Test platform and method of energy storage converter

Abstract

The invention discloses a test platform and method for an energy storage converter, and belongs to the technical field of energy storage. A 380V power grid is sequentially connected with a first circuit breaker, a first contactor, a transformer and the alternating current side of a first PCS; the direct current side of the PCS to be tested is sequentially connected with the second circuit breaker, the second contactor and the direct current sides of the first PCS and the second PCS; the alternating current side of the to-be-tested PCS is sequentially connected with a third circuit breaker, a third contactor and the alternating current side of the second PCS; the pre-charging module is connected in parallel with the first PCS; the unit controller is respectively connected with the first contactor, the second contactor, the third contactor, the pre-charging module, the PCS to be tested and each module in the AC / DC combined source. Existing products are reasonably built, a battery system does not need to be configured, laboratory arrangement and testing of experimenters can be facilitated to the maximum extent, the testing efficiency is improved, and the construction cost is reduced. Meanwhile, the operation power of the test platform can be expanded according to test requirements, and the production test efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage, and particularly to a test platform and method for an energy storage converter. Background Art

[0003] Currently, energy storage systems adopting distributed system integration solutions have gradually become mainstream. Each battery cluster is directly connected to a string-type energy storage converter (PCS) without passing through a high-voltage box. The AC sides of the PCSs are connected in parallel and then boosted by a transformer to access the 10 kV, 35 kV and above voltage-level 380 V power grid. It has significant advantages such as high comprehensive efficiency, small floor area, and high investment return.

[0004] After the PCS is produced and assembled, it needs to be subjected to charge and discharge tests. Currently, the PCS test platform needs to be equipped with a battery system as the DC power source outside the PCS to establish the DC voltage required for the operation of the PCS, resulting in a relatively high test cost for the PCS; at the same time, the life of the battery system will gradually decay with the number of charge and discharge cycles and test time of the PCS, and the battery system needs to be replaced after a certain period of time; moreover, the over-current capacity of the battery system is limited, restricting the power during the charge and discharge tests of the PCS, and unable to increase the charge and discharge power of the PCS, shorten the test cycle, and improve the test efficiency. Summary of the Invention

[0006] Aiming at the defects of the prior art, the present invention uses the produced PCS products to build an external AC-DC combined source for the PCS to be tested, replacing the battery system and the 380 V power grid, saving construction costs; at the same time, according to the test requirements, the operating power of the test platform can be expanded to improve the production test efficiency.

[0007] To achieve the above object, the present invention provides a test platform for an energy storage converter, including: a 380 V power grid, an AC-DC combined source, a PCS to be tested, a pre-charge module, a transformer, a unit controller, three circuit breakers and three contactors; the AC-DC combined source includes at least a first PCS and a second PCS; The 380 V power grid is sequentially connected to the AC side of the first PCS in the AC-DC combined source through a first circuit breaker, a first contactor, and a transformer; The DC side of the PCS to be tested is sequentially connected to the DC sides of the first PCS and the second PCS in the AC-DC combined source through a second circuit breaker and a second contactor; The AC side of the PCS to be tested is sequentially connected to the AC side of the second PCS in the AC-DC combined source through a third circuit breaker and a third contactor; The pre-charge module is connected in parallel with the first PCS; The unit controller is respectively connected to the first contactor, the second contactor, the third contactor, the pre-charge module, the PCS to be tested, and each module in the AC-DC combined power source.

[0008] Furthermore, multiple PCSs can be connected in parallel at both ends of the second PCS for capacity expansion.

[0009] Furthermore, the test platform further includes a thermal management system, which is respectively connected to the PCS to be tested and each module in the AC-DC combined power source for temperature control.

