Mineral material processing plant with ac stabilization

Abstract

A method for stabilizing the power feed to an internal power grid of a mineral material processing machine, comprising monitoring at least one quantity related to power provided to an internal AC electric power line (40) of the mineral material processing machine with a stabilizer element (50); determining whether there is a decrease in the quality of power provided to the internal AC electric power line (40) of the mineral material processing machine; in response to determining that there is a decrease in the quality of power provided to the internal AC electric power line (40) of the mineral material processing machine, feeding power to the internal AC electric power line (40) from an energy storage (60) via the stabilizer element (50) to stabilize the power of the internal AC electric power line (40); wherein in response to determining that there is no decrease in the quality of power provided to the internal AC electric power line (40) of the mineral material processing machine, determining whether there is power available for charging the energy storage (60); and in response to determining that there is power available for charging the energy storage (60), charging the energy storage (60) via the stabilizer element (50)

Description

[0001] MINERAL MATERIAL PROCESSING PLANT WITH AC STABILIZATION

[0002] TECHNICAL FIELD

[0003] The present disclosure generally relates to a mineral material processing plant and a method of operating a mineral material processing plant. The disclosure relates particularly, though not exclusively, to a mineral material processing plan with an electric drive. The disclosure relates particularly, though not exclusively, to a mineral material processing plan with alternating current stabilization

[0004] BACKGROUND

[0005] This section illustrates useful background information without admission of any technique described herein representative of the state of the art.

[0006] Mineral material processing is increasingly moving towards electric and hybrid power generation. In such power generation, the quality and amount of available power might at times be less than desired. Such fluctuations in the quality and amount of available power can be caused for example by unstable grid connection or increased power requirement of mineral material processing devices.

[0007] Previously, solutions for providing extra power to a mineral material processing device have been envisioned. However, there is need for a simple solution to stabilize the main power feed, be it from grid, from a connected plant, or from a generator.

[0008] Accordingly, the present disclosure aims to provide a solution for peak load stabilization in a mineral material processing plant.

[0009] SUMMARY

[0010] The appended claims define the scope of protection. Any examples and technical descriptions of apparatuses, products and / or methods in the description and / or drawings not covered by the claims are presented not as embodiments of the invention but as background art or examples useful for understanding the invention.

[0011] According to a first example aspect there is provided a method for stabilizing the power feed to an internal power grid of a mineral material processing machine, comprising monitoring at least one quantity related to power provided to an internal AC electric power line of the mineral material processing machine with a stabilizer element; determining whether there is a decrease in the quality of power provided to the internal AC electric power line of the mineral material processing machine; in response to determining that there is a decrease in the quality of power provided to the internal AC electric power line of the mineral material processing machine, feeding power to the internal AC electric power line from an energy storage via the stabilizer element to stabilize the power of the internal AC electric power line; wherein in response to determining that there is no decrease in the quality of power provided to the internal AC electric power line of the mineral material processing machine, determining whether there is power available for charging the energy storage; and in response to determining that there is power available for charging the energy storage, charging the energy storage via the stabilizer element.

[0012] The at least one quantity related to power may comprise voltage and / or frequency.

[0013] Determining a decrease in the quality of power provided to the internal AC electric power line may comprise determining that there is a drop in voltage and / or frequency.

[0014] The method may further comprise prior to feeding power to the internal AC electric power line, determining that the energy storage is sufficiently charged.

[0015] The method may further comprise determining the amount of power to be fed to the internal AC electric power line.

