Method for controlling compressor system, compressor for compressing working medium, compressor system for carrying out refrigeration cycle process, and refrigeration cycle system

Abstract

A method of controlling a compressor system including an electric compressor for compressing a working medium and an additional electrical load is provided. The compressor in turn comprises an electric motor for providing mechanical motion to compress the working medium, an inverter for providing single-phase or multi-phase alternating current for the electric motor, a power factor correction filter (PFC) for providing direct current for the inverter, the current input of which is connected to a grid connection point of a grid current source providing the alternating current, for powering the compressor. In order to supply power to an additional electrical load, the additional electrical load is connected to the same grid connection point as a power factor correction filter. The method includes operating a compressor system with current from a grid current source; determining at least one current characteristic value of the additional electrical load, the characteristic value describing a current consumption of the additional electrical load; and controlling a power factor correction filter of the compressor at least according to the determined at least one current characteristic value of the additional electric load.

Description

TECHNICAL FIELD

[0001] The present invention relates to a control method for a compressor system, a compressor for compressing a working medium and a refrigeration cycle system for carrying out a refrigeration cycle process. BACKGROUND

[0002] Heating, ventilation and air conditioning systems, so-called HVAC systems, are known from the prior art. One of their purposes is to control the temperature, humidity or air flow in a building or in a partial area thereof in a targeted and as efficient as possible manner.

[0003] In recent years, refrigeration cycle systems, such as heat pumps or refrigerators, are increasingly used as components of heating, ventilation and air conditioning (HVAC) systems, in particular in private households, for example as a heating system of a heating, ventilation and air conditioning system to increase the room temperature or as a refrigeration system of a heating, ventilation and air conditioning system to decrease the room temperature.

[0004] Such refrigeration cycle systems are thermodynamic operating systems which, by means of a connection to a heat source system, utilize various environmental energy sources, such as air heat, geothermal heat or water heat, for heating and / or refrigeration. For this purpose, the refrigeration cycle system is designed to carry out a thermodynamic refrigeration cycle process. In this process, the working medium of the refrigeration cycle system is compressed, expanded to be heated and cooled according to known principles, so that heat energy can be transferred to the working medium at at least one location in the refrigeration cycle system and can be extracted from the working medium at at least one other location, thereby transferring heat energy in a target system, for example a room in a building.

[0005] In the case of a need to extract heat energy from a target system, for example in the field of air conditioning, the refrigeration cycle system is usually referred to as a refrigerator; and in the case of a need to provide heat energy to a target system, the refrigeration cycle system is usually referred to as a heat pump.

[0006] In the following, such refrigerators and heat pumps are collectively referred to as "refrigeration cycle systems".

[0007] A key element in a refrigeration cycle system is usually an electric compressor for compressing the working medium to increase its pressure. For the supply of power, the electric compressor is usually connected to a grid connection point of a grid current source (in the following also referred to as grid) which provides alternating current.

[0008] The compressor takes the current required for operation from the power supply. The current taken must not exceed certain limit values which are defined in particular for multiples of the grid frequency and thus represent limit values for the harmonic content, otherwise the operation of the compressor would have a negative effect on the grid itself. These limit values are usually also prescribed by law.

[0009] In existing technologies, additional inductive components are typically used to meet these limits. These components are located at the interface with the power grid and are used to attenuate tap current to reduce harmonic content.

[0010] However, such devices suffer from high wear and tear and are not flexible enough in response to changes in operating conditions and / or environmental conditions. Furthermore, they incur additional costs and require extra installation space. Summary of the Invention

[0011] Therefore, the purpose of this invention is to provide a more efficient, economical, space-saving, and flexible solution that minimizes the negative impact on the power grid during compressor system operation without causing energy loss, and is particularly compliant with legal requirements.

[0012] To achieve this objective, the present invention provides a method according to claim 1, a compressor according to claim 15, a compressor system according to claim 16, and a refrigeration cycle system according to claim 17.

[0013] Each dependent claim relates to preferred embodiments, which may be provided individually or in combination.

[0014] According to one aspect of the invention, a method for controlling a compressor system, particularly part of a refrigeration cycle system, is provided, including an electric compressor for compressing a working medium and an additional electrical load. The compressor further includes: an electric motor for providing mechanical motion for compressing the working medium; an inverter for providing single-phase or multi-phase alternating current to the electric motor; and a power factor correction filter (PFC) for providing direct current to the inverter, its current input terminal connected to a grid connection point of a grid current source providing the alternating current for powering the compressor. For power supply, the additional electrical load and the PFC are connected to the same grid connection point. The method includes: operating the compressor system using current from the grid current source; determining at least one current characteristic value of the additional electrical load, the characteristic value describing the current consumption of the additional electrical load; and controlling the power factor correction filter of the compressor based at least on the determined at least one current characteristic value of the additional electrical load.

[0015] Preferably, multiple current characteristic values ​​of the additional electrical load are determined, and at least one current characteristic value of the additional electrical load is determined, i.e., multiple current characteristic values ​​of the additional electrical load are determined, the current characteristic values ​​describing the current consumption of the additional electrical load, and accordingly, the power factor correction filter of the compressor is controlled at least based on the determined multiple current characteristic values ​​of the additional electrical load.

[0016] In the context of this application, the term "compressor" is used differently from its usual usage, and as defined in claim 1, the power electronics (power factor correction filter) connected upstream of the electromechanical component (motor) should also be understood as part of the compressor.

[0017] A power factor correction filter (PFC) is an electrical or electronic circuit that can improve the power factor that is reduced due to distorted reactive power. In particular, the power correction filter provided for the compressor system is preferably an active power correction filter.

[0018] The method of this invention enables control of the compressor system based on the compressor's power factor correction filter, thereby improving the power factor of the entire compressor system (including additional electrical loads).

[0019] The additional electrical load is connected to the same power grid connection point as the compressor, which typically includes a passive rectifier that provides DC power to the DC load of the additional electrical load.

