A battery temperature control system circuit
Patent Information
- Application Number
- CN202522004230.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-18
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2035-09-18
AI Technical Summary
Existing 1500V mobile energy storage systems rely on DC-DC modules and 400V-900V vehicle-mounted liquid cooling units for compatibility, resulting in high costs and large space requirements, which cannot meet the stringent usage scenarios of mobile energy storage devices.
The battery temperature control system circuit includes a voltage divider module and a protection module, which can directly achieve voltage matching without the need for a DC-DC module. It uses a capacitor voltage divider and a battery cluster midpoint voltage divider scheme, combined with a protection module to monitor and protect the voltage and current.
It reduced system costs, optimized space utilization, improved the volumetric energy density and mass energy density of the equipment, enhanced the reliability and adaptability of the equipment, and met the requirements of vibration during vehicle operation and complex climatic environments.
Smart Images
Figure CN224935421U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of mobile energy storage technology, specifically to a battery temperature control system circuit design. Background Technology
[0002] In energy storage systems, the core component for battery thermal management is the liquid cooling unit. Its technology has become highly application-specific, primarily divided into two branches based on application areas: stationary energy storage liquid cooling units and vehicle-mounted mobile liquid cooling units. Stationary energy storage liquid cooling units generally use 380V / 400V industrial AC power, directly connecting to the power grid or factory power distribution system, offering stable power and a high degree of standardization. Vehicle-mounted mobile liquid cooling units, on the other hand, use 400V to 900V high-voltage DC power, drawing power directly from the battery pack, eliminating the AC / DC conversion step. However, they must withstand continuous vibration, impact, and complex climatic environments during vehicle operation, placing stringent requirements on reliability and safety.
[0003] In existing technologies, the DC-side voltage range of the battery pack in a 1500V mobile energy storage system is 1000~1500V, while the voltage adaptation range of existing vehicle-mounted mobile liquid cooling units is only 400V to 900V, which cannot directly match the operating conditions. To resolve this contradiction, existing solutions typically achieve voltage conversion by adding a DC-DC converter module. However, this approach not only increases system costs but also occupies the limited space of the mobile energy storage device, reducing the system's volumetric energy density and gravimetric energy density, thus exhibiting significant limitations. Utility Model Content
[0004] To address the issue that existing 1500V mobile energy storage systems require DC-DC modules to adapt to 400V-900V vehicle-mounted liquid cooling units, resulting in high costs and large space occupation, this invention provides a battery temperature control system circuit that can achieve voltage matching without adding a DC-DC module, thereby reducing costs and optimizing system performance.
[0005] This utility model is achieved through the following technical solution: a battery temperature control system circuit, including a mobile energy storage battery cluster, a voltage divider module, at least two sets of vehicle-mounted liquid cooling units, and a protection module; the voltage divider module is connected to the DC bus of the mobile energy storage battery cluster and is used to divide the DC bus voltage to a voltage suitable for the vehicle-mounted liquid cooling units; each set of vehicle-mounted liquid cooling units is connected to the voltage divider output terminal of the voltage divider module; the protection module is connected in series in the power supply circuit and is used to protect against voltage and current over-limit conditions.
[0006] The operating voltage range of the vehicle-mounted liquid cooling unit is 400V-900V, and the DC bus voltage range of the mobile energy storage battery cluster is 1000V-1500V.
[0007] The voltage divider module consists of two identical capacitors, C1 and C2. One end of capacitor C1 is connected to the positive terminal of the DC bus, and the other end is connected to one end of capacitor C2. The other end of capacitor C2 is connected to the negative terminal of the DC bus. One set of vehicle-mounted liquid cooling units is connected in parallel across the two ends of capacitor C1, and the other set of vehicle-mounted liquid cooling units is connected in parallel across the two ends of capacitor C2.
[0008] The voltage divider module is a midpoint clamping structure for the mobile energy storage battery cluster; the midpoint of the mobile energy storage battery cluster is led out as a voltage divider node, forming an upper half bus and a lower half bus; one set of vehicle-mounted liquid cooling units is connected between the upper half bus and the midpoint, and the other set of vehicle-mounted liquid cooling units is connected between the midpoint and the lower half bus.
[0009] The protection module includes circuit breakers QF1 and QF2, as well as an undervoltage / overvoltage trip unit. The circuit breakers are connected in series in the main power supply circuit, and the undervoltage / overvoltage trip unit is linked with the circuit breakers. When an overvoltage is detected, the circuit breaker is triggered to trip and disconnect the circuit.
