CN108809123B - Electrical consumer device and method of operation - Google Patents

Abstract

In an electric device (2), it has: a power supply group (4) with a power grid input terminal (6), and an electric consumer (10) supplied with output power (A) by the power supply group (4), wherein the power supply The group (4) comprises a PFC module (12) with an intermediate circuit (14), wherein the PFC module (12) comprises a regulator (16) for feeding said intermediate circuit (14), which is connected to an electric load ( 10) The characteristic value (K) related to the required output power (A) is positively fed back to the regulator (16). In a method for operating an electrical consumer (2), the electrical consumer (2) has a power pack (4), a consumer (10), from which an output power is supplied to the consumer (A), wherein the power pack (4) includes a PFC module (12), wherein the PFC module (12) includes a regulator (16) that will be related to the output power (A) required by the consumer (10) The characteristic value is positively fed back to the controller (16).

Description

Electrical device and method of operation

technical field

The invention relates to an electrical consumer and an operating method for operating the electrical consumer.

Background technique

Due to increasingly stringent legal regulations, more and more electronic devices have devices that optimize the received grid current with respect to the harmonics contained in the received grid current. Switching power supply packs of conventional design for consumers usually have rectifiers and smoothing capacitors. The smoothing capacitor is only charged by the consumer load when the instantaneous value of the sinusoidal line voltage increases above the DC potential of the smoothing capacitor. As a result, only brief pulses of current recharge the capacitor. Therefore, this current variation process has a large number of harmonics. Depending on the applicable standard, this may make licensing or certification difficult or impossible.

The goal of PFC (English: Power Factor Correction, Power Factor Correction) is to optimize the harmonics (whose spectrum is evaluated by the power factor) in such a way that besides the fundamental (current at 50 Hz), only a small number of harmonics are included. Power factor thus describes the ratio of received real power to apparent power. In order to optimize this ratio, the received grid current is first regulated in PFC.

It is known from DE 10 2010 063 126 A1 that a charging device is required for charging the vehicle high-voltage battery of a hybrid or electric vehicle, for example via the public power grid. Known charging devices for high-voltage batteries of vehicles generally consist of a rectifier with a power bank filter, a power factor correction circuit (PFC: Power-Factor-Correction) and a galvanic isolation device.

Contents of the invention

Within the scope of the present invention, an electrical consumer device is disclosed. Preferred or advantageous embodiments of the invention and other classes of invention emerge from the ensuing description and from the drawings.

The electrical device includes a power pack. The power pack includes a grid input. The grid input can be connected to a grid, wherein the grid conducts an alternating voltage. The electrical appliance device includes an electrical appliance. The consumer is connected to a power pack and (during operation) is supplied with output power by the power pack. The power pack includes a PFC module. The PFC module is connected to the grid input. The PFC module includes an intermediate circuit. The intermediate circuit (in operation) is fed from the grid input. The intermediate circuit (in operation) provides the output power. The PFC module includes a regulator. The controller is used (during operation) to feed output power from the grid input to the intermediate circuit. In other words, the regulator regulates the feed in terms of the amount of energy or power delivered. In this load, (during operation) a characteristic value is positively fed back to the controller. This characteristic value is related to the output power required by the consumer. The correlation can be achieved in a sufficiently known manner: for example by scaling, each unique and unambiguous mapping rule, standardization, etc. The characteristic value is, for example, the value in watts of the desired output power.

In the real sense, an "intermediate circuit" exists here in particular in a two-stage PFC-SMPS concept (English: switched-mode power supply, switched-mode power supply group). The first stage is a PFC with a DC intermediate circuit and the second stage is a main SMPS with galvanic isolation. However, the implementation can also be a single stage solution. In this single-stage scheme, two power pack stages are combined into one. The conventional DC intermediate link disappears and moves into the output capacitors of the power pack. In this sense, the current designation "intermediate circuit" can also be understood representatively as the above-mentioned "outgoing circuit". The same applies to the "intermediate circuit capacitor", which can also be the "output capacitor".