[0020] Due to this rectifier's operating mode, it will also produce a feedback effect, particularly in the form of harmonic feedback in the current shunt at the grid connection point.

[0021] Although the harmonic content of the shunt current of each component meets the specifications or limits, the combination of all loads connected to the grid connection point may not necessarily meet the requirements.

[0022] The inventors discovered that, for the compressor system structure, the limit value of the shunt current can be maintained by selectively controlling the power correction factor of the compressor. In this case, it is not necessary to change the additional electrical load itself, for example, in the form of an additional damping inductor (which would cause losses), or even to set a power factor correction filter separately at the additional electrical load.

[0023] In this case, harmonics generated by the additional electrical load can be compensated in an advantageous manner by taking into account the current characteristics at the additional electrical load to control the power factor correction filter of the compressor.

[0024] In this way, the compressor system can meet the specifications when drawing current from the grid current source without requiring structural modifications or additional components to the additional electrical load.

[0025] Therefore, this method enables efficient operation of the compressor system, especially by keeping energy losses at a low level. Furthermore, the method can be used in situations with multiple or even various different additional electrical loads, ensuring compliance with specifications simply by controlling the compressor's power correction filter.

[0026] Preferably, although the configuration of an active power factor correction filter is more complex than that of a passive circuit, it has a higher power correction factor.

[0027] The power factor correction filter preferably includes a rectifier and a boost converter, with the boost converter connected downstream of the rectifier relative to the energy flow direction from the grid current source to the motor. The boost converter is a DC-DC voltage converter whose output voltage is typically higher than its input voltage.

[0028] The rectifier can be configured as passive or active, with a preferred configuration as a passive bridge rectifier.

[0029] The additional electrical load is preferably a combination of a rectifier (especially a passive rectifier) ​​and a DC load (DC).

[0030] The additional electrical load does not include its own power factor correction filter, or at least includes a power factor correction filter with a lower power factor correction capability than the compressor's power factor correction filter.

[0031] In this case, the DC load can be a DC fan unit or its DC motor, especially in a refrigeration cycle system.

[0032] The grid current source can be, for example, a single-phase or three-phase grid current source. In other words, the grid current source can provide, for example, single-phase alternating current or three-phase alternating current (so-called three-phase current) via a grid connection point.

[0033] In this context, the method is not limited to a specific embodiment of the grid current source. Depending on the embodiment of the grid current source, the compressor and additional electrical loads may have different configurations, with their current input designed, for example, as single-phase or three-phase AC.

[0034] Similar to the case with grid current sources, the compressor's motor can be a motor that operates using single-phase or multi-phase alternating current (especially three-phase alternating current). Accordingly, the inverter is naturally configured to provide single-phase or multi-phase alternating current at its output.

[0035] In a preferred embodiment, controlling the power factor correction filter includes setting operating parameters of the power factor correction filter based on at least one current characteristic value of the determined additional electrical load, the operating parameters determining the DC output of the power factor correction filter.

[0036] In a preferred embodiment, the power factor correction filter includes at least one transistor unit, particularly a MOSFET or IGBT. The step of setting the operating parameters of the power factor correction filter to control the power factor correction filter includes setting a control signal for at least one transistor unit based on at least one or more current characteristic values ​​of the determined additional electrical load.

[0037] This provides an easy-to-implement control option, where the control signal for the transistor unit is an adjustment screw.

[0038] In a preferred embodiment, the determined at least one current characteristic value includes current intensity, particularly effective current intensity; or electrical power, particularly effective electrical power. Preferably, in the case of multiple current characteristic values, these current intensities, particularly effective current intensities, or electrical power, particularly effective electrical power, are particularly relevant to different frequencies.

[0039] By using effective values, control can be made particularly simple, thereby reducing control time.

[0040] In a preferred embodiment, the additional electrical load and the compressor are connected in parallel to each other at the grid connection point.

[0041] In a preferred embodiment, determining the at least one or more current characteristic values ​​of the additional electrical load includes: detecting a current variable, particularly the current intensity, of the current input current of the additional electrical load, and determining the at least one or more current characteristic values ​​based on the detected current variable.

[0042] The detection of current variables can be performed using suitable measuring devices, such as, in the simplest case, a voltmeter and / or an ammeter. Based on the detected current variables, the at least one or more current characteristic values ​​are determined, for example, one or more effective values ​​may be determined.

[0043] In a preferred embodiment, determining at least one or more current characteristic values ​​of the additional electrical load includes: providing a calculation model that describes the electrical structure of the additional electrical load, the calculation model of the electrical structure including one or more electrical characteristic variables of the additional electrical load; partially or entirely calculating the at least one or more current characteristic values ​​based on the provided calculation model; and outputting the calculated at least one or more current characteristic values ​​as the determined at least one or more current characteristic values ​​of the additional electrical load.

[0044] Therefore, an alternative to detecting current variables through a measuring device is provided, allowing one or more current characteristic values ​​of the additional electrical load to be determined essentially without measuring the current variable value of the additional electrical load. This eliminates the need for a corresponding measuring structure at the additional electrical load, thus saving cost and installation space.

[0045] This computational model describes the electrical structure of an additional electrical load and is suitable for determining the electrical state variables of the additional electrical load based on the input current on the load (e.g., the current intensity and / or voltage specification at the input terminal).

[0046] In this case, the calculation model can be simple, especially when the additional electrical load corresponds to a combination of rectifier and DC load, and it also has the characteristics of fast calculation speed and representative calculation results. Therefore, the accuracy of this process will not prevent the direct detection of the current variable value of the additional electrical load.

[0047] The characteristic variables of the additional electrical load can be, for example, but not limited to, the resistance, capacitance, or inductance of the additional electrical load.

[0048] The rated operating value of the DC load, such as rated power or rated current intensity, is preferably used as the input variable for the calculation model.

[0049] In a preferred embodiment, the power factor correction filter includes a rectifier having an input terminal for AC input and an output terminal for rectified output current.