[0010] It also includes a balancing maintenance module, which includes a voltage detection unit, a capacity detection unit, and a power adjustment unit; the voltage detection unit and the capacity detection unit are used to detect the voltage and capacity deviation between the upper half bus and the lower half bus; the power adjustment unit is used to control the reverse power output of the vehicle-mounted liquid cooling unit and dynamically adjust the capacity balance between the upper half bus and the lower half bus.
[0011] The beneficial effects of this utility model are: cost reduction: without the need to add a DC-DC module, voltage matching can be achieved directly through a voltage divider scheme, which significantly reduces the system hardware cost.
[0012] Space optimization: Eliminates the installation space required for DC-DC modules, improving the volumetric energy density and mass energy density of mobile energy storage devices.
[0013] Improved reliability: Through protection modules such as circuit breakers, undervoltage / overvoltage trip units, and fault-linked shutdown mechanisms, risks such as voltage over-limit and equipment failure are effectively addressed; the active balancing maintenance function of the midpoint voltage divider scheme further ensures the stability of battery cluster capacity.
[0014] High adaptability: The circuit design can withstand vibrations, shocks and complex weather conditions during vehicle operation, meeting the stringent requirements of mobile energy storage applications. Attached Figure Description
[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0016] Figure 1 This is the circuit schematic diagram of the capacitor voltage divider scheme of this utility model; Figure 2This is a circuit diagram of the midpoint voltage divider scheme for the battery cluster of this utility model. Detailed Implementation
[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0018] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model; the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In addition, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.
[0019] To achieve the above objectives, this utility model adopts two technical solutions: Capacitor voltage divider scheme, such as Figure 1 As shown Circuit structure: Two capacitors C1 and C2 of the same specification are connected in series on the 1000V~1500V DC bus. One end of capacitor C1 is connected to the positive terminal (P+) of the DC bus, and the other end is connected to one end of capacitor C2. The other end of capacitor C2 is connected to the negative terminal (P-) of the DC bus. Two 400V-900V vehicle-mounted liquid cooling units are connected in parallel across the two ends of capacitors C1 and C2 respectively.
[0020] Working principle: The series capacitors C1 and C2 divide the DC bus voltage equally. The voltage range across each capacitor is 500-750V, which is within the compatibility range of the vehicle-mounted liquid cooling unit, thus enabling direct power supply to the liquid cooling unit.
[0021] Protection mechanism: Circuit breaker QF1 and undervoltage / overvoltage trip unit are connected in series in the power supply circuit; when the power imbalance between the two sets of liquid cooling units causes the capacitor voltage deviation, but it is still within the tolerance range of the liquid cooling units, the system operates normally; if the deviation exceeds the tolerance range, the undervoltage / overvoltage trip unit triggers QF1 to trip, disconnecting the circuit to achieve protection.
[0022] Battery cluster midpoint voltage divider scheme as follows Figure 2 As shown Circuit structure: Utilizing the midpoint voltage clamping characteristic of the mobile energy storage battery cluster, the midpoint of the battery cluster is led out as a voltage divider node to form an upper half bus (positive to midpoint) and a lower half bus (midpoint to negative); two sets of vehicle-mounted liquid cooling units are respectively connected between the upper half bus and the midpoint, and between the midpoint and the lower half bus, and circuit breakers QF1 and QF2 are connected in series in the power supply circuit.
[0023] Working principle: The voltage of both the upper and lower busbars is adapted to the 400V-900V requirements of the vehicle-mounted liquid cooling unit, directly powering the liquid cooling unit; since the battery voltage does not change abruptly, the midpoint potential is stable, ensuring the reliability of voltage division.
[0024] Fault and Balance Handling: When any liquid cooling unit fails, tripping QF1 or QF2 can stop both liquid cooling units from working, avoiding excessive capacity deviation between the upper and lower halves of the battery cluster caused by the operation of a single unit; the capacity deviation is monitored in real time by the voltage detection unit and the capacity detection unit, and the power regulation unit controls the reverse power output of the liquid cooling unit to dynamically adjust the capacity balance of the upper and lower half of the bus.
