Mine enterprise operation power supply system based on multi-power composition and regulation and control mode thereof

Abstract

The invention relates to a mining enterprise operation power supply system based on multi-power composition and a regulation and control mode thereof. The mining enterprise operation power supply system comprises first-level load equipment, second-level load equipment, third-level load equipment, an external power supply network, a photovoltaic system, a light storage system, a diesel engine set and an energy management system. The energy management system controls the external power supply network, the optical storage system and / or the diesel engine set to supply power to the first-level load device, the second-level load device and the third-level load device. Multiple energy supply channels of mining enterprises are guaranteed, continuous production of mines is further stabilized, and efficient operation of a micro-grid of the mining enterprises is formed by integrating multiple power supply modes.

Description

Technical Field

[0001] The present invention relates to the field of power supply technology, and in particular to a mining enterprise power supply system based on multiple power components and a control method thereof. Background Art

[0002] Mining companies are often located in remote areas, particularly Chinese-owned mining companies in Africa, such as those in the Democratic Republic of the Congo, which face severe power shortages. This power shortage has severely impacted production at many companies. To meet annual production targets, many rely on diesel generators, but diesel generation is costly and unsustainable. Solar power can effectively overcome this problem in mines. Photovoltaic power generation systems deployed within mining areas are used to meet production and other power needs. These systems use photovoltaic modules to convert solar energy into electricity, providing green, renewable energy for the mine. This principle is based on photovoltaic power generation technology, which directly converts sunlight into electricity through the photovoltaic effect. Specifically, when solar radiation strikes a photovoltaic array (composed of multiple photovoltaic modules), the modules convert the energy into direct current (DC). This DC power is then converted to AC by an inverter for use by various electrical devices within the mine.

[0003] However, in order to ensure that mining companies have multiple energy supply channels, further stabilize mine production, and integrate multiple power supply methods to achieve efficient operation of mining companies' microgrids, this is an energy problem faced by overseas mining companies. Summary of the Invention

[0004] In response to the above problems, the present invention provides a power supply system for the microgrid operation of a mining enterprise based on three types of power: diesel generator, mains electricity and photovoltaic power.

[0005] The specific technical solution of the present invention is: a mining enterprise power supply system based on multiple power components, including primary load equipment, secondary load equipment, tertiary load equipment, an external power supply network, a photovoltaic system, a photovoltaic storage system, a diesel generator set and an energy management system; the energy management system controls the external power supply network, the photovoltaic storage system and / or the diesel generator set to supply power to the primary load equipment, the secondary load equipment and the tertiary load equipment.

[0006] Furthermore, preferably, the diesel generator set is composed of several diesel generators.

[0007] Furthermore, preferably, the photovoltaic system includes photovoltaic modules and photovoltaic inverters.

[0008] Furthermore, preferably, the first-level load equipment includes liquid circulation pump equipment in each workshop.

[0009] Further, preferably, the secondary loading equipment includes ball mill equipment.

[0010] Furthermore, preferably, the three-level load device includes a motor rectifier.

[0011] Furthermore, preferably, the energy management system includes a SCADA system, microgrid operation control, and energy management.

[0012] Another technical purpose of the present invention is to provide a control method for a mining enterprise power supply system based on multiple power components, including two modes: grid-connected operation and off-grid black start operation.

[0013] 1. When the external power supply network is connected to the grid and there is power: The photovoltaic system and the photovoltaic storage system are grid-connected and operated, with the voltage and frequency maintained stable by the external power supply network, and loads at all levels switched on and off in an orderly manner; When there is sufficient sunlight during the day, photovoltaic power supply is given priority to the load, and the excess power of the photovoltaic system can be used to charge the photovoltaic storage system; During the day when there is insufficient sunlight, if the external power grid reaches its power limit and the photovoltaic power supply + external power grid power supply is insufficient to supply the load, the diesel generator set will be started to supply power; When photovoltaic power generation is not in progress at night, the photovoltaic storage system supplies power to the SOC lower limit within a limited time, and the rest of the time is supplied by the photovoltaic storage system and the external power grid; Off-grid black start, when the external power supply network loses power: The diesel generator set serves as the main power source for black start, photovoltaic energy storage is connected to the power grid, and three levels of loads are supplied with power in an orderly manner.