[0050] The rectifier's input is connected to the current input of the power factor correction filter. This can be done directly or via other inserted electrical components such as inductors, capacitors, or resistors.

[0051] Specifically, the rectifier of the power factor correction filter is a bridge rectifier.

[0052] In a preferred embodiment, the method further includes detecting a current variable, particularly current intensity or voltage, of the output current of the rectifier at the output terminal of the rectifier; wherein the power factor correction filter controlling the compressor is also based on the detected current variable of the output current of the rectifier.

[0053] Therefore, the control of the power factor correction filter is extended by other input variables, thereby enabling more precise control.

[0054] In this case, the detected current variable can be, for example, a discrete value, a time curve, or an RMS value.

[0055] In a preferred embodiment, the power factor correction filter includes a totem-pole PFC converter.

[0056] Totem-pole PFC converters typically consist of a push-pull output stage made up of bipolar transistors or field-effect transistors and are optimized for high switching speeds. In particular, using such a totem-pole PFC converter eliminates the need for an additional passive rectifier (such as a bridge rectifier) ​​that is part of the power factor correction filter.

[0057] In a preferred embodiment of this method, the method further includes detecting current variables of the input current of the totem-pole PFC converter, particularly current intensity or voltage, wherein controlling the compressor power factor correction filter also depends on the detected current variables of the input current of the totem-pole PFC converter.

[0058] In a preferred embodiment, the method further includes detecting a current variable, particularly current intensity or voltage, of the totem-pole PFC converter output current at the output terminal of the inverter where the totem-pole PFC converter is connected. The totem-pole PFC converter is connected to the inverter at its output terminal. The control of the compressor power factor correction filter also depends on the detected current variable of the totem-pole PFC converter output current.

[0059] In a preferred embodiment, the method further includes detecting a current variable, particularly current intensity or voltage, at the current input of the power factor correction filter, wherein controlling the compressor power factor correction filter is also based on the detected current variable at the current input of the power factor correction filter.

[0060] In this case, current variables that can be detected include discrete values, time curves, or RMS values.

[0061] Therefore, the control of the power factor correction filter is extended by other input variables, thereby enabling more precise control.

[0062] In a preferred embodiment, the power factor correction filter is controlled when one or more characteristic values ​​of the current obtained by the compressor system at the grid connection point are lower than their respective predetermined limits.

[0063] Therefore, it is especially possible to ensure that the harmonic content meets the specifications.

[0064] The characteristic value can be, for example, the harmonic content at a specific frequency, or an average value derived therefrom.

[0065] In a preferred embodiment, the one or more characteristic values ​​are the amplitudes in the spectrum of the acquired current, particularly integer multiples of the fundamental frequency of the grid current source (also known as harmonics).

[0066] The spectrum provides a simple and quick method to determine the harmonic content of the acquired current.

[0067] When multiple eigenvalues ​​exist, each eigenvalue preferably corresponds to an amplitude value at a different frequency.

[0068] The spectrum is in particular the voltage spectrum of the acquired current. However, as an alternative and non-limiting example, it could also be the spectrum of the current intensity.

[0069] In a preferred embodiment, the compressor system is designed as part of a refrigeration cycle system, particularly a heat pump or a chiller, and the method is a control method for the refrigeration cycle system.

[0070] According to a second aspect of the invention, a compressor for compressing a working medium is provided, comprising: an electric motor for providing mechanical motion to compress the working medium; an inverter for providing single-phase or multi-phase alternating current to the electric motor; a power factor correction filter for providing direct current to the inverter, the current input of which is connectable to a grid connection point of a grid current source providing alternating current for powering the compressor; and a control device for controlling at least the power factor correction filter. The compressor is electric, and when the compressor and an additional electrical load are connected to the same grid connection point of the grid current source providing alternating current, the control device is used to determine at least one current characteristic value of the additional electrical load, the current characteristic value describing the current consumption of the additional electrical load, and the control device is used to control the power factor correction filter at least based on the determined at least one current characteristic value of the additional electrical load.

[0071] In this manner, a compressor is provided that, when connected to a power grid connection point along with an additional electrical load, is configured to implement the above-described method.

[0072] The advantages resulting from this are essentially the same as those of this method, and will not be elaborated upon here.

[0073] The additional electrical load preferably includes a rectifier (especially a passive rectifier) ​​and a DC load.

[0074] According to a third aspect of the invention, a compressor system, particularly a part of a refrigeration cycle system, is provided. The compressor system includes an electric compressor for compressing a working medium according to a second aspect or one of its preferred embodiments, and an additional electrical load. The compressor and the additional electrical load are configured to be connected to the same grid connection point of a grid current source providing alternating current, wherein, in this case, the compressor's control device is used to determine at least one or more current characteristic values ​​of the additional electrical load, these current characteristic values ​​describing the current consumption of the additional electrical load, and to control a power factor correction filter at least based on the determined at least one or more current characteristic values ​​of the additional electrical load.

[0075] Thus, a compressor system is provided, which is configured to implement the above method.

[0076] The advantages thus arising are essentially the same as those of the method, and will not be repeated here. This also applies to the specific embodiments described below. These embodiments largely correspond to the specific embodiments of the apparatus and the method described herein.

[0077] The compressor and the additional electrical load are preferably connected in parallel at the power grid connection point.

[0078] The grid current source can be, for example, a single-phase or three-phase grid current source. In other words, the grid current source can provide, for example, single-phase or three-phase alternating current (so-called three-phase current) through the grid connection point.

[0079] In this context, the compressor system is not limited to embodiments targeting a specific grid current source. Depending on the grid current source, the configuration of the compressor and the additional electrical load will differ; for example, its current input may be designed for single-phase or three-phase AC.

[0080] Preferably, in controlling the power factor correction filter, the control device is used to set the operating parameters of the power factor correction filter based on at least one or more current characteristic values ​​of the determined additional electrical load, the operating parameters determining the DC power output of the power factor correction filter and / or affecting the AC power obtained by the compressor from the grid current source.

