Method of controlling an electrical power system

Abstract

A control method of a power system includes determining whether a battery stock of an energy storage system is lower than a first critical value. When the battery stock is lower than the first critical value, starting the generator and judging whether the generator is abnormal or not; and when the generator is abnormal, power is supplied to the load through the energy storage system. And when the generator is normal, the generator and the energy storage system jointly supply power to the load. And determining whether the battery stock is lower than a second critical value, and when the battery stock is lower than the second critical value, unloading a part of the load.

Description

Technical Field

[0001] This disclosure relates to a method for controlling an electric power system. Background Technology

[0002] In existing power systems, when mains power fails, microgrids disconnect from the mains. At this time, the energy storage system switches from current source mode to voltage source mode to support the bus voltage and frequency within the microgrid, and maintain uninterrupted power supply to other current source devices and loads on the bus. When mains power cannot be restored in real time, the load's power consumption prioritizes renewable energy devices; if insufficient, the energy storage system provides the remaining power. However, if the renewable energy device's power output is lower than the load's power consumption, the energy storage system's battery capacity will decrease. Therefore, further power outages to the load's power circuit are necessary. Summary of the Invention

[0003] This disclosure includes a control method for a power system, comprising: determining whether the battery level of an energy storage system is lower than a first threshold; when the battery level is lower than the first threshold, starting a generator and determining whether the generator is malfunctioning; when the generator is functioning normally, providing power to the load through the generator; when the generator is malfunctioning, providing power to the load through the energy storage system and determining whether the battery level is lower than a second threshold; and when the battery level is lower than the second threshold, removing at least a portion of the load. Attached Figure Description

[0004] The contents of this case can be better understood by referring to the implementation methods in the following paragraphs and the accompanying drawings:

[0005] Figure 1A This is a schematic diagram of a power system shown according to some embodiments of the present disclosure.

[0006] Figure 1B This is a schematic diagram of a power system shown according to some embodiments of the present disclosure.

[0007] Figure 2 This is an operational flowchart of a power system according to some embodiments of the present disclosure.

[0008] Figure 3 This is an operation flowchart illustrating the generator anomaly detection operation according to some embodiments of the present disclosure.

[0009] Figure 4 This is a schematic diagram of a power system shown according to some embodiments of the present disclosure.

[0010] Figure 5 This is a schematic diagram of a power system shown according to some embodiments of the present disclosure.

[0011] Figure 6 This is a schematic diagram of a power system shown according to some embodiments of the present disclosure. Detailed Implementation

[0012] Several embodiments of the present invention will be described below with reference to the accompanying drawings. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not essential. Furthermore, for the sake of simplicity, some well-known and conventional structures and components will be shown in the drawings in a simple schematic manner.

[0013] In this document, when a component is referred to as a “connection” or “coupled,” it may mean an “electrical connection” or “electrical coupling.” “Connection” or “coupled” can also be used to indicate the operation or interaction between two or more components. Furthermore, although terms such as “first,” “second,” etc., are used herein to describe different components, these terms are merely used to distinguish components or operations described using the same technical terms. Unless the context clearly indicates otherwise, these terms do not specifically refer to or imply any order or sequence, nor are they intended to limit the invention.

[0014] This disclosure relates to a control method for a power system, including a generator and remote switches, which can be applied to uninterrupted power supply (UPS) technology to continuously supply power to multiple loads and extend power supply time. When the mains power fails, the energy storage system in the power system switches from current source mode to voltage source mode to support the voltage and frequency of the power system bus and supply power to other power supply equipment and loads on the bus. When the battery capacity in the energy storage system is insufficient, the energy storage system cannot support the power supply and voltage stabilization of the power system, therefore, it is necessary to disconnect (remove) the loads in batches. This disclosure combines generator and remote switching technologies to enhance the power supply control technology in the power system. In some embodiments, the power system can be implemented through a microgrid system.

[0015] Figure 1A This is a schematic diagram of a power system 100A illustrated according to an embodiment of the present disclosure. The power system 100A includes a controller 101, a remote transfer switch (RTS) 102, a generator 103, a mains circuit 130, an energy storage system 131, a renewable energy device 132, auxiliary power devices 133, multiple switches S1 to S5, a bus 150, multiple loads LDA1 to LDAn, and multiple load switches LDAS1 to LDASn.

