CN116231831A - Dual-power supply system and method of energy storage system - Google Patents
Dual-power supply system and method of energy storage system Download PDFInfo
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- CN116231831A CN116231831A CN202211636897.8A CN202211636897A CN116231831A CN 116231831 A CN116231831 A CN 116231831A CN 202211636897 A CN202211636897 A CN 202211636897A CN 116231831 A CN116231831 A CN 116231831A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
- H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
- H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
- H02J9/061—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems for DC powered loads
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Abstract
The invention provides a dual-power supply system and a power supply method of an energy storage system, wherein the dual-power supply system comprises a battery direct-current side power supply loop, an energy storage alternating-current side power supply loop and an EMS energy management subsystem; the input end of the battery direct-current side power supply loop is connected with the energy storage battery through a direct-current side micro-breaker, and the output end of the battery direct-current side power supply loop is connected with an electric load; the input end of the energy storage alternating current side power supply loop is connected with the power grid through a first alternating current side micro-breaker, and the output end of the energy storage alternating current side power supply loop is connected with an electric load; the direct-current side micro-breaking switch and the first alternating-current side micro-breaking switch are both in control connection with the EMS energy management subsystem; the battery direct current side power supply loop is connected with a normally closed direct current relay in series, two ends of a normally closed contact of the normally closed direct current relay are respectively connected with a direct current side micro-breaking switch and an electric load, and a driving coil of the normally closed direct current relay is connected into the energy storage alternating current side power supply loop. The invention can prolong the standby time of the power supply of the system, is suitable for severe application environment, does not need to increase the heat dissipation of the air conditioner and reduces the design cost of the system.
Description
Technical Field
The invention relates to the technical field of energy storage systems, in particular to a dual-power supply system and a power supply method of an energy storage system.
Background
In the energy storage system project, a UPS (Uninterruptible Power Supply ) is generally added as a power supply device of a control loop, and under the condition of abnormality of an external alternating current power supply, the control loop can be maintained to continuously run for a certain period of time, or a key function of supplying power in the off-grid black start process of the system is achieved.
However, the capacity of the built-in battery of the UPS is limited, long-time standby power cannot be achieved, after a certain period of operation, the capacity of the built-in battery is seriously attenuated, the built-in battery or the whole UPS needs to be replaced frequently, the UPS has high requirements on environmental conditions, an air conditioner needs to be additionally arranged to provide a good operation environment for the UPS, and the design cost of the system is greatly increased.
Disclosure of Invention
The technical problems to be solved by the invention are as follows: the dual-power supply system and the power supply method of the energy storage system are provided to replace a UPS power supply scheme, so that the system power supply standby time can be prolonged, the energy storage system is suitable for a severe application environment, the heat dissipation of an air conditioner is not required to be increased, and the design cost of the system is reduced.
In order to solve the technical problems, the invention adopts the following technical scheme:
a dual power supply system of an energy storage system comprises a battery direct-current side power supply loop and an energy storage alternating-current side power supply loop;
the input end of the battery direct-current side power supply loop is connected with the energy storage battery through a direct-current side micro-breaker, and the output end of the battery direct-current side power supply loop is connected with an electric load;
the input end of the energy storage alternating current side power supply loop is connected with a power grid through a first alternating current side micro-breaker, and the output end of the energy storage alternating current side power supply loop is connected with the power load;
the battery direct current side power supply loop is connected with a normally-closed direct current relay in series, two ends of a normally-closed contact of the normally-closed direct current relay are respectively connected with the direct current side micro-switch and the power load, and a driving coil of the normally-closed direct current relay is connected to the energy storage alternating current side power supply loop and is used for driving the normally-closed contact of the normally-closed direct current relay to be disconnected when voltage passes through the energy storage alternating current side power supply loop.
In order to solve the technical problems, another technical scheme provided by the invention is as follows:
a dual-power supply method of an energy storage system is applied to the dual-power supply system of the energy storage system, and comprises the following steps:
in the grid-connected mode, a first alternating current side micro-breaking switch in an energy storage alternating current side power supply loop is closed, grid side alternating current is converged into a rectifier bridge stack through the first alternating current side micro-breaking switch, and direct current is output after rectification to supply power for an electricity load;
when the power grid is in off-grid mode, no alternating current is input at the power grid side, no voltage passes through the energy storage alternating current side power supply loop, the first alternating current side micro-switch is opened, at the moment, the direct current side micro-switch in the battery direct current side power supply loop is closed, and the energy storage battery direct current is output to the power utilization load through the direct current side micro-switch and the normally closed contact of the normally closed direct current relay;
when the power grid side resumes work, the off-grid mode is converted into a grid-connected mode, the first alternating-current side micro-switch is closed again at the moment, voltage passes through the energy storage alternating-current side power supply loop, the driving coil of the normally-closed direct-current relay works to drive the normally-closed contact of the normally-closed direct-current relay in the battery direct-current side power supply loop to be disconnected, and the battery direct-current side power supply loop stops supplying power to the power utilization load and only the energy storage alternating-current side power supply loop supplies power to the power utilization load.
