阅读说明：本技术 用于操作电子控制器的方法 (Method for operating an electronic control unit ) 是由 马可·佐丹 史蒂文·刘 于 2019-12-24 设计创作，主要内容包括：描述一种用于操作电子控制器的方法,其中电子控制器能被连接至负载(100)用于为其供电并包括DC总线和连接至DC总线而以总线电压Vdc被供电的逆变器级(13)。电子控制器还包括连接至逆变器级(13)且用于控制逆变器级(13)并生成用于以可调整方式为负载(100)供电的电源电流Iout的控制设备(14)。方法包括：步骤A–测量DC总线的总线电压Vdc的值；步骤B–隔离总线电压Vdc的振荡分量Vdc-o并对比振荡分量和阈值Vth；步骤C–如果振荡分量Vdc-o大于阈值Vth,控制逆变器级(13)以将补偿电流Iadd添加至电源电流Iout。补偿电流Iadd被调制以生成至DC总线的补偿电压Vadd,使得总线电压Vdc的振荡分量Vdc-o与补偿电压Vadd的结合具有小于或等于初始振荡分量Vdc-o的值。(A method for operating an electronic controller is described, wherein the electronic controller is connectable to a load (100) for powering the same and comprises a DC bus and an inverter stage (13) connected to the DC bus to be powered at a bus voltage Vdc. The electronic controller further comprises a control device (14) connected to the inverter stage (13) and for controlling the inverter stage (13) and generating a supply current Iout for adjustably powering the load (100). The method comprises the following steps: step A-measuring a value of a bus voltage Vdc of the DC bus; step B-isolating the oscillation component Vdc-o of the bus voltage Vdc and comparing the oscillation component with a threshold Vth; step C-if the oscillation component Vdc-o is greater than the threshold Vth, the inverter stage (13) is controlled to add the compensation current Iadd to the power supply current Iout. The compensation current Iadd is modulated to generate a compensation voltage Vadd to the DC bus such that the oscillating component Vdc-o of the bus voltage Vdc in combination with the compensation voltage Vadd has a value less than or equal to the initial oscillating component Vdc-o.)

1. A method for operating an electronic controller connectable to a load (100) for supplying power to the load (100) and comprising a DC bus and an inverter stage (13) connected to the DC bus (12) to be supplied with power at a bus voltage Vdc, the electronic controller further comprising a control device (14) connected to the inverter stage (13) for controlling the inverter stage (13) and generating a supply current Iout for supplying power to the load (100) in an adjustable manner, the method comprising:

step A-measuring a value of a bus voltage Vdc of the DC bus (12);

step B-isolating an oscillation component Vdc-o of said bus voltage Vdc and comparing said oscillation component Vdc-o with a threshold Vth;

step C-if said oscillating component Vdc-o is greater than said threshold Vth, controlling said inverter stage (13) to add a compensation current Iadd to said power supply current Iout;

wherein the compensation current Iadd is modulated to generate a compensation voltage Vadd to the DC bus (12) such that a combination of the oscillation component Vdc-o and the compensation voltage Vadd has a value less than or equal to an initial oscillation component Vdc-o.

2. The operating method of claim 1, wherein the compensation current Iadd is modulated to generate a compensation voltage Vadd to the DC bus (12) such that the oscillating component Vdc-o of the bus voltage Vdc in combination with the compensation voltage Vadd has a value less than or equal to the threshold Vth.

3. The method of operation of claim 1 or 2, wherein said steps A, B and C are repeated cyclically at regular time intervals Tc.

4. The operating method according to claim 1 or 2, wherein said step a comprises measuring an oscillating ripple component of said bus voltage Vdc; the step C includes generating the compensation current Iadd such that the compensation voltage Vadd has a tendency designed to generate destructive interference to the pulsating component.

5. The operating method according to claim 4, wherein the threshold value Vth is set such that the compensation voltage Vadd destructively interferes with the ripple component, preferably the threshold value Vth is set to Vth-0 to cancel the ripple component.

6. The operating method according to claim 1 or 2, wherein said step a is carried out by measuring a signal representative of the value of said bus voltage Vdc and constituting a fraction of said bus voltage Vdc.

