generation system.

Furthermore, the emergency power device has a control device which is connected to the generator via a signal line. In the control device, as described below in connection with the method according to the invention, so that at this point reference is also made to these explanations in full in order to avoid repetition, control signals are generated by means of which the generator, in particular its performance

mance, is regulated.

For this purpose, a measuring device is assigned to the generator, which has an interface to the control device. This measuring device generates measuring signals, on the basis of which the control device then carries out the control

signals are generated. “Generating” can mean, on the one hand, that the

be in order.

The measuring device is now designed in a special way. According to the invention, the measuring device is designed to generate measured values relating to the operating point of the generator. Taking into account the general definition of the operating point above, the measuring device is designed in a preferred embodiment to measure the electrical voltage and/or the electrical current and/or the ratio of electrical voltage to electrical current.

According to the invention, the control device is provided in such a way that it is able to regulate the operating point of the generator based on the measured values generated. The measured values generated by the measuring device are transmitted to the control device and further processed there. In particular, control signals are generated on the basis of the measured values, which are then provided to the generator by the control device. For example, as will be described in more detail below, an AVR (Automatic Voltage Regulation) control device can be assigned to the generator. The control signals generated by the control device are then transmitted from the control device to the AVR control device. The generator, i.e. its operating point, is then regulated using the control signals.

How this can be realized is described below using preferred embodiments.

be.

For example, a storage device can be provided in which reference values in relation to the recorded measured values, possibly also the measured values generated by the measuring device, are stored at least temporarily. The storage device can have an interface to an external input device or for receiving external data. In this way, it is possible to subsequently import and/or change reference values. For example, the reference values are coordinated with a specific inverter. It is now possible to replace the inverters in an energy generation system. The required reference values relating to the replaced inverter can then be stored in the storage device. The storage device is assigned to the control device. For example, the storage device can be a component of the control device. Or, the storage device is an independent component that is connected to the control device via an interface.

In a preferred embodiment, the reference values are stored in the storage device in the form of at least one predetermined characteristic curve, in particular in the form of at least one characteristic curve of a device for generating electrical energy of the energy generation device, optionally a photovoltaic device or a device for generating electrical energy based on wind power. This is described in greater detail below in connection with the energy generation system according to the invention and with the method according to the invention, so that at this point, in order to avoid repetition, reference is also made in full to these statements below and

is referred to.

referred to and referenced below.

Furthermore, in a preferred embodiment, an AVR (Automatic Voltage Regulation) control device associated with the generator can be provided, wherein the control device is connected to the AVR control device via a signal line. The AVR control device is associated with the generator.

Typically, the task of an AVR control system is to keep the generator's output voltage constant and to compensate for voltage changes.

This is to avoid damage to the generator.

In the present case, however, the AVR control device preferably takes on a different task. Here, the AVR control device triggers a change, in particular a change in the excitation voltage. The AVR control device interacts with the generator and can throttle its excitation voltage when a maximum value is reached. A change in the excitation voltage of the generator can be triggered by the AVR control device via the control signal generated in the control device, as is also described in more detail below in connection with the method according to the invention, so that at this point full reference is also made to the corresponding explanations below.

taken and referred to.

Realize benefits:

Complete autonomy even in bad weather

Direct charging of the battery storage on the DC side Continuous current flow even at peak loads

No installation necessary “plug and play”

Reliable thanks to diesel engine with 11 consumption per hour Comfortable electric starter

Suitable for single-family homes and small businesses

No damage due to voltage or frequency errors (DC-side feed into the PV inverter)

According to the second aspect of the invention, a power generation system is provided

which has the features of independent claim 12.

The energy generation system, which is preferably a home system, has a device for generating electrical energy, which is in particular a photovoltaic device or a device for generating electrical energy based on wind power. Furthermore, the energy generation system has a device for storing the generated electrical energy, in particular a battery device. Finally, the energy generation system also has an inverter, in particular a hybrid inverter, which is connected to an electrical network, in particular a home network, via a line. With regard to this energy generation system, in order to avoid repetition, reference is also made to the statements above, including the description page.

management, reference is made and referred to.

and referred to.

