Circuit switching device for energy storage system

Abstract

The utility model discloses a circuit switching device for an energy storage system. The circuit switching device is installed between every two same phases of two power supplies needing to be switched. The energy storage system circuit switching device comprises a main power supply input end, a standby power supply input end and an output end. The circuit switching device further comprises a switching device and a thyristor connected with the switching device. The thyristor is in communication connection with a thyristor driver; the switching device, the thyristor and the thyristor driver are all arranged in the outer shell. According to the utility model, when a certain phase goes wrong, only the corresponding circuit switching device needs to be replaced, and the whole switch box does not need to be replaced, so that the maintenance cost and time are obviously reduced, and the reliability of a system is improved.

Description

Technical Field

[0001] This utility model relates to the field of energy storage systems, and in particular to a circuit switching device for energy storage systems. Background Technology

[0002] In energy storage systems, when inverters switch between grid connection and off-grid operation, significant transient inrush currents are generated due to differences in load characteristics. These currents are often several times the rated current, which can easily cause power outages in the electrical system and have a serious impact on the entire electrical system.

[0003] To address the risk of load power loss caused by inrush currents, existing technologies utilize Automatic Transfer Switches (ATS). ATSs can quickly respond to mains power failures and switch to backup power within a short time, reducing load power loss time. ATSs employ a mechanical structure, using contactors as the switching actuators, and control is achieved through a secondary circuit composed of intermediate relays or logic control modules. However, the main drawback of ATSs is that the contactors in the main circuit require continuous power supply from the secondary circuit, and the switching time under heavy loads is relatively long, typically exceeding 100 milliseconds, which can still lead to load power loss and system shutdown. To solve this problem, existing technologies use Static Transfer Switches (STS) instead of ATSs as the transfer switch. STSs have a standard switching time of no more than 8 milliseconds, thus avoiding load power loss.

[0004] However, the drawback of this existing technology is that in energy storage systems, the STS (Self-Switching Transmission System) is integrated into a single switch box. If one phase fails, the entire switch box needs to be replaced or repaired. This switch box contains circuit switching devices for multiple phases, as well as complex internal connections and control logic. Diagnosing the entire switch box requires testing and inspecting each component, making it more difficult to pinpoint the exact location of the fault and increasing the time consumed during replacement. Replacing or repairing the entire switch box typically means shutting down the entire system or part of the system, resulting in high maintenance costs. Utility Model Content

[0005] In view of the above-mentioned deficiencies of the prior art, the present invention provides a circuit switching device for an energy storage system. When a problem occurs in a certain phase, only the corresponding circuit switching device needs to be replaced, without replacing the entire switch box, which significantly reduces maintenance costs and time and improves system reliability.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A circuit switching device for an energy storage system is installed between every two identical phases of two power sources that need to be switched; the circuit switching device includes a main power input terminal, a backup power input terminal, and an output terminal; the circuit switching device also includes a switching device and a thyristor connected to the switching device; the thyristor is communicatively connected to a thyristor driver; the switching device, the thyristor, and the thyristor driver are all housed within a housing.

[0008] A switching device and a thyristor work together to address load power outages caused by inrush currents, enabling switching between mains and backup power. The switching device, as a mechanical switch, has its normally open contact connected to the mains power and its normally closed contact connected to the backup power. When the mains power is operating normally, the switching device is energized, allowing the mains power to supply power to the load through its normally open contact. When the mains power fails, the switching device releases, and the load switches to the backup power through its normally closed contact. The thyristor controls the electronic connections during power switching. The thyristor's on / off state is controlled by its gate signal. When the mains power is normal, the thyristor remains off, allowing mains power to supply power. When the mains power fails, triggering the thyristor's gate signal turns it on, switching the load to the backup power.

