A generator protection device suitable for a ship direct current integrated power system

Abstract

The application relates to a generator protection device suitable for a ship direct-current integrated power system, which is used for the protection of a protection area of all lines and equipment between a generator outlet and a converter valve side, a hardware system adopts an embedded close-coupling main processor architecture, a main processor module adopts a high-performance general ARM+FPGA structure, is used for realizing collection, measurement and communication functions, is connected with a control system, realizes the protection of short-circuit, overload, overvoltage, undervoltage, ratio differential, phase differential and excitation system faults, can reliably act when generator overload, short-circuit, overvoltage, inter-turn short-circuit and other faults occur in the protection area, can trip a circuit breaker, isolate faults, protect the generator, and can directly collect and return data on the direct-current side of the generator rectifier to the control system, is used for tracking frequency changes, and can calculate the frequency, fundamental voltage and current effective values and AC / DC power in real time, can display real-time analog quantities, and is convenient for operation and maintenance personnel to observe the generator operation state.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of ship direct current comprehensive power system, in particular to a kind of ship direct current comprehensive power system is adopted in the technical scheme of generator protection device of electrically excited synchronous generator combined with uncontrolled rectification. BACKGROUND

[0002] Energy crisis and increasingly stringent emission regulations become the severe test that shipping industry has to face, in the face of energy shortage and emission regulations strict problem, using new type direct current comprehensive power system becomes the important direction of future development of ship, direct current comprehensive power system is currently applied more and more in ocean-going transport ship (small and medium-sized container ship, chemical tanker etc.), tug, ferry, yacht, official ship etc.

[0003] Ship direct current comprehensive power system integrates traditional diesel engine propulsion, variable frequency drive and ship power system and automatic control system, involves many devices, different devices have different use combinations in different operating modes, and it is a highly integrated system of machine and electricity.

[0004] For the direct current comprehensive power system using electrically excited synchronous generator combined with uncontrolled rectification, the system protection faces the following difficulties: 1) when short circuit fault occurs between the generator and the circuit breaker, due to the unidirectional conduction characteristic of the diode rectification module, at this time the fault current passes through the circuit breaker, causing the circuit breaker to fail to act, unable to effectively protect the system, and cannot meet the above specification requirements; 2) when a short circuit fault occurs on the DC side, if the fuse fails to effectively fuse in a short time, due to the lack of short circuit protection capability of the diode module, the short circuit current may damage the rectifier diode module and the generator stator winding; 3) the diode rectification module has no voltage regulation capability and cannot realize overvoltage protection; 4) the direct current comprehensive power system has high requirements on the sampling rate and sampling accuracy of the DC side voltage and current signal collection, so that the EMS control system can realize real-time power distribution, power limitation and other related control functions. SUMMARY

[0005] Based on the above problems, the present application provides a generator protection device suitable for ship direct current comprehensive power system, which can provide differential protection and overvoltage protection, solving the problem that the circuit breaker protection of the uncontrolled rectification AC generator in the direct current comprehensive power system cannot provide short circuit and overvoltage protection. In addition, the device also provides backup generator AC side short circuit protection, DC side short circuit protection and generator excitation system fault protection, etc. protection function, improves the reliability of the generator and the ship hybrid power system, and reduces the risk of power loss of the whole ship.

[0006] The technical scheme of the present application is: a generator protection device suitable for a ship direct current comprehensive power system, used for protecting all lines and equipment between the generator outlet and the converter valve side, the hardware system adopts an embedded tightly coupled main processor architecture, the main processor module adopts a high-performance general-purpose ARM+FPGA structure, and can support a microsecond-level operation interval; used for realizing collection, measurement and communication functions, and connecting a control system to realize protection of short circuit, overload, overvoltage, undervoltage, ratio differential, phase differential and excitation system fault, and can reliably act when a generator overload, short circuit, overvoltage, inter-turn short circuit and the like occur in the protection zone, trip a circuit breaker, isolate the fault, protect the generator, and directly collect and return the data on the direct current side of the generator rectifier to the control system for tracking frequency changes, and calculate the frequency, fundamental voltage and current effective value and AC / DC power in real time, and display real-time analog quantities to facilitate operation and maintenance personnel to observe the generator operation state.

[0007] Further, the main processor module sends analog quantities and switching quantities to the control system through Modbus communication for signal processing of the control system.

[0008] Further, the main processor module and the collection module are placed in layers, and strong and weak electricity are separated, so that the entire generator protection device is compact and has high reliability, and is suitable for compact space application requirements of offshore platforms and ships.

[0009] Further, the generator protection device is also provided with a power supply, an analog quantity conversion, an analog quantity output, an input and output, a protection processor and an Ethernet communication module.