The invention has the beneficial effects that: the invention provides a dual-power supply system and a power supply method of an energy storage system, which are used for switching the mode of supplying power from a power grid side under the grid and supplying power from an energy storage battery under the off-grid by controlling the on-off of a first alternating-current side micro-break switch in an energy storage alternating-current side power supply loop and a direct-current side micro-break switch in a battery direct-current side power supply loop, so that the dual-power supply of the energy storage system is realized, and the standby time of the power supply of the system is prolonged; and a normally-closed direct current relay is introduced into the battery direct current side power supply loop, and a driving coil of the normally-closed direct current relay is connected into the energy storage alternating current side power supply loop so as to drive a normally-closed contact of the normally-closed direct current relay to be disconnected when the power supply is recovered at the power grid side, thereby automatically disconnecting the power supply of the energy storage battery in the battery direct current side power supply loop and preferentially adopting the power grid for power supply. The UPS equipment is eliminated integrally, the system is suitable for severe application environments, the heat dissipation of an air conditioner is not required to be increased, and the design cost of the system is effectively reduced.
Drawings
FIG. 1 is a schematic circuit diagram of a dual power supply system of an energy storage system according to an embodiment of the present invention;
fig. 2 is a schematic diagram of power supply on the power grid side in an energy storage ac side power supply loop of a dual-power supply system of an energy storage system according to an embodiment of the present invention;
fig. 3 is a schematic diagram of internal power supply of a battery in a dc side power supply loop of a dual-power supply system of an energy storage system according to an embodiment of the present invention;
fig. 4 is a schematic diagram of external power supply of a battery in a battery dc side power supply loop of a dual-power supply system of an energy storage system according to an embodiment of the present invention;
fig. 5 is a schematic diagram of power supply of an energy storage converter in an energy storage ac side power supply loop of a dual-power supply system of an energy storage system according to an embodiment of the present invention;
fig. 6 is a flowchart of a dual power supply method of an energy storage system according to an embodiment of the present invention.
Description of the reference numerals:
PCS, energy storage converter; UR, rectifier bridge stack; FU, fuse;
k1, a first alternating-current side micro-switch is turned off; k2, a second alternating-current side micro-switch; k3, a direct current side micro-switch; KM1, a normally closed direct current relay; KM2, high-voltage relay;
d1, a first anti-reflection diode; d2, a second anti-reflection diode; d3, a third anti-reflection diode.
Detailed Description
In order to describe the technical contents, the achieved objects and effects of the present invention in detail, the following description will be made with reference to the embodiments in conjunction with the accompanying drawings.
Referring to fig. 1 to 5, a dual-power supply system of an energy storage system includes a battery dc side power supply loop and an energy storage ac side power supply loop;
the input end of the battery direct-current side power supply loop is connected with the energy storage battery through a direct-current side micro-breaker, and the output end of the battery direct-current side power supply loop is connected with an electric load;
the input end of the energy storage alternating current side power supply loop is connected with a power grid through a first alternating current side micro-breaker, and the output end of the energy storage alternating current side power supply loop is connected with the power load;
the battery direct current side power supply loop is connected with a normally-closed direct current relay in series, two ends of a normally-closed contact of the normally-closed direct current relay are respectively connected with the direct current side micro-switch and the power load, and a driving coil of the normally-closed direct current relay is connected to the energy storage alternating current side power supply loop and is used for driving the normally-closed contact of the normally-closed direct current relay to be disconnected when voltage passes through the energy storage alternating current side power supply loop.
From the above description, the beneficial effects of the invention are as follows: the double-power supply of the energy storage system is realized by controlling the on-off of a first alternating-current side micro-switch in an energy storage alternating-current side power supply loop and a direct-current side micro-switch in a battery direct-current side power supply loop, so that the double-power supply of the energy storage system is realized in a mode of supplying power from a power grid side under the grid and supplying power from an energy storage battery under the grid, and the standby time of the system power supply is prolonged; and a normally-closed direct current relay is introduced into the battery direct current side power supply loop, and a driving coil of the normally-closed direct current relay is connected into the energy storage alternating current side power supply loop so as to drive a normally-closed contact of the normally-closed direct current relay to be disconnected when the power supply is recovered at the power grid side, thereby automatically disconnecting the power supply of the energy storage battery in the battery direct current side power supply loop and preferentially adopting the power grid for power supply. The UPS equipment is eliminated integrally, the system is suitable for severe application environments, the heat dissipation of an air conditioner is not required to be increased, and the design cost of the system is effectively reduced.
