Power supply control system and energy storage system

Abstract

The utility model relates to the field of power electronics, discloses a power supply control system and an energy storage system, and aims to provide a standby power supply and improve the reliability of the system. The power supply control system comprises a first energy storage cabinet and a standby power supply. The first energy storage cabinet comprises a first AC / DC module, a first DC / DC module, a first diode unit, a local switching unit and an external switching unit. The first input end of the first diode unit is connected with the positive electrode output end of the first AC / DC module and the positive electrode output end of the first DC / DC module through the local switching unit, the second input end of the first diode unit is connected with the output end of the external switching unit, and the output end of the first diode unit is connected with the positive electrode of a load; the first DC / DC module is used for adjusting the direct current output by the battery in the first energy storage cabinet into the direct current of the target working voltage; the first AC / DC module is used for converting alternating current commercial power into direct current of target working voltage.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronics, and in particular to a power supply control system and an energy storage system. Background Art

[0002] With the development of new energy, energy storage systems have been widely used. Energy storage systems have diversified application scenarios, including peak-valley arbitrage, demand management, transformer expansion and other working modes. As an important part of the energy storage system, the energy storage cabinet also needs to ensure the power supply of the control system in the energy storage system. The DC loads in the control system mainly include fire detectors, water immersion sensors, energy management systems (EMS), battery management systems (BMS), etc. Most of these DC loads require uninterruptible power supply.

[0003] The traditional solution uses a dual power switching mode to provide uninterrupted power supply for DC loads. However, in the dual power switching mode, since the depth of discharge (DOD) of the energy storage cabinet battery is generally set relatively high, when the AC power is lost for a long time, the energy storage cabinet battery is required to be used as a DC power supply to power the DC load for a long time, which may cause the battery in the energy storage cabinet to run out of power and reduce the battery life. Utility Model Content

[0004] The utility model provides a power supply control system and an energy storage system, which are used to set the backup time of the battery of the first energy storage cabinet during the switching process of the DC power supply and the AC power supply in the first energy storage cabinet, thereby solving the problem that the battery of the first energy storage cabinet may be depleted, and at the same time ensuring that when the AC mains and the DC backup power of the first energy storage cabinet lose power at the same time, power is supplied by the backup power supply, and the backup time is set to prevent the battery of the backup power supply from being depleted, thereby improving the reliability of the power supply control system and the battery life.

[0005] The first aspect of the utility model provides a power supply control system, the power supply control system includes a first energy storage cabinet and a backup power supply, the first energy storage cabinet includes: a first AC / DC module, a first DC / DC module and a first control module, the first control module includes a first diode unit, a first local switching unit and a first external switching unit, the first local switching unit includes at least one relay, and the first external switching unit includes at least two relays; the first input end of the first diode unit is respectively connected to the positive output end of the first AC / DC module and the positive output end of the first DC / DC module through the first local switching unit, the second input end of the first diode unit is connected to the output end of the first external switching unit, and the output end of the first diode unit is connected to the positive pole of the load; the first diode unit is used to connect the first The voltage of one input terminal or the voltage of the second input terminal is output to the positive electrode of the load; the first local switching unit is used to control the conduction time between the positive output terminal of the first DC / DC module and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay; the first external switching unit is used to control the conduction time between the positive output terminal of the backup power supply and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay; the first DC / DC module has a DC input terminal, which is used to connect to the battery, and the first DC / DC module is used to adjust the DC power output by the battery in the first energy storage cabinet to the DC power of the target working voltage; the first AC / DC module has an AC input terminal, which is used to connect to the AC mains, and the first AC / DC module is used to convert the AC mains into the DC power of the target working voltage.

[0006] In a feasible implementation manner, the first control module further includes a second diode unit; a first input end of the second diode unit is connected to the positive output end of the first AC / DC module, a second input end of the second diode unit is connected to the positive output end of the first DC / DC module, and an output end of the second diode unit is connected to the first input end of the first diode unit; the second diode unit is used to output the voltage of the first input end or the voltage of the second input end to the first input end of the first diode unit.

[0007] In a feasible implementation manner, the first local switching unit includes a first power-off delay relay, and the contact of the first power-off delay relay is a first delayed disconnection contact; the first external switching unit includes an energy storage capacitor, a first power-on delay relay and a first intermediate relay, the contact of the first power-on delay relay is a first delayed disconnection contact, and the contact of the first intermediate relay is a first normally closed contact; the two ends of the coil in the first power-off delay relay are respectively connected to the positive and negative output ends of the first AC / DC module; the first end of the first delayed disconnection contact is connected to the positive output end of the first DC / DC module, and the second end of the first delayed disconnection contact is connected to the second input end of the second diode unit. Connection; the first end of the coil in the first power-on delay relay is connected to the second end of the first normally closed contact and the first end of the first delayed disconnecting break contact, the second end of the coil in the first power-on delay relay is connected to the negative output end of the backup power supply, the negative output end of the first DC / DC module, the first end of the first intermediate relay, the first end of the energy storage capacitor, and the negative pole of the load; the second end of the first delayed disconnecting break contact is connected to the second input end of the first diode unit; the second end of the first intermediate relay is connected to the second end of the energy storage capacitor, the first input end of the first diode unit, and the output end of the second diode unit; the first end of the first normally closed contact is connected to the positive output end of the backup power supply.

[0008] In a feasible implementation manner, the first local switching unit includes a first intermediate relay and a first power-on delay relay, the contact of the first intermediate relay is a first normally closed contact, and the contact of the first power-on delay relay is a first delayed disconnection break contact; the first external switching unit includes an energy storage capacitor, a second power-on delay relay and a second intermediate relay, the contact of the second power-on delay relay is a second delayed disconnection break contact, and the contact of the second intermediate relay is a second normally closed contact; the two ends of the coil in the first intermediate relay are respectively connected to the positive and negative output ends of the first AC / DC module; the first end of the first normally closed contact is connected to the positive output end of the first DC / DC module, and the second end of the first normally closed contact is connected to the first end of the coil of the first power-on delay relay and the first end of the first delayed disconnection break contact; the second end of the first delayed disconnection break contact is connected to the positive and negative output ends of the first AC / DC module; The second input end of the second diode unit is connected; the second end of the coil of the first power-on delay relay is connected to the negative output end of the first DC / DC module, the first end of the second intermediate relay, the first end of the energy storage capacitor, the second end of the coil in the second power-on delay relay, the negative output end of the backup power supply, and the negative pole of the load; the first end of the coil in the second power-on delay relay is connected to the second end of the second normally closed contact and the first end of the second delayed disconnection break contact; the first end of the second normally closed contact is connected to the positive output end of the backup power supply; the second end of the second delayed disconnection break contact is connected to the second input end of the first diode unit; the second end of the second intermediate relay is connected to the second end of the energy storage capacitor, the first input end of the first diode unit, and the output end of the second diode unit; the first end of the second normally closed contact is connected to the positive output end of the backup power supply.

[0009] In a feasible implementation manner, the first local switching unit includes a battery management system BMS, a first intermediate relay and a second intermediate relay, the contact of the first intermediate relay is a first normally open contact, and the contact of the second intermediate relay is a first normally closed contact; the first external switching unit includes an energy storage capacitor, a first power-on delay relay and a third intermediate relay, the contact of the first power-on delay relay is a first delayed disconnection contact, and the contact of the third intermediate relay is a second normally closed contact; the two ends of the coil in the first intermediate relay are respectively connected to the positive and negative output ends of the first AC / DC module; the two ends of the first normally open contact are connected to the digital input end of the BMS; the coil of the second intermediate relay is connected to the high-side digital output end of the BMS, and the output voltage of the high-side output end is the power supply voltage of the BMS; the first end of the second normally closed contact is connected to the positive and negative output ends of the first AC / DC module; The positive output end of the first DC / DC module is connected, and the second end of the second normally closed contact is connected to the second input end of the second diode unit; the first end of the coil in the first power-on delay relay is connected to the second end of the second normally closed contact and the first end of the first delayed disconnection break contact, and the second end of the coil in the first power-on delay relay is connected to the negative output end of the backup power supply, the negative output end of the first DC / DC module, the first end of the third intermediate relay, the first end of the energy storage capacitor, and the negative pole of the load; the second end of the first delayed disconnection break contact is connected to the second input end of the first diode unit; the second end of the third intermediate relay is connected to the second end of the energy storage capacitor, the first input end of the first diode unit, and the output end of the second diode unit; the first end of the second normally closed contact is connected to the positive output end of the backup power supply.

[0010] In a feasible implementation manner, the first local switching unit includes a battery management system BMS, a first intermediate relay and a DC circuit breaker, wherein the contact of the first intermediate relay is a first normally open contact; the first external switching unit includes an energy storage capacitor, a first power-on delay relay and a second intermediate relay, wherein the contact of the first power-on delay relay is a first delayed disconnection contact, and the contact of the second intermediate relay is a first normally closed contact; the two ends of the coil in the first intermediate relay are respectively connected to the positive and negative output ends of the first AC / DC module; the two ends of the first normally open contact are connected to the digital input end of the BMS; the positive output end of the first DC / DC module is connected to the second input end of the second diode unit after passing through the DC circuit breaker. , the negative output end of the first DC / DC module is connected to the first end of the second intermediate relay, the first end of the energy storage capacitor, the second end of the coil in the first power-on delay relay, the negative output end of the backup power supply, and the negative pole of the load after passing through the DC circuit breaker; the first end of the coil in the first power-on delay relay is connected to the second end of the first normally closed contact and the first end of the first delayed disconnection break contact; the second end of the first delayed disconnection break contact is connected to the second input end of the first diode unit; the second end of the second intermediate relay is connected to the second end of the energy storage capacitor, the first input end of the first diode unit, and the output end of the second diode unit; the first end of the first normally closed contact is connected to the positive output end of the backup power supply.

[0011] In a feasible implementation manner, the first DC / DC module includes a working voltage protection unit, and the working voltage protection unit is used to stop outputting direct current when the output voltage of the first DC / DC module is less than a voltage threshold, and the voltage threshold is greater than an undervoltage protection value of the battery.

[0012] In a feasible implementation manner, a closing self-locking button is provided on the circuit where the positive output terminal of the first DC / DC module is located, and the closing self-locking button is used to provide a black start function and an emergency shutdown function.

[0013] In a feasible implementation manner, the backup power supply of the first energy storage cabinet is the second energy storage cabinet, the first energy storage cabinet and the second energy storage cabinet serve as backup power for each other, the second energy storage cabinet comprises: a second AC / DC module, a second DC / DC module and a second control module, the second control module comprises a third diode unit, a fourth diode unit, a second local switching unit and a second external switching unit, the second local switching unit comprises at least one relay, and the second external switching unit comprises at least two relays; the first input end of the fourth diode unit is connected to the positive output end of the second AC / DC module, the second input end of the fourth diode unit is connected to the positive output end of the second DC / DC module, the output end of the fourth diode unit is connected to the first input end of the third diode unit, the second input end of the third diode unit is connected to the output end of the second external switching unit, and the output end of the third diode unit is connected to the positive electrode of the load; the third diode unit is used for The voltage of the first input terminal or the voltage of the second input terminal is output to the positive electrode of the load; the fourth diode unit is used to output the voltage of the first input terminal or the voltage of the second input terminal to the first input terminal of the third diode unit; the second local switching unit is used to control the conduction time between the positive output terminal of the second DC / DC module and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay; the second external switching unit is used to control the conduction time between the positive output terminal of the first energy storage cabinet and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay; the second DC / DC module has a DC input terminal, which is used to connect to the battery, and the second DC / DC module is used to adjust the DC power output by the battery in the second energy storage cabinet to the DC power of the target working voltage; the second AC / DC module has an AC input terminal, which is used to connect to the AC mains, and the second AC / DC module is used to convert the AC mains into the DC power of the target working voltage.