[0010] Further, the protection and measurement interface of the generator protection device is realized by a single device, protection starts and trips, corresponding trip signals are sent to the generator field weakening system and the AC circuit breaker, and the fault or abnormal working condition in the region is cleared to ensure safe operation of the system.

[0011] Further, the generator protection device provides cross differential protection for the lines and equipment between the stator winding of the multi-phase generator and the multi-phase rectifier, and can rapidly disconnect the generator circuit breaker and stop the machine after a short circuit fault occurs.

[0012] Further, the generator protection device is used in cooperation with the DC side fuse to provide backup protection for the DC side short circuit fault, and in the case of a DC side short circuit fault, if the fuse cannot be effectively fused in a short time, the circuit breaker can be disconnected in a very short time to reduce the influence of the DC side short circuit fault on the diode module and the generator.

[0013] Further, the generator protection device also provides backup generator AC side short circuit protection, DC side short circuit protection and generator excitation system fault protection, and improves the reliability of the generator and the ship hybrid power system and reduces the risk of power loss of the entire ship.

[0014] Further, the generator protection device transmits all the tripping signals of the protection to the de-excitation system, the Modbus client and the protection fault recording information system respectively; is used for realizing the protection configuration self-checking function, the protection configuration has the fault recording function, and the recording range includes the input analog quantity, the switch quantity and the protection calculation digital quantity; the protection configuration event recording function communicates with the Modbus client system through the LAN network.

[0015] The beneficial effects of the present application are:

[0016] The generator protection device is a secondary device, has the functions of protection, measurement, communication and the like, is configured with more than ten kinds of protections such as short-circuit, overload, overvoltage, undervoltage, ratio differential, inter-phase differential, excitation system fault and the like, can reliably act when the faults such as generator overload, short-circuit, overvoltage, inter-turn short-circuit and the like occur in the protection area, tripping of the circuit breaker, isolation of the fault and protection of the generator. The generator protection device can directly collect and return the data on the DC side of the generator rectifier to the EMS control system, at the same time, the generator protection device can track the frequency change, and calculate the frequency, the effective value of the fundamental voltage and current, the AC / DC power and the like in real time, for real-time analog display, facilitating the operation and maintenance personnel to observe the generator operation state. Through the Modbus communication, the analog quantity and the switch quantity can be sent to the control system, for signal processing of the control system. The device solves the problem that the circuit breaker of the generator cannot provide short-circuit protection, overvoltage protection and the like when the uncontrolled rectification is used in the ship DC comprehensive power system.

[0017] The device also provides backup generator AC side short-circuit protection, DC side short-circuit protection and generator excitation system fault protection and the like, improves the reliability of the generator and the ship hybrid power system and reduces the risk of power loss of the whole ship. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the hardware schematic diagram of the generator protection device of the present application;

[0019] Figure 2 It is the protection function configuration schematic diagram of the generator protection device in the embodiment of the present application;

[0020] Figure 3 It is the excitation system fault protection principle diagram in the present application;

[0021] Figure 4 It is the timing sequence cooperation schematic diagram of the generator protection device and the circuit breaker in the embodiment of the present application. DETAILED DESCRIPTION

[0022] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0023] like Figures 1 to 4 As shown in the figure, an embodiment of the present invention provides a generator protection device suitable for a ship's DC integrated power system, comprising: a relay protection device integrating a processor, analog-to-digital technology, Ethernet communication technology, and graphical visual programming technology. To meet the specific application requirements of the generator protection device, an "ARM+FPGA" architecture is used to construct the interconnected system. Each functional module can be flexibly configured on the high-speed interconnected system, and the device has good maintainability. The synchronous generator protection device is equipped with power supply, analog-to-digital conversion, analog-to-analog output, digital input / output, protection processor, and Ethernet communication modules.

[0024] The protection range of the generator protection device is: the protection area of ​​the generator protection device is all lines and equipment between the generator outlet and the converter valve side.

[0025] The generator protection device is configured as follows: Its protection functions and measurement interfaces are implemented using a single device. Upon activation, the protection trips, and the generator protection device sends the corresponding trip signal to the generator demagnetization system and AC circuit breaker to clear faults or abnormal operating conditions within the designated area, ensuring the safe operation of the system. All protection devices possess all required protection functions and can independently provide comprehensive and accurate protection for the protected equipment.

[0026] The generator protection device features at least the following functional characteristics: The protection design comprehensively considers all aspects of AC and DC system operation and equipment stress, and possesses the function of preventing maloperation caused by inconsistent transient characteristics of instrument transformers; the protection distinguishes different fault states and executes actions in stages according to the different degrees and development trends of the faults. All protection trip signals are transmitted to the demagnetization system, the Modbus client, and the protection fault recording information; the protection is equipped with a self-test function, and when the protection host or board fails, the program exits the protection in advance to prevent maloperation. Station engineers can optimize and correct the protection parameters during system operation; the protection is equipped with a built-in fault recording function, and the recording range includes input analog quantities, switch quantities, and protection calculation digital quantities; the protection is equipped with an event logging function and communicates with the Modbus client system via a LAN network.

