附录A
Circuit Breaker
Control and selection of the circuit breaker
Circuit breaker control mode selection and control mode of substation, the size of the substation and other factors. Substation control mode is different, different size, circuit breaker control mode also vary accordingly.
According to the working voltage of control circuit, the circuit breaker control mode can be divided into two kinds of, heavy current and weak current control. According to the operation mode, can be divided into one control two kinds of control and line selection.
So-called high voltage control, is from the control equipment of commands to the circuit breaker operating mechanism, the working voltage of the control circuit for dc 110 v or 220 v. According to the control site, divided into two kinds of centralized control and local control; According to the jump, switching circuit monitoring, divided into two kinds of lighting monitoring and audio surveillance; According to the connection of control circuit is divided into control switch has a fixed position is not corresponding to the connection with control switch contact automatic reset.
Weak current control can be divided into the following two cases.
(1) the working voltage of circuit breaker control circuit into two parts, low voltage and heavy current issue commands control equipment is working voltage weak current is usually 48 v. Command is issued, and then through the middle and weak electricity conversion link weak current signal conversion to high voltage signal, command, to the circuit breaker operating mechanism. Intermediate conversion links between circuit breaker and at the same structure and high voltage control circuit. This weak current control, is essentially the layout on the control panel of weak electrochemical control equipment.
(2) from the control equipment to the working voltage of circuit breaker operating mechanism of all circuits are all elv. This way of command signal transmission distance is relatively close, the circuit breaker operation and power is large, it is not suitable for 220500 kv substation.
Low voltage line selection control wiring is more complex, more operation steps, hard to ensure its reliability. 220-500 kv substation circuit breaker, do not recommend using low voltage line selection control.
Common characteristic is due to the weak current control on the control panel using the miniaturizati
on of the weak current control device, the control panel on the unit area can be assigned by the control loop. Under the condition of same number of controlled object, compared with the high voltage control, can reduce the area of the control panel, convenient monitoring and operational personnel; Reduced the master control room construction area, reduce the investment in civil engineering. This is a major advantage of the weak current control. But weak current equipment there is insufficient, low voltage terminal and weak current equipment of electrical insulation distance is small, be afraid of dust, especially under the condition of dust containing conductive material more dangerous; Weak current equipment terminals and screen after the weak current connection terminals and soft line connection with welding, due to close the distance between the terminal, when check line and cleaning pay special attention to prevent short circuit between terminals; In addition, there is low mechanical strength, off contact capacity small, poor anti-jamming performance shortcomings.
High voltage control can be divided into high voltage one to one direct control and high voltage line selection control. Very few of the latter in the practical engineering applications. High voltage one to one direct control method has simple control circuit, power supply voltage of a single operation, the operation personnel easy to grasp, convenient maintenance, high reliability advantages, all kinds of used in substation is put into operation a major control method.
High voltage control, because of the working voltage of control equipment is higher, to meet the requirements of insulation distance, control equipment, terminal
equipment such as the volume is big, and within the unit area on the control panel can decorate less control goes back from them. In substation scale, more cases of the object, and the control panel. This not only increases the surface area of the main control room, increasing the cost of civil engineering, at the same time, due to the large surveillance plane, is unfavorable to the normal monitoring and operation.
At present, the control method is: one to one direct control, station is not a conventional control panel, control was achieved by independent measurement device. The old station is also gradually according to the methods of modification.
When in breaker control circuit design should pay attention to the following basic requirements.
(1) shall have the monitoring circuit of the control power. Circuit breaker control power is the most important, once lost power supply, circuit breaker can't operate. Whatever the reason, therefore, when the circuit breaker control power supply disappears, should sound and light signals, prompt the personnel on duty timely processing.
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(2) should be regularly monitored circuit breaker jump, switching circuit integrity, when tripping or switching circuit malfunction, should signal circuit breaker control circuit disconnection.
(3) should be prevent electric lock circuit breaker "jump", "jump" to the circuit breaker is very dangerous, easy to cause body damage, even caused an explosion of the circuit breaker, so blocking measures must be taken. At present, the microcomputer protection device and the operation of the circuit breaker loop in the default configuration, have prevent breaker "jump" electrical circuits. Practical application, use and can only use one to prevent the circuit breaker electric circuits of the "jump". Design and operation, should strictly for manufacturer to design the part of the circuit.