[0010] The present invention also provides a testing method for an energy storage converter, based on the above-mentioned testing platform for the energy storage converter, which is characterized by including the following steps: (1) Manually close the first circuit breaker, the second circuit breaker, and the third circuit breaker. At the same time, the unit controller controls the first contactor, the second contactor, and the contactor inside the pre-charge module to close, controls the first PCS to start, and controls the first PCS to operate in the constant DC voltage mode; at the same time, the thermal management system starts to control the temperature of the PCS to be tested and each module in the AC-DC combined power source; (2) The unit controller controls the third contactor to close, controls the second PCS to start, and controls the second PCS to operate in the off-grid mode; (3) After the external AC and DC power sources of the PCS to be tested are started according to steps (1) and (2), the unit controller controls the PCS to be tested to perform charge or discharge testing; (4) After the PCS to be tested completes the test, the unit controller controls the second PCS to stop, separates the third contactor, and turns off the AC power source; the unit controller controls the first PCS to stop, separates the first contactor, and turns off the DC power source; the unit controller controls the third contactor to close, and controls the discharge circuit in the pre-charge module to discharge the PCS to be tested and the AC-DC combined power source. After the discharge is completed, the discharge circuit and the third contactor are separated; manually disconnect the first circuit breaker, the second circuit breaker, and the third circuit breaker.

[0011] Advantages of the present invention: By reasonably building with existing products (PCS products produced), the present invention does not require a battery system, which can greatly facilitate laboratory layout and tester testing, improve testing efficiency, and reduce construction costs. At the same time, according to the testing needs, the operating power of the testing platform can be expanded to improve production testing efficiency. Description of the Drawings

[0012] Figure 1 It is a schematic structural diagram of the testing platform for the energy storage converter according to the embodiment of the present invention.

[0013] Figure 2 It is a schematic flowchart of the testing method for the energy storage converter according to the embodiment of the present invention. Detailed implementation manners

[0015] The present invention will be further explained and described below in conjunction with the accompanying drawings and embodiments.

[0016] As Figure 1 shown, an energy storage converter test platform and method are provided in an embodiment of the present invention. The test platform includes: a 380V power grid, an AC-DC combined source, a PCS to be tested, a pre-charge module, a transformer, a unit controller, a thermal management system, three circuit breakers, and three contactors. Among them, the AC-DC combined source includes at least a first PCS (1# PCS) and a second PCS (2# PCS), both of which are existing products (PCS products produced). The entire test platform is reasonably built by using existing products, without the need to configure a battery system, which can most conveniently arrange the laboratory and facilitate the testing of experimenters, improve the testing efficiency, and reduce the construction cost. The specific connection relationship is as follows: The 380V power grid is sequentially connected to the AC side of the first PCS (1# PCS) in the first circuit breaker (QF1), the first contactor (KM1), the transformer, and the AC-DC combined source; the DC side of the PCS to be tested is sequentially connected to the second circuit breaker (QF2), the second contactor (KM2), and the DC sides of the first PCS (1# PCS) and the second PCS (2# PCS) in the AC-DC combined source; the AC side of the PCS to be tested is sequentially connected to the third circuit breaker (QF3), the third contactor (KM3), and the AC side of the second PCS (2# PCS) in the AC-DC combined source; the pre-charge module is connected in parallel with the first PCS (1# PCS); the unit controller is respectively connected to the first contactor (KM1), the second contactor (KM3), the third contactor (KM3), the pre-charge module, the PCS to be tested, and each module in the AC-DC combined source; the thermal management system is respectively connected to the PCS to be tested and each module in the AC-DC combined source for temperature control.

[0017] The pre-charge module is composed of a contactor and a resistor, and is used to charge the DC side capacitor of the first PCS with a small current to avoid damage to the capacitor caused by a large current impact, pre-charge to the DC voltage condition required for inversion, start the first PCS, and then disconnect the pre-charge module.

[0018] According to the high-power requirement of the PCS to be tested, more PCSs can be connected in parallel at both ends of the second PCS (2# PCS) for capacity expansion.

[0019] Based on the above platform, an embodiment of the present invention also provides an energy storage converter test method, including the following steps: S101. Manually close the first circuit breaker (QF1), the second circuit breaker (QF2), and the third circuit breaker (QF3). At the same time, the unit controller controls the first contactor (KM1), the second contactor (KM2), and the contactor inside the pre-charge module to close, controls the first PCS (1#PCS) to start, and controls the first PCS (1#PCS) to operate in the constant DC voltage mode. At the same time, the thermal management system starts to control the temperature of each module in the PCS to be tested and the AC-DC combined power source.