[0081] Preferably, the power factor correction filter includes at least one transistor unit, particularly a MOSFET or IGBT, and setting the operating parameters of the power factor correction filter to control the power factor correction filter includes setting a control signal for the at least one transistor unit based on at least one current characteristic value of the determined additional electrical load. For this purpose, the control device preferably includes a PWM calculation unit (PWM: Pulse Width Modulation) that provides the PWM signal as the control signal.

[0082] Preferably, the compressor system includes a current measuring device for detecting a current variable, particularly the current intensity, present at the current input terminal of the additional electrical load. This current measuring device is coupled to a control device, and the control device is configured to determine at least one or more current characteristic values ​​of the additional electrical load based on the detected current variable.

[0083] However, preferably, the control device can also determine one or more current characteristic values ​​of the additional electrical load in other ways. For this purpose, the control device preferably includes a calculation model unit that provides a calculation model describing the electrical structure of the additional electrical load, the calculation model of which includes one or more electrical characteristic variables of the additional electrical load. Furthermore, the calculation model unit is configured to determine at least one or more current characteristic values ​​of the additional electrical load based on the provided calculation model, and output these characteristic values ​​for further use by the control device.

[0084] It is preferable to use the rated operating value of the additional electrical load (e.g., rated power or rated current intensity) as the input variable for the calculation model. Alternatively, the detected operating value of the additional electrical load can also be used in the calculation model.

[0085] The power factor correction filter preferably includes a rectifier having an input terminal for AC input and an output terminal for rectified output current. Specifically, the rectifier is a bridge rectifier, wherein the input terminal of the rectifier is the current input terminal of the power factor correction filter and can be connected to the grid connection point.

[0086] In this embodiment with a rectifier, the compressor system preferably includes a first current measuring device configured to detect a current variable of the rectifier's output current, particularly the current intensity or voltage, wherein the control device is configured to also control the compressor's power factor correction filter based on the current variable of the rectifier's output current detected by the current measuring device.

[0087] More preferably, the compressor system includes a current measuring device located at the power grid connection point, the current measuring device being configured to detect current variables, particularly current intensity or voltage, at the current input terminal of the power factor correction filter, wherein the control device is configured to also control the compressor's power factor correction filter based on the current variables at the current input terminal of the power factor correction filter detected by another current measuring device.

[0088] According to a fourth aspect, a refrigeration cycle system is provided, configured to perform a refrigeration cycle process based on a working medium. In particular, the refrigeration cycle system is a heat pump or a refrigerator. The refrigeration cycle system includes a compressor system designed according to a third aspect or one of its preferred embodiments. The compressor is configured to compress the working medium of the refrigeration cycle system.

[0089] The refrigeration cycle system is configured to perform a refrigeration cycle process in which the working medium of the refrigeration cycle system is compressed and expanded according to known thermodynamic principles to achieve heating and cooling, so that thermal energy can be transferred to the working medium at at least one point in the refrigeration cycle system, and thermal energy can be extracted from the working medium at at least one other point.

[0090] Preferably, the refrigeration cycle system for the refrigeration cycle process includes an expansion device for expanding the working medium, an evaporator for evaporating the working medium, and a condenser for condensing the working medium.

[0091] In this configuration, the working medium flows sequentially through the compressor, condenser, expander, and evaporator in a repetitive cycle. Heat can be transferred to the working medium at the evaporator and extracted from the condenser. The condenser and evaporator are preferably designed as heat exchangers, such as layered heat exchangers.

[0092] The additional electrical load preferably includes a rectifier, particularly a passive rectifier, preferably a bridge rectifier, and a DC load, particularly a DC fan unit and / or a DC circulating pump. The DC fan unit and / or DC circulating pump operate with DC power and are powered by a grid current source through the rectifier.

[0093] The working medium should be understood as any fluid suitable for a refrigeration cycle system, and for this purpose, it can be compressed, liquefied, expanded, and evaporated in the device, wherein the working medium is generally, but not limited to, a refrigerant, such as propane or refrigerant R32, or a fluorocarbon.

[0094] The DC fan unit is specifically a fan unit of the heat exchanger in the refrigeration cycle system, which is preferably part of an external unit of the refrigeration cycle system. The heat exchanger can specifically serve as an evaporator and / or condenser for the working medium of the refrigeration cycle system. Attached Figure Description

[0095] Other aspects and their advantages, as well as exemplary embodiments of the above aspects, will now be described in more detail with the aid of the accompanying drawings.

[0096] Figure 1 A flowchart illustrating a first exemplary embodiment of the method according to the present invention is shown schematically.

[0097] Figure 2 The structure of a first exemplary embodiment of the compressor system according to the present invention is schematically shown.

[0098] Figure 3 The structure of a second exemplary embodiment of the compressor system according to the present invention is schematically shown.

[0099] Figure 4The structure of a third exemplary embodiment of the compressor system according to the present invention is schematically shown.

[0100] Figure 5 The structure of the control device of a fourth exemplary embodiment of the compressor system according to the present invention is schematically shown.

[0101] It should be emphasized that the present invention is by no means limited to the exemplary embodiments and their exemplary features described below. The present invention also includes modifications to certain exemplary embodiments, particularly modifications and / or combinations thereof made to one or more features of the exemplary embodiments within the scope of the independent claims.

[0102] 1 Compressor; 2 Additional electrical load; 11 Motor; 12 Inverter; 13 Power factor correction filter; 14 Control device; 15 Current measurement device (voltage measurement device) at the grid connection point; 21 Rectifier for the additional electrical load; 22 DC load; 23 Operating data providing unit; 24 Inductor; 131 Rectifier; 132 Boost converter; 133 First current measurement device for the power factor correction filter; 134 Second current measurement device (voltage measurement device) for the power factor correction filter; 135 Totem pole PFC converter; 141 Voltage regulator; 142 Current intensity regulator; 143 Calculation model unit; 144 Compensation unit; 145 PWM calculation unit; 301 Diode; 302 Transistor (MOSFET); 1000 Compressor system; 2000 Grid connection point. Specific Implementation

[0103] Figure 1 A flowchart illustrating a first exemplary embodiment of the method according to the present invention is shown schematically.

