Micro-grid power supply system

Abstract

The utility model discloses a micro-grid power supply system, and the system comprises an energy storage device which is used for providing energy storage electric energy during discharging; the generator set provides electric energy for the generator during operation; the first switch is electrically connected between the mains supply and the energy storage device; the second switch is electrically connected between the energy storage device and the generator set; the voltage controller is used for detecting the voltage of the electric energy of the mains supply to output a first detection signal and detecting the voltage of the electric energy of the generator to output a second detection signal; the micro-grid controller is used for controlling the first switch to carry out mains supply grid connection and controlling the second switch to carry out generator set grid connection; and the phase measurement control equipment is used for measuring phase information of the mains supply electric energy, the energy storage electric energy and the generator electric energy, so that the micro-grid controller adjusts the phase of the energy storage electric energy according to a measurement result of the phase measurement control equipment.

Description

Technical Field

[0001] The present application relates to the field of power supply systems, and in particular to a microgrid power supply system. Background Art

[0002] The microgrid power supply system is a new microgrid composed of distributed power sources and adjacent loads, which can be used in conjunction with the mains. When the mains system is supplying power normally, the microgrid system can be connected in parallel with the mains and operate together. When the mains power supply is abnormal, such as when the mains fails or the power quality does not meet the demand, the microgrid system can be disconnected from the mains and operate independently.

[0003] The disconnection and paralleling procedures of traditional microgrid power supply systems often face challenges in timing control, because traditional microgrid power supply systems may face abnormal current or voltage waveforms caused by problems such as phase inconsistency and / or frequency instability, resulting in the risk of instability in traditional microgrid power supply systems.

[0004] Therefore, how to develop a microgrid power supply system that overcomes the above-mentioned defects is the most urgent issue to be solved. Utility Model Content

[0005] The purpose of the present application is to provide a microgrid power supply system, which uses a phase measurement control device to measure the phase information of the mains power, energy storage power and generator power to confirm whether the energy storage power is successfully phase-locked with the mains power, and then allows the energy storage device to be connected in parallel with the mains power when the phase lock is successful, or uses a phase measurement control device to confirm whether the energy storage power and the generator power are successfully phase-locked, and then allows the energy storage device to be connected in parallel with the generator set when the phase lock is successful, thereby reducing the instantaneous instability of the microgrid power supply system and ensuring the stable operation of the microgrid power supply system.

[0006] To achieve the aforementioned purpose, a preferred embodiment of the present application provides a microgrid power supply system, which is electrically connected to the mains and includes: at least one load; an energy storage device, electrically connected to at least one load, for charging or discharging operation, and providing a stored energy during the discharging operation; a generator set, electrically connected to at least one load, providing a generator energy during operation; a first switch, electrically connected between the mains and the energy storage device; a second switch, electrically connected between the energy storage device and the generator set; a voltage controller, electrically connected to the generator set, the mains and the energy storage device, for detecting the voltage of the mains electricity and the voltage of the generator electricity; a microgrid controller, electrically connected to the first switch, the second switch, the energy storage device and the voltage controller, for controlling the operation of the first switch and the second switch; and a phase measurement control device, electrically connected to the mains, the energy storage device, the generator set and The microgrid controller is electrically connected to measure the phase information of the mains power, the energy storage power and the generator power respectively; wherein the phase measurement control device measures the phase information of the energy storage power and the mains power, and the energy storage device adjusts the voltage of the energy storage power according to the measurement result of the phase measurement control device, and the microgrid controller controls the first switch to be turned on so that the energy storage device is connected in parallel with the mains when the measurement result of the phase measurement control device reflects that the phase difference between the energy storage power and the mains power is zero; wherein the phase measurement control device measures the phase information of the energy storage power and the generator power, and the energy storage device adjusts the voltage of the energy storage power according to the measurement result of the phase measurement control device, and the microgrid controller controls the second switch to be turned on so that the energy storage device is connected in parallel with the generator set when the measurement result of the phase measurement control device reflects that the phase difference between the energy storage power and the generator power is zero.