7. The operating method according to claim 1 or 2, wherein said step a is repeated cyclically at predetermined time intervals.

8. The method of operation of claim 1 or 2, comprising:

step D, before said step C, comprising the confirmation of the value of said bus voltage Vdc;

said step C is only performed if said confirmation has a positive result.

9. The method of operation of claim 1 or 2, wherein the compensation current Iadd is proportional and is selected from:

-proportional to the amplitude or half amplitude of said oscillating component Vdc-o of said bus voltage Vdc, Iadd-K (Vdc-o);

-proportional to the difference between said oscillation component Vdc-o and said threshold Vth associated with the sign of said oscillation component Vdc-o, Iadd ═ K (Vdc-o- (Vth x sgn (Vdc-o))).

10. The operating method according to claim 1 or 2, wherein the magnitude of the compensation current Iadd is limited to a value not greater than 50% of the magnitude of the power supply current Iout, preferably not greater than 30% of the magnitude of the power supply current Iout.

Technical Field

The present invention relates to a method for operating an electronic controller, in particular designed for controlling a compressor of a refrigerator.

In particular, the invention relates to a method for operating an electronic controller equipped with a rectifying stage or voltage converter, such as a PFC unit, and an inverter connected to a DC bus for a DC power supply.

Background

The expression "ripple" or "voltage ripple" as used herein refers to voltage oscillations which are superimposed on a constant voltage value to cumulatively determine, for example, the voltage at the DC bus and which, in a power supply system (e.g. single-phase or three-phase), are derived from the direct voltage (DC) obtained from the alternating voltage. At present, power supply controllers are generally known for user equipment, which comprise a voltage rectification stage or active switching with a DC link stage and a DC bus stage capacitor with a capacitor unit downstream of the voltage rectification stage or active switching.

The DC link may have an inductance, known by the generic term as DC-choke and/or conversion stage, designed for Power Factor Correction (PFC) at the input.

Downstream of the DC stage, there is a controlled inverter stage for determining the operating control of the user equipment, such as, for example, for controlling the operating speed of a compressor, for example of the turbo or rolling type, with pistons, rotors, double stage, screw type, etc., applied in refrigerators, and in particular of the positive displacement type.

It is currently known that these types of controllers can cause voltage ripple and corresponding current to increase with high and different amplitudes, and this can adversely affect the duration of the capacitor and have a negative impact on the voltage control performed by the inverter.

These effects are also caused and/or enhanced by the inductive-capacitive interaction between the capacitors of the DC bus and the DC choke inductance or inductive effect of the coils of the PFC unit.

Once these voltage ripple increases are triggered, the voltage ripple increases tend to be self-sustaining due to current oscillations that occur due to non-ideal behavior of the electronic components of the controller, such as, for example, due to the inductance at the capacitor and saturation of parasitic currents.

This effect, even if it does not cause blocking, can produce a reduction and periodic oscillation of the voltage of the DC bus and reach values that can also exceed the declared rating of the component.

Disclosure of Invention

The problem forming the basis of the present invention is to overcome the drawbacks of the conventional controllers described above.

The object of the present invention is therefore to solve this problem by providing a method for operating an electronic controller which allows to obtain a control of the voltage controlled by the inverter which is reliable and precise, long lasting, and guarantees a long life of the electronic components of the controller and in particular of the capacitor elements of the DC bus.

In the context of this object, it is an object of the invention to provide a method for operating an electronic controller which allows an increase in the amplitude of the voltage ripple to be counteracted.

It is a further object of the present invention to provide a method for operating an electronic controller which allows any increase in voltage ripple to be compensated for by controlling the inverter.

It is a further object of the present invention to provide a method for operating an electronic controller which allows to generate currents having a phase difference with respect to those currents associated with voltage ripple.