In normal or normal operation, the power pack is connected to an electrical network, wherein the electrical network conducts an alternating voltage. Supply output power to electrical appliances. The PFC module is fed from the grid input and provides output power. The controller takes (beziehen) output power from the grid input and feeds this output power into the intermediate circuit, positively feeds the characteristic value to the controller, where it is provided either directly by the PFC module or by another stage of the power pack Output Power. For example, in the power group, the main power group is connected in the direction from the PFC module to the electric appliance. In the present case, it is assumed for simplicity that there are no power losses, so the full output power is taken from the grid, which in turn passes through the PFC module and possibly other components of the power pack, and is received by the consumer.

According to the invention, in the regulator of the PFC module, a positive feedback of information about the power consumed by the consumer that must be provided by the PFC module takes place. In particular, the regulator regulates the voltage in the intermediate circuit to a desired value, whereby energy or power is taken from the grid input and supplied to the intermediate circuit. According to the invention, the power required by the consumer is taken into account at the latest at the moment when the consumer requires this power, or even earlier (see below), so that the controller can respond particularly quickly or in advance to changes in the power demand at the intermediate circuit React. This is not possible when the voltage at the intermediate circuit has already dropped. Conventional regulators are only able to react when the DC link voltage has changed due to load changes in the consumers. The response time of the controller to changes in the power demand of consumers is thus improved compared to conventional controllers which include a feedback of the intermediate circuit voltage to the controller.

Overall, this results in an improved power supply by the power pack or the PFC module during operation.

In a preferred embodiment, the characteristic value is related to a demand of the electrical consumer for output power that can only be expected in the future after a predicted time has elapsed. At the (current) point in time at which the characteristic value is supplied to the controller or taken into account in the controller, the power consumption of the consumer is taken into account which will be in the future with a predicted time delay. This results in a predictive, that is to say a pre-regulation, which can react to expected power fluctuations already in advance. Prediction methods are sufficiently known from various technical fields that a suitable prediction method can be selected here. Specific examples for implementing such predictions are set forth below. The power pack can thus react particularly efficiently to fluctuations in the power demand of the electrical consumers.

In a preferred embodiment, the predicted time is in the range of double digit microseconds up to double digit milliseconds. The forecast time is the time between the current use time of the characteristic value in the regulator and the expected demand moment for the output power. Especially small ranges between three-digit microseconds and single-digit milliseconds are possible. In particular in the embodiments mentioned below, such prediction times can be implemented particularly simply.

In a preferred embodiment, the consumer has an input signal or can be supplied with an input signal. The consumer's demand is related to the input signal (its content). The eigenvalues are then found from the input signal.

In this case, the current or future demand of the consumer for output power can already be inferred by analyzing or evaluating the input signal supplied to the consumer, since this requirement is dependent on said signal. The information in the characteristic value then relates to the power requirement of the increased input signal processed in the electrical consumer, wherein the information is at least partially present in the input signal, for example in the form of its temporal profile. Actual demand depends only on current buffs. Corresponding embodiments can also be used for input signals that are not known before they are supplied to consumers.

By ascertaining the characteristic values from the (current) input signal, a time advantage or a forecast can be achieved if the demand for the consumer does not arise until after the input signal is already available for analysis. In particular, the demand in the consumer is not generated until after a propagation time has elapsed after the input signal has reached the consumer. The eigenvalues are then ascertained from the input signal at least until the propagation time has completely expired. The prediction, ie the information about the desired output power, is thus already obtained before the output power is actually produced. Therefore, the prediction can be carried out particularly simply. In this case, the forecast time is the time between the characterization of an input signal known in advance and the actual demand for output power (related to the temporally "delayed" input signal) in the consumer.

In a preferred variant of this embodiment, the input signal is an input signal that is at least segmentally advanced, ie is known in advance before being supplied to the consumer. Then, the eigenvalues are calculated in advance from the input signals known in advance. Thus, the demand for power in the consumer is predictively known in advance. For example, if the input signal is an audio signal to be amplified, presented by a data carrier, and the audio signal is therefore already completely known on the data carrier, ie (long before) the actual presentation, it is especially possible to completely advance Find the corresponding needs. Thus, the audio signal can be analyzed and the corresponding requirements can be calculated predictively in advance and can thus be provided to the controller with an appropriate lead time.