Further, the energy storage alternating current side power supply loop also comprises an energy storage converter and a second alternating current side micro-switch;
the alternating-current end of the energy storage converter is connected with the first alternating-current side micro-break switch in parallel with the power load through the second alternating-current side micro-break switch;
and the direct-current end of the energy storage converter is connected with the energy storage battery.
It can be seen from the above description that, in order to perfect the performance of the energy storage system, the energy storage converter is added, so that on one hand, when the power grid side is abnormal, the off-grid power-on operation outputs electric energy to supply power to the power utilization load, and on the other hand, when the normal power utilization load is not powered, the alternating current on the power grid side is converted into direct current to charge the energy storage battery, so that the sufficient electric quantity of the energy storage battery is ensured, and the power supply duration of the energy storage system is further prolonged.
Further, the first ac side micro-switch and the second ac side micro-switch are mechanically interlocked switches to each other.
As can be seen from the above description, the first ac side micro-switch and the second ac side micro-switch adopt a mechanical interlocking manner, that is, only one of the two micro-switches can be closed at the same time, or both of the two micro-switches are open, when the power grid side supplies power to the power-consuming load, the first ac side micro-switch is closed, the second ac side micro-switch is in an open state under the mechanical interlocking structure, and the energy storage converter does not work to reduce the consumption of the power grid side voltage; when the power grid side is abnormal, namely off-grid, the second alternating current side micro-breaking switch is closed, the first alternating current side micro-breaking switch is in an open state under a mechanical interlocking structure, and at the moment, no voltage passes through the energy storage alternating current side power supply loop.
Further, a rectifier bridge stack is connected in series in the energy storage alternating current side power supply loop;
the input end of the rectifier bridge is connected with the first alternating-current side micro-break switch and the second alternating-current side micro-break switch through an alternating-current bus, and the output end of the rectifier bridge is connected with the electricity load and used for rectifying alternating current stored on the power grid side or the energy storage converter into direct current and outputting the direct current to supply power for the electricity load.
As can be seen from the above description, since the electric load is usually powered by direct current, a rectifier bridge is introduced to rectify the alternating current on the grid side or the energy storage converter side into direct current to be output in an uncontrolled manner so as to supply power to the electric load.
Further, the energy storage battery comprises a battery interior and a battery exterior;
the battery is internally connected with the normally-closed direct-current relay through the direct-current side micro-switch;
the outside of the battery is connected with the normally closed direct current relay through a first anti-diode;
a high-voltage relay is connected in series between the inside of the battery and the outside of the battery, and the high-voltage relay is in control connection with the EMS energy management subsystem;
and the direct-current end of the energy storage converter is connected with the outside of the battery.
As can be seen from the above description, the energy storage battery is usually equipped with a main control box for managing the battery, the main control box contains a high-voltage relay, the inside of the battery is the front end of the high-voltage relay, and when the high-voltage relay does not act, i.e. the contacts are not closed, the inside of the battery has voltage all the time; the external part of the battery is the rear end of the high-voltage relay, and voltage exists outside the battery only when the contact of the high-voltage relay is closed, so that the energy storage battery is divided into the inside and the outside according to the high-voltage relay, after the direct-current side micro-switch is closed in an off-grid state, the internal power supply of the battery is transmitted to an electric load through the normally-closed direct-current relay to supply power to an EMS energy management subsystem, the EMS energy management subsystem starts to control the high voltage on the energy storage battery, namely, the contact of the high-voltage relay is controlled to be attracted, the voltage exists outside the battery at the moment, then the direct-current side micro-switch is disconnected, and the outside of the battery supplies power to the electric load. The battery can provide a high-voltage signal for the power supply outside the battery just like uninterrupted UPS (uninterrupted Power supply), and is not used for continuously supplying power to an electric load, so that the direct-current side micro-switch can be turned off after the voltage outside the battery exists; meanwhile, the first anti-reverse diode can prevent the short circuit problem caused by inconsistent internal voltage and external voltage of the battery in the high-voltage buffering process outside the battery, and plays a role in protection.
Further, a fuse is connected in series between the direct-current side micro-breaking switch and the inside of the battery.
From the above description, it can be seen that the fuse is added in the dc side power supply loop of the battery, so that the fuse effectively protects the components in the loop when the loop is short-circuited, and further protects the energy storage system.