This object, as well as these and other objects that will appear more fully hereinafter, are achieved by a method for operating an electronic controller. An electronic controller connectable to a load for powering the load and comprising a DC bus and an inverter stage connected to the DC bus to be powered at a bus voltage Vdc, the electronic controller further comprising a control device connected to the inverter stage for controlling the inverter stage and generating in an adjustable manner a supply current Iout for powering the load, the method comprising: step A-measuring a value of a bus voltage Vdc of the DC bus; step B-isolating the oscillation component Vdc-o of the bus voltage Vdc and comparing the oscillation component Vdc-o with a threshold Vth; step C-if the oscillation component Vdc-o is greater than the threshold Vth, controlling the inverter stage (13) to add the compensation current Iadd to the power supply current Iout; wherein the compensation current Iadd is modulated to generate a compensation voltage Vadd to the DC bus (12) such that the combination of the oscillation component Vdc-o and the compensation voltage Vadd has a value less than or equal to the initial oscillation component Vdc-o.

In one embodiment, the compensation current Iadd is modulated to generate a compensation voltage Vadd to the DC bus (12) such that the oscillating component Vdc-o of the bus voltage Vdc in combination with the compensation voltage Vadd has a value less than or equal to a threshold Vth.

In one embodiment, steps A, B and C are repeated cyclically at regular time intervals Tc.

In one embodiment, step a includes measuring an oscillating ripple component of the bus voltage Vdc; step C includes generating the compensation current Iadd such that the compensation voltage Vadd has a tendency to be designed to generate destructive interference to the pulsating component.

In one embodiment, the threshold Vth is set such that the compensation voltage Vadd interferes with the ripple component in a destructive manner, preferably the threshold Vth is set to Vth of 0 to cancel the ripple component.

In one embodiment, step a is performed by measuring a signal representative of the value of the bus voltage Vdc and constituting a fraction of the bus voltage Vdc.

In one embodiment, step a is repeated cyclically at predetermined time intervals.

In one embodiment, the method further comprises: step D, before step C, comprises the confirmation of the value of the bus voltage Vdc. Step C is only performed if the confirmation has a positive result.

In one embodiment, the compensation current Iadd is proportional and is selected from: proportional to the amplitude or half-amplitude of the oscillating component Vdc-o of the bus voltage Vdc, Iadd-K (Vdc-o); in proportion to the difference between said oscillation component Vdc-o and said threshold Vth associated with the sign of said oscillation component Vdc-o, Iadd ═ K (Vdc-o- (Vth x sgn (Vdc-o))).

In one embodiment, the magnitude of the compensation current Iadd is limited to a value not greater than 50% of the magnitude of the power supply current Iout, preferably not greater than 30% of the magnitude of the power supply current Iout.

The method according to the invention ensures a better control of the supply voltage and/or a greater duration of the capacitors of the DC bus, in particular preventing damage caused by the ripple of the overvoltage.

Drawings

Further features and advantages of the invention will emerge from the description of a preferred but not exclusive embodiment of a method for operating an electronic controller, illustrated by way of example in the accompanying drawings, in which:

FIG. 1 is a simplified diagram of an electronic controller;

fig. 2 is a simplified flow diagram illustrating a method for operating an electronic controller in accordance with the present invention.

Detailed Description

With particular reference to the preceding figures, reference numeral 10 indicates, in its entirety, an electronic controller which can be connected to a load 100 for powering the load and which comprises:

-a rectification stage 11;

-a DC bus 12;

an inverter stage 13 connected to the rectification stage 11 by a DC bus 12, the DC bus 12 being used to supply the inverter stage 13 with a bus voltage Vdc;

a control device 14 connected to the inverter stage 13 for controlling the inverter stage 13 to adjustably generate a supply current Iout for powering the load 100.

In particular, the load 100 may be a compressor of a refrigerator, in which case the control device 14 will be used to control the inverter stage 13 to operate the compressor according to a variable rotation state.

The operating method according to the invention can therefore be designed in particular for the operation of a compressor of an electronic controller for operating a refrigerator, for example of the turbine type or of the rolling type, with variable speed.