[0016] According to a second example aspect there is provided a mineral material processing machine, comprising at least one processing device operated with an electric drive; an internal AC electric power line configured to provide power to the at least one processing device; a stabilizer element connected to the internal AC electric power line; an energy storage; wherein the stabilizer element is configured to: monitor at least one quantity related to power provided to an internal AC electric power line of the mineral material processing machine with; determine whether there is a decrease in the quality of power provided to the internal AC electric power line of the mineral material processing machine; in response to determining that there is a decrease in the quality of power provided to the internal AC electric power line of the mineral material processing machine, feed power to the internal AC electric power line from an energy storage to stabilize the power of the internal AC electric power line; wherein in response to determining that there is no decrease in the quality of power provided to the internal AC electric power line of the mineral material processing machine, determine whether there is power available for charging the energy storage; and in response to determining that there is power available for charging the energy storage, charge the energy storage.

[0017] The stabilizer element may comprise a two-way AC / DC-converter.

[0018] The at least one processing device operated with an electric drive may comprise a crusher or a screen.

[0019] The at least one quantity related to power may comprise voltage and / or frequency.

[0020] According to a third example aspect there is provided a control system for a mineral material processing machine, comprising a stabilizer element configured to be connected to an internal AC electric power line of a mineral material processing machine and configured to cause carrying out the method of the first example aspect.

[0021] Different non-binding example aspects and embodiments have been illustrated in the foregoing. The embodiments in the foregoing are used merely to explain selected aspects or steps that may be utilized in different implementations. Some embodiments may be presented only with reference to certain example aspects. It should be appreciated that corresponding embodiments may apply to other example aspects as well.

[0022] BRIEF DESCRIPTION OF THE FIGURES

[0023] Some example embodiments will be described with reference to the accompanying figures, in which:

[0024] Fig. 1 schematically shows a block view of a mineral material processing machine according to an example embodiment;

[0025] Fig. 2 schematically shows a block view of a mineral material processing machine according to an example embodiment; and

[0026] Fig. 3 shows a flow chart of a method according to an example embodiment. DETAILED DESCRIPTION

[0027] In the following description, like reference signs denote like elements or steps.

[0028] Figs. 1 and 2 schematically show a block view of a mineral material processing machine 100 according to an example embodiment.

[0029] In an example embodiment, the mineral material processing machine 100 comprises a mobile mineral material processing machine such as a track or wheel mounted mobile crusher or a mobile screen.

[0030] The mineral material processing machine 100 comprises at least one processing device operated with an electric drive, or motor, M1 .

[0031] In an example embodiment, the at least one processing device driven by an electric drive M1 comprises a crusher. In an example embodiment, the crusher is selected from the group of jaw crusher, cone crusher, gyratory crusher, horizontal shaft impactor, vertical shaft impactor and high pressure grinding roll crusher. In an example embodiment, the processing device driven by an electric drive M1 comprises a screen.

[0032] In a further example embodiment, the mineral material processing machine comprises more than one processing device driven by an electric drive, for example both a crusher and a screen. In a still further example embodiment, the at least one processing device is driven by another electric drive, for example electric drive M4 or M5.

[0033] The mineral material processing machine 100, in an example embodiment, further comprises at least one converter element 70a, 70b configured to provide power to the electric drives, or motors, M1-M3. In an example embodiment, the at least one converter element 70a, 70b comprises an AC / AC-converter. In an example embodiment, the converter element 70b is configured to provide power to the electric drives M2 and M3 and to adjust the operation of said electric drives with respect to each other.

[0034] The mineral material processing machine 100 further comprises at least one auxiliary device directly or indirectly participating in mineral material processing and operated with an electric drive, or motor, M4-M5. The at least one auxiliary device, in an example embodiment, comprises a conveyor, a pump, a feeder, a magnetic separator, air blower separator, a fan blower, crawler tracks, and / or actuators for moving, e.g. raising and lowering, parts of the mineral material processing machine 100. In a further example embodiment, the mineral material processing machine 100 comprises further electric drives and / or electric components not shown in Figs. 1 and 2.

[0035] The mineral material processing machine 100, in an example embodiment, comprises a motor 10, for example a diesel motor, and a generator G coupled to the motor 10 for generating AC electric power.