[0014] The diesel generator set and solar storage system are shut down, and all load equipment are automatically locked and shut down; The diesel generator set automatically switches to busbar mode for startup / or manually switches to busbar mode for startup, serving as the main power source to establish voltage and frequency; Manually start the first-level load equipment, that is, start the liquid flow pump equipment in each workshop, and start it with the frequency converter; The photovoltaic energy storage system is started and connected to the grid in VSG mode; then, the photovoltaic system is connected to the grid and operates under limited power while providing a clear supply power value.

[0015] After the system maintains stable operation, start the secondary load equipment one by one, that is, start the semi-autogenous grinding mill and ball mill one by one; After the power margin is determined by manual calculation, the three-level load equipment is started in the established order, and then the motor rectifier transformer is started.

[0016] The beneficial effects of the present invention are as follows: in the event of a power outage in the external power supply network (mains), after the diesel generator starts normally as the main power source, workers can manually turn on the first-level load; the energy storage is started and connected to the grid in PQ mode, and the photovoltaic grid is started, and together with the diesel generator, they provide orderly power to the three levels of loads in the mining area.

[0017] In the presence of an external power grid (mains), both the energy storage system and the photovoltaic system are grid-connected to maximize photovoltaic power generation, with photovoltaic power generation prioritized for economical electricity use. The mining enterprise microgrid power supply system, comprised of a diesel generator, utility power, and photovoltaic power generation, integrates multiple power supply methods to achieve efficient operation of the mining enterprise microgrid, ensuring diverse energy supply channels for the mining enterprise, further stabilizing the mine's power supply and enabling sustained and stable production. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the system layout for implementing the first embodiment of the present invention; Figure 2 Schematic diagram of the control method of the present invention. DETAILED DESCRIPTION

[0019] In order to make the technical problems and technical solutions solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0021] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances. Example 1

[0022] like Figure 1As shown, the project is located in the Mabende mining area in the Democratic Republic of the Congo. The installed PV capacity is 8 MWp (DC side) and the rated capacity is 6.6 MW (AC side). The installed energy storage capacity is 6 MWh, with 4 MWh installed during the current phase. The Mabende mining area is located at 11°08'30"S, 27°27'01"E, at an altitude of 1,250 meters. The plant load is supplied by a 10kV line. The average load at the mining area is approximately 13 MW, and the mine is currently facing severe power supply shortages.

[0023] It includes primary load equipment, secondary load equipment, tertiary load equipment, external power supply network, photovoltaic system, photovoltaic storage system, diesel generator set and energy management system; the energy management system is responsible for regulating the external power supply network, photovoltaic storage system and diesel generator set to ensure that they can provide stable power supply for primary, secondary and tertiary load equipment.

[0024] The planned installed capacity of the PV system is 8.03 megawatts peak (MWp), with a rated capacity of 6.6 MW, and a capacity-to-load ratio of 1.22. The project is divided into one PV array, with each PV string equipped with 26 PV modules, for a total of 13,728 585Wp N-type monocrystalline silicon bifacial PV modules. Each PV array consists of 528 strings, 22 300kW string inverters, and one 6,600kW box-type transformer. The PV system uses 22 Huawei SACU string inverters.

[0025] The solar-plus-storage system has a total storage capacity of 6MW / 6MWh. The project is equipped with one energy storage unit, consisting of three 2MW / 2MWh lithium iron phosphate energy storage units, each comprising 30 units. These units are connected to a 10kV busbar via a 6.8MW box-type transformer. The energy storage system utilizes 20 Huawei SACU string-type energy storage converters.

[0026] The external power grid (mains) sets a power limit (e.g., 5MW). Approximately one hour after exceeding 5MW, the mains dispatcher will implement measures to limit power usage. If power cannot be reduced below the limit, the mains power may be disconnected. Currently, the operating power is around 13MW.