[0016] like Figure 1AAs shown, the mains circuit 130 is connected to bus 150 via switch S1. Generator 103 is connected to bus 150 via switch S2. Energy storage system 131 is connected to bus 150 via switch S3. Renewable energy device 132 is connected to bus 150 via switch S4. Auxiliary power device 133 is connected to bus 150 via switch S5. Multiple loads LDA1 to LDAn are connected to bus 150 via load switches LDAS1 to LDASn, where n is a positive integer. In some embodiments, the renewable energy device 132 can be implemented using solar panels.

[0017] In some embodiments, the remote switching switch 102 detects the voltage of the mains circuit 130, the generator 103, and the energy storage system 131, and transmits the voltage information to the controller 101. The controller 101 controls the switching on and off of switches S1 to S5 and multiple load switches LDAS1 to LDASn based on the voltage of the mains circuit 130, the generator 103, and the energy storage system 131.

[0018] Figure 1B This is a schematic diagram of a power system 100B illustrated according to an embodiment of the present disclosure. Power system 100B is a variation of power system 100A. The components of power system 100B use the same designation as those of power system 100A. For the sake of brevity, the discussion will focus on the parts of power system 100B that differ from power system 100A, rather than their similarities.

[0019] Compared to power system 100A, power system 100B further includes mains circuit 2 140, renewable energy device 141, multiple loads LDB1 to LDBn, switches S6 to S8, and load switches LDBS1 to LDBSn. Mains circuit 1 130 and mains circuit 2 140 are connected via switch S6, and mains circuit 2 140 is connected to bus 150 via switch S8.

[0020] In some embodiments, the remote switching switch 102 further detects the voltage of the mains circuit 2 140 and transmits the voltage information to the controller 101. The controller 101 is also used to control the switching on and off of switches S6 to S8 and multiple load switches LDBS1 to LDBSn based on the voltage of the mains circuit 2 140, the generator 103 and the energy storage system 131.

[0021] Figure 2 This is an operational flowchart illustrating a power system control method 200 according to an embodiment of the present disclosure. The control method 200 includes multiple operations 201 to 217.

[0022] Please refer to Figure 1A , Figure 1B and Figure 2The control method 200 can be executed by power systems 100A and / or 100B. However, the embodiments disclosed herein are not limited thereto. In various embodiments, the control method 200 can be executed by various power systems. The control method 200 will be described below using components of power system 100A as examples.

[0023] In operation 201, the remote switching switch 102 detects the voltage of the mains circuit 130 and transmits the voltage information to the controller 101 via a signal.

[0024] In some embodiments, when the voltage level of the mains circuit 130 is less than or greater than the default operating range voltage level of the mains power, the controller 101 determines that the mains circuit 130 is malfunctioning. When the voltage level of the mains circuit 130 is within the default operating range voltage level of the mains power, the controller 101 determines that the mains circuit 130 is operating normally.

[0025] When an anomaly occurs in the mains circuit 130, the remote switching switch 102 begins to read the voltage of the generator 103 and the energy storage system 131, and the controller 101 disconnects the switch S1 connected to the mains circuit 130. When an anomaly occurs in the mains circuit 130, the power system 100A executes operation 202 after operation 201. When the mains circuit 130 is operating normally, the remote switching switch 102 continuously monitors the voltage of the mains circuit 130, and the controller 101 continuously keeps the switch S1 connecting the mains circuit 130 and the bus 150 open, so that the mains circuit 130 continuously supplies power to the loads LDA1 to LDA1.

[0026] In operation 202, power system 100A performs islanding operation. In some embodiments, islanding operation can mean that in the absence of a mains power supply, the loads LDA1 to LDAn are powered by the internal power supply unit of power system 100A. Specifically, when a fault occurs in mains circuit 130, controller 101 disconnects switch S1, and the loads LDA1 to LDAn are powered by energy storage system 131 and renewable energy unit 132. Power system 100 then performs operation 203 after operation 202.

[0027] In operation 203, the controller 101 continuously determines whether the mains circuit 130 is abnormal, whether the regenerative energy device 132 has insufficient power, and whether the state of charge (SOC) of the energy storage system 131 is below a first threshold. In some embodiments, when the power of the regenerative energy device 132 is greater than the power of the loads LDA1 to LDAN, the controller 101 determines that the regenerative energy device 132 has sufficient power. When the power of the regenerative energy device 132 is less than the power of the loads LDA1 to LDAN, the controller 101 determines that the regenerative energy device 132 has insufficient power.