[0104] The method is implemented on a compressor system comprising an electric compressor for compressing a working medium and an additional electrical load. The compressor further includes an electric motor for providing mechanical motion to compress the working medium, an inverter supplying single-phase or multi-phase AC power to the motor, and a power factor correction filter supplying DC power to the inverter. The current input of the filter is connected to a grid connection point of the mains current source providing AC power to supply power to the compressor. For power supply, the additional electrical load is connected to the same grid connection point as the power factor correction filter.

[0105] In step S1, the compressor system is operated using current from the mains current source.

[0106] In step S2, at least one current characteristic value of the additional electrical load is determined, the current characteristic value describing the current consumption of the additional electrical load; and

[0107] Therefore, step S2 preferably includes sub-steps S2.1 to S2.3.

[0108] In step S2.1, a calculation model describing the electrical structure of the additional electrical load is provided, the calculation model of the electrical structure including one or more electrical characteristic variables of the additional electrical load.

[0109] In step S2.2, the at least one current characteristic value is calculated based on the calculation model provided in step S2.1.

[0110] In step S2.3, the at least one current characteristic value calculated in step S2.2 is output as the determined current characteristic value of the additional electrical load.

[0111] In step S3, the power factor correction filter of the compressor is controlled at least according to the at least one current characteristic value of the additional electrical load determined in step S2.

[0112] This method can advantageously compensate for harmonics generated by the additional electrical load by evaluating at least one current characteristic value at the additional electrical load during the control of the compressor's power factor correction filter.

[0113] This allows the compressor system to meet specifications when disconnecting current from the grid without requiring structural modifications to the additional electrical load or the addition of additional components (such as energy-consuming elements).

[0114] In this regard, the method enables the compressor system to operate efficiently, and in particular, keeps energy losses at a low level.

[0115] Figure 2 The structure of a first exemplary embodiment of the compressor system 1000 according to the present invention is schematically shown.

[0116] The compressor system includes a compressor 1 and an additional electrical load 2, which are connected to the same grid connection point 2000 that provides AC power from the grid current source, specifically in the form of a parallel circuit.

[0117] The additional electrical load 2 preferably includes a rectifier 21 (specifically a passive rectifier) ​​and a DC load 22 powered by the rectifier. Optionally (but not necessarily), the additional electrical load 2 may also include an inductor 24 connected upstream of the rectifier 21.

[0118] The compressor 1 is an electric compressor 1 used for compressing the working medium, which includes an electric motor 11 for providing mechanical motion for compressing the working medium, an inverter 12, a power factor correction filter 13, and a control device 14.

[0119] Inverter 12 provides single-phase or multi-phase AC power to motor 11; in this example, it is three-phase AC power.

[0120] The power factor correction filter 13, in turn, provides DC power to the inverter 12, wherein the current input terminal of the power factor correction filter 13 can be connected to the grid connection point 2000 for powering the compressor 1, as is shown in the exemplary embodiment.

[0121] The control device 14 is used to control at least the power factor correction filter 13.

[0122] The control device 14 is used to determine at least one current characteristic value of the additional electrical load 2, which describes the current consumption of the additional electrical load 2, and to control the power factor correction filter 13 based at least on the determined at least one current characteristic value.

[0123] The compressor system 1000 shown allows for the advantageous compensation of harmonics generated by the additional electrical load 2 by evaluating at least one current characteristic value at the additional electrical load 2 during the control of the power factor correction filter 13 of the compressor 1 by the control device 14.

[0124] In this way, the specifications can be met when the compressor system 1000 is disconnected from the grid current source without requiring structural modifications to the additional electrical load 2 or the addition of additional components (such as energy-consuming elements).

[0125] In this regard, a high-efficiency compressor system 1000 is provided, wherein, in particular, energy loss is kept at a low level.

[0126] Figure 3 The structure of a second exemplary embodiment of the compressor system according to the present invention is schematically shown.

[0127] The compressor system 1000 includes a compressor 1 and an additional electrical load 2, which are connected (particularly in the form of a parallel circuit) to the same grid connection point 2000 of the grid current source that provides alternating current.

[0128] The additional electrical load 2 preferably includes a rectifier 21 (particularly a passive rectifier, which in the exemplary embodiment shown is configured as a bridge rectifier based on diode 301) and a DC load 22 powered by the rectifier.

[0129] The compressor 1 is an electric compressor 1 for compressing the working medium, which includes an electric motor 11 for providing mechanical motion for compressing the working medium, an inverter 12, a power factor correction filter 13, and a control device not shown in the figure.

[0130] Inverter 12 provides single-phase or multi-phase AC power to motor 11; in this example, it is three-phase AC power.

[0131] The inverter 12 is preferably composed of multiple transistor units, and more preferably of multiple MOSFETs 302 or IGBTs.

[0132] The power factor correction filter 13, in turn, provides DC power to the inverter 12, wherein the current input terminal of the power factor correction filter 13 can be connected to the grid connection point 2000 for supplying power to the compressor 1, as has been done in the exemplary embodiment shown.

[0133] The power factor correction filter 13 preferably includes a rectifier 131, particularly a passive rectifier, which is configured as a bridge rectifier based on diode 301 in the exemplary embodiment shown.

[0134] In addition, the power factor correction filter 13 includes a boost converter 132 connected downstream of the rectifier 131. The boost converter, as an active power factor correction filter, has at least one transistor unit, which can be configured as a MOSFET 302 or an IGBT.

[0135] In Figure 3, the voltage at the current input terminal of the power factor correction filter 13 is represented by "u_ac", the current intensity at the interface between the rectifier 131 and the boost converter 132 is represented by "i_pfc", the voltage at the interface between the power factor correction filter 13 and the inverter 12 is represented by "u_dc", the current intensity at the input terminal of the additional electrical load 2 is represented by "i_load", and the current intensity at the grid connection point 2000 is represented by "i_grid".