On February 2, 1997, 220 kv line A phase fault of A certain power plant, line on both sides of the right protection device, but when reclosing circuit breaker are produced on both sides "jump" phenomenon. Among them, the power plant side of circuit breaker open final in a row, hydraulic fell sharply, circuit breaker stay in us
after rejected points. Due to the fault point not resection, the 220 kv circuit breaker failure protection action will bus coupler circuit breaker and all components of resection, on a bus a bus power outage
s. Accident examination revealed: fault line of the power plant side split-phase operation box, keep the coil spring prevention relay voltage polarity reverse, defend jump circuit fails to play a role, to cause the circuit breaker "jump" phenomenon: the client is due to its anti jump in the relay coil short-circuit current, and lead to defend jump circuit fails to play a role.
Circuit breaker "jump" phenomenon is generally tripping and closing loop through to occurs at the same time. "Jump" prevention circuit design should make there was a "jump" circuit breaker, the circuit breaker lockout to trip position.
(4) jump, closing orders should be long enough, and when the tripping or closing, after the completion of the command pulse should be able to remove automatically. Usually consists of circuit breaker auxiliary contacts automatically disconnect jump, switching circuit.
(5) for circuit breaker jump, switching state, should have a clear position signal, fault automatic tripping, automatic switching, should have obvious action signal.
(6) the operation of the circuit breaker dynamic disappear or inadequate, for example, spring spring not taut, hydraulic or pneumatic pressure to reduce, etc., should be closed circuit breaker action, and a signal; SF6 gas insulated circuit breaker, when the SF6 gas pressure drops and circuit breaker can
not be reliable operation, should also blocking the action of circuit breaker, and a signal.
In the case of lines or transformers trouble-free, pressure reduce atresia trip circuit. If you don't locking at this time, once a line or transformer failure, due to the circuit breaker pressure has been reduced, the main contactor has no arc suppression ability, may cause the circuit breaker explosion and its consequence is unimaginable.
(7) under the condition of meet the above requirements, makes every effort to control circuit wiring is simple, the equipment and use the least amount of cable.
附录B
断路器
控制方式及选择
断路器的控制方式选择与变电所的控制方式、变电所的规模等因素有关。变电所的控制方式不同、规模不同，断路器的控制方式也相应而异。
按控制回路的工作电压，断路器的控制方式可分为强电控制和弱电控制两种。按操作方式，可分为一对一控制和选线控制两种。
所谓强电控制，就是从发出操作命令的控制设备到断路器的操动机构，整个控制回路的工作电压均为直流110V或220V。根据控制地点，分为集中控制与就地控制两种；按跳、合闸回路监视，分为灯光监视和音响监视两种；按控制回路接线分为控制开关具有固定位置的不对应接线与控制开关触点自动复位的接线。
弱电控制分为以下两种情况。
（1）断路器控制回路的工作电压分成弱电和强电两部分，发出操作命令的控制设备工作电压是弱电一般是48V。命令发出后，再经过中间强弱电转换环节把弱电命令信号转换成强电信号，送至断路器的操动机构。中间转换环节和断路器之间的回路结构与强电控制相同。这种弱电控制，实质上只是把布置在控制屏上的控制设备弱电化了。
（2）从控制设备到断路器的操动机构全部回路的工作电压均为弱电。这种方式的命令信号传输距离较近，断路器的操动功率又比较大，它不适用于220500kV 变电所。
弱电选线控制的接线比较复杂，操作步骤较多，其可靠性难以保证。220－500kV变电所的断路器，不推荐采用弱电选线控制。
弱电控制的共同特点是由于在控制屏上采用了小型化的弱电控制设备，控制屏上单位面积内可布置的
控制回路多。在相同数量的被控对象情况下，与强电控制相比，可以减少控制屏的面积，方便运行人员监视和操作；减少了主控制室的建筑面积，降低土建工程投资。这是采用弱电控制的主要优点。但是弱电设备也存在着不足，弱电端子和弱电设备中的电气绝缘距离较小，怕积灰尘，特别是灰尘中含有导电物质的情况下更危险；弱电设备的端子和屏后的弱电连接端子与软线的连接多采用焊接，由于端子间距离较近，在查线和清扫时特别注意防止端子间的短路；另外，还有机械强度低，触点断开的容量小，抗干扰性能差等缺点。
强电控制分为强电一对一直接控制和强电选线控制。后者在实际工程中应用的很少。强电一对一直接控制方式具有控制回路简单，操作电源电压单一，运行人员容易掌握，维护方便，可靠性较高等优点，是国内投入运行的各类变电所中采用的一种主要的控制方式。
强电控制，因控制设备的工作电压比较高，为满足绝缘距离的要求，控制设备、接线端子排等设备体积都比较大，而在控制屏上单位面积内可布置的控制回路数却较少。在变电所规模大，被控对象多的情况下，所需的控制屏数量多。这不仅加大了主控制室的面积，增加了土建工程的费用，同时，由于监视面过大，也不利于正常的监视和操作。

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