In a preferred variant of this embodiment, the input signal is a signal supplied from the outside to the consumer device. "Externally" means that the signal does not originate within the consumer, in particular is not generated by or associated with the power pack, ie the input signal is only processed inside the consumer. The consumer is, for example, an amplifier device in order to amplify the input signal and to output it again as an output signal, possibly with a time delay. Thanks to the invention, such a device can also be operated advantageously.

In a preferred variant of this embodiment, the consumer device is an amplifier device, in particular an audio amplifier device, and the input signal is a signal, in particular an audio signal, to be amplified by the amplifier device. The (audio) signal is thus fed to an (audio) amplifier, amplified and output again (possibly with a time delay) by the amplifier.

In a preferred variant of this embodiment, the characteristic value is a characteristic value which is dependent on the desired output signal and thus on the output power of the input signal processed in the consumer. Since the processing in the consumer is generally known, the desired output signal and thus the output power can be inferred from the input signal. In this case, for example, the output power of the amplifier arrangement is also taken into account, and the power requirement for the amplified useful signal or input signal is taken into account. The desired power consumption is a function of the desired output power. This relationship can be ascertained particularly easily.

In a preferred variant of this embodiment, the consumer includes a digital signal processor (DSP). The signal processor is located in the signal path of the input signal inside the consumer. This signal processing has an internal propagation time. That is, the signal fed into the signal processor leaves the signal processor after said propagation time. The future demand for output power is then ascertained from the input signal, at least not yet delayed by the full propagation time. The consumption is then ascertained after the processing time that the input signal consumes from feeding until ascertaining in the DSP. Prediction time remains as the remainder of the propagation time (subtracting the processing time from the propagation time). After the predicted time, the input signal leaves the DSP and is amplified, ie output power is produced immediately thereafter.

In particular, the consumer is again an amplifier device, which includes an amplifier and a DSP. In this case, the DSP is arranged upstream of the amplifier with respect to the input signal. In other words, at least part of the processing time of the signal in the DSP is used as the prediction time, so that the information about the power requirement of the amplifier is already fed back positively in the PFC controller in advance. In particular, the information for the feature values is extracted from the undelayed input signal, ie in the uppermost temporal layer of the DSP. Then, the total delay time in DSP can be used as prediction time for PFC.

In a preferred embodiment, the controller has a desired input and an actual input. An actual value related to the current actual voltage in the intermediate circuit is fed to the actual input. The desired value, which is dependent on the desired voltage in the intermediate circuit, is passed to the desired input. The expected value is ascertained from the characteristic values. The positive feedback of this characteristic value or of the correspondingly included information acts on the desired value and thus flows into the controller in a positive feedback manner. The invention can therefore be realized particularly simply and cost-effectively. Especially in the simplest case, the desired value is the desired value of the desired voltage and the actual value is the actual value of the actual voltage. However, any desired mapping rules, scaling, normalization, etc. can also be re-implemented here as dependencies.

Within the scope of the invention, a method for operating an electrical consumer is also disclosed. As an electrical consumer, an electrical consumer according to the invention operates, which has: a power pack with a mains input, which is connected to a power grid that conducts an AC voltage; a consumer connected to the power pack , the electrical appliance is supplied with output power by a power supply group, wherein the power supply group includes a PFC module connected to the grid input terminal with an intermediate circuit, and the intermediate circuit feeds power from the grid input terminal and provides output power, wherein the PFC module A controller is included for feeding the output power from the network input to the intermediate circuit, wherein a characteristic value relating to the output power required by the consumer is positively fed back to the controller.

The method, at least some of the embodiments of the method, and the corresponding advantages have already been explained expediently in conjunction with the electrical consumer device according to the invention.

In a preferred embodiment, the method is carried out by means of the electrical consumer device according to the invention or one of the embodiments of the electrical consumer device.