[0009] The complex circuit switching mechanism within the switch box is broken down into smaller, more manageable, and replaceable circuit switching unit units. Since each phase's circuit switching mechanism is designed as an independent unit, each unit has its own input, output, and control components. Each phase's circuit switching mechanism (including the switching device and thyristor) is encapsulated within a housing, forming an independent unit responsible for switching the power supply to that phase. The circuit switching mechanisms are installed between every two identical phases of the two power supplies to be switched; the main power input, backup power input, and output are connected to the same phases of the main power supply, backup power supply, and load, respectively. For example, in a three-phase electrical system, there would be a circuit switching unit installed on phase R, with its main power input connected to the main power supply phase R, its backup power input connected to the backup power supply phase R, and its output connected to the load phase R. There would also be a circuit switching unit installed on phase S, a circuit switching unit installed on phase T, and a circuit switching unit installed on phase N. When power switching is required, the four circuit switching units mentioned above switch power in unison under the synchronous control signal of the thyristor driver.

[0010] Preferably, the switching device is connected in parallel with an absorption circuit for absorbing turn-off spikes.

[0011] Sucking circuits typically consist of one or more components connected in parallel. When a switching device opens, the current in the inductor does not disappear instantly but is transferred to the sucking circuit. These components work together to dissipate or store the energy released by the inductor as heat, electric field energy, or magnetic field energy, thereby reducing voltage spikes. When a switching device opens, a large back electromotive force may be generated, causing voltage spikes. Sucking circuits can absorb these spikes, protecting the circuit. Semiconductor devices such as thyristors are very sensitive to voltage spikes, which may exceed their rated values, causing damage. Sucking circuits can protect these devices from voltage spikes. Voltage spikes can generate electromagnetic interference, affecting the normal operation of other electronic devices. Sucking circuits can reduce this interference, improving the system's electromagnetic compatibility. By reducing the impact of voltage spikes on components in the circuit, sucking circuits help extend the lifespan of relays, thyristors, and other components.

[0012] Preferably, the absorption circuit includes an absorption diode and an absorption resistor connected to the absorption diode.

[0013] A snubber diode is a diode used to withstand high-voltage transients. When a switching device is turned off, the snubber diode clamps voltage spikes generated in the circuit, preventing the voltage from exceeding a safe value. This allows the energy released by the inductor to be directed to a safe discharge path, typically back to the power supply or ground. By limiting voltage spikes, the snubber diode protects other components in the circuit, such as thyristors and relays, from high-voltage damage. A snubber resistor dissipates energy, converting the energy released by the inductor into heat, thereby reducing energy in the circuit and lowering voltage spikes. When the switching device is turned off, the snubber diode first clamps the voltage, and then the snubber resistor dissipates the energy; both work together to reduce voltage spikes. This combination not only protects the circuit from voltage spikes but also reduces the risk of device damage due to improper energy dissipation.

[0014] Preferably, the thyristor driver is connected to a synchronous calibrator for periodically calibrating the control signal of the thyristor driver.

[0015] A synchronization calibrator adjusts the clock of the thyristor drivers, ensuring that all drivers trigger the thyristors at the same time. Simultaneously, the calibrator detects synchronization errors in the thyristor drivers caused by temperature variations and component aging, and makes corresponding adjustments. Regular synchronization calibration helps reduce the accumulation of errors during system operation and improves the long-term stability of the system. By ensuring accurate thyristor synchronization, the risk of equipment damage caused by synchronization errors is reduced.

[0016] Preferably, the thyristor is a bidirectional thyristor.

[0017] A bidirectional thyristor can respond to both forward and reverse trigger signals, thus controlling current flow in both directions. Using a bidirectional thyristor as the thyristor allows for conduction in both directions and offers high compatibility with AC circuits. Replacing two unidirectional thyristors with a bidirectional thyristor simplifies circuit design, reduces the number of required components, and consequently lowers cost and space requirements. Since only one thyristor is needed to handle current in both directions, power loss and heat generation are reduced, improving overall system efficiency.

[0018] Preferably, the switching device is a relay, a mechanical switch, or a circuit breaker.

