Safe power supply system and power supply method

Abstract

The invention relates to the technical field of power supplies, and particularly discloses a safe power supply system and a power supply method.The input end of an active controllable rectifier is externally connected with different types of alternating current through a selective switch, the active controllable rectifier outputs direct current to a direct current bus, and a super capacitor bank is connected with the direct current bus; an external energy storage super capacitor of the converter is connected to a direct-current bus through a direct-current switch; the energy storage super capacitor stores electric quantity, and the capacitor management system is used for managing, protecting and monitoring the energy storage super capacitor; and the energy management system reads information of the load and the energy storage management system, and issues a charging and discharging instruction and a power value to the converter according to the states of the load and the energy storage management system / electric quantity of the capacitor / chargeable and dischargeable power of the capacitor. According to the invention, through cooperative work of the active controllable rectifier and the converter, the influence of unstable factors on the power supply side on the load end is effectively isolated. According to the invention, by accurately controlling the working states of the active controllable rectifier and the converter, the harmonic content in the power supply network and the electric equipment is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power supplies, and specifically refers to a safe power supply system and a power supply method. Background Art

[0002] During the drilling process, due to different drilling depths, geology, wellbore factors and other downhole complex conditions, the power consumption of the load is unstable, and the load power will peak uncertainly. Usually, the peak power duration does not exceed 30s. Although the time is very short, for safety and normal operation, it is required that the matching power capacity be calculated according to the load peak power.

[0003] During the operation of the equipment, the harmonic content is high, the current harmonic content exceeds 30%, and the voltage harmonic exceeds 10%. Usually, there are no corresponding devices for harmonic control at the construction site. High harmonic content will increase the heat loss of the power supply line and electrical equipment, and affect the operation safety of the equipment. The compensation devices such as SVG used on site basically compensate the power supply end, and the compensation for the power consumption end is insufficient, resulting in too low power factor of the entire power supply network and increased power consumption.

[0004] During the production process, sudden power outages may occur, leading to production safety problems and easy damage to production equipment. The conventional drilling site power supply is single and cannot perform multi-power supply. When the grid power supply voltage is low, it affects the normal use of grid power by electrical equipment.

[0005] Therefore, a safe power supply system and a power supply method have become urgent problems to be solved by people. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a safe power supply system and a power supply method. The power supply side is provided to the load side through the safe power supply system, and the load side will not interfere with or pollute the power supply side, and solve the harmonic and power factor problems of the power supply end and the power consumption end.

[0007] When the power supply side fluctuates greatly, is unstable, or has a long-term low voltage, etc., the safe power supply system first rectifies into direct current, and then inverses the direct current into stable alternating current to play a role of stabilizing voltage and current for the load.

[0008] When the load suddenly increases or decreases, the safe power supply system performs peak shaving and valley filling through the super capacitor bank on the DC bus to isolate the power impact between the power supply side and the load side.

[0009] When the power supply side has a voltage loss or a power outage, the safe power supply will independently supply power to the load side for a certain period of time.

[0010] To solve the above technical problems, the technical solution provided by the present invention is: a safe power supply system, including an active controllable rectifier, an inverter, an energy storage super capacitor, an energy storage management system, and an energy management system;

[0011] The input end of the active controllable rectifier is externally connected to the alternating current of the national power grid or the alternating current output by the generator set through a selector switch. The active controllable rectifier outputs direct current to the DC bus, and the energy storage supercapacitor is connected to the DC bus;

[0012] The converter is connected to the energy storage supercapacitor and is connected to the DC bus through a DC switch;

[0013] The energy storage supercapacitor stores electric energy, and the energy storage management system is used for the management, protection and monitoring of the energy storage supercapacitor;

[0014] The energy management system reads the information of the load and the energy storage management system, and issues charge and discharge instructions and power values to the converter according to the state of the load and the energy storage management system / the electric quantity of the energy storage supercapacitor / the charge and discharge power of the energy storage supercapacitor.