[0136] The above names will be used in the following descriptions. Figure 5 Exemplary embodiments are shown below.

[0137] The control device is used to control at least the power factor correction filter 13.

[0138] The control device is used to determine at least one current characteristic value of the additional electrical load 2, which describes the current consumption of the additional electrical load 2, and to control the power factor correction filter 13 based on at least the determined at least one current characteristic value.

[0139] The compressor system 1000 shown is able to advantageously compensate for the harmonics generated by the additional electrical load 2 by evaluating at least one current characteristic value at the additional electrical load 2 during the control of the power factor correction filter 13 of the compressor 1 by the control device 14.

[0140] In this way, specifications can be met when the compressor system 1000 is disconnected from the grid current source without requiring structural modifications to the additional electrical load 2 or the addition of additional components (such as energy-consuming elements).

[0141] Therefore, a high-efficiency compressor system 1000 is provided, wherein, in particular, energy loss is kept at a low level.

[0142] Figure 4 The structure of a third exemplary embodiment of the compressor system 1000 according to the present invention is schematically shown.

[0143] The third exemplary embodiment differs from the compressor system 1000 of the second exemplary embodiment only in the configuration of the power factor correction filter 13, which in this example has a totem pole topology.

[0144] Therefore, the power factor correction filter 13 preferably includes a totem-pole PFC converter 135, whose current input is connected to the grid connection point 2000 and whose output is connected to the inverter 12, for example, by inserting a capacitor (see...). Figure 4 ).

[0145] The totem-pole PFC converter 135 can be composed of multiple MOSFETs 302 or IGBTs, which can be, for example, but not limited to, according to Figure 4 The circuit diagram in the diagram is used for layout.

[0146] Preferably, the inductor 24 can be connected upstream of the totem pole PFC converter 135 in the energy flow direction from the grid connection point 2000 to the motor 11.

[0147] The rest of the structure is basically the same as Figure 3 The corresponding structure is as described above, and will not be elaborated upon here.

[0148] Figure 5 The structure of the control device 14 of the compressor system according to the present invention is schematically shown.

[0149] The compressor system includes a compressor for compressing a working medium, the compressor including an electric motor for providing mechanical motion to compress the working medium, an inverter for providing single-phase or multi-phase AC power to the electric motor, a power factor correction filter 13 for providing DC power to the inverter, and a control device 14. The current input terminal of the power factor correction filter 13 can be connected to the grid connection point of the grid current source providing AC power for supplying power to the compressor. The control device 14 is used to control at least the power factor correction filter 13.

[0150] In addition to the compressor, the compressor system also includes at least one additional electrical load. The compressor and the additional electrical load are connected to the same grid connection point of the grid current source that provides alternating current. In this case, the compressor control unit 14 is used to determine at least one current characteristic value of the additional electrical load, which describes the current consumption of the additional electrical load, and to control the power factor correction filter 13 based at least on the determined at least one current characteristic value of the additional electrical load.

[0151] The power factor correction filter of this exemplary embodiment preferably includes a rectifier (particularly a passive rectifier) ​​and a boost converter connected downstream thereof, the boost converter comprising at least one transistor unit.

[0152] The additional electrical load and compressor are connected in parallel at the grid connection point.

[0153] In addition to the power factor correction filter 13 and the control device 14, Figure 5 The compressor component mentioned above is not shown in the image.

[0154] The structure of the control device 14 will be described below to illustrate the control sequence of the power factor correction filter 13 therein.

[0155] For example, Figure 5 The control device 14 shown can be used for Figure 2 or Figure 3 The compressor system shown is an example, but not limited to it.

[0156] To explain these orders, part of the reference... Figure 3 The current variables in the text include "u_dc", "u_ac", and "i_pfc", but this does not mean... Figure 5 The control device 14 shown is limited to Figure 3 The compressor system shown. (Reference) Figure 3 This is only to better explain the sequence in the control device.

[0157] The control device 14 preferably includes a voltage regulator 141, a current intensity regulator 142, a calculation model unit 143, a compensation unit 144, and a PWM calculation unit 145.

[0158] In addition, the compressor system includes a current measuring device 15 (preferably a voltage measuring device) located at the power grid connection point, a first current measuring device 133 of the power factor correction filter 13, a second current measuring device 134 of the power factor correction filter 13, and an operating data providing unit 23.

[0159] The first current measuring device 133 is installed at the output terminal of the rectifier of the power factor correction filter, and is specifically used to measure the current intensity of the rectifier output current at that location.Figure 3 In the exemplary embodiment shown, the current intensity corresponds to the current intensity i_pfc at that location.

[0160] The second current measuring device 134 is disposed at the interface between the power factor correction filter and the inverter, and is particularly used to measure the voltage at that point. Figure 3 In the exemplary embodiment shown, the voltage corresponds to the voltage u_dc at that location.

[0161] The current measuring device 15, located at the point of connection to the power grid, is particularly used for measuring the voltage at that location. Figure 3 In the exemplary embodiment shown, the voltage corresponds to the voltage u_ac at that location.

[0162] The operating data providing unit 23 includes operating data of the additional electrical load, particularly for recording data related to its rated operation, such as rated power or rated current intensity. In an exemplary embodiment where the additional electrical load is a DC fan unit or a DC circulating pump, the operating data may be data related to the rotational speed of the fan unit or DC circulating pump, describing the absolute rotational speed or the ratio of the rotational speed to the rated rotational speed value.

[0163] although Figure 5 Components 133 and 134 are not drawn within the rectangle shown in Figure 13, but they are still components of the power factor correction filter 13 in the illustrated exemplary embodiment. The second current measuring device 134 can also be configured as a component of the inverter.

[0164] Voltage regulator 141 is coupled to second current measuring device 134 and receives its voltage measurement value as an input variable. Based on the received voltage measurement value and the corresponding predetermined voltage setting value, voltage regulator 141 is configured to determine the set value of the current intensity of the power factor correction filter rectifier output current.