[0036] The mineral material processing machine 100, in an example embodiment, comprises means for connecting the machine to an external source of electric power 20, such as power grid. In an example embodiment, the external source of electric power comprises a power feed from a further mineral material processing machine.

[0037] The mineral material processing machine 100, in an example embodiment, further comprises a switching element 30 for connecting the power from the generator 10 and / or the external source of electric power 20 to the internal AC electric power line 40 of the mineral material processing machine 100 and, in an example embodiment, to another mineral material processing machine 200.

[0038] The mineral material processing machine 100, in an example embodiment, further comprises a stabilizer element 50 connected to the internal AC electric power line 40 of the mineral material processing machine. In an example embodiment, the stabilizer element 50 comprises a two-way AC / DC-converter, components relating to supply protection and electric filters.

[0039] In an example embodiment, the stabilizer element 50 is configured to monitor at least one quantity related to power, for example related to the quality of the electricity provided to the internal AC electric power line 40. In an example embodiment, the at least one quantity comprises voltage and / or frequency. In a further example embodiment, instead or in addition to monitoring the at least one quantity related to the quality of the electricity provided to the internal AC electric power line 40, the stabilizer element 50 is configured to monitor, or receive information such as measurement values, related to the power feed from a further mineral material processing machine.

[0040] In an example embodiment, the stabilizer element 50 is connected to an energy storage 60. In an example embodiment, the energy storage 60 comprises a battery and / or a high- capacity capacitor.

[0041] In an example embodiment, the stabilizer element 50 is configured to charge the energy storage 60, depending on the monitored at least one quantity related to power, i.e. if there is available power for charging the energy storage.

[0042] In an example embodiment, the stabilizer element 50 is configured to feed energy form the energy storage to the internal AC electric power line in order to stabilize the power of the internal AC electric power line 40 if its quality is decreased. That is if the monitored at least one quantity related to power should experience a quality issue, such as voltage or frequency drop, the stabilizer element 50 is configured to compensate the power quality by feeding energy from the energy storage 60 to the internal AC electric power line 40.

[0043] In an example embodiment, the stabilizer element 50 is configured to monitor, or receive information such as measurement values of, a further quantity or quantities related to the power feed to the internal AC electric power line 40, such as amount of energy provided.

[0044] In a further example embodiment, shown in Fig. 2, the mineral material processing machine 100, comprises an internal DC power line 90 in addition to the internal AC power line 40. In such an embodiment, at least one inverter element 80a, 80b is connected to the internal DC electric power line 90 configured to provide power to the electric drives, or motors, M1-M3, and the stabilizer element 50 is configured to provide energy to the at least one inverter element 80a, 80b via the internal DC electric power line 90.

[0045] In a still further example embodiment, the mineral material processing machine 100, comprises electric drives, or motors, connected to both the internal DC power line via the at least one inverter element 80a, 80b and the internal AC electric power line 40 via the at least one converter element 70a, 70b.

[0046] In an example embodiment, the stabilizer element 50 is provided as a separate module that is configured to be connected to a power grid of a mineral material processing machine.

[0047] Fig. 3 shows a flow chart of a method according to an example embodiment.

[0048] At step 310 the AC stabilization according to an example embodiment is started using the stabilizer element 50. In an example embodiment, prior to starting the stabilization, the stabilizer element 50 is connected to the internal AC electric power line of the mineral material processing machine and to the energy storage 60. The stabilizer element is in connection with the control system of the mineral material processing machine or plant.

[0049] At step 320, the at least on quantity related to power, for example related to the quality of the electricity, provided to the internal AC electric power line is monitored using the stabilizer element 50. In an example embodiment, the at least one quantity comprises voltage and / or frequency. In an example embodiment, the monitoring comprises measuring the at least one quantity using the stabilizer element 50, i.e. the stabilizer element in an embodiment comprises means for measuring the at least one quantity related to power. In a further example embodiment, the stabilizer element 50 receives data concerning the at least one quantity, such as measurement values for example from a control system of the mineral material processing machine. At step 330, it is determined whether there is a decrease in the quality of power provided to the internal AC electric power line of the mineral material processing machine. In an example embodiment, determining a decrease in the power quality comprises determining that there is a drop in voltage and / or frequency.