[0007] In the microgrid power supply system of the above-mentioned preferred embodiment, when the energy storage device confirms that the AC power is normal based on the first detection signal, and the energy storage device receives a parallel instruction output by the microgrid controller, the energy storage device adjusts the voltage of the energy storage electric energy so that the energy storage electric energy is phase-locked with the AC power energy, and the phase measurement control device measures the phase information of the energy storage electric energy and the AC power energy to confirm whether the phase difference between the energy storage electric energy and the AC power energy is zero, and transmits a first success signal to the microgrid controller when the phase difference is zero, so that the microgrid controller controls the first switch to turn on and allows the energy storage device to be connected in parallel with the AC power.

[0008] In the microgrid power supply system of the above-mentioned preferred embodiment, when the energy storage device confirms that the city power is abnormal based on the first detection signal, and the microgrid controller communicates with the energy storage device and learns that the energy storage device is normal and the amount of the stored energy is lower than a threshold value, the microgrid controller drives the generator set to operate, and the energy storage device adjusts the voltage of the stored energy so that the stored energy is phase-locked with the generator energy, and the phase measurement control device measures the phase information of the stored energy and the generator energy to confirm whether the phase difference between the stored energy and the generator energy is zero, and transmits a second success signal to the microgrid controller when the phase difference is zero, so that the microgrid controller controls the second switch to turn on and allows the energy storage device to be connected in parallel with the generator set.

[0009] In the microgrid power supply system of the above-mentioned preferred embodiment, the microgrid power supply system includes at least one renewable energy power generation device electrically connected to the at least one load to provide renewable electric energy.

[0010] In the microgrid power supply system of the above preferred embodiment, when the microgrid controller confirms that the mains power is normal according to the first detection signal, the microgrid controller controls the second switch to be disconnected.

[0011] In the microgrid power supply system of the above preferred embodiment, when the microgrid controller confirms that the mains power is abnormal based on the first detection signal, the microgrid controller controls the first switch to be disconnected.

[0012] In the microgrid power supply system of the above preferred embodiment, the microgrid controller communicates with the voltage controller, the energy storage device and the phase measurement control device.

[0013] In the microgrid power supply system of the above preferred embodiment, the turned-on first switch feeds back a first parallel signal to the microgrid controller.

[0014] In the microgrid power supply system of the above preferred embodiment, the turned-on second switch feeds back a second parallel signal to the microgrid controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the system architecture of a microgrid power supply system according to a preferred embodiment of the present application;

[0016] Figure 2 for Figure 1 A flowchart of the steps of the control method of the microgrid power supply system shown;

[0017] Figure 3 for Figure 2 A schematic diagram of the flow of mains grid connection in the control method of the microgrid power supply system shown; and

[0018] Figure 4 for Figure 2 A schematic diagram of the flow chart of grid connection of a generator set in a control method of a microgrid power supply system is shown.

[0019] Description of Reference Numerals

[0020] 1: Microgrid power supply system,

[0021] 2: City electricity,

[0022] 3: Load,

[0023] 4: Energy storage device,

[0024] 5: Generator set,

[0025] SW1: First switch,

[0026] SW2: Second switch,

[0027] 6: Voltage controller,

[0028] 7: Microgrid controller,

[0029] 8: Phase measurement control equipment,

[0030] 9: Renewable energy power generation equipment,

[0031] S1~S6: Steps of control method,

[0032] S30~S35: Mains grid connection process,

[0033] S50~S56: Generator grid connection process. DETAILED DESCRIPTION

[0034] Some typical embodiments that embody the features and advantages of the present application will be described in detail in the following description. It should be understood that the present application can have various changes in different ways without departing from the scope of the present application, and the descriptions and illustrations therein are essentially used for illustrative purposes, rather than for limiting the present application.