[0014] The second aspect of the present invention provides an energy storage system, comprising a power control system and an energy management system in any one of the embodiments of the first aspect, wherein the energy management system is used to perform energy management on batteries of each energy storage cabinet in the power control system.

[0015] In the technical solution provided by the utility model, the power control system includes a first energy storage cabinet and a backup power supply, the first energy storage cabinet includes: a first AC / DC module, a first DC / DC module and a first control module, the first control module includes a first diode unit, a first local switching unit and a first external switching unit, the first local switching unit includes at least one relay, and the first external switching unit includes at least two relays; the first input end of the first diode unit is connected to the positive output end of the first AC / DC module and the positive output end of the first DC / DC module respectively through the first local switching unit, the second input end of the first diode unit is connected to the output end of the first external switching unit, and the output end of the first diode unit is connected to the positive pole of the load; the first diode unit is used to convert the voltage of the first input end or the voltage of the second input terminal is output to the positive electrode of the load; the first local switching unit is used to control the conduction time between the positive output terminal of the first DC / DC module and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay; the first external switching unit is used to control the conduction time between the positive output terminal of the backup power supply and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay; the first DC / DC module has a DC input terminal, which is used to connect to the battery, and the first DC / DC module is used to adjust the DC power output by the battery in the first energy storage cabinet to the DC power of the target working voltage; the first AC / DC module has an AC input terminal, which is used to connect to the AC mains, and the first AC / DC module is used to convert the AC mains into the DC power of the target working voltage. The utility model sets the backup time of the battery of the first energy storage cabinet during the switching process between the DC power supply and the AC power supply in the first energy storage cabinet, thereby solving the problem that the battery of the first energy storage cabinet may run out of power. At the same time, it ensures that when the AC mains and the DC backup power of the first energy storage cabinet lose power at the same time, power is supplied by the backup power supply, and the backup time is set to prevent the battery of the backup power supply from running out of power, thereby improving the reliability of the power supply control system and the service life of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of a power supply control system in an embodiment of the utility model;

[0017] Figure 2 Another schematic diagram of a power supply control system in an embodiment of the utility model;

[0018] Figure 3 A structural schematic diagram of the first energy storage cabinet in an embodiment of the utility model;

[0019] Figure 4 A schematic diagram of a connection relationship between the first energy storage cabinet and the second energy storage cabinet in an embodiment of the utility model;

[0020] Figure 5This is another structural schematic diagram of the first energy storage cabinet in the embodiment of the utility model;

[0021] Figure 6 A schematic diagram of a connection relationship between the first energy storage cabinet and the second energy storage cabinet in an embodiment of the utility model;

[0022] Figure 7 This is another structural schematic diagram of the first energy storage cabinet in the embodiment of the utility model;

[0023] Figure 8 A schematic diagram of a connection relationship between the first energy storage cabinet and the second energy storage cabinet in an embodiment of the utility model;

[0024] Fig. 9 This is another structural schematic diagram of the first energy storage cabinet in the embodiment of the utility model;

[0025] Fig.10 This is a schematic diagram of another connection relationship between the first energy storage cabinet and the second energy storage cabinet in an embodiment of the utility model. DETAILED DESCRIPTION

[0026] The utility model provides a power supply control system and an energy storage system, which are used to set the backup time of the battery of the first energy storage cabinet during the switching process of the DC power supply and the AC power supply in the first energy storage cabinet, thereby solving the problem that the battery of the first energy storage cabinet may be depleted, and at the same time ensuring that when the AC mains and the DC backup power of the first energy storage cabinet lose power at the same time, power is supplied by the backup power supply, and the backup time is set to prevent the battery of the backup power supply from being depleted, thereby improving the reliability of the power supply control system and the battery life.

[0027] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the utility model described here, for example, can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] like Figure 1 As shown, an embodiment of the utility model provides a power supply control system, the power supply control system includes a first energy storage cabinet and a backup power supply, and the first energy storage cabinet specifically includes:

[0029] A first AC / DC module 110, a first DC / DC module 120 and a first control module 130, wherein the first control module 130 includes a first diode unit 131, a first local switching unit 132 and a first external switching unit 133, wherein the first local switching unit 132 includes at least one relay, and the first external switching unit 133 includes two relays;

[0030] The first input end of the first diode unit 131 is connected to the positive output end of the first AC / DC module 110 and the positive output end of the first DC / DC module 120 through the first local switching unit 132, the second input end of the first diode unit 131 is connected to the output end of the first external switching unit 132, and the output end of the first diode unit 131 is connected to the positive electrode of the load;

[0031] The first diode unit 131 is used to output the voltage of the first input terminal or the voltage of the second input terminal to the positive electrode of the load;

[0032] The first local switching unit 132 is used to control the conduction time between the positive output terminal of the first DC / DC module and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay;

[0033] The first external switching unit 133 is used to control the conduction time between the positive output terminal of the backup power supply and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay;

[0034] The first DC / DC module 120 has a DC input terminal, which is used to connect to a battery. The first DC / DC module is used to adjust the DC power output by the battery in the first energy storage cabinet to DC power of a target working voltage;

[0035] The first AC / DC 110 module has an AC input terminal, which is used to connect to the AC mains. The first AC / DC module is used to convert the AC mains into DC power of a target working voltage.

[0036] Among them, the battery connected to the DC input terminal can be arranged inside the energy storage cabinet or outside the energy storage cabinet. For multiple energy storage cabinets, some batteries can be arranged inside the energy storage cabinet and some batteries can be arranged outside the energy storage cabinet at the same time. The present application does not limit this. For ease of understanding, in this embodiment and subsequent embodiments, the battery is arranged in the energy storage cabinet as an example, that is, the battery of the first energy storage cabinet is arranged inside the first energy storage cabinet, and the battery of the second energy storage cabinet is arranged inside the second energy storage cabinet.

[0037] The utility model sets the backup time of the battery in the first energy storage cabinet during the switching process between the DC power supply and the AC power supply in the first energy storage cabinet to prevent the battery in the first energy storage cabinet from running out of power. At the same time, it can be ensured that when the AC mains and the DC backup power of the first energy storage cabinet lose power at the same time, power is supplied by the backup power supply, and the backup time of the backup power supply is set to prevent the battery in the backup power supply from running out of power, thereby improving the reliability of the power supply control system and increasing the service life of the battery.

[0038] It should be noted that two input terminals of the first AC / DC module 110 are connected to the AC mains, and two input terminals of the first DC / DC module 120 are connected to the battery of the first energy storage cabinet.

[0039] It can be understood that at least one relay in the first local switching unit 132 can select a relay model with a delay function or control the signal sending time through the battery management system BMS to realize the delay function, thereby controlling the power supply time of the first DC / DC module in the first energy storage cabinet to the load, avoiding the battery of the first energy storage cabinet from running out of power, affecting the battery life; at least one relay in the first external switching unit 133 can select a relay model with a delay function to control the signal sending time to realize the delay function, thereby controlling the power supply time of the first DC / DC module in the backup power supply to the load, avoiding the battery of the backup power supply from running out of power, affecting the battery life.

[0040] In a possible implementation, Figure 2 As shown, the first control module 130 further includes a second diode unit 134;

[0041] The first input end of the second diode unit 134 is connected to the positive output end of the first AC / DC module, the second input end of the second diode unit 134 is connected to the positive output end of the first DC / DC module, and the output end of the second diode unit 134 is connected to the first input end of the first diode unit 131;

[0042] The second diode unit 134 is used to output the voltage of the first input terminal or the voltage of the second input terminal to the first input terminal of the first diode unit 131 .

[0043] The positive output terminals of the first AC / DC module and the first DC / DC module are simultaneously connected to the two input terminals of the second diode unit. For example, the specific structure of the second diode unit is as follows: Figure 3 As shown, the second diode unit DK2 is composed of two diodes, forming two power supply circuits, one circuit is: first input terminal V1-first diode VD1-output terminal V0, and the other circuit is: second input terminal V2-second diode VD2-output terminal V0. The circuit corresponding to which input terminal has a larger voltage is turned on.

[0044] In a possible implementation, Figure 3 As shown, the first local switching unit 132 includes a first power-off delay relay KT1, and the contact of the first power-off delay relay KT1 is a first delayed disconnection contact KT1-1; the first external switching unit 133 includes an energy storage capacitor C, a first power-on delay relay KT2 and a first intermediate relay KM1, the contact of the first power-on delay relay KT2 is a first delayed disconnection contact KT2-2, and the contact of the first intermediate relay KM1 is a first normally closed contact;

[0045] The two ends of the coil in the first power-off delay relay KT1 are respectively connected to the positive and negative output ends of the first AC / DC module SP1;

[0046] A first end of the first delayed opening make contact KT1-1 is connected to the positive output end of the first DC / DC module SP2, and a second end of the first delayed opening make contact KT1-1 is connected to the second input end of the second diode unit;

[0047] The first end of the coil in the first power-on delay relay KT2 is connected to the second end of the first normally closed contact and the first end of the first delayed opening break contact KT2-2, and the second end of the coil in the first power-on delay relay KT2 is connected to the negative output end of the standby power supply, the negative output end of the first DC / DC module SP2, the first end of the first intermediate relay KM1, the first end of the energy storage capacitor C, and the negative electrode of the load;

[0048] The second end of the first delayed breaking contact KT2-2 is connected to the second input end of the first diode unit DK1; the second end of the first intermediate relay KM1 is connected to the second end of the energy storage capacitor C, the first input end of the first diode unit DK1, and the output end of the second diode unit DK2;

[0049] The first end of the first normally closed contact is connected to the positive output end of the backup power supply.