In a preferred embodiment, the energy generation system has an MPP charge controller that is connected to the device for generating electrical energy, the device for storing the generated electrical energy, the emergency power device and the inverter. Alternatively, the MPP charge controller can also be a component of the inverter. Such MPP charge controllers are generally known to those skilled in the art. The MPP charge controller adapts its input voltage to the device for generating electrical energy, for example a photovoltaic device, so that it can deliver maximum power.

In photovoltaic systems, the optimal operating point with maximum power output is not constant, but depends on external factors such as the current irradiance and the temperature of the module. Therefore, the load resistance of the photovoltaic system is influenced by an electronically controlled circuit so that the load resistance is continuously adjusted and tracked so that it is almost exactly the same as the current internal resistance of the photovoltaic system and thus the power output of the photovoltaic system is always maximum under different operating conditions. In practice, the optimal operating point is set and continuously tracked by the MPP charge controller.

According to the third aspect of the invention, a method for controlling the operating point of a generator of an emergency power device for a power generation system is provided, which has the features of independent claim 14. In particular, a method for controlling the operating point of a generator of an emergency power device according to the first aspect of the

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as referred to and referenced in the general description.

According to the invention, the method is characterized by the following steps:

a) A measuring device assigned to the generator is used to generate, in particular continuously, measured values relating to the operating point of the generator. For example, the measuring device measures the electrical voltage and/or the electrical current and/or the ratio of electrical voltage to electrical current.

b) The generated measured values are transmitted via an interface to a generator

assigned control device.

c) In the control device, based on the measured values generated, a control signal for regulating the operating point of the generator is generated and made available to the generator, for example transmitted to an AVR control device assigned to the generator. This can be done in different ways. For example, the control signal for regulating the operating point of the generator can be generated by comparing the measured values generated by the measuring device with reference values in a comparator device. In particular, the control signal for regulating the operating point of the generator can be generated by comparing the measured values generated by the measuring device with a predetermined characteristic curve, in particular in the form of at least one characteristic curve of a device for generating electrical energy of the energy generation device, optionally a photovoltaic device or a device for generating electrical energy based on wind power.

d) The operating point of the generator is then adjusted according to the available

For example, the control signal in the

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operating point or according to a specified characteristic curve.

In a preferred embodiment, the generator can be assigned an AVR (Automatic Voltage Regulation) control device, wherein the control signals generated in the control device trigger a change in the excitation voltage of the generator by the AVR control device.

According to the fourth aspect of the invention, a method for controlling an energy generation system is provided, which has the features of independent claim 19. In particular, a method for controlling an energy generation system is provided according to the third aspect of the invention. To avoid repetition, reference is therefore made here in full to the statements on the third aspect of the invention and to the general description.

description and cross-referenced.

The energy generation system has the following components: a device for generating electrical energy, in particular a photovoltaic device or a device for generating electrical energy based on wind power; a device for storing the generated electrical energy, in particular a battery device; an inverter which is connected to an electrical network, in particular a house network, via a line, and also an emergency power device with a generator which has a system interface to the energy generation system, in particular to an MPP charge controller, a control device which is connected to the generator via a signal line, and a measuring device assigned to the generator which has an interface to the control device. In particular, the emergency power device is designed according to the first aspect of the invention. To avoid repetition, reference is therefore made in full at this point to the statements on the first aspect of the invention and to the general description and

grasslands.

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a) During operation of the device for generating electrical energy, the generated electrical energy is stored in the device for storing electrical energy and/or the inverter is supplied with electrical energy in accordance with

the characteristic curve of the device for generating electrical energy;

(b) During operation of the generator, in particular when the generator of the emergency power device replaces or supplements the device for generating electrical energy, the electrical energy generated by the generator is stored in the device for storing electrical energy and/or the inverter is supplied with electrical energy generated by the generator.

When the emergency power device, in particular its generator, is connected, in particular to an MPP charge controller, the device for generating electrical energy is separated from the inverter.

