DSPC172H ABB主控CPU 模块
现代电源
功能描述.1隔离保险商实验室，UL™ 定义了现代电源中使用的几种隔离类型。UL（UL1950 E199929）将安全超低电压（SELV）定义为二次电路，其设计和保护应确保在正常和单一故障条件下，任何两个可接近部件之间的电压，或可接近部件与设备接地端子之间的电压不超过稳态42 V峰值或60 VDC超过1秒。.1.1操作或功能隔离操作或功能性隔离仅通过使用高电位（hipot）测试来定义。通常，这种隔离被定义为在变压器结构中使用绝缘导线作为主要隔离屏障。hipot 1秒持续时间测试（介电电压、耐压测试）是用于验证隔离栅是否正常工作的生产测试。具有操作隔离的产品不得用作安全隔离系统的元件。.1.2基本或增强绝缘基本或增强隔离由电源一次和二次电路之间的规定爬电和间隙限制定义。基本隔离是在变压器结构中除了绝缘线之外，还使用隔离屏障。输入和输出电路也必须以规定的距离物理隔离。.1.3持续电压对于没有特定安全机构批准（操作隔离）的装置，正常操作中可施加在部件两端的持续电压小于42.4 VRMS或60 VDC。确保输入和输出电压保持正常SELV限制。离测试电压代表对瞬态电压的抗扰度。
生产测试
如果设备在连续施加超过42.4 VRMS或60 VDC电压的情况下能够正常运行，则必须将隔离栅两侧的电路视为在不安全电压下运行，并且根据安全标准要求，进一步的隔离或绝缘系统必须在这些电路和任何用户可访问的电路之间形成屏障。1.4隔离电压Hipot试验、闪光试验、耐受电压、耐压、介电耐受电压和隔离试验电压都是与同一事物相关的术语：在设计用于提供电气隔离的部件上施加规定时间的试验电压，以验证该隔离的完整性。TI的DCP02系列直流-直流转换器均在1.0 kVAC下进行了一秒钟的100%生产测试。1.5重复的高压隔离测试屏障组件的重复高压隔离测试可能会降低隔离能力，具体取决于材料、结构和环境。DCP02系列直流-直流转换器具有环形漆包线隔离变压器，初级和次级绕组之间没有额外的绝缘。虽然器件可以承受几倍于规定测试电压的电压，但隔离能力取决于导线绝缘。任何材料，包括这种搪瓷（通常是聚氨酯），在承受非常高的外加电压时，都容易发生最终的化学降解。因此，严格限制高压试验和重复高压隔离试验的次数。但是，如果绝对需要，将电压从规定的测试电压降低20%，每次测试的持续时间限制为1秒。
Modern power supply
Function description 1 Isolated Underwriters Laboratories, UL ™ Several isolation types used in modern power supply are defined. UL (UL1950 E199929) defines safety ultra-low voltage (SELV) as a secondary circuit, and its design and protection shall ensure that under normal and single fault conditions, the voltage between any two accessible components, or between the accessible components and the equipment grounding terminal, does not exceed the steady state 42 V peak value or 60 VDC for more than 1 second 1.1 Operation or functional isolation Operation or functional isolation is only defined by using a high potential (hipot) test. Generally, this isolation is defined as the use of insulated conductors as the main isolation barrier in the transformer structure. Hipot 1s duration test (dielectric voltage and withstand voltage test) is a production test used to verify whether the barrier works normally. Products with operational isolation shall not be used as components of the safety isolation system 1.2 Basic or enhanced insulation Basic or enhanced isolation is defined by the specified creepage and clearance limits between the primary and secondary power circuits. Basic isolation refers to the use of isolation barriers in addition to insulated wires in the transformer structure. Input and output circuits must also be physically isolated at a specified distance 1.3 Continuous voltage For devices without specific safety authority approval (operation isolation), the continuous voltage that can be applied at both ends of the component in normal operation is less than 42.4 VRMS or 60 VDC. Ensure that the input and output voltages remain within the normal SELV limits. The isolated test voltage represents immunity to transient voltage.
Production test
If the equipment can operate normally when more than 42.4 VRMS or 60 VDC voltage is continuously applied, the circuits on both sides of the barrier must be considered as operating under unsafe voltage, and according to the requirements of safety standards, further isolation or insulation systems must form barriers between these circuits and the circuits accessible to any user. 1.4 Isolation voltage Hipot test, flash test, withstand voltage, withstand voltage, dielectric withstand voltage and isolation test voltage are terms related to the same thing: apply test voltage for a specified time on the parts designed to provide electrical isolation to verify the integrity of the isolation. TI's DCP02 series DC to DC converters were 100% production tested at 1.0 kVAC for one second. 1.5 Repeated high voltage isolation tests Repeated high voltage isolation tests of barrier components may reduce the isolation capability, depending on the material, structure and environment. DCP02 series DC to DC converters have ring enamelled wire isolation transformers, with no additional insulation between the primary and secondary windings. Although the device can withstand a voltage several times the specified test voltage, the isolation capability depends on the wire insulation. Any material, including this kind of enamel (usually polyurethane), is prone to final chemical degradation when subjected to very high applied voltage. Therefore, the times of high voltage test and repeated high voltage isolation test shall be strictly limited. However, if absolutely necessary, reduce the voltage from the specified test voltage by 20% and limit the duration of each test to 1 second.