[0028] In some embodiments, when the mains circuit 130 resumes normal operation, the remote switching switch 102 detects the voltage of the mains circuit 130, and the controller 101 puts on the switch S1 connecting the mains circuit 130 and the bus 150, so that the mains circuit 130 and the renewable energy device 132 supply power to the loads LDA1 to LDA1.

[0029] In some embodiments, when the renewable energy device 132 has a margin or the SOC of the energy storage system 131 is higher than a first threshold, the renewable energy device 132 and the energy storage system 131 supply power to the loads LDA1 to LDA1, and the power system 100A repeatedly performs operation 203.

[0030] In some embodiments, when the renewable energy device 132 has no margin and the SOC is below a first threshold, the power system 100A performs operation 204 after operation 203.

[0031] In operation 204, controller 101 executes an automatic start-up procedure and an anomaly detection procedure for generator 103. Power system 100A executes operation 205 after operation 204.

[0032] In operation 205, controller 101 determines whether generator 103 is malfunctioning. Details regarding the operation of determining whether generator 103 is malfunctioning are as follows. Figure 3 The embodiments are described in detail below. In some embodiments, when the controller 101 determines that the generator 103 is abnormal, the power system 100A executes operation 206 after operation 205. When the controller 101 determines that the generator 103 is operating normally, the power system 100 executes operation 209 after operation 205.

[0033] In operation 206, energy storage system 131 supplies power to loads LDA1 to LDA1 and maintains the voltage level of bus 150. Power system 100A executes operation 207 after operation 206.

[0034] In operation 207, controller 101 determines whether the State of Charge (SOC) of energy storage system 131 is below a second threshold. In some embodiments, when the SOC of energy storage system 131 is below the second threshold, power system 100A executes operation 208 after operation 207. When the SOC of energy storage system 131 is above the second threshold, power system 100A executes operation 206 again after operation 207, and maintains the voltage level of bus 150 through energy storage system 131. In some embodiments, the second threshold is lower than the first threshold and is expressed as a percentage of the total energy capacity of the energy storage system.

[0035] In operation 208, in response to the SOC of the energy storage system 131 falling below the second threshold, the controller 101 automatically disconnects the loads LDA1 to LDAn. Specifically, when the SOC of the energy storage system 131 falls below the second threshold, the controller 101 disconnects a portion of the switches LDAS1 to LDASn, thereby decoupling the corresponding portions of the loads LDA1 to LDAn from the bus 150.

[0036] In some embodiments, the controller 101 selects a portion of loads LDA1 to LDA1 for disconnection based on a priority list. For example, if the priority of load LDA1 is lower than that of loads LDA2 to LDA1, the controller 101 prioritizes disconnecting load LDA1 in operation 208, that is, disconnecting switch LDA1. At this time, loads LDA2 to LDA1 have not yet been disconnected and are being powered by the energy storage system 131.

[0037] In operation 209, in response to controller 101 determining that generator 103 is abnormal, remote switch 102 performs voltage detection on generator 103 and energy storage system 131. Power system 100A executes operation 210 after operation 209.

[0038] In operation 210, controller 101 performs phase-locked synchronization of generator 103 and energy storage system 131. Specifically, phase-locked synchronization means that controller 101 synchronizes the voltage and frequency of generator 103 with the voltage and frequency of energy storage system 131. After operation 210, generator 103 and energy storage system 131 have the same voltage and frequency. Power system 100 executes operation 211 after operation 210.

[0039] In operation 211, controller 101 switches the voltage source from energy storage system 131 to generator 103, that is, controller 101 engages switch S2 connecting generator 103 and bus 150. Power system 100 then performs operation 212 after operation 211.

[0040] In operation 212, controller 101 determines whether the voltage source switching in operation 211 was successful. Specifically, when the voltage levels at both ends of switch S2 are the same, controller 101 determines that the voltage source switching was successful. When the voltage level and frequency at one end of switch S2 are different from those at the other end, controller 101 determines that the voltage source switching was unsuccessful. When controller 101 determines that the voltage source switching was unsuccessful, power system 100 repeats operation 204 after operation 212, and controller 101 performs an anomaly detection procedure on generator 103. When controller 101 determines that the voltage source switching was successful, power system 100 executes operation 213 after operation 212.