If, during generator operation, measured values relating to the operating point of the generator are generated, in particular continuously, via a measuring device assigned to the generator, the measured values generated are preferably transmitted via an interface to a control device assigned to the generator. In the control device, based on the measured values generated, a control signal for regulating the operating point of the generator is generated and made available to the generator, for example transmitted to an AVR control device assigned to the generator. The operating point of the generator is then

controlled according to the received control signal.

Preferably, during generator operation, the operating point of the generator is controlled by means of the control device of the emergency power device in such a way that it simulates the characteristic curve of the device for generating electrical energy, for example a photovoltaic device, in relation to the inverter. This characteristic

line is preferably stored in the control device of the emergency power device.

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In a preferred embodiment, the method is designed such that during generator operation, measured values relating to the operating point of the generator are generated via the measuring device, in particular current values are measured, that the measured values generated are compared with reference values, and that when the measured values generated reach the reference values, the operating point of the generator, in particular the excitation of the generator, is adjusted. This can be done, for example, by means of an AVR control device assigned to the generator.

In a preferred embodiment, when the inverter is supplied with electrical energy generated by the generator, it can adapt its control direction to the electrical energy received from the generator.

The figures show the subject matter of the invention in more detail using an exemplary embodiment.

Figure 1 shows a schematic representation of an energy generation system according to the invention;

Figure 2 shows a schematic representation of an emergency power device according to the invention;

Figure 3 is a curve showing how the MPP tracking of an inverter

inverter functions schematically; and Figure 4 shows the curve of a power control of the generator by means of the control device of the emergency power device.

Figure 1 shows an energy generation system 1 which is designed to provide electrical energy for a home network 10. The energy generation system 1 initially has a device 3 for generating electrical

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The MPP charge controller 9 is also connected to an inverter 5, in particular a hybrid inverter, via a line 8. On the output side, the inverter 5 is connected to the house network 10, which also

can still be connected to a supply network 11.

As can be seen from Figure 2, an essential component of the emergency power device 2 is a generator 21, which is driven by an actuator device 20, for example a diesel engine. The generator 21 is connected to the MPP charge controller 9 of the energy generation system 1 via the system interface 6. A rectifier 30 is also connected in between, which is connected to the generator 21 via a line 22. In the line 22 between the generator 21 and the rectifier 30 there is a measuring device 23, which is designed to measure the electrical current and/or the electrical voltage and/or the ratio of electrical voltage to electrical current, in each case of the generator 21. The measuring device 23 is connected via a signal line 24 to a control device 25, which in turn is connected via a signal line 26 to an AVR control device 27 assigned to the generator 21. In the control device 25, control signals are generated on the basis of the received measured values from the measuring device 23 and transmitted to the AVR control device 27, whereby a change

change in the excitation voltage of the generator 21.

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when it is snowy or does not produce any energy due to darkness.

The basic components of the emergency power device are the actuator device 20 in the form of a combustion engine, the generator 21 and the rectifier 30. The engine draws fuel from a tank that is permanently available and thus converts chemical energy into kinetic energy. This kinetic energy in turn drives the generator 21, which produces an alternating voltage. In the

In rectifier 30 this alternating voltage is rectified and smoothed.

If, for example, direct current is used in the range between 400 and 800 volts, the generator 21 is connected directly to the MPP charge controller 9 of the inverter 5 via the rectifier 30 and the system interface 6. After about one minute, the generator 21 goes into full power operation and thus feeds the inverter 5 with the maximum power.

This then supplies the power either directly to the storage device 4 or, after conversion, to the connected house network 10. When the storage device 4 is again 100% full and any large consumers in the house, such as heat pumps, electric stoves or other heavy consumers, have been switched off, the emergency power device 2 can be switched off again because then the house network 10 is again supplied directly from the storage device 4. Therefore, the emergency power device 2 is the advantageous extension for any island system.

location,

The inverter 5 is always supplied with current/voltage according to the characteristic curve of the device 3 for generating electrical energy, here the photovoltaic device. If the emergency power device 2 is used instead of the device 3

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In operation, for example, a voltage of 500 V is used. The inverter 5 increases the voltage in incremental steps, with the current being continuously measured via the measuring device 23 until it reaches a lower limit. This triggers a change (reduction) in the excitation voltage in the generator 21.