[0050] For example, Figure 3As shown, the self-locking button SB2 is pressed, the AC mains and the battery of the first energy storage cabinet are input at the same time, the input of the first AC / DC module SP1 is energized (the voltage is regulated to be greater than the output voltage of the first DC / DC module), and the output end of the first AC / DC module SP1 outputs the target working voltage. Under the action of the target working voltage, the coil of the first power-off delay relay KT1 is energized, and the first delayed disconnecting make contact KT1-1 is closed. The power supplies of the first AC / DC module SP1 and the first DC / DC module SP2 are simultaneously connected to the second diode switching unit DK2. Since the output voltage of the first AC / DC module SP1 is regulated to be greater than the output voltage of the first DC / DC module SP2, the first input end V1 to the output end V0 of the second diode switching unit DK2 is turned on. At this time, the first intermediate relay KM1 is energized, the first normally closed contact is disconnected, and there is no voltage input to the second input end of the first diode switching unit DK1. The first diode switching unit DK1 outputs the voltage of the first input end V1, and the AC mains of the first energy storage cabinet supplies the DC load. When the AC mains loses power, the coil of the first power-off delay relay KT1 loses power, and the first delayed disconnection contact KT1-1 disconnects. It automatically disconnects after reaching the preset timing time, controls the backup time of the battery in the first energy storage cabinet, and prevents the battery in the first energy storage cabinet from running out of power. If the AC mains is restored during the power supply delay process of the first DC / DC module SP2 (i.e., the first DC / DC module supplies power, and the preset timing time has not been reached), then after the first AC / DC module SP2 provides voltage to the coil of the first power-off delay relay KT1, the coil of the first power-off delay relay KT1 is energized, and the first delayed disconnection contact KT1-1 of KT1 remains closed. At this time, the output voltage of the first AC / DC module SP1 is higher than the output voltage of the first DC / DC module SP2, and the load is switched to AC mains power supply. When the AC power fails next time, the first power-off delay relay KT1 will restart the timing delay disconnection, and this cycle will repeat automatically. When the first energy storage cabinet performs the above-mentioned dual power switching, the coil of the first intermediate relay KM1 is energized and works, the first normally closed contact of KM1 is disconnected, and power cannot be drawn from the battery of the backup power supply. When the AC mains and the battery of the first energy storage cabinet lose power at the same time, the first intermediate relay KM1 loses power, the first normally closed contact of KM1 closes, and the coil of the first power-on delay relay KT2 is energized. At this time, the backup power supply is switched to power. When the preset timing length of KT2 is reached, the first delayed disconnecting moving breaking contact KT2-2 is automatically disconnected, controlling the backup power supply time provided by the backup power supply to the first energy storage cabinet, preventing the backup power supply battery from running out of power, improving the safety and reliability of the power control system, and increasing the battery life.

[0051] The function of the first diode unit DK1 is to isolate the power output of the first energy storage cabinet from the power output of the backup power supply to prevent the two power supplies from being connected in parallel, thereby avoiding repeated actions of the first intermediate relay KM1. The function of the second diode unit DK2 is to isolate the main power output of the first AC / DC module from the backup power output of the first DC / DC module to prevent the two power supplies from being connected in parallel, thereby avoiding repeated actions of the first power-off delay relay KT1. It is understandable that in this embodiment, the coil of the first power-off delay relay KT1 can also be directly connected to the LN ends of the AC mains, and only the coil operating voltage needs to be modified during selection, and the second diode unit DK2 can be cancelled at this time.

[0052] It should be noted that because the intermediate relay is a mechanical structure, the relay action time takes tens of milliseconds. When the power-off delay output time is less than the relay action time, it will cause the load to have a short power-off restart. In order to avoid power-off restart, a storage capacitor can be provided, such as Figure 3 As shown, the energy storage capacitor C is connected between the output end of the second diode switching unit DK2 and the negative electrode of the load. During the power circuit switching delay period between the first energy storage cabinet and the backup power supply through the first intermediate relay KM1, the energy storage capacitor C supports the DC load power supply to prevent the load from powering off and restarting.

[0053] The minimum capacity of the energy storage capacitor C meets the requirement: C = 2 × P × t / (U1 2 -U2 2 ), where C is the capacity of the energy storage capacitor (in mF), P is the power of the DC load (in W), t is the time required for the capacitor to support (in ms); U1 is the rated voltage of the DC load for normal operation (in V), and U2 is the minimum voltage of the DC load for normal operation (in V).

[0054] Optionally, the first DC / DC module may further include an operating voltage protection unit, which is used to stop outputting direct current when the output voltage of the first DC / DC module is less than a voltage threshold, and the voltage threshold is greater than an undervoltage protection value of the battery.

[0055] The working voltage protection unit sets the lower limit value (i.e., voltage threshold) of the power supply working voltage of the first DC / DC module according to the capacity configuration of different batteries. The lower limit value can be slightly larger than the battery undervoltage protection value, that is, the first DC / DC module stops output before the battery performs undervoltage protection, so as to prevent the battery from running out of power.

[0056] Optionally, a self-locking button is provided on the loop where the positive output terminal of the first DC / DC module is located, and the self-locking button is used to provide a black start function and an emergency shutdown function.

[0057] like Figure 3As shown, the self-locking button SB2 is always closed under normal working conditions and is only used to disconnect or close the output circuit of the first DC / DC module, control the disconnection and conduction of the output circuit of the first DC / DC module, perform emergency control or maintenance, or perform a black start of part of the circuit.

[0058] It should be noted that if the capacity of a single contact of the relay does not meet the load current requirements, it can be expanded by connecting multiple contacts in parallel to meet the requirements, such as Figure 3 As shown in the figure, the number of the first delayed opening and closing contacts KT1-1 of KT1 is two, and it can also be drawn as one or more than two in parallel. The contacts drawn in the accompanying drawings do not represent a limit on the number of contacts, and can be selected according to actual needs, and there is no limit on the specific number.

[0059] It is understandable that the first AC / DC module and the first DC / DC module also need to be grounded, such as Figure 3 As shown in the figure, both the first AC / DC module and the first DC / DC module in this embodiment and subsequent embodiments need to be grounded, which will not be described separately.

[0060] It should be noted that when the AC mains of the first energy storage cabinet fails, the AC mains of the backup power supply also fails, and the battery of the backup power supply provides DC power; when the AC mains line of the first energy storage cabinet fails, the AC mains of the backup power supply is normal, and the AC mains of the backup power supply is converted into DC power for power supply.

[0061] It is also understandable that Figure 4 As shown, when the backup power supply of the first energy storage cabinet is the second energy storage cabinet, that is, the power control system includes the first energy storage cabinet and the second energy storage cabinet at the same time, the first energy storage cabinet and the second energy storage cabinet serve as backup power for each other, and the second energy storage cabinet in the power control system includes:

[0062] A second AC / DC module SP3, a second DC / DC module SP4 and a second control module, the second control module includes a third diode unit DK3, a fourth diode unit DK4, a second local switching unit and a second external switching unit, the second local switching unit includes at least one relay, and the second external switching unit includes at least two relays;

[0063] A first input end of the fourth diode unit DK4 is connected to the positive output end of the second AC / DC module SP3, a second input end of the fourth diode unit DK4 is connected to the positive output end of the second DC / DC module SP4, an output end of the fourth diode unit DK4 is connected to a first input end of the third diode unit DK3, a second input end of the third diode unit DK3 is connected to the output end of the second external switching unit, and an output end of the third diode unit DK3 is connected to the positive electrode of the load;

[0064] The third diode unit DK3 is used to output the voltage of the first input terminal or the voltage of the second input terminal to the positive electrode of the load; the fourth diode unit DK4 is used to output the voltage of the first input terminal or the voltage of the second input terminal to the first input terminal of the third diode unit DK3;

[0065] The second local switching unit is used to control the conduction time between the positive output terminal of the second DC / DC module SP4 and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay;

[0066] The second external switching unit is used to control the conduction time between the positive output terminal of the first energy storage cabinet and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay;

[0067] The second DC / DC module SP4 has a DC input terminal, which is used to connect to the battery. The second DC / DC module SP4 is used to adjust the DC power output by the battery in the second energy storage cabinet to DC power of the target working voltage;

[0068] The second AC / DC module SP3 has an AC input terminal, which is used to be connected to the AC mains. The second AC / DC module SP3 is used to convert the AC mains into DC power of a target working voltage.

[0069] For example, Figure 4As shown, for the second energy storage cabinet, the self-locking button SB2 of the second energy storage cabinet is pressed, the AC mains and the battery of the second energy storage cabinet are input simultaneously, the second AC / DC module SP3 input is energized (the voltage is regulated to be greater than the output voltage of the second DC / DC module SP4), and the output end of the second AC / DC module SP3 outputs the target working voltage. Under the action of the target working voltage, the coil of the first power-off delay relay KT1 is energized, the first delayed disconnection moving contact KT1-1 is closed, and the power supplies of the second AC / DC module SP3 and the second DC / DC module SP4 are simultaneously connected to the fourth diode switching unit DK4. Since the output voltage of the second AC / DC module SP3 is regulated to be greater than the output voltage of the second DC / DC module SP4, the first input end V1 to the output end V0 of the fourth diode switching unit DK4 is turned on. At this time, the first intermediate relay KM1 is energized, the first normally closed contact is disconnected, and there is no voltage input to the second input end of the third diode switching unit DK3. The third diode switching unit DK3 outputs the voltage of the first input end V1, and the AC mains of the second energy storage cabinet supplies the DC load. When the AC mains power of the second energy storage cabinet is lost or the AC power supply line fails, the coil of the first power-off delay relay KT1 loses power, and the first delayed disconnection contact KT1-1 is disconnected. It automatically disconnects after reaching the preset timing time, controls the backup time of the battery in the second energy storage cabinet, and prevents the battery of the second energy storage cabinet from running out of power. If the AC mains power is restored during the power supply delay process of the second DC / DC module SP4 (i.e., the second DC / DC module supplies power and the preset timing time has not been reached), then after the second AC / DC module SP3 provides voltage to the coil of the first power-off delay relay KT1, the coil of the first power-off delay relay KT1 is energized, and the first delayed disconnection contact KT1-1 of KT1 remains closed. At this time, the output voltage of the second AC / DC module SP3 is higher than the output voltage of the second DC / DC module SP4, and the load is switched to AC mains power supply. When the AC power supply loses power next time, the first power-off delay relay KT1 will be delayed disconnected again, and this cycle will be repeated automatically.

[0070] When the second energy storage cabinet performs the above-mentioned dual power switching, the coil of the first intermediate relay KM1 is energized and works, the first normally closed contact of KM1 is disconnected, and power cannot be drawn from the first energy storage cabinet. When the AC mains and battery of the second energy storage cabinet lose power at the same time, the first intermediate relay KM1 loses power, the first normally closed contact of KM1 closes, and the coil of the first power-on delay relay KT2 is energized. At this time, the power is supplied by the first energy storage cabinet. When the preset timing length of KT2 is reached, the first delayed disconnecting moving breaking contact KT2-2 is automatically disconnected, controlling the backup power time provided by the first energy storage cabinet for the second energy storage cabinet, preventing the battery of the first energy storage cabinet from running out of power, improving the safety and reliability of the power control system, and increasing the battery life.

[0071] Similarly, when the structures of the first energy storage cabinet and the second energy storage cabinet are the same, the working process of the second energy storage cabinet is similar to that of the first energy storage cabinet, except that the backup power supply of the second energy storage cabinet is provided by the first energy storage cabinet, and the backup power supply of the first energy storage cabinet is provided by the second energy storage cabinet, and other parts are the same. When there are a first energy storage cabinet and a second energy storage cabinet with the same structure, and the first energy storage cabinet and the second energy storage cabinet serve as backup power for each other, then their connection relationship is as follows: Figure 4 As shown. Under normal circumstances, the two energy storage cabinets (the first energy storage cabinet and the second energy storage cabinet) work independently and serve as backup for each other. The working principles of the two energy storage cabinets serving as backup for each other are the same. When the power supply of one energy storage cabinet fails, the power supply of the other energy storage cabinet serves as backup, and the backup time is controlled to prevent the battery from running out of power.