Further, the DC/DC converter is also included;
and the normally closed direct current relay and the output end of the rectifier bridge stack are connected with the power utilization load through the DC/DC converter.
As is apparent from the above description, the DC/DC converter may convert voltages on the grid side, the energy storage converter side, and the energy storage battery side into rated input voltages suitable for the electric load to supply the electric load with power.
Further, a second anti-reverse diode is connected in series between the rectifier bridge stack and the DC/DC converter.
Further, a third anti-reverse diode is connected in series between the normally closed direct current relay and the DC/DC converter.
As can be seen from the above description, the second anti-reverse diode and the third anti-reverse diode both function to prevent current from flowing backward in the loop, and avoid short circuit of the loop.
Referring to fig. 6, a dual-power supply method of an energy storage system is applied to the dual-power supply system of an energy storage system, and includes the steps of:
in the grid-connected mode, a first alternating current side micro-breaking switch in an energy storage alternating current side power supply loop is closed, grid side alternating current is converged into a rectifier bridge stack through the first alternating current side micro-breaking switch, and direct current is output after rectification to supply power for an electricity load;
when the power grid is in off-grid mode, no alternating current is input at the power grid side, no voltage passes through the energy storage alternating current side power supply loop, the first alternating current side micro-switch is opened, at the moment, the direct current side micro-switch in the battery direct current side power supply loop is closed, and the energy storage battery direct current is output to the power utilization load through the direct current side micro-switch and the normally closed contact of the normally closed direct current relay;
when the power grid side resumes work, the off-grid mode is converted into a grid-connected mode, the first alternating-current side micro-switch is closed again at the moment, voltage passes through the energy storage alternating-current side power supply loop, the driving coil of the normally-closed direct-current relay works to drive the normally-closed contact of the normally-closed direct-current relay in the battery direct-current side power supply loop to be disconnected, and the battery direct-current side power supply loop stops supplying power to the power utilization load and only the energy storage alternating-current side power supply loop supplies power to the power utilization load.
From the above description, the beneficial effects of the invention are as follows: based on the same technical conception, the dual-power supply system of the energy storage system is adopted, and the dual-power supply method of the energy storage system is provided, wherein the dual-power supply of the energy storage system is realized by controlling the on-off of a first alternating-current side micro-break switch in an energy storage alternating-current side power supply loop and a direct-current side micro-break switch in a battery direct-current side power supply loop to switch the power supply from a power grid side to the power grid and from an energy storage battery to the power grid, so that the standby time of the power supply of the system is prolonged; and a normally-closed direct current relay is introduced into the battery direct current side power supply loop, and a driving coil of the normally-closed direct current relay is connected into the energy storage alternating current side power supply loop so as to drive a normally-closed contact of the normally-closed direct current relay to be disconnected when the power supply is recovered at the power grid side, thereby automatically disconnecting the power supply of the energy storage battery in the battery direct current side power supply loop and preferentially adopting the power grid for power supply. The UPS equipment is eliminated integrally, the system is suitable for severe application environments, the heat dissipation of an air conditioner is not required to be increased, and the design cost of the system is effectively reduced.
The invention relates to a dual-power supply system and a power supply method of an energy storage system, which are used for replacing a power supply scheme that UPS is adopted as control loop power supply equipment in the traditional energy storage system to maintain continuous operation of the system for a certain period of time under the condition of abnormality of an external alternating current power supply.
Referring to fig. 1, a first embodiment of the present invention is as follows:
a dual power supply system of an energy storage system, as shown in figure 1, comprises a battery direct current side power supply loop and an energy storage alternating current side power supply loop.
The input end of the battery direct-current side power supply loop is connected with the energy storage battery through a direct-current side micro-switch K3, and the output end of the battery direct-current side power supply loop is connected with an electric load; the input end of the energy storage alternating current side power supply loop is connected with a power grid through a first alternating current side micro-switch K1, and the output end of the energy storage alternating current side power supply loop is connected with an electric load; the battery direct current side power supply loop is connected with a normally-closed direct current relay KM1 in series, two ends of a normally-closed contact of the normally-closed direct current relay KM1 are respectively connected with a direct current side micro-breaking switch K3 and an electricity utilization load, and a driving coil of the normally-closed direct current relay KM1 is connected to the energy storage alternating current side power supply loop and used for driving the normally-closed contact of the normally-closed direct current relay KM1 to be disconnected when voltage passes through the energy storage alternating current side power supply loop.