[0025] Example 1: Application of Capacitor Voltage Divider Scheme In the 2400kWh 1500V mobile energy storage system, two 1000μF / 800V electrolytic capacitors, C1 and C2, are connected in series to the DC bus. When the bus voltage is 1500V, C1 and C2 each divide the voltage by 750V; when the bus voltage drops to 1000V, each divides the voltage by 500V, both within the operating range of the 400V-900V vehicle-mounted liquid-cooled chiller. The protection module uses a 50A rated current circuit breaker QF1 and a matching undervoltage / overvoltage trip unit, with an undervoltage threshold of 380V and an overvoltage threshold of 920V. When the power deviation of the liquid-cooled chiller causes the voltage of C1 to rise to 930V, the overvoltage trip unit triggers QF1 to trip, cutting off the power supply circuit.
[0026] Example 2: Application of the midpoint voltage divider scheme in battery clusters In the same 2400kWh 1500V mobile energy storage system, the battery clusters are divided into upper and lower clusters, with a midpoint. Two liquid-cooled units are connected to the upper cluster-midpoint and midpoint-lower cluster circuits, respectively, and connected in series with 32A circuit breakers QF1 and QF2. The voltage detection unit monitors the voltage of the upper and lower clusters in real time. When the voltage of the upper cluster is detected to be 50V higher than that of the lower cluster, the power regulation unit controls liquid-cooled unit 1 to output 10kW of power in reverse to dynamically balance the capacity deviation. When a short-circuit fault occurs in liquid-cooled unit 1, QF1 trips immediately, and QF2 is simultaneously disconnected to prevent the lower cluster from continuously discharging and causing capacity imbalance.
[0027] The above embodiments demonstrate that the present invention can effectively adapt a 1500V mobile energy storage system to a traditional vehicle-mounted liquid cooling unit, meet temperature control requirements without the need for a DC-DC module, and has both cost advantages and reliability.
Claims
1. A battery temperature control system circuit, characterized in that, The device includes a mobile energy storage battery cluster, a voltage divider module, at least two sets of vehicle-mounted liquid cooling units, and a protection module. The voltage divider module is connected to the DC bus of the mobile energy storage battery cluster and is used to divide the DC bus voltage to a voltage suitable for the vehicle-mounted liquid cooling units. Each set of vehicle-mounted liquid cooling units is connected to the voltage divider output terminal of the voltage divider module. The protection module is connected in series in the power supply circuit and is used to protect against voltage and current over-limit conditions.
2. The battery temperature control system circuit according to claim 1, characterized in that, The operating voltage range of the vehicle-mounted liquid cooling unit is 400V-900V, and the DC bus voltage range of the mobile energy storage battery cluster is 1000V-1500V.
3. A battery temperature control system circuit according to claim 1 or 2, characterized in that, The voltage divider module consists of two identical capacitors, C1 and C2. One end of capacitor C1 is connected to the positive terminal of the DC bus, and the other end is connected to one end of capacitor C2. The other end of capacitor C2 is connected to the negative terminal of the DC bus. One set of vehicle-mounted liquid cooling units is connected in parallel across the two ends of capacitor C1, and the other set of vehicle-mounted liquid cooling units is connected in parallel across the two ends of capacitor C2.
4. A battery temperature control system circuit according to claim 1 or 2, characterized in that, The voltage divider module is a midpoint clamping structure for the mobile energy storage battery cluster; the midpoint of the mobile energy storage battery cluster is led out as a voltage divider node, forming an upper half bus and a lower half bus; one set of vehicle-mounted liquid cooling units is connected between the upper half bus and the midpoint, and the other set of vehicle-mounted liquid cooling units is connected between the midpoint and the lower half bus.
5. The battery temperature control system circuit according to claim 1, characterized in that, The protection module includes circuit breakers QF1 and QF2, as well as an undervoltage / overvoltage trip unit. The circuit breakers are connected in series in the main power supply circuit, and the undervoltage / overvoltage trip unit is linked with the circuit breakers. When an overvoltage is detected, the circuit breaker is triggered to trip and disconnect the circuit.
6. The battery temperature control system circuit according to claim 4, characterized in that, It also includes a balancing maintenance module, which includes a voltage detection unit, a capacity detection unit, and a power adjustment unit; the voltage detection unit and the capacity detection unit are used to detect the voltage and capacity deviation between the upper half bus and the lower half bus; the power adjustment unit is used to control the reverse power output of the vehicle-mounted liquid cooling unit and dynamically adjust the capacity balance between the upper half bus and the lower half bus.