5MW10MWh储能系统的额定容量和实际容量之间隔着哪些效率折损？
What is the efficiency loss between the rated capacity and actual capacity of a 5MW10MWh energy storage system?
本篇文章从标准和实际角度了解下储能各环节的效率问题，知道电池到变压器之间的效率转换，对于我们合理设计变压器容量至关重要。This article explores the efficiency issues of various energy storage links from both standard and practical perspectives. Understanding the efficiency conversion between batteries and transformers is crucial for us to design transformer capacity reasonably.
以我们大储中常见的5MW/10MWh储能系统举例，10MWh是系统的标称电池容量，也叫装机容量或额定容量，但实际配置的电池容量需根据效率、损耗进行调整。所以，我们在计算评估时，10MW这个数据仅供参考，无法精准计算。效率应该如何相对准确的理论计算呢？Taking the commonly used 5MW/10MWh energy storage system in our large storage system as an example, 10MWh is the nominal battery capacity of the system, also known as installed capacity or rated capacity, but the actual configured battery capacity needs to be adjusted based on efficiency and loss. So, when calculating and evaluating, the data of 10MW is for reference only and cannot be accurately calculated. How should efficiency be relatively accurately calculated theoretically?
一、直流侧
1、DC side
根据上面图片，我们先看电池柜，也即直流侧。对于电池来说，我们按照《GBT 44026-2024 预制舱式锂离子电池储能系统技术规范》中理想状态的最低标准要求88%计算，实际很多企业能做到90%以上，尤其按单向算更高：Based on the picture above, let’s first take a look at the battery cabinet, which is the DC side. For batteries, we calculate according to the minimum standard requirement of 88% in the ideal state of the “GBT 44026-2024 Technical Specification for Prefabricated Cabin Lithium ion Battery Energy Storage System”. In reality, many enterprises can achieve over 90%, especially when calculated unidirectionally。
若用户要求直流侧放电容量为10MWh，在进行实际容量配置时，需要考虑电池系统的效率和电池系统充放电深度（对于磷酸铁锂电池假设按较高的90%DOD考虑），则实际配置容量应为：10000kWh/电池系统效率/DOD=10000kWh/88%/90%≈12626.26kWh。If the user requests a DC side discharge capacity of 10MWh, when configuring the actual capacity, the efficiency of the battery system and the depth of charge and discharge of the battery system need to be considered (assuming a higher 90% DOD for lithium iron phosphate batteries). The actual configured capacity should be:10000kWh/battery system efficiency/DOT=10000kWh/88%/90% ≈ 12626.26kWh.
PS：同样根据上述国标关于超发要求如下：直流舱在正常运行电压范围内，在110%额定功率条件下,持续运行时间应不少于10min；在120%额定功率条件下,持续运行时间应不少于1min。PS： According to the above national standards, the requirements for overloading are as follows:PS： The continuous operation time of the DC cabin should not be less than 10 minutes under the condition of 110% rated power within the normal operating voltage range; At 120% rated power, the continuous operation time should not be less than 1 minute.
二、交流侧
2、 Communication side
其一是PCS交流侧：
One is the PCS AC side:
在直流侧放电容量的基础上，将直流侧线损和PCS效率考虑进去，一般来说线路效率99.5%以上，PCS效率97%以上，不同厂家，不同产品，不同环境等会有差异，这里提供经验数字仅方便评估。具体计算同直流侧的计算方法，这里不再重复。按照《GB∕T 36558-2018 电力系统电化学储能系统通用技术条件》看，最低也是94%，如下截图：On the basis of the discharge capacity on the DC side, the DC side line loss and PCS efficiency are taken into account. Generally speaking, the line efficiency is above 99.5% and the PCS efficiency is above 97%. There may be differences among different manufacturers, products, environments, etc. Here, empirical figures are provided for evaluation purposes only. The specific calculation method for the DC side will not be repeated here. According to GB/T 36558-2018 General Technical Conditions for Electrochemical Energy Storage Systems in Power Systems, the minimum requirement is also 94%, as shown in the screenshot below:
其过载能力按照《GB T 34120-2017 电化学储能系统储能变流器技术规范》：储能变流器交流侧电流在110%额定电流下,持续运行时间应不少于10min;储能变流器交流侧电流在120%额定电流下,持续运行时间应不少于1min。当然，实际有的PCS宣传可以长时间1.1倍运行。Its overload capacity shall be in accordance with the “GB T 34120-2017 Technical Specification for Energy Storage Inverters in Electrochemical Energy Storage Systems”: the AC side current of the energy storage inverter shall operate continuously for not less than 10 minutes at 110% of the rated current; The AC side current of the energy storage inverter should run continuously for no less than 1 minute at 120% of the rated current. Of course, some PCS promotions can actually run 1.1 times longer.
其二是35kV箱变交流侧：The second is the AC side of the 35kV box transformer:
这里的损耗源于两点，一个是变压器本身的损耗，具体取决于变压器容量和能效等级，按目前通常的变压器能效要求，一般都是大于99%。另一点便是辅助变携带的部分供电设备，通常用电量不会超过5%。The loss here comes from two points. One is the loss of the transformer itself, which depends on the transformer capacity and energy efficiency level. According to the current usual transformer energy efficiency requirements, it is generally greater than 99%. Another point is that the auxiliary transformer carries some power supply equipment, which usually consumes no more than 5% of electricity.
在整个系统里，再往后考虑也是同样的逻辑，还未考虑公共连接点、充放电次数、电池衰减率、电池一致性等因素。In the entire system, the same logic applies even further, without considering factors such as common connection points, number of charge and discharge cycles, battery decay rate, and battery consistency.
以上就说这么多，在实际工程应用中，对于储能容量，目前还缺乏统一的标准规定：对于工商业储能项目来说，由于商业模式较为清晰，其实用户更关注的是公共连接点的放电容量；对于新能源配套储能项目来说，由于商业模式不清晰，储能配置主要受政策引导，用户配置储能是为了完成光伏并网，自然是能少配就少配，故常按额定容量配置。That’s all for now. In practical engineering applications, there is currently a lack of unified standard regulations for energy storage capacity. For industrial and commercial energy storage projects, due to the clear business model, users are more concerned about the discharge capacity of the public connection point; For new energy supporting energy storage projects, due to unclear business models, energy storage configurations are mainly guided by policies. Users configure energy storage to achieve photovoltaic grid connection, so it is natural to allocate as little as possible, so it is often configured according to the rated capacity.
OTGOLD 于 2025年4月8日 星期二