[0041] In operation 213, controller 101 distributes power to generator 103 and energy storage system 131. Specifically, controller 101 calculates the power difference based on the power provided by renewable energy device 132 and the power required by multiple loads LDA1 to LDA1, and controller 101 controls generator 103 to supply power equal to the calculated power difference to power system 100A. Power system 100 executes operation 214 after operation 213.

[0042] In some embodiments, when the power output provided by the renewable energy device 132 is less than the power required by the multiple loads LDA1 to LDA1, the generator 103 provides power such that the sum of the power provided by the renewable energy device 132 and the generator 103 equals the power required by the loads LDA1 to LDA1. In some embodiments, when the power output provided by the renewable energy device 132 is less than the power required by the multiple loads LDA1 to LDA1, the generator 103 and the energy storage system 131 jointly provide power such that the sum of the power provided by the renewable energy device 132, the energy storage system, and the generator 103 equals the power required by the loads LDA1 to LDA1. In some embodiments, when the power provided by the renewable energy device 132 is greater than the power required by the loads LDA1 to LDA1, the controller 101 controls the energy storage system 131 to absorb power such that the power absorbed by the energy storage system 131 equals the power difference between the power provided by the renewable energy device 132 and the power required by the loads LDA1 to LDA1.

[0043] For example, when the loads LDA1 to LDA1 require 20kW of power and the renewable energy device 132 provides 8kW of power output, the controller 101 controls the generator 103 to provide 20kW - 8kW = 12kW of power output to the loads LDA1 to LDA1. In another embodiment, when the loads LDA1 to LDA1 require 20kW of power, the renewable energy device 132 provides 8kW of power output, and the controller 101 controls the energy storage system 131 to provide 5kW of power output, the remaining power of 20kW - 8kW - 5kW = 7kW is supplied by the generator 103, thus jointly supplying power to the loads LDA1 to LDA1. For another example, when the power required by the loads LDA1 to LDA1 is 20kW and the power provided by the renewable energy device 132 is 25kW, the controller 101 controls the energy storage system 131 to absorb 25kW-20kW=5kW from the bus 150 to offset the excessive power of the renewable energy device 132, so that the renewable energy device 132 will not send reverse power to the generator 103.

[0044] In operation 214, controller 101 determines whether generator 103 is low on fuel. Specifically, when the fuel level of generator 103 is lower than a preset fuel value, controller 101 determines that generator 103 is low on fuel. When the fuel level of generator 103 is higher than the preset fuel value, controller 101 determines that generator 103 has sufficient fuel. When controller 101 determines that generator 103 is low on fuel, power system 100 executes operation 215 after operation 214. When controller 101 determines that generator 103 has sufficient fuel, power system 100 executes operation 216 after operation 214.

[0045] In operation 215, controller 101 switches the voltage source from generator 103 to energy storage system 131, that is, disconnects switch S2 connecting generator 103 and bus 150, and power system 100 returns to operation 207 after operation 215.

[0046] In operation 216, controller 101 determines whether the State of Charge (SOC) of energy storage system 131 is below a second threshold. Specifically, when the power demanded by loads LDA1 to LDA1 exceeds the power supplied by renewable energy device 132 and generator 103, and the SOC of energy storage system 131 is below the second threshold, power system 100 executes operation 217 after operation 216. When the power demanded by loads LDA1 to LDA1 exceeds the power supplied by renewable energy device 132 and generator 103, but the SOC of energy storage system 131 is above the second threshold, power system 100A returns to operation 213 after operation 216.

[0047] For example, when the power supplied by the generator 103 and the power supplied by the renewable energy device 132 are less than the power required by the loads LDA1 to LDA1, the energy storage system 131 provides power to the loads LDA1 to LDA1 to meet their power requirements.

[0048] In operation 217, in response to the SOC of the energy storage system 131 falling below the second threshold, the controller 101 automatically disconnects the loads LDA1 to LDAn. Specifically, when the SOC of the energy storage system 131 falls below the second threshold, the controller 101 disconnects a portion of the switches LDAS1 to LDASn, thereby decoupling the corresponding portions of the loads LDA1 to LDAn from the bus 150.