In this embodiment, the first ac side micro-switch K1 in the energy storage ac side power supply loop and the dc side micro-switch K3 in the battery dc side power supply loop are controlled to switch the power supply from the grid side under the grid and from the energy storage battery under the off-grid, so as to realize dual power supply of the energy storage system and prolong the standby time of the power supply of the system; and a normally-closed direct current relay KM1 is introduced into the battery direct current side power supply loop, and a driving coil of the normally-closed direct current relay KM1 is connected into the energy storage alternating current side power supply loop so as to drive a normally-closed contact of the normally-closed direct current relay KM1 to be disconnected when the power supply is restored at the power grid side, thereby automatically disconnecting the power supply of the energy storage battery in the battery direct current side power supply loop and preferentially adopting the power grid for power supply. The UPS equipment is eliminated integrally, the system is suitable for severe application environments, the heat dissipation of an air conditioner is not required to be increased, and the design cost of the system is effectively reduced.
Referring to fig. 1, a second embodiment of the present invention is as follows:
in this embodiment, as shown in fig. 1, the energy storage ac side power supply circuit further includes an energy storage converter PCS and a second ac side micro-switch K2.
The alternating-current end of the energy storage converter PCS is connected with the first alternating-current side micro-switch K1 in parallel to an electric load through the second alternating-current side micro-switch K2, and the direct-current end of the energy storage converter PCS is connected with an energy storage battery.
In this embodiment, in order to perfect the performance of the energy storage system, therefore, the PCS of the energy storage converter is added, so that on one hand, when the power grid side is abnormal, the off-grid power-on operation outputs electric energy to supply power to the power utilization load, and on the other hand, when the normal power utilization load is not powered, the ac on the power grid side is converted into dc to charge the energy storage battery, so that sufficient electric quantity of the energy storage battery is ensured, and the power supply duration of the energy storage system is further prolonged.
In this embodiment, the first ac side micro-switch K1 and the second ac side micro-switch K2 are mechanical interlocking switches. The first alternating-current side micro-switch K1 and the second alternating-current side micro-switch K2 are in a mechanical interlocking mode, namely, only one or both of the two micro-switches can be closed at the same time, when the power grid side supplies power to the power utilization load, the first alternating-current side micro-switch K1 is closed, the second alternating-current side micro-switch K2 is in an open state under the mechanical interlocking structure, and the energy storage converter PCS does not work to reduce the consumption of the power grid side voltage; when the power grid side is abnormal, namely off-grid, the second alternating current side micro-breaking switch K2 is closed, the first alternating current side micro-breaking switch K1 is in an open state under a mechanical interlocking structure, and at the moment, no voltage passes through the energy storage alternating current side power supply loop.
It should be noted that, in the embodiment, the first ac side micro-switch K1 and the second ac side micro-switch K2 are only used as a part of the power supply loop of the energy storage ac side, and when the energy storage converter PCS is needed to convert the ac power on the grid side into the dc power for supplying power to the energy storage battery, other charging circuits can be added according to actual needs, which is not limited herein.
As shown in fig. 1, in this embodiment, a rectifying bridge UR is further connected in series in the power supply loop of the energy storage ac side, and the input end of the rectifying bridge UR is connected to the first ac side micro-switch K1 and the second ac side micro-switch K2 through an ac bus, and the output end of the rectifying bridge UR is connected to the power load, so as to rectify the ac stored in the power grid side or the energy storage converter PCS into dc and output the dc to supply power to the power load.
That is, since the electric load is usually supplied with dc power, ac power on the grid side or the PCS side of the energy storage converter is not rectified into dc power by introducing a rectifier bridge UR to supply power to the electric load.
Meanwhile, since the power supply voltage of the power load generally has a requirement, as shown in fig. 1, the dual-power supply system of the energy storage system of the embodiment further comprises a DC/DC converter, wherein the normally closed DC relay KM1 and the output end of the rectifier bridge stack UR are connected with the power load through the DC/DC converter. I.e. the DC/DC converter may convert the voltage on the grid side, the energy storage converter PCS side and the energy storage battery side to a rated input voltage suitable for the electrical load for powering the electrical load.
Referring to fig. 1, a third embodiment of the present invention is as follows:
on the basis of the first embodiment or the second embodiment, in this embodiment, in order to perfect the control policy, an EMS energy management subsystem is introduced, where the EMS energy management subsystem may be used as a control center and also as an electrical load, and is powered by the dual-power supply system of this embodiment.
In this embodiment, the energy storage battery includes a battery interior and a battery exterior, and the battery interior is connected with the normally closed dc relay KM1 through the dc side micro-switch K3; the outside of the battery is connected with a normally closed direct current relay KM1 through a first anti-diode; meanwhile, a high-voltage relay KM2 is connected in series between the inside of the battery and the outside of the battery, and the high-voltage relay KM2 is in control connection with an EMS energy management subsystem; the direct current end of the energy storage converter PCS is connected with the outside of the battery.