The present invention is based on the following recognition, observation or consideration and also has the following embodiments. Here, the described embodiments are also referred to as "the described invention" in part in simplified form. In this case, the embodiments described may also comprise or correspond to parts or combinations of the above-mentioned embodiments and/or optionally also embodiments not mentioned so far.

The invention is based on the insight that in conventional PFCs the output voltage plays only a minor role and can only be regulated with low dynamics for control-technical reasons. In principle, therefore, power packs with PFC function usually have a relatively slow transient response, can only adjust accordingly slowly to load jumps at the output and react correspondingly slowly to severe voltage drops and voltage overshoots . If the transient behavior of the PFC stage is unacceptable for the application, it is therefore necessary in many cases to connect a second power pack stage with greater regulation dynamics between the PFC and the consumers.

In a contemporary audio amplifier, the power bank is designed, for example, in two stages and consists of a PFC and a mains power bank, which is often designed unregulated for cost and efficiency reasons. A single-stage implementation with a single-stage PFC is also possible.

If power is now suddenly required on the amplifier, this leads to a voltage drop (Spannungseinbruch) at the output capacitor of the mains power pack. Although the mains power pack may be able to keep the voltage drop low through its own regulation (if it exists), it nevertheless draws jumpy high currents from the intermediate circuit capacitance. Due to the fundamentally determined low voltage regulation dynamics of the PFC, the PFC can only react slowly to new load situations. This inevitably leads to severe voltage drops on the intermediate circuit. Depending on the mains pack topology, this can also cause problems with the mains pack, so that the output voltage drops. The latter can be a problem especially in unregulated mains power pack topologies. The mains group topology only transfers the intermediate circuit voltage to the output voltage side with a fixed transfer factor and therefore also transfers the load drop of the intermediate circuit voltage.

The invention is based on the idea that since the DSP in the amplifier knows the generated output power at any moment (sometimes before the output power is generated), the idea consists in realizing the described Positive feedback.

This signal is supplied to a regulator (feedback) of the intermediate circuit voltage and is positively fed back. In the case of an optimal design, the PFC reacts to changing load conditions before the voltage drop begins and reduces the drop significantly.

The focus of the invention is to prevent the voltage drop across the intermediate circuit capacitor. In order not to negatively influence the power factor of the circuit too strongly, the signal of the positive feedback can be limited in a way. This can be achieved, for example, by filtering the signal. It is also conceivable that the positive feedback is only activated starting from a defined threshold value.

However, the invention can be used generally: in addition to audio amplifiers, the principle of positive feedback of output power can also be used in a number of other applications. The stability of the internal operating voltage can always be increased by means of the invention if the consumers operated by the PFC-capable power pack have high dynamics. Since currently in most cases the electronics are controlled via a digital control unit, in many cases suitable signals are available regarding the power produced by consumers (in the future), which are positively fed back to the PFC in a suitable manner level regulator.

According to the invention, an improved transient behavior of the PFC circuit for dynamic loads in electrical consumers, in particular in audio amplifiers, is obtained, in particular by positive feedback of the amplifier power, the output power.

Description of drawings

Other features, effects and advantages of the present invention can be obtained from the following description of preferred embodiments of the present invention and from the drawings. Here it is shown in a schematic principle overview:

Fig. 1 shows an electrical device according to the present invention;

FIG. 2 shows a timing diagram of the variables generated in the consumer.

Detailed ways

FIG. 1 shows an electrical consumer device 2 with a power pack 4 . The power pack 4 has a grid input 6 which is connected to a grid 8 . The grid 8 conducts an alternating voltage, which is indicated by a wavy line. Furthermore, the consumer arrangement 2 includes a consumer 10 , which is supplied with an output power A (symbolized) by the power pack 4 during normal operation. The power pack 4 includes a PFC module 12 which is connected to the grid input 6 and which includes an intermediate circuit 14 . The intermediate circuit 14 feeds power or energy from the grid input 6 and provides an output power A. The PFC module 12 also includes a regulator 16 , which feeds the output power A from the network input 6 to the intermediate circuit 14 and regulates this feed. A characteristic value K that is dependent on the required output power A in the consumer 10 is fed back to the regulator 16 .