[0049] Figure 3 This is a flowchart illustrating the operation of a generator anomaly detection method 300 according to some embodiments of this disclosure. Figure 3 As shown, method 300 includes multiple operations 301 to 305.

[0050] refer to Figure 2 and Figure 3Method 300 is the method for judging the abnormality of generator 103 in operation 205. Specifically, after the controller 101 executes the automatic start-up procedure and the abnormality judgment procedure on generator 103, the controller 101 further executes method 300 and judges whether generator 103 is abnormal according to operations 301 to 305.

[0051] In operation 301, controller 101 executes an anomaly detection procedure on generator 103. Power system 100 executes operation 302 after operation 301.

[0052] In operation 302, controller 101 determines whether the generator 103 has sufficient fuel. In some embodiments, controller 101 reads the fuel level in the generator 103's fuel tank. If the level is higher than a limit, controller 101 determines that the generator 103 has sufficient fuel. When the fuel capacity in the generator 103's fuel tank is lower than a limit, controller 101 determines that the generator 103 has insufficient fuel.

[0053] In some embodiments, when the controller 101 determines that the generator 103 has sufficient fuel, the power system 100 executes operation 303 after operation 302. When the controller 101 determines that the generator 103 has insufficient fuel, the generator 103 is considered abnormal.

[0054] In operation 303, controller 101 determines whether the voltage and frequency of generator 103 meet the rated values. Specifically, when the voltage level of generator 103 is within the default operating voltage level range, and the frequency of generator 103 is within the default operating frequency range, controller 101 determines that generator 103 meets the rated values, and generator 103 is normal. When the voltage level of generator 103 is less than or greater than the default voltage level range, or the frequency of generator 103 is less than or greater than the default frequency range, controller 101 determines that generator 103 does not meet the rated values, and power system 100 executes operation 304 after operation 303.

[0055] In operation 304, the controller 101 automatically detects the voltage and frequency output by the generator 103 and performs parameter compensation based on the rated values. In some embodiments, when the voltage level and frequency of the generator 103 are lower than the default voltage level and frequency, the controller 101 performs parameter compensation based on the difference between the voltage and frequency of the generator 103 and the corresponding rated values. Specifically, when the voltage level of the generator 103 is lower than the rated voltage value, the generator 103 is adjusted based on the voltage difference between the voltage level and the rated voltage value to increase the voltage. When the frequency of the generator 103 is lower than the rated frequency value, the generator 103 is adjusted based on the frequency difference between the frequency and the rated frequency value to increase the frequency.

[0056] For example, when the voltage level and frequency of generator 103 are 470V and 58Hz respectively, and the corresponding rated values ​​are 480V and 60Hz respectively, controller 101 compensates the voltage level of generator 103 from 470V to 480V and the frequency of generator 103 from 58Hz to 60Hz. Power system 100 executes operation 305 after operation 304.

[0057] In operation 305, controller 101 determines whether the difference between the voltage and frequency of generator 103 and their rated values ​​is below the compensation range. Specifically, controller 101 can compensate for insufficient voltage and frequency of generator 103 to a limited extent. That is, controller 101 adjusts the voltage and frequency of generator 103 within a limited compensation range to correspondingly increase the voltage and frequency of generator 103 to their rated values.

[0058] In some embodiments, when the voltage of generator 103 cannot be adjusted to the rated voltage value, or when the frequency of generator 103 cannot be adjusted to the rated frequency value, controller 101 determines that generator 103 is abnormal. Specifically, when the difference between the voltage and frequency of generator 103 and their rated values ​​is higher than the compensation range of controller 101, controller 101 determines that generator 103 is abnormal. When the difference between the voltage and frequency of generator 103 and their rated values ​​is lower than or equal to the compensation range of controller 101, controller 101 determines that generator 103 is normal, and power system 100 repeats operation 303 after operation 305.

[0059] In some embodiments, the method 300 for determining generator malfunction can be used Figure 1A The power system 100A in Figure 1B The power system 100B or other similar power systems described herein, but this disclosure is not limited to these power systems.

[0060] Figure 4 This is a schematic diagram of a power system 400 according to some embodiments of the present disclosure. (See also:) Figure 1B and Figure 4 Power system 400 is an embodiment of power system 100B.