In this embodiment, the energy storage battery is usually equipped with a main control box to manage the battery, the main control box contains a high-voltage relay KM2, the inside of the battery is the front end of the high-voltage relay KM2, and when the high-voltage relay KM2 does not act, i.e. the contacts are not closed, the inside of the battery has voltage; the outside of the battery is the rear end of the high-voltage relay KM2, and voltage exists outside the battery only when the contact of the high-voltage relay KM2 is closed, so that the energy storage battery is divided into the inside and the outside according to the high-voltage relay KM2, after the direct-current side micro-switch K3 is closed in an off-grid state, the internal power supply of the battery is transmitted to an electric load through the normally-closed direct-current relay KM1 to supply power for an EMS energy management subsystem, the EMS energy management subsystem is started to control the high voltage on the energy storage battery, namely, the contact of the high-voltage relay KM2 is controlled to be attracted, the voltage exists outside the battery at the moment, then the direct-current side micro-switch K3 is disconnected, and the outside of the battery supplies power for the electric load. The battery can provide a high-voltage signal for the power supply outside the battery just like uninterrupted UPS (uninterrupted Power supply), and is not used for continuously supplying power to an electric load, so that the direct-current side micro-switch K3 can be disconnected after the voltage exists outside the battery; meanwhile, the first anti-reverse diode D1 can prevent the short circuit problem caused by inconsistent internal voltage and external voltage of the battery in the high-voltage buffering process outside the battery, and plays a role in protection.
In addition, as shown in fig. 1, in this embodiment, a fuse FU is further connected in series between the dc side micro-breaker K3 and the battery, so that the circuit effectively protects components in the circuit when a short circuit occurs, and further protects the energy storage system; a second anti-reverse diode D2 is also connected in series between the rectifier bridge reactor UR and the DC/DC converter, and a third anti-reverse diode D3 is also connected in series between the normally closed DC relay KM1 and the DC/DC converter, in this embodiment, the second anti-reverse diode D2 and the third anti-reverse diode D3 both play a role in preventing current in the loop from flowing reversely, avoiding a short circuit of the loop, and perfecting the performance of the energy storage system.
Referring to fig. 2 to 6, a fourth embodiment of the present invention is as follows:
the dual-power supply method of the energy storage system is applied to the dual-power supply system of the energy storage system in the third embodiment, as shown in fig. 6, and includes the steps of:
in the grid-connected mode, a first alternating-current side micro-break switch K1 in an energy storage alternating-current side power supply loop is closed, grid-side alternating current is converged into a rectifier bridge reactor UR through the first alternating-current side micro-break switch K1, and direct current is output after rectification to supply power for an electric load;
when the power grid is in off-grid mode, no alternating current is input, no voltage passes through the energy storage alternating current side power supply loop, the first alternating current side micro-switch K1 is opened, the direct current side micro-switch K3 in the battery direct current side power supply loop is closed at the moment, and direct current on the energy storage battery side is output to power utilization loads through the direct current side micro-switch K3 and the normally closed contact of the normally closed direct current relay KM 1;
when the power grid side resumes work, the off-grid mode is converted into a grid-connected mode, at the moment, the first alternating-current side micro-switch K1 is closed again, voltage passes through the energy storage alternating-current side power supply loop, the driving coil of the normally-closed direct-current relay KM1 works, the normally-closed contact of the normally-closed direct-current relay KM1 in the battery direct-current side power supply loop is driven to be disconnected, the battery direct-current side power supply loop stops supplying power to the power utilization load, and the energy storage alternating-current side power supply loop only supplies power to the power utilization load.
In this embodiment, based on the same technical concept, the dual-power supply system of the energy storage system is matched with the dual-power supply system of the energy storage system, and the dual-power supply method of the energy storage system is provided, and the dual-power supply of the energy storage system is realized by controlling the on-off of a first alternating-current side micro-break switch K1 in an energy storage alternating-current side power supply loop and a direct-current side micro-break switch K3 in a battery direct-current side power supply loop to switch and supply power from a power grid side to an off-grid and supply power from an energy storage battery, so that the standby time of the power supply of the system is prolonged; and a normally-closed direct current relay KM1 is introduced into the battery direct current side power supply loop, and a driving coil of the normally-closed direct current relay KM1 is connected into the energy storage alternating current side power supply loop so as to drive a normally-closed contact of the normally-closed direct current relay KM1 to be disconnected when the power supply is restored at the power grid side, thereby automatically disconnecting the power supply of the energy storage battery in the battery direct current side power supply loop and preferentially adopting the power grid for power supply. The UPS equipment is eliminated integrally, the system is suitable for severe application environments, the heat dissipation of an air conditioner is not required to be increased, and the design cost of the system is effectively reduced.