[0035] In order to facilitate understanding of the present application technology, Figure 1 Four different lines are shown, representing power lines, voltage measurement signal lines, phase measurement signal lines and digital signal transmission lines. The power lines represent the transmission lines of power, the voltage measurement signal lines represent the transmission lines of voltage measurement signals, the phase measurement signal lines represent the transmission lines of phase measurement signals, and the digital signal transmission lines represent the transmission lines of digital signals (signals for bidirectional communication between components).

[0036] See also Figure 1 , Figure 2, Figure 3 and Figure 4 ,in Figure 1 This is a schematic diagram of the system architecture of a microgrid power supply system according to a preferred embodiment of the present application. Figure 2 for Figure 1 The step flow chart of the control method of the microgrid power supply system shown in FIG. Figure 3 for Figure 2 The schematic diagram of the mains grid connection process in the control method of the microgrid power supply system shown in FIG. Figure 4 for Figure 2 Schematic diagram of the generator set grid connection process in the control method of the microgrid power supply system shown. In the present application, the microgrid power supply system 1 is electrically connected to the mains 2 to receive the mains power energy provided by the mains 2, and the microgrid power supply system 1 includes at least one load 3, an energy storage device 4, a generator set 5, a first switch SW1, a second switch SW2, a voltage controller 6, a microgrid controller 7, a phase measurement control device 8 and a renewable energy generation device 9.

[0037] The number of loads 3 can be, for example Figure 1 Multiple loads are shown, but only one load may be provided. In some embodiments, at least one load 3 among the multiple loads 3 is a charging station.

[0038] The energy storage device 4 is electrically connected to at least one load 3 and may include at least one energy storage battery (not shown). The energy storage device 4 uses the energy storage battery to perform charging or discharging operations, wherein the energy storage device 4 provides stored energy during the discharging operation. The generator set 5 is electrically connected to at least one load 3, and the generator set 5 provides generator power during operation. The first switch SW1 is electrically connected between the mains 2 and the energy storage device 4. The second switch SW2 is electrically connected between the energy storage device 4 and the generator set 5.

[0039] The voltage controller 6 is electrically connected to the generator set 5, the mains 2 and the energy storage device 4. The voltage controller 6 is used to detect the voltage of the mains power of the mains 2 and output a first detection signal accordingly, and to detect the voltage of the generator power and output a second detection signal accordingly.

[0040] The microgrid controller 7 is electrically connected to the first switch SW1, the second switch SW2, the energy storage device 4 and the voltage controller 6 to control the operation of the first switch SW1 and the second switch SW2, and communicate with the voltage controller 6, the energy storage device 4 and the phase measurement control device 8, and receive the first detection signal output by the voltage controller 6 and output the second detection signal.

[0041] The phase measurement control device 8 is electrically connected to the mains 2, the energy storage device 4, the generator set 5 and the microgrid controller 6, and is used to respectively measure the phase information of the mains power of the mains 2, the stored energy of the energy storage device 4 and the generator energy of the generator set 5, and output the corresponding phase measurement results to the microgrid controller 7, so that the microgrid controller 7 drives the energy storage device 4 to adjust the stored energy according to the phase measurement results.

[0042] In the present application, the phase measurement control device 8 measures the phase information of the energy storage electric energy and the mains electric energy, and the energy storage device 4 adjusts the voltage of the energy storage electric energy according to the measurement result of the phase measurement control device 8, and the microgrid controller 7 controls the first switch SW1 to be turned on so that the energy storage device is connected in parallel with the mains when the measurement result of the phase measurement control device reflects that the phase difference between the energy storage electric energy and the mains electric energy is zero. In addition, the phase measurement control device 8 measures the phase information of the energy storage electric energy and the generator electric energy, and the energy storage device 4 adjusts the voltage of the energy storage electric energy according to the measurement result of the phase measurement control device 8, and the microgrid controller 7 controls the second switch SW2 to be turned on so that the energy storage device 4 is connected in parallel with the generator set 5 when the measurement result of the phase measurement control device 8 reflects that the phase difference between the energy storage electric energy and the generator electric energy is zero.