[0020] Among them, the DC voltage target value can be set.

[0021] S102. The unit controller controls the third contactor (KM3) to close, controls the second PCS (2#PCS) to start, and controls the second PCS (2#PCS) to operate in the off-grid mode.

[0022] According to the high-power requirement of the PCS to be tested, PCSs can be connected in parallel at both ends of the second PCS (2#PCS) for capacity expansion and start synchronously with the second PCS (2#PCS).

[0023] S103. After the external AC and DC power sources of the PCS to be tested are started according to steps S101 and S102, the unit controller controls the PCS to be tested to perform charge or discharge tests.

[0024] After the PCS to be tested completes the test, the unit controller controls the second PCS (2#PCS) to stop, separates the third contactor (KM3), and closes the AC power source; the unit controller controls the first PCS (1#PCS) to stop, separates the first contactor (KM1), and closes the DC power source; the unit controller controls the third contactor (KM3) to close, and controls the discharge circuit in the pre-charge module to discharge the PCS to be tested and the AC-DC combined power source. After the discharge is completed, the discharge circuit and the third contactor (KM3) are separated; manually disconnect the first circuit breaker (QF1), the second circuit breaker (QF2), and the third circuit breaker (QF3).

[0025] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the principle and spirit of the present invention shall be included within the protection scope of the present invention.

Claims

1. A test platform for energy storage converter, characterized in that: include: 380V power grid, AC / DC combined source, PCS to be tested, pre-charge module, transformer, unit controller, three circuit breakers and three contactors; the AC / DC combined source includes at least a first PCS and a second PCS; The 380V power grid is sequentially connected to the first circuit breaker, the first contactor, the transformer and the AC side of the first PCS in the AC / DC combined source; The DC side of the PCS to be tested is sequentially connected to the second circuit breaker, the second contactor and the DC side of the first PCS and the second PCS in the AC / DC combined source; The AC side of the PCS to be tested is sequentially connected to the third circuit breaker, the third contactor and the AC side of the second PCS in the AC / DC combined source; The pre-charge module is connected in parallel with the first PCS; The unit controller is respectively connected to the first contactor, the second contactor, the third contactor, the pre-charge module, the PCS to be tested and each module in the AC / DC combined source.

2. The test platform for the energy storage converter according to claim 1, characterized in that: The two ends of the second PCS can be expanded by connecting multiple PCSs in parallel.

3. The test platform for the energy storage converter according to claim 1, characterized in that: The test platform also includes a thermal management system, which is respectively connected to the PCS to be tested and each module in the AC / DC combined source for temperature control.

4. A method for testing an energy storage converter, based on the test platform for the energy storage converter according to any one of claims 1 to 3, characterized in that: The steps include: (1) Manually close the first circuit breaker, the second circuit breaker, and the third circuit breaker. At the same time, the unit controller controls the first contactor, the second contactor, and the contactor inside the pre-charge module to be attracted, controls the first PCS to start, and controls the first PCS to operate in constant DC voltage mode; at the same time, the thermal management system is started to control the temperature of the PCS to be tested and each module in the AC / DC combined source; (2) The unit controller controls the third contactor to close, controls the second PCS to start, and controls the second PCS to operate in off-grid mode; (3) After the external AC and DC sources of the PCS to be tested are started according to steps (1) and (2), the unit controller controls the PCS to be tested to perform a charging or discharging test; (4) After the PCS to be tested completes the test, the unit controller controls the second PCS to shut down, separates the third contactor, and turns off the AC source; The unit controller controls the first PCS to shut down, separates the first contactor, and turns off the DC source; the unit controller controls the third contactor to close, and controls the discharge circuit in the pre-charge module to discharge the PCS to be tested and the AC / DC combined source, and separates the discharge circuit and the third contactor after the discharge is completed; the first circuit breaker, the second circuit breaker, and the third circuit breaker are manually disconnected.

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