The measured value (current) is compared in the control device 25 with the stored characteristic curve by means of a comparator device and gives a control signal between 0 and 5 V to the AVR control device 27. This triggers the above-mentioned change in the excitation voltage for the generator 21 according to the control signal

out of.

Furthermore, the characteristic curve in the control device 25 can be reprogrammed at any time. This makes it possible to use any inverter 5 without mechanical modifications to the rest of the energy generation system 1.

The curve shown in Figure 3 shows how the MPP tracking of the inverter 5 works schematically. The curve shown is the power characteristic of a photovoltaic device.

The power control of the generator 21 via the control device 25 simulates exactly this curve. In the freely programmable control device 25,

the curve can also be adapted for other power units.

For example, the current is measured continuously. If a reference value, for example current, is reached that is set in the control device 25 and is preferably adjustable, the excitation of the generator 21 is reduced and the output voltage thus drops. The inverter 5 recognizes that the

17

18

10 11 12

20 21 22 23 24 25 26 27 28

30

Power generation system emergency power device

Device for generating electrical energy Device for storing the generated electrical energy Inverter

System interface

Supply line

Line

MPP charge controller

Home network

Supply network

Line

Actuator device

Generator

Line to rectifier

Measuring device

Measurement line

Control device

Signal line

AVR (Automatic Voltage Control) Line section

Rectifier

19

Claims (25)