[0015] Furthermore, the converter detects three indicators of the voltage, frequency and waveform provided by the generator set to the power grid, performs phase locking, controls the turning on of the IGBT through internal software calculation and processing, and provides active power or reactive power to the power grid according to the needs of the power grid and parameter setting.

[0016] Furthermore, when the energy storage supercapacitor is charging, the current direction is from the power grid through three-phase rectification to the energy storage supercapacitor; when discharging, the current direction passes through the DC bus, and then generates sinusoidal alternating current through three-phase inversion and output filtering, and the output is fed into the power grid.

[0017] Furthermore, the active controllable rectifier converts three-phase alternating current into direct current and supplies it to the intermediate DC bus; the intermediate DC bus supplies power to the inverter module of the operating generator; there are several active controllable rectifiers, and their power distribution status is set distribution.

[0018] Furthermore, the energy management system detects the operating power of the load through a current transmitter. When the power P of the load 负 exceeds the rated power P of the generator set 发 , the converter compensates the excess active power to the power grid of the generator, that is, P 补 = P 负 - P 发 ; when the power P of the load 负 is lower than the rated power P of the generator set 发 , and the battery power is lower than the set value, the converter charges the battery, and the charging power P 充 = P 发 - P 负 .

[0019] Further, it also includes a supercapacitor cooling system, which includes a liquid cooling unit, liquid cooling pipes, and a water cooling plate. The liquid cooling pipes connect the liquid cooling unit and the water cooling plate, and the energy storage supercapacitor is fixed on the water cooling plate.

[0020] Further, it also includes an air-conditioning heat dissipation system, which is used for heating, ventilation, and air conditioning of the power supply system.

[0021] The present invention also provides a power supply method for a safety power supply system. Alternating current from the national grid or a generator is externally connected and introduced into the input end of an active controllable rectifier through a selection switch. Through internal processing in the active controllable rectifier, direct current with any value within a certain range is output to the DC bus, and an energy storage supercapacitor is connected to the DC bus side;

[0022] According to the operating characteristics of the load end, the safety power supply system performs peak shaving and valley filling on the load end to stabilize the power supply state on the power supply side; the energy management system participates in voltage regulation at the DC bus bar end;

[0023] When the load suddenly increases, the DC bus voltage and current decrease, and the energy storage supercapacitor discharges to perform power compensation for the DC bus, so that the DC bus stabilizes the voltage and current, thereby enabling the converter to stably supply power to the AC bus load end. At the same time, due to the stable change of the DC bus power, there is no load impact on the upper grid power supply side either.

[0024] When the load is suddenly unloaded, the AC bus voltage and current increase, then the supercapacitor is charged. At the same time, the voltage and current increase at the AC bus load end due to the sudden unloading of the load will be inverted to the AC bus through the converter, so that there will be no impact on the voltage and current at the load end and the power supply end;

[0025] When the power supply side suddenly loses voltage or power, the energy management system issues commands to the supercapacitor and the converter. The energy storage supercapacitor discharges according to the power state of the DC bus, and the converter inverts the direct current on the DC bus into a stable alternating current power supply required by the load.

[0026] The advantages of the present invention compared with the prior art are as follows:

[0027] 1. Through the coordinated operation of the active controllable rectifier and the converter, the system can rectify unstable alternating current into direct current and then invert it into stable alternating current to supply the load, effectively isolating the influence of unstable factors on the power supply side on the load end.

[0028] When the load suddenly increases, the energy storage supercapacitor bank can quickly discharge for power compensation to ensure the stability of the DC bus voltage and current, thereby protecting the load from the impact of electrical energy. Conversely, when the load suddenly decreases, the excess electrical energy will be absorbed by the supercapacitor, avoiding the impact on the power supply network.

[0029] In the case of power loss or power cut on the power supply side, the system can automatically switch to the independent power supply mode to provide power support for the load for a certain period of time, ensuring production safety.

[0030] 2. By precisely controlling the operating states of the active controlled rectifier and the inverter, the present invention effectively reduces the harmonic content in the power supply network and electrical equipment, reduces heat loss, and improves the operating efficiency and safety of the equipment.