Fig. 2 to 5 are specific principle process diagrams of a dual-power supply method of an energy storage system in this embodiment, as shown in fig. 2, when the grid-connected operation is performed, the power supply voltage at the power grid side is normal, at this time, the first ac side micro-switch K1 is closed, the ac at the power grid side is rectified into a DC voltage through the rectifier bridge stack UR in an uncontrolled manner, and then the DC voltage is sent to the DC/DC converter through the second anti-reflection diode D2, and the DC/DC converter works to output a 24V power supply voltage to supply power to each device in the energy storage system.
When the power grid side is abnormal, the energy storage system is in an off-grid running state, the second alternating current side micro-switch K2 is closed at the moment (it is to be noted that although the second alternating current side micro-switch K2 is closed at the moment, the energy storage converter PCS is not started, and the power grid side is abnormal, so that no voltage passes through a loop where the second alternating current side micro-switch K2 is located, and the advantage of firstly closing the second alternating current side micro-switch K2 is that after the voltage is generated by starting the power grid of the energy storage converter PCS, the impact caused by the voltage can be effectively buffered), and the first alternating current side micro-switch K1 is opened due to the mechanical interlocking. Then, the direct-current side micro-switch K3 is closed, and the internal voltage of the battery is converted into 24V power supply voltage by the DC/DC converter through the fuse FU, the direct-current side micro-switch K3, the normally closed direct-current relay KM1, the third anti-reflection diode D3 and the DC/DC converter in sequence, so that each device in the energy storage system is temporarily powered, namely as shown in figure 3.
At this time, the EMS energy management subsystem starts working under the condition of internal power supply of the battery, controls the contact of the high-voltage relay KM2 to be attracted, and applies high voltage to the outside of the battery, and at this time, the dc side micro-switch K3 can be turned off to convert the internal power supply of the battery into the external power supply of the battery, i.e., as shown in fig. 4.
Further, after the energy storage system controls the energy storage converter PCS to start to operate off the grid, an alternating current bus in the energy storage alternating current side power supply loop passes through under the action of the second alternating current side micro-switch K2 which is already closed, at the moment, the driving coil of the normally-closed direct current relay KM1 detects that the voltage in the energy storage alternating current side power supply loop exists, namely, the normally-closed contact of the normally-closed direct current relay KM1 is driven to be disconnected, the power supply loop outside the battery is disconnected, and the energy storage converter PCS supplies power for equipment in the energy storage system, namely, as shown in fig. 5.
The operation stability of the energy storage system is that the power is preferentially taken from the alternating current side to supply power for the power load, and the power is converted into direct current side power when the energy storage system is stopped or the PCS of the energy storage converter is abnormally shut down.
Meanwhile, if the power grid side is recovered to be normal, the first alternating current side micro-switch K1 can be closed again, and the power supply for the power utilization load by the power grid side is recovered.
In summary, the dual-power supply system and the power supply method of the energy storage system provided by the invention have the following beneficial effects:
1. the UPS equipment is canceled, the system does not need to increase the heat dissipation scheme of the air conditioner, and the environmental adaptability of the system is improved;
2. compared with the traditional UPS power supply, the multi-path power supply power taking mode effectively avoids the condition that the system cannot operate due to the failure of single UPS equipment;
3. in off-grid application scenes, the power supply is more stable and reliable, and the energy storage battery system can be started to run in a black mode as long as the energy storage battery system is powered on.
The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, and all equivalent changes made by the specification and drawings of the present invention, or direct or indirect application in the relevant art, are included in the scope of the present invention.
Claims (10)
1. The dual-power supply system of the energy storage system is characterized by comprising a battery direct-current side power supply loop and an energy storage alternating-current side power supply loop;
the input end of the battery direct-current side power supply loop is connected with the energy storage battery through a direct-current side micro-breaker, and the output end of the battery direct-current side power supply loop is connected with an electric load;
the input end of the energy storage alternating current side power supply loop is connected with a power grid through a first alternating current side micro-breaker, and the output end of the energy storage alternating current side power supply loop is connected with the power load;
the battery direct current side power supply loop is connected with a normally-closed direct current relay in series, two ends of a normally-closed contact of the normally-closed direct current relay are respectively connected with the direct current side micro-switch and the power load, and a driving coil of the normally-closed direct current relay is connected to the energy storage alternating current side power supply loop and is used for driving the normally-closed contact of the normally-closed direct current relay to be disconnected when voltage passes through the energy storage alternating current side power supply loop.