[0072] In a possible implementation, Figure 5 As shown, the first local switching unit 132 includes a first intermediate relay KM1 and a first power-on delay relay KT1, the contact of the first intermediate relay KM1 is a first normally closed contact, and the contact of the first power-on delay relay KT1 is a first delayed disconnection contact KT1-2; the first external switching unit 133 includes an energy storage capacitor C, a second power-on delay relay KT2 and a second intermediate relay KM2, the contact of the second power-on delay relay KT2 is a second delayed disconnection contact KT2-1, and the contact of the second intermediate relay KM2 is a second normally closed contact;

[0073] The two ends of the coil in the first intermediate relay KM1 are respectively connected to the positive and negative output terminals of the first AC / DC module;

[0074] The first end of the first normally closed contact is connected to the positive output end of the first DC / DC module, and the second end of the first normally closed contact is connected to the first end of the coil of the first power-on delay relay KT1 and the first end of the first delayed opening break contact KT1-2;

[0075] The second end of the first delayed breaking contact KT1-2 is connected to the second input end of the second diode unit DK2;

[0076] The second end of the coil of the first power-on delay relay KT1 is connected to the negative output end of the first DC / DC module, the first end of the second intermediate relay KM2, the first end of the energy storage capacitor C, the second end of the coil of the second power-on delay relay KT2, the negative output end of the standby power supply, and the negative pole of the load;

[0077] The first end of the coil in the second power-on delay relay KT2 is connected to the second end of the second normally closed contact and the first end of the second delayed opening break contact KT2-1;

[0078] A first end of the second normally closed contact is connected to the positive output end of the backup power supply;

[0079] The second end of the second delayed-off break contact KT2-1 is connected to the second input end of the first diode unit DK1; the second end of the second intermediate relay KM2 is connected to the second end of the energy storage capacitor C, the first input end of the first diode unit DK1, and the output end of the second diode unit DK2;

[0080] The first end of the second normally closed contact is connected to the positive output end of the backup power supply.

[0081] For example, Figure 5 As shown, the self-locking button SB2 is pressed, the AC mains and the battery of the first energy storage cabinet are input at the same time, the first AC / DC module SP1 input is energized (the voltage adjustment is greater than the DC / DC output voltage), and the power supplies of the first AC / DC module SP1 and the first DC / DC module SP2 are simultaneously connected to the second diode switching unit DK2. Since the output voltage of the first AC / DC module SP1 is adjusted to be greater than the output voltage of the first DC / DC module SP2, the first input terminal V1 to the output terminal V0 in the second diode switching unit DK2 is turned on, and the output terminal of the first AC / DC module SP1 outputs the target working voltage. Under the action of the target working voltage, the coil of the first intermediate relay KM1 is energized, the first normally closed contact is disconnected, the output of the first DC / DC module SP2 is interrupted, the first power-on delay relay KT1 is de-energized, and the timing is not counted. The first delayed disconnection breaking contact KT1-2 is normally closed, and the AC mains of the first energy storage cabinet supplies the DC load. When the AC mains fails, the first intermediate relay KM1 loses power, the first normally closed contact closes, the first power-on delay relay KT1 is powered, and the battery of the first energy storage cabinet supplies the DC load, and the timing starts. After the timing reaches the preset timing length, the first delayed disconnection contact KT1-2 is disconnected, and the first DC / DC module SP2 stops supplying power to the DC load, limiting the backup time of the battery in the first energy storage cabinet and preventing the battery of the first energy storage cabinet from running out of power. If the AC mains is restored during the timing of the first power-on delay relay KT1, the coil of the first intermediate relay KM1 is powered, the first normally closed contact of KM1 is disconnected, the coil of the first power-on delay relay KT1 loses power, and the first delayed disconnection contact KT1-2 is normally closed. At this time, the first AC / DC module SP1 switches to power the load. When the AC power fails next time, the first power-on delay relay KT1 will start timing and delay disconnection again, and this cycle will repeat automatically.

[0082] When the first energy storage cabinet performs the above-mentioned dual power switching, the coil of the second intermediate relay KM2 is energized and works, and the second normally closed contact of KM2 is disconnected, and power cannot be drawn from the backup power supply. When the AC mains and battery of the first energy storage cabinet lose power at the same time, the second intermediate relay KM2 loses power, the second normally closed contact of KM2 closes, and the coil of the second power-on delay relay KT2 is energized. At this time, the backup power supply is switched to power. When the preset timing length of KT2 is reached, the second delayed disconnecting moving breaking contact KT2-1 is automatically disconnected, controlling the backup power supply time provided by the backup power supply to the first energy storage cabinet, preventing the backup power supply battery from running out of power, improving the safety and reliability of the power control system, and increasing the battery life.

[0083] The function of the first diode unit DK1 is to isolate the power output of the first energy storage cabinet from the power output of the backup power supply to prevent the two power supplies from being connected in parallel, thereby avoiding repeated actions of the second intermediate relay KM2. The function of the second diode unit DK2 is to isolate the main power output of the first AC / DC module from the backup power output of the first DC / DC module to prevent the two power supplies from being connected in parallel, thereby avoiding repeated actions of the first intermediate relay KM1. It is understandable that in this embodiment, the coil of the first intermediate relay KM1 can also be directly connected to the LN ends of the AC mains, and only the coil operating voltage needs to be modified during selection, and the second diode unit DK2 can be cancelled at this time.

[0084] It should be noted that because the intermediate relay is a mechanical structure, the relay action time takes tens of milliseconds. When the power-off delay output time is less than the relay action time, it will cause the load to have a short power-off restart. In order to avoid power-off restart, a storage capacitor can be provided, such as Figure 5 As shown, the energy storage capacitor C is connected between the output end of the second diode switching unit DK2 and the negative electrode of the load. During the power circuit switching delay period between the first energy storage cabinet and the backup power supply through the second intermediate relay KM2, the energy storage capacitor C supports the DC load power supply to avoid power failure and restart of the load.

[0085] The minimum capacity of the energy storage capacitor C meets the requirement: C = 2 × P × t / (U1 2 -U2 2 ), where C is the capacity of the energy storage capacitor (in mF), P is the power of the DC load (in W), t is the time required for the capacitor to support (in ms); U1 is the rated voltage for the normal operation of the DC load (in V), and U2 is the minimum voltage for the normal operation of the DC load (in V). The first intermediate relay KM1 and the second intermediate relay KM2 can be replaced by solid-state relays to achieve the same function. When replaced by solid-state relays, the energy storage capacitor C can be eliminated because the action time of the solid-state relay is very short.

[0086] Optionally, the first DC / DC module may further include an operating voltage protection unit, which is used to stop outputting direct current when the output voltage of the first DC / DC module is less than a voltage threshold, and the voltage threshold is greater than an undervoltage protection value of the battery.

[0087] The working voltage protection unit sets the lower limit value (i.e., voltage threshold) of the power supply working voltage of the first DC / DC module according to the capacity configuration of different batteries. The lower limit value can be slightly larger than the battery undervoltage protection value, that is, the first DC / DC module stops output before the battery performs undervoltage protection, so as to prevent the battery from running out of power.

[0088] Optionally, a self-locking button is provided on the loop where the positive output terminal of the first DC / DC module is located, and the self-locking button is used to provide a black start function and an emergency shutdown function.

[0089] like Figure 5 As shown, the self-locking button SB2 is always closed under normal working conditions and is only used to disconnect or close the output circuit of the first DC / DC module, control the disconnection and conduction of the output circuit of the first DC / DC module, perform emergency control or maintenance, or perform a black start of part of the circuit.

[0090] It should be noted that if the capacity of a single contact of the relay does not meet the load current requirements, it can be expanded by connecting multiple contacts in parallel to meet the requirements, such as Figure 5 As shown, the number of the first delayed opening and closing contacts KT1-1 of KT1 in the figure is two, and it can also be drawn as one or more in parallel; the number of the second delayed opening and closing contacts KT2-1 of KT2 in the figure is two, and it can also be drawn as one or more in parallel; the two contacts drawn in the figure; the number of the first normally closed contacts of KM1 in the figure is two, and it can also be drawn as one or more in parallel, and the number of the second normally closed contacts of KM2 in the figure is two, and it can also be drawn as one or more in parallel; drawing contacts in the drawings does not represent a limitation on the number of contacts, and they can be selected according to actual needs, and the specific number is not limited.

[0091] It should be noted that when the AC mains of the first energy storage cabinet fails, the AC mains of the backup power supply also fails, and the battery of the backup power supply provides DC power; when the AC mains line of the first energy storage cabinet fails, the AC mains of the backup power supply is normal, and the AC mains of the backup power supply is converted into DC power for power supply.

[0092] It is also understandable that Figure 6 As shown, when the backup power supply of the first energy storage cabinet is the second energy storage cabinet, that is, the power control system includes the first energy storage cabinet and the second energy storage cabinet at the same time, the first energy storage cabinet and the second energy storage cabinet serve as backup power for each other, and the second energy storage cabinet in the power control system includes:

[0093] A second AC / DC module SP3, a second DC / DC module SP4 and a second control module, the second control module includes a third diode unit DK3, a fourth diode unit DK4, a second local switching unit and a second external switching unit, the second local switching unit includes at least one relay, and the second external switching unit includes at least two relays;

[0094] A first input end of the fourth diode unit DK4 is connected to the positive output end of the second AC / DC module SP3, a second input end of the fourth diode unit DK4 is connected to the positive output end of the second DC / DC module SP4, an output end of the fourth diode unit DK4 is connected to a first input end of the third diode unit DK3, a second input end of the third diode unit DK3 is connected to the output end of the second external switching unit, and an output end of the third diode unit DK3 is connected to the positive electrode of the load;

[0095] The third diode unit DK3 is used to output the voltage of the first input terminal or the voltage of the second input terminal to the positive electrode of the load; the fourth diode unit DK4 is used to output the voltage of the first input terminal or the voltage of the second input terminal to the first input terminal of the third diode unit DK3;

[0096] The second local switching unit is used to control the conduction time between the positive output terminal of the second DC / DC module SP4 and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay;

[0097] The second external switching unit is used to control the conduction time between the positive output terminal of the first energy storage cabinet and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay;

[0098] The second DC / DC module SP4 has a DC input terminal, which is used to connect to the battery. The second DC / DC module SP4 is used to adjust the DC power output by the battery in the second energy storage cabinet to DC power of the target working voltage;

[0099] The second AC / DC module SP3 has an AC input terminal, which is used to be connected to the AC mains. The second AC / DC module SP3 is used to convert the AC mains into DC power of a target working voltage.