[0027] Currently, six additional 1.8MW diesel generators will be installed, each with a stable output of approximately 1.25MW, which can be increased to 1.6MW in a short period of time (10 minutes). The existing six 1.2MW diesel generators have a stable output of approximately 0.45MW, which can be increased to 0.8MW in a short period of time (10 minutes).

[0028] The primary load equipment consists of liquid flow pumps in each workshop, with a load requirement of 1.6MW. Almost all motors are started with inverters and do not require specific starting current. After a mains power outage, the primary loads are started first.

[0029] The secondary load equipment consists of ball mills, one 1.25MW semi-autogenous mill and three 1.12MW ball mills each. The operating load requirement is 1.5MW, and the instantaneous starting current is high, approximately 500A at 10kV. After the primary load stabilizes, the secondary load is started manually, with one unit stabilizing before the next.

[0030] Level 3 load equipment is a motor rectifier / transformer starter with a load requirement of 0-13MW. This can be adjusted during off-grid operation depending on power supply conditions. The instantaneous starting current on the 10kV side is approximately 100A, and the operating load under current utility power is currently around 10MW. After the photovoltaic power supply is connected to the grid, some loads can be enabled if there is sufficient power supply capacity.

[0031] The energy management system includes SCADA system, microgrid operation control, and energy management.

[0032] SCADA functions: (1) Photovoltaic real-time monitoring SACU is used to monitor various operating data, status parameters and alarm information of photovoltaic power stations in real time.

[0033] Real-time monitoring of photovoltaic inverters, including: PV inverter DC side voltage and current; AC side voltage and current; real-time power generation; accumulated power generation; fault alarm information; equipment operating status; start and stop control and power limit control of PV inverter.

[0034] (2) Energy storage power station operation monitoring SACU can monitor the operation information and alarm information of the energy storage power station in real time and conduct comprehensive statistical analysis to ensure comprehensive monitoring of the energy storage power station.

[0035] PCS related parameters include: DC side voltage / current / power, PCS three-phase active power, reactive power, three-phase voltage, three-phase current, power factor, frequency, operating status, alarm and fault information, as well as charge and discharge capacity.

[0036] The battery management system displays common information such as the total voltage, current, average temperature, charge and discharge current and power limit of each battery group, the maximum / minimum single-cell battery voltage and number, the maximum / minimum single-cell battery temperature and number, the balancing status of each battery cell, fault and alarm information, chargeable capacity, dischargeable capacity, etc.

[0037] The working status of auxiliary equipment, such as temperature control system, fire protection system, access control system, flood alarm system and other safety equipment, forms an electrical interlock. Once a fault is detected, the running battery equipment will be cut off in time.

[0038] (3) Diesel generator monitoring The diesel generator controller can be used to monitor the real-time operation information and alarm information of the diesel generator, including: power generation power, voltage, current, working status of each diesel generator, and operation alarm information.

[0039] (4) 10kV distribution network information monitoring By accessing the data from the distribution network integrated automation system, real-time power monitoring of each circuit load is achieved, which is used for coordinated control of the solar-storage-diesel microgrid.

[0040] Microgrid real-time stability control: During a utility power outage, the diesel generator becomes the primary power source. Calculating the power of the diesel generator, photovoltaics, and energy storage system provides the available load power, providing a basis for applying impact loads. The energy storage converter operates in VSG mode, providing rapid control and response capabilities to frequency fluctuations. The microgrid control system manages power and energy balance on timescales exceeding minutes.

[0041] (2) Black start control After a utility power outage, the diesel generator automatically switches to busbar mode, or manually switches to busbar mode, establishing the system's rated operating voltage and frequency. The energy storage VSG operates, and the PV system is grid-connected. Using power indicators from the diesel generator, PV system, and energy storage, primary loads, secondary impact loads, and tertiary loads are gradually enabled.