[0061] like Figure 4 In the illustrated embodiment, the power system 400 operates in an islanded state and uses the energy storage system 131 as a voltage source. In some embodiments, the power system 400 may correspond to Figure 2A schematic diagram of operation 203. When the controller 101 determines that the renewable energy device 132 has sufficient capacity or the SOC of the energy storage system 131 is higher than the first threshold, the energy storage system 131, the renewable energy device 132, and the auxiliary power supply device 133 supply power to the loads LDA1~LDAn and LDB1~LDBn of the power system 400. In some embodiments, the power system 400 may correspond to Figure 2 The schematic diagram of operation 206. When the controller 101 determines that the renewable energy device 132 has no margin or the SOC of the energy storage system 131 is lower than the first critical value, and the controller 101 determines that the generator 103 is abnormal, the energy storage system 131 supplies power to the loads LDA1~LDAn and LDB1~LDBn, and maintains the system voltage of the power system 400.

[0062] Specifically, in the power system 400, when the controller 101 determines that the mains circuit 1130 and mains circuit 2140 are abnormal, the controller 101 disconnects the switches S1 and S8 corresponding to the mains circuit 1130 and mains circuit 2140 to the bus 150. In some embodiments, when the controller 101 further determines that the renewable energy device 132 has a margin or the SOC of the energy storage system 131 is higher than a first threshold value, the energy storage system 131 acts as a voltage source to maintain the voltage level of the bus 150, and the energy storage system 131 and the renewable energy device 132 jointly supply power to multiple loads LDA1 to LDAN and LDB1 to LDBn. In other embodiments, when the controller 101 further determines that the renewable energy device 132 has no margin or the SOC of the energy storage system 131 is lower than the first threshold value, and the controller 101 determines that the generator 103 is abnormal, the energy storage system 131 acts as a voltage source to maintain the voltage level of the bus 150 and to supply power to multiple loads LDA1 to LDAN and LDB1 to LDBn.

[0063] Figure 5 This is a schematic diagram of a power system 500 according to some embodiments of the present disclosure. (See reference...) Figure 1B and Figure 5 Power system 500 is an embodiment of power system 100B.

[0064] like Figure 5 In the illustrated embodiment, the power system 500 operates in an islanded state and uses the generator 103 as a voltage source. In some embodiments, the power system 500 may correspond to Figure 2The schematic diagram of operation 213. When the controller 101 determines that the renewable energy device 132 has no margin or the SOC of the energy storage system 131 is lower than the first critical value, and when the controller 101 further determines in operation 205 that the generator is operating normally, the generator 103 and the energy storage system 131 jointly supply power to the loads LDA1~LDAn and LDB1~LDBn of the power system 500, and the generator 103 maintains the voltage level of the bus 150.

[0065] Specifically, in the power system 500, when the controller 101 determines that the mains circuit 1130 and mains circuit 2140 are abnormal, the controller 101 disconnects the switches S1 and S8 corresponding to the mains circuit 1130 and mains circuit 2140 to the bus 150. In some embodiments, when the controller 101 determines that the renewable energy device 132 has no margin or the SOC of the energy storage system 131 is lower than the first threshold value, and the controller 101 determines that the generator 103 is operating normally, the generator 103 acts as a voltage source to maintain the voltage level of the bus 150, and together with the energy storage system 131, supplies power to multiple loads LDA1 to LDAN and LDB1 to LDBn.

[0066] Figure 6 This is a schematic diagram of a power system 600 according to some embodiments of the present disclosure. (See also:) Figure 1B and Figure 6 Power system 600 is an embodiment of power system 100B.

[0067] like Figure 6 In the illustrated embodiment, the power system 600 is in grid-connected operation and uses the mains power circuit 1130 as its voltage source. In some embodiments, such as Figure 6 As shown, controller 101 determines that mains circuit 2 140 is abnormal, and switch S8 is in the off state. Conversely, controller 101 determines that mains circuit 1 130 is operating normally, and therefore uses mains circuit 1 130 as a voltage source to maintain the voltage level of bus 150. When mains circuit 1 130 is determined to be operating normally, mains circuit 1 130 and regenerative energy device 132 supply power to the loads LDA1~LDAn and LDB1~LDBn of power system 600, and switch S2 connecting generator 103 and bus 150 remains off.