[0100] For example, Figure 6As shown, for the second energy storage cabinet, the self-locking button SB2 is pressed, the AC mains and the battery of the second energy storage cabinet are input at the same time, the second AC / DC module SP3 input is energized (the voltage is adjusted to be greater than the output voltage of the second DC / DC module SP4), and the power supplies of the second AC / DC module SP3 and the second DC / DC module SP4 are simultaneously connected to the fourth diode switching unit DK4. Since the output voltage of the second AC / DC module SP3 is adjusted to be greater than the output voltage of the second DC / DC module SP4, the first input terminal V1 to the output terminal V0 in the fourth diode switching unit DK4 is turned on, and the output terminal of the second AC / DC module SP3 outputs the target working voltage. Under the action of the target working voltage, the coil of the first intermediate relay KM1 is energized, the first normally closed contact is disconnected, the output of the second DC / DC module SP4 is interrupted, the first power-on delay relay KT1 is de-energized, and the timing is not stopped. The first delayed disconnection breaking contact KT1-2 is normally closed, and the AC mains of the second energy storage cabinet supplies the DC load. When the AC mains fails, the first intermediate relay KM1 loses power, the first normally closed contact closes, the first power-on delay relay KT1 is powered, and the battery in the second energy storage cabinet supplies the DC load, and the timing starts. After the preset timing time is reached, the first delayed disconnection contact KT1-2 is disconnected, and the second DC / DC module SP4 stops supplying power to the DC load, limiting the backup time of the battery in the second energy storage cabinet and preventing the battery in the second energy storage cabinet from running out of power. If the AC mains is restored during the timing of the first power-on delay relay KT1, the coil of the first intermediate relay KM1 is powered, the first normally closed contact of KM1 is disconnected, the coil of the first power-on delay relay KT1 loses power, and the first delayed disconnection contact KT1-2 is normally closed. At this time, the load is powered by the second AC / DC module SP3. When the AC power fails next time, the first power-on delay relay KT1 will start timing and delay disconnection again, and this cycle will repeat automatically. When the second energy storage cabinet performs the above-mentioned dual power switching, the coil of the second intermediate relay KM2 is energized and works, and the second normally closed contact of KM2 is disconnected, and power cannot be drawn from the first energy storage cabinet. When the AC mains and battery of the second energy storage cabinet lose power at the same time, the second intermediate relay KM2 loses power, the second normally closed contact of KM2 closes, and the coil of the second power-on delay relay KT2 is energized. At this time, the power is supplied by the first energy storage cabinet. When the preset timing length of KT2 is reached, the second delayed disconnecting moving breaking contact KT2-1 is automatically disconnected, controlling the backup power time provided by the battery of the first energy storage cabinet for the second energy storage cabinet, preventing the battery of the first energy storage cabinet from running out of power, improving the safety and reliability of the power control system, and increasing the battery life.

[0101] Similarly, when the structures of the first energy storage cabinet and the second energy storage cabinet are the same, the working process of the second energy storage cabinet is similar to that of the first energy storage cabinet, except that the backup power supply of the second energy storage cabinet is provided by the first energy storage cabinet, and the backup power supply of the first energy storage cabinet is provided by the second energy storage cabinet, and other parts are the same. When there are a first energy storage cabinet and a second energy storage cabinet with the same structure, and the first energy storage cabinet and the second energy storage cabinet serve as backup power for each other, then their connection relationship is as follows: Figure 6 As shown. Under normal circumstances, the two energy storage cabinets (the first energy storage cabinet and the second energy storage cabinet) work independently and serve as backup for each other. The working principles of the two energy storage cabinets serving as backup for each other are the same. When the power supply of one energy storage cabinet fails, the power supply of the other energy storage cabinet serves as backup, and the backup time is controlled to prevent the battery from running out of power.

[0102] In a possible implementation, Figure 7 As shown, the first local switching unit 132 includes a battery management system BMS, a first intermediate relay KM1 and a second intermediate relay KM2, the contact of the first intermediate relay KM1 is a first normally open contact, and the contact of the second intermediate relay KM2 is a first normally closed contact; the first external switching unit 133 includes an energy storage capacitor C, a first power-on delay relay KT1 and a third intermediate relay KM3, the contact of the first power-on delay relay KT1 is a first delayed disconnection contact KT1-2, and the contact of the third intermediate relay KM3 is a second normally closed contact;

[0103] The two ends of the coil in the first intermediate relay KM1 are respectively connected to the positive and negative output terminals of the first AC / DC module;

[0104] Both ends of the first normally open contact are connected to the digital input terminals of the BMS;

[0105] The coil of the second intermediate relay KM2 is connected to the high-side digital output terminal of the BMS, and the output voltage of the high-side output terminal is the power supply voltage of the BMS;

[0106] A first end of the second normally closed contact is connected to the positive output end of the first DC / DC module, and a second end of the second normally closed contact is connected to the second input end of the second diode unit DK2;

[0107] The first end of the coil in the first power-on delay relay KT1 is connected to the second end of the second normally closed contact and the first end of the first delayed opening break contact KT1-2, and the second end of the coil in the first power-on delay relay KT1 is connected to the negative output end of the backup power supply, the negative output end of the first DC / DC module, the first end of the third intermediate relay KM3, the first end of the energy storage capacitor C, and the negative electrode of the load;

[0108] The second end of the first delayed breaking contact KT1-2 is connected to the second input end of the first diode unit DK1; the second end of the third intermediate relay KM3 is connected to the second end of the energy storage capacitor, the first input end of the first diode unit DK1, and the output end of the second diode unit DK2;

[0109] The first end of the second normally closed contact is connected to the positive output end of the backup power supply.

[0110] For example, Figure 7 As shown, the coil of the second intermediate relay KM2 is connected to the high-side output terminal DO of the BMS, and the voltage when DO is output is the power supply voltage of the BMS. Press the self-locking button SB2, at this time, the coil of KM2 is de-energized, the first normally closed contact of KM2 is closed, the AC mains and the battery of the first energy storage cabinet are input at the same time, and the power supplies of the first AC / DC module SP1 and the first DC / DC module SP2 are simultaneously connected to the second diode unit DK2. Since the output voltage of the first AC / DC module SP1 is adjusted to be greater than the output voltage of the first DC / DC module SP2, the first input terminal V1 to the output terminal V0 in the second diode switching unit DK2 is turned on, and the AC mains of the first energy storage cabinet supplies the DC load. When the AC mains loses power, the digital input terminal DI of the BMS collects the signal that the first normally open contact changes from the closed position to the open position, and the first DC / DC module SP2 supplies power to the DC load, without delay switching. When the BMS detects that the contact signal of KM1 changes from the closed position to the open position, the BMS starts timing internally. After the preset timing duration is reached, the high-side output terminal DO of the BMS outputs a voltage, the second intermediate relay KM2 is energized, and the corresponding first normally closed contact is controlled to be disconnected. The battery of the first energy storage cabinet stops supplying power to the DC load, and the backup time of the battery in the first energy storage cabinet is controlled to prevent the battery of the first energy storage cabinet from running out of power. If the first DC / DC module is supplying power, and the AC mains is restored during the BMS timing, the BMS detects that the first normally closed contact (the contact of KM1) changes from the open position to the closed position, stops timing and resets the current timing. At this time, the output voltage of the first AC / DC module is high, and it automatically switches to AC mains power supply, and this cycle repeats automatically. When the first energy storage cabinet performs the above-mentioned dual power switching, the third intermediate relay KM3 is energized and works, and the second normally closed contact corresponding to KM3 is disconnected, and it cannot draw power from the backup power supply. When the AC mains and battery of the first energy storage cabinet lose power at the same time, the third intermediate relay KM3 loses power, the second normally closed contact of KM3 closes, and the first power-on delay relay KT1 is energized and works. At this time, the backup power supply is switched to power. When the preset timing length of the first power-on delay relay KT1 is reached, the first delayed disconnecting moving-breaking contact KT1-2 is automatically disconnected, controlling the backup power time provided by the backup power supply to the first energy storage cabinet, preventing the backup power supply battery from running out of power, improving the safety and reliability of the power control system, and increasing the battery life.

[0111] The function of the first diode unit DK1 is to isolate the power output of the first energy storage cabinet from the power output of the backup power supply to prevent the two power supplies from being connected in parallel, thereby avoiding repeated actions of the first intermediate relay KM1. The function of the second diode unit DK2 is to isolate the main power output of the first AC / DC module from the backup power output of the first DC / DC module to prevent the two power supplies from being connected in parallel, thereby avoiding repeated actions of the first power-off delay relay KT1. It is understandable that in this embodiment, the coil of the first power-off delay relay KT1 can also be directly connected to the LN ends of the AC mains, and only the coil operating voltage needs to be modified during selection, and the second diode unit DK2 can be cancelled at this time.

[0112] It should be noted that because the intermediate relay is a mechanical structure, the relay action time takes tens of milliseconds. When the power-off delay output time is less than the relay action time, it will cause the load to have a short power-off restart. In order to avoid power-off restart, a storage capacitor can be provided, such as Figure 7 As shown, the energy storage capacitor C is connected between the output end of the second diode switching unit DK2 and the negative electrode of the load. During the power circuit switching delay period between the first energy storage cabinet and the backup power supply through the third intermediate relay KM3, the energy storage capacitor C supports the DC load power supply to prevent the load from powering off and restarting.

[0113] The minimum capacity of the energy storage capacitor C meets the requirement: C = 2 × P × t / (U1 2 -U2 2 ), where C is the capacity of the energy storage capacitor (in mF), P is the power of the DC load (in W), t is the time required for the capacitor to support (in ms); U1 is the rated voltage of the DC load for normal operation (in V), and U2 is the minimum voltage of the DC load for normal operation (in V).

[0114] Among them, the first intermediate relay, the second intermediate relay and the third intermediate relay can also be replaced by solid-state relays or other types of relays to achieve the same functions, and the details are not repeated here.

[0115] It should be noted that the contact of the second intermediate relay KM2 can also be a second normally open contact. Then, when the contact of the first intermediate relay KM1 changes from open position to closed position, the input terminal DI of the BMS receives a signal, and the output terminal DO of the BMS outputs a DC24V voltage, so that the second normally open contact of KM2 is closed, and the power supplies of the first AC / DC module SP1 and the first DC / DC module SP2 are simultaneously connected to the second diode unit DK2. Since the output voltage of the first AC / DC module SP1 is adjusted to be greater than the output voltage of the first DC / DC module SP2, the V1-V0 loop in the second diode unit DK2 is turned on, and the AC mains supplies power to the DC load. When the AC mains loses power, the first DC / DC module SP2 supplies power to the DC load, and there is no delay switching. At the same time, the BMS detects that the contact signal of the first intermediate relay KM1 changes from closed to open, and the BMS starts timing internally. After the preset timing duration is reached, the high-side output DO of the BMS stops outputting DC24V voltage, the coil of the second intermediate relay KM2 loses power, the second normally open contact of KM2 is disconnected, and the battery stops supplying power to the DC load, thereby controlling the battery backup time and preventing the battery from running out of power.

[0116] Optionally, the first DC / DC module may further include an operating voltage protection unit, which is used to stop outputting direct current when the output voltage of the first DC / DC module is less than a voltage threshold, and the voltage threshold is greater than an undervoltage protection value of the battery.

[0117] The working voltage protection unit sets the lower limit value (i.e., voltage threshold) of the power supply working voltage of the first DC / DC module according to the capacity configuration of different batteries. The lower limit value can be slightly larger than the battery undervoltage protection value, that is, the first DC / DC module stops output before the battery performs undervoltage protection, so as to prevent the battery from running out of power.