Operationally, a method for operating an electronic controller according to the present invention comprises:

step a-measuring the value of the bus voltage Vdc of the DC bus 12;

step B-isolating the oscillation component Vdc-o of the bus voltage Vdc and comparing the oscillation component Vdc-o with a threshold Vth;

step C-if the bus voltage value Vdc is greater than the threshold Vth, the inverter stage 13 is controlled to add a compensation current Iadd to the supply current Iout, wherein the compensation current Iadd is modulated to generate a compensation voltage Vadd at the DC bus 12, such that the combination of the oscillation component Vdc-o of the bus voltage Vdc and the compensation voltage Vadd has a value less than the initial oscillation component Vdc-o, and preferably less than the threshold Vth. Preferably, the comparison of step B is performed between the absolute value of the amplitude or half-amplitude of the oscillation component Vdc-o and the threshold Vth.

Steps A, B and C may be repeated cyclically, continuously, or at time intervals Tc, which may be regular.

Step a may comprise measuring an oscillating ripple component of the bus voltage Vdc.

Step C, accordingly, may include generating the compensation current Iadd such that the compensation voltage Vadd has a tendency designed to produce destructive interference to the pulsating component.

In particular, step C may generate the compensation current Iadd such that the compensation voltage Vadd is such that: its combination with the oscillating component Vdc-o of the bus voltage Vdc constitutes a compensated voltage Vcomp ═ Vdc-o + Vadd, which is less than or equal to the oscillating component Vdc-o of the bus voltage Vdc before the combination, and preferably less than the threshold voltage Vth.

Further, the threshold Vth may be set to tend to cancel the ripple component of the bus voltage Vdc.

To this end, step C may include generating the compensation current Iadd such that the compensation voltage Vadd interferes with the pulsating component in a destructive manner, eliminating it.

For example, the control device 14 may perform step a by measuring a signal representative of the value of the bus voltage Vdc and constituting a fraction of the bus voltage Vdc.

In the method according to the invention, step a may be cyclically repeated with a predetermined law, for example with a frequency selected between 125ps and 250 ps.

Step a may be performed by a digital-to-analog converter connectable to the control device 14.

The method according to the invention may comprise a step D, which precedes step C, comprising the verification of the value of the bus voltage Vdc.

The method according to the invention may comprise performing step C only if said confirmation has a positive result.

The method according to the invention may comprise performing step B only if said confirmation has a positive result.

The validation may consist in verifying whether the value of the bus Vdc is within a predetermined range Vdc-min, Vdc-max.

The operation of isolating the oscillating component Vdc-o of the bus voltage Vdc of step a may comprise, for example, using a low pass filter to obtain a constant component Vdc-c of the bus voltage Vdc and subtracting the constant component Vdc-c from the bus voltage Vdc, or the operation may comprise using a high pass filter.

The compensation current Iadd can be modulated in accordance with the oscillation component Vdc-o to have a destructive effect on the oscillation component Vdc-o.

In order not to disturb the operation of the load 100, the method may be such that the intensity of the compensation current Iadd is limited to a value not greater than 50% of the intensity of the supply current Iout of the load 100, and preferably not greater than 30% of the intensity of the supply current Iout of the load 100.

The threshold Vth may be selected according to implementation requirements as appropriate for the present invention, and may also have a zero value (Vth ═ 0), that is, the compensation effect by applying the compensation voltage Vadd will always be effective with a voltage ripple that is not zero.

In particular, the threshold Vth derives from design considerations for the series connection of the capacitors and is also based on the expected lifetime of the electronic controller.

In particular, the longer the expected lifetime of the inverter stage 13, the lower the pressure that needs to be derived from the ripple of the bus voltage Vdc, and therefore the lower the threshold Vth must be, for the same level of degradation of the series of capacitances of the DC bus.

The threshold Vth may also be selected according to the power level generated by the inverter stage 13, for example, in a proportional manner within a maximum tolerance limit, for which power in such a way as to compensate for the abnormal absorption of the pressure at the series connection of the capacitors.

By implementing the method according to the invention, if the oscillating component of the bus voltage Vdc, i.e. the amplitude or half-amplitude of the bus voltage in absolute terms, is greater than the tolerance value, i.e. greater than the threshold value Vth, an additional current is generated which discharges the series-connected capacitors of the DC bus 12, reducing the oscillating component Vdc-o of the bus voltage Vdc.