[0031] The energy management system can adjust the charge and discharge strategy of the inverter in real time according to the load and energy storage status, ensuring that the power factor of the entire power supply network remains at a high level, reducing power consumption, and saving energy costs.

[0032] 3. The present invention supports the connection of alternating current from the national power grid or the alternating current output by the generator, and flexibly switches the power supply source through the selection switch, improving the adaptability and reliability of the system.

[0033] The energy storage supercapacitor bank can not only provide power compensation during load fluctuations, but also be used as a backup power supply when the grid voltage is low, ensuring the normal operation of electrical equipment.

[0034] 4. The supercapacitor cooling system equipped with the present invention efficiently dissipates heat from the energy storage supercapacitor through the liquid cooling unit, liquid cooling pipeline and water cooling plate, ensuring its stable operation in a high-temperature environment and extending its service life.

[0035] The air-conditioning cooling system provides good heating, ventilation and air-conditioning functions for the entire power supply system, further improving the stability and reliability of the system. Brief Description of the Drawings

[0036] Figure 1 is the circuit principle of the safety power supply system Figure 1 .

[0037] Figure 2 is the circuit principle of the safety power supply system Figure 2 .

[0038] Figure 3 is the power topology diagram of the inverter.

[0039] Figure 4 is the structural schematic diagram of the supercapacitor cooling system.

[0040] As shown in the figure: 1. Liquid cooling unit, 2. Liquid cooling pipeline, 3. Water cooling plate. Detailed Embodiments

[0041] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "vertical", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings. These are only for convenience in describing the present invention and simplifying the description, 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 thus should not be construed as a limitation to the present invention.

[0042] In the present invention, unless otherwise clearly specified and defined, the terms "installed", "connected", "joined", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] The following further elaborates on a safety power supply system and a power supply method of the present invention with reference to the drawings.

[0044] Combined with the attached Figures 1-4 , the specific implementation process of a safety power supply system and a power supply method of the present invention is as follows:

[0045] A safety power supply system includes an active front-end converter (AFE), a power conversion system (PCS), an energy storage supercapacitor, an energy storage management system (CMS), and a power management system (PMS).

[0046] The input end of the active front-end converter is externally connected to the alternating current of the national power grid or the 600V / 50Hz alternating current output by a diesel generator set through a selector switch, and outputs direct current with any value within the range of DC875 - DC975V to the DC bus, and the energy storage supercapacitor is connected to the DC bus. The active front-end converter can convert three-phase alternating current into direct current, supply the intermediate DC bus, and power the inverter module of the operating generator; there are several active front-end converters, and their power distribution states are set distributions, that is, the user independently sets the power of each active front-end converter. Among them, Figure 1 and Figure 2 take three as an example.

[0047] The relevant parameters of the active front-end converter (AFE) are as shown in Table 1 below.

[0048] Table 1: Active Front-End Converter Parameter Table

[0049]

[0050] The external energy storage supercapacitor of the converter is connected to the DC bus through a DC switch. The converter realizes the power conversion between the AC bus power grid and the energy storage supercapacitor, and monitors and manages the conversion process. During charging, the current flows from the power grid through three-phase rectification to the energy storage supercapacitor. During discharging, the current passes through the DC bus, then generates sinusoidal alternating current through three-phase inversion and output filtering, and the output is fed into the power grid.

[0051] The converter can detect three indicators of the voltage, frequency, and waveform provided by the generator set to the power grid, and perform phase locking. It controls the turning on of the IGBT through internal software calculation and processing, and provides active power or reactive power to the power grid according to the power grid needs and parameter settings.

[0052] The energy storage supercapacitor stores electricity and is used to provide power compensation during load mutation or power supply interruption. Requirements for the discharging power of the energy storage supercapacitor: the maximum compensation power is not higher than 3000KW, the discharging duration at the maximum compensation power is not less than 240s, and the effective capacity is 200KwH. The capacitor management system is used for the management, protection, and monitoring of the energy storage supercapacitor.