[0042] The system adopts a three-layer architecture: local control layer, coordination control layer and energy management layer; (1) Local control layer: Photovoltaic inverter: MPPT control, receiving start / stop control and power limit instructions from the photovoltaic SACU.

[0043] PV SACU: Centrally collects data from 22 PV inverters and uploads PV field data to the microgrid controller via Ethernet / MODBUS. Receives PV power limit (total value) commands from the microgrid controller.

[0044] Energy Storage Converter: The SACU centrally collects operational data from 20 energy storage converters, the BMS, prefabricated cabin auxiliary equipment, and one step-up transformer, and uploads this data to the microgrid controller via Ethernet / MODBUS protocol. It also receives control commands from the microgrid controller regarding the start and stop, black start, and operating mode of the energy storage power station.

[0045] The diesel generator controller is connected to the microgrid controller after converting its 485 interface to an optical port. The controller transmits information such as the generator's operating status, operating voltage, and current and power to the EMS. Upon receiving utility power, the generator automatically synchronizes with the grid.

[0046] (2) Coordination and control layer The coordination control layer consists of a microgrid controller and supporting network equipment. It simultaneously accesses data from photovoltaic stations, energy storage stations, diesel engines, and distribution networks, and uses this communication data to perform real-time control of the photovoltaic, diesel, and energy storage microgrid.

[0047] Mainly realize: photovoltaic / energy storage / diesel engine coordinated operation control, switching control between different operation modes, and microgrid stability control. Connect to the energy management layer switch through the network port / Modbus protocol, receive and execute control commands issued by the energy management layer.

[0048] In the event of a power outage, the diesel generator, acting as the primary power source, starts up normally, and workers manually turn on the primary load. The energy storage system then connects to the grid in PQ mode, and the photovoltaic system connects to the grid, working in conjunction with the diesel generator to provide orderly power to the three levels of loads in the mining area. This maximizes photovoltaic power generation, and the monitoring interface displays the current maximum available power value.

[0049] When the external power supply grid (mains electricity) is available, the energy storage system and the photovoltaic system are connected to the grid and operate, giving priority to photovoltaic power generation to achieve economical and efficient electricity use.

[0050] When the energy storage photovoltaic system is out of power due to maintenance, operation and maintenance work or long-term rainy weather, the site load can be reversely powered by the mine's external power supply network (mains power) or diesel generator sets. Example 2

[0051] like Figure 2 As shown in the figure, a control method for the power supply system of a mining enterprise based on multiple power components includes two modes: grid-connected operation and off-grid black start operation.

[0052] 1. When the external power supply network is connected to the grid and there is power: (1) The photovoltaic system and the photovoltaic storage system are connected to the grid, and the voltage and frequency are maintained stable by the external power supply network, and the loads at all levels are switched on and off in an orderly manner; (2) When there is sufficient sunlight during the day, photovoltaic power supply is preferred for load power supply, and the excess power of the photovoltaic system can be used to charge the photovoltaic storage system; (3) When there is insufficient sunlight during the day and the power of the external power supply network is limited, resulting in the combined power supply of photovoltaic power supply and the external power supply network still being unable to meet the load demand, the diesel generator set is started to provide supplementary power supply.

[0053] (4) When photovoltaic power generation is not in progress at night, the photovoltaic storage system supplies power to the lower limit of the SOC within a limited time, and the rest of the time is supplied by the photovoltaic storage system and the external power grid; 2. Off-grid black start, when the external power supply network loses power: The diesel generator set serves as the main power source for a black start, and photovoltaic energy storage is connected to the grid, providing orderly power supply to three levels of loads. (1) The diesel generator set and solar storage system are shut down, and all load equipment are automatically locked and shut down; (2) The diesel generator set automatically switches to busbar mode and starts up / or manually switches to busbar mode and starts up, serving as the main power source to establish voltage and frequency; (3) Manually start the first-level load equipment, that is, start the liquid flow pump equipment in each workshop and start it with the frequency converter; (4) PV energy storage is turned on and connected to the grid in VSG mode; PV is connected to the grid and operates with limited power, giving the power supply value; (5) After the system maintains stable operation, start the secondary load equipment one by one, that is, start the semi-autogenous grinding mill and ball mill one by one; (6) Manually calculate the power margin, start the three-level load equipment in sequence, and start the motor rectifier transformer.