[0118] Optionally, a self-locking button is provided on the loop where the positive output terminal of the first DC / DC module is located, and the self-locking button is used to provide a black start function and an emergency shutdown function.

[0119] like Figure 7 As shown, the self-locking button SB2 is always closed under normal working conditions and is only used to disconnect or close the output circuit of the first DC / DC module, control the disconnection and conduction of the output circuit of the first DC / DC module, perform emergency control or maintenance, or perform a black start of part of the circuit.

[0120] It should be noted that if the capacity of a single contact of the relay does not meet the load current requirements, it can be expanded by connecting multiple contacts in parallel to meet the requirements, such as Figure 7As shown in the figure, the number of the third normally closed contacts of KM2 is two, and it can also be drawn as one or more in parallel; the number of the first delayed-opening moving-breaking contacts KT1-2 of KT1 is two, and it can also be drawn as one or more in parallel; the contacts shown in the accompanying drawings do not represent a limitation on the number of contacts, but are only a schematic diagram of the positions of the contacts, which can be selected according to actual needs, and the specific number is not limited. KM3 and KM1 are similar, and the details will not be repeated here.

[0121] It should be noted that when the AC mains of the first energy storage cabinet fails, the AC mains of the backup power supply also fails, and the battery of the backup power supply provides DC power; when the AC mains line of the first energy storage cabinet fails, the AC mains of the backup power supply is normal, and the AC mains of the backup power supply is converted into DC power for power supply.

[0122] It is also understandable that Figure 8 As shown, when the backup power supply of the first energy storage cabinet is the second energy storage cabinet, that is, the power control system includes the first energy storage cabinet and the second energy storage cabinet at the same time, the first energy storage cabinet and the second energy storage cabinet serve as backup power for each other, and the second energy storage cabinet in the power control system includes:

[0123] A second AC / DC module SP3, a second DC / DC module SP4 and a second control module, the second control module includes a third diode unit DK3, a fourth diode unit DK4, a second local switching unit and a second external switching unit, the second local switching unit includes at least one relay, and the second external switching unit includes at least two relays;

[0124] A first input end of the fourth diode unit DK4 is connected to the positive output end of the second AC / DC module SP3, a second input end of the fourth diode unit DK4 is connected to the positive output end of the second DC / DC module SP4, an output end of the fourth diode unit DK4 is connected to a first input end of the third diode unit DK3, a second input end of the third diode unit DK3 is connected to the output end of the second external switching unit, and an output end of the third diode unit DK3 is connected to the positive electrode of the load;

[0125] The third diode unit DK3 is used to output the voltage of the first input terminal or the voltage of the second input terminal to the positive electrode of the load; the fourth diode unit DK4 is used to output the voltage of the first input terminal or the voltage of the second input terminal to the first input terminal of the third diode unit DK3;

[0126] The second local switching unit is used to control the conduction time between the positive output terminal of the second DC / DC module SP4 and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay;

[0127] The second external switching unit is used to control the conduction time between the positive output terminal of the first energy storage cabinet and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay;

[0128] The second DC / DC module SP4 has a DC input terminal, which is used to connect to the battery. The second DC / DC module SP4 is used to adjust the DC power output by the battery in the second energy storage cabinet to DC power of the target working voltage;

[0129] The second AC / DC module SP3 has an AC input terminal, which is used to be connected to the AC mains. The second AC / DC module SP3 is used to convert the AC mains into DC power of a target working voltage.

[0130] For example, Figure 8As shown, for the second energy storage cabinet, the coil of the second intermediate relay KM2 is connected to the high-side output terminal DO of the BMS, and the voltage when DO is output is the power supply voltage of the BMS. Press the self-locking button SB2, at this time, the coil of KM2 is de-energized, the first normally closed contact of KM2 is closed, the AC mains and the battery of the second energy storage cabinet are input at the same time, and the power supply of the second AC / DC module SP3 and the second DC / DC module SP4 are simultaneously connected to the fourth diode unit DK4. Since the output voltage of the second AC / DC module SP3 is adjusted to be greater than the output voltage of the second DC / DC module SP4, the first input terminal V1 to the output terminal V0 in the fourth diode switching unit DK4 is turned on, and the AC mains of the second energy storage cabinet supplies the DC load. When the AC mains loses power, the digital input terminal DI of the BMS collects the signal that the first normally open contact changes from the closed position to the open position, and the second DC / DC module SP4 supplies power to the DC load, without delay switching. When the BMS detects that the contact signal of KM1 changes from the closed position to the open position, the BMS starts timing internally. After the preset timing duration is reached, the high-side output terminal DO of the BMS outputs a voltage, the second intermediate relay KM2 is energized, and the corresponding first normally closed contact is controlled to be disconnected. The battery of the second energy storage cabinet stops supplying power to the DC load, and the backup time of the battery in the second energy storage cabinet is controlled to prevent the battery of the second energy storage cabinet from running out of power. If the second DC / DC module SP4 supplies power, and the AC mains is restored during the BMS timing, the BMS detects that the first normally closed contact (the contact of KM1) changes from the open position to the closed position, stops timing and resets the current timing. At this time, the output voltage of the second AC / DC module SP3 is high, and it automatically switches to AC mains power supply, and this cycle repeats automatically. When the second energy storage cabinet performs the above-mentioned dual power switching, the third intermediate relay KM3 is energized and works, and the second normally closed contact corresponding to KM3 is disconnected, and it cannot draw power from the first energy storage cabinet. When the AC mains and battery of the second energy storage cabinet lose power at the same time, the third intermediate relay KM3 loses power, the second normally closed contact of KM3 closes, and the first power-on delay relay KT1 is energized and works. At this time, the first energy storage cabinet supplies power. When the preset timing length of the first power-on delay relay KT1 is reached, the first delayed disconnecting moving-breaking contact KT1-2 is automatically disconnected, controlling the backup power time provided by the first energy storage cabinet for the second energy storage cabinet, preventing the battery of the first energy storage cabinet from running out of power, improving the safety and reliability of the power control system, and increasing the battery life.

[0131] Similarly, when the structures of the first energy storage cabinet and the second energy storage cabinet are the same, the working process of the second energy storage cabinet is similar to that of the first energy storage cabinet, except that the backup power supply of the second energy storage cabinet is provided by the first energy storage cabinet, and the backup power supply of the first energy storage cabinet is provided by the second energy storage cabinet, and other parts are the same. When there are a first energy storage cabinet and a second energy storage cabinet with the same structure, and the first energy storage cabinet and the second energy storage cabinet serve as backup power for each other, then their connection relationship is as follows: Figure 8As shown. Under normal circumstances, the two energy storage cabinets (the first energy storage cabinet and the second energy storage cabinet) work independently and serve as backup for each other. The working principles of the two energy storage cabinets serving as backup for each other are the same. When the power supply of one energy storage cabinet fails, the power supply of the other energy storage cabinet serves as backup, and the backup time is controlled to prevent the battery from running out of power.

[0132] In a possible implementation, Fig. 9 As shown, the first local switching unit 132 includes a battery management system BMS, a first intermediate relay KM1 and a DC circuit breaker QF, and the contact of the first intermediate relay KM1 is a first normally open contact; the first external switching unit 133 includes an energy storage capacitor C, a first power-on delay relay KT1 and a second intermediate relay KM2, and the contact of the first power-on delay relay KT1 is a first delayed disconnection contact KT1-2, and the contact of the second intermediate relay KM2 is a first normally closed contact;

[0133] The two ends of the coil in the first intermediate relay KM1 are respectively connected to the positive and negative output terminals of the first AC / DC module;

[0134] Both ends of the first normally open contact are connected to the digital input terminals of the BMS;

[0135] The positive output end of the first DC / DC module is connected to the second input end of the second diode unit DK2 after passing through the DC circuit breaker QF, and the negative output end of the first DC / DC module is connected to the first end of the second intermediate relay KM2, the first end of the energy storage capacitor C, the second end of the coil in the first power-on delay relay KT1, the negative output end of the standby power supply, and the negative pole of the load after passing through the DC circuit breaker QF;

[0136] The first end of the coil in the first power-on delay relay KT1 is connected to the second end of the first normally closed contact and the first end of the first delayed opening break contact KT1-2;

[0137] The second end of the first delayed breaking contact KT1-2 is connected to the second input end of the first diode unit DK1; the second end of the second intermediate relay KM2 is connected to the second end of the energy storage capacitor C, the first input end of the first diode unit DK1, and the output end of the second diode unit DK2;

[0138] The first end of the first normally closed contact is connected to the positive output end of the backup power supply.

[0139] For example, Fig. 9As shown, the first normally open contact of the first intermediate relay KM1 is connected to the digital input terminal DI of the BMS. Press the self-locking button SB2 to manually close the DC circuit breaker QF, and the AC mains and battery are input at the same time. The AC mains is used as an AC power supply to input the first AC / DC module SP1, and the battery of the first energy storage cabinet is used as a DC power supply to input the first DC / DC module SP2. The output terminal of the first AC / DC module SP1 outputs the target working voltage, the coil of the first intermediate relay KM1 is energized, and the first normally open contact corresponding to the first intermediate relay KM1 is closed. The digital input terminal DI of the BMS collects the signal that the first normally open contact changes from the open position to the closed position. At this time, the electric operator of the DC circuit breaker QF is energized to prepare for the circuit breaker action. The first AC / DC module SP1 and the first DC / DC module SP2 are simultaneously connected to the second diode unit DK2. Since the output voltage of the first AC / DC module SP1 is adjusted to be greater than the output voltage of the first DC / DC module SP2, the V1-V0 circuit of the second diode unit DK2 is turned on, and the AC mains supplies power to the DC load. When the AC mains fails, the first DC / DC module SP2 is switched to supply power to the DC load without delay. At the same time, the DI of the BMS detects the signal that the contact of the first intermediate relay KM1 changes from the closed position to the open position, and the BMS starts timing. After the preset timing duration is reached, the BMS's opening control DO output port controls the QF electric operator to open the gate, and the first DC / DC module SP2 stops supplying power to the DC load, thereby controlling the battery backup time and preventing the battery from running out of power. If the DC / DC module SP2 is supplying power, and the AC mains is restored during the BMS timing, the BMS detects that the contact of the first intermediate relay KM1 changes from the open position to the closed position, stops timing and resets the current timing, and the BMS's closing control DO output port controls the QF electric operator to close the gate. At this time, the output voltage of the first AC / DC module SP1 is higher than the output voltage of the first DC / DC module SP2, and the load automatically switches to AC mains power. When the AC power fails next time, the above process is repeated, and the cycle is repeated automatically. When the first energy storage cabinet performs the above-mentioned dual power switching, the second intermediate relay KM2 is powered on and works, and the second normally closed contact of KM2 is disconnected, and power cannot be drawn from the backup power supply. When the AC mains and battery of the first energy storage cabinet lose power at the same time, the third intermediate relay KM3 loses power, the first normally closed contact of KM3 closes, and the first power-on delay relay KT1 is powered on and works. At this time, the backup power supply is switched to power. When the preset timing length of the first power-on delay relay KT1 is reached, the first delay disconnecting moving breaking contact KT1-2 is automatically disconnected, controlling the backup power supply time provided by the backup power supply to the first energy storage cabinet, preventing the backup power supply battery from running out of power, improving the safety and reliability of the power control system, and increasing the battery life.