2. The dual power supply system of an energy storage system of claim 1, wherein said energy storage ac side power loop further comprises an energy storage converter and a second ac side micro-switch;
the alternating-current end of the energy storage converter is connected with the first alternating-current side micro-break switch in parallel with the power load through the second alternating-current side micro-break switch;
and the direct-current end of the energy storage converter is connected with the energy storage battery.
3. The dual power supply system of an energy storage system of claim 2, wherein said first ac side micro-switch and said second ac side micro-switch are mechanically interlocked switches.
4. The dual power supply system of an energy storage system as defined in claim 2, wherein a rectifier bridge is further connected in series in said energy storage ac side power supply loop;
the input end of the rectifier bridge is connected with the first alternating-current side micro-break switch and the second alternating-current side micro-break switch through an alternating-current bus, and the output end of the rectifier bridge is connected with the electricity load and used for rectifying alternating current stored on the power grid side or the energy storage converter into direct current and outputting the direct current to supply power for the electricity load.
5. The dual power supply system of an energy storage system of claim 4, further comprising an EMS energy management subsystem, said energy storage battery including a battery interior and a battery exterior;
the battery is internally connected with the normally-closed direct-current relay through the direct-current side micro-switch;
the outside of the battery is connected with the normally closed direct current relay through a first anti-diode;
a high-voltage relay is connected in series between the inside of the battery and the outside of the battery, and the high-voltage relay is in control connection with the EMS energy management subsystem;
and the direct-current end of the energy storage converter is connected with the outside of the battery.
6. The dual power supply system of claim 5, wherein a fuse is further connected in series between the dc side micro-breaker and the battery.
7. The dual power supply system of an energy storage system of claim 4, further comprising a DC/DC converter;
and the normally closed direct current relay and the output end of the rectifier bridge stack are connected with the power utilization load through the DC/DC converter.
8. The dual power supply system of claim 7, wherein a second anti-reflection diode is further connected in series between the rectifier bridge stack and the DC/DC converter.
9. The dual power supply system of claim 7, wherein a third anti-reflection diode is further connected in series between the normally-closed DC relay and the DC/DC converter.
10. A dual power supply method of an energy storage system, applied to the dual power supply system of an energy storage system as claimed in any one of claims 1 to 9, comprising the steps of:
in the grid-connected mode, a first alternating current side micro-breaking switch in an energy storage alternating current side power supply loop is closed, grid side alternating current is converged into a rectifier bridge stack through the first alternating current side micro-breaking switch, and direct current is output after rectification to supply power for an electricity load;
when the power grid is in off-grid mode, no alternating current is input at the power grid side, no voltage passes through the energy storage alternating current side power supply loop, the first alternating current side micro-switch is opened, at the moment, the direct current side micro-switch in the battery direct current side power supply loop is closed, and the energy storage battery direct current is output to the power utilization load through the direct current side micro-switch and the normally closed contact of the normally closed direct current relay;
when the power grid side resumes work, the off-grid mode is converted into a grid-connected mode, the first alternating-current side micro-switch is closed again at the moment, voltage passes through the energy storage alternating-current side power supply loop, the driving coil of the normally-closed direct-current relay works to drive the normally-closed contact of the normally-closed direct-current relay in the battery direct-current side power supply loop to be disconnected, and the battery direct-current side power supply loop stops supplying power to the power utilization load and only the energy storage alternating-current side power supply loop supplies power to the power utilization load.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117833323A (en) * | 2024-03-05 | 2024-04-05 | 中国华能集团清洁能源技术研究院有限公司 | High-voltage direct-hanging energy storage system, black start method thereof, electronic equipment and storage medium |
| CN117833323B (en) * | 2024-03-05 | 2024-05-31 | 中国华能集团清洁能源技术研究院有限公司 | High-voltage direct-hanging energy storage system, black start method thereof, electronic equipment and storage medium |
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2022
- 2022-12-15 CN CN202211636897.8A patent/CN116231831A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117833323A (en) * | 2024-03-05 | 2024-04-05 | 中国华能集团清洁能源技术研究院有限公司 | High-voltage direct-hanging energy storage system, black start method thereof, electronic equipment and storage medium |
| CN117833323B (en) * | 2024-03-05 | 2024-05-31 | 中国华能集团清洁能源技术研究院有限公司 | High-voltage direct-hanging energy storage system, black start method thereof, electronic equipment and storage medium |
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