[0053] The energy management system reads the information of the load and the energy storage management system, and issues charging and discharging instructions and power values to the converter according to the status of the two, the capacitor power, and the charge and discharge power of the capacitor. The energy management system detects the operating power of the load through a current transmitter. When the power P of the load 负 exceeds the rated power P of the generator set 发 , the converter compensates the excess active power to the power grid of the generator, that is, P 补 =P 负 -P 发 ; when the power P of the load 负 is lower than the rated power P of the generator set 发 , and the battery power is lower than the set value, the converter charges the battery at a certain power, and the charging power P 充 =P 发 -P 负 . The energy management system detects the operating power of the load through a current transmitter and adjusts the charging and discharging strategy of the converter according to the power difference between the load and the generator set.

[0054] The supercapacitor cooling system includes a liquid cooling unit 1, liquid cooling pipes 2, and a water cooling plate 3. The liquid cooling pipes 2 connect the liquid cooling unit 1 and the water cooling plate 3. The energy storage supercapacitor is fixed on the water cooling plate 3 to dissipate heat from the energy storage supercapacitor, ensuring its normal operation in a high-temperature environment.

[0055] The air-conditioning cooling system is used to heat, ventilate, and condition the power system as a whole, improving the system's stability and service life. One industrial air-conditioning system on the market with a refrigeration power that meets the heat dissipation of all equipment in the present invention can be selected. Specifically, the following conditions should be met:

[0056] The heating, ventilation, and air-conditioning of this air conditioner comply with the provisions of GB 50019 and GB 50016. Energy storage systems with requirements for winter operating ambient temperature should be equipped with heating facilities. For those with a summer operating ambient temperature requirement not exceeding 30°C, explosion-proof air conditioners should be set up.

[0057] The air conditioner should have the following protection functions:

[0058] 1) Protection against open-phase and phase-reversal of the power supply phase sequence.

[0059] 2) Overload and overheat protection for each motor.

[0060] 3) Protection against abnormal pressure in the refrigeration system.

[0061] 4) Protection against abnormal temperature.

[0062] 5) Alarm for sensor failure.

[0063] 6) Protection for the temperature of the inner tray of the evaporator.

[0064] 7) Fire alarm interlock protection.

[0065] The present invention can also be paired with an automatic fire protection system. When building each part, a fire protection passage should be reserved, and a fire automatic alarm system and a gas automatic fire extinguishing system should be set up. The gas automatic fire extinguishing system can adopt a heptafluoropropane automatic fire extinguishing system.

[0066] To reduce the occurrence of faults, the energy storage supercapacitor clusters can also be strongly grouped and isolated from each other using flame-retardant cabinets; in case of a fire, the disaster can be controlled inside the capacitor cabinets to prevent the spread of the disaster.

[0067] A power supply method for a safe power system includes the following steps:

[0068] Connect the alternating current from the national power grid or the generator externally, and introduce it into the input end of the active controllable rectifier through a selector switch, and output direct current with any value within a certain range to the DC bus.

[0069] According to the operating characteristics of the load end, the safe power system performs peak shaving and valley filling on the load end to stabilize the power supply state on the power supply side. The energy management system participates in voltage regulation at the DC busbar end to ensure the stability of the voltage and current of the DC bus.

[0070] When the load suddenly increases, the energy storage supercapacitor discharges to compensate the power for the DC bus, stabilizing the voltage and current of the DC bus, so that the converter can stably supply power to the load end of the AC bus.

[0071] When the load is suddenly unloaded, the voltage and current of the AC bus increase, then the supercapacitor is charged, and at the same time, the converter inversely converts the excess electric energy back to the AC bus to avoid voltage and current shocks.

[0072] When the power supply side suddenly loses voltage or power, the energy management system commands the energy storage supercapacitor to discharge, and the converter inversely converts the direct current into a stable alternating current power supply required by the load to ensure that the load does not lose power.