[0050] At step 340, in response to a determination that there is a decrease in the quality of power provided to the internal AC electric power line of the mineral material processing machine, the stabilizer element 50 is configured to feed power to the internal AC electric power line 40 from the energy storage 60 in order to stabilize the power of the internal AC electric power line 40. In an example embodiment, prior to feeding power, it is determined that the energy storage 60 is sufficiently charged in order to protect the energy storage, such as a battery.

[0051] The amount and quality of the power fed to the internal AC electric power line 40 is determined in such a way as to stabilize the monitored quantities, i.e. the power quality, to desired values. In an example embodiment, the amount and quality of the power fed is estimated based on the principle of peak shaving. In further example embodiment, the amount and quality of the power fed is determined based on integrated average power use.

[0052] At step 350, in response to a determination that there is no decrease in the quality of power provided to the internal AC electric power line of the mineral material processing machine, the stabilizer element 50 is configured to determine whether there is power available for charging the energy storage 60.

[0053] At step 360, in response to determination that there is power available for charging the energy storage 60, the energy storage 60 is charged.

[0054] Example of the method according to example embodiments is as follows. During operation of the mineral material processing machine situations arise in which the power feed to the mineral material processing machine is insufficient. Such a situation may arise for external and internal reasons. For example in case of the material being processed being more difficult to crush and requiring more power than planned for or in case of the generator being unable to provide enough power, or the external grid experiencing power quality fluctuations, or the feeding machine being overloaded. In such a situation, the stabilizer element 50 is configured to transfer energy from the energy storage 60 to the internal AC electric power line of the mineral material processing machine and to stabilize the quality of the power of the AC power grid so that the operation of the mineral material processing machine may continue uninterrupted.

[0055] Without in any way limiting the scope of the appended claims, some technical effects of the method and mineral material processing machine according to example embodiments are explained in the following.

[0056] The example embodiments are configured to provide stable power to the internal power grid of a mineral material processing plant for uninterrupted and stable operation.

[0057] Accordingly, a technical effect of example embodiment of the invention is to provide more energy security during operation. A further technical effect of the example embodiments of the invention is to increase the lifetime of components. A still further technical effect of the example embodiments of the invention is to enable mineral material processing in situations of low quality power feed. A still further technical effect of the example embodiments of the invention is to enable designing for smaller average power thus decreasing costs and weight of for example the generator and the motor used to drive it. A still further technical effect of the example embodiments of the invention is to provide a modular stabilizer element that can be retrofitted to an existing mineral material processing machine.

[0058] Various embodiments have been presented. It should be appreciated that in this document, words comprise; include; and contain are each used as open-ended expressions with no intended exclusivity.

[0059] The foregoing description has provided by way of non-limiting examples of particular implementations and embodiments a full and informative description of the best mode presently contemplated by the inventors for carrying out the invention. It is however clear to a person skilled in the art that the invention is not restricted to details of the embodiments presented in the foregoing, but that it can be implemented in other embodiments using equivalent means or in different combinations of embodiments without deviating from the characteristics of the invention.

[0060] Furthermore, some of the features of the afore-disclosed example embodiments may be used to advantage without the corresponding use of other features. As such, the foregoing description shall be considered as merely illustrative of the principles of the present invention, and not in limitation thereof. Hence, the scope of the invention is only restricted by the appended patent claims.