1. Emergency power device (2) for an energy generation system (1), comprising a generator (21) which has a system interface (6) to the energy generation system (1), in particular to an inverter (5) of the energy generation system (1), a control device (25) which is connected to the generator (21) via a signal line (26), and a measuring device (23) associated with the generator (21) which has an interface to the control device (23), characterized, that the measuring device (23) is designed to generate measured values relating to the operating point of the generator (21), and that the control device (25) is provided such that it is able to regulate the operating point of the generator (21) based on the generated measured values. geln. 2. Emergency power device according to claim 1, further comprising a comparator device for comparing the measured values generated by the measuring device (23) with reference values, and that the comparator device is optionally in the control device (25) or in the measuring device (23). 3. Emergency power device according to claim 1 or 2, further comprising a storage device in which reference values with respect to the detected measured values are at least temporarily stored, and that the storage device is assigned to the control device (25). 4. Emergency power device according to claim 3, characterized in that the reference values are in the form of at least one predetermined characteristic curve, in particular in the form of at least one characteristic curve of a device (3) for generating electrical energy the energy generation facility, optionally a photovoltaic facility or 20 storage device. 5. Emergency power device according to one of claims 1 to 4, characterized in that the control device (25) is provided in such a way that it is able to control the generator (21) to its optimum operating point or according to a predetermined to regulate the given characteristic curve. 6. Emergency power device according to one of claims 1 to 5, characterized in that the measuring device (23) is part of the control device (25), or that the measuring device (23) is connected to the control device (25) via a measuring line (24). 7. Emergency power device according to one of claims 1 to 6, characterized in that the measuring device (23) is designed to measure the electrical voltage and/or the electrical current and/or the ratio of electrical voltage to electrical current. 8. Emergency power device according to one of claims 1 to 7, further comprising an AVR (Automatic Voltage Regulation) control device (27) assigned to the generator (21), and that the control device (25) is connected to the AVR control device (27) via a signal line (26). 9. Emergency power device according to one of claims 1 to 8, further comprising a rectifier (30) which is connected on the input side to the generator (21) via a line (22) and which is connected on the output side to the energy generation system (1) via the system interface (6). 10. Emergency power device according to one of claims 1 to 9, characterized in that the measuring device (23) is arranged on/in the generator (21) or in the line (22) from the generator (21) to the rectifier (30). 21 an actuator device (20) for the generator (21). 12. Energy generation system (1), comprising a device (3) for generating electrical energy, in particular a photovoltaic device or a device for generating electrical energy based on wind power, a device (4) for storing the generated electrical energy, in particular a battery device; an inverter (5) which is connected via a line to an electrical network, in particular a house network (10), and further comprising an emergency power device (2) according to one of claims 1 to 11. 13. Energy generation system according to claim 12, further comprising an MPP charge controller (9) which is connected to the device (3) for generating electrical energy, the device (4) for storing the generated electrical energy, the emergency power device (2) and the inverter (5), or which is a component of the inverter (5). 14. Method for controlling the operating point of a generator (21) of an emergency power device (2) for an energy generation system (1), in particular a generator (21) of an emergency power device (2) according to one of claims 1 to 11, characterized by the following steps: a) via a measuring device (23) associated with the generator (21), measured values relating to the operating point of the generator (21) are generated, in particular continuously; b) The measured values generated are transmitted via an interface to a control device (25) associated with the generator (21); c) In the control device (25), based on the generated measured values, a control signal for regulating the operating point of the generator (21) is generated and provided to the generator (21); 22 Control signal regulated. 15. Method according to claim 14, characterized in that the control signal for regulating the operating point of the generator (21) is generated by comparing the measured values generated by the measuring device (23) with reference values. 16. Method according to claim 15, characterized in that the control signal for regulating the operating point of the generator (21) is generated by comparing in the comparator device the measured values generated by the measuring device (23) with reference values in the form of a predetermined characteristic curve, in particular in the form of at least one characteristic curve of a device (3) for generating electrical energy of the energy generation device (1), optionally a photovoltaic device or a device for generating electrical energy based on wind power. will be. 17. Method according to one of claims 14 to 16, characterized in that the measuring device (23) measures the electrical voltage and/or the electrical current and/or the ratio of electrical voltage to electrical current, will measure. 18. Method according to one of claims 14 to 17, characterized in that an AVR (Automatic Voltage Regulation) control device (27) is assigned to the generator (21), and that the control signal generated in the control device (25) triggers a change in the excitation voltage of the generator (21) by the AVR control device (27). 19. Method for controlling an energy generation system (1), in particular an energy generation system (1) according to one of claims 12 or 13, comprising a device (3) for generating electrical energy, in particular a photovoltaic device or a device for generating electrical energy 23 characterized by the following steps: a) During operation of the device (3) for generating electrical energy, the generated electrical energy is stored in the device (4) for storing the electrical energy and/or the inverter (5) is supplied with electrical energy according to the characteristic curve of the device (3) for generating electrical energy; b) During operation of the generator (21), in particular when the generator (21) of the emergency power device (2) replaces the device (3) for generating electrical energy, the electrical energy generated by the generator (21) is stored in the device (4) for storing the electrical energy and/or the inverter (5) is supplied with electrical energy generated by the generator (21). 20. Method according to claim 19, characterized in that during generator operation, measured values relating to the operating point of the generator (21) are generated, in particular continuously, via a measuring device (23) assigned to the generator (21); that the generated measured values are transmitted via an interface to a control device (25) assigned to the generator (21); that in the control device (25), based on the generated measured values, a control signal for regulating the operating point of the generator (21) is generated and provided to the generator (21), in particular via an AVR control device (Automatic Voltage Regulation) (27) assigned to the generator (21); and that the 24 is regulated. 21. Method according to claim 19 or 20, characterized in that during generator operation, the operating point of the generator (21) is regulated by means of the control device (25) of the emergency power device (2) in such a way that it follows the characteristic curve of the device (3) for generating electrical energy with respect to the inverter (5). Energy simulated. 22. Method according to claim 20 or 21, characterized in that during generator operation, measured values relating to the operating point of the generator (21) are generated via the measuring device (23), in particular current values are measured, that the measured values generated are compared with reference values, and that when the measured values generated reach the reference values, the operating point of the generator (21), in particular the excitation of the generator, is adjusted. 23. Method according to claim 22, characterized in that the inverter (5), when it is supplied with electrical energy generated by the generator (21), adapts its control direction to the electrical energy received from the generator (21). gy adapts. 25