FIG. 2 a shows a time sequence diagram, wherein the time t is shown as a time line (Zeitstrahl). Time t0 is marked.

In the simplest case, an output power A0 (currently) consumed by the consumer 10 , which is required by the consumer 10 at time t0 , is considered in FIG. 1 . In this case, the eigenvalue K is derived from the current output power A0 at time t0, and this eigenvalue (delay time due to processing/signal lines etc. is ignored here) is positively fed back to on regulator 16.

FIG. 1 also shows an alternative situation: here, it is already known at time t0 that the consumer will require output power A1 at a later time t1. Thus, for example, a prediction time TP between t0 and t1 results, for example 100 ms. In this alternative case, characteristic value K is correlated (at time t0 ) with desired future output power A1 and is supplied to controller 16 at time t0 . The corresponding temporal behavior is shown alternatively in FIG. 2 . The controller can now "advance", ie correct or preset its control behavior prospectively by means of an advance of the forecast time TP, so that at time t1 the output power A1 is ensured, while the PFC continues to operate optimally here. This presupposes that it is known at the current time t0 in each case how much power A1 the consumer 10 needs at a future time t1—after the predicted time TP has elapsed at the current time t0—. In this case, characteristic value K (used at time t0 ) correlates with a future expected demand for output power A1 of electrical consumer 10 after elapse of predicted time TP (at time t1 ).

In this example, the dependence of the output power A on the characteristic value K is achieved by the consumer 10 having an input signal E or feeding such a signal to the consumer. The consumer 10 is an amplifier device, here an audio amplifier device. The input signal E is an audio signal. The input signal E is a signal provided outside the electrical consumer 10 , ie from the electrical consumer device 2 , and originates, for example, from a CD player. The demand of the electrical consumer 10 for the output power A is related to the input signal E. Therefore, the eigenvalue K is obtained from the input signal E. In this example, the input signal E is an input signal E known completely in advance (here several hours) before the time t0, i.e. an audio signal, the recording of which has been completed and stored here Available on audio CD. The power requirement A for all playback moments of the audio signal is known from the properties of the audio signal and the amplifier. In this respect, the characteristic for each arbitrary instant t0 is therefore already ascertained long before the actual instant t0 (in which the output power A is required in the consumer 10 ), e.g. several hours or minutes before. Value K.

The input signal E is processed in the consumer 10 and output again as an output signal S, here for the purpose of actuating or operating a loudspeaker (not shown). The output signal S is thus the processed input signal E. The output power A0 or A1 etc. is required to generate the output signal S immediately at the instant t0 or t1 respectively. In this case, the characteristic value K is related to the desired output power A of the processed input signal E.

FIG. 1 shows the signal path 18 of the input signal E within the consumer 10 , which is indicated by an arrow. In signal path 18 , consumer 10 includes a digital signal processor (DSP) 20 . The signal processor has an internal propagation time L which is required for the input signal E in order to reach its input from its input. In other words, in the DSP 20, the input signal E is delayed by the propagation time L. The future demand for the output power A in relation to the input signal E results from the input signal E after the processing time V has already elapsed in the DSP 20 , but not yet the full propagation time L. Therefore, the predicted time TP is the remaining part of the propagation event time L minus the processing time V: therefore, the characteristic value K related to the output power A1 at time t1=t0+TP is known at time t0. FIG. 2b shows the corresponding temporal behavior on the timeline at time t. At a first instant, the feed of the input signal E into the DSP 20 takes place. At a subsequent instant t0, the ascertainment of the characteristic value K from the input signal E is carried out or completed. At time t1 , processed input signal E leaves DSP 20 and at time t1 output power A1 is generated in consumer 10 .

In an alternative embodiment, the controller 16 has (only indicated symbolically in FIG. 1 ) a desired input 22 a and an actual input 22 b. A value that is dependent on the current actual voltage UI in the intermediate circuit 14 is passed to the actual input 22 b. A value that is dependent on desired voltage US is fed to desired input 22 a. In this case, the value of desired voltage US is ascertained from characteristic value K. (indicated by arrows in Figure 1).