[0054] When the external power grid (mains) is connected, the diesel generator set automatically switches to grid-connected operation (without system outage), and the loads remain connected. The PV-storage system remains connected, and the energy storage system switches to PQ mode (or VSG mode). The control strategy switches from off-grid mode to grid-connected mode. Additional loads can be manually enabled as needed. If the owner cannot provide communication with the diesel generator, the operator can manually enter the current mains power supply status.

[0055] The present invention is described in detail above through specific and preferred embodiments, but those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A mining enterprise power supply system based on multiple power components, characterized in that: It includes primary load equipment, secondary load equipment, tertiary load equipment, an external power supply network, a photovoltaic system, a photovoltaic storage system, a diesel generator set and an energy management system; the energy management system controls the external power supply network, the photovoltaic storage system and / or the diesel generator set to supply power to the primary load equipment, the secondary load equipment and the tertiary load equipment.

2. The mining enterprise operation power supply system based on multiple power components according to claim 1 is characterized in that: The diesel generator set is composed of several diesel generators.

3. The mining enterprise operation power supply system based on multiple power components according to claim 1 is characterized in that: The photovoltaic system includes a photovoltaic module and a photovoltaic inverter.

4. The mining enterprise operation power supply system based on multiple power components according to claim 1 is characterized in that: The first-level load equipment includes liquid circulation pump equipment in each workshop.

5. The mining enterprise operation power supply system based on multiple power components according to claim 1 is characterized in that: The secondary load equipment includes various ball mill equipment.

6. The mining enterprise operation power supply system based on multiple power components according to claim 1 is characterized in that: The three-level load equipment includes a motor rectifier.

7. The mining enterprise operation power supply system based on multiple power components according to claim 1 is characterized in that: The energy management system includes SCADA system, microgrid operation control, and energy management.

8. A control method for a mining enterprise power supply system based on multiple power components, characterized in that: It includes two modes: grid-connected operation and off-grid black start operation.

1. When the external power supply network is connected to the grid and there is power: (1) The photovoltaic system and the photovoltaic storage system are connected to the grid, and the voltage and frequency are maintained stable by the external power supply network, and the loads at all levels are switched on and off in an orderly manner; (2) When there is sufficient sunlight during the day, photovoltaic power supply is preferred for load power supply, and the excess power of the photovoltaic system can be used to charge the photovoltaic storage system; (3) When there is insufficient sunlight during the day, if the external power supply network reaches its power limit and the photovoltaic power supply + external power supply network power supply is insufficient to supply the load, the diesel generator set is started to supply power; (4) When photovoltaic power generation is not in progress at night, the photovoltaic storage system supplies power to the lower limit of the SOC within a limited time, and the rest of the time is supplied by the photovoltaic storage system and the external power grid; 2. Off-grid black start, when the external power supply network loses power: The diesel generator set serves as the main power source for a black start, and photovoltaic energy storage is connected to the grid, providing orderly power supply to three levels of loads. (1) The diesel generator set and solar storage system are shut down, and all load equipment are automatically locked and shut down; (2) The diesel generator set automatically switches to busbar mode and starts up / or manually switches to busbar mode and starts up, serving as the main power source to establish voltage and frequency; (3) Manually start the first-level load equipment, that is, start the liquid flow pump equipment in each workshop and start it with the frequency converter; (4) PV energy storage is turned on and connected to the grid in VSG mode; PV is connected to the grid and operates with limited power, giving the power supply value; (5) After the system maintains stable operation, start the secondary load equipment one by one, that is, start the semi-autogenous grinding mill and ball mill one by one; (6) Manually calculate the power margin, start the three-level load equipment in sequence, and start the motor rectifier transformer.

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