[0027] The generator protection device monitors and determines inter-phase faults.

[0028] The fundamental current difference between phases is calculated, and the difference between the maximum and minimum of the two-phase fundamental current exceeds the reference value, and the protection timing limit acts. The differential action logic is as follows:

[0029] I OP >k rel I set , wherein I op is the differential current; I set is the current setting value; k rel is the reliability coefficient.

[0030] I OP = I cdmax -I cdmin

[0031] I cdmax = MAX(|IArms-IBrms|,|IBrms-ICrms|,|ICrms-IArms|)

[0032] I cdmin = MIN(|IArms-IBrms|,|IBrms-ICrms|,|ICrms-IArms|)

[0033] wherein I cdmax is the maximum differential current; I cdmin is the minimum differential current; IArms, IBrms, ICrms are the effective values of A, B, and C three-phase currents, and the current direction is positive to the frequency converter.

[0034] The generator protection device monitors and determines the internal short circuit fault of the generator:

[0035] The fundamental current difference is calculated when the internal short circuit fault occurs, and the protection timing limit acts when the differential current is greater than the reference value; the protection has a current braking characteristic. In addition, in the case of high differential current, the protection trips quickly. The ratio differential action logic is as follows:

[0036]

[0037] The differential quick-break action equation is as follows:

[0038] I op >I cdsd .

[0039] In the formula: I op is the differential current; I cdqd is the differential current starting value; I res is the braking current; I res0 is the minimum braking current, which is fixed as the rated current I e of the differential protection; K is the slope; I cdsdThe difference between the flow rate and the determined value.

[0040]

[0041] In the formula: The flow into the generator current, The frequency converter valve side mutual inductor current, I op The differential current, I res The braking current. The direction of each side current is positive to the frequency converter.

[0042] The generator protection device overvoltage fault monitoring and fault determination:

[0043] Measure the generator three-phase fundamental voltage, and the voltage exceeds the reference value, time limit action. Overvoltage action logic as follows:

[0044]

[0045] In the formula: U OV The generator phase voltage; U e The rated voltage of the generator; k is the coefficient.

[0046] The generator protection device for excitation system fault monitoring and fault determination:

[0047] When the generator is running normally, receive the AVR freeze signal or no generator induction voltage and excitation voltage, the protection time limit action.

[0048] The normal operation criterion of the generator is as follows:

[0049]

[0050] In the formula: UG is the fundamental phase voltage of the generator; Ue is the rated voltage of the generator; k is the proportional coefficient.

[0051] The generator protection device for overload fault monitoring and fault determination:

[0052] Measure the three-phase fundamental current, and when the cumulative heat is greater than the overload setting value, the protection action.

[0053] The generator protection device for AC short circuit fault monitoring and fault determination:

[0054] Measure the three-phase fundamental current, and when the current exceeds the reference value, time limit action. The action algorithm is as follows:

[0055] I OC >kI e In the formula: I oc The AC fundamental current; I e The rated current, k is the proportional coefficient.

[0056] The generator protection device monitors and judges the DC overcurrent fault:

[0057] The DC current is measured, and the current exceeds the reference value, and the time limit acts. The action algorithm is as follows:

[0058] I d >I set , wherein: I d is the DC current, I set is the overcurrent action current setting value.

[0059] The generator protection device monitors and judges the DC voltage signal breakage fault:

[0060] The DC voltage current is measured, and the voltage is lower than the voltage reference value, and the current is greater than the current reference value, and the time limit acts.

[0061] When the generator AC side short circuit fault, the protection time sequence of the circuit breaker matched with the generator protection device is as follows:

[0062] The differential protection configured by the generator protection device will act when the generator circuit breaker trips, and the protection of the generator is completed. Due to the unidirectional conduction characteristic of the diode, there will be no fault current flowing through the circuit breaker when the generator AC side short circuit fault occurs. If the generator protection device is not configured, the circuit breaker will not act under this fault relying on its own protection logic.

[0063] When the DC side short circuit fault, the protection time sequence of the circuit breaker matched with the generator protection device is as follows:

[0064] The fuse configured by the DC distribution board will first melt, realizing the protection of the non-fault area in the DC distribution board. If the fuse protection fails, the DC side short circuit fault current protection configured by the generator protection device will send an action signal at this time, and the generator circuit breaker will act after receiving the signal, completing the isolation of the fault; if the circuit breaker does not receive the action instruction of the generator protection device, the circuit breaker will act and trip relying on its own protection logic after detecting the overcurrent, completing the isolation of the fault.