[0073] The above describes the present invention and its implementation manners. This description is not restrictive. What is shown in the drawings is only one of the implementation manners of the present invention, and the actual structure is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and design similar structural manners and embodiments without creative efforts without departing from the gist of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. A safety power supply system, characterized in that: It includes an active controlled rectifier, an inverter, an energy storage supercapacitor, an energy storage management system, and an energy management system; The input end of the active controlled rectifier is externally connected to the alternating current of the national power grid or the alternating current output by a generator set through a selector switch. The active controlled rectifier outputs direct current to the DC bus, and the energy storage supercapacitor is connected to the DC bus; The inverter is connected to the energy storage supercapacitor and is connected to the DC bus through a DC switch; The energy storage supercapacitor stores electricity, and the energy storage management system is used for the management, protection, and monitoring of the energy storage supercapacitor; The energy management system reads the information of the load and the energy storage management system, and issues charge and discharge instructions and power values to the inverter according to the state of the load and the energy storage management system / the electricity quantity of the energy storage supercapacitor / the charge and discharge power of the energy storage supercapacitor.

2. The safety power supply system according to claim 1, wherein: The inverter detects three indicators of the voltage, frequency, and waveform provided by the generator set to the power grid, performs phase locking, controls the turning on of the IGBT through internal software calculation and processing, and provides active power or reactive power to the power grid according to the needs of the power grid and parameter setting.

3. The safety power supply system according to claim 2, wherein: When the energy storage supercapacitor is charging, the current direction is from the power grid through three-phase rectification to the energy storage supercapacitor; when discharging, the current direction passes through the DC bus, and then through three-phase inversion and output filtering to generate sinusoidal alternating current, which is output and fed into the power grid.

4. A safety power supply system according to claim 3, characterized in that: The active controlled rectifier converts three-phase alternating current into direct current and supplies it to the intermediate DC bus; the intermediate DC bus supplies power to the inverter module of the operating generator; there are several active controlled rectifiers, and their power distribution status is set distribution.

5. A safety power supply system according to claim 4, characterized in that: The energy management system detects the operating power of the load through a current transmitter. When the power P of the load 负 exceeds the rated power P of the generator set 发 , the converter compensates the active power exceeding to the power grid of the generator, that is, P 补 = P 负 - P 发 ; when the power P of the load 负 is lower than the rated power P of the generator set 发 , and the battery power is lower than the set value, the converter charges the battery, and the charging power P 充 = P 发 - P 负 .

6. The safety power supply system according to claim 5, wherein: It also includes a supercapacitor cooling system, which includes a liquid cooling unit, liquid cooling pipes, and a water cooling plate. The liquid cooling pipes connect the liquid cooling unit and the water cooling plate, and the energy storage supercapacitor is fixed on the water cooling plate.

7. A safety power supply system according to claim 1, characterized in that: It also includes an air-conditioning heat dissipation system, which is used for heating, ventilation, and air conditioning of the power supply system.

8. A power supply method for a safety power supply system according to any one of claims 1-7, characterized in that: The alternating current of the national power grid or the alternating current of the generator is externally connected, introduced into the input end of the active controlled rectifier through a selector switch, and after internal processing by the active controlled rectifier, direct current with any value within a certain range is output to the DC bus, and an energy storage supercapacitor is connected to the DC bus side; According to the operating characteristics of the load end, the safety power supply system performs peak shaving and valley filling on the load end to stabilize the power supply state of the power supply side; the energy management system participates in the voltage regulation of the DC busbar end; When the load suddenly increases, the voltage and current of the DC busbar decrease, and the energy storage supercapacitor discharges to compensate the power of the DC busbar, so that the DC busbar is stabilized in voltage and current, so that the inverter can stably supply power to the AC busbar load end. At the same time, because the power change of the DC busbar is stable, there is no load impact on the upper power grid power supply side. When the load is suddenly unloaded, the voltage and current of the AC busbar increase, then the supercapacitor is charged. At the same time, the voltage and current increase of the AC busbar load end caused by the sudden unloading of the load will be inverted to the AC busbar through the inverter, so that the voltage and current of the load end and the power supply end will not be impacted; When the power supply side suddenly loses voltage or power, the energy management system issues commands to the supercapacitor and the converter. The energy storage supercapacitor discharges according to the power state of the DC bus, and the converter converts the DC power on the DC bus into a stable AC power supply required by the load.

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