Claims

CLAIMS1 .A method for stabilizing the power feed to an internal power grid of a mineral material processing machine, comprising generating AC electric power with a motor (10) and a generator (G) coupled to the motor (10); connecting the power from the generator (10) to an internal AC electric power line (40) of the mineral material processing machine via a switching element (30), wherein the internal AC electric power line (40) is configured to provide power to at least a crusher of the mineral material processing machine; monitoring at least one quantity related to power provided to an internal AC electric power line (40) of the mineral material processing machine with a stabilizer element (50); determining whether there is a decrease in the quality of power provided to the internal AC electric power line (40) of the mineral material processing machine; in response to determining that there is a decrease in the quality of power provided to the internal AC electric power line (40) of the mineral material processing machine, feeding power to the internal AC electric power line (40) from an energy storage (60) via the stabilizer element (50) to stabilize the power of the internal AC electric power line (40); wherein in response to determining that there is no decrease in the quality of power provided to the internal AC electric power line (40) of the mineral material processing machine, determining whether there is power available for charging the energy storage (60); and in response to determining that there is power available for charging the energy storage (60), charging the energy storage (60) via the stabilizer element (50).

2. The method of claim 1 , wherein the at least one quantity related to power comprises voltage and / or frequency.

3. The method of any one of the preceding claims, wherein determining a decrease in the quality of power provided to the internal AC electric power line (40) comprises determining that there is a drop in voltage and / or frequency.

4. The method of any one of the preceding claims, further comprising prior to feeding power to the internal AC electric power line (40), determining that the energy storage (60) is sufficiently charged.

5. The method of any one of the preceding claims, further comprising determining the amount of power to be fed to the internal AC electric power line (40).

6. A mineral material processing machine, comprising a motor (10) and a generator (G) coupled to the motor (10) for generating AC electric power; at least one processing device operated with an electric drive, wherein the at least one processing device comprises at least a crusher; a switching element (30) for connecting the power from the generator (10) to an internal AC electric power line (40) of the mineral material processing machine, wherein the internal AC electric power line (40) is configured to provide power at least to the crusher; a stabilizer element (50) connected to the internal AC electric power line (40); and an energy storage (60); wherein the stabilizer element (50) is configured to: monitor at least one quantity related to power provided to an internal AC electric power line (40) of the mineral material processing machine with; determine whether there is a decrease in the quality of power provided to the internal AC electric power line (40) of the mineral material processing machine; in response to determining that there is a decrease in the quality of power provided to the internal AC electric power line (40) of the mineral material processing machine, feed power to the internal AC electric power line (40) from an energy storage (60) to stabilize the power of the internal AC electric power line (40); wherein in response to determining that there is no decrease in the quality of power provided to the internal AC electric power line (40) of the mineral material processing machine, determine whether there is power available for charging the energy storage (60); and in response to determining that there is power available for charging the energy storage (60), charge the energy storage (60).

7. The mineral material processing machine of claim 6, wherein the stabilizer element(50) comprises a two-way AC / DC-converter.

8. The mineral material processing machine of claim 6 or 7, wherein the at least one processing device operated with an electric drive comprises a crusher and / or a screen.

9. The mineral material processing machine of any preceding claim, wherein the at least one quantity related to power comprises voltage and / or frequency.

10. A control system for a mineral material processing machine, comprising a stabilizer element (50) configured to be connected to an internal AC electric power line (40)of a mineral material processing machine, wherein the internal AC electric power line (40) is configured to provide power to at least a crusher, the stabilizer element (50) being configured to monitor at least one quantity related to power provided to the internal AC electric power line (40) of the mineral material processing machine with; determine whether there is a decrease in the quality of power provided to the internal AC electric power line (40) of the mineral material processing machine; in response to determining that there is a decrease in the quality of power provided to the internal AC electric power line (40) of the mineral material processing machine, feed power to the internal AC electric power line (40) from an energy storage (60) to stabilize the power of the internal AC electric power line (40); wherein in response to determining that there is no decrease in the quality of power provided to the internal AC electric power line (40) of the mineral material processing machine, determine whether there is power available for charging the energy storage (60); and in response to determining that there is power available for charging the energy storage (60), charge the energy storage (60).

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