In a method for operating an electrical consumer device 2, the following procedure is carried out:

Connect the grid input 6 to the grid 8 . The consumer 10 is connected to the power pack 4 and the output power A is supplied by the power pack 4 . The intermediate circuit 14 is fed from the grid input 6 and also supplies the output power A. Find the eigenvalue K related to the required output power A. The characteristic value K is positively fed back to the controller 16 . The different types of dependence of the output power A on the characteristic value K have been explained above.

Claims (9)

1. An electrical consumer device (2) comprising:

a power supply unit (4) having a power supply input (6) which can be connected to a power supply (8) for conducting an alternating voltage,

an electrical consumer (10) connected to the power pack (4), the electrical consumer being supplied with output power (A) by the power pack (4),

wherein the power supply group (4) comprises a PFC module (12) connected to the grid input (6) with an intermediate loop (14), which is fed from the grid input (6) and which provides the output power (A),

wherein the PFC module (12) comprises a regulator (16) for feeding the intermediate circuit (14) with output power (A) from the grid input (6),

it is characterized in that the method comprises the steps of,

a characteristic value (K) which is associated with the output power (A) required by the consumer (10) is positively fed back to the regulator (16), wherein the consumer (10) has an input signal (E) and the demand of the consumer (10) for the output power (A) is associated with the input signal (E), wherein the characteristic value (K) is determined from the input signal (E).

2. The electrical consumer device (2) according to claim 1, characterized in that the characteristic value (K) relates to a desired demand for the output power (a) of the electrical consumer (10) after a predicted Time (TP) has elapsed in the future.

3. The electrical consumer device (2) according to any one of claims 1 to 2, wherein the input signal (E) is a previously known input signal (E) at least in sections before being fed to the electrical consumer (10), and the characteristic value (K) is determined in advance from the previously known input signal (E).

4. A consumer device (2) according to any one of claims 1 to 3, characterized in that the input signal (E) is a signal externally fed to the consumer device (2).

5. The electrical consumer device (2) according to any one of claims 1 to 4, wherein the electrical consumer device (2) is an amplifier device and the input signal (E) is a signal to be amplified.

6. The electrical consumer device (2) according to any one of claims 1 to 5, wherein the characteristic value (K) is a characteristic value (K) which is related to a desired output signal (S) of an input signal (E) processed in the electrical consumer (10).

7. The electrical consumer device (2) according to any one of claims 1 to 6, characterized in that the electrical consumer (10) comprises a digital signal processor (20) in a signal path (18) for the input signal (E), the digital signal processor having an internal propagation time (L), and that the future demand for the output power (a) is ascertained from the input signal (E) which has not been delayed by at least the total propagation time (L).

8. The electrical consumer device (2) according to any one of claims 1 to 7, wherein the regulator (16) has a desired input (22 a) and an actual input (22 b), wherein an actual value related to a current actual voltage (UI) in the intermediate circuit (14) is directed onto the actual input (22 b) and a desired value related to a desired voltage (US) in the intermediate circuit (14) is directed onto the desired input (22 a), wherein the desired value is determined from the characteristic value.

9. A method for operating an electrical consumer device (2), the electrical consumer device having:

a power supply unit (4) having a power supply input (6) which is connected to a power supply (8) for conducting an alternating voltage,

an electrical consumer (10) connected to the power pack (4), the electrical consumer being supplied with output power (A) by the power pack (4),

wherein the power supply group (4) comprises a PFC module (12) connected to the grid input (6) with an intermediate loop (14), which is fed from the grid input (6) and which provides the output power (A),

wherein the PFC module (12) comprises a regulator (16) for feeding the intermediate circuit (14) with the output power (A) from the grid input (6),

it is characterized in that the method comprises the steps of,

-positive feedback of a characteristic value (K) relating to the output power (a) required by the consumer (10) to the regulator (16), wherein the consumer (10) has an input signal (E) and the demand of the consumer (10) for the output power (a) is related to the input signal (E), wherein the characteristic value (K) is determined from the input signal (E).

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