[0019] In the circuit switching devices of an energy storage system, the choice of which type of switching device to use depends on specific application requirements, including factors such as cost, response speed, safety, and maintenance requirements. If fast response and high reliability are required, a relay may be chosen; if cost is a consideration, a mechanical switch can be selected; if safety and protection functions are paramount, a circuit breaker can be chosen.

[0020] Preferably, the housing is equipped with a heat dissipation device.

[0021] Thyristors can generate a lot of heat in high-power applications, and poor heat dissipation can lead to overheating and damage. Effective heat dissipation devices, such as heat sinks, fans, or liquid cooling systems, can ensure that thyristors operate at safe temperatures.

[0022] Preferably, the circuit switching device includes an input filter and an output filter.

[0023] Input filters are primarily used to suppress high-frequency noise and interference from the power supply, ensuring a clean and stable power signal entering the circuit switching device. When transient voltage spikes occur in the power supply, the input filter can effectively absorb these spikes, protecting downstream circuit components from damage. Output filters reduce electromagnetic interference generated by the circuit switching device to the external environment, smoothing the output signal, reducing voltage fluctuations, and ensuring a stable power supply to the load equipment. The combined use of input and output filters in a circuit switching device can significantly improve the overall system performance, enhancing not only the reliability of the circuit switching device but also its adaptability to various application scenarios.

[0024] Compared with the prior art, the beneficial effects of this utility model are reflected in:

[0025] 1. Because the circuit switching device for each phase is independent, when a problem occurs in the circuit switching device of a certain phase, maintenance personnel can quickly locate the problem and replace only the circuit switching device for that phase. This avoids diagnosing and replacing the entire switch box, greatly reducing maintenance time and costs, thereby reducing system downtime and improving system availability and reliability.

[0026] 2. Thyristors have advantages such as small size, high efficiency, and long life. They can also handle transient large currents and respond to control signals very quickly, enabling rapid switching between main power and backup power, usually at the millisecond level, which helps reduce load power outage time.

[0027] 3. Thyristors have very low losses when conducting, which means that energy loss is small during power switching, thus improving the energy efficiency of the system. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the circuit switching device in Embodiment 1.

[0029] in:

[0030] 1. Main power input terminal; 2. Backup power input terminal; 3. Output terminal; 4. Switching device; 5. Thyristor; 6. Housing; 7. Thyristor driver; 8. Snubber circuit. Detailed Implementation

[0031] To make the technical means, inventive features, objectives, and effects of this utility model readily understandable, the present utility model is further described below in conjunction with specific illustrations. However, this utility model is not limited to the following embodiments.

[0032] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which this utility model can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0033] Example 1:

[0034] like Figure 1The circuit switching device shown is installed between every two identical phases of two power sources that need to be switched. The circuit switching device includes a main power input terminal 1, a backup power input terminal 2, and an output terminal 3. The circuit switching device also includes a switching device 4 and a thyristor 5 connected to the switching device 4. The thyristor 5 is communicatively connected to a thyristor driver 7. The switching device 4, the thyristor 5, and the thyristor driver 7 are all housed within a housing 6.

[0035] Switching device 4 and thyristor 5 work together to solve the load power outage problem caused by inrush current and realize the switching between main power supply and backup power supply. Switching device 4, as a mechanical switch, has its normally open contact connected to the main power supply and its normally closed contact connected to the backup power supply. When the main power supply is working normally, switching device 4 is energized, allowing the main power supply to supply power to the load through its normally open contact. When the main power supply fails, switching device 4 is released, and the load switches to the backup power supply through the normally closed contact of switching device 4. Thyristor 5 is used to control the electronic connection during the power switching process. The conduction and turn-off of thyristor 5 can be controlled by controlling its gate signal. When the main power supply is normal, thyristor 5 can remain in the off state, allowing the main power supply to provide power. When the main power supply fails, triggering the gate signal of thyristor 5 turns it on, thereby switching the load to the backup power supply.