[0068] Specifically, in the power system 600, when the controller 101 determines that the mains circuit 1 130 is operating normally while the mains circuit 2 140 is abnormal, the controller will disconnect the switch S8 connecting the mains circuit 2 140 and the bus 150, and use the mains circuit 1 130 as a voltage source to maintain the voltage level of the bus 150.

[0069] In some embodiments, when the renewable energy device 132 has a margin or the SOC of the energy storage system 131 is higher than a first threshold, the energy storage system 131, the renewable energy device 132, and the mains circuit 1130 together provide power to the loads LDA1 to LDAN and LDB1 to LDBn.

[0070] Unless otherwise specified, the terms used herein generally have their ordinary meaning in the context of this art, the content of this description, and the specific content thereof. Certain terms used to describe this description will be discussed elsewhere in this specification to provide additional guidance to those skilled in the art in describing this description.

[0071] While specific embodiments of this disclosure have been described with reference to the above embodiments, these embodiments are not intended to limit this disclosure. Various alternatives and modifications can be made by those skilled in the art without departing from the principles and spirit of this disclosure. Therefore, the scope of protection of this disclosure is determined by the appended claims.

[0072] Explanation of reference numerals in the attached figures

[0073] 100A, 100B: Power system

[0074] 101: Controller

[0075] 102: Remote switching switch

[0076] 103: Generator,

[0077] 130: Mains circuit / Mains circuit 1

[0078] 131: Energy storage system

[0079] 132: Renewable energy devices

[0080] 133: Auxiliary electrical equipment;

[0081] 140: Mains circuit 2,

[0082] 200: Methods

[0083] 201-217: Operation,

[0084] 300: Methods

[0085] 301-305: Operation,

[0086] 400, 500, 600: Power system

[0087] LDA1~LDAn: Load,

[0088] LDB1~LDBn: Load,

[0089] LDAS1~LDASn: Load switches

[0090] LDBS1~LDBSn: Load switches

[0091] S1~S8: Switches.

Claims

1. A control method for a power system, wherein, include: Determine whether the battery capacity of an energy storage system is below a first critical value; When the battery level is below the first critical value, a generator is started and it is determined whether the generator is malfunctioning. When the generator is functioning normally, it provides power to multiple loads. When the generator malfunctions, the energy storage system provides power to multiple loads and determines whether the battery level is below a second critical value. as well as When the battery level falls below the second threshold, at least a portion of the load is removed.

2. The method according to claim 1, wherein, Determining whether the generator is malfunctioning includes: To determine if the generator has sufficient fuel, among other things... When the generator is low on fuel, it is considered to be malfunctioning.

3. The method according to claim 2, wherein, Determining whether the generator is malfunctioning also includes: When the generator has sufficient fuel, determine whether the generator's voltage meets a rated voltage value and whether the generator's frequency meets a rated frequency value; and When the voltage is lower than the rated voltage, the generator is adjusted according to the voltage difference between the voltage and the rated voltage to increase the voltage.

4. The method according to claim 3, wherein, Determining whether the generator is malfunctioning also includes: When the frequency is lower than the rated frequency, the generator is adjusted according to the frequency difference between the frequency and the rated frequency to increase the frequency.

5. The method according to claim 4, wherein, Determining whether the generator is malfunctioning also includes: The generator is considered abnormal if the voltage cannot be adjusted to the rated value or the frequency cannot be adjusted to the rated value.

6. The method according to claim 1, wherein, Further includes: When the generator is determined to be normal, a power difference between the first power and the second power is calculated based on a first power provided by a regenerative energy device through a bus to multiple loads and a second power required by the multiple loads; and When the first power is greater than the second power, the power difference is absorbed from the bus through the energy storage system.

7. The method according to claim 6, wherein, Determining whether the generator is malfunctioning also includes: When the second power is greater than the first power, the power difference is supplied to multiple loads through the generator and the bus.

8. The method according to claim 1, wherein, The first critical value is greater than the second critical value.

9. The method according to claim 1, wherein, Further includes: When the battery level falls below the first critical value and the generator is determined to be malfunctioning, a switch on the generator is disconnected, and it is determined whether the battery level falls below the second critical value; and When the battery capacity is higher than the second threshold, the energy storage system provides power to multiple loads.

10. The method according to claim 1, wherein, Further includes: When the battery level is below the first critical value and the generator is determined to be normal, the voltage and frequency of the generator are synchronized with the voltage and frequency of the energy storage system.

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