[0043] Further explanation, in the present application, the microgrid controller 7 will confirm whether the mains power is normal according to the first detection signal, and output a parallel command to the energy storage device 4 when confirming that the mains power is normal. When the energy storage device 4 receives the parallel command output by the microgrid controller 7, the energy storage device 4 is driven by the microgrid controller 7 to adjust the voltage of the energy storage power so that the energy storage power and the mains power are phase-locked. The phase measurement control device 8 measures the phase information of the mains power of the mains 2 and the energy storage power of the energy storage device 4 respectively to confirm whether the energy storage power and the mains power are successfully phase-locked, wherein the phase-locking success mentioned here means that the phase difference between the energy storage power and the mains power is zero, and transmits a first success signal to the microgrid controller 7 when confirming that the phase-locking is successful. When receiving the first success signal, the microgrid controller 7 controls the first switch SW1 to turn on, so that the energy storage device 4 is connected in parallel with the mains 2. In addition, the turned-on first switch SW1 also returns the first parallel signal to the microgrid controller 7.

[0044] When the microgrid controller 7 confirms that the mains power is abnormal based on the first detection signal, and the microgrid controller 7 communicates with the energy storage device 4 and learns that the energy storage device 4 is normal and the amount of energy storage power is lower than the threshold value, the microgrid controller 7 drives the generator set 5 to operate, and the microgrid controller 7 drives the energy storage device 4 to adjust the voltage of the energy storage power so that the energy storage power and the generator power are phase-locked. The phase measurement control device 8 measures the phase information of the generator power of the generator set 5 and the energy storage power of the energy storage device 4 respectively to confirm whether the energy storage power and the generator power are successfully phase-locked, wherein the phase lock success here means that the phase difference between the energy storage power and the generator power is zero, and transmits a second success signal to the microgrid controller 7 when the phase lock is confirmed to be successful. When receiving the second success signal, the microgrid controller 7 controls the second switch SW2 to turn on, so that the energy storage device 4 is connected in parallel with the generator set 5. In addition, the turned-on second switch SW2 also returns the second parallel signal to the microgrid controller 7.

[0045] In some embodiments, when the microgrid controller 7 confirms that the mains power is normal according to the first detection signal, the microgrid controller 7 controls the second switch SW2 to be disconnected. When the microgrid controller 7 confirms that the mains power is abnormal according to the first detection signal, the microgrid controller 7 controls the first switch SW1 to be disconnected.

[0046] In some embodiments, the microgrid power supply system 1 further includes at least one renewable energy power generation device 9. The renewable energy power generation device 9 may be, for example but not limited to, a solar power generation device 9. The renewable energy power generation device 9 is electrically connected to at least one load 3 to provide renewable electric energy.

[0047] Please refer to Figure 2 , Figure 3 and Figure 4 And cooperate Figure 1 In the present application, the control method of the microgrid power supply system 1 includes the following steps.

[0048] In step S1 , the microgrid controller 7 confirms whether the mains power is normal according to the first detection signal.

[0049] Step S2 , when the microgrid controller 7 confirms that the mains power is normal according to the first detection signal in step S1 , the energy storage device 4 confirms whether the parallel connection instruction output by the microgrid controller 7 is received.

[0050] Step S3, when the energy storage device 4 confirms that it has received the parallel connection instruction output by the microgrid controller 7 in step S2, the microgrid power supply system 1 executes the mains grid connection process.

[0051] Step S4, when the microgrid controller 7 confirms that the mains power is abnormal according to the first detection signal in step S1, the microgrid controller 7 communicates with the energy storage device 4 and confirms whether the amount of the stored energy is lower than the threshold value when it is confirmed that the energy storage device 4 has no abnormality.