[0036] The complex circuit switching mechanism within the switch box is broken down into smaller, more manageable, and replaceable circuit switching unit units. Since each phase's circuit switching mechanism is designed as an independent unit, each unit has its own input, output, and control components. Each phase's circuit switching mechanism (including the switching device 4 and thyristor 5) is encapsulated in a housing 6, forming an independent unit responsible for power switching in that phase. The main power input 1, backup power input 2, and output 3 are connected to the same phases of the main power supply, backup power supply, and load, respectively. For example, in a three-phase electrical system, there would be a circuit switching unit installed on phase R, with its main power input 1 connected to the main power supply phase R, its backup power input 2 connected to the backup power supply phase R, and its output 3 connected to the load phase R. There would also be a circuit switching unit installed on phase S, a circuit switching unit installed on phase T, and a circuit switching unit installed on phase N. When power switching is required, the four circuit switching units mentioned above will switch power in unison under the synchronous control signal of the thyristor driver 7.

[0037] Because each phase's circuit switching device is independent, maintenance personnel can quickly locate the problem and replace only the switching device for that phase when a fault occurs. This avoids diagnosing and replacing the entire switch box, significantly reducing maintenance time and costs, thereby minimizing system downtime and improving system availability and reliability. Furthermore, thyristor 5 can respond to control signals very quickly, enabling rapid switching between main and backup power supplies, typically on the order of milliseconds, which helps reduce load outage time. Thyristor 5 also has very low conduction losses, meaning minimal energy loss during power switching, improving system energy efficiency.

[0038] Furthermore, the switching device 4 is connected in parallel with an absorption circuit 8 for absorbing turn-off spikes. The absorption circuit 8 includes an absorption diode and an absorption resistor connected to the absorption diode. The absorption circuit 8 typically consists of one or more components connected in parallel. When the switching device 4 is turned off, the current in the inductor does not disappear instantaneously but is transferred to the absorption circuit. These components work together to dissipate or store the energy released by the inductor as heat, electric field energy, or magnetic field energy, thereby reducing voltage spikes. When the switching device 4 is turned off, a large back electromotive force may be generated, leading to voltage spikes. The absorption circuit can absorb these spikes, protecting the circuit. Semiconductor devices such as thyristors 5 are very sensitive to voltage spikes; spike voltages may exceed their rated values, causing device damage. The absorption circuit can protect these devices from the effects of voltage spikes. Voltage spikes may generate electromagnetic interference, affecting the normal operation of other electronic devices. The absorption circuit can reduce this interference, improving the system's electromagnetic compatibility. By reducing the impact of voltage spikes on components in the circuit, the absorption circuit helps extend the lifespan of relays, thyristors, and other components.

[0039] A snubber diode is a diode used to withstand high-voltage transients. When switch 4 is open, the snubber diode clamps voltage spikes generated in the circuit, preventing the voltage from exceeding safe levels. This allows the energy released by the inductor to be directed to a safe discharge path, typically back to the power supply or ground. By limiting voltage spikes, the snubber diode protects other components in the circuit, such as thyristors and relays, from high-voltage damage. The snubber resistor dissipates energy, converting the energy released by the inductor into heat, thereby reducing energy in the circuit and lowering voltage spikes. When switch 4 is open, the snubber diode first clamps the voltage, and then the snubber resistor dissipates the energy; both work together to reduce voltage spikes. This combination not only protects the circuit from voltage spikes but also reduces the risk of device damage due to improper energy dissipation.

[0040] The thyristor driver 7 is connected to a synchronization calibrator for periodically calibrating the control signal of the thyristor driver 7. The synchronization calibrator adjusts the clock of the thyristor driver 7 to ensure that all drivers trigger the thyristor 5 at the same time. Simultaneously, the synchronization calibrator can detect synchronization errors in the thyristor driver 7 caused by temperature variations and component aging, and make corresponding adjustments. Periodic synchronization calibration helps reduce the accumulation of errors during system operation and improves the long-term stability of the system. By ensuring accurate synchronization of the thyristor 5, the risk of equipment damage caused by synchronization errors is reduced.