An additional current can be obtained according to the invention, which additionally imposes a compensation current Iadd to the supply current Iout at the output from the inverter stage 13.

Setting the compensation current Iadd in this way generates additional power at the output of the inverter stage 13, implying electrical power at the DC bus 12, which then requires a current from the series of capacitors of the DC bus 12.

By implementing the method according to the invention, this requested power will have a tendency to reflect the destructive interference of the ripple oscillation in terms of the destructive interference, so that the extra current is drawn from the same series of capacitors, obtaining the desired effect of discharging the series of capacitors, i.e. reducing the load of the series of capacitors, that is to say reducing the bus voltage Vdc.

In other words, in the method according to the invention, the link between the compensation current Iadd set at the output from the inverter stage 13 and the subsequent additional current at the series connection of the capacitors is used at the bus voltage Vdc by the active electrical power.

The compensation current Iadd from the output of the inverter stage 13 may be controlled by a current regulation loop of the inverter stage 13. In particular, in the case of a compressor as load 100, the current component linked to the active power will be directly linked to the production of the drive torque of the compressor.

The compensation current Iadd set towards the load 100 is selected to be of a value such that the effect of the compensation current Iadd towards the load 100 (e.g., as a disturbing moment if the load 100 is a compressor) is negligible with respect to the current that would otherwise be present.

As previously described, the compensation current Iadd may be selected to be proportional to the difference between the measured value of the oscillating component Vdc-o of the bus voltage Vdc and the threshold Vth.

In case the load 100 is a compressor, the compensation current Iadd will be added to the current needed to generate the torque necessary for rotating the compressor, and the resulting sum becomes the reference of the regulation loop of the inverter stage 13.

In other words, the intensity of the compensation current Iadd may be selected in such a way as not to determine a variation of the torque generated only by the supply current Iout of not more than 50% and preferably not more than 30% of the torque itself.

In particular, if the absolute value of the oscillation component Vdc-o is greater than the threshold Vth, the compensation current Iadd may be proportional to the amplitude or half amplitude of the oscillation component Vdc-o of the bus voltage Vdc, e.g., according to the formula Iadd-K (Vdc-c) -KVdc-o, where K is a constant.

In such a case, the compensation current Iadd will be injected with a value proportional to the oscillation component Vdc-o as long as the absolute value of the oscillation component Vdc-o exceeds the threshold Vth.

This allows the reaction of the system to be immediate and intense and efficient. Alternatively, in order to have a gentle compensation effect, the compensation current Iadd may be proportional to the difference between the oscillation component Vdc-o and the threshold Vth having the sign of the oscillation component Vdc-o, i.e., K (Vdc-o- (Vth x sgn (Vdc-o))), according to the formula Iadd, wherein sgn (Vdc-o) — 1 if Vdc-o < 0; if VDC-o >0, sgn (VDC-o) ═ 1; or sgn (VDC-o) is 0 if VDC-o is 0.

It has thus been shown how the present invention achieves the set aims and objects.

In particular, a method for operating an electronic controller is provided that allows to control the voltage to be obtained, controllable by an inverter, which is reliable and precise, long lasting, and guarantees a long life of the electronic components of the controller and in particular of the series connection of the capacitors of the DC bus.

Furthermore, a method for operating an electronic controller is provided that allows to counteract an increase in the amplitude of the voltage ripple and compensate for any increase in the voltage ripple by controlling the inverter.

A method for operating an electronic controller according to the invention allows to generate currents having a phase difference with respect to those currents associated with voltage ripple.

The invention, as it is conceived, is susceptible of numerous modifications and variations, all falling within the scope of protection of the appended claims.

Moreover, all the details may be replaced with other technically equivalent elements.

In practice, the form and dimensions may vary according to the needs as the case may be, as well as the state of the art.

Where constructional and technical features mentioned in the following claims are followed by signs or reference signs, the signs or reference signs have been used only for the purpose of increasing the intelligibility of the claims and accordingly the signs or reference signs do not constitute in any way a limitation to the interpretation of each element identified by way of example only by reference to the signs or reference signs.