[0052] Step S5, when the microgrid controller 7 communicates with the energy storage device 4 in step S4 to confirm that the amount of stored energy is lower than the threshold value, the microgrid controller 7 drives the generator set 5 to operate, and the microgrid power supply system 1 executes the generator set grid connection process.

[0053] Step S6, when the microgrid controller 7 communicates with the energy storage device 4 in step S4 and confirms that the amount of stored energy is equal to or higher than the threshold value, the microgrid controller 7 drives the energy storage device 4 to provide stored energy, so that the load 3 operates using the stored energy.

[0054] In addition, the mains grid connection process in step S3 further includes the following steps.

[0055] In step S30 , the voltage controller 6 detects the voltage of the mains power energy of the mains 2 to output a first detection signal.

[0056] In step S31, the microgrid controller 7 drives the energy storage device 4 to adjust the voltage of the energy storage electric energy so that the energy storage electric energy is phase-locked with the mains electric energy.

[0057] In step S32, the phase measurement control device 8 measures the phase information of the mains power of the mains 2 and the energy storage power of the energy storage device 4 respectively to confirm whether the energy storage power and the mains power are successfully phase-locked.

[0058] Step S33 , when the phase measurement control device 8 confirms that the energy storage power and the mains power are successfully phase-locked in step S32 , the phase measurement control device 8 transmits a first success signal to the microgrid controller 7 .

[0059] In step S34 , the microgrid controller 7 controls the first switch SW1 to be turned on when receiving the first success signal, so that the energy storage device 4 is connected in parallel with the mains 2 .

[0060] In step S32, when the phase measurement control device 8 confirms that the energy storage power and the mains power have not been successfully phase-locked, step S31 is re-executed.

[0061] In some embodiments, the mains grid connection process of step S3 further includes step S35 , wherein the turned-on first switch SW1 feeds back a first parallel connection signal to the microgrid controller 7 .

[0062] In addition, the generator set grid connection process in step S5 also includes the following steps.

[0063] In step S50 , the microgrid controller 7 drives the generator set 5 to operate.

[0064] In step S51 , the voltage controller 6 detects the voltage of the generator power of the generator set 5 to output a second detection signal.

[0065] In step S52, the microgrid controller 7 drives the energy storage device 4 to adjust the voltage of the energy storage electric energy so that the energy storage electric energy is phase-locked with the generator electric energy.

[0066] In step S53, the phase measurement control device 8 measures the phase information of the generator power of the generator set 5 and the energy storage power of the energy storage device 4 respectively to confirm whether the energy storage power and the generator power are successfully phase-locked.

[0067] Step S54 , when the phase measurement control device 8 confirms that the energy storage power and the generator power are successfully phase-locked in step S53 , the phase measurement control device 8 transmits a second success signal to the microgrid controller 7 .

[0068] In step S55 , the microgrid controller 7 controls the second switch SW2 to be turned on when receiving the second success signal, so that the energy storage device 4 is connected in parallel with the generator set 5 .

[0069] In step S53, when the phase measurement control device 8 confirms that the energy storage electric energy and the generator electric energy have not been successfully phase-locked, step S52 is re-executed.

[0070] In some embodiments, the generator set grid-connected process of step S5 further includes step S56 , wherein the turned-on second switch SW2 feeds back a second parallel connection signal to the microgrid controller 7 .

[0071] In summary, the present application provides a microgrid power supply system, which uses phase measurement and control equipment to measure the phase information of AC power, energy storage power and generator power to confirm whether the energy storage power is successfully phase-locked with the AC power, and then allows the energy storage device to be connected in parallel with the AC power only when the phase lock is successful, or uses phase measurement and control equipment to confirm whether the energy storage power and the generator power are successfully phase-locked, and then allows the energy storage device to be connected in parallel with the generator set only when the phase lock is successful, thereby reducing the instantaneous instability of the microgrid power supply system and ensuring the stable operation of the microgrid power supply system.