[0165] Current regulator 142 is coupled to voltage regulator 141 and receives a setpoint current intensity determined by voltage regulator 141 as an input variable. Furthermore, current regulator 142 is coupled to first measuring device 133 and receives its measured current intensity as another input variable. Based on the received measured current intensity (as the actual value) and the setpoint current intensity received from voltage regulator 141, current regulator 142 is configured to determine a first control signal for the power factor correction filter such that the voltage at the interface between the power factor correction factor and the inverter conforms as closely as possible to a predetermined voltage setpoint.

[0166] The calculation model unit 143 is coupled to the operating data providing unit 23 and receives operating data of the additional electrical load as input variables from the operating data providing unit 23. The calculation model unit 143 provides a calculation model describing the electrical structure of the additional electrical load, which includes one or more electrical characteristic variables of the additional electrical load. The calculation model unit 143 is used to determine at least one current characteristic value of the additional electrical load based on the provided calculation model and the input variables from the operating data providing unit 23 (specifically, in the form of current intensity, preferably in the form of the amplitude and phase angle of various harmonics of the current), and is also used to transmit these values ​​to the compensation unit 144. Figure 3 In an exemplary embodiment, the determined current intensity corresponds to the current intensity i_load at that location or its estimated value.

[0167] Compensation unit 144 is coupled to calculation model unit 143 and receives at least one current characteristic value (current intensity in this example) determined by calculation model unit 143 as an input variable. Additionally, compensation unit 142 is coupled to first measuring device 133 and receives its current intensity measurement value as another input variable. Based on the received current intensity measurement value and the determined at least one current characteristic value, compensation unit 144 determines the current intensity at the power connection point. Figure 3 In an exemplary embodiment, the determined current intensity corresponds to the current intensity i_grid at that location or its estimated value.

[0168] Preferably, the aforementioned variables are detected as time curves, or the variables determined therefrom are determined as time curves.

[0169] Based on the current intensity of the determined grid connection point, the compensation unit 144 is used to determine the compensation signal and transmit it to the PWM calculation unit 145.

[0170] In this case, the compensation signal is determined under the premise of reducing the harmonic content of the grid connection point current.

[0171] The PWM calculation unit 145 now receives a first control signal from the current intensity regulator 142, a compensation signal from the compensation unit 144, and a voltage measurement value from the current measuring device 15 at the grid connection point, and determines the PWM control signal of the transistor unit of the power factor correction filter 13 based on these signals, which is transmitted from the PWM calculation unit to the transistor unit.

[0172] Transistors driven in this manner allow harmonics generated by additional electrical loads to be compensated in a favorable manner by controlling the power factor correction filter of the compressor.

[0173] In this way, the compressor system can meet specifications when it is disconnected from the grid current source without requiring structural modifications to the additional electrical load or the addition of additional components (such as energy-consuming elements).

[0174] In this regard, a highly efficient compressor system is provided, which in particular can keep energy loss at a low level.

[0175] Exemplary embodiments of the present invention and their advantages have been described in detail above with reference to the accompanying drawings.

[0176] It should be emphasized again that the present invention is by no means limited to the exemplary embodiments and their exemplary features described above. The present invention also includes modifications to specific exemplary embodiments, particularly modifications and / or combinations thereof made to one or more features of the exemplary embodiments within the scope of the independent claims.

Claims

1. A control method for a compressor system (1000), in particular a part of a refrigeration cycle system, comprising an electric compressor (1) for compressing a working medium and an additional electric load (2), characterized in that the compressor (1) comprising: an electric motor (11) for providing a mechanical movement for compressing the working medium; an inverter (12) for providing a single-phase or multi-phase alternating current for the electric motor (11); and a power factor correction filter (13) for providing a direct current for the inverter (12), the current input of which is connected to a grid connection point (2000) of a grid current source providing the alternating current, for powering the compressor (1), for powering the additional electric load (2), the additional electric load (2) is connected to the same grid connection point (2000) as the power factor correction filter (13), wherein the method comprises: operating the compressor system (1000) with current from the grid current source; determining at least one current characteristic value of the additional electric load (2), the current characteristic value describing a current consumption of the additional electric load (2); and controlling the power factor correction filter (13) of the compressor (1) at least in dependence on the determined at least one current characteristic value of the additional electric load (2).

2. The method of claim 1, wherein, the controlling the power factor correction filter (13) comprises: setting an operating parameter of the power factor correction filter (13) at least in dependence on the determined at least one current characteristic value of the additional electric load (2), the operating parameter determining the direct current output by the power factor correction filter (13) and / or influencing the alternating current taken from the grid current source by the compressor (1).

3. The method of claim 2, wherein, the power factor correction filter (13) comprises at least one transistor unit, in particular a MOSFET (302) or an IGBT, and the setting an operating parameter of the power factor correction filter (13) to control the power factor correction filter (13) comprises: setting a control signal of the at least one transistor unit at least in dependence on the determined at least one current characteristic value of the additional electric load (2).

4. The method according to any one of claims 1 to 3, characterized in that, the determined at least one current characteristic value comprises a current strength, in particular an effective current strength; or an electric power, in particular an effective electric power.

5. The method according to any one of claims 1 to 4, characterized in that, the additional electric load (2) and the compressor (1) are connected in parallel at the grid connection point (2000).

6. The method according to any one of claims 1 to 5, characterized in that, the determining at least one current characteristic value of the additional electric load (2) comprises: detecting a current variable, in particular a current strength, of a current input current of the additional electric load (2); determining the at least one current characteristic value based on the detected current variable.

7. The method according to any one of claims 1 to 5, characterized in that, the determining at least one current characteristic value of the additional electric load (2) comprises: providing a computational model describing an electrical structure of the additional electric load (2), the computational model of the electrical structure comprising one or more electrical characteristic variables of the additional electric load (2); calculating the at least one current characteristic value based on the provided computational model; The calculated at least one current characteristic value is output as the determined current characteristic value of the additional electrical load (2).