[0140] The function of the first diode unit DK1 is to isolate the power output of the first energy storage cabinet from the power output of the backup power supply to prevent the two power supplies from being connected in parallel, thereby avoiding repeated actions of the first intermediate relay KM1. The function of the second diode unit DK2 is to isolate the main power output of the first AC / DC module from the backup power output of the first DC / DC module to prevent the two power supplies from being connected in parallel, thereby avoiding repeated actions of the first power-off delay relay KT1. It is understandable that in this embodiment, the coil of the first intermediate relay KM1 can also be directly connected to the LN ends of the AC mains, and only the coil operating voltage needs to be modified during selection, and the second diode unit DK2 can be cancelled at this time.

[0141] It should be noted that because the intermediate relay is a mechanical structure, the relay action time takes tens of milliseconds. When the power-off delay output time is less than the relay action time, it will cause the load to have a short power-off restart. In order to avoid power-off restart, a storage capacitor can be provided, such as Fig. 9 As shown, the energy storage capacitor C is connected between the output end of the second diode switching unit DK2 and the negative electrode of the load. During the power circuit switching delay period between the first energy storage cabinet and the backup power supply through the second intermediate relay KM2, the energy storage capacitor C supports the DC load power supply to avoid power failure and restart of the load.

[0142] The minimum capacity of the energy storage capacitor C meets the requirement: C = 2 × P × t / (U1 2 -U2 2 ), where C is the capacity of the energy storage capacitor (in mF), P is the power of the DC load (in W), t is the time required for the capacitor to support (in ms); U1 is the rated voltage of the DC load for normal operation (in V), and U2 is the minimum voltage of the DC load for normal operation (in V).

[0143] Among them, the first intermediate relay and the second intermediate relay can also be replaced by solid-state relays or other types of relays to achieve the same function, and the details are not repeated here.

[0144] Optionally, the first DC / DC module may further include an operating voltage protection unit, which is used to stop outputting direct current when the output voltage of the first DC / DC module is less than a voltage threshold, and the voltage threshold is greater than an undervoltage protection value of the battery.

[0145] The working voltage protection unit sets the lower limit value (i.e., voltage threshold) of the power supply working voltage of the first DC / DC module according to the capacity configuration of different batteries. The lower limit value can be slightly larger than the battery undervoltage protection value, that is, before the battery undervoltage protection, the first DC / DC module stops output due to undervoltage protection, thereby preventing the battery from running out of power.

[0146] Optionally, a self-locking button is provided on the loop where the positive output terminal of the first DC / DC module is located, and the self-locking button is used to provide a black start function and an emergency shutdown function.

[0147] like Fig. 9 As shown, the self-locking button SB2 is always closed under normal working conditions and is only used to disconnect or close the output circuit of the first DC / DC module, control the disconnection and conduction of the output circuit of the first DC / DC module, perform emergency control or maintenance, or perform a black start of part of the circuit.

[0148] It should be noted that if the capacity of a single contact of the time delay relay does not meet the load current requirements, it can be expanded by connecting multiple contacts in parallel to meet the requirements, such as Fig. 9 As shown in the figure, the number of the third normally closed contacts of KM2 is two, and it can also be drawn as one or more in parallel; the number of the first delayed opening moving breaking contacts KT1-2 of KT1 is two, and it can also be drawn as one or more in parallel; the contacts shown in the accompanying drawings do not represent a limitation on the number of contacts, but are only a schematic diagram of the positions of the contacts, which can be selected according to actual needs, and the specific number is not limited.

[0149] It should be noted that when the AC mains of the first energy storage cabinet fails, the AC mains of the backup power supply also fails, and the battery of the backup power supply provides DC power; when the AC mains line of the first energy storage cabinet fails, the AC mains of the backup power supply is normal, and the AC mains of the backup power supply is converted into DC power for power supply.

[0150] It is also understandable that Fig.10 As shown, when the backup power supply of the first energy storage cabinet is the second energy storage cabinet, that is, the power control system includes the first energy storage cabinet and the second energy storage cabinet at the same time, the first energy storage cabinet and the second energy storage cabinet serve as backup power for each other, and the second energy storage cabinet in the power control system includes:

[0151] A second AC / DC module SP3, a second DC / DC module SP4 and a second control module, the second control module includes a third diode unit DK3, a fourth diode unit DK4, a second local switching unit and a second external switching unit, the second local switching unit includes at least one relay, and the second external switching unit includes at least two relays;

[0152] A first input end of the fourth diode unit DK4 is connected to the positive output end of the second AC / DC module SP3, a second input end of the fourth diode unit DK4 is connected to the positive output end of the second DC / DC module SP4, an output end of the fourth diode unit DK4 is connected to a first input end of the third diode unit DK3, a second input end of the third diode unit DK3 is connected to the output end of the second external switching unit, and an output end of the third diode unit DK3 is connected to the positive electrode of the load;

[0153] The third diode unit DK3 is used to output the voltage of the first input terminal or the voltage of the second input terminal to the positive electrode of the load; the fourth diode unit DK4 is used to output the voltage of the first input terminal or the voltage of the second input terminal to the first input terminal of the third diode unit DK3;

[0154] The second local switching unit is used to control the conduction time between the positive output terminal of the second DC / DC module SP4 and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay;

[0155] The second external switching unit is used to control the conduction time between the positive output terminal of the first energy storage cabinet and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay;

[0156] The second DC / DC module SP4 has a DC input terminal, which is used to connect to the battery. The second DC / DC module SP4 is used to adjust the DC power output by the battery in the second energy storage cabinet to DC power of the target working voltage;

[0157] The second AC / DC module SP3 has an AC input terminal, which is used to be connected to the AC mains. The second AC / DC module SP3 is used to convert the AC mains into DC power of a target working voltage.

[0158] For example, Fig.10As shown, for the second energy storage cabinet, the first normally open contact of the first intermediate relay KM1 is connected to the digital input terminal DI of the BMS. Press the self-locking button SB2 to manually close the DC circuit breaker QF, and the AC mains and battery are input at the same time. The AC mains is used as an AC power supply to input the second AC / DC module SP3, and the battery of the second energy storage cabinet is used as a DC power supply to input the second DC / DC module SP4. The output terminal of the second AC / DC module SP3 outputs the target working voltage, the coil of the first intermediate relay KM1 is energized, and the first normally open contact corresponding to the first intermediate relay KM1 is closed. The digital input terminal DI of the BMS collects the signal that the first normally open contact changes from the open position to the closed position. At this time, the electric operator of the DC circuit breaker QF is energized to prepare for the circuit breaker action. The second AC / DC module SP3 and the second DC / DC module SP4 are simultaneously connected to the fourth diode unit DK4. Since the output voltage of the second AC / DC module SP3 is adjusted to be greater than the output voltage of the second DC / DC module SP4, the V1-V0 circuit of the fourth diode unit DK4 is turned on, and the AC mains supplies power to the DC load. When the AC mains fails, the second DC / DC module SP4 is switched to supply power to the DC load without delay. At the same time, the DI of the BMS detects the signal that the contact of the first intermediate relay KM1 changes from the closed position to the open position, and the BMS starts timing. After the preset timing duration is reached, the BMS's opening control DO output port controls the QF electric operator to open the gate, and the second DC / DC module SP4 stops supplying power to the DC load, thereby controlling the battery backup time and preventing the battery of the second energy storage cabinet from running out of power. If the second DC / DC module SP4 is powered and the AC mains is restored during the BMS timing, the BMS detects that the contact of the first intermediate relay KM1 changes from the open position to the closed position, stops timing and resets the current timing, and the BMS's closing control DO output port controls the QF electric operator to close the gate. At this time, the output voltage of the second AC / DC module SP3 is higher than the output voltage of the second DC / DC module SP4, and the load automatically switches to AC mains power. When the AC power fails next time, the above process is repeated, and the cycle is repeated automatically. When the second energy storage cabinet performs the above-mentioned dual power switching, the second intermediate relay KM2 is powered on and works, and the second normally closed contact of KM2 is disconnected, and power cannot be drawn from the first energy storage cabinet. When the AC mains and battery of the second energy storage cabinet lose power at the same time, the third intermediate relay KM3 loses power, the first normally closed contact of KM3 closes, and the first power-on delay relay KT1 is powered on and works. At this time, the power is supplied by the first energy storage cabinet. When the preset timing length of the first power-on delay relay KT1 is reached, the first delay disconnecting moving breaking contact KT1-2 is automatically disconnected, controlling the backup power time provided by the first energy storage cabinet for the second energy storage cabinet, preventing the battery of the first energy storage cabinet from running out of power, improving the safety and reliability of the power control system, and improving the battery life.

[0159] Similarly, when the structures of the first energy storage cabinet and the second energy storage cabinet are the same, the working process of the second energy storage cabinet is similar to that of the first energy storage cabinet, except that the backup power supply of the second energy storage cabinet is provided by the first energy storage cabinet, and the backup power supply of the first energy storage cabinet is provided by the second energy storage cabinet, and other parts are the same. When there are a first energy storage cabinet and a second energy storage cabinet with the same structure, and the first energy storage cabinet and the second energy storage cabinet serve as backup power for each other, then their connection relationship is as follows: Fig.10 As shown. Under normal circumstances, the two energy storage cabinets (the first energy storage cabinet and the second energy storage cabinet) work independently and serve as backup for each other. The working principles of the two energy storage cabinets serving as backup for each other are the same. When the power supply of one of the energy storage cabinets fails, the power supply of the other energy storage cabinet serves as backup, and the backup time is controlled to prevent the battery from running out of power. In this embodiment, the BMS is used to stop timing and return to zero when the digital input terminal detects that the first normally open contact changes from the open position to the closed position, and controls the electric operation of the DC circuit breaker to close; the BMS is also used to start timing when the digital input terminal detects that the first normally open contact changes from the closed position to the open position, and controls the electric operation of the DC circuit breaker to open after a preset timing period.

[0160] It can also be understood that the specific structure between the first energy storage cabinet and the second energy storage cabinet can be the same or different, that is, the first local switching unit and the second local switching unit can be the same or different; the first external switching unit and the second external switching unit can be the same or different, and can be combined according to the local switching unit structure and the external switching unit structure provided in this embodiment and subsequent embodiments, and are not limited here. The specific structure of the second local switching unit can refer to the structure of the first local switching unit in any of the above embodiments, and the structure of the second external switching unit can also refer to the structure of the first external switching unit in any of the above embodiments.

[0161] It should be noted that the utility model solves the problem of battery power loss that may be caused by using the battery of the first energy storage cabinet as a backup power supply, and can not only meet the uninterrupted switching of the DC power supply and the AC power supply of the first energy storage cabinet, but also set the backup time of the battery of a single energy storage cabinet to prevent the battery of the first energy storage cabinet from being power-deficient, and can also ensure that when a battery failure occurs in the first energy storage cabinet, resulting in simultaneous power failure of the AC mains and the DC backup power in the first energy storage cabinet, power is taken from the second energy storage cabinet as a backup, which does not affect the normal operation of the power control system, and avoids reducing the service life of the battery of the energy storage cabinet due to the long-term backup power of the battery of the second energy storage cabinet, and improves the safety and reliability of the system.