Claims

1. A microgrid power supply system, wherein: Connected to a mains supply and comprising: At least one load; an energy storage device, electrically connected to the at least one load, for performing a charging or discharging operation and providing a stored energy during the discharging operation; a generator set, electrically connected to the at least one load, and providing a generator power when in operation; a first switch electrically connected between the mains and the energy storage device; a second switch electrically connected between the energy storage device and the generator set; a voltage controller, electrically connected to the generator set, the mains and the energy storage device, for detecting the voltage of a mains electric energy of the mains to output a first detection signal, and detecting the voltage of the generator electric energy to output a second detection signal; a microgrid controller, electrically connected to the first switch, the second switch, the energy storage device and the voltage controller, for controlling the operation of the first switch and the second switch; and a phase measurement control device, electrically connected to the mains, the energy storage device, the generator set and the microgrid controller, for respectively measuring phase information of the mains power, the energy storage device and the generator power; The phase measurement control device measures the phase information of the energy storage electric energy and the mains electric energy, and the energy storage device adjusts the voltage of the energy storage electric energy according to the measurement result of the phase measurement control device, and the microgrid controller controls the first switch to be turned on so that the energy storage device is connected in parallel with the mains when the measurement result of the phase measurement control device reflects that the phase difference between the energy storage electric energy and the mains electric energy is zero; The phase measurement control device measures the phase information of the energy storage electric energy and the generator electric energy, and the energy storage device adjusts the voltage of the energy storage electric energy according to the measurement result of the phase measurement control device. When the measurement result of the phase measurement control device reflects that the phase difference between the energy storage electric energy and the generator electric energy is zero, the microgrid controller controls the second switch to turn on so that the energy storage device is connected in parallel with the generator set.

2. The microgrid power supply system according to claim 1, wherein: When the energy storage device confirms that the AC power is normal based on the first detection signal, and the energy storage device receives a parallel instruction output by the microgrid controller, the energy storage device adjusts the voltage of the energy storage electric energy so that the energy storage electric energy is phase-locked with the AC power energy, and the phase measurement control device measures the phase information of the energy storage electric energy and the AC power energy to confirm whether the phase difference between the energy storage electric energy and the AC power energy is zero, and transmits a first success signal to the microgrid controller when the phase difference is zero, so that the microgrid controller controls the first switch to turn on and allows the energy storage device to be connected in parallel with the AC power.

3. The microgrid power supply system according to claim 1, wherein: When the energy storage device confirms that the city power is abnormal based on the first detection signal, and the microgrid controller communicates with the energy storage device and learns that the energy storage device is normal and the amount of the stored energy is lower than a threshold value, the microgrid controller drives the generator set to operate, and the energy storage device adjusts the voltage of the stored energy so that the stored energy is phase-locked with the generator energy, and the phase measurement control device measures the phase information of the stored energy and the generator energy to confirm whether the phase difference between the stored energy and the generator energy is zero, and transmits a second success signal to the microgrid controller when the phase difference is zero, so that the microgrid controller controls the second switch to turn on and allows the energy storage device to be connected in parallel with the generator set.

4. The microgrid power supply system according to claim 1, wherein: The microgrid power supply system includes at least one renewable energy power generation device electrically connected to the at least one load to provide renewable electric energy.

5. The microgrid power supply system according to claim 1, wherein: When the microgrid controller confirms that the mains power is normal according to the first detection signal, the microgrid controller controls the second switch to be disconnected.

6. The microgrid power supply system according to claim 1, wherein: When the microgrid controller confirms that the mains power is abnormal according to the first detection signal, the microgrid controller controls the first switch to be disconnected.

7. The microgrid power supply system according to claim 1, wherein: The microgrid controller communicates with the voltage controller, the energy storage device and the phase measurement control equipment.

8. The microgrid power supply system according to claim 1, wherein: The turned-on first switch feeds back a first parallel signal to the microgrid controller.

9. The microgrid power supply system according to claim 1, wherein: The turned-on second switch feeds back a second parallel signal to the microgrid controller.

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