[0041] Thyristor 5 is a bidirectional thyristor. Thyristors are divided into unidirectional and bidirectional types. A bidirectional thyristor is also called a three-terminal bidirectional thyristor, or TRIAC for short. Structurally, a bidirectional thyristor is equivalent to two unidirectional thyristors connected in reverse. This type of thyristor has bidirectional conduction capability, and its on / off state is determined by the control electrode G. Applying a positive pulse (or negative pulse) to the control electrode G will turn it on in the forward (or reverse) direction. The advantages of bidirectional thyristors are simple control circuits and no reverse withstand voltage issues, making them particularly suitable for use as AC contactless switches. Bidirectional thyristors can respond to both forward and reverse trigger signals, thereby controlling the current flow in both directions. Using a bidirectional thyristor as thyristor 5 allows for conduction in both directions and has high compatibility with AC circuits. Using a bidirectional thyristor can replace two unidirectional thyristors, simplifying circuit design, reducing the number of required components, and thus reducing cost and space requirements. Since only one thyristor is needed to handle current in both directions, power loss and heat generation can be reduced, improving the efficiency of the entire system.

[0042] Switching device 4 can be a relay, a mechanical switch, or a circuit breaker. The choice of which type of switching device 4 to use in the circuit switching device of an energy storage system depends on specific application requirements, including factors such as cost, response speed, safety, and maintenance requirements. If fast response and high reliability are required, a relay may be chosen; if cost is a consideration, a mechanical switch may be selected; if safety and protection functions are paramount, a circuit breaker may be chosen.

[0043] The housing 6 contains a heat dissipation device. In high-power applications, the thyristor 5 may generate a significant amount of heat; inadequate heat dissipation could lead to overheating and damage. Effective heat dissipation devices, such as heat sinks, fans, or liquid cooling systems, ensure that the thyristor 5 operates at a safe temperature.

[0044] Circuit switching devices comprise input and output filters. The input filter primarily suppresses high-frequency noise and interference from the power supply, ensuring a clean and stable power signal entering the circuit switching device. When transient voltage spikes occur in the power supply, the input filter effectively absorbs these spikes, protecting downstream circuit components from damage. The output filter reduces electromagnetic interference generated by the circuit switching device to the external environment, smoothing the output signal, reducing voltage fluctuations, and ensuring a stable power supply to the load equipment. The combined use of input and output filters in a circuit switching device significantly improves the overall system performance, enhancing not only the reliability of the circuit switching device but also its adaptability to various application scenarios.

Claims

1. A circuit switching device for an energy storage system, characterized by, It is installed between two same phases of two power sources which need to be switched; the circuit switching device of the energy storage system comprises a main power input (1), a standby power input (2) and an output (3); the circuit switching device further comprises a switching device (4) and a thyristor (5) connected with the switching device (4); the thyristor (5) is communicatively connected with a thyristor driver (7); the switching device (4), the thyristor (5) and the thyristor driver (7) are all arranged in an outer housing (6).

2. The circuit switching device for an energy storage system of claim 1, wherein, The switching device (4) is connected in parallel with an absorption circuit (8) for absorbing off-sharp peaks.

3. The circuit switching device for an energy storage system of claim 2, wherein, The absorption circuit (8) comprises an absorption diode and an absorption resistor connected with the absorption diode.

4. The circuit switching device for an energy storage system of claim 1, wherein, The thyristor driver (7) is connected with a synchronous calibrator for calibrating the control signal of the thyristor driver (7) periodically.

5. The circuit switching device for an energy storage system of claim 1, wherein, The thyristor (5) is a bidirectional thyristor.

6. The circuit switching device for an energy storage system of claim 1, wherein, The switching device (4) is a relay or a mechanical switch or a circuit breaker.

7. The circuit switching device for an energy storage system of claim 1, wherein, The outer housing (6) is provided with a heat dissipation device.

8. Circuit switching device for an energy storage system according to any of claims 1 to 7, characterized in that The circuit switching device comprises an input filter and an output filter.

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