[0162] The utility model also provides an energy storage system, comprising a power control system and an energy management system in any of the above embodiments, wherein the energy management system is used to perform energy management on batteries of each energy storage cabinet in the power control system.

[0163] In the utility model, a delayed protection function is provided for the battery in the dual power switching circuit of a single energy storage cabinet. During the switching process between the DC power supply and the AC power supply, the battery backup time is set by delaying the opening or closing of the relay contacts to control the length of time the battery supplies power to the load, thereby avoiding the problem of battery power loss caused by long-term battery backup and extending the battery life. At the same time, the uninterrupted switching between the AC power supply and the DC power supply ensures the reliability of the DC load power supply.

[0164] Finally, it should be noted that the above embodiments are only specific implementation methods of the utility model, which are used to illustrate the technical solution of the utility model, rather than to limit it. The protection scope of the utility model is not limited thereto. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art should understand that any technician familiar with the technical field can still modify the technical solution recorded in the above embodiments within the technical scope disclosed by the utility model, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solution of the embodiment of the utility model, and should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model shall be based on the protection scope of the claims.

Claims

1. A power supply control system, characterized in that: The power control system includes a first energy storage cabinet and a backup power supply, wherein the first energy storage cabinet includes: a first AC / DC module, a first DC / DC module and a first control module, wherein the first control module comprises a first diode unit, a first local switching unit and a first external switching unit, wherein the first local switching unit comprises at least one relay, and the first external switching unit comprises at least two relays; The first input end of the first diode unit is connected to the positive output end of the first AC / DC module and the positive output end of the first DC / DC module respectively through the first local switching unit, the second input end of the first diode unit is connected to the output end of the first external switching unit, and the output end of the first diode unit is connected to the positive electrode of the load; The first diode unit is used to output the voltage of the first input terminal or the voltage of the second input terminal to the positive electrode of the load; The first local switching unit is used to control the conduction time between the positive output terminal of the first DC / DC module and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay; The first external switching unit is used to control the conduction time between the positive output terminal of the backup power supply and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay; The first DC / DC module has a DC input terminal, the DC input terminal is used to connect to the battery, and the first DC / DC module is used to adjust the DC power output by the battery in the first energy storage cabinet to DC power of the target working voltage; The first AC / DC module has an AC input terminal, which is used to connect to the AC mains. The first AC / DC module is used to convert the AC mains into DC power of a target working voltage.

2. The power supply control system according to claim 1, characterized in that: The first control module further includes a second diode unit; The first input end of the second diode unit is connected to the positive output end of the first AC / DC module, the second input end of the second diode unit is connected to the positive output end of the first DC / DC module, and the output end of the second diode unit is connected to the first input end of the first diode unit; The second diode unit is used for outputting the voltage of the first input terminal or the voltage of the second input terminal to the first input terminal of the first diode unit.

3. The power supply control system according to claim 2, characterized in that: The first local switching unit includes a first power-off delay relay, the contact of which is a first delayed-off make contact; the first external switching unit includes an energy storage capacitor, a first power-on delay relay and a first intermediate relay, the contact of which is a first delayed-off make contact, and the contact of the first intermediate relay is a first normally closed contact; Two ends of the coil in the first power-off delay relay are respectively connected to the positive and negative output ends of the first AC / DC module; The first end of the first delayed-off make contact is connected to the positive output end of the first DC / DC module, and the second end of the first delayed-off make contact is connected to the second input end of the second diode unit; The first end of the coil in the first power-on delay relay is connected to the second end of the first normally closed contact and the first end of the first delayed breaking contact, and the second end of the coil in the first power-on delay relay is connected to the negative output end of the backup power supply, the negative output end of the first DC / DC module, the first end of the first intermediate relay, the first end of the energy storage capacitor, and the negative electrode of the load; The second end of the first delayed-off break contact is connected to the second input end of the first diode unit; the second end of the first intermediate relay is connected to the second end of the energy storage capacitor, the first input end of the first diode unit, and the output end of the second diode unit; The first end of the first normally closed contact is connected to the positive output end of the backup power supply.

4. The power control system according to claim 2, characterized in that: The first local switching unit includes a first intermediate relay and a first power-on delay relay, the contact of the first intermediate relay is a first normally closed contact, and the contact of the first power-on delay relay is a first delayed disconnection contact; the first external switching unit includes an energy storage capacitor, a second power-on delay relay and a second intermediate relay, the contact of the second power-on delay relay is a second delayed disconnection contact, and the contact of the second intermediate relay is a second normally closed contact; Two ends of the coil in the first intermediate relay are connected to the positive and negative output ends of the first AC / DC module respectively; The first end of the first normally closed contact is connected to the positive output end of the first DC / DC module, and the second end of the first normally closed contact is connected to the first end of the coil of the first power-on delay relay and the first end of the first delayed opening break contact; The second end of the first delayed-open break contact is connected to the second input end of the second diode unit; The second end of the coil of the first power-on delay relay is connected to the negative output end of the first DC / DC module, the first end of the second intermediate relay, the first end of the energy storage capacitor, the second end of the coil of the second power-on delay relay, the negative output end of the backup power supply, and the negative pole of the load; The first end of the coil in the second power-on delay relay is connected to the second end of the second normally closed contact and the first end of the second delayed opening break contact; The first end of the second normally closed contact is connected to the positive output end of the backup power supply; The second end of the second delayed-opening break contact is connected to the second input end of the first diode unit; the second end of the second intermediate relay is connected to the second end of the energy storage capacitor, the first input end of the first diode unit, and the output end of the second diode unit.

5. The power control system according to claim 2, characterized in that: The first local switching unit includes a battery management system BMS, a first intermediate relay and a second intermediate relay, the contact of the first intermediate relay is a first normally open contact, and the contact of the second intermediate relay is a first normally closed contact; the first external switching unit includes an energy storage capacitor, a first power-on delay relay and a third intermediate relay, the contact of the first power-on delay relay is a first delayed disconnection contact, and the contact of the third intermediate relay is a second normally closed contact; Two ends of the coil in the first intermediate relay are connected to the positive and negative output ends of the first AC / DC module respectively; Both ends of the first normally open contact are connected to the digital input terminals of the BMS; The coil of the second intermediate relay is connected to the high-side digital output terminal of the BMS, and the output voltage of the high-side output terminal is the power supply voltage of the BMS; A first end of the second normally closed contact is connected to the positive output end of the first DC / DC module, and a second end of the second normally closed contact is connected to the second input end of the second diode unit; The first end of the coil in the first power-on delay relay is connected to the second end of the second normally closed contact and the first end of the first delayed opening break contact, and the second end of the coil in the first power-on delay relay is connected to the negative output end of the backup power supply, the negative output end of the first DC / DC module, the first end of the third intermediate relay, the first end of the energy storage capacitor, and the negative electrode of the load; The second end of the first delayed-off break contact is connected to the second input end of the first diode unit; the second end of the third intermediate relay is connected to the second end of the energy storage capacitor, the first input end of the first diode unit, and the output end of the second diode unit; The first end of the second normally closed contact is connected to the positive output end of the backup power supply.

6. The power supply control system according to claim 2, characterized in that: The first local switching unit includes a battery management system BMS, a first intermediate relay and a DC circuit breaker, and the contact of the first intermediate relay is a first normally open contact; the first external switching unit includes an energy storage capacitor, a first power-on delay relay and a second intermediate relay, the contact of the first power-on delay relay is a first delayed disconnection contact, and the contact of the second intermediate relay is a first normally closed contact; Two ends of the coil in the first intermediate relay are connected to the positive and negative output ends of the first AC / DC module respectively; Both ends of the first normally open contact are connected to the digital input terminals of the BMS; The positive output end of the first DC / DC module is connected to the second input end of the second diode unit after passing through the DC circuit breaker, and the negative output end of the first DC / DC module is connected to the first end of the second intermediate relay, the first end of the energy storage capacitor, the second end of the coil in the first power-on delay relay, the negative output end of the backup power supply, and the negative pole of the load after passing through the DC circuit breaker; The first end of the coil in the first power-on delay relay is connected to the second end of the first normally closed contact and the first end of the first delayed opening break contact; The second end of the first delayed-off break contact is connected to the second input end of the first diode unit; the second end of the second intermediate relay is connected to the second end of the energy storage capacitor, the first input end of the first diode unit, and the output end of the second diode unit; The first end of the first normally closed contact is connected to the positive output end of the backup power supply.

7. The power supply control system according to any one of claims 1 to 6, characterized in that: The first DC / DC module includes a working voltage protection unit, and the working voltage protection unit is used to stop outputting direct current when the output voltage of the first DC / DC module is less than a voltage threshold, and the voltage threshold is greater than an undervoltage protection value of the battery.

8. The power supply control system according to any one of claims 1 to 6, characterized in that: A closing self-locking button is provided on the circuit where the positive output terminal of the first DC / DC module is located, and the closing self-locking button is used to provide a black start function and an emergency shutdown function.

9. The power control system according to claim 2, characterized in that: The backup power source of the first energy storage cabinet is the second energy storage cabinet, the first energy storage cabinet and the second energy storage cabinet serve as backup power for each other, and the second energy storage cabinet includes: a second AC / DC module, a second DC / DC module, and a second control module, wherein the second control module includes a third diode unit, a fourth diode unit, a second local switching unit, and a second external switching unit, wherein the second local switching unit includes at least one relay, and the second external switching unit includes at least two relays; The first input end of the fourth diode unit is connected to the positive output end of the second AC / DC module, the second input end of the fourth diode unit is connected to the positive output end of the second DC / DC module, the output end of the fourth diode unit is connected to the first input end of the third diode unit, the second input end of the third diode unit is connected to the output end of the second external switching unit, and the output end of the third diode unit is connected to the positive electrode of the load; The third diode unit is used to output the voltage of the first input terminal or the voltage of the second input terminal to the positive electrode of the load; the fourth diode unit is used to output the voltage of the first input terminal or the voltage of the second input terminal to the first input terminal of the third diode unit; The second local switching unit is used to control the conduction time between the positive output terminal of the second DC / DC module and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay; The second external switching unit is used to control the conduction time between the positive output terminal of the first energy storage cabinet and the positive electrode of the load by delaying the opening or closing of the corresponding contacts of each relay; The second DC / DC module has a DC input terminal, the DC input terminal is used to connect to the battery, and the second DC / DC module is used to adjust the DC power output by the battery in the second energy storage cabinet to DC power of the target working voltage; The second AC / DC module has an AC input terminal, which is used to connect to the AC mains. The second AC / DC module is used to convert the AC mains into DC power of a target working voltage.

10. An energy storage system, characterized in that: It comprises a plurality of power control systems and energy management systems as described in any one of claims 1 to 9, wherein the energy management system is used to perform energy management on batteries of each energy storage cabinet in the power control system.

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