8. The method according to any one of claims 1 to 7, characterized in that, The power factor correction filter (13) comprises a rectifier (131), the rectifier (131) comprising an input for an alternating current input and an output for a rectified output current, the rectifier (131) being in particular a bridge rectifier.

9. The method of claim 8, wherein, The method further comprises: detecting a current variable, in particular a current intensity or a voltage, of the output current of the rectifier (131) at the output of the rectifier (131); wherein the controlling the power factor correction filter (13) of the compressor (1) is further based on the detected current variable of the output current of the rectifier (131).

10. The method according to any one of claims 1 to 7, characterized in that, The power factor correction filter (13) comprises a totem pole PFC converter (135).

11. The method of claim 10, wherein, The method further comprises: detecting a current variable, in particular a current intensity or a voltage, of the input current of the totem pole PFC converter (135), wherein the controlling the power factor correction filter (13) of the compressor (1) is further based on the detected current variable of the input current of the totem pole PFC converter (135).

12. The method according to any one of claims 1 to 11, characterized in that, The method further comprises: detecting a current variable, in particular a current intensity or a voltage, of the current at the current input of the power factor correction filter (13); wherein the controlling the power factor correction filter (13) of the compressor (1) is further based on the detected current variable of the current at the current input of the power factor correction filter (13).

13. The method according to any one of claims 1 to 12, characterized in that, The controlling the power factor correction filter (13) is performed in case one or more characteristic values of a current acquired by the compressor system (1000) at the grid connection point (2000) are below respective predetermined limit values, Preferably, the one or more characteristic values are amplitudes in a frequency spectrum of the acquired current, in particular corresponding to integer multiples of a fundamental frequency of the grid current source.

14. The method according to any one of claims 1 to 13, characterized in that, wherein The compressor system (1000) is designed as part of a refrigeration cycle system, in particular a heat pump or a chiller, and the method is a method for controlling the refrigeration cycle system.

15. Compressor (1) for compressing a working medium, comprising: an electric motor (11) for providing mechanical movement to compress the working medium; an inverter (12) for providing single-phase or multi-phase alternating current for the electric motor (11); a power factor correction filter (13) for providing direct current for the inverter (12), a current input of which is connectable to a grid connection point (2000) of a grid current source providing alternating current for powering the compressor (1); and a control device (14) for at least controlling the power factor correction filter (13); The calculated at least one current characteristic value is output as the determined current characteristic value of the additional electrical load (2). The power factor correction filter (13) comprises a rectifier (131), the rectifier (131) comprising an input for an alternating current input and an output for a rectified output current, the rectifier (131) being in particular a bridge rectifier. The method further comprises: detecting a current variable, in particular a current intensity or a voltage, of the output current of the rectifier (131) at the output of the rectifier (131); wherein the controlling the power factor correction filter (13) of the compressor (1) is further based on the detected current variable of the output current of the rectifier (131). The power factor correction filter (13) comprises a totem pole PFC converter (135). The method further comprises: detecting a current variable, in particular a current intensity or a voltage, of the input current of the totem pole PFC converter (135), wherein the controlling the power factor correction filter (13) of the compressor (1) is further based on the detected current variable of the input current of the totem pole PFC converter (135). The method further comprises: detecting a current variable, in particular a current intensity or a voltage, of the current at the current input of the power factor correction filter (13); wherein the controlling the power factor correction filter (13) of the compressor (1) is further based on the detected current variable of the current at the current input of the power factor correction filter (13). The controlling the power factor correction filter (13) is performed in case one or more characteristic values of a current acquired by the compressor system (1000) at the grid connection point (2000) are below respective predetermined limit values, Preferably, the one or more characteristic values are amplitudes in a frequency spectrum of the acquired current, in particular corresponding to integer multiples of a fundamental frequency of the grid current source. wherein The compressor system (1000) is designed as part of a refrigeration cycle system, in particular a heat pump or a chiller, and the method is a method for controlling the refrigeration cycle system.

15. Compressor (1) for compressing a working medium, comprising: an electric motor (11) for providing mechanical movement to compress the working medium; an inverter (12) for providing single-phase or multi-phase alternating current for the electric motor (11); a power factor correction filter (13) for providing direct current for the inverter (12), a current input of which is connectable to a grid connection point (2000) of a grid current source providing alternating current for powering the compressor (1); and a control device (14) for at least controlling the power factor correction filter (13); characterized in that the compressor (1) is electrically driven, in that the control device (14) is configured to determine at least one current characteristic value of the additional electrical load (2) describing a current consumption of the additional electrical load (2) when the compressor (1) and the additional electrical load (2) are connected to the same grid connection point (2000) of an electrical grid current source providing alternating current, and in that the control device (14) is configured to control the power factor correction filter (13) at least in dependence on the determined at least one current characteristic value of the additional electrical load (2).

16. Compressor system (1000), in particular as part of a refrigeration cycle system, comprising an electric compressor (1) for compressing a working medium according to claim 15; and an additional electrical load (2); wherein the compressor (1) and the additional electrical load (2) are connected to the same grid connection point (2000) of an electrical grid current source providing alternating current, in particular in parallel, wherein in this case the control device (14) of the compressor (1) is configured to determine at least one current characteristic value of the additional electrical load (2) describing a current consumption of the additional electrical load (2) and to control the power factor correction filter (13) at least in dependence on the determined at least one current characteristic value of the additional electrical load (2), wherein the additional electrical load (2) preferably comprises a rectifier (21), in particular a passive rectifier, and a direct current load (22).

17. A refrigeration cycle system for performing a refrigeration cycle process based on a working medium, wherein, the refrigeration cycle system is in particular a heat pump or a refrigerator, comprising a compressor system (1000) according to claim 16, the compressor (1) of the compressor system (1000) being configured to compress a working medium of the refrigeration cycle system.

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