[0065] When the overload fault, the protection time sequence of the circuit breaker matched with the generator protection device is as follows:

[0066] The overload protection configured by the generator protection device will send an action signal, and the generator circuit breaker will act after receiving the signal, so that the generator exits the operation; if the circuit breaker does not receive the action instruction of the generator protection device, the circuit breaker will act and trip relying on its own protection logic after detecting the overload, completing the protection of the generator.

[0067] When the AC overvoltage fault, the protection time sequence of the circuit breaker matched with the generator protection device is as follows:

[0068] Under this fault, the overvoltage protection configured by the generator protection device will send an action signal, and the generator circuit breaker will act after receiving the signal, so that the generator is taken out of operation.

[0069] When an AC under-voltage fault occurs, the protection time sequence of the circuit breaker matched with the generator protection device is as follows:

[0070] Under this fault, the under-voltage protection configured by the generator protection device will send an action signal, and the generator circuit breaker will act after receiving the signal, so that the generator is taken out of operation.

[0071] When the excitation system fails, the protection time sequence of the circuit breaker matched with the generator protection device is as follows:

[0072] The excitation protection configured by the generator protection device will send an action signal, and the generator circuit breaker will act after receiving the signal, so that the generator is taken out of operation. The circuit breaker itself does not configure excitation protection function, and the circuit breaker alone cannot complete the protection of the generator under this fault condition.

[0073] As Figure 2 The figure is a schematic diagram of the configuration, data acquisition and function configuration of the generator protection device in the embodiment of the present application. The device acquires the voltage and current information of the generator side, the voltage and current information of the AC side of the frequency converter, and the voltage and current information of the DC side. Based on the above-mentioned acquired data, fault protection is made, and the fault protection setting value of the generator protection device is shown in Table 1.

[0074] Table 1

[0075]

[0076] The above examples only illustrate the principles and specific steps of the present application, and are not used to limit the present application. Any related professional technical personnel can make corresponding deformation and optimization on the basis of not violating the principles of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A generator protection device suitable for a ship's DC integrated power system, used as a protection zone for all lines and equipment between the generator outlet and the converter valve side, characterized in that: The hardware system adopts an embedded, tightly coupled main processor architecture. The main processor module uses a high-performance general-purpose ARM+FPGA structure, capable of supporting microsecond-level computation intervals. It is used to implement data acquisition, measurement, and communication functions, and connects to the control system to provide protection against short circuits, overloads, overvoltages, undervoltages, ratio differentials, phase-to-phase differentials, and excitation system faults. It can reliably operate when generator overloads, short circuits, overvoltages, or inter-turn short circuits occur within the protected area, tripping the circuit breaker to isolate the fault and protect the generator. It also directly acquires and transmits DC-side data from the generator rectifier back to the control system to track frequency changes, calculate the frequency, fundamental voltage and current RMS values, and AC / DC power in real time, and display real-time analog quantities for easy monitoring of generator operating status by maintenance personnel. The protection and measurement interfaces of the generator protection device are implemented using a single device. Protection starts and trips, sending corresponding trip signals to the generator demagnetization system and AC circuit breakers to clear faults or abnormal operating conditions within the area, ensuring safe system operation. The generator protection device connects the multi-phase generator stator windings to the multi-phase rectifier. The system provides transverse differential protection for the lines and equipment between generators, enabling rapid disconnection of the generator circuit breaker and shutdown / demagnetization after a short-circuit fault. The generator protection device works in conjunction with the DC-side fuse to provide backup protection for DC-side short-circuit faults. In the event of a DC-side short-circuit fault, if the fuse fails to blow effectively within a short time, it can disconnect the circuit breaker in a very short time, reducing the impact of the DC-side short-circuit fault on the diode module and generator. The generator protection device also provides backup AC-side short-circuit protection, DC-side short-circuit protection, and generator excitation system fault protection, improving the reliability of the generator and the ship's hybrid power system and reducing the risk of a complete power outage. The generator protection device transmits all protection trip signals to the demagnetization system, the Modbus client, and the protection fault recording information system. It is used to implement the protection configuration self-test function, and the protection configuration has a fault recording function, recording parameters including analog inputs, switch inputs, and digital inputs for protection calculations. The protection configuration also has an event logging function, communicating with the Modbus client system via a LAN network.

2. The generator protection device for a ship's DC integrated power system according to claim 1, characterized in that: The main processor module sends analog and digital signals to the control system via Modbus communication for signal processing.

3. The generator protection device for a ship's DC integrated power system according to claim 1, characterized in that: The main processing module and the acquisition module are placed in layers, and the strong and weak currents are separated, making the entire generator protection device compact and highly reliable, suitable for the compact space application requirements of offshore platforms and ships.

4. The generator protection device for a ship's DC integrated power system according to claim 1, characterized in that: The generator protection device is also equipped with a power supply, analog-to-analog converter, analog-to-output converter, digital input / output converter, protection processor, and Ethernet communication module.

Images